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Henriques-Santos BM, Baker D, Zhou N, Snavely T, Sacchettini JC, Pietrantonio PV. Target-based discovery of antagonists of the tick (Rhipicephalus microplus) kinin receptor identifies small molecules that inhibit midgut contractions. PEST MANAGEMENT SCIENCE 2024; 80:5168-5179. [PMID: 38899490 DOI: 10.1002/ps.8242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 05/23/2024] [Accepted: 06/02/2024] [Indexed: 06/21/2024]
Abstract
BACKGROUND A GPCR (G protein-coupled receptor) target-based approach was applied to identify antagonists of the arthropod-specific tick kinin receptor. These small molecules were expected to reproduce the detrimental phenotypic effects that had been observed in Rhipicephalus microplus females when the kinin receptor was silenced by RNA interference. Rhipicephalus microplus, the southern cattle tick, cattle fever tick, or Asian blue tick, is the vector of pathogenic microorganisms causing the deadly bovine babesiosis and anaplasmosis. The widespread resistance to acaricides in tick populations worldwide emphasizes that exploring novel targets for effective tick control is imperative. RESULTS Fifty-three structural analogs of previously identified tick kinin antagonists were screened in a 'dual-addition' calcium fluorescence assay using a CHO-K1 cell line expressing the tick kinin receptor. Seven molecules were validated as non-cytotoxic antagonists, four of which were partial (SACC-0428764, SACC-0428780, SACC-0428800, and SACC-0428803), and three were full antagonists (SACC-0428799, SACC-0428801, and SACC-0428815). Four of these antagonists (SACC-0428764, SACC-0428780, SACC-0428799, and SACC-0428815) also inhibited the tick midgut contractions induced by the myotropic kinin agonist analog 1728, verifying their antagonistic bioactivity. The small molecules were tested on recombinant human neurokinin (NK) receptors, the one most similar to the invertebrate kinin receptors. Most molecules were inhibitors of the NK1 receptor, except SACC-0412066, a previously identified tick kinin receptor antagonist, which inhibited the NK1 receptor only at the highest concentration tested (25 μm). None of the molecules inhibited the NK3 human receptor. CONCLUSION Molecules identified through this approach could be useful probes for studying the tick kinin signaling system and midgut physiology. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
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Affiliation(s)
| | - Dwight Baker
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Nian Zhou
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Thomas Snavely
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - James C Sacchettini
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
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Hernandez JR, Xiong C, Pietrantonio PV. A fluorescently-tagged tick kinin neuropeptide triggers peristalsis and labels tick midgut muscles. Sci Rep 2024; 14:10863. [PMID: 38740831 DOI: 10.1038/s41598-024-61570-w] [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: 02/17/2024] [Accepted: 05/07/2024] [Indexed: 05/16/2024] Open
Abstract
Ticks are blood-feeding arthropods that require heme for their successful reproduction. During feeding they also acquire pathogens that are subsequently transmitted to humans, wildlife and/or livestock. Understanding the regulation of tick midgut is important for blood meal digestion, heme and nutrient absorption processes and for aspects of pathogen biology in the host. We previously demonstrated the activity of tick kinins on the cognate G protein-coupled receptor. Herein we uncovered the physiological role of the kinin receptor in the tick midgut. A fluorescently-labeled kinin peptide with the endogenous kinin 8 sequence (TMR-RK8), identical in the ticks Rhipicephalus microplus and R. sanguineus, activated and labeled the recombinant R. microplus receptor expressed in CHO-K1 cells. When applied to the live midgut the TMR-RK8 labeled the kinin receptor in muscles while the labeled peptide with the scrambled-sequence of kinin 8 (TMR-Scrambled) did not. The unlabeled kinin 8 peptide competed TMR-RK8, decreasing confocal microscopy signal intensity, indicating TMR-RK8 specificity to muscles. TMR-RK8 was active, inducing significant midgut peristalsis that was video-recorded and evaluated with video tracking software. The TMR-Scrambled peptide used as a negative control did not elicit peristalsis. The myotropic function of kinins in eliciting tick midgut peristalsis was established.
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Affiliation(s)
- Jonathan R Hernandez
- Department of Entomology, Texas A&M University, College Station, TX, 77843-2475, USA
| | - Caixing Xiong
- Department of Entomology, Texas A&M University, College Station, TX, 77843-2475, USA
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Waldman J, Klafke GM, Tirloni L, Logullo C, da Silva Vaz I. Putative target sites in synganglion for novel ixodid tick control strategies. Ticks Tick Borne Dis 2023; 14:102123. [PMID: 36716581 PMCID: PMC10033424 DOI: 10.1016/j.ttbdis.2023.102123] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/23/2022] [Accepted: 01/07/2023] [Indexed: 01/21/2023]
Abstract
Acaricide resistance is a global problem that has impacts worldwide. Tick populations with broad resistance to all commercially available acaricides have been reported. Since resistance selection in ticks and their role in pathogen transmission to animals and humans result in important economic and public health burden, it is essential to develop new strategies for their control (i.e., novel chemical compounds, vaccines, biological control). The synganglion is the tick central nervous system and it is responsible for synthesizing and releasing signaling molecules with different physiological functions. Synganglion proteins are the targets of the majority of available acaricides. In this review we provide an overview of the mode-of-action and resistance mechanisms against neurotoxic acaricides in ticks, as well as putative target sites in synganglion, as a supporting tool to identify new target proteins and to develop new strategies for tick control.
