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Nogueira LS, Crémazy A, Wood CM. The role of the carapace in the accumulation of metals from seawater in the green crab (Carcinus maenas): Studies with radio-labeled calcium, zinc, and nickel. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 945:174008. [PMID: 38901594 DOI: 10.1016/j.scitotenv.2024.174008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 04/22/2024] [Accepted: 06/13/2024] [Indexed: 06/22/2024]
Abstract
The role of the carapace in the uptake and storage of newly accumulated metals was investigated in the green crab exposed to environmentally relevant concentrations of calcium ([Ca] = 389 mg L-1 or 9.7 mmol L-1), zinc ([Zn] = 82 μg L-1 or 1.25 μmol L-1), and nickel ([Ni] = 8.2 μg L-1 or 0.14 μmol L-1) in 12 °C seawater, using radio-tracers (45Ca, 65Zn, 63Ni). After 24-h exposure, carapace exhibited the highest concentration of newly accumulated Ca, whereas carapace and gills exhibited the highest concentrations of both newly accumulated Zn and Ni relative to other tissues. For all three metals, the carapace accounted for >85 % of the total body burden. Acute temperature changes (to 2 °C and 22 °C) revealed the highest overall temperature coefficient Q10 (2.15) for Ca uptake into the carapace, intermediate Q10 for Ni (1.87) and lowest Q10 (1.45) for Zn. New Ca uptake into the carapace continued linearly with time for 24 h, new Zn uptake gradually deviated from linearity, whereas Ni uptake reached a plateau by 6 h. Attachment of a rubber membrane to the dorsal carapace, thereby shielding about 20 % of the total crab surface area from the external water, eliminated both new Zn and Ni incorporation into the shielded carapace, whereas 36 % of new Ca incorporation persisted. When recently euthanized crabs were exposed, new Zn uptake into the carapace remained unchanged, whereas Ca and Ni uptake were reduced by 89 % and 71 %, respectively. We conclude that the carapace is a very important uptake and storage site for all three metals. All of the uptake of new Zn and new Ni, and most of the uptake of new Ca into this tissue comes directly from the external water. For Zn, the mechanism involves only physicochemical processes, whereas for Ca and Ni, life-dependent processes make the major contribution.
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Affiliation(s)
- Lygia S Nogueira
- Bamfield Marine Science Centre, Bamfield, British Columbia V0R 1B0, Canada; University of British Columbia, Department of Zoology, Vancouver, BC V6T 1Z4, Canada; CAPES Foundation, Ministry of Education of Brazil, Brasília, DF 70040-020, Brazil
| | - Anne Crémazy
- Bamfield Marine Science Centre, Bamfield, British Columbia V0R 1B0, Canada; University of British Columbia, Department of Zoology, Vancouver, BC V6T 1Z4, Canada; Centre Eau Terre Environnement, Institut National de la Recherche Scientifique, Québec, QC G1K 9A9, Canada.
| | - Chris M Wood
- Bamfield Marine Science Centre, Bamfield, British Columbia V0R 1B0, Canada; University of British Columbia, Department of Zoology, Vancouver, BC V6T 1Z4, Canada; McMaster University, Dept. of Biology, Hamilton, Ontario L8S 4K1, Canada
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2
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Lopez-Charcas O, Benouna O, Lemoine R, Rosendo-Pineda MJ, Anguheven-Ledezma TG, Sandoval-Vazquez L, Gallegos-Gomez ML, Robles-Martinez L, Herrera-Carrillo Z, Ramírez-Aragón M, Alfaro A, Chadet S, Ferro F, Besson P, Jiang LH, Velu SE, Guerrero-Hernandez A, Roger S, Gomora JC. Blockade of Ca V3 calcium channels and induction of G 0/G 1 cell cycle arrest in colon cancer cells by gossypol. Br J Pharmacol 2024. [PMID: 39081110 DOI: 10.1111/bph.16497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 05/29/2024] [Accepted: 06/04/2024] [Indexed: 08/30/2024] Open
Abstract
BACKGROUND AND PURPOSE Gastrointestinal tumours overexpress voltage-gated calcium (CaV3) channels (CaV3.1, 3.2 and 3.3). CaV3 channels regulate cell growth and apoptosis colorectal cancer. Gossypol, a polyphenolic aldehyde found in the cotton plant, has anti-tumour properties and inhibits CaV3 currents. A systematic study was performed on gossypol blocking mechanism on CaV3 channels and its potential anticancer effects in colon cancer cells, which express CaV3 isoforms. EXPERIMENTAL APPROACH Transcripts for CaV3 proteins were analysed in gastrointestinal cancers using public repositories and in human colorectal cancer cell lines HCT116, SW480 and SW620. The gossypol blocking mechanism on CaV3 channels was investigated by combining heterologous expression systems and patch-clamp experiments. The anti-tumoural properties of gossypol were estimated by cell proliferation, viability and cell cycle assays. Ca2+ dynamics were evaluated with cytosolic and endoplasmic reticulum (ER) Ca2+ indicators. KEY RESULTS High levels of CaV3 transcripts correlate with poor prognosis in gastrointestinal cancers. Gossypol blockade of CaV3 isoforms is concentration- and use-dependent interacting with the closed, activated and inactivated conformations of CaV3 channels. Gossypol and CaV3 channels down-regulation inhibit colorectal cancer cell proliferation by arresting cell cycles at the G0/G1 and G2/M phases, respectively. CaV3 channels underlie the vectorial Ca2+ uptake by endoplasmic reticulum in colorectal cancer cells. CONCLUSION AND IMPLICATIONS Gossypol differentially blocked CaV3 channel and its anticancer activity was correlated with high levels of CaV3.1 and CaV3.2 in colorectal cancer cells. The CaV3 regulates cell proliferation and Ca2+ dynamics in colorectal cancer cells. Understanding this blocking mechanism maybe improve cancer therapies.
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Grants
- SPF201909009198 Fondation pour la Recherche Médicale (FRM), France
- BB/C517317/1 Biotechnology and Biological Sciences Research Council, UK
- G2022026006L National High-End Foreign Expert Recruitment Plan of China, China
- pre-R01grant O'Neal Comprehensive Cancer Center, USA
- CVU1148606 Consejo Nacional de Ciencia y Tecnologia (CONACYT), Mexico
- PrixRubanRoseAvenir Le Cancer du sein, parlons-en, France
- 16IRTSTHN020 Department of Education of the Henan Province, China
- Ministère de la Recherche et des Technologies, France
- A1-S-19171 Consejo Nacional de Ciencia y Tecnologia (CONACYT), Mexico
- Université de Tours, France
- IN209820 PAPIIT-DGAPA-UNAM, Mexico
- NavMetarget Conseil Régional du Centre-Val de Loire, France
- 1R21CA226491 National Institutes of Health (NIH), USA
- 099758/Z/12/Z Wellcome Trust, UK
- CanalEx Conseil Régional du Centre-Val de Loire, France
- I1200/320/2022 CVU 369878 Consejo Nacional de Ciencia y Tecnologia (CONACYT), Mexico
- Ligue Nationale Contre le Cancer, Interrégion Grand-Ouest: comités 29, 36, 86 and 37, France
- 2016PN-KFKT-06 Disciplinary Group of Psychology and Neuroscience, Xinxiang Medical University, China
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Affiliation(s)
- Osbaldo Lopez-Charcas
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Oumnia Benouna
- Université de Tours, Inserm U1327 ISCHEMIA 'Membrane Signalling and Inflammation in Reperfusion Injuries', Tours, France
| | - Roxane Lemoine
- Université de Tours, Inserm U1327 ISCHEMIA 'Membrane Signalling and Inflammation in Reperfusion Injuries', Tours, France
| | - Margarita Jacaranda Rosendo-Pineda
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Tonantzin Guadalupe Anguheven-Ledezma
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | | | | | - Leticia Robles-Martinez
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Zazil Herrera-Carrillo
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
- Centro de Investigación en Ciencias de la Salud (CICSA), Universidad Anáhuac, Mexico City, Mexico
| | - Miguel Ramírez-Aragón
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Ana Alfaro
- Servicio de Anatomía Patológica, Hospital General de México 'Dr. Eduardo Liceaga', Mexico City, Mexico
| | - Stéphanie Chadet
- Université de Tours, Inserm U1327 ISCHEMIA 'Membrane Signalling and Inflammation in Reperfusion Injuries', Tours, France
| | - Fabio Ferro
- Université de Tours, Inserm U1327 ISCHEMIA 'Membrane Signalling and Inflammation in Reperfusion Injuries', Tours, France
| | - Pierre Besson
- Université de Tours, Inserm U1327 ISCHEMIA 'Membrane Signalling and Inflammation in Reperfusion Injuries', Tours, France
| | - Lin-Hua Jiang
- Université de Tours, Inserm U1327 ISCHEMIA 'Membrane Signalling and Inflammation in Reperfusion Injuries', Tours, France
- Department of Physiology and Pathophysiology and Sino-UK Joint Laboratory of Brain Function and Injury of Henan Province, Xinxiang Medical University, Xinxiang, China
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Sadanandan E Velu
- Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama, USA
- O'Neal Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | | | - Sébastien Roger
- Université de Tours, Inserm U1327 ISCHEMIA 'Membrane Signalling and Inflammation in Reperfusion Injuries', Tours, France
| | - Juan Carlos Gomora
- Departamento de Neuropatología Molecular, División de Neurociencias, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
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Griffith EY, ElSayed M, Dura-Bernal S, Neymotin SA, Uhlrich DJ, Lytton WW, Zhu JJ. Mechanism of an Intrinsic Oscillation in Rat Geniculate Interneurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.06.597830. [PMID: 38895250 PMCID: PMC11185623 DOI: 10.1101/2024.06.06.597830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Depolarizing current injections produced a rhythmic bursting of action potentials - a bursting oscillation - in a set of local interneurons in the lateral geniculate nucleus (LGN) of rats. The current dynamics underlying this firing pattern have not been determined, though this cell type constitutes an important cellular component of thalamocortical circuitry, and contributes to both pathologic and non-pathologic brain states. We thus investigated the source of the bursting oscillation using pharmacological manipulations in LGN slices in vitro and in silico. 1. Selective blockade of calcium channel subtypes revealed that high-threshold calcium currentsI L andI P contributed strongly to the oscillation. 2. Increased extracellular K+ concentration (decreased K+currents) eliminated the oscillation. 3. Selective blockade of K+ channel subtypes demonstrated that the calcium-sensitive potassium current (I A H P ) was of primary importance. A morphologically simplified, multicompartment model of the thalamic interneuron characterized the oscillation as follows: 1. The low-threshold calcium currentI T provided the strong initial burst characteristic of the oscillation. 2. Alternating fluxes through high-threshold calcium channels andI A H P then provided the continuing oscillation's burst and interburst periods respectively. This interplay betweenI L andI A H P contrasts with the current dynamics underlying oscillations in thalamocortical and reticularis neurons, which primarily involveI T andI H , orI T andI A H P respectively. These findings thus point to a novel electrophysiological mechanism for generating intrinsic oscillations in a major thalamic cell type. Because local interneurons can sculpt the behavior of thalamocortical circuits, these results suggest new targets for the manipulation of ascending thalamocortical network activity.
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Affiliation(s)
- Erica Y Griffith
- Department of Neural and Behavioral Sciences, SUNY Downstate Health Sciences University, Brooklyn, NY
- Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY
| | - Mohamed ElSayed
- Department of Psychiatry, Geisel School of Medicine at Dartmouth, Hanover, NH
- Department of Biomedical Engineering, SUNY Downstate School of Graduate Studies, Brooklyn, NY
- Department of Psychiatry, New Hampshire Hospital, Concord, NH
| | - Salvador Dura-Bernal
- Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY
| | - Samuel A Neymotin
- Center for Biomedical Imaging and Neuromodulation, Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY
- Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Daniel J Uhlrich
- Department of Neuroscience, University of Wisconsin-Madison, Madison, WI, USA
| | - William W Lytton
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, NY
- Department of Neurology, Kings County Hospital, Brooklyn, NY
| | - J Julius Zhu
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA
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Qi J, Li H, Yang Y, Sun X, Wang J, Han X, Chu X, Sun Z, Chu L. Mechanistic insights into the ameliorative effects of hypoxia-induced myocardial injury by Corydalis yanhusuo total alkaloids: based on network pharmacology and experiment verification. Front Pharmacol 2024; 14:1275558. [PMID: 38273838 PMCID: PMC10808789 DOI: 10.3389/fphar.2023.1275558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 12/15/2023] [Indexed: 01/27/2024] Open
Abstract
Introduction: Corydalis yanhusuo total alkaloids (CYTA) are the primary active ingredients in yanhusuo, known for their analgesic and cardioprotective effects. However, the mechanisms underlying the treatment of Myocardial ischemia (MI) with CYTA have not been reported. The purpose of this study was to explore the protective effect of CYTA on MI and its related mechanisms. Methods: A network pharmacology was employed to shed light on the targets and mechanisms of CYTA's action on MI. The protective effect of CYTA against hypoxia damage was evaluated in H9c2 cells. Furthermore, the effects of CYTA on L-type Ca2+ current (ICa-L), contractile force, and Ca2+ transient in cardiomyocytes isolated from rats were investigated using the patch clamp technique and IonOptix system. The network pharmacology revealed that CYTA could regulate oxidative stress, apoptosis, and calcium signaling. Cellular experiments demonstrated that CYTA decreased levels of CK, LDH, and MDA, as well as ROS production and Ca2+ concentration. Additionally, CYTA improved apoptosis and increased the activities of SOD, CAT, and GSH-Px, along with the levels of ATP and Ca2+-ATPase content and mitochondrial membrane potential. Moreover, CYTA inhibited ICa-L, cell contraction, and Ca2+ transient in cardiomyocytes. Results: These findings suggest that CYTA has a protective effect on MI by inhibiting oxidative stress, mitochondrial damage, apoptosis and Ca2+ overload. Discussion: The results prove that CYTA might be a potential natural compound in the field of MI treatment, and also provide a new scientific basis for the its utilization.
