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Guillen N. Signals and signal transduction pathways in Entamoeba histolytica during the life cycle and when interacting with bacteria or human cells. Mol Microbiol 2020; 115:901-915. [PMID: 33249684 DOI: 10.1111/mmi.14657] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 01/17/2023]
Abstract
Entamoeba histolytica is the etiological agent of amebiasis in humans. This ameba parasite resides as a commensal in the intestine where it shares intestinal resources with the bacterial microbiome. In the intestinal ecosystem, the ameba encysts and eventually develops disease by invading the tissues. E. histolytica possesses cell surface receptors for the proper sensing of signals involved in encystation or sustaining parasite interaction with bacteria and human cells. Among those receptors are the Gal/GalNAc lectin, G protein-coupled receptors, and transmembrane kinases. In addition there are recently discovered, promising proteins, including orthologs of Toll-type receptors and β trefoil lectins. These proteins trigger a wide variety of signal transduction pathways; however, most of the players involved in the signaling pathways evoked in this parasite are unknown. This review provides an overview of amoebic receptors and their role in encystation, adherence to bacteria or human cells, as well as the reported intracellular signal transduction processes that they can trigger. This knowledge is essential for understanding the lifestyle of E. histolytica and its cytopathic effect on bacteria and human cells that are responsible for infection.
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Affiliation(s)
- Nancy Guillen
- Institut Pasteur, Centre National de la Recherche Scientifique, CNRS-ERL9195, Paris, France
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2
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Castellanos-Castro S, Bolaños J, Orozco E. Lipids in Entamoeba histolytica: Host-Dependence and Virulence Factors. Front Cell Infect Microbiol 2020; 10:75. [PMID: 32211340 PMCID: PMC7075943 DOI: 10.3389/fcimb.2020.00075] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 02/14/2020] [Indexed: 11/19/2022] Open
Abstract
Lipids are essential players in parasites pathogenesis. In particular, the highly phagocytic trophozoites of Entamoeba histolytica, the causative agent of amoebiasis, exhibit a dynamic membrane fusion and fission, in which lipids strongly participate; particularly during the overstated motility of the parasite to reach and attack the epithelia and ingest target cells. Synthesis and metabolism of lipids in this protozoan present remarkable difference with those performed by other eukaryotes. Here, we reviewed the current knowledge on lipids in E. histolytica. Trophozoites synthesize phosphatidylcholine and phosphatidylethanolamine by the Kennedy pathway; and sphingolipids, phosphatidylserine, and phosphatidylinositol, by processes similar to those used by other eukaryotes. However, trophozoites lack enzymes for cholesterol and fatty acids synthesis, which are scavenged from the host or culture medium by specific mechanisms. Cholesterol, a fundamental molecule for the expression of virulence, is transported from the medium into the trophozoites by EhNPC1 and EhNPC2 proteins. Inside cells, lipids are distributed by different pathways, including by the participation of the endosomal sorting complex required for transport (ESCRT), involved in vesicle fusion and fission. Cholesterol interacts with the phospholipid lysobisphosphatidic acid (LBPA) and EhADH, an ALIX family protein, also involved in phagocytosis. In this review, we summarize the known information on phospholipids synthesis and cholesterol transport as well as their metabolic pathways in E. histolytica; highlighting the mechanisms used by trophozoites to dispose lipids involved in the virulence processes.
