Multiple extracellular signals are required for long-term oligodendrocyte survival.
We showed previously that oligodendrocytes and their precursors require continuous signalling by protein trophic factors to avoid programmed cell death in culture. Here we show that three classes of such trophic factors promote oligodendrocyte survival in vitro: (1) insulin and insulin-like growth factors (IGFs), (2) neurotrophins, particularly neurotrophin-3 (NT-3), and (3) ciliary-neurotrophic factor (CNTF), leukemia inhibitory factor (LIF) and interleukin 6 (IL-6). A single factor, or combinations of factors within the same class, promote only short-term survival of oligodendrocytes and their precursors, while combinations of factors from different classes promote survival additively. Long-term survival of oligodendrocytes in vitro requires at least one factor from each class, suggesting that multiple signals may be required for long-term oligodendrocyte survival in vivo. We also show that CNTF promotes oligodendrocyte survival in vivo, that platelet-derived growth factor (PDGF) can promote the survival of oligodendrocyte precursors in vitro by acting on a novel, very high affinity PDGF receptor, and that, in addition to its effect on survival, NT-3 is a potent mitogen for oligodendrocyte precursor cells.
Department of Biology, University College, London, UK.
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Barres
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Schmid
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Sendnter
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Raff
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002478:Cells, Cultured; D020934:Ciliary Neurotrophic Factor; D006131:Growth Inhibitors / Q000502:physiology; D006133:Growth Substances / Q000502:physiology*; D007328:Insulin / Q000502:physiology; D015850:Interleukin-6 / Q000502:physiology; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines / Q000502:physiology; D009414:Nerve Growth Factors / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000502:physiology; D020933:Neurotrophin 3; D009836:Oligodendroglia / Q000502:physiology*; D010982:Platelet-Derived Growth Factor / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000502:physiology*; D013002:Somatomedins / Q000502:physiology
D020934:Ciliary Neurotrophic Factor; D006131:Growth Inhibitors; D006133:Growth Substances; D007328:Insulin; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008222:Lymphokines; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D020933:Neurotrophin 3; D010982:Platelet-Derived Growth Factor; D013002:Somatomedins