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Ekoka E, Maharaj S, Nardini L, Dahan-Moss Y, Koekemoer LL. 20-Hydroxyecdysone (20E) signaling as a promising target for the chemical control of malaria vectors. Parasit Vectors 2021; 14:86. [PMID: 33514413 PMCID: PMC7844807 DOI: 10.1186/s13071-020-04558-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 12/19/2020] [Indexed: 01/07/2023] Open
Abstract
With the rapid development and spread of resistance to insecticides among anopheline malaria vectors, the efficacy of current World Health Organization (WHO)-approved insecticides targeting these vectors is under threat. This has led to the development of novel interventions, including improved and enhanced insecticide formulations with new targets or synergists or with added sterilants and/or antimalarials, among others. To date, several studies in mosquitoes have revealed that the 20-hydroxyecdysone (20E) signaling pathway regulates both vector abundance and competence, two parameters that influence malaria transmission. Therefore, insecticides which target 20E signaling (e.g. methoxyfenozide and halofenozide) may be an asset for malaria vector control. While such insecticides are already commercially available for lepidopteran and coleopteran pests, they still need to be approved by the WHO for malaria vector control programs. Until recently, chemicals targeting 20E signaling were considered to be insect growth regulators, and their effect was mostly studied against immature mosquito stages. However, in the last few years, promising results have been obtained by applying methoxyfenozide or halofenozide (two compounds that boost 20E signaling) to Anopheles populations at different phases of their life-cycle. In addition, preliminary studies suggest that methoxyfenozide resistance is unstable, causing the insects substantial fitness costs, thereby potentially circumventing one of the biggest challenges faced by current vector control efforts. In this review, we first describe the 20E signaling pathway in mosquitoes and then summarize the mechanisms whereby 20E signaling regulates the physiological processes associated with vector competence and vector abundance. Finally, we discuss the potential of using chemicals targeting 20E signaling to control malaria vectors.![]()
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Affiliation(s)
- Elodie Ekoka
- WITS Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. .,Centre for Emerging, Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa.
| | - Surina Maharaj
- WITS Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Emerging, Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Luisa Nardini
- WITS Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Emerging, Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Yael Dahan-Moss
- WITS Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Emerging, Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
| | - Lizette L Koekemoer
- WITS Research Institute for Malaria, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.,Centre for Emerging, Zoonotic & Parasitic Diseases, National Institute for Communicable Diseases, Johannesburg, South Africa
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Wen F, Caputo G, Hooey S, Bowman S, Pinkney K, Krell PJ, Arif B, Doucet D. Establishment of a cell line from the ash and privet borer beetle Tylonotus bimaculatus Haldeman and assessment of its sensitivity to diacylhydrazine insecticides. In Vitro Cell Dev Biol Anim 2015; 51:905-14. [PMID: 25952767 DOI: 10.1007/s11626-015-9917-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 04/14/2015] [Indexed: 12/18/2022]
Abstract
A novel cell line, NRCAN-Tb521, was developed from larvae of the longhorn beetle Tylonotus bimaculatus (Coleoptera: Cerambycidae), a pest of North American ash trees. The cell line has been successfully passaged more than 50 times and displayed very strong attachment to the substrate and a modal chromosomal count distribution of 19. Sequencing of a 649 bp fragment of the mitochondrial cytochrome oxidase I gene confirmed the identity of NRCAN-Tb521 as T. bimaculatus. The response of the cell line to 20-hydroxyecdysone and diacylhydrazine ecdysone agonist insecticides was also studied. At 10(-6) M, 20-hydroxyecdysone, tebufenozide, methoxyfenozide and halofenozide triggered the production of numerous filamentous cytoplasmic extensions, and the cells tended to form aggregates, indicative of a cell differentiation response. This response was followed by a strong decrease in viability after 4 d. Reverse transcription polymerase chain reaction (PCR) experiments and sequencing of PCR fragments showed that the 20E receptor gene EcR is expressed in the cells and that 20E, tebufenozide, methoxyfenozide and halofenozide also induce the expression of the nuclear hormone receptor gene HR3. This report establishes that NRCAN-Tb521 is a valuable in vitro model to study effects of ecdysone agonists in wood-boring cerambycids.
