Fig. 5

Identification of hepatocyte growth factor as an antiapoptotic mediator. Multiple surviving clusters of cardiomyocytes were found within the infarcted area after receiving Wilms’ tumor factor 1 (WT1)-positive (WT1^pos) cell injection (WT1-pos) (a). These cardiomyocytes showed a lower prevalence of apoptotic events evidenced by caspase 3 (Casp3) staining compared with the WT1^neg cell-injected hearts (WT1-neg) (b, c). Transcriptional analysis revealed a significant upregulation of hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF)a in WT1^pos cells, whereas insulin-like growth factor (IGF)-1, VEGF-b, and fibroblast growth factor (FGF)-2 remained unchanged (d). The conditioned medium from the WT1^pos cells prevented the H₂O₂-induced apoptosis in neonatal cardiomyocytes, evidenced by the reduced transition of aggregates (red) to monomers (green) of JC-1 dye (e, f), which was blocked by the addition of HGF antibody (+AB) and was mimicked by the addition of recombinant HGF protein (+HGF). Arrow in (a) indicates the site of injection. **p < 0.01. TGF transforming growth factor