PARP-1在光诱导视网膜神经节细胞凋亡中的作用

The role of PARP-1 on light-induced apoptosis of cultural retinal ganglion cells

目的研究核酶PARP-1在光诱导的视网膜神经节细胞(RGCs)凋亡中的作用。方法应用1000 Lux光诱导视网膜神经节细胞-5(RGC-5)光损伤模型;利用MTT、APOPercentageTM实验及原位TUNEL确定光诱导RGC-5细胞死亡的模式;通过半定量RT-PCR和Western blot方法评估光对RGC-5细胞中核酶PARP-1表达的影响;探讨PARP-1抑制剂尼克酰胺和NU1025对光损伤中RGC-5细胞的保护作用。结果1000 Lux光以时间依赖的方式降低体外培养的RGC-5细胞活性,光暴露4d明显诱导RGC-5细胞凋亡。RGC-5细胞光损伤导致核酶PARP-1转录和表达的上调(F=224.59,P<0.01,n=12,ANOVA,Dunnett t test),PARP-1抑制剂尼克酰胺和NU1025显著提高细胞活性(F=312.87,P<0.01,n=12,ANOVA,Dunnett t test)。结论1000 Lux光可以诱导体外培养的RGC-5细胞凋亡,核酶PARP-1在该细胞凋亡分子机制中起重要作用。

Objective Poly ADP-ribose polymerase-1（PARP-1）,a conservative nuclear enzyme,is mainly responsible for DNA repairing.Light might be an insult to induce DNA damage and further activated PARP-1.Present study was to explore the role of PARP-1 on light-induced apoptosis of cultured retinal ganglion cells （RGCs）. Methods The light-injured model of RGC-5 cells was established by using 1 000 Lux-light.And then MTT,APOPercentageTM and in-situ TUNEL assay were used to confirm the cell death pattern caused by light exposure.The expression of PARP-1 was determined by using semi-quantitative RT-PCR and Western blot respectively.And the neuroprotective effect of nicotinamide and NU1025,as PARP-1 inhibitors,on the light-injured RGC-5 cells was assessed by MTT assay. Results MTT assay showed that the exposure of 1 000 Lux-light was able to reduce RGC-5 cells viability in a time-dependent manner,and the cell death pattern was further confirmed through apoptosis pathway by using APOPercentageTM and in-situ TUNEL assay.In addition,the transcription and expression of PARP-1 were markedly up-regulated in the light-injured RGC-5 cells compared with control cells （F=224.59,P〈0.01）.The PARP-1 inhibitors,nicotinamide and NU1025 significantly increased cell viability when cells were exposed to 1 000 Lux light （F=312.87,P〈0.01）. Conclusion Exposure of 1 000 Lux-light can result in RGC-5 cell apoptosis in vitro,and PARP-1 plays an important role in this apoptotic cascade.