Fig. 2

Epicardial Chemokine Expression Directs Superficial Coronary Revascularization (A–D) Ventricles at 10 dpci stained for epicardium (white), endothelium (green), CMs (red), and DNA (blue). High-magnification images of intra-ventricular sprouting coronaries (Ai, Bi; EGFP+ yellow arrowheads) and superficial coronaries (Aii, Bii; EGFP+, magenta arrowheads) in DMSO- (A) and MTZ- (B) treated animals. Number of superficial cECs (C) and intra-ventricular coronaries (D) in DMSO- (n = 6) and MTZ- (n = 6) treated animals at 10 dpci. (E) 7 dpci ventricle stained for cxcl12b:YFP expression (white), coronary ECs (green), CMs (red), and DNA (blue). High-magnification images of regenerating epicardium upregulating cxcl12b:YFP expression. (F) qPCR analysis of aldh1a2 and cxcl12b mRNA levels in sorted tcf21:RFP+ cells from 7 days post-sham (dps) and 7 dpci ventricles (n = 4). (G–K) 7 dpci ventricle stained for cxcl12b:YFP expression (green), activated epicardium and endocardium (white), CMs (red), and DNA (blue) (G). High-magnification images of regenerating cxcl12b:YFP+ epicardium (yellow arrowheads) and activated endocardium negative for cxcl12b:YFP expression (magenta arrowheads). Wholemount images of Tg(fli1a:EGFP) WT (H) and cxcr4a−/− (I) ventricles at 7 dpci. (I) High-magnification image shows an intra-ventricular sprouting coronary in a cxcr4a−/− heart (white arrowhead). Number of superficial cECs (J) and intra-ventricular coronaries (K) in WT (n = 6) and cxcr4a−/− (n = 6) animals at 7 dpci. Data in graphs expressed as mean ± SEM. ∗∗p < 0.01. Scale bars: 100 μm. See also Figures S4 and S5; Table S1.