To Örebro University

In acute aristolochic acid nephropathy (AAN), aristolochic acid (AA) induces renal injury and tubulointerstitial fibrosis. However, the roles of microRNAs (miRNAs/miRs) and mRNAs involved in AAN are not clearly understood. The aim of the present study was to examine AA-induced genome-wide differentially expressed (DE) miRNAs and DE mRNAs using deep sequencing in mouse kidneys, and to analyze their regulatory networks. In the present self-controlled study, mice were treated with 5 mg/kg/day AA for 5 days, following unilateral nephrectomy. AA-induced renal injury and tubulointerstitial fibrosis were detected using hematoxylin and eosin staining and Masson's trichrome staining in the mouse kidneys. A total of 82 DE miRNAs and 4,605 DE mRNAs were identified between the AA-treated group and the self-control group. Of these DE miRNAs and mRNAs, some were validated using reverse transcription-quantitative PCR. Expression levels of the profibrotic miR-21, miR-433 and miR-132 families were significantly increased, whereas expression levels of the anti-fibrotic miR-122-5p and let-7a-1-3p were significantly decreased. Functions and signaling pathways associated with the DE miRNAs and mRNAs were analyzed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG). A total of 767 DE pairs (in opposing directions) of miRNAs and their mRNA targets were identified. Among these, regulatory networks of miRNAs and mRNAs were analyzed using KEGG to identify enriched signaling pathways and extracellular matrix-associated pathways. In conclusion, the present study identified genome-wide DE miRNAs and mRNAs in the kidneys of AA-treated mice, as well as their regulatory pairs and signaling networks. The present results may improve the understanding of the role of DE miRNAs and their mRNA targets in the pathophysiology of acute AAN.