The Apoptosis Of RGCs After Intravitreal Injection Of Slit₂siRNA Into The Acute And Chronic Rat Ocular Hypertension Models

Objectives: To establish stable acute and chronic rat glaucoma models, clarify theexpression of BDNF and Slit₂mRNA in retina of rat glaucoma model, and observe theeffect of RNAi technique usage in retinal neuroprotection, we aim to upregulate theexpression of BDNF and reduce the apoptosis of RGC in retina by downregulating theexpression of slit₂mRNA in retina.Methods:â‘ To select a stable rat nerve damage mode between high intraocularpressure model and rat nerve crush model;â‘¡To establish a rat chronic elevated intraocularpressure glaucoma model combined with ligation of episcleral veins and cauterization oflimbus arcades;â‘¢The eyes of rats after successful being made model were enucleated andprocessed for paraffin sectioning. Each eye was oriented so that the sections (5-μmthickness) were cut from the superior to the inferior edge. BDNF was traced byimmunohistochemistry SP method and Slit₂mRNA was evaluated by In situ hybridizationmethod;â‘£we used 32 gauges needle to inject the given slit₂mRNA in differentconcentration into vitreous body of the acute and chronic rat glaucoma models. Eyes wereenucleated and processed for paraffin sectioning. Each eye was oriented so that the sections(5-μm thickness) were cut from the superior to the inferior edge. BDNF was traced byimmunohistochemistry SP method and Slit₂mRNA was evaluated by In situ hybridizationmethod and TUNEL assays were performed on 5-um slides of rat eye to detect the RGCapoptosis.Resultsâ‘ We selected the nerve crush 20s as the model for neuroprotection research;â‘¡we established a reliable glaucoma rat model by episcleral veins ligation combined withcauterization of limbus arcades;â‘¢Expressions of BDNF were detected in retinal ganglioncell layer and inner nuclear layer. In situ hybridization studies indicated that the slit₂mRNAwas specifically expressed in the RGC layer of rat retina and upregulated in the glaucoma rat model;â‘£Different concentration of srSlit₂mRNA in acute and chronic rat model led todownreguiate Slit₂mRNA in retina and upregulate BDNF in retina and alleviate theapoptosis of RGCs, however, the outcomes were more abvious in chronic glaucoma model.Conclusions Introvitreal injection slit₂mRNA in glaucoma rat models could benefitfor neuroprotection through upregulating BDNF expression and downregulating theapoptosis of RGCs in the retina.