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Li B, Zhao A, Tian T, Yang X. Mechanobiological insight into brain diseases based on mechanosensitive channels: Common mechanisms and clinical potential. CNS Neurosci Ther 2024; 30:e14809. [PMID: 38923822 PMCID: PMC11197048 DOI: 10.1111/cns.14809] [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: 02/28/2024] [Revised: 05/15/2024] [Accepted: 06/02/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND As physical signals, mechanical cues regulate the neural cells in the brain. The mechanosensitive channels (MSCs) perceive the mechanical cues and transduce them by permeating specific ions or molecules across the plasma membrane, and finally trigger a series of intracellular bioelectrical and biochemical signals. Emerging evidence supports that wide-distributed, high-expressed MSCs like Piezo1 play important roles in several neurophysiological processes and neurological disorders. AIMS To systematically conclude the functions of MSCs in the brain and provide a novel mechanobiological perspective for brain diseases. METHOD We summarized the mechanical cues and MSCs detected in the brain and the research progress on the functional roles of MSCs in physiological conditions. We then concluded the pathological activation and downstream pathways triggered by MSCs in two categories of brain diseases, neurodegenerative diseases and place-occupying damages. Finally, we outlined the methods for manipulating MSCs and discussed their medical potential with some crucial outstanding issues. RESULTS The MSCs present underlying common mechanisms in different brain diseases by acting as the "transportation hubs" to transduce the distinct signal patterns: the upstream mechanical cues and the downstream intracellular pathways. Manipulating the MSCs is feasible to alter the complicated downstream processes, providing them promising targets for clinical treatment. CONCLUSIONS Recent research on MSCs provides a novel insight into brain diseases. The common mechanisms mediated by MSCs inspire a wide range of therapeutic potentials targeted on MSCs in different brain diseases.
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Affiliation(s)
- Bolong Li
- Shenzhen Key Laboratory of Translational Research for Brain Diseases, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdongChina
- College of Life SciencesUniversity of Chinese Academy of ScienceBeijingChina
| | - An‐ran Zhao
- Shenzhen Key Laboratory of Translational Research for Brain Diseases, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdongChina
- College of Life SciencesUniversity of Chinese Academy of ScienceBeijingChina
- Faculty of Life and Health SciencesShenzhen University of Advanced TechnologyShenzhenGuangdongChina
| | - Tian Tian
- Shenzhen Key Laboratory of Translational Research for Brain Diseases, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdongChina
- Faculty of Life and Health SciencesShenzhen University of Advanced TechnologyShenzhenGuangdongChina
| | - Xin Yang
- Shenzhen Key Laboratory of Translational Research for Brain Diseases, the Brain Cognition and Brain Disease Institute, Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdongChina
- Faculty of Life and Health SciencesShenzhen University of Advanced TechnologyShenzhenGuangdongChina
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2
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Davis MJ, Zawieja SD. Pacemaking in the lymphatic system. J Physiol 2024. [PMID: 38520402 DOI: 10.1113/jp284752] [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: 11/30/2023] [Accepted: 02/08/2024] [Indexed: 03/25/2024] Open
Abstract
Lymphatic collecting vessels exhibit spontaneous phasic contractions that are critical for lymph propulsion and tissue fluid homeostasis. This rhythmic activity is driven by action potentials conducted across the lymphatic muscle cell (LMC) layer to produce entrained contractions. The contraction frequency of a lymphatic collecting vessel displays exquisite mechanosensitivity, with a dynamic range from <1 to >20 contractions per minute. A myogenic pacemaker mechanism intrinsic to the LMCs was initially postulated to account for pressure-dependent chronotropy. Further interrogation into the cellular constituents of the lymphatic vessel wall identified non-muscle cell populations that shared some characteristics with interstitial cells of Cajal, which have pacemaker functions in the gastrointestinal and lower urinary tracts, thus raising the possibility of a non-muscle cell pacemaker. However, recent genetic knockout studies in mice support LMCs and a myogenic origin of the pacemaker activity. LMCs exhibit stochastic, but pressure-sensitive, sarcoplasmic reticulum calcium release (puffs and waves) from IP3R1 receptors, which couple to the calcium-activated chloride channel Anoctamin 1, causing depolarisation. The resulting electrical activity integrates across the highly coupled lymphatic muscle electrical syncytia through connexin 45 to modulate diastolic depolarisation. However, multiple other cation channels may also contribute to the ionic pacemaking cycle. Upon reaching threshold, a voltage-gated calcium channel-dependent action potential fires, resulting in a nearly synchronous calcium global calcium flash within the LMC layer to drive an entrained contraction. This review summarizes the key ion channels potentially responsible for the pressure-dependent chronotropy of lymphatic collecting vessels and various mechanisms of IP3R1 regulation that could contribute to frequency tuning.
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Affiliation(s)
- Michael J Davis
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO, USA
| | - Scott D Zawieja
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO, USA
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3
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Davis MJ, Earley S, Li YS, Chien S. Vascular mechanotransduction. Physiol Rev 2023; 103:1247-1421. [PMID: 36603156 PMCID: PMC9942936 DOI: 10.1152/physrev.00053.2021] [Citation(s) in RCA: 50] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 09/26/2022] [Accepted: 10/04/2022] [Indexed: 01/07/2023] Open
Abstract
This review aims to survey the current state of mechanotransduction in vascular smooth muscle cells (VSMCs) and endothelial cells (ECs), including their sensing of mechanical stimuli and transduction of mechanical signals that result in the acute functional modulation and longer-term transcriptomic and epigenetic regulation of blood vessels. The mechanosensors discussed include ion channels, plasma membrane-associated structures and receptors, and junction proteins. The mechanosignaling pathways presented include the cytoskeleton, integrins, extracellular matrix, and intracellular signaling molecules. These are followed by discussions on mechanical regulation of transcriptome and epigenetics, relevance of mechanotransduction to health and disease, and interactions between VSMCs and ECs. Throughout this review, we offer suggestions for specific topics that require further understanding. In the closing section on conclusions and perspectives, we summarize what is known and point out the need to treat the vasculature as a system, including not only VSMCs and ECs but also the extracellular matrix and other types of cells such as resident macrophages and pericytes, so that we can fully understand the physiology and pathophysiology of the blood vessel as a whole, thus enhancing the comprehension, diagnosis, treatment, and prevention of vascular diseases.
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Affiliation(s)
- Michael J Davis
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Scott Earley
- Department of Pharmacology, University of Nevada, Reno, Nevada
| | - Yi-Shuan Li
- Department of Bioengineering, University of California, San Diego, California
- Institute of Engineering in Medicine, University of California, San Diego, California
| | - Shu Chien
- Department of Bioengineering, University of California, San Diego, California
- Institute of Engineering in Medicine, University of California, San Diego, California
- Department of Medicine, University of California, San Diego, California
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4
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Abstract
Pericytes, attached to the surface of capillaries, play an important role in regulating local blood flow. Using optogenetic tools and genetically encoded reporters in conjunction with confocal and multiphoton imaging techniques, the 3D structure, anatomical organization, and physiology of pericytes have recently been the subject of detailed examination. This work has revealed novel functions of pericytes and morphological features such as tunneling nanotubes in brain and tunneling microtubes in heart. Here, we discuss the state of our current understanding of the roles of pericytes in blood flow control in brain and heart, where functions may differ due to the distinct spatiotemporal metabolic requirements of these tissues. We also outline the novel concept of electro-metabolic signaling, a universal mechanistic framework that links tissue metabolic state with blood flow regulation by pericytes and vascular smooth muscle cells, with capillary KATP and Kir2.1 channels as primary sensors. Finally, we present major unresolved questions and outline how they can be addressed.
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Affiliation(s)
- Thomas A Longden
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Neurovascular Interactions, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Guiling Zhao
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Molecular Cardiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ashwini Hariharan
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Neurovascular Interactions, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - W Jonathan Lederer
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA; ,
- Laboratory of Molecular Cardiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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5
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Hurley M, Kaur S, Walton R, Power A, Haïssaguerre M, Bernus O, Ward ML, White E. Endocardial role in arrhythmias induced by acute ventricular stretch and the involvement of Purkinje fibres, in isolated rat hearts. Curr Res Physiol 2023; 6:100098. [PMID: 36814643 PMCID: PMC9939534 DOI: 10.1016/j.crphys.2023.100098] [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: 10/21/2022] [Revised: 01/13/2023] [Accepted: 01/25/2023] [Indexed: 02/04/2023] Open
Abstract
Purkinje fibres (PFs) play an important role in some ventricular arrhythmias and acute ventricular stretch can evoke mechanically-induced arrhythmias. We tested whether PFs and specifically TRPM4 channels, play a role in these mechanically-induced arrhythmias. Pseudo-ECGs and left ventricular (LV) activation, measured by optical mapping, were recorded in isolated, Langendorff-perfused, rat hearts. The LV endocardial surface was irrigated with experimental agents, via an indwelling catheter. The number and period of ectopic activations was measured during LV lumen inflation via an indwelling fluid-filled balloon (100 μL added over 2 s, maintained for 38 s). Mechanically-induced arrhythmias occurred during balloon inflation: they were multifocal, maximal in the first 5 s and ceased within 20 s. Optical mapping revealed activation patterns indicating PF-mediated and ectopic focal sources. Irrigation of the LV lumen with Lugol solution (IK/I2) for 10s reduced ectopics by 93% (n = 16, P < 0.001); with ablation of endocardial PFs confirmed by histology. Five min irrigation of the LV lumen with 50 μM 9-Phenanthrol, a blocker of TRPM4 channels, reduced ectopics by 39% (n = 15, P < 0.01). Immunohistochemistry confirmed that TRPM4 was more abundant in PFs than myocardium. Our results show that the endocardial surface plays an important role in these mechanically-induced ectopic activations. Ectopic activation patterns indicate a participation of PFs in these arrhythmias, with a potential involvement of TRPM4 channels, shown by the reduction of arrhythmias by 9-Phenanthrol.
