title: Fibroblast growth factor-2 requires glial-cell-line-derived neurotrophic factor for exerting its neuroprotective actions on glutamate-lesioned hippocampal neurons.
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.
authors.affiliation: Department of Neuroanatomy and Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Im Neuenheimer Feld 307, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Lenhard
authors.forename: Andreas
authors.initials: A
authors.lastname: Schober
authors.forename: Clemens
authors.initials: C
authors.lastname: Suter-Crazzolara
authors.forename: Klaus
authors.initials: K
authors.lastname: Unsicker
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D002545:Brain Ischemia / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D016923:Cell Death / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism / Q000494:pharmacology; D029721:Drosophila Proteins; D004347:Drug Interactions / Q000502:physiology; D005260:Female; D005333:Fetus; D016222:Fibroblast Growth Factor 2 / Q000378:metabolism / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000502:physiology; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D018698:Glutamic Acid / Q000378:metabolism* / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D021962:Membrane Microdomains / Q000378:metabolism; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D018696:Neuroprotective Agents / Q000494:pharmacology*; D010766:Phosphorylation; D011247:Pregnancy; D011518:Proto-Oncogene Proteins / Q000235:genetics; D051096:Proto-Oncogene Proteins c-ret; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology
chemical_list: D000906:Antibodies; D016207:Cytokines; D029721:Drosophila Proteins; C495041:Gdnf protein, rat; C494989:Gfra1 protein, rat; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D018696:Neuroprotective Agents; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2; D018698:Glutamic Acid; D051096:Proto-Oncogene Proteins c-ret; D020794:Receptor Protein-Tyrosine Kinases; C416649:Ret protein, Drosophila; C495001:Ret protein, rat