Toll-like receptor 4 (TLR4) contri<em>b</em>utes to the pathogenesis of coronary ischemia/reperfusion (IR). To test whether the new TLR4 antagonist, ApTOLL, may prevent coronary IR damage, we administered 0.078 mg/kg ApTOLL or Place<em>b</em>o in pigs su<em>b</em>jected to IR, analyzing the levels of cardiac troponins, matrix metalloproteinases, pro-, and anti-inflammatory cytokines, heart function, and tissue integrity over a period of 7 days after IR. Our results show that ApTOLL reduced cardiac troponin-1 24 h after administration, improving heart function, as detected <em>b</em>y a significant recovery of the left ventricle ejection fraction (LVEF) and the shortening fraction (FS) cardiac parameters. The extension of necrotic and fi<em>b</em>rotic areas was also reduced, as detected <em>b</em>y Evans <em>b</em>lue/2,3,5-triphenyltetrazolium chloride (TTC) staining, Hematoxylin/Eosine, and Masson Trichrome staining of heart sections, together with a significant reduction in the expression of the extracellular matrix-degrading, matrix metalloproteinase 9. Finally, the expression of the following cytokines, CCL1, CCL2, MIP1-A-<em>B</em>, CCL5, CD40L, C5/C5A, CXCL1, CXCL10, CXCL11, CXCL12, G-CSF, GM-CSF, ICAM-1, INF-g, <em>IL1</em>-a, ILI-<em>b</em>, IL-1Ra, IL2, IL4, IL5, IL6, IL8, <em>IL1</em>0, <em>IL1</em>2, <em>IL1</em>3, <em>IL1</em>6, <em>IL1</em>7-A, <em>IL1</em>7- E, <em>IL1</em>8, IL21, IL27, IL32, MIF, SERPIN-E1, TNF-a, and TREM-1, were also assayed, detecting a pronounced decrease of pro-inflammatory cytokines after 7 days of treatment with ApTOLL. Altogether, our results show that ApTOLL is a promising new tool for the treatment of acute myocardial infarction (AMI).
Keywords: ApTOLL; acute myocardial infarction; cytokines; matrix metalloproteinases; toll-like receptor 4.