Cargando…

Human BCL-G regulates secretion of inflammatory chemokines but is dispensable for induction of apoptosis by IFN-γ and TNF-α in intestinal epithelial cells

Proteins of the BCL-2 family are evolutionarily conserved modulators of apoptosis that function as sensors of cellular integrity. Over the past three decades multiple BCL-2 family members have been identified, many of which are now fully incorporated into regulatory networks governing the mitochondr...

Descripción completa

Detalles Bibliográficos
Autores principales: Woznicki, Jerzy A., Flood, Peter, Bustamante-Garrido, Milan, Stamou, Panagiota, Moloney, Gerry, Fanning, Aine, Zulquernain, Syed Akbar, McCarthy, Jane, Shanahan, Fergus, Melgar, Silvia, Nally, Ken
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985252/
https://www.ncbi.nlm.nih.gov/pubmed/31988296
http://dx.doi.org/10.1038/s41419-020-2263-0
_version_ 1783491782520078336
author Woznicki, Jerzy A.
Flood, Peter
Bustamante-Garrido, Milan
Stamou, Panagiota
Moloney, Gerry
Fanning, Aine
Zulquernain, Syed Akbar
McCarthy, Jane
Shanahan, Fergus
Melgar, Silvia
Nally, Ken
author_facet Woznicki, Jerzy A.
Flood, Peter
Bustamante-Garrido, Milan
Stamou, Panagiota
Moloney, Gerry
Fanning, Aine
Zulquernain, Syed Akbar
McCarthy, Jane
Shanahan, Fergus
Melgar, Silvia
Nally, Ken
author_sort Woznicki, Jerzy A.
collection PubMed
description Proteins of the BCL-2 family are evolutionarily conserved modulators of apoptosis that function as sensors of cellular integrity. Over the past three decades multiple BCL-2 family members have been identified, many of which are now fully incorporated into regulatory networks governing the mitochondrial apoptotic pathway. For some, however, an exact role in cell death signalling remains unclear. One such ‘orphan’ BCL-2 family member is BCL-G (or BCL2L14). In this study we analysed gastrointestinal expression of human BCL-G in health and disease states, and investigated its contribution to inflammation-induced tissue damage by exposing intestinal epithelial cells (IEC) to IFN-γ and TNF-α, two pro-inflammatory mediators associated with gut immunopathology. We found that both BCL-G splice variants — BCL-G(S) (short) and BCL-G(L) (long) — were highly expressed in healthy gut tissue, and that their mRNA levels decreased in active inflammatory bowel diseases (for BCL-G(S)) and colorectal cancer (for BCL-G(S/L)). In vitro studies revealed that IFN-γ and TNF-α synergised to upregulate BCL-G(S/L) and to trigger apoptosis in colonic epithelial cell lines and primary human colonic organoids. Using RNAi, we showed that synergistic induction of IEC death was STAT1-dependent while optimal expression of BCL-G(S/L) required STAT1, NF-κB/p65 and SWI/SNF-associated chromatin remodellers BRM and BRG1. To test the direct contribution of BCL-G to the effects of IFN-γ and TNF-α on epithelial cells, we used RNAi- and CRISPR/Cas9-based perturbations in parallel with isoform-specific overexpression of BCL-G, and found that BCL-G was dispensable for Th1 cytokine-induced apoptosis of human IEC. Instead, we discovered that depletion of BCL-G differentially affected secretion of inflammatory chemokines CCL5 and CCL20, thus uncovering a non-apoptotic immunoregulatory function of this BCL-2 family member. Taken together, our data indicate that BCL-G may be involved in shaping immune responses in the human gut in health and disease states through regulation of chemokine secretion rather than intestinal apoptosis.
format Online
Article
Text
id pubmed-6985252
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher Nature Publishing Group UK
record_format MEDLINE/PubMed
spelling pubmed-69852522020-01-28 Human BCL-G regulates secretion of inflammatory chemokines but is dispensable for induction of apoptosis by IFN-γ and TNF-α in intestinal epithelial cells Woznicki, Jerzy A. Flood, Peter Bustamante-Garrido, Milan Stamou, Panagiota Moloney, Gerry Fanning, Aine Zulquernain, Syed Akbar McCarthy, Jane Shanahan, Fergus Melgar, Silvia Nally, Ken Cell Death Dis Article Proteins of the BCL-2 family are evolutionarily conserved modulators of apoptosis that function as sensors of cellular integrity. Over the past three decades multiple BCL-2 family members have been identified, many of which are now fully incorporated into regulatory networks governing the mitochondrial apoptotic pathway. For some, however, an exact role in cell death signalling