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Opposition between PKC isoforms regulates histone deimination and neutrophil extracellular chromatin release
In response to inflammation, neutrophils deiminate histones and externalize chromatin. Neutrophil extracellular traps (NETs) are an innate immune defense mechanism, yet NETs also may aggravate chronic inflammatory and autoimmune disorders. Activation of peptidylarginine deiminase 4 (PAD4) is associa...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2013
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3576869/ https://www.ncbi.nlm.nih.gov/pubmed/23430963 http://dx.doi.org/10.3389/fimmu.2013.00038 |
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author | Neeli, Indira Radic, Marko |
author_facet | Neeli, Indira Radic, Marko |
author_sort | Neeli, Indira |
collection | PubMed |
description | In response to inflammation, neutrophils deiminate histones and externalize chromatin. Neutrophil extracellular traps (NETs) are an innate immune defense mechanism, yet NETs also may aggravate chronic inflammatory and autoimmune disorders. Activation of peptidylarginine deiminase 4 (PAD4) is associated with NET release (NETosis) but the precise mechanisms of PAD4 regulation are unknown. We observed that, in human neutrophils, calcium ionophore induced histone deimination, whereas phorbol myristate acetate (PMA), an activator of protein kinase C (PKC), suppressed ionophore-induced deimination. Conversely, low doses of chelerythrine and sanguinarine, two inhibitors of PKC, reversed PMA inhibition and enhanced ionophore-stimulated deimination. In addition, a peptide inhibitor of PKCα superinduced ionophore activation of PAD4, thus identifying PKCα as the PMA-induced inhibitor of PAD4. At higher doses, chelerythrine, sanguinarine, and structurally unrelated PKC inhibitors blocked histone deimination, suggesting that a different PKC isoform activates histone deimination. We identify PKCζ as activator of PAD4 because a specific peptide inhibitor of this PKC isoform suppressed histone deimination. Confocal microscopy confirmed that, in the presence of PMA, NETosis proceeds without detectable histone deimination, and that ionophore cooperates with PMA to induce more extensive NET release. Broad inhibition of PKC by chelerythrine or specific inhibition of PKCζ suppressed NETosis. Our observations thus reveal an intricate antagonism between PKC isoforms in the regulation of histone deimination, identify a dominant role for PKCα in the repression of histone deimination, and assign essential functions to PKCζ in the activation of PAD4 and the execution of NETosis. The precise balance between opposing PKC isoforms in the regulation of NETosis affirms the idea that NET release underlies specific and vitally important evolutionary selection pressures. |
format | Online Article Text |
id | pubmed-3576869 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2013 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-35768692013-02-21 Opposition between PKC isoforms regulates histone deimination and neutrophil extracellular chromatin release Neeli, Indira Radic, Marko Front Immunol Immunology In response to inflammation, neutrophils deiminate histones and externalize chromatin. Neutrophil extracellular traps (NETs) are an innate immune defense mechanism, yet NETs also may aggravate chronic inflammatory and autoimmune disorders. Activation of peptidylarginine deiminase 4 (PAD4) is associated with NET release (NETosis) but the precise mechanisms of PAD4 regulation are unknown. We observed that, in human neutrophils, calcium ionophore induced histone deimination, whereas phorbol myristate acetate (PMA), an activator of protein kinase C (PKC), suppressed ionophore-induced deimination. Conversely, low doses of chelerythrine and sanguinarine, two inhibitors of PKC, reversed PMA inhibition and enhanced ionophore-stimulated deimination. In addition, a peptide inhibitor of PKCα superinduced ionophore activation of PAD4, thus identifying PKCα as the PMA-induced inhibitor of PAD4. At higher doses, chelerythrine, sanguinarine, and structurally unrelated PKC inhibitors blocked histone deimination, suggesting that a different PKC isoform activates histone deimination. We identify PKCζ as activator of PAD4 because a specific peptide inhibitor of this PKC isoform suppressed histone deimination. Confocal microscopy confirmed that, in the presence of PMA, NETosis proceeds without detectable histone deimination, and that ionophore cooperates with PMA to induce more extensive NET release. Broad inhibition of PKC by chelerythrine or specific inhibition of PKCζ suppressed NETosis. Our observations thus reveal an intricate antagonism between PKC isoforms in the regulation of histone deimination, identify a dominant role for PKCα in the repression of histone deimination, and assign essential functions to PKCζ in the activation of PAD4 and the execution of NETosis. The precise balance between opposing PKC isoforms in the regulation of NETosis affirms the idea that NET release underlies specific and vitally important evolutionary selection pressures. Frontiers Media S.A. 2013-02-20 /pmc/articles/PMC3576869/ /pubmed/23430963 http://dx.doi.org/10.3389/fimmu.2013.00038 Text en Copyright © Neeli and Radic. http://creativecommons.org/licenses/by/3.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc. |
spellingShingle | Immunology Neeli, Indira Radic, Marko Opposition between PKC isoforms regulates histone deimination and neutrophil extracellular chromatin release |
title | Opposition between PKC isoforms regulates histone deimination and neutrophil extracellular chromatin release |
title_full | Opposition between PKC isoforms regulates histone deimination and neutrophil extracellular chromatin release |
title_fullStr | Opposition between PKC isoforms regulates histone deimination and neutrophil extracellular chromatin release |
title_full_unstemmed | Opposition between PKC isoforms regulates histone deimination and neutrophil extracellular chromatin release |
title_short | Opposition between PKC isoforms regulates histone deimination and neutrophil extracellular chromatin release |
title_sort | opposition between pkc isoforms regulates histone deimination and neutrophil extracellular chromatin release |
topic | Immunology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3576869/ https://www.ncbi.nlm.nih.gov/pubmed/23430963 http://dx.doi.org/10.3389/fimmu.2013.00038 |
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