<![CDATA[Biotechnology Forums - Stem Cells]]> https://www.biotechnologyforums.com/ Thu, 23 Apr 2026 14:12:28 +0000 MyBB <![CDATA[Stem cells project and experiment topics]]> https://www.biotechnologyforums.com/thread-8288.html Mon, 20 Nov 2017 08:19:54 +0000 asif khan]]> https://www.biotechnologyforums.com/thread-8288.html <![CDATA[Paraplegic rats walk and regain feeling after stem cell treatment]]> https://www.biotechnologyforums.com/thread-8286.html Fri, 17 Nov 2017 07:42:39 +0000 Lavkeshsharma]]> https://www.biotechnologyforums.com/thread-8286.html Paralyzed rats implanted with engineered tissue containing human stem cells were able to walk independently and regained sensory perception in their hind legs and tail. The implanted rats also show some degree of healing in their spinal cords. The research demonstrates the great potential of stem cells to treat spinal cord injury.



Engineered tissue containing human stem cells has allowed paraplegic rats to walk independently and regain sensory perception. The implanted rats also show some degree of healing in their spinal cords. The research, published in Frontiers in Neuroscience, demonstrates the great potential of stem cells -- undifferentiated cells that can develop into numerous different types of cells -- to treat spinal cord injury.

Spinal cord injuries often lead to paraplegia. Achieving substantial recovery following a complete spinal cord tear, or transection, is an as-yet unmet challenge.

Led by Dr. Shulamit Levenberg, of the Technion-Israel Institute of Technology, the researchers implanted human stem cells into rats with a complete spinal cord transection. The stem cells, which were derived from the membrane lining of the mouth, were induced to differentiate into support cells that secrete factors for neural growth and survival.

The work involved more than simply inserting stem cells at various intervals along the spinal cord. The research team also built a three-dimensional scaffold that provided an environment in which the stem cells could attach, grow and differentiate into support cells. This engineered tissue was also seeded with human thrombin and fibrinogen, which served to stabilize and support neurons in the rat's spinal cord.

Rats treated with the engineered tissue containing stem cells showed higher motor and sensory recovery compared to control rats. Three weeks after introduction of the stem cells, 42% of the implanted paraplegic rats showed a markedly improved ability to support weight on their hind limbs and walk. 75% of the treated rats also responded to gross stimuli to the hind limbs and tail.

In contrast, control paraplegic rats that did not receive stem cells showed no improved mobility or sensory responses.

In addition, the lesions in the spinal cords of the treated rats subsided to some extent. This indicates that their spinal cords were healing.

While the results are promising, the technique did not work for all implanted rats. An important area for further research will be to determine why stem cell implantation worked in some cases but not others. As the research team notes, "This warrants further investigation to shed light on the mechanisms underlying the observed recovery, to enable improved efficacy and to define the intervention optimal for treatment of spinal cord injury."

Although the study in itself does not solve the challenge of providing medical treatments for spinal cord injury in humans, it nevertheless points the way to that solution.Although there is still some way to go before it can be applied in humans, this research gives hope.

Representative images of rat posture 43-days following implantation of an induced-construct (bottom) vs. transection only (top).
]]> Paralyzed rats implanted with engineered tissue containing human stem cells were able to walk independently and regained sensory perception in their hind legs and tail. The implanted rats also show some degree of healing in their spinal cords. The research demonstrates the great potential of stem cells to treat spinal cord injury.



Engineered tissue containing human stem cells has allowed paraplegic rats to walk independently and regain sensory perception. The implanted rats also show some degree of healing in their spinal cords. The research, published in Frontiers in Neuroscience, demonstrates the great potential of stem cells -- undifferentiated cells that can develop into numerous different types of cells -- to treat spinal cord injury.

Spinal cord injuries often lead to paraplegia. Achieving substantial recovery following a complete spinal cord tear, or transection, is an as-yet unmet challenge.

Led by Dr. Shulamit Levenberg, of the Technion-Israel Institute of Technology, the researchers implanted human stem cells into rats with a complete spinal cord transection. The stem cells, which were derived from the membrane lining of the mouth, were induced to differentiate into support cells that secrete factors for neural growth and survival.

The work involved more than simply inserting stem cells at various intervals along the spinal cord. The research team also built a three-dimensional scaffold that provided an environment in which the stem cells could attach, grow and differentiate into support cells. This engineered tissue was also seeded with human thrombin and fibrinogen, which served to stabilize and support neurons in the rat's spinal cord.

Rats treated with the engineered tissue containing stem cells showed higher motor and sensory recovery compared to control rats. Three weeks after introduction of the stem cells, 42% of the implanted paraplegic rats showed a markedly improved ability to support weight on their hind limbs and walk. 75% of the treated rats also responded to gross stimuli to the hind limbs and tail.

In contrast, control paraplegic rats that did not receive stem cells showed no improved mobility or sensory responses.

In addition, the lesions in the spinal cords of the treated rats subsided to some extent. This indicates that their spinal cords were healing.

While the results are promising, the technique did not work for all implanted rats. An important area for further research will be to determine why stem cell implantation worked in some cases but not others. As the research team notes, "This warrants further investigation to shed light on the mechanisms underlying the observed recovery, to enable improved efficacy and to define the intervention optimal for treatment of spinal cord injury."

Although the study in itself does not solve the challenge of providing medical treatments for spinal cord injury in humans, it nevertheless points the way to that solution.Although there is still some way to go before it can be applied in humans, this research gives hope.

Representative images of rat posture 43-days following implantation of an induced-construct (bottom) vs. transection only (top).
]]> <![CDATA[Cancer stem cells: Does tumor response to therapy?]]> https://www.biotechnologyforums.com/thread-7199.html Wed, 25 Nov 2015 11:47:15 +0000 priyap01]]> https://www.biotechnologyforums.com/thread-7199.html
A surge in therapeutic research activities funded by governments across the world has immensely propelled the global stems market. However, the high cost of stem cell treatment and stringent government regulations against the harvesting of stem cells are expected to restrain the growth of the global stem cells market.
This study report aims to help global entities make well-informed business decisions based on expert analysis and accurate data. 

Overview

A number of factors spur the stem cell market’s growth. Some of the main factors driving the market are the increasing funding from various government and private organizations, rising global awareness about stem cell therapies, and growing industry focus on stem cell research.

Among the key factors, the growing ubiquity of stem cell banking services, greater government support, the growing trend of medical tourism, and the presence of several unmet medical needs are some additional factors favorable for this market. Government support for the stem cells field is mainly directed towards the clinical research and development of stem cells. This factor also highlights the increased awareness of drug discovery and screening, stem cell banking services, and other regenerative treatment options, which is expected to fuel the demand for stem cells in developed as well as emerging regions.

Unmet Medical Needs and Increasing Government Support Boost Global Stem Cells Market

As the volume of unmet medical needs and incidence of chronic illnesses grows, it fuels the number of R&D activities in the field of stem cells. Improved government support and availability of funding for clinical research in stem cells have fostered increased growth opportunities for the stem cells market. The market for stem cells is also capitalizing on the growing awareness regarding the available options for regenerative treatment, the importance of stem cells in drug discovery, and stem cells banking services.

Rapid proliferation of medical tourism facilities across countries such as India, Brazil, China, Malaysia, and Mexico also aids the development of the stem cells market in Latin America and Asia Pacific. Apart from the aforementioned market drivers, a multitude of factors present substantial growth opportunities before the market, such as rising disposable incomes in developing economies, development of the contract research industry, increasing prevalence of neurodegenerative diseases, and the need to replace animal tissue in drug discovery. 

Reference: http://www.transparencymarketresearch.co...arket.html]]>
A surge in therapeutic research activities funded by governments across the world has immensely propelled the global stems market. However, the high cost of stem cell treatment and stringent government regulations against the harvesting of stem cells are expected to restrain the growth of the global stem cells market.
This study report aims to help global entities make well-informed business decisions based on expert analysis and accurate data. 

Overview

A number of factors spur the stem cell market’s growth. Some of the main factors driving the market are the increasing funding from various government and private organizations, rising global awareness about stem cell therapies, and growing industry focus on stem cell research.

Among the key factors, the growing ubiquity of stem cell banking services, greater government support, the growing trend of medical tourism, and the presence of several unmet medical needs are some additional factors favorable for this market. Government support for the stem cells field is mainly directed towards the clinical research and development of stem cells. This factor also highlights the increased awareness of drug discovery and screening, stem cell banking services, and other regenerative treatment options, which is expected to fuel the demand for stem cells in developed as well as emerging regions.

Unmet Medical Needs and Increasing Government Support Boost Global Stem Cells Market

As the volume of unmet medical needs and incidence of chronic illnesses grows, it fuels the number of R&D activities in the field of stem cells. Improved government support and availability of funding for clinical research in stem cells have fostered increased growth opportunities for the stem cells market. The market for stem cells is also capitalizing on the growing awareness regarding the available options for regenerative treatment, the importance of stem cells in drug discovery, and stem cells banking services.

Rapid proliferation of medical tourism facilities across countries such as India, Brazil, China, Malaysia, and Mexico also aids the development of the stem cells market in Latin America and Asia Pacific. Apart from the aforementioned market drivers, a multitude of factors present substantial growth opportunities before the market, such as rising disposable incomes in developing economies, development of the contract research industry, increasing prevalence of neurodegenerative diseases, and the need to replace animal tissue in drug discovery. 

Reference: http://www.transparencymarketresearch.co...arket.html]]> <![CDATA[Umbilical Cord Banking Benefits and Applications]]> https://www.biotechnologyforums.com/thread-2731.html Fri, 13 Dec 2013 13:46:07 +0000 Jessica]]> https://www.biotechnologyforums.com/thread-2731.html (1).

HISTORY OF UMBILICAL CORD BANKING:

Year - Event
• 1988 - Transplantation of umbilical cord blood in a Fanconi anemia patient with cord blood from a sibling who had the same HLA (human leukocyte antigen)
• 1991 - Opening of the 1st unrelated Cord Blood Bank (CBB) with the help of voluntary donors in New York.
• After 1996 - The need to build Cord Blood Units (CBUs) of high quality to coordinate the transplantation of cord blood.
• 1998 - In order to coordinate the data in each CBB, both nationally and internationally, NETCORD was set up
• Currently- Cord Blood Banking is flourishing

The accreditation of CBBs the world over is done by NetCord-FACT (NetCord- Foundation for the Accreditation of Cellular Therapy) (2).

Since the last 25 years, the concept of umbilical cord banking has slowly gained importance in this country (3). India has three public umbilical cord banks: Relicord, Jeevan Cord and Stemcyte. The private umbilical cord banks are seven in number; they are Life Cell, Cryo Banks, Cryosave, Cord Life, Baby Cell, Stem One and ISSL (International Stem Cell Service) (4).

TYPES OF UMBILICAL CORD BANKING:

• Cord Blood Banking- After a child’s birth, the collection and storage of blood from the inside of the umbilical cord is done. This is called cord blood banking. The cord blood is stored by two types of banks:

1. Public - These banks store the cord blood by marking it anonymously. One cannot get back the donated cord blood back from the bank.

2. Private - Personalized use by the entire family. Some amount of money has to be paid to take advantage of this set up.

The regulation of cord blood banks is done by the U.S. Food and Drug Administration (5).

• Cord Tissue Banking- It is the collection, testing, processing and preserving the cord tissue for further treatment processes.

The distinguishing factor between cord blood stem cells and cord tissue stem cells:

The main difference is the type of stem cells that are present in both of them. Cord blood contains haematopoietic stem cells whereas cord tissue contains mesenchymal stem cells (6).

BENEFITS:

1. Collecting the cord blood from the newborn is fully risk free and does not require much effort. There is no inconvenience caused either to the mother or her baby.

2. It can be used anytime as per requirements after completing the due process of collection and the necessary tests. The storage of the cord blood is done in a freezer.

3. Transplantation of cord blood does not necessitate that the donor and the recipient have to match fully; a partial match will also make the process a success.

4. The complications seen in patients of cord blood transplants are very few. Even viruses have a very slim chance of spreading infection in the patient (7).


5. If the cord blood stem cells are kept for personalized use in the future, there is an assurance of a match and the sample can be taken up for use immediately (8).

6. The use of umbilical cord blood cells in research dispels many doubts that come up in the field of embryonic stem cell research (as the embryo is not destroyed) (9).


7. The umbilical cord banks contain cord blood and cord tissue. The cord tissue is composed of mesenchymal stem cells that are genetically very stable. This is of great help in clinical trials for various diseases such as Crohn’s disease, multiple sclerosis etc (10).

APPLICATIONS OF UMBILICAL CORD BLOOD STEM CELLS:

1. Some genetic diseases can be taken care of by transfusing cord blood to the patient e.g. sickle cell anemia (6).

2. In the pediatric population malignancy of the blood can be treated with cord blood transplants (this is for those patients who do not have a family donor).

3. Neurological diseases can be treated with umbilical cord stem cells as they exhibit plasticity. In suitable conditions, they are capable of self-differentiation into cells such as neural cells, cardiac cells etc (7).

4. The stem cells in umbilical cord blood contribute in regenerating insulin, one of the methods to treat juvenile diabetes.

5. In immunotherapy, umbilical cord blood samples act as sources of Treg cells. Treg cells are CD4+ T helper cells that help in immune cell homeostasis (3), (11).

LATEST NEWS REGARDING UMBILICAL CORD STEM CELLS:

1. Development of artificial skin from umbilical cord stem cells (12).

2. Increase in survival rates of patients suffering from leukemia & lymphoma, using UCB stem cells (13).


3. Treating a small child with cerebral palsy using UCB autologous stem cells (14).

4. Reducing pain in the knees through stem cells from umbilical cords (15).

REFERENCES:

1. http://en.wikipedia.org/wiki/Umbilical_cord

2. Navarrete C, Contreras M. Cord Blood Banking: a historical perspective. British Journal of Haematology. 2009; 147: 236-245.

3. http://health.india.com/diseases-conditi...treatment/

4. McKenna D, Sheth J. Umbilical cord Blood: Current status & promise for the future. Indian J Med Res 134. 2011; 261-269.

5. http://kidshealth.org/parent/_cancer_cen...blood.html

6. http://www.cryo-cell.com/cord-tissue-banking

7. http://www.disabled-world.com/news/resea...atment.php

8. http://specialsections.suntimes.com/heal...blood.html

9. Umbilical Cord Blood Banking. RANZCOG College Statement (C-Obs 18). 2013; 1-3.

10. Gong W, Han Z, et al. Banking human umbilical cord-derived mesenchymal stromal cells for clinical use. Cell Transplantation. 2012; 21: 207-216.

