title: Nerve growth factor-induced glutamate release is via p75 receptor, ceramide, and Ca(2+) from ryanodine receptor in developing cerebellar neurons.
abstract: Very little is known about the contribution of a low affinity neurotrophin receptor, p75, to neurotransmitter release. Here we show that nerve growth factor (NGF) induced a rapid release of glutamate and an increase of Ca2+ in cerebellar neurons through a p75-dependent pathway. The NGF-induced release occurred even in the presence of the Trk inhibitor K252a. The release caused by NGF but not brain-derived neurotrophic factor was enhanced in neurons overexpressing p75. Further, after transfection of p75-small interfering RNA, which down-regulated the endogenous p75 expression, the NGF-induced release was inhibited, suggesting that the NGF-induced glutamate release was through p75. We found that the NGF-increased Ca2+ was derived from the ryanodine-sensitive Ca2+ receptor and that the NGF-increased Ca2+ was essential for the NGF-induced glutamate release. Furthermore, scyphostatin, a sphingomyelinase inhibitor, blocked the NGF-dependent Ca2+ increase and glutamate release, suggesting that a ceramide produced by sphingomyelinase was required for the NGF-stimulated Ca2+ increase and glutamate release. This action of NGF only occurred in developing neurons whereas the brain-derived neurotrophic factor-mediated Ca2+ increase and glutamate release was observed at the mature neuronal stage. Thus, we demonstrate that NGF-mediated neurotransmitter release via the p75-dependent pathway has an important role in developing neurons.
authors.affiliation: Neuronics R G Special Division for Human Life Technology National Institute of Advanced Industrial Science and Technology (AIST) Midorigaoka, Ikeda, Osaka 563-8577, Japan. numakawa@ncnp.go.jp
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Numakawa
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nakayama
authors.forename: Shingo
authors.initials: S
authors.lastname: Suzuki
authors.forename: Takekazu
authors.initials: T
authors.lastname: Kubo
authors.forename: Futoshi
authors.initials: F
authors.lastname: Nara
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Numakawa
authors.forename: Daisaku
authors.initials: D
authors.lastname: Yokomaku
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Araki
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Ishimoto
authors.forename: Akihiko
authors.initials: A
authors.lastname: Ogura
authors.forename: Takahisa
authors.initials: T
authors.lastname: Taguchi
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000577:Amides / Q000494:pharmacology; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002478:Cells, Cultured; D002518:Ceramides / Q000378:metabolism*; D002531:Cerebellum / Q000378:metabolism*; D002614:Chelating Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D004789:Enzyme Activation; D018698:Glutamic Acid / Q000378:metabolism*; D015151:Immunoblotting; D007150:Immunohistochemistry; D008274:Magnesium / Q000378:metabolism; D020932:Nerve Growth Factor / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D011753:Pyrones / Q000494:pharmacology; D051381:Rats; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism*; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
chemical_list: D000577:Amides; D000596:Amino Acids; D002518:Ceramides; D002614:Chelating Agents; D011753:Pyrones; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor; D019837:Ryanodine Receptor Calcium Release Channel; C121123:scyphostatin; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; D018698:Glutamic Acid; D004533:Egtazic Acid; D020932:Nerve Growth Factor; D013108:Sphingomyelin Phosphodiesterase; D008274:Magnesium; D002118:Calcium