Overexpression of PTEN suppresses lipopolysaccharide-induced lung fibroblast proliferation, differentiation and collagen secretion through inhibition of the PI3-K-Akt-GSK3beta pathway.
Overexpression of PTEN suppresses lipopolysaccharide-induced lung fibroblast proliferation, differentiation and collagen secretion through inhibition of the PI3-K-Akt-GSK3beta pathway.
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PTEN 过表达通过抑制 PI3-K-Akt-GSK3beta 通路抑制脂多糖诱导的肺成纤维细胞增殖、分化和胶原蛋白分泌
DOI：
10.1186/2045-3701-4-2
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发表时间：
2014-01-06
影响因子：
7.5
通讯作者：
Wang X
中科院分区：
文献类型：
--
作者：
He Z;Deng Y;Li W;Chen Y;Xing S;Zhao X;Ding J;Gao Y;Wang X
肺成纤维细胞异常且不受控制的增殖可能会导致肺纤维化。脂多糖（LPS）可通过激活磷酸肌醇3-激酶（PI3-K）通路诱导成纤维细胞增殖与分化。然而，LPS促进肺纤维化发展的具体机制尚不清楚。为了研究PI3-K通路抑制因子——磷酸酶及张力蛋白同源物（PTEN）对LPS诱导的肺成纤维细胞增殖、分化、胶原蛋白分泌以及PI3-K激活的作用，我们将PTEN过表达慢病毒转染至经LPS处理或未经LPS处理的培养小鼠肺成纤维细胞中，通过MTT法和流式细胞术检测细胞增殖情况。采用蛋白质免疫印迹法或实时逆转录聚合酶链反应（real - time RT - PCR）检测PTEN、α - 平滑肌肌动蛋白（α - SMA）、糖原合成酶激酶3β（GSK3β）的表达以及Akt的磷酸化水平。通过孔雀石绿法检测PTEN的磷酸酶活性。采用酶联免疫吸附试验（ELISA）检测细胞培养上清液中I型前胶原C端前肽（PICP）的含量。
我们发现，PTEN过表达可有效提高PTEN的表达水平及磷酸酶活性，同时抑制LPS诱导的成纤维细胞增殖、分化和胶原蛋白分泌。LPS诱导的PTEN过表达转染细胞中，Akt的磷酸化水平以及GSK3β蛋白的表达水平显著低于LPS诱导的未转染细胞，而PTEN抑制剂bpV（phen）可逆转这一现象。
综上所述，我们的研究结果表明，PTEN的过表达及其磷酸酶活性的增强，可通过使PI3 - K - Akt - GSK3β信号通路失活，抑制LPS诱导的肺成纤维细胞增殖、分化和胶原蛋白分泌，而选择性PTEN抑制剂可消除这种抑制作用。因此，PTEN的表达及其磷酸酶活性可能是LPS诱导的肺纤维化的潜在治疗靶点。与PTEN表达水平相比，PTEN的磷酸酶活性在影响肺成纤维细胞增殖、分化和胶原蛋白分泌方面更为关键。
BackgroundAbnormal and uncontrolled proliferation of lung fibroblasts may contribute to pulmonary fibrosis. Lipopolysaccharide (LPS) can induce fibroblast proliferation and differentiation through activation of phosphoinositide3-Kinase (PI3-K) pathway. However, the detail mechanism by which LPS contributes to the development of lung fibrosis is not clearly understood. To investigate the role of phosphatase and tensin homolog (PTEN), a PI3-K pathway suppressor, on LPS-induced lung fibroblast proliferation, differentiation, collagen secretion and activation of PI3-K, we transfected PTEN overexpression lentivirus into cultured mouse lung fibroblasts with or without LPS treatment to evaluate proliferation by MTT and Flow cytometry assays. Expression of PTEN, alpha-smooth muscle actin (alpha-SMA), glycogen synthase kinase 3 beta (GSK3beta) and phosphorylation of Akt were determined by Western-blot or real-time RT-PCR assays. The PTEN phosphorylation activity was measured by a malachite green-based assay. The content of C-terminal propeptide of type I procollagen (PICP) in cell culture supernatants was examined by ELISA.ResultsWe found that overexpression of PTEN effectively increased expression and phosphatase activity of PTEN, and concomitantly inhibited LPS-induced fibroblast proliferation, differentiation and collagen secretion. Phosphorylation of Akt and GSK3beta protein expression levels in the LPS-induced PTEN overexpression transfected cells were significantly lower than those in the LPS-induced non-transfected cells, which can be reversed by the PTEN inhibitor, bpV(phen).ConclusionsCollectively, our results show that overexpression and induced phosphatase activity of PTEN inhibits LPS-induced lung fibroblast proliferation, differentiation and collagen secretion through inactivation of PI3-K-Akt-GSK3beta signaling pathways, which can be abrogated by a selective PTEN inhibitor. Thus, expression and phosphatase activity of PTEN could be a potential therapeutic target for LPS-induced pulmonary fibrosis. Compared with PTEN expression level, phosphatase activity of PTEN is more crucial in affecting lung fibroblast proliferation, differentiation and collagen secretion.
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影响因子：
64.5
作者：
Brunet, A;Bonni, A;Greenberg, ME
通讯作者：
Greenberg, ME
影响因子：
5
作者：
Beckner, ME;Gobbel, GT;Pollack, IF
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64.8
作者：
CROSS, DAE;ALESSI, DR;HEMMINGS, BA
通讯作者：
HEMMINGS, BA