Resveratrol improves the progression of osteoarthritis by regulating cholesterol metabolism

Abstract Osteoarthritis (OA) is considered a metabolic disorder.This study investigated the effect of resveratrol (RES) on cholesterol accumulation in osteoarthritic articular cartilage via the SIRT1/FoxO1 pathway. Interleukin (IL)-1β-treated chondrocytes that mimic OA chondrocytes were used in in vitro experiments. The optimal RES concentration was selected based on the results of chondrocyte proliferation in the Cell Counting Kit-8 assay. Western blotting, immunofluorescence, and reverse transcription-quantitative polymerase chain reaction were performed. For the animal experiments, mice were randomly divided into the RES group (n = 15), medial meniscus destabilization group (n = 15), and Sham group (n = 15), and each group received the same dose of RES or saline. Articular cartilage tissue was obtained eight weeks after surgery for relevant histological analysis. Clinical tissue test results suggest that downregulation of the SIRT1/FoxO1 pathway is associated with cholesterol buildup in OA chondrocytes. For the in vitro studies, RES increased SIRT1expression and FoxO1 phosphorylation in IL-1β-treated chondrocytes, promoted the expression of cholesterol efflux factors (LXRα, ABCA1, and ApoA1), and inhibited the expression of cholesterol synthesis-related factors (SREBP-2and HMGCR). This reduced IL-1β-induced chondrocytes cholesterol accumulation. SIRT1 inhibition prevented the RES-mediated reduction in cholesterol buildup. Inhibiting FoxO1but not SIRT1reduced FoxO1phosphorylation and increased cholesterol buildup in cultured chondrocytes. Additionally, in vivo experiments have shown that RES can alleviate cholesterol buildup and pathological changes in OA cartilage. Our findings suggest that RES regulates cholesterol buildup in osteoarthritic articular cartilage via the SIRT1/FoxO1 pathway, thereby improving the progression of OA.