1
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Tsai SH, Wu YC, Palomino DF, Schroeder FC, Pan CL. Peripheral peroxisomal β-oxidation engages neuronal serotonin signaling to drive stress-induced aversive memory in C. elegans. Cell Rep 2024; 43:113996. [PMID: 38520690 PMCID: PMC11087011 DOI: 10.1016/j.celrep.2024.113996] [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: 09/03/2023] [Revised: 02/06/2024] [Accepted: 03/08/2024] [Indexed: 03/25/2024] Open
Abstract
Physiological dysfunction confers negative valence to coincidental sensory cues to induce the formation of aversive associative memory. How peripheral tissue stress engages neuromodulatory mechanisms to form aversive memory is poorly understood. Here, we show that in the nematode C. elegans, mitochondrial disruption induces aversive memory through peroxisomal β-oxidation genes in non-neural tissues, including pmp-4/very-long-chain fatty acid transporter, dhs-28/3-hydroxylacyl-CoA dehydrogenase, and daf-22/3-ketoacyl-CoA thiolase. Upregulation of peroxisomal β-oxidation genes under mitochondrial stress requires the nuclear hormone receptor NHR-49. Importantly, the memory-promoting function of peroxisomal β-oxidation is independent of its canonical role in pheromone production. Peripheral signals derived from the peroxisomes target NSM, a critical neuron for memory formation under stress, to upregulate serotonin synthesis and remodel evoked responses to sensory cues. Our genetic, transcriptomic, and metabolomic approaches establish peroxisomal lipid signaling as a crucial mechanism that connects peripheral mitochondrial stress to central serotonin neuromodulation in aversive memory formation.
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Affiliation(s)
- Shang-Heng Tsai
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan; Center for Precision Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
| | - Yu-Chun Wu
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan; Center for Precision Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan
| | - Diana Fajardo Palomino
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Frank C Schroeder
- Boyce Thompson Institute and Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Chun-Liang Pan
- Institute of Molecular Medicine, College of Medicine, National Taiwan University, Taipei 10002, Taiwan.
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2
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Vodičková A, Müller-Eigner A, Okoye CN, Bischer AP, Horn J, Koren SA, Selim NA, Wojtovich AP. Mitochondrial energy state controls AMPK-mediated foraging behavior in C. elegans. SCIENCE ADVANCES 2024; 10:eadm8815. [PMID: 38630817 PMCID: PMC11023558 DOI: 10.1126/sciadv.adm8815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 03/14/2024] [Indexed: 04/19/2024]
Abstract
Organisms surveil and respond to their environment using behaviors entrained by metabolic cues that reflect food availability. Mitochondria act as metabolic hubs and at the center of mitochondrial energy production is the protonmotive force (PMF), an electrochemical gradient generated by metabolite consumption. The PMF serves as a central integrator of mitochondrial status, but its role in governing metabolic signaling is poorly understood. We used optogenetics to dissipate the PMF in Caenorhabditis elegans tissues to test its role in food-related behaviors. Our data demonstrate that PMF reduction in the intestine is sufficient to initiate locomotor responses to acute food deprivation. This behavioral adaptation requires the cellular energy regulator AMP-activated protein kinase (AMPK) in neurons, not in the intestine, and relies on mitochondrial dynamics and axonal trafficking. Our results highlight a role for intestinal PMF as an internal metabolic cue, and we identify a bottom-up signaling axis through which changes in the PMF trigger AMPK activity in neurons to promote foraging behavior.
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Affiliation(s)
- Anežka Vodičková
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Annika Müller-Eigner
- Research Group Epigenetics, Metabolism and Longevity, Research Institute for Farm Animal Biology (FBN), Dummerstorf 18196, Germany
| | - Chidozie N. Okoye
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Andrew P. Bischer
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Jacob Horn
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Shon A. Koren
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, USA
| | - Nada Ahmed Selim
- Department of Pharmacology and Physiology, University of Rochester Medical Center, Rochester, NY, USA
| | - Andrew P. Wojtovich
- Department of Anesthesiology and Perioperative Medicine, University of Rochester Medical Center, Rochester, NY, USA
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3
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Lin C, Shan Y, Wang Z, Peng H, Li R, Wang P, He J, Shen W, Wu Z, Guo M. Molecular and circuit mechanisms underlying avoidance of rapid cooling stimuli in C. elegans. Nat Commun 2024; 15:297. [PMID: 38182628 PMCID: PMC10770330 DOI: 10.1038/s41467-023-44638-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Accepted: 12/21/2023] [Indexed: 01/07/2024] Open
Abstract
The mechanisms by which animals respond to rapid changes in temperature are largely unknown. Here, we found that polymodal ASH sensory neurons mediate rapid cooling-evoked avoidance behavior within the physiological temperature range in C. elegans. ASH employs multiple parallel circuits that consist of stimulatory circuits (AIZ, RIA, AVA) and disinhibitory circuits (AIB, RIM) to respond to rapid cooling. In the stimulatory circuit, AIZ, which is activated by ASH, releases glutamate to act on both GLR-3 and GLR-6 receptors in RIA neurons to promote reversal, and ASH also directly or indirectly stimulates AVA to promote reversal. In the disinhibitory circuit, AIB is stimulated by ASH through the GLR-1 receptor, releasing glutamate to act on AVR-14 to suppress RIM activity. RIM, an inter/motor neuron, inhibits rapid cooling-evoked reversal, and the loop activities thus equally stimulate reversal. Our findings elucidate the molecular and circuit mechanisms underlying the acute temperature stimuli-evoked avoidance behavior.
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Affiliation(s)
- Chenxi Lin
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yuxin Shan
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhongyi Wang
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
- College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hui Peng
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Rong Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Pingzhou Wang
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Junyan He
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Weiwei Shen
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
| | - Zhengxing Wu
- Key Laboratory of Molecular Biophysics of Ministry of Education, Institute of Biophysics and Biochemistry, and Department of Biophysics and Molecular Physiology, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Min Guo
- College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, China.
- College of Biomedicine and Health, Huazhong Agricultural University, Wuhan, 430070, China.
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4
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Lemieux GA, Yoo S, Lin L, Vohra M, Ashrafi K. The steroid hormone ADIOL promotes learning by reducing neural kynurenic acid levels. Genes Dev 2023; 37:998-1016. [PMID: 38092521 PMCID: PMC10760639 DOI: 10.1101/gad.350745.123] [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: 04/24/2023] [Accepted: 11/22/2023] [Indexed: 12/28/2023]
Abstract
Reductions in brain kynurenic acid levels, a neuroinhibitory metabolite, improve cognitive function in diverse organisms. Thus, modulation of kynurenic acid levels is thought to have therapeutic potential in a range of brain disorders. Here we report that the steroid 5-androstene 3β, 17β-diol (ADIOL) reduces kynurenic acid levels and promotes associative learning in Caenorhabditis elegans We identify the molecular mechanisms through which ADIOL links peripheral metabolic pathways to neural mechanisms of learning capacity. Moreover, we show that in aged animals, which normally experience rapid cognitive decline, ADIOL improves learning capacity. The molecular mechanisms that underlie the biosynthesis of ADIOL as well as those through which it promotes kynurenic acid reduction are conserved in mammals. Thus, rather than a minor intermediate in the production of sex steroids, ADIOL is an endogenous hormone that potently regulates learning capacity by causing reductions in neural kynurenic acid levels.
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Affiliation(s)
- George A Lemieux
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Shinja Yoo
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Lin Lin
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Mihir Vohra
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Kaveh Ashrafi
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
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5
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Bechtel W, Bich L. Using neurons to maintain autonomy: Learning from C. elegans. Biosystems 2023; 232:105017. [PMID: 37666409 DOI: 10.1016/j.biosystems.2023.105017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/29/2023] [Accepted: 08/29/2023] [Indexed: 09/06/2023]
Abstract
Understanding how biological organisms are autonomous-maintain themselves far from equilibrium through their own activities-requires understanding how they regulate those activities. In multicellular animals, such control can be exercised either via endocrine signaling through the vasculature or via neurons. In C. elegans this control is exercised by a well-delineated relatively small but distributed nervous system that relies on both chemical and electric transmission of signals. This system provides resources to integrate information from multiple sources as needed to maintain the organism. Especially important for the exercise of neural control are neuromodulators, which we present as setting agendas for control through more traditional electrical signaling. To illustrate how the C. elegans nervous system integrates multiple sources of information in controlling activities important for autonomy, we focus on feeding behavior and responses to adverse conditions. We conclude by considering how a distributed nervous system without a centralized controller is nonetheless adequate for autonomy.
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Affiliation(s)
- William Bechtel
- Department of Philosophy; University of California, San Diego; La Jolla, CA 92093-0119, USA.
| | - Leonardo Bich
- IAS-Research Centre for Life, Mind and Society; Department of Philosophy; University of the Basque Country (UPV/EHU); Avenida de Tolosa 70; Donostia-San Sebastian, 20018; Spain.
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6
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Pritz C, Itskovits E, Bokman E, Ruach R, Gritsenko V, Nelken T, Menasherof M, Azulay A, Zaslaver A. Principles for coding associative memories in a compact neural network. eLife 2023; 12:74434. [PMID: 37140557 PMCID: PMC10159626 DOI: 10.7554/elife.74434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 03/08/2023] [Indexed: 05/05/2023] Open
Abstract
A major goal in neuroscience is to elucidate the principles by which memories are stored in a neural network. Here, we have systematically studied how four types of associative memories (short- and long-term memories, each as positive and negative associations) are encoded within the compact neural network of Caenorhabditis elegans worms. Interestingly, sensory neurons were primarily involved in coding short-term, but not long-term, memories, and individual sensory neurons could be assigned to coding either the conditioned stimulus or the experience valence (or both). Moreover, when considering the collective activity of the sensory neurons, the specific training experiences could be decoded. Interneurons integrated the modulated sensory inputs and a simple linear combination model identified the experience-specific modulated communication routes. The widely distributed memory suggests that integrated network plasticity, rather than changes to individual neurons, underlies the fine behavioral plasticity. This comprehensive study reveals basic memory-coding principles and highlights the central roles of sensory neurons in memory formation.
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Affiliation(s)
- Christian Pritz
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eyal Itskovits
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eduard Bokman
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Rotem Ruach
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Vladimir Gritsenko
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tal Nelken
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Mai Menasherof
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Aharon Azulay
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Alon Zaslaver
- Department of Genetics, Silberman Institute for Life Sciences, Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, Israel
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7
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Alberts C, Owe-Larsson M, Urbanska EM. New Perspective on Anorexia Nervosa: Tryptophan-Kynurenine Pathway Hypothesis. Nutrients 2023; 15:nu15041030. [PMID: 36839388 PMCID: PMC9967350 DOI: 10.3390/nu15041030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023] Open
Abstract
Anorexia nervosa (AN), affecting up to 4% of all females and 0.3% of all males globally, remains the neuropsychiatric disorder with the highest mortality rate. However, the response to the current therapeutic options is rarely satisfactory. Considering the devastating prognosis of survival among patients with AN, further research aimed at developing novel, more effective therapies for AN is essential. Brain and serum tryptophan is mostly converted along the kynurenine pathway into multiple neuroactive derivatives, whereas only 1-2% is used for the synthesis of serotonin. This narrative review provides an update on the experimental and clinical research data concerning the metabolism of tryptophan along the kynurenine pathway in anorexia nervosa based on the available literature. We propose that in AN, lower levels of L-kynurenine and kynurenic acid result in diminished stimulation of the aryl hydrocarbon receptor, which could contribute to abnormally low body weight. The impact of L-kynurenine supplementation on anorexia in animal models and the effects of changes in tryptophan and downstream kynurenines on the clinical progression of AN require further investigation. Moreover, prospective clinical studies on larger cohorts of restrictive and binge-eating/purging AN patients and assessing the potential benefit of L-kynurenine as an add-on therapeutic agent, should follow.
