title: Ethanol inhibits neuritogenesis induced by astrocyte muscarinic receptors.
abstract: In utero alcohol exposure can lead to fetal alcohol spectrum disorders, characterized by cognitive and behavioral deficits. In vivo and in vitro studies have shown that ethanol alters neuronal development. We have recently shown that stimulation of M(3) muscarinic receptors in astrocytes increases the synthesis and release of fibronectin, laminin, and plasminogen activator inhibitor-1, causing neurite outgrowth in hippocampal neurons. As M(3) muscarinic receptor signaling in astroglial cells is strongly inhibited by ethanol, we hypothesized that ethanol may also inhibit neuritogenesis in hippocampal neurons induced by carbachol-stimulated astrocytes. In the present study, we report that the effect of carbachol-stimulated astrocytes on hippocampal neuron neurite outgrowth was inhibited in a concentration-dependent manner (25-100 mM) by ethanol. This effect was because of the inhibition of the release of fibronectin, laminin, and plasminogen activator inhibitor-1. Similar effects on neuritogenesis and on the release of astrocyte extracellular proteins were observed after the incubation of astrocytes with carbachol in the presence of 1-butanol, another short-chain alcohol, which like ethanol is a competitive substrate for phospholipase D, but not by tert-butanol, its analog that is not a substrate for this enzyme. This study identifies a potential novel mechanism involved in the developmental effects of ethanol mediated by the interaction of ethanol with cell signaling in astrocytes, leading to an impairment in neuron-astrocyte communication.
authors.affiliation: Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA 98105, USA. marinag@u.washington.edu
authors.forename: Marina
authors.initials: M
authors.lastname: Guizzetti
authors.forename: Nadia H
authors.initials: NH
authors.lastname: Moore
authors.forename: Gennaro
authors.initials: G
authors.lastname: Giordano
authors.forename: Kathryn L
authors.initials: KL
authors.lastname: VanDeMark
authors.forename: Lucio G
authors.initials: LG
authors.lastname: Costa
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D000440:Butanols / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D002478:Cells, Cultured; D002492:Central Nervous System Depressants; D002540:Cerebral Cortex / Q000166:cytology; D018679:Cholinergic Agonists / Q000494:pharmacology; D018920:Coculture Techniques / Q000379:methods; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004622:Embryo, Mammalian; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D000431:Ethanol / Q000494:pharmacology*; D005353:Fibronectins / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006624:Hippocampus / Q000166:cytology; D007797:Laminin / Q000378:metabolism; D018613:Microscopy, Confocal / Q000379:methods; D008954:Models, Biological; D016501:Neurites / Q000187:drug effects* / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000187:drug effects; D017395:Plasminogen Activator Inhibitor 1 / Q000378:metabolism; D051381:Rats; D011976:Receptors, Muscarinic / Q000378:metabolism*; D014404:Tubulin / Q000378:metabolism
chemical_list: D000440:Butanols; D002492:Central Nervous System Depressants; D018679:Cholinergic Agonists; D005353:Fibronectins; D007797:Laminin; D017395:Plasminogen Activator Inhibitor 1; D011976:Receptors, Muscarinic; C488416:Tubb3 protein, rat; D014404:Tubulin; D000431:Ethanol; D002217:Carbachol