Fig. 9: Engraftment of mature and immature cardiomyocytes into infarcted rat hearts.

a Representative immunostaining of whole rat hearts 2 and 8 weeks following transplantation of the mature and immature cardiomyocyte populations. b Quantification of graft size generated from the transplanted mature and immature cells (N = 8 recipients of 2-week immature cells, 6 recipients of 2-week mature cells, 8 recipients of 8-week immature cells, and 9 recipients of 8-week mature cells). c Representative immunostaining of human cardiomyocyte grafts 2 and 8 weeks following transplantation of the indicated cardiomyocyte populations. Scale bar: 20 um. d Quantification of sarcomere length in cardiomyocytes in grafts (2 and 8 weeks) generated from immature and mature cells (N = 8 recipients of 2-week immature cells, 5 recipients of 2-week mature cells, 8 recipients of 8-week immature cells, and 8 recipients of 8-week mature cells). e Representative immunostaining showing Ki67⁺ cells in cardiomyocyte grafts generated from immature and mature cells. Scale bar: 20 um. f Quantification of the percentage of Ki67⁺ cardiomyocytes in grafts (2 and 8 weeks) derived from immature and mature cells (N = 8 recipients of 2-week immature cells, 5 recipients of 2-week mature cells, 8 recipients of 8-week immature cells, and 8 recipients of 8-week mature cells). g Representative immunostaining showing CX43 expression in grafts derived from immature and mature cells. Scale bar: 20 um. h Quantification of CX43 expression in grafts (2 and 8 weeks) derived from immature and mature cells (N = 8 recipients of 2-week immature cells, 5 recipients of 2-week mature cells, 8 recipients of 8-week immature cells, and 8 recipients of 8-week mature cells). Quantification of the sarcomere length, the proportion of Ki67⁺ cardiomyocytes, and CX43 expression was evaluated from 5 to 10 randomly selected areas of cTNT⁺ grafted cardiomyocytes and averaged for each transplanted heart. All statistical analyses were performed by one-way ANOVA with Tukey’s multiple comparisons (****p < 0.0001). Data are presented as mean values ± SEM.