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Chueycham S, Srisomsap C, Chokchaichamnankit D, Svasti J, Hummel K, Nöbauer K, Hekmat O, Razzazi-Fazeli E, Kingtong S. Toxicity of DDT to the hooded oyster Saccostrea cucullata: Mortality, histopathology and molecular mechanisms as revealed by a proteomic approach. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 225:112729. [PMID: 34478977 DOI: 10.1016/j.ecoenv.2021.112729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/21/2021] [Accepted: 08/27/2021] [Indexed: 06/13/2023]
Abstract
Dichlorodiphenyltrichloroethane (DDT), a persistent organochlorine pesticide, has been linked to adverse biological effects in organisms. However, there is limited knowledge about its toxic effects on marine organisms and the underlying molecular mechanisms. This study investigated the toxic effects of DDT in the hooded oyster Saccostrea cucullata. The oysters were exposed to DDT at concentrations of 0, 10, 50, 100, 500, 1000 and 2000 µg/L for 96 h and the LC50 (96 h) was 891.25 µg/L. Two sublethal concentrations (10 and 100 µg/L) were used to investigate the histopathological effects and the proteome response. Histopathological results showed that DDT caused the alteration of mantle tissue. This included the induction of mucocytes in the epithelium and the inflammatory effect in the connective tissue indicated by the enlargement of blood sinus and hemocyte aggregation within the sinus. Proteomic results showed that, amongst approximately 500 protein spots that were detected across 2DE gels, 51 protein spots were differentially expressed (P < 0.01; fold change > 1.2). Of these, 29 protein spots were identified by LC-MS/MS. These included 23 up-regulated, 5 down-regulated and 1 fluctuating spots. Thus, we observed that stress response and cytoskeletal proteins are the central targets of DDT action. Furthermore, DDT alters the expression of proteins involved in energy metabolism, calcium homeostasis and other proteins of unknown function. Additionally, proteomic results clearly elucidated the molecular response of the histopathological changes which were driven by the alteration of cytoskeletal proteins. Our results improve the current knowledge of toxicity of the DDT to histology and molecular response of oyster proteome to DDT exposure. In addition, histopathological changes will be beneficial for the development of an appropriate guideline for health assessment of this species in ecotoxicological context.
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Affiliation(s)
- Supatta Chueycham
- Environmental Science Program, Faculty of Science, Burapha University, Chonburi 20131, Thailand
| | - Chantragan Srisomsap
- Laboratory of Biochemistry, Chulabhorn Research Institute, Vibhavadi-Rangsit Highway, Bangkok 10210, Thailand
| | - Daranee Chokchaichamnankit
- Laboratory of Biochemistry, Chulabhorn Research Institute, Vibhavadi-Rangsit Highway, Bangkok 10210, Thailand
| | - Jisnuson Svasti
- Laboratory of Biochemistry, Chulabhorn Research Institute, Vibhavadi-Rangsit Highway, Bangkok 10210, Thailand
| | - Karin Hummel
- VetCore Facility for Research, University of Veterinary Medicine, Veterinärplatz 1, Vienna 1210, Austria
| | - Katharina Nöbauer
- VetCore Facility for Research, University of Veterinary Medicine, Veterinärplatz 1, Vienna 1210, Austria
| | - Omid Hekmat
- VetCore Facility for Research, University of Veterinary Medicine, Veterinärplatz 1, Vienna 1210, Austria
| | - Ebrahim Razzazi-Fazeli
- VetCore Facility for Research, University of Veterinary Medicine, Veterinärplatz 1, Vienna 1210, Austria
| | - Sutin Kingtong
- Department of Biology, Faculty of Science, Burapha University, 169 Long-Haad Bangsaen Road, Chonburi 20131, Thailand.