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Affiliation(s)
- Jiaying Qi
- School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Haoying Li
- School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Yakun Yang
- School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Xiaoqi Sun
- School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Jianxin Wang
- School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Xue Han
- School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Xi Chu
- The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Zhenqing Sun
- Qingdao Hiser Hospital Affiliated of Qingdao University (Qingdao Traditional Chinese Medicine Hospital), Qingdao, Shandong, China
| | - Li Chu
- School of Pharmacy, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
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5
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Kumar N, Thorat ST, Gite A, Patole PB. Synergistic effect of nickel and temperature on gene expression, multiple stress markers, and depuration: an acute toxicity in fish. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:123729-123750. [PMID: 37991621 DOI: 10.1007/s11356-023-30996-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 11/06/2023] [Indexed: 11/23/2023]
Abstract
Aquatic animals are prone to extinction due to metal pollution and global climate change. Even though the fish and their products are also unsafe for human consumption, their exports have been rejected due to inorganic and organic contaminants. Nickel (Ni) is a metal that induces toxicity and accumulates in the aquatic ecosystem, posing health threats to humans, animals, and fish. In light of the above, our present investigation aimed to determine the median lethal concentration (96 h-LC50) of nickel alone and concurrent with high temperature (34 °C) (Ni + T) using static non-renewable bioassay toxicity test in Pangasianodon hypophthalmus. The groups treated under exposure to Ni reared under control condition (25-28.9 °C) and Ni + T exposure group reread under 34 °C. In this study, chose the definitive dose of Ni and Ni + T as 17, 18, 19, and 20 mg L-1 after the range finding test. The median lethal concentration of Ni and Ni + T was determined as 19.38 and 18.75 mg L-1, respectively at 96 h. Oxidative stress viz. catalase (CAT), superoxide dismutase (SOD), glutathione-s-transferase (GST), and glutathione peroxidase (GPx) in the liver, gill, and kidney were noticeably elevated with Ni and Ni + T during 96 h. Whereas, the CAT, GPx, and SOD gene expressions were significantly upregulated with Ni and Ni + T. Trilox equivalent anti-oxidant capacity (TEAC), cupric reducing anti-oxidant capacity (CUPRIC), ferric reducing ability of plasma (FRAP), ethoxy resorufin-O-deethylase (EROD), and acetylcholine esterase (AChE) were reduced due to exposure to Ni and Ni + T. Cellular metabolic stress and lipid peroxidation were highly affected due to Ni and Ni + T exposure. The immunological status, as indicated by total protein, albumin, globulin, A:G ratio, and nitro blue tetrazolium chloride (NBT), was severely affected by the toxicity of Ni and Ni + T. Moreover, the gene expression of interleukin (IL), tumor necrosis factor (TNFα), toll-like receptor (TLR), and total immunoglobulin (Ig) was remarkably downregulated following exposure to Ni and Ni + T. HSP 70, iNOS expression, ATPase, Na + /K + -ATPase, cortisol, and blood glucose was significantly elevated with Ni and Ni + T in P. hypophthalmus. The bioaccumulation of Ni in fish tissues and experimental water was determined. The kidney and liver tissues were highly accumulated with Ni, whereas DNA damage was reported in gill tissue. Interestingly, depuration study revealed that at the 28th day, the Ni bioaccumulation was below the maximum residue limit (MRL) level. Therefore, the present study revealed that Ni and Ni + T led to dysfunctional gene and metabolic regulation affecting physiology and genotoxicity. The bioaccumulation and depuration results also indicate higher residual occurrence of Ni in water and aquatic organisms for longer periods.
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Affiliation(s)
- Neeraj Kumar
- ICAR-National Institute of Abiotic Stress Management, Baramati, Pune-413115, India.
| | - Supriya T Thorat
- ICAR-National Institute of Abiotic Stress Management, Baramati, Pune-413115, India
| | - Archana Gite
- ICAR-National Institute of Abiotic Stress Management, Baramati, Pune-413115, India
| | - Pooja B Patole
- ICAR-National Institute of Abiotic Stress Management, Baramati, Pune-413115, India
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6
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El-Lakany MA, Haghbin N, Arora N, Hashad AM, Mironova GY, Sancho M, Gros R, Welsh DG. Ca V3.1 channels facilitate calcium wave generation and myogenic tone development in mouse mesenteric arteries. Sci Rep 2023; 13:20407. [PMID: 37989780 PMCID: PMC10663617 DOI: 10.1038/s41598-023-47715-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 11/17/2023] [Indexed: 11/23/2023] Open
Abstract
The arterial myogenic response to intraluminal pressure elicits constriction to maintain tissue perfusion. Smooth muscle [Ca2+] is a key determinant of constriction, tied to L-type (CaV1.2) Ca2+ channels. While important, other Ca2+ channels, particularly T-type could contribute to pressure regulation within defined voltage ranges. This study examined the role of one T-type Ca2+ channel (CaV3.1) using C57BL/6 wild type and CaV3.1-/- mice. Patch-clamp electrophysiology, pressure myography, blood pressure and Ca2+ imaging defined the CaV3.1-/- phenotype relative to C57BL/6. CaV3.1-/- mice had absent CaV3.1 expression and whole-cell current, coinciding with lower blood pressure and reduced mesenteric artery myogenic tone, particularly at lower pressures (20-60 mmHg) where membrane potential is hyperpolarized. This reduction coincided with diminished Ca2+ wave generation, asynchronous events of Ca2+ release from the sarcoplasmic reticulum, insensitive to L-type Ca2+ channel blockade (Nifedipine, 0.3 µM). Proximity ligation assay (PLA) confirmed IP3R1/CaV3.1 close physical association. IP3R blockade (2-APB, 50 µM or xestospongin C, 3 µM) in nifedipine-treated C57BL/6 arteries rendered a CaV3.1-/- contractile phenotype. Findings indicate that Ca2+ influx through CaV3.1 contributes to myogenic tone at hyperpolarized voltages through Ca2+-induced Ca2+ release tied to the sarcoplasmic reticulum. This study helps establish CaV3.1 as a potential therapeutic target to control blood pressure.
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Affiliation(s)
- Mohammed A El-Lakany
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada.
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt.
| | - Nadia Haghbin
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Naman Arora
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Ahmed M Hashad
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt
| | - Galina Yu Mironova
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Maria Sancho
- Department of Physiology, Faculty of Medicine, Complutense University of Madrid, Madrid, Spain
| | - Robert Gros
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada
| | - Donald G Welsh
- Department of Physiology & Pharmacology, Schulich School of Medicine, Robarts Research Institute, University of Western Ontario, 1151 Richmond Road N, London, ON, N6A 5B7, Canada.
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Lauerer RJ, Lerche H. Voltage-gated calcium channels in genetic epilepsies. J Neurochem 2023. [PMID: 37822150 DOI: 10.1111/jnc.15983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/17/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
Voltage-gated calcium channels (VGCC) are abundant in the central nervous system and serve a broad spectrum of functions, either directly in cellular excitability or indirectly to regulate Ca2+ homeostasis. Ca2+ ions act as one of the main connections in excitation-transcription coupling, muscle contraction and excitation-exocytosis coupling, including synaptic transmission. In recent years, many genes encoding VGCCs main α or additional auxiliary subunits have been associated with epilepsy. This review sums up the current state of knowledge on disease mechanisms and provides guidance on disease-specific therapies where applicable.
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Affiliation(s)
- Robert J Lauerer
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University and University Hospital Tuebingen, Tuebingen, Germany
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University and University Hospital Tuebingen, Tuebingen, Germany
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8
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Rangel-Galván M, Rangel-Galván V, Rangel-Huerta A. T-type calcium channel modulation by hydrogen sulfide in neuropathic pain conditions. Front Pharmacol 2023; 14:1212800. [PMID: 37529702 PMCID: PMC10387653 DOI: 10.3389/fphar.2023.1212800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 07/05/2023] [Indexed: 08/03/2023] Open
Abstract
Neuropathic pain can appear as a direct or indirect nerve damage lesion or disease that affects the somatosensory nervous system. If the neurons are damaged or indirectly stimulated, immune cells contribute significantly to inflammatory and neuropathic pain. After nerve injury, peripheral macrophages/spinal microglia accumulate around damaged neurons, producing endogenous hydrogen sulfide (H2S) through the cystathionine-γ-lyase (CSE) enzyme. H2S has a pronociceptive modulation on the Cav3.2 subtype, the predominant Cav3 isoform involved in pain processes. The present review provides relevant information about H2S modulation on the Cav3.2 T-type channels in neuropathic pain conditions. We have discussed that the dual effect of H2S on T-type channels is concentration-dependent, that is, an inhibitory effect is seen at low concentrations of 10 µM and an augmentation effect on T-current at 100 µM. The modulation mechanism of the Cav3.2 channel by H2S involves the direct participation of the redox/Zn2+ affinity site located in the His191 in the extracellular loop of domain I of the channel, involving a group of extracellular cysteines, comprising C114, C123, C128, and C1333, that can modify the local redox environment. The indirect interaction pathways involve the regulation of the Cav3.2 channel through cytokines, kinases, and post-translational regulators of channel expression. The findings conclude that the CSE/H2S/Cav3.2 pathway could be a promising therapeutic target for neuropathic pain disorders.
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Affiliation(s)
- Maricruz Rangel-Galván
- Biothecnology Department, Metropolitan Polytechnic University of Puebla, Puebla, Puebla, Mexico
| | - Violeta Rangel-Galván
- Nursing and Physiotherapy Department, University of Professional Development, Tijuana, Baja California, Mexico
| | - Alejandro Rangel-Huerta
- Faculty of Computer Science, Meritorious Autonomous University of Puebla, Puebla, Puebla, Mexico
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Martinez Damonte V, Pomrenze MB, Manning CE, Casper C, Wolfden AL, Malenka RC, Kauer JA. Somatodendritic Release of Cholecystokinin Potentiates GABAergic Synapses Onto Ventral Tegmental Area Dopamine Cells. Biol Psychiatry 2023; 93:197-208. [PMID: 35961792 PMCID: PMC9976994 DOI: 10.1016/j.biopsych.2022.06.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 06/01/2022] [Accepted: 06/10/2022] [Indexed: 11/02/2022]
Abstract
BACKGROUND Neuropeptides are contained in nearly every neuron in the central nervous system and can be released not only from nerve terminals but also from somatodendritic sites. Cholecystokinin (CCK), among the most abundant neuropeptides in the brain, is expressed in the majority of midbrain dopamine neurons. Despite this high expression, CCK function within the ventral tegmental area (VTA) is not well understood. METHODS We confirmed CCK expression in VTA dopamine neurons through immunohistochemistry and in situ hybridization and detected optogenetically induced CCK release using an enzyme-linked immunosorbent assay. To investigate whether CCK modulates VTA circuit activity, we used whole-cell patch clamp recordings in mouse brain slices. We infused CCK locally in vivo and tested food intake and locomotion in fasted mice. We also used in vivo fiber photometry to measure Ca2+ transients in dopamine neurons during feeding. RESULTS Here we report that VTA dopamine neurons release CCK from somatodendritic regions, where it triggers long-term potentiation of GABAergic (gamma-aminobutyric acidergic) synapses. The somatodendritic release occurs during trains of optogenetic stimuli or prolonged but modest depolarization and is dependent on synaptotagmin-7 and T-type Ca2+ channels. Depolarization-induced long-term potentiation is blocked by a CCK2 receptor antagonist and mimicked by exogenous CCK. Local infusion of CCK in vivo inhibits food consumption and decreases distance traveled in an open field test. Furthermore, intra-VTA-infused CCK reduced dopamine cell Ca2+ signals during food consumption after an overnight fast and was correlated with reduced food intake. CONCLUSIONS Our experiments introduce somatodendritic neuropeptide release as a previously unknown feedback regulator of VTA dopamine cell excitability and dopamine-related behaviors.
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10
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IL-6 evoked biochemical changes in prostate cancer cells. Cytokine 2023; 161:156079. [PMID: 36372008 DOI: 10.1016/j.cyto.2022.156079] [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: 07/18/2022] [Revised: 10/05/2022] [Accepted: 10/21/2022] [Indexed: 11/12/2022]
Abstract
The pro-inflammatory cytokine IL-6 has been associated with the progression of PCa to a castration-resistant phenotype. In this work, we characterized the biochemical changes evoked by IL-6 in three different models of PCa cells, including LNCaP, C4-2, and PC3. The effect of IL-6 on PCa cells was compared with the effect obtained by co-stimulation with the cAMP-inducing agent forskolin (FSK). Stimulation of LNCaP cells with IL-6 or IL-6 + FSK evoked increased expression of the neuroendocrine marker tubulin IIIβ and Cav3.2 T-type Ca2+ channel subunit. PC3 cells, representing a more advanced state of PCa, had high levels of tubulin IIIβ expression without any further changes observed by treatment with IL-6 or IL-6 + FSK. Elevated expression of the glucocorticoid receptor was observed in PC3, but not in LNCaP or C4-2 cells. Glucocorticoid receptor expression was not regulated by IL-6 stimulation of LNCaP or C4-2 cells. IL-6 acting alone or together with FSK evoked a significant reduction in the expression of the transcription factor REST and retinoblastoma tumor suppressor protein Rb1. In LNCaP cells, IL-6 acting alone or together with FSK had no effect on the expression of several biological markers of advanced PCa, including Aurora kinase A, valosin-containing protein, calcium-sensing receptor, calreticulin, S100A protein, and Protein S. In PC3 cells, co-treatment with IL-6 + FSK evoked increased expression of REST and S100A proteins, as well as a reduction in Protein S levels. These findings reveal a complex pattern of biochemical changes in PCa cells under the influence of IL-6.
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Kuznetsov SV, Kuznetsova NN. Effects of Ni2+ on Heart and Respiratory Rhythms in Newborn Rats. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022050088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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12
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T-Type Calcium Channels: A Mixed Blessing. Int J Mol Sci 2022; 23:ijms23179894. [PMID: 36077291 PMCID: PMC9456242 DOI: 10.3390/ijms23179894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 08/26/2022] [Accepted: 08/29/2022] [Indexed: 11/17/2022] Open
Abstract
The role of T-type calcium channels is well established in excitable cells, where they preside over action potential generation, automaticity, and firing. They also contribute to intracellular calcium signaling, cell cycle progression, and cell fate; and, in this sense, they emerge as key regulators also in non-excitable cells. In particular, their expression may be considered a prognostic factor in cancer. Almost all cancer cells express T-type calcium channels to the point that it has been considered a pharmacological target; but, as the drugs used to reduce their expression are not completely selective, several complications develop, especially within the heart. T-type calcium channels are also involved in a specific side effect of several anticancer agents, that act on microtubule transport, increase the expression of the channel, and, thus, the excitability of sensory neurons, and make the patient more sensitive to pain. This review puts into context the relevance of T-type calcium channels in cancer and in chemotherapy side effects, considering also the cardiotoxicity induced by new classes of antineoplastic molecules.
