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High Constitutive Glucocorticoid Receptor β in Human Neutrophils Enables Them to Reduce Their Spontaneous Rate of Cell Death in Response to Corticosteroids

Neutrophils are markedly less sensitive to glucocorticoids than T cells, making it difficult to control inflammation in neutrophil-mediated diseases. Development of new antiinflammatory strategies for such diseases would be aided by an understanding of mechanisms underlying differential steroid resp...

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Autores principales: Strickland, Ian, Kisich, Kevin, Hauk, Pia J., Vottero, Alessandra, Chrousos, George P., Klemm, Dwight J., Leung, Donald Y.M.
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 2001
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2193396/
https://www.ncbi.nlm.nih.gov/pubmed/11238589
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author Strickland, Ian
Kisich, Kevin
Hauk, Pia J.
Vottero, Alessandra
Chrousos, George P.
Klemm, Dwight J.
Leung, Donald Y.M.
author_facet Strickland, Ian
Kisich, Kevin
Hauk, Pia J.
Vottero, Alessandra
Chrousos, George P.
Klemm, Dwight J.
Leung, Donald Y.M.
author_sort Strickland, Ian
collection PubMed
description Neutrophils are markedly less sensitive to glucocorticoids than T cells, making it difficult to control inflammation in neutrophil-mediated diseases. Development of new antiinflammatory strategies for such diseases would be aided by an understanding of mechanisms underlying differential steroid responsiveness. Two protein isoforms of the human glucocorticoid receptor (GR) exist, GRα and GRβ, which arise from alternative splicing of the GR pre-mRNA primary transcripts. GRβ does not bind glucocorticoids and is an inhibitor of GRα activity. Relative amounts of these two GRs can therefore determine the level of glucocorticoid sensitivity. In this study, human neutrophils and peripheral blood mononuclear cells (PBMCs) were studied to determine the relative amounts of each GR isoform. The mean fluorescence intensity (MFI) using immunofluorescence analysis for GRα was 475 ± 62 and 985 ± 107 for PBMCs and neutrophils, respectively. For GRβ, the MFI was 350 ± 60 and 1,389 ± 143 for PBMCs and neutrophils, respectively (P < 0.05). After interleukin (IL)-8 stimulation of neutrophils, there was a statistically significant increase in intensity of GRβ staining to 2,497 ± 140 (P < 0.05). No change in GRα expression was observed. This inversion of the GRα/GRβ ratio in human neutrophils compared with PBMCs was confirmed by quantitative Western analysis. Increased GRβ mRNA expression in neutrophils at baseline, and after IL-8 exposure, was observed using RNA dot blot analysis. Increased levels of GRα/GRβ heterodimers were found in neutrophils as compared with PBMCs using coimmunoprecipitation/Western analysis. Transfection of mouse neutrophils, which do not contain GRβ, resulted in a significant reduction in the rate of cell death when treated with dexamethasone. We conclude that high constitutive expression of GRβ by human neutrophils may provide a mechanism by which these cells escape glucocorticoid-induced cell death. Moreover, upregulation of this GR by proinflammatory cytokines such as IL-8 further enhances their survival in the presence of glucocorticoids during inflammation.
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spelling pubmed-21933962008-04-14 High Constitutive Glucocorticoid Receptor β in Human Neutrophils Enables Them to Reduce Their Spontaneous Rate of Cell Death in Response to Corticosteroids Strickland, Ian Kisich, Kevin Hauk, Pia J. Vottero, Alessandra Chrousos, George P. Klemm, Dwight J. Leung, Donald Y.M. J Exp Med Original Article Neutrophils are markedly less sensitive to glucocorticoids than T cells, making it difficult to control inflammation in neutrophil-mediated diseases. Development of new antiinflammatory strategies for such diseases would be aided by an understanding of mechanisms underlying differential steroid responsiveness. Two protein isoforms of the human glucocorticoid receptor (GR) exist, GRα and GRβ, which arise from alternative splicing of the GR pre-mRNA primary transcripts. GRβ does not bind glucocorticoids and is an inhibitor of GRα activity. Relative amounts of these two GRs can therefore determine the level of glucocorticoid sensitivity. In this study, human neutrophils and peripheral blood mononuclear cells (PBMCs) were studied to determine the relative amounts of each GR isoform. The mean fluorescence intensity (MFI) using immunofluorescence analysis for GRα was 475 ± 62 and 985 ± 107 for PBMCs and neutrophils, respectively. For GRβ, the MFI was 350 ± 60 and 1,389 ± 143 for PBMCs and neutrophils, respectively (P < 0.05). After interleukin (IL)-8 stimulation of neutrophils, there was a statistically significant increase in intensity of GRβ staining to 2,497 ± 140 (P < 0.05). No change in GRα expression was observed. This inversion of the GRα/GRβ ratio in human neutrophils compared with PBMCs was confirmed by quantitative Western analysis. Increased GRβ mRNA expression in neutrophils at baseline, and after IL-8 exposure, was observed using RNA dot blot analysis. Increased levels of GRα/GRβ heterodimers were found in neutrophils as compared with PBMCs using coimmunoprecipitation/Western analysis. Transfection of mouse neutrophils, which do not contain GRβ, resulted in a significant reduction in the rate of cell death when treated with dexamethasone. We conclude that high constitutive expression of GRβ by human neutrophils may provide a mechanism by which these cells escape glucocorticoid-induced cell death. Moreover, upregulation of this GR by proinflammatory cytokines such as IL-8 further enhances their survival in the presence of glucocorticoids during inflammation. The Rockefeller University Press 2001-03-05 /pmc/articles/PMC2193396/ /pubmed/11238589 Text en © 2001 The Rockefeller University Press This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Original Article
Strickland, Ian
Kisich, Kevin
Hauk, Pia J.
Vottero, Alessandra
Chrousos, George P.
Klemm, Dwight J.
Leung, Donald Y.M.
High Constitutive Glucocorticoid Receptor β in Human Neutrophils Enables Them to Reduce Their Spontaneous Rate of Cell Death in Response to Corticosteroids
title High Constitutive Glucocorticoid Receptor β in Human Neutrophils Enables Them to Reduce Their Spontaneous Rate of Cell Death in Response to Corticosteroids
title_full High Constitutive Glucocorticoid Receptor β in Human Neutrophils Enables Them to Reduce Their Spontaneous Rate of Cell Death in Response to Corticosteroids
title_fullStr High Constitutive Glucocorticoid Receptor β in Human Neutrophils Enables Them to Reduce Their Spontaneous Rate of Cell Death in Response to Corticosteroids
title_full_unstemmed High Constitutive Glucocorticoid Receptor β in Human Neutrophils Enables Them to Reduce Their Spontaneous Rate of Cell Death in Response to Corticosteroids
title_short High Constitutive Glucocorticoid Receptor β in Human Neutrophils Enables Them to Reduce Their Spontaneous Rate of Cell Death in Response to Corticosteroids
title_sort high constitutive glucocorticoid receptor β in human neutrophils enables them to reduce their spontaneous rate of cell death in response to corticosteroids
topic Original Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2193396/
https://www.ncbi.nlm.nih.gov/pubmed/11238589
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