枇杷叶三萜酸对TGF-β_1刺激的人胚肺成纤维细胞转分化及ERK通路的影响

The mechanism of Triterpene acids of loquat on transforming growth factor-β_1(TGF-β_1) induced lung fibroblast-myofibroblast transdifferentiation and ERK1/2 signaling way

目的研究枇杷叶三萜酸(Triterpene acids of loquat,TAL)对转化生长因子β1(TGF-β1)刺激人胚肺成纤维细胞转分化、胶原合成及ERK通路的影响。方法体外培养人胚肺成纤维细胞(HFL-Ⅰ),MTT比色法测定TAL对HFL-Ⅰ细胞的增殖抑制率。RT-PCR检测每组中结缔组织生长因子(connective tissue growth factor,CTGF)、平滑肌肌动蛋白(α-smooth muscle actin,α-SMA)、Ⅰ型胶原(CⅠ)、Ⅲ型胶原(CⅢ)mRNA的水平,Western blot检测各组细胞中p-ERK1/2和ERK1/2表达水平。结果 TAL呈剂量和时间依赖性抑制HFL-Ⅰ细胞的增殖(P<0.05),并能够降低CⅠ、CⅢ、α-SMA、CTGF的过度表达(P<0.05);Western blot结果显示TAL能降低TGF-β1刺激组p-ERK1/2的表达,而对ERK1/2的表达没有差异。结论 TAL能抑制HFL-Ⅰ的增殖,同时也能使活化后HFL-Ⅰ中的α-SMA生成减少,CTGF、胶原和p-ERK1/2表达降低。

Aim To investigate the effects of Triterpene acids of loquat（TAL）on transforming growth factor-β1（TGF-β1）induced human fetal lung fibroblasts transdifferentiation,connective tissue growth factor（CTGF）,collagen expression and ERK pathway.Methods Human fetal lung fibroblasts（HFL-Ⅰ） were cultured in vitro,TAL on HFL-Ⅰ cell proliferation rate was assayed by MTT colorimetric,the levels of CTGF,α-SMA,col-1,col-3 mRNA in each group were evaluated by RT-PCR,and the expression levels of P-ERK1/2 and total-ERK1/2 in each group were detected by Western blot.Results The proliferation of HFL-Ⅰ cells was inhibited by TAL in a dose-and-time dependent manner.the results of RT-PCR showed that TAL（50 mg·L-1） could reduce the overexpression of type 1 collagen,type 3 collagen,α-SMA and CTGF（P0.05）;the results of Western blot showed that TAL could reduce the expression of the P-ERK1/2 in TGF-β1 group,while total ERK1/2 expression was of no significant difference.Conclusion TAL can inhibit the proliferation of HFL-Ⅰ and reduce the production of α-SMA,suggesting that TAL can inhibit the activation of HFL-Ⅰ stimulated by TGF-β1.It also can inhibit the over-expression of CTGF and CⅠ and CⅢ,reduce the accumulation of extracellular matrix,as well as inhibit and delay the expression of p-ERK1/2.TAL may play against the pulmonary fibrosis through these mechanisms.