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Davison A, Lux UT, Brandstätter JH, Babai N. T-Type Ca 2+ Channels Boost Neurotransmission in Mammalian Cone Photoreceptors. J Neurosci 2022; 42:6325-6343. [PMID: 35803735 PMCID: PMC9398539 DOI: 10.1523/jneurosci.1878-21.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 06/13/2022] [Accepted: 06/22/2022] [Indexed: 11/21/2022] Open
Abstract
It is a commonly accepted view that light stimulation of mammalian photoreceptors causes a graded change in membrane potential instead of developing a spike. The presynaptic Ca2+ channels serve as a crucial link for the coding of membrane potential variations into neurotransmitter release. Cav1.4 L-type Ca2+ channels are expressed in photoreceptor terminals, but the complete pool of Ca2+ channels in cone photoreceptors appears to be more diverse. Here, we discovered, employing whole-cell patch-clamp recording from cone photoreceptor terminals in both sexes of mice, that their Ca2+ currents are composed of low- (T-type Ca2+ channels) and high- (L-type Ca2+ channels) voltage-activated components. Furthermore, Ca2+ channels exerted self-generated spike behavior in dark membrane potentials, and spikes were generated in response to light/dark transition. The application of fast and slow Ca2+ chelators revealed that T-type Ca2+ channels are located close to the release machinery. Furthermore, capacitance measurements indicated that they are involved in evoked vesicle release. Additionally, RT-PCR experiments showed the presence of Cav3.2 T-type Ca2+ channels in cone photoreceptors but not in rod photoreceptors. Altogether, we found several crucial functions of T-type Ca2+ channels, which increase the functional repertoire of cone photoreceptors. Namely, they extend cone photoreceptor light-responsive membrane potential range, amplify dark responses, generate spikes, increase intracellular Ca2+ levels, and boost synaptic transmission.SIGNIFICANCE STATEMENT Photoreceptors provide the first synapse for coding light information. The key elements in synaptic transmission are the voltage-sensitive Ca2+ channels. Here, we provide evidence that mouse cone photoreceptors express low-voltage-activated Cav3.2 T-type Ca2+ channels in addition to high-voltage-activated L-type Ca2+ channels. The presence of T-type Ca2+ channels in cone photoreceptors appears to extend their light-responsive membrane potential range, amplify dark response, generate spikes, increase intracellular Ca2+ levels, and boost synaptic transmission. By these functions, Cav3.2 T-type Ca2+ channels increase the functional repertoire of cone photoreceptors.
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Affiliation(s)
- Adam Davison
- Department of Biology, Animal Physiology/Neurobiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Uwe Thorsten Lux
- Department of Biology, Animal Physiology/Neurobiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Johann Helmut Brandstätter
- Department of Biology, Animal Physiology/Neurobiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Norbert Babai
- Department of Biology, Animal Physiology/Neurobiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
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14
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Harding EK, Zamponi GW. Central and peripheral contributions of T-type calcium channels in pain. Mol Brain 2022; 15:39. [PMID: 35501819 PMCID: PMC9063214 DOI: 10.1186/s13041-022-00923-w] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 04/13/2022] [Indexed: 02/06/2023] Open
Abstract
AbstractChronic pain is a severely debilitating condition that reflects a long-term sensitization of signal transduction in the afferent pain pathway. Among the key players in this pathway are T-type calcium channels, in particular the Cav3.2 isoform. Because of their biophysical characteristics, these channels are ideally suited towards regulating neuronal excitability. Recent evidence suggests that T-type channels contribute to excitability of neurons all along the ascending and descending pain pathways, within primary afferent neurons, spinal dorsal horn neurons, and within pain-processing neurons in the midbrain and cortex. Here we review the contribution of T-type channels to neuronal excitability and function in each of these neuronal populations and how they are dysregulated in chronic pain conditions. Finally, we discuss their molecular pharmacology and the potential role of these channels as therapeutic targets for chronic pain.
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15
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Villalobos CA, Basso MA. Optogenetic activation of the inhibitory nigro-collicular circuit evokes contralateral orienting movements in mice. Cell Rep 2022; 39:110699. [PMID: 35443172 PMCID: PMC10144672 DOI: 10.1016/j.celrep.2022.110699] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/20/2021] [Accepted: 03/29/2022] [Indexed: 11/03/2022] Open
Abstract
We report that increasing inhibition from the basal ganglia (BG) to the superior colliculus (SC) through the substantia nigra pars reticulata (nigra) using in vivo optogenetic activation of GABAergic terminals in mice produces contralateral orienting movements. These movements are unexpected because decreases, and not increases, in nigral activity are generally associated with the initiation of orienting movements. We found that, in slice recordings, the same optogenetic stimulation of nigral terminals producing movements in vivo evokes post-inhibitory rebound depolarization followed by Na+ spikes in SC output neurons. Moreover, blocking T-type Ca2+ channels in slices prevent post-inhibitory rebound and subsequent Na+ spiking in SC output neurons and also reduce the likelihood of contralateral orienting in vivo. On the basis of these results, we propose that, in addition to the permissive role, the BG may play an active role in the generation of orienting movements in mice by driving post-inhibitory rebound depolarization in SC output neurons.
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Affiliation(s)
- Claudio A Villalobos
- Fuster Laboratory of Cognitive Neuroscience, Department of Psychiatry and Biobehavioral Sciences, The Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
| | - Michele A Basso
- Fuster Laboratory of Cognitive Neuroscience, Department of Psychiatry and Biobehavioral Sciences, The Jane and Terry Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA.
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16
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Zhu T, Wang Y. T-type Ca 2+ channels play a dual role in modulating the excitability of dorsal root ganglia neurons. Mol Pain 2022; 18:17448069221132224. [PMID: 36163701 PMCID: PMC9536108 DOI: 10.1177/17448069221132224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
A subgroup of low-threshold dorsal root ganglia (DRG) neurons discharge action potentials (APs) with an afterdepolarizing potential (ADP). The ADP is formed by T-type Ca2+ currents. It is known that T-type Ca2+ currents contribute to neuropathic pain. However, the change in ADP-firing of injured DRG neurons has not been widely studied yet. Here we applied patch clamp to record ADP-firing and T-type Ca2+ currents in intact and chronically compressed DRG (CCD) neurons and examined T-type Ca2+ channel proteins expression with western blotting. After CCD injury, the incidences of both ADP firing and non-ADP burst firing increased, and T-type Ca2+ channels contributed to both of these firing patterns. The neurons discharging large-amplitude-ADP firing were TTX-insensitive, implying that high-density T-type Ca2+ channels might cooperate with TTX-insensitive Na+ channels to reduce the AP threshold. By contrast, the neurons displaying non-ADP burst firing were TTX-sensitive, implying that low density T-type Ca2+ channels may cooperate with TTX-sensitive Na+ channels to increase AP number. In DRG neurons, T-type Ca2+ currents density varied widely, ranging between 100 pA/pF and 5 pA/pF. After injury, the proportion of DRG neurons with large T-type Ca2+ currents increased in parallel with the increase in the incidence of large-amplitude-ADP firing. And in addition to Cav3.2, Cav3.3 channels are also likely to contribute to low-threshold firing. The data revealed that T-type Ca2+ channels may play a dual role in modulating the injured neurons' high excitability through a cooperative process with Na+ channels, thereby contributing to neuropathic pain.
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Affiliation(s)
- Tong Zhu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Clinical Experimental Center, Xi'an International Medical Center Hospital, Xi'an, China
| | - Yuying Wang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi'an Jiaotong University Health Science Center, Xi'an, China.,Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, 12480Xi'an Jiaotong University, Xi'an, China.,Institute of Neuroscience, Translational Medicine Institute, Xi'an Jiaotong University Health Science Center, Xi'an, China
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17
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Papazoglou A, Arshaad MI, Henseler C, Daubner J, Broich K, Hescheler J, Ehninger D, Haenisch B, Weiergräber M. Ca v3 T-Type Voltage-Gated Ca 2+ Channels and the Amyloidogenic Environment: Pathophysiology and Implications on Pharmacotherapy and Pharmacovigilance. Int J Mol Sci 2022; 23:3457. [PMID: 35408817 PMCID: PMC8998330 DOI: 10.3390/ijms23073457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 12/07/2022] Open
Abstract
Voltage-gated Ca2+ channels (VGCCs) were reported to play a crucial role in neurotransmitter release, dendritic resonance phenomena and integration, and the regulation of gene expression. In the septohippocampal system, high- and low-voltage-activated (HVA, LVA) Ca2+ channels were shown to be involved in theta genesis, learning, and memory processes. In particular, HVA Cav2.3 R-type and LVA Cav3 T-type Ca2+ channels are expressed in the medial septum-diagonal band of Broca (MS-DBB), hippocampal interneurons, and pyramidal cells, and ablation of both channels was proven to severely modulate theta activity. Importantly, Cav3 Ca2+ channels contribute to rebound burst firing in septal interneurons. Consequently, functional impairment of T-type Ca2+ channels, e.g., in null mutant mouse models, caused tonic disinhibition of the septohippocampal pathway and subsequent enhancement of hippocampal theta activity. In addition, impairment of GABA A/B receptor transcription, trafficking, and membrane translocation was observed within the septohippocampal system. Given the recent findings that amyloid precursor protein (APP) forms complexes with GABA B receptors (GBRs), it is hypothesized that T-type Ca2+ current reduction, decrease in GABA receptors, and APP destabilization generate complex functional interdependence that can constitute a sophisticated proamyloidogenic environment, which could be of potential relevance in the etiopathogenesis of Alzheimer's disease (AD). The age-related downregulation of T-type Ca2+ channels in humans goes together with increased Aβ levels that could further inhibit T-type channels and aggravate the proamyloidogenic environment. The mechanistic model presented here sheds new light on recent reports about the potential risks of T-type Ca2+ channel blockers (CCBs) in dementia, as observed upon antiepileptic drug application in the elderly.
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Affiliation(s)
- Anna Papazoglou
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (A.P.); (M.I.A.); (C.H.); (J.D.)
| | - Muhammad Imran Arshaad
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (A.P.); (M.I.A.); (C.H.); (J.D.)
| | - Christina Henseler
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (A.P.); (M.I.A.); (C.H.); (J.D.)
| | - Johanna Daubner
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (A.P.); (M.I.A.); (C.H.); (J.D.)
| | - Karl Broich
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (K.B.); (B.H.)
| | - Jürgen Hescheler
- Faculty of Medicine, Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, 50931 Cologne, Germany;
- Center of Physiology and Pathophysiology, Faculty of Medicine, University of Cologne, Robert-Koch-Str. 39, 50931 Cologne, Germany
| | - Dan Ehninger
- Translational Biogerontology, German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Venusberg-Campus 1/99, 53127 Bonn, Germany;
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Venusberg-Campus 1/99, 53127 Bonn, Germany
| | - Britta Haenisch
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (K.B.); (B.H.)
- German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Venusberg-Campus 1/99, 53127 Bonn, Germany
- Center for Translational Medicine, Medical Faculty, University of Bonn, 53113 Bonn, Germany
| | - Marco Weiergräber
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (A.P.); (M.I.A.); (C.H.); (J.D.)
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175 Bonn, Germany; (K.B.); (B.H.)
- Faculty of Medicine, Institute of Neurophysiology, University of Cologne, Robert-Koch-Str. 39, 50931 Cologne, Germany;
- Center of Physiology and Pathophysiology, Faculty of Medicine, University of Cologne, Robert-Koch-Str. 39, 50931 Cologne, Germany
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18
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Sato T, Arimura T, Murata K, Kawamura M, Obama W, Suzuki M, Nakauchi Y, Tominaga A, Morita M, Hiraoka K, Takayama-Watanabe E, Watanabe A. Differences of Extracellular Cues and Ca 2+ Permeable Channels in the Signaling Pathways for Inducing Amphibian Sperm Motility. Zoolog Sci 2021; 38:343-351. [PMID: 34342955 DOI: 10.2108/zs200159] [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: 10/29/2020] [Accepted: 02/24/2021] [Indexed: 11/17/2022]
Abstract
Low osmolality of freshwater and/or sperm motility-initiating substance (SMIS) induce amphibian sperm motility through increases in intracellular Ca2+. In the internally fertilizing newt Cynops pyrrhogaster, the sperm motility-initiating substance engages T type voltage-dependent Ca2 + channels and N-methyl D-aspartate-type glutamate receptors to initiate sperm motility and L type voltage-dependent Ca2+ channels to enhance motility. In the present study, differences in the usages of SMIS and Ca2+ permeable channels for sperm motility regulation were examined in amphibians that undergo different reproductive modes. Proteins of 14-17 kDa were detected by antibody against the active site peptide of SMIS in the oviduct secretion of internal fertilizers (C. pyrrhogaster, Cynops ensicauda, and Ambystoma mexicanum) and arboreal fertilizers (Rhacophorus arboreus and Rhacophorus schlegelii), but not in Buergeria japonica, an external fertilizer in freshwater. In the pharmacological study, a blocker of some transient receptor potential channels (RN1734) additionally suppressed enhancement of sperm motility in C. pyrrhogaster. In R. schlegelii, blockers of four types of channels differently suppressed sperm motility induced by low osmolality with or without the active site peptide of SMIS. Notably, blockers of L type voltage-dependent Ca2+ channels (nifedipine) and N-methyl D-aspartate-type glutamate receptors (MK801) suppressed sperm motility in the presence and the absence of the peptide, respectively. Low osmolality-induced sperm motility was suppressed by RN1734 and MK801 in B. japonica, but not in Xenopus laevis. These results reveal complex differences in the signaling pathways for inducing sperm motility that may be partly related to reproductive modes in amphibians.
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Affiliation(s)
- Tae Sato
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan
| | - Takeshi Arimura
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan
| | - Kenji Murata
- Center for Health & the Environment, University of California Davis, Davis CA 95616, USA
| | - Maako Kawamura
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan
| | - Wataru Obama
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan
| | - Megumu Suzuki
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan
| | - Yuni Nakauchi
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan
| | - Atsushi Tominaga
- Faculty of Education, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
| | - Masaya Morita
- Sesoko Station, Tropical Biosphere Research Center, University of the Ryukyus, Sesoko, Motobu, Okinawa 905-0227, Japan
| | - Kiyoshi Hiraoka
- Expo Memorial Tsukuba Advanced Technology Center, Fujikin Incorporated, Tsukuba, Ibaraki 305-0841, Japan
| | | | - Akihiko Watanabe
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan,
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Stecyk JAW, Barber RG, Cussins J, Hall D. Indirect evidence that anoxia exposure and cold acclimation alter transarcolemmal Ca 2+ flux in the cardiac pacemaker, right atrium and ventricle of the red-eared slider turtle (Trachemys scripta). Comp Biochem Physiol A Mol Integr Physiol 2021; 261:111043. [PMID: 34332046 DOI: 10.1016/j.cbpa.2021.111043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 07/22/2021] [Accepted: 07/23/2021] [Indexed: 12/15/2022]
Abstract
We indirectly assessed if altered transarcolemmal Ca2+ flux accompanies the decreased cardiac activity displayed by Trachemys scripta with anoxia exposure and cold acclimation. Turtles were first acclimated to 21 °C or 5 °C and held under normoxic (21N; 5N) or anoxic conditions (21A; 5A). We then compared the response of intrinsic heart rate (fH) and maximal developed force of spontaneously contracting right atria (Fmax,RA), and maximal developed force of isometrically-contracting ventricular strips (Fmax,V), to Ni2+ (0.1-10 mM), which respectively blocks T-type Ca2+ channels, L-type Ca2+ channels and the Na+-Ca2+-exchanger at the low, intermediate and high concentrations employed. Dose-response curves were established in simulated in vivo normoxic (Sim Norm) or simulated in vivo anoxic extracellular conditions (Sim Anx; 21A and 5A preparations). Ni2+ decreased intrinsic fH, Fmax,RA and Fmax,V of 21N tissues in a concentration-dependent manner, but the responses were blunted in 21A tissues in Sim Norm. Similarly, dose-response curves for Fmax,RA and Fmax,V of 5N tissues were right-shifted, whereas anoxia exposure at 5 °C did not further alter the responses. The influence of Sim Anx was acclimation temperature-, cardiac chamber- and contractile parameter-dependent. Combined, the findings suggest that: (1) reduced transarcolemmal Ca2+ flux in the cardiac pacemaker is a potential mechanism underlying the slowed intrinsic fH of anoxic turtles at 21 °C, but not 5 °C, (2) a downregulation of transarcolemmal Ca2+ flux may aid cardiac anoxia survival at 21 °C and prime the turtle myocardium for winter anoxia and (3) confirm that altered extracellular conditions with anoxia exposure can modify turtle cardiac transarcolemmal Ca2+ flux.
