“Latest Stem Cells News”

Understanding the genetic underpinnings of the biology of stem cells is crucial for their use in disease research and treatment. Scientists have identified a variety of genetic factors that maintain self renewal properties in embryonic, fetal, and adult stem cells. But whether these cell types are controlled by the same or different molecules is a persisting question.

Recent work from HSCI Principal Faculty Konrad Hochedlinger, PhD, begins to crack that mystery. Sox2 is a gene whose expression is required for maintaining pluripotency in early embryonic cells and regulating tissue development in the fetal stage. But until now, Sox2 expression had only been observed fleetingly in a few adult stem cells.

Hochedlinger and his team have shown that Sox2 is nearly pervasive among adult stem cells, absent in only a few tissue types such as muscle, blood, and heart. The work, which establishes Sox2 as the only known factor to control self renewal across all three stem cell types, provides fertile ground for a variety of investigations.

In particular, since Sox2 expression can be seen as a marker for adult stem cells, it may provide an easier way to isolate and manipulate the otherwise difficult cellular population. Additionally, manipulating Sox2 expression could help generate particular adult stem cell types from embryonic stem cells, as well as particular desired tissue types from adult stem cells.

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While only a small portion of autism spectrum disorders (ASDs) can be traced to their genetic roots, those that can are most often part of Fragile X syndrome (FXS), the most commonly known single-gene cause of autism. FXS is associated with the loss of the FMR protein (FMRP) coded by the mental retardation gene 1, FMR1 gene.

While scientists understand the biochemical nuances of these mutations, their implications on neuronal development and function remain a mystery. To address this puzzle, HSCI Associate Faculty member Stephen Haggarty, PhD, reprogrammed a series of both mutated and non-mutated cells back into a stem cell state in which they have the ability to derive new tissues.

Haggarty and his team found that the FMR1 mutations present in the induced pluripotent stem cells (iPSCs) do not always resemble those in the naturally occurring cells from which they came. This offers valuable information as other researchers begin to design investigations using these iPSCs.

Additionally, the team used the cell lines to generate a variety of neuronal cell types. While FMRP loss did not prevent neurodevelopment, it did impact cell quality, suggesting an important role for FMRP early in human neurodevelopment. These findings will allow researchers to characterize existing drugs and develop new therapies for the treatment of some ASDs.

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CINCINNATI—New research from the University of Cincinnati may help in the recovery of lost vision for patients with corneal scarring.

Winston Whei-Yang Kao, PhD, professor of ophthalmology, along with other researchers in UC’s ophthalmology department found that transplanting human umbilical mesenchymal stem cells into mouse models that lack the protein lumican restored the transparency of cloudy and thin corneas.

Mesenchymal stem cells are “multi-potent” stem cells that can differentiate into a variety of cell types.

These findings are being presented Dec. 8 in San Diego at the 49th Annual Meeting of the American Society of Cell Biology.

“Corneal transplantation is currently the only true cure for restoration of eyesight that may have been lost due to corneal scarring caused by infection, mechanical and chemical wounds and congenital defects of genetic mutations,” Kao says. “However, the number of donated corneas suitable for transplantation is decreasing as the number of individuals receiving refractive surgeries, like LASIK, increases.”

“Worldwide, there is a shortage of suitable corneas for transplantation, and at the present time, there is no effective alternative procedure besides corneal transplantation to treat corneal blindness,” he continues. “There is a large need to develop alternative treatment regimens, one of which may be the transplantation of mesenchymal stem cells.”

Researchers used mouse models that did not have the lumican gene, also known as lumican knock-out models. Lumican is a protein that controls the formation and maintenance of transparent corneas.

“Lumican knock-out models manifested thin and cloudy corneas,” he says. “Transplantation of the umbilical stem cells significantly improved transparency and increased corneal stromal thickness in these mice.”

In addition, Kao says, the umbilical mesenchymal stem cells survived in the mouse stroma (connective tissue) for more than three months with minimal or no rejection and became corneal cells, repairing lost functions caused by mutations.

