Glycosylation is altered by ethanol in rat hippocampal cultured neurons.
OBJECTIVE
Glycoproteins, such as adhesion molecules and growth factors, participate in the regulation of nervous system development. Ethanol affects the synthesis, intracellular transport, distribution, and secretion of N-glycoproteins in different cell types, including astrocytes and hepatocytes, suggesting alterations in the glycosylation process. We analysed the effect of exposure to low doses of ethanol (30 mm, 7 days) on glycosylation in cultured hippocampal neurons.


METHODS
Neurons were incubated for short (5 min) and long (90 min) periods with the radioactively labelled carbohydrate precursors 2-deoxy-glucose, N-acetyl-D-mannosamine and mannose. The uptake and metabolism of these precursors, as well as the radioactivity distribution in protein gels, were analysed. The levels of the glucose transporters GLUT1 and GLUT3 were also determined.


RESULTS
Ethanol exposure reduces the synthesis of proteins, DNA and RNA and decreased the uptake of mannose, but not of 2-deoxy-glucose and N-acetyl-D-mannosamine, and it increased the protein levels of both glucose transporters. Moreover, it altered the carbohydrate moiety of several proteins. Finally, alcohol treatment results in an increment of cell surface glycoconjugates containing terminal non-reduced mannose.


CONCLUSIONS
Alcohol-induced alterations in glycosylation of proteins in neurons could be a key mechanism involved in the teratogenic effects of alcohol exposure on brain development.
Braza-Boïls
Aitana
A
Section of Cell Biology and Pathology, Center for Investigation, Hospital La Fe, Valencia, Spain.
Tomás
Mónica
M
Marín
María Pilar
MP
Megías
Luis
L
Sancho-Tello
María
M
Fornas
Eugenio
E
Renau-Piqueras
Jaime
J
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D015153:Blotting, Western; D002455:Cell Division; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D000431:Ethanol / Q000494:pharmacology*; D019084:Fluorescent Antibody Technique, Indirect; D051272:Glucose Transporter Type 1; D006031:Glycosylation / Q000187:drug effects; D006624:Hippocampus / Q000166:cytology*; D008854:Microscopy, Electron; D009005:Monosaccharides / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats
D051272:Glucose Transporter Type 1; D009005:Monosaccharides; D000431:Ethanol