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Garin T, Brin C, Préveaux A, Brault A, Briand M, Simonin M, Barret M, Journet L, Sarniguet A. The type VI secretion system of Stenotrophomonas rhizophila CFBP13503 limits the transmission of Xanthomonas campestris pv. campestris 8004 from radish seeds to seedlings. Mol Plant Pathol 2024; 25:e13412. [PMID: 38279854 PMCID: PMC10777753 DOI: 10.1111/mpp.13412] [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] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 10/20/2023] [Accepted: 11/27/2023] [Indexed: 01/29/2024]
Abstract
Stenotrophomonas rhizophila CFBP13503 is a seedborne commensal bacterial strain, which is efficiently transmitted to seedlings and can outcompete the phytopathogenic bacterium Xanthomonas campestris pv. campestris (Xcc8004). The type VI secretion system (T6SS), an interference contact-dependent mechanism, is a critical component of interbacterial competition. The involvement of the T6SS of S. rhizophila CFBP13503 in the inhibition of Xcc8004 growth and seed-to-seedling transmission was assessed. The T6SS cluster of S. rhizophila CFBP13503 and nine putative effectors were identified. Deletion of two T6SS structural genes, hcp and tssB, abolished the competitive advantage of S. rhizophila against Xcc8004 in vitro. The population sizes of these two bacterial species were monitored in seedlings after inoculation of radish seeds with mixtures of Xcc8004 and either S. rhizophila wild-type (wt) strain or isogenic hcp mutant. A significant decrease in the population size of Xcc8004 was observed during confrontation with the S. rhizophila wt in comparison with T6SS-deletion mutants in germinated seeds and seedlings. We found that the T6SS distribution among 835 genomes of the Stenotrophomonas genus is scarce. In contrast, in all available S. rhizophila genomes, T6SS clusters are widespread and mainly belong to the T6SS group i4. In conclusion, the T6SS of S. rhizophila CFBP13503 is involved in the antibiosis against Xcc8004 and reduces seedling transmission of Xcc8004 in radish. The distribution of this T6SS cluster in the S. rhizophila complex could make it possible to exploit these strains as biocontrol agents against X. campestris pv. campestris.
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Affiliation(s)
- Tiffany Garin
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Chrystelle Brin
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Anne Préveaux
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Agathe Brault
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Martial Briand
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Marie Simonin
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Matthieu Barret
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
| | - Laure Journet
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie, Bioénergies et Biotechnologie, Institut de Microbiologie de la MéditerranéeAix‐Marseille Université‐CNRS, UMR 7255MarseilleFrance
| | - Alain Sarniguet
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAVAngersFrance
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Leau A, Denery‐Papini S, Bodinier M, Dijk W. Tolerance to heated egg in egg allergy: Explanations and implications for prevention and treatment. Clin Transl Allergy 2023; 13:e12312. [PMID: 38146801 PMCID: PMC10734553 DOI: 10.1002/clt2.12312] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 10/02/2023] [Accepted: 10/26/2023] [Indexed: 12/27/2023] Open
Abstract
Hen's egg allergy is the second most frequent food allergy found in children. Allergic symptoms can be caused by raw or heated egg, but a majority of egg-allergic children can tolerate hard-boiled or baked egg. Understanding the reasons for the tolerance towards heated egg provides clues about the molecular mechanisms involved in egg allergy, and the differential allergenicity of heated and baked egg might be exploited to prevent or treat egg allergy. In this review, we therefore discuss (i) why some patients are able to tolerate heated egg; by highlighting the structural changes of egg white (EW) proteins upon heating and their impact on immunoreactivity, as well as patient characteristics, and (ii) to what extent heated or baked EW might be useful for primary prevention strategies or oral immunotherapy. We describe that the level of immunoreactivity towards EW helps to discriminate patients tolerant or reactive to heated or baked egg. Furthermore, the use of heated or baked egg seems effective in primary prevention strategies and might limit adverse reactions. Oral immunotherapy is a promising treatment strategy, but it can sometimes cause significant adverse events. The use of heated or baked egg might limit these, but current literature is insufficient to conclude about its efficacy.
