Lysocardiolipin acyltransferase regulates TGF-β mediated lung fibroblast differentiation
Lysocardiolipin acyltransferase regulates TGF-β mediated lung fibroblast differentiation
复制标题
Lysocardiolipin 酰基转移酶调节 TGF-β 介导的肺成纤维细胞分化。
DOI：
10.1016/j.freeradbiomed.2017.07.023
复制
发表时间：
2017-11-01
影响因子：
7.4
通讯作者：
Natarajan, Viswanathan
中科院分区：
文献类型：
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作者：
Huang, Long Shuang;Jiang, Peiyue;Natarajan, Viswanathan
溶血心磷脂酰基转移酶（LYCAT）是一种心磷脂重塑酶，在线粒体功能和血管发育中起关键作用。我们先前报道了外周血单核细胞中LYCAT mRNA水平降低与IPF患者肺功能预后不良和生存率降低相关。进一步LYCAT过表达减少肺纤维化，LYCAT敲低加重实验性肺纤维化。已知NADPH氧化酶4（NOX 4）表达和氧化应激有助于肺成纤维细胞分化和纤维化进展。在这项研究中，我们研究了LYCAT在TGF-β介导的人肺成纤维细胞分化为肌成纤维细胞中的作用，以及这是否通过线粒体超氧化物和NOX 4介导的过氧化氢（H2 O2）产生而发生。我们的数据表明，与对照组相比，LYCAT表达在从IPF患者和博来霉素攻击小鼠分离的原代肺成纤维细胞中上调。在体外，siRNA介导的SMAD 3消耗抑制人肺成纤维细胞中TGF-β刺激的LYCAT表达。ChIP免疫沉淀分析显示TGF-β刺激SMAD 2/3与内源性LYCAT启动子结合，SMAD 2/3结合位点（-179/-183和-540/-544）的突变降低了TGF-β刺激的LYCAT启动子活性。LYCAT过表达减弱TGF-β诱导的人肺成纤维细胞线粒体和细胞内氧化应激、NOX 4表达和分化。此外，用线粒体超氧化物清除剂Mito-TEMPO预处理阻断TGF-β诱导的人肺成纤维细胞的线粒体超氧化物、NOX 4表达和分化。用N 0X 1/N 0X 4抑制剂GKT 137831处理人肺成纤维细胞也减弱了TGF-β诱导的成纤维细胞分化和线粒体氧化应激。总的来说，这些结果表明，LYCAT是TGF-β诱导的肺成纤维细胞分化的负调节剂，通过调节线粒体超氧化物和NOX 4依赖的H2 O2的产生，这可能是一个潜在的治疗目标，为人类肺纤维化。
Lysocardiolipin acyltransferase (LYCAT), a cardiolipin remodeling enzyme, plays a key role in mitochondrial function and vascular development. We previously reported that reduced LYCAT mRNA levels in peripheral blood mononuclear cells correlated with poor pulmonary function outcomes and decreased survival in IPF patients. Further LYCAT overexpression reduced lung fibrosis, and LYCAT knockdown accentuated experimental pulmonary fibrosis. NADPH Oxidase 4 (NOX4) expression and oxidative stress are known to contribute to lung fibroblast differentiation and progression of fibrosis. In this study, we investigated the role of LYCAT in TGF-beta mediated differentiation of human lung fibroblasts to myofibroblasts, and whether this occurred through mitochondrial superoxide and NOX4 mediated hydrogen peroxide (H2O2) generation. Our data indicated that LYCAT expression was up-regulated in primary lung fibroblasts isolated from IPF patients and bleomycin-challenged mice, compared to controls. In vitro, siRNA-mediated SMAD3 depletion inhibited TGF-beta stimulated LYCAT expression in human lung fibroblasts. ChIP immunoprecipitation assay revealed TGF-beta stimulated SMAD2/3 binding to the endogenous LYCAT promoter, and mutation of the SMAD2/3 binding sites (-179/-183 and -540/-544) reduced TGF-beta-stimulated LYCAT promoter activity. Overexpression of LYCAT attenuated TGF-beta-induced mitochondrial and intracellular oxidative stress, NOX4 expression and differentiation of human lung fibroblasts. Further, pretreatment with Mito-TEMPO, a mitochondrial superoxide scavenger, blocked TGF-beta-induced mitochondrial superoxide, NOX4 expression and differentiation of human lung fibroblasts. Treatment of human lung fibroblast with NOX1/NOX4 inhibitor, GKT137831, also attenuated TGF-beta induced fibroblast differentiation and mitochondrial oxidative stress. Collectively, these results suggest that LYCAT is a negative regulator of TGF-beta-induced lung fibroblast differentiation by modulation of mitochondrial superoxide and NOX4 dependent H2O2 generation, and this may serve as a potential therapeutic target for human lung fibrosis.