Fig. 5

Fig. 5

BMP Signaling Is Required for Myocardial Regeneration and Is Sufficient to Enhance It

(A) Expression of noggin3 in hsp70l:nog3 transgenics for 6 hr is sufficient to significantly reduce nuclear pSmad1/5/8 accumulation in cardiomyocytes (CMs; positive for myosin heavy chain, MHC) at the wound border at 7 dpi. h.s., heat shock. Average percentage of cardiomyocytes expressing pSmad1/5/8 relative to that in wild-type hearts is plotted. Error bars represent SEM. Student’s t test, **p = 0.003. Scale bar, 25 µm.

(B) GFP immunofluorescence analysis reveals wound size (dashed lines) at 21 dpi on heart sections of hsp70l:nog3; myl7:GFP, and hsp70l:bmp2b; myl7:GFP double transgenics and their respective myl7:GFP-only siblings (labelled “wild-type”) subjected to the depicted heat-shock regime. Size of the GFP-negative area relative to the whole ventricle and normalized to heat-shocked myl7:GFP-only siblings is plotted. Error bars represent SEM. Student’s t test, **p = 0.0081 (nog3), *p = 0.018 (bmp2b). Scale bar, 100 µm.

(C) Acid fuchsin orange G (AFOG) staining reveals wound size (dashed lines) at 21 dpi on heart sections of hsp70l:nog3, hsp70l:bmp2b transgenics and wild-type siblings subjected to the depicted heat-shock regime. Size of the wound tissue (red and purple staining) relative to the whole ventricle and normalized to heat-shocked wild-type siblings is plotted on the right. Error bars represent SEM. Student’s t test, *p = 0.002 (nog3), *p = 0.016 (bmp2b). Scale bar, 100 µm.