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Affiliation(s)
- Jéssica Waldman
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Guilherme Marcondes Klafke
- Instituto de Pesquisas Veterinárias Desidério Finamor - Centro de Pesquisa em Saúde Animal, Secretaria da Agricultura, Pecuária e Desenvolvimento Rural, Eldorado do Sul, RS, Brazil; Instituto Nacional de Ciência e Tecnologia - Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - Lucas Tirloni
- Laboratory of Bacteriology, Tick-Pathogen Transmission Unit, National Institute of Allergy and Infectious Diseases, Hamilton, MT, USA
| | - Carlos Logullo
- Instituto Nacional de Ciência e Tecnologia - Entomologia Molecular, Rio de Janeiro, RJ, Brazil; Laboratório de Bioquímica de Artrópodes Hematófagos, IBqM, Universidade Federal do Rio de Janeiro, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Itabajara da Silva Vaz
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Instituto Nacional de Ciência e Tecnologia - Entomologia Molecular, Rio de Janeiro, RJ, Brazil; Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Wulff JP, Temeyer KB, Tidwell JP, Schlechte KG, Lohmeyer KH, Pietrantonio PV. Periviscerokinin (Cap 2b; CAPA) receptor silencing in females of Rhipicephalus microplus reduces survival, weight and reproductive output. Parasit Vectors 2022; 15:359. [PMID: 36203198 PMCID: PMC9535995 DOI: 10.1186/s13071-022-05457-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Accepted: 08/24/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The cattle fever tick, Rhipicephalus (Boophilus) microplus, is a vector of pathogens causative of babesiosis and anaplasmosis, both highly lethal bovine diseases that affect cattle worldwide. In Ecdysozoa, neuropeptides and their G-protein-coupled receptors play a critical integrative role in the regulation of all physiological processes. However, the physiological activity of many neuropeptides is still unknown in ticks. Periviscerokinins (CAP2b/PVKs) are neuropeptides associated with myotropic and diuretic activities in insects. These peptides have been identified only in a few tick species, such as Ixodes ricinus, Ixodes scapularis and R. microplus, and their cognate receptor only characterized for the last two. METHODS Expression of the periviscerokinin receptor (Rhimi-CAP2bR) was investigated throughout the developmental stages of R. microplus and silenced by RNA interference (RNAi) in the females. In a first experiment, three double-stranded (ds) RNAs, named ds680-805, ds956-1109 and ds1102-1200, respectively, were tested in vivo. All three caused phenotypic effects, but only the last one was chosen for subsequent experiments. Resulting RNAi phenotypic variables were compared to those of negative controls, both non-injected and dsRNA beta-lactamase-injected ticks, and to positive controls injected with beta-actin dsRNA. Rhimi-CAP2bR silencing was verified by quantitative reverse-transcriptase PCR in whole females and dissected tissues. RESULTS Rhimi-CAP2bR transcript expression was detected throughout all developmental stages. Rhimi-CAP2bR silencing was associated with increased female mortality, decreased weight of surviving females and of egg masses, a delayed egg incubation period and decreased egg hatching (P < 0.05). CONCLUSIONS CAP2b/PVKs appear to be associated with the regulation of female feeding, reproduction and survival. Since the Rhimi-CAP2bR loss of function was detrimental to females, the discovery of antagonistic molecules of the CAP2b/PVK signaling system should cause similar effects. Our results point to this signaling system as a promising target for tick control.
