Fig. 3.

HIF-2α upregulates chemokine expression in RA cartilage tissue. a, b Empty virus (Ad-C) or Ad-Epas1 (1 × 10⁹ plaque-forming unit ) was injected into mouse knee joints. Representative hematoxylin/safranin O-stained images in cartilage and pannus regions a. Results of RT-PCR and qRT-PCR analysis of the indicated genes in cartilage tissue b (n = 4). c, d Typical immunofluorescence microscopy images of DAPI, HIF-2α, CXCL1, CXCL2, and CCL5 in cartilage tissue of mice after IA injection with Ad-Epas1 c or CIA d. Values presented as mean ± standard error of the mean (*P <0.01). Scale bar: 50 μm. C cartilage, CIA collagen-induced arthritis, DAPI 4′,6-diamidino-2-phenylindole, HIF hypoxia-inducible factor, P pannus