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Perales-Salinas V, Purushotham SS, Buskila Y. Curcumin as a potential therapeutic agent for treating neurodegenerative diseases. Neurochem Int 2024; 178:105790. [PMID: 38852825 DOI: 10.1016/j.neuint.2024.105790] [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: 05/07/2024] [Revised: 06/04/2024] [Accepted: 06/06/2024] [Indexed: 06/11/2024]
Abstract
Neurodegenerative diseases are characterized by the progressive loss of neuronal structure and function, posing a tremendous burden on health systems worldwide. Although the underlying pathological mechanisms for various neurodegenerative diseases are still unclear, a common pathological hallmark is the abundance of neuroinflammatory processes, which affect both disease onset and progression. In this review, we explore the pathways and role of neuroinflammation in various neurodegenerative diseases and further assess the potential use of curcumin, a natural spice with antioxidant and anti-inflammatory properties that has been extensively used worldwide as a traditional medicine and potential therapeutic agent. Following the examination of preclinical and clinical studies that assessed curcumin as a potential therapeutic agent, we highlight the bioavailability of curcumin in the body and discuss both the challenges and benefits of using curcumin as a therapeutic compound for treating neurodegeneration. Although elucidating the involvement of curcumin in aging and neurodegeneration has great potential for developing future CNS-related therapeutic targets, further research is required to elucidate the mechanisms by which Curcumin affects brain physiology, especially BBB integrity, under both physiological and disease conditions.
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Affiliation(s)
| | | | - Yossi Buskila
- School of Medicine, Western Sydney University, Campbelltown, NSW, 2560, Australia; The MARCS Institute, Western Sydney University, Penrith, NSW, 2751, Australia.
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Goniotaki D, Tamagnini F, Biasetti L, Rumpf SL, Troakes C, Pollack SJ, Ukwesa S, Sun H, Kraev I, Serpell LC, Noble W, Staras K, Hanger DP. Tau-mediated synaptic dysfunction is coupled with HCN channelopathy. Alzheimers Dement 2024. [PMID: 38994745 DOI: 10.1002/alz.14074] [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: 01/29/2024] [Revised: 05/01/2024] [Accepted: 05/25/2024] [Indexed: 07/13/2024]
Abstract
INTRODUCTION In tauopathies, altered tau processing correlates with impairments in synaptic density and function. Changes in hyperpolarization-activated cyclic nucleotide-gated (HCN) channels contribute to disease-associated abnormalities in multiple neurodegenerative diseases. METHODS To investigate the link between tau and HCN channels, we performed histological, biochemical, ultrastructural, and functional analyses of hippocampal tissues from Alzheimer's disease (AD), age-matched controls, Tau35 mice, and/or Tau35 primary hippocampal neurons. RESULTS Expression of specific HCN channels is elevated in post mortem AD hippocampus. Tau35 mice develop progressive abnormalities including increased phosphorylated tau, enhanced HCN channel expression, decreased dendritic branching, reduced synapse density, and vesicle clustering defects. Tau35 primary neurons show increased HCN channel expression enhanced hyperpolarization-induced membrane voltage "sag" and changes in the frequency and kinetics of spontaneous excitatory postsynaptic currents. DISCUSSION Our findings are consistent with a model in which pathological changes in tauopathies impact HCN channels to drive network-wide structural and functional synaptic deficits. HIGHLIGHTS Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are functionally linked to the development of tauopathy. Expression of specific HCN channels is elevated in the hippocampus in Alzheimer's disease and the Tau35 mouse model of tauopathy. Increased expression of HCN channels in Tau35 mice is accompanied by hyperpolarization-induced membrane voltage "sag" demonstrating a detrimental effect of tau abnormalities on HCN channel function. Tau35 expression alters synaptic organization, causing a loosened vesicle clustering phenotype in Tau35 mice.
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Affiliation(s)
- Despoina Goniotaki
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
| | - Francesco Tamagnini
- Department of Pharmacy, School of Chemistry, Food and Pharmacy, University of Reading, Reading, UK
| | - Luca Biasetti
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, UK
| | - Svenja-Lotta Rumpf
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
| | - Claire Troakes
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
| | - Saskia J Pollack
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
| | - Shalom Ukwesa
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
| | - Haoyue Sun
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
| | - Igor Kraev
- Electron Microscopy Suite, STEM Faculty, The Open University, Milton Keynes, UK
| | - Louise C Serpell
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, UK
| | - Wendy Noble
- Department of Clinical and Biomedical Sciences, University of Exeter, Exeter, UK
| | - Kevin Staras
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Brighton, UK
| | - Diane P Hanger
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology & Neuroscience, Maurice Wohl Clinical Neuroscience Institute, King's College London, London, UK
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Odierna GL, Vucic S, Dyer M, Dickson T, Woodhouse A, Blizzard C. How do we get from hyperexcitability to excitotoxicity in amyotrophic lateral sclerosis? Brain 2024; 147:1610-1621. [PMID: 38408864 PMCID: PMC11068114 DOI: 10.1093/brain/awae039] [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: 07/17/2023] [Revised: 11/15/2023] [Accepted: 12/10/2023] [Indexed: 02/28/2024] Open
Abstract
Amyotrophic lateral sclerosis is a devastating neurodegenerative disease that, at present, has no effective cure. Evidence of increased circulating glutamate and hyperexcitability of the motor cortex in patients with amyotrophic lateral sclerosis have provided an empirical support base for the 'dying forward' excitotoxicity hypothesis. The hypothesis postulates that increased activation of upper motor neurons spreads pathology to lower motor neurons in the spinal cord in the form of excessive glutamate release, which triggers excitotoxic processes. Many clinical trials have focused on therapies that target excitotoxicity via dampening neuronal activation, but not all are effective. As such, there is a growing tension between the rising tide of evidence for the 'dying forward' excitotoxicity hypothesis and the failure of therapies that target neuronal activation. One possible solution to these contradictory outcomes is that our interpretation of the current evidence requires revision in the context of appreciating the complexity of the nervous system and the limitations of the neurobiological assays we use to study it. In this review we provide an evaluation of evidence relevant to the 'dying forward' excitotoxicity hypothesis and by doing so, identify key gaps in our knowledge that need to be addressed. We hope to provide a road map from hyperexcitability to excitotoxicity so that we can better develop therapies for patients suffering from amyotrophic lateral sclerosis. We conclude that studies of upper motor neuron activity and their synaptic output will play a decisive role in the future of amyotrophic lateral sclerosis therapy.