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Affiliation(s)
- Juan P. Wulff
- Department of Entomology, Texas A&M University, College Station, TX 77843-2475 USA
| | - Kevin B. Temeyer
- Knipling-Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, United States Department of Agriculture–Agricultural Research Service, 2700 Fredericksburg Road, Kerrville, TX 78028-9184 USA
| | - Jason P. Tidwell
- Cattle Fever Tick Research Laboratory, United States Department of Agriculture–Agricultural Research Service, 22675 N. Moorefield Rd. Building 6419, Edinburg, TX 78541-5033 USA
| | - Kristie G. Schlechte
- Knipling-Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, United States Department of Agriculture–Agricultural Research Service, 2700 Fredericksburg Road, Kerrville, TX 78028-9184 USA
| | - Kimberly H. Lohmeyer
- Knipling-Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, United States Department of Agriculture–Agricultural Research Service, 2700 Fredericksburg Road, Kerrville, TX 78028-9184 USA
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5
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Wulff JP, Temeyer KB, Tidwell JP, Schlechte KG, Xiong C, Lohmeyer KH, Pietrantonio PV. Pyrokinin receptor silencing in females of the southern cattle tick Rhipicephalus (Boophilus) microplus is associated with a reproductive fitness cost. Parasit Vectors 2022; 15:252. [PMID: 35818078 PMCID: PMC9272880 DOI: 10.1186/s13071-022-05349-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/28/2022] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Rhipicephalus microplus is the vector of deadly cattle pathogens, especially Babesia spp., for which a recombinant vaccine is not available. Therefore, disease control depends on tick vector control. However, R. microplus populations worldwide have developed resistance to available acaricides, prompting the search for novel acaricide targets. G protein-coupled receptors (GPCRs) are involved in the regulation of many physiological processes and have been suggested as druggable targets for the control of arthropod vectors. Arthropod-specific signaling systems of small neuropeptides are being investigated for this purpose. The pyrokinin receptor (PKR) is a GPCR previously characterized in ticks. Myotropic activity of pyrokinins in feeding-related tissues of Rhipicephalus sanguineus and Ixodes scapularis was recently reported. METHODS The R. microplus pyrokinin receptor (Rhimi-PKR) was silenced through RNA interference (RNAi) in female ticks. To optimize RNAi, a dual-luciferase assay was applied to determine the silencing efficiency of two Rhimi-PKR double-stranded RNAs (dsRNA) prior to injecting dsRNA in ticks to be placed on cattle. Phenotypic variables of female ticks obtained at the endpoint of the RNAi experiment were compared to those of control female ticks (non-injected and beta-lactamase dsRNA-injected). Rhimi-PKR silencing was verified by quantitative reverse-transcriptase PCR in whole females and dissected tissues. RESULTS The Rhimi-PKR transcript was expressed in all developmental stages. Rhimi-PKR silencing was confirmed in whole ticks 4 days after injection, and in the tick carcass, ovary and synganglion 6 days after injection. Rhimi-PKR silencing was associated with an increased mortality and decreased weight of both surviving females and egg masses (P < 0.05). Delays in repletion, pre-oviposition and incubation periods were observed (P < 0.05). CONCLUSIONS Rhimi-PKR silencing negatively affected female reproductive fitness. The PKR appears to be directly or indirectly associated with the regulation of female feeding and/or reproductive output in R. microplus. Antagonists of the pyrokinin signaling system could be explored for tick control.
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Affiliation(s)
- Juan P. Wulff
- Department of Entomology, Texas A&M University, College Station, TX 77843-2475 USA
| | - Kevin B. Temeyer
- Knipling-Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, United States Department of Agriculture-Agricultural Research Service (USDA-ARS), 2700 Fredericksburg Road, Kerrville, TX 78028-9184 USA
| | - Jason P. Tidwell
- Cattle Fever Tick Research Laboratory, USDA-ARS, 22675 N. Moorefield Rd. Building 6419, Edinburg, TX 78541-5033 USA
| | - Kristie G. Schlechte
- Knipling-Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, United States Department of Agriculture-Agricultural Research Service (USDA-ARS), 2700 Fredericksburg Road, Kerrville, TX 78028-9184 USA
| | - Caixing Xiong
- Department of Entomology, Texas A&M University, College Station, TX 77843-2475 USA
| | - Kimberly H. Lohmeyer
- Knipling-Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, United States Department of Agriculture-Agricultural Research Service (USDA-ARS), 2700 Fredericksburg Road, Kerrville, TX 78028-9184 USA
| | - Patricia V. Pietrantonio
- Knipling-Bushland U.S. Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, United States Department of Agriculture-Agricultural Research Service (USDA-ARS), 2700 Fredericksburg Road, Kerrville, TX 78028-9184 USA
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Cerqueira APM, Santos MDC, dos Santos Júnior MC, Botura MB. Molecular targets for the development of new acaricides against Rhipicephalus microplus: a review. Parasitology 2022; 149:1019-1026. [PMID: 35514112 PMCID: PMC11010478 DOI: 10.1017/s0031182022000506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 04/06/2022] [Accepted: 04/06/2022] [Indexed: 11/06/2022]
Abstract
The cattle tick Rhipicephalus microplus is an ectoparasite with high economic importance to bovine culture, mainly in tropical and subtropical regions. The resistance of the tick from the commercial acaricides has hindered its control, thus motivating the search for new strategies. The purpose of this study was to perform a critical review about the main molecular targets of R. microplus that are useful for the discovery of new acaricides. Bibliographic search was conducted in the databases PubMed, ScienceDirect and CAB Direct, using the following descriptors: ‘Rhipicephalus microplus’, ‘Boophilus microplus’, ‘molecular targets’ and ‘action’, published between 2010 and 2021. Out of the 212 publications identified, 17 articles were selected for study inclusion. This review described 14 molecular targets and among these 4 are targets from commercial acaricides. Most of them are enzymes to catalyse important reactions to tick survival, related to energetic metabolism, mechanisms of biotransformation and neurotransmission. The data will be helpful in the development of new more effective and selective acaricides.
