Department of Health Toxicology, Xiangya School of Public Health, Central South University, Changsha, Hunan Province, China.
The First Affiliated Hospital of Xi'An Jiaotong University, China.
Toxicol In Vitro. 2023 Oct;92:105657. doi: 10.1016/j.tiv.2023.105657. Epub 2023 Aug 4.
The mechanism of action of MicroRNA-30a(miR-30a) and Snail, a transcription factor, in silica(SiO2) dust-induced pulmonary EMT and secondary pulmonary fibrosis remains elusive. In this study, the cellular EMT model induced by the stimulation of A549 cells with SiO2 was established. A549 cells were transfected with miR-30a mimic and miR-30a inhibitor and the SNAIL gene was silenced to examine the mechanism of miR-30a targeting Snail to regulate silica dust-induced EMT. The results showed that 50 μg/mL SiO2 stained A549 cells for 24 h could induce EMT in A549 cells. Exposure of A549 cells to SiO2 dust decreased miR-30a expression, as well as mRNA and protein expression levels of E-cad. Conversely, SiO2 exposure increased mRNA and protein expression levels of α-SMA, vimentin, and Snail. The miR-30a mimic upregulated mRNA and protein expression levels of E-cadherin in SiO2-induced A549 cells, while downregulating mRNA and protein expression levels of α-SMA, vimentin and Snail. MiR-30a inhibitors have the opposite effect. Silencing the SNAIL gene, followed by SiO2 dust-induced stimulation of A549 cells, could enhance mRNA and protein expression levels of E-cad, whereas those of α-SMA and vimentin were reduced. Altogether, we found that miR-30a directly targeted Snail and inhibited its expression, thereby delaying silica induced pulmonary EMT.
微小 RNA-30a(miR-30a)和转录因子 Snail 在二氧化硅(SiO2)粉尘诱导的肺上皮间质转化(EMT)和继发性肺纤维化中的作用机制尚不清楚。本研究通过刺激 A549 细胞建立了由 SiO2 诱导的细胞 EMT 模型。转染 miR-30a 模拟物和 miR-30a 抑制剂沉默 SNAIL 基因，研究 miR-30a 靶向 Snail 调节二氧化硅粉尘诱导的 EMT 的机制。结果表明，50μg/mL SiO2 染 A549 细胞 24 h 可诱导 A549 细胞 EMT。SiO2 暴露降低了 miR-30a 的表达以及 E-钙粘蛋白的 mRNA 和蛋白表达水平。相反，SiO2 暴露增加了α-SMA、波形蛋白和 Snail 的 mRNA 和蛋白表达水平。miR-30a 模拟物上调了 SiO2 诱导的 A549 细胞中 E-钙粘蛋白的 mRNA 和蛋白表达水平，而下调了α-SMA、波形蛋白和 Snail 的 mRNA 和蛋白表达水平。miR-30a 抑制剂则有相反的作用。沉默 SNAIL 基因后，再用 SiO2 粉尘刺激 A549 细胞，可增强 E-钙粘蛋白的 mRNA 和蛋白表达水平，而α-SMA 和波形蛋白的表达水平则降低。总之，我们发现 miR-30a 可直接靶向 Snail 并抑制其表达，从而延缓二氧化硅诱导的肺 EMT。
