Department of Plastic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Department of Plastic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Eur J Pharmacol. 2019 Nov 5;862:172531. doi: 10.1016/j.ejphar.2019.172531. Epub 2019 Jul 10.
Bronchial and alveolar epithelial cell apoptosis is a vital step in smoke-induced lung injury. We investigated whether and how microRNA (miRNA) Let-7f-1-3p would regulate smoke-induced apoptosis in bronchial and alveolar epithelial cells. Human small airway epithelial cells (HSAEC) and human pulmonary alveolar epithelial cells (HPAEpiC) were cultured using an air-liquid interface cell culture system. These cells were treated with Let-7f-1-3p agomir or antagomir for 24 h before smoke exposure or sham operation, after which the cells were rinsed and cultured for 24 h before cell viability, apoptosis, cytolysis, Caspase-9/8/3 activity assays, quantitative real-time polymerase chain reaction and Western blot. Bioinformatic and luciferase reporter assays were performed to predict or verify the target gene of Let-7f-1-3p. We found that smoke exposure significantly reduced Let-7f-1-3p expression level in HSAEC and HPAEpiC. Let-7f-1-3p agomir significantly attenuated cell apoptosis, cytolysis and Caspase-3, -8 and -9 activation while rescuing cell viability of smoke-exposed HSAEC and HPAEpiC. Let-7f-1-3p agomir downregulated tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), Fas ligand (FasL) and B-cell lymphoma-2 (Bcl2)-like protein 11 (Bim) protein level in HSAEC and HPAEpiC. Forkhead box-O1 (FOXO1) was verified as a putative regulatory target of Let-7f-1-3p. Smoke exposure increased FOXO1 mRNA and protein level in HSAEC and HPAEpiC, which was attenuated by Let-7f-1-3p agomir treatment. FOXO1 inhibition by small-molecule drug partially attenuated the increase in smoke-exposed HSAEC and HPAEpiC apoptosis, cytolysis and the decrease in cell viability caused by Let-7f-1-3p antagomir treatment. We concluded Let-7f-1-3p attenuated smoke-induced apoptosis in HSAEC and HPAEpiC by targeting FOXO1.
支气管和肺泡上皮细胞凋亡是烟雾诱导肺损伤的一个重要步骤。我们研究了 microRNA (miRNA) Let-7f-1-3p 是否以及如何调节支气管和肺泡上皮细胞的烟雾诱导凋亡。用人小气道上皮细胞（HSAEC）和人肺泡上皮细胞（HPAEpiC）进行气液界面细胞培养系统培养。这些细胞在用 Let-7f-1-3p agomir 或 antagomir 处理 24 小时后进行烟雾暴露或假手术，然后冲洗细胞并培养 24 小时，进行细胞活力、细胞凋亡、细胞溶解、Caspase-9/8/3 活性测定、实时定量聚合酶链反应和 Western blot。生物信息学和荧光素酶报告基因实验用于预测或验证 Let-7f-1-3p 的靶基因。我们发现，烟雾暴露显著降低了 HSAEC 和 HPAEpiC 中的 Let-7f-1-3p 表达水平。Let-7f-1-3p agomir 显著减弱了烟雾暴露的 HSAEC 和 HPAEpiC 的细胞凋亡、细胞溶解和 Caspase-3、-8 和 -9 的激活，同时挽救了细胞活力。Let-7f-1-3p agomir 下调了肿瘤坏死因子相关凋亡诱导配体（TRAIL）、Fas 配体（FasL）和 B 细胞淋巴瘤-2（Bcl2）样蛋白 11（Bim）在 HSAEC 和 HPAEpiC 中的蛋白水平。叉头框 O1（FOXO1）被验证为 Let-7f-1-3p 的一个潜在调节靶点。烟雾暴露增加了 HSAEC 和 HPAEpiC 中的 FOXO1 mRNA 和蛋白水平，而 Let-7f-1-3p agomir 处理则减弱了这一作用。小分子药物抑制 FOXO1 部分减弱了 Let-7f-1-3p antagomir 处理引起的烟雾暴露的 HSAEC 和 HPAEpiC 凋亡、细胞溶解和细胞活力下降。我们得出结论，Let-7f-1-3p 通过靶向 FOXO1 来减弱 HSAEC 和 HPAEpiC 中的烟雾诱导凋亡。
