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Al-Jawabreh R, Anderson R, Atkinson LE, Bickford-Smith J, Bradbury RS, Breloer M, Bryant AS, Buonfrate D, Cadd LC, Crooks B, Deiana M, Grant W, Hallem E, Hedtke SM, Hunt V, Khieu V, Kikuchi T, Kounosu A, Lastik D, van Lieshout L, Liu Y, McSorley HJ, McVeigh P, Mousley A, Murcott B, Nevin WD, Nosková E, Pomari E, Reynolds K, Ross K, Streit A, Suleiman M, Tiberti N, Viney M. Strongyloides questions-a research agenda for the future. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230004. [PMID: 38008122 PMCID: PMC10676812 DOI: 10.1098/rstb.2023.0004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 09/29/2023] [Indexed: 11/28/2023] Open
Abstract
The Strongyloides genus of parasitic nematodes have a fascinating life cycle and biology, but are also important pathogens of people and a World Health Organization-defined neglected tropical disease. Here, a community of Strongyloides researchers have posed thirteen major questions about Strongyloides biology and infection that sets a Strongyloides research agenda for the future. This article is part of the Theo Murphy meeting issue 'Strongyloides: omics to worm-free populations'.
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Affiliation(s)
| | - Roy Anderson
- Department of Infectious Disease Epidemiology, Imperial College London, London SW7 2BX, UK
| | - Louise E. Atkinson
- School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, UK
| | | | | | - Minka Breloer
- Bernhard Nocht Institute for Tropical Medicine, Hamburg 20359, Germany
| | - Astra S. Bryant
- Department of Physiology and Biophysics, University of Washington, Seattle 98195, USA
| | - Dora Buonfrate
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona 37024, Italy
| | - Luke C. Cadd
- School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, UK
| | - Bethany Crooks
- School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, UK
| | - Michela Deiana
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona 37024, Italy
| | - Warwick Grant
- Department of Environment and Genetics, La Trobe University, Bundoora, Victoria 3083, Australia
| | - Elissa Hallem
- Department of Microbiology, Immunology, and Molecular Genetics, Molecular Biology Institute, University of California Los Angeles, Los Angeles 90095, USA
| | - Shannon M. Hedtke
- Department of Environment and Genetics, La Trobe University, Bundoora, Victoria 3083, Australia
| | - Vicky Hunt
- Life Sciences Department, University of Bath, Bath BA2 7AY, UK
| | - Virak Khieu
- National Centre for Parasitology, Entomology and Malaria Control, Cambodia Ministry of Health, Cambodia
| | - Taisei Kikuchi
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8652, Japan
| | - Asuka Kounosu
- Division of Parasitology, Department of Infectious Diseases, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Dominika Lastik
- Life Sciences Department, University of Bath, Bath BA2 7AY, UK
| | - Lisette van Lieshout
- Leiden University Center for Infectious Diseases, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
| | - Yuchen Liu
- Department of Evolution, Ecology & Behaviour, University of Liverpool, Liverpool L69 7ZB, UK
| | - Henry J. McSorley
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Paul McVeigh
- School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, UK
| | - Angela Mousley
- School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, UK
| | - Ben Murcott
- Life Sciences Department, University of Bath, Bath BA2 7AY, UK
| | - William David Nevin
- Department of Infectious Diseases, Imperial College London, London SW7 2BX, UK
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK
| | - Eva Nosková
- Department of Botany and Zoology, Faculty of Science, Masaryk University, 611 37 Brno, Czech Republic
- Institute of Vertebrate Biology, Czech Academy of Sciences, 603 65 Brno, Czech Republic
| | - Elena Pomari
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona 37024, Italy
| | - Kieran Reynolds
- Life Sciences Department, University of Bath, Bath BA2 7AY, UK
| | - Kirstin Ross
- Environmental Health, College of Science and Engineering, Flinders University, South Australia 5042, Australia
| | - Adrian Streit
- Department of Integrative Evolutionary Biology, Max Planck Institute for Biology Tübingen, Tübingen 72076, Germany
| | - Mona Suleiman
- Life Sciences Department, University of Bath, Bath BA2 7AY, UK
| | - Natalia Tiberti
- Department of Infectious Tropical Diseases and Microbiology, IRCCS Sacro Cuore Don Calabria Hospital, Verona 37024, Italy
| | - Mark Viney
- Department of Evolution, Ecology & Behaviour, University of Liverpool, Liverpool L69 7ZB, UK
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Irvine A, Huws SA, Atkinson LE, Mousley A. Exploring the antimicrobial peptidome of nematodes through phylum-spanning in silico analyses highlights novel opportunities for pathogen control. PLoS Negl Trop Dis 2023; 17:e0011618. [PMID: 37672536 PMCID: PMC10506718 DOI: 10.1371/journal.pntd.0011618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 09/18/2023] [Accepted: 08/23/2023] [Indexed: 09/08/2023] Open
Abstract
Antimicrobial Peptides (AMPs) are key constituents of the invertebrate innate immune system and provide critical protection against microbial threat. Nematodes display diverse life strategies where they are exposed to heterogenous, microbe rich, environments highlighting their need for an innate immune system. Within the Ecdysozoa, arthropod AMPs have been well characterised, however nematode-derived AMP knowledge is limited. In this study the distribution and abundance of putative AMP-encoding genes was examined in 134 nematode genomes providing the most comprehensive profile of AMP candidates within phylum Nematoda. Through genome and transcriptome analyses we reveal that phylum Nematoda is a rich source of putative AMP diversity and demonstrate (i) putative AMP group profiles that are influenced by nematode lifestyle where free-living nematodes appear to display enriched putative AMP profiles relative to parasitic species; (ii) major differences in the putative AMP profiles between nematode clades where Clade 9/V and 10/IV species possess expanded putative AMP repertoires; (iii) AMP groups with highly restricted profiles (e.g. Cecropins and Diapausins) and others [e.g. Nemapores and Glycine Rich Secreted Peptides (GRSPs)] which are more widely distributed; (iv) complexity in the distribution and abundance of CSαβ subgroup members; and (v) that putative AMPs are expressed in host-facing life stages and biofluids of key nematode parasites. These data indicate that phylum Nematoda displays diversity in putative AMPs and underscores the need for functional characterisation to reveal their role and importance to nematode biology and host-nematode-microbiome interactions.
