HIF-1α/2α expression in myeloid-specific KO mice targeting the HIF pathway. (A) Images of the colon of wild-type (WT), myeloid-specific Hif-1a KO (hMRP8 Hif-1a KO) or von Hippel Lindau (Vhl) KO (hMRP8 Vhl KO) mice, immunostained for MRP8 (green) and the DNA-binding regions of Hif-1a mRNA (red). Mice were fed with 5% DSS for 4 days prior to immunostaining analyses. Note that there were no MRP8-positive cells that were positive for Hif-1a mRNA in hMRP8 Hif-1a KO (middle column) mice, but we observed many cells that were double positive for MRP8 and Hif-1a mRNA in hMRP8 Vhl KO mice (right column). (B) Images of the colon of hMRP8 Vhl KO mice fed with 5% DSS as in A, immunostained for MRP8 (green) and HIF-1α (red, upper row) or HIF-2α (red, bottom row). DAPI-stained nuclei are shown in blue. White boxes in A and B indicate the regions magnified in the lower or right images, respectively. Yellow arrowheads in A and B indicate cells positive for both markers. Scale bars: 100 μm.