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Sierra-López F, Castelan-Ramírez I, Hernández-Martínez D, Salazar-Villatoro L, Segura-Cobos D, Flores-Maldonado C, Hernández-Ramírez VI, Villamar-Duque TE, Méndez-Cruz AR, Talamás-Rohana P, Omaña-Molina M. Extracellular Vesicles Secreted by Acanthamoeba culbertsoni Have COX and Proteolytic Activity and Induce Hemolysis. Microorganisms 2023; 11:2762. [PMID: 38004773 PMCID: PMC10673465 DOI: 10.3390/microorganisms11112762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
Several species of Acanthamoeba genus are potential pathogens and etiological agents of several diseases. The pathogenic mechanisms carried out by these amoebae in different target tissues have been documented, evidencing the relevant role of contact-dependent mechanisms. With the purpose of describing the pathogenic processes carried out by these protozoans more precisely, we considered it important to determine the emission of extracellular vesicles (EVs) as part of the contact-independent pathogenicity mechanisms of A. culbertsoni, a highly pathogenic strain. Through transmission electronic microscopy (TEM) and nanoparticle tracking analysis (NTA), EVs were characterized. EVs showed lipid membrane and a size between 60 and 855 nm. The secretion of large vesicles was corroborated by confocal and TEM microscopy. The SDS-PAGE of EVs showed proteins of 45 to 200 kDa. Antigenic recognition was determined by Western Blot, and the internalization of EVs by trophozoites was observed through Dil-labeled EVs. In addition, some EVs biological characteristics were determined, such as proteolytic, hemolytic and COX activity. Furthermore, we highlighted the presence of leishmanolysin in trophozites and EVs. These results suggest that EVs are part of a contact-independent mechanism, which, together with contact-dependent ones, allow for a better understanding of the pathogenicity carried out by Acanthamoeba culbertsoni.
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Affiliation(s)
- Francisco Sierra-López
- Laboratory of Amphizoic Amoebae, Faculty of Superior Studies Iztacala, Medicine, National Autonomous University of Mexico (UNAM), Tlalnepantla 54090, Mexico (I.C.-R.); (D.H.-M.); (D.S.-C.); (A.R.M.-C.)
| | - Ismael Castelan-Ramírez
- Laboratory of Amphizoic Amoebae, Faculty of Superior Studies Iztacala, Medicine, National Autonomous University of Mexico (UNAM), Tlalnepantla 54090, Mexico (I.C.-R.); (D.H.-M.); (D.S.-C.); (A.R.M.-C.)
| | - Dolores Hernández-Martínez
- Laboratory of Amphizoic Amoebae, Faculty of Superior Studies Iztacala, Medicine, National Autonomous University of Mexico (UNAM), Tlalnepantla 54090, Mexico (I.C.-R.); (D.H.-M.); (D.S.-C.); (A.R.M.-C.)
| | - Lizbeth Salazar-Villatoro
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies, National Polytechnic Institute (IPN), Mexico City 07360, Mexico; (L.S.-V.); (V.I.H.-R.); (P.T.-R.)
| | - David Segura-Cobos
- Laboratory of Amphizoic Amoebae, Faculty of Superior Studies Iztacala, Medicine, National Autonomous University of Mexico (UNAM), Tlalnepantla 54090, Mexico (I.C.-R.); (D.H.-M.); (D.S.-C.); (A.R.M.-C.)
| | - Catalina Flores-Maldonado
- Department of Physiology, Biophysics and Neurosciences, Center for Research and Advanced Studies, National Polytechnic Institute (IPN), Mexico City 07360, Mexico;
| | - Verónica Ivonne Hernández-Ramírez
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies, National Polytechnic Institute (IPN), Mexico City 07360, Mexico; (L.S.-V.); (V.I.H.-R.); (P.T.-R.)
| | - Tomás Ernesto Villamar-Duque
- General Biotery, Faculty of Superior Studies Iztacala, Biology, National Autonomous University of Mexico (UNAM), Tlalnepantla 54090, Mexico;
| | - Adolfo René Méndez-Cruz
- Laboratory of Amphizoic Amoebae, Faculty of Superior Studies Iztacala, Medicine, National Autonomous University of Mexico (UNAM), Tlalnepantla 54090, Mexico (I.C.-R.); (D.H.-M.); (D.S.-C.); (A.R.M.-C.)