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Affiliation(s)
- Allister Irvine
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Sharon A. Huws
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Louise E. Atkinson
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Angela Mousley
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
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3
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Irvine A, McKenzie D, McCoy CJ, Graham RLJ, Graham C, Huws SA, Atkinson LE, Mousley A. Novel integrated computational AMP discovery approaches highlight diversity in the helminth AMP repertoire. PLoS Pathog 2023; 19:e1011508. [PMID: 37523405 PMCID: PMC10414684 DOI: 10.1371/journal.ppat.1011508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 08/10/2023] [Accepted: 06/23/2023] [Indexed: 08/02/2023] Open
Abstract
Antimicrobial Peptides (AMPs) are immune effectors that are key components of the invertebrate innate immune system providing protection against pathogenic microbes. Parasitic helminths (phylum Nematoda and phylum Platyhelminthes) share complex interactions with their hosts and closely associated microbiota that are likely regulated by a diverse portfolio of antimicrobial immune effectors including AMPs. Knowledge of helminth AMPs has largely been derived from nematodes, whereas the flatworm AMP repertoire has not been described. This study highlights limitations in the homology-based approaches, used to identify putative nematode AMPs, for the characterisation of flatworm AMPs, and reveals that innovative algorithmic AMP prediction approaches provide an alternative strategy for novel helminth AMP discovery. The data presented here: (i) reveal that flatworms do not encode traditional lophotrochozoan AMP groups (Big Defensin, CSαβ peptides and Myticalin); (ii) describe a unique integrated computational pipeline for the discovery of novel helminth AMPs; (iii) reveal >16,000 putative AMP-like peptides across 127 helminth species; (iv) highlight that cysteine-rich peptides dominate helminth AMP-like peptide profiles; (v) uncover eight novel helminth AMP-like peptides with diverse antibacterial activities, and (vi) demonstrate the detection of AMP-like peptides from Ascaris suum biofluid. These data represent a significant advance in our understanding of the putative helminth AMP repertoire and underscore a potential untapped source of antimicrobial diversity which may provide opportunities for the discovery of novel antimicrobials. Further, unravelling the role of endogenous worm-derived antimicrobials and their potential to influence host-worm-microbiome interactions may be exploited for the development of unique helminth control approaches.
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Affiliation(s)
- Allister Irvine
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Darrin McKenzie
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Ciaran J. McCoy
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Robert L. J. Graham
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Ciaren Graham
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Sharon A. Huws
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Louise E. Atkinson
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Angela Mousley
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
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Cadd LC, Crooks B, Marks NJ, Maule AG, Mousley A, Atkinson LE. The Strongyloides bioassay toolbox: A unique opportunity to accelerate functional biology for nematode parasites. Mol Biochem Parasitol 2022; 252:111526. [PMID: 36240960 DOI: 10.1016/j.molbiopara.2022.111526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/04/2022] [Accepted: 10/10/2022] [Indexed: 12/31/2022]
Abstract
Caenorhabditis elegans is a uniquely powerful tool to aid understanding of fundamental nematode biology. While C. elegans boasts an unrivalled array of functional genomics tools and phenotype bioassays the inherent differences between free-living and parasitic nematodes underscores the need to develop these approaches in tractable parasite models. Advances in functional genomics approaches, including RNA interference and CRISPR/Cas9 gene editing, in the parasitic nematodes Strongyloides ratti and Strongyloides stercoralis provide a unique and timely opportunity to probe basic parasite biology and reveal novel anthelmintic targets in species that are both experimentally and therapeutically relevant pathogens. While Strongyloides functional genomics tools have progressed rapidly, the complementary range of bioassays required to elucidate phenotypic outcomes post-functional genomics remain more limited in scope. To adequately support the exploitation of functional genomic pipelines for studies of gene function in Strongyloides a comprehensive set of species- and parasite-specific quantitative bioassays are required to assess nematode behaviours post-genetic manipulation. Here we review the scope of the current Strongyloides bioassay toolbox, how established Strongyloides bioassays have advanced knowledge of parasite biology, opportunities for Strongyloides bioassay development and, the need for investment in tractable model parasite platforms such as Strongyloides to drive the discovery of novel targets for parasite control.
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Affiliation(s)
- Luke C Cadd
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, UK
| | - Bethany Crooks
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, UK
| | - Nikki J Marks
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, UK
| | - Aaron G Maule
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, UK
| | - Angela Mousley
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, UK
| | - Louise E Atkinson
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, UK.
