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Guo H, Chen H, Yang Y, Xie D, Dang Y, Xiang M, Yu Y. Neurotoxicity of tetrabromobisphenol-A-bis(2,3-dibromopropyl ether) through the GABAergic and serotonergic neurotransmission in Caenorhabditis elegans. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 357:124392. [PMID: 38897283 DOI: 10.1016/j.envpol.2024.124392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 06/06/2024] [Accepted: 06/17/2024] [Indexed: 06/21/2024]
Abstract
Tetrabromobisphenol-A-bis(2,3-dibromopropyl ether) (TBBPA-BDBPE), a novel additive brominated flame retardant, is being developed for use in polyolefin and copolymers. Despite its emerging application, the neurotoxicity and mechanisms of action of TBBPA-BDBPE remain unexplored. Caenorhabditis elegans was utilized as the model organism to study the neurotoxic effects of TBBPA-BDBPE across environmental concentrations ranging from 0 to 100 μg/L. This investigation focused on various toxicological endpoints such as locomotive behavior, neuronal injury, neurotransmitter transmission, and the regulation of nervous system-related gene expression. Acute exposure to TBBPA-BDBPE at concentrations of 10-100 μg/L significantly impaired nematode movement, indicating potential neurotoxicity. In transgenic nematodes, this exposure also caused damage to γ-aminobutyric acid (GABAergic) and serotonergic neurons, along with notable changes in the levels of GABAergic and serotonergic neurotransmitters. Further molecular studies indicated alterations in neurotransmission-related genes (cat-4, mod-1, unc-25, and unc-47). Molecular docking analysis confirmed the binding affinity of TBBPA-BDBPE to key neurotransmission proteins-CAT-4, MOD-1, UNC-25, and UNC-47. These findings demonstrate that TBBPA-BDBPE exerts neurotoxic effects by impacting GABAergic and serotonergic neurotransmission in nematodes. This study provides new insights into the potential environmental risks of TBBPA-BDBPE.
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Affiliation(s)
- Hongzhi Guo
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China; College of Environmental and Chemical Engineering, Chongqing Three Gorges University, Wanzhou, 404100, China
| | - Haibo Chen
- Institute for Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai, 200444, China
| | - Yue Yang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China; School of Public Health, China Medical University, Liaoning, 110122, China
| | - Dongli Xie
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China; College of Environmental and Chemical Engineering, Chongqing Three Gorges University, Wanzhou, 404100, China
| | - Yao Dang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
| | - Mingdeng Xiang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China
| | - Yunjiang Yu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, 510655, China.
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Kwon S, Park KS, Yoon KH. Dissecting the Neuronal Contributions of the Lipid Regulator NHR-49 Function in Lifespan and Behavior in C. elegans. Life (Basel) 2023; 13:2346. [PMID: 38137948 PMCID: PMC10744624 DOI: 10.3390/life13122346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/11/2023] [Accepted: 12/13/2023] [Indexed: 12/24/2023] Open
Abstract
Although the importance of lipid homeostasis in neuronal function is undisputed, how they are regulated within neurons to support their unique function is an area of active study. NHR-49 is a nuclear hormone receptor functionally similar to PPARα, and a major lipid regulator in C. elegans. Although expressed in most tissues, little is known about its roles outside the intestine, the main metabolic organ of C. elegans. Here, using tissue- and neuron-type-specific transgenic strains, we examined the contribution of neuronal NHR-49 to cell-autonomous and non-autonomous nhr-49 mutant phenotypes. We examined lifespan, brood size, early egg-laying, and reduced locomotion on food. We found that lifespan and brood size could be rescued by neuronal NHR-49, and that NHR-49 in cholinergic and serotonergic neurons is sufficient to restore lifespan. For behavioral phenotypes, NHR-49 in serotonergic neurons was sufficient to control egg-laying, whereas no single tissue or neuron type was able to rescue the enhanced on-food slowing behavior. Our study shows that NHR-49 can function in single neuron types to regulate C. elegans physiology and behavior, and provides a platform to further investigate how lipid metabolism in neurons impact neuronal function and overall health of the organism.
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Affiliation(s)
- Saebom Kwon
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea;
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea
- Department of Global Medical Science, Yonsei University of Wonju College of Medicine, 20 Ilsan-ro, Wonju 26426, Republic of Korea
| | - Kyu-Sang Park
- Department of Physiology, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea;
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea
- Department of Global Medical Science, Yonsei University of Wonju College of Medicine, 20 Ilsan-ro, Wonju 26426, Republic of Korea
| | - Kyoung-hye Yoon
- Mitohormesis Research Center, Yonsei University Wonju College of Medicine, Wonju 26426, Republic of Korea
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Yemini E. Systems neuroscience: Foraging through serotonin's tangled web. Curr Biol 2023; 33:R767-R770. [PMID: 37490863 DOI: 10.1016/j.cub.2023.06.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/27/2023]
Abstract
Serotonin signaling is conserved in regulating animal behaviors. A new paper decodes the nonlinear effects of all serotonin receptor combinations on foraging behaviors. The authors introduce a brain-wide multiscale method to dissect receptor dynamics, receptor effects on neural activity, and resulting behavioral changes.
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Affiliation(s)
- Eviatar Yemini
- University of Massachusetts, Department of Neurobiology, Worcester, MA 01605, USA.
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Yu Y, Xie D, Yang Y, Tan S, Li H, Dang Y, Xiang M, Chen H. Carboxyl-modified polystyrene microplastics induces neurotoxicity by affecting dopamine, glutamate, serotonin, and GABA neurotransmission in Caenorhabditis elegans. JOURNAL OF HAZARDOUS MATERIALS 2023; 445:130543. [PMID: 36493651 DOI: 10.1016/j.jhazmat.2022.130543] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Microplastics (MPs) are ubiquitous in various environmental media and have potential toxicity. However, the neurotoxicity of carboxyl-modified polystyrene microplastics (PS-COOH) and their mechanisms remain unclear. In this study, Caenorhabditis elegans was used as a model to examine the neurotoxicity of polystyrene microplastic (PS) and PS-COOH concentrations ranging from 0.1 to 100 μg/L. Locomotion behavior, neuron development, neurotransmitter level, and neurotransmitter-related gene expression were selected as assessment endpoints. Exposure to low concentrations (1 μg/L) of PS-COOH caused more severe neurotoxicity than exposure to pristine PS. In transgenic nematodes, exposure to PS-COOH at 10-100 μg/L significantly increased the fluorescence intensity of dopaminergic, glutamatergic, serotonergic, and aminobutyric acid (GABA)ergic neurons compared to that of the control. Further studies showed that exposure to 100 μg/L PS-COOH can significantly affect the levels of glutamate, serotonin, dopamine, and GABA in nematodes. Likewise, in the present study, the expression of genes involved in neurotransmission was altered in worms. These results suggest that PS-COOH exerts neurotoxicity by affecting neurotransmission of dopamine, glutamate, serotonin, and GABA. This study provides new insights into the underlying mechanisms and potential risks associated with PS-COOH.
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Affiliation(s)
- Yunjiang Yu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China.
| | - Dongli Xie
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China; College of Environmental and Chemical Engineering, Chongqing Three Gorges University, Wanzhou 404100, China
| | - Yue Yang
- Xi 'an Jiaotong University Second Affiliated Hospital, Xi 'an 710004, China
| | - Shihui Tan
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China; School of Public Health, China Medical University, Liaoning 110122, China
| | - Hongyan Li
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Yao Dang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Mingdeng Xiang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Haibo Chen
- Institute for Environmental pollution and health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
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Di Rocco M, Galosi S, Follo FC, Lanza E, Folli V, Martire A, Leuzzi V, Martinelli S. Phenotypic Assessment of Pathogenic Variants in GNAO1 and Response to Caffeine in C. elegans Models of the Disease. Genes (Basel) 2023; 14:319. [PMID: 36833246 PMCID: PMC9957173 DOI: 10.3390/genes14020319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 01/13/2023] [Accepted: 01/22/2023] [Indexed: 01/28/2023] Open
Abstract
De novo mutations affecting the G protein α o subunit (Gαo)-encoding gene (GNAO1) cause childhood-onset developmental delay, hyperkinetic movement disorders, and epilepsy. Recently, we established Caenorhabditis elegans as an informative experimental model for deciphering pathogenic mechanisms associated with GNAO1 defects and identifying new therapies. In this study, we generated two additional gene-edited strains that harbor pathogenic variants which affect residues Glu246 and Arg209-two mutational hotspots in Gαo. In line with previous findings, biallelic changes displayed a variable hypomorphic effect on Gαo-mediated signaling that led to the excessive release of neurotransmitters by different classes of neurons, which, in turn, caused hyperactive egg laying and locomotion. Of note, heterozygous variants showed a cell-specific dominant-negative behavior, which was strictly dependent on the affected residue. As with previously generated mutants (S47G and A221D), caffeine was effective in attenuating the hyperkinetic behavior of R209H and E246K animals, indicating that its efficacy is mutation-independent. Conversely, istradefylline, a selective adenosine A2A receptor antagonist, was effective in R209H animals but not in E246K worms, suggesting that caffeine acts through both adenosine receptor-dependent and receptor-independent mechanisms. Overall, our findings provide new insights into disease mechanisms and further support the potential efficacy of caffeine in controlling dyskinesia associated with pathogenic GNAO1 mutations.
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Affiliation(s)
- Martina Di Rocco
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy
- Department of Human Neuroscience, ‘Sapienza’ University of Rome, 00185 Rome, Italy
| | - Serena Galosi
- Department of Human Neuroscience, ‘Sapienza’ University of Rome, 00185 Rome, Italy
| | - Francesca C. Follo
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Enrico Lanza
- Center for Life Nano Science, Istituto Italiano di Tecnologia, 00161 Rome, Italy
| | - Viola Folli
- Center for Life Nano Science, Istituto Italiano di Tecnologia, 00161 Rome, Italy
- D-tails s.r.l., 00165 Rome, Italy
| | - Alberto Martire
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, ‘Sapienza’ University of Rome, 00185 Rome, Italy
| | - Simone Martinelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy
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da Silva TC, da Silveira TL, Dos Santos LV, Arantes LP, Martins RP, Soares FAA, Dalla Corte CL. Exogenous Adenosine Modulates Behaviors and Stress Response in Caenorhabditis elegans. Neurochem Res 2023; 48:117-130. [PMID: 36018438 DOI: 10.1007/s11064-022-03727-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 07/14/2022] [Accepted: 08/15/2022] [Indexed: 01/11/2023]
Abstract
Adenosine, a purine nucleoside with neuromodulatory actions, is part of the purinergic signaling system (PSS). Caenorhabditis elegans is a free-living nematode found in soil, used in biological research for its advantages as an alternative experimental model. Since there is a lack of evidence of adenosine's direct actions and the PSS's participation in this animal, such an investigation is necessary. In this research, we aimed to test the effects of acute and chronic adenosine at 1, 5, and 10 mM on nematode's behaviors, morphology, survival after stress conditions, and on pathways related to the response to oxidative stress (DAF-16/FOXO and SKN-1) and genes products downstream these pathways (SOD-3, HSP-16.2, and GCS-1). Acute or chronic adenosine did not alter the worms' morphology analyzed by the worms' length, width, and area, nor interfered with reproductive behavior. On the other hand, acute and chronic adenosine modulated the defecation rate, pharyngeal pumping rate, and locomotion, in addition, to interacting with stress response pathways in C. elegans. Adenosine interfered in the speed and mobility of the worms analyzed. In addition, both acute and chronic adenosine presented modulatory effects on oxidative stress response signaling. Acute adenosine prevented the heat-induced-increase of DAF-16 activation and SOD-3 levels, while chronic adenosine per se induced DAF-16 activation and prevented heat-induced-increase of HSP-16.2 and SKN-1 levels. Together, these results indicate that exogenous adenosine has physiological and biochemical effects on C. elegans and describes possible purinergic signaling in worms.
