Researchers find a way to restore the corneal surface -
Discovery should translate quickly into improved human therapies
A Boston-based scientific collaboration led by Harvard Stem cell Institute (HSCI) researchers has discovered a way to gather the best type of cells for the regeneration of the damaged cornea clear membrane that covers the pupil and focuses light on the back of the eye . The investigators report in the journal Nature that purifies human stem cells can be used to improve the long-term vision in mice. The team is currently pursuing FDA approval of the technology before moving to clinical trials of patients.
The study, conducted by researchers co-managers Natasha Frank, MD, and Markus Frank, MD, is a highly collaborative effort with the work done at the Massachusetts Eye and Ear / Schepens Eye Institute research, children's Hospital Boston, Brigham and Women's Hospital, and the US Department of Veterans Affairs Boston Healthcare System.
corneal blindness is a clouding of vision that results when blood vessels grow into the cornea. It can be caused by injury, infection or an autoimmune disease that destroys an active population of regeneration of stem cells located in an area located behind the cornea, known as the lamina. Limbal stem cell transplants from a deceased donor or intact eye had promising results, but the results were contradictory.
"previously published work on the transplantation of skin cells limbic showed that when more than three percent of the transplanted cells were stem cells, the transplants were successful, for at least three hundred and transplants are not "HSCI affiliated member said Natasha Frank Faculty.
"the question in the field then was whether we could expand the limbal stem cells. But until this study there was no specific marker that could isolate these cells," said Frank, who is a doctor of VA Boston Healthcare system and Brigham and women's Hospital and Harvard medical School assistant professor of medicine in the Division of genetics at Brigham and women's Hospital.
The biomarker researchers found ABCB5 is the protein which is located on the surface of limbal stem cells. The team then developed an antibody that could mark the limbal stem cells in a general sample of human limbal cells, making it possible to only purify the cells responsible for the successful transplant limbal cells.
The researchers transplanted limbal stem cells purified human adults in damage to corneal blindness and checked to see if mice corneas had repulsed five weeks later, and 13 months later. They found that mice corneas looked normal, with the same thickness and protein expression as corneas of healthy mice.
"I think a very exciting part of the study is that while there is much evidence that adult stem cells contribute to the regeneration of tissues, what we see is essentially the first evidence that you can take adult stem cells and push the organ that has been damaged, "said Frank.
The following research team hopes to find a way to replicate the limbal stem cells so that a single eye donor can produce enough transplantable cells to help several patients. They will also be partnering with biopharmaceutical companies to produce commercial grades of ABCB5 antibodies to humans, and they plan to work more with co-author Victor Perez, MD, professor of ophthalmology at the Bascom Palmer Eye Institute at Miami, to move the techniques used in this study in clinical trials.
"This discovery is now much easier to restore the surface of the cornea. It is a very good example of basic research are rapidly moving to the implementation of the translation," said Bruce Ksander, PhD , associate researcher at the Schepens Eye Research Institute and co-first author of the study with postdoctoral fellow Paraskevi Kolovou, MD.
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