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Liu R, Collier JM, Abdul-Rahman NH, Capuk O, Zhang Z, Begum G. Dysregulation of Ion Channels and Transporters and Blood-Brain Barrier Dysfunction in Alzheimer's Disease and Vascular Dementia. Aging Dis 2024; 15:1748-1770. [PMID: 38300642 PMCID: PMC11272208 DOI: 10.14336/ad.2023.1201] [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: 09/13/2023] [Accepted: 12/01/2023] [Indexed: 02/02/2024] Open
Abstract
The blood-brain barrier (BBB) plays a critical role in maintaining ion and fluid homeostasis, essential for brain metabolism and neuronal function. Regulation of nutrient, water, and ion transport across the BBB is tightly controlled by specialized ion transporters and channels located within its unique cellular components. These dynamic transport processes not only influence the BBB's structure but also impact vital signaling mechanisms, essential for its optimal function. Disruption in ion, pH, and fluid balance at the BBB is associated with brain pathology and has been implicated in various neurological conditions, including stroke, epilepsy, trauma, and neurodegenerative diseases such as Alzheimer's disease (AD). However, knowledge gaps exist regarding the impact of ion transport dysregulation on BBB function in neurodegenerative dementias. Several factors contribute to this gap: the complex nature of these conditions, historical research focus on neuronal mechanisms and technical challenges in studying the ion transport mechanisms in in vivo models and the lack of efficient in vitro BBB dementia models. This review provides an overview of current research on the roles of ion transporters and channels at the BBB and poses specific research questions: 1) How are the expression and activity of key ion transporters altered in AD and vascular dementia (VaD); 2) Do these changes contribute to BBB dysfunction and disease progression; and 3) Can restoring ion transport function mitigate BBB dysfunction and improve clinical outcomes. Addressing these gaps will provide a greater insight into the vascular pathology of neurodegenerative disorders.
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Affiliation(s)
- Ruijia Liu
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
- Department of Neurology, The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Jenelle M Collier
- Department of Neurology, The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
- Center for Neuroscience, University of Pittsburgh, Pittsburgh, PA, USA.
| | | | - Okan Capuk
- Department of Neurology, The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Zhongling Zhang
- Department of Neurology, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China.
| | - Gulnaz Begum
- Department of Neurology, The Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh, Pittsburgh, PA, USA.
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Liang P, Wan YCS, Yu K, Hartzell HC, Yang H. Niclosamide potentiates TMEM16A and induces vasoconstriction. J Gen Physiol 2024; 156:e202313460. [PMID: 38814250 PMCID: PMC11138202 DOI: 10.1085/jgp.202313460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 03/15/2024] [Accepted: 05/22/2024] [Indexed: 05/31/2024] Open
Abstract
The TMEM16A calcium-activated chloride channel is a promising therapeutic target for various diseases. Niclosamide, an anthelmintic medication, has been considered a TMEM16A inhibitor for treating asthma and chronic obstructive pulmonary disease (COPD) but was recently found to possess broad-spectrum off-target effects. Here, we show that, under physiological Ca2+ (200-500 nM) and voltages, niclosamide acutely potentiates TMEM16A. Our computational and functional characterizations pinpoint a putative niclosamide binding site on the extracellular side of TMEM16A. Mutations in this site attenuate the potentiation. Moreover, niclosamide potentiates endogenous TMEM16A in vascular smooth muscle cells, triggers intracellular calcium increase, and constricts the murine mesenteric artery. Our findings advise caution when considering clinical applications of niclosamide as a TMEM16A inhibitor. The identification of the putative niclosamide binding site provides insights into the mechanism of TMEM16A pharmacological modulation and provides insights into developing specific TMEM16A modulators to treat human diseases.
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Affiliation(s)
- Pengfei Liang
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
| | - Yui Chun S. Wan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
| | - Kuai Yu
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - H. Criss Hartzell
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA, USA
| | - Huanghe Yang
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
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3
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Harlow RC, Pea GA, Broyhill SE, Patro A, Bromert KH, Stewart RH, Heaps CL, Castorena-Gonzalez JA, Dongaonkar RM, Zawieja SD. Loss of anoctamin 1 reveals a subtle role for BK channels in lymphatic muscle action potentials. J Physiol 2024; 602:3351-3373. [PMID: 38704841 PMCID: PMC11250503 DOI: 10.1113/jp285459] [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: 10/21/2023] [Accepted: 04/11/2024] [Indexed: 05/07/2024] Open
Abstract
Ca2+ signalling plays a crucial role in determining lymphatic muscle cell excitability and contractility through its interaction with the Ca2+-activated Cl- channel anoctamin 1 (ANO1). In contrast, the large-conductance (BK) Ca2+-activated K+ channel (KCa) and other KCa channels have prominent vasodilatory actions by hyperpolarizing vascular smooth muscle cells. Here, we assessed the expression and contribution of the KCa family to mouse and rat lymphatic collecting vessel contractile function. The BK channel was the only KCa channel consistently expressed in fluorescence-activated cell sorting-purified mouse lymphatic muscle cell lymphatic muscle cells. We used a pharmacological inhibitor of BK channels, iberiotoxin, and small-conductance Ca2+-activated K+ channels, apamin, to inhibit KCa channels acutely in ex vivo isobaric myography experiments and intracellular membrane potential recordings. In basal conditions, BK channel inhibition had little to no effect on either mouse inguinal-axillary lymphatic vessel (MIALV) or rat mesenteric lymphatic vessel contractions or action potentials (APs). We also tested BK channel inhibition under loss of ANO1 either by genetic ablation (Myh11CreERT2-Ano1 fl/fl, Ano1ismKO) or by pharmacological inhibition with Ani9. In both Ano1ismKO MIALVs and Ani9-pretreated MIALVs, inhibition of BK channels increased contraction amplitude, increased peak AP and broadened the peak of the AP spike. In rat mesenteric lymphatic vessels, BK channel inhibition also abolished the characteristic post-spike notch, which was exaggerated with ANO1 inhibition, and significantly increased the peak potential and broadened the AP spike. We conclude that BK channels are present and functional on mouse and rat lymphatic muscle cells but are otherwise masked by the dominance of ANO1. KEY POINTS: Mouse and rat lymphatic muscle cells express functional BK channels. BK channels make little contribution to either rat or mouse lymphatic collecting vessel contractile function in basal conditions across a physiological pressure range. ANO1 limits the peak membrane potential achieved in the action potential and sets a plateau potential limiting the voltage-dependent activation of BK. BK channels are activated when ANO1 is absent or blocked and slightly impair contractile strength by reducing the peak membrane potential achieved in the action potential spike and accelerating the post-spike repolarization.
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Affiliation(s)
- Rebecca C Harlow
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, USA
| | - Grace A Pea
- Department of Medical Pharmacology & Physiology, University of Missouri, Columbia, MO, USA
| | - Sarah E Broyhill
- Department of Medical Pharmacology & Physiology, University of Missouri, Columbia, MO, USA
| | - Advaya Patro
- Department of Medical Pharmacology & Physiology, University of Missouri, Columbia, MO, USA
| | - Karen H Bromert
- Department of Medical Pharmacology & Physiology, University of Missouri, Columbia, MO, USA
| | - Randolph H Stewart
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, USA
| | - Cristine L Heaps
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, USA
| | | | - Ranjeet M Dongaonkar
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, USA
| | - Scott D Zawieja
- Department of Medical Pharmacology & Physiology, University of Missouri, Columbia, MO, USA
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4
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Raut S, Singh K, Sanghvi S, Loyo-Celis V, Varghese L, Singh E, Gururaja Rao S, Singh H. Chloride ions in health and disease. Biosci Rep 2024; 44:BSR20240029. [PMID: 38573803 PMCID: PMC11065649 DOI: 10.1042/bsr20240029] [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: 01/09/2024] [Revised: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 04/06/2024] Open
Abstract
Chloride is a key anion involved in cellular physiology by regulating its homeostasis and rheostatic processes. Changes in cellular Cl- concentration result in differential regulation of cellular functions such as transcription and translation, post-translation modifications, cell cycle and proliferation, cell volume, and pH levels. In intracellular compartments, Cl- modulates the function of lysosomes, mitochondria, endosomes, phagosomes, the nucleus, and the endoplasmic reticulum. In extracellular fluid (ECF), Cl- is present in blood/plasma and interstitial fluid compartments. A reduction in Cl- levels in ECF can result in cell volume contraction. Cl- is the key physiological anion and is a principal compensatory ion for the movement of the major cations such as Na+, K+, and Ca2+. Over the past 25 years, we have increased our understanding of cellular signaling mediated by Cl-, which has helped in understanding the molecular and metabolic changes observed in pathologies with altered Cl- levels. Here, we review the concentration of Cl- in various organs and cellular compartments, ion channels responsible for its transportation, and recent information on its physiological roles.