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Affiliation(s)
- Thayanara Cruz da Silva
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil
| | - Tássia Limana da Silveira
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil
| | - Luiza Venturini Dos Santos
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil
| | - Leticia Priscila Arantes
- Instituto Latino-Americano de Ciências da Vida e da Natureza, Universidade Federal da Integração Latino-Americana, Foz do Iguaçu, Paraná, 85866-000, Brazil
| | - Rodrigo Pereira Martins
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil
| | - Félix Alexandre Antunes Soares
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil
| | - Cristiane Lenz Dalla Corte
- Departamento de Bioquímica e Biologia Molecular, Programa de Pós-graduação em Ciências Biológicas: Bioquímica Toxicológica, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Av. Roraima nº 1000, Camobi, Santa Maria, RS, 97105-900, Brazil.
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Zhan C, Chen L, Guo D, Sun J, Duan Y, Zhang P, Li P, Ma L, Xu M, Wang Y, Bao H, Gao G, Liu L, Zhang K. An Intestinal Symbiotic Bacterial Strain of Oscheius chongmingensis Modulates Host Viability at Both Global and Post-Transcriptional Levels. Int J Mol Sci 2022; 23:ijms232314692. [PMID: 36499019 PMCID: PMC9739912 DOI: 10.3390/ijms232314692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/08/2022] [Accepted: 11/21/2022] [Indexed: 11/27/2022] Open
Abstract
A rhabditid entomopathogenic nematode (EPN), Oscheius chongmingensis, has a stable symbiotic relationship with the bacterial strain Serratia nematodiphila S1 harbored in its intestines and drastically reduced viability when associated with a non-native strain (186) of the same bacterial species. This nematode is thus a good model for understanding the molecular mechanisms and interactions involved between a nematode host and a member of its intestinal microbiome. Transcriptome analysis and RNA-seq data indicated that expression levels of the majority (8797, 87.59%) of mRNAs in the non-native combination of O. chongmingensis and S. nematodiphila 186 were downregulated compared with the native combination, including strain S1. Accordingly, 88.84% of the total uniq-sRNAs mapped in the O. chongmingensis transcriptome were specific between the two combinations. Six DEGs, including two transcription factors (oc-daf-16 and oc-goa-1) and four kinases (oc-pdk-1, oc-akt-1, oc-rtk, and oc-fak), as well as an up-regulated micro-RNA, oc-miR-71, were found to demonstrate the regulatory mechanisms underlying diminished host viability induced by a non-native bacterial strain. Oc-rtk and oc-fak play key roles in the viability regulation of O. chongmingensis by positively mediating the expression of oc-daf-16 to indirectly impact its longevity and stress tolerances and by negatively regulating the expression of oc-goa-1 to affect the olfactory chemotaxis and fecundity. In response to the stress of invasion by the non-native strain, the expression of oc-miR-71 in the non-native combination was upregulated to downregulate the expression of its targeting oc-pdk-1, which might improve the localization and activation of the transcription factor DAF-16 in the nucleus to induce longevity extension and stress resistance enhancement to some extent. Our findings provide novel insight into comprehension of how nematodes deal with the stress of encountering novel potential bacterial symbionts at the physiological and molecular genetic levels and contribute to improved understanding of host-symbiont relationships generally.
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Affiliation(s)
- Chengxiu Zhan
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Long Chen
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Dandan Guo
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jing Sun
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yunbin Duan
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Panjie Zhang
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Pengpeng Li
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Lijun Ma
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Man Xu
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Ying Wang
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Haoran Bao
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Guofu Gao
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Liwang Liu
- National Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Biology and Germplasm Enhancement of Horticultural Crop (East China), Ministry of Agriculture and Rural Affairs, College of Horiticulture, Nanjing Agricultural University, Nanjing 210095, China
- Correspondence: (L.L.); (K.Z.)
| | - Keyun Zhang
- College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
- Correspondence: (L.L.); (K.Z.)
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Liu M, Gao X, Shan S, Li Y, Wang J, Lu W. Eleutheroside E reduces intestinal fat accumulation in Caenorhabditis elegans through neuroendocrine signals. JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE 2022; 102:5219-5228. [PMID: 35297055 DOI: 10.1002/jsfa.11875] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 01/13/2022] [Accepted: 03/14/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND Acanthopanax senticosus, a small woody shrub of the family Araliaceae, can be used as a functional food with multiple biological activities. Eleutheroside E (EE), an important active component of A. senticosus, has significant effects on neurological diseases. However, whether EE can regulate lipid metabolism has not been reported. The brain can mediate communication between neurons and intestinal cells through long-distance neuroendocrine signals. We speculated that EE might regulate the intestinal lipid metabolism of Caenorhabditis elegans through neuroendocrine signals. RESULTS First, we found that EE reduced the intestinal fat content of C. elegans, without affecting development, reproduction, food intake or movement. In addition, EE significantly regulated genes and metabolites related to lipid metabolism. EE extensively affected fatty acid synthesis, β-oxidation and lipolysis processes, and regulated the content of various fatty acid and lipid metabolism intermediates. We finally proved that EE reduced intestinal fat storage through serotonin and neuropeptide flp-7-npr-22 pathways in the nervous system. CONCLUSION EE is expected to be a functional food that regulates lipid metabolism. © 2022 Society of Chemical Industry.
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Affiliation(s)
- Mengyao Liu
- Institute of Extreme Environment Nutrition and Protection, Harbin Institute of Technology, Harbin, China
- National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, Harbin Institute of Technology, Harbin, China
- School of Chemical Engineering and Chemistry, Harbin Institute of Technology, Harbin, China
| | - Xin Gao
- Institute of Extreme Environment Nutrition and Protection, Harbin Institute of Technology, Harbin, China
- National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, Harbin Institute of Technology, Harbin, China
- School of Chemical Engineering and Chemistry, Harbin Institute of Technology, Harbin, China
| | - Shan Shan
- Institute of Extreme Environment Nutrition and Protection, Harbin Institute of Technology, Harbin, China
- National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, Harbin Institute of Technology, Harbin, China
- School of Chemical Engineering and Chemistry, Harbin Institute of Technology, Harbin, China
| | - Yongzhi Li
- Key Laboratory of Astronaut Health Center, China Astronaut Research and Training Center, Beijing, China
| | - Jiaping Wang
- Key Laboratory of Astronaut Health Center, China Astronaut Research and Training Center, Beijing, China
| | - Weihong Lu
- Institute of Extreme Environment Nutrition and Protection, Harbin Institute of Technology, Harbin, China
- National and Local Joint Engineering Laboratory for Synthesis, Transformation and Separation of Extreme Environmental Nutrients, Harbin Institute of Technology, Harbin, China
- School of Chemical Engineering and Chemistry, Harbin Institute of Technology, Harbin, China
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Zhang X, Ye Y, Sun J, Xu Y, Huang Y, Wang JS, Tang L, Ji J, Chen BY, Sun X. Polygonatum sibiricum polysaccharide extract relieves FB1-induced neurotoxicity by reducing oxidative stress and mitochondrial damage in Caenorhabditis elegans. FOOD BIOSCI 2022. [DOI: 10.1016/j.fbio.2022.101939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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10
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Debnath A, Williams PDE, Bamber BA. Reduced Ca2+ transient amplitudes may signify increased or decreased depolarization depending on the neuromodulatory signaling pathway. Front Neurosci 2022; 16:931328. [PMID: 35937887 PMCID: PMC9354622 DOI: 10.3389/fnins.2022.931328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 06/27/2022] [Indexed: 11/13/2022] Open
Abstract
Neuromodulators regulate neuronal excitability and bias neural circuit outputs. Optical recording of neuronal Ca2+ transients is a powerful approach to study the impact of neuromodulators on neural circuit dynamics. We are investigating the polymodal nociceptor ASH in Caenorhabditis elegans to better understand the relationship between neuronal excitability and optically recorded Ca2+ transients. ASHs depolarize in response to the aversive olfactory stimulus 1-octanol (1-oct) with a concomitant rise in somal Ca2+, stimulating an aversive locomotory response. Serotonin (5-HT) potentiates 1-oct avoidance through Gαq signaling, which inhibits L-type voltage-gated Ca2+ channels in ASH. Although Ca2+ signals in the ASH soma decrease, depolarization amplitudes increase because Ca2+ mediates inhibitory feedback control of membrane potential in this context. Here, we investigate octopamine (OA) signaling in ASH to assess whether this negative correlation between somal Ca2+ and depolarization amplitudes is a general phenomenon, or characteristic of certain neuromodulatory pathways. Like 5-HT, OA reduces somal Ca2+ transient amplitudes in ASH neurons. However, OA antagonizes 5-HT modulation of 1-oct avoidance behavior, suggesting that OA may signal through a different pathway. We further show that the pathway for OA diminution of ASH somal Ca2+ consists of the OCTR-1 receptor, the Go heterotrimeric G-protein, and the G-protein activated inwardly rectifying channels IRK-2 and IRK-3, and this pathway reduces depolarization amplitudes in parallel with somal Ca2+ transient amplitudes. Therefore, even within a single neuron, somal Ca2+ signal reduction may indicate either increased or decreased depolarization amplitude, depending on which neuromodulatory signaling pathways are activated, underscoring the need for careful interpretation of Ca2+ imaging data in neuromodulatory studies.
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Affiliation(s)
- Arunima Debnath
- Department of Biological Sciences, The University of Toledo, Toledo, OH, United States
| | - Paul D. E. Williams
- Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA, United States
| | - Bruce A. Bamber
- Department of Biological Sciences, The University of Toledo, Toledo, OH, United States
- *Correspondence: Bruce A. Bamber,
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Bates K, Le KN, Lu H. Deep learning for robust and flexible tracking in behavioral studies for C. elegans. PLoS Comput Biol 2022; 18:e1009942. [PMID: 35395006 PMCID: PMC9020731 DOI: 10.1371/journal.pcbi.1009942] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 04/20/2022] [Accepted: 02/21/2022] [Indexed: 12/02/2022] Open
Abstract
Robust and accurate behavioral tracking is essential for ethological studies. Common methods for tracking and extracting behavior rely on user adjusted heuristics that can significantly vary across different individuals, environments, and experimental conditions. As a result, they are difficult to implement in large-scale behavioral studies with complex, heterogenous environmental conditions. Recently developed deep-learning methods for object recognition such as Faster R-CNN have advantages in their speed, accuracy, and robustness. Here, we show that Faster R-CNN can be employed for identification and detection of Caenorhabditis elegans in a variety of life stages in complex environments. We applied the algorithm to track animal speeds during development, fecundity rates and spatial distribution in reproductive adults, and behavioral decline in aging populations. By doing so, we demonstrate the flexibility, speed, and scalability of Faster R-CNN across a variety of experimental conditions, illustrating its generalized use for future large-scale behavioral studies.
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Affiliation(s)
- Kathleen Bates
- Interdisciplinary Program in Bioengineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
| | - Kim N. Le
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States of America
| | - Hang Lu
- Interdisciplinary Program in Bioengineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia, United States of America
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, Georgia, United States of America
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12
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A serotonergic circuit regulates aversive associative learning under mitochondrial stress in
C. elegans. Proc Natl Acad Sci U S A 2022; 119:e2115533119. [PMID: 35254908 PMCID: PMC8931235 DOI: 10.1073/pnas.2115533119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Significance
Physiological stress triggers avoidance behavior, allowing the animals to stay away from potential threats and optimize their chance of survival. Mitochondrial disruption, a common physiological stress in diverse species, induces the nematode
Caenorhabditis elegans
to avoid non-pathogenic bacteria through a serotonergic neuronal circuit. We find that distinct neurons, communicated through serotonin and a specific serotonin receptor, are required for the formation and retrieval of this learned aversive behavior. This learned avoidance behavior is associated with increased serotonin synthesis, altered neuronal response property, and reprogramming of locomotion patterns. The circuit and neuromodulatory mechanisms described here offer important insights for stress-induced avoidance behavior.
