The <i>miR-15a-5p-XIST-CUL3</i> regulatory axis is important for sepsis-induced acute kidney injury

Abstract

<b>Background:</b> Acute kidney injury (AKI) refers to a sudden loss of renal function. This study was performed to identify the key RNAs acting in the mechanism of sepsis-induced AKI. <b>Methods:</b> Microarray dataset GSE94717 (including six sepsis-induced AKI samples and three control samples) was downloaded from Gene Expression Omnibus database. Differentially expressed miRNAs (DE-miRNAs) were identified. The miRNA targets were predicted and enrichment analysis was performed. Protein-protein interaction (PPI) and competing endogenous RNA (ceRNA) regulatory networks were constructed. Mouse podocytes were treated with lipopolysaccharide (LPS), following by cell viability and PCR analysis. Cellular apoptosis and the ceRNA network were validated. <b>Results:</b> Thirty-one common DE-miRNAs (two up-regulated and 29 down-regulated) by AKI versus control and male AKI versus control were identified. We found the targets of <i>miR-15a-5p</i>, <i>miR-15b-5p</i>, and <i>miR-16-5p</i> were involved in mTOR signaling pathway, and those of <i>miR-29b-3p and miR-16-5p</i> were enriched in PI3K-Akt signaling pathway. RNAs including <i>miR-15b-5p</i>, <i>miR-15a-5p</i>, <i>miR-107</i>, <i>XIST</i>, <i>miR-16-5p</i>, and cullin 3 gene (<i>CUL3</i>) were included in the ceRNA regulatory network. The downregulation of <i>miR-15a-5p</i> and <i>miR-15b-5p</i> and the upregulation of lncRNA <i>XIST</i> and <i>CUL3</i> gene were validated using qPCR. The <i>miR-15a-5p-XIST-CUL3</i> regulatory axis was identified and was validated. We confirmed that LPS inhibited the growth of mouse podocytes and seven of the ten miRNAs, but upregulated <i>XIST</i> and <i>CUL3</i>. Transfection analysis showed XIST siRNA enhanced LPS-induced MPC5 cell apoptosis and <i>miR-15a-5p</i> inhibitor reserved it, so did as <i>CUL3</i> overexpression for <i>miR-15a-5p</i> mimics. <b>Conclusion:</b> The <i>miR-15a-5p-XIST-CUL3</i> regulatory axis was related to the pathogenesis of sepsis-induced AKI. Highlights Totally, 31 miRNAs were dysregulated between disease and control groups. <i>MiR-15a-5p</i>, <i>miR-15b-5p</i>, and <i>miR-16-5p</i> were involved in mTOR signaling pathway. <i>MiR-16-5p</i> and <i>miR-29b-3p</i> were implicated in PI3K-Akt signaling pathway. The miR-15a-5p-XIST-CUL3 axis was critical for sepsis-induced AKI.