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Crooks BA, Mckenzie D, Cadd LC, McCoy CJ, McVeigh P, Marks NJ, Maule AG, Mousley A, Atkinson LE. Pan-phylum In Silico Analyses of Nematode Endocannabinoid Signalling Systems Highlight Novel Opportunities for Parasite Drug Target Discovery. Front Endocrinol (Lausanne) 2022; 13:892758. [PMID: 35846343 PMCID: PMC9283691 DOI: 10.3389/fendo.2022.892758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 04/20/2022] [Indexed: 11/13/2022] Open
Abstract
The endocannabinoid signalling (ECS) system is a complex lipid signalling pathway that modulates diverse physiological processes in both vertebrate and invertebrate systems. In nematodes, knowledge of endocannabinoid (EC) biology is derived primarily from the free-living model species Caenorhabditis elegans, where ECS has been linked to key aspects of nematode biology. The conservation and complexity of nematode ECS beyond C. elegans is largely uncharacterised, undermining the understanding of ECS biology in nematodes including species with key importance to human, veterinary and plant health. In this study we exploited publicly available omics datasets, in silico bioinformatics and phylogenetic analyses to examine the presence, conservation and life stage expression profiles of EC-effectors across phylum Nematoda. Our data demonstrate that: (i) ECS is broadly conserved across phylum Nematoda, including in therapeutically and agriculturally relevant species; (ii) EC-effectors appear to display clade and lifestyle-specific conservation patterns; (iii) filarial species possess a reduced EC-effector complement; (iv) there are key differences between nematode and vertebrate EC-effectors; (v) life stage-, tissue- and sex-specific EC-effector expression profiles suggest a role for ECS in therapeutically relevant parasitic nematodes. To our knowledge, this study represents the most comprehensive characterisation of ECS pathways in phylum Nematoda and inform our understanding of nematode ECS complexity. Fundamental knowledge of nematode ECS systems will seed follow-on functional studies in key nematode parasites to underpin novel drug target discovery efforts.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Louise E. Atkinson
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
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6
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McKay FM, McCoy CJ, Crooks B, Marks NJ, Maule AG, Atkinson LE, Mousley A. In silico analyses of neuropeptide-like protein (NLP) profiles in parasitic nematodes. Int J Parasitol 2022; 52:77-85. [PMID: 34450132 PMCID: PMC8764417 DOI: 10.1016/j.ijpara.2021.07.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/01/2021] [Accepted: 07/05/2021] [Indexed: 01/06/2023]
Abstract
Nematode parasite infections cause disease in humans and animals and threaten global food security by reducing productivity in livestock and crop farming. The escalation of anthelmintic resistance in economically important nematode parasites underscores the need for the identification of novel drug targets in these worms. Nematode neuropeptide signalling is an attractive system for chemotherapeutic exploitation, with neuropeptide G-protein coupled receptors (NP-GPCRs) representing the lead targets. In order to successfully validate NP-GPCRs for parasite control it is necessary to characterise their function and importance to nematode biology. This can be aided through identification of receptor activating ligand(s) via deorphanisation. Such efforts require the identification of all neuropeptide ligands within parasites. Here we mined the genomes of nine therapeutically relevant pathogenic nematodes to characterise the neuropeptide-like protein complements and demonstrate that: (i) parasitic nematodes possess a reduced complement of neuropeptide-like protein-encoding genes relative to Caenorhabditis elegans; (ii) parasite neuropeptide-like protein profiles are broadly conserved between nematode clades; (iii) five Ce-nlps are completely conserved across the nematode species examined; (iv) the extent and position of neuropeptide-like protein-motif conservation is variable; (v) novel RPamide-encoding genes are present in parasitic nematodes; (vi) novel Allatostatin-C-like peptide encoding genes are present in both C. elegans and parasitic nematodes; (vii) novel neuropeptide-like protein families are absent in C. elegans; and (viii) highly conserved nematode neuropeptide-like proteins are bioactive. These data highlight the complexity of nematode neuropeptide-like proteins and reveal the need for nomenclature revision in this diverse neuropeptide family. The identification of neuropeptide-like protein ligands, and characterisation of those with functional relevance, advance our understanding of neuropeptide signalling to support exploitation of the neuropeptidergic system as an anthelmintic target.
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Affiliation(s)
- Fiona M McKay
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, United Kingdom
| | - Ciaran J McCoy
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, United Kingdom
| | - Bethany Crooks
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, United Kingdom
| | - Nikki J Marks
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, United Kingdom
| | - Aaron G Maule
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, United Kingdom
| | - Louise E Atkinson
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, United Kingdom
| | - Angela Mousley
- Microbes & Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, 19 Chlorine Gardens, Belfast BT9 5DL, United Kingdom.
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Dagenais M, Gerlach JQ, Wendt GR, Collins JJ, Atkinson LE, Mousley A, Geary TG, Long T. Analysis of Schistosoma mansoni Extracellular Vesicles Surface Glycans Reveals Potential Immune Evasion Mechanism and New Insights on Their Origins of Biogenesis. Pathogens 2021; 10:1401. [PMID: 34832557 PMCID: PMC8617790 DOI: 10.3390/pathogens10111401] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 12/26/2022] Open
Abstract
Parasitic helminths are master manipulators of host immunity. Their strategy is complex and involves the release of excreted/secreted products, including extracellular vesicles (EVs). The protein and miRNA contents of EVs have been characterised for many parasitic helminths but, despite reports suggesting the importance of EV surface carbohydrate structures (glycans) in the interactions with target cells and thus subsequent effector functions, little is known about parasite EV glycomics. Using lectin microarrays, we identified several lectins that exhibit strong adhesion to Schistosoma mansoni EVs, suggesting the presence of multiple glycan structures on these vesicles. Interestingly, SNA-I, a lectin that recognises structures with terminal sialic acid, displayed strong affinity for S. mansoni EVs, which was completely abolished by neuraminidase treatment, suggesting sialylation in the EV sample. This finding is of interest, as sialic acids play important roles in the context of infection by aiding immune evasion, affecting target recognition, cell entry, etc., but are not thought to be synthesised by helminths. These data were validated by quantitative analysis of free sialic acid released from EVs following treatment with neuraminidase. Lectin histochemistry and fluorescence in situ hybridisation analyses on whole adult worms suggest the involvement of sub-tegumental cell bodies, as well as the digestive and excretory systems, in the release of EVs. These results support previous reports of EV biogenesis diversity in trematodes and potentially highlight new means of immune modulation and evasion employed by schistosomes.