“Our results suggest a potential treatment regimen for congenital and/or acquired corneal diseases,” he says, adding that the availability of human umbilical stem cells is almost unlimited. “These stem cells are easy to isolate and can be recovered quickly from storage when treating patients.

“These findings have the potential to create new and better treatments—and an improved quality of life—for patients with vision loss due to corneal injury.”

This study was funded by grants from the National Eye Institute, Research to Prevent Blindness and the Ohio Lions Eye Research Foundation.

from http://healthnews.uc.edu/news/?/9613/

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SANUWAVE Inc., an emerging medical technology company focused on the development and commercialization of non-invasive, biological response activating devices in the regenerative medicine area, reported that scientific findings titled “Extracorporeal Shock Wave Stimulation of Osteoprogenitor Cells” were presented at the 2009 International Bone-Tissue-Engineering Congress (“Bone-Tec”) in Hannover, Germany, which was held October 9-11, 2009.

Dr. Myron Spector, PhD, Professor of Orthopaedic Surgery (Biomaterials) at Harvard Medical School, Director of Orthopaedic Research at Brigham and Women’s Hospital and Director of Tissue Engineering at VA Boston Healthcare System, was an invited guest speaker at the Conference. The Bone–Tec Congress featured an international scientific forum to discuss progresses in modern bone tissue regeneration and extended a worldwide network to exchange findings on the latest developments.

Dr. Spector’s team employed SANUWAVE’s Pulsed Acoustic Cellular Expression (PACE™) technology in preclinical research to create autogenous sources of stem cells for bone tissue engineering. Results support the proposition that PACE™ could be employed as a non-invasive technique to cause proliferation and thickening of the cambium layer of the femur’s periosteum for the subsequent intraoperative harvesting of progenitor stem cells days later for bone or cartilage regeneration.

PACE™ stimulated a dramatic proliferation and thickening (up to 10 fold) of osteoprogenitor stem cells, precursors to bone and cartilage cells, in the cambium layer of the periosteum in the femur of the adult rats within 4 days. Neovascularization and new bone formation within the thickened periosteum were also evident after 4 days.

Dr. Spector said, “This research has shown great potential. Through more study, this technology could further advance tissue engineering autologous transplant techniques towards clinical applications such as bone reconstruction and cartilage defect repair.” (…)

from http://www.sanuwave.com

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The addition of two particular gene snippets to a skin cell’s usual genetic material is enough to turn that cell into a fully functional neuron, report researchers from the Stanford University School of Medicine. The finding, published online July 13 in Nature, is one of just a few recent reports of ways to create human neurons in a lab dish.

The new capability to essentially grow neurons from scratch is a big step for neuroscience research, which has been stymied by the lack of human neurons for study. Unlike skin cells or blood cells, neurons are not something that’s easy for a living human to donate for research.

“A major problem in neurobiology has been the lack of a good human model,” said senior author Gerald Crabtree, MD, professor of pathology and of developmental biology. “Neurons aren’t like blood. They’re not something people want to give up.”

Generating neurons from easily accessible cells, such as skin cells, makes possible new ways to study neuronal development, model disease processes and test treatments.

It also helps advance the effort, still in its infancy, to replace damaged or dead neurons with new ones.

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Stanford University’s Faculty Senate today approved the creation of what officials believe is the first PhD program devoted solely to stem cell science in the nation and, perhaps, the world. The new doctoral program in stem cell biology and regenerative medicine is also the first interdisciplinary doctoral program created by the School of Medicine in recent years.

School officials say the fact that the university is taking the rare step of creating a new doctoral program acknowledges the growing importance of stem cell research in the realm of biomedical science. The senate’s initial approval of the program extends for five years.

“Stem cell biology is a distinct discipline that requires unique skills and includes a scope of knowledge and a skill set that is not covered by other disciplines,” said Renee Reijo Pera, PhD, professor of obstetrics and gynecology and director of the new PhD program.

Program leaders note that Stanford is among a small number of U.S. universities that have the necessary ingredients to create a doctoral program teaching the full range of stem cell science. They add that although a few other schools have recently established PhD programs involving stem cell biology, Stanford is the first to create a free-standing doctoral program dedicated solely to stem cell biology and regenerative medicine.

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