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13
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Aripiprazole Offsets Mutant ATXN3-Induced Motor Dysfunction by Targeting Dopamine D2 and Serotonin 1A and 2A Receptors in C. elegans. Biomedicines 2022; 10:biomedicines10020370. [PMID: 35203579 PMCID: PMC8962381 DOI: 10.3390/biomedicines10020370] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 01/14/2023] Open
Abstract
The atypical antipsychotic aripiprazole is a Food and Drug Administration-approved drug for the treatment of psychotic, mood, and other psychiatric disorders. Previous drug discovery efforts pinpointed aripiprazole as an effective suppressor of Machado–Joseph disease (MJD) pathogenesis, as its administration resulted in a reduced abundance and aggregation of mutant Ataxin-3 (ATXN3) proteins. Dopamine partial agonism and functional selectivity have been proposed as the main pharmacological mechanism of action of aripiprazole in the treatment of psychosis; however, this mechanism remains to be determined in the context of MJD. Here, we focus on confirming the efficacy of aripiprazole to reduce motor dysfunction in vivo, using a Caenorhabditis elegans (C. elegans) model of MJD, and on unveiling the drug targets required for its positive action against mutant ATXN3 pathogenesis. We employed pharmacogenetics and pharmacological approaches to identify which dopamine and serotonin receptors are critical for aripiprazole-mediated improvements in motor function. We demonstrated that dopamine D2-like and serotonin 5-HT1A and 5-HT2A receptors play important roles in this process. Our findings strengthen the relevance of dopaminergic and serotoninergic signaling modulation against mutant ATXN3-mediated pathogenesis. The identification of aripiprazole’s cellular targets, relevant for MJD and perhaps other neurodegenerative diseases, may pave the way for prospective drug discovery and development campaigns aiming to improve the features of this prototypical compound and reduce side effects not negligible in the case of aripiprazole.
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14
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Di Rocco M, Galosi S, Lanza E, Tosato F, Caprini D, Folli V, Friedman J, Bocchinfuso G, Martire A, Di Schiavi E, Leuzzi V, Martinelli S. Caenorhabditis elegans provides an efficient drug screening platform for GNAO1-related disorders and highlights the potential role of caffeine in controlling dyskinesia. Hum Mol Genet 2021; 31:929-941. [PMID: 34622282 PMCID: PMC8947233 DOI: 10.1093/hmg/ddab296] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 10/04/2021] [Accepted: 10/04/2021] [Indexed: 12/12/2022] Open
Abstract
Dominant GNAO1 mutations cause an emerging group of childhood-onset neurological disorders characterized by developmental delay, intellectual disability, movement disorders, drug-resistant seizures and neurological deterioration. GNAO1 encodes the α-subunit of an inhibitory GTP/GDP-binding protein regulating ion channel activity and neurotransmitter release. The pathogenic mechanisms underlying GNAO1-related disorders remain largely elusive and there are no effective therapies. Here, we assessed the functional impact of two disease-causing variants associated with distinct clinical features, c.139A > G (p.S47G) and c.662C > A (p.A221D), using Caenorhabditis elegans as a model organism. The c.139A > G change was introduced into the orthologous position of the C. elegans gene via CRISPR/Cas9, whereas a knock-in strain carrying the p.A221D variant was already available. Like null mutants, homozygous knock-in animals showed increased egg laying and were hypersensitive to aldicarb, an inhibitor of acetylcholinesterase, suggesting excessive neurotransmitter release by different classes of motor neurons. Automated analysis of C. elegans locomotion indicated that goa-1 mutants move faster than control animals, with more frequent body bends and a higher reversal rate and display uncoordinated locomotion. Phenotypic profiling of heterozygous animals revealed a strong hypomorphic effect of both variants, with a partial dominant-negative activity for the p.A221D allele. Finally, caffeine was shown to rescue aberrant motor function in C. elegans harboring the goa-1 variants; this effect is mainly exerted through adenosine receptor antagonism. Overall, our findings establish a suitable platform for drug discovery, which may assist in accelerating the development of new therapies for this devastating condition, and highlight the potential role of caffeine in controlling GNAO1-related dyskinesia.
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Affiliation(s)
- Martina Di Rocco
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 00161, Italy.,Department of Human Neuroscience, "Sapienza" University of Rome, Rome 00185, Italy
| | - Serena Galosi
- Department of Human Neuroscience, "Sapienza" University of Rome, Rome 00185, Italy
| | - Enrico Lanza
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome 00161, Italy
| | - Federica Tosato
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Davide Caprini
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome 00161, Italy
| | - Viola Folli
- Center for Life Nano Science, Istituto Italiano di Tecnologia, Rome 00161, Italy
| | - Jennifer Friedman
- UCSD Department of Neuroscience and Pediatrics, Rady Children's Hospital Division of Neurology; Rady Children's Institute for Genomic Medicine, San Diego, USA
| | - Gianfranco Bocchinfuso
- Department of Chemical Sciences and Technologies, University of Rome "Tor Vergata", Rome, 00133, Italy
| | - Alberto Martire
- National Center for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome 00161, Italy
| | - Elia Di Schiavi
- Institute of Biosciences and BioResources, National Research Council, Naples 80131, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, "Sapienza" University of Rome, Rome 00185, Italy
| | - Simone Martinelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome 00161, Italy
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15
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Chen H, Hua X, Yang Y, Wang C, Jin L, Dong C, Chang Z, Ding P, Xiang M, Li H, Yu Y. Chronic exposure to UV-aged microplastics induces neurotoxicity by affecting dopamine, glutamate, and serotonin neurotransmission in Caenorhabditis elegans. JOURNAL OF HAZARDOUS MATERIALS 2021; 419:126482. [PMID: 34186424 DOI: 10.1016/j.jhazmat.2021.126482] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 06/06/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
Microplastics are ubiquitous in all environments and exert toxic effects in various organisms. However, the neurotoxicity and underlying mechanisms of long-term exposure to MPs aged under UV radiation remain largely unclear. In this study, Caenorhabditis elegans was treated with 0.1-100 μg/L virgin and aged polystyrene microplastics (PS-MPs) for 10 d, with locomotion behavior, neuronal development, neurotransmitter content, and neurotransmission-related to gene expression as endpoints. Using locomotion behavior as an endpoint, chronic exposure to aged PS-MPs at low concentrations (1 μg/L) caused more severe neurotoxicity than that to virgin PS-MPs. In transgenic nematodes, exposure to 10-100 μg/L aged PS-MPs significantly influenced the fluorescence intensity and percentage of worms with neurodegeneration of dopaminergic, glutamatergic, and serotonergic neurons compared with control. Further investigations showed that the content of glutamate, serotonin, and dopamine was significantly influenced in nematodes chronically exposed to 100 μg/L of aged PS-MPs. Similarly, neurotransmission-related gene (e.g., eat-4, dat-1, and tph-1) expression was also altered in nematodes. These results indicate that aged PS-MPs exert neurotoxicity owing to their effects on dopamine, glutamate, and serotonin neurotransmission. This study provides insights into the underlying mechanisms and potential risks of PS-MPs after UV radiation.
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Affiliation(s)
- Haibo Chen
- Institute for Environmental pollution and health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China; State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Xin Hua
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Yue Yang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China; School of Public Health, China Medical University, Liaoning 110122, China
| | - Chen Wang
- Institute for Environmental pollution and health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Lide Jin
- Institute for Environmental pollution and health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Chenyin Dong
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Zhaofeng Chang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Ping Ding
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Mingdeng Xiang
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Hui Li
- Institute for Environmental pollution and health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
| | - Yunjiang Yu
- State Environmental Protection Key Laboratory of Environmental Pollution Health Risk Assessment, South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China.
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16
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Chandler R, Cogo S, Lewis P, Kevei E. Modelling the functional genomics of Parkinson's disease in Caenorhabditis elegans: LRRK2 and beyond. Biosci Rep 2021; 41:BSR20203672. [PMID: 34397087 PMCID: PMC8415217 DOI: 10.1042/bsr20203672] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 08/03/2021] [Accepted: 08/13/2021] [Indexed: 12/12/2022] Open
Abstract
For decades, Parkinson's disease (PD) cases have been genetically categorised into familial, when caused by mutations in single genes with a clear inheritance pattern in affected families, or idiopathic, in the absence of an evident monogenic determinant. Recently, genome-wide association studies (GWAS) have revealed how common genetic variability can explain up to 36% of PD heritability and that PD manifestation is often determined by multiple variants at different genetic loci. Thus, one of the current challenges in PD research stands in modelling the complex genetic architecture of this condition and translating this into functional studies. Caenorhabditis elegans provide a profound advantage as a reductionist, economical model for PD research, with a short lifecycle, straightforward genome engineering and high conservation of PD relevant neural, cellular and molecular pathways. Functional models of PD genes utilising C. elegans show many phenotypes recapitulating pathologies observed in PD. When contrasted with mammalian in vivo and in vitro models, these are frequently validated, suggesting relevance of C. elegans in the development of novel PD functional models. This review will discuss how the nematode C. elegans PD models have contributed to the uncovering of molecular and cellular mechanisms of disease, with a focus on the genes most commonly found as causative in familial PD and risk factors in idiopathic PD. Specifically, we will examine the current knowledge on a central player in both familial and idiopathic PD, Leucine-rich repeat kinase 2 (LRRK2) and how it connects to multiple PD associated GWAS candidates and Mendelian disease-causing genes.
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Affiliation(s)
| | - Susanna Cogo
- School of Biological Sciences, University of Reading, Reading, RG6 6AH, U.K
- Department of Biology, University of Padova, Padova, Via Ugo Bassi 58/B, 35121, Italy
| | - Patrick A. Lewis
- Royal Veterinary College, University of London, London, NW1 0TU, U.K
- Department of Neurodegenerative Disease, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG, U.K
| | - Eva Kevei
- School of Biological Sciences, University of Reading, Reading, RG6 6AH, U.K
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17
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Wang D, Dao M, Muntean BS, Giles AC, Martemyanov KA, Grill B. Genetic modeling of GNAO1 disorder delineates mechanisms of Gαo dysfunction. Hum Mol Genet 2021; 31:510-522. [PMID: 34508586 PMCID: PMC8863422 DOI: 10.1093/hmg/ddab235] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/30/2021] [Accepted: 08/09/2021] [Indexed: 12/26/2022] Open
Abstract
GNAO1 encephalopathy is a neurodevelopmental disorder with a spectrum of symptoms that include dystonic movements, seizures and developmental delay. While numerous GNAO1 mutations are associated with this disorder, the functional consequences of pathological variants are not completely understood. Here, we deployed the invertebrate C. elegans as a whole-animal behavioral model to study the functional effects of GNAO1 disorder-associated mutations. We tested several pathological GNAO1 mutations for effects on locomotor behaviors using a combination of CRISPR/Cas9 gene editing and transgenic overexpression in vivo. We report that all three mutations tested (G42R, G203R and R209C) result in strong loss of function defects when evaluated as homozygous CRISPR alleles. In addition, mutations produced dominant negative effects assessed using both heterozygous CRISPR alleles and transgenic overexpression. Experiments in mice confirmed dominant negative effects of GNAO1 G42R, which impaired numerous motor behaviors. Thus, GNAO1 pathological mutations result in conserved functional outcomes across animal models. Our study further establishes the molecular genetic basis of GNAO1 encephalopathy, and develops a CRISPR-based pipeline for functionally evaluating mutations associated with neurodevelopmental disorders.