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Affiliation(s)
- Satish K. Raut
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Kulwinder Singh
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Shridhar Sanghvi
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
- Department of Molecular Cellular and Developmental Biology, The Ohio State University, Columbus, OH, U.S.A
| | - Veronica Loyo-Celis
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Liyah Varghese
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | - Ekam R. Singh
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
| | | | - Harpreet Singh
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, U.S.A
- Department of Molecular Cellular and Developmental Biology, The Ohio State University, Columbus, OH, U.S.A
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Mahapatra C, Kumar R. Biophysical Mechanisms of Vaginal Smooth Muscle Contraction: The Role of the Membrane Potential and Ion Channels. PATHOPHYSIOLOGY 2024; 31:225-243. [PMID: 38804298 PMCID: PMC11130850 DOI: 10.3390/pathophysiology31020018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/10/2024] [Accepted: 05/14/2024] [Indexed: 05/29/2024] Open
Abstract
The vagina is an essential component of the female reproductive system and is responsible for providing female sexual satisfaction. Vaginal smooth muscle contraction plays a crucial role in various physiological processes, including sexual arousal, childbirth, and urinary continence. In pathophysiological conditions, such as pelvic floor disorders, aberrations in vaginal smooth muscle function can lead to urinary incontinence and pelvic organ prolapse. A set of cellular and sub-cellular physiological mechanisms regulates the contractile properties of the vaginal smooth muscle cells. Calcium influx is a crucial determinant of smooth muscle contraction, facilitated through voltage-dependent calcium channels and calcium release from intracellular stores. Comprehensive reviews on smooth muscle biophysics are relatively scarce within the scientific literature, likely due to the complexity and specialized nature of the topic. The objective of this review is to provide a comprehensive description of alterations in the cellular physiology of vaginal smooth muscle contraction. The benefit associated with this particular approach is that conducting a comprehensive examination of the cellular mechanisms underlying contractile activation will enable the creation of more targeted therapeutic agents to control vaginal contraction disorders.
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Affiliation(s)
- Chitaranjan Mahapatra
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94158, USA
- Paris Saclay Institute of Neuroscience, 91440 Saclay, France
| | - Ravinder Kumar
- Department of Pathology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN 38163, USA
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Wang J, Luo J, Liu Y, Jiang Y, Qu X, Liu C, Xiang Y, Qin X. Stress stimulation promotes the injury repair process of airway epithelial cells through the [Cl -] i-FAK signaling axis. Respir Physiol Neurobiol 2024; 323:104237. [PMID: 38354845 DOI: 10.1016/j.resp.2024.104237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 01/25/2024] [Accepted: 02/06/2024] [Indexed: 02/16/2024]
Abstract
The airway epithelium serves as a critical interface with the external environment, making it vulnerable to various external stimuli. Airway epithelial stress acts as a catalyst for the onset of numerous pulmonary and systemic diseases. Our previous studies have highlighted the impact of acute stress stimuli, especially bacterial lipopolysaccharide (LPS) and hydrogen peroxide (H2O2), on the continuous elevation of intracellular chloride concentration ([Cl-]i). However, the precise mechanism behind this [Cl-]i elevation and the consequential effects of such stress on the injury repair function of airway epithelial cells remain unclear. Our findings indicate that H2O2 induces an elevation in [Cl-]i by modulating the expression of CF transmembrane conductance regulator (CFTR) and Ca-activated transmembrane protein 16 A (TMEM16A) in airway epithelial cells (BEAS-2B), whereas LPS achieves this solely through CFTR. Subsequently, the elevated [Cl-]i level facilitated the injury repair process of airway epithelial cells by activating focal adhesion kinase (FAK). In summary, the [Cl-]i-FAK axis appears to play a promoting effect on the injury repair process triggered by stress stimulation. Furthermore, our findings suggest that abnormalities in the [Cl-]i-FAK signaling axis may play a crucial role in the pathogenesis of chronic airway diseases. Therefore, controlling the structure and function of airway epithelial barriers through the modulation of [Cl-]i holds promising prospects for future applications in managing and treating such conditions.
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Affiliation(s)
- Jia Wang
- Hunan Provincial People's Hospital, The First-affiliated Hospital of Hunan Normal University, Changsha 410016, China; Department of Physiology, School of Basic Medicine, Central South University, Changsha 410000, China
| | - Jinhua Luo
- Department of Physiology, School of Basic Medicine, Central South University, Changsha 410000, China
| | - Yanjuan Liu
- Hunan Provincial People's Hospital, The First-affiliated Hospital of Hunan Normal University, Changsha 410016, China
| | - Yu Jiang
- Hunan Provincial People's Hospital, The First-affiliated Hospital of Hunan Normal University, Changsha 410016, China
| | - Xiangping Qu
- Department of Physiology, School of Basic Medicine, Central South University, Changsha 410000, China
| | - Chi Liu
- Department of Physiology, School of Basic Medicine, Central South University, Changsha 410000, China
| | - Yang Xiang
- Department of Physiology, School of Basic Medicine, Central South University, Changsha 410000, China.
| | - Xiaoqun Qin
- Department of Physiology, School of Basic Medicine, Central South University, Changsha 410000, China.
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7
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Raghavan S, Brishti MA, Bernardelli A, Mata-Daboin A, Jaggar JH, Leo MD. Extracellular glucose and dysfunctional insulin receptor signaling independently upregulate arterial smooth muscle TMEM16A expression. Am J Physiol Cell Physiol 2024; 326:C1237-C1247. [PMID: 38581667 PMCID: PMC11193522 DOI: 10.1152/ajpcell.00555.2023] [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: 10/23/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 04/08/2024]
Abstract
Diabetes alters the function of ion channels responsible for regulating arterial smooth muscle membrane potential, resulting in vasoconstriction. Our prior research demonstrated an elevation of TMEM16A in diabetic arteries. Here, we explored the mechanisms involved in Transmembrane protein 16A (TMEM16A) gene expression. Our data indicate that a Snail-mediated repressor complex regulates arterial TMEM16A gene transcription. Snail expression was reduced in diabetic arteries while TMEM16A expression was upregulated. The TMEM16A promoter contained three canonical E-box sites. Electrophoretic mobility and super shift assays revealed that the -154 nt E-box was the binding site of the Snail repressor complex and binding of the repressor complex decreased in diabetic arteries. High glucose induced a biphasic contractile response in pressurized nondiabetic mouse hindlimb arteries incubated ex vivo. Hindlimb arteries incubated in high glucose also showed decreased phospho-protein kinase D1 and TMEM16A expression. In hindlimb arteries from nondiabetic mice, administration of a bolus dose of glucose activated protein kinase D1 signaling to induce Snail degradation. In both in vivo and ex vivo conditions, Snail expression exhibited an inverse relationship with the expression of protein kinase D1 and TMEM16A. In diabetic mouse arteries, phospho-protein kinase D1 increased while Akt2 and pGSK3β levels declined. These results indicate that in nondiabetic mice, high glucose triggers a transient deactivation of the Snail repressor complex to increase arterial TMEM16A expression independently of insulin signaling. Conversely, insulin resistance activates GSK3β signaling and enhances arterial TMEM16A channel expression. These data have uncovered the Snail-mediated regulation of arterial TMEM16A expression and its dysfunction during diabetes.NEW & NOTEWORTHY The calcium-activated chloride channel, TMEM16A, is upregulated in the diabetic vasculature to cause increased vasoconstriction. In this paper, we have uncovered that the TMEM16A gene expression is controlled by a Snail-mediated repressor complex that uncouples with both insulin-dependent and -independent pathways to allow for upregulated arterial protein expression thereby causing vasoconstriction. The paper highlights the effect of short- and long-term glucose-induced dysfunction of an ion channel expression as a causative factor in diabetic vascular disease.
