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Iribarren PA, Di Marzio LA, Berazategui MA, Saura A, Coria L, Cassataro J, Rojas F, Navarro M, Alvarez VE. Depolymerization of SUMO chains induces slender to stumpy differentiation in T. brucei bloodstream parasites. PLoS Pathog 2024; 20:e1012166. [PMID: 38635823 PMCID: PMC11060531 DOI: 10.1371/journal.ppat.1012166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 04/30/2024] [Accepted: 04/01/2024] [Indexed: 04/20/2024] Open
Abstract
Trypanosoma brucei are protozoan parasites that cause sleeping sickness in humans and nagana in cattle. Inside the mammalian host, a quorum sensing-like mechanism coordinates its differentiation from a slender replicative form into a quiescent stumpy form, limiting growth and activating metabolic pathways that are beneficial to the parasite in the insect host. The post-translational modification of proteins with the Small Ubiquitin-like MOdifier (SUMO) enables dynamic regulation of cellular metabolism. SUMO can be conjugated to its targets as a monomer but can also form oligomeric chains. Here, we have investigated the role of SUMO chains in T. brucei by abolishing the ability of SUMO to polymerize. We have found that parasites able to conjugate only SUMO monomers are primed for differentiation. This was demonstrated for monomorphic lines that are normally unable to produce stumpy forms in response to quorum sensing signaling in mice, and also for pleomorphic cell lines in which stumpy cells were observed at unusually low parasitemia levels. SUMO chain mutants showed a stumpy compatible transcriptional profile and better competence to differentiate into procyclics. Our study indicates that SUMO depolymerization may represent a coordinated signal triggered during stumpy activation program.
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Affiliation(s)
- Paula Ana Iribarren
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo Ugalde”–IIBIO (UNSAM-CONICET), San Martin, Buenos Aires, Argentina
| | - Lucía Ayelén Di Marzio
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo Ugalde”–IIBIO (UNSAM-CONICET), San Martin, Buenos Aires, Argentina
| | - María Agustina Berazategui
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo Ugalde”–IIBIO (UNSAM-CONICET), San Martin, Buenos Aires, Argentina
| | - Andreu Saura
- Instituto de Parasitología y Biomedicina “López-Neyra”, CSIC (IPBLN-CSIC), Granada, Spain
| | - Lorena Coria
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo Ugalde”–IIBIO (UNSAM-CONICET), San Martin, Buenos Aires, Argentina
| | - Juliana Cassataro
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo Ugalde”–IIBIO (UNSAM-CONICET), San Martin, Buenos Aires, Argentina
| | - Federico Rojas
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Miguel Navarro
- Instituto de Parasitología y Biomedicina “López-Neyra”, CSIC (IPBLN-CSIC), Granada, Spain
| | - Vanina Eder Alvarez
- Instituto de Investigaciones Biotecnológicas “Dr. Rodolfo Ugalde”–IIBIO (UNSAM-CONICET), San Martin, Buenos Aires, Argentina
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Yang X, Yang J, Lyu M, Li Y, Liu A, Shen B. The α subunit of AMP-activated protein kinase is critical for the metabolic success and tachyzoite proliferation of Toxoplasma gondii. Microb Biotechnol 2024; 17:e14455. [PMID: 38635138 PMCID: PMC11025617 DOI: 10.1111/1751-7915.14455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 03/06/2024] [Accepted: 03/09/2024] [Indexed: 04/19/2024] Open
Abstract
Toxoplasma gondii is a zoonotic parasite infecting humans and nearly all warm-blooded animals. Successful parasitism in diverse hosts at various developmental stages requires the parasites to fine tune their metabolism according to environmental cues and the parasite's needs. By manipulating the β and γ subunits, we have previously shown that AMP-activated protein kinase (AMPK) has critical roles in regulating the metabolic and developmental programmes. However, the biological functions of the α catalytic subunit have not been established. T. gondii encodes a canonical AMPKα, as well as a KIN kinase whose kinase domain has high sequence similarities to those of classic AMPKα proteins. Here, we found that TgKIN is dispensable for tachyzoite growth, whereas TgAMPKα is essential. Depletion of TgAMPKα expression resulted in decreased ATP levels and reduced metabolic flux in glycolysis and the tricarboxylic acid cycle, confirming that TgAMPK is involved in metabolic regulation and energy homeostasis in the parasite. Sequential truncations at the C-terminus found an α-helix that is key for the function of TgAMPKα. The amino acid sequences of this α-helix are not conserved among various AMPKα proteins, likely because it is involved in interactions with TgAMPKβ, which only have limited sequence similarities to AMPKβ in other eukaryotes. The essential role of the less conserved C-terminus of TgAMPKα provides opportunities for parasite specific drug designs targeting TgAMPKα.
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Affiliation(s)
- Xuke Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
- Research Center for Infectious Diseases, Department of Pathogen Biology, School of Basic Medical SciencesAnhui Medical UniversityHefeiChina
| | - Jichao Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
| | - Mengyu Lyu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
| | - Yaqiong Li
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
| | - Anqi Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
| | - Bang Shen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary MedicineHuazhong Agricultural UniversityWuhanHubei ProvinceChina
- Hubei Hongshan LaboratoryWuhanHubei ProvinceChina
- Key Laboratory of Preventive Medicine in Hubei ProvinceHuazhong Agricultural UniversityWuhanHubei ProvinceChina
- Shenzhen Institute of Nutrition and HealthHuazhong Agricultural UniversityShenzhenGuangdong ProvinceChina
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Yan M, Liu H, Su Y, Bi X, Yang N, Lin R, Lü G. Inhibition of AMPK activation in Echinococcus granulosus sensu stricto limits the parasite's glucose metabolism and survival. Antimicrob Agents Chemother 2024; 68:e0120223. [PMID: 38349157 PMCID: PMC10916388 DOI: 10.1128/aac.01202-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Accepted: 01/04/2024] [Indexed: 03/07/2024] Open
Abstract
Cystic echinococcosis (CE) is a zoonotic parasitic disease caused by larvae of the Echinococcus granulosus sensu lato (s.l.) cluster. There is an urgent need to develop new drug targets and drug molecules to treat CE. Adenosine monophosphate (AMP)-activated protein kinase (AMPK), a serine/threonine protein kinase consisting of α, β, and γ subunits, plays a key role in the regulation of energy metabolism. However, the role of AMPK in regulating glucose metabolism in E. granulosus s.l. and its effects on parasite viability is unknown. In this study, we found that targeted knockdown of EgAMPKα or a small-molecule AMPK inhibitor inhibited the viability of E. granulosus sensu stricto (s.s.) and disrupted the ultrastructure. The results of in vivo experiments showed that the AMPK inhibitor had a significant therapeutic effect on E. granulosus s.s.-infected mice and resulted in the loss of cellular structures of the germinal layer. In addition, the inhibition of the EgAMPK/EgGLUT1 pathway limited glucose uptake and glucose metabolism functions in E. granulosus s.s.. Overall, our results suggest that EgAMPK can be a potential drug target for CE and that inhibition of EgAMPK activation is an effective strategy for the treatment of disease.
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Affiliation(s)
- Mingzhi Yan
- State Key Laboratory of Pathogenesis, Prevention, and Treatment of Central Asian High Incidence Diseases, Clinical Medical Research Institute, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Hui Liu
- State Key Laboratory of Pathogenesis, Prevention, and Treatment of Central Asian High Incidence Diseases, Clinical Medical Research Institute, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Yansen Su
- Institute of Artificial Intelligence, Hefei Comprehensive National Science Center, Hefei, China
- Anhui University, Hefei, China
| | - Xiaojuan Bi
- State Key Laboratory of Pathogenesis, Prevention, and Treatment of Central Asian High Incidence Diseases, Clinical Medical Research Institute, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Ning Yang
- State Key Laboratory of Pathogenesis, Prevention, and Treatment of Central Asian High Incidence Diseases, Clinical Medical Research Institute, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
| | - Renyong Lin
- State Key Laboratory of Pathogenesis, Prevention, and Treatment of Central Asian High Incidence Diseases, Clinical Medical Research Institute, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
- Basic Medical College, Xinjiang Medical University, Urumqi, China
| | - Guodong Lü
- State Key Laboratory of Pathogenesis, Prevention, and Treatment of Central Asian High Incidence Diseases, Clinical Medical Research Institute, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, China
- College of Pharmacy, Xinjiang Medical University, Urumqi, China
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Morrison LJ, Steketee PC, Tettey MD, Matthews KR. Pathogenicity and virulence of African trypanosomes: From laboratory models to clinically relevant hosts. Virulence 2023; 14:2150445. [PMID: 36419235 DOI: 10.1080/21505594.2022.2150445] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 11/17/2022] [Indexed: 11/25/2022] Open
Abstract
African trypanosomes are vector-borne protozoa, which cause significant human and animal disease across sub-Saharan Africa, and animal disease across Asia and South America. In humans, infection is caused by variants of Trypanosoma brucei, and is characterized by varying rate of progression to neurological disease, caused by parasites exiting the vasculature and entering the brain. Animal disease is caused by multiple species of trypanosome, primarily T. congolense, T. vivax, and T. brucei. These trypanosomes also infect multiple species of mammalian host, and this complexity of trypanosome and host diversity is reflected in the spectrum of severity of disease in animal trypanosomiasis, ranging from hyperacute infections associated with mortality to long-term chronic infections, and is also a main reason why designing interventions for animal trypanosomiasis is so challenging. In this review, we will provide an overview of the current understanding of trypanosome determinants of infection progression and severity, covering laboratory models of disease, as well as human and livestock disease. We will also highlight gaps in knowledge and capabilities, which represent opportunities to both further our fundamental understanding of how trypanosomes cause disease, as well as facilitating the development of the novel interventions that are so badly needed to reduce the burden of disease caused by these important pathogens.
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Affiliation(s)
- Liam J Morrison
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
| | - Pieter C Steketee
- Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Midlothian, UK
| | - Mabel D Tettey
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
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Calvo-Alvarez E, Ngoune JMT, Sharma P, Cooper A, Camara A, Travaillé C, Crouzols A, MacLeod A, Rotureau B. FLAgellum Member 8 modulates extravascular distribution of African trypanosomes. PLoS Pathog 2023; 19:e1011220. [PMID: 38127941 PMCID: PMC10769064 DOI: 10.1371/journal.ppat.1011220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 01/05/2024] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
In the mammalian host, the biology of tissue-dwelling Trypanosoma brucei parasites is not completely understood, especially the mechanisms involved in their extravascular colonization. The trypanosome flagellum is an essential organelle in multiple aspects of the parasites' development. The flagellar protein termed FLAgellar Member 8 (FLAM8) acts as a docking platform for a pool of cyclic AMP response protein 3 (CARP3) that is involved in signaling. FLAM8 exhibits a stage-specific distribution suggesting specific functions in the mammalian and vector stages of the parasite. Analyses of knockdown and knockout trypanosomes in their mammalian forms demonstrated that FLAM8 is not essential in vitro for survival, growth, motility and stumpy differentiation. Functional investigations in experimental infections showed that FLAM8-deprived trypanosomes can establish and maintain an infection in the blood circulation and differentiate into insect transmissible forms. However, quantitative bioluminescence imaging and gene expression analysis revealed that FLAM8-null parasites exhibit a significantly impaired dissemination in the extravascular compartment, that is restored by the addition of a single rescue copy of FLAM8. In vitro trans-endothelial migration assays revealed significant defects in trypanosomes lacking FLAM8. FLAM8 is the first flagellar component shown to modulate T. brucei distribution in the host tissues, possibly through sensing functions, contributing to the maintenance of extravascular parasite populations in mammalian anatomical niches, especially in the skin.
