Fig. 1

MiR-128 increases as the heart progresses from neonate to adult. a Evaluation of wild-type mouse cardiomyocyte (CM) proliferative activity using Ki67 immunostaining at postnatal day 1 (P1), P7, and P28. Scale bars, 25 µm. b Percentage of CM Ki67⁺/cTnT⁺ in P1, P7, and P28 hearts (n = 5 mice for each time point, ~600 CMs/heart). c Wheat germ agglutinin (WGA) staining of P1, P7, and P28 hearts. Scale bars, 25 µm. d Quantification of CM size in P1, P7, and P28 hearts stained with WGA (n = 5 mice for each time point, ~250 CMs/heart). e Evaluation of miR-128 expression level during heart development using qPCR analysis, including embryonic day 14.5 (E14.5), E19.5, P1, P3, P7, P14, and P28 hearts (n = 5). f qPCR analysis of miR-128 expression in neonatal (P1) and adult (P28) CMs (n = 5). g Comparison of miR-128 expression by qPCR in cardiac fibroblast (CF) and CMs (n = 5). Statistical significance was calculated using ANOVA in b, d and Student’s t-test in f, g. Data are represented as means ± SEM. *P < 0.05