Fig. 6

LPP in chondrocyte lysates promotes NLRP3 inflammasome-mediated pyroptosis in FLSs. (A). Venn diagram of screened proteins detected by LC‒MS from CLs and FLSs isolated from 3 different groups (Ligand A/B/C) of OA patients with CL stimulation. (B). Co-IP analysis of LPP pulled down from NLRP3 in FLSs with or without CL pretreatment. (C). qRT‒PCR analysis of CAV1, IL-1β, IL-18, NLRP3, TNF-α, TLR4, and MMP13 levels in cells with or without recombinant LPP protein treatment (n = 6). (D). WB and quantification of CAV1, NLRP3, and LPP levels in FLSs with and without LPP treatment. (E). The pyroptotic rates of FLSs with and without recombinant LPP protein treatment were quantified via flow cytometry with double Annexin V-FITC/PI staining (n = 3). (F). Representative images of the coimmunofluorescence of CAV1 (green fluorescence) and NLRP3 (red fluorescence) with and without LPP treatment are shown. (G). Schematic representation of the mechanisms by which CLs regulate synovitis. All the data are presented as the means ± SEMs. Paired t tests and one-way analysis of variance (ANOVA) were used for statistical analysis. * p < 0.05, ** p < 0.01, ***p < 0.001. LC‒MS