世界中医药

目的：探讨姜黄素对大鼠视网膜缺血/再灌注损伤(RIRI)时内质网应激(ERS)的影响。方法：选取清洁级Sprague-Dawley(SD)雄性大鼠96只，采用随机数字表法分为3组(n=32)：对照组(C组)、缺血/再灌注组(I/R组)和姜黄素组(CUR组)。I/R组和CUR组采用前房灌注法使眼内压升高而制备大鼠RIRI模型，缺血60 min，再灌注24 h后结束实验。于缺血前60 min时，CUR组腹腔注射姜黄素100 mg/kg，C组和I/R组腹腔注射等容量生理盐水。各组于再灌注24 h时处死8只大鼠，取视网膜组织，光镜下观察病理学改变；采用TUNEL法检测视网膜组织细胞凋亡情况并计算凋亡指数(AI)。3组于再灌注24 h时处死8只大鼠，取视网膜组织，电镜下观察大鼠视网膜组织超微结构改变。3组于再灌注24 h时处死8只大鼠，取视网膜组织，逆转录-聚合酶链式反应(RT-PCR)检测大鼠视网膜组织中CCAAT增强子结合蛋白(C/EBP)同源蛋白(CHOP)、活化的转录因子4(ATF4)和X-盒结合蛋白-1(XBP1）mRNA表达。3组于再灌注24 h时处死8只大鼠，取视网膜组织，蛋白免疫印迹法(Western Blot)检测大鼠视网膜组织中、B淋巴细胞瘤-2基因(Bcl-2)、Bcl-2相关X蛋白(Bax)及含半胱氨酸的天冬氨酸蛋白水解酶3(caspase-3)的蛋白表达，计算Bcl-2/Bax比值。结果:与C组比较，I/R组大鼠视网膜组织XBP-1、ATF4和CHOP mRNA表达明显上调(P<0.05)；与I/R组比较，CUR组大鼠视网膜组织XBP-1、ATF4和CHOP mRNA表达明显下调(P<0.05)。与C组比较，I/R组大鼠视网膜组织CHOP、Bax和caspase-3蛋白表达升高，Bcl-2蛋白表达及Bcl-2/Bax比值均下降，与C组比较，差异均有统计学意义(P<0.05)，CUR组大鼠视网膜组织CHOP、Bax和caspase-3蛋白表达下降，Bcl-2蛋白表达及Bcl-2/Bax比值均升高，与I/R组比较，差异均有统计学意义(P<0.05)。与C组比较，I/R组大鼠视网膜组织出现形态结构及超微结构损伤，AI值升高(P<0.05)。与I/R组比较，CUR组大鼠视网膜组织形态结构及超微结构损伤均减轻，AI值降低(P<0.05)。结论:姜黄素可减轻大鼠RIRI，其机制可能与抑制ERS介导的细胞凋亡有关。

English Summary:

To investigate the effect of curcumin on endoplasmic reticulum stress (ERS) retinal ischemia/reperfusion injury (RIRI) in rats.Methods:A total of 96 Sprague-Dawley (SD) male rats were randomly divided into normal control group (C group)，ischemia/reperfusion group (I/R group) and curcumin group (CUR group)，with 32 rats in each group.The rat model of RIRI was established by using anterior chamber eannulafion to elevate intra-ocular pressure above systolic pressure for 60 minutes，and the test was finished after 24 h for reperfusion.Curcumin (100 mg/kg) was injected into the abdominal cavity 60 min before ischemia in CUR group，and the same dose of 0.9% normal saline was injected into the abdominal cavity at the same time points in C group and I/R group，respectively.In order to take the retinal tissue of rats，I/R model was established successfully and then eight rats were sacrificed 24 h after reperfusion，the changes of pathology of retinal tissue of rat were observed after conventional hematoxylin-eosin (HE) staining，and the cell apoptosis was detected by TUNEL method and the apoptosis index (AI) of retinal ganglion was calculated.Eight rats were sacrificed 24 h after reperfusion and retinal tissue was collected，and the ultrastructural changes of retinal tissue of rats were observed by transmission electron microscope.Eight rats were sacrificed 24 h after reperfusion and retinal tissue was collected，and the expressions of CCAAT-enhancer binding protein homologous protein (CHOP)，activation of transcription factors (ATF4) and X-4 box binding protein 1 (XBP1) mRNA in retinal tissue were detected by reverse transcription-polymerase chain reaction (RT-PCR).Eight rats were sacrificed 24 h after reperfusion and retinal tissue was collected，and the expressions of CHOP，B-cell lymphoma-2 (Bcl-2)，Bcl-2 associated X protein (Bax) and cysteinyl aspartate specific proteinase 3 (caspase-3) proteins in retinal tissue were measured by Western Bolt，and the ratio of Bcl-2 to Bax was calculated.Results:Compared with C group，the expressions of XBP1，ATF4 and CHOP mRNA of retinal tissue were significantly increased (P<0.05) in I/R group.Compared with I/R group，the expressions of XBP1，ATF4 and CHOP mRNA of retinal tissue were significantly decreased (P<0.05) in CUR group.Compared with C group，the expressions of CHOP，Bax and caspase-3 proteins were significantly higher (P<0.05)，while the expression of Bcl-2 protein and the ratio of Bcl-2 to Bax were both lower (P<0.05) in I/R group.Compared with I/R group，the expressions of CHOP，Bax and caspase-3 protein were significantly lower (P<0.05)，while the expression of Bcl-2 protein and the ratio of Bcl-2 to Bax were both higher (P<0.05) in CUR group.Compared with C group，the structure and the ultrastructure of retinal tissue of rats were more significantly injured，and AI was higher (P<0.05) in I/R group.Compared with I/R group，the injuries of the structure and the ultrastructure of retinal tissue of rats were distinctly alleviative，and AI was lower (P<0.05) in CUR group.Conclusion:Curcumin can significantly reduce RIRI in rats，and the mechanism may be related to alleviate ERS related cell apoptosis of retina.

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