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Affiliation(s)
- Dandan Wang
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98101, USA
| | - Maria Dao
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Brian S Muntean
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Andrew C Giles
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Brock Grill
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA 98101, USA.,Department of Pediatrics, University of Washington School of Medicine, Seattle, WA, USA.,Department of Pharmacology, University of Washington School of Medicine, Seattle, WA, USA
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18
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Levi-Ferber M, Shalash R, Le-Thomas A, Salzberg Y, Shurgi M, Benichou JI, Ashkenazi A, Henis-Korenblit S. Neuronal regulated ire- 1-dependent mRNA decay controls germline differentiation in Caenorhabditis elegans. eLife 2021; 10:65644. [PMID: 34477553 PMCID: PMC8416019 DOI: 10.7554/elife.65644] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Accepted: 08/13/2021] [Indexed: 12/17/2022] Open
Abstract
Understanding the molecular events that regulate cell pluripotency versus acquisition of differentiated somatic cell fate is fundamentally important. Studies in Caenorhabditis elegans demonstrate that knockout of the germline-specific translation repressor gld-1 causes germ cells within tumorous gonads to form germline-derived teratoma. Previously we demonstrated that endoplasmic reticulum (ER) stress enhances this phenotype to suppress germline tumor progression(Levi-Ferber et al., 2015). Here, we identify a neuronal circuit that non-autonomously suppresses germline differentiation and show that it communicates with the gonad via the neurotransmitter serotonin to limit somatic differentiation of the tumorous germline. ER stress controls this circuit through regulated inositol requiring enzyme-1 (IRE-1)-dependent mRNA decay of transcripts encoding the neuropeptide FLP-6. Depletion of FLP-6 disrupts the circuit’s integrity and hence its ability to prevent somatic-fate acquisition by germline tumor cells. Our findings reveal mechanistically how ER stress enhances ectopic germline differentiation and demonstrate that regulated Ire1-dependent decay can affect animal physiology by controlling a specific neuronal circuit.
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Affiliation(s)
- Mor Levi-Ferber
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Rewayd Shalash
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Adrien Le-Thomas
- Cancer Immunology, Genentech, South San Francisco, United States
| | - Yehuda Salzberg
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
| | - Maor Shurgi
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Jennifer Ic Benichou
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Avi Ashkenazi
- Cancer Immunology, Genentech, South San Francisco, United States
| | - Sivan Henis-Korenblit
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
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19
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Ravi B, Zhao J, Chaudhry I, Signorelli R, Bartole M, Kopchock RJ, Guijarro C, Kaplan JM, Kang L, Collins KM. Presynaptic Gαo (GOA-1) signals to depress command neuron excitability and allow stretch-dependent modulation of egg laying in Caenorhabditis elegans. Genetics 2021; 218:6284136. [PMID: 34037773 DOI: 10.1093/genetics/iyab080] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/18/2021] [Indexed: 12/29/2022] Open
Abstract
Egg laying in the nematode worm Caenorhabditis elegans is a two-state behavior modulated by internal and external sensory input. We have previously shown that homeostatic feedback of embryo accumulation in the uterus regulates bursting activity of the serotonergic HSN command neurons that sustains the egg-laying active state. How sensory feedback of egg release signals to terminate the egg-laying active state is less understood. We find that Gαo, a conserved Pertussis Toxin-sensitive G protein, signals within HSN to inhibit egg-laying circuit activity and prevent entry into the active state. Gαo signaling hyperpolarizes HSN, reducing HSN Ca2+ activity and input onto the postsynaptic vulval muscles. Loss of inhibitory Gαo signaling uncouples presynaptic HSN activity from a postsynaptic, stretch-dependent homeostat, causing precocious entry into the egg-laying active state when only a few eggs are present in the uterus. Feedback of vulval opening and egg release activates the uv1 neuroendocrine cells which release NLP-7 neuropeptides which signal to inhibit egg laying through Gαo-independent mechanisms in the HSNs and Gαo-dependent mechanisms in cells other than the HSNs. Thus, neuropeptide and inhibitory Gαo signaling maintains a bi-stable state of electrical excitability that dynamically controls circuit activity in response to both external and internal sensory input to drive a two-state behavior output.
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Affiliation(s)
- Bhavya Ravi
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL USA 33136.,Department of Biology, University of Miami, Coral Gables, FL USA 33146
| | - Jian Zhao
- Department of Neuroscience, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.,Department of Molecular Biology, Massachusetts General Hospital, Boston, MA USA 02114
| | - I Chaudhry
- Department of Biology, University of Miami, Coral Gables, FL USA 33146
| | | | - Mattingly Bartole
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL USA 33136.,Department of Biology, University of Miami, Coral Gables, FL USA 33146
| | | | | | - Joshua M Kaplan
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA USA 02114
| | - Lijun Kang
- Department of Neuroscience, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Kevin M Collins
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL USA 33136.,Department of Biology, University of Miami, Coral Gables, FL USA 33146
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20
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Kumar S, Olson AC, Koelle MR. The neural G protein Gαo tagged with GFP at an internal loop is functional in C. elegans. G3-GENES GENOMES GENETICS 2021; 11:6277897. [PMID: 34003969 PMCID: PMC8496287 DOI: 10.1093/g3journal/jkab167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 05/01/2021] [Indexed: 11/23/2022]
Abstract
Gαo is the alpha subunit of the major heterotrimeric G protein in neurons and mediates signaling by every known neurotransmitter, yet the signaling mechanisms activated by Gαo remain to be fully elucidated. Genetic analysis in Caenorhabditis elegans has shown that Gαo signaling inhibits neuronal activity and neurotransmitter release, but studies of the molecular mechanisms underlying these effects have been limited by lack of tools to complement genetic studies with other experimental approaches. Here, we demonstrate that inserting the green fluorescent protein (GFP) into an internal loop of the Gαo protein results in a tagged protein that is functional in vivo and that facilitates cell biological and biochemical studies of Gαo. Transgenic expression of Gαo-GFP rescues the defects caused by loss of endogenous Gαo in assays of egg laying and locomotion behaviors. Defects in body morphology caused by loss of Gαo are also rescued by Gαo-GFP. The Gαo-GFP protein is localized to the plasma membrane of neurons, mimicking localization of endogenous Gαo. Using GFP as an epitope tag, Gαo-GFP can be immunoprecipitated from C. elegans lysates to purify Gαo protein complexes. The Gαo-GFP transgene reported in this study enables studies involving in vivo localization and biochemical purification of Gαo to compliment the already well-developed genetic analysis of Gαo signaling.
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Affiliation(s)
- Santosh Kumar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 USA
| | - Andrew C Olson
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 USA
| | - Michael R Koelle
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520 USA
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21
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Ma CIJ, Burgess J, Brill JA. Maturing secretory granules: Where secretory and endocytic pathways converge. Adv Biol Regul 2021; 80:100807. [PMID: 33866198 DOI: 10.1016/j.jbior.2021.100807] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 03/10/2021] [Accepted: 03/18/2021] [Indexed: 10/21/2022]
Abstract
Secretory granules (SGs) are specialized organelles responsible for the storage and regulated release of various biologically active molecules from the endocrine and exocrine systems. Thus, proper SG biogenesis is critical to normal animal physiology. Biogenesis of SGs starts at the trans-Golgi network (TGN), where immature SGs (iSGs) bud off and undergo maturation before fusing with the plasma membrane (PM). How iSGs mature is unclear, but emerging studies have suggested an important role for the endocytic pathway. The requirement for endocytic machinery in SG maturation blurs the line between SGs and another class of secretory organelles called lysosome-related organelles (LROs). Therefore, it is important to re-evaluate the differences and similarities between SGs and LROs.
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Affiliation(s)
- Cheng-I Jonathan Ma
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, Room 15.9716, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada; Institute of Medical Science, University of Toronto, Medical Sciences Building, Room 2374, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Jason Burgess
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, Room 15.9716, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada; Department of Molecular Genetics, University of Toronto, Medical Sciences Building, Room 4396, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada
| | - Julie A Brill
- Cell Biology Program, The Hospital for Sick Children, PGCRL Building, Room 15.9716, 686 Bay Street, Toronto, Ontario, M5G 0A4, Canada; Institute of Medical Science, University of Toronto, Medical Sciences Building, Room 2374, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada; Department of Molecular Genetics, University of Toronto, Medical Sciences Building, Room 4396, 1 King's College Circle, Toronto, Ontario, M5S 1A8, Canada.
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22
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Viri V, Cornaglia M, Atakan HB, Lehnert T, Gijs MAM. An in vivo microfluidic study of bacterial transit in C. elegans nematodes. LAB ON A CHIP 2020; 20:2696-2708. [PMID: 32633746 DOI: 10.1039/d0lc00064g] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Caenorhabditis elegans (C. elegans) constitutes an important model organism for use in nutrition and aging studies. We report a novel method for studying the dynamics of Escherichia coli (E. coli) bacterial transit through the worms' intestine. A microfluidic chip was designed for alternating C. elegans on-chip culture and immobilization, thereby enabling periodic high-resolution time-lapse imaging at single-worm resolution over several days. Immobilization was achieved in a reversible way using arrays of tapered channels suitable for assay parallelization. Dedicated C. elegans feeding protocols were applied. Two E. coli bacterial strains, HT115 and OP50, respectively labeled with green fluorescent protein (GFP) and red fluorescent protein (RFP), were used as food source and imaged with fluorescence microscopy techniques to measure relevant parameters of the bacterial transit process. Feeding behavior and E. coli transit dynamics in the whole intestinal tract of the worms were characterized in an automated way over the first 3 days of adulthood, revealing both fast transit phenomena and variations in microbial accumulation. In particular, we studied the bacterial food transit periodicity in wild-type and eat-2 (ad465) mutant C. elegans strains in both trapped and free-swimming conditions. In order to further demonstrate the versatility of our microfluidic platform, we also studied drug-induced modifications of the bacterial transit by measuring the response of the worms' intestine to exposure to the neurotransmitter serotonin.
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Affiliation(s)
- Vittorio Viri
- Laboratory of Microsystems, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
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23
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Castaneda PG, Cecchetelli AD, Pettit HN, Cram EJ. Gα/GSA-1 works upstream of PKA/KIN-1 to regulate calcium signaling and contractility in the Caenorhabditis elegans spermatheca. PLoS Genet 2020; 16:e1008644. [PMID: 32776941 PMCID: PMC7444582 DOI: 10.1371/journal.pgen.1008644] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 08/20/2020] [Accepted: 06/29/2020] [Indexed: 11/18/2022] Open
Abstract
Correct regulation of cell contractility is critical for the function of many biological systems. The reproductive system of the hermaphroditic nematode C. elegans contains a contractile tube of myoepithelial cells known as the spermatheca, which stores sperm and is the site of oocyte fertilization. Regulated contraction of the spermatheca pushes the embryo into the uterus. Cell contractility in the spermatheca is dependent on actin and myosin and is regulated, in part, by Ca2+ signaling through the phospholipase PLC-1, which mediates Ca2+ release from the endoplasmic reticulum. Here, we describe a novel role for GSA-1/Gαs, and protein kinase A, composed of the catalytic subunit KIN-1/PKA-C and the regulatory subunit KIN-2/PKA-R, in the regulation of Ca2+ release and contractility in the C. elegans spermatheca. Without GSA-1/Gαs or KIN-1/PKA-C, Ca2+ is not released, and oocytes become trapped in the spermatheca. Conversely, when PKA is activated through either a gain of function allele in GSA-1 (GSA-1(GF)) or by depletion of KIN-2/PKA-R, the transit times and total numbers, although not frequencies, of Ca2+ pulses are increased, and Ca2+ propagates across the spermatheca even in the absence of oocyte entry. In the spermathecal-uterine valve, loss of GSA-1/Gαs or KIN-1/PKA-C results in sustained, high levels of Ca2+ and a loss of coordination between the spermathecal bag and sp-ut valve. Additionally, we show that depleting phosphodiesterase PDE-6 levels alters contractility and Ca2+ dynamics in the spermatheca, and that the GPB-1 and GPB-2 Gβ subunits play a central role in regulating spermathecal contractility and Ca2+ signaling. This work identifies a signaling network in which Ca2+ and cAMP pathways work together to coordinate spermathecal contractions for successful ovulations.