| | - Patricia Talamás-Rohana
- Department of Infectomics and Molecular Pathogenesis, Center for Research and Advanced Studies, National Polytechnic Institute (IPN), Mexico City 07360, Mexico; (L.S.-V.); (V.I.H.-R.); (P.T.-R.)
| | - Maritza Omaña-Molina
- Laboratory of Amphizoic Amoebae, Faculty of Superior Studies Iztacala, Medicine, National Autonomous University of Mexico (UNAM), Tlalnepantla 54090, Mexico (I.C.-R.); (D.H.-M.); (D.S.-C.); (A.R.M.-C.)
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Wang X, Chen J, Zheng J. The roles of COX-2 in protozoan infection. Front Immunol 2023; 14:955616. [PMID: 36875123 PMCID: PMC9978824 DOI: 10.3389/fimmu.2023.955616] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 02/06/2023] [Indexed: 02/18/2023] Open
Abstract
Protozoan diseases cause great harm in animal husbandry and require human-provided medical treatment. Protozoan infection can induce changes in cyclooxygenase-2 (COX-2) expression. The role played by COX-2 in the response to protozoan infection is complex. COX-2 induces and regulates inflammation by promoting the synthesis of different prostaglandins (PGs), which exhibit a variety of biological activities and participate in pathophysiological processes in the body in a variety of ways. This review explains the roles played by COX-2 in protozoan infection and analyzes the effects of COX-2-related drugs in protozoan diseases.
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Affiliation(s)
- Xinlei Wang
- Department of Clinical Laboratory, The Second Hospital of Jilin University, Jilin University, Changchun, China
| | - Jie Chen
- Institute of Theoretical Chemistry, Jilin University, Changchun, China
| | - Jingtong Zheng
- Department of Pathogenobiology, College of Basic Medical Sciences, Jilin University, Changchun, China
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Hernández-Ramírez VI, Estrada-Figueroa LA, Medina Y, Lizarazo-Taborda MR, Toledo-Leyva A, Osorio-Trujillo C, Morales-Mora D, Talamás-Rohana P. A monoclonal antibody against a Leishmania mexicana COX-like enzymatic activity also recognizes similar proteins in different protozoa of clinical importance. Parasitol Res 2023; 122:479-492. [PMID: 36562799 DOI: 10.1007/s00436-022-07746-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 11/28/2022] [Indexed: 12/24/2022]
Abstract
In Leishmania mexicana, the protease gp63 has been documented as the protein responsible for cyclooxygenase (COX) activity. The present work aimed to obtain a monoclonal antibody capable of recognizing this protein without blocking the COX-like enzymatic activity. The antibody produced by the selected hybridoma was named D12 mAb. The antigen recognized by the D12 mAb was characterized by the determination of COX activity associated with immune complexes in the presence of exogenous arachidonic acid (AA) using the commercial Activity Assay Abcam kit. LSM-SMS analysis validated the identity of the antigen associated with the D12 mAb as the L. mexicana protease gp63. Confocal microscopy assays with the D12 mAb detected, by cross-recognition, similar proteins in other protozoan parasites. COX-like molecules are located in vesicular structures, homogeneously distributed throughout the cytoplasm in amastigotes (intracellular infectious phase) and promastigotes of L. mexicana, and trophozoites of Entamoeba histolytica, Acanthamoeba castellanii, and Naegleria fowleri. However, in Giardia duodenalis trophozoites, the distribution of the COX-like molecule was also in perinuclear areas. In comparison, in Trypanosoma cruzi trypomastigotes, the distribution was mainly observed in the plasma membrane. Structural analyses of COX-2-like antigens revealed continuous and discontinuous epitopes for B cells, which could be relevant in the cross-reaction of D12 mAb with the analyzed parasites. These results indicate that the D12 mAb against the L. mexicana gp63 also recognizes a COX-like molecule in several protozoan parasites, suggesting that this D12 mAb could potentially be used in combined therapies against infectious diseases.