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Affiliation(s)
- Somasundaram Raghavan
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Masuma Akter Brishti
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Angelica Bernardelli
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Alejandro Mata-Daboin
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - Jonathan H Jaggar
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, United States
| | - M Dennis Leo
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, United States
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee, United States
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Al-Hosni R, Kaye R, Choi CS, Tammaro P. The TMEM16A channel as a potential therapeutic target in vascular disease. Curr Opin Nephrol Hypertens 2024; 33:161-169. [PMID: 38193301 PMCID: PMC10842660 DOI: 10.1097/mnh.0000000000000967] [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] [Indexed: 01/10/2024]
Abstract
PURPOSE OF REVIEW The transmembrane protein 16A (TMEM16A) Ca 2+ -activated Cl - channel constitutes a key depolarising mechanism in vascular smooth muscle and contractile pericytes, while in endothelial cells the channel is implicated in angiogenesis and in the response to vasoactive stimuli. Here, we offer a critical analysis of recent physiological investigations and consider the potential for targeting TMEM16A channels in vascular disease. RECENT FINDINGS Genetic deletion or pharmacological inhibition of TMEM16A channels in vascular smooth muscle decreases artery tone and lowers systemic blood pressure in rodent models. Inhibition of TMEM16A channels in cerebral cortical pericytes protects against ischemia-induced tissue damage and improves microvascular blood flow in rodent stroke models. In endothelial cells, the TMEM16A channel plays varied roles including modulation of cell division and control of vessel tone through spread of hyperpolarisation to the smooth muscle cells. Genetic studies implicate TMEM16A channels in human disease including systemic and pulmonary hypertension, stroke and Moyamoya disease. SUMMARY The TMEM16A channel regulates vascular function by controlling artery tone and capillary diameter as well as vessel formation and histology. Preclinical and clinical investigations are highlighting the potential for therapeutic exploitation of the channel in a range of maladaptive states of the (micro)circulation.
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Affiliation(s)
- Rumaitha Al-Hosni
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford, UK
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Xiao C, Sun Y, Huang H, Yue X, Song Z, David T, Xu S. Cellular communication among smooth muscle cells: The role of membrane potential via connexins. J Theor Biol 2024; 576:111627. [PMID: 37977477 DOI: 10.1016/j.jtbi.2023.111627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/16/2023] [Accepted: 09/25/2023] [Indexed: 11/19/2023]
Abstract
Communication via action potentials among neurons has been extensively studied. However, effective communication without action potentials is ubiquitous in biological systems, yet it has received much less attention in comparison. Multi-cellular communication among smooth muscles is crucial for regulating blood flow, for example. Understanding the mechanism of this non-action potential communication is critical in many cases, like synchronization of cellular activity, under normal and pathological conditions. In this paper, we employ a multi-scale asymptotic method to derive a macroscopic homogenized bidomain model from the microscopic electro-neutral (EN) model. This is achieved by considering different diffusion coefficients and incorporating nonlinear interface conditions. Subsequently, the homogenized macroscopic model is used to investigate communication in multi-cellular tissues. Our computational simulations reveal that the membrane potential of syncytia, formed by interconnected cells via connexins, plays a crucial role in propagating oscillations from one region to another, providing an effective means for fast cellular communication. Statement of Significance: In this study, we investigated cellular communication and ion transport in vascular smooth muscle cells, shedding light on their mechanisms under normal and abnormal conditions. Our research highlights the potential of mathematical models in understanding complex biological systems. We developed effective macroscale electro-neutral bi-domain ion transport models and examined their behavior in response to different stimuli. Our findings revealed the crucial role of connexinmediated membrane potential changes and demonstrated the effectiveness of cellular communication through syncytium membranes. Despite some limitations, our study provides valuable insights into these processes and emphasizes the importance of mathematical modeling in unraveling the complexities of cellular communication and ion transport.
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Affiliation(s)
- Chun Xiao
- School of Mathematics and Statistics, Lingnan Normal University, Zhanjiang, 524048, China.
| | - Yishui Sun
- Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge CB3 0WA, United Kingdom.
| | - Huaxiong Huang
- Research Center for Mathematics, Advanced Institute of Natural Sciences, Beijing Normal University, Zhuhai, Guangdong, 519088, China; Guangdong Provincial Key Laboratory of Interdisciplinary Research and Application for Data Science, BNU-HKBU United International College, Zhuhai, Guangdong, 519088, China; Laboratory of Mathematics and Complex Systems, MOE, Beijing Normal University, 100875, Beijing, China; Department of Mathematics and Statistics York University, Toronto, ON, M3J 1P3, Canada.
| | - Xingye Yue
- School of Mathematical Sciences, Soochow University, Suzhou 215006, China.
| | - Zilong Song
- Math and Statistics Department, Utah State University, Old Main Hill, Logan , UT 84322, USA.
| | - Tim David
- Department of Mechanical Engineering, College of Engineering, University of Canterbury, Private Bag 4800, Christchurch, 8041, New Zealand.
| | - Shixin Xu
- Zu Chongzhi Center for Mathematics and Computational Sciences (CMCS), Duke Kunshan University, Kunshan, 215316, China.
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10
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Grainger N. Identifying peristaltic pacemaker cells in the upper urinary tract. J Physiol 2024. [PMID: 38180778 DOI: 10.1113/jp284754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Accepted: 12/18/2023] [Indexed: 01/06/2024] Open
Abstract
Urine expulsion from the upper urinary tract is a necessary process that eliminates waste, promotes renal filtration and prevents nephron damage. To facilitate the movement of urine boluses throughout the upper urinary tract, smooth muscle cells that line the renal pelvis contract in a coordinated effort to form peristaltic waves. Resident pacemaker cells in the renal pelvis are critical to this process and spontaneously evoke transient depolarizations that initiate each peristaltic wave and establish rhythmic contractions. Renal pacemakers have been termed atypical smooth muscle cells due to their low expression of smooth muscle myosin and poor organization of myofilaments compared to typical (or contractile) smooth muscle cells that perform peristalsis. Recent findings discovered that pacemaker cells also express the tyrosine kinase receptor PDGFRα, enabling their identification and purification amongst other renal pelvis cell types. Improved identification methods have determined that the calcium-activated chloride channel, ANO1, is expressed by pacemaker cells and may contribute to spontaneous depolarization. A greater understanding of pacemaker and peristaltic mechanisms is warranted since aberrant contractile function may underlie diseases such as hydronephrosis, a deleterious condition that can cause significant and irreversible nephron injury.