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Affiliation(s)
- Amanda Ponce Morais Cerqueira
- Departamento de Biologia, Programa de Pós-Graduação em Biotecnologia, Universidade Estadual de Feira de Santana, Feira de Santana, BA, Brazil
| | - Matheus da Cunha Santos
- Departamento de Saúde, Universidade Estadual de Feira de Santana, Feira de Santana, BA, Brazil
| | | | - Mariana Borges Botura
- Departamento de Saúde, Universidade Estadual de Feira de Santana, Feira de Santana, BA, Brazil
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Waldman J, Xavier MA, Vieira LR, Logullo R, Braz GRC, Tirloni L, Ribeiro JMC, Veenstra JA, Silva Vaz ID. Neuropeptides in Rhipicephalus microplus and other hard ticks. Ticks Tick Borne Dis 2022; 13:101910. [PMID: 35121230 PMCID: PMC9477089 DOI: 10.1016/j.ttbdis.2022.101910] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 01/24/2022] [Accepted: 01/25/2022] [Indexed: 12/15/2022]
Abstract
The synganglion is the central nervous system of ticks and, as such, controls tick physiology. It does so through the production and release of signaling molecules, many of which are neuropeptides. These peptides can function as neurotransmitters, neuromodulators and/or neurohormones, although in most cases their functions remain to be established. We identified and performed in silico characterization of neuropeptides present in different life stages and organs of Rhipicephalus microplus, generating transcriptomes from ovary, salivary glands, fat body, midgut and embryo. Annotation of synganglion transcripts led to the identification of 32 functional categories of proteins, of which the most abundant were: secreted, energetic metabolism and oxidant metabolism/detoxification. Neuropeptide precursors are among the sequences over-represented in R. microplus synganglion, with at least 5-fold higher transcription compared with other stages/organs. A total of 52 neuropeptide precursors were identified: ACP, achatin, allatostatins A, CC and CCC, allatotropin, bursicon A/B, calcitonin A and B, CCAP, CCHamide, CCRFamide, CCH/ITP, corazonin, DH31, DH44, eclosion hormone, EFLamide, EFLGGPamide, elevenin, ETH, FMRFamide myosuppressin-like, glycoprotein A2/B5, gonadulin, IGF, inotocin, insulin-like peptides, iPTH, leucokinin, myoinhibitory peptide, NPF 1 and 2, orcokinin, proctolin, pyrokinin/periviscerokinin, relaxin, RYamide, SIFamide, sNPF, sulfakinin, tachykinin and trissin. Several of these neuropeptides have not been previously reported in ticks, as the presence of ETH that was first clearly identified in Parasitiformes, which include ticks and mites. Prediction of the mature neuropeptides from precursor sequences was performed using available information about these peptides from other species, conserved domains and motifs. Almost all neuropeptides identified are also present in other tick species. Characterizing the role of neuropeptides and their respective receptors in tick physiology can aid the evaluation of their potential as drug targets.
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Affiliation(s)
- Jéssica Waldman
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Marina Amaral Xavier
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - Larissa Rezende Vieira
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Raquel Logullo
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Gloria Regina Cardoso Braz
- Departamento de Bioquímica, Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia - Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - Lucas Tirloni
- Tick-Pathogen Transmission Unit, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases, Hamilton, MT, USA
| | - José Marcos C Ribeiro
- Vector Biology Section, Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases, Rockville, MD, USA
| | - Jan A Veenstra
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine, UMR 5287 CNRS, Université de Bordeaux, Bordeaux, France
| | - Itabajara da Silva Vaz
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; Instituto Nacional de Ciência e Tecnologia - Entomologia Molecular, Rio de Janeiro, RJ, Brazil; Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
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Xiong C, Wulff JP, Nachman RJ, Pietrantonio PV. Myotropic Activities of Tick Pyrokinin Neuropeptides and Analog in Feeding Tissues of Hard Ticks (Ixodidae). Front Physiol 2022; 12:826399. [PMID: 35242048 PMCID: PMC8887807 DOI: 10.3389/fphys.2021.826399] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 12/20/2021] [Indexed: 12/19/2022] Open
Abstract
Neuropeptides regulate many important physiological processes in animals. The G protein-coupled receptors of corresponding small neuropeptide ligands are considered promising targets for controlling arthropod pests. Pyrokinins (PKs) are pleiotropic neuropeptides that, in some insect species, stimulate muscle contraction and modulate pheromone biosynthesis, embryonic diapause, and feeding behavior. However, their function remains unknown in ticks. In this study, we reported the myotropic activity of tick endogenous PKs and a PK agonist analog, PK-PEG8 (MS[PEG8]-YFTPRLa), on feeding tissues of two tick species representing the family Ixodidae lineages, namely, Prostriata (Ixodes scapularis) and Metastriata (Rhipicephalus sanguineus). First, we predicted the sequences of two periviscerokinins (PVK), one with a derived ending RNa and five PKs encoded by the CAPA peptide precursor from R. sanguineus and found the encoded PKs were identical to those of R. microplus identified previously. The pharynx-esophagus of both tick species responded with increased contractions to 10 μM of the endogenous PK as well as to PK-PEG8 but not to the scrambled PK peptide, as expected. A dose-dependent myotropic activity of the PK-PEG8 was found for both tick species, validating the analog activity previously found in the pyrokinin recombinant receptor assay. In agreement with the tissue activity elicited, we quantified the relative transcript abundance of R. sanguineus PK receptor in unfed female ticks and found it was the highest in the feeding tissues extracted from the capitulum and lowest in the reproductive tissue. This is the first report of the activity of pyrokinins in ticks. These findings strongly indicate the potential role of PKs in regulating tick blood feeding and therefore, making the tick PK receptor a potential target for interference.