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Affiliation(s)
- Estefanía Calvo-Alvarez
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201, Department of Parasites and Insect Vectors, Institut Pasteur, Université Paris Cité, Paris, France
| | - Jean Marc Tsagmo Ngoune
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201, Department of Parasites and Insect Vectors, Institut Pasteur, Université Paris Cité, Paris, France
| | - Parul Sharma
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201, Department of Parasites and Insect Vectors, Institut Pasteur, Université Paris Cité, Paris, France
- Sorbonne Université, ED515 Complexité du Vivant, Paris, France
| | - Anneli Cooper
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom
| | - Aïssata Camara
- Parasitology Unit, Institut Pasteur of Guinea, Conakry, Guinea
| | - Christelle Travaillé
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201, Department of Parasites and Insect Vectors, Institut Pasteur, Université Paris Cité, Paris, France
- Photonic BioImaging (UTechS PBI), Institut Pasteur, Université Paris Cité, Paris, France
| | - Aline Crouzols
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201, Department of Parasites and Insect Vectors, Institut Pasteur, Université Paris Cité, Paris, France
| | - Annette MacLeod
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary, and Life Sciences, Henry Wellcome Building for Comparative Medical Sciences, Glasgow, Scotland, United Kingdom
| | - Brice Rotureau
- Trypanosome Transmission Group, Trypanosome Cell Biology Unit, INSERM U1201, Department of Parasites and Insect Vectors, Institut Pasteur, Université Paris Cité, Paris, France
- Parasitology Unit, Institut Pasteur of Guinea, Conakry, Guinea
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McWilliam KR. Cell-cell communication in African trypanosomes. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001388. [PMID: 37643128 PMCID: PMC10482365 DOI: 10.1099/mic.0.001388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 08/15/2023] [Indexed: 08/31/2023]
Abstract
Years of research have shown us that unicellular organisms do not exist entirely in isolation, but rather that they are capable of an altogether far more sociable way of living. Single cells produce, receive and interpret signals, coordinating and changing their behaviour according to the information received. Although this cell-cell communication has long been considered the norm in the bacterial world, an increasing body of knowledge is demonstrating that single-celled eukaryotic parasites also maintain active social lives. This communication can drive parasite development, facilitate the invasion of new niches and, ultimately, influence infection outcome. In this review, I present the evidence for cell-cell communication during the life cycle of the African trypanosomes, from their mammalian hosts to their insect vectors, and reflect on the many remaining unanswered questions in this fascinating field.
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Affiliation(s)
- K. R. McWilliam
- Institute for Immunology and Infection Research, School of Biological Sciences, King’s Buildings, University of Edinburgh, Charlotte Auerbach Road, Edinburgh, EH9 3FL, UK
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Romano PS, Akematsu T, Besteiro S, Bindschedler A, Carruthers VB, Chahine Z, Coppens I, Descoteaux A, Alberto Duque TL, He CY, Heussler V, Le Roch KG, Li FJ, de Menezes JPB, Menna-Barreto RFS, Mottram JC, Schmuckli-Maurer J, Turk B, Tavares Veras PS, Salassa BN, Vanrell MC. Autophagy in protists and their hosts: When, how and why? AUTOPHAGY REPORTS 2023; 2:2149211. [PMID: 37064813 PMCID: PMC10104450 DOI: 10.1080/27694127.2022.2149211] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 11/15/2022] [Indexed: 03/12/2023]
Abstract
Pathogenic protists are a group of organisms responsible for causing a variety of human diseases including malaria, sleeping sickness, Chagas disease, leishmaniasis, and toxoplasmosis, among others. These diseases, which affect more than one billion people globally, mainly the poorest populations, are characterized by severe chronic stages and the lack of effective antiparasitic treatment. Parasitic protists display complex life-cycles and go through different cellular transformations in order to adapt to the different hosts they live in. Autophagy, a highly conserved cellular degradation process, has emerged as a key mechanism required for these differentiation processes, as well as other functions that are crucial to parasite fitness. In contrast to yeasts and mammals, protist autophagy is characterized by a modest number of conserved autophagy-related proteins (ATGs) that, even though, can drive the autophagosome formation and degradation. In addition, during their intracellular cycle, the interaction of these pathogens with the host autophagy system plays a crucial role resulting in a beneficial or harmful effect that is important for the outcome of the infection. In this review, we summarize the current state of knowledge on autophagy and other related mechanisms in pathogenic protists and their hosts. We sought to emphasize when, how, and why this process takes place, and the effects it may have on the parasitic cycle. A better understanding of the significance of autophagy for the protist life-cycle will potentially be helpful to design novel anti-parasitic strategies.
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Affiliation(s)
- Patricia Silvia Romano
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
| | - Takahiko Akematsu
- Department of Biosciences, College of Humanities and Sciences, Nihon University, Tokyo, Japan
| | | | | | - Vern B Carruthers
- Department of Microbiology and Immunology, University of Michigan School of Medicine, Ann Arbor, MI, USA
| | - Zeinab Chahine
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA
| | - Isabelle Coppens
- Department of Molecular Microbiology and Immunology. Department of Molecular Microbiology and Immunology. Johns Hopkins Malaria Research Institute. Johns Hopkins University Bloomberg School of Public Health. Baltimore 21205, MD, USA
| | - Albert Descoteaux
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique, Laval, QC
| | - Thabata Lopes Alberto Duque
- Autophagy Inflammation and Metabolism Center, University of New Mexico Health Sciences Center, Albuquerque, NM, USA; Department of Molecular Genetics and Microbiology, University of New Mexico Health Sciences Center, Albuquerque, NM, USA
| | - Cynthia Y He
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Volker Heussler
- Institute of Cell Biology.University of Bern. Baltzerstr. 4 3012 Bern
| | - Karine G Le Roch
- Department of Molecular, Cell and Systems Biology, University of California Riverside, CA, USA
| | - Feng-Jun Li
- Department of Biological Sciences, National University of Singapore, Singapore
| | | | | | - Jeremy C Mottram
- York Biomedical Research Institute, Department of Biology, University of York, York, UK
| | | | - Boris Turk
- Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, SI-1000 Ljubljana, Slovenia
| | - Patricia Sampaio Tavares Veras
- Laboratory of Host-Parasite Interaction and Epidemiology, Gonçalo Moniz Institute, Fiocruz-Bahia
- National Institute of Science and Technology of Tropical Diseases - National Council for Scientific Research and Development (CNPq)
| | - Betiana Nebai Salassa
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
| | - María Cristina Vanrell
- Laboratorio de Biología de Trypanosoma cruzi y de la célula hospedadora. Instituto de Histología y Embriología de Mendoza. Universidad Nacional de Cuyo. (IHEM-CONICET-UNCUYO). Facultad de Ciencias Médicas. Universidad Nacional de Cuyo. Av. Libertador 80 (5500), Mendoza, Argentina
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Rapid metabolic reprogramming mediated by the AMP-activated protein kinase during the lytic cycle of Toxoplasma gondii. Nat Commun 2023; 14:422. [PMID: 36702847 PMCID: PMC9880002 DOI: 10.1038/s41467-023-36084-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Accepted: 01/12/2023] [Indexed: 01/27/2023] Open
Abstract
The ubiquitous pathogen Toxoplasma gondii has a complex lifestyle with different metabolic activities at different stages that are intimately linked to the parasitic environments. Here we identified the eukaryotic regulator of cellular homeostasis AMP-activated protein kinase (AMPK) in Toxoplasma and discovered its role in metabolic programming during parasite's lytic cycle. The catalytic subunit AMPKα is quickly phosphorylated after the release of intracellular parasites to extracellular environments, driving energy-producing catabolism to power parasite motility and invasion into host cells. Once inside host cells, AMPKα phosphorylation is reduced to basal level to promote a balance between energy production and biomass synthesis, allowing robust parasite replication. AMPKγ depletion abolishes AMPKα phosphorylation and suppresses parasite growth, which can be partially rescued by overexpressing wildtype AMPKα but not the phosphorylation mutants. Thus, through the cyclic reprogramming by AMPK, the parasites' metabolic needs at each stage are satisfied and the lytic cycle progresses robustly.
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Catacalos C, Krohannon A, Somalraju S, Meyer KD, Janga SC, Chakrabarti K. Epitranscriptomics in parasitic protists: Role of RNA chemical modifications in posttranscriptional gene regulation. PLoS Pathog 2022; 18:e1010972. [PMID: 36548245 PMCID: PMC9778586 DOI: 10.1371/journal.ppat.1010972] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
"Epitranscriptomics" is the new RNA code that represents an ensemble of posttranscriptional RNA chemical modifications, which can precisely coordinate gene expression and biological processes. There are several RNA base modifications, such as N6-methyladenosine (m6A), 5-methylcytosine (m5C), and pseudouridine (Ψ), etc. that play pivotal roles in fine-tuning gene expression in almost all eukaryotes and emerging evidences suggest that parasitic protists are no exception. In this review, we primarily focus on m6A, which is the most abundant epitranscriptomic mark and regulates numerous cellular processes, ranging from nuclear export, mRNA splicing, polyadenylation, stability, and translation. We highlight the universal features of spatiotemporal m6A RNA modifications in eukaryotic phylogeny, their homologs, and unique processes in 3 unicellular parasites-Plasmodium sp., Toxoplasma sp., and Trypanosoma sp. and some technological advances in this rapidly developing research area that can significantly improve our understandings of gene expression regulation in parasites.
