Mobilized Peripheral Stem Cells for Retina Repair?

A welcome announcement from the researchers at University of Florida earlier in the month on the possibility of using patient's own mobilized bone marrow stem cells in peripheral blood to restore lost retinal pigment epithelium (RPE).

RPE is important as it forms the nourishing outer barrier of the retina and supports the cells that receive light for transmission through our optic nerve to our brain. Essentially, damaged RPE results in macular degeneration (important for fine work and reading) which often happens with age.

Interestingly, scientists were able to establish that RPE cells could replenish naturally in animals that received bone marrow cells. What they did was to use bone marrow stem cells from normal male mice and put them into albino females with acute RPE injuries. The scientists were able to track the male pigment producing cells in the female albino recipients, proof that the stem cells were the reason for regenerating the RPEs.

The interesting part is that the stem cells were able to travel to the site of injury from the blood stream and repair the damaged RPEs which were thought incapable of regeneration in adults.

"The dogma has been that we're born with a fixed amount of RPE, but there is growing evidence retinal progenitor cells exist in the adult," said Lawrence Rizzolo, Ph.D., a Yale University associate professor of anatomy and experimental surgery and of ophthalmology and visual science.

"To derive cells of neuronal lineage from cells of bone-marrow lineage is significant, if the finding stands up to the test of time. Compared to RPE transplantation, there are a lot of advantages if someone's own bone marrow could supply the cells, because it's a ready source and the cells would not be rejected by the patient. Further, if bone-marrow progenitors circulating in the blood could be attracted to sites of disease, surgery could be avoided."

Sight is such an important sense, probably more than smell and likely on par with hearing and touch. If a stem cell infusion could restore RPEs and at least help stop the progress of macular degeneration, this would really be a treatment categorized under anti-aging. Apart from mice, I'm wondering when they'll start enrolling humans into the trial.