Figure 4. aYAP modRNA improves heart function and suppresses cardiac hypertrophy.

(A) Experimental design. IR and modRNA injection was performed as described in the material and methods. Red fluorescence beads were injected into the left ventricle after LAD ligation to label blood perfused ventricle. In this long term study, mouse heart function was measured by echocardiography at 1 d, 1, and 4 wk after IR. 1 mo after IR and modRNA treatment, hearts were collected for analysis. (B) EF% measured by echocardiography at 1 d after IR. Sham, n = 4; Veh+IR, n = 6; aYAP+IR, n = 5. (C) EF% measured by echocardiography. EF% was analyzed by paired t test. (D) Heart weight and tibia length ratio. Sham, n = 6; Veh+IR, n = 10; aYAP+IR, n = 10. One-way ANOVA post hoc tests. *P < 0.05. (E) Upper panel: morphology and AAR of hearts receiving different treatment. Micro red fluorescence beads were used to indicate blow flow. AAR region without red fluorescence beads was depicted by dotted lines. Lower panel: Sirius Red and fast green staining of heart sections. Bar = 1 mm. (F) Ratio between AAR and left ventricle surface area. N = 5. (G) Scar size normalized with AAR. (H) Septum thickness. (F, G, H) N = 5. t test *P < 0.05. (I) WGA staining of heart cross sections. Bar = 50 µm. (J) Quantification of septum CM cross-sectional area. In each group, 150 septum CMs were randomly measured. Mann–Whitney test: **P < 0.01. (K) qRT-PCR measurement of Mhy6 and Nppa mRNA level. N = 4. One-way ANOVA post hoc tests. *P < 0.05.