Abstract
FGF-2 is a potent neurotrophic factor for several populations of CNS neurons and has been shown to protect hippocampal neurons from glutamate-induced cell death in vitro and in vivo. Mechanisms underlying the neurotrophic and protective actions of FGF-2 have been resolved only in part. Using glutamate-treated cultured hippocampal neurons we show that FGF-2 shares its neuroprotective capacity with GDNF. Hippocampal neurons express glial-cell-line-derived neurotrophic factor (GDNF), its receptors c-Ret and the lipid-anchored GDNF family receptor-alpha1 (GFRalpha-1), and the FGF receptor 1 (FGFR I). Neutralizing antibodies to GDNF abolish the neuroprotective effect of FGF-2. In support of the notion that GDNF is required to permit the protective effects of FGF-2 we find that FGF-2 up-regulates GDNF and GFRalpha-1 in hippocampal neurons. Furthermore, FGF-2-induced GDNF causes enhanced phosphorylation of c-Ret and the signaling components Akt and Erk. A putative downstream target of FGF-2 and GDNF are bcl-2 gene family members, whose mRNAs are differentially up-regulated by the two factors. Together, these data suggest that GDNF is an important protective factor for glutamate-lesioned hippocampal neurons and an essential mediator of the neuroprotective actions of FGF-2.
(c) 2002 Elsevier Science (USA).
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Antibodies / pharmacology
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Apoptosis / drug effects
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Apoptosis / genetics
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Brain Ischemia / drug therapy*
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Brain Ischemia / metabolism
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Brain Ischemia / physiopathology
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Cell Death / drug effects*
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Cell Death / physiology
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Cells, Cultured
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Cytokines / metabolism
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Cytokines / pharmacology
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Drosophila Proteins*
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Drug Interactions / physiology
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Female
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Fetus
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Fibroblast Growth Factor 2 / metabolism
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Fibroblast Growth Factor 2 / pharmacology*
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Gene Expression Regulation / drug effects
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Gene Expression Regulation / physiology
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Glial Cell Line-Derived Neurotrophic Factor
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Glial Cell Line-Derived Neurotrophic Factor Receptors
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Glutamic Acid / metabolism*
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Glutamic Acid / pharmacology
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Hippocampus / drug effects
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Hippocampus / metabolism
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Hippocampus / physiopathology
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Membrane Microdomains / metabolism
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Nerve Growth Factors*
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Nerve Tissue Proteins / antagonists & inhibitors*
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / metabolism
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Neurons / drug effects*
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Neurons / metabolism
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Neuroprotective Agents / pharmacology*
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Phosphorylation
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Pregnancy
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Proto-Oncogene Proteins / genetics
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Proto-Oncogene Proteins c-ret
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RNA, Messenger / metabolism
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Rats
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Rats, Wistar
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Receptor Protein-Tyrosine Kinases / genetics
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Signal Transduction / physiology
Substances
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Antibodies
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Cytokines
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Drosophila Proteins
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Gdnf protein, rat
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Gfra1 protein, rat
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Glial Cell Line-Derived Neurotrophic Factor
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Glial Cell Line-Derived Neurotrophic Factor Receptors
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Nerve Growth Factors
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Nerve Tissue Proteins
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Neuroprotective Agents
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Proto-Oncogene Proteins
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RNA, Messenger
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Fibroblast Growth Factor 2
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Glutamic Acid
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Proto-Oncogene Proteins c-ret
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Receptor Protein-Tyrosine Kinases
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Ret protein, Drosophila
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Ret protein, rat