1
|
Sonkodi B. Commentary: Effects of combined treatment with transcranial and peripheral electromagnetic stimulation on performance and pain recovery from delayed onset muscle soreness induced by eccentric exercise in young athletes. A randomized clinical trial. Front Physiol 2024; 15:1380261. [PMID: 38798879 PMCID: PMC11116897 DOI: 10.3389/fphys.2024.1380261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 04/26/2024] [Indexed: 05/29/2024] Open
Affiliation(s)
- Balázs Sonkodi
- Department of Health Sciences and Sport Medicine, Hungarian University of Sports Science, Budapest, Hungary
- Department of Sports Medicine, Semmelweis University, Budapest, Hungary
| |
Collapse
|
2
|
Sonkodi B. Progressive Irreversible Proprioceptive Piezo2 Channelopathy-Induced Lost Forced Peripheral Oscillatory Synchronization to the Hippocampal Oscillator May Explain the Onset of Amyotrophic Lateral Sclerosis Pathomechanism. Cells 2024; 13:492. [PMID: 38534336 DOI: 10.3390/cells13060492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 02/18/2024] [Accepted: 02/28/2024] [Indexed: 03/28/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a mysterious lethal multisystem neurodegenerative disease that gradually leads to the progressive loss of motor neurons. A recent non-contact dying-back injury mechanism theory for ALS proposed that the primary damage is an acquired irreversible intrafusal proprioceptive terminal Piezo2 channelopathy with underlying genetic and environmental risk factors. Underpinning this is the theory that excessively prolonged proprioceptive mechanotransduction under allostasis may induce dysfunctionality in mitochondria, leading to Piezo2 channelopathy. This microinjury is suggested to provide one gateway from physiology to pathophysiology. The chronic, but not irreversible, form of this Piezo2 channelopathy is implicated in many diseases with unknown etiology. Dry eye disease is one of them where replenishing synthetic proteoglycans promote nerve regeneration. Syndecans, especially syndecan-3, are proposed as the first critical link in this hierarchical ordered depletory pathomechanism as proton-collecting/distributing antennas; hence, they may play a role in ALS pathomechanism onset. Even more importantly, the shedding or charge-altering variants of Syndecan-3 may contribute to the Piezo2 channelopathy-induced disruption of the Piezo2-initiated proton-based ultrafast long-range signaling through VGLUT1 and VGLUT2. Thus, these alterations may not only cause disruption to ultrafast signaling to the hippocampus in conscious proprioception, but could disrupt the ultrafast proprioceptive signaling feedback to the motoneurons. Correspondingly, an inert Piezo2-initiated proton-based ultrafast signaled proprioceptive skeletal system is coming to light that is suggested to be progressively lost in ALS. In addition, the lost functional link of the MyoD family of inhibitor proteins, as auxiliary subunits of Piezo2, may not only contribute to the theorized acquired Piezo2 channelopathy, but may explain how these microinjured ion channels evolve to be principal transcription activators.
Collapse
Affiliation(s)
- Balázs Sonkodi
- Department of Health Sciences and Sport Medicine, Hungarian University of Sports Science, 1123 Budapest, Hungary
- Department of Sports Medicine, Semmelweis University, 1122 Budapest, Hungary
| |
Collapse
|
3
|
Martín-Cruces J, Cuendias P, García-Mesa Y, Cobo JL, García-Suárez O, Gaite JJ, Vega JA, Martín-Biedma B. Proprioceptive innervation of the human lips. Anat Rec (Hoboken) 2024; 307:669-676. [PMID: 37712912 DOI: 10.1002/ar.25324] [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: 04/03/2023] [Revised: 08/20/2023] [Accepted: 08/25/2023] [Indexed: 09/16/2023]
Abstract
The objective of this study was to analyze the proprioceptive innervation of human lips, especially of the orbicularis oris muscle, since it is classically accepted that facial muscles lack typical proprioceptors, that is, muscle spindles, but recently this has been doubted. Upper and lower human lips (n = 5) from non-embalmed frozen cadavers were immunostained for detection of S100 protein (to identify nerves and sensory nerve formations), myosin heavy chain (to label muscle fibers within muscle spindles), and the mechano-gated ion channel PIEZO2. No muscle spindles were found, but there was a high density of sensory nerve formations, which were morphologically heterogeneous, and in some cases resemble Ruffini-like and Pacinian sensory corpuscles. The axons of these sensory formations displayed immunoreactivity for PIEZO2. Human lip muscles lack typical proprioceptors but possess a dense sensory innervation which can serve the lip proprioception.
Collapse
Affiliation(s)
- José Martín-Cruces
- Departamento de Morfología y Biología Celular, Grupo SINPOS, Universidad de Oviedo, Oviedo, Spain
| | - Patricia Cuendias
- Departamento de Morfología y Biología Celular, Grupo SINPOS, Universidad de Oviedo, Oviedo, Spain
| | - Yolanda García-Mesa
- Departamento de Morfología y Biología Celular, Grupo SINPOS, Universidad de Oviedo, Oviedo, Spain
| | - Juan L Cobo
- Departamento de Morfología y Biología Celular, Grupo SINPOS, Universidad de Oviedo, Oviedo, Spain
- Instituto Asturiano de Odontología, Oviedo, Spain
| | - Olivia García-Suárez
- Departamento de Morfología y Biología Celular, Grupo SINPOS, Universidad de Oviedo, Oviedo, Spain
| | - Juan J Gaite
- Departamento de Morfología y Biología Celular, Grupo SINPOS, Universidad de Oviedo, Oviedo, Spain
- Unidad Dental, Clínica Universitaria de Navarra, Pamplona, Spain
| | - José A Vega
- Departamento de Morfología y Biología Celular, Grupo SINPOS, Universidad de Oviedo, Oviedo, Spain
- Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Providencia-Santiago de Chile, Chile
| | - Benjamín Martín-Biedma
- Departamento de Cirugía y Especialidades Médico-Quirúrgicas, Universidad de Santiago de Compostela, Santiago, Spain
| |
Collapse
|
4
|
Bornstein B, Watkins B, Passini FS, Blecher R, Assaraf E, Sui XM, Brumfeld V, Tsoory M, Kröger S, Zelzer E. The mechanosensitive ion channel ASIC2 mediates both proprioceptive sensing and spinal alignment. Exp Physiol 2024; 109:135-147. [PMID: 36951012 PMCID: PMC10988735 DOI: 10.1113/ep090776] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 02/20/2023] [Indexed: 03/24/2023]
Abstract
By translating mechanical forces into molecular signals, proprioceptive neurons provide the CNS with information on muscle length and tension, which is necessary to control posture and movement. However, the identities of the molecular players that mediate proprioceptive sensing are largely unknown. Here, we confirm the expression of the mechanosensitive ion channel ASIC2 in proprioceptive sensory neurons. By combining in vivo proprioception-related functional tests with ex vivo electrophysiological analyses of muscle spindles, we showed that mice lacking Asic2 display impairments in muscle spindle responses to stretch and motor coordination tasks. Finally, analysis of skeletons of Asic2 loss-of-function mice revealed a specific effect on spinal alignment. Overall, we identify ASIC2 as a key component in proprioceptive sensing and a regulator of spine alignment.
Collapse
Affiliation(s)
- Bavat Bornstein
- Department of Molecular GeneticsWeizmann Institute of ScienceRehovotIsrael
| | - Bridgette Watkins
- Department of Physiological Genomics, Biomedical CenterLudwig‐Maximilians‐UniversityPlanegg‐MartinsriedGermany
| | - Fabian S. Passini
- Department of Molecular GeneticsWeizmann Institute of ScienceRehovotIsrael
| | - Ronen Blecher
- Orthopedic DepartmentAssuta Ashdod University Hospital, Ashdod, Israel, affiliated to Ben Gurion University of the NegevBeer ShebaIsrael
| | - Eran Assaraf
- Department of Orthopedic SurgeryShamir Medical Center, Assaf HaRofeh Campus, Zeffifin, Israel, affiliated to Sackler Faculty of Medicine, Tel Aviv UniversityTel AvivIsrael
| | - Xiao Meng Sui
- Department of Chemical Research SupportWeizmann Institute of ScienceRehovotIsrael
| | - Vlad Brumfeld
- Department of Chemical Research SupportWeizmann Institute of ScienceRehovotIsrael
| | - Michael Tsoory
- Department of Veterinary ResourcesWeizmann Institute of ScienceRehovotIsrael
| | - Stephan Kröger
- Department of Physiological Genomics, Biomedical CenterLudwig‐Maximilians‐UniversityPlanegg‐MartinsriedGermany
| | - Elazar Zelzer
- Department of Molecular GeneticsWeizmann Institute of ScienceRehovotIsrael
| |
Collapse
|
5
|
Lin Y, Lee C, Sung J, Chen C. Genetic exploration of roles of acid-sensing ion channel subtypes in neurosensory mechanotransduction including proprioception. Exp Physiol 2024; 109:66-80. [PMID: 37489658 PMCID: PMC10988671 DOI: 10.1113/ep090762] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 07/03/2023] [Indexed: 07/26/2023]
Abstract
Although acid-sensing ion channels (ASICs) are proton-gated ion channels responsible for sensing tissue acidosis, accumulating evidence has shown that ASICs are also involved in neurosensory mechanotransduction. However, in contrast to Piezo ion channels, evidence of ASICs as mechanically gated ion channels has not been found using conventional mechanoclamp approaches. Instead, ASICs are involved in the tether model of mechanotransduction, with the channels gated via tethering elements of extracellular matrix and intracellular cytoskeletons. Methods using substrate deformation-driven neurite stretch and micropipette-guided ultrasound were developed to reveal the roles of ASIC3 and ASIC1a, respectively. Here we summarize the evidence supporting the roles of ASICs in neurosensory mechanotransduction in knockout mouse models of ASIC subtypes and provide insight to further probe their roles in proprioception.
Collapse
Affiliation(s)
- Yi‐Chen Lin
- Department of Neurology, Wan Fang HospitalTaipei Medical UniversityTaipeiTaiwan
- The Ph.D. Program for Translational MedicineTaipei Medical University and Academia SinicaNew Taipei CityTaiwan
- Taipei Neuroscience InstituteTaipei Medical UniversityNew Taipei CityTaiwan
- Institute of Biomedical SciencesAcademia SinicaTaipeiTaiwan
| | - Cheng‐Han Lee
- Institute of Biomedical SciencesAcademia SinicaTaipeiTaiwan
- Neuroscience Program of Academia SinicaAcademia SinicaTaipeiTaiwan
| | - Jia‐Ying Sung
- Department of Neurology, Wan Fang HospitalTaipei Medical UniversityTaipeiTaiwan
- Taipei Neuroscience InstituteTaipei Medical UniversityNew Taipei CityTaiwan
- Department of Neurology, School of Medicine, College of MedicineTaipei Medical UniversityTaipeiTaiwan
| | - Chih‐Cheng Chen
- The Ph.D. Program for Translational MedicineTaipei Medical University and Academia SinicaNew Taipei CityTaiwan
- Institute of Biomedical SciencesAcademia SinicaTaipeiTaiwan
- Neuroscience Program of Academia SinicaAcademia SinicaTaipeiTaiwan
- Taiwan Mouse Clinic – National Comprehensive Mouse Phenotyping and Drug Testing CenterAcademia SinicaTaipeiTaiwan
- TMU Neuroscience Research Center, Taipei Medical UniversityNew Taipei CityTaiwan
| |
Collapse
|
6
|
Thompson KJ, Watson S, Zanato C, Dall'Angelo S, De Nooij JC, Pace‐Bonello B, Shenton FC, Sanger HE, Heinz BA, Broad LM, Grosjean N, McQuillian JR, Dubini M, Pyner S, Greig I, Zanda M, Bleakman D, Banks RW, Bewick GS. The atypical 'hippocampal' glutamate receptor coupled to phospholipase D that controls stretch-sensitivity in primary mechanosensory nerve endings is homomeric purely metabotropic GluK2. Exp Physiol 2024; 109:81-99. [PMID: 37656490 PMCID: PMC10988755 DOI: 10.1113/ep090761] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Accepted: 08/08/2023] [Indexed: 09/02/2023]
Abstract
A metabotropic glutamate receptor coupled to phospholipase D (PLD-mGluR) was discovered in the hippocampus over three decades ago. Its pharmacology and direct linkage to PLD activation are well established and indicate it is a highly atypical glutamate receptor. A receptor with the same pharmacology is present in spindle primary sensory terminals where its blockade can totally abolish, and its activation can double, the normal stretch-evoked firing. We report here the first identification of this PLD-mGluR protein, by capitalizing on its expression in primary mechanosensory terminals, developing an enriched source, pharmacological profiling to identify an optimal ligand, and then functionalizing it as a molecular tool. Evidence from immunofluorescence, western and far-western blotting indicates PLD-mGluR is homomeric GluK2, since GluK2 is the only glutamate receptor protein/receptor subunit present in spindle mechanosensory terminals. Its expression was also found in the lanceolate palisade ending of hair follicle, also known to contain the PLD-mGluR. Finally, in a mouse model with ionotropic function ablated in the GluK2 subunit, spindle glutamatergic responses were still present, confirming it acts purely metabotropically. We conclude the PLD-mGluR is a homomeric GluK2 kainate receptor signalling purely metabotropically and it is common to other, perhaps all, primary mechanosensory endings.