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Affiliation(s)
- Nathan Grainger
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, Nevada, USA
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11
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Mata-Daboin A, Garrud TAC, Fernandez-Pena C, Peixoto-Neves D, Leo MD, Bernardelli AK, Singh P, Malik KU, Jaggar JH. Vasodilators activate the anion channel TMEM16A in endothelial cells to reduce blood pressure. Sci Signal 2023; 16:eadh9399. [PMID: 37963195 PMCID: PMC10694922 DOI: 10.1126/scisignal.adh9399] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 10/20/2023] [Indexed: 11/16/2023]
Abstract
Systemic blood pressure is acutely controlled by total peripheral resistance as determined by the diameter of small arteries and arterioles, the contractility of which is regulated by endothelial cells lining the lumen of blood vessels. We investigated the physiological functions of the chloride (Cl-) channel TMEM16A in endothelial cells. TMEM16A channels generated calcium (Ca2+)-activated Cl- currents in endothelial cells from control (TMEM16Afl/fl) mice that were absent in those from mice with tamoxifen-inducible, endothelial cell-specific knockout of TMEM16A (TMEM16A ecKO). TMEM16A currents in endothelial cells were activated by the muscarinic receptor agonist acetylcholine and an agonist of the Ca2+ channel TRPV4, which localized in nanoscale proximity with TMEM16A as assessed by single-molecule localization imaging of endothelial cells. Acetylcholine stimulated TMEM16A currents by activating Ca2+ influx through surface TRPV4 channels without altering the nanoscale properties of TMEM16A and TRPV4 surface clusters or their colocalization. In pressurized arteries, activation of TMEM16A channels in endothelial cells induced by acetylcholine; TRPV4 channel stimulation; or intraluminal ATP, another vasodilator, produced hyperpolarization and dilation. Furthermore, deficiency of TMEM16A channels in endothelial cells resulted in increased systemic blood pressure in conscious mice. These data indicate that vasodilators stimulate TRPV4 channels, leading to Ca2+-dependent activation of nearby TMEM16A channels in endothelial cells to produce arterial hyperpolarization, vasodilation, and reduced blood pressure. Thus, TMEM16A is an anion channel in endothelial cells that regulates arterial contractility and blood pressure.
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Affiliation(s)
- Alejandro Mata-Daboin
- Department of Physiology, University of Tennessee Health Science Center, Memphis TN 38163
| | - Tessa A. C. Garrud
- Department of Physiology, University of Tennessee Health Science Center, Memphis TN 38163
| | - Carlos Fernandez-Pena
- Department of Physiology, University of Tennessee Health Science Center, Memphis TN 38163
| | | | - M. Dennis Leo
- Department of Physiology, University of Tennessee Health Science Center, Memphis TN 38163
| | | | - Purnima Singh
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis TN 38163
| | - Kafait U. Malik
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis TN 38163
| | - Jonathan H. Jaggar
- Department of Physiology, University of Tennessee Health Science Center, Memphis TN 38163
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Akin EJ, Aoun J, Jimenez C, Mayne K, Baeck J, Young MD, Sullivan B, Sanders KM, Ward SM, Bulley S, Jaggar JH, Earley S, Greenwood IA, Leblanc N. ANO1, CaV1.2, and IP3R form a localized unit of EC-coupling in mouse pulmonary arterial smooth muscle. J Gen Physiol 2023; 155:e202213217. [PMID: 37702787 PMCID: PMC10499037 DOI: 10.1085/jgp.202213217] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/01/2023] [Accepted: 08/29/2023] [Indexed: 09/14/2023] Open
Abstract
Pulmonary arterial (PA) smooth muscle cells (PASMC) generate vascular tone in response to agonists coupled to Gq-protein receptor signaling. Such agonists stimulate oscillating calcium waves, the frequency of which drives the strength of contraction. These Ca2+ events are modulated by a variety of ion channels including voltage-gated calcium channels (CaV1.2), the Tmem16a or Anoctamin-1 (ANO1)-encoded calcium-activated chloride (CaCC) channel, and Ca2+ release from the sarcoplasmic reticulum through inositol-trisphosphate receptors (IP3R). Although these calcium events have been characterized, it is unclear how these calcium oscillations underly a sustained contraction in these muscle cells. We used smooth muscle-specific ablation of ANO1 and pharmacological tools to establish the role of ANO1, CaV1.2, and IP3R in the contractile and intracellular Ca2+ signaling properties of mouse PA smooth muscle expressing the Ca2+ biosensor GCaMP3 or GCaMP6. Pharmacological block or genetic ablation of ANO1 or inhibition of CaV1.2 or IP3R, or Ca2+ store depletion equally inhibited 5-HT-induced tone and intracellular Ca2+ waves. Coimmunoprecipitation experiments showed that an anti-ANO1 antibody was able to pull down both CaV1.2 and IP3R. Confocal and superresolution nanomicroscopy showed that ANO1 coassembles with both CaV1.2 and IP3R at or near the plasma membrane of PASMC from wild-type mice. We conclude that the stable 5-HT-induced PA contraction results from the integration of stochastic and localized Ca2+ events supported by a microenvironment comprising ANO1, CaV1.2, and IP3R. In this model, ANO1 and CaV1.2 would indirectly support cyclical Ca2+ release events from IP3R and propagation of intracellular Ca2+ waves.
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Affiliation(s)
- Elizabeth J. Akin
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, Reno, NV, USA
| | - Joydeep Aoun
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, Reno, NV, USA
| | - Connor Jimenez
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, Reno, NV, USA
| | - Katie Mayne
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, Reno, NV, USA
| | - Julius Baeck
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, Reno, NV, USA
| | - Michael D. Young
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, Reno, NV, USA
| | - Brennan Sullivan
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, Reno, NV, USA
| | - Kenton M. Sanders
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Sean M. Ward
- Department of Physiology and Cell Biology, University of Nevada, Reno School of Medicine, Reno, NV, USA
| | - Simon Bulley
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jonathan H. Jaggar
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Scott Earley
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, Reno, NV, USA
| | - Iain A. Greenwood
- Department of Vascular Pharmacology, Molecular and Clinical Science Research Institute, St. George’s University of London, London, UK
| | - Normand Leblanc
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, Reno, NV, USA
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13
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Mata-Daboin A, Garrud TAC, Fernandez-Pena C, Peixoto-Neves D, Leo MD, Bernardelli AK, Singh P, Malik KU, Jaggar JH. Vasodilators activate TMEM16A channels in endothelial cells to reduce blood pressure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.02.543450. [PMID: 37333248 PMCID: PMC10274675 DOI: 10.1101/2023.06.02.543450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Endothelial cells (ECs) regulate vascular contractility to control regional organ blood flow and systemic blood pressure. Several cation channels are expressed in ECs which regulate arterial contractility. In contrast, the molecular identity and physiological functions of anion channels in ECs is unclear. Here, we generated tamoxifen-inducible, EC-specific TMEM16A knockout ( TMEM16A ecKO) mice to investigate the functional significance of this chloride (Cl - ) channel in the resistance vasculature. Our data demonstrate that TMEM16A channels generate calcium-activated Cl - currents in ECs of control ( TMEM16A fl/fl ) mice that are absent in ECs of TMEM16A ecKO mice. Acetylcholine (ACh), a muscarinic receptor agonist, and GSK101, a TRPV4 agonist, activate TMEM16A currents in ECs. Single molecule localization microscopy data indicate that surface TMEM16A and TRPV4 clusters locate in very close nanoscale proximity, with ∼18% exhibiting overlap in ECs. ACh stimulates TMEM16A currents by activating Ca 2+ influx through surface TRPV4 channels without altering the size or density of TMEM16A or TRPV4 surface clusters, their spatial proximity or colocalization. ACh-induced activation of TMEM16A channels in ECs produces hyperpolarization in pressurized arteries. ACh, GSK101 and intraluminal ATP, another vasodilator, all dilate pressurized arteries through TMEM16A channel activation in ECs. Furthermore, EC-specific knockout of TMEM16A channels elevates systemic blood pressure in conscious mice. In summary, these data indicate that vasodilators stimulate TRPV4 channels, leading to Ca 2+ -dependent activation of nearby TMEM16A channels in ECs to produce arterial hyperpolarization, vasodilation and a reduction in blood pressure. We identify TMEM16A as an anion channel present in ECs that regulates arterial contractility and blood pressure. One sentence summary Vasodilators stimulate TRPV4 channels, leading to calcium-dependent activation of nearby TMEM16A channels in ECs to produce arterial hyperpolarization, vasodilation and a reduction in blood pressure.
