METHODS: COPD-like cell injury was induced by treating human bronchial epithelioid cells (16HBE) with cigarette smoke extract (CSE). The expression of circ_0000157, miR-149-5p, bromodomain containing 4 (BRD4), BCL2-associated x protein (Bax) and B-cell lymphoma-2 (Bcl-2) was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) or Western blotting. Enzyme-linked immunosorbent assay was performed to detect interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels. Malondialdehyde (MDA) production was detected by a lipid peroxidation MDA assay kit. Superoxide dismutase (SOD) activity was analyzed by a SOD activity assay kit.
RESULTS: Circ_0000157 and BRD4 expression were upregulated, while miR-149-5p expression was downregulated in the blood of smokers with COPD and CSE-induced 16HBE cells compared with control groups. CSE treatment inhibited 16HBE cell proliferation and induced cell apoptosis, inflammation, and oxidative stress; however, these effects were remitted when circ_0000157 expression was decreased. In addition, circ_0000157 acted as a miR-149-5p sponge and regulated CSE-caused 16HBE cell damage by targeting miR-149-5p. The overexpression of BRD4, a target gene of miR-149-5p, attenuated the inhibitory effects of miR-149-5p introduction on CSE-induced cell damage. Further, circ_0000157 modulated BRD4 expression by associating with miR-149-5p in CSE-treated 16HBE cells.
CONCLUSIONS: Circ_0000157 knockdown ameliorated CSE-caused 16HBE cell damage by targeting the miR-149-5p/BRD4 pathway, providing a potential therapeutic strategy for clinic intervention in COPD.
方法:用香烟烟雾提取物(CSE)处理人支气管上皮样细胞(16HBE)诱导COPD样细胞损伤。circ_0000157,miR-149-5p,含溴结构域4(BRD4),通过定量实时聚合酶链反应(qRT-PCR)或Western印迹分析BCL2相关的x蛋白(Bax)和B细胞淋巴瘤2(Bcl-2)。采用酶联免疫吸附法检测白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)水平。通过脂质过氧化MDA测定试剂盒检测丙二醛(MDA)的产生。通过SOD活性测定试剂盒分析超氧化物歧化酶(SOD)活性。
结果:Circ_0000157和BRD4表达上调,而与对照组相比,患有COPD和CSE诱导的16HBE细胞的吸烟者血液中miR-149-5p表达下调。CSE处理抑制16HBE细胞增殖,诱导细胞凋亡,炎症,和氧化应激;然而,当circ_0000157表达降低时,这些作用得以缓解。此外,circ_0000157充当miR-149-5p海绵,通过靶向miR-149-5p调节CSE引起的16HBE细胞损伤。miR-149-5p的靶基因BRD4的过表达,降低miR-149-5p导入对CSE诱导的细胞损伤的抑制作用。Further,circ_0000157通过与CSE处理的16HBE细胞中的miR-149-5p结合来调节BRD4表达。
结论:Circ_0000157敲低通过靶向miR-149-5p/BRD4途径改善CSE引起的16HBE细胞损伤,为COPD的临床干预提供潜在的治疗策略。