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Lavy M, Gauttier V, Dumont A, Chocteau F, Deshayes S, Fresquet J, Dehame V, Girault I, Trilleaud C, Neyton S, Mary C, Juin P, Poirier N, Barillé-Nion S, Blanquart C. ChemR23 activation reprograms macrophages toward a less inflammatory phenotype and dampens carcinoma progression. Front Immunol 2023; 14:1196731. [PMID: 37539056 PMCID: PMC10396772 DOI: 10.3389/fimmu.2023.1196731] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/21/2023] [Indexed: 08/05/2023] Open
Abstract
Introduction Tumor Associated Macrophages (TAM) are a major component of the tumor environment and their accumulation often correlates with poor prognosis by contributing to local inflammation, inhibition of anti-tumor immune response and resistance to anticancer treatments. In this study, we thus investigated the anti-cancer therapeutic interest to target ChemR23, a receptor of the resolution of inflammation expressed by macrophages, using an agonist monoclonal antibody, αChemR23. Methods Human GM-CSF, M-CSF and Tumor Associated Macrophage (TAM)-like macrophages were obtained by incubation of monocytes from healthy donors with GM-CSF, M-CSF or tumor cell supernatants (Breast cancer (BC) or malignant pleural mesothelioma (MPM) cells). The effects of αChemR23 on macrophages were studied at the transcriptomic, protein and functional level. Datasets from The Cancer Genome Atlas (TCGA) were used to study CMKLR1 expression, coding for ChemR23, in BC and MPM tumors. In vivo, αChemR23 was evaluated on overall survival, metastasis development and transcriptomic modification of the metastatic niche using a model of resected triple negative breast cancer. Results We show that ChemR23 is expressed at higher levels in M-CSF and tumor cell supernatant differentiated macrophages (TAM-like) than in GM-CSF-differentiated macrophages. ChemR23 activation triggered by αChemR23 deeply modulates M-CSF and TAM-like macrophages including profile of cell surface markers, cytokine secretion, gene mRNA expression and immune functions. The expression of ChemR23 coding gene (CMKLR1) strongly correlates to TAM markers in human BC tumors and MPM and its histological detection in these tumors mainly corresponds to TAM expression. In vivo, treatment with αChemR23 agonist increased mouse survival and decreased metastasis occurrence in a model of triple-negative BC in correlation with modulation of TAM phenotype in the metastatic niche. Conclusion These results open an attractive opportunity to target TAM and the resolution of inflammation pathways through ChemR23 to circumvent TAM pro-tumoral effects.
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Affiliation(s)
| | | | - Alison Dumont
- Nantes Université, Inserm UMR 1307, CNRS UMR 6075, Université d’Angers, CRCI2NA, Nantes, France
| | - Florian Chocteau
- Nantes Université, Inserm UMR 1307, CNRS UMR 6075, Université d’Angers, CRCI2NA, Nantes, France
| | - Sophie Deshayes
- Nantes Université, Inserm UMR 1307, CNRS UMR 6075, Université d’Angers, CRCI2NA, Nantes, France
| | - Judith Fresquet
- Nantes Université, Inserm UMR 1307, CNRS UMR 6075, Université d’Angers, CRCI2NA, Nantes, France
| | - Virginie Dehame
- Nantes Université, Inserm UMR 1307, CNRS UMR 6075, Université d’Angers, CRCI2NA, Nantes, France
- Nantes Université, CHU Nantes, service de pneumologie, l'institut du thorax, Nantes, France
| | | | | | | | | | - Philippe Juin
- Nantes Université, Inserm UMR 1307, CNRS UMR 6075, Université d’Angers, CRCI2NA, Nantes, France
- ICO René Gauducheau, Saint Herblain, France
| | | | - Sophie Barillé-Nion
- Nantes Université, Inserm UMR 1307, CNRS UMR 6075, Université d’Angers, CRCI2NA, Nantes, France
| | - Christophe Blanquart
- Nantes Université, Inserm UMR 1307, CNRS UMR 6075, Université d’Angers, CRCI2NA, Nantes, France
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Fizanne L, Villard A, Benabbou N, Recoquillon S, Soleti R, Delage E, Wertheimer M, Vidal‐Gómez X, Oullier T, Chaffron S, Martínez MC, Neunlist M, Boursier J, Andriantsitohaina R. Faeces-derived extracellular vesicles participate in the onset of barrier dysfunction leading to liver diseases. J Extracell Vesicles 2023; 12:e12303. [PMID: 36708245 PMCID: PMC9883837 DOI: 10.1002/jev2.12303] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [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: 08/01/2022] [Revised: 11/24/2022] [Accepted: 12/08/2022] [Indexed: 01/29/2023] Open
