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Osteoarthritis (OA) is characterized by an imbalance between M1 and M2 polarized synovial macrophages. Quercetin has shown protective effects against OA by altering M1/M2‐polarized macrophages, but the underlying mechanisms remain unclear. In this study, rat chondrocytes were treated with 10 ng/mL of IL‐1β. To create M1‐polarized macrophages in vitro, rat bone marrow‐derived macrophages (rBMDMs) were treated with 100 ng/mL LPS. To mimic OA conditions observed in vivo, a co‐culture system of chondrocytes and macrophages was established. ATP release assays, immunofluorescence assays, Fluo‐4 AM staining, Transwell assays, ELISA assays, and flow cytometry were performed. Male adult Sprague–Dawley (SD) rats were used to create an OA model. Histological analyses, including H&E, and safranin O‐fast green staining were performed. Our data showed a quercetin‐mediated suppression of calcium ion influx and ATP release, with concurrent downregulation of TRPV1 and P2X7 in the chondrocytes treated with IL‐1β. Activation of TRPV1 abolished the quercetin‐mediated effects on calcium ion influx and ATP release in chondrocytes treated with IL‐1β. In the co‐culture system, overexpression of P2X7 in macrophages attenuated the quercetin‐mediated effects on M1 polarization, migration, and inflammation. Either P2X7 or NLRP3 knockdown attenuated IL‐1β‐induced M1/M2 polarization, migration, and inflammation. Moreover, overexpression of TRPV1 reduced the quercetin‐mediated suppressive effects on OA by promoting M1/M2‐polarized macrophages in vivo. Collectively, our data showed that quercetin‐induced suppression of TRPV1 leads to a delay in OA progression by shifting the macrophage polarization from M1 to M2 subtypes via modulation of the P2X7/NLRP3 pathway. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effect of transverse tibial bone transport on the expression of angiogenesis-related growth factors in the serum of diabetic foot patients., Methods: Between January 2018 and December 2018, 10 patients who suffered from diabetes mellitus accompanied with Wagner stage 4 diabetic foot underwent transverse tibial bone transport. There were 5 males and 5 females with an average age of 59.2 years (range, 51-70 years). The duration of diabetes was 2-60 months, with an average of 24.2 months. The duration of diabetic foot was 30-120 days, with an average of 54.1 days. Peripheral venous blood was taken at 1 day before operation and at 1, 4, 11, 18, 28, and 35 days after operation. The serum was centrifuged and subjected to ELISA test to detect the expression levels of serum vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and platelet-derived growth factor (PDGF)., Results: The levels of serum VEGF, bFGF, and EGF increased rapidly at 11 days after operation, and the expression levels of the factors at 11, 18, 28, and 35 days were significantly higher than those before operation ( P <0.05). The expression level of PDGF increased suddenly at 18 days after operation, and the expression level of PDGF at 18, 28, and 35 days was significantly higher than that before operation ( P <0.05)., Conclusion: Transverse tibial bone transport for the treatment of diabetic foot can significantly increase the expression of serum angiogenesis-related growth factors in early stage, which may be the mechanism of promoting the healing of diabetic foot wounds.