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Affiliation(s)
- G Lorenzo Odierna
- Tasmanian School of Medicine, University of Tasmania, Hobart, TAS 7000, Australia
| | - Steve Vucic
- Brain and Nerve Research Center, The University of Sydney, Sydney 2050, Australia
| | - Marcus Dyer
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
- Department of Pharmaceutical and Pharmacological Sciences, Center for Neurosciences, Vrije Universiteit Brussel (VUB), 1090 Brussels, Belgium
| | - Tracey Dickson
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
| | - Adele Woodhouse
- The Wicking Dementia Centre, University of Tasmania, Hobart, TAS 7000, Australia
| | - Catherine Blizzard
- Tasmanian School of Medicine, University of Tasmania, Hobart, TAS 7000, Australia
- Menzies Institute for Medical Research, University of Tasmania, Hobart, TAS 7000, Australia
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Costa-Pinto S, Gonçalves-Ribeiro J, Tedim-Moreira J, Socodato R, Relvas JB, Sebastião AM, Vaz SH. Communication defects with astroglia contribute to early impairments in the motor cortex plasticity of SOD1 G93A mice. Neurobiol Dis 2024; 193:106435. [PMID: 38336279 DOI: 10.1016/j.nbd.2024.106435] [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: 10/13/2023] [Revised: 02/06/2024] [Accepted: 02/06/2024] [Indexed: 02/12/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease, involving the selective degeneration of cortical upper synapses in the primary motor cortex (M1). Excitotoxicity in ALS occurs due to an imbalance between excitation and inhibition, closely linked to the loss/gain of astrocytic function. Using the ALS SOD1G93A mice, we investigated the astrocytic contribution for the electrophysiological alterations observed in the M1 of SOD1G93A mice, throughout disease progression. Results showed that astrocytes are involved in synaptic dysfunction observed in presymptomatic SOD1G93A mice, since astrocytic glutamate transport currents are diminished and pharmacological inhibition of astrocytes only impaired long-term potentiation and basal transmission in wild-type mice. Proteomic analysis revealed major differences in neuronal transmission, metabolism, and immune system in upper synapses, confirming early communication deficits between neurons and astroglia. These results provide valuable insights into the early impact of upper synapses in ALS and the lack of supportive functions of cortical astrocytes, highlighting the possibility of manipulating astrocytes to improve synaptic function.
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Affiliation(s)
- Sara Costa-Pinto
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal
| | - Joana Gonçalves-Ribeiro
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal
| | - Joana Tedim-Moreira
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), University of Porto, Porto 4200-135, Portugal; Department of Biomedicine, Faculty of Medicine, University of Porto, Porto 4200-135, Portugal
| | - Renato Socodato
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), University of Porto, Porto 4200-135, Portugal
| | - João B Relvas
- Instituto de Investigação e Inovação em Saúde and Instituto de Biologia Molecular e Celular (IBMC), University of Porto, Porto 4200-135, Portugal; Department of Biomedicine, Faculty of Medicine, University of Porto, Porto 4200-135, Portugal
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal
| | - Sandra H Vaz
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon 1649-028, Portugal.
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Xie C, Kessi M, Yin F, Peng J. Roles of KCNA2 in Neurological Diseases: from Physiology to Pathology. Mol Neurobiol 2024:10.1007/s12035-024-04120-9. [PMID: 38517617 DOI: 10.1007/s12035-024-04120-9] [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: 03/31/2023] [Accepted: 03/10/2024] [Indexed: 03/24/2024]
Abstract
Potassium voltage-gated channel subfamily a member 2 (Kv1.2, encoded by KCNA2) is highly expressed in the central and peripheral nervous systems. Based on the patch clamp studies, gain-of function (GOF), loss-of-function (LOF), and a mixed type (GOF/LOF) variants can cause different conditions/disorders. KCNA2-related neurological diseases include epilepsy, intellectual disability (ID), attention deficit/hyperactive disorder (ADHD), autism spectrum disorder (ASD), pain as well as autoimmune and movement disorders. Currently, the molecular mechanisms for the reported variants in causing diverse disorders are unknown. Consequently, this review brings up to date the related information regarding the structure and function of Kv1.2 channel, expression patterns, neuronal localizations, and tetramerization as well as important cell and animal models. In addition, it provides updates on human genetic variants, genotype-phenotype correlations especially highlighting the deep insight into clinical prognosis of KCNA2-related developmental and epileptic encephalopathy, mechanisms, and the potential treatment targets for all KCNA2-related neurological disorders.
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Affiliation(s)
- Changning Xie
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Hunan, Changsha, 410008, China
| | - Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Hunan, Changsha, 410008, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Hunan, Changsha, 410008, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Hunan, Changsha, 410008, China.
- Hunan Intellectual and Development Disabilities Research Center, Hunan, Changsha, 410008, China.
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Sharples SA, Broadhead MJ, Gray JA, Miles GB. M-type potassium currents differentially affect activation of motoneuron subtypes and tune recruitment gain. J Physiol 2023; 601:5751-5775. [PMID: 37988235 DOI: 10.1113/jp285348] [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: 07/27/2023] [Accepted: 10/25/2023] [Indexed: 11/23/2023] Open
Abstract
The size principle is a key mechanism governing the orderly recruitment of motor units and is believed to be dependent on passive properties of the constituent motoneurons. However, motoneurons are endowed with voltage-sensitive ion channels that create non-linearities in their input-output functions. Here we describe a role for the M-type potassium current, conducted by KCNQ channels, in the control of motoneuron recruitment in mice. Motoneurons were studied with whole-cell patch clamp electrophysiology in transverse spinal slices and identified based on delayed (fast) and immediate (slow) onsets of repetitive firing. M-currents were larger in delayed compared to immediate firing motoneurons, which was not reflected by variations in the presence of Kv7.2 or Kv7.3 subunits. Instead, a more depolarized spike threshold in delayed-firing motoneurons afforded a greater proportion of the total M-current to become activated within the subthreshold voltage range, which translated to a greater influence on their recruitment with little influence on their firing rates. Pharmacological activation of M-currents also influenced motoneuron recruitment at the population level, producing a rightward shift in the recruitment curve of monosynaptic reflexes within isolated mouse spinal cords. These results demonstrate a prominent role for M-type potassium currents in regulating the function of motor units, which occurs primarily through the differential control of motoneuron subtype recruitment. More generally, these findings highlight the importance of active properties mediated by voltage-sensitive ion channels in the differential control of motoneuron recruitment, which is a key mechanism for the gradation of muscle force. KEY POINTS: M-currents exert an inhibitory influence on spinal motor output. This inhibitory influence is exerted by controlling the recruitment, but not the firing rate, of high-threshold fast-like motoneurons, with limited influence on low-threshold slow-like motoneurons. Preferential control of fast motoneurons may be linked to a larger M-current that is activated within the subthreshold voltage range compared to slow motoneurons. Larger M-currents in fast compared to slow motoneurons are not accounted for by differences in Kv7.2 or Kv7.3 channel composition. The orderly recruitment of motoneuron subtypes is shaped by differences in the contribution of voltage-gated ion channels, including KCNQ channels. KCNQ channels may provide a target to dynamically modulate the recruitment gain across the motor pool and readily adjust movement vigour.
