Induction of eryptosis by low concentrations of E. coli alpha-hemolysin

Autores
Carrizo Velásquez, Fernanda; Maté, Sabina María; Bakás, Laura Susana; Herlax, Vanesa Silvana
Año de publicación
2015
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Uropathogenic strains of Escherichia coli deliver the toxin alpha-hemolysin (HlyA) to optimize the host environment for the spread of infection. It was reported that at high concentrations, the toxin forms pores in eukaryotic membranes, leading to cell lysis, while lower concentrations have appeared to interfere with host-cell-signaling pathways causing cell death by apoptosis. Nevertheless, what is not clear is how often HlyA reaches levels that are high enough to lyse host target cells during the course of an infection. In the present investigation, we demonstrate that a low toxin concentration induces the suicidal death of erythrocytes (eryptosis), the major cell type present in blood. Eryptosis is triggered both by an increment in intracellular calcium and by ceramide. Since we have previously demonstrated that a low concentration of HlyA induces an increase in intraerythrocyte calcium, in the present experiments we have shown that this ion activates calpains, which hydrolyze skeleton proteins such as spectrin, ankyrin, protein 4.1 and the electrophoretic Band-3 species, thus resulting in morphologic changes in the erythrocytes. We furthermore observed that a low toxin concentration induced the activation of endogenous sphingomyelinases that in turn increased the amount of ceramide in erythrocyte membranes. Both spectrin proteolysis and ceramide formation may cause the exposure of phosphatidylserine on the membrane so as to trigger a macrophage engulfment of the erythrocyte. By this means eryptosis may be an advantageous mechanism for removing defective erythrocytes before hemolysis.
Instituto de Investigaciones Bioquímicas de La Plata
Facultad de Ciencias Exactas
Materia
Bioquímica
Abbreviations HlyA alpha hemolysin
PC phosphatidylcholine
PS phosphatidylserine
SM sphingomyelin
SMase sphingomyelinase
Nivel de accesibilidad
acceso abierto
Condiciones de uso
http://creativecommons.org/licenses/by-nc-sa/4.0/
Repositorio
SEDICI (UNLP)
Institución
Universidad Nacional de La Plata
OAI Identificador
oai:sedici.unlp.edu.ar:10915/86388

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spelling Induction of eryptosis by low concentrations of E. coli alpha-hemolysinCarrizo Velásquez, FernandaMaté, Sabina MaríaBakás, Laura SusanaHerlax, Vanesa SilvanaBioquímicaAbbreviations HlyA alpha hemolysinPC phosphatidylcholinePS phosphatidylserineSM sphingomyelinSMase sphingomyelinaseUropathogenic strains of Escherichia coli deliver the toxin alpha-hemolysin (HlyA) to optimize the host environment for the spread of infection. It was reported that at high concentrations, the toxin forms pores in eukaryotic membranes, leading to cell lysis, while lower concentrations have appeared to interfere with host-cell-signaling pathways causing cell death by apoptosis. Nevertheless, what is not clear is how often HlyA reaches levels that are high enough to lyse host target cells during the course of an infection. In the present investigation, we demonstrate that a low toxin concentration induces the suicidal death of erythrocytes (eryptosis), the major cell type present in blood. Eryptosis is triggered both by an increment in intracellular calcium and by ceramide. Since we have previously demonstrated that a low concentration of HlyA induces an increase in intraerythrocyte calcium, in the present experiments we have shown that this ion activates calpains, which hydrolyze skeleton proteins such as spectrin, ankyrin, protein 4.1 and the electrophoretic Band-3 species, thus resulting in morphologic changes in the erythrocytes. We furthermore observed that a low toxin concentration induced the activation of endogenous sphingomyelinases that in turn increased the amount of ceramide in erythrocyte membranes. Both spectrin proteolysis and ceramide formation may cause the exposure of phosphatidylserine on the membrane so as to trigger a macrophage engulfment of the erythrocyte. By this means eryptosis may be an advantageous mechanism for removing defective erythrocytes before hemolysis.Instituto de Investigaciones Bioquímicas de La PlataFacultad de Ciencias Exactas2015info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionArticulohttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdf2779-2788http://sedici.unlp.edu.ar/handle/10915/86388enginfo:eu-repo/semantics/altIdentifier/issn/0005-2736info:eu-repo/semantics/altIdentifier/doi/10.1016/j.bbamem.2015.08.012info:eu-repo/semantics/openAccesshttp://creativecommons.org/licenses/by-nc-sa/4.0/Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)reponame:SEDICI (UNLP)instname:Universidad Nacional de La Platainstacron:UNLP2025-09-29T11:16:54Zoai:sedici.unlp.edu.ar:10915/86388Institucionalhttp://sedici.unlp.edu.ar/Universidad públicaNo correspondehttp://sedici.unlp.edu.ar/oai/snrdalira@sedici.unlp.edu.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:13292025-09-29 11:16:54.445SEDICI (UNLP) - Universidad Nacional de La Platafalse
dc.title.none.fl_str_mv Induction of eryptosis by low concentrations of E. coli alpha-hemolysin
title Induction of eryptosis by low concentrations of E. coli alpha-hemolysin
spellingShingle Induction of eryptosis by low concentrations of E. coli alpha-hemolysin
Carrizo Velásquez, Fernanda
