Figure 5
Histology and immunohistochemical analysis of MI rat heart 1 month after epicardial engraftment of MSC-patch: (a) LV short axis HES assessment showed enhancement of parietal thickness. The dotted line delimits the engrafted MSC-patch (red arrows) and MI native tissue, (b) moderated and localized infiltration with macrophages and polymorphonuclear leukocytes documented in the patch’s area (black arrow), (c) Red Sirius assessment showing dense collagen thickness of the engrafted patch and collagen from chronic MI; the black arrows indicate fibrous reactions around 7/0 prolene stitch (blue). Immunohistochemical analysis showed in (d) that engrafted MSC’s area expressed desmin (black arrows depict some positive yellow-brownish DAB staining, in (e, X100) and (f, X400) that engrafted MSC’s area expressed dense tissue positively stained for α-smooth muscle actinin showing dense neo-vessels network (black arrows) between the grafted area and the native myocardial tissue.