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5/07/2012 3:37 PM | Comments: 0

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Principal investigator Dr.Freda Miller is shown in an undated handout photo.Canadian researchers have found that a drug widely used to treat Type 2 diabetes can help trigger the mechanism that signals stem cells to become brain cells.THE CANADIAN PRESS/HO - Hospital for Sick Children

TORONTO - A drug commonly used to control Type 2 diabetes can help trigger stem cells to produce new brain cells, providing hope of a potential means to treat brain injuries and even neurodegenerative diseases like Alzheimer's, researchers say.

A study by scientists at Toronto's Hospital for Sick Children found the drug metformin helps activate the mechanism that signals stem cells to generate neurons and other brain cells.

"If you could take stem cells that normally reside in our brains and somehow use drugs to recruit them into becoming appropriate neural cell types, then you may be able to promote repair and recovery in at least some of the many brain disorders and injuries for which we currently have no treatment," said principal investigator Freda Miller.

"This work is happening against a background of a lot of excitement in the stem cell field about the idea that since we now know that we have stem cells in many of our adult tissues, then perhaps if we could figure out how to pharmacologically tweak those stem cells, then perhaps we could help to promote tissue repair," added Miller, a senior scientist at SickKids.

The research, published online Thursday in the journal Cell Stem Cell, involved lab-dish experiments using both mouse and human brain stem cells, as well as learning and memory tests performed on live mice given the drug.

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Diabetes drug triggers neuron growth, potential to regenerate brain cells: study

ScienceDaily (July 5, 2012) In the July 6 issue of Cell Stem Cell, researchers at the University of California, San Diego School of Medicine describe how human epidermal progenitor cells and stem cells control transcription factors to avoid premature differentiation, preserving their ability to produce new skin cells throughout life.

The findings provide new insights into the role and importance of exosomes and their targeted gene transcripts, and may help point the way to new drugs or therapies for not just skin diseases, but other disorders in which stem and progenitor cell populations are affected.

Stem cells, of course, are specialized cells capable of endlessly replicating to become any type of cell needed, a process known as differentiation. Progenitor cells are more limited, typically differentiating into a specific type of cell and able to divide only a fixed number of times.

Throughout life, human skin self-renews. Progenitor and stem cells deep in the epidermis constantly produce new skin cells called keratinocytes that gradually rise to the surface where they will be sloughed off. One of the ways that stem and progenitor cells maintain internal health during their lives is through the exosome -- a collection of approximately 11 proteins responsible for degrading and recycling different RNA elements, such as messenger RNA that wear out or that contain errors resulting in the translation of dysfunctional proteins which could potentially be deleterious to the cell.

"In short," said George L. Sen, PhD, assistant professor of medicine and cellular and molecular medicine, "the exosome functions as a surveillance system in cells to regulate the normal turnover of RNAs as well as to destroy RNAs with errors in them."

Sen and colleagues Devendra S. Mistry, PhD, a postdoctoral research fellow, and staff scientist Yifang Chen, MD, PhD, discovered that in the epidermis the exosome functions to target and destroy mRNAs that encode for transcription factors that induce differentiation. Specifically, they found that the exosome degrades a transcription factor called GRHL3 in epidermal progenitor cells, keeping the latter undifferentiated. Upon receiving differentiation inducing signals, the progenitor cells lose expression of certain subunits of the exosome which leads to higher levels of GRHL3 protein. This increase in GRHL3 levels promotes the differentiation of the progenitor cells.

"Without a functioning exosome in progenitor cells," said Sen, "the progenitor cells prematurely differentiate due to increased levels of GRHL3 resulting in loss of epidermal tissue over time."

Sen said the findings could have particular relevance if future research determines that mutations in exosome genes are linked to skin disorders or other diseases. "Recently there was a study showing that recessive mutations in a subunit of the exosome complex can lead to pontocerebellar hypoplasia, a rare neurological disorder characterized by impaired development or atrophy of parts of the brain," said Sen. "This may potentially be due to loss of progenitor cells. Once mutations in exosome complex genes are identified in either skin diseases or other diseases like pontocerebellar hypoplasia, it may be possible to design drugs targeting these defects."

