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Adedeji EO, Beder T, Damiani C, Cappelli A, Accoti A, Tapanelli S, Ogunlana OO, Fatumo S, Favia G, Koenig R, Adebiyi E. Combination of computational techniques and RNAi reveal targets in Anopheles gambiae for malaria vector control. PLoS One 2024; 19:e0305207. [PMID: 38968330 PMCID: PMC11226046 DOI: 10.1371/journal.pone.0305207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 05/25/2024] [Indexed: 07/07/2024] Open
Abstract
Increasing reports of insecticide resistance continue to hamper the gains of vector control strategies in curbing malaria transmission. This makes identifying new insecticide targets or alternative vector control strategies necessary. CLassifier of Essentiality AcRoss EukaRyote (CLEARER), a leave-one-organism-out cross-validation machine learning classifier for essential genes, was used to predict essential genes in Anopheles gambiae and selected predicted genes experimentally validated. The CLEARER algorithm was trained on six model organisms: Caenorhabditis elegans, Drosophila melanogaster, Homo sapiens, Mus musculus, Saccharomyces cerevisiae and Schizosaccharomyces pombe, and employed to identify essential genes in An. gambiae. Of the 10,426 genes in An. gambiae, 1,946 genes (18.7%) were predicted to be Cellular Essential Genes (CEGs), 1716 (16.5%) to be Organism Essential Genes (OEGs), and 852 genes (8.2%) to be essential as both OEGs and CEGs. RNA interference (RNAi) was used to validate the top three highly expressed non-ribosomal predictions as probable vector control targets, by determining the effect of these genes on the survival of An. gambiae G3 mosquitoes. In addition, the effect of knockdown of arginase (AGAP008783) on Plasmodium berghei infection in mosquitoes was evaluated, an enzyme we computationally inferred earlier to be essential based on chokepoint analysis. Arginase and the top three genes, AGAP007406 (Elongation factor 1-alpha, Elf1), AGAP002076 (Heat shock 70kDa protein 1/8, HSP), AGAP009441 (Elongation factor 2, Elf2), had knockdown efficiencies of 91%, 75%, 63%, and 61%, respectively. While knockdown of HSP or Elf2 significantly reduced longevity of the mosquitoes (p<0.0001) compared to control groups, Elf1 or arginase knockdown had no effect on survival. However, arginase knockdown significantly reduced P. berghei oocytes counts in the midgut of mosquitoes when compared to LacZ-injected controls. The study reveals HSP and Elf2 as important contributors to mosquito survival and arginase as important for parasite development, hence placing them as possible targets for vector control.
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Affiliation(s)
- Eunice O. Adedeji
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
- Department of Biochemistry, Covenant University, Ota, Ogun State, Nigeria
- School of Biosciences & Veterinary Medicine, University of Camerino, Camerino, Italy
- Department of Biology, University of York, York, United Kingdom
| | - Thomas Beder
- Medical Department II, Hematology and Oncology, University Medical Center Schleswig-Holstein, Kiel, Germany
- University Cancer Center Schleswig-Holstein, University Medical Center Schleswig-Holstein, Kiel and Lübeck, Germany
- Institute for Infectious Diseases and Infection Control (IIMK, RG Systemsbiology), Jena University Hospital, Jena, Germany
| | - Claudia Damiani
- School of Biosciences & Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Alessia Cappelli
- School of Biosciences & Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Anastasia Accoti
- School of Biosciences & Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Sofia Tapanelli
- Department of Life Sciences, Imperial College, London, United Kingdom
| | - Olubanke O. Ogunlana
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
- Department of Biochemistry, Covenant University, Ota, Ogun State, Nigeria
- African Center of Excellence in Bioinformatics & Data Intensive Science, Makerere University, Kampala, Uganda
| | - Segun Fatumo
- Department of Non-Communicable Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Guido Favia
- School of Biosciences & Veterinary Medicine, University of Camerino, Camerino, Italy
| | - Rainer Koenig
- Institute for Infectious Diseases and Infection Control (IIMK, RG Systemsbiology), Jena University Hospital, Jena, Germany
| | - Ezekiel Adebiyi
- Covenant University Bioinformatics Research (CUBRe), Covenant University, Ota, Ogun State, Nigeria
- African Center of Excellence in Bioinformatics & Data Intensive Science, Makerere University, Kampala, Uganda
- Division of Applied Bioinformatics, German Cancer Research Center (DKFZ), Heidelberg, Germany
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Barbosa RC, Godoy RSM, Ferreira PG, Mendes TAO, Ramalho-Ortigão M, Ribeiro JMC, Martins GF. Exploring the midgut physiology of the non-haematophagous mosquito Toxorhynchites theobaldi. Open Biol 2024; 14:230437. [PMID: 38955221 DOI: 10.1098/rsob.230437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 06/11/2024] [Indexed: 07/04/2024] Open
Abstract
Toxorhynchites mosquitoes have an exclusively phytophagous feeding habit as adults, which leads to significant differences in their morphophysiology compared with haematophagous mosquitoes. However, the molecular mechanisms of digestion in this mosquito are not well understood. In this study, RNA sequencing of the posterior midgut (PMG) of the mosquito Toxorhynchites theobaldi was undertaken, highlighting its significance in mosquito digestion. Subsequently, a comparison was made between the differential gene expression of the PMG and that of the anterior midgut. It was found that the most abundant proteases in the PMG were trypsin and chymotrypsin, and the level of gene expression for enzymes essential for digestion (such as serine protease, α-amylase and pancreatic triacylglycerol lipase) and innate immune response (including catalase, cecropin-A2 and superoxide dismutase) was like that of haematophagous mosquitoes. Peritrophin-1 was detected in the entire midgut, with an elevated expression level in the PMG. Based on our findings, it is hypothesized that a non-haematophagic habit might have been exhibited by the ancestor of Tx. theobaldi, and this trait may have been retained. This study represents a pioneering investigation at the molecular level of midgut contents in a non-haematophagous mosquito. The findings offer valuable insights into the evolutionary aspects of feeding habits in culicids.
