内质网应激在UCH-L1抑制剂诱导细胞凋亡中的作用

Role of endoplasmic reticulum stress in cell apoptosis induced by UCH-L1 inhibitor

目的探讨内质网应激(ERS)在泛素羧基末端水解酶-1(UCH-L1)抑制剂导致的细胞损伤过程中的作用。方法采用50μmol/L的UCH-L1抑制剂处理人神经母细胞瘤SK-N-SH细胞。于处理前(对照组)和处理后不同时间点(2、4、6、12、24h),分别采用MTT比色法和Western blotting法检测细胞活力和ERS相关蛋白Bip/Grp78、Xbp-1、p-eIF2α及其促凋亡转录因子CHOP/Gadd153的表达。结果MTT比色法检测发现,50μmol/LUCH-L1抑制剂处理后4h,SK-N-SH细胞活力下降43.1%(P<0.05),且随处理时间的延长继续呈现显著下降趋势(P<0.01)。Western blotting检测显示,经50μmol/LUCH-L1抑制剂处理后,SK-N-SH细胞ERS相关蛋白Bip/Grp78、p-eIF2α和Xbp-1表达分别于处理后2、4、6h时显著增加;转录因子CHOP/Gadd153表达则在处理后2h和4h时略有增加,6h后达到高峰。结论在UCH-L1抑制剂诱导的细胞凋亡过程中,ERS是导致细胞损伤的路径之一。

Objective To investigate the role of endoplasmic reticulum stress （ERS） in cell apoptosis induced by ubiquitin carboxy-terminal hydrolases L1 （UCH-L1） inhibitor. Methods Human neuroblastoma SK-N-SH cells were treated with 50 μmol/L UCH-L1 inhibitor. Before the treatment （control group） and 2, 4, 6, 12 and 24 h after the treatment, the cellular viability was assessed by MTT assay, and Western blotting was employed to detect ERS associated proteins （Bip/Grp78, Xbp-1 and p-eIF2α）and CHOP/Gadd153. Results It was revealed by MTT assay that 4 h after treatment with 50 μmol/L UCH-L1 inhibitor, the cell viability of SK-N-SH was decreased by 43. 1% （P 〈 0.05）, and continued to be significantly decreased with time （P 〈 0.01 ）. It was indicated by Western blotting that ERS associated proteins Bip/Grp78, p-eIF2α and Xbp-1 of SK-N-SH cells were significantly increased 2, 4 and 6 h after treatment, and CHOP/Gadd153 was slightly increased 2 and 4 h and reached the peak 6 h after treatment. Conclusion ERS may be involved in the apoptosis induced by UCH-L1 inhibitor.