Funding for this research came, in part, from the National Institutes of Health grant K01AR057828-04 and a Ray Thomas Edwards Award.

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The key (proteins) to self-renewing skin

(PRWEB) July 05, 2012

Researchers at Adelaide University have developed a potential therapy for stroke victims utilizing dental stem cells to regenerate damaged brain cells.

The study involved the use of human dental pulp stem cells in rats suffering from post- stroke symptoms. The stem cells were transplanted into the damaged brains of the rats with the rats showing significant improvement in brain function, motor skills and cognitive abilities within several weeks. The therapy poses a new possibility for patients who have suffered a stroke. Patients will be able to use stem cells extracted from their own teeth to regenerate damaged brain tissue. The use of autologous stem cells eliminates the risk of rejection and the need for immune-suppression drugs and results in a more positive outcome. The research is so promising that the researchers hope to begin clinical trials within three to four years.

The research is another example of the inherent plasticity of dental stem cells, i.e. their ability to differentiate into a wide range of tissue types that may be utilized to treat a broad array of disease, trauma and injury. Banking your own valuable dental stem cells for use in emerging regenerative therapies is both convenient and affordable and as easy as a trip to the dentists.

To learn more about how you can bank your valuable dental stem cells , visit http://www.StemSave.com or call 877-783-6728 (877-StemSave) today.

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StemSave - Researchers Utilize Dental Stem Cells for Stroke Treatment

Public release date: 4-Jul-2012 [ | E-mail | Share ]

Contact: Daniel Stimson, NINDS nindspressteam@ninds.nih.gov 301-496-5751 NIH/National Institute of Neurological Disorders and Stroke

Researchers have taken a step toward personalized medicine for Parkinson's disease, by investigating signs of the disease in patient-derived cells and testing how the cells respond to drug treatments. The study was funded by the National Institutes of Health.

The researchers collected skin cells from patients with genetically inherited forms of Parkinson's and reprogrammed those cells into neurons. They found that neurons derived from individuals with distinct types of Parkinson's showed common signs of distress and vulnerability in particular, abnormalities in the cellular energy factories known as mitochondria. At the same time, the cells' responses to different treatments depended on the type of Parkinson's each patient had.

The results were published in Science Translational Medicine.

"These findings suggest new opportunities for clinical trials of Parkinson's disease, in which cell reprogramming technology could be used to identify the patients most likely to respond to a particular intervention," said Margaret Sutherland, Ph.D., a program director at NIH's National Institute of Neurological Disorders and Stroke (NINDS).

A consortium of researchers conducted the study with primary funding from NINDS. The consortium is led by Ole Isacson, M.D., Ph.D., a professor of neurology at McLean Hospital and Harvard Medical School in Boston.

The NINDS consortium's first goal was to transform the patients' skin cells into induced pluripotent stem (iPS) cells, which are adult cells that have been reprogrammed to behave like embryonic stem cells. The consortium researchers then used a combination of growth conditions and growth-stimulating molecules to coax these iPS cells into becoming neurons, including the type that die in Parkinson's disease.

Parkinson's disease affects a number of brain regions, including a motor control area of the brain called the substantia nigra. There, it destroys neurons that produce the chemical dopamine. Loss of these neurons leads to involuntary shaking, slowed movements, muscle stiffness and other symptoms. Medications can help manage the symptoms, but there is no treatment to slow or stop the disease.

Most cases of Parkinson's are sporadic, meaning that the cause is unknown. However, genetics plays a strong role. There are 17 regions of the genome with common variations that affect the risk of developing Parkinson's disease. Researchers have also identified nine genes that, when mutated, can cause the disease.

