1
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Liu CC, Khan A, Seban N, Littlejohn N, Shah A, Srinivasan S. A homeostatic gut-to-brain insulin antagonist restrains neuronally stimulated fat loss. Nat Commun 2024; 15:6869. [PMID: 39127676 PMCID: PMC11316803 DOI: 10.1038/s41467-024-51077-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 07/29/2024] [Indexed: 08/12/2024] Open
Abstract
In C. elegans mechanisms by which peripheral organs relay internal state information to the nervous system remain unknown, although strong evidence suggests that such signals do exist. Here we report the discovery of a peptide of the ancestral insulin superfamily called INS-7 that functions as an enteroendocrine peptide and is secreted from specialized cells of the intestine. INS-7 secretion is stimulated by food withdrawal, increases during fasting and acts as a bona fide gut-to-brain peptide that attenuates the release of a neuropeptide that drives fat loss in the periphery. Thus, INS-7 functions as a homeostatic signal from the intestine that gates the neuronal drive to stimulate fat loss during food shortage. Mechanistically, INS-7 functions as an antagonist at the canonical DAF-2 receptor and functions via FOXO and AMPK signaling in ASI neurons. Phylogenetic analysis suggests that INS-7 bears greater resemblance to members of the broad insulin/relaxin superfamily than to conventional mammalian insulin and IGF peptides. The discovery of an endogenous insulin antagonist secreted by specialized intestinal cells with enteroendocrine functions suggests unexpected and important properties of the intestine and its role in directing neuronal functions.
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Affiliation(s)
- Chung-Chih Liu
- Department of Neuroscience and Dorris Neuroscience Center, The Scripps Research Institute, San Diego, CA, USA
- The Skaggs Graduate School of Chemical and Biological Sciences, The Scripps Research Institute, San Diego, CA, USA
| | - Ayub Khan
- Department of Neuroscience and Dorris Neuroscience Center, The Scripps Research Institute, San Diego, CA, USA
| | - Nicolas Seban
- Department of Neuroscience and Dorris Neuroscience Center, The Scripps Research Institute, San Diego, CA, USA
| | - Nicole Littlejohn
- Department of Neuroscience and Dorris Neuroscience Center, The Scripps Research Institute, San Diego, CA, USA
| | - Aayushi Shah
- Department of Neuroscience and Dorris Neuroscience Center, The Scripps Research Institute, San Diego, CA, USA
| | - Supriya Srinivasan
- Department of Neuroscience and Dorris Neuroscience Center, The Scripps Research Institute, San Diego, CA, USA.
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2
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Nava S, Palma W, Wan X, Oh JY, Gharib S, Wang H, Revanna JS, Tan M, Zhang M, Liu J, Chen CH, Lee JS, Perry B, Sternberg PW. A cGAL-UAS bipartite expression toolkit for Caenorhabditis elegans sensory neurons. Proc Natl Acad Sci U S A 2023; 120:e2221680120. [PMID: 38096407 PMCID: PMC10743456 DOI: 10.1073/pnas.2221680120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Accepted: 10/05/2023] [Indexed: 12/18/2023] Open
Abstract
Animals integrate sensory information from the environment and display various behaviors in response to external stimuli. In Caenorhabditis elegans hermaphrodites, 33 types of sensory neurons are responsible for chemosensation, olfaction, and mechanosensation. However, the functional roles of all sensory neurons have not been systematically studied due to the lack of facile genetic accessibility. A bipartite cGAL-UAS system has been previously developed to study tissue- or cell-specific functions in C. elegans. Here, we report a toolkit of new cGAL drivers that can facilitate the analysis of a vast majority of the 60 sensory neurons in C. elegans hermaphrodites. We generated 37 sensory neuronal cGAL drivers that drive cGAL expression by cell-specific regulatory sequences or intersection of two distinct regulatory regions with overlapping expression (split cGAL). Most cGAL-drivers exhibit expression in single types of cells. We also constructed 28 UAS effectors that allow expression of proteins to perturb or interrogate sensory neurons of choice. This cGAL-UAS sensory neuron toolkit provides a genetic platform to systematically study the functions of C. elegans sensory neurons.
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Affiliation(s)
- Stephanie Nava
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Wilber Palma
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Xuan Wan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Jun Young Oh
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Shahla Gharib
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Han Wang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Jasmin S. Revanna
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Minyi Tan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Mark Zhang
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Jonathan Liu
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Chun-Hao Chen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - James S. Lee
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Barbara Perry
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
| | - Paul W. Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA91125
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3
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Liu CC, Khan A, Seban N, Littlejohn N, Srinivasan S. A homeostatic gut-to-brain insulin antagonist restrains neuronally stimulated fat loss. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.20.563330. [PMID: 37961386 PMCID: PMC10634694 DOI: 10.1101/2023.10.20.563330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
In C. elegans mechanisms by which peripheral organs relay internal state information to the nervous system remain unknown, although strong evidence suggests that such signals do exist. Here we report the discovery of a peptide of the ancestral insulin superfamily called INS-7 that functions as an enteroendocrine peptide and is secreted from specialized cells of the intestine. INS-7 secretion increases during fasting, and acts as a bona fide gut-to-brain homeostatic signal that attenuates neuronally induced fat loss during food shortage. INS-7 functions as an antagonist at the canonical DAF-2 receptor in the nervous system, and phylogenetic analysis suggests that INS-7 bears greater resemblance to members of the broad insulin/relaxin superfamily than to conventional mammalian insulin and IGF peptides. The discovery of an endogenous insulin antagonist secreted by specialized intestinal cell with enteroendocrine functions suggests that much remains to be learned about the intestine and its role in directing neuronal functions.
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4
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Cheng Y, Hou BH, Xie GL, Shao YT, Yang J, Xu C. Transient inhibition of mitochondrial function by chrysin and apigenin prolong longevity via mitohormesis in C. elegans. Free Radic Biol Med 2023; 203:24-33. [PMID: 37023934 DOI: 10.1016/j.freeradbiomed.2023.03.264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 04/08/2023]
Abstract
Mild inhibition of mitochondrial function leads to longevity. Genetic disruption of mitochondrial respiratory components either by mutation or RNAi greatly extends the lifespan in yeast, worms, and drosophila. This has given rise to the idea that pharmacologically inhibiting mitochondrial function would be a workable strategy for postponing aging. Toward this end, we used a transgenic worm strain that expresses the firefly luciferase enzyme widely to evaluate compounds by tracking real-time ATP levels. We identified chrysin and apigenin, which reduced ATP production and increased the lifespan of worms. Mechanistically, we discovered that chrysin and apigenin transiently inhibit mitochondrial respiration and induce an early ROS, and the lifespan-extending effect is dependent on transient ROS formation. We also show that AAK-2/AMPK, DAF-16/FOXO, and SKN-1/NRF-2 are required for chrysin or apigenin-mediated lifespan extension. Temporary increases in ROS levels trigger an adaptive response in a mitohormetic way, thereby increasing oxidative stress capacity and cellular metabolic adaptation, finally leading to longevity. Thus, chrysin and apigenin represent a class of compounds isolated from natural products that delay senescence and improve age-related diseases by inhibiting mitochondrial function and shed new light on the function of additional plant-derived polyphenols in enhancing health and delaying aging. Collectively, this work provides an avenue for pharmacological inhibition of mitochondrial function and the mechanism underlining their lifespan-extending properties.
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Affiliation(s)
- Yu Cheng
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Bing-Hao Hou
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Gui-Lin Xie
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Ya-Ting Shao
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Jie Yang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China.
| | - Chen Xu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China.
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5
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Yu J, Vogt MC, Fox BW, Wrobel CJJ, Fajardo Palomino D, Curtis BJ, Zhang B, Le HH, Tauffenberger A, Hobert O, Schroeder FC. Parallel pathways for serotonin biosynthesis and metabolism in C. elegans. Nat Chem Biol 2023; 19:141-150. [PMID: 36216995 PMCID: PMC9898190 DOI: 10.1038/s41589-022-01148-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 08/19/2022] [Indexed: 02/06/2023]
Abstract
The neurotransmitter serotonin plays a central role in animal behavior and physiology, and many of its functions are regulated via evolutionarily conserved biosynthesis and degradation pathways. Here we show that in Caenorhabditis elegans, serotonin is abundantly produced in nonneuronal tissues via phenylalanine hydroxylase, in addition to canonical biosynthesis via tryptophan hydroxylase in neurons. Combining CRISPR-Cas9 genome editing, comparative metabolomics and synthesis, we demonstrate that most serotonin in C. elegans is incorporated into N-acetylserotonin-derived glucosides, which are retained in the worm body and further modified via the carboxylesterase CEST-4. Expression patterns of CEST-4 suggest that serotonin or serotonin derivatives are transported between different tissues. Last, we show that bacterial indole production interacts with serotonin metabolism via CEST-4. Our results reveal a parallel pathway for serotonin biosynthesis in nonneuronal cell types and further indicate that serotonin-derived metabolites may serve distinct signaling functions and contribute to previously described serotonin-dependent phenotypes.
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Affiliation(s)
- Jingfang Yu
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Merly C Vogt
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY, USA
| | - Bennett W Fox
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Chester J J Wrobel
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Diana Fajardo Palomino
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Brian J Curtis
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Bingsen Zhang
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Henry H Le
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Arnaud Tauffenberger
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA
| | - Oliver Hobert
- Department of Biological Sciences, Columbia University, Howard Hughes Medical Institute, New York, NY, USA.
| | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA.
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6
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Application of Caenorhabditis elegans in Lipid Metabolism Research. Int J Mol Sci 2023; 24:ijms24021173. [PMID: 36674689 PMCID: PMC9860639 DOI: 10.3390/ijms24021173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/01/2023] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
Over the last decade, the development and prevalence of obesity have posed a serious public health risk, which has prompted studies on the regulation of adiposity. With the ease of genetic manipulation, the diversity of the methods for characterizing body fat levels, and the observability of feeding behavior, Caenorhabditis elegans (C. elegans) is considered an excellent model for exploring energy homeostasis and the regulation of the cellular fat storage. In addition, the homology with mammals in the genes related to the lipid metabolism allows many aspects of lipid modulation by the regulators of the central nervous system to be conserved in this ideal model organism. In recent years, as the complex network of genes that maintain an energy balance has been gradually expanded and refined, the regulatory mechanisms of lipid storage have become clearer. Furthermore, the development of methods and devices to assess the lipid levels has become a powerful tool for studies in lipid droplet biology and the regulation of the nematode lipid metabolism. Herein, based on the rapid progress of C. elegans lipid metabolism-related studies, this review outlined the lipid metabolic processes, the major signaling pathways of fat storage regulation, and the primary experimental methods to assess the lipid content in nematodes. Therefore, this model system holds great promise for facilitating the understanding, management, and therapies of human obesity and other metabolism-related diseases.
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7
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Armingol E, Ghaddar A, Joshi CJ, Baghdassarian H, Shamie I, Chan J, Her HL, Berhanu S, Dar A, Rodriguez-Armstrong F, Yang O, O’Rourke EJ, Lewis NE. Inferring a spatial code of cell-cell interactions across a whole animal body. PLoS Comput Biol 2022; 18:e1010715. [PMID: 36395331 PMCID: PMC9714814 DOI: 10.1371/journal.pcbi.1010715] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 12/01/2022] [Accepted: 11/07/2022] [Indexed: 11/18/2022] Open
Abstract
Cell-cell interactions shape cellular function and ultimately organismal phenotype. Interacting cells can sense their mutual distance using combinations of ligand-receptor pairs, suggesting the existence of a spatial code, i.e., signals encoding spatial properties of cellular organization. However, this code driving and sustaining the spatial organization of cells remains to be elucidated. Here we present a computational framework to infer the spatial code underlying cell-cell interactions from the transcriptomes of the cell types across the whole body of a multicellular organism. As core of this framework, we introduce our tool cell2cell, which uses the coexpression of ligand-receptor pairs to compute the potential for intercellular interactions, and we test it across the Caenorhabditis elegans' body. Leveraging a 3D atlas of C. elegans' cells, we also implement a genetic algorithm to identify the ligand-receptor pairs most informative of the spatial organization of cells across the whole body. Validating the spatial code extracted with this strategy, the resulting intercellular distances are negatively correlated with the inferred cell-cell interactions. Furthermore, for selected cell-cell and ligand-receptor pairs, we experimentally confirm the communicatory behavior inferred with cell2cell and the genetic algorithm. Thus, our framework helps identify a code that predicts the spatial organization of cells across a whole-animal body.
