Figure 3. MSC-induced M2-polarization of macrophages is essential for protection of heart function in MI-mice. In order to evaluate the function of MSC-induced M2-polarization of macrophages in MI-mice, we set up 4 groups of mice. Group 1, mice received sham surgery and injection of saline (Sham). Group 2, mice received MI surgery and injection of saline (MI). Group 3, mice received MI surgery and injection of MSCs (MI+MSCs). Group 4, mice received MI surgery, injection of MSCs and injection of TNF-α, which helps to maintain a M1-phenotype of macrophages (MI+MSCs+ TNF-α). Four weeks after MI/MSCs/TNF-α treatment, the mouse heart function was assessed using ventricular catheterization. (A) End systolic pressure-volume relationship (ESPVR) (B) left ventricular end systolic pressure (LVESP) (C) Positive maximal pressure derivative (+dP/dt). *p<0.05. N=5.