Stem cell therapy makes cloudy corneas clear, according to Pitt researchersApril 09, 2009Stem cells collected from human corneas restore transparency and don't trigger a rejection response when injected into eyes that are scarred and hazy, according to experiments conducted in mice by researchers at the University of Pittsburgh School of Medicine. Their study will be published in the journal Stem Cells and appears online today. The findings suggest that cell-based therapies might be an effective way to treat human corneal blindness and vision impairment due to the scarring that occurs after infection, trauma and other common eye problems, said senior investigator James L. Funderburgh, Ph.D., associate professor, Department of Ophthalmology. The Pitt corneal stem cells were able to remodel scar-like tissue back to normal. "Our experiments indicate that after stem cell treatment, mouse eyes that initially had corneal defects looked no different than mouse eyes that had never been damaged," Dr. Funderburgh said. The ability to grow millions of the cells in the lab could make it possible to create an off-the-shelf product, which would be especially useful in countries that have limited medical and surgical resources but a great burden of eye disease due to infections and trauma. "Corneal scars are permanent, so the best available solution is corneal transplant," Dr. Funderburgh said. "Transplants have a high success rate, but they don't last forever. The current popularity of LASIK corrective eye surgery is expected to substantially reduce the availability of donor tissue because the procedure alters the cornea in a way that makes it unsuitable for transplantation." A few years ago, Dr. Funderburgh and other University of Pittsburgh researchers identified stem cells in a layer of the cornea called the stroma, and they recently showed that even after many rounds of expansion in the lab, these cells continued to produce the biochemical components, or matrix, of the cornea. One such protein is called lumican, which plays a critical role in giving the cornea the correct structure to make it transparent. Mice that lack the ability to produce lumican develop opaque areas of their corneas comparable to the scar tissue that human eyes form in response to trauma and inflammation, Dr. Funderburgh said. But three months after the lumican-deficient mouse eyes were injected with human adult corneal stem cells, transparency was restored. The cornea and its stromal stem cells themselves appear to be "immune privileged," meaning they don't trigger a significant immune response even when transplanted across species, as in the Pitt experiments. "Several kinds of experiments indicated that the human cells were alive and making lumican, and that the tissue had rebuilt properly," Dr. Funderburgh noted. In the next steps, the researchers intend to use the stem cells to treat lab animals that have corneal scars to see if they, too, can be repaired with stem cells. Under the auspices of UPMC Eye Center's recently established Center for Vision Restoration, they plan also to develop the necessary protocols to enable clinical testing of the cells. University of Pittsburgh Schools of the Health Sciences |
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| Related Stem Cells Current Events and Stem Cells News Articles First use of antibody and stem cell transplantation to successfully treat advanced leukemia For the first time, researchers at Fred Hutchinson Cancer Research Center have reported the use of a radiolabeled antibody to deliver targeted doses of radiation, followed by a stem cell transplant, to successfully treat a group of leukemia and pre-leukemia patients for whom there previously had been no other curative treatment options. Magnetic nanoparticles to simultaneously diagnose, monitor and treat Whether it's magnetic nanoparticles (mNPs) giving an army of 'therapeutically armed' white blood cells direction to invade a deadly tumour's territory, or the use of mNPs to target specific nerve channels and induce nerve-led behaviour (such as the life-dependant thumping of our hearts), mNPs have come a long way in the past decade. Of mice and men: Stem cells and ethical uncertainties The recent creation of live mice from induced pluripotent stem cells (iPSCs) not only represents a remarkable scientific achievement, but also raises important issues, according to bioethicists at The Johns Hopkins University's Berman Institute of Bioethics. NIH-funded researchers transform embryonic stem cells into human germ cells Researchers funded in part by the National Institutes of Health have discovered how to transform human embryonic stem cells into germ cells, the embryonic cells that ultimately give rise to sperm and eggs. Stem cell therapy may offer hope for acute lung injury Researchers at the University of Illinois at Chicago College of Medicine have shown that adult stem cells from bone marrow can prevent acute lung injury in a mouse model of the disease. Placental precursor stem cells require testosterone-free environment to survive Trophoblast stem cells (TSCs), cells found in the layer of peripheral embryonic stem cells from which the placenta is formed, are thought to exhibit "immune privilege" that aids cell survivability and is potentially beneficial for cell and gene therapies. Endocrine Society calls for expanded scope and funding for stem cell research Stem cell research holds great promise for the treatment of millions of Americans with debilitating and possibly fatal diseases. Experimental treatments restore partial vision to blind people Two experimental treatments, a retinal prosthesis and fetal tissue transplant, restored some vision to people with blinding eye diseases. The findings, presented at Neuroscience 2009, the annual meeting of the Society for Neuroscience and the world's largest source of emerging news on brain science and health, may lead to new treatments for the blind. Scientists demonstrate link between genetic defect and brain changes in schizophrenia Researchers at the University of North Carolina at Chapel Hill School of Medicine have found that the 22q11 gene deletion - a mutation that confers the highest known genetic risk for schizophrenia - is associated with changes in the development of the brain that ultimately affect how its circuit elements are assembled. Small mechanical forces have big impact on embryonic stem cells Applying a small mechanical force to embryonic stem cells could be a new way of coaxing them into a specific direction of differentiation, researchers at the University of Illinois report. Applications for force-directed cell differentiation include therapeutic cloning and regenerative medicine. More Stem Cells Current Events and Stem Cells News Articles |
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