黄芪甲苷减轻镉致TM3细胞Cx43表达下降及缝隙连接细胞间通讯功能减退

Astragaloside suppresses the decrease of connexin43 expression and junctional intercellular communication hypofunction in TM3 cells

目的探讨黄芪甲苷(As)对镉(Cd)致TM3细胞连接蛋白43(Cx43)表达改变及由Cx43介导的缝隙连接细胞间通讯(GJIC)功能改变的保护作用。方法用TM3细胞系作为研究对象,设对照组、As(20 mg/L)组、Cd(10μmol/L)组、Cd加As组,免疫组织化学方法分析Cx43阳性产物表达,荧光定量PCR检测Cx43 mRNA表达,Western blot检测Cx43蛋白表达,划痕标记染料示踪技术(SLDT)检测GJIC功能。结果与对照组相比,Cd组TM3细胞Cx43阳性产物表达的平均吸光度值(A_(OD))显著降低(P<0.01),Cx43 mRNA和蛋白表达下降(P<0.01),TM3细胞GJIC功能降低(P<0.01);Cd+As组TM3细胞Cx43阳性产物表达虽较对照组减弱但明显高于相应Cd组(P<0.01),Cx43 mRNA、蛋白表达及GJIC功能虽比对照组降低,但较Cd组高(P<0.01)。结论黄芪甲苷对镉致TM3细胞Cx43表达下降及GJIC功能减退有明显的拮抗作用。

Objective To investigate the protective effect of astragaloside（ As） against cadmium（ Cd） toxicity on the expression of connexin43（ Cx43） and the changes of connexin43-mediated gap junctional intercellular communication（ GJIC） in TM3 cells. Methods The TM3 cells were randomly divided into control,As（ 20 mg/L）,Cd（ 10 μmol/L） and Cd ＋ As. The expression of connexin 43（ Cx43） was detected by immunohistochemistry.RT-PCR was used to detect the expression levels of Cx43 mRNA,and the Western blot was used to detect the expression levels of Cx43 protein. Furthermore, the GJIC was estimated by scrape-loading and dye transfer（ SLDT）. Results Compared with the control group,the average optical density（ A） of the positive product of Cx43 in Cd group was obviously decreased（ P〈 0. 01）,the expression levels of Cx43 mRNA and protein in Cd group were decreased（ P〈 0. 01）,and the GJIC of TM3 cells was also decreased（ P〈 0. 01）. On further analysis,the positive productives of Cx43,the expression levels of Cx43 mRNA and protein and GJIC of TM3 cells in Cd ＋ As group were significantly higher than those in Cd group,though lower than of the control group.Conclusions As inhibits the down-regulation of the expression levels of Cx43 and damage of GJIC of TM3 cells induced by Cd.