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14
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Romero-Martínez BS, Sommer B, Solís-Chagoyán H, Calixto E, Aquino-Gálvez A, Jaimez R, Gomez-Verjan JC, González-Avila G, Flores-Soto E, Montaño LM. Estrogenic Modulation of Ionic Channels, Pumps and Exchangers in Airway Smooth Muscle. Int J Mol Sci 2023; 24:ijms24097879. [PMID: 37175587 PMCID: PMC10178541 DOI: 10.3390/ijms24097879] [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: 02/08/2023] [Revised: 02/28/2023] [Accepted: 02/28/2023] [Indexed: 05/15/2023] Open
Abstract
To preserve ionic homeostasis (primarily Ca2+, K+, Na+, and Cl-), in the airway smooth muscle (ASM) numerous transporters (channels, exchangers, and pumps) regulate the influx and efflux of these ions. Many of intracellular processes depend on continuous ionic permeation, including exocytosis, contraction, metabolism, transcription, fecundation, proliferation, and apoptosis. These mechanisms are precisely regulated, for instance, through hormonal activity. The lipophilic nature of steroidal hormones allows their free transit into the cell where, in most cases, they occupy their cognate receptor to generate genomic actions. In the sense, estrogens can stimulate development, proliferation, migration, and survival of target cells, including in lung physiology. Non-genomic actions on the other hand do not imply estrogen's intracellular receptor occupation, nor do they initiate transcription and are mostly immediate to the stimulus. Among estrogen's non genomic responses regulation of calcium homeostasis and contraction and relaxation processes play paramount roles in ASM. On the other hand, disruption of calcium homeostasis has been closely associated with some ASM pathological mechanism. Thus, this paper intends to summarize the effects of estrogen on ionic handling proteins in ASM. The considerable diversity, range and power of estrogens regulates ionic homeostasis through genomic and non-genomic mechanisms.
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Affiliation(s)
- Bianca S Romero-Martínez
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Bettina Sommer
- Laboratorio de Hiperreactividad Bronquial, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", Ciudad de México 14080, Mexico
| | - Héctor Solís-Chagoyán
- Neurociencia Cognitiva Evolutiva, Centro de Investigación en Ciencias Cognitivas, Universidad Autónoma del Estado de Morelos, Cuernavaca 62209, Mexico
| | - Eduardo Calixto
- Departamento de Neurobiología, Dirección de Investigación en Neurociencias, Instituto Nacional de Psiquiatría "Ramón de la Fuente Muñiz", Ciudad de México 14370, Mexico
| | - Arnoldo Aquino-Gálvez
- Laboratorio de Biología Molecular, Departamento de Fibrosis Pulmonar, Instituto Nacional de Enfermedades Respiratorias Ismael Cosío Villegas, México City 14080, Mexico
| | - Ruth Jaimez
- Laboratorio de Estrógenos y Hemostasis, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Juan C Gomez-Verjan
- Dirección de Investigación, Instituto Nacional de Geriatría (INGER), Ciudad de México 10200, Mexico
| | - Georgina González-Avila
- Laboratorio de Oncología Biomédica, Instituto Nacional de Enfermedades Respiratorias "Ismael Cosío Villegas", México City 14080, Mexico
| | - Edgar Flores-Soto
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
| | - Luis M Montaño
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
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15
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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: 45] [Impact Index Per Article: 45.0] [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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16
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Jimenez C, Hawn MB, Akin E, Leblanc N. Translational potential of targeting Anoctamin-1-Encoded Calcium-Activated chloride channels in hypertension. Biochem Pharmacol 2022; 206:115320. [PMID: 36279919 DOI: 10.1016/j.bcp.2022.115320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 10/13/2022] [Accepted: 10/17/2022] [Indexed: 12/14/2022]
Abstract
Calcium-activated chloride channels (CaCC) provide a depolarizing stimulus to a variety of tissues through chloride efflux in response to a rise in internal Ca2+ and voltage. One of these channels, Anoctamin-1 (ANO1 or TMEM16A) is now recognized to play a central role in promoting smooth muscle tone in various types of blood vessels. Its role in hypertension, and thus the therapeutic promise of targeting ANO1, is less straightforward. This review gives an overview of our current knowledge about the potential role ANO1 may play in hypertension within the systemic, portal, and pulmonary vascular systems and the importance of this information when pursuing potential treatment strategies. While the role of ANO1 is well-established in several forms of pulmonary hypertension, its contributions to both the generation of vascular tone and its role in hypertension within the systemic and portal systems are much less clear. This, combined with ANO1's various roles throughout a multitude of tissues throughout the body, command caution when targeting ANO1 as a therapeutic target and may require tissue-selective strategies.
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Affiliation(s)
- Connor Jimenez
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Matthew B Hawn
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Elizabeth Akin
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, 1664 North Virginia Street, Reno, Nevada 89557, USA
| | - Normand Leblanc
- Department of Pharmacology and Center of Biomedical Research Excellence (COBRE) for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, 1664 North Virginia Street, Reno, Nevada 89557, USA.
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17
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Goto K, Kitazono T. Chloride Ions, Vascular Function and Hypertension. Biomedicines 2022; 10:biomedicines10092316. [PMID: 36140417 PMCID: PMC9496098 DOI: 10.3390/biomedicines10092316] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/10/2022] [Accepted: 09/15/2022] [Indexed: 11/26/2022] Open
Abstract
Blood pressure is determined by cardiac output and systemic vascular resistance, and mediators that induce vasoconstriction will increase systemic vascular resistance and thus elevate blood pressure. While peripheral vascular resistance reflects a complex interaction of multiple factors, vascular ion channels and transporters play important roles in the regulation of vascular tone by modulating the membrane potential of vascular cells. In vascular smooth muscle cells, chloride ions (Cl−) are a type of anions accumulated by anion exchangers and the anion–proton cotransporter system, and efflux of Cl− through Cl− channels depolarizes the membrane and thereby triggers vasoconstriction. Among these Cl− regulatory pathways, emerging evidence suggests that upregulation of the Ca2+-activated Cl− channel TMEM16A in the vasculature contributes to the increased vascular contractility and elevated blood pressure in hypertension. A robust accumulation of intracellular Cl− in vascular smooth muscle cells through the increased activity of Na+–K+–2Cl− cotransporter 1 (NKCC1) during hypertension has also been reported. Thus, the enhanced activity of both TMEM16A and NKCC1 could act additively and sequentially to increase vascular contractility and hence blood pressure in hypertension. In this review, we discuss recent findings regarding the role of Cl− in the regulation of vascular tone and arterial blood pressure and its association with hypertension, with a particular focus on TMEM16A and NKCC1.
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Affiliation(s)
- Kenichi Goto
- Department of Health Sciences, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
- Correspondence:
| | - Takanari Kitazono
- Department of Medicine and Clinical Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan
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18
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Amano T, Yamamura A, Fujiwara M, Hirai S, Kondo R, Suzuki Y, Yamamura H. Upregulated ClC3 channels/transporters elicit swelling-activated Cl - currents and induce excessive cell proliferation in idiopathic pulmonary arterial hypertension. Biol Pharm Bull 2022; 45:1684-1691. [PMID: 35989293 DOI: 10.1248/bpb.b22-00513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pulmonary arterial hypertension (PAH) is characterized by vascular remodeling of the pulmonary artery, which is mainly attributed to the excessive proliferation of pulmonary arterial smooth muscle cells (PASMCs) comprising the medial layer of pulmonary arteries. The activity of ion channels associated with cytosolic Ca2+ signaling regulates the pathogenesis of PAH. Limited information is currently available on the role of Cl- channels in PASMCs. Therefore, the functional expression of ClC3 channels/transporters was herein investigated in the PASMCs of normal subjects and patients with idiopathic pulmonary arterial hypertension (IPAH). Expression analyses revealed the upregulated expression of ClC3 channels/transporters at the mRNA and protein levels in IPAH-PASMCs. Hypoosmotic perfusion (230 mOsm) evoked swelling-activated Cl- currents (ICl-swell) in normal-PASMCs, whereas 100 μM 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid (DIDS) exerted the opposite effects. The siRNA knockdown of ClC3 did not affect ICl-swell. On the other hand, ICl-swell was larger in IPAH-PASMCs and inhibited by DIDS and the siRNA knockdown of ClC3. IPAH-PASMCs grew more than normal-PASMCs. The growth of IPAH-PASMCs was suppressed by niflumic acid and DIDS, but not by 9-anthracenecarboxylic acid or T16Ainh-A01. The siRNA knockdown of ClC3 also inhibited the proliferation of IPAH-PASMCs. Collectively, the present results indicate that upregulated ClC3 channels/transporters are involved in ICl-swell and the excessive proliferation of IPAH-PASMCs, thereby contributing to the pathogenesis of PAH. Therefore, ClC3 channels/transporters have potential as a target of therapeutic drugs for the treatment of PAH.