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Affiliation(s)
- Charl Alberts
- Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego 8B, 20-059 Lublin, Poland
| | - Maja Owe-Larsson
- Department of Histology and Embryology, Center of Biostructure Research, Medical University of Warsaw, Chałubińskiego 5, 02-004 Warsaw, Poland
- Laboratory of Center for Preclinical Research, Department of Experimental and Clinical Physiology, Medical University of Warsaw, Banacha 1B, 02-097 Warsaw, Poland
| | - Ewa M. Urbanska
- Laboratory of Cellular and Molecular Pharmacology, Department of Experimental and Clinical Pharmacology, Medical University of Lublin, Jaczewskiego 8B, 20-059 Lublin, Poland
- Correspondence:
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8
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Choi HS, Bhat A, Howington MB, Schaller ML, Cox RL, Huang S, Beydoun S, Miller HA, Tuckowski AM, Mecano J, Dean ES, Jensen L, Beard DA, Evans CR, Leiser SF. FMO rewires metabolism to promote longevity through tryptophan and one carbon metabolism in C. elegans. Nat Commun 2023; 14:562. [PMID: 36732543 PMCID: PMC9894935 DOI: 10.1038/s41467-023-36181-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 01/19/2023] [Indexed: 02/04/2023] Open
Abstract
Flavin containing monooxygenases (FMOs) are promiscuous enzymes known for metabolizing a wide range of exogenous compounds. In C. elegans, fmo-2 expression increases lifespan and healthspan downstream of multiple longevity-promoting pathways through an unknown mechanism. Here, we report that, beyond its classification as a xenobiotic enzyme, fmo-2 expression leads to rewiring of endogenous metabolism principally through changes in one carbon metabolism (OCM). These changes are likely relevant, as we find that genetically modifying OCM enzyme expression leads to alterations in longevity that interact with fmo-2 expression. Using computer modeling, we identify decreased methylation as the major OCM flux modified by FMO-2 that is sufficient to recapitulate its longevity benefits. We further find that tryptophan is decreased in multiple mammalian FMO overexpression models and is a validated substrate for FMO-2. Our resulting model connects a single enzyme to two previously unconnected key metabolic pathways and provides a framework for the metabolic interconnectivity of longevity-promoting pathways such as dietary restriction. FMOs are well-conserved enzymes that are also induced by lifespan-extending interventions in mice, supporting a conserved and important role in promoting health and longevity through metabolic remodeling.
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Affiliation(s)
- Hyo Sub Choi
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ajay Bhat
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Marshall B Howington
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Megan L Schaller
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Rebecca L Cox
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Shijiao Huang
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Safa Beydoun
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Hillary A Miller
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Angela M Tuckowski
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Joy Mecano
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Elizabeth S Dean
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Lindy Jensen
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Daniel A Beard
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Charles R Evans
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Scott F Leiser
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48109, USA.
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48109, USA.
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9
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Yu YV, Xue W, Chen Y. Multisensory Integration in Caenorhabditis elegans in Comparison to Mammals. Brain Sci 2022; 12:brainsci12101368. [PMID: 36291302 PMCID: PMC9599712 DOI: 10.3390/brainsci12101368] [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: 08/31/2022] [Revised: 09/28/2022] [Accepted: 10/03/2022] [Indexed: 11/30/2022] Open
Abstract
Multisensory integration refers to sensory inputs from different sensory modalities being processed simultaneously to produce a unitary output. Surrounded by stimuli from multiple modalities, animals utilize multisensory integration to form a coherent and robust representation of the complex environment. Even though multisensory integration is fundamentally essential for animal life, our understanding of the underlying mechanisms, especially at the molecular, synaptic and circuit levels, remains poorly understood. The study of sensory perception in Caenorhabditis elegans has begun to fill this gap. We have gained a considerable amount of insight into the general principles of sensory neurobiology owing to C. elegans’ highly sensitive perceptions, relatively simple nervous system, ample genetic tools and completely mapped neural connectome. Many interesting paradigms of multisensory integration have been characterized in C. elegans, for which input convergence occurs at the sensory neuron or the interneuron level. In this narrative review, we describe some representative cases of multisensory integration in C. elegans, summarize the underlying mechanisms and compare them with those in mammalian systems. Despite the differences, we believe C. elegans is able to provide unique insights into how processing and integrating multisensory inputs can generate flexible and adaptive behaviors. With the emergence of whole brain imaging, the ability of C. elegans to monitor nearly the entire nervous system may be crucial for understanding the function of the brain as a whole.
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Affiliation(s)
- Yanxun V. Yu
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430070, China
- Frontier Science Center for Immunology and Metabolism, Wuhan University, Wuhan 430070, China
- Correspondence: or
| | - Weikang Xue
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430070, China
| | - Yuanhua Chen
- Department of Neurology, Medical Research Institute, Zhongnan Hospital of Wuhan University, Wuhan University, Wuhan 430070, China
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10
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Wang Y, Guo K, Wang Q, Zhong G, Zhang W, Jiang Y, Mao X, Li X, Huang Z. Caenorhabditis elegans as an emerging model in food and nutrition research: importance of standardizing base diet. Crit Rev Food Sci Nutr 2022; 64:3167-3185. [PMID: 36200941 DOI: 10.1080/10408398.2022.2130875] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
As a model organism that has helped revolutionize life sciences, Caenorhabditis elegans has been increasingly used in nutrition research. Here we explore the tradeoffs between pros and cons of its use as a dietary model based primarily on literature review from the past decade. We first provide an overview of its experimental strengths as an animal model, focusing on lifespan and healthspan, behavioral and physiological phenotypes, and conservation of key nutritional pathways. We then summarize recent advances of its use in nutritional studies, e.g. food preference and feeding behavior, sugar status and metabolic reprogramming, lifetime and transgenerational nutrition tracking, and diet-microbiota-host interactions, highlighting cutting-edge technologies originated from or developed in C. elegans. We further review current challenges of using C. elegans as a nutritional model, followed by in-depth discussions on potential solutions. In particular, growth scales and throughputs, food uptake mode, and axenic culture of C. elegans are appraised in the context of food research. We also provide perspectives for future development of chemically defined nematode food ("NemaFood") for C. elegans, which is now widely accepted as a versatile and affordable in vivo model and has begun to show transformative potential to pioneer nutrition science.
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Affiliation(s)
- Yuqing Wang
- Institute for Food Nutrition and Human Health, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Guangdong Province Key Laboratory for Biocosmetics, Guangzhou, China
| | - Kaixin Guo
- Institute for Food Nutrition and Human Health, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- The First Affiliated Hospital of Shenzhen University, Shenzhen, China
| | - Qiangqiang Wang
- Institute for Food Nutrition and Human Health, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Guangdong Province Key Laboratory for Biocosmetics, Guangzhou, China
| | - Guohuan Zhong
- Institute for Food Nutrition and Human Health, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Center for Bioresources and Drug Discovery, School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, China
| | - Wenjun Zhang
- Center for Bioresources and Drug Discovery, School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, China
| | - Yiyi Jiang
- Guangdong Province Key Laboratory for Biocosmetics, Guangzhou, China
- Perfect Life & Health Institute, Zhongshan, Guangdong, China
| | - Xinliang Mao
- Guangdong Province Key Laboratory for Biocosmetics, Guangzhou, China
- Perfect Life & Health Institute, Zhongshan, Guangdong, China
| | - Xiaomin Li
- Guangdong Province Key Laboratory for Biocosmetics, Guangzhou, China
- Perfect Life & Health Institute, Zhongshan, Guangdong, China
| | - Zebo Huang
- Institute for Food Nutrition and Human Health, School of Food Science and Engineering, South China University of Technology, Guangzhou, China
- Guangdong Province Key Laboratory for Biocosmetics, Guangzhou, China
- Center for Bioresources and Drug Discovery, School of Biosciences and Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou, China
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11
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Apex Predator Nematodes and Meso-Predator Bacteria Consume Their Basal Insect Prey through Discrete Stages of Chemical Transformations. mSystems 2022; 7:e0031222. [PMID: 35543104 PMCID: PMC9241642 DOI: 10.1128/msystems.00312-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial symbiosis drives physiological processes of higher-order systems, including the acquisition and consumption of nutrients that support symbiotic partner reproduction. Metabolic analytics provide new avenues to examine how chemical ecology, or the conversion of existing biomass to new forms, changes over a symbiotic life cycle. We applied these approaches to the nematode Steinernema carpocapsae, its mutualist bacterium, Xenorhabdus nematophila, and the insects they infect. The nematode-bacterium pair infects, kills, and reproduces in an insect until nutrients are depleted. To understand the conversion of insect biomass over time into either nematode or bacterium biomass, we integrated information from trophic, metabolomic, and gene regulation analyses. Trophic analysis established bacteria as meso-predators and primary insect consumers. Nematodes hold a trophic position of 4.6, indicative of an apex predator, consuming bacteria and likely other nematodes. Metabolic changes associated with Galleria mellonella insect bioconversion were assessed using multivariate statistical analyses of metabolomics data sets derived from sampling over an infection time course. Statistically significant, discrete phases were detected, indicating the insect chemical environment changes reproducibly during bioconversion. A novel hierarchical clustering method was designed to probe molecular abundance fluctuation patterns over time, revealing distinct metabolite clusters that exhibit similar abundance shifts across the time course. Composite data suggest bacterial tryptophan and nematode kynurenine pathways are coordinated for reciprocal exchange of tryptophan and NAD+ and for synthesis of intermediates that can have complex effects on bacterial phenotypes and nematode behaviors. Our analysis of pathways and metabolites reveals the chemistry underlying the recycling of organic material during carnivory. IMPORTANCE The processes by which organic life is consumed and reborn in a complex ecosystem were investigated through a multiomics approach applied to the tripartite Xenorhabdus bacterium-Steinernema nematode-Galleria insect symbiosis. Trophic analyses demonstrate the primary consumers of the insect are the bacteria, and the nematode in turn consumes the bacteria. This suggests the Steinernema-Xenorhabdus mutualism is a form of agriculture in which the nematode cultivates the bacterial food sources by inoculating them into insect hosts. Metabolomics analysis revealed a shift in biological material throughout progression of the life cycle: active infection, insect death, and conversion of cadaver tissues into bacterial biomass and nematode tissue. We show that each phase of the life cycle is metabolically distinct, with significant differences including those in the tricarboxylic acid cycle and amino acid pathways. Our findings demonstrate that symbiotic life cycles can be defined by reproducible stage-specific chemical signatures, enhancing our broad understanding of metabolic processes that underpin a three-way symbiosis.
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Liu H, Wu T, Canales XG, Wu M, Choi MK, Duan F, Calarco JA, Zhang Y. Forgetting generates a novel state that is reactivatable. SCIENCE ADVANCES 2022; 8:eabi9071. [PMID: 35148188 PMCID: PMC8836790 DOI: 10.1126/sciadv.abi9071] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Accepted: 12/21/2021] [Indexed: 05/21/2023]
Abstract
Forgetting is defined as a time-dependent decline of a memory. However, it is not clear whether forgetting reverses the learning process to return the brain to the naive state. Here, using the aversive olfactory learning of pathogenic bacteria in C. elegans, we show that forgetting generates a novel state of the nervous system that is distinct from the naive state or the learned state. A transient exposure to the training condition or training odorants reactivates this novel state to elicit the previously learned behavior. An AMPA receptor and a type II serotonin receptor act in the central neuron of the learning circuit to decrease and increase the speed to reach this novel state, respectively. Together, our study systematically characterizes forgetting and uncovers conserved mechanisms underlying the rate of forgetting.
