Fig. 1

Wnt/β-Catenin regulates the early stages of zebrafish heart regeneration

(A) Schematic of adult zebrafish heart ablation experiments.

(B–E) Immunohistochemistry of uninjured (UI), 3, 7, and 30 dpi adult zebrafish hearts. Insets show representative areas of the heart, magnified, and with channels split. Scale bar for B–E: 100 μm, area of inset: 200 μm², scale bar in insets: 25 μm. Blue-DAPI, Red-Pcna, and Green-Mef2c. Yellow arrow heads denote proliferating cardiomyocytes that are Pcna and Mef2c positive.

(F and G) Quantification of cardiomyocyte abundance and cardiomyocyte proliferation. After injury, there is a significant increase in proliferating cardiomyocytes as seen by the double staining of Mef2c and Pcna. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001; one-way ANOVA performed. n = 2–3 biological replicates.

(H) Protein analysis of UI and 3 dpi hearts for Wnt targets Axin, c-Myc, and Pcna.

(I) Quantification of protein analysis in (H). ∗p < 0.05, two-tailed t test performed. N = 3 biological replicates with each N being 3–5 pooled hearts.

(J) Schematic of adult zebrafish heart ablation and heat shock protocol for Wnt/β-catenin modulation fish.

(K) Protein analysis of Wnt/β-catenin modulation during adult zebrafish heart regeneration.

(L and M) Quantification of protein abundance in (K). ∗p < 0.05, two-tailed t test performed. N = 2–5 biological replicates with each N being 3–5 pooled hearts.

(N) Quantification of cardiomyocyte proliferation in the context of Wnt/β-catenin repression via hsDkk1b.

(O) Immunohistochemistry images of cardiomyocyte proliferation at 3 days postinjury during Wnt/β-catenin inhibition via hsDkk1b overexpression; all animals were presented with MTZ. Scale bar: 25 μm. Blue-DAPI, Red-Pcna, and Green-Mef2c. Yellow arrow heads denote proliferating cardiomyocytes that are Pcna and Mef2c positive. ∗p < 0.05, N = 3–6. One-way ANOVA was performed. Bar graphs show individual data points with error bars representing standard error of the mean. Source data are provided as a Data S2.