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

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...

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Detalles Bibliográficos
Autores principales:	Carrizo Velásquez, Fernanda, Maté, Sabina María, Bakás, Laura Susana, Herlax, Vanesa Silvana
Formato:	Articulo
Lenguaje:	Inglés
Publicado:	2015
Materias:	Bioquímica Abbreviations HlyA alpha hemolysin PC phosphatidylcholine PS phosphatidylserine SM sphingomyelin SMase sphingomyelinase
Acceso en línea:	http://sedici.unlp.edu.ar/handle/10915/86388
Aporte de:	SEDICI (UNLP) de Universidad Nacional de La Plata

id	I19-R120-10915-86388
record_format	dspace
institution	Universidad Nacional de La Plata
institution_str	I-19
repository_str	R-120
collection	SEDICI (UNLP)
language	Inglés
topic	Bioquímica Abbreviations HlyA alpha hemolysin PC phosphatidylcholine PS phosphatidylserine SM sphingomyelin SMase sphingomyelinase
spellingShingle	Bioquímica Abbreviations HlyA alpha hemolysin PC phosphatidylcholine PS phosphatidylserine SM sphingomyelin SMase sphingomyelinase Carrizo Velásquez, Fernanda Maté, Sabina María Bakás, Laura Susana Herlax, Vanesa Silvana Induction of eryptosis by low concentrations of E. coli alpha-hemolysin
topic_facet	Bioquímica Abbreviations HlyA alpha hemolysin PC phosphatidylcholine PS phosphatidylserine SM sphingomyelin SMase sphingomyelinase
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.
format	Articulo Articulo
author	Carrizo Velásquez, Fernanda Maté, Sabina María Bakás, Laura Susana Herlax, Vanesa Silvana
author_facet	Carrizo Velásquez, Fernanda Maté, Sabina María Bakás, Laura Susana Herlax, Vanesa Silvana
author_sort	Carrizo Velásquez, Fernanda
title	Induction of eryptosis by low concentrations of E. coli alpha-hemolysin
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
publishDate	2015
url	http://sedici.unlp.edu.ar/handle/10915/86388
work_keys_str_mv	AT carrizovelasquezfernanda inductionoferyptosisbylowconcentrationsofecolialphahemolysin AT matesabinamaria inductionoferyptosisbylowconcentrationsofecolialphahemolysin AT bakaslaurasusana inductionoferyptosisbylowconcentrationsofecolialphahemolysin AT herlaxvanesasilvana inductionoferyptosisbylowconcentrationsofecolialphahemolysin
bdutipo_str	Repositorios
_version_	1764820489635627009

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

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