Curative effect evaluation of MSCs-MK by echocardiography in rats after myocardial infarction. A: Survival rate estimated by the Kaplan-Meier method in sham rats (sham; n = 12, none died), MI rats treated by PBS (PBS; n = 12, 7 died), MI rats treated with MSCs (MSCs; n = 12, 6 died), with MSCs-GFP (MSCs-GFP; n = 12, 7 died) and with MSCs-MK (MSCs-MK; n = 12, 3 died). Survival rates of MSCs-MK were significantly higher than for MSCs and MSCs-GFP. B: Representative echocardiography findings in the MSCs-MK group before MI (pre-operation) and 4, 8 and 12 weeks after MI (post-treatment). C, D, E and F: Measurements were performed at baseline before MI and 4, 8 and 12 weeks after MI, as indicated. (C) Left ventricular end-diastolic diameter (LVEDD). (D) Left ventricular end-systolic diameter (LVESD). (E) Fractional shortening (FS). (F) Ejection fraction (EF). *indicates p< 0.05 vs. the PBS group at the same time-point, one-way ANOVA. All values represent mean ± SEM. MI, Myocardial infarction; MSCs-GFP, Mesenchymal stem cells-green fluorescent protein; MSCs-MK, Mesenchymal stem cells-midkine.