Abstract 18513: CXCl16 Promotes Ly6Chigh Monocyte/Macrophage Infiltration and Impairs Cardiac Function After Acute Myocardial Infarction

Objective: CXCL16 has been implicated in the pathogenesis of atherosclerosis, but the function of CXCL16 in myocardial infarction (MI) is unknown. This research examines the effects of CXCL16 in myocardial infarcted mice. Methods and results: MI was induced in 8 to 12 week-old male mice (C57BL/6 background) by permanent coronary ligation of the left anterior descending artery (LAD). The expression of CXCL16 was increased in the heart of mice after MI on day 1. Compared to WT mice, CXCL16 knockout (CXCL16 KO) mice showed improved cardiac function by echocardiography and attenuated infarct size by Masson trichrome staining on 14 days after MI. FACS analysis of cardiac tissue of mice on 3 days after MI showed an increased infiltration of CD45+CD11b+F4/80+ monocytes/macrophages, including Ly6Chigh monocytes/macrophages and Ly6Clow monocytes/macrophages. Q-PCR analysis demonstrated that TNFα and IL1β were highly expressed in Ly6Chigh monocytes/macrophages, while IL4 and TGFβ were highly expressed in Ly6Clow mo...