lncRNA-SNHG1竞争结合miR-326调控TNFSF14和PTBP1促进矽尘诱导肺纤维化的机制研究

The regulation of lncRNAs and miRNAs on the inflammation and fibrotic process are new field in the pathogenesis of silicosis. Our previous research observed that up-regulated miR-326 level could attenuate silica-induced pulmonary fibrosis in mice, and its potential targets TNFSF14, PTBP1 and lncRNA-SNHG1, which could sponge miR-326, were probably key regulator of silicosis. In this project, miR-326 will be used as the starting point, the virus vector technology were utilized to construct over-expression/interference miR-326 model in silica-induced pulmonary fibrosis mice, lung epithelial cells and lung fibroblasts cells, and combine with target genes and lncRNA-SNHG1 plasmid and siRNA transfection to confirm the regulation of miR-326 on TNFSF14 and PTBP1 and reveal the mechanism of lncRNA-SNHG1 regulates TNFSF14 and PTBP1 to promote silica-induced pulmonary fibrosis by competitively binding miR-326. The expected results will help to deepen and improve the content of lncRNAs and miRNAs in the regulation of silicosis process, and provide new targets for the development of ideal therapeutic drugs of silicosis.

lncRNAs与miRNAs调控炎症和肺纤维化是矽肺发病机制研究的新领域。申请者前期研究发现上调miR-326可减轻矽尘诱导的小鼠肺纤维化，且其潜在靶基因TNFSF14和PTBP1及可竞争结合miR-326的lncRNA-SNHG1均可能参与调控矽肺病理进程。本项目拟以miR-326为切入点，运用病毒载体技术构建过表达/干扰miR-326的矽尘诱导小鼠肺纤维化模型及肺上皮细胞、肺成纤维细胞模型，采用靶基因和lncRNA-SNHG1过表达质粒/siRNA转染，通过在整体、细胞和分子水平系统研究，明确miR-326靶向TNFSF14和PTBP1调控矽尘诱导的肺纤维化及阐明lncRNA-SNHG1竞争结合miR-326调控TNFSF14和PTBP1促进矽尘诱导肺纤维化的作用及分子机制。预期结果将有助于深化和完善lncRNAs和miRNAs调控矽肺病的内容，也为研发矽肺病理想治疗药物提供新的靶标。

长期吸入工作环境中含游离二氧化硅的粉尘可引起进行性肺纤维化，导致矽肺。矽肺是世界上危害最严重的职业病之一，研究其发病机制对矽肺的防治具有重要意义。长链非编码RNA(lncRNA)和miRNA在纤维化疾病的病理过程中发挥着重要作用。然而，特异性lncRNA和miRNA在调节矽尘诱导肺纤维化中的作用尚不明确。本研究通过气管内灌注二氧化硅颗粒建立肺纤维化小鼠模型，采用qRT-PCR方法检测lncRNA-SNHG1、miR-326在肺组织和TGF-β1处理的成纤维细胞中的表达。设计siRNA和质粒在成纤维细胞中抑制或过表达lncRNA-SNHG1，并构建miRNA模拟物在体内和体外过表达miR-326的水平研究lncRNA-SNHG1的作用及其分子机制。结果发现lncRNA-SNHG1在小鼠纤维化肺组织和TGF-β1处理的成纤维细胞中高表达。此外，lncRNA-SNHG1高表达促进成纤维细胞的迁移、侵袭和纤维化分子的分泌，而lncRNA-SNHG1低表达则发挥相反的作用。进一步的机制研究表明，miR-326是lncRNA-SNHG1的潜在靶点。在小鼠肺组织和成纤维细胞中lncRNA-SNHG1的表达水平与miR-326呈明显负相关。结合在二氧化硅颗粒暴露小鼠模型中过表达miR-326可以减轻肺纤维化的作用，本研究发现lncRNA-SNHG1通过调控miR-326，从而加速成纤维细胞向肌成纤维细胞的转化，促进肺纤维化的发展。本研究还发现miR-326可以通过靶向TNFSF14和PTBP1抑制二氧化硅诱导的肺部炎症和促进成纤维细胞的自噬活性，以及miR-503和miR-138可以通过抑制上皮间质转化、成纤维细胞的激活和肌成纤维细胞的分化也参与了二氧化硅诱导肺纤维化的调控。本研究揭示了lncRNA-SNHG1通过调控miR-326促进肺纤维化的关键机制，为矽肺的潜在治疗靶点研究提供实验资料。