Figure 3.

Systemic depletion of macrophages reduced the benefits of PCSK9 knockout in cardiac repair after myocardial infarction. (a) After being adaptively fed for 6 days, Cl₂MDP or PBS were injected into the tail vein to systemically deplete macrophages. (b) Immunohistochemical staining for F4/80 expression in mouse hearts from Cl₂MDP- and PBS-treated mice after myocardial infarction. Scale bar = 50 μm, n = 5. Quantitative analysis by ImageJ for F4/80⁺ cells of myocardium in (b). (c, d) Cardiac function measured by echocardiography after Cl₂MDP and PBS treatment in the WT ischemia group, n = 4. (e, f) Cardiac function measured by echocardiography after Cl₂MDP and PBS treatment in the PCSK9^−/− ischemia group, n = 4. ^∗P < 0.05; ^∗∗P < 0.01; ^∗∗∗P < 0.001; ns: not significant.