Cargando…

The Involvement of Acetaldehyde in Ethanol-Induced Cell Cycle Impairment

Background: Hepatocytes metabolize the vast majority of ingested ethanol. This metabolic activity results in hepatic toxicity and impairs the ability of hepatocytes to replicate. Previous work by our group has shown that ethanol metabolism results in a G2/M cell cycle arrest. The intent of these stu...

Descripción completa

Detalles Bibliográficos
Autores principales: Scheer, Marc A., Schneider, Katrina J., Finnigan, Rochelle L., Maloney, Eamon P., Wells, Mark A., Clemens, Dahn L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4919912/
https://www.ncbi.nlm.nih.gov/pubmed/27043646
http://dx.doi.org/10.3390/biom6020017
_version_ 1782439320850792448
author Scheer, Marc A.
Schneider, Katrina J.
Finnigan, Rochelle L.
Maloney, Eamon P.
Wells, Mark A.
Clemens, Dahn L.
author_facet Scheer, Marc A.
Schneider, Katrina J.
Finnigan, Rochelle L.
Maloney, Eamon P.
Wells, Mark A.
Clemens, Dahn L.
author_sort Scheer, Marc A.
collection PubMed
description Background: Hepatocytes metabolize the vast majority of ingested ethanol. This metabolic activity results in hepatic toxicity and impairs the ability of hepatocytes to replicate. Previous work by our group has shown that ethanol metabolism results in a G2/M cell cycle arrest. The intent of these studies was to discern the roles of acetaldehyde and reactive oxygen, two of the major by-products of ethanol metabolism, in the G2/M cell cycle arrest. Methods: To investigate the role of ethanol metabolites in the cell cycle arrest, VA-13 and VL-17A cells were used. These are recombinant Hep G2 cells that express alcohol dehydrogenase or alcohol dehydrogenase and cytochrome P450 2E1, respectively. Cells were cultured with or without ethanol, lacking or containing the antioxidants N-acetylcysteine (NAC) or trolox, for three days. Cellular accumulation was monitored by the DNA content of the cultures. The accumulation of the cyclin-dependent kinase, Cdc2 in the inactive phosphorylated form (p-Cdc2) and the cyclin-dependent kinase inhibitor p21 were determined by immunoblot analysis. Results: Cultures maintained in the presence of ethanol demonstrated a G2/M cell cycle arrest that was associated with a reduction in DNA content and increased levels of p-Cdc2 and p21, compared with cells cultured in its absence. Inclusion of antioxidants in the ethanol containing media was unable to rescue the cells from the cell cycle arrest or these ethanol metabolism-mediated effects. Additionally, culturing the cells in the presence of acetaldehyde alone resulted in increased levels of p-Cdc2 and p21. Conclusions: Acetaldehyde produced during ethanol oxidation has a major role in the ethanol metabolism-mediated G2/M cell cycle arrest, and the concurrent accumulation of p21 and p-Cdc2. Although reactive oxygen species are thought to have a significant role in ethanol-induced hepatocellular damage, they may have a less important role in the inability of hepatocytes to replace dead or damaged cells.
format Online
Article
Text
id pubmed-4919912
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-49199122016-06-24 The Involvement of Acetaldehyde in Ethanol-Induced Cell Cycle Impairment Scheer, Marc A. Schneider, Katrina J. Finnigan, Rochelle L. Maloney, Eamon P. Wells, Mark A. Clemens, Dahn L. Biomolecules Article Background: Hepatocytes metabolize the vast majority of ingested ethanol. This metabolic activity results in hepatic toxicity and impairs the ability of hepatocytes to replicate. Previous work by our group has shown that ethanol metabolism results in a G2/M cell cycle arrest. The intent of these studies was to discern the roles of acetaldehyde and reactive oxygen, two of the major by-products of ethanol metabolism, in the G2/M cell cycle arrest. Methods: To investigate the role of ethanol metabolites in the cell cycle arrest, VA-13 and VL-17A cells were used. These are recombinant Hep G2 cells that express alcohol dehydrogenase or alcohol dehydrogenase and cytochrome P450 2E1, respectively. Cells were cultured with or without ethanol, lacking or containing the antioxidants N-acetylcysteine (NAC) or trolox, for three days. Cellular accumulation was monitored by the DNA content of the cultures. The accumulation of the cyclin-dependent kinase, Cdc2 in the inactive phosphorylated form (p-Cdc2) and the cyclin-dependent kinase inhibitor p21 were determined by immunoblot analysis. Results: Cultures maintained in the presence of ethanol demonstrated a G2/M cell cycle arrest that was associated with a reduction in DNA content and increased levels of p-Cdc2 and p21, compared with cells cultured in its absence. Inclusion of antioxidants in the ethanol containing media was unable to rescue the cells from the cell cycle arrest or these ethanol metabolism-mediated effects. Additionally, culturing the cells in the presence of acetaldehyde alone resulted in increased levels of p-Cdc2 and p21. Conclusions: Acetaldehyde produced during ethanol oxidation has a major role in the ethanol metabolism-mediated G2/M cell cycle arrest, and the concurrent accumulation of p21 and p-Cdc2. Although reactive oxygen species are thought to have a significant role in ethanol-induced hepatocellular damage, they may have a less important role in the inability of hepatocytes to replace dead or damaged cells. MDPI 2016-03-31 /pmc/articles/PMC4919912/ /pubmed/27043646 http://dx.doi.org/10.3390/biom6020017 Text en © 2016 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons by Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Scheer, Marc A.
Schneider, Katrina J.
Finnigan, Rochelle L.
Maloney, Eamon P.
Wells, Mark A.
Clemens, Dahn L.
The Involvement of Acetaldehyde in Ethanol-Induced Cell Cycle Impairment
title The Involvement of Acetaldehyde in Ethanol-Induced Cell Cycle Impairment
title_full The Involvement of Acetaldehyde in Ethanol-Induced Cell Cycle Impairment
title_fullStr The Involvement of Acetaldehyde in Ethanol-Induced Cell Cycle Impairment
title_full_unstemmed The Involvement of Acetaldehyde in Ethanol-Induced Cell Cycle Impairment
title_short The Involvement of Acetaldehyde in Ethanol-Induced Cell Cycle Impairment
title_sort involvement of acetaldehyde in ethanol-induced cell cycle impairment
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4919912/
https://www.ncbi.nlm.nih.gov/pubmed/27043646
http://dx.doi.org/10.3390/biom6020017
work_keys_str_mv AT scheermarca theinvolvementofacetaldehydeinethanolinducedcellcycleimpairment
AT schneiderkatrinaj theinvolvementofacetaldehydeinethanolinducedcellcycleimpairment
AT finniganrochellel theinvolvementofacetaldehydeinethanolinducedcellcycleimpairment
AT maloneyeamonp theinvolvementofacetaldehydeinethanolinducedcellcycleimpairment
AT wellsmarka theinvolvementofacetaldehydeinethanolinducedcellcycleimpairment
AT clemensdahnl theinvolvementofacetaldehydeinethanolinducedcellcycleimpairment
AT scheermarca involvementofacetaldehydeinethanolinducedcellcycleimpairment
AT schneiderkatrinaj involvementofacetaldehydeinethanolinducedcellcycleimpairment
AT finniganrochellel involvementofacetaldehydeinethanolinducedcellcycleimpairment
AT maloneyeamonp involvementofacetaldehydeinethanolinducedcellcycleimpairment
AT wellsmarka involvementofacetaldehydeinethanolinducedcellcycleimpairment
AT clemensdahnl involvementofacetaldehydeinethanolinducedcellcycleimpairment