Figure 8.

miR-486 is necessary for exercise-induced myocardial protection

(A) RT-PCR for miR-486 expression in the mouse heart and isolated mouse cardiomyocytes (CMs) or cardiac fibroblasts (CFs) from swimming or sedentary mice (n = 5–6). (B) Schematic diagram showing that mice were injected with miR-486 sponge AAV9 and then subjected to 3 weeks of swimming exercise before cardiac ischemia/reperfusion (I/R) injury. (C) The 2,3,5-triphenyltetrazolium chloride (TTC) staining for infarct size at 24 h after cardiac I/R injury as determined by the infarct-size/area-at-risk (INF/AAR) ratio. The area-at-risk/left-ventricle-weight (AAR/LV) ratio represents the homogeneity of surgery (n = 6 for sedentary mice, n = 10 for swimming mice). (D) RT-PCR for miR-486 expression in mouse heart tissues at 1 week post cardiac I/R injury (n = 6 for sedentary mice, n = 11–12 for swimming mice). (E) Echocardiography for left-ventricular ejection fraction (EF, %) and fractional shortening (FS, %) in mice at 1 week after I/R injury (n = 6 for sedentary mice, n = 11–12 for swimming mice). (F) TUNEL staining for myocardial apoptosis in α-actinin-labeled cardiomyocytes (n = 6). Scale bar, 100 μm. (G) Western blot for Bax/Bcl-2 ratio, cleaved-caspase-3/caspase-3 ratio, PTEN, and FoxO1 in mouse heart tissues (n = 6). Data between two groups were compared by unpaired two-tailed Student's t test. Data among four groups were compared by two-way ANOVA followed by Tukey’s post hoc test. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001.