Fig. 2.

HIF-2α upregulates chemokine expression in FLS and chondrocytes. Microarray analysis of chemokines in primary culture mouse FLS a or articular chondrocytes b infected with 800 MOI of Ad-C and Ad-Epas1. Relative mRNA levels against Ad-C are shown (n = 3). c, d Primary cultures of mouse articular chondrocytes were left untreated (None) or infected with Ad-C (800 MOI) and the indicated amounts (MOI) of Ad-Epsa1 for 24 hours. Levels of indicated mRNA were determined with qRT-PCR c and RT-PCR d analyses. Transcripts of the indicated genes were examined using RT-PCR d and quantified with qRT-PCR c (n = 5). e HIF-2α binding sites in promoters of indicated chemokines. ChIP assays in chondrocytes infected with 800 MOI Ad-C or Ad-Epas1. The histone H3 antibody was used as the positive control and IgG as a negative control. f The indicated HRE sites in each chemokine promoter were amplified from immunoprecipitated DNA (left) and pre-immunoprecipitated DNA (right; input). Values presented as mean ± standard error of the mean (*P <0.005). FLS fibroblast-like synoviocytes, HIF hypoxia-inducible factor, HRE hypoxia-inducible factor responsive element