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Mi-Ichi F, Hamano S, Yoshida H. Links between cholesteryl sulfate-dependent and -independent processes in the morphological and physiological changes of Entamoeba encystation. Parasitol Int 2024; 99:102844. [PMID: 38103862 DOI: 10.1016/j.parint.2023.102844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/20/2023] [Accepted: 12/10/2023] [Indexed: 12/19/2023]
Abstract
The protozoan parasite Entamoeba histolytica causes amoebiasis, a global public health problem. Amoebiasis is solely transmitted by cysts that are produced from proliferative trophozoites by encystation in the large intestine of humans. During encystation, various metabolites, pathways, and cascades sequentially orchestrate the morphological and physiological changes required to produce cysts. Cholesteryl sulfate (CS) has recently been revealed to be among the key molecules that control the morphological and physiological changes of encystation by exerting pleiotropic effects. CS promotes the rounding of encysting Entamoeba cells and maintains this spherical morphology as encysting cells are surrounded by the cyst wall, a prerequisite for resistance against environmental stresses. CS is also involved in the development of membrane impermeability, another prerequisite for resistance. The initiation of cyst wall formation is, however, CS-independent. Here, we overview CS-dependent and -independent processes during encystation and discuss their functional linkage. We also discuss a potential transcriptional cascade that controls the processes necessary to produce dormant Entamoeba cysts.
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Affiliation(s)
- Fumika Mi-Ichi
- Central Laboratory, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan; The Joint Research Center on Tropical Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.
| | - Shinjiro Hamano
- The Joint Research Center on Tropical Diseases, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan; Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Hiroki Yoshida
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan
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Mi-Ichi F, Yoshida H. Unique Features of Entamoeba Sulfur Metabolism; Compartmentalization, Physiological Roles of Terminal Products, Evolution and Pharmaceutical Exploitation. Int J Mol Sci 2019; 20:ijms20194679. [PMID: 31546588 PMCID: PMC6801973 DOI: 10.3390/ijms20194679] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 09/18/2019] [Accepted: 09/19/2019] [Indexed: 11/16/2022] Open
Abstract
Sulfur metabolism is essential for all living organisms. Recently, unique features of the Entamoeba metabolic pathway for sulfated biomolecules have been described. Entamoeba is a genus in the phylum Amoebozoa and includes the causative agent for amoebiasis, a global public health problem. This review gives an overview of the general features of the synthesis and degradation of sulfated biomolecules, and then highlights the characteristics that are unique to Entamoeba. Future biological and pharmaceutical perspectives are also discussed.
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Affiliation(s)
- Fumika Mi-Ichi
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan.
| | - Hiroki Yoshida
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan.
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Mi-Ichi F, Miyake Y, Tam VK, Yoshida H. A Flow Cytometry Method for Dissecting the Cell Differentiation Process of Entamoeba Encystation. Front Cell Infect Microbiol 2018; 8:250. [PMID: 30087858 PMCID: PMC6066566 DOI: 10.3389/fcimb.2018.00250] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/02/2018] [Indexed: 12/24/2022] Open
Abstract
Amoebiasis is caused by Entamoeba histolytica infection, a protozoan parasite belonging to the phylum Amoebozoa. This parasite undergoes a fundamental cell differentiation process from proliferative trophozoite to dormant cyst, termed “encystation.” The cysts formed by encystation are solely responsible for the transmission of amoebiasis; therefore, Entamoeba encystation is an important subject from both biological and medical perspectives. Here, we have established a flow cytometry strategy for not only determining the percentage of formed cysts but also for monitoring changes in cell populations during encystation. This strategy together with fluorescence microscopy enables visualization of the cell differentiation process of Entamoeba encystation. We also standardized another flow cytometry protocol for counting live trophozoites. These two different flow cytometry techniques could be integrated into 96-well plate-based bioassays for monitoring the processes of cyst formation and trophozoite proliferation, which are crucial to maintain the Entamoeba life cycle. The combined two systems enabled us to screen a chemical library, the Pathogen Box of the Medicine for Malaria Venture, to obtain compounds that inhibit either the formation of cysts or the proliferation of trophozoites, or both. This is a prerequisite for the development of new drugs against amoebiasis, a global public health problem. Collectively, the two different 96-well plate-based Entamoeba bioassay and flow cytometry analysis systems (cyst formation and trophozoite proliferation) provide a methodology that can not only overcome the limitations of standard microscopic counting but also is effective in applied as well as basic Entamoeba biology.