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Affiliation(s)
- Erick Armingol
- Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, California, United States of America
- Department of Pediatrics, University of California, San Diego, La Jolla, California, United States of America
| | - Abbas Ghaddar
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Chintan J. Joshi
- Department of Pediatrics, University of California, San Diego, La Jolla, California, United States of America
| | - Hratch Baghdassarian
- Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, California, United States of America
- Department of Pediatrics, University of California, San Diego, La Jolla, California, United States of America
| | - Isaac Shamie
- Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, California, United States of America
- Department of Pediatrics, University of California, San Diego, La Jolla, California, United States of America
| | - Jason Chan
- Poway High School, Poway, California, United States of America
| | - Hsuan-Lin Her
- Bioinformatics and Systems Biology Graduate Program, University of California, San Diego, La Jolla, California, United States of America
| | - Samuel Berhanu
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Anushka Dar
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | | | - Olivia Yang
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
| | - Eyleen J. O’Rourke
- Department of Biology, University of Virginia, Charlottesville, Virginia, United States of America
- Department of Cell Biology, School of Medicine of University of Virginia, Charlottesville, Virginia, United States of America
| | - Nathan E. Lewis
- Department of Pediatrics, University of California, San Diego, La Jolla, California, United States of America
- Department of Bioengineering, University of California, San Diego, La Jolla, California, United States of America
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8
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Long HQ, Gao J, He SQ, Han JF, Tu Y, Chen N. The role of crm-1 in ionizing radiation-induced nervous system dysfunction in Caenorhabditis elegans. Neural Regen Res 2022; 18:1386-1392. [PMID: 36453427 PMCID: PMC9838165 DOI: 10.4103/1673-5374.357908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Ionizing radiation can cause changes in nervous system function. However, the underlying mechanism remains unclear. In this study, Caenorhabditis elegans (C. elegans) was irradiated with 75 Gy of 60Co whole-body γ radiation. Behavioral indicators (head thrashes, touch avoidance, and foraging), and the development of dopaminergic neurons related to behavioral function, were evaluated to assess the effects of ionizing radiation on nervous system function in C. elegans. Various behaviors were impaired after whole-body irradiation and degeneration of dopamine neurons was observed. This suggests that 75 Gy of γ radiation is sufficient to induce nervous system dysfunction. The genes nhr-76 and crm-1, which are reported to be related to nervous system function in human and mouse, were screened by transcriptome sequencing and bioinformatics analysis after irradiation or sham irradiation. The expression levels of these two genes were increased after radiation. Next, RNAi technology was used to inhibit the expression of crm-1, a gene whose homologs are associated with motor neuron development in other species. Downregulation of crm-1 expression effectively alleviated the deleterious effects of ionizing radiation on head thrashes and touch avoidance. It was also found that the expression level of crm-1 was regulated by the nuclear receptor gene nhr-76. The results of this study suggest that knocking down the expression level of nhr-76 can reduce the expression level of crm-1, while down-regulating the expression level of crm-1 can alleviate behavioral disorders induced by ionizing radiation. Therefore, inhibition of crm-1 may be of interest as a potential therapeutic target for ionizing radiation-induced neurological dysfunction.
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Affiliation(s)
- Hui-Qiang Long
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu Province, China,State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, Jiangsu Province, China,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu Province, China
| | - Jin Gao
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu Province, China,State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, Jiangsu Province, China,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu Province, China
| | - Shu-Qing He
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu Province, China
| | - Jian-Fang Han
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu Province, China,State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, Jiangsu Province, China,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu Province, China
| | - Yu Tu
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu Province, China,State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, Jiangsu Province, China,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu Province, China,Correspondence to: Yu Tu, ; Na Chen, .
| | - Na Chen
- Suzhou Medical College of Soochow University, Suzhou, Jiangsu Province, China,State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, Jiangsu Province, China,Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, Suzhou, Jiangsu Province, China,Correspondence to: Yu Tu, ; Na Chen, .
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9
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Serotonin and dopamine modulate aging in response to food odor and availability. Nat Commun 2022; 13:3271. [PMID: 35672307 PMCID: PMC9174215 DOI: 10.1038/s41467-022-30869-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/12/2022] [Indexed: 01/27/2023] Open
Abstract
An organism's ability to perceive and respond to changes in its environment is crucial for its health and survival. Here we reveal how the most well-studied longevity intervention, dietary restriction, acts in-part through a cell non-autonomous signaling pathway that is inhibited by the presence of attractive smells. Using an intestinal reporter for a key gene induced by dietary restriction but suppressed by attractive smells, we identify three compounds that block food odor effects in C. elegans, thereby increasing longevity as dietary restriction mimetics. These compounds clearly implicate serotonin and dopamine in limiting lifespan in response to food odor. We further identify a chemosensory neuron that likely perceives food odor, an enteric neuron that signals through the serotonin receptor 5-HT1A/SER-4, and a dopaminergic neuron that signals through the dopamine receptor DRD2/DOP-3. Aspects of this pathway are conserved in D. melanogaster. Thus, blocking food odor signaling through antagonism of serotonin or dopamine receptors is a plausible approach to mimic the benefits of dietary restriction.
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10
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Riedl J, Fieseler C, Zimmer M. Tyraminergic corollary discharge filters reafferent perception in a chemosensory neuron. Curr Biol 2022; 32:3048-3058.e6. [PMID: 35690069 DOI: 10.1016/j.cub.2022.05.051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/10/2022] [Accepted: 05/18/2022] [Indexed: 12/25/2022]
Abstract
Interpreting sensory information requires its integration with the current behavior of the animal. However, how motor-related circuits influence sensory information processing is incompletely understood. Here, we report that current locomotor state directly modulates the activity of BAG CO2 sensory neurons in Caenorhabditis elegans. By recording neuronal activity in animals freely navigating CO2 landscapes, we found that during reverse crawling states, BAG activity is suppressed by tyraminergic corollary discharge signaling. We provide genetic evidence that tyramine released from the RIM reversal interneurons extrasynaptically activates the inhibitory chloride channel LGC-55 in BAG. Disrupting this pathway genetically leads to excessive behavioral responses to CO2 stimuli. Moreover, we find that LGC-55 signaling cancels out perception of self-produced CO2 and O2 stimuli when animals reverse into their own gas plume in ethologically relevant aqueous environments. Our results show that sensorimotor integration involves corollary discharge signals directly modulating chemosensory neurons.
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Affiliation(s)
- Julia Riedl
- Department of Neuroscience and Developmental Biology, Vienna BioCenter (VBC), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Charles Fieseler
- Department of Neuroscience and Developmental Biology, Vienna BioCenter (VBC), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria
| | - Manuel Zimmer
- Department of Neuroscience and Developmental Biology, Vienna BioCenter (VBC), University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria; Research Institute of Molecular Pathology (IMP), Vienna BioCenter (VBC), Campus-Vienna-Biocenter 1, 1030 Vienna, Austria.
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11
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Handley A, Wu Q, Sherry T, Cornell R, Pocock R. Diet-responsive transcriptional regulation of insulin in a single neuron controls systemic metabolism. PLoS Biol 2022; 20:e3001655. [PMID: 35594303 PMCID: PMC9162364 DOI: 10.1371/journal.pbio.3001655] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 06/02/2022] [Accepted: 04/29/2022] [Indexed: 11/18/2022] Open
Abstract
Metabolic homeostasis is coordinated through a robust network of signaling pathways acting across all tissues. A key part of this network is insulin-like signaling, which is fundamental for surviving glucose stress. Here, we show that Caenorhabditis elegans fed excess dietary glucose reduce insulin-1 (INS-1) expression specifically in the BAG glutamatergic sensory neurons. We demonstrate that INS-1 expression in the BAG neurons is directly controlled by the transcription factor ETS-5, which is also down-regulated by glucose. We further find that INS-1 acts exclusively from the BAG neurons, and not other INS-1-expressing neurons, to systemically inhibit fat storage via the insulin-like receptor DAF-2. Together, these findings reveal an intertissue regulatory pathway where regulation of insulin expression in a specific neuron controls systemic metabolism in response to excess dietary glucose. Metabolic homeostasis is coordinated through a robust network of signaling pathways acting across all tissues. This study shows that Caenorhabditis elegans nematodes fed excess dietary glucose reduce the expression of insulin-1 specifically in the BAG glutamatergic sensory neurons, and that insulin-1 produced by these neurons systemically inhibits fat storage via the insulin-like receptor DAF-2.
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Affiliation(s)
- Ava Handley
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
- * E-mail: (AH); (RP)
| | - Qiuli Wu
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
- Key Laboratory of Developmental Genes and Human Diseases in Ministry of Education, Medical School of Southeast University, Nanjing, China
| | - Tessa Sherry
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Rebecca Cornell
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
| | - Roger Pocock
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
- * E-mail: (AH); (RP)
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12
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Kirchweger B, Klein-Junior LC, Pretsch D, Chen Y, Cretton S, Gasper AL, Heyden YV, Christen P, Kirchmair J, Henriques AT, Rollinger JM. Azepine-Indole Alkaloids From Psychotria nemorosa Modulate 5-HT 2A Receptors and Prevent in vivo Protein Toxicity in Transgenic Caenorhabditis elegans. Front Neurosci 2022; 16:826289. [PMID: 35360162 PMCID: PMC8963987 DOI: 10.3389/fnins.2022.826289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/18/2022] [Indexed: 11/26/2022] Open
Abstract
Nemorosine A (1) and fargesine (2), the main azepine-indole alkaloids of Psychotria nemorosa, were explored for their pharmacological profile on neurodegenerative disorders (NDs) applying a combined in silico–in vitro–in vivo approach. By using 1 and 2 as queries for similarity-based searches of the ChEMBL database, structurally related compounds were identified to modulate the 5-HT2A receptor; in vitro experiments confirmed an agonistic effect for 1 and 2 (24 and 36% at 10 μM, respectively), which might be linked to cognition-enhancing properties. This and the previously reported target profile of 1 and 2, which also includes BuChE and MAO-A inhibition, prompted the evaluation of these compounds in several Caenorhabditis elegans models linked to 5-HT modulation and proteotoxicity. On C. elegans transgenic strain CL4659, which expresses amyloid beta (Aβ) in muscle cells leading to a phenotypic paralysis, 1 and 2 reduced Aβ proteotoxicity by reducing the percentage of paralyzed worms to 51%. Treatment of the NL5901 strain, in which α-synuclein is yellow fluorescent protein (YFP)-tagged, with 1 and 2 (10 μM) significantly reduced the α-synuclein expression. Both alkaloids were further able to significantly extend the time of metallothionein induction, which is associated with reduced neurodegeneration of aged brain tissue. These results add to the multitarget profiles of 1 and 2 and corroborate their potential in the treatment of NDs.
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Affiliation(s)
- Benjamin Kirchweger
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Vienna, Austria
| | - Luiz C Klein-Junior
- School of Health Sciences, Universidade do Vale do Itajaí (UNIVALI), Itajaí, Brazil.,Laboratory of Pharmacognosy and Quality Control of Phytomedicines, Faculty of Pharmacy, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Dagmar Pretsch
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Vienna, Austria
| | - Ya Chen
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Sylvian Cretton
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - André L Gasper
- Herbarium Dr. Roberto Miguel Klein, Department of Natural Sciences, Universidade Regional de Blumenau (FURB), Blumenau, Brazil
| | - Yvan Vander Heyden
- Department of Analytical Chemistry, Applied Chemometrics and Molecular Modeling, Center for Pharmaceutical Research (CePhaR), Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Philippe Christen
- Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
| | - Johannes Kirchmair
- Department of Pharmaceutical Sciences, Division of Pharmaceutical Chemistry, University of Vienna, Vienna, Austria
| | - Amélia T Henriques
- Laboratory of Pharmacognosy and Quality Control of Phytomedicines, Faculty of Pharmacy, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Judith M Rollinger
- Department of Pharmaceutical Sciences, Division of Pharmacognosy, University of Vienna, Vienna, Austria
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13
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Schwartz EKC, Sosner EN, Desmond HE, Lum SJ, Sze JY, Mobbs CV. Serotonin and Dopamine Mimic Glucose-Induced Reinforcement in C. elegans: Potential Role of NSM Neurons and the Serotonin Subtype 4 Receptor. Front Physiol 2022; 12:783359. [PMID: 34987416 PMCID: PMC8721000 DOI: 10.3389/fphys.2021.783359] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Accepted: 11/22/2021] [Indexed: 12/17/2022] Open
Abstract
Food produces powerful reinforcement that can lead to overconsumption and likely contributes to the obesity epidemic. The present studies examined molecular mechanisms mediating food-induced reinforcement in the model system C. elegans. After a 1-h training session during which food (bacteria) is paired with the odorant butanone, odor preference for butanone robustly increased. Glucose mimicked this effect of bacteria. Glucose-induced odor preference was enhanced similarly by prior food withdrawal or blocking glucose metabolism in the presence of food. Food- and glucose-induced odor preference was mimicked by serotonin signaling through the serotonin type-4 (5-HT4) receptor. Dopamine (thought to act primarily through a D1-like receptor) facilitated, whereas the D2 agonist bromocriptine blocked, food- and glucose-induced odor preference. Furthermore, prior food withdrawal similarly influenced reward produced by serotonin, dopamine, or food, implying post-synaptic enhancement of sensitivity to serotonin and dopamine. These results suggest that glucose metabolism plays a key role in mediating both food-induced reinforcement and enhancement of that reinforcement by prior food withdrawal and implicate serotonergic signaling through 5-HT4 receptor in the re-enforcing properties of food.