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Affiliation(s)
- Renata C Barbosa
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
| | - Raquel S M Godoy
- Fundação Oswaldo Cruz, Instituto René Rachou, Fiocruz, Belo Horizonte, Minas Gerais 30190-002, Brazil
| | - Priscila G Ferreira
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, Minas Gerais 50670-900, Brazil
| | - Tiago A O Mendes
- Departamento de Bioquímica e Biologia Molecular, Universidade Federal de Viçosa, Viçosa, Minas Gerais 50670-900, Brazil
| | | | - José M C Ribeiro
- Section of Vector Biology, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, MD 20852, USA
| | - Gustavo F Martins
- Departamento de Biologia Geral, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570-900, Brazil
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HARAGUCHI A, TAKANO M, FUJIWARA K, HAKOZAKI J, NAKAYAMA K, NAKAMURA S, YOSHIKAWA Y, FUKUMOTO S, KUSAKISAKO K, IKADAI H. Searching for new molecules involved in Anopheles mosquitoes' response to Plasmodium infection. J Vet Med Sci 2024; 86:485-492. [PMID: 38569883 PMCID: PMC11144534 DOI: 10.1292/jvms.24-0008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 03/21/2024] [Indexed: 04/05/2024] Open
Abstract
Plasmodium parasites within mosquitoes are exposed to various physiological processes, such as blood meal digestion activity, the gonotrophic cycle, and host responses preventing the entry of parasites into the midgut wall. However, when in vitro-cultured ookinetes are injected into the hemocoel of mosquitoes, Plasmodium parasites are not affected by the vertebrate host's blood contents and do not pass through the midgut epithelial cells. This infection method might aid in identifying mosquito-derived factors affecting Plasmodium development within mosquitoes. This study investigated novel mosquito-derived molecules related to parasite development in Anopheles mosquitoes. We injected in vitro-cultured Plasmodium berghei (ANKA strain) ookinetes into female and male Anopheles stephensi (STE2 strain) mosquitoes and found that the oocyst number was significantly higher in males than in females, suggesting that male mosquitoes better support the development of parasites. Next, RNA-seq analysis was performed on the injected female and male mosquitoes to identify genes exhibiting changes in expression. Five genes with different expression patterns between sexes and greatest expression changes were identified as being potentially associated with Plasmodium infection. Two of the five genes also showed expression changes with infection by blood-feeding, indicating that these genes could affect the development of Plasmodium parasites in mosquitoes.