11. http://www.ebioscience.com/cell-type/t-r...-cells.htm

12. http://health.india.com/news/scientists-...ical-cord/

13. http://www.sciencedaily.com/releases/201...104923.htm

14. http://www.prnewswire.co.uk/news-release...24971.html

15. http://www.king5.com/health/New-stem-cel...46291.html

Written and emailed by Ms. Deepti Narayan ( also writes on BiotechArticles.com)]]> (1).

HISTORY OF UMBILICAL CORD BANKING:

Year - Event
• 1988 - Transplantation of umbilical cord blood in a Fanconi anemia patient with cord blood from a sibling who had the same HLA (human leukocyte antigen)
• 1991 - Opening of the 1st unrelated Cord Blood Bank (CBB) with the help of voluntary donors in New York.
• After 1996 - The need to build Cord Blood Units (CBUs) of high quality to coordinate the transplantation of cord blood.
• 1998 - In order to coordinate the data in each CBB, both nationally and internationally, NETCORD was set up
• Currently- Cord Blood Banking is flourishing

The accreditation of CBBs the world over is done by NetCord-FACT (NetCord- Foundation for the Accreditation of Cellular Therapy) (2).

Since the last 25 years, the concept of umbilical cord banking has slowly gained importance in this country (3). India has three public umbilical cord banks: Relicord, Jeevan Cord and Stemcyte. The private umbilical cord banks are seven in number; they are Life Cell, Cryo Banks, Cryosave, Cord Life, Baby Cell, Stem One and ISSL (International Stem Cell Service) (4).

TYPES OF UMBILICAL CORD BANKING:

• Cord Blood Banking- After a child’s birth, the collection and storage of blood from the inside of the umbilical cord is done. This is called cord blood banking. The cord blood is stored by two types of banks:

1. Public - These banks store the cord blood by marking it anonymously. One cannot get back the donated cord blood back from the bank.

2. Private - Personalized use by the entire family. Some amount of money has to be paid to take advantage of this set up.

The regulation of cord blood banks is done by the U.S. Food and Drug Administration (5).

• Cord Tissue Banking- It is the collection, testing, processing and preserving the cord tissue for further treatment processes.

The distinguishing factor between cord blood stem cells and cord tissue stem cells:

The main difference is the type of stem cells that are present in both of them. Cord blood contains haematopoietic stem cells whereas cord tissue contains mesenchymal stem cells (6).

BENEFITS:

1. Collecting the cord blood from the newborn is fully risk free and does not require much effort. There is no inconvenience caused either to the mother or her baby.

2. It can be used anytime as per requirements after completing the due process of collection and the necessary tests. The storage of the cord blood is done in a freezer.

3. Transplantation of cord blood does not necessitate that the donor and the recipient have to match fully; a partial match will also make the process a success.

4. The complications seen in patients of cord blood transplants are very few. Even viruses have a very slim chance of spreading infection in the patient (7).


5. If the cord blood stem cells are kept for personalized use in the future, there is an assurance of a match and the sample can be taken up for use immediately (8).

6. The use of umbilical cord blood cells in research dispels many doubts that come up in the field of embryonic stem cell research (as the embryo is not destroyed) (9).


7. The umbilical cord banks contain cord blood and cord tissue. The cord tissue is composed of mesenchymal stem cells that are genetically very stable. This is of great help in clinical trials for various diseases such as Crohn’s disease, multiple sclerosis etc (10).

APPLICATIONS OF UMBILICAL CORD BLOOD STEM CELLS:

1. Some genetic diseases can be taken care of by transfusing cord blood to the patient e.g. sickle cell anemia (6).

2. In the pediatric population malignancy of the blood can be treated with cord blood transplants (this is for those patients who do not have a family donor).

3. Neurological diseases can be treated with umbilical cord stem cells as they exhibit plasticity. In suitable conditions, they are capable of self-differentiation into cells such as neural cells, cardiac cells etc (7).

4. The stem cells in umbilical cord blood contribute in regenerating insulin, one of the methods to treat juvenile diabetes.

5. In immunotherapy, umbilical cord blood samples act as sources of Treg cells. Treg cells are CD4+ T helper cells that help in immune cell homeostasis (3), (11).

LATEST NEWS REGARDING UMBILICAL CORD STEM CELLS:

1. Development of artificial skin from umbilical cord stem cells (12).

2. Increase in survival rates of patients suffering from leukemia & lymphoma, using UCB stem cells (13).


3. Treating a small child with cerebral palsy using UCB autologous stem cells (14).

4. Reducing pain in the knees through stem cells from umbilical cords (15).

REFERENCES:

1. http://en.wikipedia.org/wiki/Umbilical_cord

2. Navarrete C, Contreras M. Cord Blood Banking: a historical perspective. British Journal of Haematology. 2009; 147: 236-245.

3. http://health.india.com/diseases-conditi...treatment/

4. McKenna D, Sheth J. Umbilical cord Blood: Current status & promise for the future. Indian J Med Res 134. 2011; 261-269.

5. http://kidshealth.org/parent/_cancer_cen...blood.html

6. http://www.cryo-cell.com/cord-tissue-banking

7. http://www.disabled-world.com/news/resea...atment.php

8. http://specialsections.suntimes.com/heal...blood.html

9. Umbilical Cord Blood Banking. RANZCOG College Statement (C-Obs 18). 2013; 1-3.

10. Gong W, Han Z, et al. Banking human umbilical cord-derived mesenchymal stromal cells for clinical use. Cell Transplantation. 2012; 21: 207-216.

11. http://www.ebioscience.com/cell-type/t-r...-cells.htm

12. http://health.india.com/news/scientists-...ical-cord/

13. http://www.sciencedaily.com/releases/201...104923.htm

14. http://www.prnewswire.co.uk/news-release...24971.html

15. http://www.king5.com/health/New-stem-cel...46291.html

Written and emailed by Ms. Deepti Narayan ( also writes on BiotechArticles.com)]]> <![CDATA[Reprogramming Somatic Cells to a Pluripotent State]]> https://www.biotechnologyforums.com/thread-2305.html Mon, 24 Jun 2013 17:09:44 +0000 sale0303]]> https://www.biotechnologyforums.com/thread-2305.html Future Goals and Possibility of Somatic Cells Reprogramming to a Pluripotent State.

Most of our somatic cells are highly differentiated and they are not able to divide and regenerate our body. Some specialised cells are able to divide, but huge step in human medicine would be discovery of genes which can turn somatic cells to a pluripotent state.

Discovery of a master gene, which can program somatic cells to a pluripotent state, would lead to great progress for all of modern human regenerative medicine; it would obviate the need for human cloning, with all its ethical or moral implications. Pluripotent stem cell is able to give rise to differentiated derivatives of all three germ layers. Cells of the inner cell mass and embryonic stem cells are pluripotent.

Several years ago was demonstrated that pluripotent embryonic stem cells could be generated from both embryonic and adult mouse fibroblasts by retroviral conversion of four genes: Oct4, Sox2, Klf4 and c-Myc. The induced pluripotent stem cells, displayed morphology and growth properties typical of embryonic stem cells. Global gene-expression profiling of induced pluripotent stem cells discovered that these cells cluster more closely with embryonic stem cells than with fibroblasts. The different analysis showed genes which were expressed at higher levels in embryonic stem cells than in induced pluripotent stem cells. Oct4 was found partially methylated, or incompletely reprogrammed in induced pluripotent stem cells. When the pluripotent potential of the cells was tested, it turned out that, even though induced pluripotent stem cells were prepared for multi-lineage differentiation capability in vitro, in vivo they could contribute to fetal but not to adult mouse development. This was probably due to the fact that expression of all four factors was driven by constitutively active promoters, which are not able to mediate transgene down-regulation throughout differentiation.

Induced pluripotent stem cell isolation from drug selected fibroblast which carries a neomycin gene inserted within the Oct4 locus resulted instead in the generation of induced pluripotent stem cells with gene expression, chromatin, and DNA methylation characteristics. Oct4 in induced pluripotent stem cells displayed increased developmental potency, which was identical to the one showed by embryonic stem cells. Expression analysis of transduced and endogenous Oct4, Sox2, Klf4 and Myc genes showed that retroviral transgenes are silenced during the induction of Oct4 induced pluripotent stem cells. This result indicates that exogenous Oct4, Sox2, Klf4, and Myc are essential for the induction of embryonic stem- like characteristics, however that the activity of the endogenous genes must be engaged in order to achieve pluripotency and full differentiation potential. But, induced pluripotent stem cells derived animals developed tumors, probably due to the reactivation of the some transgenes, like Myc transgene. Successful reprogramming of fibroblasts was shown to be accomplished without c Myc, but evidence that induced pluripotent stem cells derived by Oct4, Sox2, and Klf4 transduction will not induce tumor formation in adult mice is still missing.

Induced pluripotent stem cells can be isolated from non-transgenic fibroblasts by using exclusively morphological criteria for the recognition of embryonic stem- like colonies after viral transduction. This methodology provides a rate of reprogramming efficiency higher than observed using drug selection. Fetal and adult fibroblasts are not the only differentiated somatic cell type that can give rise to induced pluripotent stem cells. Non-terminally differentiated cells were shown to be reprogrammed to a pluripotent state by inducible expression of the four factors, while mature cell reprogramming needed furtheter genetic manipulation.

New study

The scientists came to the brilliant conclusion. When the process of mouse induced pluripotent stem cells derivation was monitored at totally different time-points for pluripotency marker gene expression, alkaline phosphatase first, SSEA1, and at last Nanog and Oct4 were consistently found to be switched on in a sequential temporal order. This knowledge would point towards the existence of an iter of gene reprogramming which is defined and gradual, rather than chaotic. Further confirmation of this hypothesis was given by a comprehensive integrative genomic characterization of cells during induced pluripotent stem cells generation. Cells were transduced with inducible viral vectors encoding for the four factors and sampled at day 4, 8, 12, and 16 of initial induction for expression profiling.

Conclusion

The therapeutic potential of induced pluripotent cells was tested in a sickle cell anemia mouse model. Autologous induced pluripotent stem cells were generated from skin cells of a diseased animal, targeted for correction of the endogenous human sickle hemoglobin gene and induced to differentiate into hematopoietic progenitors. The efficient treatment of sickle cell anemia obtained by transplantation of these host specific cells into the diseased mouse provides a proof of principle for the clinical achievements that combined gene and cell therapy can lead to. Significantly, induced pluripotent cells have also been derived from human fetal, neonatal, and adult fibroblasts by ectopic expression of the same four-factor cocktail that yielded mouse induced pluripotent stem cells. Unfortunately, genetic manipulation of cells brings inevitable drawbacks: ectopic expression of tumor suppressor genes causes tumorigenicity, and random insertion of the viral sequences within the genome may produce unwanted mutagenesis events. Nonetheless, an essential step forward in coupled gene repair plus cell therapy has been made. We have learned that the fundamental transcriptional network governing pluripotency in humans and mice is conserved, regardless of the differences between the two species for growth factor requirements. As of these days, the complete image eventually appears in its amazing completeness, thanks to scientists who apply the missing piece of the puzzle and obtained induced pluripotent stem cells by the ‘simple’ protein transduction of the four factors. Some ethical issues, such as failure rate, problems during later development, and abnormal gene expression patterns may still represent the problem, but with further advances in medicine and technology will solve these issues as well as ethical and moral.]]> Future Goals and Possibility of Somatic Cells Reprogramming to a Pluripotent State.

Most of our somatic cells are highly differentiated and they are not able to divide and regenerate our body. Some specialised cells are able to divide, but huge step in human medicine would be discovery of genes which can turn somatic cells to a pluripotent state.

Discovery of a master gene, which can program somatic cells to a pluripotent state, would lead to great progress for all of modern human regenerative medicine; it would obviate the need for human cloning, with all its ethical or moral implications. Pluripotent stem cell is able to give rise to differentiated derivatives of all three germ layers. Cells of the inner cell mass and embryonic stem cells are pluripotent.

Several years ago was demonstrated that pluripotent embryonic stem cells could be generated from both embryonic and adult mouse fibroblasts by retroviral conversion of four genes: Oct4, Sox2, Klf4 and c-Myc. The induced pluripotent stem cells, displayed morphology and growth properties typical of embryonic stem cells. Global gene-expression profiling of induced pluripotent stem cells discovered that these cells cluster more closely with embryonic stem cells than with fibroblasts. The different analysis showed genes which were expressed at higher levels in embryonic stem cells than in induced pluripotent stem cells. Oct4 was found partially methylated, or incompletely reprogrammed in induced pluripotent stem cells. When the pluripotent potential of the cells was tested, it turned out that, even though induced pluripotent stem cells were prepared for multi-lineage differentiation capability in vitro, in vivo they could contribute to fetal but not to adult mouse development. This was probably due to the fact that expression of all four factors was driven by constitutively active promoters, which are not able to mediate transgene down-regulation throughout differentiation.

Induced pluripotent stem cell isolation from drug selected fibroblast which carries a neomycin gene inserted within the Oct4 locus resulted instead in the generation of induced pluripotent stem cells with gene expression, chromatin, and DNA methylation characteristics. Oct4 in induced pluripotent stem cells displayed increased developmental potency, which was identical to the one showed by embryonic stem cells. Expression analysis of transduced and endogenous Oct4, Sox2, Klf4 and Myc genes showed that retroviral transgenes are silenced during the induction of Oct4 induced pluripotent stem cells. This result indicates that exogenous Oct4, Sox2, Klf4, and Myc are essential for the induction of embryonic stem- like characteristics, however that the activity of the endogenous genes must be engaged in order to achieve pluripotency and full differentiation potential. But, induced pluripotent stem cells derived animals developed tumors, probably due to the reactivation of the some transgenes, like Myc transgene. Successful reprogramming of fibroblasts was shown to be accomplished without c Myc, but evidence that induced pluripotent stem cells derived by Oct4, Sox2, and Klf4 transduction will not induce tumor formation in adult mice is still missing.

Induced pluripotent stem cells can be isolated from non-transgenic fibroblasts by using exclusively morphological criteria for the recognition of embryonic stem- like colonies after viral transduction. This methodology provides a rate of reprogramming efficiency higher than observed using drug selection. Fetal and adult fibroblasts are not the only differentiated somatic cell type that can give rise to induced pluripotent stem cells. Non-terminally differentiated cells were shown to be reprogrammed to a pluripotent state by inducible expression of the four factors, while mature cell reprogramming needed furtheter genetic manipulation.