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Affiliation(s)
- Caixing Xiong
- Department of Entomology, Texas A&M University, College Station, TX, United States
| | - Juan P Wulff
- Department of Entomology, Texas A&M University, College Station, TX, United States
| | - Ronald J Nachman
- Insect Neuropeptide Lab, Insect Control and Cotton Disease Research Unit, Southern Plains Agricultural Research Center, USDA-ARS, College Station, TX, United States
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9
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Xiong C, Baker D, Pietrantonio PV. A random small molecule library screen identifies novel antagonists of the kinin receptor from the cattle fever tick, Rhipicephalus microplus (Acari: Ixodidae). PEST MANAGEMENT SCIENCE 2021; 77:2238-2251. [PMID: 33415807 DOI: 10.1002/ps.6249] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 12/17/2020] [Accepted: 01/07/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND The southern cattle tick, Rhipicephalus microplus, is a primary vector of the deadly bovine disease babesiosis. Worldwide populations of ticks have developed resistance to acaricides, underscoring the need for novel target discovery for tick control. The arthropod-specific R. microplus kinin receptor is such a target, previously validated by silencing, which resulted in female reproductive fitness costs, including a reduced percentage of eggs hatching. RESULTS In order to identify potent small molecules that bind and activate or inhibit the kinin receptor, a high-throughput screening (HTS) assay was developed using a CHO-K1 cell line expressing the recombinant tick kinin receptor (BMLK3 ). A total of ~20 000 molecules from a random in-house small molecule library were screened in a 'dual-addition' calcium fluorescence assay. This was followed by dose-response validation of the hit molecules identified both from HTS and an in silico screen of ~390 000 molecules. We validated 29 antagonists, 11 of them were full antagonists with IC50 values between 0.67 and 8 μmol L-1 . To explore the structure-activity relationships (SAR) of the small molecules, we tested the activities of seven analogs of the most potent identified antagonist, additionally discovering three full antagonists and four partial antagonists. These three potent antagonists (IC50 < 3.2 μmol L-1 ) were validated in vitro using the recombinant mosquito kinin receptor and showed similar antagonistic activities. In vivo, these three compounds also inhibited the mosquito hindgut contraction rate induced by a myotropic kinin agonist analog 1728. CONCLUSION Antagonists identified in this study could become pesticide leads and are reagents for probing the kinin signaling system. © 2021 Society of Chemical Industry.
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Affiliation(s)
- Caixing Xiong
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Dwight Baker
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
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10
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Nässel DR. Leucokinin and Associated Neuropeptides Regulate Multiple Aspects of Physiology and Behavior in Drosophila. Int J Mol Sci 2021; 22:1940. [PMID: 33669286 PMCID: PMC7920058 DOI: 10.3390/ijms22041940] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/08/2021] [Accepted: 02/10/2021] [Indexed: 12/17/2022] Open
Abstract
Leucokinins (LKs) constitute a family of neuropeptides identified in numerous insects and many other invertebrates. LKs act on G-protein-coupled receptors that display only distant relations to other known receptors. In adult Drosophila, 26 neurons/neurosecretory cells of three main types express LK. The four brain interneurons are of two types, and these are implicated in several important functions in the fly's behavior and physiology, including feeding, sleep-metabolism interactions, state-dependent memory formation, as well as modulation of gustatory sensitivity and nociception. The 22 neurosecretory cells (abdominal LK neurons, ABLKs) of the abdominal neuromeres co-express LK and a diuretic hormone (DH44), and together, these regulate water and ion homeostasis and associated stress as well as food intake. In Drosophila larvae, LK neurons modulate locomotion, escape responses and aspects of ecdysis behavior. A set of lateral neurosecretory cells, ALKs (anterior LK neurons), in the brain express LK in larvae, but inconsistently so in adults. These ALKs co-express three other neuropeptides and regulate water and ion homeostasis, feeding, and drinking, but the specific role of LK is not yet known. This review summarizes Drosophila data on embryonic lineages of LK neurons, functional roles of individual LK neuron types, interactions with other peptidergic systems, and orchestrating functions of LK.
