硫辛酸对镉致大鼠肝细胞GJIC损伤的保护作用

Protective effects of lipoic acid on cadmium-induced GJIC inhibition in BRL3A cells

为了探讨硫辛酸对镉致大鼠肝细胞缝隙链接通讯（gap junctional intercellular communication，GJIC）损伤的影响及作用机制，本试验以大鼠肝细胞系BRL3A细胞为对象，以2．5μmol／L醋酸镉、50μmol／L硫辛酸、5μmol／L 18—β-甘草次酸处理细胞，Hoechst33258观察细胞核形态、细胞实时分析技术检测细胞指数，划痕染料标记示踪法（SL／DT）检测GJIC，免疫荧光技术观察缝隙连接蛋白Cx43分布，Western blot检测Cx43表达水平。结果显示：硫辛酸能有效缓解2．5μmol／L醋酸镉引起的BRL3A细胞形态学改变、细胞指数下降、GJIC抑制以及细胞膜上连接蛋白Cx43分布减少和表达水平下降。结果表明：硫辛酸对镉致大鼠肝细胞损伤有保护作用，其机制与GJIC有关。

To investigate the effects of lipoic acid on cadmium-induced GJIC inhibition in BRL3A cells,in this study,BRL3A cells were treated with 2.5 μmol/L of cadmium acetate（Cd）,50 μmol/ L lipoic acid（LA） and 5 μmol/L 18-beta-glycyrrhetinic acid（GA） for 12 hours. Apoptotic morphological changes induced by Cd in BRL3A cells were observed with Hoechst33258 staining. The cell index was determined by real time cellular analysis system（RTCA）. The GJIC between BRL3A cells was detected by the scrape loading dye transfer assay（SL/DT）. The distribution of connexin 43（Cx43） was observed using confocal laser scanning microscopy. The expression of Cx43 was determined by western blot. The results showed that 2.5 μmol/L cadmium acetate can change the cellular morphology of BRL3A cells, down-regulate cell index,inhibit the function of GJIC between cells,damage the localization of Cx43, and down-regulate Cx43 expression. LA has the protective effects on the Cd-induced cyto-damage via GJIC.