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Affiliation(s)
- Maude Dagenais
- Institute of Parasitology, McGill University, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada; (T.G.G.); (T.L.)
| | - Jared Q. Gerlach
- Glycoscience Group, Advanced Glycoscience Research Cluster, National Centre for Biomedical Engineering Science, National University of Ireland Galway, H91 TK33 Galway, Ireland;
| | - George R. Wendt
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (G.R.W.); (J.J.C.III)
| | - James J. Collins
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; (G.R.W.); (J.J.C.III)
| | - Louise E. Atkinson
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University-Belfast, Belfast BT9 5DL, UK; (L.E.A.); (A.M.)
| | - Angela Mousley
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University-Belfast, Belfast BT9 5DL, UK; (L.E.A.); (A.M.)
| | - Timothy G. Geary
- Institute of Parasitology, McGill University, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada; (T.G.G.); (T.L.)
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University-Belfast, Belfast BT9 5DL, UK; (L.E.A.); (A.M.)
| | - Thavy Long
- Institute of Parasitology, McGill University, Ste-Anne-de-Bellevue, QC H9X 3V9, Canada; (T.G.G.); (T.L.)
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Atkinson LE, Liu Y, McKay F, Vandewyer E, Viau C, Irvine A, Rosa BA, Li Z, Liang Q, Marks NJ, Maule AG, Mitreva M, Beets I, Li L, Mousley A. Ascaris suum Informs Extrasynaptic Volume Transmission in Nematodes. ACS Chem Neurosci 2021; 12:3176-3188. [PMID: 34347433 DOI: 10.1021/acschemneuro.1c00281] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Neural circuit synaptic connectivities (the connectome) provide the anatomical foundation for our understanding of nematode nervous system function. However, other nonsynaptic routes of communication are known in invertebrates including extrasynaptic volume transmission (EVT), which enables short- and/or long-range communication in the absence of synaptic connections. Although EVT has been highlighted as a facet of Caenorhabditis elegans neurosignaling, no experimental evidence identifies body cavity fluid (pseudocoelomic fluid; PCF) as a vehicle for either neuropeptide or biogenic amine transmission. In the parasitic nematode Ascaris suum, FMRFamide-like peptides encoded on flp-18 potently stimulate female reproductive organs but are expressed in cells that are anatomically distant from the reproductive organ, with no known synaptic connections to this tissue. Here we investigate nonsynaptic neuropeptide signaling in nematodes mediated by the body cavity fluid. Our data show that (i) A. suum PCF (As-PCF) contains a catalog of neuropeptides including FMRFamide-like peptides and neuropeptide-like proteins, (ii) the A. suum FMRFamide-like peptide As-FLP-18A dominates the As-PCF peptidome, (iii) As-PCF potently modulates nematode reproductive muscle function ex vivo, mirroring the effects of synthetic FLP-18 peptides, (iv) As-PCF activates the C. elegans FLP-18 receptors NPR-4 and -5, (v) As-PCF alters C. elegans behavior, and (vi) FLP-18 and FLP-18 receptors display pan-phylum distribution in nematodes. This study provides the first direct experimental evidence to support an extrasynaptic volume route for neuropeptide transmission in nematodes. These data indicate nonsynaptic signaling within the nematode functional connectome and are particularly pertinent to receptor deorphanization approaches underpinning drug discovery programs for nematode pathogens.
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Affiliation(s)
- Louise E Atkinson
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, U.K
| | - Yang Liu
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Fiona McKay
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, U.K
| | - Elke Vandewyer
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
| | - Charles Viau
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, U.K
| | - Allister Irvine
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, U.K
| | - Bruce A Rosa
- McDonnell Genome Institute, and Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63108, United States
| | - Zihui Li
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Qingxiao Liang
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, U.K
| | - Nikki J Marks
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, U.K
| | - Aaron G Maule
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, U.K
| | - Makedonka Mitreva
- McDonnell Genome Institute, and Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63108, United States
| | - Isabel Beets
- Department of Biology, KU Leuven, Naamsestraat 59, 3000 Leuven, Belgium
| | - Lingjun Li
- School of Pharmacy and Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53705, United States
| | - Angela Mousley
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 5DL, U.K
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Atkinson LE, McCoy CJ, Crooks BA, McKay FM, McVeigh P, McKenzie D, Irvine A, Harrington J, Rosa BA, Mitreva M, Marks NJ, Maule AG, Mousley A. Phylum-Spanning Neuropeptide GPCR Identification and Prioritization: Shaping Drug Target Discovery Pipelines for Nematode Parasite Control. Front Endocrinol (Lausanne) 2021; 12:718363. [PMID: 34659113 PMCID: PMC8515059 DOI: 10.3389/fendo.2021.718363] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/20/2021] [Indexed: 11/24/2022] Open
Abstract
Nematode parasites undermine human health and global food security. The frontline anthelmintic portfolio used to treat parasitic nematodes is threatened by the escalation of anthelmintic resistance, resulting in a demand for new drug targets for parasite control. Nematode neuropeptide signalling pathways represent an attractive source of novel drug targets which currently remain unexploited. The complexity of the nematode neuropeptidergic system challenges the discovery of new targets for parasite control, however recent advances in parasite 'omics' offers an opportunity for the in silico identification and prioritization of targets to seed anthelmintic discovery pipelines. In this study we employed Hidden Markov Model-based searches to identify ~1059 Caenorhabditis elegans neuropeptide G-protein coupled receptor (Ce-NP-GPCR) encoding gene homologs in the predicted protein datasets of 10 key parasitic nematodes that span several phylogenetic clades and lifestyles. We show that, whilst parasitic nematodes possess a reduced complement of Ce-NP-GPCRs, several receptors are broadly conserved across nematode species. To prioritize the most appealing parasitic nematode NP-GPCR anthelmintic targets, we developed a novel in silico nematode parasite drug target prioritization pipeline that incorporates pan-phylum NP-GPCR conservation, C. elegans-derived reverse genetics phenotype, and parasite life-stage specific expression datasets. Several NP-GPCRs emerge as the most attractive anthelmintic targets for broad spectrum nematode parasite control. Our analyses have also identified the most appropriate targets for species- and life stage- directed chemotherapies; in this context we have identified several NP-GPCRs with macrofilaricidal potential. These data focus functional validation efforts towards the most appealing NP-GPCR targets and, in addition, the prioritization strategy employed here provides a blueprint for parasitic nematode target selection beyond NP-GPCRs.
