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Qu G, Merchant JP, Clatot J, DeFlitch LM, Frederick DJ, Tang S, Salvatore M, Zhang X, Li J, Anderson SA, Goldberg EM. Targeted blockade of aberrant sodium current in a stem cell-derived neuron model of SCN3A encephalopathy. Brain 2024; 147:1247-1263. [PMID: 37935051 PMCID: PMC10994535 DOI: 10.1093/brain/awad376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 09/30/2023] [Accepted: 10/20/2023] [Indexed: 11/09/2023] Open
Abstract
Missense variants in SCN3A encoding the voltage-gated sodium (Na+) channel α subunit Nav1.3 are associated with SCN3A-related neurodevelopmental disorder (SCN3A-NDD), a spectrum of disease that includes epilepsy and malformation of cortical development. How genetic variation in SCN3A leads to pathology remains unclear, as prior electrophysiological work on disease-associated variants has been performed exclusively in heterologous cell systems. To further investigate the mechanisms of SCN3A-NDD pathogenesis, we used CRISPR/Cas9 gene editing to modify a control human induced pluripotent stem cell (iPSC) line to express the recurrent de novo missense variant SCN3A c.2624T>C (p.Ile875Thr). With the established Ngn2 rapid induction protocol, we generated glutamatergic forebrain-like neurons (iNeurons), which we showed to express SCN3A mRNA and Nav1.3-mediated Na+ currents. We performed detailed whole-cell patch clamp recordings to determine the effect of the SCN3A-p.Ile875Thr variant on endogenous Na+ currents in, and intrinsic excitability of, human neurons. Compared to control iNeurons, variant-expressing iNeurons exhibit markedly increased slowly-inactivating/persistent Na+ current, abnormal firing patterns with paroxysmal bursting and plateau-like potentials with action potential failure, and a hyperpolarized voltage threshold for action potential generation. We then validated these findings using a separate iPSC line generated from a patient harbouring the SCN3A-p.Ile875Thr variant compared to a corresponding CRISPR-corrected isogenic control line. Finally, we found that application of the Nav1.3-selective blocker ICA-121431 normalizes action potential threshold and aberrant firing patterns in SCN3A-p.Ile1875Thr iNeurons; in contrast, consistent with action as a Na+ channel blocker, ICA-121431 decreases excitability of control iNeurons. Our findings demonstrate that iNeurons can model the effects of genetic variation in SCN3A yet reveal a complex relationship between gain-of-function at the level of the ion channel versus impact on neuronal excitability. Given the transient expression of SCN3A in the developing human nervous system, selective blockade or suppression of Nav1.3-containing Na+ channels could represent a therapeutic approach towards SCN3A-NDD.
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Affiliation(s)
- Guojie Qu
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Julie P Merchant
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Jérôme Clatot
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Leah M DeFlitch
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Danny J Frederick
- Department of Child and Adolescent Psychiatry, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Sheng Tang
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Madeleine Salvatore
- Department of Child and Adolescent Psychiatry, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Xiaohong Zhang
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Jianping Li
- Department of Child and Adolescent Psychiatry, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Stewart A Anderson
- The Epilepsy NeuroGenetics Initiative, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Child and Adolescent Psychiatry, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Psychiatry, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
| | - Ethan M Goldberg
- Division of Neurology, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
- The Epilepsy NeuroGenetics Initiative, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA
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Song T, Deng J, Chen C, Wang X, Han T, Wang X, Fang T, Tian X, Fang F. Long-term effectiveness and tolerability of ketogenic diet therapy in patients with genetic developmental and epileptic encephalopathy onset within the first 6 months of life. Epilepsia Open 2024; 9:643-652. [PMID: 38235958 PMCID: PMC10984301 DOI: 10.1002/epi4.12899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 12/31/2023] [Accepted: 01/03/2024] [Indexed: 01/19/2024] Open
Abstract
OBJECTIVE To investigate the effectiveness and tolerability of ketogenic diet therapy (KDT) in patients with developmental and epileptic encephalopathy (DEE) associated with genetic etiology which onset within the first 6 months of life, and to explore the association between response to KDT and genotype/clinical parameters. METHODS We retrospectively reviewed data from patients with genetic DEE who started KDT at Beijing Children's Hospital between January 1, 2016, and December 31, 2021. RESULTS A total of 32 patients were included, involving 14 pathogenic or likely pathogenic single genes, and 16 (50.0%) patients had sodium/potassium channel gene variants. The median age at onset of epilepsy was 1.0 (IQR: 0.1, 3.0) months. The median age at initiation of KDT was 10.0 (IQR: 5.3, 13.8) months and the median duration of maintenance was 14.0 (IQR: 7.0, 26.5) months, with a mean blood β-hydroxybutyrate of 2.49 ± 0.62 mmol/L. During the maintenance period of KDT, 26 (81.3%) patients had a ≥50% reduction of seizure frequency, of which 12 (37.5%) patients achieved seizure freedom. Better responses were observed in patients with STXBP1 variants, with four out of five patients achieving seizure freedom. There were no statistically differences in the age of onset, duration of epilepsy before KDT, blood ketone values, or the presence of ion channel gene variants between the seizure-free patients and the others. The most common adverse effects were gastrointestinal side effects, which occurred in 21 patients (65.6%), but all were mild and easily corrected. Only one patient discontinued KDT due to nephrolithiasis. SIGNIFICANCE KDT is effective in treating early onset genetic DEE, and no statistically significant relationship has been found between genotype and effectiveness in this study. KDT is well tolerated in most young patients, with mild and reversible gastrointestinal side effects being the most common, but usually not the reason to discontinue KDT. PLAIN LANGUAGE SUMMARY This study evaluated the response and side effects of ketogenic diet therapy (KDT) in patients who had seizures within the first 6 months of life, and were diagnosed with genetic developmental and epileptic encephalopathy (DEE), a type of severe epilepsy with developmental delay caused by gene variants. Thirty-two patients involving 14 gene variants who started KDT at Beijing Children's Hospital between were included. KDT was effective in treating early onset genetic DEE in this cohort, and patients with STXBP1 variants responded better; however, no statistically significant relationship was found between gene variant and response. Most young patients tolerated KDT well, with mild and reversible gastrointestinal side effects being the most common.
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Affiliation(s)
- Tianyu Song
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Jie Deng
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Chunhong Chen
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Xiaohui Wang
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Tongli Han
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Xu Wang
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Tie Fang
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Xiaojuan Tian
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
| | - Fang Fang
- Department of Neurology, Beijing Children's HospitalCapital Medical University, National Center for Children's HealthBeijingChina
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Hill SF, Yu W, Ziobro J, Chalasani S, Reger F, Meisler MH. Long-Term Downregulation of the Sodium Channel Gene Scn8a Is Therapeutic in Mouse Models of SCN8A Epilepsy. Ann Neurol 2024; 95:754-759. [PMID: 38113311 DOI: 10.1002/ana.26861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 11/06/2023] [Accepted: 12/14/2023] [Indexed: 12/21/2023]
Abstract
OBJECTIVE De novo mutations of the voltage-gated sodium channel gene SCN8A cause developmental and epileptic encephalopathy (DEE). Most pathogenic variants result in gain-of-function changes in activity of the sodium channel Nav1.6, poorly controlled seizures, and significant comorbidities. In previous work, an antisense oligonucleotide (ASO) reduced Scn8a transcripts and increased lifespan after neonatal administration to a mouse model. Here, we tested long-term ASO treatment initiated after seizure onset, as required for clinical application. METHODS ASO treatment was initiated after observation of a convulsive seizure and repeated at 4 to 6 week intervals for 1 year. We also tested the long-term efficacy of an AAV10-short hairpin RNA (shRNA) virus administered on P1. RESULTS Repeated treatment with the Scn8a ASO initiated after seizure onset provided long-term survival and reduced seizure frequency during a 12 month observation period. A single treatment with viral shRNA was also protective during 12 months of observation. INTERPRETATION Downregulation of Scn8a expression that is initiated after the onset of seizures is effective for long-term treatment in a model of SCN8A-DEE. Repeated ASO administration or a single dose of viral shRNA prevented seizures and extended survival through 12 months of observation. ANN NEUROL 2024;95:754-759.
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Affiliation(s)
- Sophie F Hill
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States
- Department of Human Genetics, University of Michigan, Ann Arbor, MI
| | - Wenxi Yu
- Department of Human Genetics, University of Michigan, Ann Arbor, MI
| | - Julie Ziobro
- Department of Pediatrics, University of Michigan, Ann Arbor, MI
| | - Sanjna Chalasani
- Department of Human Genetics, University of Michigan, Ann Arbor, MI
| | - Faith Reger
- Department of Human Genetics, University of Michigan, Ann Arbor, MI
| | - Miriam H Meisler
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States
- Department of Human Genetics, University of Michigan, Ann Arbor, MI
- Department of Neurology, University of Michigan, Ann Arbor, MI
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Yang Y, Chen Z, Zhou J, Jiang S, Wang G, Wan L, Yu J, Jiang M, Wang Y, Hu J, Liu X, Wang Y. Anti-PD-1 treatment protects against seizure by suppressing sodium channel function. CNS Neurosci Ther 2024; 30:e14504. [PMID: 37904722 PMCID: PMC11017438 DOI: 10.1111/cns.14504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 10/05/2023] [Accepted: 10/06/2023] [Indexed: 11/01/2023] Open
Abstract
AIMS Although programmed cell death protein 1 (PD-1) typically serves as a target for immunotherapies, a few recent studies have found that PD-1 is expressed in the nervous system and that neuronal PD-1 might play a crucial role in regulating neuronal excitability. However, whether brain-localized PD-1 is involved in seizures and epileptogenesis is still unknown and worthy of in-depth exploration. METHODS The existence of PD-1 in human neurons was confirmed by immunohistochemistry, and PD-1 expression levels were measured by real-time quantitative PCR (RT-qPCR) and western blotting. Chemoconvulsants, pentylenetetrazol (PTZ) and cyclothiazide (CTZ), were applied for the establishment of in vivo (rodents) and in vitro (primary hippocampal neurons) models of seizure, respectively. SHR-1210 (a PD-1 monoclonal antibody) and sodium stibogluconate (SSG, a validated inhibitor of SH2-containing protein tyrosine phosphatase-1 [SHP-1]) were administrated to investigate the impact of PD-1 pathway blockade on epileptic behaviors of rodents and epileptiform discharges of neurons. A miRNA strategy was applied to determine the impact of PD-1 knockdown on neuronal excitability. The electrical activities and sodium channel function of neurons were determined by whole-cell patch-clamp recordings. The interaction between PD-1 and α-6 subunit of human voltage-gated sodium channel (Nav1.6) was validated by performing co-immunostaining and co-immunoprecipitation (co-IP) experiments. RESULTS Our results reveal that PD-1 protein and mRNA levels were upregulated in lesion cores compared with perifocal tissues of surgically resected specimens from patients with intractable epilepsy. Furthermore, we show that anti-PD-1 treatment has anti-seizure effects both in vivo and in vitro. Then, we reveal that PD-1 blockade can alter the electrophysiological properties of sodium channels. Moreover, we reveal that PD-1 acts together with downstream SHP-1 to regulate sodium channel function and hence neuronal excitability. Further investigation suggests that there is a direct interaction between neuronal PD-1 and Nav1.6. CONCLUSION Our study reveals that neuronal PD-1 plays an important role in epilepsy and that anti-PD-1 treatment protects against seizures by suppressing sodium channel function, identifying anti-PD-1 treatment as a novel therapeutic strategy for epilepsy.
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Affiliation(s)
- Yuling Yang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan HospitalFudan UniversityShanghaiChina
| | - Zhiyun Chen
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan HospitalFudan UniversityShanghaiChina
| | - Jing Zhou
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan HospitalFudan UniversityShanghaiChina
- Rehabilitation CenterShenzhen Second People's Hospital/The First Affiliated Hospital of Shenzhen University Health Science CenterShenzhenChina
| | - Shize Jiang
- Department of Neurosurgery, Huashan HospitalFudan UniversityShanghaiChina
| | - Guoxiang Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan HospitalFudan UniversityShanghaiChina
| | - Li Wan
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan HospitalFudan UniversityShanghaiChina
- Rehabilitation CenterShenzhen Second People's Hospital/The First Affiliated Hospital of Shenzhen University Health Science CenterShenzhenChina
| | - Jiangning Yu
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan HospitalFudan UniversityShanghaiChina
| | - Min Jiang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan HospitalFudan UniversityShanghaiChina
| | - Yulong Wang
- Rehabilitation CenterShenzhen Second People's Hospital/The First Affiliated Hospital of Shenzhen University Health Science CenterShenzhenChina
| | - Jie Hu
- Department of Neurosurgery, Huashan HospitalFudan UniversityShanghaiChina
| | - Xu Liu
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan HospitalFudan UniversityShanghaiChina
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Zhongshan HospitalFudan UniversityShanghaiChina
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Hauser FE, Xiao D, Van Nynatten A, Brochu-De Luca KK, Rajakulendran T, Elbassiouny AE, Sivanesan H, Sivananthan P, Crampton WGR, Lovejoy NR. Ecologically mediated differences in electric organ discharge drive evolution in a sodium channel gene in South American electric fishes. Biol Lett 2024; 20:20230480. [PMID: 38412964 PMCID: PMC10898970 DOI: 10.1098/rsbl.2023.0480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/29/2024] [Indexed: 02/29/2024] Open
Abstract
Active electroreception-the ability to detect objects and communicate with conspecifics via the detection and generation of electric organ discharges (EODs)-has evolved convergently in several fish lineages. South American electric fishes (Gymnotiformes) are a highly species-rich group, possibly in part due to evolution of an electric organ (EO) that can produce diverse EODs. Neofunctionalization of a voltage-gated sodium channel gene accompanied the evolution of electrogenic tissue from muscle and resulted in a novel gene (scn4aa) uniquely expressed in the EO. Here, we investigate the link between variation in scn4aa and differences in EOD waveform. We combine gymnotiform scn4aa sequences encoding the C-terminus of the Nav1.4a protein, with biogeographic data and EOD recordings to test whether physiological transitions among EOD types accompany differential selection pressures on scn4aa. We found positive selection on scn4aa coincided with shifts in EOD types. Species that evolved in the absence of predators, which likely selected for reduced EOD complexity, exhibited increased scn4aa evolutionary rates. We model mutations in the protein that may underlie changes in protein function and discuss our findings in the context of gymnotiform signalling ecology. Together, this work sheds light on the selective forces underpinning major evolutionary transitions in electric signal production.
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Affiliation(s)
- Frances E. Hauser
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
| | - Dawn Xiao
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
| | - Alexander Van Nynatten
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord St, Toronto, Ontario, Canada M5S 3G5
| | - Kristen K. Brochu-De Luca
- Department of Entomology, Pennsylvania State University, 501 ASI Building, University Park, PA 16802, USA
- School of Chemistry, Environmental and Life Sciences, University of The Bahamas, Oakes Field Campus, Nassau, New Providence, The Bahamas
| | - Thanara Rajakulendran
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
| | - Ahmed E. Elbassiouny
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord St, Toronto, Ontario, Canada M5S 3G5
| | - Harunya Sivanesan
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
| | - Pradeega Sivananthan
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
| | - William G. R. Crampton
- Department of Biology, University of Central Florida, 4110 Libra Dr, Orlando, FL 32816, USA
| | - Nathan R. Lovejoy
- Department of Biological Sciences, University of Toronto Scarborough, 1265 Military Trail, Toronto, Ontario, Canada M1C 1A4
- Department of Cell and Systems Biology, University of Toronto, 25 Harbord St, Toronto, Ontario, Canada M5S 3G5
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks St, Toronto, Ontario, Canada M5S 3B2
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Zhang Z, Brugada P, Weiss JN, Qu Z. Phase 2 Re-Entry Without I to: Role of Sodium Channel Kinetics in Brugada Syndrome Arrhythmias. JACC Clin Electrophysiol 2023; 9:2459-2474. [PMID: 37831035 DOI: 10.1016/j.jacep.2023.08.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/27/2023] [Accepted: 08/23/2023] [Indexed: 10/14/2023]
Abstract
BACKGROUND In Brugada syndrome (BrS), phase 2 re-excitation/re-entry (P2R) induced by the transient outward potassium current (Ito) is a proposed arrhythmia mechanism; yet, the most common genetic defects are loss-of-function sodium channel mutations. OBJECTIVES The authors used computer simulations to investigate how sodium channel dysfunction affects P2R-mediated arrhythmogenesis in the presence and absence of Ito. METHODS Computer simulations were carried out in 1-dimensional cables and 2-dimensional tissue using guinea pig and human ventricular action potential models. RESULTS In the presence of Ito sufficient to generate robust P2R, reducing sodium current (INa) peak amplitude alone only slightly potentiated P2R. When INa inactivation kinetics were also altered to simulate reported effects of BrS mutations and sodium channel blockers, however, P2R occurred even in the absence of Ito. These effects could be potentiated by delaying L-type calcium channel activation or increasing ATP-sensitive potassium current, consistent with experimental and clinical findings. INa-mediated P2R also accounted for sex-related, day and night-related, and fever-related differences in arrhythmia risk in BrS patients. CONCLUSIONS Altered INa kinetics synergize powerfully with reduced INa amplitude to promote P2R-induced arrhythmias in BrS in the absence of Ito, establishing a robust mechanistic link between altered INa kinetics and the P2R-mediated arrhythmia mechanism.
