Yang Tao, Liang Ying, Lin Qinlu, Liu Junwen, Luo Feijun, Li Xinhua, Zhou Hui, Zhuang Sheng, Zhang Hongliang
National Engineering Laboratory for Rice and By-product Deep Processing, Central South University of Forestry and Technology, Changsha 410004, Hunan Province, People's Republic of China.
J Cell Biochem. 2013 Jun;114(6):1336-42. doi: 10.1002/jcb.24474.
TGFβ1 is very important in the synthesis and degradation of extracellular matrix, and also in the mediation of human lung fibroblasts proliferation, and miR-29 plays an important role in this process. To explore the interactions of miR-29 family members and TGFβ1, the effects of transforming growth factor TGFβ1 on the expression of miR-29 and whether miR-29 is involved in pro-survival signaling pathways mediated by TGFβ1 were examined in human lung fibroblasts. Treatment of the human embryonic lung fibroblast cell line IMR90 with TGFβ1 caused a decrease in expression of miR-29a/b/c by real-time PCR analysis. TGFβ1 stimulation increased cell proliferation, colony formation and up-regulated expression of COL1A1; transfecting with miR-29a/b/c mimics reverse TGFβ1-induced phenotype changes in IMR90 cells. Western blot analyses showed that TGFβ1 treatment unchanged total protein expression levels of PI3K or AKT, but the expression levels of p-PI3K, p-AKT, and COL1A1 were increased; and miR-19a/b/c mimics interfering blocked phosphorylation of PI3K or AKT and decreased expression of COL1A1 after TGFβ1 treatment. The results indicate that TGFβ1 beta uses the PI3k-Akt pathway in these embryonic fibroblasts and miR29 blocks this activation pathway. It indicates a novel biological function of the PI3K-Akt pathway in IMR90. Elevated expression of miR-29 may play an important role in the pathogenesis of diseases related to fibrogenic reactions in human lung fibroblasts.
转化生长因子β1（TGFβ1）在细胞外基质的合成与降解中非常重要，在介导人肺成纤维细胞增殖方面也很重要，而微小RNA-29（miR-29）在此过程中发挥重要作用。为了探究miR-29家族成员与TGFβ1的相互作用，在人肺成纤维细胞中检测了转化生长因子TGFβ1对miR-29表达的影响以及miR-29是否参与由TGFβ1介导的促生存信号通路。通过实时定量聚合酶链反应（PCR）分析，用TGFβ1处理人胚肺成纤维细胞系IMR90后，miR-29a/b/c的表达下降。TGFβ1刺激增加了细胞增殖、集落形成并上调了Ⅰ型胶原α1（COL1A1）的表达；用miR-29a/b/c模拟物转染可逆转TGFβ1诱导的IMR90细胞表型变化。蛋白质免疫印迹分析表明，TGFβ1处理未改变磷脂酰肌醇-3激酶（PI3K）或蛋白激酶B（AKT）的总蛋白表达水平，但磷酸化PI3K（p-PI3K）、磷酸化AKT（p-AKT）和COL1A1的表达水平增加；TGFβ1处理后，miR-19a/b/c模拟物干扰可阻断PI3K或AKT的磷酸化并降低COL1A1的表达。结果表明，TGFβ1在这些胚胎成纤维细胞中利用PI3K-Akt信号通路，而miR29阻断了该激活通路。这表明PI3K-Akt信号通路在IMR90细胞中具有一种新的生物学功能。miR-29表达升高可能在人肺成纤维细胞中与纤维化反应相关疾病的发病机制中起重要作用。
