Effect of TREM2 on cardiomyocyte apoptosis after MI. The Ad.TREM2 transfection decreased cell apoptosis after myocardial infection. TUNEL staining showed that TREM2 adenovirus transfection significantly reduced the number of apoptotic cells after MI compared to Ad.Null transfection and MI group. Histogram showed the number of apoptotic cells in all groups. Magnification: ×200; bar: 100 µm; n=5, *, P<0.05 vs. MI and Ad.Null group. TREM2, triggering receptor expressed on myeloid cells-2; MI, myocardial infarction. DAPI, 4',6-diamidino-2-phenylindole; TnI, troponin I.