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Affiliation(s)
- Simon A Sharples
- School of Psychology and Neuroscience, University of St Andrews, Fife, UK
| | | | - James A Gray
- School of Psychology and Neuroscience, University of St Andrews, Fife, UK
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St Andrews, Fife, UK
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Dyer MS, Odierna GL, Clark RM, Woodhouse A, Blizzard CA. Synaptic remodeling follows upper motor neuron hyperexcitability in a rodent model of TDP-43. Front Cell Neurosci 2023; 17:1274979. [PMID: 37941604 PMCID: PMC10628445 DOI: 10.3389/fncel.2023.1274979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 10/05/2023] [Indexed: 11/10/2023] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is an incurable disease characterized by relentlessly progressive degeneration of the corticomotor system. Cortical hyperexcitability has been identified as an early pre-symptomatic biomarker of ALS. This suggests that hyperexcitability occurs upstream in the ALS pathological cascade and may even be part of the mechanism that drives development of symptoms or loss of motor neurons in the spinal cord. However, many studies also indicate a loss to the synaptic machinery that mediates synaptic input which raises the question of which is the driver of disease, and which is a homeostatic response. Herein, we used an inducible mouse model of TDP-43 mediated ALS that permits for the construction of detailed phenotypic timelines. Our work comprehensively describes the relationship between intrinsic hyperexcitability and altered synaptic input onto motor cortical layer 5 pyramidal neurons over time. As a result, we have constructed the most complete timeline of electrophysiological changes following induction of TDP-43 dysfunction in the motor cortex. We report that intrinsic hyperexcitability of layer 5 pyramidal neurons precedes changes to excitatory synaptic connections, which manifest as an overall loss of inputs onto layer 5 pyramidal neurons. This finding highlights the importance of hyperexcitability as a primary mechanism of ALS and re-contextualizes synaptic changes as possibly representing secondary adaptive responses. Recognition of the relationship between intrinsic hyperexcitability and reduced excitatory synaptic input has important implications for the development of useful therapies against ALS. Novel strategies will need to be developed that target neuronal output by managing excitability against synapses separately.
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Affiliation(s)
- Marcus S. Dyer
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
- Department of Pharmaceutical and Pharmacological Sciences, Center for Neurosciences, Vrije Universiteit Brussel, Brussels, Belgium
| | - G. Lorenzo Odierna
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Rosemary M. Clark
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Adele Woodhouse
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
| | - Catherine A. Blizzard
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
- Tasmanian School of Medicine, College of Health and Medicine, University of Tasmania, Hobart, TAS, Australia
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Purushotham SS, Buskila Y. Astrocytic modulation of neuronal signalling. FRONTIERS IN NETWORK PHYSIOLOGY 2023; 3:1205544. [PMID: 37332623 PMCID: PMC10269688 DOI: 10.3389/fnetp.2023.1205544] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 05/18/2023] [Indexed: 06/20/2023]
Abstract
Neuronal signalling is a key element in neuronal communication and is essential for the proper functioning of the CNS. Astrocytes, the most prominent glia in the brain play a key role in modulating neuronal signalling at the molecular, synaptic, cellular, and network levels. Over the past few decades, our knowledge about astrocytes and their functioning has evolved from considering them as merely a brain glue that provides structural support to neurons, to key communication elements. Astrocytes can regulate the activity of neurons by controlling the concentrations of ions and neurotransmitters in the extracellular milieu, as well as releasing chemicals and gliotransmitters that modulate neuronal activity. The aim of this review is to summarise the main processes through which astrocytes are modulating brain function. We will systematically distinguish between direct and indirect pathways in which astrocytes affect neuronal signalling at all levels. Lastly, we will summarize pathological conditions that arise once these signalling pathways are impaired focusing on neurodegeneration.
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Affiliation(s)
| | - Yossi Buskila
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
- The MARCS Institute, Western Sydney University, Campbelltown, NSW, Australia
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Konopka A, Atkin JD. The Role of DNA Damage in Neural Plasticity in Physiology and Neurodegeneration. Front Cell Neurosci 2022; 16:836885. [PMID: 35813507 PMCID: PMC9259845 DOI: 10.3389/fncel.2022.836885] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 05/09/2022] [Indexed: 12/15/2022] Open
Abstract
Damage to DNA is generally considered to be a harmful process associated with aging and aging-related disorders such as neurodegenerative diseases that involve the selective death of specific groups of neurons. However, recent studies have provided evidence that DNA damage and its subsequent repair are important processes in the physiology and normal function of neurons. Neurons are unique cells that form new neural connections throughout life by growth and re-organisation in response to various stimuli. This “plasticity” is essential for cognitive processes such as learning and memory as well as brain development, sensorial training, and recovery from brain lesions. Interestingly, recent evidence has suggested that the formation of double strand breaks (DSBs) in DNA, the most toxic form of damage, is a physiological process that modifies gene expression during normal brain activity. Together with subsequent DNA repair, this is thought to underlie neural plasticity and thus control neuronal function. Interestingly, neurodegenerative diseases such as Alzheimer’s disease, amyotrophic lateral sclerosis, frontotemporal dementia, and Huntington’s disease, manifest by a decline in cognitive functions, which are governed by plasticity. This suggests that DNA damage and DNA repair processes that normally function in neural plasticity may contribute to neurodegeneration. In this review, we summarize current understanding about the relationship between DNA damage and neural plasticity in physiological conditions, as well as in the pathophysiology of neurodegenerative diseases.
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Affiliation(s)
- Anna Konopka
- Centre for Motor Neuron Disease Research, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
- *Correspondence: Anna Konopka
| | - Julie D. Atkin
- Centre for Motor Neuron Disease Research, Macquarie Medical School, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, Australia
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Cortical Hyperexcitability in the Driver’s Seat in ALS. CLINICAL AND TRANSLATIONAL NEUROSCIENCE 2022. [DOI: 10.3390/ctn6010005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal disease characterized by the degeneration of cortical and spinal motor neurons. With no effective treatment available to date, patients face progressive paralysis and eventually succumb to the disease due to respiratory failure within only a few years. Recent research has revealed the multifaceted nature of the mechanisms and cell types involved in motor neuron degeneration, thereby opening up new therapeutic avenues. Intriguingly, two key features present in both ALS patients and rodent models of the disease are cortical hyperexcitability and hyperconnectivity, the mechanisms of which are still not fully understood. We here recapitulate current findings arguing for cell autonomous and non-cell autonomous mechanisms causing cortical excitation and inhibition imbalance, which is involved in the degeneration of motor neurons in ALS. Moreover, we will highlight recent evidence that strongly indicates a cardinal role for the motor cortex as a main driver and source of the disease, thus arguing for a corticofugal trajectory of the pathology.