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Affiliation(s)
- Verónica I Hernández-Ramírez
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y Estudios Avanzados, CINVESTAV-IPN, Ciudad de México, CP, 07360, México
| | - Luis A Estrada-Figueroa
- Instituto Mexicano de la Propiedad Industrial, Arenal Número 550, Primer piso, Pueblo Santa María, Ciudad de México, CP16020, México
| | - Yolanda Medina
- Laboratorio de Anticuerpos Monoclonales Unidad de Desarrollo Tecnológico e Investigación Molecular INDRE, Francisco de P. Miranda 177, Lomas de Plateros, Álvaro Obregón, Ciudad México, CP 01480, México
| | - Mélida R Lizarazo-Taborda
- Programa de Maestría en Microbiología Médica, Departamento de Microbiología y Patología, Centro Universitario de Ciencias de la Salud, Universidad de Guadalajara, Guadalajara, Jalisco, México
| | - Alfredo Toledo-Leyva
- Instituto Nacional de Cancerología., Av. San Fernando 22, Belisario Domínguez Secc 16, Tlalpan, Ciudad de México, CP 14080, México
| | - Carlos Osorio-Trujillo
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y Estudios Avanzados, CINVESTAV-IPN, Ciudad de México, CP, 07360, México
| | - Daniel Morales-Mora
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y Estudios Avanzados, CINVESTAV-IPN, Ciudad de México, CP, 07360, México
| | - Patricia Talamás-Rohana
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y Estudios Avanzados, CINVESTAV-IPN, Ciudad de México, CP, 07360, México.
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Łanocha-Arendarczyk N, Baranowska-Bosiacka I, Kot K, Gutowska I, Kolasa-Wołosiuk A, Chlubek D, Kosik-Bogacka D. Expression and Activity of COX-1 and COX-2 in Acanthamoeba sp.-Infected Lungs According to the Host Immunological Status. Int J Mol Sci 2018; 19:ijms19010121. [PMID: 29301283 PMCID: PMC5796070 DOI: 10.3390/ijms19010121] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 12/26/2017] [Accepted: 12/27/2017] [Indexed: 12/20/2022] Open
Abstract
Little is known about the pathomechanism of pulmonary infections caused by Acanthamoeba sp. Therefore, the aim of this study was to determine whether Acanthamoeba sp. may affect the expression and activity of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2), resulting in the altered levels of their main products, prostaglandins (PGE₂) and thromboxane B₂ (TXB₂), in lungs of immunocompetent or immunosuppressed hosts. Acanthamoeba sp. induced a strong expression of COX-1 and COX-2 proteins in the lungs of immunocompetent mice, which, however, did not result in significant differences in the expression of PGE₂ and TXB₂. Our immunohistochemical analysis showed that immunosuppression induced by glucocorticoids in Acanthamoeba sp.-infected mice caused a decrease in COX-1 and COX-2 (not at the beginning of infection) in lung tissue. These results suggest that similar to COX-2, COX-1 is an important mediator of the pathophysiology in experimental pulmonary acanthamoebiasis. We suggest that the signaling pathways important for Acanthamoeba sp. induction of lung infection might interact with each other and depend on the host immune status.
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Affiliation(s)
- Natalia Łanocha-Arendarczyk
- Department of Biology and Medical Parasitology, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland.
| | - Irena Baranowska-Bosiacka
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland.
| | - Karolina Kot
- Department of Biology and Medical Parasitology, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland.
| | - Izabela Gutowska
- Department of Biochemistry and Human Nutrition, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland.
| | - Agnieszka Kolasa-Wołosiuk
- Department of Histology and Embryology, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland.
| | - Dariusz Chlubek
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland.
| | - Danuta Kosik-Bogacka
- Department of Biology and Medical Parasitology, Pomeranian Medical University in Szczecin, 70-204 Szczecin, Poland.
