PARTIAL-PURIFICATION OF A NOVEL MITOGEN FOR OLIGODENDROGLIA

A protein with a MW(app) of 50-70 kDa isolated from the salt extract o f crude membranes from neonatal rat brain increases the numbers of oli godendroglia in mixed glial cultures prepared from neonatal rat cerebr al white matter, After partial purification by ion exchange and gel ex clusion chromatography, and elution from an SDS-polyacrylamide gel, th is protein (''oligodendroglial trophic factor,'' OTF) elicited half-ma ximal oligodendroglial recruitment at a concentration of 5 ng/mL, OTF is a mitogen for oligodendroglia, and to a lesser extent, for oligoden droglial progenitor (O2A) cells, but does not stimulate proliferation of astroglia, Schwann cells, or endoneurial fibroblasts, OTF, unlike p latelet-derived growth factor (PDGF), is not an oligodendroglial survi val factor, Antibodies against PDGF and basic fibroblast growth factor (bFGF) do not interfere with the accumulation of oligodendroglia indu ced by OTF, When OTF is given simultaneously with either PDGF or bFGF, there is an additive increase in the numbers of cells of the oligoden droglial lineage. (C) 1995 Wiley-Liss, Inc.