Roles And Mechanisms Of MicroRNA-411 By Targeting HIF-1? Regulates Chondrocyte Autophagy In Osteoarthritis

Objective: Osteoarthritis(OA)is one of the most common joint disease worldwide and is characterized by the progressive degeneration of articular cartilage,the incidence of OA is increasing year by year.The molecular basis of OA involves various factors and has not been fully clarified,such as inflammatory,degradation,and chondrocyte apoptosis and autophagy.Autophagy is a conserved catabolic process that involves cellular degradation through the lysosomal machinery.It maintains cellular and tissue homeostasis by removing damaged macromolecular substances and organelles and regenerating metabolic precursors.Previous studies have demonstrated that microRNA and autophagy play essential roles in OA.However,It has not been related reports about the mechanism of miR-411 and autophagy in chondrocytes.This study aimed to clarify the interrelationship between miR-411 and autophagy in osteoarthritis chondrocyte and the potential mechanisms.Methods: The potential targets of miRNA-411 were identified by TargetScan analysis and dual luciferase reporter assay.OA condition in chondrocyte C28/I2 cells was induced by treatment with interleukin 1beta(IL-1?).The chondrocyte were divided into four groups: the IL-1?-induced group,the IL-1?-induced group + the miR-411 mimics group,the IL-1?-induced group + the miR-411 inhibitor group,and IL-1?induce group + negative control group.Then quantitative real-timePolymerase Chain Reaction(qRT-PCR)was used to detect the expression levels of miR-411 and HIF-1? and the expression levels of autophagy related proteins(HIF-1?,LC3,p62,ULK-1 and Beclin-1)were detected by western blot.LC3 expression was assessed by immunofluorescence.The above methods confirmed the roles of miR-411 and HIF-1? in chondrocytes autophagy.Results: TargetScan analysis showed that HIF-1? mRNA is directly targeted by miR-411,which was confirmed by luciferase reporter assay.miR-411 mimic group decreased HIF-1? levels in chondrocytes while miR-411 inhibitor group increased HIF-1? levels in chondrocytes by qRT-PCR and Western blot.The expression levels of LC3,ULK-1,P62,and Beclin-1 in chondrocytes was induced by miR-411 inhibitor and was downregulated by miR-411 mimics.In addition,miR-411 mimics reduced the expression level of LC3 by immunofluorescence analysis.Conclusions: Our results demonstrate that miR-411 and HIF-1?play important roles in the occurrence and development of IL-1?-induced OA.The miR-411 regulates chondrocyte autophagy by targeting HIF-1?,suggesting that regulating autophagy by miR-411 might be a therapeutic strategy and provide new targets for new treatment of OA.