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Affiliation(s)
- He Liu
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Taihong Wu
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Xicotencatl Gracida Canales
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Min Wu
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Myung-Kyu Choi
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Fengyun Duan
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - John A. Calarco
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario M5S 3G5, Canada
| | - Yun Zhang
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
- Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
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Aripiprazole Offsets Mutant ATXN3-Induced Motor Dysfunction by Targeting Dopamine D2 and Serotonin 1A and 2A Receptors in C. elegans. Biomedicines 2022; 10:biomedicines10020370. [PMID: 35203579 PMCID: PMC8962381 DOI: 10.3390/biomedicines10020370] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/26/2022] [Accepted: 01/27/2022] [Indexed: 01/14/2023] Open
Abstract
The atypical antipsychotic aripiprazole is a Food and Drug Administration-approved drug for the treatment of psychotic, mood, and other psychiatric disorders. Previous drug discovery efforts pinpointed aripiprazole as an effective suppressor of Machado–Joseph disease (MJD) pathogenesis, as its administration resulted in a reduced abundance and aggregation of mutant Ataxin-3 (ATXN3) proteins. Dopamine partial agonism and functional selectivity have been proposed as the main pharmacological mechanism of action of aripiprazole in the treatment of psychosis; however, this mechanism remains to be determined in the context of MJD. Here, we focus on confirming the efficacy of aripiprazole to reduce motor dysfunction in vivo, using a Caenorhabditis elegans (C. elegans) model of MJD, and on unveiling the drug targets required for its positive action against mutant ATXN3 pathogenesis. We employed pharmacogenetics and pharmacological approaches to identify which dopamine and serotonin receptors are critical for aripiprazole-mediated improvements in motor function. We demonstrated that dopamine D2-like and serotonin 5-HT1A and 5-HT2A receptors play important roles in this process. Our findings strengthen the relevance of dopaminergic and serotoninergic signaling modulation against mutant ATXN3-mediated pathogenesis. The identification of aripiprazole’s cellular targets, relevant for MJD and perhaps other neurodegenerative diseases, may pave the way for prospective drug discovery and development campaigns aiming to improve the features of this prototypical compound and reduce side effects not negligible in the case of aripiprazole.
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Bhat US, Shahi N, Surendran S, Babu K. Neuropeptides and Behaviors: How Small Peptides Regulate Nervous System Function and Behavioral Outputs. Front Mol Neurosci 2021; 14:786471. [PMID: 34924955 PMCID: PMC8674661 DOI: 10.3389/fnmol.2021.786471] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/11/2021] [Indexed: 11/13/2022] Open
Abstract
One of the reasons that most multicellular animals survive and thrive is because of the adaptable and plastic nature of their nervous systems. For an organism to survive, it is essential for the animal to respond and adapt to environmental changes. This is achieved by sensing external cues and translating them into behaviors through changes in synaptic activity. The nervous system plays a crucial role in constantly evaluating environmental cues and allowing for behavioral plasticity in the organism. Multiple neurotransmitters and neuropeptides have been implicated as key players for integrating sensory information to produce the desired output. Because of its simple nervous system and well-established neuronal connectome, C. elegans acts as an excellent model to understand the mechanisms underlying behavioral plasticity. Here, we critically review how neuropeptides modulate a wide range of behaviors by allowing for changes in neuronal and synaptic signaling. This review will have a specific focus on feeding, mating, sleep, addiction, learning and locomotory behaviors in C. elegans. With a view to understand evolutionary relationships, we explore the functions and associated pathophysiology of C. elegans neuropeptides that are conserved across different phyla. Further, we discuss the mechanisms of neuropeptidergic signaling and how these signals are regulated in different behaviors. Finally, we attempt to provide insight into developing potential therapeutics for neuropeptide-related disorders.
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Affiliation(s)
- Umer Saleem Bhat
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
- Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, India
| | - Navneet Shahi
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| | - Siju Surendran
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
| | - Kavita Babu
- Centre for Neuroscience, Indian Institute of Science, Bengaluru, India
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Wasson JA, Harris G, Keppler-Ross S, Brock TJ, Dar AR, Butcher RA, Fischer SEJ, Kagias K, Clardy J, Zhang Y, Mango SE. Neuronal control of maternal provisioning in response to social cues. SCIENCE ADVANCES 2021; 7:7/34/eabf8782. [PMID: 34417172 PMCID: PMC8378817 DOI: 10.1126/sciadv.abf8782] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 06/30/2021] [Indexed: 05/03/2023]
Abstract
Mothers contribute cytoplasmic components to their progeny in a process called maternal provisioning. Provisioning is influenced by the parental environment, but the molecular pathways that transmit environmental cues between generations are not well understood. Here, we show that, in Caenorhabditis elegans, social cues modulate maternal provisioning to regulate gene silencing in offspring. Intergenerational signal transmission depends on a pheromone-sensing neuron and neuronal FMRFamide (Phe-Met-Arg-Phe)-like peptides. Parental FMRFamide-like peptide signaling dampens oxidative stress resistance and promotes the deposition of mRNAs for translational components in progeny, which, in turn, reduces gene silencing. This study identifies a previously unknown pathway for intergenerational communication that links neuronal responses to maternal provisioning. We suggest that loss of social cues in the parental environment represents an adverse environment that stimulates stress responses across generations.
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Affiliation(s)
| | - Gareth Harris
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA
- Department of Biology, California State University Channel Islands, Camarillo, CA, USA
| | | | | | - Abdul R Dar
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Rebecca A Butcher
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Sylvia E J Fischer
- Division of Infectious Diseases, Boston Children's Hospital, Boston, MA, USA
| | - Konstantinos Kagias
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA
| | - Jon Clardy
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Cambridge, MA, USA
| | - Yun Zhang
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA, USA.
| | - Susan E Mango
- Biozentrum, University of Basel, Basel, Switzerland.
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Rawsthorne H, Calahorro F, Holden-Dye L, O’ Connor V, Dillon J. Investigating autism associated genes in C. elegans reveals candidates with a role in social behaviour. PLoS One 2021; 16:e0243121. [PMID: 34043629 PMCID: PMC8158995 DOI: 10.1371/journal.pone.0243121] [Citation(s) in RCA: 2] [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: 11/26/2020] [Accepted: 03/29/2021] [Indexed: 11/18/2022] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterised by a triad of behavioural impairments and includes disruption in social behaviour. ASD has a clear genetic underpinning and hundreds of genes are implicated in its aetiology. However, how single penetrant genes disrupt activity of neural circuits which lead to affected behaviours is only beginning to be understood and less is known about how low penetrant genes interact to disrupt emergent behaviours. Investigations are well served by experimental approaches that allow tractable investigation of the underpinning genetic basis of circuits that control behaviours that operate in the biological domains that are neuro-atypical in autism. The model organism C. elegans provides an experimental platform to investigate the effect of genetic mutations on behavioural outputs including those that impact social biology. Here we use progeny-derived social cues that modulate C. elegans food leaving to assay genetic determinants of social behaviour. We used the SAFRI Gene database to identify C. elegans orthologues of human ASD associated genes. We identified a number of mutants that displayed selective deficits in response to progeny. The genetic determinants of this complex social behaviour highlight the important contribution of synaptopathy and implicates genes within cell signalling, epigenetics and phospholipid metabolism functional domains. The approach overlaps with a growing number of studies that investigate potential molecular determinants of autism in C. elegans. However, our use of a complex, sensory integrative, emergent behaviour provides routes to enrich new or underexplored biology with the identification of novel candidate genes with a definable role in social behaviour.
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Affiliation(s)
- Helena Rawsthorne
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
| | - Fernando Calahorro
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
| | - Lindy Holden-Dye
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
| | - Vincent O’ Connor
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
| | - James Dillon
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton, United Kingdom
- * E-mail:
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Marx W, Lane M, Hockey M, Aslam H, Berk M, Walder K, Borsini A, Firth J, Pariante CM, Berding K, Cryan JF, Clarke G, Craig JM, Su KP, Mischoulon D, Gomez-Pinilla F, Foster JA, Cani PD, Thuret S, Staudacher HM, Sánchez-Villegas A, Arshad H, Akbaraly T, O'Neil A, Segasby T, Jacka FN. Diet and depression: exploring the biological mechanisms of action. Mol Psychiatry 2021; 26:134-150. [PMID: 33144709 DOI: 10.1038/s41380-020-00925-x] [Citation(s) in RCA: 245] [Impact Index Per Article: 81.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 10/01/2020] [Accepted: 10/09/2020] [Indexed: 02/08/2023]
Abstract
The field of nutritional psychiatry has generated observational and efficacy data supporting a role for healthy dietary patterns in depression onset and symptom management. To guide future clinical trials and targeted dietary therapies, this review provides an overview of what is currently known regarding underlying mechanisms of action by which diet may influence mental and brain health. The mechanisms of action associating diet with health outcomes are complex, multifaceted, interacting, and not restricted to any one biological pathway. Numerous pathways were identified through which diet could plausibly affect mental health. These include modulation of pathways involved in inflammation, oxidative stress, epigenetics, mitochondrial dysfunction, the gut microbiota, tryptophan-kynurenine metabolism, the HPA axis, neurogenesis and BDNF, epigenetics, and obesity. However, the nascent nature of the nutritional psychiatry field to date means that the existing literature identified in this review is largely comprised of preclinical animal studies. To fully identify and elucidate complex mechanisms of action, intervention studies that assess markers related to these pathways within clinically diagnosed human populations are needed.
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Affiliation(s)
- Wolfgang Marx
- Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Food & Mood Centre, Geelong, VIC, Australia.
| | - Melissa Lane
- Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Food & Mood Centre, Geelong, VIC, Australia
| | - Meghan Hockey
- Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Food & Mood Centre, Geelong, VIC, Australia
| | - Hajara Aslam
- Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Food & Mood Centre, Geelong, VIC, Australia
| | - Michael Berk
- Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Food & Mood Centre, Geelong, VIC, Australia
- Orygen, The National Centre of Excellence in Youth Mental Health, Centre for Youth Mental Health, Florey Institute for Neuroscience and Mental Health, Melbourne, VIC, Australia
- Department of Psychiatry, The University of Melbourne, Melbourne, VIC, Australia
| | - Ken Walder
- Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Metabolic Research Unit, Geelong, VIC, Australia
| | - Alessandra Borsini
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Joseph Firth
- Division of Psychology and Mental Health, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- NICM Health Research Institute, Western Sydney University, Westmead, NSW, Australia
| | - Carmine M Pariante
- Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Kirsten Berding
- APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - John F Cryan
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Gerard Clarke
- APC Microbiome Ireland, University College Cork, Cork, Ireland
- Department of Psychiatry and Neurobehavioural Science, University College Cork, Cork, Ireland
- INFANT Research Centre, University College Cork, Cork, Ireland
| | - Jeffrey M Craig
- Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Geelong, VIC, Australia
| | - Kuan-Pin Su
- Departments of Psychiatry and Mind-Body Interface Laboratory (MBI-Lab), China Medical University Hospital, Taichung, Taiwan
- An-Nan Hospital, China Medical University, Tainan, Taiwan
- College of Medicine, China Medical University, Taichung, Taiwan
| | - David Mischoulon
- Department of Psychiatry, Depression Clinical and Research Program, Massachusetts General Hospital, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
| | - Fernando Gomez-Pinilla
- Departments of Neurosurgery and Integrative Biology and Physiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Jane A Foster
- Department of Psychiatry & Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada
| | - Patrice D Cani
- UCLouvain, Université catholique de Louvain, WELBIO-Walloon Excellence in Life Sciences and BIOtechnology, Louvain Drug Research Institute, Metabolism and Nutrition Research Group, Brussels, Belgium
| | - Sandrine Thuret
- Basic and Clinical Neuroscience Department, Institute of Psychiatry Psychology and Neuroscience, King's College London, London, UK
| | - Heidi M Staudacher
- Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Food & Mood Centre, Geelong, VIC, Australia
| | - Almudena Sánchez-Villegas
- Nutrition Research Group, Research Institute of Biomedical and Health Sciences, University of Las Palmas de Gran Canaria, Gran Canaria, Spain
- Biomedical Research Center Network on Obesity and Nutrition (CIBERobn) Physiopathology of Obesity and Nutrition, Institute of Health Carlos III, Madrid, Spain
| | - Husnain Arshad
- Université Paris-Saclay, UVSQ, Inserm, CESP, "DevPsy", 94807, Villejuif, France
| | - Tasnime Akbaraly
- Université Paris-Saclay, UVSQ, Inserm, CESP, "DevPsy", 94807, Villejuif, France
- Department of Epidemiology and Public Health, University College London, London, UK
| | - Adrienne O'Neil
- Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Food & Mood Centre, Geelong, VIC, Australia
| | - Toby Segasby
- Basic and Clinical Neuroscience Department, Institute of Psychiatry Psychology and Neuroscience, King's College London, London, UK
| | - Felice N Jacka
- Deakin University, IMPACT (the Institute for Mental and Physical Health and Clinical Translation), Food & Mood Centre, Geelong, VIC, Australia
- Centre for Adolescent Health, Murdoch Children's Research Institute, Melbourne, VIC, Australia
- Black Dog Institute, Randwick, NSW, Australia
- James Cook University, Townsville, QLD, Australia
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IL4I1 Is a Metabolic Immune Checkpoint that Activates the AHR and Promotes Tumor Progression. Cell 2020; 182:1252-1270.e34. [PMID: 32818467 DOI: 10.1016/j.cell.2020.07.038] [Citation(s) in RCA: 250] [Impact Index Per Article: 62.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 05/25/2020] [Accepted: 07/28/2020] [Indexed: 01/01/2023]
Abstract
Aryl hydrocarbon receptor (AHR) activation by tryptophan (Trp) catabolites enhances tumor malignancy and suppresses anti-tumor immunity. The context specificity of AHR target genes has so far impeded systematic investigation of AHR activity and its upstream enzymes across human cancers. A pan-tissue AHR signature, derived by natural language processing, revealed that across 32 tumor entities, interleukin-4-induced-1 (IL4I1) associates more frequently with AHR activity than IDO1 or TDO2, hitherto recognized as the main Trp-catabolic enzymes. IL4I1 activates the AHR through the generation of indole metabolites and kynurenic acid. It associates with reduced survival in glioma patients, promotes cancer cell motility, and suppresses adaptive immunity, thereby enhancing the progression of chronic lymphocytic leukemia (CLL) in mice. Immune checkpoint blockade (ICB) induces IDO1 and IL4I1. As IDO1 inhibitors do not block IL4I1, IL4I1 may explain the failure of clinical studies combining ICB with IDO1 inhibition. Taken together, IL4I1 blockade opens new avenues for cancer therapy.