Collapse
Affiliation(s)
- Karen J. Thompson
- Institute of Medical Sciences, School of Medicine, Medical Sciences & NutritionUniversity of AberdeenAberdeenUK
| | - Sonia Watson
- Institute of Medical Sciences, School of Medicine, Medical Sciences & NutritionUniversity of AberdeenAberdeenUK
| | - Chiara Zanato
- Institute of Medical Sciences, School of Medicine, Medical Sciences & NutritionUniversity of AberdeenAberdeenUK
| | - Sergio Dall'Angelo
- Institute of Medical Sciences, School of Medicine, Medical Sciences & NutritionUniversity of AberdeenAberdeenUK
| | | | | | | | | | | | | | - Noelle Grosjean
- CNRS UMR 5297, Interdisciplinary Institute of NeuroscienceUniversity of BordeauxBordeauxFrance
| | - Jessica R. McQuillian
- Institute of Medical Sciences, School of Medicine, Medical Sciences & NutritionUniversity of AberdeenAberdeenUK
| | - Marina Dubini
- Institute of Medical Sciences, School of Medicine, Medical Sciences & NutritionUniversity of AberdeenAberdeenUK
| | - Susan Pyner
- Department of BiosciencesDurham UniversityDurhamUK
| | - Iain Greig
- Institute of Medical Sciences, School of Medicine, Medical Sciences & NutritionUniversity of AberdeenAberdeenUK
| | - Matteo Zanda
- Institute of Medical Sciences, School of Medicine, Medical Sciences & NutritionUniversity of AberdeenAberdeenUK
| | | | | | - Guy S. Bewick
- Institute of Medical Sciences, School of Medicine, Medical Sciences & NutritionUniversity of AberdeenAberdeenUK
| |
Collapse
|
7
|
Housley SN, Powers RK, Nardelli P, Lee S, Blum K, Bewick GS, Banks RW, Cope TC. Biophysical model of muscle spindle encoding. Exp Physiol 2024; 109:55-65. [PMID: 36966478 PMCID: PMC10988694 DOI: 10.1113/ep091099] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 03/09/2023] [Indexed: 03/27/2023]
Abstract
Muscle spindles encode mechanosensory information by mechanisms that remain only partially understood. Their complexity is expressed in mounting evidence of various molecular mechanisms that play essential roles in muscle mechanics, mechanotransduction and intrinsic modulation of muscle spindle firing behaviour. Biophysical modelling provides a tractable approach to achieve more comprehensive mechanistic understanding of such complex systems that would be difficult/impossible by more traditional, reductionist means. Our objective here was to construct the first integrative biophysical model of muscle spindle firing. We leveraged current knowledge of muscle spindle neuroanatomy and in vivo electrophysiology to develop and validate a biophysical model that reproduces key in vivo muscle spindle encoding characteristics. Crucially, to our knowledge, this is the first computational model of mammalian muscle spindle that integrates the asymmetric distribution of known voltage-gated ion channels (VGCs) with neuronal architecture to generate realistic firing profiles, both of which seem likely to be of great biophysical importance. Results predict that particular features of neuronal architecture regulate specific characteristics of Ia encoding. Computational simulations also predict that the asymmetric distribution and ratios of VGCs is a complementary and, in some instances, orthogonal means to regulate Ia encoding. These results generate testable hypotheses and highlight the integral role of peripheral neuronal structure and ion channel composition and distribution in somatosensory signalling.
Collapse
Affiliation(s)
| | - Randal K. Powers
- Department of Physiology and BiophysicsUniversity of WashingtonSeattleWAUSA
| | - Paul Nardelli
- School of Biological SciencesGeorgia Institute of TechnologyAtlantaGA
| | - Sebinne Lee
- School of Biological SciencesGeorgia Institute of TechnologyAtlantaGA
| | - Kyle Blum
- Department of Physiology, Feinberg School of MedicineNorthwestern UniversityChicagoILUSA
| | - Guy S. Bewick
- Institute of Medical ScienceUniversity of AberdeenAberdeenUK
| | | | - Timothy C. Cope
- School of Biological SciencesGeorgia Institute of TechnologyAtlantaGA
- W. H. Coulter Department of Biomedical EngineeringEmory University and Georgia Institute of Technology, Georgia Institute of TechnologyAtlantaGA
| |
Collapse
|
8
|
Cheng YR, Chi CH, Lee CH, Lin SH, Min MY, Chen CC. Probing the Effect of Acidosis on Tether-Mode Mechanotransduction of Proprioceptors. Int J Mol Sci 2023; 24:12783. [PMID: 37628964 PMCID: PMC10454156 DOI: 10.3390/ijms241612783] [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: 07/06/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
Proprioceptors are low-threshold mechanoreceptors involved in perceiving body position and strain bearing. However, the physiological response of proprioceptors to fatigue- and muscle-acidosis-related disturbances remains unknown. Here, we employed whole-cell patch-clamp recordings to probe the effect of mild acidosis on the mechanosensitivity of the proprioceptive neurons of dorsal root ganglia (DRG) in mice. We cultured neurite-bearing parvalbumin-positive (Pv+) DRG neurons on a laminin-coated elastic substrate and examined mechanically activated currents induced through substrate deformation-driven neurite stretch (SDNS). The SDNS-induced inward currents (ISDNS) were indentation depth-dependent and significantly inhibited by mild acidification (pH 7.2~6.8). The acid-inhibiting effect occurred in neurons with an ISDNS sensitive to APETx2 (an ASIC3-selective antagonist) inhibition, but not in those with an ISNDS resistant to APETx2. Detailed subgroup analyses revealed ISDNS was expressed in 59% (25/42) of Parvalbumin-positive (Pv+) DRG neurons, 90% of which were inhibited by APETx2. In contrast, an acid (pH 6.8)-induced current (IAcid) was expressed in 76% (32/42) of Pv+ DRG neurons, 59% (21/32) of which were inhibited by APETx2. Together, ASIC3-containing channels are highly heterogenous and differentially contribute to the ISNDS and IAcid among Pv+ proprioceptors. In conclusion, our findings highlight the importance of ASIC3-containing ion channels in the physiological response of proprioceptors to acidic environments.
Collapse
Affiliation(s)
- Yuan-Ren Cheng
- Department of Life Science, National Taiwan University, Taipei 10090, Taiwan;
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Chih-Hung Chi
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Cheng-Han Lee
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Shing-Hong Lin
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
| | - Ming-Yuan Min
- Department of Life Science, National Taiwan University, Taipei 10090, Taiwan;
| | - Chih-Cheng Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan
- Neuroscience Program of Academia Sinica, Academia Sinica, Taipei 11529, Taiwan
| |
Collapse
|
9
|
Gündoğdu AÇ, Özyurt R. Resveratrol downregulates ENaCs through the activation of AMPK in human colon cancer cells. Tissue Cell 2023; 82:102071. [PMID: 36965273 DOI: 10.1016/j.tice.2023.102071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 03/11/2023] [Accepted: 03/12/2023] [Indexed: 03/14/2023]
Abstract
Epithelial sodium channels (ENaCs) are critically engaged in a number of hallmarks of cancer progression, including proliferation, migration, invasion and apoptosis. Thus, the inhibition of ENaCs possesses therapeutic potential in cancer. Resveratrol, a natural polyphenol with anti-carcinogenic activity, is a potent activator of 5' AMP-activated protein kinase (AMPK) which reduces the abundance of ENaCs in the cell membrane by causing the internalization of the β subunit. However, the effect of resveratrol on ENaCs in cancer cells is unknown. Therefore, in this study, we aimed to investigate the effects of resveratrol on ENaCs in human colon cancer cells HCT116 and HT29. The influences of resveratrol either alone or together with AMPK inhibitor compound C (CC), and ENaC inhibitor amiloride on cell viability were examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The expression levels of phospho-AMPK Thr172 and βENaC in cells were determined by immunofluorescence staining, and the expression of apoptotic markers Caspase-3 and Caspase-9 were analyzed by qRT-PCR. Resveratrol was found to activate AMPK in a dose-dependent manner. Both AMPK activation by resveratrol and ENaC inhibition by amiloride decreased cell viability and increased apoptosis significantly. AMPK activation also reduced βENaC expression in cells. Our results suggest that ENaC inhibition through AMPK activation might be a potential mechanism underlying the anti-cancer effects of resveratrol.
Collapse
Affiliation(s)
- Ayşe Çakır Gündoğdu
- Department of Histology and Embryology, Faculty of Medicine, Kütahya Health Sciences University, Kütahya, Turkiye.
| | - Rumeysa Özyurt
- Department of Physiology, Faculty of Medicine, Kütahya Health Sciences University, Kütahya, Turkiye
| |
Collapse
|
10
|
Wilkinson KA. Molecular determinants of mechanosensation in the muscle spindle. Curr Opin Neurobiol 2022; 74:102542. [PMID: 35430481 PMCID: PMC9815952 DOI: 10.1016/j.conb.2022.102542] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 01/12/2022] [Accepted: 03/13/2022] [Indexed: 01/11/2023]
Abstract
The muscle spindle (MS) provides essential sensory information for motor control and proprioception. The Group Ia and II MS afferents are low threshold slowly-adapting mechanoreceptors and report both static muscle length and dynamic muscle movement information. The exact molecular mechanism by which MS afferents transduce muscle movement into action potentials is incompletely understood. This short review will discuss recent evidence suggesting that PIEZO2 is an essential mechanically sensitive ion channel in MS afferents and that vesicle-released glutamate contributes to maintaining afferent excitability during the static phase of stretch. Other mechanically gated ion channels, voltage-gated sodium channels, other ion channels, regulatory proteins, and interactions with the intrafusal fibers are also important for MS afferent mechanosensation. Future studies are needed to fully understand mechanosensation in the MS and whether different complements of molecular mediators contribute to the different response properties of Group Ia and II afferents.
Collapse
|
11
|
Sivils A, Yang F, Wang JQ, Chu XP. Acid-Sensing Ion Channel 2: Function and Modulation. MEMBRANES 2022; 12:membranes12020113. [PMID: 35207035 PMCID: PMC8880099 DOI: 10.3390/membranes12020113] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 01/08/2023]
Abstract
Acid-sensing ion channels (ASICs) have an important influence on human physiology and pathology. They are members of the degenerin/epithelial sodium channel family. Four genes encode at least six subunits, which combine to form a variety of homotrimers and heterotrimers. Of these, ASIC1a homotrimers and ASIC1a/2 heterotrimers are most widely expressed in the central nervous system (CNS). Investigations into the function of ASIC1a in the CNS have revealed a wealth of information, culminating in multiple contemporary reviews. The lesser-studied ASIC2 subunits are in need of examination. This review will focus on ASIC2 in health and disease, with discussions of its role in modulating ASIC function, synaptic targeting, cardiovascular responses, and pharmacology, while exploring evidence of its influence in pathologies such as ischemic brain injury, multiple sclerosis, epilepsy, migraines, drug addiction, etc. This information substantiates the ASIC2 protein as a potential therapeutic target for various neurological, psychological, and cerebrovascular diseases.