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Affiliation(s)
- Perla G. Castaneda
- Department of Biology, Northeastern University, Boston, MA, United States
| | | | - Hannah N. Pettit
- Department of Biology, Northeastern University, Boston, MA, United States
| | - Erin J. Cram
- Department of Biology, Northeastern University, Boston, MA, United States
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Heger P, Zheng W, Rottmann A, Panfilio KA, Wiehe T. The genetic factors of bilaterian evolution. eLife 2020; 9:e45530. [PMID: 32672535 PMCID: PMC7535936 DOI: 10.7554/elife.45530] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 07/03/2020] [Indexed: 12/13/2022] Open
Abstract
The Cambrian explosion was a unique animal radiation ~540 million years ago that produced the full range of body plans across bilaterians. The genetic mechanisms underlying these events are unknown, leaving a fundamental question in evolutionary biology unanswered. Using large-scale comparative genomics and advanced orthology evaluation techniques, we identified 157 bilaterian-specific genes. They include the entire Nodal pathway, a key regulator of mesoderm development and left-right axis specification; components for nervous system development, including a suite of G-protein-coupled receptors that control physiology and behaviour, the Robo-Slit midline repulsion system, and the neurotrophin signalling system; a high number of zinc finger transcription factors; and novel factors that previously escaped attention. Contradicting the current view, our study reveals that genes with bilaterian origin are robustly associated with key features in extant bilaterians, suggesting a causal relationship.
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Affiliation(s)
- Peter Heger
- Institute for Genetics, Cologne Biocenter, University of CologneCologneGermany
| | - Wen Zheng
- Institute for Genetics, Cologne Biocenter, University of CologneCologneGermany
| | - Anna Rottmann
- Institute for Genetics, Cologne Biocenter, University of CologneCologneGermany
| | - Kristen A Panfilio
- Institute for Zoology: Developmental Biology, Cologne Biocenter, University of CologneCologneGermany
- School of Life Sciences, University of Warwick, Gibbet Hill CampusCoventryUnited Kingdom
| | - Thomas Wiehe
- Institute for Genetics, Cologne Biocenter, University of CologneCologneGermany
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25
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Igarashi R, Sugi T, Sotoma S, Genjo T, Kumiya Y, Walinda E, Ueno H, Ikeda K, Sumiya H, Tochio H, Yoshinari Y, Harada Y, Shirakawa M. Tracking the 3D Rotational Dynamics in Nanoscopic Biological Systems. J Am Chem Soc 2020; 142:7542-7554. [DOI: 10.1021/jacs.0c01191] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Ryuji Igarashi
- Institute for Quantum Life Science, National Institute for Quantum and Radiological Science and Technology, Anagawa 4-9-1, Inage-ku, Chiba 263-8555, Japan
- National Institute for Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Anagawa 4-9-1,
Inage-ku, Chiba 263-8555, Japan
- JST, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Takuma Sugi
- Division of Integrated Sciences for Life, Graduate School of Integrated Sciences for Life, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Shingo Sotoma
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-Ku, Kyoto 615-8510, Japan
- Institute for Protein Research (IPR), Osaka University, 3-2 Yamadaoka,
Suita-shi, Osaka 565-0871, Japan
| | - Takuya Genjo
- Institute for Quantum Life Science, National Institute for Quantum and Radiological Science and Technology, Anagawa 4-9-1, Inage-ku, Chiba 263-8555, Japan
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-Ku, Kyoto 615-8510, Japan
| | - Yuta Kumiya
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-Ku, Kyoto 615-8510, Japan
| | - Erik Walinda
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan
| | - Hiroshi Ueno
- Department of Applied Chemistry, Graduate School of Engineering, University of Tokyo, Tokyo 113-8656, Japan
| | - Kazuhiro Ikeda
- Advanced Materials Laboratory, Sumitomo Electric Industries, Ltd., 1-1-1, Koyakita, Itami, Hyogo 664-0016, Japan
| | - Hitoshi Sumiya
- Advanced Materials Laboratory, Sumitomo Electric Industries, Ltd., 1-1-1, Koyakita, Itami, Hyogo 664-0016, Japan
| | - Hidehito Tochio
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-Ku, Kyoto 615-8510, Japan
- Department of Biophysics, Graduate School of Science, Kyoto University, Kitashirakawa-Oiwake, Sakyo, Kyoto 606-8502, Japan
| | - Yohsuke Yoshinari
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yoshie Harada
- Institute for Protein Research (IPR), Osaka University, 3-2 Yamadaoka,
Suita-shi, Osaka 565-0871, Japan
- Center for Quantum Information and Quantum Biology, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka 565-0871, Japan
| | - Masahiro Shirakawa
- Institute for Quantum Life Science, National Institute for Quantum and Radiological Science and Technology, Anagawa 4-9-1, Inage-ku, Chiba 263-8555, Japan
- Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Nishikyo-Ku, Kyoto 615-8510, Japan
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Kutnyánszky V, Hargitai B, Hotzi B, Kosztelnik M, Ortutay C, Kovács T, Győry E, Bördén K, Princz A, Tavernarakis N, Vellai T. Sex-specific regulation of neuronal functions in Caenorhabditis elegans: the sex-determining protein TRA-1 represses goa-1/Gα(i/o). Mol Genet Genomics 2019; 295:357-371. [DOI: 10.1007/s00438-019-01625-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 11/06/2019] [Indexed: 02/08/2023]
Abstract
AbstractFemales and males differ substantially in various neuronal functions in divergent, sexually dimorphic animal species, including humans. Despite its developmental, physiological and medical significance, understanding the molecular mechanisms by which sex-specific differences in the anatomy and operation of the nervous system are established remains a fundamental problem in biology. Here, we show that in Caenorhabditis elegans (nematodes), the global sex-determining factor TRA-1 regulates food leaving (mate searching), male mating and adaptation to odorants in a sex-specific manner by repressing the expression of goa-1 gene, which encodes the Gα(i/o) subunit of heterotrimeric G (guanine–nucleotide binding) proteins triggering physiological responses elicited by diverse neurotransmitters and sensory stimuli. Mutations in tra-1 and goa-1 decouple behavioural patterns from the number of X chromosomes. TRA-1 binds to a conserved binding site located in the goa-1 coding region, and downregulates goa-1 expression in hermaphrodites, particularly during embryogenesis when neuronal development largely occurs. These data suggest that the sex-determination machinery is an important modulator of heterotrimeric G protein-mediated signalling and thereby various neuronal functions in this organism and perhaps in other animal phyla.
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27
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Ackley BD. Behavior: Should I Stay or Should I Go? Curr Biol 2019; 29:R842-R844. [DOI: 10.1016/j.cub.2019.07.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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28
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Liu P, Shao H, Ding X, Yang R, Rui Q, Wang D. Dysregulation of Neuronal Gαo Signaling by Graphene Oxide in Nematode Caenorhabditis elegans. Sci Rep 2019; 9:6026. [PMID: 30988375 PMCID: PMC6465305 DOI: 10.1038/s41598-019-42603-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 03/28/2019] [Indexed: 12/29/2022] Open
Abstract
Exposure to graphene oxide (GO) induced some dysregulated microRNAs (miRNAs), such as the increase in mir-247, in nematode Caenorhabditis elegans. We here further identified goa-1 encoding a Gαo and pkc-1 encoding a serine/threonine protein kinase as the targets of neuronal mir-247 in the regulation of GO toxicity. GO exposure increased the expressions of both GOA-1 and PKC-1. Mutation of goa-1 or pkc-1 induced a susceptibility to GO toxicity, and suppressed the resistance of mir-247 mutant to GO toxicity. GOA-1 and PKC-1 could also act in the neurons to regulate the GO toxicity, and neuronal overexpression of mir-247 could not affect the resistance of nematodes overexpressing neuronal goa-1 or pkc-1 lacking 3'-UTR to GO toxicity. In the neurons, GOA-1 acted upstream of diacylglycerol kinase/DGK-1 and PKC-1 to regulate the GO toxicity. Moreover, DGK-1 and GOA-1 functioned synergistically in the regulation of GO toxicity. Our results highlight the crucial role of neuronal Gαo signaling in response to GO in nematodes.
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Affiliation(s)
- Peidang Liu
- Medical School, Southeast University, Nanjing, 210009, China
| | - Huimin Shao
- Medical School, Southeast University, Nanjing, 210009, China
| | - Xuecheng Ding
- Medical School, Southeast University, Nanjing, 210009, China
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ruilong Yang
- Medical School, Southeast University, Nanjing, 210009, China
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qi Rui
- College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China
| | - Dayong Wang
- Medical School, Southeast University, Nanjing, 210009, China.
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29
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Ravi B, Garcia J, Collins K. The HSN egg-laying command neurons regulate the defecation motor program in Caenorhabditis elegans: Integration. MICROPUBLICATION BIOLOGY 2019; 2019. [PMID: 32550458 PMCID: PMC7252377 DOI: 10.17912/micropub.biology.000095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- Bhavya Ravi
- Neuroscience Program, Miller School of Medicine, University of Miami, Miami, FL 33136.,Present address: Department of Neurology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Jessica Garcia
- Department of Biology, University of Miami, Coral Gables, FL 33146
| | - Kevin Collins
- Neuroscience Program, Miller School of Medicine, University of Miami, Miami, FL 33136.,Department of Biology, University of Miami, Coral Gables, FL 33146
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30
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Ravi B, Collins K. Ca 2+ activity in the HSN egg-laying command neurons and animal age is accompanied by a delay in the defecation motor program in Caenorhabditis elegans (I). MICROPUBLICATION BIOLOGY 2019; 2019. [PMID: 32550471 PMCID: PMC7255765 DOI: 10.17912/micropub.biology.000093] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Bhavya Ravi
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL 33136.,Present address: Department of Neurology and Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Kevin Collins
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL 33136.,Department of Biology, University of Miami, Coral Gables, FL 33146
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31
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Koelle MR. Neurotransmitter signaling through heterotrimeric G proteins: insights from studies in C. elegans. WORMBOOK : THE ONLINE REVIEW OF C. ELEGANS BIOLOGY 2018; 2018:1-52. [PMID: 26937633 PMCID: PMC5010795 DOI: 10.1895/wormbook.1.75.2] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Neurotransmitters signal via G protein coupled receptors (GPCRs) to modulate activity of neurons and muscles. C. elegans has ∼150 G protein coupled neuropeptide receptor homologs and 28 additional GPCRs for small-molecule neurotransmitters. Genetic studies in C. elegans demonstrate that neurotransmitters diffuse far from their release sites to activate GPCRs on distant cells. Individual receptor types are expressed on limited numbers of cells and thus can provide very specific regulation of an individual neural circuit and behavior. G protein coupled neurotransmitter receptors signal principally via the three types of heterotrimeric G proteins defined by the G alpha subunits Gαo, Gαq, and Gαs. Each of these G alpha proteins is found in all neurons plus some muscles. Gαo and Gαq signaling inhibit and activate neurotransmitter release, respectively. Gαs signaling, like Gαq signaling, promotes neurotransmitter release. Many details of the signaling mechanisms downstream of Gαq and Gαs have been delineated and are consistent with those of their mammalian orthologs. The details of the signaling mechanism downstream of Gαo remain a mystery. Forward genetic screens in C. elegans have identified new molecular components of neural G protein signaling mechanisms, including Regulators of G protein Signaling (RGS proteins) that inhibit signaling, a new Gαq effector (the Trio RhoGEF domain), and the RIC-8 protein that is required for neuronal Gα signaling. A model is presented in which G proteins sum up the variety of neuromodulator signals that impinge on a neuron to calculate its appropriate output level.