New study

The scientists came to the brilliant conclusion. When the process of mouse induced pluripotent stem cells derivation was monitored at totally different time-points for pluripotency marker gene expression, alkaline phosphatase first, SSEA1, and at last Nanog and Oct4 were consistently found to be switched on in a sequential temporal order. This knowledge would point towards the existence of an iter of gene reprogramming which is defined and gradual, rather than chaotic. Further confirmation of this hypothesis was given by a comprehensive integrative genomic characterization of cells during induced pluripotent stem cells generation. Cells were transduced with inducible viral vectors encoding for the four factors and sampled at day 4, 8, 12, and 16 of initial induction for expression profiling.

Conclusion

The therapeutic potential of induced pluripotent cells was tested in a sickle cell anemia mouse model. Autologous induced pluripotent stem cells were generated from skin cells of a diseased animal, targeted for correction of the endogenous human sickle hemoglobin gene and induced to differentiate into hematopoietic progenitors. The efficient treatment of sickle cell anemia obtained by transplantation of these host specific cells into the diseased mouse provides a proof of principle for the clinical achievements that combined gene and cell therapy can lead to. Significantly, induced pluripotent cells have also been derived from human fetal, neonatal, and adult fibroblasts by ectopic expression of the same four-factor cocktail that yielded mouse induced pluripotent stem cells. Unfortunately, genetic manipulation of cells brings inevitable drawbacks: ectopic expression of tumor suppressor genes causes tumorigenicity, and random insertion of the viral sequences within the genome may produce unwanted mutagenesis events. Nonetheless, an essential step forward in coupled gene repair plus cell therapy has been made. We have learned that the fundamental transcriptional network governing pluripotency in humans and mice is conserved, regardless of the differences between the two species for growth factor requirements. As of these days, the complete image eventually appears in its amazing completeness, thanks to scientists who apply the missing piece of the puzzle and obtained induced pluripotent stem cells by the ‘simple’ protein transduction of the four factors. Some ethical issues, such as failure rate, problems during later development, and abnormal gene expression patterns may still represent the problem, but with further advances in medicine and technology will solve these issues as well as ethical and moral.]]> <![CDATA[Tooth Regeneration: Grow Your Teeth Like an Alligator!]]> https://www.biotechnologyforums.com/thread-2249.html Wed, 22 May 2013 04:05:23 +0000 Malithi Weerakkody]]> https://www.biotechnologyforums.com/thread-2249.html Proceedings of the National Academy of Sciences, in May 2013, provides an insight into the regulation of multiple tooth regeneration of the American alligator. The researchers predict that understanding the mechanisms related to the development and renewal of tooth in this crocodile model will be useful in finding a way to stimulate the teeth regrowth in adult humans.

Alligator teeth are not that different from ours!

Crocodiles exhibit the same complex dental architecture and morphological characteristics as mammals such as thecodont teeth (teeth that are embedded in sockets). They also have a secondary palate like that of the mammals. In addition, unlike humans, they have the capability of renewing their teeth many times within their lifetime. Thus the alligators can be considered a classic model to be used in tooth regeneration studies.

One crocodile tooth renews about 50 times

Crocodiles are polyphyodont i.e., their teeth are continuously shed and replaced during the existence of the animal. It is estimated that one crocodile may replace each of its 80 tooth about 50 times throughout its lifespan. Humans however, are diphyodont, meaning that they can grow only two successive sets of teeth within their lifetime: the deciduous (milk) teeth, which are followed by the permanent (adult) teeth. After that they lose their ability for tooth renewal.

The present study observed that each tooth of an alligator behaves like a complex ‘family unit’. Each of these units comprises of a functional tooth which is the most mature tooth, a successional tooth that will later be developed in to a functional tooth and the dental lamina. These components were found to be at different stages of development. Furthermore, the researchers were able to identify a type of cells in the dental lamina of the alligators which they suspect to be dormant teeth stem cells that can be activated when a functional tooth is shed or extracted.

The research also provides information about the signalling molecules that plays a critical role in tooth development and renewal of the alligators.

Humans may have the potential for tooth regeneration

Dental lamina, the source of odontogenic stem cells for cyclic tooth regeneration, usually begins to degrade in humans after the generation of secondary tooth. Thus the humans lose the ability of regenerating their adult teeth. However, a remnant of it still exists and may initiate odontogenic tumors later in life. Previous literature reveals the presence of teeth stem cells in adult humans. Although these cells retain the ability of differentiation, they cannot generate a whole new tooth.
 
the following video can provide a basic idea of human tooth development.


No more dentures!

Tooth loss is a common problem that may occur due to various reasons including fractures, physical injuries, tooth decay and infections of the gum. Though this condition is rarely critical, it often results in aesthetic and psychological concerns thus necessitating in replacement of tooth.

Current options available for tooth replacement include techniques such as dental implants made out of biocompatible materials like titanium that can be inserted in the teeth bone. However the success of these implants is not completely satisfactory in terms of their performance and long-term stability. Therefore, many recent researchers focus on the potential of odontogenic stem cells to grow living tooth with proper functional characteristics. Several studies report regeneration of teeth using stem cells in vitro, although their use in dental practice is still challenging owing to factors such as high risk of rejection.

The current research however, promises of a future potential of regeneration of teeth in vivo. These findings suggest the possibility of using this knowledge for stimulating the dormant stem cells present in the remnant human dental lamina to initiate tooth regeneration process. In addition, the researchers hope that this will help in treating oral diseased that involve supernumery teeth formation.

Reference

Wu, P., Wu, X., Jiang, T. X., Elsey, R. M., Temple, B. L., Divers, S. J., ... & Chuong, C. M. (2013). Specialized stem cell niche enables repetitive renewal of alligator teeth. Proceedings of the National Academy of Sciences.

http://www.pnas.org/content/early/2013/0...0.abstract]]> Proceedings of the National Academy of Sciences, in May 2013, provides an insight into the regulation of multiple tooth regeneration of the American alligator. The researchers predict that understanding the mechanisms related to the development and renewal of tooth in this crocodile model will be useful in finding a way to stimulate the teeth regrowth in adult humans.

Alligator teeth are not that different from ours!

Crocodiles exhibit the same complex dental architecture and morphological characteristics as mammals such as thecodont teeth (teeth that are embedded in sockets). They also have a secondary palate like that of the mammals. In addition, unlike humans, they have the capability of renewing their teeth many times within their lifetime. Thus the alligators can be considered a classic model to be used in tooth regeneration studies.

One crocodile tooth renews about 50 times

Crocodiles are polyphyodont i.e., their teeth are continuously shed and replaced during the existence of the animal. It is estimated that one crocodile may replace each of its 80 tooth about 50 times throughout its lifespan. Humans however, are diphyodont, meaning that they can grow only two successive sets of teeth within their lifetime: the deciduous (milk) teeth, which are followed by the permanent (adult) teeth. After that they lose their ability for tooth renewal.

The present study observed that each tooth of an alligator behaves like a complex ‘family unit’. Each of these units comprises of a functional tooth which is the most mature tooth, a successional tooth that will later be developed in to a functional tooth and the dental lamina. These components were found to be at different stages of development. Furthermore, the researchers were able to identify a type of cells in the dental lamina of the alligators which they suspect to be dormant teeth stem cells that can be activated when a functional tooth is shed or extracted.

The research also provides information about the signalling molecules that plays a critical role in tooth development and renewal of the alligators.

Humans may have the potential for tooth regeneration

Dental lamina, the source of odontogenic stem cells for cyclic tooth regeneration, usually begins to degrade in humans after the generation of secondary tooth. Thus the humans lose the ability of regenerating their adult teeth. However, a remnant of it still exists and may initiate odontogenic tumors later in life. Previous literature reveals the presence of teeth stem cells in adult humans. Although these cells retain the ability of differentiation, they cannot generate a whole new tooth.
 
the following video can provide a basic idea of human tooth development.


No more dentures!

Tooth loss is a common problem that may occur due to various reasons including fractures, physical injuries, tooth decay and infections of the gum. Though this condition is rarely critical, it often results in aesthetic and psychological concerns thus necessitating in replacement of tooth.

Current options available for tooth replacement include techniques such as dental implants made out of biocompatible materials like titanium that can be inserted in the teeth bone. However the success of these implants is not completely satisfactory in terms of their performance and long-term stability. Therefore, many recent researchers focus on the potential of odontogenic stem cells to grow living tooth with proper functional characteristics. Several studies report regeneration of teeth using stem cells in vitro, although their use in dental practice is still challenging owing to factors such as high risk of rejection.

The current research however, promises of a future potential of regeneration of teeth in vivo. These findings suggest the possibility of using this knowledge for stimulating the dormant stem cells present in the remnant human dental lamina to initiate tooth regeneration process. In addition, the researchers hope that this will help in treating oral diseased that involve supernumery teeth formation.

Reference

Wu, P., Wu, X., Jiang, T. X., Elsey, R. M., Temple, B. L., Divers, S. J., ... & Chuong, C. M. (2013). Specialized stem cell niche enables repetitive renewal of alligator teeth. Proceedings of the National Academy of Sciences.

http://www.pnas.org/content/early/2013/0...0.abstract]]> <![CDATA[Instability of Stem Cells]]> https://www.biotechnologyforums.com/thread-2222.html Sun, 12 May 2013 23:51:02 +0000 sale0303]]> https://www.biotechnologyforums.com/thread-2222.html
Embryonic Stem Cells

Main concern with embryonic stem cells is related to uncontrolled growth. Embryonic stem cells are cells which tend to grow fast. However, the rapidly growth must be carefully guided by researchers. These stem cells need to be cultivated and directed into specialised cells with great care because the potential for remaining stem cells to grow uncontrolled could be terrible. These uncontrolled stem cells could eventually form tumours. Embryonic stem cells division are subject to errors during cell division that can result in abnormal chromosome forms. Cytogenetics, the study of abnormal chromosomes, has shown that stem cells tend to show the chromosome aberrations. The most frequent change in human embryonic stem cells involves gain of chromosomes 12 or 17, which both are associated with cancer. There is no way to differentiate embryonic stem cells with abnormal chromosomes form and normal stem cells without genetic testing, because both express the same proteins and specifically stem cell markers. Additionally, the presence of chromosome changes does not affect the ability of these cells to different into appropriate cell types. However, most of these divisions lead to cell death, as a result accidents in division, which lead to extra or missing chromosomes.
Some researchers claim normal chromosomes in human embryonic cells after prolonged time in culture, even after 100 passages. Others have reported recurrent aberrations involving chromosomes 12 and 17 occurring between passages 25 and 45. Despite optimal culture techniques, the genetic integrity of embryonic stem cells is difficult to keep, because of the stresses of tissue culture and the other pressures exerted on the cells after cultures have been frozen and thawed. Cryopreserved embryonic stem cells tend to grow poorly after thawing. Some cells with a growth rate resulting from an extra chromosome 12 or 17 can increase in number and eventually overgrow the normal cells.

Adult Stem Cells

Unlike embryonic stem cells, which can give rise to any lineage, adult stem cells can only generate cells of a specific lineage. Adult stem cells are present in specialized tissues throughout the body, such as bone marrow or skin, and are capable of unlimited production of differentiated cells. For adult stem cells to be able to divide continuously, they must have an active telomerase gene, which is characteristic of all embryonic stem cells. The presence of the telomerase gene enables stem cells to maintain the integrity of the chromosomes throughout many cell divisions, whereas differentiated cells of the body do not have this gene and therefore can undergo only a limited number of divisions. There is a general belief that cancer cells derive from mutated adult stem cells because differentiated cells have a limited life-span and therefore cannot accumulate the necessary mutations for malignant transformation.

Most mutations in adult stem cells that give rise to cancer or leukemia tend to be lineage specific because certain changes will promote growth in one tissue, but not another. Chronic myeloid leukemia is example. Chronic myeloid leukemia is caused by specific chromosome mutations in a bone marrow stem cell. The normal stem cells in the bone marrow divide only when more blood cells are needed, and they become quiet as a result of continuous blood cell production by the mutated stem cells. This enables the abnormal stem cells populating the bone marrow to divide continuously. The mutation in chronic myeloid leukemia includes specific mutations between chromosomes 9 and 22, but this chromosome aberration has no effect in any other tissue because chromosome changes associated with cancer are lineage specific.

The fact that cultured adult stem cells can undergo tissue-specific chromosome changes associated with malignant diseases emphasizes the need to ensure that any adult stem cells used therapeutically, including reprogrammed cells, be monitored for genetic changes.

Examples

Scientists have tried embryonic stem cell transplantation in animal experimental models for stroke. Undifferentiated embryonic stem cells that were transplanted into the rat brain, migrated to the damaged area and differentiated into neurons along the border of the lesion. When the same cell line was transplanted into the mouse brain, the embryonic cells did not migrate but remained in one area to produce malignant carcinomas. Embryonic stem cells were undifferentiated or pre-differentiated in vitro to neural progenitor cells.

Mouse embryonic stem cells can differentiate into liver cells in culture. When mice were injected in the spleen with 9 day old cultures, the cells migrated to the liver and generated liver cells. However, when 9 day old and 15 day old cell cultures were injected directly into the mouse liver, there was a high incidence of tumor formation. The authors conclude that even in 15 day old cultures, undifferentiated embryonic stem cells can persist that are capable of forming tumors when transplanted.

