Researchers at Harvard Medical School Use Stem Cells to Regrow Corneas

In collaboration with several area hospitals, researchers at Harvard Medical School (HMS) have discovered a potential vision restoration technique that could benefit those with damaging eye diseases.

Detailed in a new study published in the July 2 issue of Nature, the technique uses the ABCB5 molecule, a gene required for corneal development and repair, to identify hard-to-find limbal stem cells located in the area of the eye which separates the cornea from the sclera.

Marcus Frank, an assistant professor at HMS and a senior investigator in the study, says that the ABCB5 molecule keeps limbal stem cells alive. This is crucial, as loss of these stem cells is a leading cause of blindness, which, according to the World Health Organization, affects as many as 39 million people worldwide.

Researchers utilized a mouse model to conduct their investigation. According to an HMS report:

In this study, researchers were able to use antibodies detecting ABCB5 to zero in on the stem cells in tissue from deceased human donors and use them to regrow corneas in mice. That’s an anatomically correct, fully functional, human cornea.

Transplants consisting of human ABCB5-positive limbal stem cells resulted in restoration and long-term maintenance of a normal clear cornea, whereas control mice that received either no cells or ABCB5-negative cells failed to restore the cornea.

According to the report, investigators believe these findings are significant to the study of stem cells as a whole. The research is among the “first-known examples of constructing a tissue from an adult-derived human stem cell.”

“Limbal stem cells are very rare, and successful transplants are dependent on these rare cells,” HMS assistant professor and co-lead author Bruce Ksander said in the report. “This finding will now make it much easier to restore the corneal surface. It’s a very good example of basic research moving quickly to a translational application.”