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Affiliation(s)
- Miriam Hurley
- School of Biomedical Sciences, University of Leeds, Leeds, UK
| | - Sarbjot Kaur
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Richard Walton
- Université Bordeaux, INSERM Centre de recherche Cardio-Thoracique de Bordeaux, Pessac, Bordeaux, France,IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation, Bordeaux Université, Pessac, Bordeaux, France
| | - Amelia Power
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Michel Haïssaguerre
- Université Bordeaux, INSERM Centre de recherche Cardio-Thoracique de Bordeaux, Pessac, Bordeaux, France,IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation, Bordeaux Université, Pessac, Bordeaux, France,Bordeaux University Hospital (CHU), Electrophysiology and Ablation Unit, Pessac, France
| | - Olivier Bernus
- Université Bordeaux, INSERM Centre de recherche Cardio-Thoracique de Bordeaux, Pessac, Bordeaux, France,IHU Liryc, Electrophysiology and Heart Modeling Institute, Fondation, Bordeaux Université, Pessac, Bordeaux, France
| | - Marie-Louise Ward
- Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Ed White
- School of Biomedical Sciences, University of Leeds, Leeds, UK,Corresponding author. Garstang Building, School of Biomedical Sciences, University of Leeds, LS29JT, Leeds, UK.
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6
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Yang H, Tenorio Lopes L, Barioni NO, Roeske J, Incognito AV, Baker J, Raj SR, Wilson RJA. The molecular makeup of peripheral and central baroreceptors: stretching a role for Transient Receptor Potential (TRP), Epithelial Sodium Channel (ENaC), Acid Sensing Ion Channel (ASIC), and Piezo channels. Cardiovasc Res 2022; 118:3052-3070. [PMID: 34734981 DOI: 10.1093/cvr/cvab334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 09/27/2021] [Accepted: 10/29/2021] [Indexed: 12/16/2022] Open
Abstract
The autonomic nervous system maintains homeostasis of cardiovascular, respiratory, gastrointestinal, urinary, immune, and thermoregulatory function. Homeostasis involves a variety of feedback mechanisms involving peripheral afferents, many of which contain molecular receptors sensitive to mechanical deformation, termed mechanosensors. Here, we focus on the molecular identity of mechanosensors involved in the baroreflex control of the cardiovascular system. Located within the walls of the aortic arch and carotid sinuses, and/or astrocytes in the brain, these mechanosensors are essential for the rapid moment-to-moment feedback regulation of blood pressure (BP). Growing evidence suggests that these mechanosensors form a co-existing system of peripheral and central baroreflexes. Despite the importance of these molecules in cardiovascular disease and decades of research, their precise molecular identity remains elusive. The uncertainty surrounding the identity of these mechanosensors presents a major challenge in understanding basic baroreceptor function and has hindered the development of novel therapeutic targets for conditions with known arterial baroreflex impairments. Therefore, the purpose of this review is to (i) provide a brief overview of arterial and central baroreflex control of BP, (ii) review classes of ion channels currently proposed as the baroreflex mechanosensor, namely Transient Receptor Potential (TRP), Epithelial Sodium Channel (ENaC), Acid Sensing Ion Channel (ASIC), and Piezo, along with additional molecular candidates that serve mechanotransduction in other organ systems, and (iii) summarize the potential clinical implications of impaired baroreceptor function in the pathophysiology of cardiovascular disease.
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Affiliation(s)
- Hannah Yang
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Luana Tenorio Lopes
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Nicole O Barioni
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Jamie Roeske
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Anthony V Incognito
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Jacquie Baker
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Satish R Raj
- Department of Cardiac Sciences, Libin Cardiovascular Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
| | - Richard J A Wilson
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada.,Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, 3330 Hospital Dr. N.W., Calgary, AB T2N4N1, Canada
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7
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King DR, Sedovy MW, Eaton X, Dunaway LS, Good ME, Isakson BE, Johnstone SR. Cell-To-Cell Communication in the Resistance Vasculature. Compr Physiol 2022; 12:3833-3867. [PMID: 35959755 DOI: 10.1002/cphy.c210040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The arterial vasculature can be divided into large conduit arteries, intermediate contractile arteries, resistance arteries, arterioles, and capillaries. Resistance arteries and arterioles primarily function to control systemic blood pressure. The resistance arteries are composed of a layer of endothelial cells oriented parallel to the direction of blood flow, which are separated by a matrix layer termed the internal elastic lamina from several layers of smooth muscle cells oriented perpendicular to the direction of blood flow. Cells within the vessel walls communicate in a homocellular and heterocellular fashion to govern luminal diameter, arterial resistance, and blood pressure. At rest, potassium currents govern the basal state of endothelial and smooth muscle cells. Multiple stimuli can elicit rises in intracellular calcium levels in either endothelial cells or smooth muscle cells, sourced from intracellular stores such as the endoplasmic reticulum or the extracellular space. In general, activation of endothelial cells results in the production of a vasodilatory signal, usually in the form of nitric oxide or endothelial-derived hyperpolarization. Conversely, activation of smooth muscle cells results in a vasoconstriction response through smooth muscle cell contraction. © 2022 American Physiological Society. Compr Physiol 12: 1-35, 2022.
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Affiliation(s)
- D Ryan King
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA
| | - Meghan W Sedovy
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA.,Translational Biology, Medicine, and Health Graduate Program, Virginia Tech, Blacksburg, Virginia, USA
| | - Xinyan Eaton
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA
| | - Luke S Dunaway
- Robert M. Berne Cardiovascular Research Centre, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Miranda E Good
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Brant E Isakson
- Robert M. Berne Cardiovascular Research Centre, University of Virginia School of Medicine, Charlottesville, Virginia, USA.,Department of Molecular Physiology and Biophysics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Scott R Johnstone
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Center for Vascular and Heart Research, Virginia Tech, Roanoke, Virginia, USA.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
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Burboa PC, Puebla M, Gaete PS, Durán WN, Lillo MA. Connexin and Pannexin Large-Pore Channels in Microcirculation and Neurovascular Coupling Function. Int J Mol Sci 2022; 23:ijms23137303. [PMID: 35806312 PMCID: PMC9266979 DOI: 10.3390/ijms23137303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 01/27/2023] Open
Abstract
Microcirculation homeostasis depends on several channels permeable to ions and/or small molecules that facilitate the regulation of the vasomotor tone, hyperpermeability, the blood–brain barrier, and the neurovascular coupling function. Connexin (Cxs) and Pannexin (Panxs) large-pore channel proteins are implicated in several aspects of vascular physiology. The permeation of ions (i.e., Ca2+) and key metabolites (ATP, prostaglandins, D-serine, etc.) through Cxs (i.e., gap junction channels or hemichannels) and Panxs proteins plays a vital role in intercellular communication and maintaining vascular homeostasis. Therefore, dysregulation or genetic pathologies associated with these channels promote deleterious tissue consequences. This review provides an overview of current knowledge concerning the physiological role of these large-pore molecule channels in microcirculation (arterioles, capillaries, venules) and in the neurovascular coupling function.
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Affiliation(s)
- Pía C. Burboa
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, 185 South Orange Avenue, Newark, NJ 07103, USA; (P.C.B.); (W.N.D.)
- Departamento de Morfología y Función, Facultad de Salud y Ciencias Sociales, Sede Santiago Centro, Universidad de las Américas, Avenue República 71, Santiago 8370040, Chile;
| | - Mariela Puebla
- Departamento de Morfología y Función, Facultad de Salud y Ciencias Sociales, Sede Santiago Centro, Universidad de las Américas, Avenue República 71, Santiago 8370040, Chile;
| | - Pablo S. Gaete
- Department of Physiology and Membrane Biology, University of California at Davis, Davis, CA 95616, USA;
| | - Walter N. Durán
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, 185 South Orange Avenue, Newark, NJ 07103, USA; (P.C.B.); (W.N.D.)
- Rutgers School of Graduate Studies, 185 South Orange Avenue, Newark, NJ 07103, USA
| | - Mauricio A. Lillo
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, 185 South Orange Avenue, Newark, NJ 07103, USA; (P.C.B.); (W.N.D.)
- Correspondence:
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9
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Csípő T, Czikora Á, Fülöp GÁ, Gulyás H, Rutkai I, Tóth EP, Pórszász R, Szalai A, Bölcskei K, Helyes Z, Pintér E, Papp Z, Ungvári Z, Tóth A. A Central Role for TRPM4 in Ca 2+-Signal Amplification and Vasoconstriction. Int J Mol Sci 2022; 23:1465. [PMID: 35163382 PMCID: PMC8836177 DOI: 10.3390/ijms23031465] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/18/2022] [Accepted: 01/22/2022] [Indexed: 02/05/2023] Open
Abstract
Transient receptor potential melastatin-4 (TRPM4) is activated by an increase in intracellular Ca2+ concentration and is expressed on smooth muscle cells (SMCs). It is implicated in the myogenic constriction of cerebral arteries. We hypothesized that TRPM4 has a general role in intracellular Ca2+ signal amplification in a wide range of blood vessels. TRPM4 function was tested with the TRPM4 antagonist 9-phenanthrol and the TRPM4 activator A23187 on the cardiovascular responses of the rat, in vivo and in isolated basilar, mesenteric, and skeletal muscle arteries. TRPM4 inhibition by 9-phenanthrol resulted in hypotension and a decreased heart rate in the rat. TRPM4 inhibition completely antagonized myogenic tone development and norepinephrine-evoked vasoconstriction, and depolarization (high extracellular KCl concentration) evoked vasoconstriction in a wide range of peripheral arteries. Vasorelaxation caused by TRPM4 inhibition was accompanied by a significant decrease in intracellular Ca2+ concentration, suggesting an inhibition of Ca2+ signal amplification. Immunohistochemistry confirmed TRPM4 expression in the smooth muscle cells of the peripheral arteries. Finally, TRPM4 activation by the Ca2+ ionophore A23187 was competitively inhibited by 9-phenanthrol. In summary, TRPM4 was identified as an essential Ca2+-amplifying channel in peripheral arteries, contributing to both myogenic tone and agonist responses. These results suggest an important role for TRPM4 in the circulation. The modulation of TRPM4 activity may be a therapeutic target for hypertension. Furthermore, the Ca2+ ionophore A23187 was identified as the first high-affinity (nanomolar) direct activator of TRPM4, acting on the 9-phenanthrol binding site.
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Affiliation(s)
- Tamás Csípő
- Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (T.C.); (Á.C.); (G.Á.F.); (H.G.); (I.R.); (E.P.T.); (Z.P.)
- Doctoral School of Kálmán Laki, University of Debrecen, 4032 Debrecen, Hungary
| | - Ágnes Czikora
- Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (T.C.); (Á.C.); (G.Á.F.); (H.G.); (I.R.); (E.P.T.); (Z.P.)
| | - Gábor Á. Fülöp
- Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (T.C.); (Á.C.); (G.Á.F.); (H.G.); (I.R.); (E.P.T.); (Z.P.)