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Affiliation(s)
- Louise E. Atkinson
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Ciaran J. McCoy
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Bethany A. Crooks
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Fiona M. McKay
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Paul McVeigh
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Darrin McKenzie
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Allister Irvine
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - John Harrington
- Boehringer Ingelheim Animal Health, Athens, GA, United States
| | - Bruce A. Rosa
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, United States
| | - Makedonka Mitreva
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
- McDonnell Genome Institute, Washington University School of Medicine, St. Louis, MO, United States
| | - Nikki J. Marks
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Aaron G. Maule
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
| | - Angela Mousley
- Microbes and Pathogen Biology, The Institute for Global Food Security, School of Biological Sciences, Queen’s University Belfast, Belfast, United Kingdom
- *Correspondence: Angela Mousley,
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Adisakwattana P, Yoonuan T, Phuphisut O, Poodeepiyasawat A, Homsuwan N, Gordon CA, McManus DP, Atkinson LE, Mousley A, Gobert GN. Clinical helminthiases in Thailand border regions show elevated prevalence levels using qPCR diagnostics combined with traditional microscopic methods. Parasit Vectors 2020; 13:416. [PMID: 32787935 PMCID: PMC7425172 DOI: 10.1186/s13071-020-04290-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 08/05/2020] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Under-regulated national borders in Southeast Asia represent potential regions for enhanced parasitic helminth transmission and present barriers to helminthiasis disease control. METHODS Three Thailand border regions close to Myanmar, Laos and Cambodia were surveyed for clinical parasitic helminth disease. In-field microscopy was performed on stools from 567 individuals. Sub-samples were transported to Bangkok for molecular analysis comprising three multiplex qPCR assays. RESULTS The overall helminth infection prevalence was 17.99% as assessed by Kato-Katz and 24.51% by qPCR. The combined prevalence of the two methods was 28.57%; the most predominant species detected were Opisthorchis viverrini (18.34%), hookworm (6.88%; Ancylostoma spp. and Necator americanus), Ascaris lumbricoides (2.29%) and Trichuris trichiura (1.76%). CONCLUSIONS These data demonstrate the value of molecular diagnostics for determining more precise prevalence levels of helminthiases in Southeast Asia. Availability of such accurate prevalence information will help guide future public health initiatives and highlights the need for more rigorous surveillance and timely intervention in these regions.
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Affiliation(s)
- Poom Adisakwattana
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
| | - Tippayarat Yoonuan
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Orawan Phuphisut
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Akkarin Poodeepiyasawat
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Nirundorn Homsuwan
- Department of Helminthology, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand
| | - Catherine A Gordon
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, 4006, Australia
| | - Donald P McManus
- Molecular Parasitology Laboratory, Infectious Diseases Division, QIMR Berghofer Medical Research Institute, Brisbane, 4006, Australia
| | - Louise E Atkinson
- School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK
| | - Angela Mousley
- School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK
| | - Geoffrey N Gobert
- School of Biological Sciences, Queen's University Belfast, Belfast, BT9 5DL, UK.
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Atkinson LE, Miskelly IR, Moffett CL, McCoy CJ, Maule AG, Marks NJ, Mousley A. Unraveling flp-11/flp-32 dichotomy in nematodes. Int J Parasitol 2016; 46:723-36. [PMID: 27451358 PMCID: PMC5038847 DOI: 10.1016/j.ijpara.2016.05.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 05/24/2016] [Accepted: 05/25/2016] [Indexed: 01/17/2023]
Abstract
FMRFamide-like peptide (FLP) signalling systems are core to nematode neuromuscular function. Novel drug discovery efforts associated with nematode FLP/FLP receptor biology are advanced through the accumulation of basic biological data that can reveal subtle complexities within the neuropeptidergic system. This study reports the characterisation of FMRFamide-like peptide encoding gene-11 (flp-11) and FMRFamide-like peptide encoding gene-32 (flp-32), two distinct flp genes which encode the analogous peptide, AMRN(A/S)LVRFamide, in multiple nematode species - the only known example of this phenomenon within the FLPergic system of nematodes. Using bioinformatics, in situ hybridisation, immunocytochemistry and behavioural assays we show that: (i) flp-11 and -32 are distinct flp genes expressed individually or in tandem across multiple nematode species, where they encode a highly similar peptide; (ii) flp-11 does not appear to be the most widely expressed flp in Caenorhabditis elegans; (iii) in species expressing both flp-11 and flp-32, flp-11 displays a conserved, restricted expression pattern across nematode clades and lifestyles; (iv) in species expressing both flp-11 and flp-32, flp-32 expression is more widespread and less conserved than flp-11; (v) in species expressing only flp-11, the flp-11 expression profile is more similar to the flp-32 profile observed in species expressing both; and (vi) FLP-11 peptides inhibit motor function in multiple nematode species. The biological significance and evolutionary origin of flp-11 and -32 peptide duplication remains unclear despite attempts to identify a common ancestor; this may become clearer as the availability of genomic data improves. This work provides insight into the complexity of the neuropeptidergic system in nematodes, and begins to examine how nematodes may compensate for structural neuronal simplicity. From a parasite control standpoint, this work underscores the importance of basic biological data, and has wider implications for the utility of C. elegans as a model for parasite neurobiology.
