An Antiapoptotic Peptide for Neuroprotection in Glaucoma

Purpose: Axonal degeneration and death of retinal ganglion cells (RGC) are primary contributors to vision loss in glaucoma. The purpose of this study was to determine if intraperitoneal administration of the core peptide derived from small heat shock protein αB-crystallin (ABCP) could inhibit RGC death in animal models of glaucoma. Materials and Methods: Brown Norway rats were retrogradely labeled (to detect RGCs) using Fluoro-gold and IOP was elevated (150 mmHg/days) in one eye using the Morrison’s method, while the contralateral eye served as control. The rats were intraperitoneally injected with 10μg of ABCP (n=3 animals per group) three times per week for five weeks. Surviving RGCs were counted in retinal flat mounts. In another model of ischemia reperfusion (I/R) injury, C57BL/6 mice were subjected to IOP elevation of 120 mmHg for 30 min, followed by rapid reperfusion. Intraperitoneal ABCP injections were given 3h before and immediately after the procedure and then once daily post I/R injury for 14 days. RGC apoptosis was assessed using a TUNEL assay (n=2 animals per group). Results: Intraperitoneal injections of ABCP significantly (p Conclusions: Intraperitoneally administered ABCP peptide was able to significantly attenuate RGC death in two animal models of glaucoma. These findings suggest that ABCP has the potential to be developed as a neuroprotective agent in glaucoma.