- Doctoral School of Kálmán Laki, University of Debrecen, 4032 Debrecen, Hungary
| | - Hajnalka Gulyás
- Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (T.C.); (Á.C.); (G.Á.F.); (H.G.); (I.R.); (E.P.T.); (Z.P.)
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (R.P.); (A.S.)
- Doctoral School of Pharmaceutical Sciences, University of Debrecen, 4032 Debrecen, Hungary
| | - Ibolya Rutkai
- Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (T.C.); (Á.C.); (G.Á.F.); (H.G.); (I.R.); (E.P.T.); (Z.P.)
| | - Enikő Pásztorné Tóth
- Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (T.C.); (Á.C.); (G.Á.F.); (H.G.); (I.R.); (E.P.T.); (Z.P.)
| | - Róbert Pórszász
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (R.P.); (A.S.)
| | - Andrea Szalai
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (R.P.); (A.S.)
| | - Kata Bölcskei
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, 7624 Pécs, Hungary; (K.B.); (Z.H.); (E.P.)
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
| | - Zsuzsanna Helyes
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, 7624 Pécs, Hungary; (K.B.); (Z.H.); (E.P.)
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
| | - Erika Pintér
- Department of Pharmacology and Pharmacotherapy, Medical School, University of Pécs, 7624 Pécs, Hungary; (K.B.); (Z.H.); (E.P.)
- Szentágothai Research Centre, University of Pécs, 7624 Pécs, Hungary
| | - Zoltán Papp
- Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (T.C.); (Á.C.); (G.Á.F.); (H.G.); (I.R.); (E.P.T.); (Z.P.)
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, 4032 Debrecen, Hungary
| | - Zoltán Ungvári
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA;
- International Training Program in Geroscience, Department of Public Health, Semmelweis University, 1089 Budapest, Hungary
- The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
| | - Attila Tóth
- Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary; (T.C.); (Á.C.); (G.Á.F.); (H.G.); (I.R.); (E.P.T.); (Z.P.)
- HAS-UD Vascular Biology and Myocardial Pathophysiology Research Group, Hungarian Academy of Sciences, 4032 Debrecen, Hungary
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10
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Jackson WF. Calcium-Dependent Ion Channels and the Regulation of Arteriolar Myogenic Tone. Front Physiol 2021; 12:770450. [PMID: 34819877 PMCID: PMC8607693 DOI: 10.3389/fphys.2021.770450] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/11/2021] [Indexed: 11/25/2022] Open
Abstract
Arterioles in the peripheral microcirculation regulate blood flow to and within tissues and organs, control capillary blood pressure and microvascular fluid exchange, govern peripheral vascular resistance, and contribute to the regulation of blood pressure. These important microvessels display pressure-dependent myogenic tone, the steady state level of contractile activity of vascular smooth muscle cells (VSMCs) that sets resting arteriolar internal diameter such that arterioles can both dilate and constrict to meet the blood flow and pressure needs of the tissues and organs that they perfuse. This perspective will focus on the Ca2+-dependent ion channels in the plasma and endoplasmic reticulum membranes of arteriolar VSMCs and endothelial cells (ECs) that regulate arteriolar tone. In VSMCs, Ca2+-dependent negative feedback regulation of myogenic tone is mediated by Ca2+-activated K+ (BKCa) channels and also Ca2+-dependent inactivation of voltage-gated Ca2+ channels (VGCC). Transient receptor potential subfamily M, member 4 channels (TRPM4); Ca2+-activated Cl− channels (CaCCs; TMEM16A/ANO1), Ca2+-dependent inhibition of voltage-gated K+ (KV) and ATP-sensitive K+ (KATP) channels; and Ca2+-induced-Ca2+ release through inositol 1,4,5-trisphosphate receptors (IP3Rs) participate in Ca2+-dependent positive-feedback regulation of myogenic tone. Calcium release from VSMC ryanodine receptors (RyRs) provide negative-feedback through Ca2+-spark-mediated control of BKCa channel activity, or positive-feedback regulation in cooperation with IP3Rs or CaCCs. In some arterioles, VSMC RyRs are silent. In ECs, transient receptor potential vanilloid subfamily, member 4 (TRPV4) channels produce Ca2+ sparklets that activate IP3Rs and intermediate and small conductance Ca2+ activated K+ (IKCa and sKCa) channels causing membrane hyperpolarization that is conducted to overlying VSMCs producing endothelium-dependent hyperpolarization and vasodilation. Endothelial IP3Rs produce Ca2+ pulsars, Ca2+ wavelets, Ca2+ waves and increased global Ca2+ levels activating EC sKCa and IKCa channels and causing Ca2+-dependent production of endothelial vasodilator autacoids such as NO, prostaglandin I2 and epoxides of arachidonic acid that mediate negative-feedback regulation of myogenic tone. Thus, Ca2+-dependent ion channels importantly contribute to many aspects of the regulation of myogenic tone in arterioles in the microcirculation.
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Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, College of Osteopathic Medicine, Michigan State University, East Lansing, MI, United States
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11
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Kuppusamy M, Ottolini M, Sonkusare SK. Role of TRP ion channels in cerebral circulation and neurovascular communication. Neurosci Lett 2021; 765:136258. [PMID: 34560190 PMCID: PMC8572163 DOI: 10.1016/j.neulet.2021.136258] [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: 05/25/2021] [Revised: 08/26/2021] [Accepted: 08/28/2021] [Indexed: 11/17/2022]
Abstract
The dynamic regulation of blood flow is essential for meeting the high metabolic demands of the brain and maintaining brain function. Cerebral blood flow is regulated primarily by 1) the intrinsic mechanisms that determine vascular contractility and 2) signals from neurons and astrocytes that alter vascular contractility. Stimuli from neurons and astrocytes can also initiate a signaling cascade in the brain capillary endothelium to increase regional blood flow. Recent studies provide evidence that TRP channels in endothelial cells, smooth muscle cells, neurons, astrocytes, and perivascular nerves control cerebrovascular contractility and cerebral blood flow. TRP channels exert their functional effects either through cell membrane depolarization or by serving as a Ca2+ influx pathway. Endothelial cells and astrocytes also maintain the integrity of the blood-brain barrier. Both endothelial cells and astrocytes express TRP channels, and an increase in endothelial TRP channel activity has been linked with a disrupted endothelial barrier function. Therefore, TRP channels can play a potentially important role in regulating blood-brain barrier integrity. Here, we review the regulation of cerebrovascular contractility by TRP channels under healthy and disease conditions and their potential roles in maintaining blood-brain barrier function.
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Affiliation(s)
- Maniselvan Kuppusamy
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, USA
| | - Matteo Ottolini
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, USA; Department of Pharmacology, University of Virginia-School of Medicine, Charlottesville, VA, USA
| | - Swapnil K Sonkusare
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, USA; Department of Molecular Physiology and Biological Physics, University of Virginia-School of Medicine, Charlottesville, VA, USA.
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12
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Ali S, Solano AS, Gonzales AL, Thakore P, Krishnan V, Yamasaki E, Earley S. Nitric Oxide Signals Through IRAG to Inhibit TRPM4 Channels and Dilate Cerebral Arteries. FUNCTION (OXFORD, ENGLAND) 2021; 2:zqab051. [PMID: 34734188 PMCID: PMC8557268 DOI: 10.1093/function/zqab051] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/30/2021] [Accepted: 10/05/2021] [Indexed: 01/12/2023]
Abstract
Nitric oxide (NO) relaxes vascular smooth muscle cells (SMCs) and dilates blood vessels by increasing intracellular levels of cyclic guanosine monophosphate (cGMP), which stimulates the activity of cGMP-dependent protein kinase (PKG). However, the vasodilator mechanisms downstream of PKG remain incompletely understood. Here, we found that transient receptor potential melastatin 4 (TRPM4) cation channels, which are activated by Ca2+ released from the sarcoplasmic reticulum (SR) through inositol triphosphate receptors (IP3Rs) under native conditions, are essential for SMC membrane depolarization and vasoconstriction. We hypothesized that signaling via the NO/cGMP/PKG pathway causes vasodilation by inhibiting TRPM4. We found that TRPM4 currents activated by stretching the plasma membrane or directly activating IP3Rs were suppressed by exogenous NO or a membrane-permeable cGMP analog, the latter of which also impaired IP3R-mediated release of Ca2+ from the SR. The effects of NO on TRPM4 activity were blocked by inhibition of soluble guanylyl cyclase or PKG. Notably, upon phosphorylation by PKG, IRAG (IP3R-associated PKG substrate) inhibited IP3R-mediated Ca2+ release, and knockdown of IRAG expression diminished NO-mediated inhibition of TRPM4 activity and vasodilation. Using superresolution microscopy, we found that IRAG, PKG, and IP3Rs form a nanoscale signaling complex on the SR of SMCs. We conclude that NO/cGMP/PKG signaling through IRAG inhibits IP3R-dependent activation of TRPM4 channels in SMCs to dilate arteries. SIGNIFICANCE STATEMENT Nitric oxide is a gaseous vasodilator produced by endothelial cells that is essential for cardiovascular function. Although NO-mediated signaling pathways have been intensively studied, the mechanisms by which they relax SMCs to dilate blood vessels remain incompletely understood. In this study, we show that NO causes vasodilation by inhibiting the activity of Ca2+-dependent TRPM4 cation channels. Probing further, we found that NO does not act directly on TRPM4 but instead initiates a signaling cascade that inhibits its activation by blocking the release of Ca2+ from the SR. Thus, our findings reveal the essential molecular pathways of NO-induced vasodilation-a fundamental unresolved concept in cardiovascular physiology.