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Affiliation(s)
- Asako HARAGUCHI
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Aomori, Japan
| | - Makoto TAKANO
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Aomori, Japan
| | - Kanta FUJIWARA
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Aomori, Japan
| | - Jun HAKOZAKI
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Aomori, Japan
| | - Kazuhiko NAKAYAMA
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Aomori, Japan
| | - Sakure NAKAMURA
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Aomori, Japan
| | - Yasunaga YOSHIKAWA
- Laboratory of Veterinary Biochemistry, School of Veterinary Medicine, Kitasato University, Aomori, Japan
| | - Shinya FUKUMOTO
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
| | - Kodai KUSAKISAKO
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Aomori, Japan
| | - Hiromi IKADAI
- Laboratory of Veterinary Parasitology, School of Veterinary Medicine, Kitasato University, Aomori, Japan
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Skorokhod O, Vostokova E, Gilardi G. The role of P450 enzymes in malaria and other vector-borne infectious diseases. Biofactors 2024; 50:16-32. [PMID: 37555735 DOI: 10.1002/biof.1996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 07/24/2023] [Indexed: 08/10/2023]
Abstract
Vector-borne infectious diseases are still an important global health problem. Malaria is the most important among them, mainly pediatric, life-threatening disease. Malaria and other vector-borne disorders caused by parasites, bacteria, and viruses have a strong impact on public health and significant economic costs. Most vector-borne diseases could be prevented by vector control, with attention to the ecological and biodiversity conservation aspects. Chemical control with pesticides and insecticides is widely used as a measure of prevention although increasing resistance to insecticides is a serious issue in vector control. Metabolic resistance is the most common mechanism and poses a big challenge. Insect enzyme systems, including monooxygenase CYP P450 enzymes, are employed by vectors mainly to metabolize insecticides thus causing resistance. The discovery and application of natural specific inhibitors/blockers of vector P450 enzymes as synergists for commonly used pesticides will contribute to the "greening" of insecticides. Besides vector CYPs, host CYP enzymes could also be exploited to fight against vector-borne diseases: using mostly their detoxifying properties and involvement in the immune response. Here, we review published research data on P450 enzymes from all players in vector-borne infections, that is, pathogens, vectors, and hosts, regarding the potential role of CYPs in disease. We discuss strategies on how to exploit cytochromes P450 in vector-borne disease control.
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Affiliation(s)
- Oleksii Skorokhod
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy
| | - Ekaterina Vostokova
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy
| | - Gianfranco Gilardi
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy
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Hernandez-Caballero I, Hellgren O, Garcia-Longoria Batanete L. Genomic advances in the study of the mosquito vector during avian malaria infection. Parasitology 2023; 150:1330-1339. [PMID: 37614176 PMCID: PMC10941221 DOI: 10.1017/s0031182023000756] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 07/28/2023] [Accepted: 07/28/2023] [Indexed: 08/25/2023]
Abstract
Invertebrate host–parasite associations are one of the keystones in order to understand vector-borne diseases. The study of these specific interactions provides information not only about how the vector is affected by the parasite at the gene-expression level, but might also reveal mosquito strategies for blocking the transmission of the parasites. A very well-known vector for human malaria is Anopheles gambiae. This mosquito species has been the main focus for genomics studies determining essential key genes and pathways over the course of a malaria infection. However, to-date there is an important knowledge gap concerning other non-mammophilic mosquito species, for example some species from the Culex genera which may transmit avian malaria but also zoonotic pathogens such as West Nile virus. From an evolutionary perspective, these 2 mosquito genera diverged 170 million years ago, hence allowing studies in both species determining evolutionary conserved genes essential during malaria infections, which in turn might help to find key genes for blocking malaria cycle inside the mosquito. Here, we extensively review the current knowledge on key genes and pathways expressed in Anopheles over the course of malaria infections and highlight the importance of conducting genomic investigations for detecting pathways in Culex mosquitoes linked to infection of avian malaria. By pooling this information, we underline the need to increase genomic studies in mosquito–parasite associations, such as the one in Culex–Plasmodium, that can provide a better understanding of the infection dynamics in wildlife and reduce the negative impact on ecosystems.
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Affiliation(s)
- Irene Hernandez-Caballero
- Department of Anatomy, Cellular Biology and Zoology, University of Extremadura, E-06071 Badajoz, Spain
| | - Olof Hellgren
- Molecular Ecology and Evolution Lab, Department of Biology, Lund University, Sölvegatan 37, SE-22362, Sweden
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Hepnarova V, Hrabinova M, Muckova L, Kucera T, Schmidt M, Dolezal R, Gorecki L, Hrabcova V, Korabecny J, Mezeiova E, Jun D, Pejchal J. Non-covalent acetylcholinesterase inhibitors: In vitro screening and molecular modeling for novel selective insecticides. Toxicol In Vitro 2022; 85:105463. [PMID: 36041654 DOI: 10.1016/j.tiv.2022.105463] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 07/27/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022]
Abstract
Insecticides represent the most crucial element in the integrated management approach to malaria and other vector-borne diseases. The evolution of insect resistance to long-used substances and the toxicity of organophosphates (OPs) and carbamates are the main factors contributing to the development of new, environmentally safe pesticides. In our work, fourteen compounds of 7-methoxytacrine-tacrine heterodimers were tested for their insecticidal effect. Compounds were evaluated in vitro on insect acetylcholinesterase from Anopheles gambiae (AgAChE) and Musca domestica (MdAChE). The evaluation was executed in parallel with testing on human erythrocyte acetylcholinesterase (HssAChE) and human butyrylcholinesterase (HssBChE) using a modified Ellman's method. Compound efficacy was determined as IC50 values for the respective enzymes and selectivity indexes were expressed to compare the interspecies selectivity. Docking studies were performed to predict the binding modes of selected compounds. K1328 and K1329 provided high HssAChE/AgAChE selectivity outperforming standard pesticides (carbofuran and bendiocarb), and thus can be considered as suitable lead structure for novel anticholinesterase insecticides.
