Upregulation of CREM-1 relates to retinal ganglion cells apoptosis after light-induced damage in vivo.

Previous studies have shown activation of cyclic AMP response element-binding protein (CREB) family is involved in the retinal ganglion cells (RGCs) protection. However, the function of cyclic AMP response element modulator-1 (CREM-1), one member of the CREB family, is still with limited acquaintance. To investigate whether CREM-1 is involved in RGCs death, we performed a light-induced retinal damage model in adult rats. Upregulation of CREM-1 was observed in retina after light-induced damage by performing western blot. Immunofluorescent labeling indicated that upregulated CREM-1 was localized mainly in the RGCs. We also investigated co-localization of CREM-1 with active-caspase-3 and TUNEL (apoptotic markers) in the retina after light-induced damage. In addition, the expression patterns of B cell lymphoma/leukemia-2 and Bcl-2 associated X protein were parallel with that of CREM-1. Collectively, we hypothesized upregulation of CREM-1 in the retina was associated with RGCs death after light-induced damage.