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Affiliation(s)
- Taiki Amano
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Aya Yamamura
- Department of Physiology, Aichi Medical University
| | - Moe Fujiwara
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Seiji Hirai
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
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19
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Kawata N, Kondo R, Suzuki Y, Yamamura H. Increased TMEM16A-mediated Ca 2+-activated Cl - currents in portal vein smooth muscle cells of caveolin 1-deficient mice. Biol Pharm Bull 2022; 45:1692-1698. [PMID: 35989294 DOI: 10.1248/bpb.b22-00514] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ca2+-activated Cl- (ClCa) channels regulate membrane excitability and myogenic tone in vascular smooth muscles. TMEM16A-coding proteins are mainly responsible for functional ClCa channels in vascular smooth muscles, including portal vein smooth muscles (PVSMs). Caveolae are cholesterol-rich and Ω-shaped invaginations on the plasma membrane that structurally contributes to effective and efficient signal transduction. Caveolin 1 (Cav1) accumulates in caveolae to form functional complexes among receptors, ion channels, and kinases. The present study examined the functional roles of Cav1 in the expression and activity of ClCa channels in the portal vein smooth muscle cells (PVSMCs) of wild-type (WT) and Cav1-knockout (KO) mice. Contractile experiments revealed that the amplitude of spontaneous PVSM contractions was larger in Cav1-KO mice than WT mice. Under whole-cell patch-clamp configurations, ClCa currents were markedly inhibited by 1 μM Ani9 (a selective TMEM16A ClCa channel blocker) in WT and Cav1-KO PVSMCs. However, Ani9-sensitive ClCa currents were significantly larger in Cav1-KO PVSMCs than in WT PVSMCs. Expression analyses showed that TMEM16A expression levels were higher in Cav1-KO PVSMs than in WT PVSMs. Therefore, the caveolar structure formed by Cav1 negatively regulates the expression and activity of TMEM16A-mediated ClCa channels in vascular smooth muscle cells.
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Affiliation(s)
- Naoki Kawata
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University
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20
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Delpire E, Ben-Ari Y. A Wholistic View of How Bumetanide Attenuates Autism Spectrum Disorders. Cells 2022; 11:cells11152419. [PMID: 35954263 PMCID: PMC9367773 DOI: 10.3390/cells11152419] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/22/2022] [Accepted: 08/03/2022] [Indexed: 01/27/2023] Open
Abstract
The specific NKCC1 cotransporter antagonist, bumetanide, attenuates the severity of Autism Spectrum Disorders (ASD), and many neurodevelopmental or neurodegenerative disorders in animal models and clinical trials. However, the pervasive expression of NKCC1 in many cell types throughout the body is thought to challenge the therapeutic efficacy of bumetanide. However, many peripheral functions, including intestinal, metabolic, or vascular, etc., are perturbed in brain disorders contributing to the neurological sequels. Alterations of these functions also increase the incidence of the disorder suggesting complex bidirectional links with the clinical manifestations. We suggest that a more holistic view of ASD and other disorders is warranted to account for the multiple sites impacted by the original intra-uterine insult. From this perspective, large-spectrum active repositioned drugs that act centrally and peripherally might constitute a useful approach to treating these disorders.
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Affiliation(s)
- Eric Delpire
- Departments of Anesthesiology and Molecular Physiology & Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
- Correspondence:
| | - Yehezkel Ben-Ari
- NeuroChlore, Campus Scientifique de Luminy, 163 Route de Luminy, 13273 Marseilles, France
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21
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Al-Hosni R, Ilkan Z, Agostinelli E, Tammaro P. The pharmacology of the TMEM16A channel: therapeutic opportunities. Trends Pharmacol Sci 2022; 43:712-725. [PMID: 35811176 DOI: 10.1016/j.tips.2022.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 12/15/2022]
Abstract
The TMEM16A Ca2+-gated Cl- channel is involved in a variety of vital physiological functions and may be targeted pharmacologically for therapeutic benefit in diseases such as hypertension, stroke, and cystic fibrosis (CF). The determination of the TMEM16A structure and high-throughput screening efforts, alongside ex vivo and in vivo animal studies and clinical investigations, are hastening our understanding of the physiology and pharmacology of this channel. Here, we offer a critical analysis of recent developments in TMEM16A pharmacology and reflect on the therapeutic opportunities provided by this target.
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Affiliation(s)
- Rumaitha Al-Hosni
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Zeki Ilkan
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Emilio Agostinelli
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Paolo Tammaro
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
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22
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Korte N, Ilkan Z, Pearson CL, Pfeiffer T, Singhal P, Rock JR, Sethi H, Gill D, Attwell D, Tammaro P. The Ca2+-gated channel TMEM16A amplifies capillary pericyte contraction and reduces cerebral blood flow after ischemia. J Clin Invest 2022; 132:e154118. [PMID: 35316222 PMCID: PMC9057602 DOI: 10.1172/jci154118] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 03/16/2022] [Indexed: 11/26/2022] Open
Abstract
Pericyte-mediated capillary constriction decreases cerebral blood flow in stroke after an occluded artery is unblocked. The determinants of pericyte tone are poorly understood. We show that a small rise in cytoplasmic Ca2+ concentration ([Ca2+]i) in pericytes activated chloride efflux through the Ca2+-gated anion channel TMEM16A, thus depolarizing the cell and opening voltage-gated calcium channels. This mechanism strongly amplified the pericyte [Ca2+]i rise and capillary constriction evoked by contractile agonists and ischemia. In a rodent stroke model, TMEM16A inhibition slowed the ischemia-evoked pericyte [Ca2+]i rise, capillary constriction, and pericyte death; reduced neutrophil stalling; and improved cerebrovascular reperfusion. Genetic analysis implicated altered TMEM16A expression in poor patient recovery from ischemic stroke. Thus, pericyte TMEM16A is a crucial regulator of cerebral capillary function and a potential therapeutic target for stroke and possibly other disorders of impaired microvascular flow, such as Alzheimer's disease and vascular dementia.
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Affiliation(s)
- Nils Korte
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Zeki Ilkan
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Claire L. Pearson
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Thomas Pfeiffer
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Prabhav Singhal
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Jason R. Rock
- Center for Regenerative Medicine, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Huma Sethi
- Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, London, United Kingdom
| | - Dipender Gill
- Department of Epidemiology and Biostatistics, St Mary’s Hospital, Imperial College London, London, United Kingdom
| | - David Attwell
- Department of Neuroscience, Physiology & Pharmacology, University College London, London, United Kingdom
| | - Paolo Tammaro
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
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23
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Kondo R, Furukawa N, Deguchi A, Kawata N, Suzuki Y, Imaizumi Y, Yamamura H. Downregulation of Ca 2+-Activated Cl - Channel TMEM16A Mediated by Angiotensin II in Cirrhotic Portal Hypertensive Mice. Front Pharmacol 2022; 13:831311. [PMID: 35370660 PMCID: PMC8966666 DOI: 10.3389/fphar.2022.831311] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/01/2022] [Indexed: 12/29/2022] Open
Abstract
Portal hypertension is defined as an increased pressure in the portal venous system and occurs as a major complication in chronic liver diseases. The pathological mechanism underlying the pathogenesis and development of portal hypertension has been extensively investigated. Vascular tone of portal vein smooth muscles (PVSMs) is regulated by the activities of several ion channels, including Ca2+-activated Cl- (ClCa) channels. TMEM16A is mainly responsible for ClCa channel conductance in vascular smooth muscle cells, including portal vein smooth muscle cells (PVSMCs). In the present study, the functional roles of TMEM16A channels were examined using two experimental portal hypertensive models, bile duct ligation (BDL) mice with cirrhotic portal hypertension and partial portal vein ligation (PPVL) mice with non-cirrhotic portal hypertension. Expression analyses revealed that the expression of TMEM16A was downregulated in BDL-PVSMs, but not in PPVL-PVSMs. Whole-cell ClCa currents were smaller in BDL-PVSMCs than in sham- and PPVL-PVSMCs. The amplitude of spontaneous contractions was smaller and the frequency was higher in BDL-PVSMs than in sham- and PPVL-PVSMs. Spontaneous contractions sensitive to a specific inhibitor of TMEM16A channels, T16Ainh-A01, were reduced in BDL-PVSMs. Furthermore, in normal PVSMs, the downregulation of TMEM16A expression was mimicked by the exposure to angiotensin II, but not to bilirubin. This study suggests that the activity of ClCa channels is attenuated by the downregulation of TMEM16A expression in PVSMCs associated with cirrhotic portal hypertension, which is partly mediated by increased angiotensin II in cirrhosis.