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Sharples SA, Miles GB. Maturation of persistent and hyperpolarization-activated inward currents shapes the differential activation of motoneuron subtypes during postnatal development. eLife 2021; 10:e71385. [PMID: 34783651 PMCID: PMC8641952 DOI: 10.7554/elife.71385] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 11/15/2021] [Indexed: 12/15/2022] Open
Abstract
The size principle underlies the orderly recruitment of motor units; however, motoneuron size is a poor predictor of recruitment amongst functionally defined motoneuron subtypes. Whilst intrinsic properties are key regulators of motoneuron recruitment, the underlying currents involved are not well defined. Whole-cell patch-clamp electrophysiology was deployed to study intrinsic properties, and the underlying currents, that contribute to the differential activation of delayed and immediate firing motoneuron subtypes. Motoneurons were studied during the first three postnatal weeks in mice to identify key properties that contribute to rheobase and may be important to establish orderly recruitment. We find that delayed and immediate firing motoneurons are functionally homogeneous during the first postnatal week and are activated based on size, irrespective of subtype. The rheobase of motoneuron subtypes becomes staggered during the second postnatal week, which coincides with the differential maturation of passive and active properties, particularly persistent inward currents. Rheobase of delayed firing motoneurons increases further in the third postnatal week due to the development of a prominent resting hyperpolarization-activated inward current. Our results suggest that motoneuron recruitment is multifactorial, with recruitment order established during postnatal development through the differential maturation of passive properties and sequential integration of persistent and hyperpolarization-activated inward currents.
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Affiliation(s)
- Simon A Sharples
- School of Psychology and Neuroscience, University of St AndrewsSt AndrewsUnited Kingdom
| | - Gareth B Miles
- School of Psychology and Neuroscience, University of St AndrewsSt AndrewsUnited Kingdom
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Zhang XQ, Xu L, Yang SY, Hu LB, Dong FY, Sun BG, Shen HW. Reduced Synaptic Transmission and Intrinsic Excitability of a Subtype of Pyramidal Neurons in the Medial Prefrontal Cortex in a Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2021; 84:129-140. [PMID: 34487044 DOI: 10.3233/jad-210585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Abnormal morphology and function of neurons in the prefrontal cortex (PFC) are associated with cognitive deficits in rodent models of Alzheimer's disease (AD), particularly in cortical layer-5 pyramidal neurons that integrate inputs from different sources and project outputs to cortical or subcortical structures. Pyramidal neurons in layer-5 of the PFC can be classified as two subtypes depending on the inducibility of prominent hyperpolarization-activated cation currents (h-current). However, the differences in the neurophysiological alterations between these two subtypes in rodent models of AD remain poorly understood. OBJECTIVE To investigate the neurophysiological alterations between two subtypes of pyramidal neurons in hAPP-J20 mice, a transgenic model for early onset AD. METHODS The synaptic transmission and intrinsic excitability of pyramidal neurons were investigated using whole-cell patch recordings. The morphological complexity of pyramidal neurons was detected by biocytin labelling and subsequent Sholl analysis. RESULTS We found reduced synaptic transmission and intrinsic excitability of the prominent h-current (PH) cells but not the non-PH cells in hAPP-J20 mice. Furthermore, the function of hyperpolarization-activated cyclic nucleotide-gated (HCN) channels which mediated h-current was disrupted in the PH cells of hAPP-J20 mice. Sholl analysis revealed that PH cells had less dendritic intersections in hAPP-J20 mice comparing to control mice, implying that a lower morphological complexity might contribute to the reduced neuronal activity. CONCLUSION These results suggest that the PH cells in the medial PFC may be more vulnerable to degeneration in hAPP-J20 mice and play a sustainable role in frontal dysfunction in AD.
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Affiliation(s)
- Xiao-Qin Zhang
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China.,Key Laboratory of Addiction Research of Zhejiang Province, Ningbo Kangning Hospital, Ningbo, Zhejiang, China
| | - Le Xu
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Si-Yu Yang
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Lin-Bo Hu
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Fei-Yuan Dong
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China
| | - Bing-Gui Sun
- Department of Neurobiology, NHC and CAMS Key Laboratory of Medical Neurobiology, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Hao-Wei Shen
- Department of Pharmacology, School of Medicine, Zhejiang Key Laboratory of Pathophysiology, Ningbo University, Ningbo, Zhejiang, China.,Key Laboratory of Addiction Research of Zhejiang Province, Ningbo Kangning Hospital, Ningbo, Zhejiang, China
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13
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Catanese A, Rajkumar S, Sommer D, Freisem D, Wirth A, Aly A, Massa‐López D, Olivieri A, Torelli F, Ioannidis V, Lipecka J, Guerrera IC, Zytnicki D, Ludolph A, Kabashi E, Mulaw MA, Roselli F, Böckers TM. Synaptic disruption and CREB-regulated transcription are restored by K + channel blockers in ALS. EMBO Mol Med 2021; 13:e13131. [PMID: 34125498 PMCID: PMC8261490 DOI: 10.15252/emmm.202013131] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 05/19/2021] [Accepted: 05/21/2021] [Indexed: 11/15/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, which is still missing effective therapeutic strategies. Although manipulation of neuronal excitability has been tested in murine and human ALS models, it is still under debate whether neuronal activity might represent a valid target for efficient therapies. In this study, we exploited a combination of transcriptomics, proteomics, optogenetics and pharmacological approaches to investigate the activity-related pathological features of iPSC-derived C9orf72-mutant motoneurons (MN). We found that human ALSC9orf72 MN are characterized by accumulation of aberrant aggresomes, reduced expression of synaptic genes, loss of synaptic contacts and a dynamic "malactivation" of the transcription factor CREB. A similar phenotype was also found in TBK1-mutant MN and upon overexpression of poly(GA) aggregates in primary neurons, indicating a strong convergence of pathological phenotypes on synaptic dysregulation. Notably, these alterations, along with neuronal survival, could be rescued by treating ALS-related neurons with the K+ channel blockers Apamin and XE991, which, respectively, target the SK and the Kv7 channels. Thus, our study shows that restoring the activity-dependent transcriptional programme and synaptic composition exerts a neuroprotective effect on ALS disease progression.
