低氧对肾小管上皮细胞转化生长因子β1表达及增殖的影响

Effect of chronic hypoxia on TGF-β1 expression and proliferation in MDCK Cells

目的 探讨低氧在肾脏疾病进展中的作用机制。方法 将肾小管上皮细胞MDCK分别置于低氧3％和正常氧18％条件下,培养24,48,72和96 h。应用台盼蓝排除法计数活细胞,观察细胞增殖;应用流式细胞仪观察细胞周期;以及半定量RT-PCR检测MDCK细胞TGF-β1mRNA的表达。结果 低氧可促进MDCK细胞增殖,G0-G1期细胞比例减少,G2-M期细胞比例增多。低氧可促进TGF-β1 mRNA的表达,而且呈一定时间相关性。结论 慢性低氧致肾间质纤维化的机制与低氧引起的细胞增殖和细胞周期的改变有关,而这些改变又可能与低氧引起的细胞分泌生长因子改变有关。

Objective To investigate the effect of hypoxia on renal tubular cells and the mechanism of renal interstitial fibrosis. Methods Effect of chronic hypoxia on the proliferation, cell cycle and expression of TGF-β1 mRNA in cultured MDCK cells was examined. Quiescent cells were exposed to hypoxia (3%O2) or normoxia (18%O2) for 24, 48, 72 and 96 hours. At the end of each incubation, cellular proliferation and cell cycle were assessed by MTT method and flow cytometry, respectively. TGF-β1 mRNA level of cells were analyzed by semi-quantity RT-PCR. Results Exposure of MDCK cells to hypoxia induced a significant increase in proliferation and a significant decrease in the percentage of G0-G1 stage and a significant increase in the percentage of G2-M stage at 24, 48 and 72 hours. Meanwhile, TGF-β1 mRNA expression increased in a time-dependent manner as compared with normoxia group when MDCK cells were stimulated with 24, 48, 72 and 96 hours in hypoxia condition. Conclusion Chronic hypoxia-induced proliferation of MDCK cells is associated with increased expression of TGF-β1. Chronic hypoxia of renal tubular cells may be one of the causes of renal interstitial fibrosis.