Retinal stems cells could help treat blindness, researchers say. Photo by Requieri Tozzi
Jan. 14 (UPI) -- Retinal stem cells collected from human cadavers offer a potential treatment for blindness, according to the authors of an article published Thursday by Stem Cell Reports.
Healthy retinal pigment epithelium cells implanted under the macula of blind monkeys used in the study restored at least some vision without serious side effects, researchers from the Mount Sinai School of Medicine in New York City said.
The retinal pigment epithelium is a layer of pigmented cells in the retina and the macula is the central part of the retina.
The transplanted cells effectively took over the function of the monkeys' natural retinal pigment epithelium, enabling them to see, according to the researchers.
"We have demonstrated that [donor cells] at least partially replace function in the macula of a non-human primate," study co-author Timothy Blenkinsop said in a statement.
"Human cadaver donor-derived cells can be safely transplanted underneath the retina and replace host function, and therefore may be a promising source for rescuing vision in patients with retina diseases," said Blenkinsop, assistant professor of cell, developmental and regenerative biology at the Icahn School of Medicine at Mount Sinai.
Retinal pigment epithelium dysfunction can lead to eye disorders such as macular degeneration, causing vision loss and blindness, which affects about 200 million people worldwide, the researchers said.
The region of the eye functions as a barrier and regulator in the maintenance of normal vision.
To restore this population of cells in the primates used in this study, the researchers extracted retinal stem cells from donated cadaver adult eyes.
Using cadaver donor eyes can help ensure donor cells match well with recipients, and can serve as a recurring source of human retinal pigment epithelium, the researchers said.
Retinal pigment epithelium "patches," or small quantities of collected cells, transplanted under the primates' maculas remained "stable and integrated" for at least three months, without serious side effects such as immune-system rejection or light sensitivity.
The transplanted cells also worked well with the existing retinal pigment epithelium to support the existing photoreceptors in their eyes, which helps with light absorption, among other functions.
Transplantation of retinal pigment epithelium stem cells derived from human adult cadaver eyes could replace the defective retinal pigment epitheliums and serve as a possible treatment for macular degeneration, the study suggests.
However, additional research on this approach is necessary to explore whether stem cells derived from cadaver adult eyes can restore vision in human patients, according to the researchers.
"The results of this study suggest human adult donor retinal pigment epithelium is safe to transplant, strengthening the argument for human clinical trials for treating retina disease," Blenkinsop said.