title: Phospholipase D2 functions as a downstream signaling molecule of MAP kinase pathway in L1-stimulated neurite outgrowth of cerebellar granule neurons.
abstract: Stimulation of the neuronal cell adhesion molecule L1 in cerebellar granule neurons (CGNs) enhances neurite outgrowth and this response is inhibited by the primary alcohol ethanol. Because primary alcohols suppress the formation of the signaling lipid phosphatidic acid (PA) by phospholipase D (PLD), this observation prompted us to investigate whether PLD plays a role in the L1-mediated neurite outgrowth in CGNs. In the cerebellum of postnatal day 8 mice, PLD2 protein was abundantly expressed, while PLD1 expression was not detected. The L1-stimulated neurite outgrowth was inhibited by primary alcohols and by overexpression of lipase-deficient PLD2. Increases in cellular PA levels by direct PA application or overexpression of wild-type PLD2 mimicked the L1-dependent stimulation of neurite outgrowth. Furthermore, it was found that L1 stimulation in CGNs increased PLD activity concomitantly with phosphorylation of extracellular signal-regulated kinase (ERK), both of which were inhibited by the MAP kinase-ERK kinase (MEK) inhibitor. These results provide evidence that PLD2 functions as a downstream signaling molecule of ERK to mediate the L1-dependent neurite outgrowth of CGNs, a mechanism that may be related to alcohol-related neurodevelopmental disorders.
authors.affiliation: Department of Pharmacology, The Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Miyazaki
authors.forename: Chihiro
authors.initials: C
authors.lastname: Arikawa
authors.forename: Kouichi
authors.initials: K
authors.lastname: Itoh
authors.forename: Takehiko
authors.initials: T
authors.lastname: Sasaki
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Maehama
authors.forename: Michael A
authors.initials: MA
authors.lastname: Frohman
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Kanaho
mesh_terms: D000438:Alcohols / Q000494:pharmacology; D000818:Animals; D002478:Cells, Cultured; D002531:Cerebellum / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D020935:MAP Kinase Signaling System / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008813:Mice, Inbred ICR; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D039842:Neural Cell Adhesion Molecule L1 / Q000494:pharmacology / Q000502:physiology*; D016501:Neurites / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology*; D010739:Phospholipase D / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation / Q000187:drug effects
chemical_list: D000438:Alcohols; D004791:Enzyme Inhibitors; D039842:Neural Cell Adhesion Molecule L1; D020928:Mitogen-Activated Protein Kinases; C105606:phospholipase D2; D010739:Phospholipase D