Fig. 6

Staining of myocardial sections after MSC transplantation and engraftment. a Representative H & E staining of myocardial sections of normal heart (A1), control medium- treated mice showing necrotic regions at scale bars, 200μm (left panel) and scale bars, 100μm (right panel) (A2), MSC-transplanted mice showing reduction of necrotic regions at magnification of scale bars, 200μm (left panel) and scale bars, 100μm (right panel) (A3), and CP-transplanted mice showing loss of necrosis and restoration of normal cardiac tissue architecture (scale bars, 200μm (left panel) and scale bars, 100μm (right panel) (A4)). b Cell tracker-labeled MSCs to study homing of cells to the cardiac region. Control medium-treated mice showed lack of cell tracking labels (top). MSC-transplanted group showed clear homing of the cell tracker positive cells (indicated by arrows) (middle). Nuclei counterstained with DAPI (blue). CP-transplanted group indicated homing of cell tracker positive cells (indicated by arrows) (bottom) with significant decrease in the size of the cardiac damage. Nuclei counterstained with DAPI. c Analysis of cardiac genes in the necrotic regions of mice myocardium. Quantitative RT-PCR of troponin T (TnT), atrial natriuretic peptide (ANP), and myosin light chain (MLC) control untreated, medium-only-treated, MSC-transplanted, and CP-treated groups showed the recovery of ANP and MLC expression in MSC-treated and CP-treated groups following Doxorubicin treatment (*p < 0.05, **p < 0.01, n = 4). WJMSC Wharton’s jelly mesenchymal stem cell, H&E hematoxylin and eosin, CP cardiac progenitors, Dox doxorubicin (Color figure online)