Scientists still do not know so much about how stem cell differentiation is controlled. Further research will explain how cell signals operate to trigger cell differentiation. Current stem cell treatments may eventually become routine and regular therapies for serious disease. However, it's important that the safety of these therapies is evaluated and that caution is displayed before a therapy becomes accepted for use. This will allow full benefits of stem cell therapies for everyone.]]>
Embryonic Stem Cells

Main concern with embryonic stem cells is related to uncontrolled growth. Embryonic stem cells are cells which tend to grow fast. However, the rapidly growth must be carefully guided by researchers. These stem cells need to be cultivated and directed into specialised cells with great care because the potential for remaining stem cells to grow uncontrolled could be terrible. These uncontrolled stem cells could eventually form tumours. Embryonic stem cells division are subject to errors during cell division that can result in abnormal chromosome forms. Cytogenetics, the study of abnormal chromosomes, has shown that stem cells tend to show the chromosome aberrations. The most frequent change in human embryonic stem cells involves gain of chromosomes 12 or 17, which both are associated with cancer. There is no way to differentiate embryonic stem cells with abnormal chromosomes form and normal stem cells without genetic testing, because both express the same proteins and specifically stem cell markers. Additionally, the presence of chromosome changes does not affect the ability of these cells to different into appropriate cell types. However, most of these divisions lead to cell death, as a result accidents in division, which lead to extra or missing chromosomes.
Some researchers claim normal chromosomes in human embryonic cells after prolonged time in culture, even after 100 passages. Others have reported recurrent aberrations involving chromosomes 12 and 17 occurring between passages 25 and 45. Despite optimal culture techniques, the genetic integrity of embryonic stem cells is difficult to keep, because of the stresses of tissue culture and the other pressures exerted on the cells after cultures have been frozen and thawed. Cryopreserved embryonic stem cells tend to grow poorly after thawing. Some cells with a growth rate resulting from an extra chromosome 12 or 17 can increase in number and eventually overgrow the normal cells.

Adult Stem Cells

Unlike embryonic stem cells, which can give rise to any lineage, adult stem cells can only generate cells of a specific lineage. Adult stem cells are present in specialized tissues throughout the body, such as bone marrow or skin, and are capable of unlimited production of differentiated cells. For adult stem cells to be able to divide continuously, they must have an active telomerase gene, which is characteristic of all embryonic stem cells. The presence of the telomerase gene enables stem cells to maintain the integrity of the chromosomes throughout many cell divisions, whereas differentiated cells of the body do not have this gene and therefore can undergo only a limited number of divisions. There is a general belief that cancer cells derive from mutated adult stem cells because differentiated cells have a limited life-span and therefore cannot accumulate the necessary mutations for malignant transformation.

Most mutations in adult stem cells that give rise to cancer or leukemia tend to be lineage specific because certain changes will promote growth in one tissue, but not another. Chronic myeloid leukemia is example. Chronic myeloid leukemia is caused by specific chromosome mutations in a bone marrow stem cell. The normal stem cells in the bone marrow divide only when more blood cells are needed, and they become quiet as a result of continuous blood cell production by the mutated stem cells. This enables the abnormal stem cells populating the bone marrow to divide continuously. The mutation in chronic myeloid leukemia includes specific mutations between chromosomes 9 and 22, but this chromosome aberration has no effect in any other tissue because chromosome changes associated with cancer are lineage specific.

The fact that cultured adult stem cells can undergo tissue-specific chromosome changes associated with malignant diseases emphasizes the need to ensure that any adult stem cells used therapeutically, including reprogrammed cells, be monitored for genetic changes.

Examples

Scientists have tried embryonic stem cell transplantation in animal experimental models for stroke. Undifferentiated embryonic stem cells that were transplanted into the rat brain, migrated to the damaged area and differentiated into neurons along the border of the lesion. When the same cell line was transplanted into the mouse brain, the embryonic cells did not migrate but remained in one area to produce malignant carcinomas. Embryonic stem cells were undifferentiated or pre-differentiated in vitro to neural progenitor cells.

Mouse embryonic stem cells can differentiate into liver cells in culture. When mice were injected in the spleen with 9 day old cultures, the cells migrated to the liver and generated liver cells. However, when 9 day old and 15 day old cell cultures were injected directly into the mouse liver, there was a high incidence of tumor formation. The authors conclude that even in 15 day old cultures, undifferentiated embryonic stem cells can persist that are capable of forming tumors when transplanted.

Scientists still do not know so much about how stem cell differentiation is controlled. Further research will explain how cell signals operate to trigger cell differentiation. Current stem cell treatments may eventually become routine and regular therapies for serious disease. However, it's important that the safety of these therapies is evaluated and that caution is displayed before a therapy becomes accepted for use. This will allow full benefits of stem cell therapies for everyone.]]> <![CDATA[Stem Cell Niche | Signaling pathways and Cell differentiation]]> https://www.biotechnologyforums.com/thread-2204.html Tue, 07 May 2013 22:01:12 +0000 sale0303]]> https://www.biotechnologyforums.com/thread-2204.html Homeostasis of human body is maintained by continuous stem cells division. By self-division and differentiation of daughter cells, stem cells are responsible for replacing of short-living and highly differentiated cells in skin, testicles and blood. Of course, this process must be strictly observed, because it can cause many dysfunctions in our body. Because of their importance, stem cells should be preserved as much as possible from damage or loss.

If little amount of cells differentiate, big number of cells can be created and it can lead to secondary mutation and tumor genesis. On the other way, if big amount of cells differentiate, the stem cell population may be reduced. However, critical decision between stem cell self-renewal and differentiation is controlled by microenvironment in which stem cells are located called stem cell niche. Stem cell niches provide support for stem cells and signalization (hormonal, neural and metabolic). Niches have been found in peripheral nervous system, skin, hair follicle, prostate, blood, breast, bone marrow and intestines. Many recent studies have begun to reveal different critical components of many stem cell niches. These critical components include various cell types like inflammatory, mesenchymal, glial, vascular and neuronal, then other factors like oxygen tension, temperature and matrix rigidity.

Interactions in the stem cell niche

There are several interactions in stem cell niche. Cell- cell interactions provide structural support, produce soluble signals that control function of the stem cell and have role in adhesion. Extra cellular matrix also has interactions with stem cells, and their interaction provides mechanical signals which allow stem cells to have adequate response to physical forces from the outside. Also, temperature, chemical signals and shear forces which are provided by the stem cell niche influence stem cell behavior.

Signaling pathways

Gene activated cascade of events dictate stem cell fate and function. These signaling pathways include Notch, Sonic Hedgehog, Wnt genes and BMI-1. Role of the Notch is very important in many stem cell niches, mainly in muscles, gut, mammary gland and hematopoietic system. This signaling pathway has role in stem cell division and it is activated when ligand and Notch receptor make connection. The Wnt genes has still blur image of their function, but they may have role in direct induction of stem cell self- renewal process, and possibly, they can influence stem cells in the niche. The BMI-1 signaling pathway has been found in neuronal stem cells and hematopoietic stem cells. The most possible function of BMI-1 signaling pathway is other somatic stem cells regulation of self- renewal. Sonic hedgehog signaling controls many growth aspects, and as many studies have shown, this signaling pathway controls stem cell- like cells in neocortex and proliferation of the cells in hippocampus and ventral forebrain.

Cell differentiation in stem cell niche

In stem cell niche, when stem cells receive signal, they begin division. This division can be asymmetric, bigger part stays in niche as stem cell, and another becomes a progenitor cell, leaves stem cell niche and continues differentiation. Also, division can be symmetric, and in this division type, both stem cells remain in niche. The key role of stem cell niche is adequate signaling system, which can tell stem cells to divide or not to divide. If niche doesn’t provide appropriate signal, stem cells begin to differentiate in short amount of time. Progenitor stem cells move away from the niche, and they are escorted by guardian cells.

If cell differentiation prevailed, the stem cell population within a niche would be decreased, and if self- renewal continued uncontrolled, the result would be quick tumor development. The role of niche is obvious, because niche provides necessary balance between differentiation and division. The niche environment is responsible for inhibition or induction of stem cell differentiation or division, based on the composition and size of stem cell niche. Surrounding tissue and extracellular matrix signals provide cell identity and commands their behavior. Functional cells arising from stem cells differentiate in intermediate- differentiated progenitor cells, that after a several divisions and differentiations, become differentiated cell, without ability to proliferate and that cell is treated as finally differentiated.

In every tissue, stem cells have high capacity for proliferation, but not every human stem cell divides with high frequency. Researchers have proven this by using fluorescent labeling to mark skin stem cells. These skin stem cells within the stem cell niche began to divide rapidly.
Stem cells have enormous potential in regenerative medicine in repairing diseased or damaged tissue because of their tumor initiation role. The stem cells niche have potential role in cancer treatment. These niches are maybe potential targets for radiation and chemotherapy treatments in order to destroy tumor stem cells. For example, mammary gland stem cells are controlled by reproductive organs as well as the niche to produce new tissues in order to create more complex way of stem cell self- renewal as well as chance for tumor progression. Similar to this is prostate tumor treatment. In prostate tumor, stem cell niche is in the basal layer, proximal to urethra, and this region has been identified as stem cell niche in the prostate gland.

Conclusion

Stem cells are fantastic and promising solution for regenerative medicine, but these cells are not only important in tissue renewal. As these cells must react very fast, they receive input information from their niche, which directs their destiny. When we understand complete interaction between stem cells and niche, we will dictate their activities to promote tissue regeneration. On the other hand, targeting these niches can help us in battle against many diseases such as tumors.]]> Homeostasis of human body is maintained by continuous stem cells division. By self-division and differentiation of daughter cells, stem cells are responsible for replacing of short-living and highly differentiated cells in skin, testicles and blood. Of course, this process must be strictly observed, because it can cause many dysfunctions in our body. Because of their importance, stem cells should be preserved as much as possible from damage or loss.

If little amount of cells differentiate, big number of cells can be created and it can lead to secondary mutation and tumor genesis. On the other way, if big amount of cells differentiate, the stem cell population may be reduced. However, critical decision between stem cell self-renewal and differentiation is controlled by microenvironment in which stem cells are located called stem cell niche. Stem cell niches provide support for stem cells and signalization (hormonal, neural and metabolic). Niches have been found in peripheral nervous system, skin, hair follicle, prostate, blood, breast, bone marrow and intestines. Many recent studies have begun to reveal different critical components of many stem cell niches. These critical components include various cell types like inflammatory, mesenchymal, glial, vascular and neuronal, then other factors like oxygen tension, temperature and matrix rigidity.

Interactions in the stem cell niche

There are several interactions in stem cell niche. Cell- cell interactions provide structural support, produce soluble signals that control function of the stem cell and have role in adhesion. Extra cellular matrix also has interactions with stem cells, and their interaction provides mechanical signals which allow stem cells to have adequate response to physical forces from the outside. Also, temperature, chemical signals and shear forces which are provided by the stem cell niche influence stem cell behavior.

Signaling pathways

Gene activated cascade of events dictate stem cell fate and function. These signaling pathways include Notch, Sonic Hedgehog, Wnt genes and BMI-1. Role of the Notch is very important in many stem cell niches, mainly in muscles, gut, mammary gland and hematopoietic system. This signaling pathway has role in stem cell division and it is activated when ligand and Notch receptor make connection. The Wnt genes has still blur image of their function, but they may have role in direct induction of stem cell self- renewal process, and possibly, they can influence stem cells in the niche. The BMI-1 signaling pathway has been found in neuronal stem cells and hematopoietic stem cells. The most possible function of BMI-1 signaling pathway is other somatic stem cells regulation of self- renewal. Sonic hedgehog signaling controls many growth aspects, and as many studies have shown, this signaling pathway controls stem cell- like cells in neocortex and proliferation of the cells in hippocampus and ventral forebrain.

Cell differentiation in stem cell niche

In stem cell niche, when stem cells receive signal, they begin division. This division can be asymmetric, bigger part stays in niche as stem cell, and another becomes a progenitor cell, leaves stem cell niche and continues differentiation. Also, division can be symmetric, and in this division type, both stem cells remain in niche. The key role of stem cell niche is adequate signaling system, which can tell stem cells to divide or not to divide. If niche doesn’t provide appropriate signal, stem cells begin to differentiate in short amount of time. Progenitor stem cells move away from the niche, and they are escorted by guardian cells.

If cell differentiation prevailed, the stem cell population within a niche would be decreased, and if self- renewal continued uncontrolled, the result would be quick tumor development. The role of niche is obvious, because niche provides necessary balance between differentiation and division. The niche environment is responsible for inhibition or induction of stem cell differentiation or division, based on the composition and size of stem cell niche. Surrounding tissue and extracellular matrix signals provide cell identity and commands their behavior. Functional cells arising from stem cells differentiate in intermediate- differentiated progenitor cells, that after a several divisions and differentiations, become differentiated cell, without ability to proliferate and that cell is treated as finally differentiated.

In every tissue, stem cells have high capacity for proliferation, but not every human stem cell divides with high frequency. Researchers have proven this by using fluorescent labeling to mark skin stem cells. These skin stem cells within the stem cell niche began to divide rapidly.
Stem cells have enormous potential in regenerative medicine in repairing diseased or damaged tissue because of their tumor initiation role. The stem cells niche have potential role in cancer treatment. These niches are maybe potential targets for radiation and chemotherapy treatments in order to destroy tumor stem cells. For example, mammary gland stem cells are controlled by reproductive organs as well as the niche to produce new tissues in order to create more complex way of stem cell self- renewal as well as chance for tumor progression. Similar to this is prostate tumor treatment. In prostate tumor, stem cell niche is in the basal layer, proximal to urethra, and this region has been identified as stem cell niche in the prostate gland.

Conclusion

Stem cells are fantastic and promising solution for regenerative medicine, but these cells are not only important in tissue renewal. As these cells must react very fast, they receive input information from their niche, which directs their destiny. When we understand complete interaction between stem cells and niche, we will dictate their activities to promote tissue regeneration. On the other hand, targeting these niches can help us in battle against many diseases such as tumors.]]> <![CDATA[Influence of Heart Cells on Amniotic Stem Cells and Newest Scaffold Research]]> https://www.biotechnologyforums.com/thread-2194.html Sat, 04 May 2013 18:21:14 +0000 sale0303]]> https://www.biotechnologyforums.com/thread-2194.html
Latest studies have shown that these stem cells have huge potential in heart therapies. However, understanding of these studies is needed. The important thing is to separate things what stem cells can do with heart cells, and what they cannot. Researchers at Rice University and Texas Children's Hospital have founded that communication between these two cell types is possible. Mature heart cells and stem cells have ability to create electrical couplings between themselves like heart cells in heart tissue. During this electrical connection, stem cells cannot transform themselves to mature heart cells, and this is limitation of this method. Patients with Tetralogy of Fallot have biocompatible patches surgically placed across right ventricular outflow tract of the heart.

Procedure of stem cell implementation and scaffold types

Procedure of stem cell transplantation cannot be done without special scaffold patches. Idea of biocompatible patches seeded with stem cells is brilliant, because scaffold patches would ideally support stem cells implementation.