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Affiliation(s)
- Rubii Kondo
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Nami Furukawa
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Akari Deguchi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Naoki Kawata
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Yoshiaki Suzuki
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Yuji Imaizumi
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Hisao Yamamura
- Department of Molecular and Cellular Pharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
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24
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Lee Y, Zawieja SD, Muthuchamy M. Lymphatic Collecting Vessel: New Perspectives on Mechanisms of Contractile Regulation and Potential Lymphatic Contractile Pathways to Target in Obesity and Metabolic Diseases. Front Pharmacol 2022; 13:848088. [PMID: 35355722 PMCID: PMC8959455 DOI: 10.3389/fphar.2022.848088] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Accepted: 02/17/2022] [Indexed: 01/19/2023] Open
Abstract
Obesity and metabolic syndrome pose a significant risk for developing cardiovascular disease and remain a critical healthcare challenge. Given the lymphatic system's role as a nexus for lipid absorption, immune cell trafficking, interstitial fluid and macromolecule homeostasis maintenance, the impact of obesity and metabolic disease on lymphatic function is a burgeoning field in lymphatic research. Work over the past decade has progressed from the association of an obese phenotype with Prox1 haploinsufficiency and the identification of obesity as a risk factor for lymphedema to consistent findings of lymphatic collecting vessel dysfunction across multiple metabolic disease models and organisms and characterization of obesity-induced lymphedema in the morbidly obese. Critically, recent findings have suggested that restoration of lymphatic function can also ameliorate obesity and insulin resistance, positing lymphatic targeted therapies as relevant pharmacological interventions. There remain, however, significant gaps in our understanding of lymphatic collecting vessel function, particularly the mechanisms that regulate the spontaneous contractile activity required for active lymph propulsion and lymph return in humans. In this article, we will review the current findings on lymphatic architecture and collecting vessel function, including recent advances in the ionic basis of lymphatic muscle contractile activity. We will then discuss lymphatic dysfunction observed with metabolic disruption and potential pathways to target with pharmacological approaches to improve lymphatic collecting vessel function.
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Affiliation(s)
- Yang Lee
- Department of Medical Physiology, College of Medicine, Texas A&M University, Bryan, TX, United States
| | - Scott D Zawieja
- Medical Pharmacology and Physiology, School of Medicine, University of Missouri, Columbia, MO, United States
| | - Mariappan Muthuchamy
- Department of Medical Physiology, College of Medicine, Texas A&M University, Bryan, TX, United States
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25
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Polymodal Control of TMEM16x Channels and Scramblases. Int J Mol Sci 2022; 23:ijms23031580. [PMID: 35163502 PMCID: PMC8835819 DOI: 10.3390/ijms23031580] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/20/2022] [Accepted: 01/20/2022] [Indexed: 02/01/2023] Open
Abstract
The TMEM16A/anoctamin-1 calcium-activated chloride channel (CaCC) contributes to a range of vital functions, such as the control of vascular tone and epithelial ion transport. The channel is a founding member of a family of 10 proteins (TMEM16x) with varied functions; some members (i.e., TMEM16A and TMEM16B) serve as CaCCs, while others are lipid scramblases, combine channel and scramblase function, or perform additional cellular roles. TMEM16x proteins are typically activated by agonist-induced Ca2+ release evoked by Gq-protein-coupled receptor (GqPCR) activation; thus, TMEM16x proteins link Ca2+-signalling with cell electrical activity and/or lipid transport. Recent studies demonstrate that a range of other cellular factors—including plasmalemmal lipids, pH, hypoxia, ATP and auxiliary proteins—also control the activity of the TMEM16A channel and its paralogues, suggesting that the TMEM16x proteins are effectively polymodal sensors of cellular homeostasis. Here, we review the molecular pathophysiology, structural biology, and mechanisms of regulation of TMEM16x proteins by multiple cellular factors.
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26
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Hawn MB, Akin E, Hartzell H, Greenwood IA, Leblanc N. Molecular mechanisms of activation and regulation of ANO1-Encoded Ca 2+-Activated Cl - channels. Channels (Austin) 2021; 15:569-603. [PMID: 34488544 PMCID: PMC8480199 DOI: 10.1080/19336950.2021.1975411] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 08/29/2021] [Indexed: 01/13/2023] Open
Abstract
Ca2+-activated Cl- channels (CaCCs) perform a multitude of functions including the control of cell excitability, regulation of cell volume and ionic homeostasis, exocrine and endocrine secretion, fertilization, amplification of olfactory sensory function, and control of smooth muscle cell contractility. CaCCs are the translated products of two members (ANO1 and ANO2, also known as TMEM16A and TMEM16B) of the Anoctamin family of genes comprising ten paralogs. This review focuses on recent progress in understanding the molecular mechanisms involved in the regulation of ANO1 by cytoplasmic Ca2+, post-translational modifications, and how the channel protein interacts with membrane lipids and protein partners. After first reviewing the basic properties of native CaCCs, we then present a brief historical perspective highlighting controversies about their molecular identity in native cells. This is followed by a summary of the fundamental biophysical and structural properties of ANO1. We specifically address whether the channel is directly activated by internal Ca2+ or indirectly through the intervention of the Ca2+-binding protein Calmodulin (CaM), and the structural domains responsible for Ca2+- and voltage-dependent gating. We then review the regulation of ANO1 by internal ATP, Calmodulin-dependent protein kinase II-(CaMKII)-mediated phosphorylation and phosphatase activity, membrane lipids such as the phospholipid phosphatidyl-(4,5)-bisphosphate (PIP2), free fatty acids and cholesterol, and the cytoskeleton. The article ends with a survey of physical and functional interactions of ANO1 with other membrane proteins such as CLCA1/2, inositol trisphosphate and ryanodine receptors in the endoplasmic reticulum, several members of the TRP channel family, and the ancillary Κ+ channel β subunits KCNE1/5.