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Affiliation(s)
- Zhaoyang Zhang
- Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo, Zhejiang, China; Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Pedro Brugada
- Heart Rhythm Management Centre, Postgraduate Program in Cardiac Electrophysiology and Pacing, Universitair Ziekenhuis Brussel-Vrije Universiteit Brussel, European Reference Networks Guard-Heart, Brussels, Belgium
| | - James N Weiss
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Zhilin Qu
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, California, USA.
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Tehrani Fateh S, Bagheri S, Sadeghi H, Salehpour S, Fazeli Bavandpour F, Sadeghi B, Jamshidi S, Tonekaboni SH, Mirfakhraie R, Miryounesi M, Ghasemi MR. Extending and outlining the genotypic and phenotypic spectrum of novel mutations of NALCN gene in IHPRF1 syndrome: identifying recurrent urinary tract infection. Neurol Sci 2023; 44:4491-4498. [PMID: 37452996 DOI: 10.1007/s10072-023-06960-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Infantile hypotonia with psychomotor retardation and characteristic facies 1 (IHPRF1) is caused by biallelic mutations in the NALCN gene, the major ion channel responsible for the background Na + conduction in neurons. Through whole-exome sequencing (WES), we report three novel homozygous variants in three families, including c.1434 + 1G > A, c.3269G > A, and c.2648G > T, which are confirmed and segregated by Sanger sequencing. Consequently, intron 12's highly conserved splice donor location is disrupted by the pathogenic c.1434 + 1G > A variation, most likely causing the protein to degrade through nonsense-mediated decay (NMD). Subsequently, a premature stop codon is thus generated at amino acid 1090 of the protein as a result of the pathogenic c.3269G > A; p.W1090* variation, resulting in NMD or truncated protein production. Lastly, the missense mutation c.2648G > T; p.G883V can play a critical role in the interplay of functional domains. This study introduces recurrent urinary tract infections for the first time, broadening the phenotypic range of IHPRF1 syndrome in addition to the genotypic spectrum. This trait may result from insufficient bladder emptying, which may be related to the NALCN channelosome's function in background Na + conduction. This work advances knowledge about the molecular genetic underpinnings of IHPRF1 and introduces a novel phenotype through the widespread use of whole exome sequencing.
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Affiliation(s)
- Sahand Tehrani Fateh
- School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Saman Bagheri
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Sadeghi
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shadab Salehpour
- Department of Pediatrics, Clinical Research Development Unit, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Behnia Sadeghi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sanaz Jamshidi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyed Hassan Tonekaboni
- Department of Pediatric Neurology, School of Medicine, Pediatric Neurology Research Center, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Mirfakhraie
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Miryounesi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Mohammad-Reza Ghasemi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Liu Z, Wang Z, Wei Y, Shi J, Shi T, Chen X, Li L. Transcriptomic Profiling of Tetrodotoxin-Induced Neurotoxicity in Human Cerebral Organoids. Mar Drugs 2023; 21:588. [PMID: 37999412 PMCID: PMC10672545 DOI: 10.3390/md21110588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 10/30/2023] [Accepted: 11/07/2023] [Indexed: 11/25/2023] Open
Abstract
Tetrodotoxin (TTX) is an exceedingly toxic non-protein biotoxin that demonstrates remarkable selectivity and affinity for sodium channels on the excitation membrane of nerves. This property allows TTX to effectively obstruct nerve conduction, resulting in nerve paralysis and fatality. Although the mechanistic aspects of its toxicity are well understood, there is a dearth of literature addressing alterations in the neural microenvironment subsequent to TTX poisoning. In this research endeavor, we harnessed human pluripotent induced stem cells to generate cerebral organoids-an innovative model closely mirroring the structural and functional intricacies of the human brain. This model was employed to scrutinize the comprehensive transcriptomic shifts induced by TTX exposure, thereby delving into the neurotoxic properties of TTX and its potential underlying mechanisms. Our findings revealed 455 differentially expressed mRNAs (DEmRNAs), 212 differentially expressed lncRNAs (DElncRNAs), and 18 differentially expressed miRNAs (DEmiRNAs) in the TTX-exposed group when juxtaposed with the control cohort. Through meticulous Gene Ontology (GO) annotation, Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, and protein-protein interaction (PPI) analysis, we ascertained that these differential genes predominantly participate in the regulation of voltage-gated channels and synaptic homeostasis. A comprehensive ceRNA network analysis unveiled that DEmRNAs exert control over the expression of ion channels and neurocytokines, suggesting their potential role in mediating apoptosis.
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Affiliation(s)
- Zhanbiao Liu
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, Dalian Minzu University, Dalian 116600, China
| | - Zhe Wang
- Key Laboratory of Biotechnology and Bioresources Utilization of Ministry of Education, Dalian Minzu University, Dalian 116600, China
| | - Yue Wei
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
| | - Jingjing Shi
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
| | - Tong Shi
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
| | - Xuejun Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
| | - Liqin Li
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China (J.S.)
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9
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Riebenbauer K, Purkhauser K, Walochnik J, Urban N, Weber PB, Stamm T, Handisurya A. Detection of a knockdown mutation in the voltage-sensitive sodium channel associated with permethrin tolerance in Sarcoptes scabiei var. hominis mites. J Eur Acad Dermatol Venereol 2023; 37:2355-2361. [PMID: 37356045 DOI: 10.1111/jdv.19288] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 06/01/2023] [Indexed: 06/27/2023]
Abstract
BACKGROUND Increasing evidence has sparked a debate on the loss of sensitivity of scabies mites to conventional permethrin therapy. Mutations in the voltage-sensitive sodium channels (VSSC) were associated with knockdown resistance (kdr) in many arthropods, but have never been identified in Sarcoptes scabiei variatio (var.) hominis mites. OBJECTIVES To identify factors contributing to therapy failure. METHODS Sixty-seven mites were collected from 64 scabies-infested patients in Vienna, Austria, of whom 85.9% were refractory to prior permethrin-based treatments, and genotyped for the presence of nucleotide polymorphisms in Domain II of the VSSC, known to be associated with kdr. Information regarding previous antiscabietic therapies, decontamination procedures and possible re-infestations by contacts as well as the response to re-imposed therapies were obtained. RESULTS Sequence alignment comparisons revealed previously unidentified mutations in the coding region of Domain II of the VSSC. A novel A1663T transversion was detected in 97.0% of the mites, resulting in a non-synonymous substitution from methionine to leucine, M918L, a mutation known to confer kdr in other arthropods. In addition, a synonymous G1659A transition was identified in one mite, which otherwise showed a nucleotide sequence identical to the wild-type reference. No major inconsistencies were observed within the previous therapeutic and decontamination procedures, which could have accounted for the observed non-responsiveness to permethrin-based therapies. Subsequent cure of infestation was achieved in 65.6% of the participants, predominantly by combination therapies with topical permethrin and systemic ivermectin. However, in 14.6% of the cured cases, permethrin monotherapy sufficed for eradication of scabies, albeit in some cases prolonged exposure was necessary. CONCLUSIONS The kdr-associated M918L mutation in the VSSC gene has now emerged in S. scabiei var. hominis mites. Hence, loss of sensitivity to permethrin due to kdr-type resistance may be more prevalent than anticipated and may be decisive for the therapy responsiveness of scabies-infested patients.
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Affiliation(s)
- K Riebenbauer
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - K Purkhauser
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - J Walochnik
- Institute of Specific Prophylaxis and Tropical Medicine, Center for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria
| | - N Urban
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - P B Weber
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
| | - T Stamm
- Center for Medical Data Science, Institute of Outcomes Research, Medical University of Vienna & Ludwig Boltzmann Institute for Arthritis and Rehabilitation, Vienna, Austria
| | - A Handisurya
- Department of Dermatology, Medical University of Vienna, Vienna, Austria
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10
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McMahon KL, O'Brien H, Schroeder CI, Deuis JR, Venkatachalam D, Huang D, Green BR, Bandyopadhyay PK, Li Q, Yandell M, Safavi-Hemami H, Olivera BM, Vetter I, Robinson SD. Identification of sodium channel toxins from marine cone snails of the subgenera Textilia and Afonsoconus. Cell Mol Life Sci 2023; 80:287. [PMID: 37689602 PMCID: PMC10492761 DOI: 10.1007/s00018-023-04935-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Revised: 08/20/2023] [Accepted: 08/22/2023] [Indexed: 09/11/2023]
Abstract
Voltage-gated sodium (NaV) channels are transmembrane proteins that play a critical role in electrical signaling in the nervous system and other excitable tissues. µ-Conotoxins are peptide toxins from the venoms of marine cone snails (genus Conus) that block NaV channels with nanomolar potency. Most species of the subgenera Textilia and Afonsoconus are difficult to acquire; therefore, their venoms have yet to be comprehensively interrogated for µ-conotoxins. The goal of this study was to find new µ-conotoxins from species of the subgenera Textilia and Afonsoconus and investigate their selectivity at human NaV channels. Using RNA-seq of the venom gland of Conus (Textilia) bullatus, we identified 12 µ-conotoxin (or µ-conotoxin-like) sequences. Based on these sequences we designed primers which we used to identify additional µ-conotoxin sequences from DNA extracted from historical specimens of species from Textilia and Afonsoconus. We synthesized six of these µ-conotoxins and tested their activity on human NaV1.1-NaV1.8. Five of the six synthetic peptides were potent blockers of human NaV channels. Of these, two peptides (BuIIIB and BuIIIE) were potent blockers of hNaV1.3. Three of the peptides (BuIIIB, BuIIIE and AdIIIA) had submicromolar activity at hNaV1.7. This study serves as an example of the identification of new peptide toxins from historical DNA and provides new insights into structure-activity relationships of µ-conotoxins with activity at hNaV1.3 and hNaV1.7.
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Affiliation(s)
- Kirsten L McMahon
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Henrik O'Brien
- Biology Department, University of Utah, Salt Lake City, UT, 84112, USA
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
- Peptide Therapeutics, Genentech, 1 DNA Way, South San Francisco, CA, 94080, USA
| | - Jennifer R Deuis
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | | | - Di Huang
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Brad R Green
- Biology Department, University of Utah, Salt Lake City, UT, 84112, USA
| | | | - Qing Li
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT, 84112, USA
- Cancer Bioinformatics, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, 84112, USA
| | - Mark Yandell
- Department of Human Genetics, Utah Center for Genetic Discovery, University of Utah, Salt Lake City, UT, 84112, USA
| | | | | | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Samuel D Robinson
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia.
- Biology Department, University of Utah, Salt Lake City, UT, 84112, USA.
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11
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Asadollahi R, Delvendahl I, Muff R, Tan G, Rodríguez DG, Turan S, Russo M, Oneda B, Joset P, Boonsawat P, Masood R, Mocera M, Ivanovski I, Baumer A, Bachmann-Gagescu R, Schlapbach R, Rehrauer H, Steindl K, Begemann A, Reis A, Winkler J, Winner B, Müller M, Rauch A. Pathogenic SCN2A variants cause early-stage dysfunction in patient-derived neurons. Hum Mol Genet 2023; 32:2192-2204. [PMID: 37010102 PMCID: PMC10281746 DOI: 10.1093/hmg/ddad048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/23/2023] [Accepted: 03/19/2023] [Indexed: 04/04/2023] Open
Abstract
Pathogenic heterozygous variants in SCN2A, which encodes the neuronal sodium channel NaV1.2, cause different types of epilepsy or intellectual disability (ID)/autism without seizures. Previous studies using mouse models or heterologous systems suggest that NaV1.2 channel gain-of-function typically causes epilepsy, whereas loss-of-function leads to ID/autism. How altered channel biophysics translate into patient neurons remains unknown. Here, we investigated iPSC-derived early-stage cortical neurons from ID patients harboring diverse pathogenic SCN2A variants [p.(Leu611Valfs*35); p.(Arg937Cys); p.(Trp1716*)] and compared them with neurons from an epileptic encephalopathy (EE) patient [p.(Glu1803Gly)] and controls. ID neurons consistently expressed lower NaV1.2 protein levels. In neurons with the frameshift variant, NaV1.2 mRNA and protein levels were reduced by ~ 50%, suggesting nonsense-mediated decay and haploinsufficiency. In other ID neurons, only protein levels were reduced implying NaV1.2 instability. Electrophysiological analysis revealed decreased sodium current density and impaired action potential (AP) firing in ID neurons, consistent with reduced NaV1.2 levels. In contrast, epilepsy neurons displayed no change in NaV1.2 levels or sodium current density, but impaired sodium channel inactivation. Single-cell transcriptomics identified dysregulation of distinct molecular pathways including inhibition of oxidative phosphorylation in neurons with SCN2A haploinsufficiency and activation of calcium signaling and neurotransmission in epilepsy neurons. Together, our patient iPSC-derived neurons reveal characteristic sodium channel dysfunction consistent with biophysical changes previously observed in heterologous systems. Additionally, our model links the channel dysfunction in ID to reduced NaV1.2 levels and uncovers impaired AP firing in early-stage neurons. The altered molecular pathways may reflect a homeostatic response to NaV1.2 dysfunction and can guide further investigations.
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Affiliation(s)
- R Asadollahi
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
- Faculty of Engineering and Science, University of Greenwich London, Medway Campus, Chatham Maritime ME4 4TB, UK
| | - I Delvendahl
- Department of Molecular Life Sciences, University of Zurich, Zurich 8057, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich 8057, Switzerland
| | - R Muff
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - G Tan
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich 8057, Switzerland
| | - D G Rodríguez
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich 8057, Switzerland
| | - S Turan
- Department of Stem Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
| | - M Russo
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - B Oneda
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - P Joset
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - P Boonsawat
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - R Masood
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - M Mocera
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - I Ivanovski
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - A Baumer
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - R Bachmann-Gagescu
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - R Schlapbach
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich 8057, Switzerland
| | - H Rehrauer
- Functional Genomics Center Zurich, ETH Zurich and University of Zurich, Zurich 8057, Switzerland
| | - K Steindl
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - A Begemann
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
| | - A Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
| | - J Winkler
- Department of Molecular Neurology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
- Center for Rare Diseases Erlangen, University Hospital Erlangen, Erlangen 91054, Germany
| | - B Winner
- Department of Stem Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen 91054, Germany
- Center for Rare Diseases Erlangen, University Hospital Erlangen, Erlangen 91054, Germany
| | - M Müller
- Department of Molecular Life Sciences, University of Zurich, Zurich 8057, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich 8057, Switzerland
- University of Zurich Clinical Research Priority Program (CRPP) Praeclare – Personalized prenatal and reproductive medicine, Zurich 8006, Switzerland
- University of Zurich Research Priority Program (URPP) AdaBD: Adaptive Brain Circuits in Development and Learning, Zurich 8006, Switzerland
| | - A Rauch
- Institute of Medical Genetics, University of Zurich, Schlieren-Zurich 8952, Switzerland
- Neuroscience Center Zurich, University of Zurich, Zurich 8057, Switzerland
- University of Zurich Clinical Research Priority Program (CRPP) Praeclare – Personalized prenatal and reproductive medicine, Zurich 8006, Switzerland
- University of Zurich Research Priority Program (URPP) AdaBD: Adaptive Brain Circuits in Development and Learning, Zurich 8006, Switzerland
- University of Zurich Research Priority Program (URPP) ITINERARE: Innovative Therapies in Rare Diseases, Zurich 8006, Switzerland
- Zurich Center for Integrative Human Physiology, University of Zurich, Zurich 8057, Switzerland
- University Children's Hospital Zurich, University of Zurich, Zurich 8032, Switzerland
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12
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Marra C, Hartke TV, Ringkamp M, Goldfarb M. Enhanced sodium channel inactivation by temperature and FHF2 deficiency blocks heat nociception. Pain 2023; 164:1321-1331. [PMID: 36607284 PMCID: PMC10166761 DOI: 10.1097/j.pain.0000000000002822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 10/13/2022] [Accepted: 10/31/2022] [Indexed: 01/07/2023]
Abstract
ABSTRACT Transient voltage-gated sodium currents are essential for the initiation and conduction of action potentials in neurons and cardiomyocytes. The amplitude and duration of sodium currents are tuned by intracellular fibroblast growth factor homologous factors (FHFs/iFGFs) that associate with the cytoplasmic tails of voltage-gated sodium channels (Na v s), and genetic ablation of Fhf genes disturbs neurological and cardiac functions. Among reported phenotypes, Fhf2null mice undergo lethal hyperthermia-induced cardiac conduction block attributable to the combined effects of FHF2 deficiency and elevated temperature on the cardiac sodium channel (Na v 1.5) inactivation rate. Fhf2null mice also display a lack of heat nociception, while retaining other somatosensory capabilities. Here, we use electrophysiological and computational methods to show that the heat nociception deficit can be explained by the combined effects of elevated temperature and FHF2 deficiency on the fast inactivation gating of Na v 1.7 and tetrodotoxin-resistant sodium channels expressed in dorsal root ganglion C fibers. Hence, neurological and cardiac heat-associated deficits in Fhf2null mice derive from shared impacts of FHF deficiency and temperature towards Na v inactivation gating kinetics in distinct tissues.