Collapse
Affiliation(s)
| | | | | | - Xiang-Ping Chu
- Correspondence: ; Tel.: +1-816-235-2248; Fax: +1-816-235-6517
| |
Collapse
|
12
|
Sternberg AK, Buck VU, Classen-Linke I, Leube RE. How Mechanical Forces Change the Human Endometrium during the Menstrual Cycle in Preparation for Embryo Implantation. Cells 2021; 10:2008. [PMID: 34440776 PMCID: PMC8391722 DOI: 10.3390/cells10082008] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 07/30/2021] [Accepted: 08/03/2021] [Indexed: 12/12/2022] Open
Abstract
The human endometrium is characterized by exceptional plasticity, as evidenced by rapid growth and differentiation during the menstrual cycle and fast tissue remodeling during early pregnancy. Past work has rarely addressed the role of cellular mechanics in these processes. It is becoming increasingly clear that sensing and responding to mechanical forces are as significant for cell behavior as biochemical signaling. Here, we provide an overview of experimental evidence and concepts that illustrate how mechanical forces influence endometrial cell behavior during the hormone-driven menstrual cycle and prepare the endometrium for embryo implantation. Given the fundamental species differences during implantation, we restrict the review to the human situation. Novel technologies and devices such as 3D multifrequency magnetic resonance elastography, atomic force microscopy, organ-on-a-chip microfluidic systems, stem-cell-derived organoid formation, and complex 3D co-culture systems have propelled the understanding how endometrial receptivity and blastocyst implantation are regulated in the human uterus. Accumulating evidence has shown that junctional adhesion, cytoskeletal rearrangement, and extracellular matrix stiffness affect the local force balance that regulates endometrial differentiation and blastocyst invasion. A focus of this review is on the hormonal regulation of endometrial epithelial cell mechanics. We discuss potential implications for embryo implantation.
Collapse
Affiliation(s)
| | | | | | - Rudolf E. Leube
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany; (A.K.S.); (V.U.B.); (I.C.-L.)
| |
Collapse
|
13
|
Yan X, Zhang S, Zhao H, Liu P, Huang H, Niu W, Wang W, Zhang C. ASIC2 Synergizes with TRPV1 in the Mechano-Electrical Transduction of Arterial Baroreceptors. Neurosci Bull 2021; 37:1381-1396. [PMID: 34215968 DOI: 10.1007/s12264-021-00737-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 03/09/2021] [Indexed: 11/24/2022] Open
Abstract
Mechanosensitive ion channels (MSCs) are key molecules in the mechano-electrical transduction of arterial baroreceptors. Among them, acid-sensing ion channel 2 (ASIC2) and transient receptor potential vanilloid subfamily member 1 (TRPV1) have been studied extensively and documented to play important roles. In this study, experiments using aortic arch-aortic nerve preparations isolated from rats revealed that both ASIC2 and TRPV1 are functionally necessary, as blocking either abrogated nearly all pressure-dependent neural discharge. However, whether ASIC2 and TRPV1 work in coordination remained unclear. So we carried out cell-attached patch-clamp recordings in HEK293T cells co-expressing ASIC2 and TRPV1 and found that inhibition of ASIC2 completely blocked stretch-activated currents while inhibition of TRPV1 only partially blocked these currents. Immunofluorescence staining of aortic arch-aortic adventitia from rats showed that ASIC2 and TRPV1 are co-localized in the aortic nerve endings, and co-immunoprecipitation assays confirmed that the two proteins form a compact complex in HEK293T cells and in baroreceptors. Moreover, protein modeling analysis, exogenous co-immunoprecipitation assays, and biotin pull-down assays indicated that ASIC2 and TRPV1 interact directly. In summary, our research suggests that ASIC2 and TRPV1 form a compact complex and function synergistically in the mechano-electrical transduction of arterial baroreceptors. The model of synergism between MSCs may have important biological significance beyond ASIC2 and TRPV1.
Collapse
Affiliation(s)
- Xiaodong Yan
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Sitao Zhang
- Department of Orthopedics, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
| | - Haiyan Zhao
- Yanjing Medical College, Capital Medical University, Beijing, 101300, China
| | - Ping Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Haixia Huang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Weizhen Niu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China
| | - Wei Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing, 100069, China. .,Beijing Laboratory for Cardiovascular Precision Medicine, Capital Medical University, Beijing, 100069, China.
| | - Chen Zhang
- Department of Neurobiology, School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing, 100069, China.
| |
Collapse
|
14
|
Than K, Kim E, Navarro C, Chu S, Klier N, Occiano A, Ortiz S, Salazar A, Valdespino SR, Villegas NK, Wilkinson KA. Vesicle-released glutamate is necessary to maintain muscle spindle afferent excitability but not dynamic sensitivity in adult mice. J Physiol 2021; 599:2953-2967. [PMID: 33749829 DOI: 10.1113/jp281182] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 02/16/2021] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Muscle spindle afferents are slowly adapting low threshold mechanoreceptors that report muscle length and movement information critical for motor control and proprioception. The rapidly adapting cation channel PIEZO2 has been identified as necessary for muscle spindle afferent stretch sensitivity, although the properties of this channel suggest that additional molecular elements are necessary for mediating the complex slowly adapting response of muscle spindle afferents. We report that glutamate increases muscle spindle afferent static sensitivity in an ex vivo mouse muscle nerve preparation, although blocking glutamate packaging into vesicles by the sole vesicular glutamate transporter, VGLUT1, either pharmacologically or by transgenic knockout of one allele of VGLUT1 decreases muscle spindle afferent static but not dynamic sensitivity. Our results confirm that vesicle-released glutamate is an important contributor to maintained muscle spindle afferent excitability and may suggest a therapeutic target for normalizing muscle spindle afferent function. ABSTRACT Muscle spindle afferents are slowly adapting low threshold mechanoreceptors that have both dynamic and static sensitivity to muscle stretch. The exact mechanism by which these neurons translate muscle movement into action potentials is not well understood, although the PIEZO2 mechanically sensitive cation channel is essential for stretch sensitivity. PIEZO2 is rapidly adapting, suggesting the requirement for additional molecular elements to maintain firing during stretch. Spindle afferent sensory endings contain glutamate-filled synaptic-like vesicles that are released in a stretch- and calcium-dependent manner. Previous work has shown that glutamate can increase and a phospholipase-D coupled metabotropic glutamate antagonist can abolish firing during static stretch. Here, we test the hypothesis that vesicle-released glutamate is necessary for maintaining muscle spindle afferent excitability during static but not dynamic stretch. To test this hypothesis, we used a mouse muscle-nerve ex vivo preparation to measure identified muscle spindle afferent responses to stretch and vibration. In C57BL/6 adult mice, bath applied glutamate significantly increased the firing rate during the plateau phase of stretch but not during the dynamic phase of stretch. Blocking the packaging of glutamate into vesicles by the sole vesicular glutamate transporter, VGLUT1, either with xanthurenic acid or by using a transgenic mouse with only one copy of the VGLUT1 gene (VGLUT1+/- ), decreased muscle spindle afferent firing during sustained stretch but not during vibration. Our results suggest a model of mechanotransduction where calcium entering the PIEZO2 channel can cause the release of glutamate from synaptic-like vesicles, which then helps to maintain afferent depolarization and firing.
Collapse
Affiliation(s)
- Kimberly Than
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | - Enoch Kim
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | - Cebrina Navarro
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | - Sarah Chu
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | - Nikola Klier
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | - Alyssa Occiano
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | - Serena Ortiz
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | - Alexandra Salazar
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | - Steven R Valdespino
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | - Natanya K Villegas
- Department of Biological Sciences, San José State University, San Jose, CA, USA
| | | |
Collapse
|
15
|
Bornstein B, Konstantin N, Alessandro C, Tresch MC, Zelzer E. More than movement: the proprioceptive system as a new regulator of musculoskeletal biology. CURRENT OPINION IN PHYSIOLOGY 2021. [DOI: 10.1016/j.cophys.2021.01.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
|
16
|
Bewick GS, Banks RW. Mechanotransduction channels in proprioceptive sensory nerve terminals: still an open question? CURRENT OPINION IN PHYSIOLOGY 2021. [DOI: 10.1016/j.cophys.2020.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
17
|
Campbell T, Shenton FC, Lucking E, Pyner S, Jones JFX. Electrophysiological characterisation of atrial volume receptors using ex vivo models of isolated rat cardiac atria. Exp Physiol 2020; 105:2190-2206. [PMID: 33372723 DOI: 10.1113/ep088972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 10/12/2020] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? What ex vivo preparation of the rat's cavoatrial junction is efficient for characterising atrial mechanoreceptors? What is the main finding and its importance? Of four different ex vivo preparations, static pressure, flow, open and euthermic, the optimal preparation was the euthermic one and involved direct recording from the right cardiac vagal branch with a Langendorff style perfusion at 37°C. Type A receptors were most common, and appeared insensitive to stretch and sensitive to atrial contraction. Type B and intermediate receptors were not isolated at 20°C but were observed closer to 37°C. The findings may suggest that type A and B receptors utilise different molecular transduction mechanisms. ABSTRACT Atrial volume receptors are a family of afferent neurons whose mechanically sensitive endings terminate in the atria, particularly at the cavoatrial junctions. These mechanosensors form the afferent limb of an atrial volume receptor reflex that regulates plasma volume. The prevailing functional classification of atrial receptors arose as a result of in vivo recordings in the cat and dog and were classified as type A, B or intermediate according to the timing of peak discharge during the cardiac cycle. In contrast, there have been far fewer studies of the common small laboratory mammals such as the rat. Using several ex vivo rat cavoatrial preparations, a total of 30 successful single cavoatrial mechanosensory recordings were obtained. These experiments show that the rat possesses type A, B and intermediate atrial mechanoreceptors as described for larger mammals. Recording these cavoatrial receptors proved challenging from the main vagus, but direct recording from the cardiac vagal branch greatly increased the yield of mechanically sensitive single units. In contrast to type A units, type B atrial mechanoreceptor activity was never observed at room temperature but required elevation of temperature to a more physiological range in order to be detected. The adequate stimulus for these receptors remains unclear; however, type A atrial receptors appear insensitive to direct atrial stretch when applied using a programmable positioner. The findings may suggest that type A and type B atrial receptors utilise different molecular transduction mechanisms.
Collapse
Affiliation(s)
- Thomas Campbell
- Discipline of Anatomy, School of Medicine, University College Dublin, Dublin, Ireland
| | | | - Eric Lucking
- Discipline of Anatomy, School of Medicine, University College Dublin, Dublin, Ireland
| | - Susan Pyner
- Department of Biosciences, Durham University, Durham, UK
| | | |
Collapse
|
18
|
Barrett P, Quick TJ, Mudera V, Player DJ. Generating intrafusal skeletal muscle fibres in vitro: Current state of the art and future challenges. J Tissue Eng 2020; 11:2041731420985205. [PMID: 34956586 PMCID: PMC8693220 DOI: 10.1177/2041731420985205] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 12/12/2020] [Indexed: 01/18/2023] Open
Abstract
Intrafusal fibres are a specialised cell population in skeletal muscle, found within the muscle spindle. These fibres have a mechano-sensory capacity, forming part of the monosynaptic stretch-reflex arc, a key component responsible for proprioceptive function. Impairment of proprioception and associated dysfunction of the muscle spindle is linked with many neuromuscular diseases. Research to-date has largely been undertaken in vivo or using ex vivo preparations. These studies have provided a foundation for our understanding of muscle spindle physiology, however, the cellular and molecular mechanisms which underpin physiological changes are yet to be fully elucidated. Therefrom, the use of in vitro models has been proposed, whereby intrafusal fibres can be generated de novo. Although there has been progress, it is predominantly a developing and evolving area of research. This narrative review presents the current state of art in this area and proposes the direction of future work, with the aim of providing novel pre-clinical and clinical applications.