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Affiliation(s)
- Silvia Castellanos-Castro
- College of Sciences and Humanities, Autonomous University of Mexico City, Mexico City, Mexico.,BioImage Analysis Unit, Pasteur Institute, Paris, France
| | - Jeni Bolaños
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, Mexico.,Centro Multidisciplinario de Estudios en Biotecnología, FMVZ, Universidad Michoacana de San Nnicolás Hidalgo, Morelia, Mexico
| | - Esther Orozco
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies of the National Polytechnic Institute, Mexico City, Mexico
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Guillén N. The interaction betweenEntamoeba histolyticaand enterobacteria shed light on an ancient antibacterial response. Cell Microbiol 2019; 21:e13039. [DOI: 10.1111/cmi.13039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 04/17/2019] [Accepted: 04/30/2019] [Indexed: 01/27/2023]
Affiliation(s)
- Nancy Guillén
- Institut Pasteur Paris France
- INSBCentre National de la Recherche Scientifique, CNRS‐ERL9195 Paris France
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Bolaños J, Betanzos A, Javier-Reyna R, García- Rivera G, Huerta M, Pais-Morales J, González-Robles A, Rodríguez MA, Schnoor M, Orozco E. EhNPC1 and EhNPC2 Proteins Participate in Trafficking of Exogenous Cholesterol in Entamoeba histolytica Trophozoites: Relevance for Phagocytosis. PLoS Pathog 2016; 12:e1006089. [PMID: 28002502 PMCID: PMC5176366 DOI: 10.1371/journal.ppat.1006089] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 11/25/2016] [Indexed: 12/31/2022] Open
Abstract
Entamoeba histolytica, the highly phagocytic protozoan causative of human amoebiasis lacks the machinery to synthesize cholesterol. Here, we investigated the presence of NPC1 and NPC2 proteins in this parasite, which are involved in cholesterol trafficking in mammals. Bioinformatics analysis revealed one Ehnpc1 and two Ehnpc2 genes. EhNPC1 appeared as a transmembrane protein and both EhNPC2 as peripheral membrane proteins. Molecular docking predicted that EhNPC1 and EhNPC2 bind cholesterol and interact with each other. Genes and proteins were identified in trophozoites. Serum pulse-chase and confocal microscopy assays unveiled that after trophozoites sensed the cholesterol source, EhNPC1 and EhNPC2 were organized around the plasma membrane in a punctuated pattern. Vesicles emerged and increased in number and size and some appeared full of cholesterol with EhNPC1 or EhNPC2 facing the extracellular space. Both proteins, but mostly EhNPC2, were found out of the cell associated with cholesterol. EhNPC1 and cholesterol formed networks from the plasma membrane to the nucleus. EhNPC2 appeared in erythrocytes that were being ingested by trophozoites, co-localizing with cholesterol of erythrocytes, whereas EhNPC1 surrounded the phagocytic cup. EhNPC1 and EhNPC2 co-localized with EhSERCA in the endoplasmic reticulum and with lysobisphosphatidic acid and EhADH (an Alix protein) in phagolysosomes. Immunoprecipitation assays confirmed the EhNPC1 and EhNPC2 association with cholesterol, EhRab7A and EhADH. Serum starved and blockage of cholesterol trafficking caused a low rate of phagocytosis and incapability of trophozoites to produce damage in the mouse colon. Ehnpc1 and Ehnpc2 knockdown provoked in trophozoites a lower intracellular cholesterol concentration and a diminished rate of phagocytosis; and Ehnpc1 silencing also produced a decrease of trophozoites movement. Trafficking of EhNPC1 and EhNPC2 during cholesterol uptake and phagocytosis as well as their association with molecules involved in endocytosis strongly suggest that these proteins play a key role in cholesterol uptake. NPC1 and NPC2 proteins are involved in cholesterol trafficking in mammals. Using different approaches, we have detected the orthologues EhNPC1 and EhNPC2 proteins in Entamoeba histolytica. Trophozoites are particularly rich in membranes and vacuoles, but they do not possess the machinery to synthetize cholesterol. Thus, they are completely dependent on molecules able to “fish” cholesterol from the medium. The relevance of our findings lies in the fact that cholesterol is fundamental for endocytosis and motility; and, phagocytosis is an important nutritional and virulence factor for E. histolytica. In silico and experimental strategies, using U18666A to arrest cholesterol trafficking, as well as, knockdown mutants, showed that EhNPC1 and EhNPC2 participate in cholesterol uptake and trafficking in this parasite. They are secreted by trophozoites and directly involved in erythrophagocytosis and motility. Our findings revealed E. histolytica as one of the first protozoa in which these proteins are being characterized. Moreover, E. histolytica provides an excellent and less complicated model to elucidate the intricate event of cholesterol trafficking in eukaryotic cells. The relevance of cholesterol transport for the parasite virulence and the involvement of EhNPC1 and EhNPC2 in this process, make these proteins promising targets for therapy strategies development against the parasite.