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Affiliation(s)
- Fayuan Wen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1.,Canadian Forest Service, Natural Resources Canada, 1219 Queen St. East, Sault Ste Marie, ON, Canada, P6A 2E5
| | - Guido Caputo
- Canadian Forest Service, Natural Resources Canada, 1219 Queen St. East, Sault Ste Marie, ON, Canada, P6A 2E5
| | - Sharon Hooey
- Canadian Forest Service, Natural Resources Canada, 1219 Queen St. East, Sault Ste Marie, ON, Canada, P6A 2E5
| | - Susan Bowman
- Canadian Forest Service, Natural Resources Canada, 1219 Queen St. East, Sault Ste Marie, ON, Canada, P6A 2E5
| | - Kristine Pinkney
- Canadian Forest Service, Natural Resources Canada, 1219 Queen St. East, Sault Ste Marie, ON, Canada, P6A 2E5
| | - Peter J Krell
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada, N1G 2W1
| | - Basil Arif
- Canadian Forest Service, Natural Resources Canada, 1219 Queen St. East, Sault Ste Marie, ON, Canada, P6A 2E5
| | - Daniel Doucet
- Canadian Forest Service, Natural Resources Canada, 1219 Queen St. East, Sault Ste Marie, ON, Canada, P6A 2E5.
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Hull JJ, Chaney K, Geib SM, Fabrick JA, Brent CS, Walsh D, Lavine LC. Transcriptome-based identification of ABC transporters in the western tarnished plant bug Lygus hesperus. PLoS One 2014; 9:e113046. [PMID: 25401762 PMCID: PMC4234516 DOI: 10.1371/journal.pone.0113046] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 10/18/2014] [Indexed: 12/11/2022] Open
Abstract
ATP-binding cassette (ABC) transporters are a large superfamily of proteins that mediate diverse physiological functions by coupling ATP hydrolysis with substrate transport across lipid membranes. In insects, these proteins play roles in metabolism, development, eye pigmentation, and xenobiotic clearance. While ABC transporters have been extensively studied in vertebrates, less is known concerning this superfamily in insects, particularly hemipteran pests. We used RNA-Seq transcriptome sequencing to identify 65 putative ABC transporter sequences (including 36 full-length sequences) from the eight ABC subfamilies in the western tarnished plant bug (Lygus hesperus), a polyphagous agricultural pest. Phylogenetic analyses revealed clear orthologous relationships with ABC transporters linked to insecticide/xenobiotic clearance and indicated lineage specific expansion of the L. hesperus ABCG and ABCH subfamilies. The transcriptional profile of 13 LhABCs representative of the ABCA, ABCB, ABCC, ABCG, and ABCH subfamilies was examined across L. hesperus development and within sex-specific adult tissues. All of the transcripts were amplified from both reproductively immature and mature adults and all but LhABCA8 were expressed to some degree in eggs. Expression of LhABCA8 was spatially localized to the testis and temporally timed with male reproductive development, suggesting a potential role in sexual maturation and/or spermatozoa protection. Elevated expression of LhABCC5 in Malpighian tubules suggests a possible role in xenobiotic clearance. Our results provide the first transcriptome-wide analysis of ABC transporters in an agriculturally important hemipteran pest and, because ABC transporters are known to be important mediators of insecticidal resistance, will provide the basis for future biochemical and toxicological studies on the role of this protein family in insecticide resistance in Lygus species.
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Affiliation(s)
- J. Joe Hull
- USDA-ARS, Arid Land Agricultural Research Center, Maricopa, Arizona, United States of America
- * E-mail:
| | - Kendrick Chaney
- USDA-ARS, Arid Land Agricultural Research Center, Maricopa, Arizona, United States of America
| | - Scott M. Geib
- USDA-ARS, Daniel K. Inouye Pacific Basin Agricultural Research Center, Hilo, Hawaii, United States of America
| | - Jeffrey A. Fabrick
- USDA-ARS, Arid Land Agricultural Research Center, Maricopa, Arizona, United States of America
| | - Colin S. Brent
- USDA-ARS, Arid Land Agricultural Research Center, Maricopa, Arizona, United States of America
| | - Douglas Walsh
- Dept. of Entomology, Washington State University, Pullman, Washington, United States of America
| | - Laura Corley Lavine
- Dept. of Entomology, Washington State University, Pullman, Washington, United States of America
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Davis MB, Li T. Genomic analysis of the ecdysone steroid signal at metamorphosis onset using ecdysoneless and EcRnullDrosophila melanogaster mutants. Genes Genomics 2013; 35:21-46. [PMID: 23482860 PMCID: PMC3585846 DOI: 10.1007/s13258-013-0061-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Accepted: 07/23/2012] [Indexed: 12/13/2022]
Abstract
Steroid hormone gene regulation is often depicted as a linear transduction of the signal, from molecule release to the gene level, by activation of a receptor protein after being bound by its steroid ligand. Such an action would require that the hormone be present and bound to the receptor in order to have target gene response. Here, we present data that presents a novel perspective of hormone gene regulation, where the hormone molecule and its receptor have exclusive target gene regulation function, in addition to the traditional direct target genes. Our study is the first genome-wide analysis of conditional mutants simultaneously modeling the steroid and steroid receptor gene expression regulation. We have integrated classical genetic mutant experiments with functional genomics techniques in the Drosophila melanogaster model organism, where we interrogate the 20-hydroxyecdysone signaling response at the onset of metamorphosis. Our novel catalog of ecdysone target genes illustrates the separable transcriptional responses among the hormone, the pre-hormone receptor and the post-hormone receptor. We successfully detected traditional ecdysone target genes as common targets and also identified novel sets of target genes which where exclusive to each mutant condition. Around 12 % of the genome responds to the ecdysone hormone signal at the onset of metamorphosis and over half of these are independent of the receptor. In addition, a significant portion of receptor regulated genes are differentially regulated by the receptor, depending on its ligand state. Gene ontology enrichment analyses confirm known ecdysone regulated biological functions and also validate implicated pathways that have been indirectly associated with ecdysone signaling.
