Fu Hui-Ting, Zhang Yan, Zhang Ping, Wu Huan, Sun Xuan-Qiu, Shen Shu-Yang, Dou Dan-Bo
Department of Traditional Medicine, Shuguang Hospital affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Department of Ultrasound, Shuguang Hospital affiliated to Shanghai University of Traditional Chinese Medicine, Shanghai, China.
Transl Cancer Res. 2021 Sep;10(9):4047-4056. doi: 10.21037/tcr-20-3375.
Airway mucus acts as an indispensable protective component of innate immune response against invading pathogens. However, airway mucus hypersecretion, largely consisting of mucin 5AC (MUC5AC), is the leading cause of airflow obstruction and airway hyperresponsiveness that contributes to chronic obstructive pulmonary disease (COPD). MicroRNAs (miRNAs) are frequently dysregulated in the pathogenesis of COPD, but the definite role of miRNAs in airway mucus hypersecretion is not well understood.
A cell model of mucus hypersecretion was established in 16HBE cells by treatment with TNF-α. Cell viability and apoptosis were assessed using cell counting kit-8 (CCK-8) and flow cytometry, respectively. The aberrant expression of miR-146a-5p and miR-134-5p was assayed in TNF-α-treated 16HBE cells, and the effect of miR-146a-5p and miR-134-5p on regulating MUC5AC expression was evaluated using quantitative real-time PCR (qPCR) and Western blot analysis.
TNF-α treatment resulted in a significant decrease of cell viability, and increase of cell apoptosis and MUC5AC expression in 16HBE cells. Additionally, the expression of miR-134-5p and miR-146a-5p was markedly decreased in the cell model. Importantly, forced expression of miR-134-5p and miR-146a-5p significantly repressed TNF-α-induced upregulation of MUC5AC. Mechanistically, although miR-134-5p did not affect 16HBE cells viability and apoptosis, miR-134-5p partially blocked TNF-α-induced MUC5AC expression by inhibiting the activation of NF-κB signaling. On the other hand, miR-146a-5p enhanced cell viability and reduced cell apoptosis. miR-146a-5p also repressed TNF-α-induced MUC5AC expression by inhibiting p38 MAPK (mitogen-activated protein kinase) signaling activation.
The current data demonstrated that both miR-134-5p and miR-146a-5p conferred protection against TNF-α-induced mucus hypersecretion through repressing NF-κB and p38 MAPK signaling, indicating that miR-134-5p and miR-146a-5p may serve as the biomarker for COPD.
气道黏液是机体抵御病原体入侵的固有免疫反应中不可或缺的保护成分。然而，气道黏液高分泌主要由黏蛋白5AC（MUC5AC）组成，是气流阻塞和气道高反应性的主要原因，而气流阻塞和气道高反应性会导致慢性阻塞性肺疾病（COPD）。微小RNA（miRNA）在COPD发病机制中常出现失调，但miRNA在气道黏液高分泌中的具体作用尚不清楚。
用肿瘤坏死因子-α（TNF-α）处理16HBE细胞，建立黏液高分泌细胞模型。分别使用细胞计数试剂盒-8（CCK-8）和流式细胞术评估细胞活力和凋亡情况。检测TNF-α处理的16HBE细胞中miR-146a-5p和miR-134-5p的异常表达，并使用定量实时聚合酶链反应（qPCR）和蛋白质免疫印迹分析评估miR-146a-5p和miR-134-5p对调节MUC5AC表达的影响。
TNF-α处理导致16HBE细胞活力显著降低，细胞凋亡增加，MUC5AC表达增加。此外，在该细胞模型中，miR-134-5p和miR-146a-5p的表达明显降低。重要的是，强制表达miR-134-5p和miR-146a-5p可显著抑制TNF-α诱导的MUC5AC上调。机制上，虽然miR-134-5p不影响16HBE细胞活力和凋亡，但miR-134-5p通过抑制核因子-κB（NF-κB）信号通路的激活部分阻断TNF-α诱导的MUC5AC表达。另一方面，miR-146a-5p增强细胞活力并减少细胞凋亡。miR-146a-5p还通过抑制p38丝裂原活化蛋白激酶（MAPK）信号通路的激活来抑制TNF-α诱导的MUC5AC表达。
目前的数据表明，miR-134-5p和miR-146a-5p均可通过抑制NF-κB和p38 MAPK信号通路来抵御TNF-α诱导的黏液高分泌，这表明miR-134-5p和miR-146a-5p可能作为COPD的生物标志物。
