Novel Combinatory Approaches to Repair Visual System after Optic Nerve Damage.

摘要

Background: Death of retinal ganglion cells (RGCs) and poor regeneration are major obstacles for treating traumatic optic neuropathy after road accident, falls or combat blasts. Optic nerve regeneration from many long-term surviving RGCs, reconnecting the brain could potentially restore vision after injury. We previously determined that deletion of two genes, PTEN and SOCS3 induces optic nerve regeneration. On the other hand, genetic modification of CHOP and XBP1 in RGCs render them highly resistant to injury-induced death. Objective/hypothesis: We will use knockout mice and therapeutically relevant short hairpin RNA (shRNA) approaches to determine the combined effects of targeting PTEN/SOCS3 and CHOP/XBP1 on RGC survival and regeneration after injury. In addition, we will examine the integrity of RGC functions after modification of these genes using pattern electroretinogram (PERG). We hypothesize that combined strategies to target PTEN/SOCS3 and CHOP/XBP1 will further enhance long-term RGC survival and regeneration, and RGCs in these animals exhibit normal physiological responses. Specific Aims/Study Design: Aim 1: Use knockout mice to examine the combined effects of targeting PTEN/SOCS3 and CHOP/XBP1 on RGC survival and regeneration. PTEN/SOCS3/CHOP knockout mice will receive AAV-assisted over-expression of XBP1, followed by nerve crush injury and assessment of RGC survival and regeneration. Aim 2: Integrity of RGC functions after genetic modification of PTEN/SOCS3 or CHOP/XBP1 will be evaluated using PERG. Aim 3: Optimize shRNA approach to promote RGC survival and regeneration. PTEN, SOCS3 and CHOP will be knocked down alone or in combination using shRNAs to improve RGC survival and regeneration. Relevance: Military personnel run a high risk of incurring ocular nerve damage. This proposal will probe for genetic interventions to rescue dying neurons and promote regeneration, and restore vision, with the potential to be administered to the clinic and battlefield.