FIGURE 6.

Granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) modulates the polarization of macrophage in the aortic wall after porcine pancreatic elastase (PPE)‐mediated abdominal aortic aneurysm (AAA) induction by upregulating the expression of IRF5. (A) mRNA expression of the M1‐associated genes iNOS, IL‐6 and TNF‐α in CD45⁺CD11b⁺F4/80⁺ macrophages sorted from aortic aneurysms 7 days post AAA. n = 5 per group. **p < .01, ****p < .0001 according to unpaired two‐tailed t test or Mann–Whitney test. (B) Representative flow cytometry images (left) and quantification (right) of the proportion and number of CD11c⁺ macrophage in wild‐type and GM‐CSF^−/− mice after 7 days of PPE‐induced AAA. n = 5 per group. *p < .05 according to Mann–Whitney test. (C) AAA was induced in mice by PPE, and the mice were intraperitoneally injected with rmGM‐CSF or PBS. Representative flow cytometry images (left) and quantification (right) of the proportion and number of CD11c⁺ macrophages in aortic aneurysms 7 days after PPE‐mediated AAA formation. n = 5 per group. *p < .05, **p < .01 according to unpaired two‐tailed t test. (D) scRNA‐Seq datasets from murine ³⁰ aneurysm lesions were analyzed and tSNE plots showed the expression of Irf5 and Cd68. (E) The protein expression of IRF5 in macrophages in AAAs. Left: histogram plots displaying rmGM‐CSF (red), PBS (blue), and isotype control (gray). Right: quantification of the mean fluorescence intensity of IRF5. n = 5 per group. *p < .05 according to unpaired two‐tailed t test. (F) Bone marrow–derived macrophages were transfected with IRF5 siRNA or control siRNA. Expression of the M1‐associated genes iNOS, IL‐6 and TNF‐α was measured with real‐time PCR. n = 6 per group. **p < .01, ***p < .001, ****p < .0001 versus Control; #p < .05, ###p < .001 versus rmGM‐CSF+siIRF5 according to two‐way ANOVA