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Regulation of p53 in NIH3T3 mouse fibroblasts following hyperosmotic stress
The aim of this project was to analyze the regulation of p53 expression in NIH3T3 fibroblasts under the influence of increasing hyperosmotic stress. Expression of p53 showed a biphasic response pattern in NIH3T3 cells under increasing osmotic stress (337 mOsm to 737 mOsm) with a maximum at 587 mOsm....
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley & Sons, Ltd
2015
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4510620/ https://www.ncbi.nlm.nih.gov/pubmed/26056062 http://dx.doi.org/10.14814/phy2.12412 |
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author | Lambert, Ian Henry Enghoff, Maria Stine Brandi, Marie-Luise Hoffmann, Else Kay |
author_facet | Lambert, Ian Henry Enghoff, Maria Stine Brandi, Marie-Luise Hoffmann, Else Kay |
author_sort | Lambert, Ian Henry |
collection | PubMed |
description | The aim of this project was to analyze the regulation of p53 expression in NIH3T3 fibroblasts under the influence of increasing hyperosmotic stress. Expression of p53 showed a biphasic response pattern in NIH3T3 cells under increasing osmotic stress (337 mOsm to 737 mOsm) with a maximum at 587 mOsm. Under isotonic conditions p53 expression increased after addition of the proteasome inhibitor MG132 indicating that cellular p53 levels in unperturbed cells is kept low by proteasomal degradation. However, under hypertonic conditions p53 synthesis as well as p53 degradation were significantly reduced and it is demonstrated that the increase in p53 expression observed when tonicity is increased from 337 to 587 mOsm reflects that degradation is more inhibited than synthesis, whereas the decrease in p53 expression at higher tonicities reflects that synthesis is more inhibited than degradation. The activity of the p53 regulating proteins p38 MAP kinase and the ubiquitin ligase MDM2 were studied as a function of increasing osmolarity. MDM2 protein expression was unchanged at all osmolarities, whereas MDM2 phosphorylation (Ser(166)) increased at osmolarities up to 537 mOsm and remained constant at higher osmolarities. Phosphorylation of p38 increased at osmolarities up to 687 mOsm which correlated with an increased phosphorylation of p53 (Ser(15)) and the decreased p53 degradation. Caspase-3 activity increased gradually with hypertonicity and at 737 mOsm both Caspase-3 activity and annexin V binding are high even though p53 expression and activity are low, indicating that initiation of apoptosis under severe hypertonic conditions is not strictly controlled by p53. |
format | Online Article Text |
id | pubmed-4510620 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | John Wiley & Sons, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-45106202015-07-28 Regulation of p53 in NIH3T3 mouse fibroblasts following hyperosmotic stress Lambert, Ian Henry Enghoff, Maria Stine Brandi, Marie-Luise Hoffmann, Else Kay Physiol Rep Original Research The aim of this project was to analyze the regulation of p53 expression in NIH3T3 fibroblasts under the influence of increasing hyperosmotic stress. Expression of p53 showed a biphasic response pattern in NIH3T3 cells under increasing osmotic stress (337 mOsm to 737 mOsm) with a maximum at 587 mOsm. Under isotonic conditions p53 expression increased after addition of the proteasome inhibitor MG132 indicating that cellular p53 levels in unperturbed cells is kept low by proteasomal degradation. However, under hypertonic conditions p53 synthesis as well as p53 degradation were significantly reduced and it is demonstrated that the increase in p53 expression observed when tonicity is increased from 337 to 587 mOsm reflects that degradation is more inhibited than synthesis, whereas the decrease in p53 expression at higher tonicities reflects that synthesis is more inhibited than degradation. The activity of the p53 regulating proteins p38 MAP kinase and the ubiquitin ligase MDM2 were studied as a function of increasing osmolarity. MDM2 protein expression was unchanged at all osmolarities, whereas MDM2 phosphorylation (Ser(166)) increased at osmolarities up to 537 mOsm and remained constant at higher osmolarities. Phosphorylation of p38 increased at osmolarities up to 687 mOsm which correlated with an increased phosphorylation of p53 (Ser(15)) and the decreased p53 degradation. Caspase-3 activity increased gradually with hypertonicity and at 737 mOsm both Caspase-3 activity and annexin V binding are high even though p53 expression and activity are low, indicating that initiation of apoptosis under severe hypertonic conditions is not strictly controlled by p53. John Wiley & Sons, Ltd 2015-06-08 /pmc/articles/PMC4510620/ /pubmed/26056062 http://dx.doi.org/10.14814/phy2.12412 Text en © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society. http://creativecommons.org/licenses/by/4.0/ This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Original Research Lambert, Ian Henry Enghoff, Maria Stine Brandi, Marie-Luise Hoffmann, Else Kay Regulation of p53 in NIH3T3 mouse fibroblasts following hyperosmotic stress |
title | Regulation of p53 in NIH3T3 mouse fibroblasts following hyperosmotic stress |
title_full | Regulation of p53 in NIH3T3 mouse fibroblasts following hyperosmotic stress |
title_fullStr | Regulation of p53 in NIH3T3 mouse fibroblasts following hyperosmotic stress |
title_full_unstemmed | Regulation of p53 in NIH3T3 mouse fibroblasts following hyperosmotic stress |
title_short | Regulation of p53 in NIH3T3 mouse fibroblasts following hyperosmotic stress |
title_sort | regulation of p53 in nih3t3 mouse fibroblasts following hyperosmotic stress |
topic | Original Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4510620/ https://www.ncbi.nlm.nih.gov/pubmed/26056062 http://dx.doi.org/10.14814/phy2.12412 |
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