Isolation and purification of an epidermal growth factor receptor-related inhibitor of cell growth from cultured rat astrocytes

Astrocytes rarely undergo mitotic cell division in the developed adult. However, following injury to the central nervous system (CNS), astrocytes undergo rapid cell division and reactive astrocytes encapsulate exposed areas of the CNS producing a glial scar. Studies indicate the existence of a family of epidermal growth factor receptor (EGFr) related glycosidic mitogen inhibitors with growth inhibiting properties for astrocytes. Here, for the first time, we describe the isolation of such a factor from cultured rat astrocytes by ion-exchange and immunoaffinity chromatography. The isolated factor is glycosidic in nature, cross reacts with the anti-EGFr monoclonal antibody Clone 29.1, and inhibits the growth of primary astrocytes and N2a neuroblastoma cells in vitro. Copyright (C) 2000 Elsevier Science Ireland Ltd.