Neurotrophic factors

Abstract

Neurotrophic factors regulate neural cell survival and differentiation and control the number of retinal ganglion cells (RGCs) during retinal development. Several studies have reported a possibility that blockade of axonal transport in glaucoma leads to deficits in the neurotrophic factors and subsequent RGC death in adult eyes. Interestingly, not only mature neurotrophins but also the uncleaved neurotrophin precursors, the pro-neurotrophins, may play a critical role in survival or death of retinal neurons. Neurotrophic factors act on their receptors expressed on RGCs, but they also act on surrounding cells including Müller glia and microglia and indirectly affect the state of RGCs. Although ligand-receptor systems of neurotrophins are complex and their effects are still controversial, clinical trials using neurotrophins are underway for several retinal diseases. The current therapy for glaucoma is to lower intraocular pressure (IOP), but neurotrophic factors may be available for preventing IOP-independent RGC loss and future treatment of glaucoma.