Abstract
The role of extracellular vesicles (EVs) from faeces (fEVs) and small circulating EVs (cEVs) in liver diseases such as non-alcoholic fatty diseases (NAFLD) and non-alcoholic steatohepatitis (NASH) has not been demonstrated. fEVs and cEVs of healthy donors, NAFLD and NASH patients were isolated and characterized. The effects of EVs were evaluated in intestinal, endothelial, Kupffer and stellate cells. Non-muscular myosin light chain kinase (nmMLCK) deficient mice were used in vivo. Bacterial origins of fEVs were analysed by 16s rDNA gene sequencing. fEVs and small cEVs were composed of prokaryotic and eukaryotic origins. Only NASH-fEVs exerted deleterious effects. NASH-fEVs increased intestinal permeability and reduced expression of tight junction proteins that were prevented by nmMLCK inhibition, increased endothelial cell permeability and inflammatory cytokines and chemokines requiring TLR4/lipopolysaccharide pathway. NASH-fEVs and NASH-cEVs activated profibrotic and proinflammatory proteins of hepatic stellate cells. Treatment with NASH-fEVs evoked an increase in intestinal permeability in wild type but not in nmMLCK deficient mice. Bacterial origins of fEVs were different between NAFLD and NASH patients and 16 amplicon sequence variants were differentially abundant. We demonstrate that fEVs actively participate in barrier dysfunctions leading to liver injuries underscoring the role of nmMLCK and lipopolysaccharide carried by fEVs.
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Affiliation(s)
- Lionel Fizanne
- Laboratoire HIFIH UPRES EA 3859SFR ICAT 4208Université d'AngersAngersFrance
| | - Alexandre Villard
- Laboratoire HIFIH UPRES EA 3859SFR ICAT 4208Université d'AngersAngersFrance
- INSERM UMR1063Stress Oxydant et Pathologies MétaboliquesFaculté de SantéUniversité d'AngersUniversité Bretagne LoireAngersFrance
| | - Nadia Benabbou
- INSERM UMR1063Stress Oxydant et Pathologies MétaboliquesFaculté de SantéUniversité d'AngersUniversité Bretagne LoireAngersFrance
| | - Sylvain Recoquillon
- INSERM UMR1063Stress Oxydant et Pathologies MétaboliquesFaculté de SantéUniversité d'AngersUniversité Bretagne LoireAngersFrance
| | - Raffaella Soleti
- INSERM UMR1063Stress Oxydant et Pathologies MétaboliquesFaculté de SantéUniversité d'AngersUniversité Bretagne LoireAngersFrance
| | - Erwan Delage
- Laboratoire des Sciences du Numérique de Nantes (LS2N)CNRS UMR 6004 – Université de NantesNantesFrance
| | - Mireille Wertheimer
- INSERM UMR1063Stress Oxydant et Pathologies MétaboliquesFaculté de SantéUniversité d'AngersUniversité Bretagne LoireAngersFrance
| | - Xavier Vidal‐Gómez
- INSERM UMR1063Stress Oxydant et Pathologies MétaboliquesFaculté de SantéUniversité d'AngersUniversité Bretagne LoireAngersFrance
- PhyMedExpUniversity of MontpellierINSERM, CNRSMontpellierFrance
| | - Thibauld Oullier
- Université de NantesInsermTENSThe Enteric Nervous System in Gut and Brain DiseasesIMADNantesFrance
| | - Samuel Chaffron
- Laboratoire des Sciences du Numérique de Nantes (LS2N)CNRS UMR 6004 – Université de NantesNantesFrance
| | - M. Carmen Martínez
- INSERM UMR1063Stress Oxydant et Pathologies MétaboliquesFaculté de SantéUniversité d'AngersUniversité Bretagne LoireAngersFrance
- PhyMedExpUniversity of MontpellierINSERM, CNRSMontpellierFrance
| | - Michel Neunlist
- Université de NantesInsermTENSThe Enteric Nervous System in Gut and Brain DiseasesIMADNantesFrance
| | - Jérôme Boursier
- Laboratoire HIFIH UPRES EA 3859SFR ICAT 4208Université d'AngersAngersFrance
- Service d'Hépato‐Gastroentérologie et Oncologie DigestiveCentre Hospitalier Universitaire d'AngersAngersFrance
| | - Ramaroson Andriantsitohaina
- INSERM UMR1063Stress Oxydant et Pathologies MétaboliquesFaculté de SantéUniversité d'AngersUniversité Bretagne LoireAngersFrance
- PhyMedExpUniversity of MontpellierINSERM, CNRSMontpellierFrance