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Affiliation(s)
- Jonathan A W Stecyk
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, United States of America.
| | - Riley G Barber
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, United States of America
| | - Jace Cussins
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, United States of America
| | - Diarmid Hall
- Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, United States of America
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20
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Targeting T-type/CaV3.2 channels for chronic pain. Transl Res 2021; 234:20-30. [PMID: 33422652 PMCID: PMC8217081 DOI: 10.1016/j.trsl.2021.01.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 12/31/2020] [Accepted: 01/04/2021] [Indexed: 01/09/2023]
Abstract
T-type calcium channels regulate neuronal excitability and are important contributors of pain processing. CaV3.2 channels are the major isoform expressed in nonpeptidergic and peptidergic nociceptive neurons and are emerging as promising targets for pain treatment. Numerous studies have shown that CaV3.2 expression and/or activity are significantly increased in spinal dorsal horn and in dorsal root ganglia neurons in different inflammatory and neuropathic pain models. Pharmacological campaigns to inhibit the functional expression of CaV3.2 for treatment of pain have focused on the development of direct channel blockers, but none have produced lead candidates. Targeting the proteins that regulate the trafficking or transcription, and the ones that modify the channels via post-translational modifications are alternative means to regulate expression and function of CaV3.2 channels and hence to develop new drugs to control pain. Here we synthesize data supporting a role for CaV3.2 in numerous pain modalities and then discuss emerging opportunities for the indirect targeting of CaV3.2 channels.
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21
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Bhandari P, Vandael D, Fernández-Fernández D, Fritzius T, Kleindienst D, Önal C, Montanaro J, Gassmann M, Jonas P, Kulik A, Bettler B, Shigemoto R, Koppensteiner P. GABA B receptor auxiliary subunits modulate Cav2.3-mediated release from medial habenula terminals. eLife 2021; 10:68274. [PMID: 33913808 PMCID: PMC8121548 DOI: 10.7554/elife.68274] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 04/28/2021] [Indexed: 12/20/2022] Open
Abstract
The synaptic connection from medial habenula (MHb) to interpeduncular nucleus (IPN) is critical for emotion-related behaviors and uniquely expresses R-type Ca2+ channels (Cav2.3) and auxiliary GABAB receptor (GBR) subunits, the K+-channel tetramerization domain-containing proteins (KCTDs). Activation of GBRs facilitates or inhibits transmitter release from MHb terminals depending on the IPN subnucleus, but the role of KCTDs is unknown. We therefore examined the localization and function of Cav2.3, GBRs, and KCTDs in this pathway in mice. We show in heterologous cells that KCTD8 and KCTD12b directly bind to Cav2.3 and that KCTD8 potentiates Cav2.3 currents in the absence of GBRs. In the rostral IPN, KCTD8, KCTD12b, and Cav2.3 co-localize at the presynaptic active zone. Genetic deletion indicated a bidirectional modulation of Cav2.3-mediated release by these KCTDs with a compensatory increase of KCTD8 in the active zone in KCTD12b-deficient mice. The interaction of Cav2.3 with KCTDs therefore scales synaptic strength independent of GBR activation.
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Affiliation(s)
- Pradeep Bhandari
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - David Vandael
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | | | | | - David Kleindienst
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - Cihan Önal
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - Jacqueline Montanaro
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - Martin Gassmann
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Peter Jonas
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - Akos Kulik
- Institute of Physiology II, Faculty of Medicine, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Bernhard Bettler
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Ryuichi Shigemoto
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
| | - Peter Koppensteiner
- Institute of Science and Technology Austria (IST Austria), Klosterneuburg, Austria
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22
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Yu D, Febbo IG, Maroteaux MJ, Wang H, Song Y, Han X, Sun C, Meyer EE, Rowe S, Chen Y, Canavier CC, Schrader LA. The Transcription Factor Shox2 Shapes Neuron Firing Properties and Suppresses Seizures by Regulation of Key Ion Channels in Thalamocortical Neurons. Cereb Cortex 2021; 31:3194-3212. [PMID: 33675359 DOI: 10.1093/cercor/bhaa414] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/16/2020] [Accepted: 12/24/2020] [Indexed: 01/02/2023] Open
Abstract
Thalamocortical neurons (TCNs) play a critical role in the maintenance of thalamocortical oscillations, dysregulation of which can result in certain types of seizures. Precise control over firing rates of TCNs is foundational to these oscillations, yet the transcriptional mechanisms that constrain these firing rates remain elusive. We hypothesized that Shox2 is a transcriptional regulator of ion channels important for TCN function and that loss of Shox2 alters firing frequency and activity, ultimately perturbing thalamocortical oscillations into an epilepsy-prone state. In this study, we used RNA sequencing and quantitative PCR of control and Shox2 knockout mice to determine Shox2-affected genes and revealed a network of ion channel genes important for neuronal firing properties. Protein regulation was confirmed by Western blotting, and electrophysiological recordings showed that Shox2 KO impacted the firing properties of a subpopulation of TCNs. Computational modeling showed that disruption of these conductances in a manner similar to Shox2's effects modulated frequency of oscillations and could convert sleep spindles to near spike and wave activity, which are a hallmark for absence epilepsy. Finally, Shox2 KO mice were more susceptible to pilocarpine-induced seizures. Overall, these results reveal Shox2 as a transcription factor important for TCN function in adult mouse thalamus.
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Affiliation(s)
- Diankun Yu
- Neuroscience Program, Brain Institute, Tulane University, USA
| | | | | | - Hanyun Wang
- Neuroscience Program, Brain Institute, Tulane University, USA
| | - Yingnan Song
- Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | - Xiao Han
- Neuroscience Program, Brain Institute, Tulane University, USA
| | - Cheng Sun
- Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | - Emily E Meyer
- Neuroscience Program, Brain Institute, Tulane University, USA
| | - Stuart Rowe
- Neuroscience Program, Brain Institute, Tulane University, USA
| | - Yiping Chen
- Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
| | - Carmen C Canavier
- Cell Biology and Anatomy, LSU Health Sciences Center, New Orleans, LA 70112, USA
| | - Laura A Schrader
- Neuroscience Program, Brain Institute, Tulane University, USA.,Cell and Molecular Biology, Tulane University, New Orleans, LA 70118, USA
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23
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Lillo MA, Gaete PS, Puebla M, Burboa PC, Poblete I, Figueroa XF. Novel Pannexin-1-Coupled Signaling Cascade Involved in the Control of Endothelial Cell Function and NO-Dependent Relaxation. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:2678134. [PMID: 33688389 PMCID: PMC7914086 DOI: 10.1155/2021/2678134] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 01/03/2021] [Accepted: 01/13/2021] [Indexed: 12/11/2022]
Abstract
Deletion of pannexin-1 (Panx-1) leads not only to a reduction in endothelium-derived hyperpolarization but also to an increase in NO-mediated vasodilation. Therefore, we evaluated the participation of Panx-1-formed channels in the control of membrane potential and [Ca2+]i of endothelial cells. Changes in NO-mediated vasodilation, membrane potential, superoxide anion (O2 ·-) formation, and endothelial cell [Ca2+]i were analyzed in rat isolated mesenteric arterial beds and primary cultures of mesenteric endothelial cells. Inhibition of Panx-1 channels with probenecid (1 mM) or the Panx-1 blocking peptide 10Panx (60 μM) evoked an increase in the ACh (100 nM)-induced vasodilation of KCl-contracted mesenteries and in the phosphorylation level of endothelial NO synthase (eNOS) at serine 1177 (P-eNOSS1177) and Akt at serine 473 (P-AktS473). In addition, probenecid or 10Panx application activated a rapid, tetrodotoxin (TTX, 300 nM)-sensitive, membrane potential depolarization and [Ca2+]i increase in endothelial cells. Interestingly, the endothelial cell depolarization was converted into a transient spike after removing Ca2+ ions from the buffer solution and in the presence of 100 μM mibefradil or 10 μM Ni2+. As expected, Ni2+ also abolished the increment in [Ca2+]i. Expression of Nav1.2, Nav1.6, and Cav3.2 isoforms of voltage-dependent Na+ and Ca2+ channels was confirmed by immunocytochemistry. Furthermore, the Panx-1 channel blockade was associated with an increase in O2 ·- production. Treatment with 10 μM TEMPOL or 100 μM apocynin prevented the increase in O2 ·- formation, ACh-induced vasodilation, P-eNOSS1177, and P-AktS473 observed in response to Panx-1 inhibition. These findings indicate that the Panx-1 channel blockade triggers a novel complex signaling pathway initiated by the sequential activation of TTX-sensitive Nav channels and Cav3.2 channels, leading to an increase in NO-mediated vasodilation through a NADPH oxidase-dependent P-eNOSS1177, which suggests that Panx-1 may be involved in the endothelium-dependent control of arterial blood pressure.
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Affiliation(s)
- Mauricio A. Lillo
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8330025, Chile
| | - Pablo S. Gaete
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8330025, Chile
| | - Mariela Puebla
- Centro de Fisiología Celular e Integrativa, Facultad de Medicina-Clínica Alemana, Universidad del Desarrollo, Santiago, Chile
| | - Pía C. Burboa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8330025, Chile
| | - Inés Poblete
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8330025, Chile
| | - Xavier F. Figueroa
- Departamento de Fisiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8330025, Chile
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24
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Arshaad MI, Siwek ME, Henseler C, Daubner J, Ehninger D, Hescheler J, Sachinidis A, Broich K, Papazoglou A, Weiergräber M. Enhanced hippocampal type II theta activity AND altered theta architecture in mice lacking the Ca v3.2 T-type voltage-gated calcium channel. Sci Rep 2021; 11:1099. [PMID: 33441788 PMCID: PMC7806756 DOI: 10.1038/s41598-020-79763-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 12/08/2020] [Indexed: 12/20/2022] Open
Abstract
T-type Ca2+ channels are assumed to contribute to hippocampal theta oscillations. We used implantable video-EEG radiotelemetry and qPCR to unravel the role of Cav3.2 Ca2+ channels in hippocampal theta genesis. Frequency analysis of spontaneous long-term recordings in controls and Cav3.2-/- mice revealed robust increase in relative power in the theta (4-8 Hz) and theta-alpha (4-12 Hz) ranges, which was most prominent during the inactive stages of the dark cycles. Urethane injection experiments also showed enhanced type II theta activity and altered theta architecture following Cav3.2 ablation. Next, gene candidates from hippocampal transcriptome analysis of control and Cav3.2-/- mice were evaluated using qPCR. Dynein light chain Tctex-Type 1 (Dynlt1b) was significantly reduced in Cav3.2-/- mice. Furthermore, a significant reduction of GABA A receptor δ subunits and GABA B1 receptor subunits was observed in the septohippocampal GABAergic system. Our results demonstrate that ablation of Cav3.2 significantly alters type II theta activity and theta architecture. Transcriptional changes in synaptic transporter proteins and GABA receptors might be functionally linked to the electrophysiological phenotype.
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Affiliation(s)
- Muhammad Imran Arshaad
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Magdalena Elisabeth Siwek
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Christina Henseler
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Johanna Daubner
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Dan Ehninger
- Molecular and Cellular Cognition, German Center for Neurodegenerative Diseases (Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE), Sigmund-Freud-Str. 27, 53127, Bonn, Germany
| | - Jürgen Hescheler
- Institute of Neurophysiology, University of Cologne, Faculty of Medicine, Robert-Koch-Str. 39, 50931, Cologne, Germany
| | - Agapios Sachinidis
- Institute of Neurophysiology, University of Cologne, Faculty of Medicine, Robert-Koch-Str. 39, 50931, Cologne, Germany
| | - Karl Broich
- Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Anna Papazoglou
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany
| | - Marco Weiergräber
- Experimental Neuropsychopharmacology, Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM), Kurt-Georg-Kiesinger-Allee 3, 53175, Bonn, Germany.
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25
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Sato-Numata K, Numata T, Ueta Y, Okada Y. Expression and functions of N-type Cav2.2 and T-type Cav3.1 channels in rat vasopressin neurons under normotonic conditions. J Physiol Sci 2020; 70:49. [PMID: 33059597 PMCID: PMC10717235 DOI: 10.1186/s12576-020-00775-w] [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: 08/10/2020] [Accepted: 09/28/2020] [Indexed: 11/10/2022]
Abstract
Arginine vasopressin (AVP) neurons play essential roles in sensing the change in systemic osmolarity and regulating AVP release from their neuronal terminals to maintain the plasma osmolarity. AVP exocytosis depends on the Ca2+ entry via voltage-gated Ca2+ channels (VGCCs) in AVP neurons. In this study, suppression by siRNA-mediated knockdown and pharmacological sensitivity of VGCC currents evidenced molecular and functional expression of N-type Cav2.2 and T-type Cav3.1 in AVP neurons under normotonic conditions. Also, both the Cav2.2 and Cav3.1 currents were found to be sensitive to flufenamic acid (FFA). TTX-insensitive spontaneous action potentials were suppressed by FFA and T-type VGCC blocker Ni2+. However, Cav2.2-selective ω-conotoxin GVIA failed to suppress the firing activity. Taken together, it is concluded that Cav2.2 and Cav3.1 are molecularly and functionally expressed and both are sensitive to FFA in unstimulated rat AVP neurons. Also, it is suggested that Cav3.1 is primarily involved in their action potential generation.