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Affiliation(s)
- Michael R Koelle
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven CT 06520 USA
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32
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Kagawa-Nagamura Y, Gengyo-Ando K, Ohkura M, Nakai J. Role of tyramine in calcium dynamics of GABAergic neurons and escape behavior in Caenorhabditis elegans. ZOOLOGICAL LETTERS 2018; 4:19. [PMID: 30065850 PMCID: PMC6062986 DOI: 10.1186/s40851-018-0103-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Accepted: 07/16/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Tyramine, known as a "trace amine" in mammals, modulates a wide range of behavior in invertebrates; however, the underlying cellular and circuit mechanisms are not well understood. In the nematode Caenorhabditis elegans (C. elegans), tyramine affects key behaviors, including foraging, feeding, and escape responses. The touch-evoked backward escape response is often coupled with a sharp omega turn that allows the animal to navigate away in the opposite direction. Previous studies have showed that a metabotropic tyramine receptor, SER-2, in GABAergic body motor neurons controls deep body bending in omega turns. In this study, we focused on the role of tyramine in GABAergic head motor neurons. Our goal is to understand the mechanism by which tyraminergic signaling alters neural circuit activity to control escape behavior. RESULTS Using calcium imaging in freely moving C. elegans, we found that GABAergic RME motor neurons in the head had high calcium levels during forward locomotion but low calcium levels during spontaneous and evoked backward locomotion. This calcium decrease was also observed during the omega turn. Mutant analyses showed that tbh-1 mutants lacking only octopamine had normal calcium responses, whereas tdc-1 mutants lacking both tyramine and octopamine did not exhibit the calcium decrease in RME. This neuromodulation was mediated by SER-2. Moreover, tyraminergic RIM neuron activity was negatively correlated with RME activity in the directional switch from forward to backward locomotion. These results indicate that tyramine released from RIM inhibits RME via SER-2 signaling. The omega turn is initiated by a sharp head bend when the animal reinitiates forward movement. Interestingly, ser-2 mutants exhibited shallow head bends and often failed to execute deep-angle omega turns. The behavioral defect and the abnormal calcium response in ser-2 mutants could be rescued by SER-2 expression in RME. These results suggest that tyraminergic inhibition of RME is involved in the control of omega turns. CONCLUSION We demonstrate that endogenous tyramine downregulates calcium levels in GABAergic RME motor neurons in the head via the tyramine receptor SER-2 during backward locomotion and omega turns. Our data suggest that this neuromodulation allows deep head bending during omega turns and plays a role in the escape behavior in C. elegans.
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Affiliation(s)
- Yuko Kagawa-Nagamura
- Brain and Body System Science Institute, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570 Japan
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570 Japan
| | - Keiko Gengyo-Ando
- Brain and Body System Science Institute, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570 Japan
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570 Japan
- RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198 Japan
| | - Masamichi Ohkura
- Brain and Body System Science Institute, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570 Japan
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570 Japan
| | - Junichi Nakai
- Brain and Body System Science Institute, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570 Japan
- Graduate School of Science and Engineering, Saitama University, 255 Shimo-okubo, Sakura-ku, Saitama, 338-8570 Japan
- RIKEN Center for Brain Science, 2-1 Hirosawa, Wako-shi, Saitama, 351-0198 Japan
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Fu J, Zhang H, Huang W, Zhu X, Sheng Y, Song E, Xu T. AIM interneurons mediate feeding suppression through the TYRA-2 receptor in C. elegans. BIOPHYSICS REPORTS 2018; 4:17-24. [PMID: 29577066 PMCID: PMC5860128 DOI: 10.1007/s41048-018-0046-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 05/23/2017] [Indexed: 12/02/2022] Open
Abstract
Feeding behavior is the most fundamental behavior in C. elegans. Our previous results have dissected the central integration circuit for the regulation of feeding, which integrates opposing sensory inputs and regulates feeding behavior in a nonlinear manner. However, the peripheral integration that acts downstream of the central integration circuit to modulate feeding remains largely unknown. Here, we find that a Gαi/o-coupled tyramine receptor, TYRA-2, is involved in peripheral feeding suppression. TYRA-2 suppresses feeding behavior via the AIM interneurons, which receive tyramine/octopamine signals from RIM/RIC neurons in the central integration circuit. Our results reveal previously unidentified roles for the receptor TYRA-2 and the AIM interneurons in feeding regulation, providing a further understanding of how biogenic amines tyramine and octopamine regulate feeding behavior.
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Affiliation(s)
- Jiajun Fu
- 1National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China.,2College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Haining Zhang
- 1National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China.,3Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Wenming Huang
- 1National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China.,3Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Xinyu Zhu
- 1National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China.,3Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Yi Sheng
- 1National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China.,3Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
| | - Eli Song
- 1National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China
| | - Tao Xu
- 1National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101 China.,2College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049 China.,3Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074 China
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Topalidou I, Cooper K, Pereira L, Ailion M. Dopamine negatively modulates the NCA ion channels in C. elegans. PLoS Genet 2017; 13:e1007032. [PMID: 28968387 PMCID: PMC5638609 DOI: 10.1371/journal.pgen.1007032] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 10/12/2017] [Accepted: 09/18/2017] [Indexed: 02/07/2023] Open
Abstract
The NALCN/NCA ion channel is a cation channel related to voltage-gated sodium and calcium channels. NALCN has been reported to be a sodium leak channel with a conserved role in establishing neuronal resting membrane potential, but its precise cellular role and regulation are unclear. The Caenorhabditis elegans orthologs of NALCN, NCA-1 and NCA-2, act in premotor interneurons to regulate motor circuit activity that sustains locomotion. Recently we found that NCA-1 and NCA-2 are activated by a signal transduction pathway acting downstream of the heterotrimeric G protein Gq and the small GTPase Rho. Through a forward genetic screen, here we identify the GPCR kinase GRK-2 as a new player affecting signaling through the Gq-Rho-NCA pathway. Using structure-function analysis, we find that the GPCR phosphorylation and membrane association domains of GRK-2 are required for its function. Genetic epistasis experiments suggest that GRK-2 acts on the D2-like dopamine receptor DOP-3 to inhibit Go signaling and positively modulate NCA-1 and NCA-2 activity. Through cell-specific rescuing experiments, we find that GRK-2 and DOP-3 act in premotor interneurons to modulate NCA channel function. Finally, we demonstrate that dopamine, through DOP-3, negatively regulates NCA activity. Thus, this study identifies a pathway by which dopamine modulates the activity of the NCA channels.
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Affiliation(s)
- Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- * E-mail: (IT); (MA)
| | - Kirsten Cooper
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Laura Pereira
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, New York, United States of America
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- * E-mail: (IT); (MA)
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Antagonistic Serotonergic and Octopaminergic Neural Circuits Mediate Food-Dependent Locomotory Behavior in Caenorhabditis elegans. J Neurosci 2017; 37:7811-7823. [PMID: 28698386 DOI: 10.1523/jneurosci.2636-16.2017] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 05/18/2017] [Accepted: 07/01/2017] [Indexed: 11/21/2022] Open
Abstract
Biogenic amines are conserved signaling molecules that link food cues to behavior and metabolism in a wide variety of organisms. In the nematode Caenorhabditis elegans, the biogenic amines serotonin (5-HT) and octopamine regulate a number of food-related behaviors. Using a novel method for long-term quantitative behavioral imaging, we show that 5-HT and octopamine jointly influence locomotor activity and quiescence in feeding and fasting hermaphrodites, and we define the neural circuits through which this modulation occurs. We show that 5-HT produced by the ADF neurons acts via the SER-5 receptor in muscles and neurons to suppress quiescent behavior and promote roaming in fasting worms, whereas 5-HT produced by the NSM neurons acts on the MOD-1 receptor in AIY neurons to promote low-amplitude locomotor behavior characteristic of well fed animals. Octopamine, produced by the RIC neurons, acts via SER-3 and SER-6 receptors in SIA neurons to promote roaming behaviors characteristic of fasting animals. We find that 5-HT signaling is required for animals to assume food-appropriate behavior, whereas octopamine signaling is required for animals to assume fasting-appropriate behavior. The requirement for both neurotransmitters in both the feeding and fasting states enables increased behavioral adaptability. Our results define the molecular and neural pathways through which parallel biogenic amine signaling tunes behavior appropriately to nutrient conditions.SIGNIFICANCE STATEMENT Animals adjust behavior in response to environmental changes, such as fluctuations in food abundance, to maximize survival and reproduction. Biogenic amines, such as like serotonin, are conserved neurotransmitters that regulate behavior and metabolism in relation to energy status. Disruptions of biogenic amine signaling contribute to human neurological diseases of mood, appetite, and movement. In this study, we investigated the roles of the biogenic amines serotonin and octopamine in regulating locomotion behaviors associated with feeding and fasting in the roundworm Caenorhabditis elegans We identified neural circuits through which these signals work to govern behavior. Understanding the molecular pathways through which biogenic amines function in model organisms may improve our understanding of dysfunctions of appetite and behavior found in mammals, including humans.
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Opiates Modulate Noxious Chemical Nociception through a Complex Monoaminergic/Peptidergic Cascade. J Neurosci 2017; 36:5498-508. [PMID: 27194330 DOI: 10.1523/jneurosci.4520-15.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 04/13/2016] [Indexed: 01/11/2023] Open
Abstract
UNLABELLED The ability to detect noxious stimuli, process the nociceptive signal, and elicit an appropriate behavioral response is essential for survival. In Caenorhabditis elegans, opioid receptor agonists, such as morphine, mimic serotonin, and suppress the overall withdrawal from noxious stimuli through a pathway requiring the opioid-like receptor, NPR-17. This serotonin- or morphine-dependent modulation can be rescued in npr-17-null animals by the expression of npr-17 or a human κ opioid receptor in the two ASI sensory neurons, with ASI opioid signaling selectively inhibiting ASI neuropeptide release. Serotonergic modulation requires peptides encoded by both nlp-3 and nlp-24, and either nlp-3 or nlp-24 overexpression mimics morphine and suppresses withdrawal. Peptides encoded by nlp-3 act differentially, with only NLP-3.3 mimicking morphine, whereas other nlp-3 peptides antagonize NLP-3.3 modulation. Together, these results demonstrate that opiates modulate nociception in Caenorhabditis elegans through a complex monoaminergic/peptidergic cascade, and suggest that this model may be useful for dissecting opiate signaling in mammals. SIGNIFICANCE STATEMENT Opiates are used extensively to treat chronic pain. In Caenorhabditis elegans, opioid receptor agonists suppress the overall withdrawal from noxious chemical stimuli through a pathway requiring an opioid-like receptor and two distinct neuropeptide-encoding genes, with individual peptides from the same gene functioning antagonistically to modulate nociception. Endogenous opioid signaling functions as part of a complex, monoaminergic/peptidergic signaling cascade and appears to selectively inhibit neuropeptide release, mediated by a α-adrenergic-like receptor, from two sensory neurons. Importantly, receptor null animals can be rescued by the expression of the human κ opioid receptor, and injection of human opioid receptor ligands mimics exogenous opiates, highlighting the utility of this model for dissecting opiate signaling in mammals.
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Banerjee N, Bhattacharya R, Gorczyca M, Collins KM, Francis MM. Local neuropeptide signaling modulates serotonergic transmission to shape the temporal organization of C. elegans egg-laying behavior. PLoS Genet 2017; 13:e1006697. [PMID: 28384151 PMCID: PMC5398689 DOI: 10.1371/journal.pgen.1006697] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 04/20/2017] [Accepted: 03/15/2017] [Indexed: 11/18/2022] Open
Abstract
Animal behaviors are often composed of distinct alternating behavioral states. Neuromodulatory signals are thought to be critical for establishing stable behavioral states and for orchestrating transitions between them. However, we have only a limited understanding of how neuromodulatory systems act in vivo to alter circuit performance and shape behavior. To address these questions, we have investigated neuromodulatory signaling in the context of Caenorhabditis elegans egg-laying. Egg-laying activity cycles between discrete states-short bursts of egg deposition (active phases) that alternate with prolonged quiescent periods (inactive phases). Here using genetic, pharmacological and optogenetic approaches for cell-specific activation and inhibition, we show that a group of neurosecretory cells (uv1) located in close spatial proximity to the egg-laying neuromusculature direct the temporal organization of egg-laying by prolonging the duration of inactive phases. We demonstrate that the modulatory effects of the uv1 cells are mediated by peptides encoded by the nlp-7 and flp-11 genes that act locally to inhibit circuit activity, primarily by inhibiting vesicular release of serotonin from HSN motor neurons. This peptidergic inhibition is achieved, at least in part, by reducing synaptic vesicle abundance in the HSN motor neurons. By linking the in vivo actions of specific neuropeptide signaling systems with the generation of stable behavioral outcomes, our study reveals how cycles of neuromodulation emanating from non-neuronal cells can fundamentally shape the organization of a behavioral program.