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Abadie C, Lalande J, Tcherkez G. Exact mass GC-MS analysis: Protocol, database, advantages and application to plant metabolic profiling. Plant Cell Environ 2022; 45:3171-3183. [PMID: 35899865 PMCID: PMC9543805 DOI: 10.1111/pce.14407] [Citation(s) in RCA: 2] [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] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/21/2022] [Accepted: 07/23/2022] [Indexed: 05/14/2023]
Abstract
Plant metabolomics has been used widely in plant physiology, in particular to analyse metabolic responses to environmental parameters. Derivatization (via trimethylsilylation and methoximation) followed by GC-MS metabolic profiling is a major technique to quantify low molecular weight, common metabolites of primary carbon, sulphur and nitrogen metabolism. There are now excellent opportunities for new generation analyses, using high resolution, exact mass GC-MS spectrometers that are progressively becoming relatively cheap. However, exact mass GC-MS analyses for routine metabolic profiling are not common, since there is no dedicated available database. Also, exact mass GC-MS is usually dedicated to structural resolution of targeted secondary metabolites. Here, we present a curated database for exact mass metabolic profiling (made of 336 analytes, 1064 characteristic exact mass fragments) focused on molecules of primary metabolism. We show advantages of exact mass analyses, in particular to resolve isotopic patterns, localise S-containing metabolites, and avoid identification errors when analytes have common nominal mass peaks in their spectrum. We provide a practical example using leaves of different Arabidopsis ecotypes and show how exact mass GC-MS analysis can be applied to plant samples and identify metabolic profiles.
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Affiliation(s)
- Cyril Abadie
- Institut de Recherche en Horticulture et Semences, Université d'Angers, INRAeBeaucouzéFrance
| | - Julie Lalande
- Institut de Recherche en Horticulture et Semences, Université d'Angers, INRAeBeaucouzéFrance
| | - Guillaume Tcherkez
- Institut de Recherche en Horticulture et Semences, Université d'Angers, INRAeBeaucouzéFrance
- Research School of Biology, College of Science, Australian National UniversityCanberra ACTAustralia
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Domergue J, Abadie C, Lalande J, Deswarte J, Ober E, Laurent V, Zimmerli C, Lerebour P, Duchalais L, Bédard C, Derory J, Moittie T, Lamothe‐Sibold M, Beauchêne K, Limami AM, Tcherkez G. Grain carbon isotope composition is a marker for allocation and harvest index in wheat. Plant Cell Environ 2022; 45:2145-2157. [PMID: 35475551 PMCID: PMC9323493 DOI: 10.1111/pce.14339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 02/28/2022] [Accepted: 04/06/2022] [Indexed: 06/14/2023]
Abstract
The natural 13 C abundance (δ13 C) in plant leaves has been used for decades with great success in agronomy to monitor water-use efficiency and select modern cultivars adapted to dry conditions. However, in wheat, it is also important to find genotypes with high carbon allocation to spikes and grains, and thus with a high harvest index (HI) and/or low carbon losses via respiration. Finding isotope-based markers of carbon partitioning to grains would be extremely useful since isotope analyses are inexpensive and can be performed routinely at high throughput. Here, we took the advantage of a set of field trials made of more than 600 plots with several wheat cultivars and measured agronomic parameters as well as δ13 C values in leaves and grains. We find a linear relationship between the apparent isotope discrimination between leaves and grain (denoted as Δδcorr ), and the respiration use efficiency-to-HI ratio. It means that overall, efficient carbon allocation to grains is associated with a small isotopic difference between leaves and grains. This effect is explained by postphotosynthetic isotope fractionations, and we show that this can be modelled by equations describing the carbon isotope composition in grains along the wheat growth cycle. Our results show that 13 C natural abundance in grains could be useful to find genotypes with better carbon allocation properties and assist current wheat breeding technologies.
