Identification of LncRNAs and mRNAs involved in renal ishchemia reperfusion injury

The identification of the expression patterns of long non‑coding RNAs (lncRNAs) and mRNAs in the kidney under normal and renal ischemia/reperfusion (IR) conditions is essential for understanding the genetic mechanisms underlying the pathogenesis of renal IR injury. Here, we have carried out a genome-wide long non-coding RNA and mRNA microarray analysis in mice kidneys with IR. The data revealed that the expression profiles of lncRNAs and mRNAs in the kidneys differed markedly between the Sham group and IR group, and in total 276 differentially expressed (>2‑fold) lncRNAs (201 upregulated, 75 downregulated) and 267 mRNAs (192 upregulated, 75 downregulated) were identified. qRT-PCR analysis was performed to verify the expression patterns of several lncRNAs and mRNAs.We found a specific and strongly differentially expressed lncRNA, an renal ischemia-reperfusion (IR) injury associated RNA, termed lncRNA-IRAR, which was mainly located in tubular epithelia cells. In vitro and in vivo gain- or loss-of-function studies were performed to investigate the role of lncRNA-IRAR during renal IRI. Moreover, an expression volcano map of the differentially expressed mRNAs showed that UCP1 was the most dramatically downregulated gene, and its role in oxidative stress and apoptosis was assessed both in vitro and in vivo. Genetic deletion of UCP1 was used to investigate the effects of UCP1 on ischemia -indued acute kidney injury in mice. Renal IRI was induced by bilateral renal pedicle clamping for 30 min (IR group). Sham-operated mice underwent the same surgical procedures but without occlusion of renal pedicle. Kidneys were harvested 24 h after renal IR. Three kidney samples from each group (Sham group and IR group) were analyzed.