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Affiliation(s)
| | | | - Albert L Gonzales
- Department of Physiology and Cell Biology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, University of Nevada, Reno, NV 89557-0318, USA
| | - Pratish Thakore
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, Reno School of Medicine, University of Nevada, Reno, NV 89557-0318, USA
| | - Vivek Krishnan
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, Reno School of Medicine, University of Nevada, Reno, NV 89557-0318, USA
| | - Evan Yamasaki
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, Reno School of Medicine, University of Nevada, Reno, NV 89557-0318, USA
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13
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Kim K, Hong KS. Transient receptor potential channel-dependent myogenic responsiveness in small-sized resistance arteries. J Exerc Rehabil 2021; 17:4-10. [PMID: 33728282 PMCID: PMC7939990 DOI: 10.12965/jer.2040836.418] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 12/19/2020] [Indexed: 11/22/2022] Open
Abstract
It is well documented that the inherent ability of small arteries and arterioles to regulate intraluminal diameter in response to alterations in intravascular pressure determines peripheral vascular resistance and blood flow (termed myogenic response or pressure-induced vasoconstriction/dilation). This autoregulatory property of resistance arteries is primarily originated from mechanosensitive vascular smooth muscle cells (VSMCs). There are diverse biological apparatuses in the plasma membrane of VSMCs that sense mechanical stimuli and generate intracellular signals for the contractility of VSMCs. Although the roles of transient receptor potential (TRP) channels in pressure-induced vasoconstriction are not fully understood to date, TRP channels that are directly activated by mechanical stimuli (e.g., stretch of VSMCs) or indirectly evoked by intracellular molecules (e.g., inositol trisphosphate) provide the major sources of Ca2+ (e.g., Ca2+ influx or release from the sarcoplasmic reticulum) and in turn, evoke vascular reactivity. This review sought to summarize mounting evidence over several decades that the activation of TRP canonical, TRP melastatin, TRP vanilloid, and TRP polycystin channels contributes to myogenic vasoconstriction.
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Affiliation(s)
- Kijeong Kim
- School of Exercise & Sport Science, College of Natural Sciences, University of Ulsan, Ulsan, Korea
| | - Kwang-Seok Hong
- Department of Physical Education, College of Education, Chung-Ang University, Seoul, Korea
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14
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Jimenez I, Prado Y, Marchant F, Otero C, Eltit F, Cabello-Verrugio C, Cerda O, Simon F. TRPM Channels in Human Diseases. Cells 2020; 9:E2604. [PMID: 33291725 PMCID: PMC7761947 DOI: 10.3390/cells9122604] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/11/2022] Open
Abstract
The transient receptor potential melastatin (TRPM) subfamily belongs to the TRP cation channels family. Since the first cloning of TRPM1 in 1989, tremendous progress has been made in identifying novel members of the TRPM subfamily and their functions. The TRPM subfamily is composed of eight members consisting of four six-transmembrane domain subunits, resulting in homomeric or heteromeric channels. From a structural point of view, based on the homology sequence of the coiled-coil in the C-terminus, the eight TRPM members are clustered into four groups: TRPM1/M3, M2/M8, M4/M5 and M6/M7. TRPM subfamily members have been involved in several physiological functions. However, they are also linked to diverse pathophysiological human processes. Alterations in the expression and function of TRPM subfamily ion channels might generate several human diseases including cardiovascular and neurodegenerative alterations, organ dysfunction, cancer and many other channelopathies. These effects position them as remarkable putative targets for novel diagnostic strategies, drug design and therapeutic approaches. Here, we review the current knowledge about the main characteristics of all members of the TRPM family, focusing on their actions in human diseases.
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Affiliation(s)
- Ivanka Jimenez
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Yolanda Prado
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Felipe Marchant
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Carolina Otero
- Faculty of Medicine, School of Chemistry and Pharmacy, Universidad Andrés Bello, Santiago 8370186, Chile;
| | - Felipe Eltit
- Vancouver Prostate Centre, Vancouver, BC V6Z 1Y6, Canada;
- Department of Urological Sciences, University of British Columbia, Vancouver, BC V6Z 1Y6, Canada
| | - Claudio Cabello-Verrugio
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago 7560484, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago 8370146, Chile
| | - Oscar Cerda
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
| | - Felipe Simon
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
- Millennium Institute on Immunology and Immunotherapy, Santiago 8370146, Chile
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15
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Presa JL, Saravia F, Bagi Z, Filosa JA. Vasculo-Neuronal Coupling and Neurovascular Coupling at the Neurovascular Unit: Impact of Hypertension. Front Physiol 2020; 11:584135. [PMID: 33101063 PMCID: PMC7546852 DOI: 10.3389/fphys.2020.584135] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/04/2020] [Indexed: 12/18/2022] Open
Abstract
Components of the neurovascular unit (NVU) establish dynamic crosstalk that regulates cerebral blood flow and maintain brain homeostasis. Here, we describe accumulating evidence for cellular elements of the NVU contributing to critical physiological processes such as cerebral autoregulation, neurovascular coupling, and vasculo-neuronal coupling. We discuss how alterations in the cellular mechanisms governing NVU homeostasis can lead to pathological changes in which vascular endothelial and smooth muscle cell, pericyte and astrocyte function may play a key role. Because hypertension is a modifiable risk factor for stroke and accelerated cognitive decline in aging, we focus on hypertension-associated changes on cerebral arteriole function and structure, and the molecular mechanisms through which these may contribute to cognitive decline. We gather recent emerging evidence concerning cognitive loss in hypertension and the link with vascular dementia and Alzheimer’s disease. Collectively, we summarize how vascular dysfunction, chronic hypoperfusion, oxidative stress, and inflammatory processes can uncouple communication at the NVU impairing cerebral perfusion and contributing to neurodegeneration.
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Affiliation(s)
- Jessica L Presa
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - Flavia Saravia
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - Zsolt Bagi
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Jessica A Filosa
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
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16
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Matsumoto T, Kojima M, Takayanagi K, Katome T, Taguchi K, Kobayashi T. Impaired UTP-induced relaxation in the carotid arteries of spontaneously hypertensive rats. Purinergic Signal 2020; 16:453-461. [PMID: 32862324 DOI: 10.1007/s11302-020-09721-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 08/10/2020] [Indexed: 12/21/2022] Open
Abstract
Uridine 5'-triphosphate (UTP) has an important role as an extracellular signaling molecule that regulates inflammation, angiogenesis, and vascular tone. While chronic hypertension has been shown to promote alterations in arterial vascular tone regulation, carotid artery responses to UTP under hypertensive conditions have remained unclear. The present study investigated carotid artery responses to UTP in spontaneously hypertensive rats (SHR) and control Wistar Kyoto rats (WKY). Accordingly, our results found that although UTP promotes concentration-dependent relaxation in isolated carotid artery segments from both SHR and WKY after pretreatment with phenylephrine, SHR exhibited significantly lower arterial relaxation responses compared with WKY. Moreover, UTP-induced relaxation was substantially reduced by endothelial denudation and by the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine in both SHR and WKY. The difference in UTP-induced relaxation between both groups was abolished by the selective P2Y2 receptor antagonist AR-C118925XX and the cyclooxygenase (COX) inhibitor indomethacin but not by the thromboxane-prostanoid receptor antagonist SQ29548. Furthermore, we detected the release of PGE2, PGF2α, and PGI2 in the carotid arteries of SHR and WKY, both at baseline and in response to UTP. UTP administration also increased TXA2 levels in WKY but not SHR. Overall, our results suggest that UTP-induced relaxation in carotid arteries is impaired in SHR perhaps due to impaired P2Y2 receptor signaling, reductions in endothelial NO, and increases in the levels of COX-derived vasoconstrictor prostanoids.
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Affiliation(s)
- Takayuki Matsumoto
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, 142-8501, Japan.
| | - Mihoka Kojima
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, 142-8501, Japan
| | - Keisuke Takayanagi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, 142-8501, Japan
| | - Tomoki Katome
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, 142-8501, Japan
| | - Kumiko Taguchi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, 142-8501, Japan
| | - Tsuneo Kobayashi
- Department of Physiology and Morphology, Institute of Medicinal Chemistry, Hoshi University, Shinagawa-ku, Tokyo, 142-8501, Japan.
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17
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Hong KS, Kim K, Hill MA. Regulation of blood flow in small arteries: mechanosensory events underlying myogenic vasoconstriction. J Exerc Rehabil 2020; 16:207-215. [PMID: 32724777 PMCID: PMC7365734 DOI: 10.12965/jer.2040432.216] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 06/10/2020] [Indexed: 01/10/2023] Open
Abstract
As blood flow is proportional to the fourth power of the vascular radius small changes in the diameter of resistance arteries/arterioles following an increase in intraluminal pressure would be expected to substantially increase blood flow. However, arteriolar myocytes display an intrinsic ability to locally regulate blood flow according to metabolic demands by tuning the diameter of small arteries in response to local changes in he-modynamics. Critical to this, observations were made more than 100 years ago that mechanosensitive small arteries exhibit the "myogenic response" or pressure-induced vasoconstriction or vasodilation in re-sponse to increased or decreased intravascular pressure, respectively. Although cellular mechanisms underlying the myogenic response have now been studied extensively, the precise cellular mechanisms under-lying this intriguing phenomenon still remain uncertain. In particular, the biological machinery that senses changes in intravascular pressure in vascular smooth muscle cells have not been unquestionably identified and remain a significant issue in vascular biology to be fully elucidated. As such, this brief review focuses on putative mechanosensors that have been proposed to contribute to myogenic vasoreactivity. Specific attention is paid to the roles of integrins, G protein-coupled receptors, and cadherins.
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Affiliation(s)
- Kwang-Seok Hong
- Department of Physical Education, College of Education, Chung-Ang University, Seoul, Korea
| | - Kijeong Kim
- School of Exercise & Sport Science, College of Natural Sciences, University of Ulsan, Ulsan, Korea
| | - Michael A Hill
- Dalton Cardiovascular Research Center, University of Missouri-School of Medicine, Columbia, MO, USA.,Department of Medical Pharmacology and Physiology, University of Missouri-School of Medicine, Columbia, MO, USA
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18
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Garcia DCG, Longden TA. Ion channels in capillary endothelium. CURRENT TOPICS IN MEMBRANES 2020; 85:261-300. [PMID: 32402642 DOI: 10.1016/bs.ctm.2020.01.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Vascular beds are anatomically and functionally compartmentalized into arteries, capillaries, and veins. The bulk of the vasculature consists of the dense, anastomosing capillary network, composed of capillary endothelial cells (cECs) that are intimately associated with the parenchyma. Despite their abundance, the ion channel expression and function and Ca2+ signaling behaviors of capillaries have only recently begun to be explored in detail. Here, we discuss the established and emerging roles of ion channels and Ca2+ signaling in cECs. By mining a publicly available RNA-seq dataset, we outline the wide variety of ion channel genes that are expressed in these cells, which potentially imbue capillaries with a broad range of sensing and signal transduction capabilities. We also underscore subtle but critical differences between cEC and arteriolar EC ion channel expression that likely underlie key functional differences in ECs at these different levels of the vascular tree. We focus our discussion on the cerebral vasculature, but the findings and principles being elucidated in this area likely generalize to other vascular beds.