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Affiliation(s)
- M. B. Hawn
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - E. Akin
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - H.C. Hartzell
- Department of Cell Biology, Emory University School of Medicine, USA
| | - I. A. Greenwood
- Department of Vascular Pharmacology, St. George’s University of London, UK
| | - N. Leblanc
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
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27
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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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28
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Leo MD, Peixoto-Nieves D, Yin W, Raghavan S, Muralidharan P, Mata-Daboin A, Jaggar JH. TMEM16A channel upregulation in arterial smooth muscle cells produces vasoconstriction during diabetes. Am J Physiol Heart Circ Physiol 2021; 320:H1089-H1101. [PMID: 33449847 PMCID: PMC7988758 DOI: 10.1152/ajpheart.00690.2020] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 01/11/2021] [Accepted: 01/13/2021] [Indexed: 12/11/2022]
Abstract
The pathological involvement of anion channels in vascular dysfunction that occurs during type 2 diabetes (T2D) is unclear. Here, we tested the hypothesis that TMEM16A, a calcium-activated chloride (Cl-) channel, contributes to modifications in arterial contractility during T2D. Our data indicate that T2D increased TMEM16A mRNA in arterial smooth muscle cells and total and surface TMEM16A protein in resistance-size cerebral and hindlimb arteries of mice. To examine vascular cell types in which TMEM16A protein increased and the functional consequences of TMEM16A upregulation during T2D, we generated tamoxifen-inducible, smooth muscle cell-specific TMEM16A knockout (TMEM16A smKO) mice. T2D increased both TMEM16A protein and Cl- current density in arterial smooth muscle cells of control (TMEM16Afl/fl) mice. In contrast, T2D did not alter arterial TMEM16A protein or Cl- current density in smooth muscle cells of TMEM16A smKO mice. Intravascular pressure stimulated greater vasoconstriction (myogenic tone) in the arteries of T2D TMEM16Afl/fl mice than in the arteries of nondiabetic TMEM16Afl/fl mice. This elevation in myogenic tone in response to T2D was abolished in the arteries of T2D TMEM16A smKO mice. T2D also reduced Akt2 protein and activity in the arteries of T2D mice. siRNA-mediated knockdown of Akt2, but not Akt1, increased arterial TMEM16A protein in nondiabetic mice. In summary, data indicate that T2D is associated with an increase in TMEM16A expression and currents in arterial smooth muscle cells that produces vasoconstriction. Data also suggest that a reduction in Akt2 function drives these pathological alterations during T2D.NEW & NOTEWORTHY We investigated the involvement of TMEM16A channels in vascular dysfunction during type 2 diabetes (T2D). TMEM16A message, protein, and currents were higher in smooth muscle cells of resistance-size arteries during T2D. Pressure stimulated greater vasoconstriction in the arteries of T2D mice that was abolished in the arteries of TMEM16A smKO mice. Akt2 protein and activity were both lower in T2D arteries, and Akt2 knockdown elevated TMEM16A protein. We propose that a decrease in Akt2 function stimulates TMEM16A expression in arterial smooth muscle cells, leading to vasoconstriction during T2D.
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MESH Headings
- Animals
- Anoctamin-1/deficiency
- Anoctamin-1/genetics
- Anoctamin-1/metabolism
- Arteries/metabolism
- Arteries/physiopathology
- Diabetes Mellitus, Experimental/chemically induced
- Diabetes Mellitus, Experimental/genetics
- Diabetes Mellitus, Experimental/metabolism
- Diabetes Mellitus, Experimental/physiopathology
- Diabetes Mellitus, Type 2/chemically induced
- Diabetes Mellitus, Type 2/genetics
- Diabetes Mellitus, Type 2/metabolism
- Diabetes Mellitus, Type 2/physiopathology
- Diabetic Angiopathies/etiology
- Diabetic Angiopathies/genetics
- Diabetic Angiopathies/metabolism
- Diabetic Angiopathies/physiopathology
- HEK293 Cells
- Hindlimb/blood supply
- Humans
- Insulin Resistance
- Male
- Membrane Potentials
- Mice, Inbred C57BL
- Mice, Knockout
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiopathology
- Myocytes, Smooth Muscle/metabolism
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- Signal Transduction
- Streptozocin
- Up-Regulation
- Vasoconstriction
- Mice
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Affiliation(s)
- M Dennis Leo
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee
| | | | - Wen Yin
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Somasundaram Raghavan
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee
| | | | - Alejandro Mata-Daboin
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Jonathan H Jaggar
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee
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29
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Hariharan A, Weir N, Robertson C, He L, Betsholtz C, Longden TA. The Ion Channel and GPCR Toolkit of Brain Capillary Pericytes. Front Cell Neurosci 2020; 14:601324. [PMID: 33390906 PMCID: PMC7775489 DOI: 10.3389/fncel.2020.601324] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 11/13/2020] [Indexed: 12/14/2022] Open
Abstract
Brain pericytes reside on the abluminal surface of capillaries, and their processes cover ~90% of the length of the capillary bed. These cells were first described almost 150 years ago (Eberth, 1871; Rouget, 1873) and have been the subject of intense experimental scrutiny in recent years, but their physiological roles remain uncertain and little is known of the complement of signaling elements that they employ to carry out their functions. In this review, we synthesize functional data with single-cell RNAseq screens to explore the ion channel and G protein-coupled receptor (GPCR) toolkit of mesh and thin-strand pericytes of the brain, with the aim of providing a framework for deeper explorations of the molecular mechanisms that govern pericyte physiology. We argue that their complement of channels and receptors ideally positions capillary pericytes to play a central role in adapting blood flow to meet the challenge of satisfying neuronal energy requirements from deep within the capillary bed, by enabling dynamic regulation of their membrane potential to influence the electrical output of the cell. In particular, we outline how genetic and functional evidence suggest an important role for Gs-coupled GPCRs and ATP-sensitive potassium (KATP) channels in this context. We put forth a predictive model for long-range hyperpolarizing electrical signaling from pericytes to upstream arterioles, and detail the TRP and Ca2+ channels and Gq, Gi/o, and G12/13 signaling processes that counterbalance this. We underscore critical questions that need to be addressed to further advance our understanding of the signaling topology of capillary pericytes, and how this contributes to their physiological roles and their dysfunction in disease.
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Affiliation(s)
- Ashwini Hariharan
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Nick Weir
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Colin Robertson
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD, United States
| | - Liqun He
- Rudbeck Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Christer Betsholtz
- Rudbeck Laboratory, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.,Department of Medicine Huddinge (MedH), Karolinska Institutet & Integrated Cardio Metabolic Centre, Huddinge, Sweden
| | - Thomas A Longden
- Department of Physiology, School of Medicine, University of Maryland, Baltimore, MD, United States
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30
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Virtanen MA, Uvarov P, Hübner CA, Kaila K. NKCC1, an Elusive Molecular Target in Brain Development: Making Sense of the Existing Data. Cells 2020; 9:cells9122607. [PMID: 33291778 PMCID: PMC7761970 DOI: 10.3390/cells9122607] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 12/14/2022] Open
Abstract
Ionotropic GABA transmission is mediated by anion (mainly Cl−)-permeable GABAA receptors (GABAARs). In immature neurons, GABA exerts depolarizing and sometimes functionally excitatory actions, based on active uptake of Cl− by the Na-K-2Cl cotransporter NKCC1. While functional evidence firmly shows NKCC1-mediated ion transport in immature and diseased neurons, molecular detection of NKCC1 in the brain has turned out to be extremely difficult. In this review, we describe the highly inconsistent data that are available on the cell type-specific expression patterns of the NKCC1 mRNA and protein in the CNS. We discuss the major technical caveats, including a lack of knock-out-controlled immunohistochemistry in the forebrain, possible effects of alternative splicing on the binding of antibodies and RNA probes, and the wide expression of NKCC1 in different cell types, which make whole-tissue analyses of NKCC1 useless for studying its neuronal expression. We also review novel single-cell RNAseq data showing that most of the NKCC1 in the adult CNS may, in fact, be expressed in non-neuronal cells, especially in glia. As future directions, we suggest single-cell NKCC1 mRNA and protein analyses and the use of genetically tagged endogenous proteins or systematically designed novel antibodies, together with proper knock-out controls, for the visualization of endogenous NKCC1 in distinct brain cell types and their subcellular compartments.
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Affiliation(s)
- Mari A. Virtanen
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Pavel Uvarov
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Christian A. Hübner
- Institute of Human Genetics, Jena University Hospital, Friedrich Schiller Universität, 07747 Jena, Germany;
| | - Kai Kaila
- Molecular and Integrative Biosciences, University of Helsinki, 00014 Helsinki, Finland; (M.A.V.); (P.U.)
- Neuroscience Center, Helsinki Institute of Life Science, University of Helsinki, 00014 Helsinki, Finland
- Correspondence: ; Tel.: +358-407256759
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31
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Matchkov VV, