“Latest Stem Cells News”

Scientists seeking new ways to fight maladies ranging from arthritis and osteoporosis to broken bones that won’t heal have cleared a formidable hurdle, pinpointing and controlling a key molecular player to keep stem cells in a sort of extended infancy. It’s a step that makes treatment with the cells in the future more likely for patients.

Controlling and delaying development of the cells, known as mesenchymal (pronounced meh-ZINK-a-mill) stem cells, is a long-sought goal for researchers. It’s a necessary step for doctors who would like to expand the number of true skeletal stem cells available for a procedure before the cells start becoming specific types of cells that may – or may not – be needed in a patient with, say, weak bones from osteoporosis, or an old knee injury.

A study published this week reinforces the potential value of stem cells in repairing major injuries involving the loss of bone structure.
The study shows that delivering stem cells on a polymer scaffold to treat large areas of missing bone leads to improved bone formation and better mechanical properties compared to treatment with the scaffold alone. This type of therapeutic treatment could be a potential alternative to bone grafting operations.

“Massive bone injuries are among the most challenging problems that orthopedic surgeons face, and they are commonly seen as a result of accidents as well as in soldiers returning from war,” said the study’s lead author Robert Guldberg, a professor in Georgia Tech‘s Woodruff School of Mechanical Engineering. “This study shows that there is promise in treating these injuries by delivering stem cells to the injury site. These are injuries that would not heal without significant medical intervention.” (…)

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/

What are mesenchymal stem cells? where are they found in the human body? What are their most promising clinical applications? Gordana Vunjak-Novakovic of Columbia University gives us an answer to these questions and and an outlook on the future of mesenchymal stem cells.

With veterinarians across the country training to use stem cells for tendon and ligament repair, a professor at the University of California, Davis (UC Davis) wants to take the technology a step further by applying them to chronic, cell-based diseases.

Richard Vulliet, DVM, is very early into the work. But he is optimistic about the evidence as it exists, of course, and he may have had a success.

Vulliet has treated four dogs with degenerative myelopathy with their own stem cells, which he prefers to call mesenchymal stem cells or pluripotent marrow stromal cells. The terminology has evolved and those names are more descriptive, he says (…)

Vulliet says he got interested in treating these conditions because he was working with mesenchymal stem cells and their interaction with connective tissue, and it was boring. Then he came across two papers.

In one of the papers, Japanese researchers described treating induced cardiomyopathy in experimental rats (Circulation 2005;112:1128-35). They reported that when the cells were injected into the myocardium, function improved, and there was evidence that the cells formed new vascular structures and produced collagen.

In the other paper, researchers at Tulane University in New Orleans induced spine injuries in experimental rats and treated them with mesenchymal stem cells. When they treated the animals immediately after the injury was induced, there was no apparent effect. However, when they waited one week before treating, they found that at five weeks, seven rats out of 12 could lift their trunks with their hind legs. By comparison, none of the 10 rats that were not treated showed similar signs of improvement.

Vulliet says notions of how mesenchymal stem cells might enhance the healing process have expanded beyond the idea that the cells migrate to a site of injury, differentiate into the proper type of cell and incorporate into the tissue. They might modulate immune response as well (…)

Stem cells are an ideal entrée into real-animal research, Vulliet explains. Experiments with human subjects and stem cells are not generally allowed, and federal regulators are unclear about whether they have the authority to regulate such research, since the cells are not drugs and usually are autologous tissue (…)

from http://news.vin.com/VINNews.aspx?articleId=14031

What might become the first drug derived from human stem cells failed in two late-stage clinical trials, dealing a setback to the drug’s developer and to the stem cell field (…)

Prochymal is a preparation of mesenchymal stem cells, which are obtained from the bone marrow of healthy young adults.
Because the cells are derived from adults, they sidestep the ethical issues stemming from the destruction of human embryos needed to make embryonic stem cells. Unlike most other types of adult stem cells, mesenchymal cells grow well in culture, so thousands of doses can be produced from a single donation.

Stem cells, particularly in the form of bone marrow transplants, are already used in medicine. Osiris is hoping that Prochymal will become the first stem cell product approved by the Food and Drug Administration and sold as a mass-produced pharmaceutical product (…)

from http://www.nytimes.com/2009/09/09/health/research/09drug.html