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5
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Kutyrev IA, Biserova NM, Olennikov DN, Korneva JV, Mazur OE. Prostaglandins E 2 and D 2 –regulators of host immunity in the model parasite Diphyllobothrium dendriticum : An immunocytochemical and biochemical study. Mol Biochem Parasitol 2017; 212:33-45. [DOI: 10.1016/j.molbiopara.2017.01.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 01/18/2017] [Accepted: 01/26/2017] [Indexed: 12/01/2022]
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Kutyrev IA, Franke F, Büscher J, Kurtz J, Scharsack JP. In vitro effects of prostaglandin E2 on leucocytes from sticklebacks (Gasterosteus aculeatus) infected and not infected with the cestode Schistocephalus solidus. FISH & SHELLFISH IMMUNOLOGY 2014; 41:473-481. [PMID: 25301719 DOI: 10.1016/j.fsi.2014.09.031] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Revised: 09/22/2014] [Accepted: 09/29/2014] [Indexed: 06/04/2023]
Abstract
Many helminth parasites have evolved strategies to evade the immune response of their hosts, which includes immunomodulation. Prostaglandin E2 (PGE2) is one of the best-described immunomodulators in mammalian helminth parasite infections. We hypothesized that also in teleost fish anti-helminthic immune responses are regulated via PGE2. We used a model system consisting of the tapeworm Schistocephalus solidus and its host, the three-spined stickleback (Gasterosteus aculeatus), to investigate in vitro effects of PGE2 on head kidney leucocytes (HKL) derived from sticklebacks that were experimentally infected with S. solidus. PGE2 was tested alone or in combination with either S. solidus antigens or bacterial lipopolysaccharides (LPS). After in vitro culture, cell viability and changes in leucocyte subpopulations (granulocytes to lymphocytes ratios) were monitored by flow cytometry and HKL were tested for their capacity to produce reactive oxygen species (ROS) with a chemiluminescence assay. In short term (2 h) HKL cultures PGE2 did not change the total numbers of live HKL, but the production of ROS decreased significantly with high (0.1 μmol L(-1)) PGE2 concentrations. In long-term (96 h) cultures high PGE2 concentrations induced a sharp decrease of leucocytes viability, while low (0.1 pmol L(-1)) and intermediate (0.1 nmol L(-1)) concentrations of PGE2 caused elevated leucocyte viability compared to controls. This coincided with reduced ROS production in cultures with high PGE2 and elevated ROS production in cultures with low PGE2. Granulocyte to lymphocyte ratios increased with high PGE2 concentrations alone and in combination with S. solidus antigens and LPS, most prominently with HKL from S. solidus infected sticklebacks. The present study supports the hypothesis that PGE2 might be an immunomodulator in tapeworm-fish parasite-host interactions.
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Affiliation(s)
- Ivan A Kutyrev
- Institute of General and Experimental Biology, Siberian Branch of Russian Academy of Sciences, Sakhyanovoi St. 6, 670047 Ulan-Ude, Russian Federation; Institute for Evolution and Biodiversity, Animal Evolutionary Ecology, University of Münster, Hüfferstr. 1, 48149 Münster, Germany.
| | - Frederik Franke
- Institute for Evolution and Biodiversity, Animal Evolutionary Ecology, University of Münster, Hüfferstr. 1, 48149 Münster, Germany
| | - Janine Büscher
- Institute for Evolution and Biodiversity, Animal Evolutionary Ecology, University of Münster, Hüfferstr. 1, 48149 Münster, Germany
| | - Joachim Kurtz
- Institute for Evolution and Biodiversity, Animal Evolutionary Ecology, University of Münster, Hüfferstr. 1, 48149 Münster, Germany
| | - Jörn P Scharsack
- Institute for Evolution and Biodiversity, Animal Evolutionary Ecology, University of Münster, Hüfferstr. 1, 48149 Münster, Germany
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Siddiqui R, Khan NA. Biology and pathogenesis of Acanthamoeba. Parasit Vectors 2012; 5:6. [PMID: 22229971 PMCID: PMC3284432 DOI: 10.1186/1756-3305-5-6] [Citation(s) in RCA: 359] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 01/10/2012] [Indexed: 12/18/2022] Open
Abstract
Acanthamoeba is a free-living protist pathogen, capable of causing a blinding keratitis and fatal granulomatous encephalitis. The factors that contribute to Acanthamoeba infections include parasite biology, genetic diversity, environmental spread and host susceptibility, and are highlighted together with potential therapeutic and preventative measures. The use of Acanthamoeba in the study of cellular differentiation mechanisms, motility and phagocytosis, bacterial pathogenesis and evolutionary processes makes it an attractive model organism. There is a significant emphasis on Acanthamoeba as a Trojan horse of other microbes including viral, bacterial, protists and yeast pathogens.
