MiR-182-5p Regulates Chondrocyte Inflammation and Oxidative Stress to Promote Osteoarthritis through Targeting the SIRT1/Nrf2 Signaling Pathway

Abstract

Background: The possible molecular mechanism and the influence of microRNA-182-5p (miR-182-5p) in the oxidative stress and inflammatory response in osteoarthritis (OA) were expected to be explored in this study. Methods: Interleukin-1β (IL-1β)-induced human chondrocytes (CHON)-001 cell line was utilized to construct in vitro OA models. Real-time quantitative polymerase chain reaction (qRT-PCR) was executed for measuring silent information regulation of transcription 1 (SIRT1) and miR-182-5p expression in clinical cartilage tissue and CHON-001 cells; enzyme-linked immuno sorbent assay (ELISA), biochemical assay and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay to measure the levels of inflammatory factors, the levels of oxidative stress substances, and the proliferation rate in CHON-001 cells, respectively. Further, the targeting association of this miRNA with SIRT1 was identified via dual-luciferase reporter assay, and the expression of nuclear factor erythroid 2-associated factor 2 (Nrf2) signaling pathway-related protein in chondrocytes was checked via western blot. Results: Firstly, the OA model was successfully built via the stimulation of IL-1β in CHON-001 cells. The expression of that miRNA was observed to be high in IL-1β-induced chondrocyte samples and cartilage tissues of OA patients. Knocking down miR-182-5p triggered the Nrf2 signaling pathway in the chondrocytes and increased the cell proliferation, inhibited inflammation and oxidative stress. Furthermore, the dual-luciferase reporter assay and bioinfomatics analysis hinted that SIRT1 acted as a target gene of that miRNA. Besides, low SIRT1 expression was exhibited in OA tissues and the chondrocytes, and a negative association existed between SIRT1 expression and miR-182-5p expression. Knocking down SIRT1 counteracted the protective effects of miR-182-5p knockdown and the activation of Nrf2 pathway in the CHON-001 cells. Conclusions: Knocking miR-182-5p down in human chondrocytes prevented IL-1β-stimulated oxidative stress injury and cell inflammation by targetedly controlling SIRT1/Nrf2 signaling pathway, implying the potential of this miRNA serving as a target for treating OA.