Collapse
Affiliation(s)
- Philip Barrett
- Centre for 3D Models of Health and Disease, Division of Surgery and Interventional Science, Faculty of Medical Sciences, University College London, London, UK
| | - Tom J Quick
- Peripheral Nerve Injury Research Unit, Royal National Orthopaedic Hospital, Stanmore, UK
- UCL Centre for Nerve Engineering, University College London, London, UK
| | - Vivek Mudera
- Centre for 3D Models of Health and Disease, Division of Surgery and Interventional Science, Faculty of Medical Sciences, University College London, London, UK
| | - Darren J Player
- Centre for 3D Models of Health and Disease, Division of Surgery and Interventional Science, Faculty of Medical Sciences, University College London, London, UK
| |
Collapse
|
19
|
Housley SN, Nardelli P, Carrasco DI, Rotterman TM, Pfahl E, Matyunina LV, McDonald JF, Cope TC. Cancer Exacerbates Chemotherapy-Induced Sensory Neuropathy. Cancer Res 2020; 80:2940-2955. [PMID: 32345673 PMCID: PMC7340531 DOI: 10.1158/0008-5472.can-19-2331] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 03/11/2020] [Accepted: 04/23/2020] [Indexed: 12/30/2022]
Abstract
For the constellation of neurologic disorders known as chemotherapy-induced peripheral neuropathy, mechanistic understanding and treatment remain deficient. Here, we present the first evidence that chronic sensory neuropathy depends on nonlinear interactions between cancer and chemotherapy. Global transcriptional profiling of dorsal root ganglia revealed differential expression, notably in regulators of neuronal excitability, metabolism, and inflammatory responses, all of which were unpredictable from effects observed with either chemotherapy or cancer alone. Systemic interactions between cancer and chemotherapy also determined the extent of deficits in sensory encoding and ion channel protein expression by single mechanosensory neurons, with the potassium ion channel Kv3.3 emerging as one potential contributor to sensory neuron dysfunction. Validated measures of sensorimotor behavior in awake, behaving animals revealed dysfunction after chronic chemotherapy treatment was exacerbated by cancer. Notably, errors in precise forelimb placement emerged as a novel behavioral deficit unpredicted by our previous study of chemotherapy alone. These original findings identify novel contributors to peripheral neuropathy and emphasize the fundamental dependence of neuropathy on the systemic interaction between chemotherapy and cancer. SIGNIFICANCE: These findings highlight the need to account for pathobiological interactions between cancer and chemotherapy as a major contributor to neuropathy and will have significant and immediate impact on future investigations in this field.
Collapse
Affiliation(s)
- Stephen N Housley
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Paul Nardelli
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Dario I Carrasco
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Travis M Rotterman
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Emily Pfahl
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
| | - Lilya V Matyunina
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
- Integrated Cancer Research Center, Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
| | - John F McDonald
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia
- Integrated Cancer Research Center, Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
| | - Timothy C Cope
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia.
- W.H. Coulter Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Georgia Institute of Technology, Atlanta, Georgia
- Integrated Cancer Research Center, Parker H. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia
| |
Collapse
|
20
|
Campbell T, Jones JF. Design and implementation of a low cost, modular, adaptable and open-source XYZ positioning system for neurophysiology. HARDWAREX 2020; 7:e00098. [PMID: 35495216 PMCID: PMC9041220 DOI: 10.1016/j.ohx.2020.e00098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 01/15/2020] [Accepted: 01/20/2020] [Indexed: 05/07/2023]
Abstract
In recent years, open-source 3D printing technologies have become increasingly applied to biological research. We have created a fully open-source, versatile and low cost XYZ positioning system using 3D printer components. As this system is controlled by a Python3 based operating system running on a Raspberry Pi 3 Model B, its behaviour can be adapted to meet multiple needs in neurophysiology. We have developed two main applications of this system. First, we have created an automated microscopy script that links seamlessly with image stitching plugins in ImageJ (Fiji) allowing the user to create high resolution montages. Second, we have created a series of movement scripts allowing the application of graded rates of stretch to muscle spindles. Here we outline the construction and implementation of this system and discuss how we have utilised this tool in our research.
Collapse
Key Words
- 3D, Three Dimensional
- AC, Alternating Current
- Arduino
- Automated microscopy
- CNC, Computed Numerical Code
- DC, Direct Current
- EMI, Electromagnetic Interference
- FDM, Fused Deposition Modelling
- FFF, Fused Filament Fabrication
- GPIO, General-Purpose Input/Output
- IDE, Integrated Developer Environment
- LCD, Liquid Crystal Display
- Mechanotransduction
- NEMA17, National Electrical Manufacturers Association (stepper motor with faceplate dimensions of 1.7 × 1.7 in.)
- Neurophysiology
- OpenCV, Open Computer Vision
- PLA, Polylactic Acid
- PVA, Polyvinyl Acetate
- RAMPS 1.4, Reprap Arduino Mega Pololu Shield (version 1.4)
- Raspberry Pi
- SD Card, Secure Digital Card
- STEM, Science, Technology, Engineering and Mathematics
- STL, Stereolithography
- USB, Universal Serial Bus
- UTF-8, Unicode Transformation Format, 8-bit blocks
- VAT, Value Added Tax
- XYZ positioning system
Collapse
|
21
|
Koll R, Martorell Ribera J, Brunner RM, Rebl A, Goldammer T. Gene Profiling in the Adipose Fin of Salmonid Fishes Supports its Function as a Flow Sensor. Genes (Basel) 2019; 11:E21. [PMID: 31878086 PMCID: PMC7016824 DOI: 10.3390/genes11010021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/13/2019] [Accepted: 12/17/2019] [Indexed: 11/16/2022] Open
Abstract
In stock enhancement and sea-ranching procedures, the adipose fin of hundreds of millions of salmonids is removed for marking purposes annually. However, recent studies proved the significance of the adipose fin as a flow sensor and attraction feature. In the present study, we profiled the specific expression of 20 neuron- and glial cell-marker genes in the adipose fin and seven other tissues (including dorsal and pectoral fin, brain, skin, muscle, head kidney, and liver) of the salmonid species rainbow trout Oncorhynchus mykiss and maraena whitefish Coregonusmaraena. Moreover, we measured the transcript abundance of genes coding for 15 mechanoreceptive channel proteins from a variety of mechanoreceptors known in vertebrates. The overall expression patterns indicate the presence of the entire repertoire of neurons, glial cells and receptor proteins on the RNA level. This quantification suggests that the adipose fin contains considerable amounts of small nerve fibers with unmyelinated or slightly myelinated axons and most likely mechanoreceptive potential. The findings are consistent for both rainbow trout and maraena whitefish and support a previous hypothesis about the innervation and potential flow sensory function of the adipose fin. Moreover, our data suggest that the resection of the adipose fin has a stronger impact on the welfare of salmonid fish than previously assumed.
Collapse
Affiliation(s)
- Raphael Koll
- Fish Genetics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; (R.K.); (J.M.R.); (R.M.B.); (A.R.)
| | - Joan Martorell Ribera
- Fish Genetics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; (R.K.); (J.M.R.); (R.M.B.); (A.R.)
| | - Ronald M. Brunner
- Fish Genetics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; (R.K.); (J.M.R.); (R.M.B.); (A.R.)
| | - Alexander Rebl
- Fish Genetics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; (R.K.); (J.M.R.); (R.M.B.); (A.R.)
| | - Tom Goldammer
- Fish Genetics Unit, Institute for Genome Biology, Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, 18196 Dummerstorf, Germany; (R.K.); (J.M.R.); (R.M.B.); (A.R.)
- Professorship for Molecular Biology and Fish Genetics, Faculty of Agriculture and Environmental Sciences, University of Rostock, 18055 Rostock, Germany
| |
Collapse
|
22
|
Gerwin L, Haupt C, Wilkinson KA, Kröger S. Acetylcholine receptors in the equatorial region of intrafusal muscle fibres modulate mouse muscle spindle sensitivity. J Physiol 2019; 597:1993-2006. [PMID: 30673133 DOI: 10.1113/jp277139] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 01/22/2019] [Indexed: 01/08/2023] Open
Abstract
KEY POINTS Acetylcholine receptors are aggregated in the central regions of intrafusal muscle fibres. Single unit muscle spindle afferent responses from isolated mouse extensor digitorum longus muscle were recorded in the absence of fusimotor input to ramp and hold stretches as well as to sinusoidal vibrations in the presence and absence of the acetylcholine receptor blockers d-tubocurarine and α-bungarotoxin. Proprioceptive afferent responses to both types of stretch were enhanced in the presence of either blocker. Blocking acetylcholine uptake and vesicular acetylcholine release by hemicholinium-3 also enhanced stretch-evoked responses. These results represent the first evidence that acetylcholine receptors negatively modulate muscle spindle responses to stretch. The data support the hypothesis that the sensory nerve terminal is able to release vesicles to fine-tune proprioceptive afferent sensitivity. ABSTRACT Muscle spindles are complex stretch-sensitive mechanoreceptors. They consist of specialized skeletal muscle fibres, called intrafusal fibres, which are innervated in the central (equatorial) region by afferent sensory axons and in both polar regions by efferent γ-motoneurons. Previously it was shown that acetylcholine receptors (AChR) are concentrated in the equatorial region at the contact site between the sensory neuron and the intrafusal muscle fibre. To address the function of these AChRs, single unit sensory afferents were recorded from an isolated mouse extensor digitorum longus muscle in the absence of γ-motoneuron activity. Specifically, we investigated the responses of individual sensory neurons to ramp-and-hold stretches and sinusoidal vibrations before and after the addition of the competitive and non-competitive AChR blockers d-tubocurarine and α-bungarotoxin, respectively. The presence of either drug did not affect the resting action potential discharge frequency. However, the action potential frequencies in response to stretch were increased. In particular, frequencies of the dynamic peak and dynamic index to ramp-and-hold stretches were significantly higher in the presence of either drug. Treatment of muscle spindle afferents with the high-affinity choline transporter antagonist hemicholinium-3 similarly increased muscle spindle afferent firing frequencies during stretch. Moreover, the firing rate during sinusoidal vibration stimuli at low amplitudes was higher in the presence of α-bungarotoxin compared to control spindles also indicating an increased sensitivity to stretch. Collectively these data suggest a modulation of the muscle spindle afferent response to stretch by AChRs in the central region of intrafusal fibres possibly fine-tuning muscle spindle sensitivity.
Collapse
Affiliation(s)
- Laura Gerwin
- Department of Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, D-82152, Planegg-Martinsried, Germany.,Institute for Stem Cell Research, German Research Center for Environmental Health, Helmholtz Centre Munich, Ingolstädter Landstraße 1, D-85764, Neuherberg, Germany
| | - Corinna Haupt
- Department of Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, D-82152, Planegg-Martinsried, Germany
| | - Katherine A Wilkinson
- Department of Biological Sciences, San Jose State University, One Washington Square, San Jose, CA, 95192, USA
| | - Stephan Kröger
- Department of Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University, Großhaderner Str. 9, D-82152, Planegg-Martinsried, Germany
| |
Collapse
|
23
|
Hennes A, Held K, Boretto M, De Clercq K, Van den Eynde C, Vanhie A, Van Ranst N, Benoit M, Luyten C, Peeraer K, Tomassetti C, Meuleman C, Voets T, Vankelecom H, Vriens J. Functional expression of the mechanosensitive PIEZO1 channel in primary endometrial epithelial cells and endometrial organoids. Sci Rep 2019; 9:1779. [PMID: 30741991 PMCID: PMC6370865 DOI: 10.1038/s41598-018-38376-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 12/20/2018] [Indexed: 12/27/2022] Open
Abstract
Successful pregnancy requires the establishment of a complex dialogue between the implanting embryo and the endometrium. Knowledge regarding molecular candidates involved in this early communication process is inadequate due to limited access to primary human endometrial epithelial cells (EEC). Since pseudo-pregnancy in rodents can be induced by mechanical scratching of an appropriately primed uterus, this study aimed to investigate the expression of mechanosensitive ion channels in EEC. Poking of EEC provoked a robust calcium influx and induced an increase in current densities, which could be blocked by an inhibitor of mechanosensitive ion channels. Interestingly, RNA expression studies showed high expression of PIEZO1 in EEC of mouse and human. Additional analysis provided further evidence for the functional expression of PIEZO1 since stimulation with Yoda1, a chemical agonist of PIEZO1, induced increases in intracellular calcium concentrations and current densities in EEC. Moreover, the ion channel profile of human endometrial organoids (EMO) was validated as a representative model for endometrial epithelial cells. Mechanical and chemical stimulation of EMO induced strong calcium responses supporting the hypothesis of mechanosensitive ion channel expression in endometrial epithelial cells. In conclusion, EEC and EMO functionally express the mechanosensitive PIEZO1 channel that could act as a potential target for the development of novel treatments to further improve successful implantation processes.
