Analysis of microRNA expression profiling during paraquat-induced injury of murine lung alveolar epithelial cells

Paraquat (PQ) as a non-selective heterocyclic herbicide, has been applied worldwide for over a few decades. But PQ is very harmful to humans and rodents. The lung is the main target organ of PQ poisoning. It is an important event that lung epithelial cells are injured during PQ-induced acute lung injury and pulmonary fibrosis. As a regulator of mRNA expression, microRNA (miRNA) may play an important role in the progress. Our study was to investigate the mechanisms of PQ-induced injury of pulmonary epithelial cells through analyzing the profiling of miRNAs and their target genes. As a result, 11 differentially expressed miRNAs were screened, including 1 upregulated miRNA and 10 downregulated miRNAs in PQ-treated murine lung alveolar epithelial cells (MLE-12 cells). The bioinformatic analyses suggested that the target genes of these miRNAs were involved in mitochondrial apoptosis pathway and DNA methylation, and participated in the regulation of PI3K-Akt, mTOR, RAS, TNF, MAPK and other signal pathways which related to oxidative stress and apoptosis. This indicated that miRNAs were an important regulator of oxidative stress and apoptosis during PQ-induced injury of murine lung alveolar epithelial cells. The findings would deepen our understanding of the mechanisms of PQ-induced pulmonary injury and might provide new treatment targets for this disease.