Deficiency of Bax and Bak protects photoreceptors from light damage in vivo

Abstract

Photoreceptors of bax-/-bak-/- but neither bax-/- mice nor bak-/- mice are protected from developmental apoptosis, suggesting that bax-/-bak-/- photoreceptors may also be protected from pathologic apoptosis. To test this possibility, we exposed bax-/-bak-/- and bax-/- mice to bright light, which normally induces photoreceptor death. Photoreceptors in bax-/-bak-/- mice were protected from death compared to bax-/- mice as indicated by a reduction in the number of TUNEL-positive photoreceptor nuclei 24 h following light damage and almost complete preservation of photoreceptors 7 days following light damage. These results provide the first in vivo evidence that combined deficiency of Bax and Bak can rescue cells from a pathologic stimulus more effectively than Bax deficiency and suggest that combined deficiency of Bax and Bak may also protect cells from other insults. © 2004 Nature Publishing Group All rights reserved.