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Affiliation(s)
- Daniela C G Garcia
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Thomas A Longden
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD, United States.
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19
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Yamasaki E, Thakore P, Krishnan V, Earley S. Differential expression of angiotensin II type 1 receptor subtypes within the cerebral microvasculature. Am J Physiol Heart Circ Physiol 2020; 318:H461-H469. [PMID: 31886721 PMCID: PMC7052625 DOI: 10.1152/ajpheart.00582.2019] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/10/2019] [Accepted: 12/24/2019] [Indexed: 01/12/2023]
Abstract
Arteries and arterioles constrict in response to intraluminal pressure to generate myogenic tone, but the molecular nature of the vascular force-sensing mechanism is not fully characterized. Here, we investigated the role of angiotensin II type 1 receptors (AT1Rs) on vascular smooth muscle cells in the development of myogenic tone in cerebral parenchymal arterioles from mice. We found that pretreatment with the AT1R blocker losartan inhibited the development of myogenic tone in these vessels but did not alter the luminal diameter of arterioles with preestablished tone. Rodents express two AT1R isotypes: AT1Ra and AT1Rb. We previously demonstrated that AT1Rb is expressed at much higher levels compared with AT1Ra in cerebral pial arteries and is required for myogenic contractility in these vessels, whereas AT1Ra is unnecessary for this function. Here, we found that AT1Ra and AT1Rb are expressed at similar levels in parenchymal arterioles and that genetic knockout of AT1Ra blunted the ability of these vessels to generate myogenic tone. We also found that AT1Rb and total AT1R expression levels are much lower in parenchymal arterioles compared with pial arteries and that parenchymal arterioles are less sensitive to the vasoconstrictive effects of the endogenous AT1R ligand angiotensin II (ANG II). We conclude that 1) AT1Rs are critical for the initiation, but not the maintenance, of myogenic tone in parenchymal arterioles, and 2) lower levels of AT1Rb and total AT1R in parenchymal arterioles compared with pial arteries result in differences in myogenic and ANG II-induced vasoconstriction between these vascular segments.NEW & NOTEWORTHY Myogenic tone is critical for appropriate regulation of cerebral blood flow, but the mechanisms used by vascular smooth muscle cells to detect changes in intraluminal pressure are not fully characterized. Here, we demonstrate angiotensin II receptor type 1 (AT1R) is indispensable to initiation, but not maintenance, of myogenic tone in cerebral parenchymal arterioles. Furthermore, we demonstrate differences in AT1R expression levels lead to critical differences in contractile regulation between parenchymal arterioles and cerebral pial arteries.
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Affiliation(s)
- Evan Yamasaki
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Pratish Thakore
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Vivek Krishnan
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Scott Earley
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
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20
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Alonso-Carbajo L, Alpizar YA, Startek JB, López-López JR, Pérez-García MT, Talavera K. Activation of the cation channel TRPM3 in perivascular nerves induces vasodilation of resistance arteries. J Mol Cell Cardiol 2019; 129:219-230. [PMID: 30853321 DOI: 10.1016/j.yjmcc.2019.03.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 03/01/2019] [Accepted: 03/06/2019] [Indexed: 10/27/2022]
Abstract
The Transient Receptor Potential Melastatin 3 (TRPM3) is a Ca2+-permeable non-selective cation channel activated by the neurosteroid pregnenolone sulfate (PS). This compound was previously shown to contract mouse aorta by activating TRPM3 in vascular smooth muscle cells (VSMC), and proposed as therapeutic modulator of vascular functions. However, PS effects and the role of TRPM3 in resistance arteries remain unknown. Thus, we aimed at determining the localization and physiological role of TRPM3 in mouse mesenteric arteries. Real-time qPCR experiments, anatomical localization using immunofluorescence microscopy and patch-clamp recordings in isolated VSMC showed that TRPM3 expression in mesenteric arteries is restricted to perivascular nerves. Pressure myography experiments in wild type (WT) mouse arteries showed that PS vasodilates with a concentration-dependence that was best fit by two Hill components (effective concentrations, EC50, of 14 and 100 μM). The low EC50 component was absent in preparations from Trpm3 knockout (KO) mice and in WT arteries in the presence of the CGRP receptor antagonist BIBN 4096. TRPM3-dependent vasodilation was partially inhibited by a cocktail of K+ channel blockers, and not mediated by β-adrenergic signaling. We conclude that, contrary to what was found in aorta, PS dilates mesenteric arteries, partly via an activation of TRPM3 that triggers CGRP release from perivascular nerve endings and a subsequent activation of K+ channels in VSMC. We propose that TRPM3 is implicated in the regulation of the tone of resistance arteries and that its activation by yet unidentified endogenous damage-associated molecules lead to protective vasodilation responses in mesenteric arteries.
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Affiliation(s)
- Lucía Alonso-Carbajo
- Department of Cellular and Molecular Medicine, Laboratory of Ion Channel Research, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49, Campus Gasthuisberg, O&N1 Box 802, 3000 Leuven, Belgium; Departamento de Bioquímica y Biología Molecular y Fisiología, Instituto de Biología y Genética Molecular, Universidad de Valladolid y CSIC, Sanz y Forés 3, 47003 Valladolid, Spain
| | - Yeranddy A Alpizar
- Department of Cellular and Molecular Medicine, Laboratory of Ion Channel Research, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49, Campus Gasthuisberg, O&N1 Box 802, 3000 Leuven, Belgium
| | - Justyna B Startek
- Department of Cellular and Molecular Medicine, Laboratory of Ion Channel Research, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49, Campus Gasthuisberg, O&N1 Box 802, 3000 Leuven, Belgium
| | - José Ramón López-López
- Departamento de Bioquímica y Biología Molecular y Fisiología, Instituto de Biología y Genética Molecular, Universidad de Valladolid y CSIC, Sanz y Forés 3, 47003 Valladolid, Spain
| | - María Teresa Pérez-García
- Departamento de Bioquímica y Biología Molecular y Fisiología, Instituto de Biología y Genética Molecular, Universidad de Valladolid y CSIC, Sanz y Forés 3, 47003 Valladolid, Spain
| | - Karel Talavera
- Department of Cellular and Molecular Medicine, Laboratory of Ion Channel Research, KU Leuven, VIB Center for Brain & Disease Research, Herestraat 49, Campus Gasthuisberg, O&N1 Box 802, 3000 Leuven, Belgium.
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Startek JB, Boonen B, Talavera K, Meseguer V. TRP Channels as Sensors of Chemically-Induced Changes in Cell Membrane Mechanical Properties. Int J Mol Sci 2019; 20:E371. [PMID: 30654572 PMCID: PMC6359677 DOI: 10.3390/ijms20020371] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 01/11/2019] [Accepted: 01/12/2019] [Indexed: 12/19/2022] Open
Abstract
Transient Receptor Potential ion channels (TRPs) have been described as polymodal sensors, being responsible for transducing a wide variety of stimuli, and being involved in sensory functions such as chemosensation, thermosensation, mechanosensation, and photosensation. Mechanical and chemical stresses exerted on the membrane can be transduced by specialized proteins into meaningful intracellular biochemical signaling, resulting in physiological changes. Of particular interest are compounds that can change the local physical properties of the membrane, thereby affecting nearby proteins, such as TRP channels, which are highly sensitive to the membrane environment. In this review, we provide an overview of the current knowledge of TRP channel activation as a result of changes in the membrane properties induced by amphipathic structural lipidic components such as cholesterol and diacylglycerol, and by exogenous amphipathic bacterial endotoxins.
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Affiliation(s)
- Justyna B Startek
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven; VIB Center for Brain & Disease Research, Herestraat 49, Campus Gasthuisberg O&N1 bus 802, 3000 Leuven, Belgium.
| | - Brett Boonen
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven; VIB Center for Brain & Disease Research, Herestraat 49, Campus Gasthuisberg O&N1 bus 802, 3000 Leuven, Belgium.
| | - Karel Talavera
- Laboratory of Ion Channel Research, Department of Cellular and Molecular Medicine, KU Leuven; VIB Center for Brain & Disease Research, Herestraat 49, Campus Gasthuisberg O&N1 bus 802, 3000 Leuven, Belgium.
| | - Victor Meseguer
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández y CSIC, E-03550 Alicante , Spain.
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Low frequency pulse stimulation of Schaffer collaterals in Trpm4 -/- knockout rats differently affects baseline BOLD signals in target regions of the right hippocampus but not BOLD responses at the site of stimulation. Neuroimage 2018; 188:347-356. [PMID: 30553915 DOI: 10.1016/j.neuroimage.2018.12.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/21/2018] [Accepted: 12/11/2018] [Indexed: 11/22/2022] Open
Abstract
Electrical stimulation of right Schaffer collateral in Trpm4-/- knockout and wild type rats were used to study the role of Trpm4 channels for signal processing in the hippocampal formation. Stimulation induced neuronal activity was simultaneously monitored in the CA1 region by in vivo extracellular field recordings and in the entire brain by BOLD fMRI measurements. In wild type and Trpm4-/- knockout rats, consecutive 5 Hz pulse trains elicited similar neuronal responses in the CA1 region and similar BOLD responses in the stimulated right hippocampus. Stimulus-related positive BOLD responses were also found in the left dorsal hippocampus. In contrast to the right dorsal hippocampus, baseline BOLD signals in the left hippocampus significantly decreased during consecutive stimulation trains. Similarly, slowly developing significant declines in baseline BOLD signals, in absence of any positive BOLD responses, were also observed in the right entorhinal, right piriform cortex, right basolateral amygdala and right dorsal striatum whereas baseline BOLD signals remained almost stable in the corresponding left regions. Furthermore, significant declines in baseline BOLD signals were found in the prefrontal cortex and prelimbic/infralimbic cortex. Because significant baseline BOLD declines were only observed in target regions of the right dorsal hippocampus, it might reflect functional connectivity between these regions. In all observed regions the decline in baseline BOLD signals was significantly delayed and less pronounced in Trpm4-/- knockout rats when compared to wild type rats. Thus, either Trpm4 channels are involved in mediating these baseline BOLD shifts or functional connectivity of the hippocampus is impaired in Trpm4-/- knockout rats.