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Affiliation(s)
- Melissa B Davis
- Department of Genetics, Coverdell Biomedical Research Center, University of Georgia, 500 DW Brooks Dr S 270C, Athens, GA 30602 USA
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Tang B, Dong W, Liang P, Zhou X, Gao X. Cloning, ligand-binding, and temporal expression of ecdysteroid receptors in the diamondback moth, Plutella xylostella. BMC Mol Biol 2012; 13:32. [PMID: 23078528 PMCID: PMC3568735 DOI: 10.1186/1471-2199-13-32] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 10/11/2012] [Indexed: 01/17/2023] Open
Abstract
Background The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a devastating pest of cruciferous crops worldwide, and has developed resistance to a wide range of insecticides, including diacylhydrazine-based ecdysone agonists, a highly selective group of molt-accelerating biopesticides targeting the ecdysone receptors. Result In this study, we cloned and characterized the ecdysone receptors from P. xylostella, including the two isoforms of EcR and a USP. Sequence comparison and phylogenetic analysis showed striking conservations among insect ecdysone receptors, especially between P. xylostella and other lepidopterans. The binding affinity of ecdysteroids to in vitro-translated receptor proteins indicated that PxEcRB isoform bound specifically to ponasterone A, and the binding affinity was enhanced by co-incubation with PxUSP (Kd =3.0±1.7 nM). In contrast, PxEcRA did not bind to ponasterone A, even in the presence of PxUSP. The expression of PxEcRB were consistently higher than that of PxEcRA across each and every developmental stage, while the pattern of PxUSP expression is more or less ubiquitous. Conclusions Target site insensitivity, in which the altered binding of insecticides (ecdysone agonists) to their targets (ecdysone receptors) leads to an adaptive response (resistance), is one of the underlying mechanisms of diacylhydrazine resistance. Given the distinct differences at expression level and the ligand-binding capacity, we hypothesis that PxEcRB is the ecdysone receptor that controls the remodeling events during metamorphosis. More importantly, PxEcRB is the potential target site which is modified in the ecdysone agonist-resistant P. xylostella.
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Affiliation(s)
- Baozhen Tang
- Department of Entomology, China Agricultural University, Beijing, China
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De Geyter E, Swevers L, Soin T, Geelen D, Smagghe G. Saponins do not affect the ecdysteroid receptor complex but cause membrane permeation in insect culture cell lines. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:18-23. [PMID: 22057058 DOI: 10.1016/j.jinsphys.2011.09.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 09/02/2011] [Accepted: 09/07/2011] [Indexed: 05/25/2023]
Abstract
This project studied the effects of four saponins with a triterpenoid (Quillajasaponaria saponin and aescin) or steroid structure (digitonin and diosgenin which is the deglycosylated form of dioscin) on insect cells, namely Schneider S2 cells of Drosophila melanogaster (Diptera). A series of different experiments were performed to investigate potential mechanisms of action by saponins with regard to ecdysteroid receptor (EcR) responsiveness, cell viability, cell membrane permeation, and induction of apoptosis with DNA fragmentation and caspase-3 like activity. Major results were that (1) exposure of S2 cells containing an EcR-based reporter construct to a concentration series of each saponin scored no EcR activation, while (2) a loss of ecdysteroid signaling was observed with median inhibitory concentrations (IC(50)'s) of 3-50 μM, and in parallel (3) a concentration-dependent change in loss of cell numbers in an cell viability assay with median effective concentrations (EC(50)'s) of 8-699 μM. In continuation, it was of interest that (4) a trypan blue assay with Q. saponaria saponin confirmed the cell membrane permeation effect leading to cell toxicity with a median lethal concentration (LC(50)) value of 44 μM, and interestingly this effect was very rapid. Another three interesting observations were that (5) exposure to 20E at 500 nM as used in the EcR-based report assay induced caspase-3 like activities which may help to explain the discrepancies between loss of EcR-responsiveness and cell viability, (6) low concentrations of saponins induced DNA fragmentation and caspase-3 like activities, confirming their potential to induce apoptosis, and (7) the saponin effects were counteracted with addition of cholesterol to the culture medium. In general the data obtained provide evidence that the anti-ecdysteroid action by saponins is not based on a true antagonistic interaction with EcR signaling, but can be explained by a cytotoxic action due to permeation of the insect cell membrane.
