Figure 6.

The canonical GLP-1 (glucagon-like peptide-1) receptor expressed on myeloid cells (LysM⁺) is not responsible for cardiovascular protection by liraglutide (Lira). A, In myeloid cell (LysM⁺)-specific GLP-1 receptor knockout mice (Glp1r^flox/floxxLysM^cre, Glp1r my^−/−), mRNA expression of the Glp1r was measured in bone marrow–derived macrophages (BMDM) and expression levels are shown in relation to the background strain (LysM^cre mice). Student t test; N=3 animals per group. B, Vascular function was evaluated by endothelium-dependent (acetylcholine [ACh]) relaxation of aortic rings (isometric tension studies). Two-way ANOVA and Bonferroni multiple comparison test; N=16–22 animals per group. C, Representative (out of 3–4) Sirius red staining of aortic sections to assess vascular fibrosis. D and E, Flow cytometry of aortic cell suspensions identified Ly6G⁻Ly6C⁺ inflammatory monocytes and Ly6G⁺Ly6C⁺ neutrophils inside the vascular wall. Representative original plots of Ly6G⁻Ly6C⁺ and Ly6G⁺Ly6C⁺ cells are shown beside the quantification bar graph (for gating strategy, see Figure IV in the online-only Data Supplement). One-way ANOVA and Bonferroni multiple comparison test; N=5–9 animals per group. Data are means±SEM. ATII indicates angiotensin II; FITC, fluorescein isothiocyanate; and n.d., not detectable. *P<0.05; **P<0.01; ***P<0.001, ****P<0.0001.