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Affiliation(s)
- Vendula Hepnarova
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; University Hospital Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Martina Hrabinova
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; University Hospital Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
| | - Lubica Muckova
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; University Hospital Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Tomas Kucera
- University of Defence, Faculty of Military Health Sciences, Department of Military Medical Service Organization and Management, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
| | - Monika Schmidt
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; University Hospital Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; University Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 50003 Hradec Kralove, Czech Republic
| | - Rafael Dolezal
- University Hospital Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; University Hradec Kralove, Faculty of Science, Department of Chemistry, Rokitanskeho 62, 50003 Hradec Kralove, Czech Republic
| | - Lukas Gorecki
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; University Hospital Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Veronika Hrabcova
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; University Hospital Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Jan Korabecny
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; University Hospital Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Eva Mezeiova
- University Hospital Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic; National Institute of Mental Health, Topolova 748, 250 67 Klecany, Czech Republic
| | - Daniel Jun
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic; University Hospital Hradec Kralove, Biomedical Research Centre, Sokolska 581, 500 05 Hradec Kralove, Czech Republic
| | - Jaroslav Pejchal
- University of Defence, Faculty of Military Health Sciences, Department of Toxicology and Military Pharmacy, Trebesska 1575, 500 01 Hradec Kralove, Czech Republic
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Omotayo AI, Dogara MM, Sufi D, Shuaibu T, Balogun J, Dawaki S, Muktar B, Adeniyi K, Garba N, Namadi I, Adam HA, Adamu S, Abdullahi H, Sulaiman A, Oduola AO. High pyrethroid-resistance intensity in Culex quinquefasciatus (Say) (Diptera: Culicidae) populations from Jigawa, North-West, Nigeria. PLoS Negl Trop Dis 2022; 16:e0010525. [PMID: 35727843 PMCID: PMC9249174 DOI: 10.1371/journal.pntd.0010525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 07/01/2022] [Accepted: 05/20/2022] [Indexed: 11/26/2022] Open
Abstract
This study examined pyrethroid resistance intensity and mechanisms in Culex quinquefasciatus (Say) (Diptera: Culicidae) populations from Jigawa, North-West Nigeria. Resistance statuses to permethrin, lambda-cyhalothrin and alphacypermethrin were determined with both WHO and CDC resistance bioassays. Synergist assay was conducted by pre-exposing the populations to Piperonyl butoxide (PBO) using the WHO method. Resistance intensities to 2x, 5x and 10x of diagnostic concentrations were determined with the CDC bottle method. Species analysis and presence of knockdown mutation (Leu-Phe) were done using Polymerase Chain Reaction (PCR). Results showed that Cx. quinquefasciatus was the only Culex spp. present and “Kdr-west” mutation was not detected in all analyzed samples. Using WHO method, Cx. quinquefasciatus resistance to permethrin was detected in Dutse (12.2%) and Kafin-Hausa (77.78%). Lambda-cyhalothrin resistance was recorded only in Kafin-Hausa (83.95%) with resistance suspected in Ringim (90%). Resistance to alphacypermethrin was recorded in all locations. Pre-exposure to PBO led to 100% mortality to alphacypermethrin and lambda-cyhalothrin in Ringim while mortality to permethrin and alphacypermethrin in Dutse increased from 12.2% to 97.5% and 64.37% to 79.52% respectively. Using CDC bottle bioassay, resistance was also recorded in all populations and the result shows a significant positive correlation (R2 = 0.728, p = 0.026) with the result from the WHO bioassay. Results of resistance intensity revealed a very high level of resistance in Kafin-Hausa with susceptibility to lambda-cyhalothrin and alphacypermethrin not achieved at 10x of diagnostic doses. Resistance intensity was also high in Dutse with susceptibility to all insecticides not achieved at 5x of diagnostic doses. Widespread and high intensity of resistance in Cx. quinquefasciatus from North-West Nigeria is a major threat to the control of diseases transmitted by Culex and other mosquito species. It is a challenge that needs to be adequately addressed so as to prevent the failure of pyrethroid-based vector control tools. Development of resistance to insecticide by mosquitoes has been identified to be a major challenge in the prevention and control of diseases transmitted by mosquitoes. This informs this study that investigated the level of resistance of Culex mosquitoes from Jigawa, North-West Nigeria to Pyrethroids. The main type of Culex mosquitoes found in the sampled area was Cx. quinquefasciatus. The Cx. quinquefasciatus populations were found to be resistant to permethrin, lambda-cyhalothrin and alphacypermethrin. Resistance in Cx. quinquefasciatus from the three LGAs is more pronounced to alphacypermethrin. The methods employed by the mosquitoes in developing resistance involve detoxification of the insecticides by metabolic enzymes. Cx. quinquefasciatus from the three LGAs were observed to be highly resistant and can withstand multiple of the recommended doses. This development whereby Cx. quinquefasciatus populations were highly resistant to these recommended insecticides is of serious concern as it can lead to failure of all efforts geared towards prevention and control of diseases transmitted by Culex mosquitoes in North-West Nigeria.
