Cardiomyocytes isolated from postnatal day 1 (P1) mice were cultured in vitro and stimulated for 48 h with selected growth factors (10 ng/mL), namely CCL3, CXCL17, GAL7 (LSGAL7), IL1RA, BMP14, and BMP7. Cardiomyocytes were identified by cardiac Troponin T (cTnT) or Troponin I (cTnI) staining and analyzed by immunofluorescence for (A) cell-cycle activity (KI67) (n= 13,961 cardiomyocytes pooled from the analysis of 68 samples); representative pictures are provided; arrows point at proliferating cardiomyocytes; scale bars, 20 μm.