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Affiliation(s)
- Cassandra Catacalos
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
| | - Alexander Krohannon
- Department of BioHealth Informatics, School of Informatics and Computing, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana, United States of America
| | - Sahiti Somalraju
- Department of BioHealth Informatics, School of Informatics and Computing, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana, United States of America
| | - Kate D. Meyer
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Sarath Chandra Janga
- Department of BioHealth Informatics, School of Informatics and Computing, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, Indiana, United States of America
| | - Kausik Chakrabarti
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, United States of America
- * E-mail:
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Wen YZ, Tang HT, Cai XL, Wu N, Xu JZ, Su BX, Hide G, Lun ZR, Lai DH. PAG3 promotes the differentiation of bloodstream forms in Trypanosoma brucei and reveals the evolutionary relationship among the Trypanozoon trypanosomes. Front Cell Infect Microbiol 2022. [DOI: 10.3389/fcimb.2022.1021332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
IntroductionTrypanosoma brucei, T. evansi and T. equiperdum are members of the subgenus Trypanozoon and are highly similar morphologically and genetically. The main differences between these three species are their differentiation patterns in the hosts and the role of vectors in their life cycles. However, the mechanisms causing these differences are still controversial.MethodsPAG3 gene was accessed by PCR amplification in 26 strains of Trypanozoon and sequences were then analyzed by BLAST accompanied with T. evansitype B group. RNA interference and CRISPR/Cas9 were used for revealing possible role of PAG3 in slender to stumpy transformation.ResultsThe procyclin associated gene 3 (PAG3) can be found in the pleomorphicspecies, T.brucei, which undergoes differentiation of slender forms to the stumpy form. This differentiation process is crucial for transmission to the tsetse fly vector. However, a homologue of PAG3 was not detected in either T. evansi or in the majority of T. equiperdum strains which are allmonomorphic. Furthere xperiments in T. brucei demonstrated that, when PAG3 was down-regulated or absent, there was a significant reduction in the differentiation from slender to stumpy forms.ConclusionTherefore, we conclude that PAG3 is a key nuclear gene involved in the slender to stumpy differentiation pathway of T.brucei in the mammalian host. Loss of this gene might also offer a simple evolutionary mechanism explaining why T. evansi and some T. equiperdum have lost the ability to differentiate and have been driven to adapt to transmission cycles that by pass the tsetse vector or mechanical contact.
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Goswami P, Samanta SK, Agarwal T, Ghosh SK. Stress-responsive AMP Kinase like protein regulates encystation of Entamoeba invadens. Mol Biochem Parasitol 2022; 251:111507. [PMID: 35870645 DOI: 10.1016/j.molbiopara.2022.111507] [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: 01/20/2022] [Revised: 07/16/2022] [Accepted: 07/19/2022] [Indexed: 11/25/2022]
Abstract
Starvation is always accompanied by an increase in the ratio of AMP/ATP followed by activation of AMPK. It is one of the sensors for cellular energy status and is highly conserved across various species. Its role in the stage differentiation process of protozoan species like Giardia, Plasmodium, Trypanosome, and Toxoplasma has been reported. Since Entamoeba undergoes encystation in glucose-starved conditions; it intrigued us to investigate the existence and role of AMPK during the differentiation of trophozoites to the cyst. By employing in silico approaches, we have identified an AMPK homologue which is denominated here as EiAMPK (AMPK-like protein in Entamoeba invadens). Sequence and structural analysis indicate that EiAMPK is sequentially and structurally similar to the AMPK alpha subunit of other organisms. The recombinant form of EiAMPK was functionally active and in accordance, its activity was inhibited by an AMPK-specific inhibitor (eg. Compound C). The increased expression of EiAMPK during different stresses indicated that EiAMPK is a stress-responsive gene. To further investigate, whether EiAMPK has any role in encystation, we employed RNAi-mediated gene silencing that demonstrated its active involvement in encystation. It is known that Entamoeba maintains a flow of glucose from the glycolytic pathway to chitin synthesis for cyst wall formation during encystation. It is conceivable that EiAMPK might have a command over such glucose metabolism. As anticipated, the chitin synthesis was found greatly inhibited in both EiAMPK knockdown and Compound C treated cells, indicating that EiAMPK regulates the cyst wall chitin synthesis.
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Affiliation(s)
- Piyali Goswami
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Sintu Kumar Samanta
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Tarun Agarwal
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Sudip K Ghosh
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
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12
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Zíková A. Mitochondrial adaptations throughout the Trypanosoma brucei life cycle. J Eukaryot Microbiol 2022; 69:e12911. [PMID: 35325490 DOI: 10.1111/jeu.12911] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/18/2022] [Accepted: 03/18/2022] [Indexed: 12/01/2022]
Abstract
The unicellular parasite Trypanosoma brucei has a digenetic life cycle that alternates between a mammalian host and an insect vector. During programmed development, this extracellular parasite encounters strikingly different environments that determine its energy metabolism. Functioning as a bioenergetic, biosynthetic, and signaling center, the single mitochondrion of T. brucei is drastically remodeled to support the dynamic cellular demands of the parasite. This manuscript will provide an up-to-date overview of how the distinct T. brucei developmental stages differ in their mitochondrial metabolic and bioenergetic pathways, with a focus on the electron transport chain, proline oxidation, TCA cycle, acetate production, and ATP generation. Although mitochondrial metabolic rewiring has always been simply viewed as a consequence of the differentiation process, the possibility that certain mitochondrial activities reinforce parasite differentiation will be explored.
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Affiliation(s)
- Alena Zíková
- Biology Centre CAS, Institute of Parasitology, University of South Bohemia, Faculty of Science, České Budějovice, Czech Republic
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13
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Cai XL, Li SJ, Zhang P, Li Z, Hide G, Lai DH, Lun ZR. The Occurrence of Malignancy in Trypanosoma brucei brucei by Rapid Passage in Mice. Front Microbiol 2022; 12:806626. [PMID: 35087505 PMCID: PMC8789148 DOI: 10.3389/fmicb.2021.806626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/17/2021] [Indexed: 11/15/2022] Open
Abstract
Pleomorphic Trypanosoma brucei are best known for their tightly controlled cell growth and developmental program, which ensures their transmissibility and host fitness between the mammalian host and insect vector. However, after long-term adaptation in the laboratory or by natural evolution, monomorphic parasites can be derived. The origin of these monomorphic forms is currently unclear. Here, we produced a series of monomorphic trypanosome stocks by artificially syringe-passage in mice, creating snapshots of the transition from pleomorphism to monomorphism. We then compared these artificial monomorphic trypanosomes, alongside several naturally monomorphic T. evansi and T. equiperdum strains, with the pleomorphic T. brucei. In addition to failing to generate stumpy forms in animal bloodstream, we found that monomorphic trypanosomes from laboratory and nature exhibited distinct differentiation patterns, which are reflected by their distinct differentiation potential and transcriptional changes. Lab-adapted monomorphic trypanosomes could still be induced to differentiate, and showed only minor transcriptional differences to that of the pleomorphic slender forms but some accumulated differences were observed as the passages progress. All naturally monomorphic strains completely fail to differentiate, corresponding to their impaired differentiation regulation. We propose that the natural phenomenon of trypanosomal monomorphism is actually a malignant manifestation of protozoal cells. From a disease epidemiological and evolutionary perspective, our results provide evidence for a new way of thinking about the origin of these naturally monomorphic strains, the malignant evolution of trypanosomes may raise some concerns. Additionally, these monomorphic trypanosomes may reflect the quantitative and qualitative changes in the malignant evolution of T. brucei, suggesting that single-celled protozoa may also provide the most primitive model of cellular malignancy, which could be a primitive and inherent biological phenomenon of eukaryotic organisms from protozoans to mammals.
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Affiliation(s)
- Xiao-Li Cai
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Su-Jin Li
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Peng Zhang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Ziyin Li
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Geoff Hide
- Biomedical Research Centre, School of Science, Engineering and Environment, University of Salford, Salford, United Kingdom
| | - De-Hua Lai
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Zhao-Rong Lun
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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14
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Trypanosoma brucei Tim50 Possesses PAP Activity and Plays a Critical Role in Cell Cycle Regulation and Parasite Infectivity. mBio 2021; 12:e0159221. [PMID: 34517757 PMCID: PMC8546626 DOI: 10.1128/mbio.01592-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Trypanosoma brucei, the infective agent for African trypanosomiasis, possesses a homologue of the translocase of the mitochondrial inner membrane 50 (TbTim50). It has a pair of characteristic phosphatase signature motifs, DXDX(T/V). Here, we demonstrated that, besides its protein phosphatase activity, the recombinant TbTim50 binds and hydrolyzes phosphatidic acid in a concentration-dependent manner. Mutations of D242 and D244, but not of D345and D347, to alanine abolished these activities. In silico structural homology models identified the putative binding interfaces that may accommodate different phosphosubstrates. Interestingly, TbTim50 depletion in the bloodstream form (BF) of T. brucei reduced cardiolipin (CL) levels and decreased mitochondrial membrane potential (ΔΨ). TbTim50 knockdown (KD) also reduced the population of G2/M phase and increased that of G1 phase cells; inhibited segregation and caused overreplication of kinetoplast DNA (kDNA), and reduced BF cell growth. Depletion of TbTim50 increased the levels of AMPK phosphorylation, and parasite morphology was changed with upregulation of expression of a few stumpy marker genes. Importantly, we observed that TbTim50-depleted parasites were unable to establish infection in mice. Proteomics analysis showed reductions in levels of the translation factors, flagellar transport proteins, and many proteasomal subunits, including those of the mitochondrial heat shock locus ATPase (HslVU), which is known to play a role in regulation of kinetoplast DNA (kDNA) replication. Reduction of the level of HslV in TbTim50 KD cells was further validated by immunoblot analysis. Together, our results showed that TbTim50 is essential for mitochondrial function, regulation of kDNA replication, and the cell cycle in the BF. Therefore, TbTim50 is an important target for structure-based drug design to combat African trypanosomiasis.
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15
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Huang H, Wang L, Qian F, Chen X, Zhu H, Yang M, Zhang C, Chu M, Wang X, Huang X. Liraglutide via Activation of AMP-Activated Protein Kinase-Hypoxia Inducible Factor-1α-Heme Oxygenase-1 Signaling Promotes Wound Healing by Preventing Endothelial Dysfunction in Diabetic Mice. Front Physiol 2021; 12:660263. [PMID: 34483951 PMCID: PMC8415222 DOI: 10.3389/fphys.2021.660263] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 04/15/2021] [Indexed: 12/18/2022] Open
Abstract
Background/Aims: Diabetic foot ulcers (DFUs) present a major challenge in clinical practice, and hyperglycemia-induced angiogenesis disturbance and endothelial dysfunction likely exacerbate DFUs. The long-acting glucagon-like peptide-1 (GLP-1) analog liraglutide (Lira) is a potential activator of AMP-activated protein kinase (AMPK) that appears to enhance endothelial function and have substantial pro-angiogenesis and antioxidant stress effects. Therefore, in this study, we aimed to investigate whether the protective role of Lira in diabetic wound healing acts against the mechanisms underlying hyperglycemia-induced endothelial dysfunction and angiogenesis disturbance. Methods: Accordingly, db/db mice were assessed after receiving subcutaneous Lira injections. We also cultured human umbilical vein endothelial cells (HUVECs) in either normal or high glucose (5.5 or 33 mM glucose, respectively) medium with or without Lira for 72 h. Results: An obvious inhibition of hyperglycemia-triggered endothelial dysfunction and angiogenesis disturbance was observed; follow by a promotion of diabetic wound healing under Lira treatment combined with restored hyperglycemia-impaired AMPK signaling pathway activity. AMPKα1/2 siRNA and Compound C (Cpd C), an inhibitor of AMPK, abolished both Lira-mediated endothelial protection and pro-angiogenesis action, as well as the diabetic wound healing promoted by Lira. Furthermore, hypoxia inducible factor-1α (Hif-1α; transcription factors of AMPK substrates) knockdown in HUVECs and db/db mice demonstrated that Lira activated AMPK to prevent hyperglycemia-triggered endothelial dysfunction and angiogenesis disturbance, with a subsequent promotion of diabetic wound healing that was Hif-1α-heme oxygenase-1 (HO-1) axis-dependent. Taken together, these findings reveal that the promotion of diabetic wound healing by Lira occurs via its AMPK-dependent endothelial protection and pro-angiogenic effects, which are regulated by the Hif-1α-HO-1 axis.