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Patient-derived stem cells could improve drug research for Parkinson's

ScienceDaily (July 3, 2012) Stem cells found in amniotic fluid can be transformed into a more versatile state similar to embryonic stem cells, according to a study published July 3 in the journal Molecular Therapy. Scientists from Imperial College London and the UCL Institute of Child Health succeeded in reprogramming amniotic fluid cells without having to introduce extra genes. The findings raise the possibility that stem cells derived from donated amniotic fluid could be stored in banks and used for therapies and in research, providing a viable alternative to the limited embryonic stem cells currently available.

Amniotic fluid surrounds and nourishes the fetus in the womb. It can be extracted through the mother's abdomen using a needle in a process called amniocentesis, which is sometimes used to test for genetic diseases. The fluid contains stem cells that come from the fetus. These cells have a more limited capacity to develop into different cell types than stem cells in the embryo.

The researchers used stem cells from amniotic fluid donated by mothers undergoing amniocentesis for other purposes during the first trimester of pregnancy. The cells were grown on a gelatinous protein mixture in the lab and reprogrammed into a more primitive state by adding a drug called valproic acid to the culture medium. An extensive set of tests found that these reprogrammed cells have characteristics very similar to embryonic stem cells, which are capable of developing into any cell type in the body -- a property known as pluripotency.

Even after growing in culture for some time, the reprogrammed cells were able to develop into functioning cells of many different types, including liver, bone and nerve cells. They also maintained their pluripotency even after being frozen and rethawed.

The results suggest that stem cells derived from amniotic fluid could be used in treatments for a wide range of diseases. Donated cells could be stored in banks and used in treatments, as well as in disease research and drug screening. A previous study estimated that cells from 150 donors would provide a match for 38% of the population.

Alternatives to embryonic stem cells are keenly sought because of ethical concerns and limited availability of donor embryos. Previous research has shown that it is possible to make adult cells become pluripotent by introducing extra genes into the cells, often using viruses. However, the efficiency of the reprogramming is very low and there is a risk of problems such as tumours caused by disrupting the DNA. The new study is the first to induce pluripotency in human cells without using foreign genetic material. The pluripotent cells derived from amniotic fluid also showed some traits associated with embryonic stem cells that have not been found in induced pluripotent stem cells from other sources.

Amniocentesis is associated with a small risk of causing a miscarriage, estimated to be about one in 100.

Dr Pascale Guillot, from the Department of Surgery and Cancer at Imperial, said: "Amniotic fluid stem cells are intermediate between embryonic stem cells and adult stem cells. They have some potential to develop into different cell types but they are not pluripotent. We've shown that they can revert to being pluripotent just by adding a chemical reagent that modifies the configuration of the DNA so that genes that are expressed in the embryo get switched back on.

"These cells have a wide range of potential applications in treatments and in research. We are particularly interested in exploring their use in genetic diseases diagnosed early in life or other diseases such as cerebral palsy."

Dr Paolo De Coppi, from the UCL Institute of Child Health, who jointly led the study with Dr Guillot, said: "This study confirms that amniotic fluid is a good source of stem cells. The advantages of generating pluripotent cells without any genetic manipulation make them more likely to be used for therapy.

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Amniotic fluid yields alternatives to embryonic stem cells

ScienceDaily (July 3, 2012) searchers from the University of Maryland School of Maryland report promising results from using adult stem cells from bone marrow in mice to help create tissue cells of other organs, such as the heart, brain and pancreas -- a scientific step they hope may lead to potential new ways to replace cells lost in diseases such as diabetes, Parkinson's or Alzheimer's.

The research in collaboration with the University of Paris Descartes is published online in the June 29, 2012 edition of Comptes Rendus Biologies, a publication of the French Academy of Sciences.

"Finding stem cells capable of restoring function to different damaged organs would be the Holy Grail of tissue engineering," says lead author David Trisler, PhD, assistant professor of neurology at the University of Maryland School of Medicine.

He adds, "This research takes us another step in that process by identifying the potential of these adult bone marrow cells, or a subset of them known as CD34+ bone marrow cells, to be 'multipotent,' meaning they could transform and function as the normal cells in several different organs."