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Affiliation(s)
- Elizabeth K C Schwartz
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Eitan N Sosner
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Hayley E Desmond
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Stephanie J Lum
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Ji Ying Sze
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Charles V Mobbs
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, United States
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14
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Chauve L, Hodge F, Murdoch S, Masoudzadeh F, Mann HJ, Lopez-Clavijo AF, Okkenhaug H, West G, Sousa BC, Segonds-Pichon A, Li C, Wingett SW, Kienberger H, Kleigrewe K, de Bono M, Wakelam MJO, Casanueva O. Neuronal HSF-1 coordinates the propagation of fat desaturation across tissues to enable adaptation to high temperatures in C. elegans. PLoS Biol 2021; 19:e3001431. [PMID: 34723964 PMCID: PMC8585009 DOI: 10.1371/journal.pbio.3001431] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 11/11/2021] [Accepted: 09/29/2021] [Indexed: 11/18/2022] Open
Abstract
To survive elevated temperatures, ectotherms adjust the fluidity of membranes by fine-tuning lipid desaturation levels in a process previously described to be cell autonomous. We have discovered that, in Caenorhabditis elegans, neuronal heat shock factor 1 (HSF-1), the conserved master regulator of the heat shock response (HSR), causes extensive fat remodeling in peripheral tissues. These changes include a decrease in fat desaturase and acid lipase expression in the intestine and a global shift in the saturation levels of plasma membrane's phospholipids. The observed remodeling of plasma membrane is in line with ectothermic adaptive responses and gives worms a cumulative advantage to warm temperatures. We have determined that at least 6 TAX-2/TAX-4 cyclic guanosine monophosphate (cGMP) gated channel expressing sensory neurons, and transforming growth factor ß (TGF-β)/bone morphogenetic protein (BMP) are required for signaling across tissues to modulate fat desaturation. We also find neuronal hsf-1 is not only sufficient but also partially necessary to control the fat remodeling response and for survival at warm temperatures. This is the first study to show that a thermostat-based mechanism can cell nonautonomously coordinate membrane saturation and composition across tissues in a multicellular animal.
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Affiliation(s)
- Laetitia Chauve
- Epigenetics Department, Babraham Institute, Cambridge, United Kingdom
| | - Francesca Hodge
- Epigenetics Department, Babraham Institute, Cambridge, United Kingdom
| | - Sharlene Murdoch
- Epigenetics Department, Babraham Institute, Cambridge, United Kingdom
| | | | | | | | | | - Greg West
- Babraham Institute, Cambridge, United Kingdom
| | | | | | - Cheryl Li
- Epigenetics Department, Babraham Institute, Cambridge, United Kingdom
| | | | | | - Karin Kleigrewe
- Bavarian Centre for Biomolecular Mass Spectrometry, Freising, Germany
| | - Mario de Bono
- Institute of Science and Technology, Klosterneuburg, Austria
| | | | - Olivia Casanueva
- Epigenetics Department, Babraham Institute, Cambridge, United Kingdom
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15
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The transcription factor LAG-1/CSL plays a Notch-independent role in controlling terminal differentiation, fate maintenance, and plasticity of serotonergic chemosensory neurons. PLoS Biol 2021; 19:e3001334. [PMID: 34232959 PMCID: PMC8289040 DOI: 10.1371/journal.pbio.3001334] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 07/19/2021] [Accepted: 06/21/2021] [Indexed: 11/19/2022] Open
Abstract
During development, signal-regulated transcription factors (TFs) act as basal repressors and upon signalling through morphogens or cell-to-cell signalling shift to activators, mediating precise and transient responses. Conversely, at the final steps of neuron specification, terminal selector TFs directly initiate and maintain neuron-type specific gene expression through enduring functions as activators. C. elegans contains 3 types of serotonin synthesising neurons that share the expression of the serotonin biosynthesis pathway genes but not of other effector genes. Here, we find an unconventional role for LAG-1, the signal-regulated TF mediator of the Notch pathway, as terminal selector for the ADF serotonergic chemosensory neuron, but not for other serotonergic neuron types. Regulatory regions of ADF effector genes contain functional LAG-1 binding sites that mediate activation but not basal repression. lag-1 mutants show broad defects in ADF effector genes activation, and LAG-1 is required to maintain ADF cell fate and functions throughout life. Unexpectedly, contrary to reported basal repression state for LAG-1 prior to Notch receptor activation, gene expression activation in the ADF neuron by LAG-1 does not require Notch signalling, demonstrating a default activator state for LAG-1 independent of Notch. We hypothesise that the enduring activity of terminal selectors on target genes required uncoupling LAG-1 activating role from receiving the transient Notch signalling.
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16
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Joshi KK, Matlack TL, Pyonteck S, Vora M, Menzel R, Rongo C. Biogenic amine neurotransmitters promote eicosanoid production and protein homeostasis. EMBO Rep 2021; 22:e51063. [PMID: 33470040 PMCID: PMC7926251 DOI: 10.15252/embr.202051063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 12/07/2020] [Accepted: 12/15/2020] [Indexed: 12/31/2022] Open
Abstract
Metazoans use protein homeostasis (proteostasis) pathways to respond to adverse physiological conditions, changing environment, and aging. The nervous system regulates proteostasis in different tissues, but the mechanism is not understood. Here, we show that Caenorhabditis elegans employs biogenic amine neurotransmitters to regulate ubiquitin proteasome system (UPS) proteostasis in epithelia. Mutants for biogenic amine synthesis show decreased poly-ubiquitination and turnover of a GFP-based UPS substrate. Using RNA-seq and mass spectrometry, we found that biogenic amines promote eicosanoid production from poly-unsaturated fats (PUFAs) by regulating expression of cytochrome P450 monooxygenases. Mutants for one of these P450s share the same UPS phenotype observed in biogenic amine mutants. The production of n-6 eicosanoids is required for UPS substrate turnover, whereas accumulation of n-6 eicosanoids accelerates turnover. Our results suggest that sensory neurons secrete biogenic amines to modulate lipid signaling, which in turn activates stress response pathways to maintain UPS proteostasis.
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Affiliation(s)
- Kishore K Joshi
- Department of GeneticsThe Waksman InstituteRutgers The State University of New JerseyPiscatawayNJUSA
| | - Tarmie L Matlack
- Department of GeneticsThe Waksman InstituteRutgers The State University of New JerseyPiscatawayNJUSA
| | - Stephanie Pyonteck
- Department of GeneticsThe Waksman InstituteRutgers The State University of New JerseyPiscatawayNJUSA
| | - Mehul Vora
- Department of GeneticsThe Waksman InstituteRutgers The State University of New JerseyPiscatawayNJUSA
| | - Ralph Menzel
- Institute of Biology and EcologyHumboldt University BerlinBerlinGermany
| | - Christopher Rongo
- Department of GeneticsThe Waksman InstituteRutgers The State University of New JerseyPiscatawayNJUSA
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17
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Okabe E, Uno M, Kishimoto S, Nishida E. Intertissue small RNA communication mediates the acquisition and inheritance of hormesis in Caenorhabditis elegans. Commun Biol 2021; 4:207. [PMID: 33594200 PMCID: PMC7886853 DOI: 10.1038/s42003-021-01692-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 01/12/2021] [Indexed: 12/16/2022] Open
Abstract
Environmental conditions can cause phenotypic changes, part of which can be inherited by subsequent generations via soma-to-germline communication. However, the signaling molecules or pathways that mediate intertissue communication remain unclear. Here, we show that intertissue small RNA communication systems play a key role in the acquisition and inheritance of hormesis effects – stress-induced stress resistance – in Caenorhabditis elegans. The miRNA-processing enzyme DRSH-1 is involved in both the acquisition and the inheritance of hormesis, whereas worm-specific Argonaute (WAGO) proteins, which function with endo-siRNAs, are involved only in its inheritance. Further analyses demonstrate that the miRNA production system in the neuron and the small RNA transport machinery in the intestine are both essential for its acquisition and that both the transport of small RNAs in the germline and the germline Argonaute HRDE-1 complex are required for its inheritance. Our results thus demonstrate that overlapping and distinct roles of small RNA systems in the acquisition and inheritance of hormesis effects. Okabe et al. show that the miRNA production system in the neuron and the small RNA transport machinery in the intestine are required for the acquisition of hormesis. For its inheritance, both the transport of small RNAs in the germline and the germline Argonaute HRDE-1 complex are needed, highlighting distinct contribution of small RNA systems to hormesis.
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Affiliation(s)
- Emiko Okabe
- RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minamimachi, Chuo-ku, Kobe, 650-0047, Japan.,Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Masaharu Uno
- RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minamimachi, Chuo-ku, Kobe, 650-0047, Japan. .,Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan.
| | - Saya Kishimoto
- RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minamimachi, Chuo-ku, Kobe, 650-0047, Japan.,Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
| | - Eisuke Nishida
- RIKEN Center for Biosystems Dynamics Research, 2-2-3 Minatojima Minamimachi, Chuo-ku, Kobe, 650-0047, Japan.,Department of Cell and Developmental Biology, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto, 606-8502, Japan
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18
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Littlejohn NK, Seban N, Liu CC, Srinivasan S. A feedback loop governs the relationship between lipid metabolism and longevity. eLife 2020; 9:58815. [PMID: 33078707 PMCID: PMC7575325 DOI: 10.7554/elife.58815] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/25/2020] [Indexed: 12/16/2022] Open
Abstract
The relationship between lipid metabolism and longevity remains unclear. Although fat oxidation is essential for weight loss, whether it remains beneficial when sustained for long periods, and the extent to which it may attenuate or augment lifespan remain important unanswered questions. Here, we develop an experimental handle in the Caenorhabditis elegans model system, in which we uncover the mechanisms that connect long-term fat oxidation with longevity. We find that sustained β-oxidation via activation of the conserved triglyceride lipase ATGL-1, triggers a feedback transcriptional loop that involves the mito-nuclear transcription factor ATFS-1, and a previously unknown and highly conserved repressor of ATGL-1 called HLH-11/AP4. This feedback loop orchestrates the dual control of fat oxidation and lifespan, and shields the organism from life-shortening mitochondrial stress in the face of continuous fat oxidation. Thus, we uncover one mechanism by which fat oxidation can be sustained for long periods without deleterious effects on longevity.
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Affiliation(s)
- Nicole K Littlejohn
- Department of Neuroscience and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Nicolas Seban
- Department of Neuroscience and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Chung-Chih Liu
- Skaggs Graduate School of Chemical and Biological Sciences, The Scripps Research Institute, La Jolla, United States
| | - Supriya Srinivasan
- Department of Neuroscience and The Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
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19
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Abstract
Caenorhabditis elegans' behavioral states, like those of other animals, are shaped by its immediate environment, its past experiences, and by internal factors. We here review the literature on C. elegans behavioral states and their regulation. We discuss dwelling and roaming, local and global search, mate finding, sleep, and the interaction between internal metabolic states and behavior.
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Affiliation(s)
- Steven W Flavell
- Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - David M Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Young-Jai You
- Division of Biological Science, Graduate School of Science, Nagoya University, 464-8602, Japan
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20
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Abstract
This review article highlights our efforts to decode the role of the nervous system in regulating intestinal lipid metabolism in Caenorhabditis elegans. Capitalizing on the prescient and pioneering work of Sydney Brenner and John Sulston in establishing C. elegans as an immensely valuable model system, we have uncovered critical roles for oxygen sensing, population density sensing and food sensing in orchestrating the balance between storing lipids and utilizing them for energy in the intestine, the major organ for lipid metabolism in this model system. Our long-term goal is to reveal the integrative mechanisms and regulatory logic that underlies the complex relationship between genes, environment and internal state in the regulation of energy and whole-body physiology.