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Biserova NM, Kutyrev IA, Malakhov VV. The tapeworm Diphyllobothrium dendriticum (Cestoda) produces prostaglandin E2, a regulator of host immunity. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2011; 441:367-369. [PMID: 22227682 DOI: 10.1134/s0012496611060019] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Indexed: 05/31/2023]
Affiliation(s)
- N M Biserova
- Institute of General and Experimental Biology, Siberian Branch, Russian Academy of Sciences, Ulan-Ude, 670047, Russia
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9
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Kubata BK, Duszenko M, Martin KS, Urade Y. Molecular basis for prostaglandin production in hosts and parasites. Trends Parasitol 2007; 23:325-31. [PMID: 17531535 DOI: 10.1016/j.pt.2007.05.005] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2006] [Revised: 03/20/2007] [Accepted: 05/11/2007] [Indexed: 11/22/2022]
Abstract
Prostaglandins (PGs) comprise a family of structurally related bioactive lipid mediators that are involved in various symptoms associated with parasitic diseases. The molecular mechanisms of PG biosynthesis in animals have been studied extensively. Currently, several lines of evidence link their production with parasites. In this review we discuss the roles of PGs in parasite pathogenesis and physiology and the recent advances in our understanding of the enzymology of PG production in various parasites.
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Affiliation(s)
- Bruno Kilunga Kubata
- Biosciences Eastern and Central Africa (a NEPAD centre of excellence), PO Box 30709, 00100 Nairobi, Kenya.
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Noverr MC, Erb-Downward JR, Huffnagle GB. Production of eicosanoids and other oxylipins by pathogenic eukaryotic microbes. Clin Microbiol Rev 2003; 16:517-33. [PMID: 12857780 PMCID: PMC164223 DOI: 10.1128/cmr.16.3.517-533.2003] [Citation(s) in RCA: 171] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Oxylipins are oxygenated metabolites of fatty acids. Eicosanoids are a subset of oxylipins and include the prostaglandins and leukotrienes, which are potent regulators of host immune responses. Host cells are one source of eicosanoids and oxylipins during infection; however, another potential source of eicosanoids is the pathogen itself. A broad range of pathogenic fungi, protozoa, and helminths produce eicosanoids and other oxylipins by novel synthesis pathways. Why do these organisms produce oxylipins? Accumulating data suggest that phase change and differentiation in these organisms are controlled by oxylipins, including prostaglandins and lipoxygenase products. The precise role of pathogen-derived eicosanoids in pathogenesis remains to be determined, but the potential link between pathogen eicosanoids and the development of TH2 responses in the host is intriguing. Mammalian prostaglandins and leukotrienes have been studied extensively, and these molecules can modulate Th1 versus Th2 immune responses, chemokine production, phagocytosis, lymphocyte proliferation, and leukocyte chemotaxis. Thus, eicosanoids and oxylipins (host or microbe) may be mediators of a direct host-pathogen "cross-talk" that promotes chronic infection and hypersensitivity disease, common features of infection by eukaryotic pathogens.