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Li N, Li L, Wu M, Li Y, Yang J, Wu Y, Xu H, Luo D, Gao Y, Fei X, Jiang L. Integrated Bioinformatics and Validation Reveal Potential Biomarkers Associated With Progression of Primary Sjögren's Syndrome. Front Immunol 2021; 12:697157. [PMID: 34367157 PMCID: PMC8343000 DOI: 10.3389/fimmu.2021.697157] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 07/06/2021] [Indexed: 12/12/2022] Open
Abstract
Background Primary Sjögren’s syndrome (pSS) is a chronic systemic autoimmune disease of the exocrine glands characterized by specific pathological features. Previous studies have pointed out that salivary glands from pSS patients express a unique profile of cytokines, adhesion molecules, and chemokines compared to those from healthy controls. However, there is limited evidence supporting the utility of individual markers for different stages of pSS. This study aimed to explore potential biomarkers associated with pSS disease progression and analyze the associations between key genes and immune cells. Methods We combined our own RNA sequencing data with pSS datasets from the NCBI Gene Expression Omnibus (GEO) database to identify differentially expressed genes (DEGs) via bioinformatics analysis. Salivary gland biopsies were collected from 14 pSS patients, 6 non-pSS patients, and 6 controls. Histochemical staining and transmission electron micrographs (TEM) were performed to macroscopically and microscopically characterize morphological features of labial salivary glands in different disease stages. Then, we performed quantitative PCR to validate hub genes. Finally, we analyzed correlations between selected hub genes and immune cells using the CIBERSORT algorithm. Results We identified twenty-eight DEGs that were upregulated in pSS patients compared to healthy controls. These were mainly involved in immune-related pathways and infection-related pathways. According to the morphological features of minor salivary glands, severe interlobular and periductal lymphocytic infiltrates, acinar atrophy and collagen in the interstitium, nuclear shrinkage, and microscopic organelle swelling were observed with pSS disease progression. Hub genes based on above twenty-eight DEGs, including MS4A1, CD19, TCL1A, CCL19, CXCL9, CD3G, and CD3D, were selected as potential biomarkers and verified by RT-PCR. Expression of these genes was correlated with T follicular helper cells, memory B cells and M1 macrophages. Conclusion Using transcriptome sequencing and bioinformatics analysis combined with our clinical data, we identified seven key genes that have potential value for evaluating pSS severity.
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Affiliation(s)
- Ning Li
- Department of Stomatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Lei Li
- Department of Pathology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mengyao Wu
- Department of Stomatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Yusi Li
- Department of Stomatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Jie Yang
- Core Facility of Basic Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yicheng Wu
- Core Facility of Basic Medical Sciences, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Haimin Xu
- Department of Pathology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Danyang Luo
- Department of Stomatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Yiming Gao
- Department of Stomatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaochun Fei
- Department of Pathology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Liting Jiang
- Department of Stomatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, Shanghai, China
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Dean S. Basic Biology of Trypanosoma brucei with Reference to the Development of Chemotherapies. Curr Pharm Des 2021; 27:1650-1670. [PMID: 33463458 DOI: 10.2174/1381612827666210119105008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/01/2020] [Accepted: 12/08/2020] [Indexed: 11/22/2022]
Abstract
Trypanosoma brucei are protozoan parasites that cause the lethal human disease African sleeping sickness and the economically devastating disease of cattle, Nagana. African sleeping sickness, also known as Human African Trypanosomiasis (HAT), threatens 65 million people and animal trypanosomiasis makes large areas of farmland unusable. There is no vaccine and licensed therapies against the most severe, late-stage disease are toxic, impractical and ineffective. Trypanosomes are transmitted by tsetse flies, and HAT is therefore predominantly confined to the tsetse fly belt in sub-Saharan Africa. They are exclusively extracellular and they differentiate between at least seven developmental forms that are highly adapted to host and vector niches. In the mammalian (human) host they inhabit the blood, cerebrospinal fluid (late-stage disease), skin, and adipose fat. In the tsetse fly vector they travel from the tsetse midgut to the salivary glands via the ectoperitrophic space and proventriculus. Trypanosomes are evolutionarily divergent compared with most branches of eukaryotic life. Perhaps most famous for their extraordinary mechanisms of monoallelic gene expression and antigenic variation, they have also been investigated because much of their biology is either highly unconventional or extreme. Moreover, in addition to their importance as pathogens, many researchers have been attracted to the field because trypanosomes have some of the most advanced molecular genetic tools and database resources of any model system. The following will cover just some aspects of trypanosome biology and how its divergent biochemistry has been leveraged to develop drugs to treat African sleeping sickness. This is by no means intended to be a comprehensive survey of trypanosome features. Rather, I hope to present trypanosomes as one of the most fascinating and tractable systems to do discovery biology.
