bcl-2 overexpression reduces apoptotic photoreceptor cell death in three different retinal degenerations.

Abstract

Apoptosis of photoreceptors occurs infrequently in adult retina but can be triggered in inherited and environmentally induced retinal degenerations. The protooncogene bcl-2 is known to be a potent regulator of cell survival in neurons. We created lines of transgenic mice overexpressing bcl-2 to test for its ability to increase photoreceptor survival. Bcl-2 increased photoreceptor survival in mice with retinal degeneration caused by a defective opsin or cGMP phosphodiesterase. Overexpression of Bcl-2 in normal photoreceptors also decreased the damaging effects of constant light exposure. Apoptosis was induced in normal photoreceptors by very high levels of bcl-2. We conclude that bcl-2 is an important regulator of photoreceptor cell death in retinal degenerations.