黄芪通过c-met调控TGF-β1诱导的肾小管上皮细胞转分化

AB 目的：探讨黄芪对TGF-β1诱导的肾小管上皮细胞转分化及细胞外基质分泌的作用及机制。方法：体外培养正常大鼠肾小管上皮细胞（NRK52E）,应用倒置相差显微镜观察NRK52E细胞形态学变化;免疫组织化学染色法及实时荧光定量PCR法检测α-平滑肌肌动蛋白（α-SMA）,肝细胞生长因子HGF受体（c-met）的表达;ELISA法定量检测细胞上清液中胶原Ⅰ（Col-Ⅰ）,胶原Ⅲ（Col-Ⅲ）和纤维黏连蛋白（FN）的水平。结果：TGF-β1可诱导肾小管上皮细胞肌成纤维细胞转分化（TEMT）,TGF-β1诱导组细胞肥大、拉长,呈长梭形,α-SMA表达明显增强,Col-Ⅰ、Col-Ⅲ和FN分泌增加（P〈0.05）。加入不同浓度黄芪后,细胞形态接近正常肾小管上皮细胞形态,α-SMA表达、Col-Ⅰ、Col-Ⅲ和FN分泌均较TGF-β1诱导组明显抑制（P〈0.05）,c-met表达较TGF-β1诱导组增加（P〈0.05）且呈剂量依赖性。结论：TGF-β1可以诱导肾小管上皮细胞肌成纤维细胞转分化,增加细胞外基质成分Col-Ⅰ、Col-Ⅲ和FN的分泌;黄芪能够抑制TGF-β1诱导的NRK52E细胞转分化以及细胞外基质的分泌;黄芪抑制细胞转分化的机制可能与其增强c-met的表达有关。

Astragalus mongholicus may regulate rat renal tubular cell transdifferrentiation induced by TGF-β1 through C-met dependent pathway

Objective：To observe the effect and mechanism of Astragalus mongholicus on tubular epithelial - myofibmblast transdifferentiation and the secretion of extra cellular matrix （ECM） induced by TGF β1- Methods： Normal rats＇ tubular epithelial cells NRK52E were cultured in vitro, their morphological changes were observed by inverted phase contrast microscope, a - smooth muscle actin （a-SMA） and the receptor of hepatocyte growth factor（c- met）proteins and genes expression were assessed by irnmunohistochemistry and realtime quantitative polymerase chain reaction. The collagen I , collagen Ⅲ and fibronectin was measured by ELISA. Results：TGF- β1 could induce tubular epithelial - myofibroblast transdifferentiation, showing hypertrophy of cells elongated and fusiforrn - shaped, with significantly enhanced expression of a - SMA and increased secretion of Col - I , Col -Ⅲ and FN（ P 〈 0.05）. After adding of Astragalus mongholieus at different concentrations, the morphology of cells restored close to normal phenotype, with the expression of a- SMA and the secretion of Col - i , Col-Ⅲ and FN significantly inhibited （P 〈 0.05） and the expression of c - met significantly increased （ P 〈 0.05 ） in dose - dependent manner. Conclusion： TGF - β1 can induce tubular ep- ithelial - myofibroblast transdifferentiation and increase the level of collagen I , collagen Ⅲ and fibronectin. Astragalus mongholicus could inhibit transdifferentiation of NRK52E induced by TGF - β1 and decrease the secretion of collagen I , collagen Ⅲ and fibronectin. The effect of Astragalus mongholicus on transdifferentiation may be associated with the increased expression of c met.