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Abstract
Microbes are ubiquitous in the natural environment of Caenorhabditis elegans. Bacteria serve as a food source for C. elegans but may also cause infection in the nematode host. The sensory nervous system of C. elegans detects diverse microbial molecules, ranging from metabolites produced by broad classes of bacteria to molecules synthesized by specific strains of bacteria. Innate recognition through chemosensation of bacterial metabolites or mechanosensation of bacteria can induce immediate behavioral responses. The ingestion of nutritive or pathogenic bacteria can modulate internal states that underlie long-lasting behavioral changes. Ingestion of nutritive bacteria leads to learned attraction and exploitation of the bacterial food source. Infection, which is accompanied by activation of innate immunity, stress responses, and host damage, leads to the development of aversive behavior. The integration of a multitude of microbial sensory cues in the environment is shaped by experience and context. Genetic, chemical, and neuronal studies of C. elegans behavior in the presence of bacteria have defined neural circuits and neuromodulatory systems that shape innate and learned behavioral responses to microbial cues. These studies have revealed the profound influence that host-microbe interactions have in governing the behavior of this simple animal host.
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Affiliation(s)
- Dennis H Kim
- Division of Infectious Diseases, Boston Children's Hospital, and Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Steven W Flavell
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
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20
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Lin L, Lemieux GA, Enogieru OJ, Giacomini KM, Ashrafi K. Neural production of kynurenic acid in Caenorhabditis elegans requires the AAT-1 transporter. Genes Dev 2020; 34:1033-1038. [PMID: 32675325 PMCID: PMC7397858 DOI: 10.1101/gad.339119.120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/24/2020] [Indexed: 11/24/2022]
Abstract
In this study, Lin et al. investigated the mechanisms that import kyneurine (Kyn), a prescursor to kynurenic acid (KynA), which links peripheral metabolic status to neural functions including learning and memory, into the nervous system. They provide genetic, anatomical, biochemical, and behavioral evidence showing that in C. elegans an ortholog of the human LAT1 transporter, AAT-1, imports Kyn into sites of KynA production. Kynurenic acid (KynA) levels link peripheral metabolic status to neural functions including learning and memory. Since neural KynA levels dampen learning capacity, KynA reduction has been proposed as a therapeutic strategy for conditions of cognitive deficit such as neurodegeneration. While KynA is generated locally within the nervous system, its precursor, kynurenine (Kyn), is largely derived from peripheral resources. The mechanisms that import Kyn into the nervous system are poorly understood. Here, we provide genetic, anatomical, biochemical, and behavioral evidence showing that in C. elegans an ortholog of the human LAT1 transporter, AAT-1, imports Kyn into sites of KynA production.
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Affiliation(s)
- Lin Lin
- Department of Physiology, University of California at San Francisco, San Francisco, California 94158, USA
| | - George A Lemieux
- Department of Physiology, University of California at San Francisco, San Francisco, California 94158, USA
| | - Osatohanmwen Jessica Enogieru
- Department of Bioengineering and Therapeutic Sciences, University of California at San Francisco, San Francisco, California 94158, USA
| | - Kathleen M Giacomini
- Department of Bioengineering and Therapeutic Sciences, University of California at San Francisco, San Francisco, California 94158, USA
| | - Kaveh Ashrafi
- Department of Physiology, University of California at San Francisco, San Francisco, California 94158, USA
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Christensen EL, Beasley A, Radchuk J, Mielko ZE, Preston E, Stuckett S, Murray JI, Hudson ML. ngn-1/neurogenin Activates Transcription of Multiple Terminal Selector Transcription Factors in the Caenorhabditis elegans Nervous System. G3 (BETHESDA, MD.) 2020; 10:1949-1962. [PMID: 32273286 PMCID: PMC7263688 DOI: 10.1534/g3.120.401126] [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: 02/06/2020] [Accepted: 03/30/2020] [Indexed: 11/18/2022]
Abstract
Proper nervous system development is required for an organism's survival and function. Defects in neurogenesis have been linked to neurodevelopmental disorders such as schizophrenia and autism. Understanding the gene regulatory networks that orchestrate neural development, specifically cascades of proneural transcription factors, can better elucidate which genes are most important during early neurogenesis. Neurogenins are a family of deeply conserved factors shown to be both necessary and sufficient for the development of neural subtypes. However, the immediate downstream targets of neurogenin are not well characterized. The objective of this study was to further elucidate the role of ngn-1/neurogenin in nervous system development and to identify its downstream transcriptional targets, using the nematode Caenorhabditis elegans as a model for this work. We found that ngn-1 is required for axon outgrowth, nerve ring architecture, and neuronal cell fate specification. We also showed that ngn-1 may have roles in neuroblast migration and epithelial integrity during embryonic development. Using RNA sequencing and comparative transcriptome analysis, we identified eight transcription factors (hlh-34/NPAS1, unc-42/PROP1, ceh-17/PHOX2A, lim-4/LHX6, fax-1/NR2E3, lin-11/LHX1, tlp-1/ZNF503, and nhr-23/RORB) whose transcription is activated, either directly or indirectly, by ngn-1 Our results show that ngn-1 has a role in transcribing known terminal regulators that establish and maintain cell fate of differentiated neural subtypes and confirms that ngn-1 functions as a proneural transcription factor in C. elegans neurogenesis.
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Affiliation(s)
- Elyse L Christensen
- Department of Molecular and Cellular Biology, Kennesaw State University, GA 30144
| | - Alexandra Beasley
- Department of Molecular and Cellular Biology, Kennesaw State University, GA 30144
| | - Jessica Radchuk
- Department of Molecular and Cellular Biology, Kennesaw State University, GA 30144
| | - Zachery E Mielko
- Department of Molecular and Cellular Biology, Kennesaw State University, GA 30144
| | - Elicia Preston
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Sidney Stuckett
- Department of Molecular and Cellular Biology, Kennesaw State University, GA 30144
| | - John I Murray
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Martin L Hudson
- Department of Molecular and Cellular Biology, Kennesaw State University, GA 30144
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Ishita Y, Chihara T, Okumura M. Serotonergic modulation of feeding behavior in Caenorhabditis elegans and other related nematodes. Neurosci Res 2020; 154:9-19. [DOI: 10.1016/j.neures.2019.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/10/2019] [Accepted: 04/22/2019] [Indexed: 10/26/2022]
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Abstract
The kynurenine pathway (KP) plays a critical role in generating cellular energy in the form of nicotinamide adenine dinucleotide (NAD+). Because energy requirements are substantially increased during an immune response, the KP is a key regulator of the immune system. Perhaps more importantly in the context of psychiatry, many kynurenines are neuroactive, modulating neuroplasticity and/or exerting neurotoxic effects in part through their effects on NMDA receptor signaling and glutamatergic neurotransmission. As such, it is not surprising that the kynurenines have been implicated in psychiatric illness in the context of inflammation. However, because of their neuromodulatory properties, the kynurenines are not just additional members of a list of inflammatory mediators linked with psychiatric illness, but in preclinical studies have been shown to be necessary components of the behavioral analogs of depression and schizophrenia-like cognitive deficits. Further, as the title suggests, the KP is regulated by, and in turn regulates multiple other physiological systems that are commonly disrupted in psychiatric disorders, including endocrine, metabolic, and hormonal systems. This review provides a broad overview of the mechanistic pathways through which the kynurenines interact with these systems, thus impacting emotion, cognition, pain, metabolic function, and aging, and in so doing potentially increasing the risk of developing psychiatric disorders. Novel therapeutic approaches targeting the KP are discussed. Moreover, electroconvulsive therapy, ketamine, physical exercise, and certain non-steroidal anti-inflammatories have been shown to alter kynurenine metabolism, raising the possibility that kynurenine metabolites may have utility as treatment response or therapeutic monitoring biomarkers.
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Affiliation(s)
- Jonathan Savitz
- Laureate Institute for Brain Research, Tulsa, OK, USA.
- Oxley College of Health Sciences, The University of Tulsa, Tulsa, OK, USA.
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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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Tryptophan metabolism as a common therapeutic target in cancer, neurodegeneration and beyond. Nat Rev Drug Discov 2019; 18:379-401. [PMID: 30760888 DOI: 10.1038/s41573-019-0016-5] [Citation(s) in RCA: 746] [Impact Index Per Article: 149.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
L-Tryptophan (Trp) metabolism through the kynurenine pathway (KP) is involved in the regulation of immunity, neuronal function and intestinal homeostasis. Imbalances in Trp metabolism in disorders ranging from cancer to neurodegenerative disease have stimulated interest in therapeutically targeting the KP, particularly the main rate-limiting enzymes indoleamine-2,3-dioxygenase 1 (IDO1), IDO2 and tryptophan-2,3-dioxygenase (TDO) as well as kynurenine monooxygenase (KMO). However, although small-molecule IDO1 inhibitors showed promise in early-stage cancer immunotherapy clinical trials, a phase III trial was negative. This Review summarizes the physiological and pathophysiological roles of Trp metabolism, highlighting the vast opportunities and challenges for drug development in multiple diseases.