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Affiliation(s)
- Jean‐Baptiste Domergue
- Institut de Recherche en Horticulture et SemencesUniversité d'Angers, INRAeBeaucouzéFrance
| | - Cyril Abadie
- Institut de Recherche en Horticulture et SemencesUniversité d'Angers, INRAeBeaucouzéFrance
| | - Julie Lalande
- Institut de Recherche en Horticulture et SemencesUniversité d'Angers, INRAeBeaucouzéFrance
| | - Jean‐Charles Deswarte
- Arvalis Institut du Végétal, Pôle valorisation de l'écophysiologie, ZA des GraviersVilliers le BâcleFrance
| | - Eric Ober
- National Institute of Agricultural BotanyCambridgeUK
| | | | | | | | | | | | | | | | - Marlène Lamothe‐Sibold
- Plateforme Metabolisme MetabolomeSPOmics plant métabolisme métabolome platform, Institute of Plant Sciences Paris‐Saclay IPS2, CNRS, INRAe, University Paris‐SaclayOrsayFrance
| | - Katia Beauchêne
- Arvalis Institut du Végétal, Pôle PhenoHD3Beauce‐La‐RomaineFrance
| | - Anis M. Limami
- Institut de Recherche en Horticulture et SemencesUniversité d'Angers, INRAeBeaucouzéFrance
| | - Guillaume Tcherkez
- Institut de Recherche en Horticulture et SemencesUniversité d'Angers, INRAeBeaucouzéFrance
- Research School of Biology, ANU College of ScienceAustralian National UniversityCanberraAustralian Capital TerritoryAustralia
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Dubreil L, Ledevin M, Hervet C, Menard D, Philippe C, Michel FJ, Larcher T, Meurens F, Bertho N. The Internal Conduit System of the Swine Inverted Lymph Node. Front Immunol 2022; 13:869384. [PMID: 35734172 PMCID: PMC9207403 DOI: 10.3389/fimmu.2022.869384] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 05/12/2022] [Indexed: 12/04/2022] Open
Abstract
Lymph nodes (LN) are the crossroad where naïve lymphocytes, peripheral antigens and antigen presenting cells contact together in order to mount an adaptive immune response. For this purpose, LN are highly organized convergent hubs of blood and lymphatic vessels that, in the case of B lymphocytes, lead to the B cell follicles. Herein take place the selection and maturation of B cell clones producing high affinity antibodies directed against various antigens. Whereas the knowledge on the murine and human LN distribution systems have reached an exquisite precision those last years, the organization of the antigens and cells circulation into the inverted porcine LN remains poorly described. Using up to date microscopy tools, we described the complex interconnections between afferent lymphatics and blood vessels, perifollicular macrophages, follicular B cells and efferent blood vessels. We observed that afferent lymphatic sinuses presented an asymmetric Lyve-1 expression similar to the one observed in murine LN, whereas specialized perifollicular sinuses connect the main afferent lymphatic sinus to the B cell follicles. Finally, whereas it was long though that mature B cells egress from the inverted LN in the T cell zone through HEV, our observations are in agreement with mature B cells accessing the efferent blood circulation in the efferent, subcapsular area. This understanding of the inverted porcine LN circuitry will allow a more accurate exploration of swine pathogens interactions with the immune cells inside the LN structures. Moreover, the mix between similarities and differences of porcine inverted LN circuitry with mouse and human normal LN shall enable to better apprehend the functions and malfunctions of normal LN from a new perspective.
