Multi-Potent Sca-1+ CPCs Figure 4. Transplantation effect of cardiac multipotent cells into infarction area of mouse heart. A, Schematic representation of the time course of in vivo experiment. B, Cardiac function and dimensions analyzed by echocardiography. (*p,0.05 vs control). Abbreviations: FS, fractional shortening; EF, ejection fraction; LVDd, left ventricle end-diastolic dimension; AWT, end-diastolic anterior wall thickness. C, Heart function studies at four weeks after LAD ligation and cell transplantation. Left upper panels show representative heart sections after Masson’s trichrome staining. Left lower panel shows calculated infarction size. Middle panel shows anterior wall thickness of infarcted area. Right panel shows area of fibrosis (%) calculated by computer software. (*p,0.05 vs control). doi:10.1371/journal.pone.0025265.g004 multipotentiality [28]. On the contrary, Sca-1+ progenitor cells constitute a predominant stem cell population in the heart as compared to the c-kit+ cells [1]. We observed that the purified Sca-1+ cells expressed mature cardiomyocyte gene markers including b-MHC and MLC2a. Although a-MHC is predominant isoform of MHC in adult mouse heart, b-MHC isoform is strongly expressed in both atrial and ventricular muscle in the developing heart [26]. Additionally, MLC2a is expressed in myocardial cells during early stage of cardiac development as one of the earliest marker for differenti- ated cardiomyocytes [29]. Therefore, the gene expression of b- MHC and MLC2a markers clearly represented early commitment to cardiomyogenic lineage. The purified Sca-1+ cells also expressed Isl-1 gene, a marker for secondary heart field [10,22]. Isl-1+ cells are considered as cardiovascular precursors with the ability to differentiate into the three main cardiac cell lineages [9] and post-natal mouse heart [5]. Brachyury (Bry)+/Flk-1+ cells from mouse ES cell derived PLoS ONE | www.plosone.org 7 September 2011 | Volume 6 | Issue 9 | e25265