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Affiliation(s)
- Navonil Banerjee
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA United States of America
| | - Raja Bhattacharya
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA United States of America
| | - Michael Gorczyca
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA United States of America
| | - Kevin M. Collins
- Department of Biology, University of Miami, Coral Gables, FL United States of America
| | - Michael M. Francis
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA United States of America
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The NCA-1 and NCA-2 Ion Channels Function Downstream of G q and Rho To Regulate Locomotion in Caenorhabditis elegans. Genetics 2017; 206:265-282. [PMID: 28325749 DOI: 10.1534/genetics.116.198820] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 03/15/2017] [Indexed: 02/07/2023] Open
Abstract
The heterotrimeric G protein Gq positively regulates neuronal activity and synaptic transmission. Previously, the Rho guanine nucleotide exchange factor Trio was identified as a direct effector of Gq that acts in parallel to the canonical Gq effector phospholipase C. Here, we examine how Trio and Rho act to stimulate neuronal activity downstream of Gq in the nematode Caenorhabditis elegans Through two forward genetic screens, we identify the cation channels NCA-1 and NCA-2, orthologs of mammalian NALCN, as downstream targets of the Gq-Rho pathway. By performing genetic epistasis analysis using dominant activating mutations and recessive loss-of-function mutations in the members of this pathway, we show that NCA-1 and NCA-2 act downstream of Gq in a linear pathway. Through cell-specific rescue experiments, we show that function of these channels in head acetylcholine neurons is sufficient for normal locomotion in C. elegans Our results suggest that NCA-1 and NCA-2 are physiologically relevant targets of neuronal Gq-Rho signaling in C. elegans.
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Zang KE, Ho E, Ringstad N. Inhibitory peptidergic modulation of C. elegans serotonin neurons is gated by T-type calcium channels. eLife 2017; 6. [PMID: 28165324 PMCID: PMC5330680 DOI: 10.7554/elife.22771] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 02/06/2017] [Indexed: 12/30/2022] Open
Abstract
Serotonin is an evolutionarily ancient molecule that functions in generating and modulating many behavioral states. Although much is known about how serotonin acts on its cellular targets, how serotonin release is regulated in vivo remains poorly understood. In the nematode C. elegans, serotonin neurons that drive female reproductive behavior are directly modulated by inhibitory neuropeptides. Here, we report the isolation of mutants in which inhibitory neuropeptides fail to properly modulate serotonin neurons and the behavior they mediate. The corresponding mutations affect the T-type calcium channel CCA-1 and symmetrically re-tune its voltage-dependencies of activation and inactivation towards more hyperpolarized potentials. This shift in voltage dependency strongly and specifically bypasses the behavioral and cell physiological effects of peptidergic inhibition on serotonin neurons. Our results indicate that T-type calcium channels are critical regulators of a C. elegans serotonergic circuit and demonstrate a mechanism in which T-type channels functionally gate inhibitory modulation in vivo.
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Affiliation(s)
- Kara E Zang
- Skirball Institute for Biomolecular Medicine, The Helen L. and Martin S. Kimmel Center for Biology and Medicine, Department of Cell Biology, NYU Langone School of Medicine, New York, United States
| | - Elver Ho
- Skirball Institute for Biomolecular Medicine, The Helen L. and Martin S. Kimmel Center for Biology and Medicine, Department of Cell Biology, NYU Langone School of Medicine, New York, United States
| | - Niels Ringstad
- Skirball Institute for Biomolecular Medicine, The Helen L. and Martin S. Kimmel Center for Biology and Medicine, Department of Cell Biology, NYU Langone School of Medicine, New York, United States
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Iannacone MJ, Beets I, Lopes LE, Churgin MA, Fang-Yen C, Nelson MD, Schoofs L, Raizen DM. The RFamide receptor DMSR-1 regulates stress-induced sleep in C. elegans. eLife 2017; 6. [PMID: 28094002 PMCID: PMC5241116 DOI: 10.7554/elife.19837] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 12/16/2016] [Indexed: 11/22/2022] Open
Abstract
In response to environments that cause cellular stress, animals engage in sleep behavior that facilitates recovery from the stress. In Caenorhabditis elegans, stress-induced sleep(SIS) is regulated by cytokine activation of the ALA neuron, which releases FLP-13 neuropeptides characterized by an amidated arginine-phenylalanine (RFamide) C-terminus motif. By performing an unbiased genetic screen for mutants that impair the somnogenic effects of FLP-13 neuropeptides, we identified the gene dmsr-1, which encodes a G-protein coupled receptor similar to an insect RFamide receptor. DMSR-1 is activated by FLP-13 peptides in cell culture, is required for SIS in vivo, is expressed non-synaptically in several wake-promoting neurons, and likely couples to a Gi/o heterotrimeric G-protein. Our data expand our understanding of how a single neuroendocrine cell coordinates an organism-wide behavioral response, and suggest that similar signaling principles may function in other organisms to regulate sleep during sickness. DOI:http://dx.doi.org/10.7554/eLife.19837.001 People often feel fatigued and sleepy when they are sick. Other animals also show signs of sleepiness when ill – they stop eating, move less, and are less responsive to changes in their environment. Sickness-induced sleep helps both people and other animals to recover, and many scientists believe that this type of sleep is different than nightly sleep. Studies of sickness-induced sleep have made use of a simple worm with a simple nervous system. In this worm, a single nerve cell releases chemicals that cause the worm to fall asleep in response to illness. Animals exposed to one of these chemicals, called FLP-13, fall asleep even when they are not sick. As such, scientists would like to know which cells in the nervous system FLP-13 interacts with, what receptor the cells use to recognize this chemical, and whether it turns on cells that induce sleep or turns off the cells that cause wakefulness. Now, Iannacone et al. show that FLP-13 likely causes sleep by turning down activity in the cells in the nervous system that promote wakefulness. The experiments sifted through genetic mutations to determine which ones cause the worms not to fall asleep when FLP-13 is released. This revealed that worms with a mutation that causes them to lack a receptor protein called DMSR-1 do not become sleepy in response to FLP-13. This suggests that DMSR-1 must be essential for FLP-13 to trigger sleep. About 10% of cells in the worm’s nervous system have the DMSR-1 receptor. Some of these neurons tell the worm to move forward or to forage around for food. The experiments also showed that FLP-13 is probably not the only chemical that interacts with the DMSR-1 receptor, but the identities of these other chemicals remain unknown. Additional experiments are now needed to determine if sickness-induced sleepiness in humans and other mammals is triggered by a similar mechanism. If it is, then drugs might be developed to treat people experiencing fatigue associated with sickness as well as other unexplained cases of fatigue. DOI:http://dx.doi.org/10.7554/eLife.19837.002
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Affiliation(s)
- Michael J Iannacone
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Isabel Beets
- Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - Lindsey E Lopes
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Matthew A Churgin
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, United States
| | - Christopher Fang-Yen
- Department of Bioengineering, School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, United States
| | - Matthew D Nelson
- Department of Biology, Saint Joseph's University, Philadelphia, United States
| | - Liliane Schoofs
- Department of Biology, Katholieke Universiteit Leuven, Leuven, Belgium
| | - David M Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States.,Center for Sleep and Circadian Neurobiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
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Maya S, Prakash T, Madhu KD, Goli D. Multifaceted effects of aluminium in neurodegenerative diseases: A review. Biomed Pharmacother 2016; 83:746-754. [PMID: 27479193 DOI: 10.1016/j.biopha.2016.07.035] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 07/14/2016] [Accepted: 07/18/2016] [Indexed: 01/23/2023] Open
Abstract
Aluminium (Al) is the most common metal and widely distributed in our environment. Al was first isolated as an element in 1827, and its use began only after 1886. Al is widely used for industrial applications and consumer products. Apart from these it is also used in cooking utensils and in pharmacological agents, including antacids and antiperspirants from which the element usually enters into the human body. Evidence for the neurotoxicity of Al is described in various studies, but still the exact mechanism of Al toxicity is not known. However, the evidence suggests that the Al can potentiate oxidative stress and inflammatory events and finally leads to cell death. Al is considered as a well-established neurotoxin and have a link between the exposure and development of neurodegenerative diseases, including Amyotrophic Lateral Sclerosis (ALS), Alzheimer's disease (AD), dementia, Gulf war syndrome and Parkinsonism. Here, we review the detailed possible pathogenesis of Al neurotoxicity. This review summarizes Al induced events likewise oxidative stress, cell mediated toxicity, apoptosis, inflammatory events in the brain, glutamate toxicity, effects on calcium homeostasis, gene expression and Al induced Neurofibrillary tangle (NFT) formation. Apart from these we also discussed animal models that are commonly used for Al induced neurotoxicity and neurodegeneration studies. These models help to find out a better way to treat and prevent the progression in Al induced neurodegenerative diseases.
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Affiliation(s)
- S Maya
- Department of Pharmacology, Acharya & BM Reddy College of Pharmacy, Bangalore 560 107, Karnataka, India
| | - T Prakash
- Department of Pharmacology, Acharya & BM Reddy College of Pharmacy, Bangalore 560 107, Karnataka, India.
| | - Krishna Das Madhu
- Department of Pharmacology, Acharya & BM Reddy College of Pharmacy, Bangalore 560 107, Karnataka, India
| | - Divakar Goli
- Department of Pharmacology, Acharya & BM Reddy College of Pharmacy, Bangalore 560 107, Karnataka, India
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Serotonin promotes exploitation in complex environments by accelerating decision-making. BMC Biol 2016; 14:9. [PMID: 26847342 PMCID: PMC4743430 DOI: 10.1186/s12915-016-0232-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 01/21/2016] [Indexed: 01/22/2023] Open
Abstract
Background Fast responses can provide a competitive advantage when resources are inhomogeneously distributed. The nematode Caenorhabditis elegans was shown to modulate locomotion on a lawn of bacterial food in serotonin (5-HT)-dependent manners. However, potential roles for serotonergic signaling in responding to food discovery are poorly understood. Results We found that 5-HT signaling in C. elegans facilitates efficient exploitation in complex environments by mediating a rapid response upon encountering food. Genetic or cellular manipulations leading to deficient serotonergic signaling resulted in gradual responses and defective exploitation of a patchy foraging landscape. Physiological imaging revealed that the NSM serotonergic neurons responded acutely upon encounter with newly discovered food and were key to rapid responses. In contrast, the onset of responses of ADF serotonergic neurons preceded the physical encounter with the food. The serotonin-gated chloride channel MOD-1 and the ortholog of mammalian 5-HT1 metabotropic serotonin receptors SER-4 acted in synergy to accelerate decision-making. The relevance of responding rapidly was demonstrated in patchy environments, where the absence of 5-HT signaling was detrimental to exploitation. Conclusions Our results implicate 5-HT in a novel form of decision-making, demonstrate its fitness consequences, suggest that NSM and ADF act in concert to modulate locomotion in complex environments, and identify the synergistic action of a channel and a metabotropic receptor in accelerating C. elegans decision-making. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0232-y) contains supplementary material, which is available to authorized users.
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Abstract
Electrophysiological recordings have enabled identification of physiologically distinct yet behaviorally similar states of mammalian sleep. In contrast, sleep in nonmammals has generally been identified behaviorally and therefore regarded as a physiologically uniform state characterized by quiescence of feeding and locomotion, reduced responsiveness, and rapid reversibility. The nematode Caenorhabditis elegans displays sleep-like quiescent behavior under two conditions: developmentally timed quiescence (DTQ) occurs during larval transitions, and stress-induced quiescence (SIQ) occurs in response to exposure to cellular stressors. Behaviorally, DTQ and SIQ appear identical. Here, we use optogenetic manipulations of neuronal and muscular activity, pharmacology, and genetic perturbations to uncover circuit and molecular mechanisms of DTQ and SIQ. We find that locomotion quiescence induced by DTQ- and SIQ-associated neuropeptides occurs via their action on the nervous system, although their neuronal target(s) and/or molecular mechanisms likely differ. Feeding quiescence during DTQ results from a loss of pharyngeal muscle excitability, whereas feeding quiescence during SIQ results from a loss of excitability in the nervous system. Together these results indicate that, as in mammals, quiescence is subserved by different mechanisms during distinct sleep-like states in C. elegans.
