Transcriptional Upregulation of Genes Related to Virulence Activation in Entamoeba histolytica

Balderas-Renterı́a, Isaı́as; Garcia-Lazaro, Jose Francisco; Carranza-Rosales, Pilar; Morales-Ramos, Lilia H.; Galán-Wong, Luis J.; Muñoz-Espinosa, Linda E.

doi:10.1016/j.arcmed.2007.01.003

Cited by 9 publications

(7 citation statements)

References 34 publications

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“…Haemolytic activity has also been reported as related to pathogenicity [22, 47]. However, similarly to what was described decades ago by Keller and colleagues [48], we did not observe any correlation of this trait with virulence.…”

Section: Discussionsupporting

confidence: 87%

Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation

et al. 2016

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We here compared pathogenic (p) and non-pathogenic (np) isolates of Entamoeba histolytica to identify molecules involved in the ability of this parasite to induce amoebic liver abscess (ALA)-like lesions in two rodent models for the disease. We performed a comprehensive analysis of 12 clones (A1–A12) derived from a non-pathogenic isolate HM-1:IMSS-A and 12 clones (B1–B12) derived from a pathogenic isolate HM-1:IMSS-B. “Non-pathogenicity” included the induction of small and quickly resolved lesions while “pathogenicity” comprised larger abscess development that overstayed day 7 post infection. All A-clones were designated as non-pathogenic, whereas 4 out of 12 B-clones lost their ability to induce ALAs in gerbils. No correlation between ALA formation and cysteine peptidase (CP) activity, haemolytic activity, erythrophagocytosis, motility or cytopathic activity was found. To identify the molecular framework underlying different pathogenic phenotypes, three clones were selected for in-depth transcriptome analyses. Comparison of a non-pathogenic clone A1np with pathogenic clone B2p revealed 76 differentially expressed genes, whereas comparison of a non-pathogenic clone B8np with B2p revealed only 19 differentially expressed genes. Only six genes were found to be similarly regulated in the two non-pathogenic clones A1np and B8np in comparison with the pathogenic clone B2p. Based on these analyses, we chose 20 candidate genes and evaluated their roles in ALA formation using the respective gene-overexpressing transfectants. We conclude that different mechanisms lead to loss of pathogenicity. In total, we identified eight proteins, comprising a metallopeptidase, C2 domain proteins, alcohol dehydrogenases and hypothetical proteins, that affect the pathogenicity of E. histolytica.

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Section: Discussionsupporting

confidence: 87%

Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation

et al. 2016

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“…In E. histolytica, long-term in vitro cultivation has been related with low virulence, which is restored by liver inoculation, recovery, and cultivation under axenic conditions (Balderas-Renter ıa et al 2007;Das and Ghoshal 1976). While EDGs are scarce in long-term cultured trophozoites, they are abundant after recovery from liver lesions (Ch avez-Mungu ıa et al 2007).…”

Section: Discussionmentioning

confidence: 99%

Acanthamoeba culbertsoni: Electron‐Dense Granules in a Highly Virulent Clinical Isolate

Chávez‐Munguía¹,

Salazar‐Villatoro²,

Omaña‐Molina

et al. 2016

J Eukaryotic Microbiology

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The virulence of various amoebic parasites has been correlated with the presence of electron-dense granules (EDGs) in the cytoplasm of trophozoites. Here, we report the finding by transmission electron microscopy of a large number of EDGs in a recent culture of Acanthamoeba culbertsoni, isolated from a severe case of human keratitis. When this isolate was maintained in culture for 6 mo, the granules almost disappeared. However, after induction of mice brain lesions with the long-term cultured isolate, recovered amoebas had abundant EDGs. Trophozoites of the original isolate, or those recovered from experimental lesions, secreted EDGs into the medium when incubated with MDCK cells. To analyze a possible cytotoxic effect the conditioned medium was incubated with MDCK monolayers. After 5 h, the media containing EDGs produced opening of the tight junctions; at 24 h, cell viability was compromised, and at 48 h most of the cells were detached from the monolayer. In contrast, trophozoites in long-term cultures did not release EDGs to the medium during incubation with MDCK cells, and the corresponding conditioned medium did not have any effect on MDCK monolayers. Our observations further support the hypothesis that EDGs play a role in the cytopathogenic mechanisms of A. culbertsoni.

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“…It is well established that E. histolytica is a pathogenic organism in which its virulence varies according to environmental conditions [19]. Therefore, studies of the transcription profile and changes in gene expression under different conditions are important for understanding the pathogenesis of these parasites and physiology including regulation of the life cycle stages of differentiation, development, and tissue invasion.…”

Section: Discussionmentioning

confidence: 99%

“…The acid phosphatase has been described in parasites such as Leishmania mexicana and Trypanosoma , being an essential enzyme for recycling membrane and endocytosis [4, 19], and may have a similar function in E. histolytica . Another gene more expressed in CSP-R is the Cdc48-like protein (fragment BH18.36).…”

Section: Discussionmentioning

confidence: 99%

Entamoeba histolytica: Gene Expression Analysis of Cells Invading Tissues

Fernandes

Freitas

Martins

et al. 2014

The Scientific World Journal

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Entamoeba histolytica is a protozoan parasite that presents a risk to the health of millions of people worldwide. Due to the existence of different clinical forms caused by the parasite and also different virulence levels presented by one strain, one would expect differences in the profile of gene transcripts between virulent and nonvirulent cultures. In this study we used the differential display to select gene segments related to invasiveness of amoeba. One Brazilian strain of E. histolytica in two conditions, able or not to cause lesions in experimental animals, was used. RNA from this strain, was used to study the differential expression of genes. 29 specific gene fragments differentially expressed in the virulent strain were selected. By real-time PCR, six of these genes had confirmed their differential expression in the virulent culture. These genes may have important roles in triggering invasive amoebiasis and may be related to adaptation of trophozoites to difficulties encountered during colonization of the intestinal epithelium and liver tissue. Future studies with these genes may elucidate its actual role in tissue invasion by E. histolytica generating new pathways for diagnosis and treatment of amoebiasis.

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Transcriptional Upregulation of Genes Related to Virulence Activation in Entamoeba histolytica

Cited by 9 publications

References 34 publications

Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation

Overexpression of Differentially Expressed Genes Identified in Non-pathogenic and Pathogenic Entamoeba histolytica Clones Allow Identification of New Pathogenicity Factors Involved in Amoebic Liver Abscess Formation

Acanthamoeba culbertsoni: Electron‐Dense Granules in a Highly Virulent Clinical Isolate

Entamoeba histolytica: Gene Expression Analysis of Cells Invading Tissues

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