ACE Inhibition Modulates Myeloid Hematopoiesis after Acute Myocardial Infarction and Reduces Cardiac and Vascular Inflammation in Ischemic Heart Failure

Figures

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  Figure 1. Early ramipril treatment limits infiltration of inflammatory monocytes to the ischemic myocardium and expression of adhesion molecules after MI(myocardial infarction). (A) Kaplan–Meier survival curve after MI or MI mice with ramipril treatment vs. sham-treated (control) over the period of 28 days. n = 12–26 per group; Log-Rank (Mantel–Cox test). (B) Transthoracic echocardiography measured in parasternal long axis (PLAX) with analysis of left ventricular ejection fraction (LV-EF), left ventricular end-diastolic diameter (LV-EDV), cardiac output and stroke volume on day 6 after MI vs. sham, (top) representative PLAX B-mode images, (bottom) quantification; n = 7–8 per group; (C) mRNA expression of heart tissue of Ccl-2, Vcam-1, Il6, Il1b and iNOS (Nos2) 7 days after MI and sham operation; n = 6–7 mice per group; (D) Left: Representative gating strategies of CD45+CD3−CD11b+ and CD45+CD3−CD11b+Ly6G−Ly6Chigh. Bold numbers indicate the percentual ratio of total living cells. Right: Flow cytometry quantification of infiltrating CD11b+ myeloid cells and Ly6Chigh monocytes in the infarcted heart vs. sham operation 7 days after MI, n = 6–7 mice per group; mean + SEM, 1-way ANOVA or…

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  Figure 2. ACE (angiotensin-converting-enzyme) inhibition limits the number of circulating monocytes and retains HPSC (hematopoetic stem cells) due to upregulation of retention factors in the bone marrow and spleen. (A) Flow cytometry quantification of circulating CD11b+ myeloid cells and Ly6Chigh monocytes in whole blood 7 days after MI, n = 6–7 mice per group; (B) Quantification of LSK, HPSCs, MPPs and GMPs in the bone marrow 48 h and 7 d post-MI; left: representative FACS (fluorescent activated cell sorting) plots; bold numbers indicate percentual ratio of total living cells, right: quantification of Lineage−/Sca1+/cKit+ LSK, Lineage−/Sca1+/cKit+/CD48−/CD150+ HPSCs, Lineage−Sca1−/cKit+/CD48−/CD150− MPPs, Lineage−Sca1−/cKit+/CD16/CD32+/CD34+ GMPs per femur; n = 7–10, (C) + (D) mRNA expression of Vcam-1, Cxcl-12, Angpt1 and Kitl in the bone marrow (C) and spleen 7 days after MI (D), n = 4–8 mice per group; mean + SEM, 1-way-ANOVA or Kruskal–Wallis test with Dunn’s multiple comparisons test. * p < 0.05, ** p < 0.01, **** p < 0.0001.

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  Figure 3. In ischemic heart failure, early ACE inhibitor treatment improves vascular endothelial function due to reduction of vascular and systemic ROS. (A) Superoxide formation in whole blood measured by enhanced chemiluminescence after stimulation with PDBu 28 d after MI, n = 7–15 mice per group; (B) High-frequency ultrasound echocardiography with measurement of wall motion score index (WMSI) 4 weeks post-MI, n = 13 to 14 mice per group; (C–E) Isometric tension studies of isolated aortic segments 28 d after MI. (C) Contraction-relaxation curves in response to endothelium-dependent vasodilator acetylcholine (Ach), (D) contraction-relaxation curves in response to endothelium-independent vasodilator nitroglycerin (NTG), (E) dose-dependent contraction curve in response to the α1-agonist phenylephrine (PHE); n = 4–12 rings per group; mean + SEM; 2-way ANOVA; * p < 0.05, ** p < 0.01 (Control vs. MI), # p < 0.05, ## p < 0.01, ### p < 0.001 (MI vs. MI + ramipril); (F) Oxidative fluorescence microtopography; right: per group, one representative photomicrograph is shown. Autofluorescence of laminae produces a green signal, superoxide formation yields a red fluorescent signal; A, adventitial layer;…

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  Figure 4. Ramipril limits vascular inflammation in chronic ischemic heart failure by attenuating myeloid cell infiltration. (A) Flow cytometry quantification of aortic tissue 28 days after MI vs. sham; left: representative FACS plots, right: quantification of leucocytes (CD45+), myeloid cells (CD45+CD11b+) and monocytes (CD45+CD11b+Ly6G-Ly6Chigh/low), n = 3–8 mice per group, mean + SEM, n = 3–8 mice per group; (B) mRNA expression of aortic tissue of Ccl-2, iNOS (Nos2), eNOS and TNFalpha 28 days after MI vs. sham (+Ramipril); mean + SEM, 1-way ANOVA or Kruskal–Wallis test with Dunn’s multiple comparisons test. * p < 0.05, ** p < 0.01.