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Affiliation(s)
- Fumika Mi-Ichi
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Japan
| | - Yasunobu Miyake
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Japan
| | - Vo Kha Tam
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Japan
| | - Hiroki Yoshida
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Japan
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Mi-Ichi F, Miyamoto T, Yoshida H. Uniqueness of Entamoeba sulfur metabolism: sulfolipid metabolism that plays pleiotropic roles in the parasitic life cycle. Mol Microbiol 2017; 106:479-491. [PMID: 28884488 DOI: 10.1111/mmi.13827] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2017] [Indexed: 02/03/2023]
Abstract
Sulfur metabolism is ubiquitous and terminally synthesizes various biomolecules that are crucial for organisms, such as sulfur-containing amino acids and co-factors, sulfolipids and sulfated saccharides. Entamoeba histolytica, a protozoan parasite responsible for amoebiasis, possesses the unique sulfur metabolism features of atypical localization and its terminal product being limited to sulfolipids. Here, we present an overall scheme of E. histolytica sulfur metabolism by relating all sulfotransferases and sulfatases to their substrates and products. Furthermore, a novel sulfur metabolite, fatty alcohol disulfates, was identified and shown to play an important role in trophozoite proliferation. Cholesteryl sulfate, another synthesized sulfolipid, was previously demonstrated to play an important role in encystation, a differentiation process from proliferative trophozoite to dormant cyst. Entamoeba survives by alternating between these two distinct forms; therefore, Entamoeba sulfur metabolism contributes to the parasitic life cycle via its terminal products. Interestingly, this unique feature of sulfur metabolism is not conserved in the nonparasitic close relative of Entamoeba, Mastigamoeba, because lateral gene transfer-mediated acquisition of sulfatases and sulfotransferases, critical enzymes conferring this feature, has only occurred in the Entamoeba lineage. Hence, our findings suggest that sulfolipid metabolism has a causal relationship with parasitism.
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Affiliation(s)
- Fumika Mi-Ichi
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan
| | - Tomofumi Miyamoto
- Department of Natural Products Chemistry, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi Higashi-ku, Fukuoka 812-8582, Japan
| | - Hiroki Yoshida
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, 5-1-1 Nabeshima, Saga 849-8501, Japan
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Deloer S, Nakamura R, Mi-Ichi F, Adachi K, Kobayashi S, Hamano S. Mouse models of amoebiasis and culture methods of amoeba. Parasitol Int 2016; 65:520-525. [PMID: 27080249 DOI: 10.1016/j.parint.2016.03.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2015] [Revised: 03/17/2016] [Accepted: 03/29/2016] [Indexed: 10/21/2022]
Abstract
Entamoeba histolytica is the third leading parasitic cause of man mortality in the world. Infection occurs via ingestion of food or water contaminated with cysts of E. histolytica. Amoebae primarily colonize the intestine. The majority of amoebic infections are asymptomatic, but under some conditions, approximately 4-10% of infections progress to the invasive form of the disease. To better understand the pathogenesis of amoebiasis and the interaction between amoebae and their hosts, the development of suitable animal models is crucial. Pigs, gerbils, cats and mice are used as animal models for the study of amoebiasis in the laboratory. Among these, the most commonly used model is the mouse. In addition to intestinal amoebiasis, we developed a mouse model of liver abscess by inoculating amoeba through portal vein. However, the frequency of successful infection remains low, which is dependent on the conditions of amoebae in the laboratory. As the maintenance of virulent amoebae in the laboratory is unstable, it needs further refinement. This review summarizes mouse models of amoebiasis and the current state of laboratory culture method of amoebae.
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Affiliation(s)
- Sharmina Deloer
- Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Doctoral Leadership Program, Graduate School of Biomedical Science, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Risa Nakamura
- Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Doctoral Leadership Program, Graduate School of Biomedical Science, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan
| | - Fumika Mi-Ichi
- Divisions of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga 849-8501, Japan
| | - Keishi Adachi
- Department of Immunology, Yamaguchi University Graduate School of Medicine, Ube 755-8505, Japan
| | - Seiki Kobayashi
- Graduate School of Medicine, Department of Infectious Diseases, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Shinjiro Hamano
- Department of Parasitology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan; Doctoral Leadership Program, Graduate School of Biomedical Science, Nagasaki University, 1-12-4 Sakamoto, Nagasaki 852-8523, Japan.