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Affiliation(s)
- Christopher Marra
- Department of Biological Sciences, Hunter College of City University, New York, NY, United States
- Program in Biology, Graduate Center of City University, New York, NY, United States
| | - Timothy V. Hartke
- Department of Neurosurgery, Neurosurgery Pain Research Institute, Johns Hopkins University, Baltimore, MD, United States
| | - Matthias Ringkamp
- Department of Neurosurgery, Neurosurgery Pain Research Institute, Johns Hopkins University, Baltimore, MD, United States
| | - Mitchell Goldfarb
- Department of Biological Sciences, Hunter College of City University, New York, NY, United States
- Program in Biology, Graduate Center of City University, New York, NY, United States
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13
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Pedersen JJ, Stemmerik MG, Jacobsen LN, Skriver SV, Wilms GR, Duno M, Vissing J. Muscle fat replacement and contractility in patients with skeletal muscle sodium channel disorders. Sci Rep 2023; 13:2538. [PMID: 36782059 PMCID: PMC9925746 DOI: 10.1038/s41598-023-29759-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 02/09/2023] [Indexed: 02/15/2023] Open
Abstract
Skeletal muscle sodium channel disorders give rise to episodic symptoms such as myotonia and/or periodic paralysis. Chronic symptoms with permanent weakness are not considered characteristic of the phenotypes. Muscle fat replacement represents irreversible damage that inevitably will impact on muscle strength. This study investigates muscle fat replacement and contractility in patients with pathogenic SCN4A variants compared to healthy controls. T1-weighted and 2-point Dixon MRI of the legs were conducted to assess fat replacement. Stationary dynamometry was used to assess muscle strength. Contractility was determined by maximal muscle contraction divided by cross-sectional muscle area. The average cross-sectional intramuscular fat fraction was greater in patients compared with controls by 2.5% in the calves (95% CI 0.74-4.29%, p = 0.007) and by 2.0% in the thighs (95% CI 0.75-3.2%, p = 0.003). Muscle contractility was less in patients vs. controls by 14-27% (p < 0.05). Despite greater fat fraction and less contractility, absolute strength was not significantly less. This study quantitatively documents greater fat fraction and additionally describes difference in muscle contractility in a large cohort of patients with skeletal muscle sodium channel disorders. The clinical impact of these abnormal findings is likely limited as muscle hypertrophy in the patients served to preserve absolute muscle strength. Subgroup analysis indicated significant difference in phenotype by genotype, however these findings lack statistical significance and serve as inspiration for future researchers to probe into the geno- phenotype relationship in these disorders.Trial registration: The study was registered at http://clinicaltrials.gov (identifier: NCT04808388).
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Affiliation(s)
- Jonas Jalili Pedersen
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Inge Lehmanns Vej 7-9, 2100, Copenhagen, Denmark.
| | - Mads Godtfeldt Stemmerik
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Inge Lehmanns Vej 7-9, 2100, Copenhagen, Denmark
| | - Laura Nørager Jacobsen
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Inge Lehmanns Vej 7-9, 2100, Copenhagen, Denmark
| | - Sofie Vinther Skriver
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Inge Lehmanns Vej 7-9, 2100, Copenhagen, Denmark
| | - Gustav Rhode Wilms
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Inge Lehmanns Vej 7-9, 2100, Copenhagen, Denmark
| | - Morten Duno
- Clinical Genetic Laboratory, Department of Biochemical Genetics, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - John Vissing
- Copenhagen Neuromuscular Center, Department of Neurology, Rigshospitalet, University of Copenhagen, Inge Lehmanns Vej 7-9, 2100, Copenhagen, Denmark
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14
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Maselli K, Park H, Breilyn MS, Arens R. Severe central sleep apnea in a child with biallelic variants in NALCN. J Clin Sleep Med 2022; 18:2507-2513. [PMID: 35808948 PMCID: PMC9516572 DOI: 10.5664/jcsm.10146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022]
Abstract
The sodium leak channel, nonselective (NALCN), is necessary for the proper function of the neurons that play an important role in the sleep-wake cycle and regulation of breathing patterns during wakefulness and sleep. We report a 38-month-old male with developmental delay, hypotonia, and severe central sleep apnea with periodic breathing requiring noninvasive ventilation during sleep, who was found to have novel biallelic pathogenic variants in NALCN. A review of the literature illustrates 17 additional children with biallelic variants in the NALCN gene. The clinical and sleep manifestations of these children are discussed. CITATION Maselli K, Park H, Breilyn MS, Arens R. Severe central sleep apnea in a child with biallelic variants in NALCN. J Clin Sleep Med. 2022;18(10):2507-2513.
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Affiliation(s)
- Kristina Maselli
- Sleep Wake Disorders Center, Department of Neurology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Hyunbin Park
- Division of Pediatric Respiratory and Sleep Medicine, Department of Pediatrics, Children’s Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York
| | - Margo Sheck Breilyn
- Genetics and Genomics, Department of Pediatrics, The Mount Sinai Hospital, New York, New York
| | - Raanan Arens
- Division of Pediatric Respiratory and Sleep Medicine, Department of Pediatrics, Children’s Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York
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15
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Gao F, Wang D, Liu X, Wu YH, Wang HT, Sun SL. Sodium channel 1 subunit alpha SCNN1A exerts oncogenic function in pancreatic cancer via accelerating cellular growth and metastasis. Arch Biochem Biophys 2022; 727:109323. [PMID: 35714697 DOI: 10.1016/j.abb.2022.109323] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/05/2022] [Accepted: 06/10/2022] [Indexed: 11/24/2022]
Abstract
The identification of new diagnostic and therapeutic biomarkers might be helpful to understand molecular mechanism of cancer pathogenesis and develop anti-cancer targets. This study reported the alteration of Sodium channel 1 subunit alpha (SCNN1A) expression, its prognostic significance and biological roles in pancreatic cancer. Bioinformatics database was searched to explore the expression of SCNN1A in pancreatic cancer specimens and analysis results were further validated by qRT-PCR and Western blot assay. The correlation between SCNN1A expression and clinicopathological characteristics and its impact on survival outcome of pancreatic cancer patients were investigated using GEPIA database and Kaplan-Meier plotter. Loss- and gain-of-functional experiments in vitro were done to investigate the biological function of SCNN1A in pancreatic cancer. Bioinformatics analysis and validation experiment showed that SCNN1A was frequently overexpressed in pancreatic cancer specimens and cell lines (P < 0.001), and there were significant relevance between high SCNN1A expression and TP53 mutation (P < 0.05) as well as unfavorable prognosis of pancreatic cancer patients (HR for overall survival: 1.9, P = 0.003 and HR for disease-free survival: 1.7, P = 0.014). The silencing of SCNN1A suppressed cell proliferation, migration and invasion and induced cell apoptosis (P < 0.05), while its overexpression promoted aggressive phenotypes of pancreatic cancer cells in vitro (P < 0.05). SCNN1A possessed oncogenic function and its dysregulation could be implicated in the development and metastasis of pancreatic cancer.
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Affiliation(s)
- Feng Gao
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Dan Wang
- Department of Pancreatic Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Xun Liu
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Yun-Hao Wu
- Department of Pancreatic Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Huai-Tao Wang
- Department of Pancreatic Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Shao-Long Sun
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China.
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16
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Sun H, Nomura Y, Du Y, Liu Z, Zhorov BS, Dong K. Characterization of two kdr mutations at predicted pyrethroid receptor site 2 in the sodium channels of Aedes aegypti and Nilaparvata lugens. Insect Biochem Mol Biol 2022; 148:103814. [PMID: 35932971 PMCID: PMC10076083 DOI: 10.1016/j.ibmb.2022.103814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 07/11/2022] [Accepted: 07/17/2022] [Indexed: 05/12/2023]
Abstract
Pyrethroid insecticides prolong the opening of insect sodium channels by binding to two predicted pyrethroid receptor sites (PyR), PyR1 and PyR2. Many naturally-occurring sodium channel mutations that confer pyrethroid resistance (known as knockdown resistance, kdr) are located at PyR1. Recent studies identified two new mutations, V253F and T267A, at PyR2, which co-exist with two well-known mutations F1534C or M918T, at PyR1, in pyrethroid-resistant populations of Aedes aegypti and Nilaparvata lugens, respectively. However, the role of the V253F and T267A mutations in pyrethroid resistance has not been functionally examined. Here we report functional characterization of the V253F and T267A mutations in the Ae. aegypti sodium channel AaNav2-1 and the N. lugens sodium channel NlNav1 expressed in Xenopus oocytes. Both mutations alone reduced channel sensitivity to pyrethroids, including etofenprox. We docked etofenprox in a homology model of the pore module of the NlNav1 channel based on the crystal structure of an open prokaryotic sodium channel NavMs. In the low-energy binding pose etofenprox formed contacts with V253, T267 and a previously identified L1014 within PyR2. Combining of V253F or T267A with F1534C or M918T results in a higher level of pyrethroid insensitivity. Furthermore, both V253F and T267A mutations altered channel gating properties. However, V253F- and T267A-induced gating modifications was not observed in the double mutant channels. Our findings highlight the first example in which naturally-found combinational mutations in PyR1 and PyR2 not only confer higher level pyrethroid insensitivity, but also reduce potential fitness tradeoff in pyrethroid-resistant mosquitoes caused by kdr mutation-induced sodium channel gating modifications.
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Affiliation(s)
- Huahua Sun
- Department of Biology, Duke University, Durham, NC, USA; College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Yoshiko Nomura
- Department of Entomology, Michigan State University, East Lansing, MI, USA
| | - Yuzhe Du
- Southern Insect Management Research Unit, Agriculture Research Service, United States Department of Agriculture, 141 Experiment Station Road, Stoneville, MS, 38776, USA
| | - Zewen Liu
- College of Plant Protection, Nanjing Agricultural University, Nanjing, 210095, China
| | - Boris S Zhorov
- Department of Biochemistry and Biomedical Sciences, McMaster University, Canada; Sechenov Institute of Evolutionary Physiology & Biochemistry, Russian Academy of Sciences, St. Petersburg, 194223, Russia
| | - Ke Dong
- Department of Biology, Duke University, Durham, NC, USA; Department of Entomology, Michigan State University, East Lansing, MI, USA.
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17
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Li F, Gong X, Yuan L, Pan X, Jin H, Lu R, Wu S. Indoxacarb resistance-associated mutation of Liriomyza trifolii in Hainan, China. Pestic Biochem Physiol 2022; 183:105054. [PMID: 35430077 DOI: 10.1016/j.pestbp.2022.105054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 06/14/2023]
Abstract
Liriomyza trifolii, which has been recently prevalent in China, harms more than 300 plant species, especially cowpea in Hainan. This pest also affects the quality and production of vegetables in winter. Indoxacarb is the first commercial oxadiazine pesticide, which is a new efficient insecticide used to control pests of Diptera, including L. trifolii. The unique mechanism of indoxacarb is that indenyl is transformed into N-demethoxycarbonyl metabolite (DCJW) in insects and acts on inactivated sodium channel; DCJW could then destroy the conduction of nerve impulses, which leads to movement disorders, feeding stoppage, paralysis, and eventually the death of pests. The field population of L. trifolii developed resistance by 769 times higher than the sensitive population in Sanya, Hainan. Results revealed the existence of a mutation (i.e., V1848I) in the sixth transmembrane segment of Domain IV of the sodium channel in the field population. The homozygous resistant genotype frequency for the V1848I mutation was 10-15% among the three field-collected populations. This paper reports for the first time the presence of the kdr mutation V1848I in resistant populations of L. trifolii to indoxacarb. The present study will contribute to the understanding of the evolution of indoxacarb resistance and contribute to the development of resistance management practices for winter vegetables in Hainan.
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Affiliation(s)
- Fen Li
- The Innovation Team of Research, Development, and Application of Key Technologies for Safe Production of Tropical Crops, Hainan University, Haikou 570228, China; Sanya Nanfan Research Institute, Hainan University, Yazhou, Sanya 572024, China; Yazhou Bay Science and Technology City, Yazhou, Sanya 572024, China; College of Plant Protection, Hainan University, Haikou 570228, China
| | - Xueyan Gong
- The Innovation Team of Research, Development, and Application of Key Technologies for Safe Production of Tropical Crops, Hainan University, Haikou 570228, China; Sanya Nanfan Research Institute, Hainan University, Yazhou, Sanya 572024, China; Yazhou Bay Science and Technology City, Yazhou, Sanya 572024, China; College of Plant Protection, Hainan University, Haikou 570228, China
| | - Linlin Yuan
- The Innovation Team of Research, Development, and Application of Key Technologies for Safe Production of Tropical Crops, Hainan University, Haikou 570228, China; Sanya Nanfan Research Institute, Hainan University, Yazhou, Sanya 572024, China; Yazhou Bay Science and Technology City, Yazhou, Sanya 572024, China; College of Plant Protection, Hainan University, Haikou 570228, China
| | - Xuelian Pan
- The Innovation Team of Research, Development, and Application of Key Technologies for Safe Production of Tropical Crops, Hainan University, Haikou 570228, China; Sanya Nanfan Research Institute, Hainan University, Yazhou, Sanya 572024, China; Yazhou Bay Science and Technology City, Yazhou, Sanya 572024, China; College of Plant Protection, Hainan University, Haikou 570228, China
| | - Haifeng Jin
- The Innovation Team of Research, Development, and Application of Key Technologies for Safe Production of Tropical Crops, Hainan University, Haikou 570228, China; Sanya Nanfan Research Institute, Hainan University, Yazhou, Sanya 572024, China; Yazhou Bay Science and Technology City, Yazhou, Sanya 572024, China; College of Plant Protection, Hainan University, Haikou 570228, China
| | - Rongcai Lu
- The Innovation Team of Research, Development, and Application of Key Technologies for Safe Production of Tropical Crops, Hainan University, Haikou 570228, China; Sanya Nanfan Research Institute, Hainan University, Yazhou, Sanya 572024, China; Yazhou Bay Science and Technology City, Yazhou, Sanya 572024, China; College of Plant Protection, Hainan University, Haikou 570228, China
| | - Shaoying Wu
- The Innovation Team of Research, Development, and Application of Key Technologies for Safe Production of Tropical Crops, Hainan University, Haikou 570228, China; Sanya Nanfan Research Institute, Hainan University, Yazhou, Sanya 572024, China; Yazhou Bay Science and Technology City, Yazhou, Sanya 572024, China; College of Plant Protection, Hainan University, Haikou 570228, China.
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18
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Zhou C, Zhou Q, He X, He Y, Wang X, Zhu X, Zhang Y, Ma L. Differential modulation of C. elegans motor behavior by NALCN and two-pore domain potassium channels. PLoS Genet 2022; 18:e1010126. [PMID: 35482723 PMCID: PMC9049526 DOI: 10.1371/journal.pgen.1010126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 02/28/2022] [Indexed: 11/18/2022] Open
Abstract
Two-pore domain potassium channels (K2P) are a large family of “background” channels that allow outward “leak” of potassium ions. The NALCN/UNC80/UNC79 complex is a non-selective channel that allows inward flow of sodium and other cations. It is unclear how K2Ps and NALCN differentially modulate animal behavior. Here, we found that loss of function (lf) in the K2P gene twk-40 suppressed the reduced body curvatures of C. elegans NALCN(lf) mutants. twk-40(lf) caused a deep body curvature and extended backward locomotion, and these phenotypes appeared to be associated with neuron-specific expression of twk-40 and distinct twk-40 transcript isoforms. To survey the functions of other less studied K2P channels, we examined loss-of-function mutants of 13 additional twk genes expressed in the motor circuit and detected defective body curvature and/or locomotion in mutants of twk-2, twk-17, twk-30, twk-48, unc-58, and the previously reported twk-7. We generated presumptive gain-of-function (gf) mutations in twk-40, twk-2, twk-7, and unc-58 and found that they caused paralysis. Further analyses detected variable genetic interactions between twk-40 and other twk genes, an interdependence between twk-40 and twk-2, and opposite behavioral effects between NALCN and twk-2, twk-7, or unc-58. Finally, we found that the hydrophobicity/hydrophilicity property of TWK-40 residue 159 could affect the channel activity. Together, our study identified twk-40 as a novel modulator of the motor behavior, uncovered potential behavioral effects of five other K2P genes and suggests that NALCN and some K2Ps can oppositely affect C. elegans behavior.
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Affiliation(s)
- Chuanman Zhou
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Qian Zhou
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Xiaohui He
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Yunxia He
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Xiaoqin Wang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Xiaowei Zhu
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Yujia Zhang
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
| | - Long Ma
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, Hunan, China
- Hunan Key Laboratory of Animal Models for Human Diseases, Central South University, Changsha, Hunan, China
- Hunan Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan, China
- Hunan Key Laboratory of Molecular Precision Medicine, Central South University, Changsha, Hunan, China
- * E-mail:
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Khamtorn P, Peigneur S, Amorim FG, Quinton L, Tytgat J, Daduang S. De Novo Transcriptome Analysis of the Venom of Latrodectus geometricus with the Discovery of an Insect-Selective Na Channel Modulator. Molecules 2021; 27:molecules27010047. [PMID: 35011282 PMCID: PMC8746590 DOI: 10.3390/molecules27010047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/17/2021] [Accepted: 12/20/2021] [Indexed: 12/04/2022] Open
Abstract
The brown widow spider, Latrodectus geometricus, is a predator of a variety of agricultural insects and is also hazardous for humans. Its venom is a true pharmacopeia representing neurotoxic peptides targeting the ion channels and/or receptors of both vertebrates and invertebrates. The lack of transcriptomic information, however, limits our knowledge of the diversity of components present in its venom. The purpose of this study was two-fold: (1) carry out a transcriptomic analysis of the venom, and (2) investigate the bioactivity of the venom using an electrophysiological bioassay. From 32,505 assembled transcripts, 8 toxin families were classified, and the ankyrin repeats (ANK), agatoxin, centipede toxin, ctenitoxin, lycotoxin, scorpion toxin-like, and SCP families were reported in the L. geometricus venom gland. The diversity of L. geometricus venom was also uncovered by the transcriptomics approach with the presence of defensins, chitinases, translationally controlled tumor proteins (TCTPs), leucine-rich proteins, serine proteases, and other important venom components. The venom was also chromatographically purified, and the activity contained in the fractions was investigated using an electrophysiological bioassay with the use of a voltage clamp on ion channels in order to find if the neurotoxic effects of the spider venom could be linked to a particular molecular target. The findings show that U24-ctenitoxin-Pn1a involves the inhibition of the insect sodium (Nav) channels, BgNav and DmNav. This study provides an overview of the molecular diversity of L. geometricus venom, which can be used as a reference for the venom of other spider species. The venom composition profile also increases our knowledge for the development of novel insecticides targeting voltage-gated sodium channels.
