Fig. 3.

miR-155 is crucial for the development of CIA. On day 0, miR-155^−/− and WT mice (n = 15–17 per group) were injected intradermally with either a type II chicken collagen/Freund's complete adjuvant emulsion (CII/CFA) (200 μg) or PBS. On day 21, type II chicken collagen in PBS (200 μg) was injected i.p. Mice were killed on day 34. (A) miR-155 is up-regulated in the articular tissue of WT mice with CIA. (B and C) The incidence (B) and mean clinical score (C) are shown. In contrast to WT littermates, miR-155^−/− mice do not develop signs of CIA. (D) In contrast to WT mice, miR-155^−/− mice did not develop articular inflammation and degradation of cartilage and bone. (Magnification: ×10.) Data are means ± SEM or box-and-whisker diagrams. (n = 15–17); *P < 0.05, miR-155^−/− vs. WT mice (CIA protocol).