Fig. 4

Anti-inflammation reagents and cisapride rescue the heart regenerative capability in bre mutant after cryoinjury. (A). Representative picrosirus red staining paraffin sections of heart in bre mutant treated with DMSO (vehicle control), Dex (100 μm), MMP in (1 μm) and Cis (10 μm) illustrate the scar volume at 30 dpc. The black dashed line bounded area indicates the injured scar area. Scale bar: 100 μm. (B). Bar chart (n = 4) shows the quantification of the percentage of scar volume in panel A was significantly different between control and each treatment group at p < 0.01 (**) and p < 0.001 (***), two tail t-test. (C) Representative images of immunofluorescent labeling of cardiomyocyte (red) and PCNA (green) in the injured area of bre mutant zebrafish treated with DMSO (vehicle control), Dex (100 μm), MMP in (1 μm) and Cis(10 μm) at 7 dpc. The white arrow indicates the double positive TnnT⁺/PCNA⁺ cells in the injured area (IA). Scale bar:100 μm. (K). Bar chart shows the quantification of double positive TnnT⁺/PCNA⁺ (n = 4) in panel H, two tail t-test, p < 0.05 (*). (E) Representative heart sections of bre mutant with different treatment, displaying mitotic cells (green) in the injured area at 7 dpc. Scale bar: 100 μm. (F). Bar chart shows the quantification of mitotic cells (n = 3–4) in panel C was significantly different between each group at p < 0.01 (**), two tail t-test. (G). Representative heart sections of bre mutant zebrafish with different treatment show the α-SMA (green, white arrowhead) at 4 dpc.