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Santos HJ, Imai K, Hanadate Y, Fukasawa Y, Oda T, Mi-Ichi F, Nozaki T. Screening and discovery of lineage-specific mitosomal membrane proteins in Entamoeba histolytica. Mol Biochem Parasitol 2016; 209:10-17. [PMID: 26792249 DOI: 10.1016/j.molbiopara.2016.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 11/17/2022]
Abstract
Entamoeba histolytica, an anaerobic intestinal parasite causing dysentery and extra-intestinal abscesses in humans, possesses highly reduced and divergent mitochondrion-related organelles (MROs) called mitosomes. This organelle lacks many features associated with canonical aerobic mitochondria and even other MROs such as hydrogenosomes. The Entamoeba mitosome has been found to have a compartmentalized sulfate activation pathway, which was recently implicated to have a role in amebic stage conversion. It also features a unique shuttle system via Tom60, which delivers proteins from the cytosol to the mitosome. In addition, only Entamoeba mitosomes possess a novel subclass of β-barrel outer membrane protein called MBOMP30. With the discoveries of such unique features of mitosomes of Entamoeba, there still remain a number of significant unanswered issues pertaining to this organelle. Particularly, the present understanding of the inner mitosomal membrane of Entamoeba is extremely limited. So far, only a few homologs for transporters of various substrates have been confirmed, while the components of the protein translocation complexes appear to be absent or are yet to be discovered. Employing a similar strategy as in our previous work, we collaborated to screen and discover mitosomal membrane proteins. Using a specialized prediction pipeline, we searched for proteins possessing α-helical transmembrane domains, which are unique to E. histolytica mitosomes. From the prediction algorithm, 25 proteins emerged as candidates, two of which were initially observed to be localized to the mitosomes. Further screening and analysis of the predicted proteins may provide clues to answer key questions on mitosomal evolution, biogenesis, dynamics, and biochemical processes.
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Affiliation(s)
- Herbert J Santos
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan; Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Kenichiro Imai
- Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Yuki Hanadate
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan; Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan
| | - Yoshinori Fukasawa
- Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Toshiyuki Oda
- Biotechnology Research Institute for Drug Discovery, National Institute of Advanced Industrial Science and Technology (AIST), 2-4-7 Aomi, Koto-ku, Tokyo 135-0064, Japan
| | - Fumika Mi-Ichi
- Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan; Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Japan
| | - Tomoyoshi Nozaki
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572, Japan; Department of Parasitology, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo 162-8640, Japan.
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Abstract
SUMMARYSerum-derived fatty acids are essential for the intraerythrocytic proliferation of Plasmodium falciparum in humans. We previously reported that only limited combinations of fatty acids can support long-term parasite culture, and palmitic acid (C16:0)/oleic acid (C18:1, n-9), palmitic acid (C16:0)/vaccenic acid (C18:1, n-7), or stearic acid (C18:0) are required in these combinations, implying that these fatty acids are key molecules for intraerythrocytic parasite growth (Mi-Ichi et al.2006). Here, we analysed profiles of parasitaemia changes as well as morphologies during the erythrocytic cycle and confirmed the importance of C16:0 and C18:1, n-9. We also provide evidence that C18:1, n-9 but not other C18 monoenoic or dienoic acids maintain the synchronicity of parasite development in serum-free medium when paired with C16:0, resulting in maintained exponential growth. Thus, C18:1, n-9 is indispensable for the intraerythrocytic proliferation of P. falciparum.
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Affiliation(s)
- F Mi-Ichi
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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Mi-Ichi F, Kita K, Mitamura T. IntraerythrocyticPlasmodium falciparumutilize a broad range of serum-derived fatty acids with limited modification for their growth. Parasitology 2006; 133:399-410. [PMID: 16780611 DOI: 10.1017/s0031182006000540] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Revised: 04/19/2006] [Accepted: 04/20/2006] [Indexed: 11/05/2022]
Abstract
Plasmodium falciparumcauses the most severe form of malaria. Utilization of fatty acids in serum is thought to be necessary for survival of this parasite in erythrocytes, and thus characterization of the parasite fatty acid metabolism is important in developing a new strategy for controlling malaria. Here, we examined which combinations of fatty acids present in human serum support the continuous culture ofP.falciparumin serum-free medium. Metabolic labelling and gas chromatography analyses revealed that, despite the need for particular fatty acids for the growth of intraerythrocyticP.falciparum, it can metabolize a broad range of serum-derived fatty acids into the major lipid species of their membranes and lipid bodies. In addition, these analyses showed that the parasite's overall fatty acid composition reflects that of the medium, although the parasite has a limited capacity to desaturate and elongate serum-derived fatty acids. These results indicate that thePlasmodiumparasite is distinct from most cells, which maintain their fatty acid composition by coordinatingde novobiosynthesis, scavenging, and modification (desaturation and elongation).