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Affiliation(s)
- Ellen De Geyter
- Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
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Giraudo M, Califano J, Hilliou F, Tran T, Taquet N, Feyereisen R, Le Goff G. Effects of hormone agonists on Sf9 cells, proliferation and cell cycle arrest. PLoS One 2011; 6:e25708. [PMID: 21991338 PMCID: PMC3185036 DOI: 10.1371/journal.pone.0025708] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2011] [Accepted: 09/08/2011] [Indexed: 12/19/2022] Open
Abstract
Methoxyfenozide and methoprene are two insecticides that mimic the action of the main hormones involved in the control of insect growth and development, 20-hydroxyecdysone and juvenile hormone. We investigated their effect on the Spodoptera frugiperda Sf9 cell line. Methoxyfenozide was more toxic than methoprene in cell viability tests and more potent in the inhibition of cellular proliferation. Cell growth arrest occurred in the G2/M phase after a methoprene treatment and more modestly in G1 after methoxyfenozide treatment. Microarray experiments and real-time quantitative PCR to follow the expression of nuclear receptors ultraspiracle and ecdysone receptor were performed to understand the molecular action of these hormone agonists. Twenty-six genes were differentially expressed after methoxyfenozide treatment and 55 genes after methoprene treatment with no gene in common between the two treatments. Our results suggest two different signalling pathways in Sf9 cells.
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Affiliation(s)
- Maeva Giraudo
- Institut National de la Recherche Agronomique, UMR 1301 Interactions Biotiques et Santé Végétale, Centre National de la Recherche Scientifique, UMR 6243, Université de Nice Sophia Antipolis, Sophia-Antipolis, France
- UMR 6023 CNRS-Université Blaise Pascal, Bât. Biologie A – Campus des Cézeaux, Aubière, France
| | - Jérôme Califano
- Institut National de la Recherche Agronomique, UMR 1301 Interactions Biotiques et Santé Végétale, Centre National de la Recherche Scientifique, UMR 6243, Université de Nice Sophia Antipolis, Sophia-Antipolis, France
- Département des affaires réglementaires, Grasse, France
| | - Frédérique Hilliou
- Institut National de la Recherche Agronomique, UMR 1301 Interactions Biotiques et Santé Végétale, Centre National de la Recherche Scientifique, UMR 6243, Université de Nice Sophia Antipolis, Sophia-Antipolis, France
| | - Trang Tran
- Institut National de la Recherche Agronomique, UMR 1301 Interactions Biotiques et Santé Végétale, Centre National de la Recherche Scientifique, UMR 6243, Université de Nice Sophia Antipolis, Sophia-Antipolis, France
- Lanaud Gestion-Pôle de Lanaud, Boisseuil, France
| | - Nathalie Taquet
- Institut National de la Recherche Agronomique, UMR 1301 Interactions Biotiques et Santé Végétale, Centre National de la Recherche Scientifique, UMR 6243, Université de Nice Sophia Antipolis, Sophia-Antipolis, France
- Bioimagerie, Villeneuve Loubet, France
| | - René Feyereisen
- Institut National de la Recherche Agronomique, UMR 1301 Interactions Biotiques et Santé Végétale, Centre National de la Recherche Scientifique, UMR 6243, Université de Nice Sophia Antipolis, Sophia-Antipolis, France
| | - Gaëlle Le Goff
- Institut National de la Recherche Agronomique, UMR 1301 Interactions Biotiques et Santé Végétale, Centre National de la Recherche Scientifique, UMR 6243, Université de Nice Sophia Antipolis, Sophia-Antipolis, France
- * E-mail:
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