Bioquímica
Abbreviations HlyA alpha hemolysin
PC phosphatidylcholine
PS phosphatidylserine
SM sphingomyelin
SMase sphingomyelinase
title_short Induction of eryptosis by low concentrations of E. coli alpha-hemolysin
title_full Induction of eryptosis by low concentrations of E. coli alpha-hemolysin
title_fullStr Induction of eryptosis by low concentrations of E. coli alpha-hemolysin
title_full_unstemmed Induction of eryptosis by low concentrations of E. coli alpha-hemolysin
title_sort Induction of eryptosis by low concentrations of E. coli alpha-hemolysin
dc.creator.none.fl_str_mv Carrizo Velásquez, Fernanda
Maté, Sabina María
Bakás, Laura Susana
Herlax, Vanesa Silvana
author Carrizo Velásquez, Fernanda
author_facet Carrizo Velásquez, Fernanda
Maté, Sabina María
Bakás, Laura Susana
Herlax, Vanesa Silvana
author_role author
author2 Maté, Sabina María
Bakás, Laura Susana
Herlax, Vanesa Silvana
author2_role author
author
author
dc.subject.none.fl_str_mv Bioquímica
Abbreviations HlyA alpha hemolysin
PC phosphatidylcholine
PS phosphatidylserine
SM sphingomyelin
SMase sphingomyelinase
topic Bioquímica
Abbreviations HlyA alpha hemolysin
PC phosphatidylcholine
PS phosphatidylserine
SM sphingomyelin
SMase sphingomyelinase
dc.description.none.fl_txt_mv Uropathogenic strains of Escherichia coli deliver the toxin alpha-hemolysin (HlyA) to optimize the host environment for the spread of infection. It was reported that at high concentrations, the toxin forms pores in eukaryotic membranes, leading to cell lysis, while lower concentrations have appeared to interfere with host-cell-signaling pathways causing cell death by apoptosis. Nevertheless, what is not clear is how often HlyA reaches levels that are high enough to lyse host target cells during the course of an infection. In the present investigation, we demonstrate that a low toxin concentration induces the suicidal death of erythrocytes (eryptosis), the major cell type present in blood. Eryptosis is triggered both by an increment in intracellular calcium and by ceramide. Since we have previously demonstrated that a low concentration of HlyA induces an increase in intraerythrocyte calcium, in the present experiments we have shown that this ion activates calpains, which hydrolyze skeleton proteins such as spectrin, ankyrin, protein 4.1 and the electrophoretic Band-3 species, thus resulting in morphologic changes in the erythrocytes. We furthermore observed that a low toxin concentration induced the activation of endogenous sphingomyelinases that in turn increased the amount of ceramide in erythrocyte membranes. Both spectrin proteolysis and ceramide formation may cause the exposure of phosphatidylserine on the membrane so as to trigger a macrophage engulfment of the erythrocyte. By this means eryptosis may be an advantageous mechanism for removing defective erythrocytes before hemolysis.
Instituto de Investigaciones Bioquímicas de La Plata
Facultad de Ciencias Exactas
description Uropathogenic strains of Escherichia coli deliver the toxin alpha-hemolysin (HlyA) to optimize the host environment for the spread of infection. It was reported that at high concentrations, the toxin forms pores in eukaryotic membranes, leading to cell lysis, while lower concentrations have appeared to interfere with host-cell-signaling pathways causing cell death by apoptosis. Nevertheless, what is not clear is how often HlyA reaches levels that are high enough to lyse host target cells during the course of an infection. In the present investigation, we demonstrate that a low toxin concentration induces the suicidal death of erythrocytes (eryptosis), the major cell type present in blood. Eryptosis is triggered both by an increment in intracellular calcium and by ceramide. Since we have previously demonstrated that a low concentration of HlyA induces an increase in intraerythrocyte calcium, in the present experiments we have shown that this ion activates calpains, which hydrolyze skeleton proteins such as spectrin, ankyrin, protein 4.1 and the electrophoretic Band-3 species, thus resulting in morphologic changes in the erythrocytes. We furthermore observed that a low toxin concentration induced the activation of endogenous sphingomyelinases that in turn increased the amount of ceramide in erythrocyte membranes. Both spectrin proteolysis and ceramide formation may cause the exposure of phosphatidylserine on the membrane so as to trigger a macrophage engulfment of the erythrocyte. By this means eryptosis may be an advantageous mechanism for removing defective erythrocytes before hemolysis.
publishDate 2015
dc.date.none.fl_str_mv 2015
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
Articulo
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info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://sedici.unlp.edu.ar/handle/10915/86388
url http://sedici.unlp.edu.ar/handle/10915/86388
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/issn/0005-2736
info:eu-repo/semantics/altIdentifier/doi/10.1016/j.bbamem.2015.08.012
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
eu_rights_str_mv openAccess
rights_invalid_str_mv http://creativecommons.org/licenses/by-nc-sa/4.0/
Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
dc.format.none.fl_str_mv application/pdf
2779-2788
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repository.name.fl_str_mv SEDICI (UNLP) - Universidad Nacional de La Plata
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