BACKGROUNDProneurotrophins such as the precursor of nerve growth factor (proNGF) and the precursor of brain-derived neurotrophic factor (proBDNF) interacted with sortilin and p75(NTR) to form a complex capable of activating an apoptotic signaling. We found that the expression of p75(NTR) and sortilin was increased in ischemic retina induced by elevated intraocular pressure (IOP), but the protein expression changes of proNGF and proBDNF in the same situation were not clear. This study aimed to ascertain the protein expression changes of proNGF and proBDNF in ischemic retina induced by elevated IOP.

METHODSExpression of proBDNF and proNGF was examined by double-labeling immunochemistry in normal rat retina, examined using Western blotting and analyzed using statistical methods in ischemic retina induced by elevated IOP.

RESULTSImmunocytochemistry showed that the proBDNF expressed in the ganglion cell layer (GCL) while the proNGF primarily existed in both the nerve fiber layers (NFL) and large ganglion cell bodies of normal rat retina. Western blotting analysis demonstrated that the molecule weights of 28 kD (proBDNF)/25 kD (proNGF) band were increased significantly (P < 0.05) at days 3, 5 and 7 after retinal elevated-IOP-induced ischemia.

CONCLUSIONProBDNF expressed in the GCL and proNGF primarily presented in NFL and large ganglion cell bodies of normal rat retina, the protein expression forms of 28 kD proBDNF and 25 kD proNGF increased in ischemic retina induced by elevated IOP.