title: Exogenous gangliosides may affect methylation mechanisms in neuronal cell cultures.
abstract: Primary neurons in culture from chick embryo cerebral hemispheres were treated with a mixture of gangliosides added to the growth medium (final concentration: 10(-5)M and 10(-8)M) from the 3rd to the 6th day in vitro. Under these conditions methylation processes measured with [3H] and [35S] methionine and [3H]ethanolamine as precursors showed an increased methylation of [3H]ethanolamine containing phospholipids, a correspondent increased conversion of these compounds to [3H]choline containing phospholipids, and a general increased methylation of trichloroacetic acid precipitable macromolecules containing labeled methionine. A small increase in protein synthesis was observed after incubation of neurons with [3H]- and [35S]methionine. This was confirmed after electrophoretic separation of a protein extract with increased 3H- and 35S-labeling in protein bands with moecular weights between 50 and 60 KDaltons. A protein band of about 55 KDaltons appeared to be preferentially labelled when [3H] methionine was the precursor. The treatment with gangliosides increased the incorporation of [methyl-3H] label after incubation of neurons with [3H] methionine, into total DNA and decreased that of total RNA. The treatment of neurons in culture with exogenous gangliosides hence affects differently methylation processes, a finding which may confirm the involvement of gangliosides on the intracellular mediation of neuronal information mechanisms.
authors.affiliation: Centre de Neurochimie du CNRS, Strasbourg, France.
authors.forename: B
authors.initials: B
authors.lastname: Ferret
authors.forename: A
authors.initials: A
authors.lastname: Hubsch
authors.forename: H
authors.initials: H
authors.lastname: Dreyfus
authors.forename: R
authors.initials: R
authors.lastname: Massarelli
mesh_terms: D000818:Animals; D001921:Brain / Q000166:cytology; D002478:Cells, Cultured; D011232:Chemical Precipitation; D002642:Chick Embryo; D002794:Choline / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D019856:Ethanolamine; D004983:Ethanolamines / Q000378:metabolism; D005732:Gangliosides / Q000494:pharmacology*; D008715:Methionine / Q000378:metabolism; D008745:Methylation; D008970:Molecular Weight; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D012313:RNA / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000378:metabolism; D013462:Sulfur Radioisotopes; D014238:Trichloroacetic Acid; D014316:Tritium
chemical_list: D004983:Ethanolamines; D005732:Gangliosides; D010743:Phospholipids; D013462:Sulfur Radioisotopes; D014316:Tritium; D019856:Ethanolamine; D014238:Trichloroacetic Acid; D012313:RNA; D012436:S-Adenosylmethionine; D004247:DNA; D008715:Methionine; D002794:Choline