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Affiliation(s)
- Samuel Dean
- Warwick Medical School, University of Warwick, Coventry, CV4 7AL, United Kingdom
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4
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Direct induction of microtubule branching by microtubule nucleation factor SSNA1. Nat Cell Biol 2018; 20:1172-1180. [PMID: 30250060 PMCID: PMC6330057 DOI: 10.1038/s41556-018-0199-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2017] [Accepted: 08/20/2018] [Indexed: 12/22/2022]
Abstract
Microtubules are central elements of the eukaryotic cytoskeleton that often function as part of branched networks. Current models for branching include nucleation of new microtubules from severed microtubule seeds or from gamma-tubulin recruited to the side of a pre-existing microtubule. Here, we found that microtubules can be directly remodeled into branched structures by the microtubule-remodeling factor SSNA1 (or also NA14/DIP13). The branching activity of SSNA1 relies on its ability to self-assemble into fibrils in a head-to-tail fashion. SSNA1 fibrils guide protofilaments of a microtubule to split apart to form daughter microtubules. We further found that SSNA1 localizes at axon branching sites and has a key role in neuronal development. SSNA1 mutants that abolish microtubule branching in vitro also fail to promote axon development and branching when overexpressed in neurons. We have therefore, discovered a mechanism for microtubule-branching and implicated its role in neuronal development.
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Proximity Interactions among Basal Body Components in Trypanosoma brucei Identify Novel Regulators of Basal Body Biogenesis and Inheritance. mBio 2017; 8:mBio.02120-16. [PMID: 28049148 PMCID: PMC5210500 DOI: 10.1128/mbio.02120-16] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The basal body shares similar architecture with centrioles in animals and is involved in nucleating flagellar axonemal microtubules in flagellated eukaryotes. The early-branching Trypanosoma brucei possesses a motile flagellum nucleated from the basal body that consists of a mature basal body and an adjacent pro-basal body. Little is known about the basal body proteome and its roles in basal body biogenesis and flagellar axoneme assembly in T. brucei. Here, we report the identification of 14 conserved centriole/basal body protein homologs and 25 trypanosome-specific basal body proteins. These proteins localize to distinct subdomains of the basal body, and several of them form a ring-like structure surrounding the basal body barrel. Functional characterization of representative basal body proteins revealed distinct roles in basal body duplication/separation and flagellar axoneme assembly. Overall, this work identified novel proteins required for basal body duplication and separation and uncovered new functions of conserved basal body proteins in basal body duplication and separation, highlighting an unusual mechanism of basal body biogenesis and inheritance in this early divergent eukaryote. The basal body in the early-branching protozoan Trypanosoma brucei nucleates flagellum assembly and also regulates organelle segregation, cell morphogenesis, and cell division. However, the molecular composition and the assembly process of the basal body remain poorly understood. Here, we identify 14 conserved basal body proteins and 25 trypanosome-specific basal body proteins via bioinformatics, localization-based screening, and proximity-dependent biotin identification. We further localized these proteins to distinct subdomains of the basal body by using fluorescence microscopy and superresolution microscopy, discovered novel regulators of basal body duplication and separation, and uncovered new functions of conserved basal body proteins in basal body duplication and separation. This work lays the foundation for dissecting the mechanisms underlying basal body biogenesis and inheritance in T. brucei.
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6
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An evolutionarily conserved SSNA1/DIP13 homologue is a component of both basal and apical complexes of Toxoplasma gondii. Sci Rep 2016; 6:27809. [PMID: 27324377 PMCID: PMC4914967 DOI: 10.1038/srep27809] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/25/2016] [Indexed: 12/19/2022] Open
Abstract
Microtubule-based cytoskeletal structures have fundamental roles in several essential eukaryotic processes, including transport of intracellular constituents as well as ciliary and flagellar mobility. Temporal and spatial organisation of microtubules is determined by microtubule organising centers and a number of appendages and accessory proteins. Members of the SSNA1/DIP13 family are coiled coil proteins that are known to localise to microtubular structures like centrosomes and flagella, but are otherwise poorly characterised. We have identified a homologue of SSNA1/DIP13 in the parasitic protist Toxoplasma gondii and found it localises to parasite-specific cytoskeletal structures: the conoid in the apical complex of mature and dividing cells, and the basal complex in elongating daughter cells during cell division. This protein is dispensable for parasite growth in vitro. However, quite remarkably, this coiled coil protein is able to self-associate into higher order structures both in vitro and in vivo, and its overexpression is impairing parasite division.