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Affiliation(s)
- Pornsawan Khamtorn
- Program in Research and Development in Pharmaceuticals, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand;
| | - Steve Peigneur
- Toxicology and Pharmacology, Campus Gasthuisberg, University of Leuven (KU Leuven), 3000 Leuven, Belgium; (S.P.); (J.T.)
| | - Fernanda Gobbi Amorim
- Laboratory of Mass Spectrometry, MolSys Research Unit, Department of Chemistry, University of Liège, 4000 Liège, Belgium; (F.G.A.); (L.Q.)
| | - Loïc Quinton
- Laboratory of Mass Spectrometry, MolSys Research Unit, Department of Chemistry, University of Liège, 4000 Liège, Belgium; (F.G.A.); (L.Q.)
| | - Jan Tytgat
- Toxicology and Pharmacology, Campus Gasthuisberg, University of Leuven (KU Leuven), 3000 Leuven, Belgium; (S.P.); (J.T.)
| | - Sakda Daduang
- Center for Research and Development of Herbal Health Products (CDR-HHP), Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
- Protein and Proteomics Research Center for Commercial and Industrial Purposes (ProCCI), Khon Kaen University, Khon Kaen 40002, Thailand
- Division of Pharmacognosy and Toxicology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
- Correspondence:
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20
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Abstract
Ammonia and its amine-containing derivatives are widely found in natural decomposition byproducts. Here, we conducted biased chemoreceptor screening to investigate the mechanisms by which different concentrations of ammonium salt, urea, and putrescine in rotten fruits affect feeding and oviposition behavior. We identified three ionotropic receptors, including the two broadly required IR25a and IR76b receptors, as well as the narrowly tuned IR51b receptor. These three IRs were fundamental in eliciting avoidance against nitrogenous waste products, which is mediated by bitter-sensing gustatory receptor neurons (GRNs). The aversion of nitrogenous wastes was evaluated by the cellular requirement by expressing Kir2.1 and behavioral recoveries of the mutants in bitter-sensing GRNs. Furthermore, by conducting electrophysiology assays, we confirmed that ammonia compounds are aversive in taste as they directly activated bitter-sensing GRNs. Therefore, our findings provide insights into the ecological roles of IRs as a means to detect and avoid toxic nitrogenous waste products in nature.
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Affiliation(s)
- Subash Dhakal
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Jiun Sang
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Binod Aryal
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Youngseok Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea.
- Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul, 02707, Republic of Korea.
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21
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Zhu Q, Du Y, Nomura Y, Gao R, Cang Z, Wei GW, Gordon D, Gurevitz M, Groome J, Dong K. Charge substitutions at the voltage-sensing module of domain III enhance actions of site-3 and site-4 toxins on an insect sodium channel. Insect Biochem Mol Biol 2021; 137:103625. [PMID: 34358664 PMCID: PMC9376739 DOI: 10.1016/j.ibmb.2021.103625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/29/2021] [Accepted: 07/29/2021] [Indexed: 06/13/2023]
Abstract
Scorpion α-toxins bind at the pharmacologically-defined site-3 on the sodium channel and inhibit channel inactivation by preventing the outward movement of the voltage sensor in domain IV (IVS4), whereas scorpion β-toxins bind at site-4 on the sodium channel and enhance channel activation by trapping the voltage sensor of domain II (IIS4) in its outward position. However, limited information is available on the role of the voltage-sensing modules (VSM, comprising S1-S4) of domains I and III in toxin actions. We have previously shown that charge reversing substitutions of the innermost positively-charged residues in IIIS4 (R4E, R5E) increase the activity of an insect-selective site-4 scorpion toxin, Lqh-dprIT3-c, on BgNav1-1a, a cockroach sodium channel. Here we show that substitutions R4E and R5E in IIIS4 also increase the activity of two site-3 toxins, LqhαIT from Leiurusquinquestriatus hebraeus and insect-selective Av3 from Anemonia viridis. Furthermore, charge reversal of either of two conserved negatively-charged residues, D1K and E2K, in IIIS2 also increase the action of the site-3 and site-4 toxins. Homology modeling suggests that S2-D1 and S2-E2 interact with S4-R4 and S4-R5 in the VSM of domain III (III-VSM), respectively, in the activated state of the channel. However, charge swapping between S2-D1 and S4-R4 had no compensatory effects on gating or toxin actions, suggesting that charged residue interactions are complex. Collectively, our results highlight the involvement of III-VSM in the actions of both site 3 and site 4 toxins, suggesting that charge reversing substitutions in III-VSM allosterically facilitate IIS4 or IVS4 voltage sensor trapping by these toxins.
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Affiliation(s)
- Qing Zhu
- Key Lab of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Key Laboratory of Control Technology and Standard for Agro-product Safety and Quality, Ministry of Agriculture, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, China; Department of Entomology, Michigan State University, East Lansing, MI, USA
| | - Yuzhe Du
- Department of Entomology, Michigan State University, East Lansing, MI, USA
| | - Yoshiko Nomura
- Department of Entomology, Michigan State University, East Lansing, MI, USA
| | - Rong Gao
- Department of Hygienic Analysis and Detection, School of Public Health, Nanjing Medical University, 818 Tianyuan East Road, Nanjing, Jiangsu, China
| | - Zixuan Cang
- Department of Mathematics, Michigan State University, East Lansing, MI, USA
| | - Guo-Wei Wei
- Department of Mathematics, Michigan State University, East Lansing, MI, USA
| | - Dalia Gordon
- Department of Plant Molecular Biology & Ecology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel
| | - Michael Gurevitz
- Department of Plant Molecular Biology & Ecology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel.
| | - James Groome
- Department of Biological Sciences, Idaho State University, Pocatello, ID, USA
| | - Ke Dong
- Department of Entomology, Michigan State University, East Lansing, MI, USA; Department of Biology, Duke University, Durham, NC, USA.
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Abderemane-Ali F, Rossen ND, Kobiela ME, Craig RA, Garrison CE, Chen Z, Colleran CM, O’Connell LA, Du Bois J, Dumbacher JP, Minor DL. Evidence that toxin resistance in poison birds and frogs is not rooted in sodium channel mutations and may rely on "toxin sponge" proteins. J Gen Physiol 2021; 153:e202112872. [PMID: 34351379 PMCID: PMC8348241 DOI: 10.1085/jgp.202112872] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/30/2021] [Accepted: 07/01/2021] [Indexed: 12/18/2022] Open
Abstract
Many poisonous organisms carry small-molecule toxins that alter voltage-gated sodium channel (NaV) function. Among these, batrachotoxin (BTX) from Pitohui poison birds and Phyllobates poison frogs stands out because of its lethality and unusual effects on NaV function. How these toxin-bearing organisms avoid autointoxication remains poorly understood. In poison frogs, a NaV DIVS6 pore-forming helix N-to-T mutation has been proposed as the BTX resistance mechanism. Here, we show that this variant is absent from Pitohui and poison frog NaVs, incurs a strong cost compromising channel function, and fails to produce BTX-resistant channels in poison frog NaVs. We also show that captivity-raised poison frogs are resistant to two NaV-directed toxins, BTX and saxitoxin (STX), even though they bear NaVs sensitive to both. Moreover, we demonstrate that the amphibian STX "toxin sponge" protein saxiphilin is able to protect and rescue NaVs from block by STX. Taken together, our data contradict the hypothesis that BTX autoresistance is rooted in the DIVS6 N→T mutation, challenge the idea that ion channel mutations are a primary driver of toxin resistance, and suggest the possibility that toxin sequestration mechanisms may be key for protecting poisonous species from the action of small-molecule toxins.
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Affiliation(s)
- Fayal Abderemane-Ali
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA
| | - Nathan D. Rossen
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA
| | - Megan E. Kobiela
- School of Biological Sciences, University of Nebraska–Lincoln, Lincoln, NE
| | | | | | - Zhou Chen
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA
| | - Claire M. Colleran
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA
| | | | - J. Du Bois
- Department of Chemistry, Stanford University, Stanford, CA
| | - John P. Dumbacher
- Institute for Biodiversity Science and Sustainability, California Academy of Sciences, San Francisco, CA
- Department of Biology, San Francisco State University, San Francisco, CA
| | - Daniel L. Minor
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA
- California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, CA
- Kavli Institute for Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA
- Molecular Biophysics and Integrated Bio-imaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA
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23
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Andreazza F, Valbon WR, Wang Q, Liu F, Xu P, Bandason E, Chen M, Wu S, Smith LB, Scott JG, Jiang Y, Jiang D, Zhang A, Oliveira EE, Dong K. Sodium channel activation underlies transfluthrin repellency in Aedes aegypti. PLoS Negl Trop Dis 2021; 15:e0009546. [PMID: 34237076 PMCID: PMC8266078 DOI: 10.1371/journal.pntd.0009546] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 06/07/2021] [Indexed: 12/19/2022] Open
Abstract
Background Volatile pyrethroid insecticides, such as transfluthrin, have received increasing attention for their potent repellent activities in recent years for controlling human disease vectors. It has been long understood that pyrethroids kill insects by promoting activation and inhibiting inactivation of voltage-gated sodium channels. However, the mechanism of pyrethroid repellency remains poorly understood and controversial. Methodology/Principal findings Here, we show that transfluthrin repels Aedes aegypti in a hand-in-cage assay at nonlethal concentrations as low as 1 ppm. Contrary to a previous report, transfluthrin does not elicit any electroantennogram (EAG) responses, indicating that it does not activate olfactory receptor neurons (ORNs). The 1S-cis isomer of transfluthrin, which does not activate sodium channels, does not elicit repellency. Mutations in the sodium channel gene that reduce the potency of transfluthrin on sodium channels decrease transfluthrin repellency but do not affect repellency by DEET. Furthermore, transfluthrin enhances DEET repellency. Conclusions/Significance These results provide a surprising example that sodium channel activation alone is sufficient to potently repel mosquitoes. Our findings of sodium channel activation as the principal mechanism of transfluthrin repellency and potentiation of DEET repellency have broad implications in future development of a new generation of dual-target repellent formulations to more effectively repel a variety of human disease vectors. Vector-transmitted human diseases, such as dengue fever, represent serious global health burdens. Pyrethroids, including transfluthrin, are widely used as insecticides and repellents due to their low mammalian toxicity and relatively benign environmental impact. Pyrethroids target voltage-gated sodium channels for their insecticidal action. However, the mechanism of pyrethroid repellency remains unclear and controversial. Insect repellency is traditionally thought to be mediated by olfactory receptors. We made two important discoveries in this study, showing that transfluthrin repellency is via activation of sodium channels and transfluthrin enhances DEET repellency. Discovery of sodium channel activation as a major mechanism of pyrethroid repellency has broad significance in insect olfaction study, repellents development, and control of human disease vectors.
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Affiliation(s)
- Felipe Andreazza
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
- Department of Entomology, Universidade Federal de Viçosa, Viçosa, Brazil
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Wilson R. Valbon
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
- Department of Entomology, Universidade Federal de Viçosa, Viçosa, Brazil
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| | - Qiang Wang
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Feng Liu
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Peng Xu
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Elizabeth Bandason
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Mengli Chen
- Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou, China
| | - Shaoying Wu
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
| | - Leticia B. Smith
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - Jeffrey G. Scott
- Department of Entomology, Cornell University, Ithaca, New York, United States of America
| | - Youfa Jiang
- Jiangsu Yangnong Chemical Co., Ltd., Jiangsu, China
| | - Dingxin Jiang
- Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education, South China Agricultural University, Guangzhou, China
| | - Aijun Zhang
- Invasive Insect Biocontrol and Behavior Laboratory, Beltsville Agricultural Research Center-West, USDA-ARS, Beltsville, Maryland, United States of America
| | - Eugenio E. Oliveira
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
- Department of Entomology, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Ke Dong
- Department of Entomology, Michigan State University, East Lansing, Michigan, United States of America
- Department of Biology, Duke University, Durham, North Carolina, United States of America
- * E-mail:
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24
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Aryal B, Lee Y. Histamine gustatory aversion in Drosophila melanogaster. Insect Biochem Mol Biol 2021; 134:103586. [PMID: 33992752 DOI: 10.1016/j.ibmb.2021.103586] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/30/2021] [Accepted: 05/01/2021] [Indexed: 06/12/2023]
Abstract
Many foods and drinks contain histamine; however, the mechanisms that drive histamine taste perception have not yet been investigated. Here, we use a simple model organism, Drosophila melanogaster, to dissect the molecular sensors required to taste histamine. We first investigated histidine and histamine taste perception by performing a binary food choice assay and electrophysiology to identify essential sensilla for histamine sensing in the labellum. Histamine was found to activate S-type sensilla, which harbor bitter-sensing gustatory receptor neurons. Moreover, unbiased genetic screening for chemoreceptors revealed that a gustatory receptor, GR22e and an ionotropic receptor, IR76b are required for histamine sensing. Ectopic expression of GR22e was sufficient to induce a response in I-type sensilla, which normally do not respond to histamine. Taken together, our findings provide new insights into the mechanisms by which insects discriminate between the toxic histamine and beneficial histidine via their taste receptors.
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Affiliation(s)
- Binod Aryal
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea
| | - Youngseok Lee
- Department of Bio & Fermentation Convergence Technology, Kookmin University, Seoul, 02707, Republic of Korea; Interdisciplinary Program for Bio-Health Convergence, Kookmin University, Seoul, 02707, Republic of Korea.
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25
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Perrier S, Moreau E, Deshayes C, El-Adouzi M, Goven D, Chandre F, Lapied B. Compensatory mechanisms in resistant Anopheles gambiae AcerKis and KdrKis neurons modulate insecticide-based mosquito control. Commun Biol 2021; 4:665. [PMID: 34079061 PMCID: PMC8172894 DOI: 10.1038/s42003-021-02192-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 05/06/2021] [Indexed: 02/04/2023] Open
Abstract
In the malaria vector Anopheles gambiae, two point mutations in the acetylcholinesterase (ace-1R) and the sodium channel (kdrR) genes confer resistance to organophosphate/carbamate and pyrethroid insecticides, respectively. The mechanisms of compensation that recover the functional alterations associated with these mutations and their role in the modulation of insecticide efficacy are unknown. Using multidisciplinary approaches adapted to neurons isolated from resistant Anopheles gambiae AcerKis and KdrKis strains together with larval bioassays, we demonstrate that nAChRs, and the intracellular calcium concentration represent the key components of an adaptation strategy ensuring neuronal functions maintenance. In AcerKis neurons, the increased effect of acetylcholine related to the reduced acetylcholinesterase activity is compensated by expressing higher density of nAChRs permeable to calcium. In KdrKis neurons, changes in the biophysical properties of the L1014F mutant sodium channel, leading to enhance overlap between activation and inactivation relationships, diminish the resting membrane potential and reduce the fraction of calcium channels available involved in acetylcholine release. Together with the lower intracellular basal calcium concentration observed, these factors increase nAChRs sensitivity to maintain the effect of low concentration of acetylcholine. These results explain the opposite effects of the insecticide clothianidin observed in AcerKis and KdrKis neurons in vitro and in vivo.
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Affiliation(s)
| | | | | | | | | | - Fabrice Chandre
- MIVEGEC, UMR IRD 224-CNRS 5290-Université de Montpellier, 911 avenue Agropolis, Montpellier, Cedex 05, France
| | - Bruno Lapied
- Univ Angers, INRAE, SIFCIR, SFR QUASAV, Angers, France.
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Tucker NSG, Weeks ENI, Beati L, Kaufman PE. Prevalence and distribution of pathogen infection and permethrin resistance in tropical and temperate populations of Rhipicephalus sanguineus s.l. collected worldwide. Med Vet Entomol 2021; 35:147-157. [PMID: 32918501 DOI: 10.1111/mve.12479] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 08/08/2020] [Accepted: 08/15/2020] [Indexed: 06/11/2023]
Abstract
The brown dog tick, Rhipicephalus sanguineus sensu lato (s.l.) Latreille (Acari: Ixodidae), is a peridomestic, cosmopolitan parasite of dogs known to vector numerous pathogens of veterinary and medical importance. Recent phylogenetic analyses separate this tick into temperate and tropical lineages. Populations of Rh. sanguineus s.l. have been reported to exhibit sodium channel target site insensitivity to permethrin and etofenprox, which is likely due to the prolonged use of pyrethroids against many pests in and around the home. In this study, populations collected in the Caribbean, Africa, Asia, Europe and North America, were tested to identify the distribution of a known resistance mechanism, pathogen-vector interactions and phylogeny in relation to latitude. Using molecular assays, populations from 29 distinct locations were simultaneously geographically typed and screened for bacterial infection by Rickettsia, Ehrlichia, Babesia and Hepatozoon species, and for the presence of a sodium channel single nucleotide polymorphism known to confer permethrin resistance. Implications of these results on Rh. sanguineus s.l. management in association with geographical distribution will be discussed.
