BCL-2 OVEREXPRESSION REDUCES APOPTOTIC PHOTORECEPTOR CELL-DEATH IN 3 DIFFERENT RETINAL DEGENERATIONS

Apoptosis of photoreceptors occurs infrequently in adult retina but ca n be triggered in inherited and environmentally induced retinal degene rations. The protooncogene bcl-2 is known to be a potent regulator of cell survival in neurons. We created lines of transgenic mice overexpr essing bcl-2 to test for its ability to increase photoreceptor surviva l, bcl-2 increased photoreceptor survival in mice with retinal degener ation caused by a defective opsin or cGMP phosphodiesterase. Overexpre ssion of Bcl-2 in normal photoreceptors also decreased the damaging ef fects of constant light exposure. Apoptosis was induced in normal phot oreceptors by very high levels of bcl-2. We conclude that bcl-2 is an important regulator of photoreceptor cell death in retinal degeneratio ns.