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Affiliation(s)
- Huiya Huang
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Linlin Wang
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Fanyu Qian
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiong Chen
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Haiping Zhu
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Mei Yang
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Chunxiang Zhang
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Maoping Chu
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiaorong Wang
- The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xiaozhong Huang
- The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
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16
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Abstract
African trypanosomes are responsible for important diseases of humans and animals in sub-Saharan Africa. The best-studied species is Trypanosoma brucei, which is characterized by development in the mammalian host between morphologically slender and stumpy forms. The latter are adapted for transmission by the parasite's vector, the tsetse fly. The development of stumpy forms is driven by density-dependent quorum-sensing (QS), the molecular basis for which is now coming to light. In this review, I discuss the historical context and biological features of trypanosome QS and how it contributes to the parasite's infection dynamics within its mammalian host. Also, I discuss how QS can be lost in different trypanosome species, such as T. brucei evansi and T. brucei equiperdum, or modulated when parasites find themselves competing with others of different genotypes or of different trypanosome species in the same host. Finally, I consider the potential to exploit trypanosome QS therapeutically. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Keith R Matthews
- Institute for Immunology and Infection Research, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom;
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17
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Luzak V, López-Escobar L, Siegel TN, Figueiredo LM. Cell-to-Cell Heterogeneity in Trypanosomes. Annu Rev Microbiol 2021; 75:107-128. [PMID: 34228491 DOI: 10.1146/annurev-micro-040821-012953] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent developments in single-cell and single-molecule techniques have revealed surprising levels of heterogeneity among isogenic cells. These advances have transformed the study of cell-to-cell heterogeneity into a major area of biomedical research, revealing that it can confer essential advantages, such as priming populations of unicellular organisms for future environmental stresses. Protozoan parasites, such as trypanosomes, face multiple and often hostile environments, and to survive, they undergo multiple changes, including changes in morphology, gene expression, and metabolism. But why does only a subset of proliferative cells differentiate to the next life cycle stage? Why do only some bloodstream parasites undergo antigenic switching while others stably express one variant surface glycoprotein? And why do some parasites invade an organ while others remain in the bloodstream? Building on extensive research performed in bacteria, here we suggest that biological noise can contribute to the fitness of eukaryotic pathogens and discuss the importance of cell-to-cell heterogeneity in trypanosome infections. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Vanessa Luzak
- Division of Experimental Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Munich 82152, Germany.,Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich 82152, Germany
| | - Lara López-Escobar
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal;
| | - T Nicolai Siegel
- Division of Experimental Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Munich 82152, Germany.,Biomedical Center, Division of Physiological Chemistry, Faculty of Medicine, Ludwig-Maximilians-Universität München, Munich 82152, Germany
| | - Luisa M Figueiredo
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal;
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18
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Walsh B, Hill KL. Right place, right time: Environmental sensing and signal transduction directs cellular differentiation and motility in Trypanosoma brucei. Mol Microbiol 2021; 115:930-941. [PMID: 33434370 DOI: 10.1111/mmi.14682] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/08/2021] [Accepted: 01/09/2021] [Indexed: 11/29/2022]
Abstract
Trypanosoma brucei and other African trypanosomes are vector-borne parasites that cause substantial human suffering across sub-Saharan Africa. The T. brucei life cycle is punctuated by numerous developmental stages, each occurring in a specific environmental niche and characterized by a unique morphology, metabolism, surface protein coat, and gene expression profile. The environmental cues and signaling pathways that drive transitions between these stages remain incompletely understood. Recent studies have started to fill this gap in knowledge. Likewise, several new studies have expanded our understanding of parasite movement through specific tissues and the parasite's ability to alter movement in response to external cues. Life cycle stage differentiation and motility are intimately integrated phenomena, as parasites must be at the right place (i.e., within a specific environmental milieu) at the right time (i.e., when they are appropriately staged and preadapted for perceiving and responding to signals) in order to complete their life cycle. In this review, we highlight some of the recent work that has transformed our understanding of signaling events that control parasite differentiation and motility. Increased knowledge of T. brucei environmental sensing and signal transduction advances our understanding of parasite biology and may direct prospective chemotherapeutic and transmission blockade strategies that are critical to eradication efforts.
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Affiliation(s)
- Breanna Walsh
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, USA.,Medical Scientist Training Program, University of California Los Angeles, Los Angeles, CA, USA
| | - Kent L Hill
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, CA, USA.,California NanoSystems Institute, University of California Los Angeles, Los Angeles, CA, USA
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19
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An AMP-activated protein kinase complex with two distinctive alpha subunits is involved in nutritional stress responses in Trypanosoma cruzi. PLoS Negl Trop Dis 2021; 15:e0009435. [PMID: 34029334 PMCID: PMC8177656 DOI: 10.1371/journal.pntd.0009435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 06/04/2021] [Accepted: 05/03/2021] [Indexed: 12/14/2022] Open
Abstract
Trypanosoma cruzi, the etiological agent of Chagas disease, has a digenetic life cycle. In its passage from the insect vector to the mammalian host, and vice versa, it must be prepared to cope with abrupt changes in environmental conditions, such as carbon source, pH, temperature and osmolarity, in order to survive. Sensing and signaling pathways that allow the parasite to adapt, have unique characteristics with respect to their hosts and other free-living organisms. Many of the canonical proteins involved in these transduction pathways have not yet been found in the genomes of these parasites because they present divergences either at the functional, structural and/or protein sequence level. All of this makes these pathways promising targets for therapeutic drugs. The AMP-activated protein kinase (AMPK) is a serine/threonine kinase activated by environmental stresses such as osmotic stress, hypoxia, ischaemia and exercise that results in reduction of ATP and increase of AMP levels. Thus, AMPK is regarded as a fuel gauge, functioning both as a nutrient and an energy sensor, to maintain energy homeostasis and, eventually, to protect cells from death by nutrient starvation. In the present study we report the characterization of AMPK complexes for the first time in T. cruzi and propose the function of TcAMPK as a novel regulator of nutritional stress in epimastigote forms. We show that there is phosphotransferase activity specific for SAMS peptide in epimastigotes extracts, which is inhibited by Compound C and is modulated by carbon source availability. In addition, TcAMPKα2 subunit has an unprecedented functional substitution (Ser x Thr) at the activation loop and its overexpression in epimastigotes led to higher autophagic activity during prolonged nutritional stress. Moreover, the over-expression of the catalytic subunits resulted in antagonistic phenotypes associated with proliferation. Together, these results point to a role of TcAMPK in autophagy and nutrient sensing, key processes for the survival of trypanosomatids and for its life cycle progression. Chagas disease is caused by the protozoan parasite Trypanosoma cruzi. This silent illness is endemic in Latin-American countries and is conventionally transmitted to humans by insects from the Reduviidae family. In its passage from the insect vector to the mammalian host, and vice versa, the parasite must overcome abrupt changes in environmental conditions in order to survive. The AMP-activated protein kinase (AMPK) is a serine/threonine protein kinase activated by environmental stresses that cause imbalances of the intracellular AMP:ATP ratios. Thus, AMPK is regarded as a “fuel gauge”, functioning both as a nutrient and an energy sensor to help maintain energy homeostasis and protect cells from death by nutrient starvation. In the present study we report the characterization of AMPK complexes for the first time in T. cruzi and describe the function of AMPK as a novel regulator of nutritional stress in epimastigote forms. We demonstrate that this complex possesses specific AMPK kinase activity, is inhibited by Compound C and is modulated by carbon source availability. Together, these results point to a role of AMPK in autophagy and nutrient sensing, key processes for the survival of this parasite and for its life cycle progression.
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20
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Michels PAM, Villafraz O, Pineda E, Alencar MB, Cáceres AJ, Silber AM, Bringaud F. Carbohydrate metabolism in trypanosomatids: New insights revealing novel complexity, diversity and species-unique features. Exp Parasitol 2021; 224:108102. [PMID: 33775649 DOI: 10.1016/j.exppara.2021.108102] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 03/13/2021] [Accepted: 03/18/2021] [Indexed: 12/16/2022]
Abstract
The human pathogenic trypanosomatid species collectively called the "TriTryp parasites" - Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. - have complex life cycles, with each of these parasitic protists residing in a different niche during their successive developmental stages where they encounter diverse nutrients. Consequently, they adapt their metabolic network accordingly. Yet, throughout the life cycles, carbohydrate metabolism - involving the glycolytic, gluconeogenic and pentose-phosphate pathways - always plays a central role in the biology of these parasites, whether the available carbon and free energy sources are saccharides, amino acids or lipids. In this paper, we provide an updated review of the carbohydrate metabolism of the TriTryps, highlighting new data about this metabolic network, the interconnection of its pathways and the compartmentalisation of its enzymes within glycosomes, cytosol and mitochondrion. Differences in the expression of the branches of the metabolic network between the successive life-cycle stages of each of these parasitic trypanosomatids are discussed, as well as differences between them. Recent structural and kinetic studies have revealed unique regulatory mechanisms for some of the network's key enzymes with important species-specific variations. Furthermore, reports of multiple post-translational modifications of trypanosomal glycolytic enzymes suggest that additional mechanisms for stage- and/or environmental cues that regulate activity are operational in the parasites. The detailed comparison of the carbohydrate metabolism of the TriTryps has thus revealed multiple differences and a greater complexity, including for the reduced metabolic network in bloodstream-form T. brucei, than previously appreciated. Although these parasites are related, share many cytological and metabolic features and are grouped within a single taxonomic family, the differences highlighted in this review reflect their separate evolutionary tracks from a common ancestor to the extant organisms. These differences are indicative of their adaptation to the different insect vectors and niches occupied in their mammalian hosts.
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Affiliation(s)
- Paul A M Michels
- Centre for Immunity, Infection and Evolution and Centre for Translational and Chemical Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom.
| | - Oriana Villafraz
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, France
| | - Erika Pineda
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, France
| | - Mayke B Alencar
- Laboratory of Biochemistry of Tryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-000, Brazil
| | - Ana J Cáceres
- Laboratorio de Enzimología de Parásitos, Departamento de Biología, Facultad de Ciencias, Universidad de Los Andes, Mérida, 5101, Venezuela.
| | - Ariel M Silber
- Laboratory of Biochemistry of Tryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, 05508-000, Brazil.
| | - Frédéric Bringaud
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), Université de Bordeaux, CNRS UMR-5234, France.
