丹七散提取物抗N-甲基-D-天冬氨酸诱导的视神经节细胞凋亡机制

目的:观察丹七散提取物(DQSE)对N-甲基-D-天冬氨酸(NMDA)诱导损伤的大鼠视网膜神经节(RGCL)细胞抗凋亡作用,并探讨其作用机制。方法:Wistar大鼠随机分为对照组、NMDA组、DQSE(3.9,7.8,15.6 g·kg^-1)组和阳性对照组(MK801,NMDA抑制剂)。给药7 d后,对照组大鼠玻璃体注射生理盐水,其余组玻璃体注射NMDA制备视网膜损伤模型。给药14 d后,TUNEL法观察RGCL凋亡;免疫组织染色法检测视网膜casepase-3表达分布;Western-blotting法测定视网膜Cleaved casepase-3,-8和-9表达水平。结果:中、高剂量DQSE能显著减少大鼠RGCL的TUNEL阳性表达率(P<0.01,P<0.001)和casepase-3阳性表达率(P<0.01,P<0.001)。DQSE(3.9,7.8,15.6 g·kg^-1)剂量依赖性地降低视网膜Cleaved casepase-3,-8,和-9表达水平。结论:DQSE通过下调Cleaved caspase-3蛋白及其上游的Cleaved caspase-8、-9蛋白表达水平产生抗凋亡作用,进而减少RGCL细胞丢失,实现视网膜保护作用。

Protective effects of Danqisan extract on NMDA-injured retinal ganglion cells

OBJECTIVE To observe therapeutic action of Danqisan extract (DQSE) on retinal ganglion cell layer (RGCL) and investigate underlying mechanism.METHODS Rats were randomly divided into six groups: control group, NMDA group, DQSE groups (3.9, 7.8, 15.6 g·kg^-1) and positive control groups (MK801, NMDA inhibitors). After 7 days of medication, rats in control group were treated by intravitreal injection of normal saline, and retinopathy models were established by intravitreal injection of NMDA. After 14 days of medication, apoptosis of RGCL neuron was measured by TUNEL; RGCL caspase-3 was tested by immunohistochemistry technique; protein expression levels of Cleaved caspase-3, -8 and -9 were determined by western-blotting assay.RESULTS NMDA-induced Moderate and high dose of DQSE significantly decreased expression levels of TUNEL (P<0.01, P<0.001) and casepase-3 (P<0.01, P<0.001) in RGCL. DQS treatment (3.9, 7.8 or 15.6 g·kg^-1) could reverse over expression of Cleaved caspase-3, -8 and -9 in retina of NMDA-treated rats in a dose dependent manner.CONCLUSION DQSE can inhibit NMDA-treated RGCL neuron apoptosis by down regulating levels of caspase-3, -8 and -9, thus reduce RGCL loss and protect retina.