<p>(A) Representative images of human RA synovium immunostained for HIF-1α, HIF-2α, IL6, MMP3, and MMP13 (<i>n</i> = 10). (B) Representative images of human RA and mouse CIA synovial sections (<i>n</i> = 8) immunostained for HIF-2α and a RA synovium marker (MMP3, MMP13, or IL6) and counterstained with DAPI (triple stained). Insets are enlarged images of double-stained cells. (C) Representative images of HIF-1α and HIF-2α immunostaining in the knee synovia of CIA and NI control DBA/1J mice (<i>n</i> = 10). (D) Relative expression levels of HIF-1α and HIF-2α in synovial cells (left) (<i>n</i> = 10). HIF-2α–positive cells were counted in the indicated compartments of RA synovium (right) (<i>n</i> = 5). Values are means ± SEM (*<i>p</i><0.0005). Scale bar, 50 µm.</p