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21
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Quintana JF, Zoltner M, Field MC. Evolving Differentiation in African Trypanosomes. Trends Parasitol 2021; 37:296-303. [PMID: 33309505 DOI: 10.1016/j.pt.2020.11.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/15/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022]
Abstract
Differentiation is a central aspect of the parasite life cycle and encompasses adaptation to both host and environment. If we accept that evolution cannot anticipate an organism's needs as it enters a new environment, how do parasite differentiation pathways arise? The transition between vertebrate and insect stage African trypanosomes is probably one of the better studied and involves a cell-cycle arrested or 'stumpy' form that activates metabolic pathways advantageous to the parasite in the insect host. However, a range of stimuli and stress conditions can trigger similar changes, leading to formation of stumpy-like cellular states. We propose that the origin and optimisation of this differentiation program represents repurposing of a generic stress response to gain considerable gain-of-fitness associated with parasite transmission.
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Affiliation(s)
- Juan F Quintana
- Wellcome Centre for Integrative Parasitology, College of Medical, Veterinary and Life Sciences, Glasgow Biomedical Research Centre, University of Glasgow, Glasgow, UK; School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Martin Zoltner
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK; Biotechnology and Biomedicine Centre of the Academy of Sciences and Charles University (BIOCEV), Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Mark C Field
- School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK; Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 37005 Ceske Budejovice, Czech Republic.
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22
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Durante IM, Butenko A, Rašková V, Charyyeva A, Svobodová M, Yurchenko V, Hashimi H, Lukeš J. Large-Scale Phylogenetic Analysis of Trypanosomatid Adenylate Cyclases Reveals Associations with Extracellular Lifestyle and Host-Pathogen Interplay. Genome Biol Evol 2020; 12:2403-2416. [PMID: 33104188 PMCID: PMC7719234 DOI: 10.1093/gbe/evaa226] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/21/2020] [Indexed: 12/14/2022] Open
Abstract
Receptor adenylate cyclases (RACs) on the surface of trypanosomatids are important players in the host–parasite interface. They detect still unidentified environmental signals that affect the parasites’ responses to host immune challenge, coordination of social motility, and regulation of cell division. A lesser known class of oxygen-sensing adenylate cyclases (OACs) related to RACs has been lost in trypanosomes and expanded mostly in Leishmania species and related insect-dwelling trypanosomatids. In this work, we have undertaken a large-scale phylogenetic analysis of both classes of adenylate cyclases (ACs) in trypanosomatids and the free-living Bodo saltans. We observe that the expanded RAC repertoire in trypanosomatids with a two-host life cycle is not only associated with an extracellular lifestyle within the vertebrate host, but also with a complex path through the insect vector involving several life cycle stages. In Trypanosoma brucei, RACs are split into two major clades, which significantly differ in their expression profiles in the mammalian host and the insect vector. RACs of the closely related Trypanosoma congolense are intermingled within these two clades, supporting early RAC diversification. Subspecies of T. brucei that have lost the capacity to infect insects exhibit high numbers of pseudogenized RACs, suggesting many of these proteins have become redundant upon the acquisition of a single-host life cycle. OACs appear to be an innovation occurring after the expansion of RACs in trypanosomatids. Endosymbiont-harboring trypanosomatids exhibit a diversification of OACs, whereas these proteins are pseudogenized in Leishmania subgenus Viannia. This analysis sheds light on how ACs have evolved to allow diverse trypanosomatids to occupy multifarious niches and assume various lifestyles.
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Affiliation(s)
- Ignacio Miguel Durante
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czechia
| | - Anzhelika Butenko
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czechia.,Life Science Research Centre, Faculty of Science, University of Ostrava, Czechia
| | - Vendula Rašková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czechia.,Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czechia
| | - Arzuv Charyyeva
- Life Science Research Centre, Faculty of Science, University of Ostrava, Czechia
| | - Michaela Svobodová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czechia
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, Czechia.,Martsinovsky Institute of Medical Parasitology, Tropical and Vector Borne Diseases, Sechenov University, Moscow, Russian Federation
| | - Hassan Hashimi
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czechia.,Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czechia
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czechia.,Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czechia
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23
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Cestari I, Stuart K. The phosphoinositide regulatory network in Trypanosoma brucei: Implications for cell-wide regulation in eukaryotes. PLoS Negl Trop Dis 2020; 14:e0008689. [PMID: 33119588 PMCID: PMC7595295 DOI: 10.1371/journal.pntd.0008689] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The unicellular eukaryote Trypanosoma brucei undergoes extensive cellular and developmental changes during its life cycle. These include regulation of mammalian stage surface antigen variation and surface composition changes between life stages; switching between glycolysis and oxidative phosphorylation; differential mRNA editing; and changes in posttranscriptional gene expression, protein trafficking, organellar function, and cell morphology. These diverse events are coordinated and controlled throughout parasite development, maintained in homeostasis at each life stage, and are essential for parasite survival in both the host and insect vector. Described herein are the enzymes and metabolites of the phosphatidylinositol (PI) cellular regulatory network, its integration with other cellular regulatory systems that collectively control and coordinate these numerous cellular processes, including cell development and differentiation and the many associated complex processes in multiple subcellular compartments. We conclude that this regulation is the product of the organization of these enzymes within the cellular architecture, their activities, metabolite fluxes, and responses to environmental changes via signal transduction and other processes. We describe a paradigm for how these enzymes and metabolites could function to control and coordinate multiple cellular functions. The significance of the PI system's regulatory functions in single-celled eukaryotes to metazoans and their potential as chemotherapeutic targets are indicated.
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Affiliation(s)
- Igor Cestari
- Institute of Parasitology, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
- Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
- * E-mail: (IC); (KS)
| | - Kenneth Stuart
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Department of Global Health, University of Washington, Seattle, Washington, United States of America
- * E-mail: (IC); (KS)
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24
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New perspectives for hydrogen peroxide in the amastigogenesis of Trypanosoma cruzi in vitro. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165951. [PMID: 32861766 DOI: 10.1016/j.bbadis.2020.165951] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 12/25/2022]
Abstract
Trypanosoma cruzi has a complex life cycle involving four life stages: the replicative epimastigotes and metacyclic trypomastigotes in the invertebrate host digestive tract, and intracellular amastigotes and bloodstream trypomastigotes in the mammalian host. Trypomastigotes can invade any nucleated cell, including macrophages, which produce ROS that enhance intracellular infection. However, how ROS modulate T. cruzi infection in the mammalian cell remains unclear. Therefore, the present work aimed to investigate the role of ROS during the stimulation of amastigogenesis in vitro. Our results showed that H2O2 improves the differentiation process in vitro and that it was impaired by Peg-Catalase. However, the antioxidants GSH and NAC had no influence on induced amastigogenesis, which suggests the specificity of H2O2 to increase intracellular differentiation. Amastigogenesis physiologically occurs in low pH, thus we investigated whether parasites are able to produce ROS during amastigogenesis. Interestingly, after 60 min of differentiation induction in vitro, we observed an increase in H2O2 production, which was inhibited by the mitochondrial-targeted antioxidant, mitoTEMPO and Cyclosporine A (a mitochondrial permeability transition pore -mPTP- inhibitor), suggesting mitochondrion as a H2O2 source. Indeed, quantitative real time (qPCR) showed an increase of the mitochondrial superoxide dismutase (FeSODA) gene expression after 60 min of induced amastigogenesis, reinforcing the hypothesis of mitochondrial ROS induction during intracellular differentiation of T. cruzi. The reduction of cellular respiration and the decreased ΔΨm observed during amastigogenesis can explain the increased mitochondrial ROS through mPTP opening. In conclusion, our results suggest that H2O2 is involved in the amastigogenesis of T. cruzi.
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25
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Doleželová E, Kunzová M, Dejung M, Levin M, Panicucci B, Regnault C, Janzen CJ, Barrett MP, Butter F, Zíková A. Cell-based and multi-omics profiling reveals dynamic metabolic repurposing of mitochondria to drive developmental progression of Trypanosoma brucei. PLoS Biol 2020; 18:e3000741. [PMID: 32520929 PMCID: PMC7307792 DOI: 10.1371/journal.pbio.3000741] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 06/22/2020] [Accepted: 05/27/2020] [Indexed: 12/23/2022] Open
Abstract
Mitochondrial metabolic remodeling is a hallmark of the Trypanosoma brucei digenetic life cycle because the insect stage utilizes a cost-effective oxidative phosphorylation (OxPhos) to generate ATP, while bloodstream cells switch to aerobic glycolysis. Due to difficulties in acquiring enough parasites from the tsetse fly vector, the dynamics of the parasite's metabolic rewiring in the vector have remained obscure. Here, we took advantage of in vitro-induced differentiation to follow changes at the RNA, protein, and metabolite levels. This multi-omics and cell-based profiling showed an immediate redirection of electron flow from the cytochrome-mediated pathway to an alternative oxidase (AOX), an increase in proline consumption, elevated activity of complex II, and certain tricarboxylic acid (TCA) cycle enzymes, which led to mitochondrial membrane hyperpolarization and increased reactive oxygen species (ROS) levels. Interestingly, these ROS molecules appear to act as signaling molecules driving developmental progression because ectopic expression of catalase, a ROS scavenger, halted the in vitro-induced differentiation. Our results provide insights into the mechanisms of the parasite's mitochondrial rewiring and reinforce the emerging concept that mitochondria act as signaling organelles through release of ROS to drive cellular differentiation.
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Affiliation(s)
- Eva Doleželová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Michaela Kunzová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Mario Dejung
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Michal Levin
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Brian Panicucci
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Clément Regnault
- Welcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Christian J. Janzen
- Welcome Centre for Integrative Parasitology, Institute of Infection, Immunity and Inflammation, Glasgow Polyomics, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Michael P. Barrett
- Department of Cell and Developmental Biology, Biocenter, University Wuerzburg, Wuerzburg, Germany
| | - Falk Butter
- Institute of Molecular Biology (IMB), Mainz, Germany
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
- * E-mail:
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26
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Zoltner M, Campagnaro GD, Taleva G, Burrell A, Cerone M, Leung KF, Achcar F, Horn D, Vaughan S, Gadelha C, Zíková A, Barrett MP, de Koning HP, Field MC. Suramin exposure alters cellular metabolism and mitochondrial energy production in African trypanosomes. J Biol Chem 2020; 295:8331-8347. [PMID: 32354742 PMCID: PMC7294092 DOI: 10.1074/jbc.ra120.012355] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 04/21/2020] [Indexed: 12/27/2022] Open
Abstract
Introduced about a century ago, suramin remains a frontline drug for the management of early-stage East African trypanosomiasis (sleeping sickness). Cellular entry into the causative agent, the protozoan parasite Trypanosoma brucei, occurs through receptor-mediated endocytosis involving the parasite's invariant surface glycoprotein 75 (ISG75), followed by transport into the cytosol via a lysosomal transporter. The molecular basis of the trypanocidal activity of suramin remains unclear, but some evidence suggests broad, but specific, impacts on trypanosome metabolism (i.e. polypharmacology). Here we observed that suramin is rapidly accumulated in trypanosome cells proportionally to ISG75 abundance. Although we found little evidence that suramin disrupts glycolytic or glycosomal pathways, we noted increased mitochondrial ATP production, but a net decrease in cellular ATP levels. Metabolomics highlighted additional impacts on mitochondrial metabolism, including partial Krebs' cycle activation and significant accumulation of pyruvate, corroborated by increased expression of mitochondrial enzymes and transporters. Significantly, the vast majority of suramin-induced proteins were normally more abundant in the insect forms compared with the blood stage of the parasite, including several proteins associated with differentiation. We conclude that suramin has multiple and complex effects on trypanosomes, but unexpectedly partially activates mitochondrial ATP-generating activity. We propose that despite apparent compensatory mechanisms in drug-challenged cells, the suramin-induced collapse of cellular ATP ultimately leads to trypanosome cell death.