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Affiliation(s)
- Supriya Srinivasan
- Department of Neuroscience and Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, USA
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21
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Cruz-Corchado J, Ooi FK, Das S, Prahlad V. Global Transcriptome Changes That Accompany Alterations in Serotonin Levels in Caenorhabditis elegans. G3 (BETHESDA, MD.) 2020; 10:1225-1246. [PMID: 31996358 PMCID: PMC7144078 DOI: 10.1534/g3.120.401088] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 01/25/2020] [Indexed: 11/18/2022]
Abstract
Serotonin (5-hydroxytryptamine, 5-HT), is a phylogenetically ancient molecule best characterized as a neurotransmitter that modulates multiple aspects of mood and social cognition. The roles that 5-HT plays in normal and abnormal behavior are not fully understood but have been posited to be due to its common function as a 'defense signal'. However, 5-HT levels also systemically impact cell physiology, modulating cell division, migration, apoptosis, mitochondrial biogenesis, cellular metabolism and differentiation. Whether these diverse cellular effects of 5-HT also share a common basis is unclear. C. elegans provides an ideal system to interrogate the systemic effects of 5-HT, since lacking a blood-brain barrier, 5-HT synthesized and released by neurons permeates the organism to modulate neuronal as well as non-neuronal cells throughout the body. Here we used RNA-Seq to characterize the systemic changes in gene expression that occur in C. elegans upon altering 5-HT levels, and compared the transcriptomes to published datasets. We find that an acute increase in 5-HT is accompanied by a global decrease in gene expression levels, upregulation of genes involved in stress pathways, changes that significantly correlate with the published transcriptomes of animals that have activated defense and immune responses, and an increase in levels of phosphorylated eukaryotic initiation factor, eIF2α. In 5-HT deficient animals lacking tryptophan hydroxylase (tph-1(mg280)II) there is a net increase in gene expression, with an overrepresentation of genes related to development and chromatin. Surprisingly, the transcriptomes of animals with acute increases in 5-HT levels, and 5-HT deficiency do not overlap with transcriptomes of mutants with whom they share striking physiological resemblance. These studies are the first to catalog systemic transcriptome changes that occur upon alterations in 5-HT levels. They further show that in C. elegans changes in gene expression upon altering 5-HT levels, and changes in physiology, are not directly correlated.
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Affiliation(s)
- Johnny Cruz-Corchado
- Department of Biology, Aging Mind and Brain Initiative, Iowa Neuroscience Institute, 143 Biology Building, Iowa City, IA 52242-1324
| | - Felicia K Ooi
- Department of Biology, Aging Mind and Brain Initiative, Iowa Neuroscience Institute, 143 Biology Building, Iowa City, IA 52242-1324
| | - Srijit Das
- Department of Biology, Aging Mind and Brain Initiative, Iowa Neuroscience Institute, 143 Biology Building, Iowa City, IA 52242-1324
| | - Veena Prahlad
- Department of Biology, Aging Mind and Brain Initiative, Iowa Neuroscience Institute, 143 Biology Building, Iowa City, IA 52242-1324
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22
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Grubbs JJ, Lopes LE, van der Linden AM, Raizen DM. A salt-induced kinase is required for the metabolic regulation of sleep. PLoS Biol 2020; 18:e3000220. [PMID: 32315298 PMCID: PMC7173979 DOI: 10.1371/journal.pbio.3000220] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 03/20/2020] [Indexed: 12/16/2022] Open
Abstract
Many lines of evidence point to links between sleep regulation and energy homeostasis, but mechanisms underlying these connections are unknown. During Caenorhabditis elegans sleep, energetic stores are allocated to nonneural tasks with a resultant drop in the overall fat stores and energy charge. Mutants lacking KIN-29, the C. elegans homolog of a mammalian Salt-Inducible Kinase (SIK) that signals sleep pressure, have low ATP levels despite high-fat stores, indicating a defective response to cellular energy deficits. Liberating energy stores corrects adiposity and sleep defects of kin-29 mutants. kin-29 sleep and energy homeostasis roles map to a set of sensory neurons that act upstream of fat regulation as well as of central sleep-controlling neurons, suggesting hierarchical somatic/neural interactions regulating sleep and energy homeostasis. Genetic interaction between kin-29 and the histone deacetylase hda-4 coupled with subcellular localization studies indicate that KIN-29 acts in the nucleus to regulate sleep. We propose that KIN-29/SIK acts in nuclei of sensory neuroendocrine cells to transduce low cellular energy charge into the mobilization of energy stores, which in turn promotes sleep.
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Affiliation(s)
- Jeremy J. Grubbs
- Department of Biology, University of Nevada, Reno, Nevada, United States of America
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Lindsey E. Lopes
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | | | - David M. Raizen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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23
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Roeder T. The control of metabolic traits by octopamine and tyramine in invertebrates. J Exp Biol 2020; 223:223/7/jeb194282. [DOI: 10.1242/jeb.194282] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
ABSTRACT
Octopamine (OA) and tyramine (TA) are closely related biogenic monoamines that act as signalling compounds in invertebrates, where they fulfil the roles played by adrenaline and noradrenaline in vertebrates. Just like adrenaline and noradrenaline, OA and TA are extremely pleiotropic substances that regulate a wide variety of processes, including metabolic pathways. However, the role of OA and TA in metabolism has been largely neglected. The principal aim of this Review is to discuss the roles of OA and TA in the control of metabolic processes in invertebrate species. OA and TA regulate essential aspects of invertebrate energy homeostasis by having substantial effects on both energy uptake and energy expenditure. These two monoamines regulate several different factors, such as metabolic rate, physical activity, feeding rate or food choice that have a considerable influence on effective energy intake and all the principal contributors to energy consumption. Thereby, OA and TA regulate both metabolic rate and physical activity. These effects should not be seen as isolated actions of these neuroactive compounds but as part of a comprehensive regulatory system that allows the organism to switch from one physiological state to another.
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Affiliation(s)
- Thomas Roeder
- Kiel University, Zoology, Department of Molecular Physiology, 24098 Kiel, Germany
- DZL, German Centre for Lung Research, ARCN, 24098 Kiel, Germany
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24
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Lin Y, Yang N, Bao B, Wang L, Chen J, Liu J. Luteolin reduces fat storage inCaenorhabditis elegansby promoting the central serotonin pathway. Food Funct 2020; 11:730-740. [DOI: 10.1039/c9fo02095k] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Luteolin promotes central serotonin signaling to induce fat loss.
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Affiliation(s)
- Yan Lin
- School of Food and Biological Engineering
- Hefei University of Technology
- Hefei
- China
| | - Nan Yang
- School of Food and Biological Engineering
- Hefei University of Technology
- Hefei
- China
| | - Bin Bao
- School of Food and Biological Engineering
- Hefei University of Technology
- Hefei
- China
| | - Lu Wang
- School of Food and Biological Engineering
- Hefei University of Technology
- Hefei
- China
| | - Juan Chen
- School of Food and Biological Engineering
- Hefei University of Technology
- Hefei
- China
| | - Jian Liu
- School of Food and Biological Engineering
- Hefei University of Technology
- Hefei
- China
- Engineering Research Center of Bio-process
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25
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Bouagnon AD, Lin L, Srivastava S, Liu CC, Panda O, Schroeder FC, Srinivasan S, Ashrafi K. Intestinal peroxisomal fatty acid β-oxidation regulates neural serotonin signaling through a feedback mechanism. PLoS Biol 2019; 17:e3000242. [PMID: 31805041 PMCID: PMC6917301 DOI: 10.1371/journal.pbio.3000242] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 12/17/2019] [Accepted: 11/15/2019] [Indexed: 02/02/2023] Open
Abstract
The ability to coordinate behavioral responses with metabolic status is fundamental to the maintenance of energy homeostasis. In numerous species including Caenorhabditis elegans and mammals, neural serotonin signaling regulates a range of food-related behaviors. However, the mechanisms that integrate metabolic information with serotonergic circuits are poorly characterized. Here, we identify metabolic, molecular, and cellular components of a circuit that links peripheral metabolic state to serotonin-regulated behaviors in C. elegans. We find that blocking the entry of fatty acyl coenzyme As (CoAs) into peroxisomal β-oxidation in the intestine blunts the effects of neural serotonin signaling on feeding and egg-laying behaviors. Comparative genomics and metabolomics revealed that interfering with intestinal peroxisomal β-oxidation results in a modest global transcriptional change but significant changes to the metabolome, including a large number of changes in ascaroside and phospholipid species, some of which affect feeding behavior. We also identify body cavity neurons and an ether-a-go-go (EAG)-related potassium channel that functions in these neurons as key cellular components of the circuitry linking peripheral metabolic signals to regulation of neural serotonin signaling. These data raise the possibility that the effects of serotonin on satiety may have their origins in feedback, homeostatic metabolic responses from the periphery.
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Affiliation(s)
- Aude D. Bouagnon
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - Lin Lin
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - Shubhi Srivastava
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, United States of America
| | - Chung-Chih Liu
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, United States of America
| | - Oishika Panda
- Boyce Thompson Institute, Cornell University, Ithaca, New York, United States of America
| | - Frank C. Schroeder
- Boyce Thompson Institute, Cornell University, Ithaca, New York, United States of America
| | - Supriya Srinivasan
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, United States of America
| | - Kaveh Ashrafi
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
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Lin Y, Bao B, Yin H, Wang X, Feng A, Zhao L, Nie X, Yang N, Shi GP, Liu J. Peripheral cathepsin L inhibition induces fat loss in C. elegans and mice through promoting central serotonin synthesis. BMC Biol 2019; 17:93. [PMID: 31771567 PMCID: PMC6880508 DOI: 10.1186/s12915-019-0719-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/06/2019] [Indexed: 02/12/2023] Open
Abstract
BACKGROUND Cathepsin L and some other cathepsins have been implicated in the development of obesity in humans and mice. The functional inactivation of the proteases reduces fat accumulation during mammalian adipocyte differentiation. However, beyond degrading extracellular matrix protein fibronectin, the molecular mechanisms by which cathepsins control fat accumulation remain unclear. We now provide evidence from Caenorhabditis elegans and mouse models to suggest a conserved regulatory circuit in which peripheral cathepsin L inhibition lowers fat accumulation through promoting central serotonin synthesis. RESULTS We established a C. elegans model of fat accumulation using dietary supplementation with glucose and palmitic acid. We found that nutrient supplementation elevated fat storage in C. elegans, and along with worm fat accumulation, an increase in the expression of cpl-1 was detected using real-time PCR and western blot. The functional inactivation of cpl-1 reduced fat storage in C. elegans through activating serotonin signaling. Further, knockdown of cpl-1 in the intestine and hypodermis promoted serotonin synthesis in worm ADF neurons and induced body fat loss in C. elegans via central serotonin signaling. We found a similar regulatory circuit in high-fat diet-fed mice. Cathepsin L knockout promoted fat loss and central serotonin synthesis. Intraperitoneal injection of the cathepsin L inhibitor CLIK195 similarly reduced body weight gain and white adipose tissue (WAT) adipogenesis, while elevating brain serotonin level and WAT lipolysis and fatty acid β-oxidation. These effects of inhibiting cathepsin L were abolished by intracranial injection of p-chlorophenylalanine, inhibitor of a rate-limiting enzyme for serotonin synthesis. CONCLUSION This study reveals a previously undescribed molecular mechanism by which peripheral CPL-1/cathepsin L inhibition induces fat loss in C. elegans and mice through promoting central serotonin signaling.
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Affiliation(s)
- Yan Lin
- School of Food and Biological Engineering, Hefei University of Technology, 193 Tunxi Road, Hefei, 230009, Anhui, China
| | - Bin Bao
- School of Food and Biological Engineering, Hefei University of Technology, 193 Tunxi Road, Hefei, 230009, Anhui, China.
| | - Hao Yin
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Xin Wang
- School of Food and Biological Engineering, Hefei University of Technology, 193 Tunxi Road, Hefei, 230009, Anhui, China
| | - Airong Feng
- Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, 230026, Anhui, China
| | - Lin Zhao
- School of Food and Biological Engineering, Hefei University of Technology, 193 Tunxi Road, Hefei, 230009, Anhui, China
| | - Xianqi Nie
- School of Food and Biological Engineering, Hefei University of Technology, 193 Tunxi Road, Hefei, 230009, Anhui, China
| | - Nan Yang
- School of Food and Biological Engineering, Hefei University of Technology, 193 Tunxi Road, Hefei, 230009, Anhui, China
| | - Guo-Ping Shi
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Jian Liu
- School of Food and Biological Engineering, Hefei University of Technology, 193 Tunxi Road, Hefei, 230009, Anhui, China.
- Engineering Research Center of Bio-process, Ministry of Education, Hefei University of Technology, Hefei, 230009, China.
