2ND MESSENGER SYSTEMS IN THE REGULATION OF CYTOKINES AND ADHESION MOLECULES IN THE CENTRAL-NERVOUS-SYSTEM

Cytokines are a group of secreted proteins that exhibit diverse biolog ical activity and are especially important in immune and inflammatory responses. The inappropriate production of cytokines in the central ne rvous system (CNS) has been implicated in a number of disease states s uch as Alzheimer's disease, multiple sclerosis, and AIDS dementia comp lex. This article focuses on the biological role of three cytokines in the CNS, interleukin-6 (IL-6), tumor necrosis factor alpha, and nerve growth factor, with an emphasis on production by glial cells. We will discuss the diverse intracellular signaling pathways that regulate ex pression of these cytokines by glial cells and then describe the secon d messenger systems that mediate cytokine-induced responses in the CNS , with an emphasis on adhesion molecule expression. We conclude by dis cussing the complexities of signal transduction pathways, particularly ''cross-talk'' between different intracellular mediators. (C) 1995 Ac ademic Press, Inc.