Figure 6. BRD4 promotes the senescence of mouse peritoneal macrophages and human peripheral blood mononuclear cells. The primary peritoneal macrophages isolated from Tert-/- senescent mice and human peripheral blood mononuclear cells (PBMCs) were prepared. (A, E) SA-β-gal staining images and the corresponding quantification in peritoneal macrophages of Tert-/- mice and PBMCs. Scale bar, 50 μm. (B, F) Western blotting and statistical analysis of protein expression of aging-related markers p53, p21, and p16. (C, G) Western blot analysis of BRD2, BRD3, and BRD4 in two different cells. (D, H) Confocal microscopy was used to verify the expression of p16 and BRD4 in peritoneal macrophages of Tert-/- mice and PBMCs. Scale bar, 50 μm. (I) qRT-PCR analysis of mRNA expression of SASP in peritoneal macrophages of Tert-/- mice and PBMCs and representative differentially expressed IL-6 and CXCL1. (J) Oil Red O staining measured lipid accumulation in peritoneal macrophages and PBMCs. The number of positive results was counted. Scale bar, 50 μm. The data all represent measurement data presented as the mean ± SD. The two groups were statistically analyzed using independent sample t-test. The experiment was repeated three times. Significant differences among the different groups are indicated as *p <0.05 vs. control; **p <0.01 vs. control; ***p <0.001 vs. control; ****p <0.0001 vs. control; **p <0.01 vs. PBMC; ***p <0.001 vs. PBMC; ****p <0.0001 vs. PBMC.