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Yang W, Petersen C, Pees B, Zimmermann J, Waschina S, Dirksen P, Rosenstiel P, Tholey A, Leippe M, Dierking K, Kaleta C, Schulenburg H. The Inducible Response of the Nematode Caenorhabditis elegans to Members of Its Natural Microbiota Across Development and Adult Life. Front Microbiol 2019; 10:1793. [PMID: 31440221 PMCID: PMC6693516 DOI: 10.3389/fmicb.2019.01793] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 07/22/2019] [Indexed: 12/11/2022] Open
Abstract
The biology of all organisms is influenced by the associated community of microorganisms. In spite of its importance, it is usually not well understood how exactly this microbiota affects host functions and what are the underlying molecular processes. To rectify this knowledge gap, we took advantage of the nematode Caenorhabditis elegans as a tractable, experimental model system and assessed the inducible transcriptome response after colonization with members of its native microbiota. For this study, we focused on two isolates of the genus Ochrobactrum. These bacteria are known to be abundant in the nematode’s microbiota and are capable of colonizing and persisting in the nematode gut, even under stressful conditions. The transcriptome response was assessed across development and three time points of adult life, using general and C. elegans-specific enrichment analyses to identify affected functions. Our assessment revealed an influence of the microbiota members on the nematode’s dietary response, development, fertility, immunity, and energy metabolism. This response is mainly regulated by a GATA transcription factor, most likely ELT-2, as indicated by the enrichment of (i) the GATA motif in the promoter regions of inducible genes and (ii) of ELT-2 targets among the differentially expressed genes. We compared our transcriptome results with a corresponding previously characterized proteome data set, highlighting a significant overlap in the differentially expressed genes, the affected functions, and ELT-2 target genes. Our analysis further identified a core set of 86 genes that consistently responded to the microbiota members across development and adult life, including several C-type lectin-like genes and genes known to be involved in energy metabolism or fertility. We additionally assessed the consequences of induced gene expression with the help of metabolic network model analysis, using a previously established metabolic network for C. elegans. This analysis complemented the enrichment analyses by revealing an influence of the Ochrobactrum isolates on C. elegans energy metabolism and furthermore metabolism of specific amino acids, fatty acids, and also folate biosynthesis. Our findings highlight the multifaceted impact of naturally colonizing microbiota isolates on C. elegans life history and thereby provide a framework for further analysis of microbiota-mediated host functions.
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Affiliation(s)
- Wentao Yang
- Research Group Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Carola Petersen
- Research Group Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Research Group Comparative Immunobiology, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Barbara Pees
- Research Group Comparative Immunobiology, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Johannes Zimmermann
- Research Group Medical Systems Biology, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Silvio Waschina
- Research Group Medical Systems Biology, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Philipp Dirksen
- Research Group Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Philip Rosenstiel
- Institute for Clinical Molecular Biology, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Andreas Tholey
- Research Group Proteomics, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Matthias Leippe
- Research Group Comparative Immunobiology, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Katja Dierking
- Research Group Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Christoph Kaleta
- Research Group Medical Systems Biology, Institute for Experimental Medicine, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Hinrich Schulenburg
- Research Group Evolutionary Ecology and Genetics, Zoological Institute, Christian-Albrechts-Universität zu Kiel, Kiel, Germany.,Max Planck Institute for Evolutionary Biology, Plön, Germany
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28
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Buis A, Bellemin S, Goudeau J, Monnier L, Loiseau N, Guillou H, Aguilaniu H. Coelomocytes Regulate Starvation-Induced Fat Catabolism and Lifespan Extension through the Lipase LIPL-5 in Caenorhabditis elegans. Cell Rep 2019; 28:1041-1049.e4. [PMID: 31340142 PMCID: PMC6667774 DOI: 10.1016/j.celrep.2019.06.064] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 02/24/2019] [Accepted: 06/17/2019] [Indexed: 12/18/2022] Open
Abstract
Dietary restriction is known to extend the lifespan and reduce fat stores in most species tested to date, but the molecular mechanisms linking these events remain unclear. Here, we found that bacterial deprivation of Caenorhabditis elegans leads to lifespan extension with concomitant mobilization of fat stores. We find that LIPL-5 expression is induced by starvation and that the LIPL-5 lipase is present in coelomocyte cells and regulates fat catabolism and longevity during the bacterial deprivation response. Either LIPL-5 or coelomocyte deficiency prevents the rapid mobilization of intestinal triacylglycerol and enhanced lifespan extension in response to bacterial deprivation, whereas the combination of both defects has no additional or synergistic effect. Thus, the capacity to mobilize fat via LIPL-5 is directly linked to an animal's capacity to withstand long-term nutrient deprivation. Our data establish a role for LIPL-5 and coelomocytes in regulating fat consumption and lifespan extension upon DR.
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Affiliation(s)
- Alexia Buis
- Institut Génomique Fonctionelle de Lyon/UMR5262, 46 Allee d'Italie, 69364 Lyon Cedex 07, France; Ecole Pratique des Hautes Etudes, Les Patios Saint-Jacques, 4-14 Rue Ferrus, 75014 Paris, France
| | - Stéphanie Bellemin
- Institut Génomique Fonctionelle de Lyon/UMR5262, 46 Allee d'Italie, 69364 Lyon Cedex 07, France
| | - Jérôme Goudeau
- Institut Génomique Fonctionelle de Lyon/UMR5262, 46 Allee d'Italie, 69364 Lyon Cedex 07, France
| | - Léa Monnier
- Institut Génomique Fonctionelle de Lyon/UMR5262, 46 Allee d'Italie, 69364 Lyon Cedex 07, France
| | - Nicolas Loiseau
- INRA Toulouse, INRA ToxAlim-Integrative Toxicology & Metabolism-UMR 1331, INRA/INP/UPS, 180 chemin de Tournefeuille-BP 93173, 31027 Toulouse Cedex 3, France
| | - Hervé Guillou
- INRA Toulouse, INRA ToxAlim-Integrative Toxicology & Metabolism-UMR 1331, INRA/INP/UPS, 180 chemin de Tournefeuille-BP 93173, 31027 Toulouse Cedex 3, France
| | - Hugo Aguilaniu
- Institut Génomique Fonctionelle de Lyon/UMR5262, 46 Allee d'Italie, 69364 Lyon Cedex 07, France; Instituto Serrapilheira, Rua Dias Ferreira 78, Leblon, Rio de Janeiro, Brazil; Detaché from CNRS, Paris, France.
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29
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Reciprocal modulation of 5-HT and octopamine regulates pumping via feedforward and feedback circuits in C. elegans. Proc Natl Acad Sci U S A 2019; 116:7107-7112. [PMID: 30872487 PMCID: PMC6452730 DOI: 10.1073/pnas.1819261116] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Physiological regulation and behavior depend less on neurons than on neuronal circuits. Neurosignal integration is the basis of neurocircuit function. The modalities of neuroinformation integration are evolutionarily conserved in animals and humans. Here, we identified two modalities of neurosignal integration in two different circuits by which serotonergic ADFs regulate pharyngeal pumping in Caenorhabditis elegans: disinhibition in a feedforward circuit consisting of ADF, RIC, and SIA neurons and disexcitation, a modality of neurosignal integration suggested by this study, in a feedback circuit consisting of ADF, RIC, AWB, and ADF neurons. Feeding is vital for animal survival and is tightly regulated by the endocrine and nervous systems. To study the mechanisms of humoral regulation of feeding behavior, we investigated serotonin (5-HT) and octopamine (OA) signaling in Caenorhabditis elegans, which uses pharyngeal pumping to ingest bacteria into the gut. We reveal that a cross-modulation mechanism between 5-HT and OA, which convey feeding and fasting signals, respectively, mainly functions in regulating the pumping and secretion of both neuromodulators via ADF/RIC/SIA feedforward neurocircuit (consisting of ADF, RIC, and SIA neurons) and ADF/RIC/AWB/ADF feedback neurocircuit (consisting of ADF, RIC, AWB, and ADF neurons) under conditions of food supply and food deprivation, respectively. Food supply stimulates food-sensing ADFs to release more 5-HT, which augments pumping via inhibiting OA secretion by RIC interneurons and, thus, alleviates pumping suppression by OA-activated SIA interneurons/motoneurons. In contrast, nutrient deprivation stimulates RICs to secrete OA, which suppresses pumping via activating SIAs and maintains basal pumping and 5-HT production activity through excitation of ADFs relayed by AWB sensory neurons. Notably, the feedforward and feedback circuits employ distinct modalities of neurosignal integration, namely, disinhibition and disexcitation, respectively.
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30
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Brial F, Le Lay A, Hedjazi L, Tsang T, Fearnside JF, Otto GW, Alzaid F, Wilder SP, Venteclef N, Cazier JB, Nicholson JK, Day C, Burt AD, Gut IG, Lathrop M, Dumas ME, Gauguier D. Systems Genetics of Hepatic Metabolome Reveals Octopamine as a Target for Non-Alcoholic Fatty Liver Disease Treatment. Sci Rep 2019; 9:3656. [PMID: 30842494 PMCID: PMC6403227 DOI: 10.1038/s41598-019-40153-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 01/17/2019] [Indexed: 12/14/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is often associated with obesity and type 2 diabetes. To disentangle etiological relationships between these conditions and identify genetically-determined metabolites involved in NAFLD processes, we mapped 1H nuclear magnetic resonance (NMR) metabolomic and disease-related phenotypes in a mouse F2 cross derived from strains showing resistance (BALB/c) and increased susceptibility (129S6) to these diseases. Quantitative trait locus (QTL) analysis based on single nucleotide polymorphism (SNP) genotypes identified diet responsive QTLs in F2 mice fed control or high fat diet (HFD). In HFD fed F2 mice we mapped on chromosome 18 a QTL regulating liver micro- and macrovesicular steatosis and inflammation, independently from glucose intolerance and adiposity, which was linked to chromosome 4. Linkage analysis of liver metabolomic profiling data identified a QTL for octopamine, which co-localised with the QTL for liver histopathology in the cross. Functional relationship between these two QTLs was validated in vivo in mice chronically treated with octopamine, which exhibited reduction in liver histopathology and metabolic benefits, underlining its role as a mechanistic biomarker of fatty liver with potential therapeutic applications.
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Affiliation(s)
- Francois Brial
- Sorbonne University, University Paris Descartes, University Paris Diderot, INSERM UMR_S 1138, Cordeliers Research Centre, 75006, Paris, France
| | - Aurélie Le Lay
- Sorbonne University, University Paris Descartes, University Paris Diderot, INSERM UMR_S 1138, Cordeliers Research Centre, 75006, Paris, France
| | - Lyamine Hedjazi
- Sorbonne University, University Paris Descartes, University Paris Diderot, INSERM UMR_S 1138, Cordeliers Research Centre, 75006, Paris, France
| | - Tsz Tsang
- Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Jane F Fearnside
- School of Health and Related Research, The University of Sheffield, 30 Regent Court, Sheffield, S10 2TA, United Kingdom
| | - Georg W Otto
- Genetics and Genomic Medicine, University College London Institute of Child Health, 30 Guilford Street, London, WC1N 1EH, United Kingdom
| | - Fawaz Alzaid
- Sorbonne University, University Paris Descartes, University Paris Diderot, INSERM UMR_S 1138, Cordeliers Research Centre, 75006, Paris, France
| | - Steven P Wilder
- The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, Oxfordshire, OX3 7BN, United Kingdom
- Genomics Plc, King Charles House, Oxford, Park End Street, OX1 1JD, United Kingdom
| | - Nicolas Venteclef
- Sorbonne University, University Paris Descartes, University Paris Diderot, INSERM UMR_S 1138, Cordeliers Research Centre, 75006, Paris, France
| | - Jean-Baptiste Cazier
- Centre for Computational Biology, Medical School, University of Birmingham, Birmingham, B15 2TT, United Kingdom
| | - Jeremy K Nicholson
- Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, SW7 2AZ, United Kingdom
- The Australian National Phenome Centre, Murdoch University, Perth, WA6150, Australia
| | - Chris Day
- Faculty of Medical Sciences, Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Alastair D Burt
- Faculty of Medical Sciences, Medical School, Framlington Place, Newcastle upon Tyne, NE2 4HH, United Kingdom
- Faculty of Health and Medical Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Ivo G Gut
- CNAG-CRG, Centre for Genomic Regulation, Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 4, 08028, Barcelona, Spain
| | - Mark Lathrop
- McGill University and Genome Quebec Innovation Centre, 740 Doctor Penfield Avenue, Montreal, QC, H3A 0G1, Canada
| | - Marc-Emmanuel Dumas
- Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, SW7 2AZ, United Kingdom
- McGill University and Genome Quebec Innovation Centre, 740 Doctor Penfield Avenue, Montreal, QC, H3A 0G1, Canada
| | - Dominique Gauguier
- Sorbonne University, University Paris Descartes, University Paris Diderot, INSERM UMR_S 1138, Cordeliers Research Centre, 75006, Paris, France.
- Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, SW7 2AZ, United Kingdom.
- The Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, Oxfordshire, OX3 7BN, United Kingdom.
- McGill University and Genome Quebec Innovation Centre, 740 Doctor Penfield Avenue, Montreal, QC, H3A 0G1, Canada.
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31
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Feeding state sculpts a circuit for sensory valence in Caenorhabditis elegans. Proc Natl Acad Sci U S A 2019; 116:1776-1781. [PMID: 30651312 DOI: 10.1073/pnas.1807454116] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Hunger affects the behavioral choices of all animals, and many chemosensory stimuli can be either attractive or repulsive depending on an animal's hunger state. Although hunger-induced behavioral changes are well documented, the molecular and cellular mechanisms by which hunger modulates neural circuit function to generate changes in chemosensory valence are poorly understood. Here, we use the CO2 response of the free-living nematode Caenorhabditis elegans to elucidate how hunger alters valence. We show that CO2 response valence shifts from aversion to attraction during starvation, a change that is mediated by two pairs of interneurons in the CO2 circuit, AIY and RIG. The transition from aversion to attraction is regulated by biogenic amine signaling. Dopamine promotes CO2 repulsion in well-fed animals, whereas octopamine promotes CO2 attraction in starved animals. Biogenic amines also regulate the temporal dynamics of the shift from aversion to attraction such that animals lacking octopamine show a delayed shift to attraction. Biogenic amine signaling regulates CO2 response valence by modulating the CO2-evoked activity of AIY and RIG. Our results illuminate a new role for biogenic amine signaling in regulating chemosensory valence as a function of hunger state.
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32
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Perez-Gomez A, Carretero M, Weber N, Peterka V, To A, Titova V, Solis G, Osborn O, Petrascheck M. A phenotypic Caenorhabditis elegans screen identifies a selective suppressor of antipsychotic-induced hyperphagia. Nat Commun 2018; 9:5272. [PMID: 30532051 PMCID: PMC6288085 DOI: 10.1038/s41467-018-07684-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 11/12/2018] [Indexed: 12/30/2022] Open
Abstract
Antipsychotic (AP) drugs are used to treat psychiatric disorders but are associated with significant weight gain and metabolic disease. Increased food intake (hyperphagia) appears to be a driving force by which APs induce weight gain but the mechanisms are poorly understood. Here we report that administration of APs to C. elegans induces hyperphagia by a mechanism that is genetically distinct from basal food intake. We exploit this finding to screen for adjuvant drugs that suppress AP-induced hyperphagia in C. elegans and mice. In mice AP-induced hyperphagia is associated with a unique hypothalamic gene expression signature that is abrogated by adjuvant drug treatment. Genetic analysis of this signature using C. elegans identifies two transcription factors, nhr-25/Nr5a2 and nfyb-1/NFYB to be required for AP-induced hyperphagia. Our study reveals that AP-induced hyperphagia can be selectively suppressed without affecting basal food intake allowing for novel drug discovery strategies to combat AP-induced metabolic side effects.
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Affiliation(s)
- Anabel Perez-Gomez
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Maria Carretero
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Natalie Weber
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Veronika Peterka
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Alan To
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Viktoriya Titova
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Gregory Solis
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Olivia Osborn
- Department of Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093, USA.
| | - Michael Petrascheck
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA.
- Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA.
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Abstract
Insufficient or excessive immune responses to pathogen infection are major causes of disease. Increasing evidence indicates that the nervous system regulates the immune system to help maintain immunological homeostasis. However, the precise mechanisms of this regulation are largely unknown. Here we show the existence of an octopaminergic immunoinhibitory pathway in Caenorhabditis elegans. Our study results indicate that this pathway is tonically active under normal conditions to maintain immunological homeostasis or suppress unwanted innate immune responses but downregulated upon pathogen infection to allow enhanced innate immunity. As excessive innate immune responses have been linked to human health conditions such as Crohn's disease, rheumatoid arthritis, atherosclerosis, diabetes, and Alzheimer's disease, elucidating octopaminergic neural regulation of innate immunity could be helpful in the development of new treatments for innate immune diseases. Upon pathogen infection, the nervous system regulates innate immunity to confer coordinated protection to the host. However, the precise mechanisms of such regulation remain unclear. Previous studies have demonstrated that OCTR-1, a putative G protein-coupled receptor for catecholamine, functions in the sensory neurons designated “ASH” to suppress innate immune responses in Caenorhabditis elegans. It is unknown what molecules act as OCTR-1 ligands in the neural immune regulatory circuit. Here we identify neurotransmitter octopamine (OA) as an endogenous ligand for OCTR-1 in immune regulation and show that the OA-producing RIC neurons function in the OCTR-1 neural circuit to suppress innate immunity. RIC neurons are deactivated in the presence of pathogens but transiently activated by nonpathogenic bacteria. Our data support a model whereby an octopaminergic immunoinhibitory pathway is tonically active under normal conditions to maintain immunological homeostasis or suppress unwanted innate immune responses but downregulated upon pathogen infection to allow enhanced innate immunity. As excessive innate immune responses have been linked to a myriad of human health concerns, our study could potentially benefit the development of more-effective treatments for innate immune disorders.
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34
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Bayer EA, Hobert O. Past experience shapes sexually dimorphic neuronal wiring through monoaminergic signalling. Nature 2018; 561:117-121. [PMID: 30150774 PMCID: PMC6126987 DOI: 10.1038/s41586-018-0452-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 07/10/2018] [Indexed: 02/02/2023]
Abstract
Differences between female and male brains exist across the animal kingdom and extend from molecular to anatomical features. Here we show that sexually dimorphic anatomy, gene expression and function in the nervous system can be modulated by past experiences. In the nematode Caenorhabditis elegans, sexual differentiation entails the sex-specific pruning of synaptic connections between neurons that are shared by both sexes, giving rise to sexually dimorphic circuits in adult animals1. We discovered that starvation during juvenile stages is memorized in males to suppress the emergence of sexually dimorphic synaptic connectivity. These circuit changes result in increased chemosensory responsiveness in adult males following juvenile starvation. We find that an octopamine-mediated starvation signal dampens the production of serotonin (5-HT) to convey the memory of starvation. Serotonin production is monitored by a 5-HT1A serotonin receptor homologue that acts cell-autonomously to promote the pruning of sexually dimorphic synaptic connectivity under well-fed conditions. Our studies demonstrate how life history shapes neurotransmitter production, synaptic connectivity and behavioural output in a sexually dimorphic circuit.
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Affiliation(s)
- Emily A Bayer
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, NY, USA
| | - Oliver Hobert
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, NY, USA.
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35
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Zhu X, Liu Y, Zhang H, Liu P. Whole-genome RNAi screen identifies methylation-related genes influencing lipid metabolism in Caenorhabditis elegans. J Genet Genomics 2018; 45:259-272. [PMID: 29858166 DOI: 10.1016/j.jgg.2018.03.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 03/09/2018] [Accepted: 03/15/2018] [Indexed: 12/13/2022]
Abstract
Lipid droplets (LDs) are highly conserved multifunctional cellular organelles and aberrant lipid storage in LDs can lead to many metabolic diseases. However, the molecular mechanisms governing lipid dynamic changes remain elusive, and the high-throughput screen of genes influencing LD morphology was limited by lacking specific LD marker proteins in the powerful genetic tool Caenorhabditis elegans. In this study, we established a new method to conduct whole-genome RNAi screen using LD resident protein DHS-3 as a LD marker, and identified 78 genes involved in significant LD morphologic changes. Among them, mthf-1, as well as a series of methylation-related genes, was found dramatically influencing lipid metabolism. SREBP-1 and SCD1 homologs in C. elegans were involved in the lipid metabolic change of mthf-1(RNAi) worms, and the regulation of ATGL-1 also contributed to it by decreasing triacylglycerol (TAG) hydrolysis. Overall, this study not only identified important genes involved in LD dynamics, but also provided a new tool for LD study using C. elegans, with implications for the study of lipid metabolic diseases.
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Affiliation(s)
- Xiaotong Zhu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yangli Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pingsheng Liu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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36
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Clark T, Hapiak V, Oakes M, Mills H, Komuniecki R. Monoamines differentially modulate neuropeptide release from distinct sites within a single neuron pair. PLoS One 2018; 13:e0196954. [PMID: 29723289 PMCID: PMC5933757 DOI: 10.1371/journal.pone.0196954] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 04/23/2018] [Indexed: 12/14/2022] Open
Abstract
Monoamines and neuropeptides often modulate the same behavior, but monoaminergic-peptidergic crosstalk remains poorly understood. In Caenorhabditis elegans, the adrenergic-like ligands, tyramine (TA) and octopamine (OA) require distinct subsets of neuropeptides in the two ASI sensory neurons to inhibit nociception. TA selectively increases the release of ASI neuropeptides encoded by nlp-14 or nlp-18 from either synaptic/perisynaptic regions of ASI axons or the ASI soma, respectively, and OA selectively increases the release of ASI neuropeptides encoded by nlp-9 asymmetrically, from only the synaptic/perisynaptic region of the right ASI axon. The predicted amino acid preprosequences of genes encoding either TA- or OA-dependent neuropeptides differed markedly. However, these distinct preprosequences were not sufficient to confer monoamine-specificity and additional N-terminal peptide-encoding sequence was required. Collectively, our results demonstrate that TA and OA specifically and differentially modulate the release of distinct subsets of neuropeptides from different subcellular sites within the ASIs, highlighting the complexity of monoaminergic/peptidergic modulation, even in animals with a relatively simple nervous system.
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Affiliation(s)
- Tobias Clark
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Vera Hapiak
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Mitchell Oakes
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Holly Mills
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, United States of America
| | - Richard Komuniecki
- Department of Biological Sciences, University of Toledo, Toledo, Ohio, United States of America
- * E-mail:
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37
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Hussey R, Littlejohn NK, Witham E, Vanstrum E, Mesgarzadeh J, Ratanpal H, Srinivasan S. Oxygen-sensing neurons reciprocally regulate peripheral lipid metabolism via neuropeptide signaling in Caenorhabditis elegans. PLoS Genet 2018; 14:e1007305. [PMID: 29579048 PMCID: PMC5886693 DOI: 10.1371/journal.pgen.1007305] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 04/05/2018] [Accepted: 03/11/2018] [Indexed: 01/14/2023] Open
Abstract
The mechanisms by which the sensory environment influences metabolic homeostasis remains poorly understood. In this report, we show that oxygen, a potent environmental signal, is an important regulator of whole body lipid metabolism. C. elegans oxygen-sensing neurons reciprocally regulate peripheral lipid metabolism under normoxia in the following way: under high oxygen and food absence, URX sensory neurons are activated, and stimulate fat loss in the intestine, the major metabolic organ for C. elegans. Under lower oxygen conditions or when food is present, the BAG sensory neurons respond by repressing the resting properties of the URX neurons. A genetic screen to identify modulators of this effect led to the identification of a BAG-neuron-specific neuropeptide called FLP-17, whose cognate receptor EGL-6 functions in URX neurons. Thus, BAG sensory neurons counterbalance the metabolic effect of tonically active URX neurons via neuropeptide communication. The combined regulatory actions of these neurons serve to precisely tune the rate and extent of fat loss to the availability of food and oxygen, and provides an interesting example of the myriad mechanisms underlying homeostatic control.
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Affiliation(s)
- Rosalind Hussey
- Department of Molecular Medicine and Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, United States of America
| | - Nicole K. Littlejohn
- Department of Molecular Medicine and Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, United States of America
| | - Emily Witham
- Department of Molecular Medicine and Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, United States of America
| | - Erik Vanstrum
- Department of Molecular Medicine and Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, United States of America
| | - Jaleh Mesgarzadeh
- Department of Molecular Medicine and Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, United States of America
- Department of Biology, University of California, San Diego, La Jolla, CA, United States of America
| | - Harkaranveer Ratanpal
- Department of Molecular Medicine and Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, United States of America
| | - Supriya Srinivasan
- Department of Molecular Medicine and Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, United States of America
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38
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Navarro-Herrera D, Aranaz P, Eder-Azanza L, Zabala M, Hurtado C, Romo-Hualde A, Martínez JA, González-Navarro CJ, Vizmanos JL. Dihomo-gamma-linolenic acid induces fat loss in C. elegans in an omega-3-independent manner by promoting peroxisomal fatty acid β-oxidation. Food Funct 2018; 9:1621-1637. [PMID: 29465730 DOI: 10.1039/c7fo01625e] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Bioactive compounds, including some fatty acids (FAs), can induce beneficial effects on body fat-content and metabolism. In this work, we have used C. elegans as a model to examine the effects of several FAs on body fat accumulation. Both omega-3 and omega-6 fatty acids induced a reduction of fat content in C. elegans, with linoleic, gamma-linolenic and dihomo-gamma-linolenic acids being the most effective ones. These three FAs are sequential metabolites especially in omega-6 PUFA synthesis pathway and the effects seem to be primarily due to dihomo-gamma-linolenic acid, and independent of its transformation into omega-3 or arachidonic acid. Gene expression analyses suggest that peroxisomal beta oxidation is the main mechanism involved in the observed effect. These results point out the importance of further analysis of the activity of these omega-6 FAs, due to their potential application in obesity and related diseases.
