Department of Respiratory Medicine, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, People's Republic of China.
Department of Intensive Care Unit, The Third Affiliated Hospital of Soochow University, Changzhou, Jiangsu, People's Republic of China.
Int J Chron Obstruct Pulmon Dis. 2023 May 15;18:859-870. doi: 10.2147/COPD.S405566. eCollection 2023.
Chronic obstructive pulmonary disease (COPD) is a common respiratory disease with irreversible and progressive obstruction of airflow. Currently, there are no clinically available treatments to prevent COPD progression. Apoptosis of human lung microvascular endothelial cells (HPMECs) and bronchial epithelial cells (HBECs) is often observed in COPD, but its pathogenesis has not been fully elucidated. LncRNA maternally expressed gene 3 (MEG3) is closely related to CSE-induced apoptosis, but the specific mechanism of MEG3 in COPD is still unknown.
In the present study, cigarette smoke extract (CSE) is used to treat HPMECs and HBECs. Flow cytometry assay is used to detect the apoptosis of these cells. The expression of MEG3 in CSE-treated HPMECs and HBECs is detected by qRT-PCR. LncBase v.2 is used to predict miRNAs binding to MEG3, and miR-421 is found to bind to MEG3. Dual luciferase report analysis and RNA immunoprecipitation experiment jointly clarified the binding relationship between MEG3 and miR-421.
MiR-421 was downregulated in CSE-treated HPMECs/HBECs, and miR-421 overexpression mitigated CSE-induced apoptosis in these cells. Subsequently, DFFB was found to be directly targeted by miR-421. The overexpression of miR-421 dramatically reduced the expression level of DNA fragmentation factor subunit beta (DFFB). DFFB was found downregulated in CSE-treated HPMECs and HBECs. MEG3 contributed to the apoptosis of HPMECs and HBECs induced by CSE by regulating the miR-421/DFFB axis.
This study presents a new perspective on the diagnosis and treatment of COPD caused by CSE.
慢性阻塞性肺疾病（COPD）是一种常见的呼吸道疾病，其特征为气流不可逆性和进行性受限。目前，尚无临床可用的治疗方法来阻止 COPD 的进展。COPD 患者常出现人肺微血管内皮细胞（HPMEC）和支气管上皮细胞（HBEC）凋亡，但其发病机制尚未完全阐明。长链非编码 RNA 母源性表达基因 3（MEG3）与 CSE 诱导的细胞凋亡密切相关，但 MEG3 在 COPD 中的具体作用机制尚不清楚。
本研究采用香烟烟雾提取物（CSE）处理 HPMEC 和 HBEC，流式细胞术检测细胞凋亡情况，qRT-PCR 检测 CSE 处理的 HPMEC 和 HBEC 中 MEG3 的表达。LncBase v.2 预测与 MEG3 结合的 miRNA，发现 miR-421 与 MEG3 结合。双荧光素酶报告分析和 RNA 免疫沉淀实验共同阐明了 MEG3 与 miR-421 的结合关系。
CSE 处理的 HPMEC/HBEC 中 miR-421 表达下调，miR-421 过表达可减轻 CSE 诱导的细胞凋亡。随后发现 DFFB 是 miR-421 的直接靶基因。miR-421 过表达显著降低了 DNA 片段化因子亚基β（DFFB）的表达水平。CSE 处理的 HPMEC 和 HBEC 中 DFFB 表达下调。MEG3 通过调控 miR-421/DFFB 轴促进 CSE 诱导的 HPMEC 和 HBEC 凋亡。
本研究为 CSE 引起的 COPD 的诊断和治疗提供了新视角。