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Affiliation(s)
- Ahmed Idowu Omotayo
- Molecular Entomology and Vector Control Research Laboratory, Department of Public Health and Epidemiology, Nigeria Institute of Medical Research, Yaba, Lagos, Nigeria
- Department of Zoology, Faculty of Life Sciences, University of Ilorin, Ilorin, Kwara State, Nigeria
- * E-mail:
| | - Musa Mustapha Dogara
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Danjuma Sufi
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Tasiu Shuaibu
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Joshua Balogun
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Salwa Dawaki
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Bature Muktar
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Kamoru Adeniyi
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Nura Garba
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Isah Namadi
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Hafiz Abdullahi Adam
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Shuaibu Adamu
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
| | - Hamza Abdullahi
- Department of Biological Sciences, Federal University Kashere, Gombe State, Nigeria
| | - Abubakar Sulaiman
- Department of Biological Sciences, Federal University Dutse, Dutse, Jigawa State, Nigeria
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Pascini TV, Jeong YJ, Huang W, Pala ZR, Sá JM, Wells MB, Kizito C, Sweeney B, Alves E Silva TL, Andrew DJ, Jacobs-Lorena M, Vega-Rodríguez J. Transgenic Anopheles mosquitoes expressing human PAI-1 impair malaria transmission. Nat Commun 2022; 13:2949. [PMID: 35618711 PMCID: PMC9135733 DOI: 10.1038/s41467-022-30606-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 04/22/2022] [Indexed: 11/08/2022] Open
Abstract
In mammals, the serine protease plasmin degrades extracellular proteins during blood clot removal, tissue remodeling, and cell migration. The zymogen plasminogen is activated into plasmin by two serine proteases: tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA), a process regulated by plasminogen activator inhibitor 1 (PAI-1), a serine protease inhibitor that specifically inhibits tPA and uPA. Plasmodium gametes and sporozoites use tPA and uPA to activate plasminogen and parasite-bound plasmin degrades extracellular matrices, facilitating parasite motility in the mosquito and the mammalian host. Furthermore, inhibition of plasminogen activation by PAI-1 strongly blocks infection in both hosts. To block parasite utilization of plasmin, we engineered Anopheles stephensi transgenic mosquitoes constitutively secreting human PAI-1 (huPAI-1) in the midgut lumen, in the saliva, or both. Mosquitoes expressing huPAI-1 strongly reduced rodent and human Plasmodium parasite transmission to mosquitoes, showing that co-opting plasmin for mosquito infection is a conserved mechanism among Plasmodium species. huPAI-1 expression in saliva induced salivary gland deformation which affects sporozoite invasion and P. berghei transmission to mice, resulting in significant levels of protection from malaria. Targeting the interaction of malaria parasites with the fibrinolytic system using genetically engineered mosquitoes could be developed as an intervention to control malaria transmission.
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Affiliation(s)
- Tales V Pascini
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rm 2E20A, Rockville, MD, 20852, USA
| | - Yeong Je Jeong
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rm 2E20A, Rockville, MD, 20852, USA
| | - Wei Huang
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Zarna R Pala
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rm 2E20A, Rockville, MD, 20852, USA
| | - Juliana M Sá
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rm 2E20A, Rockville, MD, 20852, USA
| | - Michael B Wells
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, G10 Hunterian, Baltimore, MD, 21205, USA
- Department of Biomedical Sciences, Idaho College of Osteopathic Medicine, Meridian, ID, 83642, USA
| | - Christopher Kizito
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Brendan Sweeney
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rm 2E20A, Rockville, MD, 20852, USA
| | - Thiago L Alves E Silva
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rm 2E20A, Rockville, MD, 20852, USA
| | - Deborah J Andrew
- Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, G10 Hunterian, Baltimore, MD, 21205, USA
| | - Marcelo Jacobs-Lorena
- Department of Molecular Microbiology and Immunology, Malaria Research Institute, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA
| | - Joel Vega-Rodríguez
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12735 Twinbrook Parkway, Rm 2E20A, Rockville, MD, 20852, USA.
