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. 2022 Sep 18;26(20):5135–5149. doi: 10.1111/jcmm.17539

FIGURE 5.

FIGURE 5

miR‐486 expression is downregulated and SRSF3 expression is upregulated significantly in the infarct zone post‐MI, and AAV9‐miR‐486‐mediated overexpression in MI improves fibrotic pathology, fibrosis and pathological remodelling in 8‐week post‐MI hearts, which benefits the regeneration of MI. (A) miR‐486 expression was downregulated significantly in both the infarct zone and noninfarct zone. n = 3, 6 and 6 for the sham, noninfarct zone and infarct zone groups. (B) SRSF3 expression was upregulated significantly in both the infarct zone and noninfarct zone. n = 3, 5 and 5 for the sham, noninfarct zone and infarct zone groups. (C) The expression level of miR‐486 was significantly higher in the infarct zone of the AAV9‐miR‐486‐EGFP‐treated myocardium than in the AAV9‐NC‐treated myocardium. n = 3. (D) The echocardiography analysis (D1) showed that the left ventricular anterior wall in the end‐systolic phase (LVAWs, D2) and the left ventricular anterior wall in the end‐diastolic phase (LVAWd, D3) of the AAV9‐miR‐486‐EGFP‐treated group were significantly thicker than those of the AAV9‐NC‐treated group. The left ventricular end‐systolic diameter (LVESD, D4) of the AAV9‐miR‐486‐treated group was significantly smaller than that of the AAV9‐NC‐treated group, but the difference in the left ventricular end‐diastolic diameter (LVEDD, D5) between the AAV9‐miR‐486‐EGFP‐treated group and the AAV9‐NC‐treated group was not statistically significant. The ejection fraction (EF, D6) and fractional shortening (FS, D7) of the AAV9‐miR‐486‐EGFP‐treated group were significantly higher than those of the AAV9‐NC‐treated group. n = 10. (E) The analysis of Masson's trichrome staining (E1) showed that the collagen area of the infarct zone (CAIZ) in the AAV9‐miR‐486‐EGFP‐treated group was significantly smaller than that of the AAV9‐NC‐treated group (E2). The thickness of the infarcted myocardium of the left ventricle (TIM, E3) and the wall thickness of the border zone of the left ventricle (WTBZ, E4) of the AAV9‐miR‐486‐EGFP‐treated group were significantly larger than those of the AAV9‐NC‐treated group. The infarct size of the AAV9‐miR‐486‐EGFP‐treated group was significantly smaller than that of the AAV9‐NC‐treated group (E5). n = 10. (F) The treadmill test revealed that the running endurance time of the AAV9‐miR‐486‐EGFP‐treated group was significantly longer than that of the AAV9‐NC‐treated group. n = 8 and 10 for the AAV9‐NC and AAV9‐miR‐486 groups. (G) WGA staining of the cardiomyocyte area showed that the cardiomyocyte area of the AAV9‐miR‐486‐EGFP‐treated group was significantly smaller than that of the AAV9‐NC‐treated group in both the infarct zone and border zone. (G1) Representative images of the AAV9‐miR‐486‐EGFP‐ and AAV9‐NC‐treated groups in the border zone. (G2) Quantitative analysis of (G1). (G3) Representative images of the AAV9‐miR‐486‐EGFP‐ and AAV9‐NC‐treated groups in the remote zone. (G4) Quantitative analysis of G3. n = 8 and 10 for the AAV9‐NC and AAV9‐miR‐486 groups. (H) The results of anti‐vWF immunohistochemistry staining revealed that AAV9‐miR‐486‐EGFP treatment was able to improve cardiac angiogenesis in the post‐MI heart. (H1) Representative images of the AAV9‐miR‐486‐EGFP‐ and AAV9‐NC‐treated groups in the infarct zone. (H2) Quantitative analysis of (H1). (H3) Representative images of the AAV9‐miR‐486‐EGFP‐ and AAV9‐NC‐treated groups in the border zone. (H4) Quantitative analysis of H3. n = 5 and 6 for the AAV9‐NC and AAV9‐miR‐486 groups, respectively.