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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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Zhang HL, Zhang AH, Miao JH, Sun H, Yan GL, Wu FF, Wang XJ. Targeting regulation of tryptophan metabolism for colorectal cancer therapy: a systematic review. RSC Adv 2019; 9:3072-3080. [PMID: 35518968 PMCID: PMC9060217 DOI: 10.1039/c8ra08520j] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 12/23/2018] [Indexed: 12/22/2022] Open
Abstract
Colorectal cancer (CRC) is one of the most malignant cancers resulting from abnormal metabolism alterations. As one of the essential amino acids, tryptophan has a variety of physiological functions, closely related to regulation of immune system, central nervous system, gastrointestinal nervous system and intestinal microflora. Colorectal cancer, a type of high-grade malignancy disease, stems from a variety of factors and often accompanies inflammatory reactions, dysbacteriosis, and metabolic disorders. Colorectal cancer accompanies inflammation and imbalance of intestinal microbiota and affects tryptophan metabolism. It is known that metabolites, rate-limiting enzymes, and ARH in tryptophan metabolism are associated with the development of CRC. Specifically, IDO1 may be a potential therapeutic target in colorectal cancer treatment. Furthermore, the reduction of tryptophan amount is proportional to the poor quality of life for colorectal cancer patients. This paper aims to discuss the role of tryptophan metabolism in a normal organism and investigate the relationship between this amino acid and colorectal cancer. This study is expected to provide theoretical support for research related to targeted therapy for colorectal cancer. Furthermore, strategies that modify tryptophan metabolism, effectively inhibiting tumor progression, may be more effective for CRC treatment. Colorectal cancer (CRC) is one of the most malignant cancers resulting from abnormal metabolism alterations.![]()
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Affiliation(s)
- Hong-lian Zhang
- National Engineering Laboratory for the Development of Southwestern Endangered Medicinal Materials
- Guangxi Botanical Garden of Medicinal Plant
- Nanning
- China
- Sino-America Chinmedomics Technology Collaboration Center
| | - Ai-hua Zhang
- Sino-America Chinmedomics Technology Collaboration Center
- National TCM Key Laboratory of Serum Pharmacochemistry
- Chinmedomics Research Center of State Administration of TCM
- Laboratory of Metabolomics
- Department of Pharmaceutical Analysis
| | - Jian-hua Miao
- National Engineering Laboratory for the Development of Southwestern Endangered Medicinal Materials
- Guangxi Botanical Garden of Medicinal Plant
- Nanning
- China
| | - Hui Sun
- Sino-America Chinmedomics Technology Collaboration Center
- National TCM Key Laboratory of Serum Pharmacochemistry
- Chinmedomics Research Center of State Administration of TCM
- Laboratory of Metabolomics
- Department of Pharmaceutical Analysis
| | - Guang-li Yan
- Sino-America Chinmedomics Technology Collaboration Center
- National TCM Key Laboratory of Serum Pharmacochemistry
- Chinmedomics Research Center of State Administration of TCM
- Laboratory of Metabolomics
- Department of Pharmaceutical Analysis
| | - Fang-fang Wu
- National Engineering Laboratory for the Development of Southwestern Endangered Medicinal Materials
- Guangxi Botanical Garden of Medicinal Plant
- Nanning
- China
- Sino-America Chinmedomics Technology Collaboration Center
| | - Xi-jun Wang
- National Engineering Laboratory for the Development of Southwestern Endangered Medicinal Materials
- Guangxi Botanical Garden of Medicinal Plant
- Nanning
- China
- Sino-America Chinmedomics Technology Collaboration Center
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Weeks JC, Robinson KJ, Lockery SR, Roberts WM. Anthelmintic drug actions in resistant and susceptible C. elegans revealed by electrophysiological recordings in a multichannel microfluidic device. Int J Parasitol Drugs Drug Resist 2018; 8:607-628. [PMID: 30503202 PMCID: PMC6287544 DOI: 10.1016/j.ijpddr.2018.10.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 10/17/2018] [Accepted: 10/18/2018] [Indexed: 12/22/2022]
Abstract
Many anthelmintic drugs used to treat parasitic nematode infections target proteins that regulate electrical activity of neurons and muscles: ion channels (ICs) and neurotransmitter receptors (NTRs). Perturbation of IC/NTR function disrupts worm behavior and can lead to paralysis, starvation, immune attack and expulsion. Limitations of current anthelmintics include a limited spectrum of activity across species and the threat of drug resistance, highlighting the need for new drugs for human and veterinary medicine. Although ICs/NTRs are valuable anthelmintic targets, electrophysiological recordings are not commonly included in drug development pipelines. We designed a medium-throughput platform for recording electropharyngeograms (EPGs)-the electrical signals emitted by muscles and neurons of the pharynx during pharyngeal pumping (feeding)-in Caenorhabditis elegans and parasitic nematodes. The current study in C. elegans expands previous work in several ways. Detecting anthelmintic bioactivity in drugs, compounds or natural products requires robust, sustained pharyngeal pumping under baseline conditions. We generated concentration-response curves for stimulating pumping by perfusing 8-channel microfluidic devices (chips) with the neuromodulator serotonin, or with E. coli bacteria (C. elegans' food in the laboratory). Worm orientation in the chip (head-first vs. tail-first) affected the response to E. coli but not to serotonin. Using a panel of anthelmintics-ivermectin, levamisole and piperazine-targeting different ICs/NTRs, we determined the effects of concentration and treatment duration on EPG activity, and successfully distinguished control (N2) and drug-resistant worms (avr-14; avr-15; glc-1, unc-38 and unc-49). EPG recordings detected anthelmintic activity of drugs that target ICs/NTRs located in the pharynx as well as at extra-pharyngeal sites. A bus-8 mutant with enhanced permeability was more sensitive than controls to drug treatment. These results provide a useful framework for investigators who would like to more easily incorporate electrophysiology as a routine component of their anthelmintic research workflow.
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Affiliation(s)
- Janis C Weeks
- Institute of Neuroscience, University of Oregon, 1254 University of Oregon, Eugene, OR, 97403-1254, USA.
| | - Kristin J Robinson
- Institute of Neuroscience, University of Oregon, 1254 University of Oregon, Eugene, OR, 97403-1254, USA.
| | - Shawn R Lockery
- Institute of Neuroscience, University of Oregon, 1254 University of Oregon, Eugene, OR, 97403-1254, USA.
| | - William M Roberts
- Institute of Neuroscience, University of Oregon, 1254 University of Oregon, Eugene, OR, 97403-1254, USA.
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29
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Steinhauser ML, Olenchock BA, O'Keefe J, Lun M, Pierce KA, Lee H, Pantano L, Klibanski A, Shulman GI, Clish CB, Fazeli PK. The circulating metabolome of human starvation. JCI Insight 2018; 3:121434. [PMID: 30135314 DOI: 10.1172/jci.insight.121434] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/10/2018] [Indexed: 12/17/2022] Open
Abstract
The human adaptive starvation response allows for survival during long-term caloric deprivation. Whether the physiology of starvation is adaptive or maladaptive is context dependent: activation of pathways by caloric restriction may promote longevity, yet in the context of caloric excess, the same pathways may contribute to obesity. Here, we performed plasma metabolite profiling of longitudinally collected samples during a 10-day, 0-calorie fast in humans. We identify classical milestones in adaptive starvation, including the early consumption of gluconeogenic amino acids and the subsequent surge in plasma nonesterified fatty acids that marks the shift from carbohydrate to lipid metabolism, and demonstrate findings, including (a) the preferential release of unsaturated fatty acids and an associated shift in plasma lipid species with high degrees of unsaturation and (b) evidence that acute, starvation-mediated hypoleptinemia may be a driver of the transition from glucose to lipid metabolism in humans.
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Affiliation(s)
- Matthew L Steinhauser
- Department of Medicine, Division of Genetics, and.,Department of Medicine, Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Benjamin A Olenchock
- Department of Medicine, Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.,Harvard Medical School, Boston, Massachusetts, USA.,Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - John O'Keefe
- Department of Medicine, Division of Genetics, and
| | - Mingyue Lun
- Department of Medicine, Division of Genetics, and
| | - Kerry A Pierce
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Hang Lee
- Harvard Medical School, Boston, Massachusetts, USA.,MGH Biostatistics Center, Boston, Massachusetts, USA
| | - Lorena Pantano
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Anne Klibanski
- Harvard Medical School, Boston, Massachusetts, USA.,Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Gerald I Shulman
- Departments of Internal Medicine and Cellular and Molecular Physiology and Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Clary B Clish
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Pouneh K Fazeli
- Harvard Medical School, Boston, Massachusetts, USA.,Neuroendocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
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30
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Lai CQ, Smith CE, Parnell LD, Lee YC, Corella D, Hopkins P, Hidalgo BA, Aslibekyan S, Province MA, Absher D, Arnett DK, Tucker KL, Ordovas JM. Epigenomics and metabolomics reveal the mechanism of the APOA2-saturated fat intake interaction affecting obesity. Am J Clin Nutr 2018; 108:188-200. [PMID: 29901700 PMCID: PMC6454512 DOI: 10.1093/ajcn/nqy081] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Accepted: 03/28/2018] [Indexed: 12/13/2022] Open
Abstract
Background The putative functional variant -265T>C (rs5082) within the APOA2 promoter has shown consistent interactions with saturated fatty acid (SFA) intake to influence the risk of obesity. Objective The aim of this study was to implement an integrative approach to characterize the molecular basis of this interaction. Design We conducted an epigenome-wide scan on 80 participants carrying either the rs5082 CC or TT genotypes and consuming either a low-SFA (<22 g/d) or high-SFA diet (≥22 g/d), matched for age, sex, BMI, and diabetes status in the Boston Puerto Rican Health Study (BPRHS). We then validated the findings in selected participants in the Genetics of Lipid Lowering Drugs and Diet Network (GOLDN) Study (n = 379) and the Framingham Heart Study (FHS) (n = 243). Transcription and metabolomics analyses were conducted to determine the relation between epigenetic status, APOA2 mRNA expression, and blood metabolites. Results In the BPRHS, we identified methylation site cg04436964 as exhibiting significant differences between CC and TT participants consuming a high-SFA diet, but not among those consuming low-SFA. Similar results were observed in the GOLDN Study and the FHS. Additionally, in the FHS, cg04436964 methylation was negatively correlated with APOA2 expression in the blood of participants consuming a high-SFA diet. Furthermore, when consuming a high-SFA diet, CC carriers had lower APOA2 expression than those with the TT genotype. Lastly, metabolomic analysis identified 4 pathways as overrepresented by metabolite differences between CC and TT genotypes with high-SFA intake, including tryptophan and branched-chain amino acid (BCAA) pathways. Interestingly, these pathways were linked to rs5082-specific cg04436964 methylation differences in high-SFA consumers. Conclusions The epigenetic status of the APOA2 regulatory region is associated with SFA intake and APOA2 -265T>C genotype, promoting an APOA2 expression difference between APOA2 genotypes on a high-SFA diet, and modulating BCAA and tryptophan metabolic pathways. These findings identify potential mechanisms by which this highly reproducible gene-diet interaction influences obesity risk, and contribute new insights to ongoing investigations of the relation between SFA and human health. This study was registered at clinicaltrials.gov as NCT03452787.
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Affiliation(s)
- Chao-Qiang Lai
- USDA Agricultural Research Service,Address correspondence to C-QL (e-mail )
| | - Caren E Smith
- Nutrition and Genomics Laboratory, JM-USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | | | - Yu-Chi Lee
- Nutrition and Genomics Laboratory, JM-USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA
| | - Dolores Corella
- Department of Preventive Medicine, University of Valencia and CIBER Physiopathology of Obesity and Nutrition, Valencia, Spain
| | - Paul Hopkins
- Department of Cardiovascular Genetics, University of Utah, Salt Lake City, UT
| | - Bertha A Hidalgo
- Department of Epidemiology, School of Public Health, University of Alabama, Birmingham, AL
| | - Stella Aslibekyan
- Department of Epidemiology, School of Public Health, University of Alabama, Birmingham, AL
| | - Michael A Province
- Department of Genetics, Washington University School of Medicine, St. Louis, MO
| | - Devin Absher
- Hudson Alpha Institute for Biotechnology, Huntsville, AL
| | - Donna K Arnett
- College of Public Health, University of Kentucky, Lexington, KY
| | - Katherine L Tucker
- Department of Biomedical & Nutritional Sciences, University of Massachusetts Lowell, Lowell, MA
| | - Jose M Ordovas
- Nutrition and Genomics Laboratory, JM-USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA,IMDEA Food Institute, CEI UAM + CSIC, Madrid, Spain,Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
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31
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Leod KAM, Seas A, Wainwright ML, Mozzachiodi R. Effects of internal and external factors on the budgeting between defensive and non-defensive responses in Aplysia. Behav Brain Res 2018; 349:177-185. [PMID: 29704600 DOI: 10.1016/j.bbr.2018.04.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/23/2018] [Accepted: 04/13/2018] [Indexed: 10/17/2022]
Abstract
Following exposure to aversive stimuli, organisms budget their behaviors by augmenting defensive responses and reducing/suppressing non-defensive behaviors. This budgeting process must be flexible to accommodate modifications in the animal's internal and/or external state that require the normal balance between defensive and non-defensive behaviors to be adjusted. When exposed to aversive stimuli, the mollusk Aplysia budgets its behaviors by concurrently enhancing defensive withdrawal reflexes (an elementary form of learning known as sensitization) and suppressing feeding. Sensitization and feeding suppression are consistently co-expressed following different training protocols and share common temporal domains, suggesting that they are interlocked. In this study, we attempted to uncouple the co-expression of sensitization and feeding suppression using: 1) manipulation of the animal's motivational state through prolonged food deprivation and 2) extended training with aversive stimuli that induces sensitization lasting for weeks. Both manipulations uncoupled the co-expression of the above behavioral changes. Prolonged food deprivation prevented the expression of sensitization, but not of feeding suppression. Following the extended training, sensitization and feeding suppression were co-expressed only for a limited time (i.e., 24 h), after which feeding returned to baseline levels as sensitization persisted for up to seven days. These findings indicate that sensitization and feeding suppression are not interlocked and that their co-expression can be uncoupled by internal (prolonged food deprivation) and external (extended aversive training) factors. The different strategies, by which the co-expression of sensitization and feeding suppression was altered, provide an example of how budgeting strategies triggered by an identical aversive experience can vary depending on the state of the organism.