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9
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Messenger LA, Impoinvil LM, Derilus D, Yewhalaw D, Irish S, Lenhart A. A whole transcriptomic approach provides novel insights into the molecular basis of organophosphate and pyrethroid resistance in Anopheles arabiensis from Ethiopia. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2021; 139:103655. [PMID: 34562591 DOI: 10.1016/j.ibmb.2021.103655] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/15/2021] [Accepted: 09/20/2021] [Indexed: 06/13/2023]
Abstract
The development of insecticide resistance in malaria vectors is of increasing concern in Ethiopia because of its potential implications for vector control failure. To better elucidate the specificity of resistance mechanisms and to facilitate the design of control strategies that minimize the likelihood of selecting for cross-resistance, a whole transcriptomic approach was used to explore gene expression patterns in a multi-insecticide resistant population of Anopheles arabiensis from Oromia Region, Ethiopia. This field population was resistant to the diagnostic doses of malathion (average mortality of 71.9%) and permethrin (77.4%), with pools of survivors and unexposed individuals analyzed using Illumina RNA-sequencing, alongside insecticide susceptible reference strains. This population also demonstrated deltamethrin resistance but complete susceptibility to alpha-cypermethrin, bendiocarb and propoxur, providing a phenotypic basis for detecting insecticide-specific resistance mechanisms. Transcriptomic data revealed overexpression of genes including cytochrome P450s, glutathione-s-transferases and carboxylesterases (including CYP4C36, CYP6AA1, CYP6M2, CYP6M3, CYP6P4, CYP9K1, CYP9L1, GSTD3, GSTE2, GSTE3, GSTE4, GSTE5, GSTE7 and two carboxylesterases) that were shared between malathion and permethrin survivors. We also identified nineteen highly overexpressed cuticular-associated proteins (including CYP4G16, CYP4G17 and chitinase) and eighteen salivary gland proteins (including D7r4 short form salivary protein), which may be contributing to a non-specific resistance phenotype by either enhancing the cuticular barrier or promoting binding and sequestration of insecticides, respectively. These findings provide novel insights into the molecular basis of insecticide resistance in this lesser well-characterized major malaria vector species.
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Affiliation(s)
- Louisa A Messenger
- Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd. Atlanta, GA, 30329, USA; American Society for Microbiology, 1752 N Street, NW Washington, DC, 20036, USA; Department of Disease Control, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, United Kingdom
| | - Lucy Mackenzie Impoinvil
- Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd. Atlanta, GA, 30329, USA
| | - Dieunel Derilus
- Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd. Atlanta, GA, 30329, USA
| | - Delenasaw Yewhalaw
- Tropical and Infectious Diseases Research Center, Jimma University, Jimma, Ethiopia; Department of Medical Laboratory Sciences and Pathology, College of Health Sciences, Jimma University, Jimma, Ethiopia
| | - Seth Irish
- Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd. Atlanta, GA, 30329, USA; President's Malaria Initiative, Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd. Atlanta, GA, 30329, USA
| | - Audrey Lenhart
- Entomology Branch, Division of Parasitic Diseases and Malaria, Center for Global Health, U.S. Centers for Disease Control and Prevention, 1600 Clifton Rd. Atlanta, GA, 30329, USA.
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10
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Gavor E, Choong YK, Jobichen C, Mok YK, Kini RM, Sivaraman J. Structure of Aedes aegypti carboxypeptidase B1-inhibitor complex uncover the disparity between mosquito and non-mosquito insect carboxypeptidase inhibition mechanism. Protein Sci 2021; 30:2445-2456. [PMID: 34658092 PMCID: PMC8605369 DOI: 10.1002/pro.4212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 11/07/2022]
Abstract
Metallocarboxypeptidases (MCPs) in the mosquito midgut play crucial roles in infection, as well as in mosquito dietary digestion, reproduction, and development. MCPs are also part of the digestive system of plant-feeding insects, representing key targets for inhibitor development against mosquitoes/mosquito-borne pathogens or as antifeedant molecules against plant-feeding insects. Notably, some non-mosquito insect B-type MCPs are primarily insensitive to plant protease inhibitors (PPIs) such as the potato carboxypeptidase inhibitor (PCI; MW 4 kDa), an inhibitor explored for cancer treatment and insecticide design. Here, we report the crystal structure of Aedes aegypti carboxypeptidase-B1 (CPBAe1)-PCI complex and compared the binding with that of PCI-insensitive CPBs. We show that PCI accommodation is determined by key differences in the active-site regions of MCPs. In particular, the loop regions α6-α7 (Leu242 -Ser250 ) and β8-α8 (Pro269 -Pro280 ) of CPBAe1 are replaced by α-helices in PCI-insensitive insect Helicoverpa zea CPBHz. These α-helices protrude into the active-site pocket of CPBHz, restricting PCI insertion and rendering the enzyme insensitive. We further compared our structure with the only other PCI complex available, bovine CPA1-PCI. The potency of PCI against CPBAe1 (Ki = 14.7 nM) is marginally less than that of bovine CPA1 (Ki = 5 nM). Structurally, the above loop regions that accommodate PCI binding in CPBAe1 are similar to that of bovine CPA1, although observed changes in proteases residues that interact with PCI could account for the differences in affinity. Our findings suggest that PCI sensitivity is largely dictated by structural interference, which broadens our understanding of carboxypeptidase inhibition as a mosquito population/parasite control strategy.
