Contribution of neutral sphingomyelinases to in vitro virulence of Entamoeba histolytica

Urquieta-Ramírez, Luz; Ramírez-Montiel, Fátima Berenice; Andrade-Guillén, Sairy; Páramo-Pérez, Itzel; Rangel-Serrano, Ángeles; Reyes-Cortés, Ruth; Franco, Bernardo; Mendoza-Macías, Claudia Leticia; Anaya-Velázquez, Fernando; Padilla‐Vaca, Felipe

doi:10.1016/j.exppara.2018.09.015

Cited by 2 publications

(2 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently we reported that the nSMase3 of E . histolytica participate in hemolytic and cytotoxic activities, while, the nSMase1 and nSMase2 are involved in the cytopathic activity [121]. There are still new factors that remain to be elucidated and characterized to fully comprehend the virulence mechanism in this parasite.…”

Section: Discussionmentioning

confidence: 99%

Plasma membrane damage repair is mediated by an acid sphingomyelinase in Entamoeba histolytica

et al. 2019

Self Cite

View full text Add to dashboard Cite

Entamoeba histolytica is a pathogen that during its infective process confronts the host defenses, which damages the amoebic plasma membrane (PM), resulting in the loss of viability. However, it is unknown whether amoebic trophozoites are able to repair their PM when it is damaged. Acid sphingomyelinases (aSMases) have been reported in mammalian cells to promote endocytosis and removal of PM lesions. In this work, six predicted amoebic genes encoding for aSMases were found to be transcribed in the HM1:IMSS strain, finding that the EhaSM6 gene is the most transcribed in basal growth conditions and rendered a functional protein. The secreted aSMase activity detected was stimulated by Mg +2 and inhibited by Co +2 . Trophozoites that overexpress the EhaSM6 gene (HM1-SM6HA) exhibit an increase of 2-fold in the secreted aSMase activity. This transfectant trophozoites exposed to pore-forming molecules (SLO, Magainin, β-Defensin 2 and human complement) exhibited an increase from 6 to 25-fold in the secreted aSMase activity which correlated with higher amoebic viability in a Ca +2 dependent process. However, other agents that affect the PM such as hydrogen peroxide also induced an increase of secreted aSMase, but to a lesser extent. The aSMase6 enzyme is N- and C-terminal processed. Confocal and transmission electron microscopy showed that trophozoites treated with SLO presented a migration of lysosomes containing the aSMase towards the PM, inducing the formation of membrane patches and endosomes in the control strain. These cellular structures were increased in the overexpressing strain, indicating the involvement of the aSMase6 in the PM injury repair. The pore-forming molecules induced an increase in the expression of EhaSM1 , 2 , 5 and 6 genes, meanwhile, hydrogen peroxide induced an increase in all of them. In all the conditions evaluated, the EhaSM6 gene exhibited the highest levels of induction. Overall, these novel findings show that the aSMase6 enzyme from E . histolytica promotes the repair of the PM damaged with pore-forming molecules to prevent losing cell integrity. This novel system could act when encountered with the lytic defense systems of the host.

show abstract

Section: Discussionmentioning

confidence: 99%

Plasma membrane damage repair is mediated by an acid sphingomyelinase in Entamoeba histolytica

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…An increase in gene expression of amoebapores A, B, and C has been seen in virulent E. histolytica strains in comparison with less virulent Entamoeba species. Urquieta-Ramírez et al [96] mention that in a E. histolytica strain that overexpresses neutral sphingomyelinases, the gene expression levels for cysteine proteinase 5, adhesin 112, and heavy and light Gal/GalNAc lectin subunits are not affected. They propose that the increase in the cytotoxic and lytic effect of EhnSM3 overexpressing strain can be related to the sum of the effect of EhnSM3 plus amoebapores in a process cell contact-dependent manner or as a mediator by inducing the gene expression of amoebapores enabling the link between EhnSM3 with the virulence phenotype of E. histolytica.…”

Section: Pathogenesismentioning

confidence: 99%

Amoebiasis: Advances in Diagnosis, Treatment, Immunology Features and the Interaction with the Intestinal Ecosystem

Morán

Serrano-Vázquez

Rojas-Velázquez

et al. 2023

IJMS

View full text Add to dashboard Cite

This review of human amoebiasis is based on the most current knowledge of pathogenesis, diagnosis, treatment, and Entamoeba/microbiota interactions. The most relevant findings during this last decade about the Entamoeba parasite and the disease are related to the possibility of culturing trophozoites of different isolates from infected individuals that allowed the characterization of the multiple pathogenic mechanisms of the parasite and the understanding of the host–parasite relationship in the human. Second, the considerable advances in molecular biology and genetics help us to analyze the genome of Entamoeba, their genetic diversity, and the association of specific genotypes with the different amoebic forms of human amoebiasis. Based on this knowledge, culture and/or molecular diagnostic strategies are now available to determine the Entamoeba species and genotype responsible for invasive intestinal or extraintestinal amoebiasis cases. Likewise, the extensive knowledge of the immune response in amoebiasis with the appearance of new technologies made it possible to design diagnostic tools now available worldwide. Finally, the understanding of the interaction between the Entamoeba species and the intestinal microbiota aids the understanding of the ecology of this parasite in the human environment. These relevant findings will be discussed in this review.

show abstract

Contribution of neutral sphingomyelinases to in vitro virulence of Entamoeba histolytica

Cited by 2 publications

References 57 publications

Plasma membrane damage repair is mediated by an acid sphingomyelinase in Entamoeba histolytica

Plasma membrane damage repair is mediated by an acid sphingomyelinase in Entamoeba histolytica

Amoebiasis: Advances in Diagnosis, Treatment, Immunology Features and the Interaction with the Intestinal Ecosystem

Contact Info

Product

Resources

About