Sialomucin CD43 Plays a Deleterious Role in the Development of Experimental Heart Failure Induced by Pressure Overload by Modulating Cardiac Inflammation and Fibrosis

Figure 1. CD43−/− mice are protected from systolic heart failure. (A). Kaplan–Meier survival curves in WT and CD43−/− mice after TAC surgery. Survival curves were compared by log-rank (Mantel–Cox) test n=number of animals in survival curve data. Changes in ejection fraction (EF; B) and fractional shortening (FS; C) in response to TAC in WT and CD43−/− mice as measured by echocardiography. (D) Representative images of WT and CD43−/− LV section in Sham and TAC mice. Scale bars, 100μm. (E) Quantification of WT and CD43−/− cardiomyocyte area after TAC. (F) Quantification of ratio of gene expression for MHCβ and MHCα from heart lysates. *p<0.05; **p<0.01; and ***p≤0.001.

Figure 2. CD43−/− develop less fibrosis in the left ventricle (LV) in response to TAC as compared to WT mice. Representative images of perivascular (A) and interstitial (C) fibrosis after 4weeks of TAC, as demonstrated by picrosirius red staining. Scale bars, 100μm. Quantification of perivascular (B) and interstitial fibrosis (D). (E) Quantification of Collagen Ia1 and Collagen IIIa1 gene expression from heart lysates. *p≤0.05; and **p≤0.01.

Figure 3. CD43−/− mice exhibit reduced leukocyte and CD4+ T cell infiltration into the LV in response to TAC. (A). Representative hematoxylin and eosin (H&E) staining of WT and CD43−/− heart sections collected 4weeks after TAC and Sham surgery. (B) Quantification of leukocyte infiltrates in WT and CD43−/− Sham and TAC LV across the whole heart section. (C) Representative CD4 staining images of WT and CD43−/− heart sections from TAC and Sham animals. (D) Quantification of CD4+ T cell infiltrates in WT and CD43−/− Sham and TAC LV across the whole heart section. (E) Representative flow cytometric panels of CD4+ T cell. (F) Quantification of flow cytometric analysis. IC is isotype control; arrows indicate to immune reactivity for CD4 antibody. Scale bars, 100μm. *p≤0.05; and **p≤0.01.

Figure 4. CD43 modulates monocyte polarization toward M2 macrophages in vitro, and cardiac CXCL10 expression in response to TAC in vivo. (A) Representative CD11b staining images of WT and CD43−/− heart sections from TAC and Sham animals. (B) Quantification of CD11b infiltrates in WT and CD43−/− Sham and TAC LV across the whole heart section. IC is isotype control; arrows indicate immune reactivity for CD11b antibody. Scale bars, 100μm. (C,D) qPCR quantification of inducible nitric oxide synthase (iNOS; C) and Arginase I (Arg-1; D) in untreated and LPS (C) or IL-4 (D) treated bone marrow (BM) derived monocytes from WT and CD43−/− mice after 72h of stimulation. (E,F) qPCR quantification of TNFα (E) and CXCL10 (F) of WT and CD43−/− hearts harvested 4weeks after Sham or TAC surgery. *p≤0.05; and **p≤0.01.