PLATELET-DERIVED GROWTH-FACTOR PARTLY PREVENTS CHEMICALLY-INDUCED OLIGODENDROCYTE DEATH AND IMPROVES MYELIN-LIKE MEMBRANES REPAIR IN-VITRO

We have previously shown that pure oligodendrocyte (OL) secondary cult ures derived from newborn rat brain, in which cells form myelin-like m embranes, can be used as a model to investigate the putative role of g rowth factors in myelin repair. After disruption of these membranes by lysophosphatidylcholine (LPC), a 3 day treatment with 10 ng/ml basic fibroblast growth factor (bFGF) induced reconstruction of myelin figur es, albeit less compacted than in untreated controls. Here we show tha t in LPC treated cultures: 1) bFGF can not prevent OL from LPC-induced cell death; 2) platelet-derived growth factor (PDGF) pretreatment alt hough preventing some cell death does not improve recovery compared to delayed treatment; 3) PDGF is as potent as bFGF in terms of O-2A prog enitor proliferation; 4) PDGF is far more effective than bFGF, inducin g the reappearance of more myelin-like structures with a better compac tion; 5) there is no potentiation between these growth factors; and 6) after withdrawal of bFGF the compaction of myelin figures partly incr eases. These results indicate that PDGF, probably by inducing O-2A pro genitors to proliferate and then allowing them to differentiate into m ature myelinating OL, is a better candidate than bFGF to participate i n myelin repair mechanisms in the central nervous system. (C) 1996 Wil ey-Liss, Inc.