Current patches are made from synthetic fabrics or they can be obtained from cows or from patient himself. This kind of treatment is not bad, but it has limitations. These patches are more like plastic, and they don’t have ability to grow together with patients. Therefore, they have to be replaced in correlation with patients growth. Also these patches are implanted in heart and it's good for heart contraction. However, electrical signals have to go around this dead tissue. This implicates that heart has less contraction power and surely it can lead to heart failure or arrhythmias and fibrillations. When we summarize these facts we can conclude that these scaffolds have high short- and medium- term success rate and, unfortunately, long- term complications.

Newest scaffold research

Researchers have tried to discover the perfect scaffold. This perfect scaffold should be strong enough for heart contractions, porous enough to allow migration of the new differentiated cells, tough enough, but also able to degrade itself after certain amount of time. The newest discovery is scaffold which is created of polycaprolactone and double layer made from mixture of chitosan and gelatin. Researchers believe that this could be a tremendous discovery, because this scaffold has shown good properties. When in water, this scaffold degrades, but if it is placed in human body, it will degrade very slowly, over a month. This scaffold should be strong for a certain period of time that will help heart muscle to recover and to take over support process. However, many years of testing await scientists before they begin human trials, but they are very optimistic, and they expect positive results.

Directions in future researches

If scientists want to implant perfectly grown tissue that will not be rejected, they have to find out how intercellular signals can guide transformation of an amniotic stem cell into a heart cell. Research on the rats have shown that stem cells can only communicate with heart cells through channels in their membrane that provide exchange of the ions and small molecules.

A certain part of scientists suggested that physical contact between amniotic stem cells and heart cells have positive influence in differentiation of stem cells. However, scientists on the newest researches have proved that this is not correct. The newest researches showed that previous claim was incorrect because they saw only fusion of amniotic stem cell and heart cell. That is what this research was based on. Researchers wanted to see if amniotic stem cells could have characteristics of heart cells if fusion between these two cells were not allowed. They revealed results, and results have shown that it is not possible to convert an amniotic stem cell into a heart cell, but certain change in gene expression was present. The finding was connection between stem cells with a gap junction connections. This gap junction connection can transfer some really small molecules and electrical ions. These ions and molecules can diffuse between two cells connected with this junction. However, this diffusion is not possible when amniotic stem cells are not in connection with heart cells.

This research has unique approach, because other researchers approach is directly injection in heart tissue. This other approach is studying how directly injected amniotic stem cells can help in treatment of heart attack recovery. Researches from the Rice University and Texas Children's Hospital are not enthusiastic about this other research, because they think that this research will show them role of paracrine signal effects. They think that stem cells directly injected can help only in stabilization of the cells, but they cannot differentiate and create new heart tissue.

Conclusion of the research

The biggest discovery of this research is fact that cell contact between amniotic stem cells and heart cells cannot induce transformation of the stem cells, but it produces more functional gap junction connection than amniotic stem cell cultures without cell contact. However, if we want a bigger results right now, probably additional cues and maybe tighter connection between stem cells and heart cells, or maybe fusion, is required.

The ease of obtaining this type of stem cells, widely multipotent nature and rapid proliferation rate make this cell type promising source for future researches in tissue engineering.

Researchers are sure that there are plenty of methods to get amniotic fluid- derived stem cells differentiate into desired tissue for medical uses, and this research has revealed only small part of stem cell differentiation.]]>
Latest studies have shown that these stem cells have huge potential in heart therapies. However, understanding of these studies is needed. The important thing is to separate things what stem cells can do with heart cells, and what they cannot. Researchers at Rice University and Texas Children's Hospital have founded that communication between these two cell types is possible. Mature heart cells and stem cells have ability to create electrical couplings between themselves like heart cells in heart tissue. During this electrical connection, stem cells cannot transform themselves to mature heart cells, and this is limitation of this method. Patients with Tetralogy of Fallot have biocompatible patches surgically placed across right ventricular outflow tract of the heart.

Procedure of stem cell implementation and scaffold types

Procedure of stem cell transplantation cannot be done without special scaffold patches. Idea of biocompatible patches seeded with stem cells is brilliant, because scaffold patches would ideally support stem cells implementation.

Current patches are made from synthetic fabrics or they can be obtained from cows or from patient himself. This kind of treatment is not bad, but it has limitations. These patches are more like plastic, and they don’t have ability to grow together with patients. Therefore, they have to be replaced in correlation with patients growth. Also these patches are implanted in heart and it's good for heart contraction. However, electrical signals have to go around this dead tissue. This implicates that heart has less contraction power and surely it can lead to heart failure or arrhythmias and fibrillations. When we summarize these facts we can conclude that these scaffolds have high short- and medium- term success rate and, unfortunately, long- term complications.

Newest scaffold research

Researchers have tried to discover the perfect scaffold. This perfect scaffold should be strong enough for heart contractions, porous enough to allow migration of the new differentiated cells, tough enough, but also able to degrade itself after certain amount of time. The newest discovery is scaffold which is created of polycaprolactone and double layer made from mixture of chitosan and gelatin. Researchers believe that this could be a tremendous discovery, because this scaffold has shown good properties. When in water, this scaffold degrades, but if it is placed in human body, it will degrade very slowly, over a month. This scaffold should be strong for a certain period of time that will help heart muscle to recover and to take over support process. However, many years of testing await scientists before they begin human trials, but they are very optimistic, and they expect positive results.

Directions in future researches

If scientists want to implant perfectly grown tissue that will not be rejected, they have to find out how intercellular signals can guide transformation of an amniotic stem cell into a heart cell. Research on the rats have shown that stem cells can only communicate with heart cells through channels in their membrane that provide exchange of the ions and small molecules.

A certain part of scientists suggested that physical contact between amniotic stem cells and heart cells have positive influence in differentiation of stem cells. However, scientists on the newest researches have proved that this is not correct. The newest researches showed that previous claim was incorrect because they saw only fusion of amniotic stem cell and heart cell. That is what this research was based on. Researchers wanted to see if amniotic stem cells could have characteristics of heart cells if fusion between these two cells were not allowed. They revealed results, and results have shown that it is not possible to convert an amniotic stem cell into a heart cell, but certain change in gene expression was present. The finding was connection between stem cells with a gap junction connections. This gap junction connection can transfer some really small molecules and electrical ions. These ions and molecules can diffuse between two cells connected with this junction. However, this diffusion is not possible when amniotic stem cells are not in connection with heart cells.

This research has unique approach, because other researchers approach is directly injection in heart tissue. This other approach is studying how directly injected amniotic stem cells can help in treatment of heart attack recovery. Researches from the Rice University and Texas Children's Hospital are not enthusiastic about this other research, because they think that this research will show them role of paracrine signal effects. They think that stem cells directly injected can help only in stabilization of the cells, but they cannot differentiate and create new heart tissue.

Conclusion of the research

The biggest discovery of this research is fact that cell contact between amniotic stem cells and heart cells cannot induce transformation of the stem cells, but it produces more functional gap junction connection than amniotic stem cell cultures without cell contact. However, if we want a bigger results right now, probably additional cues and maybe tighter connection between stem cells and heart cells, or maybe fusion, is required.

The ease of obtaining this type of stem cells, widely multipotent nature and rapid proliferation rate make this cell type promising source for future researches in tissue engineering.

Researchers are sure that there are plenty of methods to get amniotic fluid- derived stem cells differentiate into desired tissue for medical uses, and this research has revealed only small part of stem cell differentiation.]]> <![CDATA[Stem Cell Treatments to Relieve Symptoms in Down Syndrome]]> https://www.biotechnologyforums.com/thread-2193.html Sat, 04 May 2013 18:18:56 +0000 sale0303]]> https://www.biotechnologyforums.com/thread-2193.html
Down syndrome is the leading genetic cause of mental retardation. Statistics report the incidence of Down syndrome to be 1 per 800 live birth babies, making it one of the most frequently inherited chromosomal disorders. These statistics are profoundly influenced by the age of the mother at the time of birth.

People with Down syndrome have very distinct common physical features, which include a flat face, a almond-shaped eyes, epicanthic folds of the eyelids, a small broad nose, abnormally shaped ears, a large protruding tongue, and shorter limbs, a larger-than-normal space between the first and second toes, poor muscle tone... They have also increased risk for respiratory infections, congenital heart defects, gastrointestinal obstruction, and obstructive sleep apnea, thyroid dysfunction, hearing loss, leukemia and Alzheimer’s disease.

Diagnose

There are two types of tests check for Down syndrome during a woman's pregnancy.

Screening test indentify a mother who probably carries a baby with Down syndrome. The most commonly used screening tests are the double and triple screen, also known as triple test, multiple marker screening and alpha fetoprotein plus. Screening may be a maternal blood test done in the first trimester with a special ultrasound to measure the thickness at the back of the baby’s neck (called nuchal translucency). And it can be also done a maternal blood test in the second trimester without the ultrasound. However, screening tests cannot diagnose Down syndrome or other genetic disorder. The diagnosis must be confirmed by a chromosome study (karyotype).

Diagnostic test confirm a positive result identified in a screening test. The most common are amniocentesis, chorionic villus sampling (CVS), and percutaneous umbilical blood sampling (PUBS). Each of them takes a sample from the amniotic fluid, placenta, or umbilical cord to examine the baby's chromosomes and determine an extra chromosome 21.

Therapy

Until now there was no cure for Down syndrome. Only physical therapy and speech therapy could be helpful and made life easier for patients. Following the medical problems associated with the disorder could often improve quality of life.

Stem Cells Research

A large number of Down syndrome children had already been treated with Stem Cell therapy. The results concluded that there is a statistically significant improvement in height, concentration, IQ, speech, motor skills and immune system. Stem cell therapy carried out at an early stage the typical features of Down syndrome become less pronounced and the immunological deficiencies are corrected. This syndrome is one of many conditions which have responded dramatically to stem cell therapy.

Scientists used stem cells from the developing human brain, and grow them in spherical aggregates called neurospheres. They used neurospheres from post-mortem fetuses (with and without Down syndrome), and biochemically induced to form nerve cells. The RNA proteins were extracted from the neurospheres and compared with the RNA proteins from normal neurospheres. After all experiments, it was found that one specific protein was absent from te neurospheres of patients with Down syndrome. The SCG10 gene was relatively or absolutely functionally deficient. They also discovered that certain other genes were also underexpressed, such as L1, Synapsin, and ß4- tubulin. The neurons from the defective stem cells were shorter, irregular, had misshapen axons, and fewer dendrites projected from the main body of the neuron when compared with the control.

Stem cell research discovered a substantial disorder in the genetics of the development of neurons that begins in the earliest stages of formation of the embryo with Down syndrome, resulting form a disruption of expression of certain genes of the neurons.

Cord Stem Cells Treatment

Cord blood is collected because it contains stem cells which are genetically unique. Umbilical cord blood contains stem cells of blood, a very limited amount of mesenchymal cells, and immune cells. These stem cells, at modern time, are very used for the research, how to induce regeneration in various neurological disorders, such as also Down's syndrome. Human fetal stem cell transplants are a new area.

New studies have shown that mesenchymal and CD34 stem cells from umbilical cord blood in combination with grow factor, neurotropic and antioxidant supplements, and stem cell nutrition offers the potential to increase brain tissue development and stop the production of the abnormal protein which interferes with such development.

Patients with Down syndrome had already been treated with cord driven stem cell therapy before the age of 15. The results concluded that there is a statistically significant improvement physical and mental characteristics. The typical features of Down syndrome become less pronounced and the immunological deficiencies are corrected, when treatment is applied earlier.

Umbilical cord stem cells hold promise for reducing some of the symptoms of Down syndrome. This is a new, exciting frontier for human umbilical cord stem cells.

Research efforts aspire to examine the role of individual genes developing Down syndrome and to determine why those individuals with this condition are particularly vulnerable to diseases like leukemia and autoimmune disease. Stem cell research in Down syndrome offers hope in detecting individual genes, which are responsible for complex conditions, such as hypertension, diabetes, and to create artificial chromosomes for gene therapy. There is not a specific cure for Down syndrome at present, but researchers believe that gene therapy will enhance therapeutic options for such people, in the future. A patient with Down could benefit from drugs that could help regulate proper gene expression. At the pace of present research, the future looks very hopeful.]]>
Down syndrome is the leading genetic cause of mental retardation. Statistics report the incidence of Down syndrome to be 1 per 800 live birth babies, making it one of the most frequently inherited chromosomal disorders. These statistics are profoundly influenced by the age of the mother at the time of birth.

People with Down syndrome have very distinct common physical features, which include a flat face, a almond-shaped eyes, epicanthic folds of the eyelids, a small broad nose, abnormally shaped ears, a large protruding tongue, and shorter limbs, a larger-than-normal space between the first and second toes, poor muscle tone... They have also increased risk for respiratory infections, congenital heart defects, gastrointestinal obstruction, and obstructive sleep apnea, thyroid dysfunction, hearing loss, leukemia and Alzheimer’s disease.

Diagnose

There are two types of tests check for Down syndrome during a woman's pregnancy.

Screening test indentify a mother who probably carries a baby with Down syndrome. The most commonly used screening tests are the double and triple screen, also known as triple test, multiple marker screening and alpha fetoprotein plus. Screening may be a maternal blood test done in the first trimester with a special ultrasound to measure the thickness at the back of the baby’s neck (called nuchal translucency). And it can be also done a maternal blood test in the second trimester without the ultrasound. However, screening tests cannot diagnose Down syndrome or other genetic disorder. The diagnosis must be confirmed by a chromosome study (karyotype).

Diagnostic test confirm a positive result identified in a screening test. The most common are amniocentesis, chorionic villus sampling (CVS), and percutaneous umbilical blood sampling (PUBS). Each of them takes a sample from the amniotic fluid, placenta, or umbilical cord to examine the baby's chromosomes and determine an extra chromosome 21.

Therapy

Until now there was no cure for Down syndrome. Only physical therapy and speech therapy could be helpful and made life easier for patients. Following the medical problems associated with the disorder could often improve quality of life.

Stem Cells Research

A large number of Down syndrome children had already been treated with Stem Cell therapy. The results concluded that there is a statistically significant improvement in height, concentration, IQ, speech, motor skills and immune system. Stem cell therapy carried out at an early stage the typical features of Down syndrome become less pronounced and the immunological deficiencies are corrected. This syndrome is one of many conditions which have responded dramatically to stem cell therapy.

