Fig. 1.

HIF-2α is upregulated in cartilage and pannus of mouse experimental RA joint tissue. a Left Representative images of synovium, cartilage, and pannus in ankle joints of DBA/1 J mice either immunized with type II collagen (CIA) or not immunized (NI) (n = 15). Right Representative HIF-2α immunostaining in cartilage and pannus of ankle joints of DBA/1 J mice (n = 10). b Left Representative images of synovium, cartilage, and pannus in ankle joints of 20-week-old TNFα TG mice (n = 8). Right Representative HIF-2α immunostaining in cartilage and pannus of ankle joints of TNFα TG mice (n = 8). c Left Representative images of synovium, cartilage, and pannus in ankle joints of mice transferred with K/BxN serum or control serum (n = 12). Right Representative HIF-2α immunostaining in cartilage and pannus (n = 7). d Relative expression levels of HIF-2α in cartilage and pannus. HIF-2α-positive cells were counted in the indicated RA mouse model. Values presented as mean ± standard error of the mean (*P <0.001, **P <0.0005). Scale bar: 50 μm. C cartilage, CIA collagen-induced arthritis, CON control, HIF hypoxia-inducible factor, P pannus, TG transgenic, TNFα tumor necrosis factor alpha, WT wild type