Fig. 3

IRF4^−/− mice with increased FOXP3 level and Treg numbers show reduced pulmonary vascular dysplasia and lung injury. A Demonstration of gene ablation.In this project we use CRISPR/Cas9 technology to modify IRF4 gene. The IRF4 gene has 3 transcripts. According to the structure of IRF4 gene, exon3-ex on5 of IRF4-201(ENSMUST00000021784.9) transcript is recommended as the knockout region.The region contains 421 bp coding sequence. Knock out the region will result in disruption of protein function. B C57 and IRF4.^−/− mice exposed to hyperoxia for 14 d. Mouse lung tissues are used for experiments. C Western blot of VEGFA, Ang-1 and FOXP3 protein levels in mouse lung tissues. D Flow cytometry of the number of Tregs and FOXP3 level in mouse lung tissues. E HE staining of the morphology of mouse lung tissues (× 400; scale bar, 50 μm). Black arrows refer to alveolar septa, red arrows refer to alveolar lumina. F IHC of PECAM-1 level in mouse lung tissue (× 400; scale bar, 50 μm). Data are expressed as mean ± SD. n = 6. Significant differences are expressed as *p < 0.05