Abstract：
Circular RNAs (circRNAs) are functional molecules in all kinds of fibrosis diseases. The current study was performed for the exploration of circ_0007535 in pulmonary fibrosis. RNA levels for circ_0007535, miR-18a-5p, and transforming growth factor-β receptor 1 (TGFBR1) were assayed via a reverse transcription-quantitative polymerase chain reaction. Cell growth was determined by cell counting kit-8 assay for viability and ethynyl-2\'-deoxyuridine assay for proliferation. Cell invasion and migration were examined by transwell assay and scratch assay. Western blot was performed for the detection of different proteins. Enzyme-linked immunosorbent assay was used to assess inflammatory response. The interaction analysis was conducted using dual-luciferase reporter assay, RNA immunoprecipitation assay, and biotin-coupled pull-down assay. Circ_0007535 was significantly upregulated by TGF-β1 in HFL1 cells. TGF-β1-induced proliferation, motility, ECM accumulation, and inflammatory reaction in HFL1 cells were alleviated by circ_0007535 knockdown. Circ_0007535 exhibited interaction with miR-18a-5p, and miR-18a-5p inhibition reversed all influences of circ_0007535 downregulation in TGF-β1-treated HFL1 cells. Circ_0007535 acted as a miR-18a-5p sponge to regulate the expression of downstream target TGFBR1. MiR-18a-5p induced TGFBR1 level inhibition to attenuate TGF-β1-mediated cell injury in HFL1 cells. This study evidenced that circ_0007535 facilitated TGF-β1-induced pulmonary fibrosis by depending on the absorption of miR-18a-5p to upregulate TGFBR1.
摘要：
环状RNA(circularRNAs,circRNAs)是各种纤维化疾病中的功能分子。本研究是为了探索circ_0007535在肺纤维化中的作用。circ_0007535,miR-18a-5p,和转化生长因子-β受体1（TGFBR1）通过逆转录定量聚合酶链反应进行测定。通过细胞计数试剂盒-8测定活力和乙炔基-2'-脱氧尿苷测定增殖来测定细胞生长。通过transwell测定和划痕测定检查细胞侵袭和迁移。进行蛋白质印迹以检测不同的蛋白质。酶联免疫吸附试验用于评估炎症反应。相互作用分析使用双荧光素酶报告基因测定进行，RNA免疫沉淀测定，和生物素偶联下拉法。TGF-β1在HFL1细胞中显著上调Circ_0007535。TGF-β1诱导的增殖，运动性,ECM积累，通过circ_0007535敲除减轻HFL1细胞的炎症反应。Circ_0007535表现出与miR-18a-5p的相互作用，和miR-18a-5p抑制逆转了TGF-β1处理的HFL1细胞中circ_0007535下调的所有影响。Circ_0007535作为miR-18a-5p海绵调控下游靶TGFBR1的表达。MiR-18a-5p诱导TGFBR1水平抑制以减轻TGF-β1介导的HFL1细胞损伤。该研究证明circ_0007535通过依赖于miR-18a-5p的吸收来上调TGFBR1促进TGF-β1诱导的肺纤维化。
