Inhibition of adhesion molecules markedly ameliorates cytokine-induced sustained myocardial dysfunction in dogs in vivo

Adhesion molecules are key molecules for inflammatory cardiovascular diseases and are known to be up-regulated by inflammatory cytokines. However, the role of adhesion molecules in the cytokine-induced myocardial dysfunction in vivo remains unclear. This role was examined in our novel canine model, in which chronic treatment of the heart with IL-1β-bound microspheres (MS), but not control MS, causes sustained myocardial dysfunction in vivo. The expression of P-selectin (mRNA and immunoreactivity) was more prominent in the IL-1β group than in the control group (treated with control MS alone) after MS injection. The extent of neutrophil infiltration and myocardial myeloperoxidase (MPO) activity were significantly increased in the IL-1β group (P < 0.01). Pre-treatment with SLeX-OS (a novel oligosaccharide analog of sialyl Lewis(X)) or PB1.3 (a monoclonal antibody to P-selectin) prevented the myocardial dysfunction and significantly suppressed the neutrophil infiltration and the increase in myocardial MPO activity induced by IL-1β (P < 0.01 each). These results indicate that adhesion molecules play an important role in the pathogenesis of the cytokine-induced sustained myocardial dysfunction in dogs in vivo.