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Affiliation(s)
- Alberto Catanese
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Sandeep Rajkumar
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Daniel Sommer
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Dennis Freisem
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Alexander Wirth
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Amr Aly
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - David Massa‐López
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)Ulm siteUlmGermany
| | - Andrea Olivieri
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Federica Torelli
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Valentin Ioannidis
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
| | - Joanna Lipecka
- Proteomics platform NeckerINSERM US24/CNRS UMS3633Université de Paris – Structure Fédérative de Recherche NeckerParisFrance
| | - Ida Chiara Guerrera
- Proteomics platform NeckerINSERM US24/CNRS UMS3633Université de Paris – Structure Fédérative de Recherche NeckerParisFrance
| | - Daniel Zytnicki
- SPPIN ‐ Saints‐Pères Paris Institute for the NeurosciencesCNRSUniversité de ParisParis, Paris
| | - Albert Ludolph
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)Ulm siteUlmGermany
- Department of NeurologyUlm University School of MedicineUlmGermany
| | - Edor Kabashi
- Institute of Translational Research for Neurological DisordersINSERM UMR 1163Imagine InstituteParisFrance
| | - Medhanie A Mulaw
- Internal Medicine I and Institute of Molecular Medicine and Stem Cell AgingMedical FacultyUniversity Hospital UlmUniversity of Ulm UniversityUlmGermany
| | - Francesco Roselli
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)Ulm siteUlmGermany
- Department of NeurologyUlm University School of MedicineUlmGermany
| | - Tobias M Böckers
- Institute of Anatomy and Cell BiologyUlm University School of MedicineUlmGermany
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE)Ulm siteUlmGermany
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14
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Neurophysiological Mechanisms Underlying Cortical Hyper-Excitability in Amyotrophic Lateral Sclerosis: A Review. Brain Sci 2021; 11:brainsci11050549. [PMID: 33925493 PMCID: PMC8145013 DOI: 10.3390/brainsci11050549] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neuromotor disease characterized by the loss of upper and lower motor neurons (MNs), resulting in muscle paralysis and death. Early cortical hyper-excitability is a common pathological process observed clinically and in animal disease models. Although the mechanisms that underlie cortical hyper-excitability are not completely understood, the molecular and cellular mechanisms that cause enhanced neuronal intrinsic excitability and changes in excitatory and inhibitory synaptic activity are starting to emerge. Here, we review the evidence for an anterograde glutamatergic excitotoxic process, leading to cortical hyper-excitability via intrinsic cellular and synaptic mechanisms and for the role of interneurons in establishing disinhibition in clinical and experimental settings. Understanding the mechanisms that lead to these complex pathological processes will likely produce key insights towards developing novel therapeutic strategies to rescue upper MNs, thus alleviating the impact of this fatal disease.
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15
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Jørgensen HS, Jensen DB, Dimintiyanova KP, Bonnevie VS, Hedegaard A, Lehnhoff J, Moldovan M, Grondahl L, Meehan CF. Increased Axon Initial Segment Length Results in Increased Na + Currents in Spinal Motoneurones at Symptom Onset in the G127X SOD1 Mouse Model of Amyotrophic Lateral Sclerosis. Neuroscience 2020; 468:247-264. [PMID: 33246068 DOI: 10.1016/j.neuroscience.2020.11.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 10/22/2020] [Accepted: 11/10/2020] [Indexed: 12/13/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease preferentially affecting motoneurones. Transgenic mouse models have been used to investigate the role of abnormal motoneurone excitability in this disease. Whilst an increased excitability has repeatedly been demonstrated in vitro in neonatal and embryonic preparations from SOD1 mouse models, the results from the only studies to record in vivo from spinal motoneurones in adult SOD1 models have produced conflicting findings. Deficits in repetitive firing have been reported in G93A SOD1(high copy number) mice but not in presymptomatic G127X SOD1 mice despite shorter motoneurone axon initial segments (AISs) in these mice. These discrepancies may be due to the earlier disease onset and prolonged disease progression in G93A SOD1 mice with recordings potentially performed at a later sub-clinical stage of the disease in this mouse. To test this, and to explore how the evolution of excitability changes with symptom onset we performed in vivo intracellular recording and AIS labelling in G127X SOD1 mice immediately after symptom onset. No reductions in repetitive firing were observed showing that this is not a common feature across all ALS models. Immunohistochemistry for the Na+ channel Nav1.6 showed that motoneurone AISs increase in length in G127X SOD1 mice at symptom onset. Consistent with this, the rate of rise of AIS components of antidromic action potentials were significantly faster confirming that this increase in length represents an increase in AIS Na+ channels occurring at symptom onset in this model.
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Affiliation(s)
- H S Jørgensen
- Department of Neuroscience, University of Copenhagen, Denmark
| | - D B Jensen
- Department of Neuroscience, University of Copenhagen, Denmark
| | | | - V S Bonnevie
- Department of Neuroscience, University of Copenhagen, Denmark
| | - A Hedegaard
- Department of Neuroscience, University of Copenhagen, Denmark
| | - J Lehnhoff
- Department of Neuroscience, University of Copenhagen, Denmark
| | - M Moldovan
- Department of Neuroscience, University of Copenhagen, Denmark
| | - L Grondahl
- Department of Neuroscience, University of Copenhagen, Denmark
| | - C F Meehan
- Department of Neuroscience, University of Copenhagen, Denmark.
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16
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Dyer MS, Reale LA, Lewis KE, Walker AK, Dickson TC, Woodhouse A, Blizzard CA. Mislocalisation of TDP-43 to the cytoplasm causes cortical hyperexcitability and reduced excitatory neurotransmission in the motor cortex. J Neurochem 2020; 157:1300-1315. [PMID: 33064315 DOI: 10.1111/jnc.15214] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/04/2020] [Accepted: 10/06/2020] [Indexed: 12/13/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) is a chronic neurodegenerative disease pathologically characterised by mislocalisation of the RNA-binding protein TAR-DNA-binding protein 43 (TDP-43) from the nucleus to the cytoplasm. Changes to neuronal excitability and synapse dysfunction in the motor cortex are early pathological changes occurring in people with ALS and mouse models of disease. To investigate the effect of mislocalised TDP-43 on the function of motor cortex neurons we utilised mouse models that express either human wild-type (TDP-43WT ) or nuclear localisation sequence-deficient TDP-43 (TDP-43ΔNLS ) on an inducible promoter that enriches expression to forebrain neurons. Pathophysiology was investigated through immunohistochemistry and whole-cell patch-clamp electrophysiology. Thirty days expression of TDP-43ΔNLS in adult mice did not cause any changes in the number of CTIP2-positive neurons in the motor cortex. However, at this time-point, the expression of TDP-43ΔNLS drives intrinsic hyperexcitability in layer V excitatory neurons of the motor cortex. This hyperexcitability occurs concomitantly with a decrease in excitatory synaptic input to these cells and fluctuations in both directions of ionotropic glutamate receptors. This pathophysiology is not present with TDP-43WT expression, demonstrating that the localisation of TDP-43 to the cytoplasm is crucial for the altered excitability phenotype. This study has important implications for the mechanisms of toxicity of one of the most notorious proteins linked to ALS, TDP-43. We provide the first evidence that TDP-43 mislocalisation causes aberrant synaptic function and a hyperexcitability phenotype in the motor cortex, linking some of the earliest dysfunctions to arise in people with ALS to mislocalisation of TDP-43.
