The chemokine growth-regulated oncogene-α promotes spinal cord oligodendrocyte precursor proliferation

Abstract

Chemokines, (chemotactic cytokines) are a family of regulatory molecules involved in modulating inflammatory responses. Here we demonstrate that the chemokine growth-regulated oncogene-α (GRO-α) is a potent promoter of oligodendrocyte precursor proliferation. The proliferative response of immature spinal cord oligodendrocyte precursors to their major mitogen, platelet derived growth factor (PDGF), is dramatically enhanced by GRO-α present in spinal cord conditioned medium. One source of GRO-α is a subset of spinal cord astrocytes. Cultures of astrocytes contain GRO-α mRNA and protein and secrete biologically active concentrations of GRO-α. In postnatal spinal cord white matter the location of GRO-α-immunoreactive cells is developmentally regulated: GRO-α+ cells first appear in ventral and later in dorsal spinal cord white matter. These results suggest that localized proliferation of oligodendrocytes is mediated by synergy between PDGF and GRO-α.