甲状旁腺激素对人近曲小管上皮细胞转分化及分泌结缔组织生长因子的影响

目的 探讨甲状旁腺激素（PTH）对人近曲小管上皮细胞系HK-2细胞分泌结缔组织生长因子（CTGF）及细胞转分化的影响。 方法 应用实时定量PCR和Western印迹观察PTH诱导HK-2细胞CTGF mRNA和蛋白表达情况，从转录水平探讨PTH对CTGF基因启动子活性的调控作用。应用免疫荧光技术检测PTH作用下HK-2细胞中α平滑肌肌动蛋白 （α-SMA）的表达。 结果 HK-2细胞有基础水平的CTGF mRNA和蛋白表达，PTH刺激后其表达量显著增加。PTH最佳刺激浓度是10－10 mol/L，最佳刺激时间是72 h。10－10 mol/L PTH干预HK-2细胞12 h后，荧光素酶活性较对照组显著升高（1.888±0.078比0.989±0.030，P ＜ 0.01）；光镜下可见细胞由立方形铺路石样转变为梭形，随作用时间延长转分化现象更显著。PTH刺激HK-2细胞12 h后，免疫荧光检测可见细胞质中有α-SMA表达；PTH刺激24 h后，α-SMA表达明显增多，与CTGF mRNA和蛋白表达的时间效应一致。 结论 PTH可上调HK-2细胞CTGF表达，并具有促进HK-2细胞转分化的作用。

Impact of parathyroid hormone on transition and connective tissue growth factor expression of human renal tubular epithelial cells

Objective To investigate the effect of parathyroid hormone (PTH) on the transition and connective tissue growth factor (CTGF) expression of human renal proximal tubular epithelial cell line HK-2 . Methods The expression of CTGF mRNA and protein of HK-2 cells were measured by real time RT-PCR and Western blot respectively . The effect of PTH on the phenotypic transformation of HK-2 cells was examined by light microscopy . The expression of α-smooth muscle actin (α-SMA) in HK-2 cells was detected by immunofluorescence . Results Basal level of CTGF mRNA and the protein expression were detected in HK-2 ceils . PTH upregulated the expression of CTGF mRNA and protein with the maximal response at the concentration of 10-10 mol/L and the best stimulating time was at 72 h . After exposure to PTH (10-10tool/L) for 12 hours, the highest level of luciferase activity was 1 .96 fold as compared to control (1 .888±0 .078 vs 0 .989±0 .030, P＜0 .01 ) . Untreated cells showed negligible expression of ±-SMA,whereas ±-SMA expression was significantly increased in cells treated with PTH . Conclusion PTH up-regulates CTGF expression and induces transition of HK-2 cells .