The role of cardiac resident macrophages in heart repair following myocardial infarction in mice
Objective To explore the role and mechanism of cardiac resident macrophages in heart repair after myocardial infarction in mice.Methods Macrophage-specific Cre tool mice(CX3CR1CreER-YFP mice)with doubly transgenic mice(R26tdTomato/DTR mice)were hybridized to obtain cardiac resident macrophage-specific red fluorescent labels in mice.Sixty Cx3crlCreER-YFP:R26Td/DTR hybrid mice were randomly divided into 4 groups:Sham group,DT+Sham group,MI group,and DT+MI group,with 15 mice in each group.MI group and DT+MI group underwent myocardial infarction modeling by ligating the left anterior descending coronary artery.The DT+MI group mice were induced to deplete resident macrophages in the heart tissue using diphtheria toxin(DT)to establish a cardiac resident macrophage knockout model.On the 5th day after myocardial infarction modeling,heart tissue slices of mice were stained with H-E to observe inflammation infiltration and myocardial infarct size were calculated;on the 14th day of modeling,echocardiography was used to measure cardiac function-related parameters in mice,and mRNA expression levels of inflammatory cytokines were detected.Results Compared with the MI group,the DT+MI group mice showed a significant reduction in cardiac resident macrophages([53.75±4.62]vs[6.37±1.25],P＜0.05).On the 14th day after myocardial infarction modeling,compared with the Ml group,the DT+MI group mice had significantly increased left ventricular end-diastolic diameter([5.11±0.22]mm vs[5.92±0.26]mm,P＜0.05)and left ventricular end-systolic diameter([4.77±0.17]mm vs[5.38±0.16]mm,P＜0.05),while the ejection fraction significantly decreased([27.76±1.20]％vs[17.61±0.94]％,P＜0.05);in addition,the DT+MI group mice showed increased expression levels of inflammatory cytokines,increased inflammatory cell infiltration,and significantly larger myocardial infarct size.The protein expression levels of NF-KB/p-P65 in DT+MI group mice were significantly higher than those in the MI group([0.28±0.14]vs[1.09±0.12],P＜0.05).Conclusions Cardiac resident macrophages play an important role in heart tissue repair after myocardial infarction by reducing inflammation cell infiltration and myocardial infarct size.
万方数据
维普