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Affiliation(s)
- David Navarro-Herrera
- University of Navarra, School of Science, Department of Biochemistry and Genetics, Pamplona, Spain. and University of Navarra, School of Pharmacy & Nutrition, Centre for Nutrition Research, Pamplona, Spain.
| | - Paula Aranaz
- University of Navarra, School of Pharmacy & Nutrition, Centre for Nutrition Research, Pamplona, Spain.
| | - Laura Eder-Azanza
- University of Navarra, School of Science, Department of Biochemistry and Genetics, Pamplona, Spain. and Navarra Institute for Health Research (IdiSNA), Pamplona, Spain
| | - María Zabala
- University of Navarra, School of Pharmacy & Nutrition, Centre for Nutrition Research, Pamplona, Spain.
| | - Cristina Hurtado
- University of Navarra, School of Science, Department of Biochemistry and Genetics, Pamplona, Spain. and Navarra Institute for Health Research (IdiSNA), Pamplona, Spain
| | - Ana Romo-Hualde
- University of Navarra, School of Pharmacy & Nutrition, Centre for Nutrition Research, Pamplona, Spain.
| | - J Alfredo Martínez
- University of Navarra, School of Pharmacy & Nutrition, Centre for Nutrition Research, Pamplona, Spain. and Navarra Institute for Health Research (IdiSNA), Pamplona, Spain and Spanish Biomedical Research Center in Physiopathology of Obesity and Nutrition (CIBERobn), Madrid, Spain
| | - Carlos J González-Navarro
- University of Navarra, School of Pharmacy & Nutrition, Centre for Nutrition Research, Pamplona, Spain.
| | - José L Vizmanos
- University of Navarra, School of Science, Department of Biochemistry and Genetics, Pamplona, Spain. and Navarra Institute for Health Research (IdiSNA), Pamplona, Spain
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Watts JL, Ristow M. Lipid and Carbohydrate Metabolism in Caenorhabditis elegans. Genetics 2017; 207:413-446. [PMID: 28978773 PMCID: PMC5629314 DOI: 10.1534/genetics.117.300106] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 08/02/2017] [Indexed: 12/14/2022] Open
Abstract
Lipid and carbohydrate metabolism are highly conserved processes that affect nearly all aspects of organismal biology. Caenorhabditis elegans eat bacteria, which consist of lipids, carbohydrates, and proteins that are broken down during digestion into fatty acids, simple sugars, and amino acid precursors. With these nutrients, C. elegans synthesizes a wide range of metabolites that are required for development and behavior. In this review, we outline lipid and carbohydrate structures as well as biosynthesis and breakdown pathways that have been characterized in C. elegans We bring attention to functional studies using mutant strains that reveal physiological roles for specific lipids and carbohydrates during development, aging, and adaptation to changing environmental conditions.
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Affiliation(s)
- Jennifer L Watts
- School of Molecular Biosciences and Center for Reproductive Biology, Washington State University, Pullman, Washington 99164
| | - Michael Ristow
- Energy Metabolism Laboratory, Institute of Translational Medicine, Department of Health Sciences and Technology, Swiss Federal Institute of Technology Zurich, 8603 Schwerzenbach-Zurich, Switzerland
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40
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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: 39] [Impact Index Per Article: 5.6] [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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41
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Hussey R, Stieglitz J, Mesgarzadeh J, Locke TT, Zhang YK, Schroeder FC, Srinivasan S. Pheromone-sensing neurons regulate peripheral lipid metabolism in Caenorhabditis elegans. PLoS Genet 2017; 13:e1006806. [PMID: 28545126 PMCID: PMC5456406 DOI: 10.1371/journal.pgen.1006806] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 06/02/2017] [Accepted: 05/05/2017] [Indexed: 12/03/2022] Open
Abstract
It is now established that the central nervous system plays an important role in regulating whole body metabolism and energy balance. However, the extent to which sensory systems relay environmental information to modulate metabolic events in peripheral tissues has remained poorly understood. In addition, it has been challenging to map the molecular mechanisms underlying discrete sensory modalities with respect to their role in lipid metabolism. In previous work our lab has identified instructive roles for serotonin signaling as a surrogate for food availability, as well as oxygen sensing, in the control of whole body metabolism. In this study, we now identify a role for a pair of pheromone-sensing neurons in regulating fat metabolism in C. elegans, which has emerged as a tractable and highly informative model to study the neurobiology of metabolism. A genetic screen revealed that GPA-3, a member of the Gα family of G proteins, regulates body fat content in the intestine, the major metabolic organ for C. elegans. Genetic and reconstitution studies revealed that the potent body fat phenotype of gpa-3 null mutants is controlled from a pair of neurons called ADL(L/R). We show that cAMP functions as the second messenger in the ADL neurons, and regulates body fat stores via the neurotransmitter acetylcholine, from downstream neurons. We find that the pheromone ascr#3, which is detected by the ADL neurons, regulates body fat stores in a GPA-3-dependent manner. We define here a third sensory modality, pheromone sensing, as a major regulator of body fat metabolism. The pheromone ascr#3 is an indicator of population density, thus we hypothesize that pheromone sensing provides a salient 'denominator' to evaluate the amount of food available within a population and to accordingly adjust metabolic rate and body fat levels. The central nervous system plays a vital role in regulating whole body metabolism and energy balance. However, the precise cellular, genetic and molecular mechanisms underlying these effects remain a major unsolved mystery. C. elegans has emerged as a tractable and highly informative model to study the neurobiology of metabolism. Previously, we have identified instructive roles for serotonin signaling as a surrogate for food availability, as well as oxygen sensing, in the control of whole body metabolism. In our current study we have identified a role for a pair of pheromone-sensing neurons in regulating fat metabolism in C. elegans. cAMP acts as a second messenger in these neurons, and regulates body fat stores via acetylcholine signaling in the nervous system. We find that the population-density-sensing pheromone detected by these neurons regulates body fat stores. Together, we define a third sensory modality, population density sensing, as a major regulator of body fat metabolism.
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Affiliation(s)
- Rosalind Hussey
- Department of Molecular Medicine and Department of Neuroscience, The Scripps Research Institute, La Jolla, California, United States of America
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, United States of America
| | - Jon Stieglitz
- Kellogg School of Science and Technology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Jaleh Mesgarzadeh
- Department of Molecular Medicine and Department of Neuroscience, The Scripps Research Institute, La Jolla, California, United States of America
- Department of Biology, University of California, San Diego, La Jolla, California, United States of America
| | - Tiffany T. Locke
- Department of Biology, University of California, San Diego, La Jolla, California, United States of America
| | - Ying K. Zhang
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, United States of America
| | - Frank C. Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York, United States of America
| | - Supriya Srinivasan
- Department of Molecular Medicine and Department of Neuroscience, The Scripps Research Institute, La Jolla, California, United States of America
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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42
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Handley A, Pocock R. Transcriptional control of satiety in Caenorhabditis elegans. Commun Integr Biol 2017. [PMCID: PMC5501193 DOI: 10.1080/19420889.2017.1325978] [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: 11/16/2022] Open
Abstract
Obesity is an enormous worldwide health concern. Chronic illnesses associated with obesity include type-2 diabetes, hypertension, atherosclerosis and certain cancers. Communication between fat storage organs and the brain is essential for regulating feeding, metabolism and organismal activity—and hence obesity control. Model organism research provides opportunities to decipher conserved molecular mechanisms that regulate fat storage and activity levels, which is fundamental to understanding this disorder. We recently identified a transcription factor (ETS-5) that acts in specific neurons of the nematode Caenorhabditis elegans to control intestinal fat levels. Furthermore, we discovered a feedback mechanism where intestinal fat controls feeding and motor programs, similar to humans, where a sated stomach can inhibit feeding and induce lethargy. The precise molecular signals and neuronal circuitry underpinning brain-intestinal communication in C. elegans are however yet to be discovered. As most animals store surplus energy as fat, communication mechanisms that relay external information regarding food availability and quality, and internal energy reserves are likely conserved. Therefore, our identification of a neuronally-expressed transcriptional regulator that controls intestinal fat levels opens up new avenues of investigation for the control of metabolic disease and obesity.
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Affiliation(s)
- Ava Handley
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
| | - Roger Pocock
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute and Department of Anatomy and Developmental Biology, Monash University, Melbourne, Victoria, Australia
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An Aversive Response to Osmotic Upshift in Caenorhabditis elegans. eNeuro 2017; 4:eN-NWR-0282-16. [PMID: 28451641 PMCID: PMC5399755 DOI: 10.1523/eneuro.0282-16.2017] [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: 09/16/2016] [Revised: 03/16/2017] [Accepted: 03/20/2017] [Indexed: 12/12/2022] Open
Abstract
Environmental osmolarity presents a common type of sensory stimulus to animals. While behavioral responses to osmotic changes are important for maintaining a stable intracellular osmolarity, the underlying mechanisms are not fully understood. In the natural habitat of Caenorhabditis elegans, changes in environmental osmolarity are commonplace. It is known that the nematode acutely avoids shocks of extremely high osmolarity. Here, we show that C. elegans also generates gradually increased aversion of mild upshifts in environmental osmolarity. Different from an acute avoidance of osmotic shocks that depends on the function of a transient receptor potential vanilloid channel, the slow aversion to osmotic upshifts requires the cGMP-gated sensory channel subunit TAX-2. TAX-2 acts in several sensory neurons that are exposed to body fluid to generate the aversive response through a motor network that underlies navigation. Osmotic upshifts activate the body cavity sensory neuron URX, which is known to induce aversion upon activation. Together, our results characterize the molecular and cellular mechanisms underlying a novel sensorimotor response to osmotic stimuli and reveal that C. elegans engages different behaviors and the underlying mechanisms to regulate responses to extracellular osmolarity.
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44
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Wang Z, Schaffer NE, Kliewer SA, Mangelsdorf DJ. Nuclear receptors: emerging drug targets for parasitic diseases. J Clin Invest 2017; 127:1165-1171. [PMID: 28165341 PMCID: PMC5373876 DOI: 10.1172/jci88890] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Parasitic worms infect billions of people worldwide. Current treatments rely on a small group of drugs that have been used for decades. A shortcoming of these drugs is their inability to target the intractable infectious stage of the parasite. As well-known therapeutic targets in mammals, nuclear receptors have begun to be studied in parasitic worms, where they are widely distributed and play key roles in governing metabolic and developmental transcriptional networks. One such nuclear receptor is DAF-12, which is required for normal nematode development, including the all-important infectious stage. Here we review the emerging literature that implicates DAF-12 and potentially other nuclear receptors as novel anthelmintic targets.
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Affiliation(s)
| | | | | | - David J. Mangelsdorf
- Department of Pharmacology
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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45
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The ETS-5 transcription factor regulates activity states in Caenorhabditis elegans by controlling satiety. Proc Natl Acad Sci U S A 2017; 114:E1651-E1658. [PMID: 28193866 DOI: 10.1073/pnas.1610673114] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Animal behavior is shaped through interplay among genes, the environment, and previous experience. As in mammals, satiety signals induce quiescence in Caenorhabditis elegans Here we report that the C. elegans transcription factor ETS-5, an ortholog of mammalian FEV/Pet1, controls satiety-induced quiescence. Nutritional status has a major influence on C. elegans behavior. When foraging, food availability controls behavioral state switching between active (roaming) and sedentary (dwelling) states; however, when provided with high-quality food, C. elegans become sated and enter quiescence. We show that ETS-5 acts to promote roaming and inhibit quiescence by setting the internal "satiety quotient" through fat regulation. Acting from the ASG and BAG sensory neurons, we show that ETS-5 functions in a complex network with serotonergic and neuropeptide signaling pathways to control food-regulated behavioral state switching. Taken together, our results identify a neuronal mechanism for controlling intestinal fat stores and organismal behavioral states in C. elegans, and establish a paradigm for the elucidation of obesity-relevant mechanisms.