Collapse
Affiliation(s)
- Aurélie Hennes
- Laboratory of Endometrium, Endometriosis & Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 611, 3000, Leuven, Belgium
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49 box 802, 3000, Leuven, Belgium
| | - Katharina Held
- Laboratory of Endometrium, Endometriosis & Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 611, 3000, Leuven, Belgium
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49 box 802, 3000, Leuven, Belgium
| | - Matteo Boretto
- Laboratory of Tissue Plasticity in Health and Disease, Cluster of Stem Cell and Developmental Biology, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 804, 3000, Leuven, Belgium
| | - Katrien De Clercq
- Laboratory of Endometrium, Endometriosis & Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 611, 3000, Leuven, Belgium
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49 box 802, 3000, Leuven, Belgium
| | - Charlotte Van den Eynde
- Laboratory of Endometrium, Endometriosis & Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 611, 3000, Leuven, Belgium
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49 box 802, 3000, Leuven, Belgium
| | - Arne Vanhie
- Laboratory of Endometrium, Endometriosis & Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 611, 3000, Leuven, Belgium
- Leuven University Fertility Centre, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Nele Van Ranst
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49 box 802, 3000, Leuven, Belgium
| | - Melissa Benoit
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49 box 802, 3000, Leuven, Belgium
| | - Catherine Luyten
- Laboratory of Endometrium, Endometriosis & Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 611, 3000, Leuven, Belgium
| | - Karen Peeraer
- Laboratory of Endometrium, Endometriosis & Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 611, 3000, Leuven, Belgium
- Leuven University Fertility Centre, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Carla Tomassetti
- Laboratory of Endometrium, Endometriosis & Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 611, 3000, Leuven, Belgium
- Leuven University Fertility Centre, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Christel Meuleman
- Laboratory of Endometrium, Endometriosis & Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 611, 3000, Leuven, Belgium
- Leuven University Fertility Centre, University Hospitals Leuven, Herestraat 49, 3000, Leuven, Belgium
| | - Thomas Voets
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49 box 802, 3000, Leuven, Belgium
| | - Hugo Vankelecom
- Laboratory of Tissue Plasticity in Health and Disease, Cluster of Stem Cell and Developmental Biology, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 804, 3000, Leuven, Belgium
| | - Joris Vriens
- Laboratory of Endometrium, Endometriosis & Reproductive Medicine, Department of Development and Regeneration, KU Leuven, Herestraat 49 box 611, 3000, Leuven, Belgium.
| |
Collapse
|
24
|
Missitzi J, Geladas N, Misitzi A, Misitzis L, Classen J, Klissouras V. Heritability of proprioceptive senses. J Appl Physiol (1985) 2018. [PMID: 29517423 DOI: 10.1152/japplphysiol.00544.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heritability studies using the twin model have provided the basis to disentangle genetic and environmental factors that contribute to several complex human traits. However, the relative importance of these factors to individual differences in proprioception is largely unknown despite the fact that proprioceptive senses are of great importance, allowing us to respond to stimuli stemming from the space around us and react to altering circumstances. Hence, a total of 44 healthy male twins (11 MZ and 11 DZ pairs), 19-28 yr old, were examined for movement, position, and force sense at the elbow joint, and their heritability estimates were computed. Results showed that genetic factors explained 1) 72 and 76% of the total variance of movement sense at the start and the end of the movement, respectively, 2) 60 to 77% of the total variance of position sense, depending on the angle of elbow flexion and whether forearm positioning was active or passive, and 3) 73 and 70% of the total variance of the force sense at 90 and 60° of elbow flexion, respectively. It is concluded that proprioception assessed by these conscious sensations is to a substantial degree genetically dependent, with heritability indexes ranging from 0.60 to 0.77, depending on the task. NEW & NOTEWORTHY Proprioceptive acuity varies among people, but it is not known how much of this variability is due to differences in their genes. This study is the first to report that proprioception, expressed as movement sense, position sense, and force sense, is substantially heritable, and it is conceivable that this may have implications for motor learning and control, neural development, and neurorehabilitation.
Collapse
Affiliation(s)
- Julia Missitzi
- Ergophysiology Research Laboratory, Department of Sport Medicine and Biology of Physical Activity, National and Kapodistrian University of Athens , Athens , Greece
| | - Nickos Geladas
- Ergophysiology Research Laboratory, Department of Sport Medicine and Biology of Physical Activity, National and Kapodistrian University of Athens , Athens , Greece
| | - Angelica Misitzi
- School of Medicine, National and Kapodistrian University of Athens , Athens , Greece
| | | | - Joseph Classen
- Human Motor Control and Neuroplasticity Laboratory, Department of Neurology, University of Leipzig , Leipzig , Germany
| | - Vassilis Klissouras
- Ergophysiology Research Laboratory, Department of Sport Medicine and Biology of Physical Activity, National and Kapodistrian University of Athens , Athens , Greece
| |
Collapse
|
25
|
|
26
|
Tu H, Zhang D, Li YL. Cellular and Molecular Mechanisms Underlying Arterial Baroreceptor Remodeling in Cardiovascular Diseases and Diabetes. Neurosci Bull 2018; 35:98-112. [PMID: 30146675 DOI: 10.1007/s12264-018-0274-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/31/2018] [Indexed: 01/23/2023] Open
Abstract
Clinical trials and animal experimental studies have demonstrated an association of arterial baroreflex impairment with the prognosis and mortality of cardiovascular diseases and diabetes. As a primary part of the arterial baroreflex arc, the pressure sensitivity of arterial baroreceptors is blunted and involved in arterial baroreflex dysfunction in cardiovascular diseases and diabetes. Changes in the arterial vascular walls, mechanosensitive ion channels, and voltage-gated ion channels contribute to the attenuation of arterial baroreceptor sensitivity. Some endogenous substances (such as angiotensin II and superoxide anion) can modulate these morphological and functional alterations through intracellular signaling pathways in impaired arterial baroreceptors. Arterial baroreceptors can be considered as a potential therapeutic target to improve the prognosis of patients with cardiovascular diseases and diabetes.
Collapse
Affiliation(s)
- Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA
| | - Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, NE, 68198, USA.
| |
Collapse
|
27
|
Cheng YR, Jiang BY, Chen CC. Acid-sensing ion channels: dual function proteins for chemo-sensing and mechano-sensing. J Biomed Sci 2018; 25:46. [PMID: 29793480 PMCID: PMC5966886 DOI: 10.1186/s12929-018-0448-y] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 05/15/2018] [Indexed: 12/22/2022] Open
Abstract
Background Acid-sensing ion channels (ASICs) are a group of amiloride-sensitive ligand-gated ion channels belonging to the family of degenerin/epithelial sodium channels. ASICs are predominantly expressed in both the peripheral and central nervous system and have been characterized as potent proton sensors to detect extracellular acidification in the periphery and brain. Main body Here we review the recent studies focusing on the physiological roles of ASICs in the nervous system. As the major acid-sensing membrane proteins in the nervous system, ASICs detect tissue acidosis occurring at tissue injury, inflammation, ischemia, stroke, and tumors as well as fatiguing muscle to activate pain-sensing nerves in the periphery and transmit pain signals to the brain. Arachidonic acid and lysophosphocholine have been identified as endogenous non-proton ligands activating ASICs in a neutral pH environment. On the other hand, ASICs are found involved in the tether model mechanotransduction, in which the extracellular matrix and cytoplasmic cytoskeletons act like a gating-spring to tether the mechanically activated ion channels and thus transmit the stimulus force to the channels. Accordingly, accumulating evidence has shown ASICs play important roles in mechanotransduction of proprioceptors, mechanoreceptors and nociceptors to monitor the homoeostatic status of muscle contraction, blood volume, and blood pressure as well as pain stimuli. Conclusion Together, ASICs are dual-function proteins for both chemosensation and mechanosensation involved in monitoring physiological homoeostasis and pathological signals.
Collapse
Affiliation(s)
- Yuan-Ren Cheng
- Department of Life Science, National Taiwan University, Taipei, 106, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, 128, Academia Rd. Sec. 2, Taipei, 115, Taiwan
| | - Bo-Yang Jiang
- Department of Life Science, National Taiwan University, Taipei, 106, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, 128, Academia Rd. Sec. 2, Taipei, 115, Taiwan
| | - Chih-Cheng Chen
- Department of Life Science, National Taiwan University, Taipei, 106, Taiwan. .,Institute of Biomedical Sciences, Academia Sinica, 128, Academia Rd. Sec. 2, Taipei, 115, Taiwan. .,Taiwan Mouse Clinic - National Comprehensive Mouse Phenotyping and Drug Testing Center, Academia Sinica, Taipei, 115, Taiwan.
| |
Collapse
|
28
|
Tsubouchi A, Yano T, Yokoyama TK, Murtin C, Otsuna H, Ito K. Topological and modality-specific representation of somatosensory information in the fly brain. Science 2018; 358:615-623. [PMID: 29097543 DOI: 10.1126/science.aan4428] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 09/25/2017] [Indexed: 12/11/2022]
Abstract
Insects and mammals share similarities of neural organization underlying the perception of odors, taste, vision, sound, and gravity. We observed that insect somatosensation also corresponds to that of mammals. In Drosophila, the projections of all the somatosensory neuron types to the insect's equivalent of the spinal cord segregated into modality-specific layers comparable to those in mammals. Some sensory neurons innervate the ventral brain directly to form modality-specific and topological somatosensory maps. Ascending interneurons with dendrites in matching layers of the nerve cord send axons that converge to respective brain regions. Pathways arising from leg somatosensory neurons encode distinct qualities of leg movement information and play different roles in ground detection. Establishment of the ground pattern and genetic tools for neuronal manipulation should provide the basis for elucidating the mechanisms underlying somatosensation.
Collapse
Affiliation(s)
- Asako Tsubouchi
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Yayoi, Bunkyo-ku, 113-0032 Tokyo, Japan
| | - Tomoko Yano
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Yayoi, Bunkyo-ku, 113-0032 Tokyo, Japan.,Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, 277-0882 Chiba, Japan
| | - Takeshi K Yokoyama
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Yayoi, Bunkyo-ku, 113-0032 Tokyo, Japan
| | - Chloé Murtin
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Yayoi, Bunkyo-ku, 113-0032 Tokyo, Japan.,Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, 277-0882 Chiba, Japan
| | - Hideo Otsuna
- Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA
| | - Kei Ito
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Yayoi, Bunkyo-ku, 113-0032 Tokyo, Japan. .,Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwanoha, Kashiwa, 277-0882 Chiba, Japan.,Howard Hughes Medical Institute, Janelia Research Campus, Ashburn, VA 20147, USA.,Institute of Zoology, University of Cologne, 50674 Cologne, Germany
| |
Collapse
|
29
|
Abstract
Cell bodies of trigeminal mesencephalic nucleus (Vmes) neurons are located within the central nervous system, and therefore, peripheral as well as central acidosis can modulate the excitability of Vmes neurons. Here, we report the effect of acidic pH on voltage-gated Na channels in acutely isolated rat Vmes neurons using a conventional whole-cell patch clamp technique. Acidic pH (pH 6.0) slightly but significantly shifted both the activation and steady-state fast inactivation relationships toward depolarized potentials. However, acidic pH (pH 6.0) had a minor effect on the inactivation kinetics of voltage-gated Na channels. Less sensitivity of voltage-gated Na channels to acidic pH may allow Vmes neurons to transduce the precise proprioceptive information even under acidic pH conditions.