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Affiliation(s)
- Louise E Atkinson
- Microbes & Pathogen Biology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Iain R Miskelly
- Microbes & Pathogen Biology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Christy L Moffett
- Microbes & Pathogen Biology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Ciaran J McCoy
- Microbes & Pathogen Biology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Aaron G Maule
- Microbes & Pathogen Biology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Nikki J Marks
- Microbes & Pathogen Biology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Angela Mousley
- Microbes & Pathogen Biology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK.
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McCoy CJ, Warnock ND, Atkinson LE, Atcheson E, Martin RJ, Robertson AP, Maule AG, Marks NJ, Mousley A. RNA interference in adult Ascaris suum--an opportunity for the development of a functional genomics platform that supports organism-, tissue- and cell-based biology in a nematode parasite. Int J Parasitol 2015; 45:673-8. [PMID: 26149642 PMCID: PMC4563943 DOI: 10.1016/j.ijpara.2015.05.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 05/19/2015] [Accepted: 05/22/2015] [Indexed: 11/03/2022]
Abstract
The sustainable control of animal parasitic nematodes requires the development of efficient functional genomics platforms to facilitate target validation and enhance anthelmintic discovery. Unfortunately, the utility of RNA interference (RNAi) for the validation of novel drug targets in nematode parasites remains problematic. Ascaris suum is an important veterinary parasite and a zoonotic pathogen. Here we show that adult A. suum is RNAi competent, and highlight the induction, spread and consistency of RNAi across multiple tissue types. This platform provides a new opportunity to undertake whole organism-, tissue- and cell-level gene function studies to enhance target validation processes for nematode parasites of veterinary/medical significance.
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Affiliation(s)
- Ciaran J McCoy
- Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Neil D Warnock
- Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Louise E Atkinson
- Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Erwan Atcheson
- Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Richard J Martin
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Alan P Robertson
- Department of Biomedical Sciences, Iowa State University, Ames, IA 50011, USA
| | - Aaron G Maule
- Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Nikki J Marks
- Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK
| | - Angela Mousley
- Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast BT9 7BL, UK.
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13
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Atkinson LE, Stevenson M, McCoy CJ, Marks NJ, Fleming C, Zamanian M, Day TA, Kimber MJ, Maule AG, Mousley A. flp-32 Ligand/receptor silencing phenocopy faster plant pathogenic nematodes. PLoS Pathog 2013; 9:e1003169. [PMID: 23468621 PMCID: PMC3585147 DOI: 10.1371/journal.ppat.1003169] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 12/18/2012] [Indexed: 11/27/2022] Open
Abstract
Restrictions on nematicide usage underscore the need for novel control strategies for plant pathogenic nematodes such as Globodera pallida (potato cyst nematode) that impose a significant economic burden on plant cultivation activities. The nematode neuropeptide signalling system is an attractive resource for novel control targets as it plays a critical role in sensory and motor functions. The FMRFamide-like peptides (FLPs) form the largest and most diverse family of neuropeptides in invertebrates, and are structurally conserved across nematode species, highlighting the utility of the FLPergic system as a broad-spectrum control target. flp-32 is expressed widely across nematode species. This study investigates the role of flp-32 in G. pallida and shows that: (i) Gp-flp-32 encodes the peptide AMRNALVRFamide; (ii) Gp-flp-32 is expressed in the brain and ventral nerve cord of G. pallida; (iii) migration rate increases in Gp-flp-32-silenced worms; (iv) the ability of G. pallida to infect potato plant root systems is enhanced in Gp-flp-32-silenced worms; (v) a novel putative Gp-flp-32 receptor (Gp-flp-32R) is expressed in G. pallida; and, (vi) Gp-flp-32R-silenced worms also display an increase in migration rate. This work demonstrates that Gp-flp-32 plays an intrinsic role in the modulation of locomotory behaviour in G. pallida and putatively interacts with at least one novel G-protein coupled receptor (Gp-flp-32R). This is the first functional characterisation of a parasitic nematode FLP-GPCR. Plant pathogenic nematodes compromise plant health and productivity globally and are an increasing problem due to the lack of efficient control measures. The nematode nervous system depends heavily on small proteins (neuropeptides) for communication between nerve cells and other nerve cells or other cell types. The disruption of neuropeptide signalling would dysregulate normal behaviour, offering an attractive approach to parasite control. One major group of nematode neuropeptides are the FMRFamide-like peptides (FLPs) that alter nematode behaviour by acting on receptors designated G-protein coupled receptors (GPCRs). GPCRs are attractive targets based on their potential ‘druggability;″ indeed they are targets for many human medicines. This study investigates the functional biology of flp-32, a commonly expressed nematode flp, and a novel FLP-32 receptor in a plant pathogenic nematode of major agricultural importance, Globodera pallida. We show that FLP-32 occurs widely in these parasites and interacts with a novel FLP-32 receptor to modulate their behaviour, affecting their movement and the rate at which they infect host plants. These data indicate that chemicals that activate the FLP-32 receptor in these parasites could effectively slow the worms, potentially making them less successful parasites. The conservation of the FLP-32 ligand and receptor across many different nematode parasites adds to its appeal as a potential target for broad-spectrum parasite control.