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Affiliation(s)
- Dick R Nässel
- Department of Zoology, Stockholm University, S-10691 Stockholm, Sweden
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Nässel DR, Wu SF. Leucokinins: Multifunctional Neuropeptides and Hormones in Insects and Other Invertebrates. Int J Mol Sci 2021; 22:1531. [PMID: 33546414 PMCID: PMC7913504 DOI: 10.3390/ijms22041531] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 01/28/2021] [Accepted: 01/28/2021] [Indexed: 12/27/2022] Open
Abstract
Leucokinins (LKs) constitute a neuropeptide family first discovered in a cockroach and later identified in numerous insects and several other invertebrates. The LK receptors are only distantly related to other known receptors. Among insects, there are many examples of species where genes encoding LKs and their receptors are absent. Furthermore, genomics has revealed that LK signaling is lacking in several of the invertebrate phyla and in vertebrates. In insects, the number and complexity of LK-expressing neurons vary, from the simple pattern in the Drosophila larva where the entire CNS has 20 neurons of 3 main types, to cockroaches with about 250 neurons of many different types. Common to all studied insects is the presence or 1-3 pairs of LK-expressing neurosecretory cells in each abdominal neuromere of the ventral nerve cord, that, at least in some insects, regulate secretion in Malpighian tubules. This review summarizes the diverse functional roles of LK signaling in insects, as well as other arthropods and mollusks. These functions include regulation of ion and water homeostasis, feeding, sleep-metabolism interactions, state-dependent memory formation, as well as modulation of gustatory sensitivity and nociception. Other functions are implied by the neuronal distribution of LK, but remain to be investigated.
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Affiliation(s)
- Dick R. Nässel
- Department of Zoology, Stockholm University, S-10691 Stockholm, Sweden
| | - Shun-Fan Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China;
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Mateos-Hernández L, Pipová N, Allain E, Henry C, Rouxel C, Lagrée AC, Haddad N, Boulouis HJ, Valdés JJ, Alberdi P, de la Fuente J, Cabezas-Cruz A, Šimo L. Enlisting the Ixodes scapularis Embryonic ISE6 Cell Line to Investigate the Neuronal Basis of Tick-Pathogen Interactions. Pathogens 2021; 10:pathogens10010070. [PMID: 33466622 PMCID: PMC7828734 DOI: 10.3390/pathogens10010070] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 01/03/2023] Open
Abstract
Neuropeptides are small signaling molecules expressed in the tick central nervous system, i.e., the synganglion. The neuronal-like Ixodes scapularis embryonic cell line, ISE6, is an effective tool frequently used for examining tick–pathogen interactions. We detected 37 neuropeptide transcripts in the I. scapularis ISE6 cell line using in silico methods, and six of these neuropeptide genes were used for experimental validation. Among these six neuropeptide genes, the tachykinin-related peptide (TRP) of ISE6 cells varied in transcript expression depending on the infection strain of the tick-borne pathogen, Anaplasma phagocytophilum. The immunocytochemistry of TRP revealed cytoplasmic expression in a prominent ISE6 cell subpopulation. The presence of TRP was also confirmed in A. phagocytophilum-infected ISE6 cells. The in situ hybridization and immunohistochemistry of TRP of I. scapularis synganglion revealed expression in distinct neuronal cells. In addition, TRP immunoreaction was detected in axons exiting the synganglion via peripheral nerves as well as in hemal nerve-associated lateral segmental organs. The characterization of a complete Ixodes neuropeptidome in ISE6 cells may serve as an effective in vitro tool to study how tick-borne pathogens interact with synganglion components that are vital to tick physiology. Therefore, our current study is a potential stepping stone for in vivo experiments to further examine the neuronal basis of tick–pathogen interactions.
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Affiliation(s)
- Lourdes Mateos-Hernández
- UMR BIPAR, Laboratoire de Santé Animale, ANSES, INRAE, Ecole Nationale Vétérinaire d’Alfort, Paris-Est Sup, 94700 Maisons-Alfort, France; (L.M.-H.); (E.A.); (C.R.); (A.-C.L.); (N.H.); (H.-J.B.)
| | - Natália Pipová
- Faculty of Science, Pavol Jozef Šafarik University in Košice, 04180 Košice, Slovakia;
| | - Eléonore Allain
- UMR BIPAR, Laboratoire de Santé Animale, ANSES, INRAE, Ecole Nationale Vétérinaire d’Alfort, Paris-Est Sup, 94700 Maisons-Alfort, France; (L.M.-H.); (E.A.); (C.R.); (A.-C.L.); (N.H.); (H.-J.B.)
| | - Céline Henry
- AgroParisTech, Micalis Institute, Université Paris-Saclay, PAPPSO, INRAE, 78350 Jouy-en-Josas, France;
| | - Clotilde Rouxel
- UMR BIPAR, Laboratoire de Santé Animale, ANSES, INRAE, Ecole Nationale Vétérinaire d’Alfort, Paris-Est Sup, 94700 Maisons-Alfort, France; (L.M.-H.); (E.A.); (C.R.); (A.-C.L.); (N.H.); (H.-J.B.)
| | - Anne-Claire Lagrée
- UMR BIPAR, Laboratoire de Santé Animale, ANSES, INRAE, Ecole Nationale Vétérinaire d’Alfort, Paris-Est Sup, 94700 Maisons-Alfort, France; (L.M.-H.); (E.A.); (C.R.); (A.-C.L.); (N.H.); (H.-J.B.)
