Fig. 7: Targeted inhibition of conserved pathways impairs maturation.

a Immunofluorescent (IF) staining against ACTN2 and AURKB in imCMs-AF upon transfection with shNT and shDcn, respectively. Scale bars = 25 or 10 μm. b Quantification of ACTN2⁺AURKB⁺ (a), ACTN2⁺MKI67⁺ (Supplementary Fig. 5b) or ACTN2⁺pH3⁺ (Supplementary Fig. 5c). Data are plotted as mean ± SEM from three independent experiments, ***p < 0.001, two-sided Student’s t-test. c Immunostaining against ACTN2 and Phalloidin in imCMs 3.5 days after co-culture with AFs upon depletion of NT (shNT) or Dcn (shDcn), respectively. d Percentages of CMs in different morphology grades in c. e Immunostaining against ACTN2 and Phalloidin in imCMs 3.5 days after co-culture with AFs in the presence of DMSO, Plerixafor or BP-1-102, respectively. f Percentage of CMs in different morphology grades in e. g Workflow of animal experiment. Neonatal (P1) mice were treated with DMSO, Plerixafor or BP-1-102 daily for 14 (Day 14) or 21 days (Day 21), respectively. Mice were sacrificed for immunostaining of heart sections at P14 or P21, respectively. h Immunofluorescent staining against ACTN2 and pH3 in heart sections from mice at P14. White arrows indicate co-localization. Scale bar = 10 or 25 μm. i Quantification of ACTN2⁺AURKB⁺, ACTN2⁺MKI67⁺, and ACTN2⁺pH3⁺ cells^. Data are plotted as mean ± SEM, n = 8 biologically independent mice, ***p < 0.001, two-sided Student’s t-test. j Immunofluorescent staining of ACTN2 and GJA1 in heart sections of mice treated with DMSO, Plerixafor or BP-1-102 for 14 days, respectively. White arrows indicate co-localization. Scale bars = 10 or 25 μm. k Quantification of ACTN2⁺GJA1⁺ cells in j, Data are plotted as mean ± SEM, n = 8 biologically independent mice, ***p < 0.001, two-sided Student’s t-test. Source data are provided as a Source Data file.