LncRNA NORAD deficiency alleviates kidney injury in mice and decreases the inflammatory response and apoptosis of lipopolysaccharide-stimulated HK-2 cells via the miR-577/GOLPH3 axis

Long noncoding RNAs (lncRNAs) are significant regulators for sepsis-associated acute kidney injury (AKI). Noncoding RNA activated by DNA damage (NORAD) is highly expressed in the serum of patients with neonatal sepsis. We aimed to reveal the role of NORAD in sepsis-associated AKI.In this study, we established an AKI mouse model by cecal ligation and puncture (CLP) method and used the lipopolysaccharide (LPS)-stimulated HK-2 cells as the in vitro model of AKI. We identified the upregulation of NORAD expression in AKI mice and LPS-treated HK-2 cells. Silencing of NORAD alleviated renal injury by suppressing inflammation and apoptosis in vivo. The influences of NORAD suppression on cell apoptosis and inflammatory response in LPS-treated HK-2 cells were investigated by TUNEL and western blotting. NORAD deficiency inhibited HK-2 cell apoptosis and relieved the inflammation. Moreover, we explored the underlying mechanism by which NORAD regulates HK-2 cells. MiR-577 was verified to directly bind to NORAD, and GOLPH3 was identified as a target downstream miR-577. In addition, GOLPH3 overexpression countervailed the impacts of NORAD downregulation on apoptosis and inflammation in vitro.Our findings revealed that NORAD knockdown alleviates kidney injury in mice and decreases the inflammatory response and apoptosis of LPS-stimulated HK-2 cells via the miR-577/GOLPH3 axis.