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Affiliation(s)
- Kaori Sato-Numata
- Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo, 102-0083, Japan
- Department of Physiology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Tomohiro Numata
- Department of Physiology, School of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka, 814-0180, Japan
| | - Yoichi Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, 1-1, Iseigaoka, Yahatanishi-ku, Kitakyushu-shi, Fukuoka, 807-8555, Japan
| | - Yasunobu Okada
- National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
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26
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Solé L, Wagnon JL, Tamkun MM. Functional analysis of three Na v1.6 mutations causing early infantile epileptic encephalopathy. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165959. [PMID: 32916281 DOI: 10.1016/j.bbadis.2020.165959] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 08/21/2020] [Accepted: 09/03/2020] [Indexed: 11/24/2022]
Abstract
The voltage-gated sodium channel Nav1.6 is associated with more than 300 cases of epileptic encephalopathy. Nav1.6 epilepsy-causing mutations are spread over the entire channel's structure and only 10% of mutations have been characterized at the molecular level, with most of them being gain of function mutations. In this study, we analyzed three previously uncharacterized Nav1.6 epilepsy-causing mutations: G214D, N215D and V216D, located within a mutation hot-spot at the S3-S4 extracellular loop of Domain1. Voltage clamp experiments showed a 6-16 mV hyperpolarizing shift in the activation mid-point for all three mutants. V216D presented the largest shift along with decreased current amplitude, enhanced inactivation and a lack of persistent current. Recordings at hyperpolarized potentials indicated that all three mutants presented gating pore currents. Furthermore, trafficking experiments performed in cultured hippocampal neurons demonstrated that the mutants trafficked properly to the cell surface, with no significant differences regarding surface expression within the axon initial segment or soma compared to wild-type. These trafficking data suggest that the disease-causing consequences are due to only changes in the biophysical properties of the channel. Interestingly, the patient carrying the V216D mutation, which is the mutant with the greatest electrophysiological changes as compared to wild-type, exhibited the most severe phenotype. These results emphasize that these mutations will mandate unique treatment approaches, for normal sodium channel blockers may not work given that the studied mutations present gating pore currents. This study emphasizes the importance of molecular characterization of disease-causing mutations in order to improve the pharmacological treatment of patients.
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Affiliation(s)
- Laura Solé
- Molecular, Cellular and Integrative Neurosciences Graduate Program, Colorado State University, Fort Collins, CO 80523, USA; Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA
| | - Jacy L Wagnon
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, USA
| | - Michael M Tamkun
- Molecular, Cellular and Integrative Neurosciences Graduate Program, Colorado State University, Fort Collins, CO 80523, USA; Department of Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA; Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA.
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27
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Sun Z, Gong C, Ren J, Zhang X, Wang G, Liu Y, Ren Y, Zhao Y, Yu Q, Wang Y, Hou J. Toxicity of nickel and cobalt in Japanese flounder. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 263:114516. [PMID: 32283401 DOI: 10.1016/j.envpol.2020.114516] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 03/28/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Nickel and cobalt are essential elements that become toxic at high concentrations. Little is known about nickel and cobalt toxicity in aquatic animals. This study aimed to investigate acute and chronic toxicity of nickel and cobalt in Japanese flounder (Paralichthys olivaceous), with emphasis on oxidative stress reactions, histopathological changes, and differences in gene expression. The lethal concentration for 50% mortality (LC50) in 3 and 8 cm Japanese flounder exposed to nickel for 96 h was found to be 86.2 ± 0.018 and 151.3 ± 0.039 mg/L; for cobalt exposure, LC50 was 47.5 ± 0.015 and 180.4 ± 0.034 mg/L, respectively. Chronic nickel and cobalt exposure caused different degrees of oxidative enzyme activity changes in gill, liver, and muscle tissues. Erythrocyte deformations were detected after acute or chronic exposure to nickel and cobalt. the nickel and cobalt exposure also caused pathological changes such as spherical swelling over other gill patches, rod-like proliferations in the gill patch epithelial cell layer, and disorder in hepatocyte arrangement, cell swelling, and cytoplasm loosening. RNA-Seq indicated that there were 184 upregulated and 185 downregulated genes in the liver of Japanese flounder exposed to 15 mg/L nickel for 28 d. For cobalt, 920 upregulated and 457 downregulated genes were detected. Among these differentially expressed genes, 162 were shared by both nickel and cobalt exposure. In both nickel and cobalt, pathways including fatty acid elongation, steroid biosynthesis, unsaturated fatty acid biosynthesis, fatty acid metabolism, PPAR signaling, and ferroptosis were significantly enriched. Taken together, these results aided our understanding of the toxicity of nickel and cobalt in aquatic animals.
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Affiliation(s)
- Zhaohui Sun
- Key Laboratory of Aquatic Genomics, Ministry of Agriculture, Beijing, 100141, China; Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao, 066100, China
| | - Chunguang Gong
- Ocean Collage, Agricultural University of Hebei, Qinhuangdao, 066009, China
| | - Jiangong Ren
- Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao, 066100, China
| | - Xiaoyan Zhang
- Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao, 066100, China
| | - Guixing Wang
- Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao, 066100, China
| | - Yufeng Liu
- Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao, 066100, China
| | - Yuqin Ren
- Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao, 066100, China
| | - Yaxian Zhao
- Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao, 066100, China
| | - Qinghai Yu
- Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao, 066100, China
| | - Yufen Wang
- Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao, 066100, China
| | - Jilun Hou
- Key Laboratory of Aquatic Genomics, Ministry of Agriculture, Beijing, 100141, China; Beidaihe Central Experiment Station, Chinese Academy of Fishery Sciences, Qinhuangdao, 066100, China.
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28
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Guan W, Stephens RF, Mourad O, Mehta A, Fux J, Spafford JD. Unique cysteine-enriched, D2L5 and D4L6 extracellular loops in Ca V3 T-type channels alter the passage and block of monovalent and divalent ions. Sci Rep 2020; 10:12404. [PMID: 32710088 PMCID: PMC7382465 DOI: 10.1038/s41598-020-69197-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 07/06/2020] [Indexed: 11/09/2022] Open
Abstract
Invertebrate LCaV3 shares the quintessential features of vertebrate CaV3 T-type channels, with a low threshold of channel activation, rapid activation and inactivation kinetics and slow deactivation kinetics compared to other known Ca2+ channels, the CaV1 and CaV2 channels. Unlike the vertebrates though, CaV3 T-type channels in non-cnidarian invertebrates possess an alternative exon 12 spanning the D2L5 extracellular loop, which alters the invertebrate LCaV3 channel into a higher Na+ and lower Ca2+ current passing channel, more resembling a classical NaV1 Na+ channel. Cnidarian CaV3 T-type channels can possess genes with alternative cysteine-rich, D4L6 extracellular loops in a manner reminiscent of the alternative cysteine-rich, D2L5 extracellular loops of non-cnidarian invertebrates. We illustrate here that the preferences for greater Na+ or Ca2+ ion current passing through CaV3 T-type channels are contributed by paired cysteines within D2L5 and D4L6 extracellular loops looming above the pore selectivity filter. Swapping of invertebrate tri- and tetra-cysteine containing extracellular loops, generates higher Na+ current passing channels in human CaV3.2 channels, while corresponding mono- and di-cysteine loop pairs in human CaV3.2 generates greater Ca2+ current passing, invertebrate LCaV3 channels. Alanine substitutions of unique D2L5 loop cysteines of LCaV3 channels increases relative monovalent ion current sizes and increases the potency of Zn2+ and Ni2+ block by ~ 50× and ~ 10× in loop cysteine mutated channels respectively, acquiring characteristics of the high affinity block of CaV3.2 channels, including the loss of the slowing of inactivation kinetics during Zn2+ block. Charge neutralization of a ubiquitous aspartate residue of calcium passing CaV1, CaV2 and CaV3 channels, in the outer pore of the selectivity filter residues in Domain II generates higher Na+ current passing channels in a manner that may resemble how the unique D2L5 extracellular loops of invertebrate CaV3 channels may confer a relatively higher peak current size for Na+ ions over Ca2+ The extracellular loops of CaV3 channels are not engaged with accessory subunit binding, as the other Na+ (NaV1) and Ca2+ (CaV1/CaV2) channels, enabling diversity and expansion of cysteine-bonded extracellular loops, which appears to serve, amongst other possibilities, to alter to the preferences for passage of Ca2+ or Na+ ions through invertebrate CaV3 channels.
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Affiliation(s)
- Wendy Guan
- B1-173, Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Robert F Stephens
- B1-173, Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Omar Mourad
- B1-173, Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Amrit Mehta
- B1-173, Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - Julia Fux
- B1-173, Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada
| | - J David Spafford
- B1-173, Department of Biology, University of Waterloo, Waterloo, ON, N2L 3G1, Canada.
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29
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Zhang X, Li Y, Zhang X, Piacentino V, Harris DM, Berretta R, Margulies KB, Houser SR, Chen X. A low voltage activated Ca 2+ current found in a subset of human ventricular myocytes. Channels (Austin) 2020; 14:231-245. [PMID: 32684070 PMCID: PMC7515576 DOI: 10.1080/19336950.2020.1794420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Low voltage activated (ICa-LVA) calcium currents including Cav1.3 and T-type calcium current (ICa-T) have not been reported in adult human left ventricular myocytes (HLVMs). We tried to examine their existence and possible correlation with etiology and patient characteristics in a big number of human LVMs isolated from explanted terminally failing (F) hearts, failing hearts with left ventricular assist device (F-LVAD) and nonfailing (NF) human hearts. LVA (ICa-LVA) was determined by subtracting L-type Ca2+ current (ICa-L) recorded with the holding potential of −50 mV from total Ca2+ current recorded with the holding potential of −90 mV or −70 mV. ICa- LVA was further tested with its sensitivity to 100 µM CdCl2 and tetrodotoxin. Three HLVMs (3 of 137 FHLVMs) from 2 (N = 30 hearts) failing human hearts, of which one was idiopathic and the other was due to primary pulmonary hypertension, were found with ICa-LVA. ICa-LVA in one FHLVM was not sensitive to 100 µM CdCl2 while ICa-LVA in another two FHLVMs was not sensitive to tetrodotoxin. It peaked at the voltage of −40~-20 mV and had a time-dependent decay faster than ICa-L but slower than sodium current (INa). ICa-LVA was not found in any HLVMs from NF (75 HLVMs from 17 hearts) or F-LVAD hearts (82 HLVMs from 18 hearts) but a statistically significant correlation could not be established. In conclusion, ICa-LVA was detected in some HLVMs of a small portion of human hearts that happened to be nonischemic failing hearts.
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Affiliation(s)
- Xin Zhang
- Department of Infection Diseases The First Affiliated Hospital of China Medical University , Shenyang China.,Department of Physiology and Cardiovascular Research Center, Temple University Lewis Katz School of Medicine , Philadelphia, PA, USA
| | - Yijia Li
- Department of Physiology and Cardiovascular Research Center, Temple University Lewis Katz School of Medicine , Philadelphia, PA, USA
| | - Xiaoying Zhang
- Department of Physiology and Cardiovascular Research Center, Temple University Lewis Katz School of Medicine , Philadelphia, PA, USA
| | - Valentino Piacentino
- Department of Physiology and Cardiovascular Research Center, Temple University Lewis Katz School of Medicine , Philadelphia, PA, USA.,Department Grand Strand Surgical Care, Grand Strand Regional Medical Center , Myrtle Beach, SC
| | - David M Harris
- Department of Physiology and Cardiovascular Research Center, Temple University Lewis Katz School of Medicine , Philadelphia, PA, USA.,College of Medicine, University of Central Florida , Orlando, Florida, USA
| | - Remus Berretta
- Department of Physiology and Cardiovascular Research Center, Temple University Lewis Katz School of Medicine , Philadelphia, PA, USA
| | - Kenneth B Margulies
- Department of Physiology and Cardiovascular Research Center, Temple University Lewis Katz School of Medicine , Philadelphia, PA, USA.,Department of Medicine, University of Pennsylvania , Philadelphia, PA, USA
| | - Steven R Houser
- Department of Physiology and Cardiovascular Research Center, Temple University Lewis Katz School of Medicine , Philadelphia, PA, USA
| | - Xiongwen Chen
- Department of Physiology and Cardiovascular Research Center, Temple University Lewis Katz School of Medicine , Philadelphia, PA, USA
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30
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Jahan KS, Shi J, Greenberg HZE, Khavandi S, Baudel MMA, Barrese V, Greenwood IA, Albert AP. MARCKS mediates vascular contractility through regulating interactions between voltage-gated Ca 2+ channels and PIP 2. Vascul Pharmacol 2020; 132:106776. [PMID: 32707323 PMCID: PMC7549404 DOI: 10.1016/j.vph.2020.106776] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/16/2020] [Accepted: 07/17/2020] [Indexed: 12/25/2022]
Abstract
Phosphatidylinositol 4,5-bisphosphate (PIP2) acts as substrate and unmodified ligand for Gq-protein-coupled receptor signalling in vascular smooth muscle cells (VSMCs) that is central for initiating contractility. The present work investigated how PIP2 might perform these two potentially conflicting roles by studying the effect of myristoylated alanine-rich C kinase substrate (MARCKS), a PIP2-binding protein, on vascular contractility in rat and mouse mesenteric arteries. Using wire myography, MANS peptide (MANS), a MARCKS inhibitor, produced robust contractions with a pharmacological profile suggesting a predominantly role for L-type (CaV1.2) voltage-gated Ca2+ channels (VGCC). Knockdown of MARCKS using morpholino oligonucleotides reduced contractions induced by MANS and stimulation of α1-adrenoceptors and thromboxane receptors with methoxamine (MO) and U46619 respectively. Immunocytochemistry and proximity ligation assays demonstrated that MARCKS and CaV1.2 proteins co-localise at the plasma membrane in unstimulated tissue, and that MANS and MO reduced these interactions and induced translocation of MARCKS from the plasma membrane to the cytosol. Dot-blots revealed greater PIP2 binding to MARCKS than CaV1.2 in unstimulated tissue, with this binding profile reversed following stimulation by MANS and MO. MANS evoked an increase in peak amplitude and shifted the activation curve to more negative membrane potentials of whole-cell voltage-gated Ca2+ currents, which were prevented by depleting PIP2 levels with wortmannin. This present study indicates for the first time that MARCKS is important regulating vascular contractility and suggests that disinhibition of MARCKS by MANS or vasoconstrictors may induce contraction through releasing PIP2 into the local environment where it increases voltage-gated Ca2+ channel activity.
