Protein Might One Day Prevent Blindness

Jan. 9 -- THURSDAY, Jan. 8 (HealthDay News) -- Researchers working with mice have identified a protein that appears to prolong the lives of retinal cells in both healthy and diseased eyes.

The discovery could one day lead to treatments that would prevent blindness among people genetically predisposed to develop retinal disease, the scientists said.

The protein, known as histone deacetylase 4 (HDAC4), is naturally produced by both mice and humans and is typically involved in the regulation of bone and muscle development.

Reducing the amount of HDAC4 to below-normal levels appears to lead to premature photoreceptor cell death in healthy eyes, the study revealed. In contrast, increasing quantities of this protein to above-normal levels appears to protect the lifespan of these critical vision cells -- both in healthy mouse eyes and in those mice suffering from a genetic flaw, also present in humans, that gives rise to degenerative retinal disease.

The finding -- if replicated in people -- could ultimately lead to new interventions to prevent such disease-driven blindness, or even to the development of methods to restore lost sight to diseased retinas.

"There are some inherited genetic defects that lead to the death of the two types of photoreceptor cells in the eye that capture light, first directly killing the rod cells and then the cone cells which depend on rod cell survival," explained study author Bo Chen, a postdoctoral research fellow with the Howard Hughes Medical Institute at Harvard Medical School in Boston. "So, this mutation eventually leads to complete blindness."

"But what we found," Chen noted, "is that we could actually promote the survival of these genetically affected photoreceptors by introducing more of this particular protein, even though the photoreceptors themselves continue to remain genetically defective."

Chen and his colleagues report their findings in the Jan. 9 issue of Science.

The findings are based solely on a series of neural cell experiments, focused on the retinal health of live mice, that were designed to assess the impact of both under-expression and overexpression of the HDAC4 protein.