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Affiliation(s)
- Martin Zoltner
- School of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Gustavo D Campagnaro
- Institute for Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Gergana Taleva
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Institute of Parasitology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Alana Burrell
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
| | - Michela Cerone
- Institute for Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Ka-Fai Leung
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Fiona Achcar
- Wellcome Centre for Integrative Parasitology and Glasgow Polyomics, University of Glasgow, Glasgow, United Kingdom
| | - David Horn
- School of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom
| | - Sue Vaughan
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, United Kingdom
| | - Catarina Gadelha
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Institute of Parasitology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Michael P Barrett
- Wellcome Centre for Integrative Parasitology and Glasgow Polyomics, University of Glasgow, Glasgow, United Kingdom
| | - Harry P de Koning
- Institute for Infection, Immunity, and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Mark C Field
- School of Life Sciences, University of Dundee, Dundee, Scotland, United Kingdom .,Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Institute of Parasitology, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
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27
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Subramanian G, Popli S, Chakravarty S, Taylor RT, Chakravarti R, Chattopadhyay S. The interferon-inducible protein TDRD7 inhibits AMP-activated protein kinase and thereby restricts autophagy-independent virus replication. J Biol Chem 2020; 295:6811-6822. [PMID: 32273341 DOI: 10.1074/jbc.ra120.013533] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 04/03/2020] [Indexed: 12/25/2022] Open
Abstract
The interferon system is the first line of defense against virus infection. Recently, using a high-throughput genetic screen of a human interferon-stimulated gene short-hairpin RNA library, we identified a viral restriction factor, TDRD7 (Tudor domain-containing 7). TDRD7 inhibits the paramyxo-/pneumoviruses (e.g. Sendai virus and respiratory syncytial virus) by interfering with the virus-induced cellular autophagy pathway, which these viruses use for their replication. Here, we report that TDRD7 is a viral restriction factor against herpes simplex virus (HSV-1). Using knockdown, knockout, and ectopic expression systems, we demonstrate the anti-HSV-1 activity of TDRD7 in multiple human and mouse cell types. TDRD7 inhibited the virus-activated AMP-activated protein kinase (AMPK), which was essential for HSV-1 replication. Genetic ablation or chemical inhibition of AMPK activity suppressed HSV-1 replication in multiple human and mouse cells. Mechanistically, HSV-1 replication after viral entry depended on AMPK but not on its function in autophagy. The antiviral activity of TDRD7 depended on its ability to inhibit virus-activated AMPK. In summary, our results indicate that the newly identified viral restriction factor TDRD7 inhibits AMPK and thereby blocks HSV-1 replication independently of the autophagy pathway. These findings suggest that AMPK inhibition represents a potential strategy to manage HSV-1 infections.
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Affiliation(s)
- Gayatri Subramanian
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio 43614
| | - Sonam Popli
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio 43614
| | - Sukanya Chakravarty
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio 43614
| | - R Travis Taylor
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio 43614
| | - Ritu Chakravarti
- Department of Physiology and Pharmacology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio 43614
| | - Saurabh Chattopadhyay
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio 43614
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28
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Cestari I. Phosphoinositide signaling and regulation in Trypanosoma brucei: Specialized functions in a protozoan pathogen. PLoS Pathog 2020; 16:e1008167. [PMID: 31895930 PMCID: PMC6939900 DOI: 10.1371/journal.ppat.1008167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Affiliation(s)
- Igor Cestari
- Institute of Parasitology, McGill University, Ste-Anne-de-Bellevue, Québec, Canada
- * E-mail:
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29
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Saura A, Iribarren PA, Rojas‐Barros D, Bart JM, López‐Farfán D, Andrés‐León E, Vidal‐Cobo I, Boehm C, Alvarez VE, Field MC, Navarro M. SUMOylated SNF2PH promotes variant surface glycoprotein expression in bloodstream trypanosomes. EMBO Rep 2019; 20:e48029. [PMID: 31693280 PMCID: PMC6893287 DOI: 10.15252/embr.201948029] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 09/22/2019] [Accepted: 09/26/2019] [Indexed: 01/10/2023] Open
Abstract
SUMOylation is a post-translational modification that positively regulates monoallelic expression of the trypanosome variant surface glycoprotein (VSG). The presence of a highly SUMOylated focus associated with the nuclear body, where the VSG gene is transcribed, further suggests an important role of SUMOylation in regulating VSG expression. Here, we show that SNF2PH, a SUMOylated plant homeodomain (PH)-transcription factor, is upregulated in the bloodstream form of the parasite and enriched at the active VSG telomere. SUMOylation promotes the recruitment of SNF2PH to the VSG promoter, where it is required to maintain RNA polymerase I and thus to regulate VSG transcript levels. Further, ectopic overexpression of SNF2PH in insect forms, but not of a mutant lacking the PH domain, induces the expression of bloodstream stage-specific surface proteins. These data suggest that SNF2PH SUMOylation positively regulates VSG monoallelic transcription, while the PH domain is required for the expression of bloodstream-specific surface proteins. Thus, SNF2PH functions as a positive activator, linking expression of infective form surface proteins and VSG regulation, thereby acting as a major regulator of pathogenicity.
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Affiliation(s)
- Andreu Saura
- Instituto de Parasitología y Biomedicina “López‐Neyra”CSIC (IPBLN‐CSIC)GranadaSpain
| | | | - Domingo Rojas‐Barros
- Instituto de Parasitología y Biomedicina “López‐Neyra”CSIC (IPBLN‐CSIC)GranadaSpain
| | - Jean M Bart
- Instituto de Parasitología y Biomedicina “López‐Neyra”CSIC (IPBLN‐CSIC)GranadaSpain
| | - Diana López‐Farfán
- Instituto de Parasitología y Biomedicina “López‐Neyra”CSIC (IPBLN‐CSIC)GranadaSpain
| | - Eduardo Andrés‐León
- Instituto de Parasitología y Biomedicina “López‐Neyra”CSIC (IPBLN‐CSIC)GranadaSpain
| | - Isabel Vidal‐Cobo
- Instituto de Parasitología y Biomedicina “López‐Neyra”CSIC (IPBLN‐CSIC)GranadaSpain
| | | | | | - Mark C Field
- School of Life SciencesUniversity of DundeeDundeeUK
- Biology CentreInstitute of ParasitologyCzech Academy of SciencesCeske BudejoviceCzech Republic
| | - Miguel Navarro
- Instituto de Parasitología y Biomedicina “López‐Neyra”CSIC (IPBLN‐CSIC)GranadaSpain
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30
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Rojas F, Matthews KR. Quorum sensing in African trypanosomes. Curr Opin Microbiol 2019; 52:124-129. [PMID: 31442903 DOI: 10.1016/j.mib.2019.07.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 06/28/2019] [Accepted: 07/17/2019] [Indexed: 01/17/2023]
Abstract
Many microbial eukaryotes exhibit cell-cell communication to co-ordinate group behaviours as a strategy to exploit a changed environment, adapt to adverse conditions or regulate developmental responses. Although best characterised in bacteria, eukaryotic microbes have also been revealed to cooperate to optimise their survival or dissemination. An excellent model for these processes are African trypanosomes, protozoa responsible for important human and animal disease in sub Saharan Africa. These unicellular parasites use density sensing in their mammalian host to prepare for transmission. Recently, the signal and signal transduction pathway underlying this activity have been elucidated, revealing that the parasite exploits oligopeptide signals generated by released peptidases to monitor cell density and so generate transmission stages. Here we review the evidence for this elegant quorum sensing mechanism and its parallels with similar mechanisms in other microbial systems. We also discuss its implications for disease spread in the context of coinfections involving different trypanosome species.
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Affiliation(s)
- Federico Rojas
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom.
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom.
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31
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Tripathi A, Singha UK, Paromov V, Hill S, Pratap S, Rose K, Chaudhuri M. The Cross Talk between TbTim50 and PIP39, Two Aspartate-Based Protein Phosphatases, Maintains Cellular Homeostasis in Trypanosoma brucei. mSphere 2019; 4:e00353-19. [PMID: 31391278 PMCID: PMC6686227 DOI: 10.1128/msphere.00353-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 07/08/2019] [Indexed: 12/18/2022] Open
Abstract
Trypanosoma brucei, the infectious agent of a deadly disease known as African trypanosomiasis, undergoes various stresses during its digenetic life cycle. We previously showed that downregulation of T. brucei mitochondrial inner membrane protein translocase 50 (TbTim50), an aspartate-based protein phosphatase and a component of the translocase of the mitochondrial inner membrane (TIM), increased the tolerance of procyclic cells to oxidative stress. Using comparative proteomics analysis and further validating the proteomics results by immunoblotting, here we discovered that TbTim50 downregulation caused an approximately 5-fold increase in the levels of PIP39, which is also an aspartate-based protein phosphatase and is primarily localized in glycosomes. A moderate upregulation of a number of glycosomal enzymes was also noticed due to TbTim50 knockdown. We found that the rate of mitochondrial ATP production by oxidative phosphorylation decreased and that substrate-level phosphorylation increased due to depletion of TbTim50. These results were correlated with relative increases in the levels of trypanosome alternative oxidase and hexokinase and a reduced-growth phenotype in low-glucose medium. The levels and activity of the mitochondrial superoxide dismutase and glutaredoxin levels were increased due to TbTim50 knockdown. Furthermore, we show that TbTim50 downregulation increased the cellular AMP/ATP ratio, and as a consequence, phosphorylation of AMP-activated protein kinase (AMPK) was increased. Knocking down both TbTim50 and TbPIP39 reduced PIP39 levels as well as AMPK phosphorylation and reduced T. brucei tolerance to oxidative stress. These results suggest that TbTim50 and PIP39, two protein phosphatases in mitochondria and glycosomes, respectively, cross talk via the AMPK pathway to maintain cellular homeostasis in the procyclic form of T. bruceiIMPORTANCETrypanosoma brucei, the infectious agent of African trypanosomiasis, must adapt to strikingly different host environments during its digenetic life cycle. Developmental regulation of mitochondrial activities is an essential part of these processes. We have shown previously that mitochondrial inner membrane protein translocase 50 in T. brucei (TbTim50) possesses a dually specific phosphatase activity and plays a role in the cellular stress response pathway. Using proteomics analysis, here we have elucidated a novel connection between TbTim50 and a protein phosphatase of the same family, PIP39, which is also a differentiation-related protein localized in glycosomes. We found that these two protein phosphatases cross talk via the AMPK pathway and modulate cellular metabolic activities under stress. Together, our results indicate the importance of a TbTim50 and PIP39 cascade for communication between mitochondria and other cellular parts in regulation of cell homeostasis in T. brucei.