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Affiliation(s)
- N S G Tucker
- Entomology and Nematology Department, University of Florida, Gainesville, FL, U.S.A
| | - E N I Weeks
- Entomology and Nematology Department, University of Florida, Gainesville, FL, U.S.A
| | - L Beati
- U.S. National Tick Collection, Institute for Coastal Plain Science, Georgia Southern University, Statesboro, GA, U.S.A
| | - P E Kaufman
- Entomology and Nematology Department, University of Florida, Gainesville, FL, U.S.A
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Janer EC, Díaz A, Fontes F, Baraibar F, Saporiti T, Olhagaray ME. Molecular survey of pyrethroid and fipronil resistance in isolates of Rhipicephalus microplus in the north of Uruguay. Ticks Tick Borne Dis 2021; 12:101747. [PMID: 34102575 DOI: 10.1016/j.ttbdis.2021.101747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 03/29/2021] [Accepted: 04/06/2021] [Indexed: 11/19/2022]
Abstract
The resistance of Rhipicephalus microplus to acaricides is a serious control problem, so its early diagnosis by a molecular technique is important. This study aims to develop a multiplex allele-specific polymerase chain reaction (PCR) for single-nucleotide polymorphisms (SNPs) in the para-sodium channel gene and in the GABA-Cl gene, associated with pyrethroids (cypermethrin and flumethrin) and fipronil resistance, respectively. We used 22 tick field isolates from farms with tick control problems (sampling convenience). These farms are located in departments of northern Uruguay. Three mutations in the sodium channel gene (Domain II S4-5: C190A and G215T; domain III S6: T2134A) and one in the GABA-Cl gene (A286S/L: CG856CC/TG) were studied. Mutations G215T and T213A were not detected. In all field isolates, the resistant allele (R) for C190A mutation (knockdown resistance, kdr) was detected, mainly in heterozygous individuals (SR) (11.1% to 86.7%). The highest incidence of the kdr mutant allele occurred in the Tacuarembó tick field isolates, where on 7 out of 10 farms >30% of individuals were SR and on one farm > 30% of individuals were RR. The next highest was Artigas (half of farms had>30% SR individuals and a quarter had >30% RR individuals). The resistance to dieldrin locus (rdl) mutation (CG856CC/TG) was absent in five field isolates. The highest incidenceof the mutant allele was observed in ticks from farms in Rivera (all farms had SR in >30% of individuals and two farms had RR in >12.5 and >16.7% of individuals) followed by farms in Tacuarembó (3 of 10 farms had >30% SR and 2 with >30% RR). Less than half of the farms had rdl in homozygous individuals. No significant association was observed between phenotypic bioassays and the rdl resistance allele. Several field isolates were phenotypically susceptible to the presence of the rdl allele. Several causes are possible (bioassay sensitivity, discriminating concentration). Individuals with simultaneous kdr and rdl mutations were present in 17 field isolates, and their frequency varied between 0.06% and 60%. Genotypic analysis shows that tick resistance to both acaricides, especially pyrethroids, is a serious problem. It is important to monitor the resistance using molecular techniques to plan efficient control measures. This is the first report describing kdr and rdl detection in R. microplus in Uruguay.
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Affiliation(s)
- Eleonor Castro Janer
- Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Av. Lasplaces 1620, CP 11600 Montevideo, Uruguay.
| | - André Díaz
- Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Av. Lasplaces 1620, CP 11600 Montevideo, Uruguay
| | - Florencia Fontes
- Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Av. Lasplaces 1620, CP 11600 Montevideo, Uruguay
| | - Florencia Baraibar
- Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Av. Lasplaces 1620, CP 11600 Montevideo, Uruguay
| | - Tatiana Saporiti
- Departamento de Parasitología. Plataforma de Salud Animal. Instituto Nacional de Investigación Agropecuaria. Ruta 5km 386, Tacuarembó, Uruguay
| | - María Ernestina Olhagaray
- Departamento de Patobiología, Unidad de Enfermedades Parasitarias, Facultad de Veterinaria, UDELAR. Av. Lasplaces 1620, CP 11600 Montevideo, Uruguay
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Ma H, Guo Y, Chen Z, Wang L, Tang Z, Zhang J, Miao Q, Zhai Q. Mutations in the sodium channel genes SCN1A, SCN3A, and SCN9A in children with epilepsy with febrile seizures plus(EFS+). Seizure 2021; 88:146-152. [PMID: 33895391 DOI: 10.1016/j.seizure.2021.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To explore disease-causing gene mutations of epilepsy with febrile seizures plus (EFS+) in Southern Chinese Han population. METHODS Blood samples and clinical data were collected from 49 Southern Han Chinese patients with EFS+. Gene screening was performed using whole-exome sequencing and panel sequencing for 485 epilepsy-related genes. The pathogenicity of variants was evaluated based on ACMG scoring and assessment of clinical concordance. RESULTS We identified 10 putatively causative sodium channel gene variants in 49 patients with EFS+, including 8 variants in SCN1A (R500Q appeared twice), one in SCN3A and one in SCN9A. All these missense mutations were inherited from maternal or paternal and were evaluated to be of uncertain significance according to ACMG. The clinical features of patients were in concordance with the EFS+ phenotype of the mutated SCN1A, SCN3A and SCN9A gene. The clinical phenotypes of 11 probands with these gene variants included febrile seizures plus (FS+, n=7), Dravet Syndrome (n=3), FS+ with focal seizures (n=1). Three probands with SCN1A variants (R500Q located in the non-voltage areas, or G1711D in the pore-forming domain) developed severe Dravet syndrome. The affected individuals with the other 6 SCN1A variants located outside the pore-forming domain showed mild phenotypes. Novel SCN3A variant ((D1688Y) and SCN9A variant (R185H) were identified in two probands respectively and both of the probands had FS+. CONCLUSION The SCN1A, SCN3A, and SCN9A gene mutations might be a pathogenic cause of EFS+ in Southern Chinese Han population.
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Affiliation(s)
- Hongxia Ma
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong Province, China; Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China; Department of Pediatrics, Affiliated Hospital of Guangdong Medical University, Zhanjiang, Guangdong Province, China
| | - Yuxiong Guo
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong Province, China; Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China
| | - Zhihong Chen
- Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China
| | - Lingan Wang
- Department of Neurology and Rehabilitation, Guangdong Women and Children's Hospital, Guangzhou, Guangdong Province, China
| | - Zhihong Tang
- Department of Pediatrics, Dongguan City Maternal & Child Health Hospital, Dongguan, Guangdong Province, China
| | - Jingwen Zhang
- Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China
| | - Qinfei Miao
- Shantou University, Shantou, Guangdong Province, China
| | - Qiongxiang Zhai
- The Second School of Clinical Medicine, Southern Medical University, Guangzhou, Guangdong Province, China; Department of Pediatrics, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China.
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Kubik TD, Snell TK, Saavedra-Rodriguez K, Wilusz J, Anderson JR, Lozano-Fuentes S, Black WC, Campbell CL. Aedes aegypti miRNA-33 modulates permethrin induced toxicity by regulating VGSC transcripts. Sci Rep 2021; 11:7301. [PMID: 33790374 PMCID: PMC8012613 DOI: 10.1038/s41598-021-86665-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 03/18/2021] [Indexed: 12/12/2022] Open
Abstract
Aedes aegypti is a major vector of Zika, dengue, and other arboviruses. Permethrin adulticidal spraying, which targets the voltage-gated sodium channel (VGSC), is commonly done to reduce local mosquito populations and protect humans from exposure to arbovirus pathogens transmitted by this dangerous pest. Permethrin resistance, however, is a growing problem and understanding its underlying molecular basis may identify avenues to combat it. We identified a single G:C polymorphism in pre-miR-33 that was genetically associated with permethrin resistance; resulting isoforms had structural differences that may affect DICER-1/pre-miRNA processing rates. We then assessed the effects of overexpression of pre-miR-33 isoforms on permethrin toxicological phenotypes, VGSC transcript abundance and protein levels for two genetically related mosquito strains. One strain had its naturally high permethrin resistance levels maintained by periodic treatment, and the other was released from selection. VGSC protein levels were lower in the permethrin resistant strain than in the related permethrin-susceptible strain. Overexpression of the G-pre-miR-33 isoform reduced VGSC expression levels in both strains. To further elucidate changes in gene expression associated with permethrin resistance, exome-capture gDNA deep sequencing, genetic association mapping and subsequent gene set enrichment analysis revealed that transport genes, in particular, were selected in resistant versus susceptible mosquitoes. Collectively, these data indicate that miR-33 regulates VGSC expression as part of a nuanced system of neuronal regulation that contributes to a network of heritable features determining permethrin resistance.
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Affiliation(s)
- Tristan D Kubik
- Department of Microbiology, Immunology and Pathology, Colorado State University, Campus Delivery 1685, Fort Collins, CO, 80523, USA
| | - Trey K Snell
- Department of Microbiology, Immunology and Pathology, Colorado State University, Campus Delivery 1685, Fort Collins, CO, 80523, USA
| | - Karla Saavedra-Rodriguez
- Department of Microbiology, Immunology and Pathology, Colorado State University, Campus Delivery 1685, Fort Collins, CO, 80523, USA
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Campus Delivery 1685, Fort Collins, CO, 80523, USA
| | - John R Anderson
- Department of Microbiology, Immunology and Pathology, Colorado State University, Campus Delivery 1685, Fort Collins, CO, 80523, USA
| | - Saul Lozano-Fuentes
- Department of Microbiology, Immunology and Pathology, Colorado State University, Campus Delivery 1685, Fort Collins, CO, 80523, USA
| | - William C Black
- Department of Microbiology, Immunology and Pathology, Colorado State University, Campus Delivery 1685, Fort Collins, CO, 80523, USA
| | - Corey L Campbell
- Department of Microbiology, Immunology and Pathology, Colorado State University, Campus Delivery 1685, Fort Collins, CO, 80523, USA.
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Nowicka-Bauer K, Szymczak-Cendlak M. Structure and Function of Ion Channels Regulating Sperm Motility-An Overview. Int J Mol Sci 2021; 22:ijms22063259. [PMID: 33806823 PMCID: PMC8004680 DOI: 10.3390/ijms22063259] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 12/18/2022] Open
Abstract
Sperm motility is linked to the activation of signaling pathways that trigger movement. These pathways are mainly dependent on Ca2+, which acts as a secondary messenger. The maintenance of adequate Ca2+ concentrations is possible thanks to proper concentrations of other ions, such as K+ and Na+, among others, that modulate plasma membrane potential and the intracellular pH. Like in every cell, ion homeostasis in spermatozoa is ensured by a vast spectrum of ion channels supported by the work of ion pumps and transporters. To achieve success in fertilization, sperm ion channels have to be sensitive to various external and internal factors. This sensitivity is provided by specific channel structures. In addition, novel sperm-specific channels or isoforms have been found with compositions that increase the chance of fertilization. Notably, the most significant sperm ion channel is the cation channel of sperm (CatSper), which is a sperm-specific Ca2+ channel required for the hyperactivation of sperm motility. The role of other ion channels in the spermatozoa, such as voltage-gated Ca2+ channels (VGCCs), Ca2+-activated Cl-channels (CaCCs), SLO K+ channels or voltage-gated H+ channels (VGHCs), is to ensure the activation and modulation of CatSper. As the activation of sperm motility differs among metazoa, different ion channels may participate; however, knowledge regarding these channels is still scarce. In the present review, the roles and structures of the most important known ion channels are described in regard to regulation of sperm motility in animals.
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Affiliation(s)
- Karolina Nowicka-Bauer
- Department of Chemical Physics, Faculty of Chemistry, Adam Mickiewicz University in Poznań, 61-614 Poznan, Poland
- Correspondence:
| | - Monika Szymczak-Cendlak
- Department of Animal Physiology and Development, Faculty of Biology, Adam Mickiewicz University in Poznań, 61-614 Poznan, Poland;
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Prakash C, Mishra M, Kumar P, Kumar V, Sharma D. Response of Voltage-Gated Sodium and Calcium Channels Subtypes on Dehydroepiandrosterone Treatment in Iron-Induced Epilepsy. Cell Mol Neurobiol 2021; 41:279-292. [PMID: 32318899 DOI: 10.1007/s10571-020-00851-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 04/14/2020] [Indexed: 12/28/2022]
Abstract
Epilepsy is a neurological disorder characterized by the occurrence of spontaneous and recurrent seizures. In post-traumatic epilepsy (PTE), the mechanism of epileptogenesis is very complex and seems to be linked with voltage-gated ion channels. Dehydroepiandrosterone (DHEA), a neurosteroid have shown beneficial effect against various neurological disorders. We investigated antiepileptic effect of DHEA with respect to expression of voltage-gated ion channels subtypes in iron-induced epilepsy. Iron (FeCl3) solution was intracartically injected to induce epilepsy in rats and DHEA was intraperitoneally administered for 21 days. Results showed markedly increased epileptiform seizures activity along with up-regulation of Nav1.1 and Nav1.6, and down-regulation of Cav2.1α at the mRNA and protein level in the cortex and hippocampus of epileptic rats. Moreover, the study demonstrated that these channels subtypes were predominantly expressed in the neurons. DHEA treatment has countered the epileptic seizures, down-regulated Nav1.1 and Nav1.6, and up-regulated Cav2.1α without affecting their cellular localization. In conclusion, the present study demonstrates antiepileptic potential of DHEA, escorted by regulation of Nav1.1, Nav1.6, and Cav2.1α subtypes in the neurons of iron-induced epileptic rats.
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Affiliation(s)
- Chandra Prakash
- Neurobiology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Monika Mishra
- Neurobiology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Pavan Kumar
- Department of Developmental Neurogenetics, Medical University of South Carolina, Charleston, SC, USA
| | - Vikas Kumar
- Neurobiology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Deepak Sharma
- Neurobiology Laboratory, School of Life Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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Furuta Y, Pena-Ramos O, Li Z, Chiao L, Zhou Z. Calcium ions trigger the exposure of phosphatidylserine on the surface of necrotic cells. PLoS Genet 2021; 17:e1009066. [PMID: 33571185 PMCID: PMC7904182 DOI: 10.1371/journal.pgen.1009066] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 02/24/2021] [Accepted: 01/18/2021] [Indexed: 11/18/2022] Open
Abstract
Intracellular Ca2+ level is under strict regulation through calcium channels and storage pools including the endoplasmic reticulum (ER). Mutations in certain ion channel subunits, which cause mis-regulated Ca2+ influx, induce the excitotoxic necrosis of neurons. In the nematode Caenorhabditis elegans, dominant mutations in the DEG/ENaC sodium channel subunit MEC-4 induce six mechanosensory (touch) neurons to undergo excitotoxic necrosis. These necrotic neurons are subsequently engulfed and digested by neighboring hypodermal cells. We previously reported that necrotic touch neurons actively expose phosphatidylserine (PS), an “eat-me” signal, to attract engulfing cells. However, the upstream signal that triggers PS externalization remained elusive. Here we report that a robust and transient increase of cytoplasmic Ca2+ level occurs prior to the exposure of PS on necrotic touch neurons. Inhibiting the release of Ca2+ from the ER, either pharmacologically or genetically, specifically impairs PS exposure on necrotic but not apoptotic cells. On the contrary, inhibiting the reuptake of cytoplasmic Ca2+ into the ER induces ectopic necrosis and PS exposure. Remarkably, PS exposure occurs independently of other necrosis events. Furthermore, unlike in mutants of DEG/ENaC channels, in dominant mutants of deg-3 and trp-4, which encode Ca2+ channels, PS exposure on necrotic neurons does not rely on the ER Ca2+ pool. Our findings indicate that high levels of cytoplasmic Ca2+ are necessary and sufficient for PS exposure. They further reveal two Ca2+-dependent, necrosis-specific pathways that promote PS exposure, a “two-step” pathway initiated by a modest influx of Ca2+ and further boosted by the release of Ca2+ from the ER, and another, ER-independent, pathway. Moreover, we found that ANOH-1, the worm homolog of mammalian phospholipid scramblase TMEM16F, is necessary for efficient PS exposure in thapsgargin-treated worms and trp-4 mutants, like in mec-4 mutants. We propose that both the ER-mediated and ER-independent Ca2+ pathways promote PS externalization through activating ANOH-1. Necrosis is a type of cell death that exhibits distinct morphological features such as cell and organelle swelling. Necrotic cells expose phosphatidylserine (PS)–a type of phospholipid—on their outer surfaces. Receptor molecules on phagocytes detect PS on necrotic cells and subsequently initiate the engulfment process. As necrosis is associated with stroke, cancer, neurodegenerative diseases, and heart diseases, studying necrotic cell clearance has important medical relevance. In the model organism the nematode C. elegans, we previously identified membrane proteins that promote the exposure of PS on necrotic cell surfaces by studying neurons that are induced to undergo necrosis by dominant mutations in ion channels. Here, in C. elegans, we have discovered that the necrotic insults trigger an increase of the cytoplasmic calcium ion (Ca2+), which in turn promotes PS externalization on necrotic cell surfaces. Furthermore, we have identified two different mechanisms that increase cytoplasmic Ca2+ levels, one dependent on the Ca2+ contribution from the endoplasmic reticulum (ER), the other independent of the ER. The Ca2+ signal targets ANOH-1, a worm homolog of mammalian proteins capable of externalizing PS, for promoting PS exposure on necrotic cells. Our findings reveal novel upstream regulatory mechanisms that promote necrotic cell clearance in animals.