| | - Nadia Haddad
- UMR BIPAR, Laboratoire de Santé Animale, ANSES, INRAE, Ecole Nationale Vétérinaire d’Alfort, Paris-Est Sup, 94700 Maisons-Alfort, France; (L.M.-H.); (E.A.); (C.R.); (A.-C.L.); (N.H.); (H.-J.B.)
| | - Henri-Jean Boulouis
- UMR BIPAR, Laboratoire de Santé Animale, ANSES, INRAE, Ecole Nationale Vétérinaire d’Alfort, Paris-Est Sup, 94700 Maisons-Alfort, France; (L.M.-H.); (E.A.); (C.R.); (A.-C.L.); (N.H.); (H.-J.B.)
| | - James J. Valdés
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branisovska 31, 37005 Ceske Budejovice, Czech Republic;
- Department of Virology, Veterinary Research Institute, Hudcova 70, 62100 Brno, Czech Republic
| | - Pilar Alberdi
- SaBio Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain; (P.A.); (J.d.l.F.)
- Neuroplasticity and Neurodegeneration Group, Regional Centre for Biomedical Research (CRIB), Ciu-dad Real Medical School, University of Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - José de la Fuente
- SaBio Instituto de Investigación en Recursos Cinegéticos IREC-CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain; (P.A.); (J.d.l.F.)
- Center for Veterinary Health Sciences, Department of Veterinary Pathobiology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Alejandro Cabezas-Cruz
- UMR BIPAR, Laboratoire de Santé Animale, ANSES, INRAE, Ecole Nationale Vétérinaire d’Alfort, Paris-Est Sup, 94700 Maisons-Alfort, France; (L.M.-H.); (E.A.); (C.R.); (A.-C.L.); (N.H.); (H.-J.B.)
- Correspondence: (A.C.-C.); (L.Š.); Tel.: +33-6-31-23-51-91 (A.C.-C.); +33-1-49-77-46-52 (L.Š.)
| | - Ladislav Šimo
- UMR BIPAR, Laboratoire de Santé Animale, ANSES, INRAE, Ecole Nationale Vétérinaire d’Alfort, Paris-Est Sup, 94700 Maisons-Alfort, France; (L.M.-H.); (E.A.); (C.R.); (A.-C.L.); (N.H.); (H.-J.B.)
- Correspondence: (A.C.-C.); (L.Š.); Tel.: +33-6-31-23-51-91 (A.C.-C.); +33-1-49-77-46-52 (L.Š.)
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Xiong C, Kaczmarek K, Zabrocki J, Nachman RJ, Pietrantonio PV. Activity of native tick kinins and peptidomimetics on the cognate target G protein-coupled receptor from the cattle fever tick, Rhipicephalus microplus (Acari: Ixodidae). PEST MANAGEMENT SCIENCE 2020; 76:3423-3431. [PMID: 31794138 DOI: 10.1002/ps.5704] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/13/2019] [Accepted: 11/28/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND Kinins are multifunctional neuropeptides that regulate key insect physiological processes such as diuresis, feeding, and ecdysis. However, the physiological roles of kinins in ticks are unclear. Furthermore, ticks have an expanded number of kinin paracopies in the kinin gene. Silencing the kinin receptor (KR) in females of Rhipicephalus microplus reduces reproductive fitness. Thus, it appears the kinin signaling system is important for tick physiology and its disruption may have potential for tick control. RESULTS We determined the activities of endogenous kinins on the KR, a G protein-coupled receptor, and identified potent peptidomimetics. Fourteen predicted R. microplus kinins (Rhimi-K), and 11 kinin analogs containing aminoisobutyric acid (Aib) were tested. The latter incorporated tick kinin sequences and/or were modified for enhanced resistance to arthropod peptidases. A high-throughput screen using a calcium fluorescence assay in 384-well plates was performed. All tested kinins and Aib analogs were full agonists. The most potent kinin and two kinin analogs were equipotent. Analogs 2414 ([Aib]FS[Aib]WGa) and 2412 ([Aib]FG[Aib]WGa) were the most active with EC50 values of 0.9 and 1.1 nM, respectively, matching the EC50 of the most potent tick kinin, Rhimi-K-14 (QDSFNPWGa) (EC50 = 1 nM). The potent analog 2415 ([Aib]FR[Aib]WGa, EC50 = 6.8 nM) includes both Aib molecules for resistance to peptidases and a positively charged residue, R, for enhanced water solubility and amphiphilic character. CONCLUSION These tick kinins and pseudopeptides expand the repertoire of reagents for tick physiology and toxicology towards finding novel targets for tick management. © 2019 Society of Chemical Industry.
