Preliminary analysis of differential expression of miRNA-423-5p and miRNA-26a-5p in lung tissue of early silicotic rats

Abstract

Objective: To screen the changes of microRNA (miRNA) expression profiles in lung tissues of early silicosis rats, and provide a basis for functional analysis of differential microRNA. Methods: SPF Wistar male rats were randomly divided into a negative control group and SiO(2)-exposed groups, with 30 rats in each group. The model of silicosis in rats was established by intratracheal instillation of 1 ml SiO(2) suspension, and the control rats were treated with 1mL in the same way to sterilize normal saline. The lung tissues of two group were collected at the 1, 7, 14, 21, 28 d after SiO(2)-exposed. Three of the rat lung tissues were used for pathological observation, and the other three were used to screen differentially expressed miRNAs in lung tissue by miRNA microarray technology. miRNA chip screening and RT-qPCR were used to verify the expression levels of miRNA-423-5p and miRNA-26a-5p in the two groups. miRNA-423-5p and miRNA-26a-5p are predicted by target genes and analyzed by GO (gene ontology) enrichment analysis and KEGG (kyoto encyclopedia of genes and genomes) pathway analysis. Results: In the control group, the inflammatory response of lung tissue 21 and 28 days was significantly reduced compared with 1, 7 and 14 days, and the inflammatory cells infiltrated in the lung tissue of the SiO(2)-exposed rats. The rats in the control group had a small amount of collagen at 21 and 28 days, but a large amount of collagen fiber deposition began to appear in the lung tissue of rats exposed to SiO(2) after 21 days. Compared with the control group, the expression levels of micro RNA-423-5p was significantly up-regulated and the expression of microRNA-26a-5p was significantly down-regulated in the SiO(2)-exposed rats lung tissues dust at different time points (P<0.05) . Conclusion: The up-regulation of miRNA-423-5p and the down-regulation of miRNA-26a-5p in lung tissues of early silicotic rats may be related to the occurrence and development of early silicosis.