LeftyA真核表达载体的构建及其对转化生长因子-β1诱导人肾小管上皮细胞转分化的影响

Construction of eukaryotic expression vector for LeftyA and effects of LeftyA on epithelial to mesenchymal transition of human proximal tubular epithelial cells

目的构建pcDNA3．1-LeftyA真核表达载体，观察其对转化生长因子-β1（TGF-β1）诱导人。肾小管上皮细胞（HK-2）转分化（EMT）的影响。方法基因克隆技术构建pcDNA3．1-LeftyA真核表达载体，将其瞬时转染HK-2细胞，TGF-β1（10μg／L）刺激后，观察细胞形态变化，检测E-钙黏蛋白（E—cadherin）、d-平滑肌肌动蛋白（仅-SMA）基因及蛋白的表达。结果TGF-β1刺激后HK．2细胞内E—cadherin mRNA和蛋白时间依赖性表达下调，α-SMAmRNA和蛋白时间依赖性表达上调，同时E-cadherin表达变化早于α-SMA；LeftyA蛋白可以显著抑制E—cadherin蛋白的下调表达（P〈0．05），其表达比同时间点单纯刺激组高17．6％；同时可逆转d—SMA蛋白的上调表达（P〈0．05），其蛋白表达比单纯刺激组低14．0％。结论LeftyA蛋白可以抑制TGF-β1所致的EMT。

Objective To construct the eukaryotic expression vector for LeftyA and study the effects of LeftyA on epithelial to mesenchymal transition of human proximal tubular epithelial cells induced by transforming growth factor-β1 （TGF-[M）. Methods The pcDNA3. 1-LeftyA was constructed by recombinant DNA technique. After transfection with pcDNA3. 1-LeftyA HK-2 cells were stimulated by TGF-β1 （ 10μg/L）. The morphological changes, and the expression of E-cadherin,α-SMA and LeftyA mRNA and protein were observed and detected, respectively. Results TGF-β1 could markedly decrease the expression of E-cadherin mRNA and protein in HK-2 cells induced, and dramatically increase the expression of α-SMA mRNA and protein in a time-dependent manner. Forced expression of exogenous LeftyA led to a blockage of TGF-β1-induced E-cadherin （ 17. 6% ） suppression and α-SMA induction （ 14. 0% ）. Conclusion Disruption of cell adherence is the beginning stage of EMT, and overexpression of LeftyA can suppress EMT induced by TGF-β1, which suggests a alprostadil role for LeftyA in TGF-β1-induced tubular EMT and renal fibrosis.