Diapedesis of leukocytes: antisense oligonucleotides for rescue

Ischemia-reperfusion injury is an acute inflammatory process during which leukocytes are intimately involved. In this review, we summarize the current data on the leukocyte cell adhesion cascade in ischemia-reperfusion injury, focus upon studies which have demonstrated specific cell adhesion molecule interactions which mediate the leukocyte involvement in ischemia-reperfusion injury, and suggest future avenues of therapeutic interventions. The increased adhesion between activated vascular endothelium and peripheral blood leukocytes is central to the structural and the functional impairment in ischemia-reperfusion injury. Several families of adhesion molecules, namely the selectins, the intercellular adhesion molecules (ICAMs), and the integrins expressed either on the endothelium or on the leukocytes, are involved the cascade of events. Sequential and overlapping cellular interactions between the members of the three gene families of adhesion receptors result in adhesion of the leukocytes to the endothelium and extravasation at the site of ischemia. The functional importance of ICAM-1 and its beta2 integrin ligands in ischemia-reperfusion of the kidney has been demonstrated by monoclonal antibody blockade studies, in knockout mice and by treatment with antisense oligodeoxynulceotides (ODN). We have shown that antisense ODN for ICAM-1 protected the kidney against ischemic renal failure. In addition, in transplanted kidneys, ICAM-1 inhibition by antisense ODN ameliorates ischemia-reperfusion injury and prevents delayed graft function. Recent developments in antisense ODN technology make this a promising therapeutic approach, and antisense ODN treatment of donors or donor organs for ICAM-1 may be useful for the prevention of reperfusion injury in human renal transplantation and could influence acute and chronic graft function.