Fig. 1.

Re-activation of Wnt/β-catenin signaling increases matured mouse cardiomyocyte proliferation. a Representative images of untreated control and treated matured mouse cardiomyocytes with either N-cadherin antibody (1:1000) or CHIR99021 (1 μM) immunostained for BrdU (red) and cTnT (green); BrdU and cTnT double-positive cells are marked by white arrows. Cell nuclei (blue) were stained with DAPI. Scale bar, 100 μm. b Graphical representation showing fold change in BrdU+ cardiomyocytes in N-cadherin antibody (1:1000) and CHIR99021 (1 μM)-treated cardiomyocytes compared to untreated cardiomyocytes (control). Note the ~ 1.5-fold increase in BrdU-positive cardiomyocytes in treated cardiomyocytes as compared to control. Error bars indicate s.d., n = 3 experiments, *P < 0.05 for Kruskal-Wallis one-way analysis of variance compared to control. c Quantitative PCR analysis of mRNA isolated from cardiomyocytes from untreated control and cardiomyocytes treated with N-cadherin antibody (1:1000) or CHIR99021 (1 μM). The relative gene expression levels showed that most cyclin genes were significantly upregulated in cardiomyocytes treated with either N-cadherin antibody or CHIR99021. Error bars indicate s.d., n = 3 experiments. *P < 0.05 and **P < 0.01 for Kruskal-Wallis one-way analysis of variance compared to control