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Affiliation(s)
- Kazi S Jahan
- Vascular Biology Research Centre, Molecular and Clinical Research Institute, St. George's, University of London, Cranmer Terrace, London SW17 0RE, UK
| | - Jian Shi
- Leeds Institute of Cardiovascular and Metabolic Medicine, Faculty of Medicine and Health, University of Leeds, Leeds LS2 9JT, UK
| | - Harry Z E Greenberg
- Vascular Biology Research Centre, Molecular and Clinical Research Institute, St. George's, University of London, Cranmer Terrace, London SW17 0RE, UK
| | - Sam Khavandi
- Vascular Biology Research Centre, Molecular and Clinical Research Institute, St. George's, University of London, Cranmer Terrace, London SW17 0RE, UK
| | - Miguel Martín-Aragón Baudel
- Department of Pharmacology, University of California, 451, Health Sciences Drive, Suite 3503, Davis, CA 95615, USA
| | - Vincenzo Barrese
- Department of Neurosciences, Reproductive Sciences and Dentistry, University of Naples Federico II, Corso Umberto I, 40, 80138 Napoli, NA, Italy
| | - Iain A Greenwood
- Vascular Biology Research Centre, Molecular and Clinical Research Institute, St. George's, University of London, Cranmer Terrace, London SW17 0RE, UK
| | - Anthony P Albert
- Vascular Biology Research Centre, Molecular and Clinical Research Institute, St. George's, University of London, Cranmer Terrace, London SW17 0RE, UK.
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31
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Abstract
Vascular smooth muscle cells (VSMCs) of small peripheral arteries contribute to blood pressure control by adapting their contractile state. These adaptations depend on the VSMC cytosolic Ca2+ concentration, regulated by complex local elementary Ca2+ signaling pathways. Ca2+ sparks represent local, transient, rapid calcium release events from a cluster of ryanodine receptors (RyRs) in the sarcoplasmic reticulum. In arterial SMCs, Ca2+ sparks activate nearby calcium-dependent potassium channels, cause membrane hyperpolarization and thus decrease the global intracellular [Ca2+] to oppose vasoconstriction. Arterial SMC Cav1.2 L-type channels regulate intracellular calcium stores content, which in turn modulates calcium efflux through RyRs. Cav3.2 T-type channels contribute to a minor extend to Ca2+ spark generation in certain types of arteries. Their localization within cell membrane caveolae is essential. We summarize present data on local elementary calcium signaling (Ca2+ sparks) in arterial SMCs with focus on RyR isoforms, large-conductance calcium-dependent potassium (BKCa) channels, and cell membrane-bound calcium channels (Cav1.2 and Cav3.2), particularly in caveolar microdomains.
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Affiliation(s)
- Gang Fan
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Yingqiu Cui
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Maik Gollasch
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Berlin, Germany
| | - Mario Kassmann
- Charité - Universitätsmedizin Berlin, Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Berlin, Germany
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32
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Rey S, Maton G, Satake S, Llano I, Kang S, Surmeier DJ, Silverman RB, Collin T. Physiological involvement of presynaptic L-type voltage-dependent calcium channels in GABA release of cerebellar molecular layer interneurons. J Neurochem 2020; 155:390-402. [PMID: 32491217 DOI: 10.1111/jnc.15100] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 05/11/2020] [Accepted: 05/27/2020] [Indexed: 12/30/2022]
Abstract
While high threshold voltage-dependent Ca2+ channels (VDCCs) of the N and P/Q families are crucial for evoked neurotransmitter release in the mammalian CNS, it remains unclear to what extent L-type Ca2+ channels (LTCCs), which have been mainly considered as acting at postsynaptic sites, participate in the control of transmitter release. Here, we investigate the possible role of LTCCs in regulating GABA release by cerebellar molecular layer interneurons (MLIs) from rats. We found that BayK8644 (BayK) markedly increases mIPSC frequency in MLIs and Purkinje cells (PCs), suggesting that LTCCs are expressed presynaptically. Furthermore, we observed (1) a potentiation of evoked IPSCs in the presence of BayK, (2) an inhibition of evoked IPSCs in the presence of the LTCC-specific inhibitor Compound 8 (Cp8), and (3) a strong reduction of mIPSC frequency by Cp8. BayK effects are reduced by dantrolene, suggesting that ryanodine receptors act in synergy with LTCCs. Finally, BayK enhances presynaptic AP-evoked Ca2+ transients and increases the frequency of spontaneous axonal Ca2+ transients observed in TTX. Taken together, our data demonstrate that LTCCs are of primary importance in regulating GABA release by MLIs.
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Affiliation(s)
- Stéphanie Rey
- Saints Pères Paris Institute for the Neurociences CNRS-UMR 8003, Université de Paris, Paris, France
| | - Gilliane Maton
- Institut Jacques Monod, CNRS/Université de Paris - Bâtiment Buffon, Paris, France
| | - Shin'Ichiro Satake
- Departement of Infornation Physiology, National Institute for Physiological Sciences (NIPS), Okazaki, Japan
| | - Isabel Llano
- Saints Pères Paris Institute for the Neurociences CNRS-UMR 8003, Université de Paris, Paris, France
| | - Soosung Kang
- Department of Chemistry, Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
| | - Dalton James Surmeier
- Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Richard B Silverman
- Department of Chemistry, Chemistry of Life Processes Institute, Northwestern University, Evanston, IL, USA
| | - Thibault Collin
- Saints Pères Paris Institute for the Neurociences CNRS-UMR 8003, Université de Paris, Paris, France
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33
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Functional Postnatal Maturation of the Medial Olivocochlear Efferent-Outer Hair Cell Synapse. J Neurosci 2020; 40:4842-4857. [PMID: 32430293 DOI: 10.1523/jneurosci.2409-19.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 04/19/2020] [Accepted: 05/11/2020] [Indexed: 01/07/2023] Open
Abstract
The organ of Corti, the auditory mammalian sensory epithelium, contains two types of mechanotransducer cells, inner hair cells (IHCs) and outer hair cells (OHCs). IHCs are involved in conveying acoustic stimuli to the CNS, while OHCs are implicated in the fine tuning and amplification of sounds. OHCs are innervated by medial olivocochlear (MOC) cholinergic efferent fibers. The functional characteristics of the MOC-OHC synapse during maturation were assessed by electrophysiological and pharmacological methods in mouse organs of Corti at postnatal day 11 (P11)-P13, hearing onset in altricial rodents, and at P20-P22 when the OHCs are morphologically and functionally mature. Synaptic currents were recorded in whole-cell voltage-clamped OHCs while electrically stimulating the MOC fibers. A progressive increase in the number of functional MOC-OHC synapses, as well as in their strength and efficacy, was observed between P11-13 and P20-22. At hearing onset, the MOC-OHC synapse presented facilitation during MOC fibers high-frequency stimulation that disappeared at mature stages. In addition, important changes were found in the VGCC that are coupled to transmitter release. Ca2+ flowing in through L-type VGCCs contribute to trigger ACh release together with P/Q- and R-type VGCCs at P11-P13, but not at P20-P22. Interestingly, N-type VGCCs were found to be involved in this process at P20-P22, but not at hearing onset. Moreover, the degree of compartmentalization of calcium channels with respect to BK channels and presynaptic release components significantly increased from P11-P13 to P20-P22. These results suggest that the MOC-OHC synapse is immature at the onset of hearing.SIGNIFICANCE STATEMENT The functional expression of both VGCCs and BK channels, as well as their localization with respect to the presynaptic components involved in transmitter release, are key elements in determining synaptic efficacy. In this work, we show dynamic changes in the expression of VGCCs and Ca2+-dependent BK K+ channels coupled to ACh release at the MOC-OHC synapse and their shift in compartmentalization during postnatal maturation. These processes most likely set the short-term plasticity pattern and reliability of the MOC-OHC synapse on high-frequency activity.
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Analysis of tetrodotoxin-sensitive sodium and low voltage-activated calcium channels in developing mouse retinal horizontal cells. Exp Eye Res 2020; 195:108028. [PMID: 32277973 DOI: 10.1016/j.exer.2020.108028] [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: 02/17/2020] [Revised: 03/24/2020] [Accepted: 03/29/2020] [Indexed: 11/21/2022]
Abstract
Expression patterns of voltage-gated ion channels determine the spatio-temporal dynamics of ion currents that supply excitable neurons in developing tissue with proper electrophysiological properties. The purpose of the study was to identify fast cationic inward currents in mouse retinal horizontal cells (HCs) and describe their biophysical properties at different developmental stages. We also aimed to reveal their physiological role in shaping light responses (LRs) in adult HCs. HCs were recorded in horizontal slices of wild-type mouse retina at postnatal stages ranging from p8 through p60. Voltage-dependent inward currents were isolated with appropriate voltage protocols and blockers specific for sodium and T-type calcium channels. LRs were evoked with full-field flashes (130 μW/cm2). Transient and steady inward currents were identified at all developmental stages. Transient currents were mediated by T-type calcium and TTX-sensitive sodium channels, whereas steady currents were blocked by cadmium, indicating the presence of high voltage-activated calcium channels. Activation and steady-state inactivation kinetics of T-type calcium channels revealed a contribution to the resting membrane potential during postnatal development. Additionally, both sodium and T-type calcium channels had an impact on HC LRs at light offset in adult animals. Our results showed that the voltage-dependent inward currents of postnatally developing mouse HCs consist of T-type calcium, TTX-sensitive sodium, and high voltage-activated calcium channels, and that transient ionic currents contributed to light-evoked responses of adult HCs, suggesting a role in HC information processing.
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35
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Ardestani G, Mehregan A, Fleig A, Horgen FD, Carvacho I, Fissore RA. Divalent cation influx and calcium homeostasis in germinal vesicle mouse oocytes. Cell Calcium 2020; 87:102181. [PMID: 32097818 DOI: 10.1016/j.ceca.2020.102181] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 02/11/2020] [Accepted: 02/11/2020] [Indexed: 11/30/2022]
Abstract
Prior to maturation, mouse oocytes are arrested at the germinal vesicle (GV) stage during which they experience constitutive calcium (Ca2+) influx and spontaneous Ca2+ oscillations. The oscillations cease during maturation but Ca2+ influx continues, as the oocytes' internal stores attain maximal content at the culmination of maturation, the metaphase II stage. The identity of the channel(s) that underlie this Ca2+ influx has not been completely determined. GV and matured oocytes are known to express three Ca2+ channels, CaV3.2, TRPV3 and TRPM7, but females null for each of these channels are fertile and their oocytes display minor modifications in Ca2+ homeostasis, suggesting a complex regulation of Ca2+ influx. To define the contribution of these channels at the GV stage, we used different divalent cations, pharmacological inhibitors and genetic models. We found that the three channels are active at this stage. CaV3.2 and TRPM7 channels contributed the majority of Ca2+ influx, as inhibitors and oocytes from homologous knockout (KO) lines showed severely reduced Ca2+ entry. Sr2+ influx was promoted by CaV3.2 channels, as Sr2+ oscillations were negligible in CaV3.2-KO oocytes but robust in control and Trpv3-KO GV oocytes. Mn2+ entry relied on expression of CaV3.2 and TRPM7 channels, but Ni2+ entry depended on the latter. CaV3.2 and TRPV3 channels combined to fill the Ca2+ stores, although CaV3.2 was the most impactful. Studies with pharmacological inhibitors effectively blocked the influx of divalent cations, but displayed off-target effects, and occasionally agonist-like properties. In conclusion, GV oocytes express channels mediating Ca2+ and other divalent cation influx that are pivotal for fertilization and early development. These channels may serve as targets for intervention to improve the success of assisted reproductive technologies.
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Affiliation(s)
- Goli Ardestani
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, MA, 01003, USA
| | - Aujan Mehregan
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, MA, 01003, USA
| | - Andrea Fleig
- Center for Biomedical Research at The Queen's Medical Center and University of Hawaii Cancer Center and John A. Burns School of Medicine at the University of Hawaii, Honolulu, HI, 96813, USA
| | - F David Horgen
- Department of Natural Sciences, Hawaii Pacific University, Kaneohe, HI, 96744, USA
| | - Ingrid Carvacho
- Department of Biology and Chemistry, Faculty of Basic Sciences, Universidad Católica del Maule, 3480112, Talca, Chile
| | - Rafael A Fissore
- Department of Veterinary and Animal Sciences, University of Massachusetts Amherst, 661 North Pleasant Street, Amherst, MA, 01003, USA.
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36
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In vitro characterisation of calcium influx across skin and gut epithelia of the Pacific hagfish, Eptatretus stoutii. J Comp Physiol B 2020; 190:149-160. [DOI: 10.1007/s00360-020-01262-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 11/30/2019] [Accepted: 01/09/2020] [Indexed: 01/20/2023]
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37
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To KHT, Gui P, Li M, Zawieja SD, Castorena-Gonzalez JA, Davis MJ. T-type, but not L-type, voltage-gated calcium channels are dispensable for lymphatic pacemaking and spontaneous contractions. Sci Rep 2020; 10:70. [PMID: 31919478 PMCID: PMC6952455 DOI: 10.1038/s41598-019-56953-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 12/10/2019] [Indexed: 12/28/2022] Open
Abstract
The spontaneous contractions of collecting lymphatic vessels provide an essential propulsive force to return lymph centrally. These contractions are driven by an intrinsic electrical pacemaker, working through an unknown underlying ionic mechanism that becomes compromised in some forms of lymphedema. In previous studies, T-type voltage-gated Ca2+ channels (VGCCs) were implicated in this pacemaking mechanism, based on the effects of the reputedly selective T-type VGCC inhibitors mibefradil and Ni2+. Our goal was to test this idea in a more definitive way using genetic knock out mice. First, we demonstrated through both PCR and immunostaining that mouse lymphatic muscle cells expressed Cav3.1 and Cav3.2 and produced functional T-type VGCC currents when patch clamped. We then employed genetic deletion strategies to selectively test the roles of each T-type VGCC isoform in the regulation of lymphatic pacemaking. Surprisingly, global deletion of either, or both, isoform(s) was without significant effect on either the frequency, amplitude, or fractional pump flow of lymphatic collectors from two different regions of the mouse, studied ex vivo. Further, both WT and Cav3.1-/-; 3.2-/- double knock-out lymphatic vessels responded similarly to mibefradil and Ni2+, which substantially reduced contraction amplitudes and slightly increased frequencies at almost all pressures in both strains: a pattern consistent with inhibition of L-type rather than T-type VGCCs. Neither T-type VGCC isoform was required for ACh-induced inhibition of contraction, a mechanism by which those channels in smooth muscle are thought to be targets of endothelium-derived nitric oxide. Sharp intracellular electrode measurements in lymphatic smooth muscle revealed only subtle, but not significant, differences in the resting membrane potential and action potential characteristics between vessels from wild-type and Cav3.1-/-; 3.2-/- double knock-out mice. In contrast, smooth-muscle specific deletion of the L-type VGCC, Cav1.2, completely abolished all lymphatic spontaneous contractions. Collectively our results suggest that, although T-type VGCCs are expressed in mouse lymphatic smooth muscle, they do not play a significant role in modulating the frequency of the ionic pacemaker or the amplitude of spontaneous contractions. We conclude that the effects of mibefradil and Ni2+ in other lymphatic preparations are largely or completely explained by off-target effects on L-type VGCCs, which are essential for controlling both the frequency and strength of spontaneous contractions.