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Adding dimension to cellular mechanotransduction: Advances in biomedical engineering of multiaxial cell-stretch systems and their application to cardiovascular biomechanics and mechano-signaling. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017. [DOI: 10.1016/j.pbiomolbio.2017.06.011] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Li Y, Pagano PJ. Microvascular NADPH oxidase in health and disease. Free Radic Biol Med 2017; 109:33-47. [PMID: 28274817 PMCID: PMC5482368 DOI: 10.1016/j.freeradbiomed.2017.02.049] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 02/24/2017] [Accepted: 02/28/2017] [Indexed: 02/07/2023]
Abstract
The systemic and cerebral microcirculation contribute critically to regulation of local and global blood flow and perfusion pressure. Microvascular dysfunction, commonly seen in numerous cardiovascular pathologies, is associated with alterations in the oxidative environment including potentiated production of reactive oxygen species (ROS) and subsequent activation of redox signaling pathways. NADPH oxidases (Noxs) are a primary source of ROS in the vascular system and play a central role in cardiovascular health and disease. In this review, we focus on the roles of Noxs in ROS generation in resistance arterioles and capillaries, and summarize their contributions to microvascular physiology and pathophysiology in both systemic and cerebral microcirculation. In light of the accumulating evidence that Noxs are pivotal players in vascular dysfunction of resistance arterioles, selectively targeting Nox isozymes could emerge as a novel and effective therapeutic strategy for preventing and treating microvascular diseases.
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Affiliation(s)
- Yao Li
- Department of Pharmacology & Chemical Biology, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Patrick J Pagano
- Department of Pharmacology & Chemical Biology, Vascular Medicine Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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Pires PW, Ko E, Pritchard HA, Rudokas M, Yamasaki E, Earley S. The angiotensin II receptor type 1b is the primary sensor of intraluminal pressure in cerebral artery smooth muscle cells. J Physiol 2017; 595:4735-4753. [PMID: 28475214 PMCID: PMC5509855 DOI: 10.1113/jp274310] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/03/2017] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS The angiotensin II receptor type 1b (AT1 Rb ) is the primary sensor of intraluminal pressure in cerebral arteries. Pressure or membrane-stretch induced stimulation of AT1 Rb activates the TRPM4 channel and results in inward transient cation currents that depolarize smooth muscle cells, leading to vasoconstriction. Activation of either AT1 Ra or AT1 Rb with angiotensin II stimulates TRPM4 currents in cerebral artery myocytes and vasoconstriction of cerebral arteries. The expression of AT1 Rb mRNA is ∼30-fold higher than AT1 Ra in whole cerebral arteries and ∼45-fold higher in isolated cerebral artery smooth muscle cells. Higher levels of expression are likely to account for the obligatory role of AT1 Rb for pressure-induced vasoconstriction. ABSTRACT: Myogenic vasoconstriction, which reflects the intrinsic ability of smooth muscle cells to contract in response to increases in intraluminal pressure, is critically important for the autoregulation of blood flow. In smooth muscle cells from cerebral arteries, increasing intraluminal pressure engages a signalling cascade that stimulates cation influx through transient receptor potential (TRP) melastatin 4 (TRPM4) channels to cause membrane depolarization and vasoconstriction. Substantial evidence indicates that the angiotensin II receptor type 1 (AT1 R) is inherently mechanosensitive and initiates this signalling pathway. Rodents express two types of AT1 R - AT1 Ra and AT1 Rb - and conflicting studies provide support for either isoform as the primary sensor of intraluminal pressure in peripheral arteries. We hypothesized that mechanical activation of AT1 Ra increases TRPM4 currents to induce myogenic constriction of cerebral arteries. However, we found that development of myogenic tone was greater in arteries from AT1 Ra knockout animals compared with controls. In patch-clamp experiments using native cerebral arterial myocytes, membrane stretch-induced cation currents were blocked by the TRPM4 inhibitor 9-phenanthrol in both groups. Further, the AT1 R blocker losartan (1 μm) diminished myogenic tone and blocked stretch-induced cation currents in cerebral arteries from both groups. Activation of AT1 R with angiotensin II (30 nm) also increased TRPM4 currents in smooth muscle cells and constricted cerebral arteries from both groups. Expression of AT1 Rb mRNA was ∼30-fold greater than AT1 Ra in cerebral arteries, and knockdown of AT1 Rb selectively diminished myogenic constriction. We conclude that AT1 Rb , acting upstream of TRPM4 channels, is the primary sensor of intraluminal pressure in cerebral artery smooth muscle cells.
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Affiliation(s)
- Paulo W. Pires
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Eun‐A. Ko
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Harry A.T. Pritchard
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Michael Rudokas
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Evan Yamasaki
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Scott Earley
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
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Alonso-Carbajo L, Kecskes M, Jacobs G, Pironet A, Syam N, Talavera K, Vennekens R. Muscling in on TRP channels in vascular smooth muscle cells and cardiomyocytes. Cell Calcium 2017; 66:48-61. [PMID: 28807149 DOI: 10.1016/j.ceca.2017.06.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 06/08/2017] [Accepted: 06/08/2017] [Indexed: 02/07/2023]
Abstract
The human TRP protein family comprises a family of 27 cation channels with diverse permeation and gating properties. The common theme is that they are very important regulators of intracellular Ca2+ signaling in diverse cell types, either by providing a Ca2+ influx pathway, or by depolarising the membrane potential, which on one hand triggers the activation of voltage-gated Ca2+ channels, and on the other limits the driving force for Ca2+ entry. Here we focus on the role of these TRP channels in vascular smooth muscle and cardiac striated muscle. We give an overview of highlights from the recent literature, and highlight the important and diverse roles of TRP channels in the pathophysiology of the cardiovascular system. The discovery of the superfamily of Transient Receptor Potential (TRP) channels has significantly enhanced our knowledge of multiple signal transduction mechanisms in cardiac muscle and vascular smooth muscle cells (VSMC). In recent years, multiple studies have provided evidence for the involvement of these channels, not only in the regulation of contraction, but also in cell proliferation and remodeling in pathological conditions. The mammalian family of TRP cation channels is composed by 28 genes which can be divided into 6 subfamilies groups based on sequence similarity: TRPC (Canonical), TRPM (Melastatin), TRPML (Mucolipins), TRPV (Vanilloid), TRPP (Policystin) and TRPA (Ankyrin-rich protein). Functional TRP channels are believed to form four-unit complexes in the plasma, each of them expressed with six transmembrane domain and intracellular N and C termini. Here we review the current knowledge on the expression of TRP channels in both muscle types, and discuss their functional properties and role in physiological and pathophysiological processes.
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Affiliation(s)
- Lucía Alonso-Carbajo
- Laboratory of Ion Channel Research, TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Miklos Kecskes
- Laboratory of Ion Channel Research, TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Griet Jacobs
- Laboratory of Ion Channel Research, TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Andy Pironet
- Laboratory of Ion Channel Research, TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Ninda Syam
- Laboratory of Ion Channel Research, TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium
| | - Karel Talavera
- Laboratory of Ion Channel Research, TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium.
| | - Rudi Vennekens
- Laboratory of Ion Channel Research, TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, 3000 Leuven, Belgium.
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27
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Tajada S, Moreno CM, O'Dwyer S, Woods S, Sato D, Navedo MF, Santana LF. Distance constraints on activation of TRPV4 channels by AKAP150-bound PKCα in arterial myocytes. J Gen Physiol 2017; 149:639-659. [PMID: 28507079 PMCID: PMC5460949 DOI: 10.1085/jgp.201611709] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 03/03/2017] [Accepted: 04/27/2017] [Indexed: 11/20/2022] Open
Abstract
Vascular smooth muscle tone can be regulated by angiotensin II, which enhances TRPV4 channel activity via AKAP150-bound protein kinase C. Tajada et al. show that the effect of AKAP150 on TRPV4 channels is inversely proportional to the distance between them, which varies with sex and arterial bed. TRPV4 (transient receptor potential vanilloid 4) channels are Ca2+-permeable channels that play a key role in regulating vascular tone. In arterial myocytes, opening of TRPV4 channels creates local increases in Ca2+ influx, detectable optically as “TRPV4 sparklets.” TRPV4 sparklet activity can be enhanced by the action of the vasoconstrictor angiotensin II (AngII). This modulation depends on the activation of subcellular signaling domains that comprise protein kinase C α (PKCα) bound to the anchoring protein AKAP150. Here, we used super-resolution nanoscopy, patch-clamp electrophysiology, Ca2+ imaging, and mathematical modeling approaches to test the hypothesis that AKAP150-dependent modulation of TRPV4 channels is critically dependent on the distance between these two proteins in the sarcolemma of arterial myocytes. Our data show that the distance between AKAP150 and TRPV4 channel clusters varies with sex and arterial bed. Consistent with our hypothesis, we further find that basal and AngII-induced TRPV4 channel activity decays exponentially as the distance between TRPV4 and AKAP150 increases. Our data suggest a maximum radius of action of ∼200 nm for local modulation of TRPV4 channels by AKAP150-associated PKCα.
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Affiliation(s)
- Sendoa Tajada
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Claudia M Moreno
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Samantha O'Dwyer
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Sean Woods
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
| | - Daisuke Sato
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA
| | - Manuel F Navedo
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA
| | - L Fernando Santana
- Department of Physiology and Membrane Biology, University of California Davis School of Medicine, Davis, CA
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El-Yazbi AF, Abd-Elrahman KS. ROK and Arteriolar Myogenic Tone Generation: Molecular Evidence in Health and Disease. Front Pharmacol 2017; 8:87. [PMID: 28280468 PMCID: PMC5322222 DOI: 10.3389/fphar.2017.00087] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/10/2017] [Indexed: 12/13/2022] Open
Abstract
The myogenic response is an inherent property of resistance arteries that warrants a relatively constant blood flow in response to changes in perfusion pressure and protect delicate organs from vascular insufficiencies and excessive blood flow. This fundamental phenomenon has been extensively studied aiming to elucidate the underlying mechanisms triggering smooth muscle contraction in response to intraluminal pressure elevation, particularly, Rho-associated kinase (ROK)-mediated Ca2+-independent mechanisms. The size of the resistance arteries limits the capacity to examine changes in protein phosphorylation/expression levels associated with ROK signaling. A highly sensitive biochemical detection approach was beneficial in examining the role of ROK in different force generation mechanisms along the course of myogenic constriction. In this mini review, we summarize recent results showing direct evidence for the contribution of ROK in development of myogenic response at the level of mechanotransduction, myosin light chain phosphatase inhibition and dynamic actin cytoskeleton reorganization. We will also present evidence that alterations in ROK signaling could underlie the progressive loss in myogenic response in a rat model of type 2 diabetes.