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Affiliation(s)
| | | | | | | | - Claire Philippe
- APEX, PAnTher, INRAE, Oniris, Nantes, France
- BIOEPAR, INRAE, Oniris, Nantes, France
| | | | | | - François Meurens
- BIOEPAR, INRAE, Oniris, Nantes, France
- Department of Veterinary Microbiology and Immunology, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Nicolas Bertho
- BIOEPAR, INRAE, Oniris, Nantes, France
- *Correspondence: Nicolas Bertho,
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Lopez L, Montnach J, Oliveira-Mendes B, Khakh K, Thomas B, Lin S, Caumes C, Wesolowski S, Nicolas S, Servent D, Cohen C, Béroud R, Benoit E, De Waard M. Synthetic Analogues of Huwentoxin-IV Spider Peptide With Altered Human NaV1.7/NaV1.6 Selectivity Ratios. Front Cell Dev Biol 2021; 9:798588. [PMID: 34988086 PMCID: PMC8722715 DOI: 10.3389/fcell.2021.798588] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 11/22/2021] [Indexed: 11/26/2022] Open
Abstract
Huwentoxin-IV (HwTx-IV), a peptide discovered in the venom of the Chinese bird spider Cyriopagopus schmidti, has been reported to be a potent antinociceptive compound due to its action on the genetically-validated NaV1.7 pain target. Using this peptide for antinociceptive applications in vivo suffers from one major drawback, namely its negative impact on the neuromuscular system. Although studied only recently, this effect appears to be due to an interaction between the peptide and the NaV1.6 channel subtype located at the presynaptic level. The aim of this work was to investigate how HwTx-IV could be modified in order to alter the original human (h) NaV1.7/NaV1.6 selectivity ratio of 23. Nineteen HwTx-IV analogues were chemically synthesized and tested for their blocking effects on the Na+ currents flowing through these two channel subtypes stably expressed in cell lines. Dose-response curves for these analogues were generated, thanks to the use of an automated patch-clamp system. Several key amino acid positions were targeted owing to the information provided by earlier structure-activity relationship (SAR) studies. Among the analogues tested, the potency of HwTx-IV E4K was significantly improved for hNaV1.6, leading to a decreased hNaV1.7/hNaV1.6 selectivity ratio (close to 1). Similar decreased selectivity ratios, but with increased potency for both subtypes, were observed for HwTx-IV analogues that combine a substitution at position 4 with a modification of amino acid 1 or 26 (HwTx-IV E1G/E4G and HwTx-IV E4K/R26Q). In contrast, increased selectivity ratios (>46) were obtained if the E4K mutation was combined to an additional double substitution (R26A/Y33W) or simply by further substituting the C-terminal amidation of the peptide by a carboxylated motif, linked to a marked loss of potency on hNaV1.6 in this latter case. These results demonstrate that it is possible to significantly modulate the selectivity ratio for these two channel subtypes in order to improve the potency of a given analogue for hNaV1.6 and/or hNaV1.7 subtypes. In addition, selective analogues for hNaV1.7, possessing better safety profiles, were produced to limit neuromuscular impairments.
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Affiliation(s)
- Ludivine Lopez
- L’institut du Thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
| | - Jérôme Montnach
- L’institut du Thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
| | | | | | | | - Sophia Lin
- Xenon Pharmaceuticals, Burnaby, BC, Canada
| | | | | | | | - Denis Servent
- Département Médicaments et Technologies pour La Santé (DMTS), Service d’Ingénierie Moléculaire pour La Santé (SIMoS), ERL CNRS/CEA, Institut des Sciences du Vivant Frédéric Joliot, CEA, Université Paris Saclay, Gif-sur-Yvette, France
| | | | | | - Evelyne Benoit
- Département Médicaments et Technologies pour La Santé (DMTS), Service d’Ingénierie Moléculaire pour La Santé (SIMoS), ERL CNRS/CEA, Institut des Sciences du Vivant Frédéric Joliot, CEA, Université Paris Saclay, Gif-sur-Yvette, France
| | - Michel De Waard
- L’institut du Thorax, INSERM, CNRS, UNIV NANTES, Nantes, France
- Smartox Biotechnology, Saint-Egrève, France
- LabEx « Ion Channels, Science and Therapeutics », Valbonne, France
- *Correspondence: Michel De Waard,
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9
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Oliveira‐Mendes B, Feliciangeli S, Ménard M, Chatelain F, Alameh M, Montnach J, Nicolas S, Ollivier B, Barc J, Baró I, Schott J, Probst V, Kyndt F, Denjoy I, Lesage F, Loussouarn G, De Waard M. A standardised hERG phenotyping pipeline to evaluate KCNH2 genetic variant pathogenicity. Clin Transl Med 2021; 11:e609. [PMID: 34841674 PMCID: PMC8609418 DOI: 10.1002/ctm2.609] [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] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 09/22/2021] [Accepted: 09/28/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND AIMS Mutations in KCNH2 cause long or short QT syndromes (LQTS or SQTS) predisposing to life-threatening arrhythmias. Over 1000 hERG variants have been described by clinicians, but most remain to be characterised. The objective is to standardise and accelerate the phenotyping process to contribute to clinician diagnosis and patient counselling. In silico evaluation was also included to characterise the structural impact of the variants. METHODS We selected 11 variants from known LQTS patients and two variants for which diagnosis was problematic. Using the Gibson assembly strategy, we efficiently introduced mutations in hERG cDNA despite GC-rich sequences. A pH-sensitive fluorescent tag was fused to hERG for efficient evaluation of channel trafficking. An optimised 35-s patch-clamp protocol was developed to evaluate hERG channel activity in transfected cells. R software was used to speed up analyses. RESULTS In the present work, we observed a good correlation between cell surface expression, assessed by the pH-sensitive tag, and current densities. Also, we showed that the new biophysical protocol allows a significant gain of time in recording ion channel properties and provides extensive information on WT and variant channel biophysical parameters, that can all be recapitulated in a single parameter defined herein as the repolarisation power. The impacts of the variants on channel structure were also reported where structural information was available. These three readouts (trafficking, repolarisation power and structural impact) define three pathogenicity indexes that may help clinical diagnosis. CONCLUSIONS Fast-track characterisation of KCNH2 genetic variants shows its relevance to discriminate mutants that affect hERG channel activity from variants with undetectable effects. It also helped the diagnosis of two new variants. This information is meant to fill a patient database, as a basis for personalised medicine. The next steps will be to further accelerate the process using an automated patch-clamp system.
