Microscopic images from recipient mouse hearts 4 weeks post-transplantation.

Fluorescence immunostaining of the heart tissue revealed increased angiomyogenic differentiation of the transplanted Sca-1⁺ in the infarct and peri-infarct regions 4 weeks after transplantation (GFP (green 5A1,5B1), α-actinin (red; Figure 5A2) and vWF (red; Figure 5B2)). Arrows show the merged color of red and green indicating the colocalization of α-actinin and GFP (5A3) or vWF and GFP (5B3). The nuclei were stained with DAPI (blue) (C) Immunostaining of the heart tissue revealed Cx43 (red) expression between ^GFSca-1⁺ and the host cardiomyocytes (indicated by yellow arrows). (D) Cx43 (red) expression between ^GFSca-1⁺ and the co-cultured cardiomyocytes at day 4 after co-culture. (C–D) ^GFSca-1⁺ stem cells were prelabeled with DAPI (blue), and the nuclei were double stained with SYTOX (green).