三七总皂苷对马兜铃酸I诱导的人肾小管上皮细胞转分化的影响

目的：探讨三七总皂苷（total saponins of panax notoginseng, PNS）对马兜铃酸I（aristolochic acid I,AAI）诱导的人肾小管上皮细胞株HK-2转分化的影响。方法：应用倒置相差显微镜观察HK-2细胞形态学变化；免疫组织化学方法检测α-平滑肌肌动蛋白（α-smooth muscle actin, α-SMA）的表达；ELISA法测定培养细胞上清液中转化生长因子-β1（transforming growth factor-β1, TGF-β1）的含量。结果：AA I诱导组HK-2细胞从原有典型的上皮细胞形态转变为长梭形肌成纤维细胞形态；胞浆内大量表达α-SMA，其积分光密度值增加（P<0.05）；细胞培养上清液中TGF-β1含量均增加，且呈时间依赖性（P<0.05）。不同剂量PNS治疗可减轻AA I诱导的细胞形态学改变，不同程度的抑制α-SMA的表达和TGF-β1的分泌，且呈剂量依赖性（P<0.05）。PNS对照组HK-2细胞形态学、α-SMA表达和TGF-β1分泌与空白对照组比较均无明显变化。结论：AA I可通过促进TGF-β1的分泌诱导肾小管上皮细胞转分化，促进细胞外基质α-SMA的合成；PNS可抑制AA I诱导的肾小管上皮细胞转分化作用，减少α-SMA的表达，该作用可能是通过抑制TGF-β1表达实现的。

Effect of total saponins of panax notoginseng on the transdifferentiation of human renal tubular epithelial cell induced by aristolochic acid I

ObjectiveTo study the effect of total saponins of panax notoginseng (PNS) on the transdifferentiation of human renal tubular epithelial cell induced by aristolochic acid I in vitro. Methods The morphological change of cultured tubular cells was observed by inverted phase contrast microscopy; The expression of α-smooth muscle actin (α-SMA) was assessed by immunohistochemistry; The level of transforming growth factor-β1(TGF-β1) in the culture supernatant was measured by ELISA. ResultsAristolochic acid I (AA I) caused transdifferentiation of HK-2 cells to myofibroblast-like cells and showed strong α-SMA expression, the integral optical density (IOD) value of α-SMA expression was more than that of negative control group (P<0.05), the content of TGF-β1 in supernatant was also increased in a time-dependent manner (P<0.05). The morphological change of HK-2 cells was decreased in PNS treated groups with different doses, PNS inhibited the expression of α-SMA and TGF-β1 in a dose-dependent manner (P<0.05). There was no difference in the measured indexes between PNS control group and negative control group. Conclusion AA I can increase the level of TGF-β1 and induce tubular epithelial-myofibroblast transdifferentiation to increase the expression of α-SMA; PNS down-regulate TEMT and α-SMA expression in a dose-dependent manner, the negative regulation of PNS may be partially achieved by attenuation of TGF-β1 expression.