VASCULAR CELL-ADHESION MOLECULE-1 MESSENGER-RNA IS EXPRESSED IN IMMUNE-MEDIATED AND ISCHEMIC-INJURY OF THE RAT NERVOUS-SYSTEM

In this study we used nonradioactive in situ hybridization for the cel lular localization of vascular cell adhesion molecule-1 (VCAM-1) mRNA in immune-mediated, ischemic and degenerative diseases of the rat nerv ous system. In the acute phase of experimental autoimmune encephalomye litis and neuritis VCAM-1 mRNA was expressed not only on the luminal s urface of inflamed vessels bur also in perivascular cells suggesting a functional role of VCAM-1 in both endothelial adhesion and local rest imulation of autoantigen-specific T cells. Accordingly, perivascular T cell accumulation was most pronounced at sites of local VCAM-1 mRNA e xpression. In addition, VCAM-1 mRNA was detected in the border zone ar ound photochemically induced cerebral infarcts which is the predelicti on site of T cell infiltration and expression of immune activation mar kers during the first week after ischemia. VCAM-1 mRNA was absent from the center of the infarcts as well as axotomized central and peripher al nerves undergoing Wallerian degeneration. These data indicate that VCAM-1-mediated adhesion processes are involved in immune-mediated and ischemic diseases of the nervous system but not in T cell-independent macrophage recruitment during Wallerian degeneration.