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Affiliation(s)
- Yoshitaka Furuta
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- School of Pharmacy, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa, Japan
| | - Omar Pena-Ramos
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Zao Li
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Lucia Chiao
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Zheng Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
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Zou S. Comparative Transcriptome Analysis of Toxic and Non-Toxic Nassarius Communities and Identification of Genes Involved in TTX-Adaptation. Toxins (Basel) 2020; 12:toxins12120761. [PMID: 33276679 PMCID: PMC7761612 DOI: 10.3390/toxins12120761] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 11/27/2020] [Accepted: 12/01/2020] [Indexed: 01/01/2023] Open
Abstract
Nassarius has caused serious people poisoning and death incident as a popular food due to tetrodotoxin (TTX) accumulation in their body. Understanding the genetic basis of tetrodotoxin (TTX) transformation and resistance in animals could lead to significant insights into adaptive evolution to toxins and toxin poisoning cures in medicine. Here we performed comparative transcriptome analysis for toxic and non-toxic communities in Nassarius succinctus and Nassarius variciferus to reveal their genetic expression and mutation patterns. For both species, the cellular and metabolic process, and binding and catalytic activity accounted for the top classification categories, and the toxic communities generally produced more up-regulated genes than non-toxic communities. Most unigenes and different expression genes were related to disease, e.g., heat shock protein and tissue factor pathway inhibitors, which involve detoxification and coagulation. In mutation levels, the sodium channel gene of N. succinctus had one amino acid mutation "L", which is different from that of other animals. In conclusion, the comparative transcriptome analysis of different species and populations provided an important genetic basis for adaptive evolution to toxins, health and toxin poisoning cure research for TTX in marine gastropoda mollusk. Future studies will focus on the action mechanism of the important functional gene for TTX accumulation and resistance.
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Affiliation(s)
- Shanmei Zou
- College of Resources and Environmental Science, Nanjing Agricultural University, Nanjing 210095, China
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Ravenscroft TA, Janssens J, Lee PT, Tepe B, Marcogliese PC, Makhzami S, Holmes TC, Aerts S, Bellen HJ. Drosophila Voltage-Gated Sodium Channels Are Only Expressed in Active Neurons and Are Localized to Distal Axonal Initial Segment-like Domains. J Neurosci 2020; 40:7999-8024. [PMID: 32928889 PMCID: PMC7574647 DOI: 10.1523/jneurosci.0142-20.2020] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 07/15/2020] [Accepted: 08/04/2020] [Indexed: 12/28/2022] Open
Abstract
In multipolar vertebrate neurons, action potentials (APs) initiate close to the soma, at the axonal initial segment. Invertebrate neurons are typically unipolar with dendrites integrating directly into the axon. Where APs are initiated in the axons of invertebrate neurons is unclear. Voltage-gated sodium (NaV) channels are a functional hallmark of the axonal initial segment in vertebrates. We used an intronic Minos-Mediated Integration Cassette to determine the endogenous gene expression and subcellular localization of the sole NaV channel in both male and female Drosophila, para Despite being the only NaV channel in the fly, we show that only 23 ± 1% of neurons in the embryonic and larval CNS express para, while in the adult CNS para is broadly expressed. We generated a single-cell transcriptomic atlas of the whole third instar larval brain to identify para expressing neurons and show that it positively correlates with markers of differentiated, actively firing neurons. Therefore, only 23 ± 1% of larval neurons may be capable of firing NaV-dependent APs. We then show that Para is enriched in an axonal segment, distal to the site of dendritic integration into the axon, which we named the distal axonal segment (DAS). The DAS is present in multiple neuron classes in both the third instar larval and adult CNS. Whole cell patch clamp electrophysiological recordings of adult CNS fly neurons are consistent with the interpretation that Nav-dependent APs originate in the DAS. Identification of the distal NaV localization in fly neurons will enable more accurate interpretation of electrophysiological recordings in invertebrates.SIGNIFICANCE STATEMENT The site of action potential (AP) initiation in invertebrates is unknown. We tagged the sole voltage-gated sodium (NaV) channel in the fly, para, and identified that Para is enriched at a distal axonal segment. The distal axonal segment is located distal to where dendrites impinge on axons and is the likely site of AP initiation. Understanding where APs are initiated improves our ability to model neuronal activity and our interpretation of electrophysiological data. Additionally, para is only expressed in 23 ± 1% of third instar larval neurons but is broadly expressed in adults. Single-cell RNA sequencing of the third instar larval brain shows that para expression correlates with the expression of active, differentiated neuronal markers. Therefore, only 23 ± 1% of third instar larval neurons may be able to actively fire NaV-dependent APs.
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Affiliation(s)
- Thomas A Ravenscroft
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
| | - Jasper Janssens
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium
- Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Pei-Tseng Lee
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
| | - Burak Tepe
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
| | - Paul C Marcogliese
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
| | - Samira Makhzami
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium
- Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Todd C Holmes
- Department of Physiology and Biophysics, School of Medicine, University of California at Irvine, Irvine, California 92697
| | - Stein Aerts
- VIB Center for Brain & Disease Research, KU Leuven, Leuven 3000, Belgium
- Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas 77030
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030
- Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030
- Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030
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Takai Y, Mizoguchi N, Kinoshita M, Qiu X, Shimasaki Y, Oshima Y. Establishment of a Japanese medaka (Oryzias latipes) transgenic line expressing Takifugu rubripes pufferfish saxitoxin and tetrodotoxin binding protein 1, and evaluation of tributyltin toxicity via in ovo nanoinjection. Comp Biochem Physiol C Toxicol Pharmacol 2020; 234:108785. [PMID: 32376496 DOI: 10.1016/j.cbpc.2020.108785] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/25/2020] [Accepted: 04/28/2020] [Indexed: 12/27/2022]
Abstract
Pufferfish saxitoxin and tetrodotoxin binding proteins (PSTBPs) play an important role in the toxification of certain species of pufferfish. Recombinant Takifugu rubripes PSTBP1 (rTrub.PSTBP1) is reported to bind to tributyltin, and so it has been suggested that rTrub.PSTBP1 may reduce the toxicity of tributyltin. However, the role of PSTBP1 in vivo remains to be elucidated. Here, we established a transgenic medaka line showing whole-body Renilla reniformis green fluorescent protein and Trub.PSTBP1 expression, as confirmed by real-time polymerase chain reaction and mRNA-Seq analysis. mRNA-Seq analysis also showed that cytochrome P450 superfamily genes and the gene encoding ATP-binding cassette sub-family G member 2 were highly expressed in the transgenic medaka. Using embryos of the transgenic medaka line, we conducted an in ovo nanoinjection test to examine the effect of Trub.PSTBP1 in vivo, and obtained data suggesting that Trub.PSTBP1 expression may have reduced the toxicity of tributyltin in our transgenic medaka line. Our findings will be useful for future functional analyses of Trub.PSTBP1.
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Affiliation(s)
- Yuki Takai
- Laboratory of Marine Environmental Science, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Naohiro Mizoguchi
- Laboratory of Marine Environmental Science, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Masato Kinoshita
- Department of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan
| | - Xuchun Qiu
- Institute of Environmental Health and Ecological Security, School of the Environment and Safety Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, PR China
| | - Yohei Shimasaki
- Laboratory of Marine Environmental Science, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan
| | - Yuji Oshima
- Laboratory of Marine Environmental Science, Department of Bioscience and Biotechnology, Faculty of Agriculture, Kyushu University, Fukuoka 819-0395, Japan; Institute of Nature and Environmental Technology, Kanazawa University, Kanazawa 920-1192, Japan.
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Rochtus AM, Goldstein RD, Holm IA, Brownstein CA, Pérez‐Palma E, Haynes R, Lal D, Poduri AH. The role of sodium channels in sudden unexpected death in pediatrics. Mol Genet Genomic Med 2020; 8:e1309. [PMID: 32449611 PMCID: PMC7434613 DOI: 10.1002/mgg3.1309] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 04/21/2020] [Accepted: 04/27/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Sudden Unexpected Death in Pediatrics (SUDP) is a tragic event, likely caused by the complex interaction of multiple factors. The presence of hippocampal abnormalities in many children with SUDP suggests that epilepsy-related mechanisms may contribute to death, similar to Sudden Unexplained Death in Epilepsy. Because of known associations between the genes SCN1A and SCN5A and sudden death, and shared mechanisms and patterns of expression in genes encoding many voltage-gated sodium channels (VGSCs), we hypothesized that individuals dying from SUDP have pathogenic variants across the entire family of cardiac arrhythmia- and epilepsy-associated VGSC genes. METHODS To address this hypothesis, we evaluated whole-exome sequencing data from infants and children with SUDP for variants in VGSC genes, reviewed the literature for all SUDP-associated variants in VGSCs, applied a novel paralog analysis to all variants, and evaluated all variants according to American College of Medical Genetics and Genomics (ACMG) guidelines. RESULTS In our cohort of 73 cases of SUDP, we assessed 11 variants as pathogenic in SCN1A, SCN1B, and SCN10A, genes with long-standing disease associations, and in SCN3A, SCN4A, and SCN9A, VGSC gene paralogs with more recent disease associations. From the literature, we identified 82 VGSC variants in SUDP cases. Pathogenic variants clustered at conserved amino acid sites intolerant to variation across the VGSC genes, which is unlikely to occur in the general population (p < .0001). For 54% of variants previously reported in literature, we identified conflicting evidence regarding pathogenicity when applying ACMG criteria and modern population data. CONCLUSION We report variants in several VGSC genes in cases with SUDP, involving both arrhythmia- and epilepsy-associated genes. Accurate variant assessment as well as future studies are essential for an improved understanding of the contribution of sodium channel-related variants to SUDP.
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Affiliation(s)
- Anne M. Rochtus
- Department of NeurologyBoston Children's Hospital and Harvard Medical SchoolBostonMAUSA
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Department of PediatricsUniversity of LeuvenLeuvenBelgium
| | - Richard D. Goldstein
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Department of PediatricsBoston Children’s Hospital and Harvard Medical SchoolBostonMAUSA
| | - Ingrid A. Holm
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Department of PediatricsBoston Children’s Hospital and Harvard Medical SchoolBostonMAUSA
- Department of MedicineDivision of Genetics and Genomics and the Manton Center for Orphan Disease ResearchBoston Children's HospitalBostonMAUSA
| | - Catherine A. Brownstein
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Department of PediatricsBoston Children’s Hospital and Harvard Medical SchoolBostonMAUSA
- Department of MedicineDivision of Genetics and Genomics and the Manton Center for Orphan Disease ResearchBoston Children's HospitalBostonMAUSA
| | - Eduardo Pérez‐Palma
- Genomic Medicine InstituteLerner Research InstituteCleveland ClinicClevelandOHUSA
- Cologne Center for GenomicsUniversity of CologneCologneGermany
| | - Robin Haynes
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Department of PathologyBoston Children’s Hospital and Harvard Medical SchoolBostonMAUSA
| | - Dennis Lal
- Genomic Medicine InstituteLerner Research InstituteCleveland ClinicClevelandOHUSA
- Cologne Center for GenomicsUniversity of CologneCologneGermany
- Stanley Center for Psychiatric ResearchBroad Institute of Harvard and MITCambridgeMAUSA
| | - Annapurna H. Poduri
- Department of NeurologyBoston Children's Hospital and Harvard Medical SchoolBostonMAUSA
- Robert’s Program on Sudden Death in PediatricsBoston Children’s HospitalBostonMAUSA
- Stanley Center for Psychiatric ResearchBroad Institute of Harvard and MITCambridgeMAUSA
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Chen M, Du Y, Nomura Y, Zhorov BS, Dong K. Chronology of sodium channel mutations associated with pyrethroid resistance in Aedes aegypti. Arch Insect Biochem Physiol 2020; 104:e21686. [PMID: 32378259 PMCID: PMC8060125 DOI: 10.1002/arch.21686] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 04/13/2020] [Accepted: 04/14/2020] [Indexed: 05/11/2023]
Abstract
Aedes aegypti is the primary mosquito vector of dengue, yellow fever, Zika and chikungunya. Current strategies to control Ae. aegypti rely heavily on insecticide interventions. Pyrethroids are a major class of insecticides used for mosquito control because of their fast acting, highly insecticidal activities and low mammalian toxicity. However, Ae. aegypti populations around the world have begun to develop resistance to pyrethroids. So far, more than a dozen mutations in the sodium channel gene have been reported to be associated with pyrethroid resistance in Ae. aegypti. Co-occurrence of resistance-associated mutations is common in pyrethroid-resistant Ae. aegypti populations. As global use of pyrethroids in mosquito control continues, new pyrethroid-resistant mutations keep emerging. In this microreview, we compile pyrethroid resistance-associated mutations in Ae. aegypti in a chronological order, as they were reported, and summarize findings from functional evaluation of these mutations in an in vitro sodium channel expression system. We hope that the information will be useful for tracing possible evolution of pyrethroid resistance in this important human disease vector, in addition to the development of methods for global monitoring and management of pyrethroid resistance in Ae. aegypti.
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Affiliation(s)
- Mengli Chen
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of life sciences, China Jiliang University, Hangzhou, China
| | - Yuzhe Du
- USDA-ARS, Biological Control of Pest Research Unit, 59 Lee Road, Stoneville, MS 38776, USA
| | - Yoshiko Nomura
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, MI 48824, USA
| | - Boris S. Zhorov
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8N 3Z5, Canada
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, 194223, Russia
| | - Ke Dong
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, MI 48824, USA
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Pham TD, Verlander JW, Wang Y, Romero CA, Yue Q, Chen C, Thumova M, Eaton DC, Lazo-Fernandez Y, Wall SM. Aldosterone Regulates Pendrin and Epithelial Sodium Channel Activity through Intercalated Cell Mineralocorticoid Receptor-Dependent and -Independent Mechanisms over a Wide Range in Serum Potassium. J Am Soc Nephrol 2020. [PMID: 32054691 DOI: 10.1152/ajprenal.90637.2008.-ammonia] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023] Open
Abstract
BACKGROUND Aldosterone activates the intercalated cell mineralocorticoid receptor, which is enhanced with hypokalemia. Whether this receptor directly regulates the intercalated cell chloride/bicarbonate exchanger pendrin is unclear, as are potassium's role in this response and the receptor's effect on intercalated and principal cell function in the cortical collecting duct (CCD). METHODS We measured CCD chloride absorption, transepithelial voltage, epithelial sodium channel activity, and pendrin abundance and subcellular distribution in wild-type and intercalated cell-specific mineralocorticoid receptor knockout mice. To determine if the receptor directly regulates pendrin, as well as the effect of serum aldosterone and potassium on this response, we measured pendrin label intensity and subcellular distribution in wild-type mice, knockout mice, and receptor-positive and receptor-negative intercalated cells from the same knockout mice. RESULTS Ablation of the intercalated cell mineralocorticoid receptor in CCDs from aldosterone-treated mice reduced chloride absorption and epithelial sodium channel activity, despite principal cell mineralocorticoid receptor expression in the knockout mice. With high circulating aldosterone, intercalated cell mineralocorticoid receptor gene ablation directly reduced pendrin's relative abundance in the apical membrane region and pendrin abundance per cell whether serum potassium was high or low. Intercalated cell mineralocorticoid receptor ablation blunted, but did not eliminate, aldosterone's effect on pendrin total and apical abundance and subcellular distribution. CONCLUSIONS With high circulating aldosterone, intercalated cell mineralocorticoid receptor ablation reduces chloride absorption in the CCD and indirectly reduces principal cell epithelial sodium channel abundance and function. This receptor directly regulates pendrin's total abundance and its relative abundance in the apical membrane region over a wide range in serum potassium concentration. Aldosterone regulates pendrin through mechanisms both dependent and independent of the IC MR receptor.
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Affiliation(s)
| | - Jill W Verlander
- Department of Medicine, University of Florida, Gainesville, Florida
| | | | | | | | - Chao Chen
- Department of Medicine, University of Florida, Gainesville, Florida
| | | | - Douglas C Eaton
- Departments of Medicine and
- Physiology, Emory University School of Medicine, Atlanta, Georgia; and
| | | | - Susan M Wall
- Departments of Medicine and
- Physiology, Emory University School of Medicine, Atlanta, Georgia; and
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Villar D, Klafke GM, Rodríguez-Durán A, Bossio F, Miller R, Pérez de León AA, Cortés-Vecino JA, Chaparro-Gutiérrez JJ. Resistance profile and molecular characterization of pyrethroid resistance in a Rhipicephalus microplus strain from Colombia. Med Vet Entomol 2020; 34:105-115. [PMID: 31743471 DOI: 10.1111/mve.12418] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/16/2019] [Accepted: 10/14/2019] [Indexed: 06/10/2023]
Abstract
Intensive use of chemical acaricides for the control of cattle ticks (Rhipicephalus microplus) has led to the development of multiple acaricide resistance in Colombia. The present study aimed to characterize, using toxicological bioassays and molecular biology techniques, the resistance profile of a tick strain isolated from the Arauca state, Northeast Colombia. Commercial acaricides were used in adult immersion tests to determine its in vitro efficacies. Deltamethrin showed very low activity (4-7.3%), a mixture of cypermethrin and chlorpyrifos had intermediate efficacy (64-75.2%), and ethion presented the highest activity (88.5-100%). A colony (Arauquita strain) was established and larval immersion tests confirmed high resistance level to deltamethrin (241-fold) and susceptibility to ivermectin. A quantitative polymerase chain reaction-high resolution melt technique was used to identify single nucleotide polymorphisms (SNPs) in the para-sodium channel gene. All of the genotyped individuals were mutant, presenting one (n = 7), two (n = 7) or three (n = 9) SNPs previously associated with pyrethroid resistance. Sequencing revealed a novel mutation (F712L), that was found for the first time in R. microplus ticks from South America. This is the first description of mutations associated with pyrethroid resistance in R. microplus from Colombia. The acaricide resistance pattern found in the Arauquita strain is similar to other parts of Colombia.