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Affiliation(s)
- F Mi-Ichi
- Department of Molecular Protozoology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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Yuasa K, Mi-Ichi F, Kobayashi T, Yamanouchi M, Kotera J, Kita K, Omori K. PfPDE1, a novel cGMP-specific phosphodiesterase from the human malaria parasite Plasmodium falciparum. Biochem J 2006; 392:221-9. [PMID: 16038615 PMCID: PMC1317681 DOI: 10.1042/bj20050425] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This is the first report of molecular characterization of a novel cyclic nucleotide PDE (phosphodiesterase), isolated from the human malaria parasite Plasmodium falciparum and designated PfPDE1. PfPDE1 cDNA encodes an 884-amino-acid protein, including six putative transmembrane domains in the N-terminus followed by a catalytic domain. The PfPDE1 gene is a single-copy gene consisting of two exons and a 170 bp intron. PfPDE1 transcripts were abundant in the ring form of the asexual blood stages of the parasite. The C-terminal catalytic domain of PfPDE1, produced in Escherichia coli, specifically hydrolysed cGMP with a K(m) value of 0.65 microM. Among the PDE inhibitors tested, a PDE5 inhibitor, zaprinast, was the most effective, having an IC50 value of 3.8 microM. The non-specific PDE inhibitors IBMX (3-isobutyl-1-methylxanthine), theophylline and the antimalarial chloroquine had IC50 values of over 100 microM. Membrane fractions prepared from P. falciparum at mixed asexual blood stages showed potent cGMP hydrolytic activity compared with cytosolic fractions. This hydrolytic activity was sensitive to zaprinast with an IC50 value of 4.1 microM, but insensitive to IBMX and theophylline. Furthermore, an in vitro antimalarial activity assay demonstrated that zaprinast inhibited the growth of the asexual blood parasites, with an ED50 value of 35 microM. The impact of cyclic nucleotide signalling on the cellular development of this parasite has previously been discussed. Thus this enzyme is suggested to be a novel potential target for the treatment of the disease malaria.
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Affiliation(s)
- Keizo Yuasa
- *Discovery Research Laboratories, Tanabe Seiyaku Co. Ltd., 2–50, Kawagishi 2-chome, Toda, Saitama 335-8505, Japan
| | - Fumika Mi-Ichi
- †Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 3–1 Hongo-7-chome, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tamaki Kobayashi
- †Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 3–1 Hongo-7-chome, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masaya Yamanouchi
- ‡Medicinal Chemistry Research Laboratories, Tanabe Seiyaku Co. Ltd., 16–89, Kashima 3-chome, Yodogawa-ku, Osaka 532-8505, Japan
| | - Jun Kotera
- *Discovery Research Laboratories, Tanabe Seiyaku Co. Ltd., 2–50, Kawagishi 2-chome, Toda, Saitama 335-8505, Japan
| | - Kiyoshi Kita
- †Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 3–1 Hongo-7-chome, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kenji Omori
- *Discovery Research Laboratories, Tanabe Seiyaku Co. Ltd., 2–50, Kawagishi 2-chome, Toda, Saitama 335-8505, Japan
- To whom correspondence should be addressed (email )
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Mi-Ichi F, Miyadera H, Kobayashi T, Takamiya S, Waki S, Iwata S, Shibata S, Kita K. Parasite Mitochondria as a Target of Chemotherapy: Inhibitory Effect of Licochalcone A on the Plasmodium falciparum Respiratory Chain. Ann N Y Acad Sci 2005; 1056:46-54. [PMID: 16387676 DOI: 10.1196/annals.1352.037] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Parasites have exploited unique energy metabolic pathways as adaptations to the natural host habitat. In fact, the respiratory systems of parasites typically show greater diversity in electron transfer pathways than do those of host animals. These unique aspects of parasite mitochondria and related enzymes may represent promising targets for chemotherapy. Natural products have been recognized as a source of the candidates of the specific inhibitors for such parasite respiratory chains. Chalcones was recently evaluated for its antimalarial activity in vitro and in vivo. However, its target is still unclear in malaria parasites. In this study, we investigated that licochalcone A inhibited the bc1 complex (ubiquinol-cytochrome c reductase) as well as complex II (succinate ubiquinone reductase, SQR) of Plasmodium falciparum mitochondria. In particular, licochalcone A inhibits bc1 complex activity at very low concentrations. Because the property of the P. falciparum bc1 complex is different from that of the mammalian host, chalcones would be a promising candidate for a new antimalarial drug.
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Affiliation(s)
- Fumika Mi-Ichi
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Mi-Ichi F, Takeo S, Takashima E, Kobayashi T, Kim HS, Wataya Y, Matsuda A, Torrii M, Tsuboi T, Kita K. Unique properties of respiratory chain in Plasmodium falciparum mitochondria. Adv Exp Med Biol 2003; 531:117-33. [PMID: 12916785 DOI: 10.1007/978-1-4615-0059-9_9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Affiliation(s)
- Fumika Mi-Ichi
- Dept. of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Hongo Bunkyo-ku, Tokyo 113-0033, Japan
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