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Affiliation(s)
- Jeni Bolaños
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F., México
| | - Abigail Betanzos
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F., México
- Cátedras, Consejo Nacional de Ciencia y Tecnología, D.F., México
| | - Rosario Javier-Reyna
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F., México
| | - Guillermina García- Rivera
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F., México
| | - Miriam Huerta
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F., México
| | - Jonnatan Pais-Morales
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F., México
| | - Arturo González-Robles
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F., México
| | - Mario A. Rodríguez
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F., México
| | - Michael Schnoor
- Departamento de Biomedicina Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F., México
| | - Esther Orozco
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, D.F., México
- * E-mail:
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Verma K, Nozaki T, Datta S. Role of EhRab7A in phagocytosis of type 1 fimbriated E. coli by Entamoeba histolytica. Mol Microbiol 2016; 102:1043-1061. [PMID: 27663892 DOI: 10.1111/mmi.13533] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/17/2016] [Indexed: 01/16/2023]
Abstract
Entamoeba histolytica, the causative agent of amoebic colitis and liver abscess in human, ingests the intestinal bacteria and variety of host cells. Phagocytosis of bacteria by the amebic trophozoite has been reported to be important for the virulence of the parasite. Here, we set out to characterize different stages of phagocytosis of type 1 E. coli and investigated the role of a set of amoebic Rab GTPases in the process. The localizations of the Rab GTPases during different stages of the phagocytosis were investigated using laser scanning confocal microscopy and their functional relevance were determined using fluorescence activated cell sorter based assay as well as colony forming unit assay. Our results demonstrate that EhRab7A is localized on the phagosomes and involved in both early and late stages of type 1 E. coli phagocytosis. We further showed that the E. coli or RBC containing phagosomes are distinct from the large endocytic vacuoles in the parasite which are exclusively used to transport human holotransferrin and low density lipoprotein. Remarkably, type 1 E. coli uptake was found to be insensitive to cytochalasin D treatment, suggesting that the initial stage of E. coli phagocytosis is independent of the formation of actin filaments.
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Affiliation(s)
- Kuldeep Verma
- Department of Biological Science, Indian Institute of Science Education and Research Bhopal Bypass Road, Bhauri, Bhopal, 462 066, Madhya Pradesh, India
| | - Tomoyoshi Nozaki
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo, 162-8640, Japan
| | - Sunando Datta
- Department of Biological Science, Indian Institute of Science Education and Research Bhopal Bypass Road, Bhauri, Bhopal, 462 066, Madhya Pradesh, India
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Reyna-Fabián ME, Zermeño V, Ximénez C, Flores J, Romero MF, Diaz D, Argueta J, Moran P, Valadez A, Cerritos R. Analysis of the Bacterial Diversity in Liver Abscess: Differences Between Pyogenic and Amebic Abscesses. Am J Trop Med Hyg 2015; 94:147-55. [PMID: 26572872 DOI: 10.4269/ajtmh.15-0458] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 09/19/2015] [Indexed: 11/07/2022] Open
Abstract
Several recent studies have demonstrated that virulence in Entamoeba histolytica is triggered in the presence of both pathogenic and nonpathogenic bacteria species using in vitro and in vivo experimental animal models. In this study, we examined samples aspirated from abscess material obtained from patients who were clinically diagnosed with amebic liver abscess (ALA) or pyogenic liver abscess (PLA). To determine the diversity of bacterial species in the abscesses, we performed partial 16S rRNA gene sequencing. In addition, the E. histolytica and Entamoeba dispar species were genotyped using tRNA-linked short tandem repeats as specific molecular markers. The association between clinical data and bacterial and parasite genotypes were examined through a correspondence analysis. The results showed the presence of numerous bacterial groups. These taxonomic groups constitute common members of the gut microbiota, although all of the detected bacterial species have a close phylogenetic relationship with bacterial pathogens. Furthermore, some patients clinically diagnosed with PLA and ALA were coinfected with E. dispar or E. histolytica, which suggests that the virulence of these parasites increased in the presence of bacteria. However, no specific bacterial groups were associated with this effect. Together, our results suggest a nonspecific mechanism of virulence modulation by bacteria in Entamoeba.