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Affiliation(s)
- Ahmed F El-Yazbi
- Department of Pharmacology and Toxicology, Faculty of Medicine, American University of BeirutBeirut, Lebanon; Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt
| | - Khaled S Abd-Elrahman
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt; Department of Cellular and Molecular Medicine, Faculty of Medicine, University of OttawaOttawa, ON, Canada
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29
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The TRPM4 channel is functionally important for the beneficial cardiac remodeling induced by endurance training. J Muscle Res Cell Motil 2017; 38:3-16. [DOI: 10.1007/s10974-017-9466-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 02/02/2017] [Indexed: 10/20/2022]
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30
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Li Y, Brayden JE. Rho kinase activity governs arteriolar myogenic depolarization. J Cereb Blood Flow Metab 2017; 37:140-152. [PMID: 26661251 PMCID: PMC5363734 DOI: 10.1177/0271678x15621069] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/10/2015] [Accepted: 11/11/2015] [Indexed: 11/15/2022]
Abstract
Cerebral arterioles contribute critically to regulation of local and global blood flow within the brain. Dysfunction of these blood vessels is implicated in numerous cardiovascular diseases. However, treatments are limited due to incomplete understanding of fundamental control mechanisms at this level of circulation. Emerging evidence points to a key role of Rho-associated protein kinase in regulation of microvascular contractility. This study sought to decipher the mechanisms of Rho-associated protein kinase-mediated myogenic vasoconstriction in cerebral parenchymal arterioles. Here, we report that the Rho-associated protein kinase inhibitor H1152 strongly attenuated pressure-induced constriction, cytosolic [Ca2+] increases, and depolarization of isolated parenchymal arterioles. Further, the RhoA activator CN03 potentiated parenchymal arteriole myogenic constriction and depolarization, indicating important involvement of RhoA/Rho-associated protein kinase signaling in myogenic excitation-contraction mechanisms. Because of the well-established role of TRPM4 in pressure-induced depolarization, possible modulatory effects of Rho-associated protein kinase on TRPM4 currents were explored using patch clamp electrophysiology. TRPM4 currents were suppressed by H1152 and enhanced by CN03. Finally, H1152 elevated the apparent [Ca2+]-threshold for TRPM4 activation, suggesting that Rho-associated protein kinase activates TRPM4 by increasing its Ca2+-sensitivity. Our results support a novel mechanism whereby Rho-associated protein kinase-mediated myogenic vasoconstriction occurs primarily through activation of TRPM4 channels, smooth muscle depolarization, and cytosolic [Ca2+] increases in cerebral arterioles.
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Affiliation(s)
- Yao Li
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Joseph E Brayden
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
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31
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Hong K, Zhao G, Hong Z, Sun Z, Yang Y, Clifford PS, Davis MJ, Meininger GA, Hill MA. Mechanical activation of angiotensin II type 1 receptors causes actin remodelling and myogenic responsiveness in skeletal muscle arterioles. J Physiol 2016; 594:7027-7047. [PMID: 27531064 PMCID: PMC5134373 DOI: 10.1113/jp272834] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Accepted: 08/09/2016] [Indexed: 12/15/2022] Open
Abstract
KEY POINTS Candesartan, an inverse agonist of the type 1 angiotensin II receptor (AT1 R), causes a concentration-dependent inhibition of pressure-dependent myogenic tone consistent with previous reports of mechanosensitivity of this G protein-coupled receptor. Mechanoactivation of the AT1 R occurs independently of local angiotensin II production and the type 2 angiotensin receptor. Mechanoactivation of the AT1 R stimulates actin polymerization by a protein kinase C-dependent mechanism, but independently of a change in intracellular Ca2+ . Using atomic force microscopy, changes in single vascular smooth muscle cell cortical actin are observed to remodel following mechanoactivation of the AT1 R. ABSTRACT The Gq/11 protein-coupled angiotensin II type 1 receptor (AT1 R) has been shown to be activated by mechanical stimuli. In the vascular system, evidence supports the AT1 R being a mechanosensor that contributes to arteriolar myogenic constriction. The aim of this study was to determine if AT1 R mechanoactivation affects myogenic constriction in skeletal muscle arterioles and to determine underlying cellular mechanisms. Using pressure myography to study rat isolated first-order cremaster muscle arterioles the AT1 R inhibitor candesartan (10-7 -10-5 m) showed partial but concentration-dependent inhibition of myogenic reactivity. Inhibition was demonstrated by a rightward shift in the pressure-diameter relationship over the intraluminal pressure range, 30-110 mmHg. Pressure-induced changes in global vascular smooth muscle intracellular Ca2+ (using Fura-2) were similar in the absence or presence of candesartan, indicating that AT1 R-mediated myogenic constriction relies on Ca2+ -independent downstream signalling. The diacylglycerol analogue 1-oleoyl-2-acetyl-sn-glycerol (OAG) reversed the inhibitory effect of candesartan, while this rescue effect was prevented by the protein kinase C (PKC) inhibitor GF 109203X. Both candesartan and PKC inhibition caused increased G-actin levels, as determined by Western blotting of vessel lysates, supporting involvement of cytoskeletal remodelling. At the single vascular smooth muscle cell level, atomic force microscopy showed that cell swelling (stretch) with hypotonic buffer also caused thickening of cortical actin fibres and this was blocked by candesartan. Collectively, the present studies support growing evidence for novel modes of activation of the AT1 R in arterioles and suggest that mechanically activated AT1 R generates diacylglycerol, which in turn activates PKC which induces the actin cytoskeleton reorganization that is required for pressure-induced vasoconstriction.
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Affiliation(s)
- Kwangseok Hong
- Dalton Cardiovascular Research CentreUniversity of MissouriColumbiaMO65211USA
- Department of Medical Pharmacology and PhysiologyUniversity of MissouriColumbiaMO65211USA
- Robert M. Berne Cardiovascular Research Centre and Department of Molecular Physiology and Biological PhysicsUniversity of VirginiaCharlottesvilleVA22908USA
| | - Guiling Zhao
- College of Applied Health SciencesUniversity of Illinois at ChicagoChicagoIL60612USA
| | - Zhongkui Hong
- Dalton Cardiovascular Research CentreUniversity of MissouriColumbiaMO65211USA
- Department of Biomedical EngineeringUniversity of South DakotaSioux FallsSD57107USA
| | - Zhe Sun
- Dalton Cardiovascular Research CentreUniversity of MissouriColumbiaMO65211USA
- Department of Medical Pharmacology and PhysiologyUniversity of MissouriColumbiaMO65211USA
| | - Yan Yang
- Dalton Cardiovascular Research CentreUniversity of MissouriColumbiaMO65211USA
| | - Philip S. Clifford
- College of Applied Health SciencesUniversity of Illinois at ChicagoChicagoIL60612USA
| | - Michael J. Davis
- Dalton Cardiovascular Research CentreUniversity of MissouriColumbiaMO65211USA
- Department of Medical Pharmacology and PhysiologyUniversity of MissouriColumbiaMO65211USA
| | - Gerald A. Meininger
- Dalton Cardiovascular Research CentreUniversity of MissouriColumbiaMO65211USA
- Department of Medical Pharmacology and PhysiologyUniversity of MissouriColumbiaMO65211USA
| | - Michael A. Hill
- Dalton Cardiovascular Research CentreUniversity of MissouriColumbiaMO65211USA
- Department of Medical Pharmacology and PhysiologyUniversity of MissouriColumbiaMO65211USA
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32
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Pappas AC, Koide M, Wellman GC. Purinergic signaling triggers endfoot high-amplitude Ca2+ signals and causes inversion of neurovascular coupling after subarachnoid hemorrhage. J Cereb Blood Flow Metab 2016; 36:1901-1912. [PMID: 27207166 PMCID: PMC5094310 DOI: 10.1177/0271678x16650911] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 04/25/2016] [Indexed: 01/09/2023]
Abstract
Neurovascular coupling supports brain metabolism by matching focal increases in neuronal activity with local arteriolar dilation. Previously, we demonstrated that an emergence of spontaneous endfoot high-amplitude Ca2+ signals (eHACSs) caused a pathologic shift in neurovascular coupling from vasodilation to vasoconstriction in brain slices obtained from subarachnoid hemorrhage model animals. Extracellular purine nucleotides (e.g., ATP) can trigger astrocyte Ca2+ oscillations and may be elevated following subarachnoid hemorrhage. Here, the role of purinergic signaling in subarachnoid hemorrhage-induced eHACSs and inversion of neurovascular coupling was examined by imaging parenchymal arteriolar diameter and astrocyte Ca2+ signals in rat brain slices using two-photon fluorescent and infrared-differential interference contrast microscopy. We report that broad-spectrum inhibition of purinergic (P2) receptors using suramin blocked eHACSs and restored vasodilatory neurovascular coupling after subarachnoid hemorrhage. Importantly, eHACSs were also abolished using a cocktail of inhibitors targeting Gq-coupled P2Y receptors. Further, activation of P2Y receptors in brain slices from un-operated animals triggered high-amplitude Ca2+ events resembling eHACSs and disrupted neurovascular coupling. Neither tetrodotoxin nor bafilomycin A1 affected eHACSs suggesting that purine nucleotides are not released by ongoing neurotransmission and/or vesicular release after subarachnoid hemorrhage. These results indicate that purinergic signaling via P2Y receptors contributes to subarachnoid hemorrhage-induced eHACSs and inversion of neurovascular coupling.
