lncRNA MEG8通过调控miR-367-3p/PTEN介导慢性阻塞性肺疾病发展的分子机制研究

Investigation of the molecular mechanisms by which lncRNA MEG8 mediate the development of chronic obstructive pulmonary disease by regulating miR-367-3p/PTEN

目的 探究长链非编码RNA(lncRNA)MEG8通过调控miR-367-3p/磷酸酶张力蛋白同源物基因(PTEN)介导慢性阻塞性肺疾病(COPD)发展的分子机制。方法 采用实时荧光定量聚合酶链反应(qPCR)检测16HBE细胞和COPD组织lncRNA MEG8表达水平;在香烟烟雾提取物(CSE)刺激后的16HBE细胞中过表达lncRNA MEG8及加入miR-367-3p inhibitor后同时敲减lncRNA MEG8或PTEN,采用MTT法、流式细胞术、酶联免疫吸附试验和免疫印迹法检测细胞凋亡、细胞增殖和炎症因子水平的变化;利用双荧光素酶报告系统对lncRNA MEG8、miR-367-3p、PTEN的靶向关系进行验证。结果 MEG8在CSE刺激的16HBE细胞和COPD临床组织样本中表达降低(P<0.05)。相比于CSE组,过表达MEG8后CSE刺激的16HBE细胞凋亡和炎症因子白细胞介素(IL)-1β、IL-6和肿瘤坏死因子(TNF)-α水平降低(P<0.05),促凋亡蛋白Bax、Caspase3和Cleaved-caspase3表达水平降低(P<0.05),凋亡抑制因子Bcl-2表达水平升高(P<0.05)。双荧光素酶报告基因实验验证了MEG8可靶向抑制miR-367-3p(P<0.05),同时miR-367-3p可靶向抑制PTEN的表达(P<0.05),进而抑制CSE刺激的16HBE细胞的凋亡和炎症反应(P<0.05)。在CSE刺激下,相较于Control组,加入miR-367-3p inhibitor可显著上调16HBE细胞中PTEN的蛋白表达水平(P<0.05),增强细胞增殖活性(P<0.05),减少细胞凋亡(P<0.05),显著下调促凋亡蛋白Bax、Caspase 3和Cleaved-caspase3的表达水平(P<0.05),上调抗凋亡蛋白Bcl-2的表达水平(P<0.05),抑制炎症因子IL-1β、IL-6和TNF-α的水平(P<0.05),随后敲降MEG8或PTEN可恢复PTEN的蛋白表达水平(P<0.05),抑制细胞增殖活性(P<0.05),逆转miR-367-3p inhibitor导致的细胞凋亡(P<0.05)以及对凋亡相关蛋白的调控作用(P<0.05),增强炎症因子IL-1β、IL-6和TNF-α的水平(P<0.05)。结论 MEG8通过调控miR-367-3p/PTEN轴抑制CSE刺激的16HBE细胞的凋亡和炎症反应,并可能为临床COPD的治疗提供新的治疗策略。

Objective Explore the molecular mechanism by which long chain non-coding(lncRNA)MEG8 regulates the development of chronic obstructive pulmonary disease(COPD)mediated by miR-367-3p/phosphatase and tensin homolog(PTEN).Methods Real time fluorescence quantitative polymerase chain reaction(qPCR)was used to detect the expression level of lncRNA MEG8 in 16HBE cells and clinical tissues of chronic obstructive pulmonary disease(COPD).MEG8 was overexpressed in 16HBE cells stimulated by cigarette smoke extract(CSE),and MEG8 or PTEN were simultaneously knocked down after the addition of miR-367-3p inhibitor,then MTT assay,flow cytometry,enzyme-linked immunosorbent assay,and immunoblotting were used to detect changes in cell apoptosis,proliferation,and levels of inflammatory factors.The targeting relationships of MEG8,miR-367-3p,and PTEN was verified by using the dual luciferase reporting system.Results MEG8 expression was reduced in CSE stimulated 16HBE cells and COPD clinical tissue samples(P<0.05).Compared to the CSE group,overexpression of MEG8 stimulated apoptosis and inflammatory factor interleukin(IL)-1β,IL-6 and tumor necrosis factor(TNF)-αlevels decreased(P<0.05)in 16HBE cells stimulated by CSE.The expression levels of proapoptotic proteins Bax,Caspase3,and Cleared caspase3 decreased(P<0.05),and the expression level of apoptosis inhibitory factor Bcl-2 increased(P<0.05).The double luciferase Reporter gene experiment verified that MEG8 can target to inhibit miR-367-3p(P<0.05),and miR-367-3p can target to inhibit the expression of PTEN(P<0.05),thereby inhibiting the apoptosis and inflammatory response of 16HBE cells stimulated by CSE(P<0.05).Under CSE stimulation,compared to the Control group,the addition of miR-367-3p inhibitor significantly upregulated the protein expression level of PTEN in 16HBE cells(P<0.05),enhanced cell proliferation activity(P<0.05),reduced cell apoptosis(P<0.05),significantly downregulated the expression levels of proapoptotic proteins Bax,Caspase 3,and Cleared caspase 3(P<0.05),upregulated the expression level of anti apoptotic protein Bcl-2(P<0.05),and suppressed the inflammatory factor IL-1β,IL-6 and TNF-αKnocking down MEG8 or PTEN can restore the protein expression level of PTEN(P<0.05),inhibit cell proliferation activity(P<0.05),r everse cell apoptosis caused by miR-367-3p inhibitor(P<0.05),and regulate apoptosis related proteins(P<0.05),and enhance the inflammatory factor IL-1β,IL-6 and TNF-αThe level of(P<0.05).Conclusion MEG8 inhibits the apoptosis and inflammatory response of 16HBE cells stimulated by CSE by regulating miR-367-3p/PTEN molecular axis,and may provide a potential molecular target for the treatment of COPD.