Scientists used stem cells from the developing human brain, and grow them in spherical aggregates called neurospheres. They used neurospheres from post-mortem fetuses (with and without Down syndrome), and biochemically induced to form nerve cells. The RNA proteins were extracted from the neurospheres and compared with the RNA proteins from normal neurospheres. After all experiments, it was found that one specific protein was absent from te neurospheres of patients with Down syndrome. The SCG10 gene was relatively or absolutely functionally deficient. They also discovered that certain other genes were also underexpressed, such as L1, Synapsin, and ß4- tubulin. The neurons from the defective stem cells were shorter, irregular, had misshapen axons, and fewer dendrites projected from the main body of the neuron when compared with the control.

Stem cell research discovered a substantial disorder in the genetics of the development of neurons that begins in the earliest stages of formation of the embryo with Down syndrome, resulting form a disruption of expression of certain genes of the neurons.

Cord Stem Cells Treatment

Cord blood is collected because it contains stem cells which are genetically unique. Umbilical cord blood contains stem cells of blood, a very limited amount of mesenchymal cells, and immune cells. These stem cells, at modern time, are very used for the research, how to induce regeneration in various neurological disorders, such as also Down's syndrome. Human fetal stem cell transplants are a new area.

New studies have shown that mesenchymal and CD34 stem cells from umbilical cord blood in combination with grow factor, neurotropic and antioxidant supplements, and stem cell nutrition offers the potential to increase brain tissue development and stop the production of the abnormal protein which interferes with such development.

Patients with Down syndrome had already been treated with cord driven stem cell therapy before the age of 15. The results concluded that there is a statistically significant improvement physical and mental characteristics. The typical features of Down syndrome become less pronounced and the immunological deficiencies are corrected, when treatment is applied earlier.

Umbilical cord stem cells hold promise for reducing some of the symptoms of Down syndrome. This is a new, exciting frontier for human umbilical cord stem cells.

Research efforts aspire to examine the role of individual genes developing Down syndrome and to determine why those individuals with this condition are particularly vulnerable to diseases like leukemia and autoimmune disease. Stem cell research in Down syndrome offers hope in detecting individual genes, which are responsible for complex conditions, such as hypertension, diabetes, and to create artificial chromosomes for gene therapy. There is not a specific cure for Down syndrome at present, but researchers believe that gene therapy will enhance therapeutic options for such people, in the future. A patient with Down could benefit from drugs that could help regulate proper gene expression. At the pace of present research, the future looks very hopeful.]]> <![CDATA[What Induced Pluripotent Stem Cells Can Tell Us About Disease]]> https://www.biotechnologyforums.com/thread-2180.html Wed, 01 May 2013 21:32:16 +0000 bridgettpayseur]]> https://www.biotechnologyforums.com/thread-2180.html
For many years, stem cells have been touted as a potential cure for a variety of human diseases and injuries. Stem cells are immature cells that are able to mature into a wide variety of fully developed cells. There are two main types of stem cells considered for medical research. Embryonic stem cells are obtained from early stage embryos. Adult stem cells are obtained from tissue from adults, such as bone marrow. Embryonic stem cells are more plastic than adult stem cells, which means they have the potential to mature into a broader range of cell types. However, because obtaining embryonic stem cells involves destruction of a human embryo, there are many ethical concerns to using embryonic stem cells. Because adult stem cells can be obtained from a living person, there is no such ethical concern. In addition, adult stem cells can be obtained from a patient, matured into the desired cell type, and re-injected into the patient, removing any possibility of transplant rejection.
The use of stem cells has been controversial, largely due to the use of embryos to produce the stem cells. Originally, cloning of embryonic stem cells was performed as a way for scientists to learn about diseases. In order to study these diseases, scientists began trying to understand the process of therapeutic cloning. The first successful cloning of a mammal was Dolly the sheep in the 1990s, an achievement that paved the way for researching the growth of embryonic origin cells from mammals. This achievement also proved that animal egg cells could be manipulated to help develop stem cells that could develop into every type of body cell.
One of the original goals researchers had was to be able to eventually grow organs in tissue culture to study disease states. Another long term goal of cloning was to be able to produce organs for human transplant. However, because of the nature of obtaining stem cells from embryos and the controversy involved, studies such as these were not widely accepted by the public. Researchers also wanted to grow stem cells in tissue culture dishes in order to study how normal tissue develops. Understanding how these developments occur can help researchers determine what goes wrong during the disease process.
In the past few years, researchers have discovered how to reprogram matured adult cells into a less mature state. These cells are called induced pluripotent stem cells (iPSCs). The reprogramming involves sending signals to the nucleus of the cell that tells the cell to revert to an immature, undeveloped state. iPSCs can be developed into many more types of cells than adult stem cells, and are therefore more versatile. iPSCs are very similar to embryonic stem cells, but because of their adult origin, production of these cells does not have as many ethical considerations.
iPSCs have many advantages to both embryonic stem cells as well as adult stem cells. As mentioned above, iPSCs do not pose any of the ethical dilemmas that embryonic stem cells do. In additional, because of Bush era funding restrictions, many of the embryonic stem cell lines in use today have been around for many years. These cell lines were grown with mouse origin feeder cells, meaning they are no longer consider pure human cell lines. Because of this, any mature cells derived from these embryonic stem cell lines would not be suitable for human transplantation. In addition, because of their rapid replication and the large number of generations they have been grown in culture, embryonic stem cells are prone to mutations. These mutations may also cause problems when transplanted into humans, as the cells would be highly prone to developing cancerous tumors. Because iPSCs could be developed directly from cells obtain from the patient, they would not been grown for long periods of times in mouse feeder cells, and they would not have had a chance to acquire as many mutations. This would make adult stem cells matured from iPSCs much safer for use in transplantation than cells matured from embryonic stem cells. In addition, many scientists now believe that instead of growing entire organs, such as a kidney or liver, in tissue culture, they can simply inject matured iPSCs into the patient in order to repair damaged organs. The overall desire to use stem cells to treat a multitude of human diseases remain the same, but the methods being explored have changed a great deal since studies of therapeutic cloning began.


References:
http://www.sciencedaily.com/releases/201...153449.htm]]>
For many years, stem cells have been touted as a potential cure for a variety of human diseases and injuries. Stem cells are immature cells that are able to mature into a wide variety of fully developed cells. There are two main types of stem cells considered for medical research. Embryonic stem cells are obtained from early stage embryos. Adult stem cells are obtained from tissue from adults, such as bone marrow. Embryonic stem cells are more plastic than adult stem cells, which means they have the potential to mature into a broader range of cell types. However, because obtaining embryonic stem cells involves destruction of a human embryo, there are many ethical concerns to using embryonic stem cells. Because adult stem cells can be obtained from a living person, there is no such ethical concern. In addition, adult stem cells can be obtained from a patient, matured into the desired cell type, and re-injected into the patient, removing any possibility of transplant rejection.
The use of stem cells has been controversial, largely due to the use of embryos to produce the stem cells. Originally, cloning of embryonic stem cells was performed as a way for scientists to learn about diseases. In order to study these diseases, scientists began trying to understand the process of therapeutic cloning. The first successful cloning of a mammal was Dolly the sheep in the 1990s, an achievement that paved the way for researching the growth of embryonic origin cells from mammals. This achievement also proved that animal egg cells could be manipulated to help develop stem cells that could develop into every type of body cell.
One of the original goals researchers had was to be able to eventually grow organs in tissue culture to study disease states. Another long term goal of cloning was to be able to produce organs for human transplant. However, because of the nature of obtaining stem cells from embryos and the controversy involved, studies such as these were not widely accepted by the public. Researchers also wanted to grow stem cells in tissue culture dishes in order to study how normal tissue develops. Understanding how these developments occur can help researchers determine what goes wrong during the disease process.
In the past few years, researchers have discovered how to reprogram matured adult cells into a less mature state. These cells are called induced pluripotent stem cells (iPSCs). The reprogramming involves sending signals to the nucleus of the cell that tells the cell to revert to an immature, undeveloped state. iPSCs can be developed into many more types of cells than adult stem cells, and are therefore more versatile. iPSCs are very similar to embryonic stem cells, but because of their adult origin, production of these cells does not have as many ethical considerations.
iPSCs have many advantages to both embryonic stem cells as well as adult stem cells. As mentioned above, iPSCs do not pose any of the ethical dilemmas that embryonic stem cells do. In additional, because of Bush era funding restrictions, many of the embryonic stem cell lines in use today have been around for many years. These cell lines were grown with mouse origin feeder cells, meaning they are no longer consider pure human cell lines. Because of this, any mature cells derived from these embryonic stem cell lines would not be suitable for human transplantation. In addition, because of their rapid replication and the large number of generations they have been grown in culture, embryonic stem cells are prone to mutations. These mutations may also cause problems when transplanted into humans, as the cells would be highly prone to developing cancerous tumors. Because iPSCs could be developed directly from cells obtain from the patient, they would not been grown for long periods of times in mouse feeder cells, and they would not have had a chance to acquire as many mutations. This would make adult stem cells matured from iPSCs much safer for use in transplantation than cells matured from embryonic stem cells. In addition, many scientists now believe that instead of growing entire organs, such as a kidney or liver, in tissue culture, they can simply inject matured iPSCs into the patient in order to repair damaged organs. The overall desire to use stem cells to treat a multitude of human diseases remain the same, but the methods being explored have changed a great deal since studies of therapeutic cloning began.


References:
http://www.sciencedaily.com/releases/201...153449.htm]]> <![CDATA[Latest Discoveries in Treatment of Damaged Articular Cartilage]]> https://www.biotechnologyforums.com/thread-2171.html Sun, 28 Apr 2013 21:49:28 +0000 sale0303]]> https://www.biotechnologyforums.com/thread-2171.html
Chondrocytes are the most dominant cell type in AC. They present 95 percent of the cell population. Chondrocytes also present the main resource of the self- renewal. However, they slowly replicate themselves, even when tissue is damaged. Scientist and clinicians have tried to support chondrocytes division through many tests, because even a small cartilage injury can lead to severe osteoarthritis.

Current treatments

Many treatments are tested, but only two tests have shown best results. These test are microfracture and autologous chondrocyte implantation (ACI). These two treatments of cartilage are not perfect solution because these treatments give fibrocartilage instead of hyaline cartilage. The main obstacle with this fibrocartilage treatments is lack of quality and usually patients have further operations and treatments. Stem cells are ideal for regeneration and repairing damaged cartilage tissue as long as they can fill the defect with cells. These cells have to be able to differentiate later. Embryonic stem cells (ESCs) are possible solution, because they can differentiate in many different cell types. These embryonic stem cells can have successful differentiation in presence of bone morphogenic protein 2 and 4 (BMP2 and BMP4). Also, when these cells are exposed to transforming growth factor B3 there is an increase of glycosaminoglycan and collagen amount 14 days later. Another promising type of cells is adult mesenchymal stem cell (MSC). MSCs are very good alternative in articular cartilage restoring. They adapt very good because of their plasticity and multilineage potential. Another benefit of MSCs usage is their various location. These cells can be isolated from adipose tissue, muscles and bone marrow. Likewise, MSCs are less tumorigenic cells than ESCs.

Specifications of various adult mesenchymal stem cells

Stem cells gathered from bone marrow, adipose tissue, muscle, synovial membrane and peiosteum are several types of adult mesenchymal stem cells. Of course, these cell types are not clonal populations and they are heterogeneous. Usually fetal bovine serum is widely added to culture medium for culture expansion. However, zoonotic infection and immune reactions are not excluded in these method.

Stem cell from bone marrow (BMMSC) was discovered in past and it was sensational discovery because scientist have found out cell which can divide and differentiate in osteoblasts, chondrocytes and adipocytes. This type of stem cells is most studied to induce chondrogenesis in tissue cultures. The most responsible factors are TGF-β family. TGF-β1, TGF-β2 and TGF-β3 and members of BMP family like BMP-2, BMP-6 and BMP-7 are the most promising factors in chonrogenesis induction. These factors in cooperation have shown that they can increase collagen II expression more than single growth factor. Stem cells from adipose tissue (ATMSC) has inferior chondrogenic potential in comparison with stem cells from bone marrow. These stem cells are not producing satisfying results when treated with both growth factors separately or growth factors in synergism. Despite their preferences, scientists are interested in them, because they can be easily obtained from fat tissue in comparison with painful obtaining of BMMSC.

Stem cells from muscle tissue (MDSCs) have controversial chondrogenic potential in comparison with stem cells harvested from bone marrow. However, muscles stem cells have shown different chondrogenic potential in traumatized muscle and in normal muscle. MDSCs in traumatized muscle has bigger chondrogeniic potential than MDSCs from normal muscle.

Periosteum stem cell (PMSC) is not so promising method, but it exists as an option, and the last are stem cells from synovial membrane. Synovial membrane have two types of cells, but only fibroblast like cells are used as stem cells. They have similar chondrogenic potential as BMMSC, but they are much more easily obtained from the tissue.

Newest method of treatment with peripheral blood stem cells

Cartilage defects are very problematic in orthopedics, because even a tiny cartilage lesion can lead into a deliberating osteoarthritis. The new method is really based on one of the oldest known methods. This method is microfracture. This method is just a little bit changed, but it appears to be maybe the best way of treatment. After this microfracture, patient received intra- articularly an injection of 8 ml of harvested autologous peripheral blood progenitor cells (PBPCs) and 2 ml of hyaluronic acid. Five more injections were given on a weekly basis, and later, arthroscopy confirmed existence of true hyaline. This technique is not so complicated, but recovery is very long, up to two years until patient is fully recovered even for sports activities. However, this research is indicated in treatment of localized cartilage fractures only, thus it cannot be used in treatment of widespread arthritis.

Limitations in cartilage stem cell renewal therapy

Chondrogenesis with different stem cells has been investigated for many years in past. Despite, there are questions and limitations in these therapies. For example, tissue specific mesenchymal stem cells are well known to scientists, but their growth factor response is different. Also, mesenchymal stem cells harvested from same the tissue have different properties in differentiation and proliferation. One of the big things for future treatments could be sorting the MSCs by their surface markers. On the other side, there are doubts connected with embryonic stem cells. Despite their excellent dividing ability, their oncogenic potential is one of the biggest worries between scientists. In conclusion, optimization of morphogens like BMPs and growth factors is key of success in treatment of articular cartilage regeneration with stem cells.]]>
Chondrocytes are the most dominant cell type in AC. They present 95 percent of the cell population. Chondrocytes also present the main resource of the self- renewal. However, they slowly replicate themselves, even when tissue is damaged. Scientist and clinicians have tried to support chondrocytes division through many tests, because even a small cartilage injury can lead to severe osteoarthritis.