Collapse
|
30
|
Carrasco DI, Vincent JA, Cope TC. Distribution of TTX-sensitive voltage-gated sodium channels in primary sensory endings of mammalian muscle spindles. J Neurophysiol 2017; 117:1690-1701. [PMID: 28123009 DOI: 10.1152/jn.00889.2016] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/24/2017] [Accepted: 01/24/2017] [Indexed: 12/19/2022] Open
Abstract
Knowledge of the molecular mechanisms underlying signaling of mechanical stimuli by muscle spindles remains incomplete. In particular, the ionic conductances that sustain tonic firing during static muscle stretch are unknown. We hypothesized that tonic firing by spindle afferents depends on sodium persistent inward current (INaP) and tested for the necessary presence of the appropriate voltage-gated sodium (NaV) channels in primary sensory endings. The NaV1.6 isoform was selected for both its capacity to produce INaP and for its presence in other mechanosensors that fire tonically. The present study shows that NaV1.6 immunoreactivity (IR) is concentrated in heminodes, presumably where tonic firing is generated, and we were surprised to find NaV1.6 IR strongly expressed also in the sensory terminals, where mechanotransduction occurs. This spatial pattern of NaV1.6 IR distribution was consistent for three mammalian species (rat, cat, and mouse), as was tonic firing by primary spindle afferents. These findings meet some of the conditions needed to establish participation of INaP in tonic firing by primary sensory endings. The study was extended to two additional NaV isoforms, selected for their sensitivity to TTX, excluding TTX-resistant NaV channels, which alone are insufficient to support firing by primary spindle endings. Positive immunoreactivity was found for NaV1.1, predominantly in sensory terminals together with NaV1.6 and for NaV1.7, mainly in preterminal axons. Differential distribution in primary sensory endings suggests specialized roles for these three NaV isoforms in the process of mechanosensory signaling by muscle spindles.NEW & NOTEWORTHY The molecular mechanisms underlying mechanosensory signaling responsible for proprioceptive functions are not completely elucidated. This study provides the first evidence that voltage-gated sodium channels (NaVs) are expressed in the spindle primary sensory ending, where NaVs are found at every site involved in transduction or encoding of muscle stretch. We propose that NaVs contribute to multiple steps in sensory signaling by muscle spindles as it does in other types of slowly adapting sensory neurons.
Collapse
Affiliation(s)
- Dario I Carrasco
- School of Biological Science, Georgia Institute of Technology, Atlanta Georgia
| | - Jacob A Vincent
- School of Biological Science, Georgia Institute of Technology, Atlanta Georgia
| | - Timothy C Cope
- School of Biological Science, Georgia Institute of Technology, Atlanta Georgia; .,Biomedical Engineering, Georgia Institute of Technology, Atlanta Georgia; and
| |
Collapse
|
31
|
Searching for proprioceptors in human facial muscles. Neurosci Lett 2017; 640:1-5. [PMID: 28082150 DOI: 10.1016/j.neulet.2017.01.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 01/06/2017] [Accepted: 01/07/2017] [Indexed: 12/28/2022]
Abstract
The human craniofacial muscles innervated by the facial nerve typically lack muscle spindles. However these muscles have proprioception that participates in the coordination of facial movements. A functional substitution of facial proprioceptors by cutaneous mechanoreceptors has been proposed but at present this alternative has not been demonstrated. Here we have investigated whether other kinds of sensory structures are present in two human facial muscles (zygomatic major and buccal). Human checks were removed from Spanish cadavers, and processed for immunohistochemical detection of nerve fibers (neurofilament proteins and S100 protein) and two putative mechanoproteins (acid-sensing ion channel 2 and transient receptor potential vanilloid 4) associated with mechanosensing. Nerves of different calibers were found in the connective septa and within the muscle itself. In all the muscles analysed, capsular corpuscle-like structures resembling elongated or round Ruffini-like corpuscles were observed. Moreover the axon profiles within these structures displayed immunoreactivity for both putative mechanoproteins. The present results demonstrate the presence of sensory structures in facial muscles that can substitute for typical muscle spindles as the source of facial proprioception.
Collapse
|
32
|
Liu Y, Jiang BJ, Zhao RZ, Ji HL. Epithelial Sodium Channels in Pulmonary Epithelial Progenitor and Stem Cells. Int J Biol Sci 2016; 12:1150-4. [PMID: 27570489 PMCID: PMC4997059 DOI: 10.7150/ijbs.15747] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/11/2016] [Indexed: 11/05/2022] Open
Abstract
Regeneration of the epithelium of mammalian lungs is essential for restoring normal function following injury, and various cells and mechanisms contribute to this regeneration and repair. Club cells, bronchioalveolar stem cells (BASCs), and alveolar type II epithelial cells (ATII) are dominant stem/progenitor cells for maintaining epithelial turnover and repair. Epithelial Na(+) channels (ENaC), a critical pathway for transapical salt and fluid transport, are expressed in lung epithelial progenitors, including club and ATII cells. Since ENaC activity and expression are development- and differentiation-dependent, apically located ENaC activity has therefore been used as a functional biomarker of lung injury repair. ENaC activity may be involved in the migration and differentiation of local and circulating stem/progenitor cells with diverse functions, eventually benefiting stem cells spreading to re-epithelialize injured lungs. This review summarizes the potential roles of ENaC expressed in native progenitor and stem cells in the development and regeneration of the respiratory epithelium.
Collapse
Affiliation(s)
- Yang Liu
- Institute of Lung and Molecular Therapy, Xinxiang Medical University, Xinxiang, Henan 453003, China
| | - Bi-Jie Jiang
- School of Public Health, Xinxiang Medical University, Xinxiang, Henan 453003, China
| | - Run-Zhen Zhao
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
- Texas Lung Injury Institute, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
| | - Hong-Long Ji
- Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
- Texas Lung Injury Institute, University of Texas Health Science Center at Tyler, Tyler, Texas 75708, USA
| |
Collapse
|
33
|
Schwingshackl A. The role of stretch-activated ion channels in acute respiratory distress syndrome: finally a new target? Am J Physiol Lung Cell Mol Physiol 2016; 311:L639-52. [PMID: 27521425 DOI: 10.1152/ajplung.00458.2015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 08/05/2016] [Indexed: 02/06/2023] Open
Abstract
Mechanical ventilation (MV) and oxygen therapy (hyperoxia; HO) comprise the cornerstones of life-saving interventions for patients with acute respiratory distress syndrome (ARDS). Unfortunately, the side effects of MV and HO include exacerbation of lung injury by barotrauma, volutrauma, and propagation of lung inflammation. Despite significant improvements in ventilator technologies and a heightened awareness of oxygen toxicity, besides low tidal volume ventilation few if any medical interventions have improved ARDS outcomes over the past two decades. We are lacking a comprehensive understanding of mechanotransduction processes in the healthy lung and know little about the interactions between simultaneously activated stretch-, HO-, and cytokine-induced signaling cascades in ARDS. Nevertheless, as we are unraveling these mechanisms we are gathering increasing evidence for the importance of stretch-activated ion channels (SACs) in the activation of lung-resident and inflammatory cells. In addition to the discovery of new SAC families in the lung, e.g., two-pore domain potassium channels, we are increasingly assigning mechanosensing properties to already known Na(+), Ca(2+), K(+), and Cl(-) channels. Better insights into the mechanotransduction mechanisms of SACs will improve our understanding of the pathways leading to ventilator-induced lung injury and lead to much needed novel therapeutic approaches against ARDS by specifically targeting SACs. This review 1) summarizes the reasons why the time has come to seriously consider SACs as new therapeutic targets against ARDS, 2) critically analyzes the physiological and experimental factors that currently limit our knowledge about SACs, and 3) outlines the most important questions future research studies need to address.
Collapse
|
34
|
Vagal afferents, sympathetic efferents and the role of the PVN in heart failure. Auton Neurosci 2016; 199:38-47. [DOI: 10.1016/j.autneu.2016.08.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 08/04/2016] [Accepted: 08/07/2016] [Indexed: 01/18/2023]
|
35
|
Tentonin 3/TMEM150c Confers Distinct Mechanosensitive Currents in Dorsal-Root Ganglion Neurons with Proprioceptive Function. Neuron 2016; 91:107-18. [DOI: 10.1016/j.neuron.2016.05.029] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Revised: 04/02/2016] [Accepted: 05/16/2016] [Indexed: 11/18/2022]
|
36
|
Evidence for the involvement of ASIC3 in sensory mechanotransduction in proprioceptors. Nat Commun 2016; 7:11460. [PMID: 27161260 PMCID: PMC4866049 DOI: 10.1038/ncomms11460] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 03/29/2016] [Indexed: 01/12/2023] Open
Abstract
Acid-sensing ion channel 3 (ASIC3) is involved in acid nociception, but its possible role in neurosensory mechanotransduction is disputed. We report here the generation of Asic3-knockout/eGFPf-knockin mice and subsequent characterization of heterogeneous expression of ASIC3 in the dorsal root ganglion (DRG). ASIC3 is expressed in parvalbumin (Pv+) proprioceptor axons innervating muscle spindles. We further generate a floxed allele of Asic3 (Asic3f/f) and probe the role of ASIC3 in mechanotransduction in neurite-bearing Pv+ DRG neurons through localized elastic matrix movements and electrophysiology. Targeted knockout of Asic3 disrupts spindle afferent sensitivity to dynamic stimuli and impairs mechanotransduction in Pv+ DRG neurons because of substrate deformation-induced neurite stretching, but not to direct neurite indentation. In behavioural tasks, global knockout (Asic3−/−) and Pv-Cre::Asic3f/f mice produce similar deficits in grid and balance beam walking tasks. We conclude that, at least in mouse, ASIC3 is a molecular determinant contributing to dynamic mechanosensitivity in proprioceptors. Acid-sensing ion channel 3 (ASIC3) is known to play a role in nociception, but its role in low threshold neurosensory mechanotransduction is unclear. Here, the authors target ASIC3 expression in dorsal root ganglion parvalbumin positive neurons and find ASIC3 contributes to dynamic proprioception responses.
Collapse
|
37
|
Li YL, Zhang D, Tu H, Muelleman RL. Altered ENaC is Associated With Aortic Baroreceptor Dysfunction in Chronic Heart Failure. Am J Hypertens 2016; 29:582-9. [PMID: 26297031 DOI: 10.1093/ajh/hpv141] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/28/2015] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Abnormal baroreceptor function contributes to attenuated arterial baroreflex sensitivity in chronic heart failure (CHF). As a mechanosensor in mammalian nonepithelium, the epithelial sodium channel (ENaC) is an amiloride-sensitive and voltage-independent ion channel. The ENaC is thought to be a component of baroreceptor mechanosensitive ion channels in aortic baroreceptor cell bodies and nerve terminals. In this study, therefore, we measured the expression and activation of the ENaC in nodose neuronal cell bodies and aortic baroreceptor nerve terminals in sham and CHF rats. METHODS AND RESULTS CHF was induced by surgical ligation of left coronary artery. The development of CHF was confirmed by hemodynamic and morphological characteristics. The aortic baroreceptor sensitivity was blunted in anesthetized CHF rats, compared with that in sham rats. The data from immunostaining and western blot analysis showed that the protein of β- and γ-ENaC subunits was expressed in nodose neuronal cell bodies and aortic baroreceptor nerve terminals, whereas the protein of α-ENaC subunit was undetectable. CHF reduced protein expression of β- and γ-ENaC subunits in nodose neuronal cell bodies and aortic baroreceptor nerve terminals. Additionally, the data recorded by the whole cell patch-clamp technique demonstrated that ENaC currents in aortic baroreceptor neurons were lower in CHF rats than that in sham rats. CONCLUSION These results suggest that reduced protein expression of the ENaC decreases the ENaC activation, which could be involved in attenuation of the aortic baroreceptor sensitivity in the CHF state. Baroreceptors should be a potential therapeutic target for reducing mortality in CHF.
