谷胱甘肽-S转移酶A4-4基因转染人血管平滑肌细胞及对改善硝酸甘油耐药性的作用

目的谷胱甘肽-S转移酶是一类具有拮抗氧化应激损伤的酶,谷胱甘肽-S转移酶对于人血管平滑肌细胞的硝酸甘油耐药性是否具有改善作用尚无报道。本研究探讨谷胱甘肽-S转移酶A4-4基因转染人胎主动脉平滑肌细胞,观察谷胱甘肽-S转移酶是否能够改善硝酸甘油耐药性。方法建立稳定人谷胱甘肽-S转移酶A4-4转染的人胎主动脉平滑肌细胞株,进行Western blot、免疫组织化学、MTT细胞毒理学以及一氧化氮检测。结果与野生型和空载体转染的人胎主动脉平滑肌细胞组相比,过表达人谷胱甘肽-S转移酶A4-4的人胎主动脉平滑肌细胞在硝酸甘油作用24h后明显抵抗硝酸甘油造成的细胞损伤(P<0.05);经硝酸甘油耐药性方案诱导后,人谷胱甘肽-S转移酶A4-4转染的人胎主动脉平滑肌细胞组产生的一氧化氮含量高于其他两组(P<0.01)。结论本研究发现经谷胱甘肽-S转移酶A4-4基因转染的人血管平滑肌细胞可抵抗硝酸甘油作用所致的损伤,并可能具有改善硝酸甘油耐药性的作用。

The Possible Role of Glutathione-S-Transferase A4-4 on the Development of Nitroglycerin Tolerance in Human Vascular Smooth Muscle Cells

Aim Glutathione-S-transferases (GST), enzymes with antioxidant activity, have been shown to play a protective role against oxidative stress for many cell types including human vascular smooth muscle cells, but their role in nitroglycerin (NTG) tolerance specifically has not been demonstrated. In this study, we tested the role of hGSTA4-transfection in conferring resistance to the development of tolerance on human fetal aortic smooth muscle cells (FASMC) treated with NTG. Methods A stable transfection of FASMC with cDNA of hGSTA4-4 was established. Western blot analysis, immunocytochemistry assay, MTT cytotoxicity assay and NO assay were used. Results FASMC overexpressing with the hGSTA4-4 were significantly more resistance to cytotoxic injury by NTG, assessed at 24 hours (P<0.05). NO release was higher in hGSTA4-transfected cells during NTG nontolerance and tolerance treatment compared with those in wild-type and vector-transfected FASMC (P<0.01). Conclusions This study demonstrates that hGSTA4-4 can protect smooth muscle cells from the cytotoxicity of NTG and may have a role in smooth muscle cell tolerance to NTG.