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46
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Palamiuc L, Noble T, Witham E, Ratanpal H, Vaughan M, Srinivasan S. A tachykinin-like neuroendocrine signalling axis couples central serotonin action and nutrient sensing with peripheral lipid metabolism. Nat Commun 2017; 8:14237. [PMID: 28128367 PMCID: PMC5290170 DOI: 10.1038/ncomms14237] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 12/09/2016] [Indexed: 01/13/2023] Open
Abstract
Serotonin, a central neuromodulator with ancient ties to feeding and metabolism, is a major driver of body fat loss. However, mechanisms by which central serotonin action leads to fat loss remain unknown. Here, we report that the FLP-7 neuropeptide and its cognate receptor, NPR-22, function as the ligand-receptor pair that defines the neuroendocrine axis of serotonergic body fat loss in Caenorhabditis elegans. FLP-7 is secreted as a neuroendocrine peptide in proportion to fluctuations in neural serotonin circuit functions, and its release is regulated from secretory neurons via the nutrient sensor AMPK. FLP-7 acts via the NPR-22/Tachykinin2 receptor in the intestine and drives fat loss via the adipocyte triglyceride lipase ATGL-1. Importantly, this ligand-receptor pair does not alter other serotonin-dependent behaviours including food intake. For global modulators such as serotonin, the use of distinct neuroendocrine peptides for each output may be one means to achieve phenotypic selectivity.
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Affiliation(s)
- Lavinia Palamiuc
- Department of Chemical Physiology and The Dorris Neuroscience Center, 1 Barnard Drive, Oceanside, California 92056, USA
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, USA
| | - Tallie Noble
- Mira Costa College, 1 Barnard Drive, Oceanside, California 92056, USA
| | - Emily Witham
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, USA
| | - Harkaranveer Ratanpal
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, USA
| | - Megan Vaughan
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, USA
- Kellogg School of Science and Technology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, USA
| | - Supriya Srinivasan
- Department of Chemical Physiology and The Dorris Neuroscience Center, 1 Barnard Drive, Oceanside, California 92056, USA
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, USA
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47
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Chun H, Sharma AK, Lee J, Chan J, Jia S, Kim BE. The Intestinal Copper Exporter CUA-1 Is Required for Systemic Copper Homeostasis in Caenorhabditis elegans. J Biol Chem 2016; 292:1-14. [PMID: 27881675 DOI: 10.1074/jbc.m116.760876] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/15/2016] [Indexed: 12/23/2022] Open
Abstract
Copper plays key catalytic and regulatory roles in biochemical processes essential for normal growth, development, and health. Defects in copper metabolism cause Menkes and Wilson's disease, myeloneuropathy, and cardiovascular disease and are associated with other pathophysiological states. Consequently, it is critical to understand the mechanisms by which organisms control the acquisition, distribution, and utilization of copper. The intestinal enterocyte is a key regulatory point for copper absorption into the body; however, the mechanisms by which intestinal cells transport copper to maintain organismal copper homeostasis are poorly understood. Here, we identify a mechanism by which organismal copper homeostasis is maintained by intestinal copper exporter trafficking that is coordinated with extraintestinal copper levels in Caenorhabditis elegans Specifically, we show that CUA-1, the C. elegans homolog of ATP7A/B, localizes to lysosome-like organelles (gut granules) in the intestine under copper overload conditions for copper detoxification, whereas copper deficiency results in a redistribution of CUA-1 to basolateral membranes for copper efflux to peripheral tissues. Worms defective in gut granule biogenesis exhibit defects in copper sequestration and increased susceptibility to toxic copper levels. Interestingly, however, a splice isoform CUA-1.2 that lacks a portion of the N-terminal domain is targeted constitutively to the basolateral membrane irrespective of dietary copper concentration. Our studies establish that CUA-1 is a key intestinal copper exporter and that its trafficking is regulated to maintain systemic copper homeostasis. C. elegans could therefore be exploited as a whole-animal model system to study regulation of intra- and intercellular copper trafficking pathways.
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Affiliation(s)
- Haarin Chun
- From the Department of Animal and Avian Sciences
| | | | - Jaekwon Lee
- the Redox Biology Center, Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588, and
| | - Jefferson Chan
- the Department of Chemistry, University of California at Berkeley, Berkeley, California 94720
| | - Shang Jia
- the Department of Chemistry, University of California at Berkeley, Berkeley, California 94720
| | - Byung-Eun Kim
- From the Department of Animal and Avian Sciences, .,Biological Sciences Graduate Program, University of Maryland, College Park, Maryland 20742
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48
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Berendzen KM, Durieux J, Shao LW, Tian Y, Kim HE, Wolff S, Liu Y, Dillin A. Neuroendocrine Coordination of Mitochondrial Stress Signaling and Proteostasis. Cell 2016; 166:1553-1563.e10. [PMID: 27610575 DOI: 10.1016/j.cell.2016.08.042] [Citation(s) in RCA: 158] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 04/17/2016] [Accepted: 08/17/2016] [Indexed: 01/01/2023]
Abstract
During neurodegenerative disease, the toxic accumulation of aggregates and misfolded proteins is often accompanied with widespread changes in peripheral metabolism, even in cells in which the aggregating protein is not present. The mechanism by which the central nervous system elicits a distal reaction to proteotoxic stress remains unknown. We hypothesized that the endocrine communication of neuronal stress plays a causative role in the changes in mitochondrial homeostasis associated with proteotoxic disease states. We find that an aggregation-prone protein expressed in the neurons of C. elegans binds to mitochondria, eliciting a global induction of a mitochondrial-specific unfolded protein response (UPR(mt)), affecting whole-animal physiology. Importantly, dense core vesicle release and secretion of the neurotransmitter serotonin is required for the signal's propagation. Collectively, these data suggest the commandeering of a nutrient sensing network to allow for cell-to-cell communication between mitochondria in response to protein folding stress in the nervous system.
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Affiliation(s)
- Kristen M Berendzen
- The Glenn Center for Aging Research, Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Jenni Durieux
- The Glenn Center for Aging Research, Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Li-Wa Shao
- Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Ye Tian
- The Glenn Center for Aging Research, Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Hyun-Eui Kim
- The Glenn Center for Aging Research, Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Suzanne Wolff
- The Glenn Center for Aging Research, Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Ying Liu
- Institute of Molecular Medicine, Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Andrew Dillin
- The Glenn Center for Aging Research, Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
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49
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Lee K, Goh GYS, Wong MA, Klassen TL, Taubert S. Gain-of-Function Alleles in Caenorhabditis elegans Nuclear Hormone Receptor nhr-49 Are Functionally Distinct. PLoS One 2016; 11:e0162708. [PMID: 27618178 PMCID: PMC5019492 DOI: 10.1371/journal.pone.0162708] [Citation(s) in RCA: 21] [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: 06/30/2016] [Accepted: 08/27/2016] [Indexed: 02/07/2023] Open
Abstract
Nuclear hormone receptors (NHRs) are transcription factors that regulate numerous physiological and developmental processes and represent important drug targets. NHR-49, an ortholog of Hepatocyte Nuclear Factor 4 (HNF4), has emerged as a key regulator of lipid metabolism and life span in the nematode worm Caenorhabditis elegans. However, many aspects of NHR-49 function remain poorly understood, including whether and how it regulates individual sets of target genes and whether its activity is modulated by a ligand. A recent study identified three gain-of-function (gof) missense mutations in nhr-49 (nhr-49(et7), nhr-49(et8), and nhr-49(et13), respectively). These substitutions all affect the ligand-binding domain (LBD), which is critical for ligand binding and protein interactions. Thus, these alleles provide an opportunity to test how three specific residues contribute to NHR-49 dependent gene regulation. We used computational and molecular methods to delineate how these mutations alter NHR-49 activity. We find that despite originating from a screen favoring the activation of specific NHR-49 targets, all three gof alleles cause broad upregulation of NHR-49 regulated genes. Interestingly, nhr-49(et7) and nhr-49(et8) exclusively affect nhr-49 dependent activation, whereas the nhr-49(et13) surprisingly affects both nhr-49 mediated activation and repression, implicating the affected residue as dually important. We also observed phenotypic non-equivalence of these alleles, as they unexpectedly caused a long, short, and normal life span, respectively. Mechanistically, the gof substitutions altered neither protein interactions with the repressive partner NHR-66 and the coactivator MDT-15 nor the subcellular localization or expression of NHR-49. However, in silico structural modeling revealed that NHR-49 likely interacts with small molecule ligands and that the missense mutations might alter ligand binding, providing a possible explanation for increased NHR-49 activity. In sum, our findings indicate that the three nhr-49 gof alleles are non-equivalent, and highlight the conserved V411 residue affected by et13 as critical for gene activation and repression alike.
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Affiliation(s)
- Kayoung Lee
- Graduate Program in Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- Centre for Molecular Medicine and Therapeutics and Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Grace Ying Shyen Goh
- Centre for Molecular Medicine and Therapeutics and Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
- Graduate Program in Cell and Developmental Biology, University of British Columbia, Vancouver, BC, Canada
| | - Marcus Andrew Wong
- Centre for Molecular Medicine and Therapeutics and Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
| | - Tara Leah Klassen
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada
| | - Stefan Taubert
- Graduate Program in Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- Centre for Molecular Medicine and Therapeutics and Child & Family Research Institute, University of British Columbia, Vancouver, BC, Canada
- Graduate Program in Cell and Developmental Biology, University of British Columbia, Vancouver, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
- * E-mail:
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50
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Auerbach S, Filer D, Reif D, Walker V, Holloway AC, Schlezinger J, Srinivasan S, Svoboda D, Judson R, Bucher JR, Thayer KA. Prioritizing Environmental Chemicals for Obesity and Diabetes Outcomes Research: A Screening Approach Using ToxCast™ High-Throughput Data. ENVIRONMENTAL HEALTH PERSPECTIVES 2016; 124:1141-54. [PMID: 26978842 PMCID: PMC4977057 DOI: 10.1289/ehp.1510456] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 10/09/2015] [Accepted: 02/08/2016] [Indexed: 05/23/2023]
Abstract
BACKGROUND Diabetes and obesity are major threats to public health in the United States and abroad. Understanding the role that chemicals in our environment play in the development of these conditions is an emerging issue in environmental health, although identifying and prioritizing chemicals for testing beyond those already implicated in the literature is challenging. This review is intended to help researchers generate hypotheses about chemicals that may contribute to diabetes and to obesity-related health outcomes by summarizing relevant findings from the U.S. Environmental Protection Agency (EPA) ToxCast™ high-throughput screening (HTS) program. OBJECTIVES Our aim was to develop new hypotheses around environmental chemicals of potential interest for diabetes- or obesity-related outcomes using high-throughput screening data. METHODS We identified ToxCast™ assay targets relevant to several biological processes related to diabetes and obesity (insulin sensitivity in peripheral tissue, pancreatic islet and β cell function, adipocyte differentiation, and feeding behavior) and presented chemical screening data against those assay targets to identify chemicals of potential interest. DISCUSSION The results of this screening-level analysis suggest that the spectrum of environmental chemicals to consider in research related to diabetes and obesity is much broader than indicated by research papers and reviews published in the peer-reviewed literature. Testing hypotheses based on ToxCast™ data will also help assess the predictive utility of this HTS platform. CONCLUSIONS More research is required to put these screening-level analyses into context, but the information presented in this review should facilitate the development of new hypotheses. CITATION Auerbach S, Filer D, Reif D, Walker V, Holloway AC, Schlezinger J, Srinivasan S, Svoboda D, Judson R, Bucher JR, Thayer KA. 2016. Prioritizing environmental chemicals for obesity and diabetes outcomes research: a screening approach using ToxCast™ high-throughput data. Environ Health Perspect 124:1141-1154; http://dx.doi.org/10.1289/ehp.1510456.
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Affiliation(s)
- Scott Auerbach
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Dayne Filer
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - David Reif
- Bioinformatics Research Center, Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Vickie Walker
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Alison C. Holloway
- Department of Obstetrics and Gynecology, McMaster University, Hamilton, Ontario, Canada
| | - Jennifer Schlezinger
- Department of Environmental Health, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Supriya Srinivasan
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, California, USA
| | - Daniel Svoboda
- SciOme, LLC, Research Triangle Park, North Carolina, USA
| | - Richard Judson
- National Center for Computational Toxicology, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina, USA
| | - John R. Bucher
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
| | - Kristina A. Thayer
- Division of the National Toxicology Program, National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services, Research Triangle Park, North Carolina, USA
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