Lipopolysaccharide (LPS)-treated WI-38 cells were used as cell injury models of IP. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of circ_ZNF652, miR-302e and Toll-like receptor 4 (TLR4). 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium Bromide (MTT) assay, thymidine analog 5-ethynyl-2\'-deoxyuridine (EdU) assay, and flow cytometry assay were utilized to explore cell functions. Western blot was employed to examine the protein levels of PCNA, Bcl-2, Bax, and TLR4. ELISA was used to detect the release of inflammatory cytokines. The relationship between miR-302e and circ_ZNF652 or TLR4 was verified by dual-luciferase reporter assay and RNA pull down assay.
Circ_ZNF652 was significantly up-regulated in serum of IP patients and LPS-induced WI-38 cells. Silencing circ_ZNF652 enhanced cell proliferation and inhibited cell apoptosis in LPS-induced WI-38 cells. MiR-302e was identified as a target of circ_ZNF652, and knockdown of circ_ZNF652 alleviated LPS-induced WI-38 cell injuries by up-regulating miR-302e. In addition, TLR4 was a downstream target of miR-302e. Overexpression of TLR4 recovered cell apoptosis and inflammation that were repressed by miR-302e enrichment in LPS-induced WI-38 cells.
Circ_ZNF652 regulates the expression of TLR4 by regulating miR-302e, thereby mediating cell proliferation, apoptosis and inflammation. The results provide a novel targeted therapy for IP.
使用脂多糖(LPS)处理的WI-38细胞作为IP的细胞损伤模型。采用实时定量聚合酶链反应(qRT-PCR)检测circ_ZNF652、miR-302e和Toll样受体4(TLR4)的表达。3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四唑溴化物(MTT)测定,胸苷类似物5-乙炔基-2'-脱氧尿苷(EdU)测定,和流式细胞术测定用于探索细胞功能。采用Westernblot检测PCNA蛋白水平,Bcl-2,Bax,TLR4ELISA法检测炎性细胞因子的释放。miR-302e与circ_ZNF652或TLR4之间的关系通过双荧光素酶报告基因测定和RNA下拉法进行验证。
Circ_ZNF652在IP患者血清和LPS诱导的WI-38细胞中显著上调。沉默circ_ZNF652可增强LPS诱导的WI-38细胞增殖并抑制细胞凋亡。miR-302e被鉴定为circ_ZNF652的靶标,敲低circ_ZNF652通过上调miR-302e减轻LPS诱导的WI-38细胞损伤。此外,TLR4是miR-302e的下游靶标。TLR4的过表达恢复了在LPS诱导的WI-38细胞中被miR-302e富集抑制的细胞凋亡和炎症。
Circ_ZNF652通过调节miR-302e调节TLR4的表达,从而介导细胞增殖,细胞凋亡和炎症。该结果为IP提供了新的靶向治疗。