Fig. 6

Impact of native human proteoglycan-4 (nhPRG4) treatment (100, 200 and 300 μg/mL) on toll-like receptor 2 (TLR2) activation by pooled osteoarthritis (OA) synovial fluid (SF) and pooled rheumatoid arthritis (RA) SF following proteoglycan-4 (PRG4) immunoprecipitation. TLR2-expressing human embryonic kidney (TLR2-HEK) cells were incubated with SF (5 % dilution for 24 h) in the absence or presence of nhPRG4. The 630 nm absorbance values across experimental groups were normalized to untreated controls. Data represent the mean ± SD from three independent experiments. a Impact of nhPRG4 on TLR2 activation of PRG4-immunoprecipitated OA SF (OA SF (-PRG4)). nhPRG4 treatments (200, 300 μg/mL) significantly reduced TLR2 activation by OA SF (-PRG4). nhPRG4 (300 μg/mL) treatment was more efficacious in reducing TLR2 activation than nhPRG4 (100 μg/mL); *p <0.001; **p <0.05. b Impact of nhPRG4 on TLR2 activation of PRG4-immunoprecipitated RA SF (RA SF (-PRG4)). nhPRG4 treatments (200, 300 μg/mL) significantly reduced TLR2 activation by RA SF (-PRG4). nhPRG4 (200 and 300 μg/mL) treatment was more efficacious in reducing TLR2 activation than nhPRG4 (100 μg/mlL); *p <0.001; **p <0.01