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Affiliation(s)
| | - Sylvain Feliciangeli
- Labex ICST, Université Côte d'Azur, INSERMCentre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et CellulaireValbonneFrance
| | - Mélissa Ménard
- l'Institut du ThoraxInserm UMR 1087/CNRS UMR 6291NantesFrance
| | - Frank Chatelain
- Labex ICST, Université Côte d'Azur, INSERMCentre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et CellulaireValbonneFrance
| | - Malak Alameh
- l'Institut du ThoraxInserm UMR 1087/CNRS UMR 6291NantesFrance
| | - Jérôme Montnach
- l'Institut du ThoraxInserm UMR 1087/CNRS UMR 6291NantesFrance
| | | | | | - Julien Barc
- l'Institut du ThoraxInserm UMR 1087/CNRS UMR 6291NantesFrance
| | - Isabelle Baró
- l'Institut du ThoraxInserm UMR 1087/CNRS UMR 6291NantesFrance
| | | | - Vincent Probst
- CHU Nantes, l'Institut du Thorax, INSERM, CNRSUNIV NantesNantesFrance
| | - Florence Kyndt
- CHU Nantes, l'Institut du Thorax, INSERM, CNRSUNIV NantesNantesFrance
| | - Isabelle Denjoy
- Service de Cardiologie et CNMR Maladies Cardiaques Héréditaires RaresHôpital BichatParisFrance
| | - Florian Lesage
- Labex ICST, Université Côte d'Azur, INSERMCentre National de la Recherche Scientifique, Institut de Pharmacologie Moléculaire et CellulaireValbonneFrance
| | | | - Michel De Waard
- l'Institut du ThoraxInserm UMR 1087/CNRS UMR 6291NantesFrance
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Stauffer S, Jucker M, Keggin T, Marques V, Andrello M, Bessudo S, Cheutin M, Borrero‐Pérez GH, Richards E, Dejean T, Hocdé R, Juhel J, Ladino F, Letessier TB, Loiseau N, Maire E, Mouillot D, Mutis Martinezguerra M, Manel S, Polanco Fernández A, Valentini A, Velez L, Albouy C, Pellissier L, Waldock C. How many replicates to accurately estimate fish biodiversity using environmental DNA on coral reefs? Ecol Evol 2021; 11:14630-14643. [PMID: 34765130 PMCID: PMC8571620 DOI: 10.1002/ece3.8150] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [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: 05/26/2021] [Revised: 08/31/2021] [Accepted: 09/08/2021] [Indexed: 01/22/2023] Open
Abstract
Quantifying fish species diversity in rich tropical marine environments remains challenging. Environmental DNA (eDNA) metabarcoding is a promising tool to face this challenge through the filtering, amplification, and sequencing of DNA traces from water samples. However, because eDNA concentration is low in marine environments, the reliability of eDNA to detect species diversity can be limited. Using an eDNA metabarcoding approach to identify fish Molecular Taxonomic Units (MOTUs) with a single 12S marker, we aimed to assess how the number of sampling replicates and filtered water volume affect biodiversity estimates. We used a paired sampling design of 30 L per replicate on 68 reef transects from 8 sites in 3 tropical regions. We quantified local and regional sampling variability by comparing MOTU richness, compositional turnover, and compositional nestedness. We found strong turnover of MOTUs between replicated pairs of samples undertaken in the same location, time, and conditions. Paired samples contained non-overlapping assemblages rather than subsets of one another. As a result, non-saturated localized diversity accumulation curves suggest that even 6 replicates (180 L) in the same location can underestimate local diversity (for an area <1 km). However, sampling regional diversity using ~25 replicates in variable locations (often covering 10 s of km) often saturated biodiversity accumulation curves. Our results demonstrate variability of diversity estimates possibly arising from heterogeneous distribution of eDNA in seawater, highly skewed frequencies of eDNA traces per MOTU, in addition to variability in eDNA processing. This high compositional variability has consequences for using eDNA to monitor temporal and spatial biodiversity changes in local assemblages. Avoiding false-negative detections in future biomonitoring efforts requires increasing replicates or sampled water volume to better inform management of marine biodiversity using eDNA.
