Fig. 7

Oct4 collaborated with c-Myc-transfected cMSCs to ameliorate MI pathology. A To determine the effects of Oct4 and c-Myc-treated cardiac MSCs on left ventricle structure 30 days after MI, hearts were stained with Masson’s Trichrome (Left and Middle) or hematoxylin and eosin (Right). The infarct zone of the oec-Myc-transfected cMSCs-treated group contained inflammation, fibrosis, and angiogenesis, which were favorably replaced by angiogenesis and cardiomyogenesis after co-transfection of Oct4. However, hearts of rats treated with cMSCs co-transfected with siRNAs of c-Myc and Oct4 displayed extensive fibrosis in the infarct zone demonstrated by collagen formation (blue).The PBS-treated group showed mostly inflammation and scar formation. B through E. Morphometric measurements of inflammatory cells B, viable myocardium C, relative scar area D, and collagen content (E) 30 days after cell therapy revealed a smaller and thicker scar in the oeOct4 plus c-Myc-transfected cMSCs-treated group, compared with alone cMSCs- and PBS-treated groups. Quantitative analysis of viable myocardium C in rat hearts from the different groups showed significantly larger ratios of viable myocardium in hearts treated with cMSCs receiving co-transfection of c-Myc and Oct4, compared with alone cMSCs- and PBS-treated groups. P value for the difference between groups was calculated by the Welch test followed by a Brown-Forsythe multiple comparisons test. p < 0.05: ^*vs PBS injection, ^#vs. cMSCs therapy alone, ^Δvs. Transplantation of oec-Myc transfected cMSCs, ^†vs. Transplantation of cMSCs transfected with oec-Myc plus oeOct4, ^§vs. Transplantation of cMSCs transfected with oec-Myc plus siOct4, ^║vs. Transplantation of cMSCs transfected with sic-Myc, ^¶vs. Transplantation of cMSCs transfected with sic-Myc plus oeOct4 (n = 5, each group). cMSCs indicate cardiac mesenchymal stem cells; H&E, hematoxylin and eosin; PBS, phosphate-buffered solution