Current treatments

Many treatments are tested, but only two tests have shown best results. These test are microfracture and autologous chondrocyte implantation (ACI). These two treatments of cartilage are not perfect solution because these treatments give fibrocartilage instead of hyaline cartilage. The main obstacle with this fibrocartilage treatments is lack of quality and usually patients have further operations and treatments. Stem cells are ideal for regeneration and repairing damaged cartilage tissue as long as they can fill the defect with cells. These cells have to be able to differentiate later. Embryonic stem cells (ESCs) are possible solution, because they can differentiate in many different cell types. These embryonic stem cells can have successful differentiation in presence of bone morphogenic protein 2 and 4 (BMP2 and BMP4). Also, when these cells are exposed to transforming growth factor B3 there is an increase of glycosaminoglycan and collagen amount 14 days later. Another promising type of cells is adult mesenchymal stem cell (MSC). MSCs are very good alternative in articular cartilage restoring. They adapt very good because of their plasticity and multilineage potential. Another benefit of MSCs usage is their various location. These cells can be isolated from adipose tissue, muscles and bone marrow. Likewise, MSCs are less tumorigenic cells than ESCs.

Specifications of various adult mesenchymal stem cells

Stem cells gathered from bone marrow, adipose tissue, muscle, synovial membrane and peiosteum are several types of adult mesenchymal stem cells. Of course, these cell types are not clonal populations and they are heterogeneous. Usually fetal bovine serum is widely added to culture medium for culture expansion. However, zoonotic infection and immune reactions are not excluded in these method.

Stem cell from bone marrow (BMMSC) was discovered in past and it was sensational discovery because scientist have found out cell which can divide and differentiate in osteoblasts, chondrocytes and adipocytes. This type of stem cells is most studied to induce chondrogenesis in tissue cultures. The most responsible factors are TGF-β family. TGF-β1, TGF-β2 and TGF-β3 and members of BMP family like BMP-2, BMP-6 and BMP-7 are the most promising factors in chonrogenesis induction. These factors in cooperation have shown that they can increase collagen II expression more than single growth factor. Stem cells from adipose tissue (ATMSC) has inferior chondrogenic potential in comparison with stem cells from bone marrow. These stem cells are not producing satisfying results when treated with both growth factors separately or growth factors in synergism. Despite their preferences, scientists are interested in them, because they can be easily obtained from fat tissue in comparison with painful obtaining of BMMSC.

Stem cells from muscle tissue (MDSCs) have controversial chondrogenic potential in comparison with stem cells harvested from bone marrow. However, muscles stem cells have shown different chondrogenic potential in traumatized muscle and in normal muscle. MDSCs in traumatized muscle has bigger chondrogeniic potential than MDSCs from normal muscle.

Periosteum stem cell (PMSC) is not so promising method, but it exists as an option, and the last are stem cells from synovial membrane. Synovial membrane have two types of cells, but only fibroblast like cells are used as stem cells. They have similar chondrogenic potential as BMMSC, but they are much more easily obtained from the tissue.

Newest method of treatment with peripheral blood stem cells

Cartilage defects are very problematic in orthopedics, because even a tiny cartilage lesion can lead into a deliberating osteoarthritis. The new method is really based on one of the oldest known methods. This method is microfracture. This method is just a little bit changed, but it appears to be maybe the best way of treatment. After this microfracture, patient received intra- articularly an injection of 8 ml of harvested autologous peripheral blood progenitor cells (PBPCs) and 2 ml of hyaluronic acid. Five more injections were given on a weekly basis, and later, arthroscopy confirmed existence of true hyaline. This technique is not so complicated, but recovery is very long, up to two years until patient is fully recovered even for sports activities. However, this research is indicated in treatment of localized cartilage fractures only, thus it cannot be used in treatment of widespread arthritis.

Limitations in cartilage stem cell renewal therapy

Chondrogenesis with different stem cells has been investigated for many years in past. Despite, there are questions and limitations in these therapies. For example, tissue specific mesenchymal stem cells are well known to scientists, but their growth factor response is different. Also, mesenchymal stem cells harvested from same the tissue have different properties in differentiation and proliferation. One of the big things for future treatments could be sorting the MSCs by their surface markers. On the other side, there are doubts connected with embryonic stem cells. Despite their excellent dividing ability, their oncogenic potential is one of the biggest worries between scientists. In conclusion, optimization of morphogens like BMPs and growth factors is key of success in treatment of articular cartilage regeneration with stem cells.]]> <![CDATA[Stem Cells Mature Into Brain Cells with Help from Antibody]]> https://www.biotechnologyforums.com/thread-2154.html Wed, 24 Apr 2013 14:40:05 +0000 bridgettpayseur]]> https://www.biotechnologyforums.com/thread-2154.html
Obtaining stem cells that have the ability to mature into nerve cells, and then producing the right conditions for maturation, are among the challenges scientists and clinicians face in order to begin testing stem cell therapy in patients. Indeed, producing the correct conditions in vitro to help stem cells properly mature into the correct type of cell is a major focus of research. Even when scientists are able to properly mature stem cells into nerve cells, concern arise regarding patient immune responses against donor cells. Using a the patient’s own stem cells to develop new nerve cells would remove the risk of immune rejection from transplantation.

In an accidental discovery, researchers at the Scripps Research Institute found an antibody that could induce bone marrow stem cells to develop into a nerve cell progenitor. The researchers were testing a panel of antibodies to find one capable of increasing growth in the bone marrow stem cells. The surprise discovery was very welcome by the scientists. Normally, antibodies in research are used to locate specific markers on cells, and act as labels. At times, antibody binding to a receptor on the surface of the cell has been known to activate the receptor, and cause changes in the cell. By screening a large library of antibodies against various receptors on the surface of bone marrow stem cells, the researchers unexpectedly found a method for producing nerve cells.

The researchers were screening a panel of antibodies that could recognize a specific growth-factor receptor on bone marrow stem cells. By activating this receptor, scientists can increase production of white blood cells to help mitigate the cytotoxic effects of chemotherapy in cancer patients. When researchers began testing the antibody mentioned above in culture, they noticed that the maturing stem cells became long, thin, and attached to the petri dish. They then tested these maturing cells for markers found on neural cells, and were surprised to learn that they had indeed induced maturation of neural progenitors.

The researchers are not sure why the antibody against the growth factor receptor caused the bone marrow stem cells to mature into neural progenitors. They suggest that the way the antibody binds to the receptor may have an effect on how the cell responds. Drug manufacturers have seen in recent years that how a receptor is bound by a product can have as much of an effect as what receptor is bound, and are beginning research to determine how these minor differences can be utilized and controlled.

While there have been some labs that have had success producing neural progenitor cells from bone marrow derived stem cells, the process is very difficult. First, the bone marrow derived stem cells must be reprogrammed to a more embryonic-like state that is believed to be more amenable to differentiation into various mature cell types. Then, the embryonic-like stem cells must be treated with the proper factors to induce maturation into the desired cell type. The results described above, utilizing antibody, appear to be the first demonstration of bone marrow derived stem cells being directly differentiated into neural progenitor cells. These results could dramatically simplify proposed stem cell therapies. The conventional protocol suggested for stem cell therapy involves removing bone marrow stem cells from a patient, maturing them in vitro into the proper type of cell, and then injecting the mature cells back into the patient. With the new discovery, it might be possible to inject an antibody in a patient. The antibody would help mature some of the bone marrow cells into neural progenitors, which could then migrate to sites of injury and help repair damage. This protocol would be much simpler and less expensive, and possibly be available to a larger number of patients.



References:

http://www.sciencedaily.com/releases/201...154756.htm]]>
Obtaining stem cells that have the ability to mature into nerve cells, and then producing the right conditions for maturation, are among the challenges scientists and clinicians face in order to begin testing stem cell therapy in patients. Indeed, producing the correct conditions in vitro to help stem cells properly mature into the correct type of cell is a major focus of research. Even when scientists are able to properly mature stem cells into nerve cells, concern arise regarding patient immune responses against donor cells. Using a the patient’s own stem cells to develop new nerve cells would remove the risk of immune rejection from transplantation.

In an accidental discovery, researchers at the Scripps Research Institute found an antibody that could induce bone marrow stem cells to develop into a nerve cell progenitor. The researchers were testing a panel of antibodies to find one capable of increasing growth in the bone marrow stem cells. The surprise discovery was very welcome by the scientists. Normally, antibodies in research are used to locate specific markers on cells, and act as labels. At times, antibody binding to a receptor on the surface of the cell has been known to activate the receptor, and cause changes in the cell. By screening a large library of antibodies against various receptors on the surface of bone marrow stem cells, the researchers unexpectedly found a method for producing nerve cells.

The researchers were screening a panel of antibodies that could recognize a specific growth-factor receptor on bone marrow stem cells. By activating this receptor, scientists can increase production of white blood cells to help mitigate the cytotoxic effects of chemotherapy in cancer patients. When researchers began testing the antibody mentioned above in culture, they noticed that the maturing stem cells became long, thin, and attached to the petri dish. They then tested these maturing cells for markers found on neural cells, and were surprised to learn that they had indeed induced maturation of neural progenitors.

The researchers are not sure why the antibody against the growth factor receptor caused the bone marrow stem cells to mature into neural progenitors. They suggest that the way the antibody binds to the receptor may have an effect on how the cell responds. Drug manufacturers have seen in recent years that how a receptor is bound by a product can have as much of an effect as what receptor is bound, and are beginning research to determine how these minor differences can be utilized and controlled.

While there have been some labs that have had success producing neural progenitor cells from bone marrow derived stem cells, the process is very difficult. First, the bone marrow derived stem cells must be reprogrammed to a more embryonic-like state that is believed to be more amenable to differentiation into various mature cell types. Then, the embryonic-like stem cells must be treated with the proper factors to induce maturation into the desired cell type. The results described above, utilizing antibody, appear to be the first demonstration of bone marrow derived stem cells being directly differentiated into neural progenitor cells. These results could dramatically simplify proposed stem cell therapies. The conventional protocol suggested for stem cell therapy involves removing bone marrow stem cells from a patient, maturing them in vitro into the proper type of cell, and then injecting the mature cells back into the patient. With the new discovery, it might be possible to inject an antibody in a patient. The antibody would help mature some of the bone marrow cells into neural progenitors, which could then migrate to sites of injury and help repair damage. This protocol would be much simpler and less expensive, and possibly be available to a larger number of patients.



References:

http://www.sciencedaily.com/releases/201...154756.htm]]> <![CDATA[Role of Stem Cells in Future Therapy of Multiple Sclerosis]]> https://www.biotechnologyforums.com/thread-2147.html Sat, 20 Apr 2013 15:59:43 +0000 sale0303]]> https://www.biotechnologyforums.com/thread-2147.html
Current Treatment of Multiple Sclerosis

Modern medicine has no cure for multiple sclerosis. Treatments are based on reducing the progress of the disease and management of the symptoms. Due to severity of the symptoms, in some cases there is no need for any kind of treatment.

There are three types of strategies for treatment of multiple sclerosis- treatment of attacks, slowing down of the progress and treatment of symptoms. Due to stage of disease, various drugs are used. For acute attacks glucocorticoids are used. Beta- interferons are used in modification of the multiple sclerosis course, and potassium blockers and oral vitamin D are used in treatment of the symptoms.

New Treatments of Multiple Sclerosis

There were many researches on mice, and they had encouraging results. First problem for scientist studies on mice was to find neural lesion similar to lesion in multiple sclerosis in human CNS. This problem was solved because they found out that lesions experimental autoimmune encephalomyelitis is identical to MS lesions in human CNS. These lesion were treated with stem cells, and they gave extraordinary results. Infiltrated stem cells gave gradual improvement in multiple sclerosis symptoms. This was just a beginning in treatment of multiple sclerosis with stem cells.

Therapy of MS with purified stem cells, isolated from bone marrow and umbilical cord blood, is promising way of treatment. These cells have been named CD 34+ cells. The CD 34+ cell can migrate to lesion location and there it can proliferate and differentiate in specific cell which can repair the damage. In case of multiple sclerosis, these cells transform in oligodendrocytes. This way of treatment is now under development, and we expect results as soon as possible.

Use of Various Stem Cells in Treatment of MS

Hematopoietic stem cell have been used in treatment of leukemia and other blood cancers. The bone marrow was transplanted in this process. Fortunately, scientist have discovered that this way of treatment is suitable for patients with very aggressive forms of multiple sclerosis. The procedure consists of destruction of patients immune system which has immune memory. When bone marrow is destructed, patient receives previously taken hematopoietic stem cells from himself, or from some other donor. Transplanted hematopoietic stem cells have no immune memory. Therefore, they should not have tendency of autoimmune destruction. However, this procedure is not used in treatment of every single patient with multiple sclerosis, because destruction of immune system carries certain dose of risk and possibility of fatal complication.

An ideal resource for treatment of MS with stem cells were neural stem cells. These cells were considered as very good way of filling destroyed loci with oligodendrocytes. This research showed a lot of promise, but it didn’t show expected results. Results were disappointing because, this way of treatment showed low level of oligodendrocytes renewal.

Future Possibilities of MS Treatment

Another type of cells are being tested, like precursors of oligodendrocytes. Application of cell cultures from laboratories is one of the strategies, but cells cultures should be placed in multiple regions of brain, and it is not easy goal to achieve. Another strategy is stimulation of remained brain oligodendrocyte precursors. These precursors would be transformed in oligodendrocytes and then these oligodendrocytes would migrate to demyelination loci and repair demyelinated neurons.

The Latest Discoveries in Stem Cell Treatment of MS

Scientists have discovered procedure which can convert human skin cells to neural cells. This revolutionary discovery can replace neurons in many neurodegenerative diseases like multiple sclerosis, but also in other myelin degenerative processes. In these neurodegenerative conditions myelin cells are destroyed, and they cannot be replaced. However, this newest research gives an opportunity of producing large quantities of myelinating cells which isolate communication between two neural cells. Basically, skin fibroblasts, very common cells in human skin, are converted into oligodendrocytes. This process includes reprogramming of the cell. Scientists have exchanged structure of three protein types, and that induced fibroblast to change into oligodendrocyte precursors.
Research team developed billions of induced oligodendrocytes progenitor cells in short time, and, more important thing, they have showed that these cells gave significantly improvement in reparation of oligodendrocytes in mice.