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Wu T, He K, Zhan Q, Ang S, Ying J, Zhang S, Zhang T, Xue Y, Tang M. MPA-capped CdTe quantum dots exposure causes neurotoxic effects in nematode Caenorhabditis elegans by affecting the transporters and receptors of glutamate, serotonin and dopamine at the genetic level, or by increasing ROS, or both. NANOSCALE 2015; 7:20460-20473. [PMID: 26583374 DOI: 10.1039/c5nr05914c] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
As quantum dots (QDs) are widely used in biomedical applications, the number of studies focusing on their biological properties is increasing. While several studies have attempted to evaluate the toxicity of QDs towards neural cells, the in vivo toxic effects on the nervous system and the molecular mechanisms are unclear. The aim of the present study was to investigate the neurotoxic effects and the underlying mechanisms of water-soluble cadmium telluride (CdTe) QDs capped with 3-mercaptopropionic acid (MPA) in Caenorhabditis elegans (C. elegans). Our results showed that exposure to MPA-capped CdTe QDs induced behavioral defects, including alterations to body bending, head thrashing, pharyngeal pumping and defecation intervals, as well as impaired learning and memory behavior plasticity, based on chemotaxis or thermotaxis, in a dose-, time- and size-dependent manner. Further investigations suggested that MPA-capped CdTe QDs exposure inhibited the transporters and receptors of glutamate, serotonin and dopamine in C. elegans at the genetic level within 24 h, while opposite results were observed after 72 h. Additionally, excessive reactive oxygen species (ROS) generation was observed in the CdTe QD-treated worms, which confirmed the common nanotoxicity mechanism of oxidative stress damage, and might overcome the increased gene expression of neurotransmitter transporters and receptors in C. elegans induced by long-term QD exposure, resulting in more severe behavioral impairments.
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Affiliation(s)
- Tianshu Wu
- Key Laboratory of Environmental Medicine and Engineering, Ministry of Education, School of Public Health, & Collaborative Innovation Center of Suzhou Nano Science and Technology, Southeast University, Nanjing 210009, China.
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Coleman BD, Marivin A, Parag-Sharma K, DiGiacomo V, Kim S, Pepper JS, Casler J, Nguyen LT, Koelle MR, Garcia-Marcos M. Evolutionary Conservation of a GPCR-Independent Mechanism of Trimeric G Protein Activation. Mol Biol Evol 2015; 33:820-37. [PMID: 26659249 PMCID: PMC4760084 DOI: 10.1093/molbev/msv336] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Trimeric G protein signaling is a fundamental mechanism of cellular communication in eukaryotes. The core of this mechanism consists of activation of G proteins by the guanine-nucleotide exchange factor (GEF) activity of G protein coupled receptors. However, the duration and amplitude of G protein-mediated signaling are controlled by a complex network of accessory proteins that appeared and diversified during evolution. Among them, nonreceptor proteins with GEF activity are the least characterized. We recently found that proteins of the ccdc88 family possess a Gα-binding and activating (GBA) motif that confers GEF activity and regulates mammalian cell behavior. A sequence similarity-based search revealed that ccdc88 genes are highly conserved across metazoa but the GBA motif is absent in most invertebrates. This prompted us to investigate whether the GBA motif is present in other nonreceptor proteins in invertebrates. An unbiased bioinformatics search in Caenorhabditis elegans identified GBAS-1 (GBA and SPK domain containing-1) as a GBA motif-containing protein with homologs only in closely related worm species. We demonstrate that GBAS-1 has GEF activity for the nematode G protein GOA-1 and that the two proteins are coexpressed in many cells of living worms. Furthermore, we show that GBAS-1 can activate mammalian Gα-subunits and provide structural insights into the evolutionarily conserved determinants of the GBA–G protein interface. These results demonstrate that the GBA motif is a functional GEF module conserved among highly divergent proteins across evolution, indicating that the GBA-Gα binding mode is strongly constrained under selective pressure to mediate receptor-independent G protein activation in metazoans.
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Affiliation(s)
| | - Arthur Marivin
- Department of Biochemistry, Boston University School of Medicine
| | | | | | - Seongseop Kim
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine
| | - Judy S Pepper
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine
| | - Jason Casler
- Department of Biochemistry, Boston University School of Medicine
| | - Lien T Nguyen
- Department of Biochemistry, Boston University School of Medicine
| | - Michael R Koelle
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine
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Metabotropic GABA signalling modulates longevity in C. elegans. Nat Commun 2015; 6:8828. [PMID: 26537867 PMCID: PMC4667614 DOI: 10.1038/ncomms9828] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 10/08/2015] [Indexed: 02/05/2023] Open
Abstract
The nervous system plays an important but poorly understood role in modulating longevity. GABA, a prominent inhibitory neurotransmitter, is best known to regulate nervous system function and behaviour in diverse organisms. Whether GABA signalling affects aging, however, has not been explored. Here we examined mutants lacking each of the major neurotransmitters in C. elegans, and find that deficiency in GABA signalling extends lifespan. This pro-longevity effect is mediated by the metabotropic GABAB receptor GBB-1, but not ionotropic GABAA receptors. GBB-1 regulates lifespan through G protein-PLCβ signalling, which transmits longevity signals to the transcription factor DAF-16/FOXO, a key regulator of lifespan. Mammalian GABAB receptors can functionally substitute for GBB-1 in lifespan control in C. elegans. Our results uncover a new role of GABA signalling in lifespan regulation in C. elegans, raising the possibility that a similar process may occur in other organisms. The C. elegans nervous system influences organismal lifespan but mechanistic details are poorly understood. Here, Chun et al. show that the neurotransmitter GABA regulates worm lifespan by acting on GABAB receptors in motor neurons, which activate the transcription factor DAF-16 in the intestine.
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PASTUHOV SI, HISAMOTO N, MATSUMOTO K. MAP kinase cascades regulating axon regeneration in C. elegans. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2015; 91:63-75. [PMID: 25792136 PMCID: PMC4410086 DOI: 10.2183/pjab.91.63] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 01/13/2015] [Indexed: 06/04/2023]
Abstract
Mitogen-activated protein kinase (MAPK) signaling cascades are activated by diverse stimuli such as growth factors, cytokines, neurotransmitters and various types of cellular stress. Our evolving understanding of these signal cascades has been facilitated by genetic analyses and physiological characterization in model organisms such as the nematode Caenorhabditis elegans. Genetic and biochemical studies in C. elegans have shed light on the physiological roles of MAPK cascades in the control of cell fate decision, neuronal function and immunity. Recently it was demonstrated that MAPK signaling is also important for axon regeneration in C. elegans, and the use of C. elegans as a model system has significantly advanced our understanding of the largely conserved molecular mechanisms underlying axon regeneration. This review summarizes our current understanding of the role and regulation of MAPK signaling in C. elegans axon regeneration.
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Affiliation(s)
- Strahil Iv. PASTUHOV
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Naoki HISAMOTO
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, Japan
| | - Kunihiro MATSUMOTO
- Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya, Japan
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Singh K, Ju JY, Walsh MB, DiIorio MA, Hart AC. Deep conservation of genes required for both Drosphila melanogaster and Caenorhabditis elegans sleep includes a role for dopaminergic signaling. Sleep 2014; 37:1439-51. [PMID: 25142568 DOI: 10.5665/sleep.3990] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVES Cross-species conservation of sleep-like behaviors predicts the presence of conserved molecular mechanisms underlying sleep. However, limited experimental evidence of conservation exists. Here, this prediction is tested directly. MEASUREMENTS AND RESULTS During lethargus, Caenorhabditis elegans spontaneously sleep in short bouts that are interspersed with bouts of spontaneous locomotion. We identified 26 genes required for Drosophila melanogaster sleep. Twenty orthologous C. elegans genes were selected based on similarity. Their effect on C. elegans sleep and arousal during the last larval lethargus was assessed. The 20 most similar genes altered both the quantity of sleep and arousal thresholds. In 18 cases, the direction of change was concordant with Drosophila studies published previously. Additionally, we delineated a conserved genetic pathway by which dopamine regulates sleep and arousal. In C. elegans neurons, G-alpha S, adenylyl cyclase, and protein kinase A act downstream of D1 dopamine receptors to regulate these behaviors. Finally, a quantitative analysis of genes examined herein revealed that C. elegans arousal thresholds were directly correlated with amount of sleep during lethargus. However, bout duration varies little and was not correlated with arousal thresholds. CONCLUSIONS The comprehensive analysis presented here suggests that conserved genes and pathways are required for sleep in invertebrates and, likely, across the entire animal kingdom. The genetic pathway delineated in this study implicates G-alpha S and previously known genes downstream of dopamine signaling in sleep. Quantitative analysis of various components of quiescence suggests that interdependent or identical cellular and molecular mechanisms are likely to regulate both arousal and sleep entry.
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Eom HJ, Kim H, Kim BM, Chon TS, Choi J. Integrative assessment of benzene exposure to Caenorhabditis elegans using computational behavior and toxicogenomic analyses. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:8143-8151. [PMID: 24846693 DOI: 10.1021/es500608e] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
In this study, we investigated the toxic effects of benzene to the nematode Caenorhabditis elegans in an integrative manner, using computational behavior and toxicogenomics analyses, along with survival and reproduction. Benzene exposure led to changes in locomotive behavior and reproduction decline in C. elegans. Microarray followed by pathway analysis revealed that 228 genes were differentially expressed by benzene exposure, and cyp-35a2, pmk-1, and cep-1 were selected for further reproduction and multiparametric behavior analysis. Mutant analysis showed that benzene induced reproduction decline was rescued in cyp-35a2(gk317) mutant, whereas it was significantly exacerbated in pmk-1(km25) mutant, compared with the wildtype. The multiparametric behavior analysis on the mutants of selected genes revealed that each strain exhibits different response patterns, particularly, enhanced linear movement in the cyp-35a2(gk317) mutant, whereas the changes in partial body movement were observed in the pmk-1(km25) mutant by benzene exposure. A self-organizing map revealed that the pmk-1(km25) mutant group was the most densely clustered and located on the opposite side of the map of the cyp-35a2(gk317) mutant, each crossing that of the wildtype. Overall results suggest distinct roles of cyp-35a2 and pmk-1 genes in benzene-induced alterations in behavior and reproduction in C. elegans. This study also suggests computational behavior analysis is a suitable tool for addressing the integrative impact of chemical stress alongside with toxicogenomic approach.
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Affiliation(s)
- Hyun-Jeong Eom
- School of Environmental Engineering, Graduate School of Energy and Environmental System Engineering, University of Seoul , 163 Siripdaero, Dongdaemun-gu, Seoul 130-743, Korea
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Serotonergic chemosensory neurons modify the C. elegans immune response by regulating G-protein signaling in epithelial cells. PLoS Pathog 2013; 9:e1003787. [PMID: 24348250 PMCID: PMC3861540 DOI: 10.1371/journal.ppat.1003787] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 10/09/2013] [Indexed: 01/08/2023] Open
Abstract
The nervous and immune systems influence each other, allowing animals to rapidly protect themselves from changes in their internal and external environment. However, the complex nature of these systems in mammals makes it difficult to determine how neuronal signaling influences the immune response. Here we show that serotonin, synthesized in Caenorhabditis elegans chemosensory neurons, modulates the immune response. Serotonin released from these cells acts, directly or indirectly, to regulate G-protein signaling in epithelial cells. Signaling in these cells is required for the immune response to infection by the natural pathogen Microbacterium nematophilum. Here we show that serotonin signaling suppresses the innate immune response and limits the rate of pathogen clearance. We show that C. elegans uses classical neurotransmitters to alter the immune response. Serotonin released from sensory neurons may function to modify the immune system in response to changes in the animal's external environment such as the availability, or quality, of food.
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