肌肽通过抑制ROS/NLRP3/GSDMD介导的焦亡减轻OGD/R对BV2细胞损伤

Carnosine attenuates OGD/R damage to BV2 cells by inhibiting ROS/NLRP3/GSDMD-mediated pyroptosis

目的探究肌肽对氧糖剥夺/复糖复氧(OGD/R)诱导BV2细胞损伤的保护作用及对ROS/NLRP3/GSDMD通路介导焦亡的影响。方法BV2细胞随机分为对照组(Con)、模型组(OGD/R)、肌肽组(OGD/R+CAR)、抑制剂组(OGD/R+MCC950)、肌肽+抑制剂组(OGD/R+CAR+MCC950)。采用MTT法检测细胞存活率;微量酶标法检测细胞上清液中乳酸脱氢酶(LDH)释放率;Hoechst 33342/SYTOX Green染色法检测细胞损伤情况;DCFH-DA检测细胞中ROS水平;免疫荧光观察细胞内NF-κB p65入核水平;Western blot检测细胞NLRP3、ASC、cleaved caspase-1、GSDMD-N的蛋白表达水平;ELISA检测细胞上清液中IL-1β、IL-18水平。结果与Con组相比,OGD/R组细胞存活率明显降低,LDH释放明显升高,细胞形态受损,SYTOX Green阳性率与细胞中ROS水平明显升高,细胞核中NF-κB p65荧光强度增强,细胞内NLRP3、ASC、cleaved caspase-1、GSDMD-N蛋白表达水平及IL-1β、IL-18水平明显升高。与OGD/R组相比,其他组的细胞存活率明显升高,LDH释放率明显降低,细胞损伤得到一定程度的改善,SYTOX Green阳性率和细胞中ROS生成水平明显降低,细胞核中NF-κB p65荧光强度明显降低,相关蛋白表达水平及细胞上清液中IL-1β、IL-18水平明显降低。结论肌肽通过抑制氧化应激及NF-κB激活,进而抑制NLRP3/GSDMD信号途径的焦亡对OGD/R致BV2细胞损伤发挥保护作用。

Aim To investigate the protective effect of carnosine on BV2 cell damage induced by oxygen-glucose deprivation/reperfusion(OGD/R)and its role in mediating pyrodeath through the ROS/NLRP3/GSDMD pathway.Methods BV2 cells were randomly divided into the control group(Con),model group(OGD/R),carnosine group(OGD/R+CAR),inhibitor group(OGD/R+MCC950),and carnosine+inhibitor group(OGD/R+CAR+MCC950).The cell survival rate was detected by MTT assay.The release rate of lactate dehydrogenase(LDH)in cell supernatant was detected by microenzyme labeling method.Cell damage was assessed using Hoechst 33342/SYTOX Green staining.ROS levels in cells were detected by DCFH-DA.The nucleation level of NF-κB p65 was observed by immu-nofluorescence.The protein expression levels of NLRP3,ASC,cleaved caspase-1,and GSDMD-N were detected by Western blot.The levels of IL-1βand IL-18 in the supernatant were detected by ELISA.Results Compared with Con group,the survival rate of cells in the OGD/R group was significantly reduced,LDH release was significantly raised,cell morphology was damaged,and the positive rate of SYTOX Green was significantly elevated with ROS level in cells.The fluorescence intensity of NF-κB p65 in the nucleus increased,and the protein expression levels of NLRP3,ASC,cleaved caspase-1,GSDMD-N increased significantly,and the levels of IL-1βand IL-18 in the cell superserum increased significantly.Compared with the OGD/R group,the survival rate of cells in other groups increased significantly,the LDH release rate significantly decreased,and the cell damage was improved to a certain extent.The positive rate of SYTOX Green and ROS production in cells significantly decreased,and the fluorescence intensity of NF-κB p65 in nucleus markedly decreased.The expression levels of related proteins and the levels of IL-1βand IL-18 in cell supernatant significantly decreased.Conclusion Carnosine can protect BV2 cells from OGD/R-induced damage by inhibiting oxidative stress and NF-κB activation,then inhibiting NLRP3/GSDMD signaling pathway.