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Affiliation(s)
- Kaitlyn A Mac Leod
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, TX, 78412, USA
| | - Alexandra Seas
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, TX, 78412, USA
| | - Marcy L Wainwright
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, TX, 78412, USA
| | - Riccardo Mozzachiodi
- Department of Life Sciences, Texas A&M University - Corpus Christi, Corpus Christi, TX, 78412, USA.
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32
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Rodríguez-Palero MJ, López-Díaz A, Marsac R, Gomes JE, Olmedo M, Artal-Sanz M. An automated method for the analysis of food intake behaviour in Caenorhabditis elegans. Sci Rep 2018; 8:3633. [PMID: 29483540 PMCID: PMC5832146 DOI: 10.1038/s41598-018-21964-z] [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: 09/05/2017] [Accepted: 02/09/2018] [Indexed: 11/24/2022] Open
Abstract
The study of mechanisms that govern feeding behaviour and its related disorders is a matter of global health interest. The roundworm Caenorhabditis elegans is becoming a model organism of choice to study these conserved pathways. C. elegans feeding depends on the contraction of the pharynx (pumping). Thanks to the worm transparency, pumping can be directly observed under a stereoscope. Therefore, C. elegans feeding has been historically investigated by counting pharyngeal pumping or by other indirect approaches. However, those methods are short-term, time-consuming and unsuitable for independent measurements of sizable numbers of individuals. Although some particular devices and long-term methods have been lately reported, they fail in the automated, scalable and/or continuous aspects. Here we present an automated bioluminescence-based method for the analysis and continuous monitoring of worm feeding in a multi-well format. We validate the method using genetic, environmental and pharmacological modulators of pharyngeal pumping. This flexible methodology allows studying food intake at specific time-points or during longer periods of time, in single worms or in populations at any developmental stage. Additionally, changes in feeding rates in response to differential metabolic status or external environmental cues can be monitored in real time, allowing accurate kinetic measurements.
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Affiliation(s)
- Mª Jesús Rodríguez-Palero
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Departament of Molecular Biology and Biochemical Engineering, Carretera de Utrera, km 1, 41013, Seville, Spain
| | - Ana López-Díaz
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Departament of Molecular Biology and Biochemical Engineering, Carretera de Utrera, km 1, 41013, Seville, Spain
| | - Roxane Marsac
- Institut de Biochimie et Génétique Cellulaires - C.N.R.S. UMR 5095 and Université de Bordeaux, 1, rue Camille Saint-Saëns, 33077, Bordeaux Cedex, France
| | - José-Eduardo Gomes
- Institut de Biochimie et Génétique Cellulaires - C.N.R.S. UMR 5095 and Université de Bordeaux, 1, rue Camille Saint-Saëns, 33077, Bordeaux Cedex, France
| | - María Olmedo
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Departament of Molecular Biology and Biochemical Engineering, Carretera de Utrera, km 1, 41013, Seville, Spain.
- Department of Genetics, University of Seville, Avenida Reina Mercedes s/n, 41012, Seville, Spain.
| | - Marta Artal-Sanz
- Andalusian Center for Developmental Biology, Consejo Superior de Investigaciones Científicas/Junta de Andalucía/Universidad Pablo de Olavide, Departament of Molecular Biology and Biochemical Engineering, Carretera de Utrera, km 1, 41013, Seville, Spain.
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33
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Vohra M, Lemieux GA, Lin L, Ashrafi K. Kynurenic acid accumulation underlies learning and memory impairment associated with aging. Genes Dev 2018; 32:14-19. [PMID: 29386332 PMCID: PMC5828390 DOI: 10.1101/gad.307918.117] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 12/22/2017] [Indexed: 12/27/2022]
Abstract
Vohra et al. show that in C. elegans, a significant portion of the decline in learning and memory associated with aging is due to accumulation of a metabolite called kynurenic acid (KYNA), an endogenous antagonist of neural NMDA receptors. A general feature of animal aging is decline in learning and memory. Here we show that in Caenorhabditis elegans, a significant portion of this decline is due to accumulation of kynurenic acid (KYNA), an endogenous antagonist of neural N-methyl-D-aspartate receptors (NMDARs). We show that activation of a specific pair of interneurons either through genetic means or by depletion of KYNA significantly improves learning capacity in aged animals even when the intervention is applied in aging animals. KYNA depletion also improves memory. We show that insulin signaling is one factor in KYNA accumulation.
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Affiliation(s)
- Mihir Vohra
- Department of Physiology, University of California at San Francisco, San Francisco California 94158, USA
| | - George A Lemieux
- Department of Physiology, University of California at San Francisco, San Francisco California 94158, USA
| | - Lin Lin
- Department of Physiology, University of California at San Francisco, San Francisco California 94158, USA
| | - Kaveh Ashrafi
- Department of Physiology, University of California at San Francisco, San Francisco California 94158, USA
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Gracida X, Dion MF, Harris G, Zhang Y, Calarco JA. An Elongin-Cullin-SOCS Box Complex Regulates Stress-Induced Serotonergic Neuromodulation. Cell Rep 2017; 21:3089-3101. [PMID: 29241538 PMCID: PMC6283282 DOI: 10.1016/j.celrep.2017.11.042] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 09/15/2017] [Accepted: 11/11/2017] [Indexed: 02/07/2023] Open
Abstract
Neuromodulatory cells transduce environmental information into long-lasting behavioral responses. However, the mechanisms governing how neuronal cells influence behavioral plasticity are difficult to characterize. Here, we adapted the translating ribosome affinity purification (TRAP) approach in C. elegans to profile ribosome-associated mRNAs from three major tissues and the neuromodulatory dopaminergic and serotonergic cells. We identified elc-2, an Elongin C ortholog, specifically expressed in stress-sensing amphid neuron dual ciliated sensory ending (ADF) serotonergic sensory neurons, and we found that it plays a role in mediating a long-lasting change in serotonin-dependent feeding behavior induced by heat stress. We demonstrate that ELC-2 and the von Hippel-Lindau protein VHL-1, components of an Elongin-Cullin-SOCS box (ECS) E3 ubiquitin ligase, modulate this behavior after experiencing stress. Also, heat stress induces a transient redistribution of ELC-2, becoming more nuclearly enriched. Together, our results demonstrate dynamic regulation of an E3 ligase and a role for an ECS complex in neuromodulation and control of lasting behavioral states.
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Affiliation(s)
- Xicotencatl Gracida
- FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA; Department of Organismal and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Michael F Dion
- FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA
| | - Gareth Harris
- Department of Organismal and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Yun Zhang
- Department of Organismal and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA; Center for Brain Science, Harvard University, Cambridge, MA 02138, USA.
| | - John A Calarco
- FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA; Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3G5, Canada.
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Kynurenine aminotransferase activity of Aro8/Aro9 engage tryptophan degradation by producing kynurenic acid in Saccharomyces cerevisiae. Sci Rep 2017; 7:12180. [PMID: 28939805 PMCID: PMC5610271 DOI: 10.1038/s41598-017-12392-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 09/07/2017] [Indexed: 12/12/2022] Open
Abstract
Kynurenic acid (KA) is a tryptophan (Trp) metabolite that is synthesised in a branch of kynurenine (KYN) pathway. KYN aminotransferase (KAT) catalyses deamination of KYN, yielding KA. Although KA synthesis is evolutionarily conserved from bacteria to humans, the cellular benefits of synthesising KA are unclear. In this study, we constructed a KAT-null yeast mutant defective in KA synthesis to clarify the cellular function of KA. Amino acid sequence analysis and LC/MS quantification of KA revealed that Aro8 and Aro9 are the major KATs. KA was significantly decreased in the aro8Δ aro9Δ double mutant. We found that aro8Δ aro9Δ cells did not exhibit obvious defects in growth or oxidative stress response when proper amounts of amino acids are supplied in the media. We further found that aro8Δ aro9Δ cells were sensitive to excess Trp. The Trp sensitivity was not rescued by addition of KA, suggesting that Trp sensitivity is not due to the loss of KA. In conclusion, we propose that KAT activity is required for detoxification of Trp by converting it to the less toxic KA.
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Vohra M, Lemieux GA, Lin L, Ashrafi K. The beneficial effects of dietary restriction on learning are distinct from its effects on longevity and mediated by depletion of a neuroinhibitory metabolite. PLoS Biol 2017; 15:e2002032. [PMID: 28763436 PMCID: PMC5538637 DOI: 10.1371/journal.pbio.2002032] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 06/27/2017] [Indexed: 12/27/2022] Open
Abstract
In species ranging from humans to Caenorhabditis elegans, dietary restriction (DR) grants numerous benefits, including enhanced learning. The precise mechanisms by which DR engenders benefits on processes related to learning remain poorly understood. As a result, it is unclear whether the learning benefits of DR are due to myriad improvements in mechanisms that collectively confer improved cellular health and extension of organismal lifespan or due to specific neural mechanisms. Using an associative learning paradigm in C. elegans, we investigated the effects of DR as well as manipulations of insulin, mechanistic target of rapamycin (mTOR), AMP-activated protein kinase (AMPK), and autophagy pathways-processes implicated in longevity-on learning. Despite their effects on a vast number of molecular effectors, we found that the beneficial effects on learning elicited by each of these manipulations are fully dependent on depletion of kynurenic acid (KYNA), a neuroinhibitory metabolite. KYNA depletion then leads, in an N-methyl D-aspartate receptor (NMDAR)-dependent manner, to activation of a specific pair of interneurons with a critical role in learning. Thus, fluctuations in KYNA levels emerge as a previously unidentified molecular mechanism linking longevity and metabolic pathways to neural mechanisms of learning. Importantly, KYNA levels did not alter lifespan in any of the conditions tested. As such, the beneficial effects of DR on learning can be attributed to changes in a nutritionally sensitive metabolite with neuromodulatory activity rather than indirect or secondary consequences of improved health and extended longevity.