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Affiliation(s)
- Salomé Stauffer
- Landscape EcologyInstitute of Terrestrial EcosystemsDepartment of Environmental Systems ScienceETH ZürichZürichSwitzerland
| | - Meret Jucker
- Landscape EcologyInstitute of Terrestrial EcosystemsDepartment of Environmental Systems ScienceETH ZürichZürichSwitzerland
| | - Thomas Keggin
- Landscape EcologyInstitute of Terrestrial EcosystemsDepartment of Environmental Systems ScienceETH ZürichZürichSwitzerland
- Unit of Land Change ScienceSwiss Federal Research Institute WSLBirmensdorfSwitzerland
| | - Virginie Marques
- MARBECUniv. MontpellierCNRSIFREMERIRDMontpellierFrance
- CEFEUniv. MontpellierCNRSEPHE‐PSL UniversityIRDUniv. Paul Valéry Montpellier 3MontpellierFrance
| | - Marco Andrello
- Institute for the Study of Anthropic Impacts and Sustainability in the Marine EnvironmentNational Research CouncilRomeItaly
| | - Sandra Bessudo
- Fundación Malpelo y otros ecosistemas marinosBogotáColombia
| | | | - Giomar Helena Borrero‐Pérez
- Instituto de Investigaciones Marinas y Costeras‐INVEMAR Museo de Historia Natural Marina de Colombia (MHNMC)Santa MartaColombia
| | - Eilísh Richards
- Landscape EcologyInstitute of Terrestrial EcosystemsDepartment of Environmental Systems ScienceETH ZürichZürichSwitzerland
| | | | - Régis Hocdé
- MARBECUniv. MontpellierCNRSIFREMERIRDMontpellierFrance
| | | | - Felipe Ladino
- Fundación Malpelo y otros ecosistemas marinosBogotáColombia
| | - Tom B. Letessier
- Institute of ZoologyZoological Society of LondonLondonUK
- Marine Futures LabUniversity of Western AustraliaCrawleyWAAustralia
| | | | - Eva Maire
- Lancaster Environment CentreLancaster UniversityLancasterUK
| | | | - Maria Mutis Martinezguerra
- Instituto de Investigaciones Marinas y Costeras‐INVEMAR Museo de Historia Natural Marina de Colombia (MHNMC)Santa MartaColombia
| | - Stéphanie Manel
- CEFEUniv. MontpellierCNRSEPHE‐PSL UniversityIRDUniv. Paul Valéry Montpellier 3MontpellierFrance
| | - Andrea Polanco Fernández
- Instituto de Investigaciones Marinas y Costeras‐INVEMAR Museo de Historia Natural Marina de Colombia (MHNMC)Santa MartaColombia
| | | | - Laure Velez
- MARBECUniv. MontpellierCNRSIFREMERIRDMontpellierFrance
| | - Camille Albouy
- IFREMERunité Écologie et Modèles pour l’HalieutiqueNantesFrance
| | - Loïc Pellissier
- Landscape EcologyInstitute of Terrestrial EcosystemsDepartment of Environmental Systems ScienceETH ZürichZürichSwitzerland
- Unit of Land Change ScienceSwiss Federal Research Institute WSLBirmensdorfSwitzerland
| | - Conor Waldock
- Landscape EcologyInstitute of Terrestrial EcosystemsDepartment of Environmental Systems ScienceETH ZürichZürichSwitzerland
- Unit of Land Change ScienceSwiss Federal Research Institute WSLBirmensdorfSwitzerland
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