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de la Cruz L, Bui D, Moreno CM, Vivas O. Sympathetic Motor Neuron Dysfunction is a Missing Link in Age-Associated Sympathetic Overactivity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.27.559800. [PMID: 37808870 PMCID: PMC10557755 DOI: 10.1101/2023.09.27.559800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Overactivity of the sympathetic nervous system is a hallmark of aging. The cellular mechanisms behind this overactivity remain poorly understood, with most attention paid to likely central nervous system components. In this work, we hypothesized that aging also affects the function of motor neurons in the peripheral sympathetic ganglia. To test this hypothesis, we compared the electrophysiological responses and ion-channel activity of neurons isolated from the superior cervical ganglia of young (12 weeks), middle-aged (64 weeks), and old (115 weeks) mice. These approaches showed that aging does impact the intrinsic properties of sympathetic motor neurons, increasing spontaneous and evoked firing responses. A reduction of M current emerged as a major contributor to age-related hyperexcitability. Thus, it is essential to consider the effect of aging on motor components of the sympathetic reflex as a crucial part of the mechanism involved in sympathetic overactivity.
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Affiliation(s)
- Lizbeth de la Cruz
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Derek Bui
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Claudia M. Moreno
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
- Howard Hughes Medical Institute
| | - Oscar Vivas
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
- Department of Pharmacology, University of Washington, Seattle, WA
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Hayden AN, Brandel KL, Merlau PR, Vijayakumar P, Leptich EJ, Pietryk EW, Gaytan ES, Ni CW, Chao HT, Rosenfeld JA, Arey RN. Behavioral screening of conserved RNA-binding proteins reveals CEY-1/YBX RNA-binding protein dysfunction leads to impairments in memory and cognition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.05.574402. [PMID: 38260399 PMCID: PMC10802296 DOI: 10.1101/2024.01.05.574402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
RNA-binding proteins (RBPs) regulate translation and plasticity which are required for memory. RBP dysfunction has been linked to a range of neurological disorders where cognitive impairments are a key symptom. However, of the 2,000 RBPs in the human genome, many are uncharacterized with regards to neurological phenotypes. To address this, we used the model organism C. elegans to assess the role of 20 conserved RBPs in memory. We identified eight previously uncharacterized memory regulators, three of which are in the C. elegans Y-Box (CEY) RBP family. Of these, we determined that cey-1 is the closest ortholog to the mammalian Y-Box (YBX) RBPs. We found that CEY-1 is both necessary in the nervous system for memory ability and sufficient to increase memory. Leveraging human datasets, we found both copy number variation losses and single nucleotide variants in YBX1 and YBX3 in individuals with neurological symptoms. We identified one predicted deleterious YBX3 variant of unknown significance, p.Asn127Tyr, in two individuals with neurological symptoms. Introducing this variant into endogenous cey-1 locus caused memory deficits in the worm. We further generated two humanized worm lines expressing human YBX3 or YBX1 at the cey-1 locus to test evolutionary conservation of YBXs in memory and the potential functional significance of the p.Asn127Tyr variant. Both YBX1/3 can functionally replace cey-1, and introduction of p.Asn127Tyr into the humanized YBX3 locus caused memory deficits. Our study highlights the worm as a model to reveal memory regulators and identifies YBX dysfunction as a potential new source of rare neurological disease.
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Affiliation(s)
- Ashley N Hayden
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
| | - Katie L Brandel
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
| | - Paul R Merlau
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
| | | | - Emily J Leptich
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
| | - Edward W Pietryk
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030
| | - Elizabeth S Gaytan
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
- Postbaccalaureate Research Education Program, Baylor College of Medicine, Houston, TX, 77030
| | - Connie W Ni
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
- Department of Neuroscience, Rice University, Houston, TX 77005
| | - Hsiao-Tuan Chao
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030
- Department of Pediatrics, Division of Neurology and Developmental Neuroscience, Baylor College of Medicine, Houston, TX, 77030
- Cain Pediatric Neurology Research Foundation Laboratories, Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX, 77030
- McNair Medical Institute, The Robert and Janice McNair Foundation, Houston, TX, 77030
| | - Jill A Rosenfeld
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030
- Baylor Genetics Laboratories, Houston, TX 77021
| | - Rachel N Arey
- Center for Precision Environmental Health, Baylor College of Medicine, Houston, TX, 77030
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030
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Gharat V, Peter F, de Quervain DJF, Papassotiropoulos A, Stetak A. Role of GLR-1 in Age-Dependent Short-Term Memory Decline. eNeuro 2024; 11:ENEURO.0420-23.2024. [PMID: 38519128 PMCID: PMC11005081 DOI: 10.1523/eneuro.0420-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Revised: 02/10/2024] [Accepted: 03/06/2024] [Indexed: 03/24/2024] Open
Abstract
As the global elderly population grows, age-related cognitive decline is becoming an increasingly significant healthcare issue, often leading to various neuropsychiatric disorders. Among the many molecular players involved in memory, AMPA-type glutamate receptors are known to regulate learning and memory, but how their dynamics change with age and affect memory decline is not well understood. Here, we examined the in vivo properties of the AMPA-type glutamate receptor GLR-1 in the AVA interneuron of the Caenorhabditis elegans nervous system during physiological aging. We found that both total and membrane-bound GLR-1 receptor levels decrease with age in wild-type worms, regardless of their location along the axon. Using fluorescence recovery after photobleaching, we also demonstrated that a reduction in GLR-1 abundance correlates with decreased local, synaptic GLR-1 receptor dynamics. Importantly, we found that reduced GLR-1 levels strongly correlate with the age-related decline in short-term associative memory. Genetic manipulation of GLR-1 stability, by either deleting msi-1 or expressing a ubiquitination-defective GLR-1 (4KR) variant, prevented this age-related reduction in receptor abundance and improved the short-term memory performance in older animals, which reached performance levels similar to those of young animals. Overall, our data indicate that AMPA-type glutamate receptor abundance and dynamics are key factors in maintaining memory function and that changes in these parameters are linked to age-dependent short-term memory decline.