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Affiliation(s)
- Miriam E Reyna-Fabián
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Valeria Zermeño
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Cecilia Ximénez
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Janin Flores
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Miguel F Romero
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Daniel Diaz
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Jesús Argueta
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Patricia Moran
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - Alicia Valadez
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México
| | - René Cerritos
- Departamento de Medicina Experimental, Facultad de Medicina, Universidad Nacional Autónoma de México (UNAM), México City, México; Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México (UNAM), México City, México
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Saha A, Bhattacharya S, Bhattacharya A. Regulation of serum-responsive transmembrane kinase EhTMKB1-9 by an unsaturated lipid, oleic acid in protistan parasite Entamoeba histolytica. Mol Biochem Parasitol 2014; 198:48-57. [PMID: 25497959 DOI: 10.1016/j.molbiopara.2014.12.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 11/24/2014] [Accepted: 12/01/2014] [Indexed: 10/24/2022]
Abstract
Transmembrane kinases of Entamoeba histolytica are known to play a wide range of roles from virulence, phagocytosis, and proliferation to stress response. Transmembrane kinase EhTMKB1-9 is thought to be involved in early proliferative response and it was originally identified as a serum inducible gene. Ability to stimulate EhTMKB1 expression of serum starved cells resides in unsaturated fatty acids associated with albumin fraction of serum and the mechanism of stimulation follows activation of EhTMKB1-9 promoter. Gel shift assay showed the presence of proteins that bind to the specific site of EhTMKB1-9 upstream region and the concentration of these protein(s) go down on serum starvation, but level of binding protein(s) go up on serum or fatty acid replenishment. This increase in concentration of binding molecule(s) is due to new synthesis rather than activation of existing molecule(s) as a protein synthesis inhibitor blocked enhanced level of gel shifted material on replenishment. The stimulating activity resides in the fatty acyl chain, but not in the head group. Moreover, the fatty acid initiates signaling through class I PI3 kinases that result in activation of EhTMKB1-9 expression. These results suggest a novel mechanism of gene regulation in E. histolytica, and unsaturated fatty acids as potential new signaling molecules.
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Affiliation(s)
- Arpita Saha
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Sudha Bhattacharya
- School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Alok Bhattacharya
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India.
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Evidence for a bacterial lipopolysaccharide-recognizing G-protein-coupled receptor in the bacterial engulfment by Entamoeba histolytica. EUKARYOTIC CELL 2013; 12:1433-8. [PMID: 23975887 DOI: 10.1128/ec.00150-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Entamoeba histolytica is the causative agent of amoebic dysentery, a worldwide protozoal disease that results in approximately 100,000 deaths annually. The virulence of E. histolytica may be due to interactions with the host bacterial flora, whereby trophozoites engulf colonic bacteria as a nutrient source. The engulfment process depends on trophozoite recognition of bacterial epitopes that activate phagocytosis pathways. E. histolytica GPCR-1 (EhGPCR-1) was previously recognized as a putative G-protein-coupled receptor (GPCR) used by Entamoeba histolytica during phagocytosis. In the present study, we attempted to characterize EhGPCR-1 by using heterologous GPCR expression in Saccharomyces cerevisiae. We discovered that bacterial lipopolysaccharide (LPS) is an activator of EhGPCR-1 and that LPS stimulates EhGPCR-1 in a concentration-dependent manner. Additionally, we demonstrated that Entamoeba histolytica prefers to engulf bacteria with intact LPS and that this engulfment process is sensitive to suramin, which prevents the interactions of GPCRs and G-proteins. Thus, EhGPCR-1 is an LPS-recognizing GPCR that is a potential drug target for treatment of amoebiasis, especially considering the well-established drug targeting to GPCRs.
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