Lefty蛋白拮抗人肾小管上皮细胞凋亡的研究

Inhibitory effects of Lefty protein on apoptosis of human renal tubular epithelial cells

目的 探讨Lefty蛋白对转化生长因子β1（TGF-β1）介导的人肾小管上皮细胞（HK-2）凋亡的影响。方法采用脂质体将人Lefty质粒转染入离体培养的HK-2细胞，使其稳定表达Lefty蛋白。对正常对照组（A组）和Lefty转染组（B组）细胞给予10ng／mlTGF-β1刺激后，采用Westernblot法检测各组细胞第6、12、24、48小时磷酸化Smad2／3（p-Smad2／3）表达水平，并同时采用流式细胞术检测各组细胞凋亡程度。结果TGF131刺激后，A组p-Smad2／3表达水平和细胞凋亡程度较刺激前升高（P〈0．05），而B组上述指标均低于A组（P〈0.05）。结论Lefty蛋白可拮抗TGF-19J／Smad信号转导通路，减轻TGF-β1介导的人肾小管上皮细胞凋亡。

Objective To evaluate the effects of Lefty protein on the transforming growth factor-β1 （TGF-β1）-mediated apoptosis of human renal tubular epithelial cells （HK-2）. Methods We made the HK-2 cells secreting endogenous Lefty protein stably by transfecting human lefty gene into cells. After stimulated by the recombinant human TGF-β1 （10 ng/ml）, the levels of p-Srnad2/3 protein were examined by Western blot, and flow eytometry was employed to investigate apoptosis at the 6th, 12th, 24th, and 48th h. Results After administration of TGF-β1 to renal tubular cells, the protein of p-Smad2/3 in HK-2 and apoptosis were significantly increased. These abnormalities were attenuated by liposome-mediated lefty gene transfeetion. Conclusion Lefty protein can inhibit TGF-β1/Smads signaling pathway and markedly attenuate TGF-β1-mediated apoptosis of human renal tubular epithelial cells.