Expression changes of miRNA-29b-3p and miRNA-34c-3p in lung tissue of rats exposed to silica and A549 cells / 中华劳动卫生职业病杂志

ABSTRACT

Objective@#To investigate the role of microRNA-29b-3p (miRNA-29b-3p) and miRNA-34c-3p in the process of pulmonary fibrosis, we detected the expression levels of miRNA-29b-3p and miRNA-34c-3p in the lung tissue of rats exposed to silica and A549 cells.@*Methods@#SPF male Wistar rats were randomly divided into 1, 7, 14, 21, 28 d control group and silica (SiO2) dusting group, with 6 rats in each group. One-time non-exposure method was used to infuse 1ml SiO2 suspension. The rat SiO2 dusting group was established in the liquid, and the control rats were intratracheally injected with 1 ml of sterile physiological saline in the same manner. The lung tissues of each group were collected at the corresponding time points after dusting. Three of the rats were taken out for pathological observation, and the other three were used to screen differentially expressed miRNAs in lung tissue by miRNA microarray technology. A549 cells were cultured at the in vitro cell level and divided into control group, SiO2 stimulation group and TGF-β1 stimulation group, and cells were collected at 12, 24 and 48 h after treatment. The expression levels of miRNA-29b-3p and miRNA-34c-3p in rat lung tissue and A549 cells were verified by real-time PCR (qRT-PCR), target gene prediction of miRNA-29b-3p and miRNA-34c-3p and perform GO enrichment analysis and KEGG pathway analysis.@*Results@#The weight growth rate of the control group was significantly higher than that of the SiO2 dusting group. Compared with the control group, the lung mass and lung coefficient of the SiO2 dusting group were significantly increased (P<0.05). The inflammatory response of the lungs in the control group was significantly reduced at 21 and 28 days, and the inflammatory cells infiltrated in the lung tissue of the SiO2 group. The rats in the control group had a small amount of collagen at 21 and 28 days. A large amount of collagen fiber deposition began to appear in the lung tissue of rats exposed to SiO2 for 21 days. Compared with the control group, the expression levels of miRNA-29b-3p and miRNA-34c-3p in the SiO2 dusting group were significantly down-regulated, and there was significant difference compared with the control group (P<0.05). The expression levels of miRNA-29b-3p and miRNA-34c-3p in A549 cells treated with SiO2 and human recombinant TGF-β1 were significantly lower than those in the control group at 24 h and 48 h, and the difference was statistically significant (P<0.05).@*Conclusion@#Down-regulation of miRNA-29b-3p and miR-34c-3p in rat lung tissue A549 cells may be associated with the development of early silicosis and is expected to be an indicator of early silicosis diagnosis and prognosis.