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Affiliation(s)
- Edem Gavor
- Department of Biological SciencesNational University of SingaporeSingapore
| | - Yeu Khai Choong
- Department of Biological SciencesNational University of SingaporeSingapore
| | - Chacko Jobichen
- Department of Biological SciencesNational University of SingaporeSingapore
| | - Yu Keung Mok
- Department of Biological SciencesNational University of SingaporeSingapore
| | - R. Manjunatha Kini
- Department of Biological SciencesNational University of SingaporeSingapore
- Department of Pharmacology, Yong Loo Lin School of MedicineNational University of SingaporeSingapore
| | - J. Sivaraman
- Department of Biological SciencesNational University of SingaporeSingapore
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11
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Gavor E, Choong YK, Tulsian NK, Nayak D, Idris F, Sivaraman H, Ting DHR, Sylvie A, Mok YK, Kini RM, Sivaraman J. Structure of Aedes aegypti procarboxypeptidase B1 and its binding with Dengue virus for controlling infection. Life Sci Alliance 2021; 5:5/1/e202101211. [PMID: 34750241 PMCID: PMC8605224 DOI: 10.26508/lsa.202101211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/18/2021] [Accepted: 10/19/2021] [Indexed: 12/05/2022] Open
Abstract
Using high-resolution structure, we have characterized the substrate specificity of Aedes aegypti procarboxypeptidase B1 and provided mechanistic insights into the binding and inhibition of DENV Metallocarboxypeptidases play critical roles in the development of mosquitoes and influence pathogen/parasite infection of the mosquito midgut. Here, we report the crystal structure of Aedes aegypti procarboxypeptidase B1 (PCPBAe1), characterized its substrate specificity and mechanism of binding to and inhibiting Dengue virus (DENV). We show that the activated PCPBAe1 (CPBAe1) hydrolyzes both Arg- and Lys-substrates, which is modulated by residues Asp251 and Ser239. Notably, these residues are conserved in CPBs across mosquito species, possibly required for efficient digestion of basic dietary residues that are necessary for mosquito reproduction and development. Importantly, we characterized the interaction between PCPBAe1 and DENV envelope (E) protein, virus-like particles, and infectious virions. We identified residues Asp18A, Glu19A, Glu85, Arg87, and Arg89 of PCPBAe1 are essential for interaction with DENV. PCPBAe1 maps to the dimeric interface of the E protein domains I/II (Lys64–Glu84, Val238–Val252, and Leu278–Leu287). Overall, our studies provide general insights into how the substrate-binding property of mosquito carboxypeptidases could be targeted to potentially control mosquito populations or proposes a mechanism by which PCPBAe1 binds to and inhibits DENV.
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Affiliation(s)
- Edem Gavor
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Yeu Khai Choong
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Nikhil Kumar Tulsian
- Department of Biological Sciences, National University of Singapore, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Digant Nayak
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Fakhriedzwan Idris
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore
| | - Hariharan Sivaraman
- Department of Biological Sciences, National University of Singapore, Singapore
| | - Donald Heng Rong Ting
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore
| | - Alonso Sylvie
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore
| | - Yu Keung Mok
- Department of Biological Sciences, National University of Singapore, Singapore
| | - R Manjunatha Kini
- Department of Biological Sciences, National University of Singapore, Singapore.,Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - J Sivaraman
- Department of Biological Sciences, National University of Singapore, Singapore
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12
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Dong S, Dong Y, Simões ML, Dimopoulos G. Mosquito transgenesis for malaria control. Trends Parasitol 2021; 38:54-66. [PMID: 34483052 DOI: 10.1016/j.pt.2021.08.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/01/2021] [Accepted: 08/03/2021] [Indexed: 12/14/2022]
Abstract
Malaria is one of the deadliest diseases. Because of the ineffectiveness of current malaria-control methods, several novel mosquito vector-based control strategies have been proposed to supplement existing control strategies. Mosquito transgenesis and gene drive have emerged as promising tools for preventing the spread of malaria by either suppressing mosquito populations by self-destructing mosquitoes or replacing mosquito populations with disease-refractory populations. Here we review the development of mosquito transgenesis and its application for malaria control, highlighting the transgenic expression of antiparasitic effector genes, inactivation of host factor genes, and manipulation of miRNAs and lncRNAs. Overall, from a malaria-control perspective, mosquito transgenesis is not envisioned as a stand-alone approach; rather, its use is proposed as a complement to existing vector-control strategies.