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Affiliation(s)
- Vaibhav Gharat
- Division of Molecular Neuroscience, Department of Biomedicine, University of Basel, Basel 4055, Switzerland
- Research Cluster Molecular and Cognitive Neurosciences, University of Basel, Basel 4055, Switzerland
| | - Fabian Peter
- Division of Molecular Neuroscience, Department of Biomedicine, University of Basel, Basel 4055, Switzerland
- Research Cluster Molecular and Cognitive Neurosciences, University of Basel, Basel 4055, Switzerland
| | - Dominique J-F de Quervain
- Division of Molecular Neuroscience, Department of Biomedicine, University of Basel, Basel 4055, Switzerland
- Division of Cognitive Neuroscience, Department of Biomedicine, University of Basel, Basel 4055, Switzerland
- University Psychiatric Clinics, University of Basel, Basel 4002, Switzerland
| | - Andreas Papassotiropoulos
- Division of Molecular Neuroscience, Department of Biomedicine, University of Basel, Basel 4055, Switzerland
- Research Cluster Molecular and Cognitive Neurosciences, University of Basel, Basel 4055, Switzerland
- University Psychiatric Clinics, University of Basel, Basel 4002, Switzerland
| | - Attila Stetak
- Division of Molecular Neuroscience, Department of Biomedicine, University of Basel, Basel 4055, Switzerland
- Research Cluster Molecular and Cognitive Neurosciences, University of Basel, Basel 4055, Switzerland
- University Psychiatric Clinics, University of Basel, Basel 4002, Switzerland
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Invited review: Unearthing the mechanisms of age-related neurodegenerative disease using Caenorhabditis elegans. Comp Biochem Physiol A Mol Integr Physiol 2022; 267:111166. [PMID: 35176489 DOI: 10.1016/j.cbpa.2022.111166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 12/11/2022]
Abstract
As human life expectancy increases, neurodegenerative diseases present a growing public health threat, for which there are currently few effective treatments. There is an urgent need to understand the molecular and genetic underpinnings of these disorders so new therapeutic targets can be identified. Here we present the argument that the simple nematode worm Caenorhabditis elegans is a powerful tool to rapidly study neurodegenerative disorders due to their short lifespan and vast array of genetic tools, which can be combined with characterization of conserved neuronal processes and behavior orthologous to those disrupted in human disease. We review how pre-existing C. elegans models provide insight into human neurological disease as well as an overview of current tools available to study neurodegenerative diseases in the worm, with an emphasis on genetics and behavior. We also discuss open questions that C. elegans may be particularly well suited for in future studies and how worms will be a valuable preclinical model to better understand these devastating neurological disorders.
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McCoy MT, Jayanthi S, Cadet JL. Potassium Channels and Their Potential Roles in Substance Use Disorders. Int J Mol Sci 2021; 22:1249. [PMID: 33513859 PMCID: PMC7865894 DOI: 10.3390/ijms22031249] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 01/12/2023] Open
Abstract
Substance use disorders (SUDs) are ubiquitous throughout the world. However, much remains to be done to develop pharmacotherapies that are very efficacious because the focus has been mostly on using dopaminergic agents or opioid agonists. Herein we discuss the potential of using potassium channel activators in SUD treatment because evidence has accumulated to support a role of these channels in the effects of rewarding drugs. Potassium channels regulate neuronal action potential via effects on threshold, burst firing, and firing frequency. They are located in brain regions identified as important for the behavioral responses to rewarding drugs. In addition, their expression profiles are influenced by administration of rewarding substances. Genetic studies have also implicated variants in genes that encode potassium channels. Importantly, administration of potassium agonists have been shown to reduce alcohol intake and to augment the behavioral effects of opioid drugs. Potassium channel expression is also increased in animals with reduced intake of methamphetamine. Together, these results support the idea of further investing in studies that focus on elucidating the role of potassium channels as targets for therapeutic interventions against SUDs.
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Affiliation(s)
| | | | - Jean Lud Cadet
- Molecular Neuropsychiatry Research Branch, NIDA Intramural Research Program, Baltimore, MD 21224, USA; (M.T.M.); (S.J.)
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