Figure 3.
Overexpression of individual Toll‐like receptor (TLR) signaling components in joint tissue does not cause osteoarthritis‐like changes in mice. A, Wild‐type mice were intraarticularly injected (once weekly for 3 weeks) with 1 × 109 plaque‐forming units of control adenovirus (Ad‐C) or adenovirus expressing TLR signaling components (Ad‐SAA1, Ad‐TLR‐2, Ad‐TLR‐4, Ad‐LBP, or Ad‐CD14). Ad‐HIF‐2α and Ad‐ZIP8 were used as positive controls for OA pathogenesis. Mice were euthanized at 8 weeks after the first intraarticular injection. Representative images of joint sections are shown. The boxed areas in upper rows are shown at higher magnification in lower rows. Bars = 50 μm. B, Primary‐culture mouse articular chondrocytes were infected with 800 multiplicities of infection of Ad‐C, Ad‐SAA1, Ad‐TLR‐2, Ad‐TL‐R4, Ad‐LBP, Ad‐CD14, Ad‐HIF‐2α, or Ad‐ZIP8 for 36 hours. Relative levels of mRNA for the indicated molecules were determined by quantitative reverse transcription–polymerase chain reaction analysis (n = 7 per group). Each symbol represents an individual mouse; bars show the mean ± SEM. * = P < 0.05; *** = P < 0.001, by one‐way analysis of variance with Bonferroni post hoc test. NS = not significant.