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MESH Headings
- Animals
- Calcium Channel Blockers/pharmacology
- Calcium Channels, L-Type/chemistry
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Calcium Channels, T-Type/deficiency
- Calcium Channels, T-Type/genetics
- Calcium Channels, T-Type/metabolism
- Lymphatic Vessels/physiology
- Male
- Membrane Potentials/drug effects
- Mibefradil/pharmacology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Muscle Contraction/drug effects
- Muscle Contraction/physiology
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/metabolism
- Nickel/pharmacology
- Pacemaker, Artificial
- Rats
- Rats, Wistar
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Affiliation(s)
- Kim H T To
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, 65212, USA
| | - Peichun Gui
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, 65212, USA
| | - Min Li
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, 65212, USA
| | - Scott D Zawieja
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, 65212, USA
| | - Jorge A Castorena-Gonzalez
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, 65212, USA
| | - Michael J Davis
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, 65212, USA.
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Soldado-Magraner S, Brandalise F, Honnuraiah S, Pfeiffer M, Moulinier M, Gerber U, Douglas R. Conditioning by subthreshold synaptic input changes the intrinsic firing pattern of CA3 hippocampal neurons. J Neurophysiol 2019; 123:90-106. [PMID: 31721636 DOI: 10.1152/jn.00506.2019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Unlike synaptic strength, intrinsic excitability is assumed to be a stable property of neurons. For example, learning of somatic conductances is generally not incorporated into computational models, and the discharge pattern of neurons in response to test stimuli is frequently used as a basis for phenotypic classification. However, it is increasingly evident that signal processing properties of neurons are more generally plastic on the timescale of minutes. Here we demonstrate that the intrinsic firing patterns of CA3 neurons of the rat hippocampus in vitro undergo rapid long-term plasticity in response to a few minutes of only subthreshold synaptic conditioning. This plasticity on the spike timing could also be induced by intrasomatic injection of subthreshold depolarizing pulses and was blocked by kinase inhibitors, indicating that discharge dynamics are modulated locally. Cluster analysis of firing patterns before and after conditioning revealed systematic transitions toward adapting and intrinsic burst behaviors, irrespective of the patterns initially exhibited by the cells. We used a conductance-based model to decide appropriate pharmacological blockade and found that the observed transitions are likely due to recruitment of low-voltage calcium and Kv7 potassium conductances. We conclude that CA3 neurons adapt their conductance profile to the subthreshold activity of their input, so that their intrinsic firing pattern is not a static signature, but rather a reflection of their history of subthreshold activity. In this way, recurrent output from CA3 neurons may collectively shape the temporal dynamics of their embedding circuits.NEW & NOTEWORTHY Although firing patterns are widely conserved across the animal phyla, it is still a mystery why nerve cells present such diversity of discharge dynamics upon somatic step currents. Adding a new timing dimension to the intrinsic plasticity literature, here we show that CA3 neurons rapidly adapt through the space of known firing patterns in response to the subthreshold signals that they receive from their embedding circuit, potentially adjusting their network processing to the temporal statistics of their circuit.
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Affiliation(s)
| | - Federico Brandalise
- Brain Research Institute, University of Zurich, Switzerland.,Department of Fundamental Neurosciences, University of Geneva, Switzerland
| | - Suraj Honnuraiah
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Switzerland
| | - Michael Pfeiffer
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Switzerland
| | - Marie Moulinier
- Department of Fundamental Neurosciences, University of Geneva, Switzerland
| | - Urs Gerber
- Brain Research Institute, University of Zurich, Switzerland
| | - Rodney Douglas
- Institute of Neuroinformatics, University of Zurich and ETH Zurich, Switzerland
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39
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Functional Specialization of Interneuron Dendrites: Identification of Action Potential Initiation Zone in Axonless Olfactory Bulb Granule Cells. J Neurosci 2019; 39:9674-9688. [PMID: 31662426 DOI: 10.1523/jneurosci.1763-19.2019] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/25/2019] [Accepted: 09/29/2019] [Indexed: 12/19/2022] Open
Abstract
Principal cells in the olfactory bulb (OB), mitral and tufted cells, play key roles in processing and then relaying sensory information to downstream cortical regions. How OB local circuits facilitate odor-specific responses during odor discrimination is not known but involves GABAergic inhibition mediated by axonless granule cells (GCs), the most abundant interneuron in the OB. Most previous work on GCs has focused on defining properties of distal apical dendrites where these interneurons form reciprocal dendrodendritic connections with principal cells. Less is known about the function of the proximal dendritic compartments. In the present study, we identified the likely action potentials (AP) initiation zone by comparing electrophysiological properties of rat (either sex) GCs with apical dendrites severed at different locations. We find that truncated GCs with long apical dendrites had active properties that were indistinguishable from intact GCs, generating full-height APs and short-latency low-threshold Ca2+ spikes. We then confirmed the presumed site of AP and low-threshold Ca2+ spike initiation in the proximal apical dendrite using two-photon Ca2+ photometry and focal TTX application. These results suggest that GCs incorporate two separate pathways for processing synaptic inputs: an already established dendrodendritic input to the distal apical dendrite and a novel pathway in which the cell body integrates proximal synaptic inputs, leading to spike generation in the proximal apical dendrite. Spikes generated by the proximal pathway likely enables GCs to regulate lateral inhibition by defining time windows when lateral inhibition is functional.SIGNIFICANCE STATEMENT The olfactory bulb plays a central role in processing sensory input transduced by receptor neurons. How local circuits in the bulb function to facilitate sensory processing during odor discrimination is not known but appears to involve inhibition mediated by granule cells, axonless GABAergic interneurons. Little is known about the active conductances in granule cells including where action potentials originate. Using a variety of experimental approaches, we find the Na+-based action potentials originate in the proximal apical dendrite, a region targeted by cortical feedback afferents. We also find evidence for high expression of low-voltage activated Ca2+ channels in the same region, intrinsic currents that enable GCs to spike rapidly in response to sensory input during each sniff cycle.
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40
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Liu Y, Cheng H, Tiersch TR. The role of alkalinization-induced Ca2+ influx in sperm motility activation of a viviparous fish Redtail Splitfin (Xenotoca eiseni). Biol Reprod 2019; 99:1159-1170. [PMID: 29982498 DOI: 10.1093/biolre/ioy150] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 06/28/2018] [Indexed: 11/13/2022] Open
Abstract
Mechanisms regulating sperm motility activation are generally known in oviparous fishes, but are poorly understood in viviparous species. The mechanism of osmotic-shock induced signaling for oviparous fishes is not suitable for viviparous fishes which activate sperm motility within an isotonic environment. In addition, the presence of sperm bundles in viviparous fishes further complicates study of sperm activation mechanisms. The goal of this study was to establish methodologies to detect intracellular Ca2+ signals from sperm cells within bundles, and to investigate the signaling mechanism of sperm activation of viviparous fish using Redtail Splitfin (Xenotoca eiseni) as a model. Motility was assessed by classification of bundle dissociation and computer-assisted sperm analysis, and intracellular Ca2+ was assessed using the fluorescent probe Fura-2 AM. Bundle dissociation and sperm motility increased with extracellular Ca2+ and pH levels. Intracellular Ca2+ signals were detected from sperm within bundles, and increased significantly with extracellular Ca2+ and pH levels. Major channel blockers known to inhibit Ca2+ influx (NiCl2, ruthenium red, GdCl3, SKF-96365, nimodipine, verapamil, methoxyverapamil, mibefradil, NNC 55-0396, ω-Conotoxin MVIIC, bepridil, and 2-APB) failed to inhibit Ca2+ influx, except for CdCl2, which partially inhibited the influx. We propose a novel mechanism for motility regulation of fish sperm: an alkaline environment in the female reproductive tract opens Ca2+ channels in the sperm plasma membrane without osmotic shock, and the Ca2+ influx functions as a second messenger to activate motor proteins controlling flagella movement.
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Affiliation(s)
- Yue Liu
- Aquatic Germplasm and Genetic Resources Center, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, USA
| | - Henrique Cheng
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana, USA
| | - Terrence R Tiersch
- Aquatic Germplasm and Genetic Resources Center, School of Renewable Natural Resources, Louisiana State University Agricultural Center, Baton Rouge, Louisiana, USA
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Dumenieu M, Senkov O, Mironov A, Bourinet E, Kreutz MR, Dityatev A, Heine M, Bikbaev A, Lopez-Rojas J. The Low-Threshold Calcium Channel Cav3.2 Mediates Burst Firing of Mature Dentate Granule Cells. Cereb Cortex 2019; 28:2594-2609. [PMID: 29790938 PMCID: PMC5998957 DOI: 10.1093/cercor/bhy084] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2018] [Indexed: 12/11/2022] Open
Abstract
Mature granule cells are poorly excitable neurons that were recently shown to fire action potentials, preferentially in bursts. It is believed that the particularly pronounced short-term facilitation of mossy fiber synapses makes granule cell bursting a very effective means of properly transferring information to CA3. However, the mechanism underlying the unique bursting behavior of mature granule cells is currently unknown. Here, we show that Cav3.2 T-type channels at the axon initial segment are responsible for burst firing of mature granule cells in rats and mice. Accordingly, Cav3.2 knockout mice fire tonic spikes and exhibit impaired bursting, synaptic plasticity and dentate-to-CA3 communication. The data show that Cav3.2 channels are strong modulators of bursting and can be considered a critical molecular switch that enables effective information transfer from mature granule cells to the CA3 pyramids.
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Affiliation(s)
- Mael Dumenieu
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
| | - Oleg Senkov
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Andrey Mironov
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.,Lobachevsky State University of Nizhny Novgorod, Nizhny Novgorod, Russia.,Privolzhsky Research Medical University, Nizhny Novgorod, Russia
| | - Emmanuel Bourinet
- Calcium Channel Dynamics & Nociception Group, Institute of Functional Genomics, Montpellier, France
| | - Michael R Kreutz
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany.,Leibniz Group "Dendritic Organelles and Synaptic Function," University Medical Center Hamburg-Eppendorf, Center for Molecular Neurobiology (ZMNH), Hamburg, Germany
| | - Alexander Dityatev
- Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany.,Medical Faculty, Otto-von-Guericke University, Magdeburg, Germany
| | - Martin Heine
- Research Group Molecular Physiology, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
| | - Arthur Bikbaev
- Research Group Molecular Physiology, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
| | - Jeffrey Lopez-Rojas
- Research Group Neuroplasticity, Leibniz Institute for Neurobiology, Brenneckestr. 6, Magdeburg, Germany
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Mustafá ER, Cordisco Gonzalez S, Raingo J. Ghrelin Selectively Inhibits CaV3.3 Subtype of Low-Voltage-Gated Calcium Channels. Mol Neurobiol 2019; 57:722-735. [DOI: 10.1007/s12035-019-01738-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 08/16/2019] [Indexed: 01/01/2023]
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Disruption of GpI mGluR-Dependent Cav2.3 Translation in a Mouse Model of Fragile X Syndrome. J Neurosci 2019; 39:7453-7464. [PMID: 31350260 DOI: 10.1523/jneurosci.1443-17.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Revised: 06/13/2019] [Accepted: 06/19/2019] [Indexed: 11/21/2022] Open
Abstract
Fragile X syndrome (FXS) is an inherited intellectual impairment that results from the loss of fragile X mental retardation protein (FMRP), an mRNA binding protein that regulates mRNA translation at synapses. The absence of FMRP leads to neuronal and circuit-level hyperexcitability that is thought to arise from the aberrant expression and activity of voltage-gated ion channels, although the identification and characterization of these ion channels have been limited. Here, we show that FMRP binds the mRNA of the R-type voltage-gated calcium channel Cav2.3 in mouse brain synaptoneurosomes and represses Cav2.3 translation under basal conditions. Consequently, in hippocampal neurons from male and female FMRP KO mice, we find enhanced Cav2.3 protein expression by western blotting and abnormally large R currents in whole-cell voltage-clamp recordings. In agreement with previous studies showing that FMRP couples Group I metabotropic glutamate receptor (GpI mGluR) signaling to protein translation, we find that GpI mGluR stimulation results in increased Cav2.3 translation and R current in hippocampal neurons which is disrupted in FMRP KO mice. Thus, FMRP serves as a key translational regulator of Cav2.3 expression under basal conditions and in response to GpI mGluR stimulation. Loss of regulated Cav2.3 expression could underlie the neuronal hyperactivity and aberrant calcium spiking in FMRP KO mice and contribute to FXS, potentially serving as a novel target for future therapeutic strategies.SIGNIFICANCE STATEMENT Patients with fragile X syndrome (FXS) exhibit signs of neuronal and circuit hyperexcitability, including anxiety and hyperactive behavior, attention deficit disorder, and seizures. FXS is caused by the loss of fragile X mental retardation protein (FMRP), an mRNA binding protein, and the neuronal hyperexcitability observed in the absence of FMRP likely results from its ability to regulate the expression and activity of voltage-gated ion channels. Here we find that FMRP serves as a key translational regulator of the voltage-gated calcium channel Cav2.3 under basal conditions and following activity. Cav2.3 impacts cellular excitability and calcium signaling, and the alterations in channel translation and expression observed in the absence of FMRP could contribute to the neuronal hyperactivity that underlies FXS.
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Intracerebroventricular administration of histidine reduces kainic acid-induced convulsive seizures in mice. Exp Brain Res 2019; 237:2481-2493. [PMID: 31321447 DOI: 10.1007/s00221-019-05605-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/13/2019] [Indexed: 11/27/2022]
Abstract
Kainic acid (KA)-induced seizures and other experimental models of epilepsy have been proven to be instrumental in identifying novel targets that could be responsible for human icto- and epileptogenesis. We have previously shown that the ablation of pharmacoresistant voltage-gated Ca2+ channels with Cav2.3 as central ion-conducting pore (R-type Ca2+ channel) reduces the sensitivity towards KA-induced epilepsy in mice. In vivo, Cav2.3 channels are thought to be under tight allosteric control by endogenous loosely bound trace metal cations (Zn2+ and Cu2+) that suppress channel gating via a high-affinity trace metal-binding site. Metal dyshomeostasis in the brain, which is a common feature of (KA-induced) seizures, could therefore alter the normal function of Cav2.3 channels and may shift hippocampal and neocortical signaling towards hyperexcitation. To investigate the role of loosely bound metal ions for KA-induced hyperexcitation in vivo, we examined the effects of manipulating brain trace metal homeostasis in mice. To this end, we developed a murine system for intracerebroventricular administration of trace metal ions and/or histidine (His), which can bind Zn2+ and Cu2+ and is involved in their transendothelial transport at the blood-brain barrier. Unexpectedly, our preliminary findings indicate that application of His alone but not in the presence of Zn2+ has substantial beneficial effects on the outcome of KA-induced epilepsy in mice. As such, our results emphasize previous findings on the complex, two-sided role of loosely bound metal ions with regard to neuronal excitation and degeneration under pathophysiological conditions.