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Affiliation(s)
- Marcus S Dyer
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
| | - Laura A Reale
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
| | - Katherine E Lewis
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
| | - Adam K Walker
- Neurodegeneration Pathobiology Laboratory, Queensland Brain Institute, University of Queensland, Brisbane, Qld, Australia
| | - Tracey C Dickson
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
| | - Adele Woodhouse
- Wicking Dementia Research and Education Centre, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
| | - Catherine A Blizzard
- Menzies Institute for Medical Research, College of Health and Medicine, University of Tasmania, Hobart, Tas, Australia
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17
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Popescu IR, Le KQ, Ducote AL, Li JE, Leland AE, Mostany R. Increased intrinsic excitability and decreased synaptic inhibition in aged somatosensory cortex pyramidal neurons. Neurobiol Aging 2020; 98:88-98. [PMID: 33249377 DOI: 10.1016/j.neurobiolaging.2020.10.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 09/02/2020] [Accepted: 10/08/2020] [Indexed: 10/23/2022]
Abstract
Sensorimotor performance declines during advanced age, partially due to deficits in somatosensory acuity. Cortical receptive field expansion contributes to somatosensory deficits, suggesting increased excitability or decreased inhibition in primary somatosensory cortex (S1) pyramidal neurons. To ascertain changes in excitability and inhibition, we measured both properties in neurons from vibrissal S1 in brain slices from young and aged mice. Because adapting and non-adapting neurons-the principal pyramidal types in layer 5 (L5)-differ in intrinsic properties and inhibitory inputs, we determined age-dependent changes according to neuron type. We found an age-dependent increase in intrinsic excitability in adapting neurons, caused by a decrease in action potential threshold. Surprisingly, in non-adapting neurons we found both an increase in excitability caused by increased input resistance, and a decrease in synaptic inhibition. Spike frequency adaptation, already small in non-adapting neurons, was further reduced by aging, whereas sag, a manifestation of Ih, was increased. Therefore, aging caused both decreased inhibition and increased intrinsic excitability, but these effects were specific to pyramidal neuron type.
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Affiliation(s)
- Ion R Popescu
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA.
| | - Kathy Q Le
- Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | - Alexis L Ducote
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | - Jennifer E Li
- Tulane Brain Institute, Tulane University, New Orleans, LA, USA
| | | | - Ricardo Mostany
- Department of Pharmacology, Tulane University School of Medicine, New Orleans, LA, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, USA
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18
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Stevenson R, Samokhina E, Rossetti I, Morley JW, Buskila Y. Neuromodulation of Glial Function During Neurodegeneration. Front Cell Neurosci 2020; 14:278. [PMID: 32973460 PMCID: PMC7473408 DOI: 10.3389/fncel.2020.00278] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Accepted: 08/05/2020] [Indexed: 12/12/2022] Open
Abstract
Glia, a non-excitable cell type once considered merely as the connective tissue between neurons, is nowadays acknowledged for its essential contribution to multiple physiological processes including learning, memory formation, excitability, synaptic plasticity, ion homeostasis, and energy metabolism. Moreover, as glia are key players in the brain immune system and provide structural and nutritional support for neurons, they are intimately involved in multiple neurological disorders. Recent advances have demonstrated that glial cells, specifically microglia and astroglia, are involved in several neurodegenerative diseases including Amyotrophic lateral sclerosis (ALS), Epilepsy, Parkinson's disease (PD), Alzheimer's disease (AD), and frontotemporal dementia (FTD). While there is compelling evidence for glial modulation of synaptic formation and regulation that affect neuronal signal processing and activity, in this manuscript we will review recent findings on neuronal activity that affect glial function, specifically during neurodegenerative disorders. We will discuss the nature of each glial malfunction, its specificity to each disorder, overall contribution to the disease progression and assess its potential as a future therapeutic target.
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Affiliation(s)
- Rebecca Stevenson
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Evgeniia Samokhina
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Ilaria Rossetti
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - John W. Morley
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Yossi Buskila
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
- International Centre for Neuromorphic Systems, The MARCS Institute for Brain, Behaviour and Development, Penrith, NSW, Australia
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19
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Gunes ZI, Kan VWY, Ye X, Liebscher S. Exciting Complexity: The Role of Motor Circuit Elements in ALS Pathophysiology. Front Neurosci 2020; 14:573. [PMID: 32625051 PMCID: PMC7311855 DOI: 10.3389/fnins.2020.00573] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 05/11/2020] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal disease, characterized by the degeneration of both upper and lower motor neurons. Despite decades of research, we still to date lack a cure or disease modifying treatment, emphasizing the need for a much-improved insight into disease mechanisms and cell type vulnerability. Altered neuronal excitability is a common phenomenon reported in ALS patients, as well as in animal models of the disease, but the cellular and circuit processes involved, as well as the causal relevance of those observations to molecular alterations and final cell death, remain poorly understood. Here, we review evidence from clinical studies, cell type-specific electrophysiology, genetic manipulations and molecular characterizations in animal models and culture experiments, which argue for a causal involvement of complex alterations of structure, function and connectivity of different neuronal subtypes within the cortical and spinal cord motor circuitries. We also summarize the current knowledge regarding the detrimental role of astrocytes and reassess the frequently proposed hypothesis of glutamate-mediated excitotoxicity with respect to changes in neuronal excitability. Together, these findings suggest multifaceted cell type-, brain area- and disease stage- specific disturbances of the excitation/inhibition balance as a cardinal aspect of ALS pathophysiology.