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Affiliation(s)
- Anuj Tripathi
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Ujjal K Singha
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Victor Paromov
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Salisha Hill
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Siddharth Pratap
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
| | - Kristie Rose
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, USA
| | - Minu Chaudhuri
- Department of Microbiology, Immunology, and Physiology, Meharry Medical College, Nashville, Tennessee, USA
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32
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Nucleoside analogue activators of cyclic AMP-independent protein kinase A of Trypanosoma. Nat Commun 2019; 10:1421. [PMID: 30926779 PMCID: PMC6440977 DOI: 10.1038/s41467-019-09338-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 03/07/2019] [Indexed: 02/08/2023] Open
Abstract
Protein kinase A (PKA), the main effector of cAMP in eukaryotes, is a paradigm for the mechanisms of ligand-dependent and allosteric regulation in signalling. Here we report the orthologous but cAMP-independent PKA of the protozoan Trypanosoma and identify 7-deaza-nucleosides as potent activators (EC50 ≥ 6.5 nM) and high affinity ligands (KD ≥ 8 nM). A co-crystal structure of trypanosome PKA with 7-cyano-7-deazainosine and molecular docking show how substitution of key amino acids in both CNB domains of the regulatory subunit and its unique C-terminal αD helix account for this ligand swap between trypanosome PKA and canonical cAMP-dependent PKAs. We propose nucleoside-related endogenous activators of Trypanosoma brucei PKA (TbPKA). The existence of eukaryotic CNB domains not associated with binding of cyclic nucleotides suggests that orphan CNB domains in other eukaryotes may bind undiscovered signalling molecules. Phosphoproteome analysis validates 7-cyano-7-deazainosine as powerful cell-permeable inducer to explore cAMP-independent PKA signalling in medically important neglected pathogens.
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33
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Rojas F, Silvester E, Young J, Milne R, Tettey M, Houston DR, Walkinshaw MD, Pérez-Pi I, Auer M, Denton H, Smith TK, Thompson J, Matthews KR. Oligopeptide Signaling through TbGPR89 Drives Trypanosome Quorum Sensing. Cell 2018; 176:306-317.e16. [PMID: 30503212 PMCID: PMC6333907 DOI: 10.1016/j.cell.2018.10.041] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 09/13/2018] [Accepted: 10/17/2018] [Indexed: 02/03/2023]
Abstract
Trypanosome parasites control their virulence and spread by using quorum sensing (QS) to generate transmissible “stumpy forms” in their host bloodstream. However, the QS signal “stumpy induction factor” (SIF) and its reception mechanism are unknown. Although trypanosomes lack G protein-coupled receptor signaling, we have identified a surface GPR89-family protein that regulates stumpy formation. TbGPR89 is expressed on bloodstream “slender form” trypanosomes, which receive the SIF signal, and when ectopically expressed, TbGPR89 drives stumpy formation in a SIF-pathway-dependent process. Structural modeling of TbGPR89 predicts unexpected similarity to oligopeptide transporters (POT), and when expressed in bacteria, TbGPR89 transports oligopeptides. Conversely, expression of an E. coli POT in trypanosomes drives parasite differentiation, and oligopeptides promote stumpy formation in vitro. Furthermore, the expression of secreted trypanosome oligopeptidases generates a paracrine signal that accelerates stumpy formation in vivo. Peptidase-generated oligopeptide QS signals being received through TbGPR89 provides a mechanism for both trypanosome SIF production and reception. Trypanosomes use quorum sensing to differentiate to transmissible stumpy forms A GPR89 protein with oligopeptide transport activity drives parasite differentiation Oligopeptide mixtures and synthetic di- and tripeptides promote stumpy formation Released parasite oligopeptidases generate the paracrine quorum sensing signal in vivo
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Affiliation(s)
- Federico Rojas
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Eleanor Silvester
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Julie Young
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Rachel Milne
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Mabel Tettey
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK
| | - Douglas R Houston
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Malcolm D Walkinshaw
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Irene Pérez-Pi
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Manfred Auer
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Helen Denton
- School of Biology, BSRC, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, UK
| | - Terry K Smith
- School of Biology, BSRC, University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9ST, UK
| | - Joanne Thompson
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK.
| | - Keith R Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, UK.
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β-Hydroxybutyrate Prevents Vascular Senescence through hnRNP A1-Mediated Upregulation of Oct4. Mol Cell 2018; 71:1064-1078.e5. [PMID: 30197300 DOI: 10.1016/j.molcel.2018.07.036] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 04/02/2018] [Accepted: 07/24/2018] [Indexed: 12/16/2022]
Abstract
β-hydroxybutyrate (β-HB) elevation during fasting or caloric restriction is believed to induce anti-aging effects and alleviate aging-related neurodegeneration. However, whether β-HB alters the senescence pathway in vascular cells remains unknown. Here we report that β-HB promotes vascular cell quiescence, which significantly inhibits both stress-induced premature senescence and replicative senescence through p53-independent mechanisms. Further, we identify heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) as a direct binding target of β-HB. β-HB binding to hnRNP A1 markedly enhances hnRNP A1 binding with Octamer-binding transcriptional factor (Oct) 4 mRNA, which stabilizes Oct4 mRNA and Oct4 expression. Oct4 increases Lamin B1, a key factor against DNA damage-induced senescence. Finally, fasting and intraperitoneal injection of β-HB upregulate Oct4 and Lamin B1 in both vascular smooth muscle and endothelial cells in mice in vivo. We conclude that β-HB exerts anti-aging effects in vascular cells by upregulating an hnRNP A1-induced Oct4-mediated Lamin B1 pathway.
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Abstract
To satisfy its fatty acid needs, the extracellular eukaryotic parasite Trypanosoma brucei relies on two mechanisms: uptake of fatty acids from the host and de novo synthesis. We hypothesized that T. brucei modulates fatty acid synthesis in response to environmental lipid availability. The first committed step in fatty acid synthesis is catalyzed by acetyl coenzyme A (acetyl-CoA) carboxylase (ACC) and serves as a key regulatory point in other organisms. To test our hypothesis, T. brucei mammalian bloodstream and insect procyclic forms were grown in low-, normal-, or high-lipid media and the effect on T. brucei ACC (TbACC) mRNA, protein, and enzymatic activity was examined. In bloodstream form T. brucei, media lipids had no effect on TbACC expression or activity. In procyclic form T. brucei, we detected no change in TbACC mRNA levels but observed 2.7-fold-lower TbACC protein levels and 37% lower TbACC activity in high-lipid media than in low-lipid media. Supplementation of low-lipid media with the fatty acid stearate mimicked the effect of high lipid levels on TbACC activity. In procyclic forms, TbACC phosphorylation also increased 3.9-fold in high-lipid media compared to low-lipid media. Phosphatase treatment of TbACC increased activity, confirming that phosphorylation represented an inhibitory modification. Together, these results demonstrate a procyclic-form-specific environmental lipid response pathway that regulates TbACC posttranscriptionally, through changes in protein expression and phosphorylation. We propose that this environmental response pathway enables procyclic-form T. brucei to monitor the host lipid supply and downregulate fatty acid synthesis when host lipids are abundant and upregulate fatty acid synthesis when host lipids become scarce.IMPORTANCETrypanosoma brucei is a eukaryotic parasite that causes African sleeping sickness. T. brucei is transmitted by the blood-sucking tsetse fly. In order to adapt to its two very different hosts, T. brucei must sense the host environment and alter its metabolism to maximize utilization of host resources and minimize expenditure of its own resources. One key nutrient class is represented by fatty acids, which the parasite can either take from the host or make themselves. Our work describes a novel environmental regulatory pathway for fatty acid synthesis where the parasite turns off fatty acid synthesis when environmental lipids are abundant and turns on synthesis when the lipid supply is scarce. This pathway was observed in the tsetse midgut form but not the mammalian bloodstream form. However, pharmacological activation of this pathway in the bloodstream form to turn fatty acid synthesis off may be a promising new avenue for sleeping sickness drug discovery.
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McDonald L, Cayla M, Ivens A, Mony BM, MacGregor P, Silvester E, McWilliam K, Matthews KR. Non-linear hierarchy of the quorum sensing signalling pathway in bloodstream form African trypanosomes. PLoS Pathog 2018; 14:e1007145. [PMID: 29940034 PMCID: PMC6034907 DOI: 10.1371/journal.ppat.1007145] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 07/06/2018] [Accepted: 06/07/2018] [Indexed: 01/23/2023] Open
Abstract
Trypanosoma brucei, the agents of African trypanosomiasis, undergo density-dependent differentiation in the mammalian bloodstream to prepare for transmission by tsetse flies. This involves the generation of cell-cycle arrested, quiescent, stumpy forms from proliferative slender forms. The signalling pathway responsible for the quorum sensing response has been catalogued using a genome-wide selective screen, providing a compendium of signalling protein kinases phosphatases, RNA binding proteins and hypothetical proteins. However, the ordering of these components is unknown. To piece together these components to provide a description of how stumpy formation arises we have used an extragenic suppression approach. This exploited a combinatorial gene knockout and overexpression strategy to assess whether the loss of developmental competence in null mutants of pathway components could be compensated by ectopic expression of other components. We have created null mutants for three genes in the stumpy induction factor signalling pathway (RBP7, YAK, MEKK1) and evaluated complementation by expression of RBP7, NEK17, PP1-6, or inducible gene silencing of the proposed differentiation inhibitor TbTOR4. This indicated that the signalling pathway is non-linear. Phosphoproteomic analysis focused on one pathway component, a putative MEKK, identified molecules with altered expression and phosphorylation profiles in MEKK1 null mutants, including another component in the pathway, NEK17. Our data provide a first molecular dissection of multiple components in a signal transduction cascade in trypanosomes.