remains unclear. One such ‘orphan’ BCL-2 family member is BCL-G (or BCL2L14). In this study we analysed gastrointestinal expression of human BCL-G in health and disease states, and investigated its contribution to inflammation-induced tissue damage by exposing intestinal epithelial cells (IEC) to IFN-γ and TNF-α, two pro-inflammatory mediators associated with gut immunopathology. We found that both BCL-G splice variants — BCL-G(S) (short) and BCL-G(L) (long) — were highly expressed in healthy gut tissue, and that their mRNA levels decreased in active inflammatory bowel diseases (for BCL-G(S)) and colorectal cancer (for BCL-G(S/L)). In vitro studies revealed that IFN-γ and TNF-α synergised to upregulate BCL-G(S/L) and to trigger apoptosis in colonic epithelial cell lines and primary human colonic organoids. Using RNAi, we showed that synergistic induction of IEC death was STAT1-dependent while optimal expression of BCL-G(S/L) required STAT1, NF-κB/p65 and SWI/SNF-associated chromatin remodellers BRM and BRG1. To test the direct contribution of BCL-G to the effects of IFN-γ and TNF-α on epithelial cells, we used RNAi- and CRISPR/Cas9-based perturbations in parallel with isoform-specific overexpression of BCL-G, and found that BCL-G was dispensable for Th1 cytokine-induced apoptosis of human IEC. Instead, we discovered that depletion of BCL-G differentially affected secretion of inflammatory chemokines CCL5 and CCL20, thus uncovering a non-apoptotic immunoregulatory function of this BCL-2 family member. Taken together, our data indicate that BCL-G may be involved in shaping immune responses in the human gut in health and disease states through regulation of chemokine secretion rather than intestinal apoptosis. Nature Publishing Group UK 2020-01-27 /pmc/articles/PMC6985252/ /pubmed/31988296 http://dx.doi.org/10.1038/s41419-020-2263-0 Text en © The Author(s) 2020 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
spellingShingle Article
Woznicki, Jerzy A.
Flood, Peter
Bustamante-Garrido, Milan
Stamou, Panagiota
Moloney, Gerry
Fanning, Aine
Zulquernain, Syed Akbar
McCarthy, Jane
Shanahan, Fergus
Melgar, Silvia
Nally, Ken
Human BCL-G regulates secretion of inflammatory chemokines but is dispensable for induction of apoptosis by IFN-γ and TNF-α in intestinal epithelial cells
title Human BCL-G regulates secretion of inflammatory chemokines but is dispensable for induction of apoptosis by IFN-γ and TNF-α in intestinal epithelial cells
title_full Human BCL-G regulates secretion of inflammatory chemokines but is dispensable for induction of apoptosis by IFN-γ and TNF-α in intestinal epithelial cells
title_fullStr Human BCL-G regulates secretion of inflammatory chemokines but is dispensable for induction of apoptosis by IFN-γ and TNF-α in intestinal epithelial cells
title_full_unstemmed Human BCL-G regulates secretion of inflammatory chemokines but is dispensable for induction of apoptosis by IFN-γ and TNF-α in intestinal epithelial cells
title_short Human BCL-G regulates secretion of inflammatory chemokines but is dispensable for induction of apoptosis by IFN-γ and TNF-α in intestinal epithelial cells
title_sort human bcl-g regulates secretion of inflammatory chemokines but is dispensable for induction of apoptosis by ifn-γ and tnf-α in intestinal epithelial cells
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985252/
https://www.ncbi.nlm.nih.gov/pubmed/31988296
http://dx.doi.org/10.1038/s41419-020-2263-0
work_keys_str_mv AT woznickijerzya humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells
AT floodpeter humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells
AT bustamantegarridomilan humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells
AT stamoupanagiota humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells
AT moloneygerry humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells
AT fanningaine humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells
AT zulquernainsyedakbar humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells
AT mccarthyjane humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells
AT shanahanfergus humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells
AT melgarsilvia humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells
AT nallyken humanbclgregulatessecretionofinflammatorychemokinesbutisdispensableforinductionofapoptosisbyifngandtnfainintestinalepithelialcells