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Affiliation(s)
- Zeynep I Gunes
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - Vanessa W Y Kan
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - XiaoQian Ye
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany
| | - Sabine Liebscher
- Institute of Clinical Neuroimmunology, Klinikum der Universität München, Ludwig Maximilians University Munich, Munich, Germany.,Biomedical Center, Ludwig Maximilians University Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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20
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Jara JH, Sheets PL, Nigro MJ, Perić M, Brooks C, Heller DB, Martina M, Andjus PR, Ozdinler PH. The Electrophysiological Determinants of Corticospinal Motor Neuron Vulnerability in ALS. Front Mol Neurosci 2020; 13:73. [PMID: 32508590 PMCID: PMC7248374 DOI: 10.3389/fnmol.2020.00073] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 04/15/2020] [Indexed: 12/12/2022] Open
Abstract
The brain is complex and heterogeneous. Even though numerous independent studies indicate cortical hyperexcitability as a potential contributor to amyotrophic lateral sclerosis (ALS) pathology, the mechanisms that are responsible for upper motor neuron (UMN) vulnerability remain elusive. To reveal the electrophysiological determinants of corticospinal motor neuron (CSMN, a.k.a UMN in mice) vulnerability, we investigated the motor cortex of hSOD1G93A mice at P30 (postnatal day 30), a presymptomatic time point. Glutamate uncaging by laser scanning photostimulation (LSPS) revealed altered dynamics especially within the inhibitory circuitry and more specifically in L2/3 of the motor cortex, whereas the excitatory microcircuits were unchanged. Observed microcircuitry changes were specific to CSMN in the motor column. Electrophysiological evaluation of the intrinsic properties in response to the microcircuit changes, as well as the exon microarray expression profiles of CSMN isolated from hSOD1G93A and healthy mice at P30, revealed the presence of a very dynamic set of events, ultimately directed to establish, maintain and retain the balance at this early stage. Also, the expression profile of key voltage-gated potassium and sodium channel subunits as well as of the inhibitory GABA receptor subunits and modulatory proteins began to suggest the challenges CSMN face at this early age. Since neurodegeneration is initiated when neurons can no longer maintain balance, the complex cellular events that occur at this critical time point help reveal how CSMN try to cope with the challenges of disease manifestation. This information is critically important for the proper modulation of UMNs and for developing effective treatment strategies.
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Affiliation(s)
- Javier H Jara
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Patrick L Sheets
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Maximiliano José Nigro
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Mina Perić
- Institute for Physiology and Biochemistry "Ivan Djaja", Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Carolyn Brooks
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Daniel B Heller
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Marco Martina
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Pavle R Andjus
- Institute for Physiology and Biochemistry "Ivan Djaja", Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - P Hande Ozdinler
- Davee Department of Neurology and Clinical Neurological Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
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21
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Lu TL, Lu TJ, Wu SN. Inhibitory Effective Perturbations of Cilobradine (DK-AH269), A Blocker of HCN Channels, on the Amplitude and Gating of Both Hyperpolarization-Activated Cation and Delayed-Rectifier Potassium Currents. Int J Mol Sci 2020; 21:ijms21072416. [PMID: 32244431 PMCID: PMC7177279 DOI: 10.3390/ijms21072416] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 03/17/2020] [Accepted: 03/28/2020] [Indexed: 12/19/2022] Open
Abstract
Cilobradine (CIL, DK-AH269), an inhibitor of hyperpolarization-activated cation current (Ih), has been observed to possess pro-arrhythmic properties. Whether and how CIL is capable of perturbing different types of membrane ionic currents existing in electrically excitable cells, however, is incompletely understood. In this study, we intended to examine possible modifications by it or other structurally similar compounds of ionic currents in pituitary tumor (GH3) cells and in heart-derived H9c2 cells. The standard whole-cell voltage-clamp technique was performed to examine the effect of CIL on ionic currents. GH3-cell exposure to CIL suppressed the density of hyperpolarization-evoked Ih in a concentration-dependent manner with an effective IC50 of 3.38 μM. Apart from its increase in the activation time constant of Ih during long-lasting hyperpolarization, the presence of CIL (3 μM) distinctly shifted the steady-state activation curve of Ih triggered by a 2-s conditioning pulse to a hyperpolarizing direction by 10 mV. As the impedance-frequency relation of Ih was studied, its presence raised the impedance magnitude at the resonance frequency induced by chirp voltage. CIL also suppressed delayed-rectifier K+ current (IK(DR)) followed by the accelerated inactivation time course of this current, with effective IC50 (measured at late IK(DR)) or KD value of 3.54 or 3.77 μM, respectively. As the CIL concentration increased 1 to 3 μM, the inactivation curve of IK(DR) elicited by 1- or 10-s conditioning pulses was shifted to a hyperpolarizing potential by approximately 10 mV, and the recovery of IK(DR) inactivation during its presence was prolonged. The peak Na+ current (INa) during brief depolarization was resistant to being sensitive to the presence of CIL, yet to be either decreased by subsequent addition of A-803467 or enhanced by that of tefluthrin. In cardiac H9c2 cells, unlike the CIL effect, the addition of either ivabradine or zatebradine mildly led to a lowering in IK(DR) amplitude with no conceivable change in the inactivation time course of the current. Taken together, the compound like CIL, which was tailored to block hyperpolarization-activated cation (HCN) channels effectively, was also capable of altering the amplitude and gating of IK(DR), thereby influencing the functional activities of electrically excitable cells, such as GH3 cells.
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Affiliation(s)
- Te-Ling Lu
- School of Pharmacy, China Medical University, Taichung 40402, Taiwan;
| | - Te-Jung Lu
- Department of Medical Laboratory Science and Biotechnology, Chung Hwa University of Medical Technology, Tainan 71703, Taiwan;
| | - Sheng-Nan Wu
- Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Physiology, National Cheng Kung University Medical College, Tainan 70101, Taiwan
- Department of Medical Research, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan
- Correspondence:
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22
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Gillet C, Kurth S, Kuenzel T. Muscarinic modulation of M and h currents in gerbil spherical bushy cells. PLoS One 2020; 15:e0226954. [PMID: 31940388 PMCID: PMC6961914 DOI: 10.1371/journal.pone.0226954] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 12/10/2019] [Indexed: 11/18/2022] Open
Abstract
Descending cholinergic fibers innervate the cochlear nucleus. Spherical bushy cells, principal neurons of the anterior part of the ventral cochlear nucleus, are depolarized by cholinergic agonists on two different time scales. A fast and transient response is mediated by alpha-7 homomeric nicotinic receptors while a slow and long-lasting response is mediated by muscarinic receptors. Spherical bushy cells were shown to express M3 receptors, but the receptor subtypes involved in the slow muscarinic response were not physiologically identified yet. Whole-cell patch clamp recordings combined with pharmacology and immunohistochemistry were performed to identify the muscarinic receptor subtypes and the effector currents involved. Spherical bushy cells also expressed both M1 and M2 receptors. The M1 signal was stronger and mainly somatic while the M2 signal was localized in the neuropil and on the soma of bushy cells. Physiologically, the M-current was observed for the gerbil spherical bushy cells and was inhibited by oxotremorine-M application. Surprisingly, long application of carbachol showed only a transient depolarization. Even though no muscarinic depolarization could be detected, the input resistance increased suggesting a decrease in the cell conductance that matched with the closure of M-channels. The hyperpolarization-activated currents were also affected by muscarinic activation and counteracted the effect of the inactivation of M-current on the membrane potential. We hypothesize that this double muscarinic action might allow adaptation of effects during long durations of cholinergic activation.
