Disease relevance of Entamoeba

• These results suggest that the serotonin present in Entamoeba histolytica may be important in the diarrhea seen in amebiasis [1].
• Cysteine proteinases are hypothesized to be important virulence factors of Entamoeba histolytica, the causative agent of amebic dysentery and liver abscesses [2].
• Complementation of an Escherichia coli adhE mutant by the Entamoeba histolytica EhADH2 gene provides a method for the identification of new antiamebic drugs [3].
• The primary/secondary ADH of isopropanol-producing C. beijerinckii is a type-1 enzyme and is highly conserved in Thermoanaerobacter brockii (formerly Thermoanaerobium brockii) and Entamoeba histolytica [4].
• Comparison of the peptides obtained by limit digest with protease V8 from Staphylococcus aureus shows sequences with common mobility between alpha-actin and Entamoeba actin, but additional peptides are present which may account for the different properties of the Entamoeba actin [5].

High impact information on Entamoeba

• Entamoeba histolytica: a eukaryote without glutathione metabolism [6].
• RHD3-like genes were identified from a protozoan (Entamoeba histolytica), a fungus (Saccharomyces cerevisiae), and another plant species (Oryza sativa), with the sequence identity including the putative GTP-binding motifs [7].
• An example is the galactose- and N-acetylgalactosamine-inhibitable lectin, a surface antigen of Entamoeba histolytica that has been identified as a major candidate in a vaccine to prevent amebiasis [8].
• Characterization of an immuno-dominant variable surface antigen from pathogenic and nonpathogenic Entamoeba histolytica [9].
• Rapid polymerization of Entamoeba histolytica actin induced by interaction with target cells [10].

Chemical compound and disease context of Entamoeba

• The pathogenic protozoan parasite Entamoeba histolytica, the cause of amebic dysentery and amebic liver abscess, is an obligate anaerobe, and derives energy from the fermentation of glucose to ethanol with pyruvate and acetyl coenzyme A as intermediates [3].
• A dose of the pan-caspase inhibitor benzyloxycarbonyl-V-A-D-O-methyl fluoromethyl ketone (Z-VAD-FMK; R & D Systems) given to SCID mice 2 h prior to direct hepatic inoculation with Entamoeba histolytica trophozoites, and 12 h after amebic inoculation, reduced the mean liver abscess size by 70% at 24 h compared to a control group [11].
• Amebiasis and the Entamoeba histolytica Gal/GalNAc lectin: from lab bench to bedside [12].
• Metronidazole, in a dose of 40 mg/kg body weight in 3 divided doses for 10 days was used to treat 194 patients infected with Entamoeba histolytica [13].
• When cholesterol-fed, 2- to 4-week-old guinea pigs were infected intracecally with a virulent, monoaxenic strain of Entamoeba histolytica, gross and histologically characteristic amebomas developed in 85% of the animals by the 3rd day, in 94% by the 9th day, and in 96% by the 12th day postinfection, by which time most of them had died [14].

Biological context of Entamoeba

• Establishment of adherence by Entamoeba histolytica is mediated by a 170-kD Gal/GalNAc inhibitable lectin and is required for cytolysis and phagocytosis of mammalian target cells [15].
• Transfection and transient expression of chloramphenicol acetyltransferase gene in the protozoan parasite Entamoeba histolytica [16].
• Invasiveness of Entamoeba histolytica strains that cause acute amoebiasis is characterized by aggressive behavior associated with cell motility and actin function [17].
• We present here the cloning and characterization of the EhPgp1 multidrug resistance gene promoter isolated from the Entamoeba histolytica drug-resistant mutant clone C2 [18].
• The Entamoeba histolytica mitosome has lost all but a single type of MCF protein, which transports ATP and ADP via a novel mechanism that is not reliant on a membrane potential [19].

Anatomical context of Entamoeba

• BACKGROUND & AIMS: The exact role Entamoeba histolytica cysteine proteases play in overcoming the colonic mucus barrier, as a prerequisite to epithelial cell disruption, is not known [20].
• Neurohormones in Entamoeba histolytica may act directly on colonic tissue to stimulate intestinal secretion, probably via a Ca+(+)-dependent mechanism that is blockable by verapamil, or indirectly via stimulation of prostaglandin E2 generation and release from the rat colon via a cyclic adenosine monophosphate-dependent mechanism [21].
• Identification of the galactose-adherence lectin epitopes of Entamoeba histolytica that stimulate tumor necrosis factor-alpha production by macrophages [22].
• Because many functions of yeast and human mitochondria rely on solutes transported by specialized members of this family, the Entamoeba mitosome must contain only a small subset of these processes requiring adenine nucleotide exchange [19].
• Identification and functional characterization of EhClC-A, an Entamoeba histolytica ClC chloride channel located at plasma membrane [23].

Associations of Entamoeba with chemical compounds

• Virulence of Entamoeba histolytica trophozoites. Effects of bacteria, microaerobic conditions, and metronidazole [24].
• Activation of complement by Entamoeba histolytica may be initiated by the extracellular 56-kD neutral cysteine proteinase which cleaves the alpha chain of C3 [25].
• Inhibition of the complement membrane attack complex by the galactose-specific adhesion of Entamoeba histolytica [26].
• Entamoeba histolytica in rectal biopsies can be detected most easily in ethanol-fixed tissue stained with either a fluorescent antibody or with PAS [27].
• In addition, arachidonic acid metabolites of the cyclooxygenase pathway are probably involved in the Entamoeba histolytica-induced changes in colonic transport that are not dependent on Ca++ entry [21].

Gene context of Entamoeba

• Tumor necrosis factor alpha augments nitric oxide-dependent macrophage cytotoxicity against Entamoeba histolytica by enhanced expression of the nitric oxide synthase gene [28].
• Caspase 3-dependent killing of host cells by the parasite Entamoeba histolytica [29].
• Identification, structure, and phylogenetic relationships of a mitogen-activated protein kinase homologue from the parasitic protist Entamoeba histolytica [30].
• Thus, the extracellular activity of the cysteine proteases affects chemokine-mediated responses and could be considered as part of the mechanisms used by Entamoeba histolytica to circumvent the host immune responses [31].
• An Entamoeba histolytica gene (Eh rho1) was cloned that encodes a putative low-molecular-mass GTP-binding protein, most similar to the ras homologue rho [32].

Analytical, diagnostic and therapeutic context of Entamoeba

• cDNA sequence analysis of a 29-kDa cysteine-rich surface antigen of pathogenic Entamoeba histolytica [33].
• Molecular cloning and characterization of a protein farnesyltransferase from the enteric protozoan parasite Entamoeba histolytica [34].
• We report a one-step method for the purification to homogeneity of a cysteine proteinase of Entamoeba histolytica (histolysin) by affinity chromatography of the soluble extract of the parasite on immobilized phenylalanyl(2-phenyl)aminoacetaldehyde semicarbazone [35].
• This homology was confirmed by immunoblot and indirect immunofluorescence assays with an antibody to the carboxy-terminus region of the Entamoeba histolytica PFO [36].
• A surface antigen (EH-96) of Entamoeba histolytica was demonstrated to be a plasma membrane antigen by immunoprecipitation of metabolically 35S-labeled antigen from live trophozoites, Triton X-114 detergent extracts, and plasma membrane-enriched fractions prepared by concanavalin A membrane stabilization and differential centrifugation [37].

References