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Affiliation(s)
- Caixing Xiong
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Krzysztof Kaczmarek
- Institute of Organic Chemistry, Lodz University of Technology, Lodz, Poland
- Insect Neuropeptide Lab, Insect Control and Cotton Disease Research Unit, Southern Plains Agricultural Research Center, U.S. Department of Agriculture, College Station, TX, USA
| | - Janusz Zabrocki
- Institute of Organic Chemistry, Lodz University of Technology, Lodz, Poland
- Insect Neuropeptide Lab, Insect Control and Cotton Disease Research Unit, Southern Plains Agricultural Research Center, U.S. Department of Agriculture, College Station, TX, USA
| | - Ronald J Nachman
- Insect Neuropeptide Lab, Insect Control and Cotton Disease Research Unit, Southern Plains Agricultural Research Center, U.S. Department of Agriculture, College Station, TX, USA
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Sangha V, Lange AB, Orchard I. Identification and cloning of the kinin receptor in the Chagas disease vector, Rhodnius prolixus. Gen Comp Endocrinol 2020; 289:113380. [PMID: 31891689 DOI: 10.1016/j.ygcen.2019.113380] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/23/2019] [Accepted: 12/27/2019] [Indexed: 11/24/2022]
Abstract
Within invertebrates, the kinin family of neuropeptides is responsible for the modulation of a host of physiological and behavioural processes. In Rhodnius prolixus, kinins are primarily responsible for eliciting myotropic effects on various feeding and diuresis-related tissues. Here, the R. prolixus kinin receptor (RhoprKR) has been identified, cloned and sequenced from the central nervous system (CNS) and hindgut of R. prolixus. Sequence analyses show high similarity and identity between RhoprKR and other cloned invertebrate kinin receptors. The expression profile of RhoprKR shows the RhoprKR transcript throughout the R. prolixus gut, with highest expression in the hindgut, suggesting a role of Rhopr-kinins in various aspects of feeding and digestion. RNA interference (RNAi)-mediated knockdown of the RhoprKR transcript resulted in a significant reduction of hindgut contractions in response to Rhopr-kinin 2 and an Aib-containing kinin analog. dsRhoprKR- injected insects also consumed a significantly larger meal, suggesting a role of Rhopr-kinins in satiety.
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Affiliation(s)
- Vishal Sangha
- Department of Biology University of Toronto Mississauga, 3359 Mississauga Rd, Mississauga, ON L5L 1C6, Canada.
| | - Angela B Lange
- Department of Biology University of Toronto Mississauga, 3359 Mississauga Rd, Mississauga, ON L5L 1C6, Canada.
| | - Ian Orchard
- Department of Biology University of Toronto Mississauga, 3359 Mississauga Rd, Mississauga, ON L5L 1C6, Canada.
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Xiong C, Baker D, Pietrantonio PV. The Cattle Fever Tick, Rhipicephalus microplus, as a Model for Forward Pharmacology to Elucidate Kinin GPCR Function in the Acari. Front Physiol 2019; 10:1008. [PMID: 31447698 PMCID: PMC6692460 DOI: 10.3389/fphys.2019.01008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 07/22/2019] [Indexed: 12/12/2022] Open
Abstract
The success of the acaricide amitraz, a ligand of the tick tyramine/octopamine receptor (a G protein-coupled receptor; GPCR), stimulated interest on arthropod-specific GPCRs as targets to control tick populations. This search advances tick physiology because little is known about the pharmacology of tick GPCRs, their endogenous ligands or their physiological functions. Here we explored the tick kinin receptor, a neuropeptide GPCR, and its ligands. Kinins are pleiotropic insect neuropeptides but their function in ticks is unknown. The endogenous tick kinins are unknown and their cDNAs have not been cloned in any species. In contrast, more than 271 insect kinin sequences are available in the DINeR database. To fill this gap, we cloned the kinin cDNA from the cattle fever tick, Rhipicephalus microplus, which encodes 17 predicted kinins, and verified the kinin gene structure. We predicted the kinin precursor sequences from additional seven tick species, including Ixodes scapularis. All species showed an expansion of kinin paracopies. The "kinin core" (minimal active sequence) of tick kinins FX1X2WGamide is similar to those in insects. Pro was predominant at the X2 position in tick kinins. Toward accelerating the discovery of kinin function in ticks we searched for novel synthetic receptor ligands. We developed a dual-addition assay for functional screens of small molecules and/or peptidomimetics that uses a fluorescent calcium reporter. A commercial library of fourteen small molecules antagonists of mammalian neurokinin (NK) receptors was screened using this endpoint assay. One acted as full antagonist (TKSM02) with inhibitory concentration fifty (IC50) of ∼45 μM, and three were partial antagonists. A subsequent calcium bioluminescence assay tested these four antagonists through kinetic curves and confirmed TKSM02 as full antagonist and one as partial antagonist (TKSM14). Antagonists of NK receptors displayed selectivity (>10,000-fold) on the tick kinin receptor. Three peptidomimetic ligands of the mammalian NK receptors (hemokinin 1, antagonist G, and spantide I) were tested in the bioluminescence assay but none were active. Forward approaches may accelerate discovery of kinin ligands, either as reagents for tick physiological research or as lead molecules for acaricide development, and they demonstrate that selectivity is achievable between mammalian and tick neuropeptide systems.
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Affiliation(s)
- Caixing Xiong
- Department of Entomology, Texas A&M University, College Station, TX, United States
| | - Dwight Baker
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, United States
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