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Affiliation(s)
- Charlène Gillet
- Auditory Neurophysiology Group, Department of Chemosensation, RWTH Aachen University, Worringerweg, Aachen, Germany
| | - Stefanie Kurth
- Department of Chemosensation, RWTH Aachen University, Worringerweg, Aachen, Germany
| | - Thomas Kuenzel
- Auditory Neurophysiology Group, Department of Chemosensation, RWTH Aachen University, Worringerweg, Aachen, Germany
- Department of Chemosensation, RWTH Aachen University, Worringerweg, Aachen, Germany
- * E-mail:
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23
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The Novel Direct Modulatory Effects of Perampanel, an Antagonist of AMPA Receptors, on Voltage-Gated Sodium and M-type Potassium Currents. Biomolecules 2019; 9:biom9100638. [PMID: 31652643 PMCID: PMC6843791 DOI: 10.3390/biom9100638] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Accepted: 10/20/2019] [Indexed: 12/17/2022] Open
Abstract
Perampanel (PER) is a selective blocker of AMPA receptors showing efficacy in treating various epileptic disorders including brain tumor-related epilepsy and also potential in treating motor neuron disease. However, besides its inhibition of AMPA-induced currents, whether PER has any other direct ionic effects in different types of neurons remains largely unknown. We investigated the effects of PER and related compounds on ionic currents in different types of cells, including hippocampal mHippoE-14 neurons, motor neuron-like NSC-34 cells and U87 glioma cells. We found that PER differentially and effectively suppressed the amplitude of voltage-gated Na+ currents (INa) in mHippoE-14 cells. The IC50 values required to inhibit peak and late INa were 4.12 and 0.78 μM, respectively. PER attenuated tefluthrin-induced increases in both amplitude and deactivating time constant of INa. Importantly, PER also inhibited the amplitude of M-type K+ currents (IK(M)) with an IC50 value of 0.92 μM. The suppression of IK(M) was attenuated by the addition of flupirtine or ZnCl2 but not by L-quisqualic acid or sorafenib. Meanwhile, in cell-attached configuration, PER (3 μM) decreased the activity of M-type K+ channels with no change in single-channel conductance but shifting the activation curve along the voltage axis in a rightward direction. Supportively, PER suppressed IK(M) in NSC-34 cells and INa in U87 glioma cells. The inhibitory effects of PER on both INa and IK(M), independent of its antagonistic effect on AMPA receptors, may be responsible for its wide-spectrum of effects observed in neurological clinical practice.
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Bax M, McKenna J, Do-Ha D, Stevens CH, Higginbottom S, Balez R, Cabral-da-Silva MEC, Farrawell NE, Engel M, Poronnik P, Yerbury JJ, Saunders DN, Ooi L. The Ubiquitin Proteasome System Is a Key Regulator of Pluripotent Stem Cell Survival and Motor Neuron Differentiation. Cells 2019; 8:cells8060581. [PMID: 31200561 PMCID: PMC6627164 DOI: 10.3390/cells8060581] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 05/31/2019] [Accepted: 06/04/2019] [Indexed: 12/13/2022] Open
Abstract
The ubiquitin proteasome system (UPS) plays an important role in regulating numerous cellular processes, and a dysfunctional UPS is thought to contribute to motor neuron disease. Consequently, we sought to map the changing ubiquitome in human iPSCs during their pluripotent stage and following differentiation to motor neurons. Ubiquitinomics analysis identified that spliceosomal and ribosomal proteins were more ubiquitylated in pluripotent stem cells, whilst proteins involved in fatty acid metabolism and the cytoskeleton were specifically ubiquitylated in the motor neurons. The UPS regulator, ubiquitin-like modifier activating enzyme 1 (UBA1), was increased 36-fold in the ubiquitome of motor neurons compared to pluripotent stem cells. Thus, we further investigated the functional consequences of inhibiting the UPS and UBA1 on motor neurons. The proteasome inhibitor MG132, or the UBA1-specific inhibitor PYR41, significantly decreased the viability of motor neurons. Consistent with a role of the UPS in maintaining the cytoskeleton and regulating motor neuron differentiation, UBA1 inhibition also reduced neurite length. Pluripotent stem cells were extremely sensitive to MG132, showing toxicity at nanomolar concentrations. The motor neurons were more resilient to MG132 than pluripotent stem cells but demonstrated higher sensitivity than fibroblasts. Together, this data highlights the important regulatory role of the UPS in pluripotent stem cell survival and motor neuron differentiation.
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Affiliation(s)
- Monique Bax
- Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, NSW 2522, Australia.
- School of Chemistry and Molecular Bioscience, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Jessie McKenna
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
| | - Dzung Do-Ha
- Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, NSW 2522, Australia.
- School of Chemistry and Molecular Bioscience, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Claire H Stevens
- Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, NSW 2522, Australia.
- School of Chemistry and Molecular Bioscience, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Sarah Higginbottom
- Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, NSW 2522, Australia.
- School of Chemistry and Molecular Bioscience, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Rachelle Balez
- Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, NSW 2522, Australia.
- School of Chemistry and Molecular Bioscience, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Mauricio E Castro Cabral-da-Silva
- Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, NSW 2522, Australia.
- School of Chemistry and Molecular Bioscience, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Natalie E Farrawell
- Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, NSW 2522, Australia.
- School of Chemistry and Molecular Bioscience, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Martin Engel
- Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, NSW 2522, Australia.
- School of Chemistry and Molecular Bioscience, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Philip Poronnik
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW 2050, Australia.
| | - Justin J Yerbury
- Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, NSW 2522, Australia.
- School of Chemistry and Molecular Bioscience, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
| | - Darren N Saunders
- School of Medical Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
| | - Lezanne Ooi
- Illawarra Health and Medical Research Institute, Northfields Avenue, Wollongong, NSW 2522, Australia.
- School of Chemistry and Molecular Bioscience, University of Wollongong, Northfields Avenue, Wollongong, NSW 2522, Australia.
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The differential impact of acute microglia activation on the excitability of cholinergic neurons in the mouse medial septum. Brain Struct Funct 2019; 224:2297-2309. [DOI: 10.1007/s00429-019-01905-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 06/07/2019] [Indexed: 12/30/2022]
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