Adhesion molecules in cerebral ischemia and atherosclerosis

Abstract

Adhesion molecules are integral membrane proteins that have cytoplasmic, transmembrane and extracellular domains. Dozens of different adhesion molecules have been identified, but, adhesion molecules are conventionally divided into four main groups, each of which has a different function: 1. The selectins, 2. The immunglobulin gene superfamily, 3. The integrins and 4. The cadherins. Under normal conditions, there is little or no cell-surface expression of adhesion molecules. Various inflammatory processes induce their expressions, such as atherosclerosis and cerebral ischemia, with the upregulations mediated by cytokines. Normally, vascular endothelial cells have low adhesiveness for leukocytes; however, when stimulated they express adhesion molecules at their surfaces responsible for adhesion and activation of leukocytes as a precondition for transendothelial migration of leukocytes. The effect of anti-adhesion molecule strategies in focal cerebral and spinal cord ischemia showed a beneficial effect in models in which transient focal ischemia was followed by reperfusion, but not in models of permanent ischemia. In addition anti-inflammatory agents could have reduced expression and shedding of adhesion molecules as a result of its antiinflammatory properties.