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Affiliation(s)
- Anthony C Pappas
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Masayo Koide
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - George C Wellman
- Department of Pharmacology, University of Vermont, Burlington, VT, USA .,Department of Surgery, Division of Neurosurgery, University of Vermont, Burlington, VT, USA
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Khavandi K, Baylie RA, Sugden SA, Ahmed M, Csato V, Eaton P, Hill-Eubanks DC, Bonev AD, Nelson MT, Greenstein AS. Pressure-induced oxidative activation of PKG enables vasoregulation by Ca2+ sparks and BK channels. Sci Signal 2016; 9:ra100. [PMID: 27729550 DOI: 10.1126/scisignal.aaf6625] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Activation of Ca2+-sensitive, large-conductance potassium (BK) channels in vascular smooth muscle cells (VSMCs) by local, ryanodine receptor-mediated Ca2+ signals (Ca2+ sparks) acts as a brake on pressure-induced (myogenic) vasoconstriction-a fundamental mechanism that regulates blood flow in small resistance arteries. We report that physiological intraluminal pressure within resistance arteries activated cGMP-dependent protein kinase (PKG) in VSMCs through oxidant-induced formation of an intermolecular disulfide bond between cysteine residues. Oxidant-activated PKG was required to trigger Ca2+ sparks, BK channel activity, and vasodilation in response to pressure. VSMCs from arteries from mice expressing a form of PKG that could not be activated by oxidants showed reduced Ca2+ spark frequency, and arterial preparations from these mice had decreased pressure-induced activation of BK channels. Thus, the absence of oxidative activation of PKG disabled the BK channel-mediated negative feedback regulation of vasoconstriction. Our results support the concept of a negative feedback control mechanism that regulates arterial diameter through mechanosensitive production of oxidants to activate PKG and enhance Ca2+ sparks.
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Affiliation(s)
- Kaivan Khavandi
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, Manchester Academic Health Sciences Center, Manchester, M13 9NT, UK.,King's College London, Cardiovascular Division, The British Heart Foundation Centre of Excellence, The Rayne Institute, Saint Thomas' Hospital, London, SE1 7EH, UK
| | - Rachael A Baylie
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, Manchester Academic Health Sciences Center, Manchester, M13 9NT, UK
| | - Sarah A Sugden
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, Manchester Academic Health Sciences Center, Manchester, M13 9NT, UK
| | - Majid Ahmed
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, Manchester Academic Health Sciences Center, Manchester, M13 9NT, UK.,Department of Pharmacology, University of Vermont, Vermont, 05405-0068, USA
| | - Viktoria Csato
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, Manchester Academic Health Sciences Center, Manchester, M13 9NT, UK.,Division of Clinical Physiology, Institute of Cardiology, Research Centre for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen 4012, Hungary
| | - Philip Eaton
- King's College London, Cardiovascular Division, The British Heart Foundation Centre of Excellence, The Rayne Institute, Saint Thomas' Hospital, London, SE1 7EH, UK
| | | | - Adrian D Bonev
- Department of Pharmacology, University of Vermont, Vermont, 05405-0068, USA
| | - Mark T Nelson
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, Manchester Academic Health Sciences Center, Manchester, M13 9NT, UK.,Department of Pharmacology, University of Vermont, Vermont, 05405-0068, USA
| | - Adam S Greenstein
- Institute of Cardiovascular Sciences, Faculty of Medical and Human Sciences, University of Manchester, Manchester Academic Health Sciences Center, Manchester, M13 9NT, UK
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Longden TA, Hill-Eubanks DC, Nelson MT. Ion channel networks in the control of cerebral blood flow. J Cereb Blood Flow Metab 2016; 36:492-512. [PMID: 26661232 PMCID: PMC4794103 DOI: 10.1177/0271678x15616138] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/17/2015] [Accepted: 10/14/2015] [Indexed: 12/26/2022]
Abstract
One hundred and twenty five years ago, Roy and Sherrington made the seminal observation that neuronal stimulation evokes an increase in cerebral blood flow.(1) Since this discovery, researchers have attempted to uncover how the cells of the neurovascular unit-neurons, astrocytes, vascular smooth muscle cells, vascular endothelial cells and pericytes-coordinate their activity to control this phenomenon. Recent work has revealed that ionic fluxes through a diverse array of ion channel species allow the cells of the neurovascular unit to engage in multicellular signaling processes that dictate local hemodynamics.In this review we center our discussion on two major themes: (1) the roles of ion channels in the dynamic modulation of parenchymal arteriole smooth muscle membrane potential, which is central to the control of arteriolar diameter and therefore must be harnessed to permit changes in downstream cerebral blood flow, and (2) the striking similarities in the ion channel complements employed in astrocytic endfeet and endothelial cells, enabling dual control of smooth muscle from either side of the blood-brain barrier. We conclude with a discussion of the emerging roles of pericyte and capillary endothelial cell ion channels in neurovascular coupling, which will provide fertile ground for future breakthroughs in the field.
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Affiliation(s)
- Thomas A Longden
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | | | - Mark T Nelson
- Department of Pharmacology, University of Vermont, Burlington, VT, USA Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
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Constantine M, Liew CK, Lo V, Macmillan A, Cranfield CG, Sunde M, Whan R, Graham RM, Martinac B. Heterologously-expressed and Liposome-reconstituted Human Transient Receptor Potential Melastatin 4 Channel (TRPM4) is a Functional Tetramer. Sci Rep 2016; 6:19352. [PMID: 26785754 PMCID: PMC4726259 DOI: 10.1038/srep19352] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/11/2015] [Indexed: 11/24/2022] Open
Abstract
Mutation, irregular expression and sustained activation of the Transient Receptor Potential Channel, type Melastatin 4 (TRPM4), have been linked to various cardiovascular diseases. However, much remains unknown about the structure of this important ion channel. Here, we have purified a heterologously expressed TRPM4-eGFP fusion protein and investigated the oligomeric state of TRPM4-eGFP in detergent micelles using crosslinking, native gel electrophoresis, multi-angle laser light scattering and electron microscopy. Our data indicate that TRPM4 is tetrameric, like other TRP channels studied to date. Furthermore, the functionality of liposome reconstituted TRPM4-eGFP was examined using electrophysiology. Single-channel recordings from TRPM4-eGFP proteoliposomes showed inhibition of the channel using Flufenamic acid, a well-established inhibitor of TRPM4, suggesting that the channels are functional upon reconstitution. Our characterisation of the oligomeric structure of TRPM4 and the ability to reconstitute functional channels in liposomes should facilitate future studies into the structure, function and pharmacology of this therapeutically relevant channel.
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Affiliation(s)
- Maryrose Constantine
- Victor Chang Cardiac Research Institute, Lowy Packer Building, NSW 2010
- St Vincent’s Clinical School, University of New South Wales, Sydney, NSW 2010, Australia
| | - Chu Kong Liew
- Victor Chang Cardiac Research Institute, Lowy Packer Building, NSW 2010
| | - Victor Lo
- School of Medical Sciences, The Bosch Institute, The University of Sydney, NSW 2006
| | - Alex Macmillan
- Biomedical Imaging Facility, Lowy Cancer Research Centre, The University of New South Wales, Kensington, NSW 2052, Australia
| | | | - Margaret Sunde
- School of Medical Sciences, The Bosch Institute, The University of Sydney, NSW 2006
| | - Renee Whan
- Biomedical Imaging Facility, Lowy Cancer Research Centre, The University of New South Wales, Kensington, NSW 2052, Australia
| | - Robert M. Graham
- Victor Chang Cardiac Research Institute, Lowy Packer Building, NSW 2010
- St Vincent’s Clinical School, University of New South Wales, Sydney, NSW 2010, Australia
| | - Boris Martinac
- Victor Chang Cardiac Research Institute, Lowy Packer Building, NSW 2010
- St Vincent’s Clinical School, University of New South Wales, Sydney, NSW 2010, Australia
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36
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Earley S, Brayden JE. Transient receptor potential channels in the vasculature. Physiol Rev 2015; 95:645-90. [PMID: 25834234 DOI: 10.1152/physrev.00026.2014] [Citation(s) in RCA: 301] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The mammalian genome encodes 28 distinct members of the transient receptor potential (TRP) superfamily of cation channels, which exhibit varying degrees of selectivity for different ionic species. Multiple TRP channels are present in all cells and are involved in diverse aspects of cellular function, including sensory perception and signal transduction. Notably, TRP channels are involved in regulating vascular function and pathophysiology, the focus of this review. TRP channels in vascular smooth muscle cells participate in regulating contractility and proliferation, whereas endothelial TRP channel activity is an important contributor to endothelium-dependent vasodilation, vascular wall permeability, and angiogenesis. TRP channels are also present in perivascular sensory neurons and astrocytic endfeet proximal to cerebral arterioles, where they participate in the regulation of vascular tone. Almost all of these functions are mediated by changes in global intracellular Ca(2+) levels or subcellular Ca(2+) signaling events. In addition to directly mediating Ca(2+) entry, TRP channels influence intracellular Ca(2+) dynamics through membrane depolarization associated with the influx of cations or through receptor- or store-operated mechanisms. Dysregulation of TRP channels is associated with vascular-related pathologies, including hypertension, neointimal injury, ischemia-reperfusion injury, pulmonary edema, and neurogenic inflammation. In this review, we briefly consider general aspects of TRP channel biology and provide an in-depth discussion of the functions of TRP channels in vascular smooth muscle cells, endothelial cells, and perivascular cells under normal and pathophysiological conditions.
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Affiliation(s)
- Scott Earley
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada; and Department of Pharmacology, University of Vermont College of Medicine, Burlington, Vermont
| | - Joseph E Brayden
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada; and Department of Pharmacology, University of Vermont College of Medicine, Burlington, Vermont
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Longden TA, Nelson MT. Vascular inward rectifier K+ channels as external K+ sensors in the control of cerebral blood flow. Microcirculation 2015; 22:183-96. [PMID: 25641345 PMCID: PMC4404517 DOI: 10.1111/micc.12190] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 01/16/2015] [Indexed: 12/25/2022]
Abstract
For decades it has been known that external K(+) ions are rapid and potent vasodilators that increase CBF. Recent studies have implicated the local release of K(+) from astrocytic endfeet-which encase the entirety of the parenchymal vasculature-in the dynamic regulation of local CBF during NVC. It has been proposed that the activation of KIR channels in the vascular wall by external K(+) is a central component of these hyperemic responses; however, a number of significant gaps in our knowledge remain. Here, we explore the concept that vascular KIR channels are the major extracellular K(+) sensors in the control of CBF. We propose that K(+) is an ideal mediator of NVC, and discuss KIR channels as effectors that produce rapid hyperpolarization and robust vasodilation of cerebral arterioles. We provide evidence that KIR channels, of the KIR 2 subtype in particular, are present in both the endothelial and SM cells of parenchymal arterioles and propose that this dual positioning of KIR 2 channels increases the robustness of the vasodilation to external K(+), enables the endothelium to be actively engaged in NVC, and permits electrical signaling through the endothelial syncytium to promote upstream vasodilation to modulate CBF.
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Affiliation(s)
- Thomas A Longden
- Department of Pharmacology, College of Medicine, University of Vermont, Burlington, Vermont, USA
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