In past, oligodendrocytes progenitor cells were produced only from embryonic stem cells, and this method had some limitations. The main limitation was disability to produce quick and stabile amount of oligodendrocytes, but with new method this difficulty became past. If this method shows good results on human trials, it could be common treatment for many people with myelin disorders.

Another recent study focuses on glial progenitor cells. These cells can differentiate in astrocytes and oligodendrocytes. However, this progenitor cells stop dividing themselves or even they differentiate into specialized cells, and this is the main obstacle in further research. Scientist have found out that the main role in cell division plays beta-catenin and it is regulated by glycogen synthase kinase 3 beta(GSK3B). If researchers only could block this synthase (because this GSK3B is being blocked during cell division), they would solve this problem with early differentiation.

Summary

According to these researches, MS could be stopped or even cured if at least one of these researches succeeds in their attention. Stem cells have showed that they present future in modern medicine, and it's all up to scientists to find out the best way of curing these harmful diseases.]]>
Current Treatment of Multiple Sclerosis

Modern medicine has no cure for multiple sclerosis. Treatments are based on reducing the progress of the disease and management of the symptoms. Due to severity of the symptoms, in some cases there is no need for any kind of treatment.

There are three types of strategies for treatment of multiple sclerosis- treatment of attacks, slowing down of the progress and treatment of symptoms. Due to stage of disease, various drugs are used. For acute attacks glucocorticoids are used. Beta- interferons are used in modification of the multiple sclerosis course, and potassium blockers and oral vitamin D are used in treatment of the symptoms.

New Treatments of Multiple Sclerosis

There were many researches on mice, and they had encouraging results. First problem for scientist studies on mice was to find neural lesion similar to lesion in multiple sclerosis in human CNS. This problem was solved because they found out that lesions experimental autoimmune encephalomyelitis is identical to MS lesions in human CNS. These lesion were treated with stem cells, and they gave extraordinary results. Infiltrated stem cells gave gradual improvement in multiple sclerosis symptoms. This was just a beginning in treatment of multiple sclerosis with stem cells.

Therapy of MS with purified stem cells, isolated from bone marrow and umbilical cord blood, is promising way of treatment. These cells have been named CD 34+ cells. The CD 34+ cell can migrate to lesion location and there it can proliferate and differentiate in specific cell which can repair the damage. In case of multiple sclerosis, these cells transform in oligodendrocytes. This way of treatment is now under development, and we expect results as soon as possible.

Use of Various Stem Cells in Treatment of MS

Hematopoietic stem cell have been used in treatment of leukemia and other blood cancers. The bone marrow was transplanted in this process. Fortunately, scientist have discovered that this way of treatment is suitable for patients with very aggressive forms of multiple sclerosis. The procedure consists of destruction of patients immune system which has immune memory. When bone marrow is destructed, patient receives previously taken hematopoietic stem cells from himself, or from some other donor. Transplanted hematopoietic stem cells have no immune memory. Therefore, they should not have tendency of autoimmune destruction. However, this procedure is not used in treatment of every single patient with multiple sclerosis, because destruction of immune system carries certain dose of risk and possibility of fatal complication.

An ideal resource for treatment of MS with stem cells were neural stem cells. These cells were considered as very good way of filling destroyed loci with oligodendrocytes. This research showed a lot of promise, but it didn’t show expected results. Results were disappointing because, this way of treatment showed low level of oligodendrocytes renewal.

Future Possibilities of MS Treatment

Another type of cells are being tested, like precursors of oligodendrocytes. Application of cell cultures from laboratories is one of the strategies, but cells cultures should be placed in multiple regions of brain, and it is not easy goal to achieve. Another strategy is stimulation of remained brain oligodendrocyte precursors. These precursors would be transformed in oligodendrocytes and then these oligodendrocytes would migrate to demyelination loci and repair demyelinated neurons.

The Latest Discoveries in Stem Cell Treatment of MS

Scientists have discovered procedure which can convert human skin cells to neural cells. This revolutionary discovery can replace neurons in many neurodegenerative diseases like multiple sclerosis, but also in other myelin degenerative processes. In these neurodegenerative conditions myelin cells are destroyed, and they cannot be replaced. However, this newest research gives an opportunity of producing large quantities of myelinating cells which isolate communication between two neural cells. Basically, skin fibroblasts, very common cells in human skin, are converted into oligodendrocytes. This process includes reprogramming of the cell. Scientists have exchanged structure of three protein types, and that induced fibroblast to change into oligodendrocyte precursors.
Research team developed billions of induced oligodendrocytes progenitor cells in short time, and, more important thing, they have showed that these cells gave significantly improvement in reparation of oligodendrocytes in mice.

In past, oligodendrocytes progenitor cells were produced only from embryonic stem cells, and this method had some limitations. The main limitation was disability to produce quick and stabile amount of oligodendrocytes, but with new method this difficulty became past. If this method shows good results on human trials, it could be common treatment for many people with myelin disorders.

Another recent study focuses on glial progenitor cells. These cells can differentiate in astrocytes and oligodendrocytes. However, this progenitor cells stop dividing themselves or even they differentiate into specialized cells, and this is the main obstacle in further research. Scientist have found out that the main role in cell division plays beta-catenin and it is regulated by glycogen synthase kinase 3 beta(GSK3B). If researchers only could block this synthase (because this GSK3B is being blocked during cell division), they would solve this problem with early differentiation.

Summary

According to these researches, MS could be stopped or even cured if at least one of these researches succeeds in their attention. Stem cells have showed that they present future in modern medicine, and it's all up to scientists to find out the best way of curing these harmful diseases.]]> <![CDATA[Stem Cells in ALS Treatment in Mice]]> https://www.biotechnologyforums.com/thread-2134.html Thu, 18 Apr 2013 10:53:49 +0000 sale0303]]> https://www.biotechnologyforums.com/thread-2134.html
Definitive cause of ALS is unknown. Current research focuses on many different possibilities, with some pertaining to enzyme deficiencies, infections, environmental factors, and a whole slew of other possibilities.

Upper motor neurons signs are problems you would foresee with the loss of the normal inhibitory input the UMNs usually have on the LMNs. That would lead one to see a hyperactive state in the musculature, which is indeed the case. Specific findings related to UMN degeneration include hyperreflexia, increased tone, and weakness. As opposed to the UMN, the LMN provides an excitatory component to the muscle groups so that a loss of LMN health leads to a different set of signs and symptoms. LMN signs include fasciculations, atrophy, and weakness. A combination of both UMN and LMN signs often leads a neurologist to consider ALS as the diagnosis, but not before exhausting other possible diagnoses, such as multiple sclerosis, myasthenia gravis, Eaton-Lambert syndrome, and others. For that reason, ALS is termed a diagnosis of exclusion. The ultimate cause of death in ALS patients is the loss of muscle strength to properly breathe.

Treatment

The first drug ever approved for the treatment of ALS is still used today. It is Riluzole. Its exact mechanism of action in prolonging survival in ALS patients is unknown. Riluzole has been shown to decrease glutamate release, preventing any possible toxic effects to motor neurons that could have been caused by overexcitation, something that often involves glutamate. Trials with the drug have shown a median increase in survival time of three months. It should be stressed, however, that Riluzole is by no means a cure for ALS.

The potential for stem cell research lies in the ability to regenerate both UMNs and LMNs. What some researchers emphasize is the importance of understanding the underlying principles, such as the importance of timing and cell delivery, immune modulation, and the need for a multidisciplinary approach. With a better comprehension of these factors, the treatment of amyotrophic lateral sclerosis has a better chance for being successful in patient care.

Neural Stem Cells in ALS Treatment on Mice

Transplantation of neural stem cells or their more mature progeny is considered a potentially curative therapy for patients suffering from neurodegenerative disorders. Because adult neural stem cells, in contrast with fetal neural stem cells, have a more limited capacity to proliferate in vitro, fetal neural stem cells may be the most promising cells for cellular therapy of neurodegenerative disorders. Several studies in animals have transplanted adult neural stem cells. Because the cells receive signals from the brain microenvironment, further maturation to either glial support cells or neurons can be seen. In some cases these cells integrate and contribute to physiological neural circuits. In other cases the cells make glial support cells that can also have significant effects in some animal models of disease.

In a new study, researchers used mice as experimental models. The human neural stem cells were treated with growth factors, and directed to become motor neurons. The mice were treated first with a chemical to induce amyotrophic lateral sclerosis (ALS), and then they received a transplant of the new motor neurons that had been derived from human neuron stem cells taken from human induced pluripotent stem cells.

Pluripotent stem cells are adult cells such as skin cells that have been genetically reprogrammed to an embryonic stem cell-like state. After transplantation, the stem cells migrated to the spinal cord of the mice, matured and multiplied. That study found that human neural stem cell transplantation significantly extended the lifespan of the mice by 20 days and improved their neuromuscular function by 15 percent.

Conclusion

This study showed promise for testing stem cell transplantation in human clinical trials. In amyotrophic lateral sclerosis, motor neurons die, leading to paralysis. In preclinical animal work, neural stem cells made synaptic contact with the host motor neurons and expressed neurotrophic growth factors, which are protective of cells. By analogy to mice neural stem cells, these observations may allow the development of neural stem cells transplantation for a range of disorders. In the future, patients with ALS will be treated with injection of human fetal-derived neural stem cells into the lumbar region of the spinal cord, where they will exert a neuroprotective effect. However, since the preclinical date (safety, dosage, long-term survival, post-mortem biopsy) are insufficient and clinical evidence of improvement is weak, more preclinical studies are needed prior to the development of further clinical applications. Neural stem cells may be the best way to avoid the problems. They can self-renew, make more neural stem cells and differentiate into nerve cells, in this case into motor neurons. They can also rescue nerve cells that don't work properly and help preserve and regenerate neural tissue.

There are currently no clinical trials, but a few unpublished efforts have been disclosed using neural stem cells in humans. With all the excitement and possibilities stem cells have to offer as a therapy, it is important that scientists and clinicians are careful, plan severe studies and most importantly focus on laboratory experiments that will provide answers to the many challenges that still face this therapeutic approach. To be safe and have potential in the clinic, it is important that the appropriate studies are conducted to learn more about the properties and complexities of the various stem cells.]]>
Definitive cause of ALS is unknown. Current research focuses on many different possibilities, with some pertaining to enzyme deficiencies, infections, environmental factors, and a whole slew of other possibilities.

Upper motor neurons signs are problems you would foresee with the loss of the normal inhibitory input the UMNs usually have on the LMNs. That would lead one to see a hyperactive state in the musculature, which is indeed the case. Specific findings related to UMN degeneration include hyperreflexia, increased tone, and weakness. As opposed to the UMN, the LMN provides an excitatory component to the muscle groups so that a loss of LMN health leads to a different set of signs and symptoms. LMN signs include fasciculations, atrophy, and weakness. A combination of both UMN and LMN signs often leads a neurologist to consider ALS as the diagnosis, but not before exhausting other possible diagnoses, such as multiple sclerosis, myasthenia gravis, Eaton-Lambert syndrome, and others. For that reason, ALS is termed a diagnosis of exclusion. The ultimate cause of death in ALS patients is the loss of muscle strength to properly breathe.

Treatment

The first drug ever approved for the treatment of ALS is still used today. It is Riluzole. Its exact mechanism of action in prolonging survival in ALS patients is unknown. Riluzole has been shown to decrease glutamate release, preventing any possible toxic effects to motor neurons that could have been caused by overexcitation, something that often involves glutamate. Trials with the drug have shown a median increase in survival time of three months. It should be stressed, however, that Riluzole is by no means a cure for ALS.

The potential for stem cell research lies in the ability to regenerate both UMNs and LMNs. What some researchers emphasize is the importance of understanding the underlying principles, such as the importance of timing and cell delivery, immune modulation, and the need for a multidisciplinary approach. With a better comprehension of these factors, the treatment of amyotrophic lateral sclerosis has a better chance for being successful in patient care.

Neural Stem Cells in ALS Treatment on Mice

Transplantation of neural stem cells or their more mature progeny is considered a potentially curative therapy for patients suffering from neurodegenerative disorders. Because adult neural stem cells, in contrast with fetal neural stem cells, have a more limited capacity to proliferate in vitro, fetal neural stem cells may be the most promising cells for cellular therapy of neurodegenerative disorders. Several studies in animals have transplanted adult neural stem cells. Because the cells receive signals from the brain microenvironment, further maturation to either glial support cells or neurons can be seen. In some cases these cells integrate and contribute to physiological neural circuits. In other cases the cells make glial support cells that can also have significant effects in some animal models of disease.

In a new study, researchers used mice as experimental models. The human neural stem cells were treated with growth factors, and directed to become motor neurons. The mice were treated first with a chemical to induce amyotrophic lateral sclerosis (ALS), and then they received a transplant of the new motor neurons that had been derived from human neuron stem cells taken from human induced pluripotent stem cells.

Pluripotent stem cells are adult cells such as skin cells that have been genetically reprogrammed to an embryonic stem cell-like state. After transplantation, the stem cells migrated to the spinal cord of the mice, matured and multiplied. That study found that human neural stem cell transplantation significantly extended the lifespan of the mice by 20 days and improved their neuromuscular function by 15 percent.

Conclusion

This study showed promise for testing stem cell transplantation in human clinical trials. In amyotrophic lateral sclerosis, motor neurons die, leading to paralysis. In preclinical animal work, neural stem cells made synaptic contact with the host motor neurons and expressed neurotrophic growth factors, which are protective of cells. By analogy to mice neural stem cells, these observations may allow the development of neural stem cells transplantation for a range of disorders. In the future, patients with ALS will be treated with injection of human fetal-derived neural stem cells into the lumbar region of the spinal cord, where they will exert a neuroprotective effect. However, since the preclinical date (safety, dosage, long-term survival, post-mortem biopsy) are insufficient and clinical evidence of improvement is weak, more preclinical studies are needed prior to the development of further clinical applications. Neural stem cells may be the best way to avoid the problems. They can self-renew, make more neural stem cells and differentiate into nerve cells, in this case into motor neurons. They can also rescue nerve cells that don't work properly and help preserve and regenerate neural tissue.

There are currently no clinical trials, but a few unpublished efforts have been disclosed using neural stem cells in humans. With all the excitement and possibilities stem cells have to offer as a therapy, it is important that scientists and clinicians are careful, plan severe studies and most importantly focus on laboratory experiments that will provide answers to the many challenges that still face this therapeutic approach. To be safe and have potential in the clinic, it is important that the appropriate studies are conducted to learn more about the properties and complexities of the various stem cells.]]>