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Affiliation(s)
- Mihir Vohra
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - George A Lemieux
- 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
| | - Kaveh Ashrafi
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
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Long T, Rojo-Arreola L, Shi D, El-Sakkary N, Jarnagin K, Rock F, Meewan M, Rascón AA, Lin L, Cunningham KA, Lemieux GA, Podust L, Abagyan R, Ashrafi K, McKerrow JH, Caffrey CR. Phenotypic, chemical and functional characterization of cyclic nucleotide phosphodiesterase 4 (PDE4) as a potential anthelmintic drug target. PLoS Negl Trop Dis 2017; 11:e0005680. [PMID: 28704396 PMCID: PMC5526615 DOI: 10.1371/journal.pntd.0005680] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 07/25/2017] [Accepted: 06/04/2017] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Reliance on just one drug to treat the prevalent tropical disease, schistosomiasis, spurs the search for new drugs and drug targets. Inhibitors of human cyclic nucleotide phosphodiesterases (huPDEs), including PDE4, are under development as novel drugs to treat a range of chronic indications including asthma, chronic obstructive pulmonary disease and Alzheimer's disease. One class of huPDE4 inhibitors that has yielded marketed drugs is the benzoxaboroles (Anacor Pharmaceuticals). METHODOLOGY/PRINCIPAL FINDINGS A phenotypic screen involving Schistosoma mansoni and 1,085 benzoxaboroles identified a subset of huPDE4 inhibitors that induced parasite hypermotility and degeneration. To uncover the putative schistosome PDE4 target, we characterized four PDE4 sequences (SmPDE4A-D) in the parasite's genome and transcriptome, and cloned and recombinantly expressed the catalytic domain of SmPDE4A. Among a set of benzoxaboroles and catechol inhibitors that differentially inhibit huPDE4, a relationship between the inhibition of SmPDE4A, and parasite hypermotility and degeneration, was measured. To validate SmPDE4A as the benzoxaborole molecular target, we first generated Caenorhabditis elegans lines that express a cDNA for smpde4a on a pde4(ce268) mutant (hypermotile) background: the smpde4a transgene restored mutant worm motility to that of the wild type. We then showed that benzoxaborole inhibitors of SmPDE4A that induce hypermotility in the schistosome also elicit a hypermotile response in the C. elegans lines that express the smpde4a transgene, thereby confirming SmPDE4A as the relevant target. CONCLUSIONS/SIGNIFICANCE The orthogonal chemical, biological and genetic strategies employed identify SmPDE4A's contribution to parasite motility and degeneration, and its potential as a drug target. Transgenic C. elegans is highlighted as a potential screening tool to optimize small molecule chemistries to flatworm molecular drug targets.
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Affiliation(s)
- Thavy Long
- Center for Discovery and Innovation in Parasitic Diseases, University of California San Francisco, San Francisco, California, United States of America
- Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
| | - Liliana Rojo-Arreola
- Center for Discovery and Innovation in Parasitic Diseases, University of California San Francisco, San Francisco, California, United States of America
- Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
| | - Da Shi
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Nelly El-Sakkary
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Kurt Jarnagin
- Anacor Pharmaceuticals, Inc., Palo Alto, California, United States of America
| | - Fernando Rock
- Anacor Pharmaceuticals, Inc., Palo Alto, California, United States of America
| | - Maliwan Meewan
- Anacor Pharmaceuticals, Inc., Palo Alto, California, United States of America
| | - Alberto A. Rascón
- Center for Discovery and Innovation in Parasitic Diseases, University of California San Francisco, San Francisco, California, United States of America
- Department of Pathology, 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
| | - Katherine A. Cunningham
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - George A. Lemieux
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - Larissa Podust
- Center for Discovery and Innovation in Parasitic Diseases, University of California San Francisco, San Francisco, California, United States of America
- Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
| | - Ruben Abagyan
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Kaveh Ashrafi
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - James H. McKerrow
- Center for Discovery and Innovation in Parasitic Diseases, University of California San Francisco, San Francisco, California, United States of America
- Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
| | - Conor R. Caffrey
- Center for Discovery and Innovation in Parasitic Diseases, University of California San Francisco, San Francisco, California, United States of America
- Department of Pathology, University of California San Francisco, San Francisco, California, United States of America
- * E-mail:
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Battaglia RA, Kabiraj P, Willcockson HH, Lian M, Snider NT. Isolation of Intermediate Filament Proteins from Multiple Mouse Tissues to Study Aging-associated Post-translational Modifications. J Vis Exp 2017. [PMID: 28570536 DOI: 10.3791/55655] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Intermediate filaments (IFs), together with actin filaments and microtubules, form the cytoskeleton - a critical structural element of every cell. Normal functioning IFs provide cells with mechanical and stress resilience, while a dysfunctional IF cytoskeleton compromises cellular health and has been associated with many human diseases. Post-translational modifications (PTMs) critically regulate IF dynamics in response to physiological changes and under stress conditions. Therefore, the ability to monitor changes in the PTM signature of IFs can contribute to a better functional understanding, and ultimately conditioning, of the IF system as a stress responder during cellular injury. However, the large number of IF proteins, which are encoded by over 70 individual genes and expressed in a tissue-dependent manner, is a major challenge in sorting out the relative importance of different PTMs. To that end, methods that enable monitoring of PTMs on IF proteins on an organism-wide level, rather than for isolated members of the family, can accelerate research progress in this area. Here, we present biochemical methods for the isolation of the total, detergent-soluble, and detergent-resistant fraction of IF proteins from 9 different mouse tissues (brain, heart, lung, liver, small intestine, large intestine, pancreas, kidney, and spleen). We further demonstrate an optimized protocol for rapid isolation of IF proteins by using lysing matrix and automated homogenization of different mouse tissues. The automated protocol is useful for profiling IFs in experiments with high sample volume (such as in disease models involving multiple animals and experimental groups). The resulting samples can be utilized for various downstream analyses, including mass spectrometry-based PTM profiling. Utilizing these methods, we provide new data to show that IF proteins in different mouse tissues (brain and liver) undergo parallel changes with respect to their expression levels and PTMs during aging.
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Affiliation(s)
- Rachel A Battaglia
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill
| | - Parijat Kabiraj
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill
| | - Helen H Willcockson
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill
| | - Melinda Lian
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill
| | - Natasha T Snider
- Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill;
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Williams AC, Hill LJ. Meat and Nicotinamide: A Causal Role in Human Evolution, History, and Demographics. Int J Tryptophan Res 2017; 10:1178646917704661. [PMID: 28579800 PMCID: PMC5417583 DOI: 10.1177/1178646917704661] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 03/15/2017] [Indexed: 01/15/2023] Open
Abstract
Hunting for meat was a critical step in all animal and human evolution. A key brain-trophic element in meat is vitamin B3 / nicotinamide. The supply of meat and nicotinamide steadily increased from the Cambrian origin of animal predators ratcheting ever larger brains. This culminated in the 3-million-year evolution of Homo sapiens and our overall demographic success. We view human evolution, recent history, and agricultural and demographic transitions in the light of meat and nicotinamide intake. A biochemical and immunological switch is highlighted that affects fertility in the 'de novo' tryptophan-to-kynurenine-nicotinamide 'immune tolerance' pathway. Longevity relates to nicotinamide adenine dinucleotide consumer pathways. High meat intake correlates with moderate fertility, high intelligence, good health, and longevity with consequent population stability, whereas low meat/high cereal intake (short of starvation) correlates with high fertility, disease, and population booms and busts. Too high a meat intake and fertility falls below replacement levels. Reducing variances in meat consumption might help stabilise population growth and improve human capital.
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Affiliation(s)
- Adrian C Williams
- Department of Neurology, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Lisa J Hill
- Neuroscience and Ophthalmology Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK
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40
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Ghosh DD, Nitabach MN, Zhang Y, Harris G. Multisensory integration in C. elegans. Curr Opin Neurobiol 2017; 43:110-118. [PMID: 28273525 PMCID: PMC5501174 DOI: 10.1016/j.conb.2017.01.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 01/26/2017] [Accepted: 01/30/2017] [Indexed: 12/19/2022]
Abstract
Multisensory integration is a neural process by which signals from two or more distinct sensory channels are simultaneously processed to form a more coherent representation of the environment. Multisensory integration, especially when combined with a survey of internal states, provides selective advantages for animals navigating complex environments. Despite appreciation of the importance of multisensory integration in behavior, the underlying molecular and cellular mechanisms remain poorly understood. Recent work looking at how Caenorhabditis elegans makes multisensory decisions has yielded mechanistic insights into how a relatively simple and well-defined nervous system employs circuit motifs of defined features, synaptic signals and extrasynaptic neurotransmission, as well as neuromodulators in processing and integrating multiple sensory inputs to generate flexible and adaptive behavioral outputs.
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Affiliation(s)
- D Dipon Ghosh
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, United States
| | - Michael N Nitabach
- Department of Cellular and Molecular Physiology, Yale University, New Haven, CT, United States; Department of Genetics, Yale University, New Haven, CT, United States; Kavli Institute for Neuroscience, Yale University, New Haven, CT, United States.
| | - Yun Zhang
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA, United States.
| | - Gareth Harris
- Department of Organismic and Evolutionary Biology, Center for Brain Science, Harvard University, Cambridge, MA, United States
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41
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Lovelace MD, Varney B, Sundaram G, Lennon MJ, Lim CK, Jacobs K, Guillemin GJ, Brew BJ. Recent evidence for an expanded role of the kynurenine pathway of tryptophan metabolism in neurological diseases. Neuropharmacology 2017; 112:373-388. [DOI: 10.1016/j.neuropharm.2016.03.024] [Citation(s) in RCA: 203] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 03/10/2016] [Accepted: 03/12/2016] [Indexed: 12/13/2022]
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Schwarcz R, Stone TW. The kynurenine pathway and the brain: Challenges, controversies and promises. Neuropharmacology 2017; 112:237-247. [PMID: 27511838 PMCID: PMC5803785 DOI: 10.1016/j.neuropharm.2016.08.003] [Citation(s) in RCA: 252] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 07/29/2016] [Accepted: 08/05/2016] [Indexed: 12/29/2022]
Abstract
Research on the neurobiology of the kynurenine pathway has suffered years of relative obscurity because tryptophan degradation, and its involvement in both physiology and major brain diseases, was viewed almost exclusively through the lens of the well-established metabolite serotonin. With increasing recognition that kynurenine and its metabolites can affect and even control a variety of classic neurotransmitter systems directly and indirectly, interest is expanding rapidly. Moreover, kynurenine pathway metabolism itself is modulated in conditions such as infection and stress, which are known to induce major changes in well-being and behaviour, so that kynurenines may be instrumental in the etiology of psychiatric and neurological disorders. It is therefore likely that the near future will not only witness the discovery of additional physiological and pathological roles for brain kynurenines, but also ever-increasing interest in drug development based on these roles. In particular, targeting the kynurenine pathway with new specific agents may make it possible to prevent disease by appropriate pharmacological or genetic manipulations. The following overview focuses on areas of kynurenine research which are either controversial, of major potential therapeutic interest, or just beginning to receive the degree of attention which will clarify their relevance to neurobiology and medicine. It also highlights technical issues so that investigators entering the field, and new research initiatives, are not misdirected by inappropriate experimental approaches or incorrect interpretations at this time of skyrocketing interest in the subject matter. This article is part of the Special Issue entitled 'The Kynurenine Pathway in Health and Disease'.
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Affiliation(s)
- Robert Schwarcz
- Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Trevor W Stone
- Institute of Neuroscience and Psychology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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Neural Architecture of Hunger-Dependent Multisensory Decision Making in C. elegans. Neuron 2016; 92:1049-1062. [PMID: 27866800 DOI: 10.1016/j.neuron.2016.10.030] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Revised: 08/30/2016] [Accepted: 10/10/2016] [Indexed: 01/28/2023]
Abstract
Little is known about how animals integrate multiple sensory inputs in natural environments to balance avoidance of danger with approach to things of value. Furthermore, the mechanistic link between internal physiological state and threat-reward decision making remains poorly understood. Here we confronted C. elegans worms with the decision whether to cross a hyperosmotic barrier presenting the threat of desiccation to reach a source of food odor. We identified a specific interneuron that controls this decision via top-down extrasynaptic aminergic potentiation of the primary osmosensory neurons to increase their sensitivity to the barrier. We also establish that food deprivation increases the worm's willingness to cross the dangerous barrier by suppressing this pathway. These studies reveal a potentially general neural circuit architecture for internal state control of threat-reward decision making.
