Figure 6: BIO improves cardiac remodeling with increased anti-inflammatory macrophages.

(A) Masson’s trichrome staining of rat hearts two weeks after MI shows that 0.2 mg/kg BIO treatment reduced fibrosis and scar formation (blue staining). Quantification of fibrosis indicates that BIO treatment reduces scarring after MI. n = 4 in Non MI, n = 5 in MI + Veh, n = 8 in MI + BIO group, *p < 0.05, t-test. (B) Representative electrocardiography of the treated rats two weeks after MI. Treatment with BIO improved contractility after MI. (C) The cardiac function related parameters were improved in the BIO group two weeks after MI. N = 4 in Non MI, n = 5 in MI + Veh, n = 8 in MI + BIO group, *p < 0.05, t-test. IVSd, intraventricular septal width in diastole; IVSs, intraventricular septal width in systole; LVIDd, left ventricular internal dimension in diastole; LVIDs, left ventricular internal dimension in systole; LVPWd, left ventricular posterior wall thickness in diastole; LVPWs, left ventricular posterior wall thickness in systole; EDV, end-diastolic volume; ESV, end-systolic volume; EF, ejection fraction; SV, stroke volume; FS, fractional shortening. (D) Representative images of immunofluorescent staining for the macrophage marker CD68 (green) and Arg (red) in the infarct myocardium at 14 days post-MI. Arg-expressing M2 anti-inflammatory macrophages can be identified as yellow cells in the merged images. The BIO group was observed to contain greater numbers of M2 macrophages. (E) Quantification of anti-inflammatory CD68/Arg expressing macrophages showed that BIO group contained significantly higher numbers of M2 macrophages in the infarction zone. n = 3 in Non MI, n = 3 in MI + Veh, n = 6 in MI + BIO group, *p < 0.05, t-test. (F) Quantification of the pro-cardiac fibrosis cytokine, IL-6 in the sera of rats 2 weeks after MI. BIO treated rats showed decreased IL-6 levels. n = 5, *p < 0.05, t-test.