Collapse
Affiliation(s)
- Yu-Long Li
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA; Department of Cellular and integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska, USA.
| | - Dongze Zhang
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Huiyin Tu
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Robert L Muelleman
- Department of Emergency Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| |
Collapse
|
38
|
Bewick GS. Synaptic-like vesicles and candidate transduction channels in mechanosensory terminals. J Anat 2016; 227:194-213. [PMID: 26179025 PMCID: PMC4523322 DOI: 10.1111/joa.12337] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/18/2015] [Indexed: 01/22/2023] Open
Abstract
This article summarises progress to date over an exciting and very enjoyable first 15 years of collaboration with Bob Banks. Our collaboration began when I contacted him with (to me) an unexpected observation that a dye used to mark recycling synaptic vesicle membrane at efferent terminals also labelled muscle spindle afferent terminals. This observation led to the re-discovery of a system of small clear vesicles present in all vertebrate primary mechanosensory nerve terminals. These synaptic-like vesicles (SLVs) have been, and continue to be, the major focus of our work. This article describes our characterisation of the properties and functional significance of these SLVs, combining our complementary skills: Bob’s technical expertise and encyclopaedic knowledge of mechanosensation with my experience of synaptic vesicles and the development of the styryl pyridinium dyes, of which the most widely used is FM1-43. On the way we have found that SLVs seem to be part of a constitutive glutamate secretory system necessary to maintain the stretch-sensitivity of spindle endings. The glutamate activates a highly unusual glutamate receptor linked to phospholipase D activation, which we have termed the PLD-mGluR. It has a totally distinct pharmacology first described in the hippocampus nearly 20 years ago but, like the SLVs that were first described over 50 years ago, has since been little researched. Yet, our evidence and literature searches suggest this glutamate/SLV/PLD-mGluR system is a ubiquitous feature of mechanosensory endings and, at least for spindles, is essential for maintaining mechanosensory function. This article summarises how this system integrates with the classical model of mechanosensitive channels in spindles and other mechanosensory nerve terminals, including hair follicle afferents and baroreceptors controlling blood pressure. Finally, in this time when there is an imperative to show translational relevance, I describe how this fascinating system might actually be a useful therapeutic drug target for clinical conditions such as hypertension and muscle spasticity. This has been a fascinating 15-year journey in collaboration with Bob who, as well as having an astute scientific mind, is also a great enthusiast, motivator and friend. I hope this exciting and enjoyable journey will continue well into the future.
Collapse
Affiliation(s)
- Guy S Bewick
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| |
Collapse
|
39
|
Hanukoglu I, Hanukoglu A. Epithelial sodium channel (ENaC) family: Phylogeny, structure-function, tissue distribution, and associated inherited diseases. Gene 2016; 579:95-132. [PMID: 26772908 PMCID: PMC4756657 DOI: 10.1016/j.gene.2015.12.061] [Citation(s) in RCA: 250] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 12/20/2015] [Accepted: 12/22/2015] [Indexed: 01/24/2023]
Abstract
The epithelial sodium channel (ENaC) is composed of three homologous subunits and allows the flow of Na(+) ions across high resistance epithelia, maintaining body salt and water homeostasis. ENaC dependent reabsorption of Na(+) in the kidney tubules regulates extracellular fluid (ECF) volume and blood pressure by modulating osmolarity. In multi-ciliated cells, ENaC is located in cilia and plays an essential role in the regulation of epithelial surface liquid volume necessary for cilial transport of mucus and gametes in the respiratory and reproductive tracts respectively. The subunits that form ENaC (named as alpha, beta, gamma and delta, encoded by genes SCNN1A, SCNN1B, SCNN1G, and SCNN1D) are members of the ENaC/Degenerin superfamily. The earliest appearance of ENaC orthologs is in the genomes of the most ancient vertebrate taxon, Cyclostomata (jawless vertebrates) including lampreys, followed by earliest representatives of Gnathostomata (jawed vertebrates) including cartilaginous sharks. Among Euteleostomi (bony vertebrates), Actinopterygii (ray finned-fishes) branch has lost ENaC genes. Yet, most animals in the Sarcopterygii (lobe-finned fish) branch including Tetrapoda, amphibians and amniotes (lizards, crocodiles, birds, and mammals), have four ENaC paralogs. We compared the sequences of ENaC orthologs from 20 species and established criteria for the identification of ENaC orthologs and paralogs, and their distinction from other members of the ENaC/Degenerin superfamily, especially ASIC family. Differences between ENaCs and ASICs are summarized in view of their physiological functions and tissue distributions. Structural motifs that are conserved throughout vertebrate ENaCs are highlighted. We also present a comparative overview of the genotype-phenotype relationships in inherited diseases associated with ENaC mutations, including multisystem pseudohypoaldosteronism (PHA1B), Liddle syndrome, cystic fibrosis-like disease and essential hypertension.
Collapse
Affiliation(s)
- Israel Hanukoglu
- Laboratory of Cell Biology, Faculty of Natural Sciences, Ariel University, Ariel, Israel.
| | - Aaron Hanukoglu
- Division of Pediatric Endocrinology, E. Wolfson Medical Center, Holon, Israel; Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel
| |
Collapse
|
40
|
Woo SH, Lukacs V, de Nooij JC, Zaytseva D, Criddle CR, Francisco A, Jessell TM, Wilkinson KA, Patapoutian A. Piezo2 is the principal mechanotransduction channel for proprioception. Nat Neurosci 2015; 18:1756-62. [PMID: 26551544 PMCID: PMC4661126 DOI: 10.1038/nn.4162] [Citation(s) in RCA: 352] [Impact Index Per Article: 39.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 10/13/2015] [Indexed: 12/25/2022]
Abstract
Proprioception, the perception of body and limb position, is mediated by proprioceptors, specialized mechanosensory neurons that convey information about the stretch and tension experienced by muscles, tendons, skin and joints. In mammals, the molecular identity of the stretch-sensitive channel that mediates proprioception is unknown. We found that the mechanically activated nonselective cation channel Piezo2 was expressed in sensory endings of proprioceptors innervating muscle spindles and Golgi tendon organs in mice. Two independent mouse lines that lack Piezo2 in proprioceptive neurons showed severely uncoordinated body movements and abnormal limb positions. Moreover, the mechanosensitivity of parvalbumin-expressing neurons that predominantly mark proprioceptors was dependent on Piezo2 expression in vitro, and the stretch-induced firing of proprioceptors in muscle-nerve recordings was markedly reduced in Piezo2-deficient mice. Together, our results indicate that Piezo2 is the major mechanotransducer of mammalian proprioceptors.
Collapse
Affiliation(s)
- Seung-Hyun Woo
- Howard Hughes Medical Institute, Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, USA
| | - Viktor Lukacs
- Howard Hughes Medical Institute, Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, USA
| | - Joriene C de Nooij
- Howard Hughes Medical Institute, Department of Neuroscience, Columbia University, New York, New York, USA.,Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, USA
| | - Dasha Zaytseva
- Department of Biological Sciences, San José State University, San Jose, California, USA
| | - Connor R Criddle
- Department of Biological Sciences, San José State University, San Jose, California, USA
| | - Allain Francisco
- Howard Hughes Medical Institute, Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, USA
| | - Thomas M Jessell
- Howard Hughes Medical Institute, Department of Neuroscience, Columbia University, New York, New York, USA.,Howard Hughes Medical Institute, Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York, USA
| | - Katherine A Wilkinson
- Department of Biological Sciences, San José State University, San Jose, California, USA
| | - Ardem Patapoutian
- Howard Hughes Medical Institute, Molecular and Cellular Neuroscience, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, California, USA
| |
Collapse
|
41
|
Suslak TJ, Watson S, Thompson KJ, Shenton FC, Bewick GS, Armstrong JD, Jarman AP. Piezo Is Essential for Amiloride-Sensitive Stretch-Activated Mechanotransduction in Larval Drosophila Dorsal Bipolar Dendritic Sensory Neurons. PLoS One 2015; 10:e0130969. [PMID: 26186008 PMCID: PMC4506125 DOI: 10.1371/journal.pone.0130969] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 05/27/2015] [Indexed: 01/09/2023] Open
Abstract
Stretch-activated afferent neurons, such as those of mammalian muscle spindles, are essential for proprioception and motor co-ordination, but the underlying mechanisms of mechanotransduction are poorly understood. The dorsal bipolar dendritic (dbd) sensory neurons are putative stretch receptors in the Drosophila larval body wall. We have developed an in vivo protocol to obtain receptor potential recordings from intact dbd neurons in response to stretch. Receptor potential changes in dbd neurons in response to stretch showed a complex, dynamic profile with similar characteristics to those previously observed for mammalian muscle spindles. These profiles were reproduced by a general in silico model of stretch-activated neurons. This in silico model predicts an essential role for a mechanosensory cation channel (MSC) in all aspects of receptor potential generation. Using pharmacological and genetic techniques, we identified the mechanosensory channel, DmPiezo, in this functional role in dbd neurons, with TRPA1 playing a subsidiary role. We also show that rat muscle spindles exhibit a ruthenium red-sensitive current, but found no expression evidence to suggest that this corresponds to Piezo activity. In summary, we show that the dbd neuron is a stretch receptor and demonstrate that this neuron is a tractable model for investigating mechanisms of mechanotransduction.
Collapse
Affiliation(s)
- Thomas J. Suslak
- Doctoral Training Centre in Neuroinformatics and Neural Computation, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - Sonia Watson
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Karen J. Thompson
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Fiona C. Shenton
- Institute for Ageing, University of Newcastle, Newcastle, United Kingdom
| | - Guy S. Bewick
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - J. Douglas Armstrong
- Doctoral Training Centre in Neuroinformatics and Neural Computation, University of Edinburgh, Edinburgh, United Kingdom
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
- Institute for Adaptive and Neural Computation, University of Edinburgh, Edinburgh, United Kingdom
| | - Andrew P. Jarman
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| |
Collapse
|
42
|
Ribchester RR. Some reminiscences on studies of age-dependent and activity-dependent degeneration of sensory and motor endings in mammalian skeletal muscle. J Anat 2015; 227:231-6. [PMID: 26179026 PMCID: PMC4523325 DOI: 10.1111/joa.12334] [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] [Accepted: 04/29/2015] [Indexed: 11/29/2022] Open
Abstract
I present here an overview of research on the biology of neuromuscular sensory and motor endings that was inspired and influenced partly by my educational experience in the Department of Zoology at the University of Durham, from 1971 to 1974. I allude briefly to neuromuscular synaptic structure and function in dystrophic mice, influences of activity on synapse elimination in development and regeneration, and activity-dependent protection and degeneration of neuromuscular junctions in WldS mice.
Collapse
Affiliation(s)
- Richard R Ribchester
- Euan MacDonald Centre for Motor Neurone Disease Research and Centre for Integrative Physiology, University of Edinburgh, George Square, Edinburgh, UK
| |
Collapse
|
43
|
Suslak TJ, Jarman AP. Stretching the imagination beyond muscle spindles - stretch-sensitive mechanisms in arthropods. J Anat 2015; 227:237-42. [PMID: 26076887 PMCID: PMC4523326 DOI: 10.1111/joa.12329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/26/2015] [Indexed: 11/30/2022] Open
Abstract
Much attention has been given to mammalian muscle spindles and their role in stretch‐mediated muscle proprioception. Recent studies, particularly, have sought to determine the molecular mediators of stretch‐evoked mechanotransduction, which these endings rely upon for functionality. Nonetheless, much about these endings remains unknown. Opportunities may be presented from consideration of extensive parallel research in stretch receptor mechanisms in arthropods. Such systems may provide a useful source of additional data and powerful tools for dissecting the complex systems of stretch transduction apparatus. At the least, such systems provide tractable exemplars of how organisms solve the problem of converting stretch stimuli to electrical output. Potentially, they may even provide molecular mechanisms and candidate molecular mediators of direct relevance to mammalian muscle spindles. Here we provide a brief overview of research on arthropod stretch receptors.