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Affiliation(s)
- Mairi C Noverr
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109-0642, USA
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Das S, Stevens T, Castillo C, Villasenõr A, Arredondo H, Reddy K. Lipid metabolism in mucous-dwelling amitochondriate protozoa. Int J Parasitol 2002; 32:655-75. [PMID: 12062485 DOI: 10.1016/s0020-7519(02)00006-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Entamoeba, Giardia, and trichomonads are the prominent members of a group known as 'mucosal parasites'. While Entamoeba and Giardia trophozoites colonise the small intestine, trichomonads inhabit the genitourinary tracts of humans and animals. These protozoa lack mitochondria, well-developed Golgi complexes, and other organelles typical of higher eukaryotes. Nonetheless, they have developed unique metabolic pathways that allow them to survive and multiply in the small intestine and reproductive tracts by scavenging nutrients from the host. Various investigators have shown that these protozoa are unable to synthesise the majority of their own lipids and cholesterol de novo; rather, they depend mostly on supplies from outside sources. Therefore, questions of how they transport and utilise exogenous lipids for metabolic purposes are extremely important. There is evidence suggesting that these parasites can take up the lipids and cholesterol they need from lipoprotein particles present in the host and/or in the growth medium. Studies also support the idea that individual lipid and fatty acid molecules can be transported without the help of lipoproteins. Exogenous phospholipids have been shown to undergo fatty acid remodelling (by deacylation/reacylation reactions), which allows these protozoa to alter lipids, bypassing the synthesis of entirely new phospholipid molecules. In addition, many of these amitochondriates are, however, capable of elongating/desaturating long-chain fatty acids, and assembling novel glycophospholipid molecules. In this review, progress in various aspects of lipid research on these organisms is discussed. Attempts are also made to identify steps of lipid metabolic pathways that can be used to develop chemotherapeutic agents against these and other mucosal parasites.
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Affiliation(s)
- Siddhartha Das
- Department of Biological Sciences, University of Texas at El Paso, 500 W. University Avenue, El Paso, TX 79968-0519, USA.
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Bell AS, Aoki T, Yokoyama H. Phylogenetic relationships among microsporidia based on rDNA sequence data, with particular reference to fish-infecting Microsporidium balbiani 1884 species. J Eukaryot Microbiol 2001; 48:258-65. [PMID: 11411834 DOI: 10.1111/j.1550-7408.2001.tb00313.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recently, large discrepancies have been identified between microsporidian systematics based on molecular and traditional characteristics. In the current study the 530f-580r region of the rRNA gene of eight microsporidian species was cloned and sequenced. Included were two unclassified species of Microsporidium Balbiani, 1884 and an unidentified microsporidian that infects the musculature of different sea bream species. Sequence identities in excess of 98% indicated that these three species almost certainly are members of the same genus. Phylogenetic analyses of all microsporidian sequence data available for this region of the gene (20 species) and for partial small subunit sequences (51 species of 21 genera) revealed these species to be distinct from the family Pleistophoridae Doflein, 1901 and closely related them to the genus Sproguea Weissenberg, 1976. This clade was found to comprise a sister taxon to that containing the vast majority of fish-infecting species. Broad cladistic divisions were found between terrestrial insect-infecting and fish-infecting species, which together are distant from the aquatic insect-infecting microsporidia. The rRNA gene of certain fish-infecting genera was found to be more highly conserved than previously reported. This has implications for its utility in diagnostic assays and phylogenetic studies at, or close to, the species level.
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Affiliation(s)
- A S Bell
- Department of Aquatic Bioscience, Tokyo University of Fisheries, Japan.
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Iwamoto M, Murata T, Morii H, Watanabe Y, Nakaoka Y. Activation of prostacyclin synthesis by mechanical stimulation in the ciliated protozoan Tetrahymena thermophila. Biochem Biophys Res Commun 2000; 279:635-8. [PMID: 11118337 DOI: 10.1006/bbrc.2000.3991] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We detected a HPLC peak corresponding to 6-keto-PGF(1alpha), a stable metabolite of prostacyclin (PGI(2)), in [1-(14)C]arachidonate metabolites from the ciliated protozoan Tetrahymena thermophila. Quantitative analysis of 6-keto-PGF(1alpha) by enzyme immunoassay revealed that the synthesis and release were rapidly activated by the mechanical stimulation of a short centrifugation. The activation was suppressed significantly by a cyclooxygenase inhibitor, ibuprofen, and was independent of the extracellular Ca(2+). External addition of PGI(2) and its stable analogue, beraprost, caused a transient increase in the tumbling frequency of swimming. Other prostanoids, PGE(2) and PGF(2alpha), have no effect on the swimming. These results indicate that a free-living ciliate, T. thermophila, synthesizes and has a specific sensitivity to PGI(2).
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Affiliation(s)
- M Iwamoto
- Division of Biophysical Engineering, Graduate School of Engineering Science, Osaka University, Toyonaka, Osaka, 560-8531, Japan
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