Regulation of gap junction communication by growth factors from non-neural cells to astroglia: a brief review

Abstract

Astrocytes are coupled by gap junctions, which are composed of connexins, channel-forming proteins. Connexin43 is the predominant connexin of astrocytes. Gap junctions assemble astrocytes into functional syncytia permitting exchange of small molecules including metabolites, catabolites, and second messenger molecules. Thus, gap junctions of astroglial cells serve the maintenance of extra- and intra-cellular homeostasis in the brain and eventually ascertain neuronal functions. Alterations in astroglial cell coupling can disturb this equilibrium resulting in neuronal dysfunction and death. Growth factors are an important class of substances that can influence coupling in non-neural cells. Several groups have recently carried the analyses of gap junction regulation by cytokines to the level of neural cells. This review summarizes the recent progress in this field and outlines directions of future research.