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Sunter JD, Benz C, Andre J, Whipple S, McKean PG, Gull K, Ginger ML, Lukeš J. Modulation of flagellum attachment zone protein FLAM3 and regulation of the cell shape in Trypanosoma brucei life cycle transitions. J Cell Sci 2015; 128:3117-30. [PMID: 26148511 PMCID: PMC4541047 DOI: 10.1242/jcs.171645] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 06/29/2015] [Indexed: 11/25/2022] Open
Abstract
The cell shape of Trypanosoma brucei is influenced by flagellum-to-cell-body attachment through a specialised structure – the flagellum attachment zone (FAZ). T. brucei exhibits numerous morphological forms during its life cycle and, at each stage, the FAZ length varies. We have analysed FLAM3, a large protein that localises to the FAZ region within the old and new flagellum. Ablation of FLAM3 expression causes a reduction in FAZ length; however, this has remarkably different consequences in the tsetse procyclic form versus the mammalian bloodstream form. In procyclic form cells FLAM3 RNAi results in the transition to an epimastigote-like shape, whereas in bloodstream form cells a severe cytokinesis defect associated with flagellum detachment is observed. Moreover, we demonstrate that the amount of FLAM3 and its localisation is dependent on ClpGM6 expression and vice versa. This evidence demonstrates that FAZ is a key regulator of trypanosome shape, with experimental perturbations being life cycle form dependent. An evolutionary cell biology explanation suggests that these differences are a reflection of the division process, the cytoskeleton and intrinsic structural plasticity of particular life cycle forms. Summary:Trypanosoma brucei FLAM3 is a flagellar FAZ protein. Its depletion leads to a reduction in FAZ length, which has different consequences depending on the life cycle stage of the parasite.
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Affiliation(s)
- Jack D Sunter
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Corinna Benz
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis) 37005, Czech Republic
| | - Jane Andre
- Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK
| | - Sarah Whipple
- Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK
| | - Paul G McKean
- Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK
| | - Keith Gull
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
| | - Michael L Ginger
- Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster LA1 4YQ, UK
| | - Julius Lukeš
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis) 37005, Czech Republic Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis) 37005, Czech Republic Canadian Institute for Advanced Research, Toronto, Ontario, Canada M5G 1Z8
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8
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Sudarshi D, Lawrence S, Pickrell WO, Eligar V, Walters R, Quaderi S, Walker A, Capewell P, Clucas C, Vincent A, Checchi F, MacLeod A, Brown M. Human African trypanosomiasis presenting at least 29 years after infection--what can this teach us about the pathogenesis and control of this neglected tropical disease? PLoS Negl Trop Dis 2014; 8:e3349. [PMID: 25522322 PMCID: PMC4270486 DOI: 10.1371/journal.pntd.0003349] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022] Open
Affiliation(s)
- Darshan Sudarshi
- Hospital for Tropical Diseases, University College London Hospital, London, United Kingdom
| | - Sarah Lawrence
- Hospital for Tropical Diseases, University College London Hospital, London, United Kingdom
| | | | - Vinay Eligar
- Princess of Wales Hospital, Bridgend Hospital, Wales, United Kingdom
| | - Richard Walters
- Morriston Hospital, Swansea, Wales, United Kingdom
- Princess of Wales Hospital, Bridgend Hospital, Wales, United Kingdom
| | - Shumonta Quaderi
- Hospital for Tropical Diseases, University College London Hospital, London, United Kingdom
| | - Alice Walker
- Hospital for Tropical Diseases, University College London Hospital, London, United Kingdom
| | - Paul Capewell
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Caroline Clucas
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Angela Vincent
- Nuffield Dept of Clinical Neurology, University of Oxford, Oxford, United Kingdom
| | - Francesco Checchi
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Annette MacLeod
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Michael Brown
- Hospital for Tropical Diseases, University College London Hospital, London, United Kingdom
- Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
- * E-mail:
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Goyal U, Renvoisé B, Chang J, Blackstone C. Spastin-interacting protein NA14/SSNA1 functions in cytokinesis and axon development. PLoS One 2014; 9:e112428. [PMID: 25390646 PMCID: PMC4229207 DOI: 10.1371/journal.pone.0112428] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 10/15/2014] [Indexed: 01/11/2023] Open
Abstract
Hereditary spastic paraplegias (HSPs) are a genetically diverse group of inherited neurological disorders (SPG1-72) with the cardinal feature of prominent lower-extremity spasticity due to a length-dependent axonopathy of corticospinal motor neurons. The most frequent form of autosomal dominant HSP results from mutations of the SPG4 gene product spastin. This is an ATPase associated with diverse cellular activities (AAA) protein that binds to and severs microtubules. While spastin participates in crucial cellular processes such as cytokinesis, endosomal tubulation, and axon development, its role in HSP pathogenesis remains unclear. Spastin interacts in cells with the NA14 protein, a major target for auto-antibodies in Sjögren's syndrome (nuclear autoantigen 1; SSNA1). Our analysis of endogenous spastin and NA14 proteins in HeLa cells and rat cortical neurons in primary culture revealed a clear distribution of both proteins to centrosomes, with NA14 localizing specifically to centrioles. Stable NA14 knockdown in cell lines dramatically affected cell division, in particular cytokinesis. Furthermore, overexpression of NA14 in neurons significantly increased axon outgrowth and branching, while also enhancing neuronal differentiation. We postulate that NA14 may act as an adaptor protein regulating spastin localization to centrosomes, temporally and spatially regulating the microtubule-severing activity of spastin that is particularly critical during the cell cycle and neuronal development.