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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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Mohammadi AA, Jazayeri S, Khosravi-Darani K, Solati Z, Mohammadpour N, Asemi Z, Adab Z, Djalali M, Tehrani-Doost M, Hosseini M, Eghtesadi S. The effects of probiotics on mental health and hypothalamic-pituitary-adrenal axis: A randomized, double-blind, placebo-controlled trial in petrochemical workers. Nutr Neurosci 2016; 19:387-395. [PMID: 25879690 DOI: 10.1179/1476830515y.0000000023] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVE The aim of this study was to determine effects of probiotic yogurt and multispecies probiotic capsule supplementation on mental health and hypothalamic-pituitary-adrenal axis in petrochemical workers. METHODS The present randomized double-blind, placebo-controlled trial was conducted on 70 petrochemical workers. Subjects were randomly divided into three groups to receive 100 g/day probiotic yogurt + one placebo capsule (n = 25) or one probiotic capsule daily + 100 g/day conventional yogurt (n = 25) or 100 g/day conventional yogurt + one placebo capsule (n = 20) for 6 weeks. Mental health parameters including general health questionnaire (GHQ) and depression anxiety and stress scale (DASS) scores were measured. Fasting blood samples were obtained at the beginning and 6 weeks after the intervention to quantify hypothalamic-pituitary-adrenal axis. RESULTS After 6 weeks of intervention, a significant improvement of GHQ was observed in the probiotic yogurt (18.0 ± 1.5 vs. 13.5 ± 1.9, P = 0.007) and in the probiotic capsule group (16.9 ± 1.8 vs. 9.8 ± 1.9, P = 0.001), as well as a significant improvement in DASS scores in the probiotic yogurt (23.3 ± 3.7 vs. 13.0 ± 3.7, P = 0.02) and the probiotic capsule group (18.9 ± 3.2 vs. 9.4 ± 4.0, P = 0.006). However, there was no significant improvement in the conventional yogurt group (P = 0.05 for GHQ and P = 0.08 for DASS). DISCUSSION The consumption of probiotic yogurt or a multispecies probiotic capsule had beneficial effects on mental health parameters in petrochemical workers.
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Affiliation(s)
- Ali Akbar Mohammadi
- a Department of Nutrition, School of Public Health , Iran University of Medical Sciences , Tehran , Iran
| | - Shima Jazayeri
- a Department of Nutrition, School of Public Health , Iran University of Medical Sciences , Tehran , Iran
| | - Kianoush Khosravi-Darani
- b Research Department of Food Technology Research , National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences , Tehran
| | - Zahra Solati
- c School of Nutritional Sciences and Dietetics , Tehran University of Medical Sciences , Iran
| | - Nakisa Mohammadpour
- c School of Nutritional Sciences and Dietetics , Tehran University of Medical Sciences , Iran
| | - Zatollah Asemi
- d Research Center for Biochemistry and Nutrition in Metabolic Diseases , Kashan University of Medical Sciences , Iran
| | - Zohre Adab
- c School of Nutritional Sciences and Dietetics , Tehran University of Medical Sciences , Iran
| | - Mahmoud Djalali
- c School of Nutritional Sciences and Dietetics , Tehran University of Medical Sciences , Iran
| | - Mehdi Tehrani-Doost
- e Department of Psychiatry, Roozbeh Hospital , Tehran University of Medical Sciences , Iran
| | - Mostafa Hosseini
- f Department of Epidemiology and Biostatistics, School of Public Health , Tehran University of Medical Sciences , Iran
| | - Shahryar Eghtesadi
- a Department of Nutrition, School of Public Health , Iran University of Medical Sciences , Tehran , Iran
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Ahmadi M, Roy R. AMPK acts as a molecular trigger to coordinate glutamatergic signals and adaptive behaviours during acute starvation. eLife 2016; 5. [PMID: 27642785 PMCID: PMC5028190 DOI: 10.7554/elife.16349] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 08/25/2016] [Indexed: 12/02/2022] Open
Abstract
The stress associated with starvation is accompanied by compensatory behaviours that enhance foraging efficiency and increase the probability of encountering food. However, the molecular details of how hunger triggers changes in the activity of neural circuits to elicit these adaptive behavioural outcomes remains to be resolved. We show here that AMP-activated protein kinase (AMPK) regulates neuronal activity to elicit appropriate behavioural outcomes in response to acute starvation, and this effect is mediated by the coordinated modulation of glutamatergic inputs. AMPK targets both the AMPA-type glutamate receptor GLR-1 and the metabotropic glutamate receptor MGL-1 in one of the primary circuits that governs behavioural response to food availability in C. elegans. Overall, our study suggests that AMPK acts as a molecular trigger in the specific starvation-sensitive neurons to modulate glutamatergic inputs and to elicit adaptive behavioural outputs in response to acute starvation. DOI:http://dx.doi.org/10.7554/eLife.16349.001 Animals often need to adapt to changes in food availability in order to survive. When food is in short supply and animals are starving, their energy reserves are low. To conserve energy, behaviours that are not essential to survival, like mating, are put on hold. Instead, animals channel their energies into foraging strategies that may help them find new food sources. These behavioural changes are likely to be caused by changes in brain activity triggered by starvation. It is not entirely clear how starvation changes the brain and consequently how an animal behaves. It is also difficult to study how the brain regulates behaviour in response to environmental changes like food availability in larger animals with more complex nervous systems. Instead, scientists often study less complex animals like a type of worm called C. elegans, because this model organism has a simpler nervous system and it is easier to observe its feeding behaviours. Previous observations have revealed that well-fed worms travel backwards when they are hungry, revisiting sites where they have previously found food. Yet, when the worms are starving, they move forward more frequently, presumably to find new sources of food. Now, Ahmadi and Roy show starving worms activate an enzyme called AMP-activated protein kinase (or AMPK for short). Worms genetically engineered to lack this enzyme tend to move backward when they are starved, instead of moving forward like typical starving worms. This shows that AMPK triggers a wider search for new food sources. Further experiments showed that AMPK acts to inhibit two receptors, which in turn, affects the activity of two different neurons. These two neurons work together to change the animal’s behaviour and boost the likelihood the animal will be able to find a new food source when food is scarce. More complex animals, including humans, also have the receptors and brain cells targeted by AMPK in response to starvation. Future studies are needed to determine whether a similar chain of events occurs in creatures with more complicated nervous systems. DOI:http://dx.doi.org/10.7554/eLife.16349.002
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Affiliation(s)
- Moloud Ahmadi
- Department of Biology, McGill University, Montreal, Canada
| | - Richard Roy
- Department of Biology, McGill University, Montreal, Canada
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Lemieux GA, Ashrafi K. Investigating Connections between Metabolism, Longevity, and Behavior in Caenorhabditis elegans. Trends Endocrinol Metab 2016; 27:586-596. [PMID: 27289335 PMCID: PMC4958586 DOI: 10.1016/j.tem.2016.05.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 05/18/2016] [Accepted: 05/19/2016] [Indexed: 01/19/2023]
Abstract
An overview of Caenorhabditis elegans as an experimental organism for studying energy balance is presented. Some of the unresolved questions that complicate the interpretation of lipid measurements from C. elegans are highlighted. We review studies that show that both lipid synthesis and lipid breakdown pathways are activated and needed for the longevity of hermaphrodites that lack their germlines. These findings illustrate the heterogeneity of triglyceride-rich lipid particles in C. elegans and reveal specific lipid signals that promote longevity. Finally, we provide a brief overview of feeding behavioral responses of C. elegans to varying nutritional conditions and highlight an unanticipated metabolic pathway that allows the incorporation of experience in feeding behavior.
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Affiliation(s)
| | - Kaveh Ashrafi
- University of California, San Francisco, San Francisco, CA, USA.
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Dillon J, Holden-Dye L, O'Connor V, Hopper NA. Context-dependent regulation of feeding behaviour by the insulin receptor, DAF-2, in Caenorhabditis elegans. INVERTEBRATE NEUROSCIENCE : IN 2016; 16:4. [PMID: 27209024 PMCID: PMC4875951 DOI: 10.1007/s10158-016-0187-2] [Citation(s) in RCA: 14] [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: 11/12/2015] [Accepted: 04/13/2016] [Indexed: 12/31/2022]
Abstract
Insulin signalling plays a significant role in both developmental programmes and pathways modulating the neuronal signalling that controls adult behaviour. Here, we have investigated insulin signalling in food-associated behaviour in adult C. elegans by scoring locomotion and feeding on and off bacteria, the worm's food. This analysis used mutants (daf-2, daf-18) of the insulin signalling pathway, and we provide evidence for an acute role for insulin signalling in the adult nervous system distinct from its impact on developmental programmes. Insulin receptor daf-2 mutants move slower than wild type both on and off food and showed impaired locomotory responses to food deprivation. This latter behaviour is manifest as a failure to instigate dispersal following prolonged food deprivation and suggests a role for insulin signalling in this adaptive response. Insulin receptor daf-2 mutants are also deficient in pharyngeal pumping on food and off food. Pharmacological analysis showed the pharynx of daf-2 is selectively compromised in its response to 5-HT compared to the excitatory neuropeptide FLP-17. By comparing the adaptive pharyngeal behaviour in intact worms and isolated pharyngeal preparations, we determined that an insulin-dependent signal extrinsic to the pharyngeal system is involved in feeding adaptation. Hence, we suggest that reactive insulin signalling modulates both locomotory foraging and pharyngeal pumping as the animal adapts to the absence of food. We discuss this in the context of insulin signalling directing a shift in the sensitivity of neurotransmitter systems to regulate the worm's response to changes in food availability in the environment.
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Affiliation(s)
- James Dillon
- Centre for Biological Science, University of Southampton, Highfield Campus, University Road, Southampton, Hants, SO17 1BJ, UK.
| | - Lindy Holden-Dye
- Centre for Biological Science, University of Southampton, Highfield Campus, University Road, Southampton, Hants, SO17 1BJ, UK
| | - Vincent O'Connor
- Centre for Biological Science, University of Southampton, Highfield Campus, University Road, Southampton, Hants, SO17 1BJ, UK
| | - Neil A Hopper
- Centre for Biological Science, University of Southampton, Highfield Campus, University Road, Southampton, Hants, SO17 1BJ, UK
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Ahmadi M, Roy R. 5'-AMP-Activated Protein Kinase Signaling in Caenorhabditis elegans. EXPERIENTIA SUPPLEMENTUM (2012) 2016; 107:375-388. [PMID: 27812988 DOI: 10.1007/978-3-319-43589-3_15] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
AMP-activated protein kinase (AMPK) is one of the central regulators of cellular and organismal metabolism in eukaryotes. Once activated by decreased energy levels, it induces ATP production by promoting catabolic pathways while conserving ATP by inhibiting anabolic pathways. AMPK plays a crucial role in various aspects of cellular function such as regulating growth, reprogramming metabolism, autophagy, and cell polarity. In this chapter, we focus on how recent breakthroughs made using the model organism Caenorhabditis elegans have contributed to our understanding of AMPK function and how it can be utilized in the future to elucidate hitherto unknown aspects of AMPK signaling.
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Affiliation(s)
- Moloud Ahmadi
- Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal, QC, Canada, H3A 1B1
| | - Richard Roy
- Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal, QC, Canada, H3A 1B1.
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Abstract
The compact nervous system of Caenorhabditis elegans and its genetic tractability are features that make this organism highly suitable for investigating energy balance in an animal system. Here, we focus on molecular components and organizational principles emerging from the investigation of pathways that largely originate in the nervous system and regulate feeding behavior but also peripheral fat regulation through neuroendocrine signaling. We provide an overview of studies aimed at understanding how C. elegans integrate internal and external cues in feeding behavior. We highlight some of the similarities and differences in energy balance between C. elegans and mammals. We also provide our perspective on unresolved issues, both conceptual and technical, that we believe have hampered critical evaluation of findings relevant to fat regulation in C. elegans.
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Affiliation(s)
- George A Lemieux
- Department of Physiology, University of California, San Francisco, California 94158;
| | - Kaveh Ashrafi
- Department of Physiology, University of California, San Francisco, California 94158;
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