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Affiliation(s)
- D Villar
- CIBAV Research Group, School of Veterinary Medicine, Faculty of Agrarian Science, Universidad de Antioquia, Medellín, Colombia
| | - G M Klafke
- USDA-ARS Cattle Fever Tick Research Laboratory and Veterinary Pest Genomics Center, Edinburg, TX, U.S.A
- Centro de Pesquisa em Saúde Animal (IPVDF), SEAPDR, Eldorado do Sul, Rio Grande do Sul, Brazil
| | - A Rodríguez-Durán
- Grupo de Investigación Parasitología Veterinaria, Departamento de Salud Animal, Facultad de Medicina Veterinaria y de Zootecnia, Universidad Nacional de Colombia, Sede Bogotá D.C., Colombia
| | - F Bossio
- CIBAV Research Group, School of Veterinary Medicine, Faculty of Agrarian Science, Universidad de Antioquia, Medellín, Colombia
| | - R Miller
- USDA-ARS Cattle Fever Tick Research Laboratory and Veterinary Pest Genomics Center, Edinburg, TX, U.S.A
| | - A A Pérez de León
- USDA-ARS Knipling-Bushland US Livestock Insects Research Laboratory and Veterinary Pest Genomics Center, Kerrville, TX, U.S.A
| | - J A Cortés-Vecino
- Grupo de Investigación Parasitología Veterinaria, Departamento de Salud Animal, Facultad de Medicina Veterinaria y de Zootecnia, Universidad Nacional de Colombia, Sede Bogotá D.C., Colombia
| | - J J Chaparro-Gutiérrez
- CIBAV Research Group, School of Veterinary Medicine, Faculty of Agrarian Science, Universidad de Antioquia, Medellín, Colombia
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Villanueva-Segura OK, Ontiveros-Zapata KA, Lopez-Monroy B, Ponce-Garcia G, Gutierrez-Rodriguez SM, Davila-Barboza JA, Mora-Jasso EDJ, Flores AE. Distribution and Frequency of the kdr Mutation V410L in Natural Populations of Aedes aegypti (L.) (Diptera: Culicidae) From Eastern and Southern Mexico. J Med Entomol 2020; 57:218-223. [PMID: 31504686 DOI: 10.1093/jme/tjz148] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Indexed: 05/26/2023]
Abstract
Aedes aegypti (L.) is the primary vector of the viruses that cause dengue, Zika, and chikungunya, for which effective vaccines and drugs are still lacking. Current strategies for suppressing arbovirus outbreaks based on insecticide use pose a challenge because of the rapid increase in resistance. The widespread and excessive use of pyrethroid-based insecticides has created a large selection pressure for a kdr-type resistance, caused by mutations in the para gene of the voltage-gated sodium channel (vgsc). Our objective was to evaluate the allelic frequency of natural populations of Ae. aegypti of Mexico at codon 410 of the para gene. Twenty-six Ae. aegypti populations from east and southern Mexico were genotyped for the codon 410 using allele-specific PCR. The frequencies of the L410 allele in Ae. aegypti ranged from 0.10 to 0.99; however, most of the frequencies were in the range of 0.36 to 0.64. The highest frequencies were found in three populations from the state of Veracruz, namely, Minatitlan with 0.99, Poza Rica with 0.82, and Jose Cardel with 0.97, along with populations from Cancun in Quintana Roo with 0.93, Frontera in Tabasco with 0.91, and Ciudad del Carmen in Campeche with 0.86. The frequency of the L410 allele was high in all populations of Ae. aegypti with higher values in populations of the southeast of the country. The knowledge of specific substitutions in vgsc and their interaction to confer resistance is essential to predict and develop future strategies for resistance management in Ae. aegypti in Mexico.
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Affiliation(s)
- Olga K Villanueva-Segura
- Universidad Autonoma de Nuevo Leon (UANL), Facultad de Ciencias Biologicas. Av. Universidad s/n Cd. Universitaria, San Nicolas de los Garza, N.L. Mexico
| | - Kevin A Ontiveros-Zapata
- Universidad Autonoma de Nuevo Leon (UANL), Facultad de Ciencias Biologicas. Av. Universidad s/n Cd. Universitaria, San Nicolas de los Garza, N.L. Mexico
| | - Beatriz Lopez-Monroy
- Universidad Autonoma de Nuevo Leon (UANL), Facultad de Ciencias Biologicas. Av. Universidad s/n Cd. Universitaria, San Nicolas de los Garza, N.L. Mexico
| | - Gustavo Ponce-Garcia
- Universidad Autonoma de Nuevo Leon (UANL), Facultad de Ciencias Biologicas. Av. Universidad s/n Cd. Universitaria, San Nicolas de los Garza, N.L. Mexico
| | - Selene M Gutierrez-Rodriguez
- Universidad Autonoma de Nuevo Leon (UANL), Facultad de Ciencias Biologicas. Av. Universidad s/n Cd. Universitaria, San Nicolas de los Garza, N.L. Mexico
| | - Jesus A Davila-Barboza
- Universidad Autonoma de Nuevo Leon (UANL), Facultad de Ciencias Biologicas. Av. Universidad s/n Cd. Universitaria, San Nicolas de los Garza, N.L. Mexico
| | - Esteban de J Mora-Jasso
- Universidad Autonoma de Nuevo Leon (UANL), Facultad de Ciencias Biologicas. Av. Universidad s/n Cd. Universitaria, San Nicolas de los Garza, N.L. Mexico
| | - Adriana E Flores
- Universidad Autonoma de Nuevo Leon (UANL), Facultad de Ciencias Biologicas. Av. Universidad s/n Cd. Universitaria, San Nicolas de los Garza, N.L. Mexico
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Chahal CAA, Salloum MN, Alahdab F, Gottwald JA, Tester DJ, Anwer LA, So EL, Murad MH, St Louis EK, Ackerman MJ, Somers VK. Systematic Review of the Genetics of Sudden Unexpected Death in Epilepsy: Potential Overlap With Sudden Cardiac Death and Arrhythmia-Related Genes. J Am Heart Assoc 2020; 9:e012264. [PMID: 31865891 PMCID: PMC6988156 DOI: 10.1161/jaha.119.012264] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2019] [Accepted: 09/25/2019] [Indexed: 12/29/2022]
Abstract
Background Sudden unexpected death in epilepsy (SUDEP) is the leading cause of epilepsy-related death. SUDEP shares many features with sudden cardiac death and sudden unexplained death in the young and may have a similar genetic contribution. We aim to systematically review the literature on the genetics of SUDEP. Methods and Results PubMed, MEDLINE Epub Ahead of Print, Ovid Medline In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and Scopus were searched through April 4, 2017. English language human studies analyzing SUDEP for known sudden death, ion channel and arrhythmia-related pathogenic variants, novel variant discovery, and copy number variant analyses were included. Aggregate descriptive statistics were generated; data were insufficient for meta-analysis. A total of 8 studies with 161 unique individuals were included; mean was age 29.0 (±SD 14.2) years; 61% males; ECG data were reported in 7.5% of cases; 50.7% were found prone and 58% of deaths were nocturnal. Cause included all types of epilepsy. Antemortem diagnosis of Dravet syndrome and autism (with duplication of chromosome 15) was associated with 11% and 9% of cases. The most frequently detected known pathogenic variants at postmortem were in Na+ and K+ ion channel subunits, as were novel potentially pathogenic variants (11%). Overall, the majority of variants were of unknown significance. Analysis of copy number variant was insignificant. Conclusions SUDEP case adjudication and evaluation remains limited largely because of crucial missing data such as ECGs. The most frequent pathogenic/likely pathogenic variants identified by molecular autopsy are in ion channel or arrhythmia-related genes, with an ≈11% discovery rate. Comprehensive postmortem examination should include examination of the heart and brain by specialized pathologists and blood storage.
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Affiliation(s)
- C. Anwar A. Chahal
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Mayo Clinic Graduate School of Biomedical SciencesMayo ClinicRochesterMN
- Department of Cardiovascular MedicineMayo ClinicRochesterMN
| | - Mohammad N. Salloum
- Internal MedicineIcahn School of Medicine at Mount SinaiQueens Hospital CenterNew YorkNY
| | - Fares Alahdab
- Evidence‐Based Practice Research ProgramMayo ClinicRochesterMN
- Division of Preventive, Occupational and Aerospace MedicineMayo ClinicRochesterMN
| | | | - David J. Tester
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Department of Cardiovascular MedicineMayo ClinicRochesterMN
- Windland Smith Rice Sudden Death Genomics LaboratoryMayo ClinicRochesterMN
| | - Lucman A. Anwer
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Department of Cardiovascular SurgeryMayo ClinicRochesterMN
- General SurgeryUIC/MGHChicagoIL
| | - Elson L. So
- Evidence‐Based Practice Research ProgramMayo ClinicRochesterMN
| | - Mohammad Hassan Murad
- Evidence‐Based Practice Research ProgramMayo ClinicRochesterMN
- Division of Preventive, Occupational and Aerospace MedicineMayo ClinicRochesterMN
| | - Erik K. St Louis
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Department of NeurologyMayo ClinicRochesterMN
- Mayo Center for Sleep MedicineMayo ClinicRochesterMN
| | - Michael J. Ackerman
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Mayo Clinic Graduate School of Biomedical SciencesMayo ClinicRochesterMN
- Department of Cardiovascular MedicineMayo ClinicRochesterMN
- Windland Smith Rice Sudden Death Genomics LaboratoryMayo ClinicRochesterMN
- Department of PediatricsMayo ClinicRochesterMN
| | - Virend K. Somers
- Mayo Clinic College of MedicineMayo ClinicRochesterMN
- Department of Cardiovascular MedicineMayo ClinicRochesterMN
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Horiuchi K, Kogiso T, Sagawa T, Ito T, Taniai M, Miura K, Hattori M, Morisada N, Hashimoto E, Tokushige K. Bardet-Biedl Syndrome Caused by Skipping of SCLT1 Complicated by Microvesicular Steatohepatitis. Intern Med 2020; 59:2719-2724. [PMID: 33132306 PMCID: PMC7691027 DOI: 10.2169/internalmedicine.5045-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
We treated the case of a 22-year-old male patient with liver dysfunction. At 1 year of age, hepatic fibrosis was suspected. In addition, due to the presence of retinitis pigmentosa, renal failure, obesity, mental retardation, and hypogonadism, he was diagnosed with Bardet-Biedl syndrome (BBS). Skipping of exons 14 and 17 in the sodium channel and clathrin linker 1 (SCLT1) gene was observed. At 22 years of age, the liver enzyme levels were further elevated and a diagnosis of microvesicular steatohepatitis was made. Insulin resistance, a reduction of muscle mass, an impairment of the fatty acid metabolism, and hyperleptinemia in this syndrome may cause steatohepatitis.
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Affiliation(s)
- Kentaro Horiuchi
- Institute of Gastroenterology, Department of Internal Medicine, Tokyo Women's Medical University, Japan
| | - Tomomi Kogiso
- Institute of Gastroenterology, Department of Internal Medicine, Tokyo Women's Medical University, Japan
| | - Takaomi Sagawa
- Institute of Gastroenterology, Department of Internal Medicine, Tokyo Women's Medical University, Japan
| | - Taito Ito
- Institute of Gastroenterology, Department of Internal Medicine, Tokyo Women's Medical University, Japan
| | - Makiko Taniai
- Institute of Gastroenterology, Department of Internal Medicine, Tokyo Women's Medical University, Japan
| | - Kenichiro Miura
- Department of Pediatric Nephrology, Tokyo Women's Medical University, Japan
| | - Motoshi Hattori
- Department of Pediatric Nephrology, Tokyo Women's Medical University, Japan
| | - Naoya Morisada
- Department of Pediatrics, Kobe University Graduate School of Medicine, Japan
| | | | - Katsutoshi Tokushige
- Institute of Gastroenterology, Department of Internal Medicine, Tokyo Women's Medical University, Japan
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Iacobas DA, Iacobas S, Lee PR, Cohen JE, Fields RD. Coordinated Activity of Transcriptional Networks Responding to the Pattern of Action Potential Firing in Neurons. Genes (Basel) 2019; 10:genes10100754. [PMID: 31561430 PMCID: PMC6826514 DOI: 10.3390/genes10100754] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 09/17/2019] [Accepted: 09/20/2019] [Indexed: 12/13/2022] Open
Abstract
Transcriptional responses to the appropriate temporal pattern of action potential firing are essential for long-term adaption of neuronal properties to the functional activity of neural circuits and environmental experience. However, standard transcriptome analysis methods can be too limited in identifying critical aspects that coordinate temporal coding of action potential firing with transcriptome response. A Pearson correlation analysis was applied to determine how pairs of genes in the mouse dorsal root ganglion (DRG) neurons are coordinately expressed in response to stimulation producing the same number of action potentials by two different temporal patterns. Analysis of 4728 distinct gene-pairs related to calcium signaling, 435,711 pairs of transcription factors, 820 pairs of voltage-gated ion channels, and 86,862 pairs of calcium signaling genes with transcription factors indicated that genes become coordinately activated by distinct action potential firing patterns and this depends on the duration of stimulation. Moreover, a measure of expression variance revealed that the control of transcripts abundances is sensitive to the pattern of stimulation. Thus, action potentials impact intracellular signaling and the transcriptome in dynamic manner that not only alter gene expression levels significantly (as previously reported) but also affects the control of their expression fluctuations and profoundly remodel the transcriptional networks.
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Affiliation(s)
- Dumitru A Iacobas
- Personalized Genomics Laboratory, Center for Computational Systems Biology, Prairie View A&M University, Prairie View, TX 77446, USA.
- DP Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Sanda Iacobas
- Department of Pathology, New York Medical College, Valhalla, NY 10595, USA.
| | - Philip R Lee
- Section on Nervous System Development and Plasticity, the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), NIH, Bethesda, MD 20892, USA.
| | - Jonathan E Cohen
- Division of Medical Imaging Products, U.S. Food and Drug Administration, Silver Spring, 20993 MD, USA.
| | - R Douglas Fields
- Section on Nervous System Development and Plasticity, the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), NIH, Bethesda, MD 20892, USA.
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Chen M, Du Y, Wu S, Nomura Y, Zhu G, Zhorov BS, Dong K. Molecular evidence of sequential evolution of DDT- and pyrethroid-resistant sodium channel in Aedes aegypti. PLoS Negl Trop Dis 2019; 13:e0007432. [PMID: 31158225 PMCID: PMC6564045 DOI: 10.1371/journal.pntd.0007432] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 06/13/2019] [Accepted: 05/02/2019] [Indexed: 12/19/2022] Open
Abstract
Background Multiple mutations in the voltage-gated sodium channel have been associated with knockdown resistance (kdr) to DDT and pyrethroid insecticides in a major human disease vector Aedes aegypti. One mutation, V1016G, confers sodium channel resistance to pyrethroids, but a different substitution in the same position V1016I alone had no effect. In pyrethroid-resistant Ae. aegypti populations, V1016I is often linked to another mutation, F1534C, which confers sodium channel resistance only to Type I pyrethroids including permethrin (PMT), but not to Type II pyrethroids including deltamethrin (DMT). Mosquitoes carrying both V1016G and F1534C exhibited a greater level of pyrethroid resistance than those carrying F1534C alone. More recently, a new mutation T1520I co-existing with F1534C was detected in India. However, whether V1016I or T1520I enhances pyrethroid resistance of sodium channels carrying F1534C remains unknown. Methodology/Principal findings V1016I, V1016G, T1520I and F1534C substitutions were introduced alone and in various combinations into AaNav1-1, a sodium channel from Aedes aegypti. The mutant channels were then expressed in Xenopus oocytes and examined for channel properties and sensitivity to pyrethroids using the two-electrode voltage clamping technique. The results showed that V1016I or T1520I alone did not alter the AaNav1-1 sensitivity to PMT or DMT. However, the double mutant T1520I+F1534C was more resistant to PMT than F1534C, but remained sensitive to DMT. In contrast, the double mutant V1016I+F1534C was resistant to DMT and more resistant to PMT than F1534C. Furthermore, V1016I/G and F1534C channels, but not T1520I, were resistant to dichlorodiphenyltrichloroethane (DDT). Cryo-EM structures of sodium channels suggest that T1520I allosterically deforms geometry of the pyrethroid receptor site PyR1 in AaNav1-1. The small deformation does not affect binding of DDT, PMT or DMT, but in combination with F1534C it increases the channel resistance to PMT and DDT. Conclusions/Significance Our data corroborated the previously proposed sequential selection of kdr mutations in Ae. aegypti. We proposed that mutation F1534C first emerged in response to DDT/pyrethroids providing a platform for subsequent selection of mutations V1016I and T1520I that confer greater and broader spectrum of pyrethroid resistance. Intensive use of pyrethroids has led to the selection of resistance in mosquitoes, and knockdown resistance (kdr) is one of the major mechanisms of pyrethroid resistance. So far, eleven kdr mutations were identified to be associated with pyrethroid resistance in Aedes aegypti. Among the mutations, the V1016I and T1520I substitutions were found to be associated with F1534C but rarely found alone. F1534C confers sodium channel resistance to Type I pyrethroids including permethrin (PMT). However, whether V1016I or T1520I enhances the F1534C-mediated sodium channel resistance remain unknown. In this study, our electrophysiological results confirmed their involvement in kdr and corroborate the previously proposed sequential selection of kdr mutations in Ae. aegypti: F1534C likely emerged first in response to DDT and/or pyrethroids, whereas V1016I and T1520I appeared later under more intensive selection from pyrethroid use.
