MiR-494-mediated Effects on the NF-κB Signaling Pathway Regulate Lipopolysaccharide-Induced Acute Kidney Injury in Mice.

Objective To explore the effects of miR-494 inhibition through the NF-κB signaling pathway on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) mouse model. Methods The AKI mice induced by LPS were treated with miR-494 antagomir, and the kidney parameters and indicators of oxidative stress were detected. HE and TUNEL staining were performed to observe the kidney histopathology and the apoptosis in renal tubular epithelial cells (RTECs), respectively. The ROS level was measured using dihydroethidium (DHE) staining. In addition, qRT-PCR, western blotting, immunohistochemistry (IHC), and ELISA were also used to detect gene or protein expression. Results LPS-induced AKI mice injected with the miR-494 antagomir showed reduced blood urea nitrogen (BUN) and serum creatinine (Cr) with improved kidney histopathology. The expression levels of p-IKKα/β, p-IκBα and p65 NF-κB in the nucleus were increased in kidney tissues from the LPS-induced AKI mice, and they were decreased by the miR-494 antagomir. Moreover, the results of IHC showed that the miR-494 antagomir downregulated p65 NF-κB in kidney tissues from the LPS-induced AKI mice, accompanied by decreased levels of TNF-α, IL-1β, IL-6, MDA, NO, and ROS but increased levels of SOD and GSH. In addition, the LPS-induced AKI mice had increased apoptosis in RTECs, as well as increased Caspase-3 and Bax and decreased Bcl-2, which were reversed by the miR-494 antagomir. Conclusions The inhibition of miR-494 could reduce inflammatory responses and improve oxidative stress in kidney tissues from LPS-induced AKI mice by blocking the NF-κB pathway accompanying by reduced apoptosis in RTECs.