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Affiliation(s)
- Lindsay McDonald
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Mathieu Cayla
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Alasdair Ivens
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Binny M. Mony
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Paula MacGregor
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Eleanor Silvester
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Kirsty McWilliam
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Keith R. Matthews
- Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
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Kelly S, Ivens A, Mott GA, O'Neill E, Emms D, Macleod O, Voorheis P, Tyler K, Clark M, Matthews J, Matthews K, Carrington M. An Alternative Strategy for Trypanosome Survival in the Mammalian Bloodstream Revealed through Genome and Transcriptome Analysis of the Ubiquitous Bovine Parasite Trypanosoma (Megatrypanum) theileri. Genome Biol Evol 2018; 9:2093-2109. [PMID: 28903536 PMCID: PMC5737535 DOI: 10.1093/gbe/evx152] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/12/2017] [Indexed: 12/19/2022] Open
Abstract
There are hundreds of Trypanosoma species that live in the blood and tissue spaces of their vertebrate hosts. The vast majority of these do not have the ornate system of antigenic variation that has evolved in the small number of African trypanosome species, but can still maintain long-term infections in the face of the vertebrate adaptive immune system. Trypanosoma theileri is a typical example, has a restricted host range of cattle and other Bovinae, and is only occasionally reported to cause patent disease although no systematic survey of the effect of infection on agricultural productivity has been performed. Here, a detailed genome sequence and a transcriptome analysis of gene expression in bloodstream form T. theileri have been performed. Analysis of the genome sequence and expression showed that T. theileri has a typical kinetoplastid genome structure and allowed a prediction that it is capable of meiotic exchange, gene silencing via RNA interference and, potentially, density-dependent growth control. In particular, the transcriptome analysis has allowed a comparison of two distinct trypanosome cell surfaces, T. brucei and T. theileri, that have each evolved to enable the maintenance of a long-term extracellular infection in cattle. The T. theileri cell surface can be modeled to contain a mixture of proteins encoded by four novel large and divergent gene families and by members of a major surface protease gene family. This surface composition is distinct from the uniform variant surface glycoprotein coat on African trypanosomes providing an insight into a second mechanism used by trypanosome species that proliferate in an extracellular milieu in vertebrate hosts to avoid the adaptive immune response.
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Affiliation(s)
- Steven Kelly
- Department of Plant Sciences, University of Oxford, United Kingdom
| | - Alasdair Ivens
- Centre for Immunity, Infection and Evolution and Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, United Kingdom
| | - G Adam Mott
- Centre for Immunity, Infection and Evolution and Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, United Kingdom
| | - Ellis O'Neill
- Department of Plant Sciences, University of Oxford, United Kingdom
| | - David Emms
- Department of Plant Sciences, University of Oxford, United Kingdom
| | - Olivia Macleod
- Department of Biochemistry, University of Cambridge, United Kingdom
| | - Paul Voorheis
- School of Biochemistry and Immunology, Trinity College, Dublin, Ireland
| | - Kevin Tyler
- Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich, Norfolk, United Kingdom
| | - Matthew Clark
- Earlham Institute, Norwich Research Park, Norwich, Norfolk, United Kingdom
| | - Jacqueline Matthews
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, Midlothian, United Kingdom
| | - Keith Matthews
- Centre for Immunity, Infection and Evolution and Institute for Immunology and Infection Research, School of Biological Sciences, University of Edinburgh, United Kingdom
| | - Mark Carrington
- Department of Biochemistry, University of Cambridge, United Kingdom
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Cestari I, Anupama A, Stuart K. Inositol polyphosphate multikinase regulation of Trypanosoma brucei life stage development. Mol Biol Cell 2018. [PMID: 29514930 PMCID: PMC5921579 DOI: 10.1091/mbc.e17-08-0515] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The regulation of Trypanosoma brucei life stage development remains unclear. Inositol polyphosphate multikinase regulates the development of mammalian bloodforms to insect stages that normally develop in flies. Specific inositol phosphates, perhaps as second messengers, interact with proteins of the regulatory network that controls development. Many cellular processes change during the Trypanosoma brucei life cycle as this parasite alternates between the mammalian host and tsetse fly vector. We show that the inositol phosphate pathway helps regulate these developmental changes. Knockdown of inositol polyphosphate multikinase (IPMK), which phosphorylates Ins(1,4,5)P3 and Ins(1,3,4,5)P4, resulted in changes in bloodstream forms that are characteristic of insect stage procyclic forms. These changes include expression of the procyclic surface coat, up-regulation of RNA-binding proteins that we show to regulate stage-specific transcripts, and activation of oxidative phosphorylation with increased ATP production in bloodstream forms. These changes were accompanied by development of procyclic morphology, which also occurred by the expression of a catalytically inactive IPMK, implying that regulation of these processes entails IPMK activity. Proteins involved in signaling, protein synthesis and turnover, and metabolism were affinity-enriched with the IPMK substrate or product. Developmental changes associated with IPMK knockdown or catalytic inactivation reflected processes that are enriched with inositol phosphates, and chemical and genetic perturbation of these processes affected T. brucei development. Hence, IPMK helps regulate T. brucei development, perhaps by affecting inositol phosphate interactions with proteins of the regulatory network that controls energy metabolism and development.
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Affiliation(s)
- Igor Cestari
- Center for Infectious Disease Research, Seattle, WA 98109
| | - Atashi Anupama
- Center for Infectious Disease Research, Seattle, WA 98109
| | - Kenneth Stuart
- Center for Infectious Disease Research, Seattle, WA 98109.,Department of Global Health, University of Washington, Seattle, WA 98195
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Abstract
Many pathogens evade host immunity by periodically changing the proteins they express on their surface - a phenomenon termed antigenic variation. An extreme form of antigenic variation, based around switching the composition of a Variant Surface Glycoprotein (VSG) coat, is exhibited by the African trypanosome Trypanosoma brucei, which causes human disease. The molecular details of VSG switching in T. brucei have been extensively studied over the last three decades, revealing in increasing detail the machinery and mechanisms by which VSG expression is controlled and altered. However, several key components of the models of T. brucei antigenic variation that have emerged have been challenged through recent discoveries. These discoveries include new appreciation of the importance of gene mosaics in generating huge levels of new VSG variants, the contributions of parasite development and body compartmentation in the host to the infection dynamics and, finally, potential differences in the strategies of antigenic variation and host infection used by the crucial livestock trypanosomes T. congolense and T. vivax. This review will discuss all these observations, which raise questions regarding how secure the existing models of trypanosome antigenic variation are. In addition, we will discuss the importance of continued mathematical modelling to understand the purpose of this widespread immune survival process.
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Effect of AMPK signal pathway on pathogenesis of abdominal aortic aneurysms. Oncotarget 2017; 8:92827-92840. [PMID: 29190959 PMCID: PMC5696225 DOI: 10.18632/oncotarget.21608] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Accepted: 08/26/2017] [Indexed: 12/13/2022] Open
Abstract
Background and aims Determine the effect of AMPK activation and inhibition on the development of AAA (abdominal aortic aneurysm). Methods AAA was induced in ApoE−/− mice by Ang II (Angiotensin II)-infusion. AICAR (5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside) was used as AMPK activator and Compound C was used as AMPK inhibitor. We further investigate the effect of metformin, a widely used anti-diabetic drug which could activate AMPK signal pathway, on the pathogenesis of aneurysm. Results Phospho-AMPK level was significantly decreased in AAA tissue compared with control aortas. AICAR significantly reduced the incidence, severity and mortality of aneurysm in the Ang II-infusion model. AICAR also alleviated macrophage infiltration and neovascularity in Ang II infusion model at day 28. The expression of pro-inflammatory factors, angiogenic factors and the activity of MMPs were also alleviated by AICAR during AAA induction. On the other hand, Compound C treatment did not exert obvious protective effect. AMPK activation may inhibit the activation of nuclear factor-κB (NF-κB) and signal transducer and activator of transcription-3 (STAT-3) during AAA induction. Administration of metformin also activated AMPK signal pathway and retarded AAA progression in Ang II infusion model. Conclusions Activation of AMPK signaling pathway may inhibit the Ang II-induced AAA in mice. Metformin may be a promising approach to the treatment of AAA.
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Silvester E, McWilliam KR, Matthews KR. The Cytological Events and Molecular Control of Life Cycle Development of Trypanosoma brucei in the Mammalian Bloodstream. Pathogens 2017; 6:pathogens6030029. [PMID: 28657594 PMCID: PMC5617986 DOI: 10.3390/pathogens6030029] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 06/21/2017] [Accepted: 06/22/2017] [Indexed: 12/21/2022] Open
Abstract
African trypanosomes cause devastating disease in sub-Saharan Africa in humans and livestock. The parasite lives extracellularly within the bloodstream of mammalian hosts and is transmitted by blood-feeding tsetse flies. In the blood, trypanosomes exhibit two developmental forms: the slender form and the stumpy form. The slender form proliferates in the bloodstream, establishes the parasite numbers and avoids host immunity through antigenic variation. The stumpy form, in contrast, is non-proliferative and is adapted for transmission. Here, we overview the features of slender and stumpy form parasites in terms of their cytological and molecular characteristics and discuss how these contribute to their distinct biological functions. Thereafter, we describe the technical developments that have enabled recent discoveries that uncover how the slender to stumpy transition is enacted in molecular terms. Finally, we highlight new understanding of how control of the balance between slender and stumpy form parasites interfaces with other components of the infection dynamic of trypanosomes in their mammalian hosts. This interplay between the host environment and the parasite’s developmental biology may expose new vulnerabilities to therapeutic attack or reveal where drug control may be thwarted by the biological complexity of the parasite’s lifestyle.
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Affiliation(s)
- Eleanor Silvester
- Institute for Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, King's Buildings, University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK.
| | - Kirsty R McWilliam
- Institute for Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, King's Buildings, University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK.
| | - Keith R Matthews
- Institute for Immunology and Infection Research, Centre for Immunity, Infection and Evolution, School of Biological Sciences, King's Buildings, University of Edinburgh, Charlotte Auerbach Road, Edinburgh EH9 3FL, UK.
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42
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Abstract
Cellular metabolic activity is a highly complex, dynamic, regulated process that is influenced by numerous factors, including extracellular environmental signals, nutrient availability and the physiological and developmental status of the cell. The causative agent of sleeping sickness,
Trypanosoma brucei, is an exclusively extracellular protozoan parasite that encounters very different extracellular environments during its life cycle within the mammalian host and tsetse fly insect vector. In order to meet these challenges, there are significant alterations in the major energetic and metabolic pathways of these highly adaptable parasites. This review highlights some of these metabolic changes in this early divergent eukaryotic model organism.
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Affiliation(s)
- Terry K Smith
- Biomedical Sciences Research Complex, University of St Andrews, Fife, UK
| | - Frédéric Bringaud
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234 CNRS, Université de Bordeaux, Bordeaux, France
| | - Derek P Nolan
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Luisa M Figueiredo
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
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43
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Abstract
Cellular metabolic activity is a highly complex, dynamic, regulated process that is influenced by numerous factors, including extracellular environmental signals, nutrient availability and the physiological and developmental status of the cell. The causative agent of sleeping sickness, Trypanosoma brucei, is an exclusively extracellular protozoan parasite that encounters very different extracellular environments during its life cycle within the mammalian host and tsetse fly insect vector. In order to meet these challenges, there are significant alterations in the major energetic and metabolic pathways of these highly adaptable parasites. This review highlights some of these metabolic changes in this early divergent eukaryotic model organism.
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Affiliation(s)
- Terry K Smith
- Biomedical Sciences Research Complex, University of St Andrews, Fife, UK
| | - Frédéric Bringaud
- Laboratoire de Microbiologie Fondamentale et Pathogénicité (MFP), UMR 5234 CNRS, Université de Bordeaux, Bordeaux, France
| | - Derek P Nolan
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin, Ireland
| | - Luisa M Figueiredo
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
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