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Affiliation(s)
- Mengli Chen
- Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou, China
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, United States of America
| | - Yuzhe Du
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, United States of America
| | - Shaoying Wu
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, United States of America
| | - Yoshiko Nomura
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, United States of America
| | - Guonian Zhu
- Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou, China
| | - Boris S. Zhorov
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- Sechenov Institute of Evolutionary Physiology & Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia
| | - Ke Dong
- Department of Entomology, Genetics and Neuroscience Programs, Michigan State University, East Lansing, United States of America
- * E-mail:
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Leong CS, Vythilingam I, Liew JWK, Wong ML, Wan-Yusoff WS, Lau YL. Enzymatic and molecular characterization of insecticide resistance mechanisms in field populations of Aedes aegypti from Selangor, Malaysia. Parasit Vectors 2019; 12:236. [PMID: 31097010 PMCID: PMC6521414 DOI: 10.1186/s13071-019-3472-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 04/30/2019] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND Dengue is a serious public health problem worldwide, including in Selangor, Malaysia. Being an important vector of dengue virus, Aedes aegypti are subjected to control measures which rely heavily on the usage of insecticides. Evidently, insecticide resistance in Ae. aegypti, which arise from several different point mutations within the voltage-gated sodium channel genes, has been documented in many countries. Thus, this robust study was conducted in all nine districts of Selangor to understand the mechanisms of resistance to various insecticides in Ae. aegypti. Mosquitoes were collected from dengue epidemic and non-dengue outbreak areas in Selangor. METHODS Using the Center for Disease Control and Prevention (CDC) bottle assays, the insecticide resistance status of nine different Ae. aegypti strains from Selangor was accessed. Synergism tests and biochemical assays were conducted to further understand the metabolic mechanisms of insecticide resistance. Polymerase chain reaction (PCR) amplification and sequencing of the IIP-IIS6 as well as IIIS4-IIIS6 regions of the sodium channel gene were performed to enable comparisons between susceptible and resistant mosquito strains. Additionally, genomic DNA was used for allele-specific PCR (AS-PCR) genotyping of the gene to detect the presence of F1534C, V1016G and S989P mutations. RESULTS Adult female Ae. aegypti from various locations were susceptible to malathion and propoxur. However, they exhibited different levels of resistance against dichlorodiphenyltrichloroethane (DDT) and pyrethroids. The results of synergism tests and biochemical assays indicated that the mixed functions of oxidases and glutathione S-transferases contributed to the DDT and pyrethroid resistance observed in the present study. Besides detecting three single kdr mutations, namely F1534C, V1016G and S989P, co-occurrence of homozygous V1016G/S989P (double allele) and F1534C/V1016G/S989P (triple allele) mutations were also found in Ae. aegypti. As per the results, the three kdr mutations had positive correlations with the expressions of resistance to DDT and pyrethroids. CONCLUSIONS In view of the above outcomes, it is important to seek new tools for vector management instead of merely relying on insecticides. If the latter must be used, regular monitoring of insecticide resistance should also be carried out at all dengue epidemic areas. Since the eggs of Ae. aegypti can be easily transferred from one location to another, it is probable that insecticide-resistant Ae. aegypti can be found at non-dengue outbreak sites as well.
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Affiliation(s)
- Cherng-Shii Leong
- Department of Parasitology, Faculty of Medicine, University Malaya, Kuala Lumpur, 50603 Malaysia
| | - Indra Vythilingam
- Department of Parasitology, Faculty of Medicine, University Malaya, Kuala Lumpur, 50603 Malaysia
| | - Jonathan Wee-Kent Liew
- Department of Parasitology, Faculty of Medicine, University Malaya, Kuala Lumpur, 50603 Malaysia
| | - Meng-Li Wong
- The Tropical Infectious Diseases Research and Education Centre (TIDREC), Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Wan Sulaiman Wan-Yusoff
- Department of Parasitology, Faculty of Medicine, University Malaya, Kuala Lumpur, 50603 Malaysia
| | - Yee-Ling Lau
- Department of Parasitology, Faculty of Medicine, University Malaya, Kuala Lumpur, 50603 Malaysia
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Stara J, Pekar S, Nesvorna M, Kamler M, Doskocil I, Hubert J. Spatio-temporal dynamics of Varroa destructor resistance to tau-fluvalinate in Czechia, associated with L925V sodium channel point mutation. Pest Manag Sci 2019; 75:1287-1294. [PMID: 30338625 DOI: 10.1002/ps.5242] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 08/30/2018] [Accepted: 10/13/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Extensive application of pyrethroids to control Varroa destructor, an invasive mite devastating bee colonies, has resulted in a global spread of resistant mite populations. In this study, we analyzed the spatio-temporal dynamics of resistant V. destructor populations in Czechia, stemming from the L925V mutation. Mites were collected during 2011-2018 directly or from winter beeswax debris, and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and densitometry was used to detect the L925V mutation. RESULTS Pooled samples of 10 mites were classified, based on their PCR-RFLP patterns, as tau-fluvalinate-sensitive (56%), resistant (9%), or mixed (35%), with the latter including sensitive and resistant homo- and heterozygotes. We identified two zones with higher frequencies of resistance, one in southern Moravia and the other in Bohemia. The mutant populations were evenly distributed throughout the monitored districts, with a few temporal and spatial local fluctuations. The greatest increase in resistance was observed in 2016, following massive losses of bee colonies in the winter of 2015. This event appeared to be closely associated with fluctuations in resistant mite populations and their dispersion. CONCLUSION Two outbreaks of resistance were detected in Czechia; however, the amount of applied tau-fluvalinate was not correlated with the frequency of resistance in mites. There was no remarkable increase in mite resistance in 2011-2018, although the use of tau-fluvalinate increased 40-fold between 2011 and 2015. PCR-RFLP analysis, performed on mites present in beeswax debris, is a suitable method for monitoring the L925V mutation in V. destructor. © 2018 Society of Chemical Industry.
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Affiliation(s)
| | - Stano Pekar
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Brno, Czechia
| | | | - Martin Kamler
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Prague 6-Suchdol, Czechia
- Bee Research Institute at Dol, Libcice nad Vltavou, Czechia
| | - Ivo Doskocil
- Department of Microbiology, Nutrition and Dietetics, Czech University of Life Sciences Prague, Prague 6-Suchdol, Czechia
| | - Jan Hubert
- Crop Research Institute, Prague, Czechia
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Locascio A, Andrés-Colás N, Mulet JM, Yenush L. Saccharomyces cerevisiae as a Tool to Investigate Plant Potassium and Sodium Transporters. Int J Mol Sci 2019; 20:E2133. [PMID: 31052176 PMCID: PMC6539216 DOI: 10.3390/ijms20092133] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/26/2019] [Accepted: 04/29/2019] [Indexed: 12/20/2022] Open
Abstract
Sodium and potassium are two alkali cations abundant in the biosphere. Potassium is essential for plants and its concentration must be maintained at approximately 150 mM in the plant cell cytoplasm including under circumstances where its concentration is much lower in soil. On the other hand, sodium must be extruded from the plant or accumulated either in the vacuole or in specific plant structures. Maintaining a high intracellular K+/Na+ ratio under adverse environmental conditions or in the presence of salt is essential to maintain cellular homeostasis and to avoid toxicity. The baker's yeast, Saccharomyces cerevisiae, has been used to identify and characterize participants in potassium and sodium homeostasis in plants for many years. Its utility resides in the fact that the electric gradient across the membrane and the vacuoles is similar to plants. Most plant proteins can be expressed in yeast and are functional in this unicellular model system, which allows for productive structure-function studies for ion transporting proteins. Moreover, yeast can also be used as a high-throughput platform for the identification of genes that confer stress tolerance and for the study of protein-protein interactions. In this review, we summarize advances regarding potassium and sodium transport that have been discovered using the yeast model system, the state-of-the-art of the available techniques and the future directions and opportunities in this field.
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Affiliation(s)
- Antonella Locascio
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
| | - Nuria Andrés-Colás
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
| | - José Miguel Mulet
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
| | - Lynne Yenush
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, 46022 Valencia, Spain.
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Wei Z, Yuan F, Yi Z, Wen-Qi S, Yuan-Yuan L, Zhi-Yuan Y. [Study on kdr allele mutation of Culex pipiens pallens in Zichuan District, Zibo City, Shandong Province]. Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi 2019; 31:134-138. [PMID: 31184042 DOI: 10.16250/j.32.1374.2018285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
OBJECTIVE To study the seasonal dynamics of Culex pipiens pallens and the distribution of knockdown resistance (kdr) gene related sodium channel gene polymorphism in Zichuan District, Zibo City, Shandong Province. METHODS Cx. pipiens pallens mosquitoes were collected in Zichuan District during the peak period of mosquito vector activity from 2017 to 2018. The DNA from Cx. pipiens pallens was extracted, and the genotypes and frequencies of kdr allele mutation were detected by polymerase chain reaction. RESULTS Totally 830 mosquitoes belonging to six species, including Cx. pipiens pallens, Armigeres subalbatus, Aedes albopictus, Ae. vexans, Anopheles sinensis, and Cx. tritaeniorhchus were collected in this study. The number of Cx. pipiens pallens accounted for 83.13% in total, with the density of 12.32 per lamp per night. The annual density monitoring curve of Cx. pipiens pallens showed a bimodal trend, and the peaks were observed in June and September respectively. In this study, five kdr alleles were detected at the 1 014 locus of kdr gene, with TTA (75.71%), TTT (10.00%), CTA (5.71%), TCA (4.29%), and TTC (4.29%). Two nonsynonymous nucleotide mutations were detected at site 1 014 of kdr gene, namely leucine (L1014) mutated to phenylalanine (L1014F) and serine (L1014S). The kdr gene mutation frequency (%) of Cx. pipiens pallens in Luochun Town and Taihe Town was 10.53% and 40.63%, respectively, and the difference was statistically significant ( χ2 = 8.559, P = 0.003). CONCLUSIONS Cx. pipiens pallens is the dominant mosquito species in Zichuan District. In addition, two novel mutations, CTA and TTC, are identified in the voltage-dependent sodium channel gene of Cx. pipiens pallens. The kdr genotype of Cx. pipiens pallens in Zichuan area was polymorphic.
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Affiliation(s)
- Zhang Wei
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai 200025, China
- Zichuan District Center for Disease Control and Prevention, Zibo City, Shandong Province, China
| | - Fang Yuan
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai 200025, China
| | - Zhang Yi
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai 200025, China
| | - Shi Wen-Qi
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai 200025, China
| | - Li Yuan-Yuan
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai 200025, China
| | - Yue Zhi-Yuan
- National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, WHO Collaborating Center for Tropical Diseases, Key Laboratory of Parasite and Vector Biology, National Health Commission, Shanghai 200025, China
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Chu L, Greenstein JL, Winslow RL. Na + microdomains and sparks: Role in cardiac excitation-contraction coupling and arrhythmias in ankyrin-B deficiency. J Mol Cell Cardiol 2019; 128:145-157. [PMID: 30731085 DOI: 10.1016/j.yjmcc.2019.02.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Revised: 02/01/2019] [Accepted: 02/02/2019] [Indexed: 01/25/2023]
Abstract
Cardiac sodium (Na+) potassium ATPase (NaK) pumps, neuronal sodium channels (INa), and sodium calcium (Ca2+) exchangers (NCX1) may co-localize to form a Na+ microdomain. It remains controversial as to whether neuronal INa contributes to local Na+ accumulation, resulting in reversal of nearby NCX1 and influx of Ca2+ into the cell. Therefore, there has been great interest in the possible roles of a Na+ microdomain in cardiac Ca2+-induced Ca2+ release (CICR). In addition, the important role of co-localization of NaK and NCX1 in regulating localized Na+ and Ca2+ levels and CICR in ankyrin-B deficient (ankyrin-B+/-) cardiomyocytes has been examined in many recent studies. Altered Na+ dynamics may contribute to the appearance of arrhythmias, but the mechanisms underlying this relationship remain unclear. In order to investigate this, we present a mechanistic canine cardiomyocyte model which reproduces independent local dyadic junctional SR (JSR) Ca2+ release events underlying cell-wide excitation-contraction coupling, as well as a three-dimensional super-resolution model of the Ca2+ spark that describes local Na+ dynamics as governed by NaK pumps, neuronal INa, and NCX1. The model predicts the existence of Na+ sparks, which are generated by NCX1 and exhibit significantly slower dynamics as compared to Ca2+ sparks. Moreover, whole-cell simulations indicate that neuronal INa in the cardiac dyad plays a key role during the systolic phase. Rapid inward neuronal INa can elevate dyadic [Na+] to 35-40 mM, which drives reverse-mode NCX1 transport, and therefore promotes Ca2+ entry into the dyad, enhancing the trigger for JSR Ca2+ release. The specific role of decreased co-localization of NaK and NCX1 in ankyrin-B+/- cardiomyocytes was examined. Model results demonstrate that a reduction in the local NCX1- and NaK-mediated regulation of dyadic [Ca2+] and [Na+] results in an increase in Ca2+ spark activity during isoproterenol stimulation, which in turn stochastically activates NCX1 in the dyad. This alteration in NCX1/NaK co-localization interrupts the balance between NCX1 and NaK currents in a way that leads to enhanced depolarizing inward current during the action potential plateau, which ultimately leads to a higher probability of L-type Ca2+ channel reopening and arrhythmogenic early-afterdepolarizations.
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Affiliation(s)
- Lulu Chu
- Department of Biomedical Engineering and the Institute for Computational Medicine, The Johns Hopkins University School of Medicine and Whiting School of Engineering, 3400 N Charles Street, Baltimore, MD 21218, USA.
| | - Joseph L Greenstein
- Department of Biomedical Engineering and the Institute for Computational Medicine, The Johns Hopkins University School of Medicine and Whiting School of Engineering, 3400 N Charles Street, Baltimore, MD 21218, USA.
| | - Raimond L Winslow
- Department of Biomedical Engineering and the Institute for Computational Medicine, The Johns Hopkins University School of Medicine and Whiting School of Engineering, 3400 N Charles Street, Baltimore, MD 21218, USA.
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Samantsidis GR, O'Reilly AO, Douris V, Vontas J. Functional validation of target-site resistance mutations against sodium channel blocker insecticides (SCBIs) via molecular modeling and genome engineering in Drosophila. Insect Biochem Mol Biol 2019; 104:73-81. [PMID: 30572019 DOI: 10.1016/j.ibmb.2018.12.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 12/14/2018] [Accepted: 12/14/2018] [Indexed: 06/09/2023]
Abstract
Sodium channel blocker insecticides (SCBIs) like indoxacarb and metaflumizone offer an alternative insecticide resistance management (IRM) strategy against several pests that are resistant to other compounds. However, resistance to SCBIs has been reported in several pests, in most cases implicating metabolic resistance mechanisms, although in certain indoxacarb resistant populations of Plutella xylostella and Tuta absoluta, two mutations in the domain IV S6 segment of the voltage-gated sodium channel, F1845Y and V1848I have been identified, and have been postulated through in vitro electrophysiological studies to contribute to target-site resistance. In order to functionally validate in vivo each mutation in the absence of confounding resistance mechanisms, we have employed a CRISPR/Cas9 strategy to generate strains of Drosophila melanogaster bearing homozygous F1845Y or V1848I mutations in the para (voltage-gated sodium channel) gene. We performed toxicity bioassays of these strains compared to wild-type controls of the same genetic background. Our results indicate both mutations confer moderate resistance to indoxacarb (RR: 6-10.2), and V1848I to metaflumizone (RR: 8.4). However, F1845Y confers very strong resistance to metaflumizone (RR: >3400). Our molecular modeling studies suggest a steric hindrance mechanism may account for the resistance of both V1848I and F1845Y mutations, whereby introducing larger side chains may inhibit metaflumizone binding.
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Affiliation(s)
- George-Rafael Samantsidis
- Institute of Molecular Biology & Biotechnology, Foundation for Research & Technology Hellas, 100 N. Plastira Street, GR-700 13, Heraklion Crete, Greece; Laboratory of Molecular Entomology, Department of Biology, University of Crete, GR-700 13, Heraklion Crete, Greece
| | - Andrias O O'Reilly
- School of Natural Sciences and Psychology, Liverpool John Moores University, Liverpool, UK
| | - Vassilis Douris
- Institute of Molecular Biology & Biotechnology, Foundation for Research & Technology Hellas, 100 N. Plastira Street, GR-700 13, Heraklion Crete, Greece.
| | - John Vontas
- Institute of Molecular Biology & Biotechnology, Foundation for Research & Technology Hellas, 100 N. Plastira Street, GR-700 13, Heraklion Crete, Greece; Laboratory of Pesticide Science, Department of Crop Science, Agricultural University of Athens, 75 Iera Odos Street, GR-11855, Athens, Greece.
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