Figure 4

Figure 4

Multiple cryoinjuries enhance deposition of ColXII and connective tissue in the remaining fibrotic tissue. (A) Cross sections of adult zebrafish hearts immunostained for the type XII collagen (ColXII; green) and Fibronectin (red) in uninjured hearts and at 60 dpci, following one, two, three or six cryoinjuries. The cardiac muscle is detected by F-actin staining (Phalloidin, blue). In uninjured hearts, ColXII is detected in the epicardium (E) and the junctional region (J) between the compact myocardium (CoM) and the trabecular myocardium (TrM). After cryoinjuries, the fibrotic tissue of partially regenerated hearts contains ColXII and Fibronectin (yellow through an overlay of green and red staining). (B) Cross sections of adult zebrafish hearts stained with fluorescein-conjugated lectin Ricinus communis agglutinin 1 (RCA1, green). The cardiac muscle is detected by F-actin staining (Phalloidin, red). In uninjured hearts, RCA1 labels the valve (V), the epicardium (E) and the junctional region (J) between the compact (CoM) and the trabecular myocardium (TrM). After cryoinjuries, the fibrotic tissue of partially regenerated hearts displays abundant RCA1 labelling. (C) Analysis of the percentage of ColXII-positive area per heart section. N ≥ 5. *P < 0.05; **P < 0.01; ***P < 0.001. Scatter plot of the data with a large bar indicating the mean and smaller bars representing the SEM. (D) Analysis of the percentage RCA1-positive area per heart section. N ≥ 5. *P < 0.05; **P < 0.01. Scatter plot of the data with a large bar indicating the mean and smaller bars representing the SEM.