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Affiliation(s)
- Shengzhang Dong
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Yuemei Dong
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Maria L Simões
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
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13
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Horvath TD, Dagan S, Scaraffia PY. Unraveling mosquito metabolism with mass spectrometry-based metabolomics. Trends Parasitol 2021; 37:747-761. [PMID: 33896683 PMCID: PMC8282712 DOI: 10.1016/j.pt.2021.03.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/29/2021] [Accepted: 03/30/2021] [Indexed: 02/06/2023]
Abstract
Nearly half a million people die annually due to mosquito-borne diseases. Despite aggressive mosquito population-control efforts, current strategies are limited in their ability to control these vectors. A better understanding of mosquito metabolism through modern approaches can contribute to the discovery of novel metabolic targets and/or regulators and lead to the development of better mosquito-control strategies. Currently, cutting-edge technologies such as gas or liquid chromatography-mass spectrometry-based metabolomics are considered 'mature technologies' in many life-science disciplines but are still an emerging area of research in medical entomology. This review primarily discusses recent developments and progress in the application of mass spectrometry-based metabolomics to answer multiple biological questions related to mosquito metabolism.
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Affiliation(s)
- Thomas D Horvath
- Department of Immunology and Pathology, Baylor College of Medicine, and Texas Children's Microbiome Center, Texas Children's Hospital, Houston, TX, 77030, USA
| | - Shai Dagan
- Israel Institute for Biological Research, Ness Ziona, Israel, 74100, Israel
| | - Patricia Y Scaraffia
- Department of Tropical Medicine and Vector-Borne Infectious Disease Research Center, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, 70112, USA.
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14
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2La Paracentric Chromosomal Inversion and Overexpressed Metabolic Genes Enhance Thermotolerance and Pyrethroid Resistance in the Major Malaria Vector Anopheles gambiae. BIOLOGY 2021; 10:biology10060518. [PMID: 34200806 PMCID: PMC8230517 DOI: 10.3390/biology10060518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 06/05/2021] [Accepted: 06/07/2021] [Indexed: 01/31/2023]
Abstract
Changes in global temperature are impacting the spread/intensity of vector-borne diseases, including malaria, and accelerating evolutionary/adaptive changes in vector species. These changes, including chromosomal inversions and overexpression and/or changes in allele frequencies of thermotolerance-associated genes, may facilitate insecticide resistance through pleiotropy. This study investigated the impact of thermotolerance on pyrethroid resistance in four populations of the malaria vector An. gambiae s.l., from the savanna/sub-Sahel of northern Nigeria. Anopheles coluzzii and An. gambiae s.s. were the only malaria vectors found, sympatric in all the sites, with the former species predominant. High thermotolerance was observed, with no mortality at 38 °C, and LT50 of ~44 °C. Significantly high permethrin resistance was observed (mortality < 50%) in 44 °C heat-hardened (exposure to an intermediately high temperature provides protection to a more severe temperature or insecticide) larvae from two sites, BUK and Pantami, compared with the control, and heat-hardened adult females from Auyo (mortality = 3.00% ± 1.20, χ2 = 5.83, p < 0.01) compared with the control (12.00% ± 4.65). The 2La chromosomal inversion was detected at ~50% in subset of larvae and 58% in subset of adult females genotyped. A significant association was observed (OR = 7.2, p < 0.03) between permethrin resistance and the 2La/+a rearrangement compared with 2L+a/+a, in BUK larvae. For all sites, permethrin resistance correlated with 2La/a homozygosity in adult females (R = 5.02, p = 0.01). qRT-PCR identified six genes commonly induced/overexpressed, including the heat shock protein 70 (AGAP004581) which was 2468× and 5× overexpressed in heat-hardened and permethrin-resistant females, respectively; trehalose-6-phosphate synthase (AGAP008227); and the ionotropic glutamate receptor genes, IR25a (AGAP010272) and IR21a (AGAP008511). This study highlights challenges associated with insecticide-based malaria vector control, and the epidemiological significance of taking climate variables into account for the design/choice of control measures.
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15
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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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