University of Maryland researchers previously developed a special culturing system to collect a select sample of these adult stem cells in bone marrow, which normally makes red and white blood cells and immune cells. In this project, the team followed a widely recognized study model, used to prove the multipotency of embryonic stem cells, to prove that these bone marrow stem cells could make more than just blood cells. The investigators also found that the CD34+ cells had a limited lifespan and did not produce teratomas, tumors that sometimes form with the use of embryonic stem cells and adult stem cells cultivated from other methods that require some genetic manipulation.

"When taken at an early stage, we found that the CD34+ cells exhibited similar multipotent capabilities as embryonic stem cells, which have been shown to be the most flexible and versatile. Because these CD34+ cells already exist in normal bone marrow, they offer a vast source for potential cell replacement therapy, particularly because they come from a person's own body, eliminating the need to suppress the immune system, which is sometimes required when using adults stem cells derived from other sources," explains Paul Fishman, MD, PhD, professor of neurology at the University of Maryland School of Medicine.

The researchers say that proving the potential of these adult bone marrow stem cells opens new possibilities for scientific exploration, but that more research will be needed to see how this science can be translated to humans.

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Adult stem cells from bone marrow: Cell replacement/tissue repair potential in adult bone marrow stem cells in animal ...

FOR IMMEDIATE RELEASE: July 3, 2012

UNIVERSITY OF MARYLAND SCHOOL OF MEDICINE INVESTIGATORS FIND CELL REPLACEMENT/ TISSUE REPAIR POTENTIAL IN ADULT BONE MARROW STEM CELLS IN ANIMAL MODEL

Scientists Looking for Potential Avenue to Grow Cells of Different Organs

Newswise Baltimore, MD July 3, 2012. Researchers from the University of Maryland School of Maryland report promising results from using adult stem cells from bone marrow in mice to help create tissue cells of other organs, such as the heart, brain and pancreas - a scientific step they hope may lead to potential new ways to replace cells lost in diseases such as diabetes, Parkinsons or Alzheimers. The research in collaboration with the University of Paris Descartes is published online in the June 29, 2012 edition of Comptes Rendus Biologies, a publication of the French Academy of Sciences.

Finding stem cells capable of restoring function to different damaged organs would be the Holy Grail of tissue engineering, says lead author David Trisler, PhD, assistant professor of neurology at the University of Maryland School of Medicine.

He adds, This research takes us another step in that process by identifying the potential of these adult bone marrow cells, or a subset of them known as CD34+ bone marrow cells, to be multipotent, meaning they could transform and function as the normal cells in several different organs.

University of Maryland researchers previously developed a special culturing system to collect a select sample of these adult stem cells in bone marrow, which normally makes red and white blood cells and immune cells. In this project, the team followed a widely recognized study model, used to prove the multipotency of embryonic stem cells, to prove that these bone marrow stem cells could make more than just blood cells. The investigators also found that the CD34+ cells had a limited lifespan and did not produce teratomas, tumors that sometimes form with the use of embryonic stem cells and adult stem cells cultivated from other methods that require some genetic manipulation.

When taken at an early stage, we found that the CD34+ cells exhibited similar multipotent capabilities as embryonic stem cells, which have been shown to be the most flexible and versatile. Because these CD34+ cells already exist in normal bone marrow, they offer a vast source for potential cell replacement therapy, particularly because they come from a persons own body, eliminating the need to suppress the immune system, which is sometimes required when using adults stem cells derived from other sources, explains Paul Fishman, MD, PhD, professor of neurology at the University of Maryland School of Medicine.

The researchers say that proving the potential of these adult bone marrow stem cells opens new possibilities for scientific exploration, but that more research will be needed to see how this science can be translated to humans.

The results of this international collaboration show the important role that University of Maryland School of Medicine researchers play in advancing scientific understanding, investigating new avenues for the development of potentially life-changing treatments, says E. Albert Reece, M.D., Ph.D., M.B.A., vice president for medical affairs at the University of Maryland and the John Z. and Akiko K. Bowers Distinguished Professor and dean of the University of Maryland School of Medicine.

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Study Results: Adult Stem Cells From Bone Marrow