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Affiliation(s)
- Uma Goyal
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Benoît Renvoisé
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jaerak Chang
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Craig Blackstone
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States of America
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MacLean L, Myburgh E, Rodgers J, Price HP. Imaging African trypanosomes. Parasite Immunol 2014; 35:283-94. [PMID: 23790101 PMCID: PMC3992894 DOI: 10.1111/pim.12046] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 06/18/2013] [Indexed: 12/18/2022]
Abstract
Trypanosoma brucei are extracellular kinetoplastid parasites transmitted by the blood-sucking tsetse fly. They are responsible for the fatal disease human African trypanosomiasis (HAT), also known as sleeping sickness. In late-stage infection, trypanosomes cross the blood–brain barrier (BBB) and invade the central nervous system (CNS) invariably leading to coma and death if untreated. There is no available vaccine and current late-stage HAT chemotherapy consists of either melarsoprol, which is highly toxic causing up to 8% of deaths, or nifurtimox–eflornithine combination therapy (NECT), which is costly and difficult to administer. There is therefore an urgent need to identify new late-stage HAT drug candidates. Here, we review how current imaging tools, ranging from fluorescent confocal microscopy of live immobilized cells in culture to whole-animal imaging, are providing insight into T. brucei biology, parasite-host interplay, trypanosome CNS invasion and disease progression. We also consider how imaging tools can be used for candidate drug screening purposes that could lead to new chemotherapies.
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Affiliation(s)
- L MacLean
- Centre for Immunology and Infection, Department of Biology/Hull York Medical School, University of York, Heslington, York, UK.
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Price HP, Hodgkinson MR, Wright MH, Tate EW, Smith BA, Carrington M, Stark M, Smith DF. A role for the vesicle-associated tubulin binding protein ARL6 (BBS3) in flagellum extension in Trypanosoma brucei. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1823:1178-91. [PMID: 22609302 PMCID: PMC3793860 DOI: 10.1016/j.bbamcr.2012.05.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Revised: 04/23/2012] [Accepted: 05/05/2012] [Indexed: 11/17/2022]
Abstract
The small GTPase Arl6 is implicated in the ciliopathic human genetic disorder Bardet-Biedl syndrome, acting at primary cilia in recruitment of the octomeric BBSome complex, which is required for specific trafficking events to and from the cilium in eukaryotes. Here we describe functional characterisation of Arl6 in the flagellated model eukaryote Trypanosoma brucei, which requires motility for viability. Unlike human Arl6 which has a ciliary localisation, TbARL6 is associated with electron-dense vesicles throughout the cell body following co-translational modification by N-myristoylation. Similar to the related protein ARL-3A in T. brucei, modulation of expression of ARL6 by RNA interference does not prevent motility but causes a significant reduction in flagellum length. Tubulin is identified as an ARL6 interacting partner, suggesting that ARL6 may act as an anchor between vesicles and cytoplasmic microtubules. We provide evidence that the interaction between ARL6 and the BBSome is conserved in unicellular eukaryotes. Overexpression of BBS1 leads to translocation of endogenous ARL6 to the site of exogenous BBS1 at the flagellar pocket. Furthermore, a combination of BBS1 overexpression and ARL6 RNAi has a synergistic inhibitory effect on cell growth. Our findings indicate that ARL6 in trypanosomes contributes to flagellum biogenesis, most likely through an interaction with the BBSome.
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Affiliation(s)
- Helen P Price
- Centre for Immunology and Infection, Department of Biology, University of York, Heslington, York YO10 5YW, UK.
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