Collapse
Affiliation(s)
- Thomas J Suslak
- Doctoral Training Centre in Neuroinformatics and Neural Computation, University of Edinburgh, Edinburgh, UK.,Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| | - Andrew P Jarman
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
44
|
Watson S. Modulating mechanosensory afferent excitability by an atypical mGluR. J Anat 2015; 227:214-20. [PMID: 26053109 DOI: 10.1111/joa.12319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2015] [Indexed: 11/30/2022] Open
Abstract
Mechanotransduction by proprioceptive sensory organs is poorly understood. Evidence was recently shown that muscle spindle and hair follicle primary afferents (lanceolates) constantly release glutamate from synaptic-like vesicles (SLVs) within the terminals. The secreted glutamate activates a highly unusual metabotropic glutamate receptor (mGluR) to modulate the firing rate (spindles) and SLV recycling (lanceolates). This receptor has yet to be isolated and sequenced. To further investigate this receptor's pharmacology, ligands selective for classical mGluRs have been recently characterised for their ability to alter stretch-evoked spindle firing and SLV endocytosis in these different endings. Here, it is described how the results of these screens facilitated the development of novel compounds to be used in the process of isolating and sequencing of this non-canonical mGluR. This study shows how the compounds were tested for their ability to alter stretch-evoked afferent firing in muscle spindles and SLV endocytosis in the lanceolate endings of hair follicles to ensure they maintained their ability to bind to the receptor. For the development of novel compounds, kainate was chosen as the parent ligand due to its potency and ease of chemical modification. Novel kainate derivatives were then synthesised and tested to find potent analogues suitable for 'click-chemistry', an established technique for relatively quick, cheap, stereospecific and high-yield chemical modifications (Angewandte Chemie (International ed. in English), 40, 2001, pp2004). Of the novel kainate analogues developed, unfortunately ZCZ49 and ZCZ50 lost the ability to produce a significant change in spindle stretch-evoked firing. However, ZCZ90 was as potent as kainate, increasing firing by a similar margin at 1 μm (n = 8; P < 0.001). The addition of either a biotin or a fluorescein side group to ZCZ90, using the click-chemistry technique, did not affect the potency and hence these compounds will be used in further studies of the receptor. As well as the development of these compounds, the study found not only many similarities, but also some key differences between the two types of primary mechanosensory endings investigated. These differences must be taken into account in further study. However, they also present an intriguing opportunity for these receptors to be targeted selectively to modulate ending sensitivity as treatments for muscle spasm in multiple sclerosis and spinal cord injury, and possibly even baroreceptor firing to treat hypertension.
Collapse
Affiliation(s)
- Sonia Watson
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK
| |
Collapse
|
45
|
Vincent JA, Nardelli P, Gabriel HM, Deardorff AS, Cope TC. Complex impairment of IA muscle proprioceptors following traumatic or neurotoxic injury. J Anat 2015; 227:221-30. [PMID: 26047324 DOI: 10.1111/joa.12312] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2015] [Indexed: 01/09/2023] Open
Abstract
The health of primary sensory afferents supplying muscle has to be a first consideration in assessing deficits in proprioception and related motor functions. Here we discuss the role of a particular proprioceptor, the IA muscle spindle proprioceptor in causing movement disorders in response to either regeneration of a sectioned peripheral nerve or damage from neurotoxic chemotherapy. For each condition, there is a single preferred and widely repeated explanation for disability of movements associated with proprioceptive function. We present a mix of published and preliminary findings from our laboratory, largely from in vivo electrophysiological study of treated rats to demonstrate newly discovered IA afferent defects that seem likely to make important contributions to movement disorders. First, we argue that reconnection of regenerated IA afferents with inappropriate targets, although often repeated as the reason for lost stretch-reflex contraction, is not a complete explanation. We present evidence that despite successful recovery of stretch-evoked sensory signaling, peripherally regenerated IA afferents retract synapses made with motoneurons in the spinal cord. Second, we point to evidence that movement disability suffered by human subjects months after discontinuation of oxaliplatin (OX) chemotherapy for some is not accompanied by peripheral neuropathy, which is the acknowledged primary cause of disability. Our studies of OX-treated rats suggest a novel additional explanation in showing the loss of sustained repetitive firing of IA afferents during static muscle stretch. Newly extended investigation reproduces this effect in normal rats with drugs that block Na(+) channels apparently involved in encoding static IA afferent firing. Overall, these findings highlight multiplicity in IA afferent deficits that must be taken into account in understanding proprioceptive disability, and that present new avenues and possible advantages for developing effective treatment. Extending the study of IA afferent deficits yielded the additional benefit of elucidating normal processes in IA afferent mechanosensory function.
Collapse
Affiliation(s)
- Jacob A Vincent
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH, USA
| | - Paul Nardelli
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH, USA
| | - Hanna M Gabriel
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH, USA
| | - Adam S Deardorff
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH, USA
| | - Timothy C Cope
- Department of Neuroscience, Cell Biology and Physiology, Wright State University, Dayton, OH, USA
| |
Collapse
|
46
|
Jeggle P, Smith ESJ, Stewart AP, Haerteis S, Korbmacher C, Edwardson JM. Atomic force microscopy imaging reveals the formation of ASIC/ENaC cross-clade ion channels. Biochem Biophys Res Commun 2015; 464:38-44. [PMID: 26032502 DOI: 10.1016/j.bbrc.2015.05.091] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 05/28/2015] [Indexed: 01/02/2023]
Abstract
ASIC and ENaC are co-expressed in various cell types, and there is evidence for a close association between them. Here, we used atomic force microscopy (AFM) to determine whether ASIC1a and ENaC subunits are able to form cross-clade hybrid ion channels. ASIC1a and ENaC could be co-isolated from detergent extracts of tsA 201 cells co-expressing the two subunits. Isolated proteins were incubated with antibodies against ENaC and Fab fragments against ASIC1a. AFM imaging revealed proteins that were decorated by both an antibody and a Fab fragment with an angle of ∼120° between them, indicating the formation of ASIC1a/ENaC heterotrimers.
Collapse
Affiliation(s)
- Pia Jeggle
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Ewan St J Smith
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Andrew P Stewart
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom
| | - Silke Haerteis
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstrasse 6, 91054 Erlangen, Germany
| | - Christoph Korbmacher
- Institut für Zelluläre und Molekulare Physiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Waldstrasse 6, 91054 Erlangen, Germany
| | - J Michael Edwardson
- Department of Pharmacology, University of Cambridge, Tennis Court Road, Cambridge CB2 1PD, United Kingdom.
| |
Collapse
|
47
|
Meng Q, Fang P, Hu Z, Ling Y, Liu H. Mechanotransduction of trigeminal ganglion neurons innervating inner walls of rat anterior eye chambers. Am J Physiol Cell Physiol 2015; 309:C1-10. [PMID: 25904679 DOI: 10.1152/ajpcell.00028.2015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/20/2015] [Indexed: 11/22/2022]
Abstract
To address mechanoreceptive roles of trigeminal ganglion (TG) nerve endings in the inner walls of rat anterior eye chambers, we investigated the mechanotransduction process and mechanosensitive (MS) channel on somata of TG neurons innervating this area in vitro. Rat TG neurons innervating inner walls of anterior chambers were labeled by anterior chamber injection of 1,1'-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine, 4-chlorobenzenesulfonate (FAST DiI). The neuronal cell bodies were voltage clamped using a whole cell patch-clamp technique, while it was deformed by ejection of bath solution to verify mechanotransduction. Immunofluorescence staining was performed on sections of TG ganglia to determine the specific MS channel proteins. Mechanical stimuli induced MS currents in 55 out of 96 FAST DiI-labeled TG neurons. The MS currents exhibited mechanical intensity-dependent and clamp voltage-dependent characteristics. Mechanical stimulation further enhanced the membrane potential and increased the frequency of action potentials. Transient receptor potential ankyrin 1 (TRPA1), TRP vanilloid 4 (TRPV4), acid-sensing ion channel (ASIC) 2 and ASIC3 channel proteins were expressed in FAST DiI-labeled TG neurons. The inhibitory effect of HC-030031, a specific inhibitor of TRPA1, on MS currents demonstrated that TRPA1 was an essential MS channel protein. Taken together, our results show that mechanical stimuli induce MS currents via MS channels such as TRPA1 to trigger mechanotransduction in TG neurons innervating inner walls of anterior chambers. Our results indicate the existence of mechanoreceptive TG nerve endings in inner walls of anterior chambers. Whether the mechanoreceptive TG nerve endings play a role in intraocular pressure sensation warrants further investigation.
Collapse
Affiliation(s)
- Qingli Meng
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China; and
| | - Peng Fang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China
| | - Zhuangli Hu
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China
| | - Yun Ling
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China; and
| | - Haixia Liu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China; and
| |
Collapse
|
48
|
The PDZ-domain protein Whirlin facilitates mechanosensory signaling in mammalian proprioceptors. J Neurosci 2015; 35:3073-84. [PMID: 25698744 DOI: 10.1523/jneurosci.3699-14.2015] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Mechanoreception is an essential feature of many sensory modalities. Nevertheless, the mechanisms that govern the conversion of a mechanical force to distinct patterns of action potentials remain poorly understood. Proprioceptive mechanoreceptors reside in skeletal muscle and inform the nervous system of the position of body and limbs in space. We show here that Whirlin/Deafness autosomal recessive 31 (DFNB31), a PDZ-scaffold protein involved in vestibular and auditory hair cell transduction, is also expressed by proprioceptive sensory neurons (pSNs) in dorsal root ganglia in mice. Whirlin localizes to the peripheral sensory endings of pSNs and facilitates pSN afferent firing in response to muscle stretch. The requirement of Whirlin in both proprioceptors and hair cells suggests that accessory mechanosensory signaling molecules define common features of mechanoreceptive processing across sensory systems.
Collapse
|
49
|
Franco JA, Kloefkorn HE, Hochman S, Wilkinson KA. An in vitro adult mouse muscle-nerve preparation for studying the firing properties of muscle afferents. J Vis Exp 2014:51948. [PMID: 25285602 PMCID: PMC4618553 DOI: 10.3791/51948] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Muscle sensory neurons innervating muscle spindles and Golgi tendon organs encode length and force changes essential to proprioception. Additional afferent fibers monitor other characteristics of the muscle environment, including metabolite buildup, temperature, and nociceptive stimuli. Overall, abnormal activation of sensory neurons can lead to movement disorders or chronic pain syndromes. We describe the isolation of the extensor digitorum longus (EDL) muscle and nerve for in vitro study of stretch-evoked afferent responses in the adult mouse. Sensory activity is recorded from the nerve with a suction electrode and individual afferents can be analyzed using spike sorting software. In vitro preparations allow for well controlled studies on sensory afferents without the potential confounds of anesthesia or altered muscle perfusion. Here we describe a protocol to identify and test the response of muscle spindle afferents to stretch. Importantly, this preparation also supports the study of other subtypes of muscle afferents, response properties following drug application and the incorporation of powerful genetic approaches and disease models in mice.
Collapse
Affiliation(s)
- Joy A Franco
- Department of Mechanical Engineering, San José State University
| | - Heidi E Kloefkorn
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida
| | - Shawn Hochman
- Department of Physiology, Emory University School of Medicine
| | | |
Collapse
|
50
|
Cabo R, Alonso P, Viña E, Vázquez G, Gago A, Feito J, Pérez-Moltó FJ, García-Suárez O, Vega JA. ASIC2 is present in human mechanosensory neurons of the dorsal root ganglia and in mechanoreceptors of the glabrous skin. Histochem Cell Biol 2014; 143:267-76. [DOI: 10.1007/s00418-014-1278-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/02/2014] [Indexed: 01/23/2023]
|