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Affiliation(s)
- Louise E. Atkinson
- Molecular Biosciences-Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom
| | - Michael Stevenson
- Molecular Biosciences-Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom
| | - Ciaran J. McCoy
- Molecular Biosciences-Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom
| | - Nikki J. Marks
- Molecular Biosciences-Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom
| | - Colin Fleming
- Agri-Food and Biosciences Institute, Belfast, United Kingdom
| | - Mostafa Zamanian
- Institute of Parasitology, McGill University, Ste. Anne de Bellevue, Quebec, Canada
| | - Tim A. Day
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Michael J. Kimber
- Department of Biomedical Sciences, Iowa State University, Ames, Iowa, United States of America
| | - Aaron G. Maule
- Molecular Biosciences-Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom
| | - Angela Mousley
- Molecular Biosciences-Parasitology, Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom
- * E-mail:
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Snyder PJ, Peachey H, Berlin JA, Hannoush P, Haddad G, Dlewati A, Santanna J, Loh L, Lenrow DA, Holmes JH, Kapoor SC, Atkinson LE, Strom BL. Effects of testosterone replacement in hypogonadal men. J Clin Endocrinol Metab 2000; 85:2670-7. [PMID: 10946864 DOI: 10.1210/jcem.85.8.6731] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Treatment of hypogonadal men with testosterone has been shown to ameliorate the effects of testosterone deficiency on bone, muscle, erythropoiesis, and the prostate. Most previous studies, however, have employed somewhat pharmacological doses of testosterone esters, which could result in exaggerated effects, and/or have been of relatively short duration or employed previously treated men, which could result in dampened effects. The goal of this study was to determine the magnitude and time course of the effects of physiological testosterone replacement for 3 yr on bone density, muscle mass and strength, erythropoiesis, prostate volume, energy, sexual function, and lipids in previously untreated hypogonadal men. We selected 18 men who were hypogonadal (mean serum testosterone +/- SD, 78 +/- 77 ng/dL; 2.7 +/- 2.7 nmol/L) due to organic disease and had never previously been treated for hypogonadism. We treated them with testosterone transdermally for 3 yr. Sixteen men completed 12 months of the protocol, and 14 men completed 36 months. The mean serum testosterone concentration reached the normal range by 3 months of treatment and remained there for the duration of treatment. Bone mineral density of the lumbar spine (L2-L4) increased by 7.7 +/- 7.6% (P < 0.001), and that of the femoral trochanter increased by 4.0 +/- 5.4% (P = 0.02); both reached maximum values by 24 months. Fat-free mass increased 3.1 kg (P = 0.004), and fat-free mass of the arms and legs individually increased, principally within the first 6 months. The decrease in fat mass was not statistically significant. Strength of knee flexion and extension did not change. Hematocrit increased dramatically, from mildly anemic (38.0 +/- 3.0%) to midnormal (43.1 +/- 4.0%; P = 0.002) within 3 months, and remained at that level for the duration of treatment. Prostate volume also increased dramatically, from subnormal (12.0 +/- 6.0 mL) before treatment to normal (22.4 +/- 8.4 mL; P = 0.004), principally during the first 6 months. Self-reported sense of energy (49 +/- 19% to 66 +/- 24%; P = 0.01) and sexual function (24 +/- 20% to 66 +/- 24%; P < 0.001) also increased, principally within the first 3 months. Lipids did not change. We conclude from this study that replacing testosterone in hypogonadal men increases bone mineral density of the spine and hip, fat-free mass, prostate volume, erythropoiesis, energy, and sexual function. The full effect of testosterone on bone mineral density took 24 months, but the full effects on the other tissues took only 3-6 months. These results provide the basis for monitoring the magnitude and the time course of the effects of testosterone replacement in hypogonadal men.
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Affiliation(s)
- P J Snyder
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia 19104, USA
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15
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Jordan WP, Atkinson LE, Lai C. Comparison of the skin irritation potential of two testosterone transdermal systems: an investigational system and a marketed product. Clin Ther 1998; 20:80-7. [PMID: 9522106 DOI: 10.1016/s0149-2918(98)80036-2] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Effective transdermal therapy provides controlled release of the appropriate amount of a therapeutic agent while minimizing local irritation. Transdermal administration of testosterone has the potential to produce skin irritation. This open-label, randomized, 14-day, outpatient study compared the skin irritation of an investigational testosterone transdermal system (System I) with that of a marketed testosterone transdermal system (System II) in healthy men. In Part 1 of the study. System I was applied 10 times over 14 days to the same skin site on the backs of 26 healthy men. In Part 2, the skin irritation resulting from daily application of Systems I and II was assessed over 14 days in 17 men less than 65 years of age and 16 men 65 years of age or older. At the end of Part I of the study, 65.4% of the subjects experienced no erythema, 15.4% of subjects had faint erythema, and 19.2% had moderately intense erythema immediately after System I removal. At the completion of Part 2, none of the System I application sites were assessed as having moderately intense erythema, whereas one third (33.3%) of System II application sites demonstrated moderately intense erythema. There were no differences in erythema rates between younger and older subjects with either transdermal system. During this study, repeated application of System I to the same skin site resulted in acceptable noncumulative irritation, suggesting that application-site rotation may not be necessary. A comparison of the two systems demonstrates that System I results in significantly less application-site irritation than does System II and that older men do not have a higher rate of skin reactions.
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Affiliation(s)
- W P Jordan
- ALZA Corporation, Palo Alto, California, USA
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Yu Z, Gupta SK, Hwang SS, Kipnes MS, Mooradian AD, Snyder PJ, Atkinson LE. Testosterone pharmacokinetics after application of an investigational transdermal system in hypogonadal men. J Clin Pharmacol 1997; 37:1139-45. [PMID: 9506009 DOI: 10.1002/j.1552-4604.1997.tb04298.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This open-label, randomized, placebo lead-in, three-treatment crossover study in 19 hypogonadal men (27-82 years of age) evaluated dose proportionality of serum testosterone concentrations with application of one or two investigational transdermal testosterone systems for application to the arm or torso. Testosterone in vivo kinetics profiles were determined using DeMonS, a recently developed numerical deconvolution method that estimates drug absorption at different time intervals and/or drug disposition model parameters. After application of the investigational transdermal systems, the mean serum testosterone, dihydrotestosterone, estradiol, and free testosterone concentrations were elevated to normal levels. Treatment allowed approximation of the normal circadian pattern of endogenous testosterone secretion, and the increase in serum testosterone concentrations was proportional to the surface area of systems applied. The investigational transdermal system provided effective testosterone replacement therapy as judged by pharmacokinetic parameters.