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McNally BA, Plante AE, Meredith AL. Diurnal properties of voltage-gated Ca 2+ currents in suprachiasmatic nucleus and roles in action potential firing. J Physiol 2019; 598:1775-1790. [PMID: 31177540 DOI: 10.1113/jp278327] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 06/06/2019] [Indexed: 02/04/2023] Open
Abstract
KEY POINTS Circadian oscillations in spontaneous action potential firing in the suprachiasmatic nucleus (SCN) translate time-of-day throughout the mammalian brain. The ion channels that regulate the circadian pattern of SCN firing have not been comprehensively identified. Ca2+ channels regulate action potential activity across many types of excitable cells, and the activity of L-, N-, P/Q- and R-type channels are required for normal daytime firing frequency in SCN neurons and circuit rhythms. Only the L-type Ca2+ current exhibits a day versus night difference in current magnitude, providing insight into the mechanism that produces rhythmic action potential firing in SCN. ABSTRACT The mammalian circadian clock encodes time via rhythmic action potential activity in the suprachiasmatic nucleus (SCN) of the hypothalamus, which governs daily rhythms in physiology and behaviour. SCN neurons exhibit 24 h oscillations in spontaneous firing, with higher firing during day compared to night. Several ionic currents have been identified that regulate SCN firing, including voltage-gated Ca2+ currents, but the circadian regulation of distinct voltage-gated Ca2+ channel (VGCC) components has not been comprehensively addressed. In this study, whole-cell L- (nimodipine-sensitive), N- and P/Q- (ω-agatoxin IVA, ω-conotoxin GVIA, ω-conotoxin MVIIC-sensitive), R- (Ni2+ -sensitive) and T-type (TTA-P2-sensitive) currents were recorded from day and night SCN slices. Using standard voltage protocols, Ni2+ -sensitive currents comprised the largest proportion of total VGCC current, followed by nimodipine-, ω-agatoxin IVA-, ω-conotoxin GVIA- and TTA-P2-sensitive currents. Only the nimodipine-sensitive current exhibited a diurnal difference in magnitude, with daytime current larger than night. No diurnal variation was observed for the other Ca2+ current subtypes. The difference in nimodipine-sensitive current was due to larger peak current activated during the day, not differences in inactivation, and was eliminated by Bay K8644. Blocking L-type channels decreased firing selectively during the day, consistent with higher current magnitudes, and reduced SCN circuit rhythmicity recorded by multi-electrode arrays. Yet blocking N-, P/Q- and R-type channels also decreased daytime firing, with little effect at night, and decreased circuit rhythmicity. These data identify a unique diurnal regulation of L-type current among the major VGCC subtypes in SCN neurons, but also reveal that diurnal modulation is not required for time-of-day-specific effects on firing and circuit rhythmicity.
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Affiliation(s)
- Beth A McNally
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Amber E Plante
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Andrea L Meredith
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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Lazzaro M, Krapf D, García Véscovi E. Selective blockage of Serratia marcescens ShlA by nickel inhibits the pore-forming toxin-mediated phenotypes in eukaryotic cells. Cell Microbiol 2019; 21:e13045. [PMID: 31099073 DOI: 10.1111/cmi.13045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 04/29/2019] [Accepted: 05/08/2019] [Indexed: 12/29/2022]
Abstract
Serratia marcescens is an opportunistic pathogen with increasing incidence in clinical settings. This is mainly attributed to the timely expression of a wide diversity of virulence factors and intrinsic and acquired resistance to antibiotics, including β-lactams, aminoglycosides, quinolones, and polypeptides. For these reasons, S. marcescens has been recently categorised by the World Health Organization as one priority to strengthen efforts directed to develop new antibacterial agents. Therefore, it becomes critical to understand the underlying mechanisms that allow Serratia to succeed within the host. S. marcescens ShlA pore-forming toxin mediates phenotypes that alter homeostatic and signal transduction pathways of host cells. It has been previously demonstrated that ShlA provokes cytotoxicity, haemolysis and autophagy and also directs Serratia egress and dissemination from invaded nonphagocytic cells. However, molecular details of ShlA mechanism of action are still not fully elucidated. In this work, we demonstrate that Ni2+ selectively and reversibly blocks ShlA action, turning wild-type S. marcescens into a shlA mutant strain phenocopy. Combined use of Ni2+ and calcium chelators allow to discern ShlA-triggered phenotypes that require intracellular calcium mobilisation and reveal ShlA function as a calcium channel, providing new insights into ShlA mode of action on target cells.
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Affiliation(s)
- Martina Lazzaro
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Darío Krapf
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Eleonora García Véscovi
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Universidad Nacional de Rosario, Rosario, Argentina
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Izumisawa Y, Tanaka-Yamamoto K, Ciriello J, Kitamura N, Shibuya I. Persistent cytosolic Ca 2+ increase induced by angiotensin II at nanomolar concentrations in acutely dissociated subfornical organ (SFO) neurons of rats. Brain Res 2019; 1718:137-147. [PMID: 31085158 DOI: 10.1016/j.brainres.2019.05.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 04/23/2019] [Accepted: 05/11/2019] [Indexed: 10/26/2022]
Abstract
It is known that angiotensin II (AII) is sensed by subfornical organ (SFO) to induce drinking behaviors and autonomic changes. AII at picomolar concentrations have been shown to induce Ca2+ oscillations and increase in the amplitude and frequency of spontaneous Ca2+ oscillations in SFO neurons. The present study was conducted to examine effects of nanomolar concentrations of AII using the Fura-2 Ca2+-imaging technique in acutely dissociated SFO neurons. AII at nanomolar concentrations induced an initial [Ca2+]i peak followed by a persistent [Ca2+]i increase lasting for longer than 1 hour. By contrast, [Ca2+]i responses to 50 mM K+, maximally effective concentrations of glutamate, carbachol, and vasopressin, and AII given at picomolar concentrations returned to the basal level within 20 min. The AII-induced [Ca2+]i increase was blocked by the AT1 antagonist losartan. However, losartan had no effect when added during the persistent phase. The persistent phase was suppressed by extracellular Ca2+ removal, significantly inhibited by blockers of L and P/Q type Ca2+ channels , but unaffected by inhibition of Ca2+ store Ca2+ ATPase. The persistent phase was reversibly suppressed by GABA and inhibited by CaMK and PKC inhibitors. These results suggest that the persistent [Ca2+]i increase evoked by nanomolar concentrations of AII is initiated by AT1 receptor activation and maintained by Ca2+ entry mechanisms in part through L and P/Q type Ca2+ channels, and that CaMK and PKC are involved in this process. The persistent [Ca2+]i increase induced by AII at high pathophysiological levels may have a significant role in altering SFO neuronal functions.
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Affiliation(s)
- Yu Izumisawa
- Department of Veterinary Physiology, Faculty of Agriculture, Tottori University, Tottori 680-0945, Japan
| | - Keiko Tanaka-Yamamoto
- Center for Functional Connectomics, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea
| | - John Ciriello
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Naoki Kitamura
- Department of Veterinary Physiology, Faculty of Agriculture, Tottori University, Tottori 680-0945, Japan
| | - Izumi Shibuya
- Department of Veterinary Physiology, Faculty of Agriculture, Tottori University, Tottori 680-0945, Japan.
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Lyu K, Wang X, Wang L, Wang G. Rare-earth element yttrium enhances the tolerance of curly-leaf pondweed (Potamogeton crispus) to acute nickel toxicity. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 248:114-120. [PMID: 30784830 DOI: 10.1016/j.envpol.2019.01.120] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 11/08/2018] [Accepted: 01/30/2019] [Indexed: 06/09/2023]
Abstract
Nickel is a ubiquitous heavy-metal pollutant in lakes and severely affects aquatic organisms. Aquatic plants are often initially linked to having heavy metal contents and further are proposed as phytoremediation agent to remove heavy metal from water. Although the toxic effects of nickel on aquatic plants are thoroughly explored, the effective investigation to increase Ni tolerance is still in its infancy. The role of rare-earth elements (REEs) in plant resisting heavy-metal pollution has recently received considerable interest. To explore the physiological effects of REEs on Potamogeton crispus under Ni stress, we explored whether or not the additive exposure to low-dose yttrium (Y; 2.5 μM) promotes the polyamine metabolism, antioxidation, and photosynthesis performance of P. crispus under Ni stress values of 0, 50, 100, 150, and 200 μM. Results showed that Y exposure did not influence Ni bioaccumulation in P. crispus. Furthermore, Y exposure alleviated the adverse effects of Ni stress to convergent degrees because Y positively converts putrescine into spermidine and spermine, inhibits oxidative stress, increases the total chlorophyll content, and maximum/potential quantum efficiency of photosystem II. We concluded that low-dose Y can positively regulate polyamine transformation, inhibit oxidative stress, stimulate photosynthesis, and finally promote the resist ability of P. crispus to nickel stress. Thus, REEs have potential to be applied in regulating submerged plant tolerance to aquatic heavy-metal pollution.
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Affiliation(s)
- Kai Lyu
- School of Environment, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China; Freshwater Fisheries Research Institute of Jiangsu Province, Nanjing, 210017, China.
| | - Xuan Wang
- School of Environment, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Lei Wang
- School of Environment, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China
| | - Guoxiang Wang
- School of Environment, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
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Wang L, Vanacker C, Burger LL, Barnes T, Shah YM, Myers MG, Moenter SM. Genetic dissection of the different roles of hypothalamic kisspeptin neurons in regulating female reproduction. eLife 2019; 8:e43999. [PMID: 30946012 PMCID: PMC6491090 DOI: 10.7554/elife.43999] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 04/02/2019] [Indexed: 12/12/2022] Open
Abstract
The brain regulates fertility through gonadotropin-releasing hormone (GnRH) neurons. Estradiol induces negative feedback on pulsatile GnRH/luteinizing hormone (LH) release and positive feedback generating preovulatory GnRH/LH surges. Negative and positive feedbacks are postulated to be mediated by kisspeptin neurons in arcuate and anteroventral periventricular (AVPV) nuclei, respectively. Kisspeptin-specific ERα knockout mice exhibit disrupted LH pulses and surges. This knockout approach is neither location-specific nor temporally controlled. We utilized CRISPR-Cas9 to disrupt ERα in adulthood. Mice with ERα disruption in AVPV kisspeptin neurons have typical reproductive cycles but blunted LH surges, associated with decreased excitability of these neurons. Mice with ERα knocked down in arcuate kisspeptin neurons showed disrupted cyclicity, associated with increased glutamatergic transmission to these neurons. These observations suggest that activational effects of estradiol regulate surge generation and maintain cyclicity through AVPV and arcuate kisspeptin neurons, respectively, independent from its role in the development of hypothalamic kisspeptin neurons or puberty onset.
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Affiliation(s)
- Luhong Wang
- Department of Molecular and Integrative PhysiologyUniversity of MichiganAnn ArborUnited States
| | - Charlotte Vanacker
- Department of Molecular and Integrative PhysiologyUniversity of MichiganAnn ArborUnited States
| | - Laura L Burger
- Department of Molecular and Integrative PhysiologyUniversity of MichiganAnn ArborUnited States
| | - Tammy Barnes
- Department of Internal MedicineUniversity of MichiganAnn ArborUnited States
| | - Yatrik M Shah
- Department of Molecular and Integrative PhysiologyUniversity of MichiganAnn ArborUnited States
| | - Martin G Myers
- Department of Molecular and Integrative PhysiologyUniversity of MichiganAnn ArborUnited States
- Department of Internal MedicineUniversity of MichiganAnn ArborUnited States
| | - Suzanne M Moenter
- Department of Internal MedicineUniversity of MichiganAnn ArborUnited States
- Department of Obstetrics & GynecologyUniversity of MichiganAnn ArborUnited States
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The MAP1B Binding Domain of Na v1.6 Is Required for Stable Expression at the Axon Initial Segment. J Neurosci 2019; 39:4238-4251. [PMID: 30914445 DOI: 10.1523/jneurosci.2771-18.2019] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 03/14/2019] [Accepted: 03/17/2019] [Indexed: 12/22/2022] Open
Abstract
Nav1.6 (SCN8A) is a major voltage-gated sodium channel in the mammalian CNS, and is highly concentrated at the axon initial segment (AIS). As previously demonstrated, the microtubule associated protein MAP1B binds the cytoplasmic N terminus of Nav1.6, and this interaction is disrupted by the mutation p.VAVP(77-80)AAAA. We now demonstrate that this mutation results in WT expression levels on the somatic surface but reduced surface expression at the AIS of cultured rat embryonic hippocampal neurons from both sexes. The mutation of the MAP1B binding domain did not impair vesicular trafficking and preferential delivery of Nav1.6 to the AIS; nor was the diffusion of AIS inserted channels altered relative to WT. However, the reduced AIS surface expression of the MAP1B mutant was restored to WT levels by inhibiting endocytosis with Dynasore, indicating that compartment-specific endocytosis was responsible for the lack of AIS accumulation. Interestingly, the lack of AIS targeting resulted in an elevated percentage of persistent current, suggesting that this late current originates predominantly in the soma. No differences in the voltage dependence of activation or inactivation were detected in the MAP1B binding mutant relative to WT channel. We hypothesize that MAP1B binding to the WT Nav1.6 masks an endocytic motif, thus allowing long-term stability on the AIS surface. This work identifies a critical and important new role for MAP1B in the regulation of neuronal excitability and adds to our understanding of AIS maintenance and plasticity, in addition to identifying new target residues for pathogenic mutations of SCN8A SIGNIFICANCE STATEMENT Nav1.6 is a major voltage-gated sodium channel in human brain, where it regulates neuronal activity due to its localization at the axon initial segment (AIS). Nav1.6 mutations cause epilepsy, intellectual disability, and movement disorders. In the present work, we show that loss of interaction with MAP1B within the Nav1.6 N terminus reduces the steady-state abundance of Nav1.6 at the AIS. The effect is due to increased Nav1.6 endocytosis at this neuronal compartment rather than a failure of forward trafficking to the AIS. This work confirms a new biological role of MAP1B in the regulation of sodium channel localization and will contribute to future analysis of patient mutations in the cytoplasmic N terminus of Nav1.6.
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