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Affiliation(s)
- Z Yu
- ALZA Corporation, Palo Alto, California 94303-0802, USA
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Yu Z, Gupta SK, Hwang SS, Cook DM, Duckett MJ, Atkinson LE. Transdermal testosterone administration in hypogonadal men: comparison of pharmacokinetics at different sites of application and at the first and fifth days of application. J Clin Pharmacol 1997; 37:1129-38. [PMID: 9506008 DOI: 10.1002/j.1552-4604.1997.tb04297.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this study of 13 hypogonadal men (25-69 years of age), three open-label, randomized treatments were administered to determine the pharmacokinetics of serum testosterone after application of an investigational testosterone transdermal system to the upper buttocks, upper arm, and back. Testosterone in vivo input kinetics profiles were estimated by DeMonS, a recently developed numerical deconvolution method for estimating drug absorption at different time intervals and/or drug disposition model parameters, and compared on the first and fifth days of system application. Area under the concentration-time curve from 0 to 27 hours (AUC0-27) values for testosterone after one-day applications to the upper buttocks, upper arm, and back were 9,560 ng.hr/dL, 8,651 ng.hr/dL, and 8,988 ng.hr/dL, respectively. Maximum observed concentration (Cmax) values were 482 ng/dL, 462 ng/dL, and 499 ng/dL, respectively. Serum testosterone concentrations were equivalent to each other, and Cmax values fell within the normal range. No drug accumulation was seen with repeated dosing over 5 days.
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Affiliation(s)
- Z Yu
- ALZA Corporation, Palo Alto, California 94303-0802, USA
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18
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Atkinson LE, Lincoln R, Forrest JD. The next contraceptive revolution. Fam Plann Perspect 1986; 18:19-26. [PMID: 3803545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The availability of modern birth control methods has wrought a veritable contraceptive revolution in both developed and developing countries over the past two decades. But concerns about safety, costly lawsuits involving current methods, as well as diverse and changing life-styles, have left the current array of contraceptives grossly inadequate to meet growing world-wide needs. Steroid implants and improved injectables, IUDs, barrier methods and sterilization devices should be widely available in the next few years. But the long-sought-after radically new methods that will constitute the next contraceptive revolution--like vaccines, a male contraceptive and a once-a-month pill--will not be developed in the foreseeable future without a massive infusion of new funds. The eight contraceptive research and development (R&D) programs that are responsible for more than half of all current product development efforts now spend about $30 million a year on contraceptive research. With an additional $23 million annually, they could considerably accelerate current research efforts and begin new ones on products that have become possible only as the result of recent scientific discoveries. Even this level of investment--representing a 75 percent increase over current expenditures by the eight groups--would probably not be sufficient to make optimum progress in the development of radically new methods. Since the pharmaceutical industry can no longer be depended upon to take the leading role that it did 20 years ago, current public-sector R&D organizations may need to expand their efforts to include most aspects of the process of contraceptive development and introduction, and new dedicated R&D centers will probably have to be established.(ABSTRACT TRUNCATED AT 250 WORDS)
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Atkinson LE, Lincoln R, Forrest JD. Worldwide trends in funding for contraceptive research and evaluation. Fam Plann Perspect 1985; 17:196-207. [PMID: 3843535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Bahgat MR, Atkinson LE. Contraceptive steroid administration by subdermal implants: serum concentrations of R-2323, estrogen and progesterone in rhesus monkeys. Contraception 1977; 15:335-45. [PMID: 880812 DOI: 10.1016/0010-7824(77)90119-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Sundaram K, Chang CC, Laurence KA, Brinson AO, Atkinson LE, Segal SJ. The effectiveness in rhesus monkeys of an antifertility vaccine based on neutralization of chorionic gonadotropin. Contraception 1976; 14:639-53. [PMID: 828084 DOI: 10.1016/0010-7824(76)90107-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Rodriguez G, Faundes-Latham A, Atkinson LE. An approach to the analysis of menstrual patterns in the critical evaluation of contraceptives. Stud Fam Plann 1976; 7:42-51. [PMID: 936255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
An approach to a standardized analysis of menstrual bleeding patterns is presented. The method utilizes a prospective bleeding record and characterizes the menstrual pattern of a woman according to bleeding and nonbleeding events without imposing definitions of cycle or intermenstrual bleeding. Further, the analysis is done within a time reference period similar to life-table analysis, with the experience of each woman having equal value. The method is thus applicable to the study of menstrual patterns of both normal, untreated women, and women on experimental contraceptive regimens in which expected bleeding patterns are disrupted. The methodology is aided by computer programs to process the data and by the use of standard statistical packages for comparison of output data of different groups.
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Bahgat MR, Atkinson LE, Brinson AO, Segal SJ. Treatment of postpartum rhesus monkeys with progestogen: appearance in milk and effects on lactation. Contraception 1975; 12:665-78. [PMID: 812634 DOI: 10.1016/s0010-7824(75)80050-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Atkinson LE, Hotchkiss J, Fritz GR, Surve AH, Neill JD, Knobil E. Circulating levels of steroids and chorionic gonadotropin during pregnancy in the rhesus monkey, with special attention to the rescue of the corpus luteum in early pregnancy. Biol Reprod 1975; 12:335-45. [PMID: 1222158 DOI: 10.1095/biolreprod12.3.335] [Citation(s) in RCA: 86] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Hotchkiss J, Atkinson LE, Knobil E. Time course of serum estrogen and luteinizing hormone (LH) concentrations during the menstrual cycle of the rhesus monkey. Endocrinology 1971; 89:177-83. [PMID: 4995997 DOI: 10.1210/endo-89-1-177] [Citation(s) in RCA: 414] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Monroe SE, Atkinson LE, Knobil E. Patterns of circulating luteinizing hormone and their relation to plasma progesterone levels during the menstrual cycle of the Rhesus monkey. Endocrinology 1970; 87:453-5. [PMID: 4987451 DOI: 10.1210/endo-87-3-453] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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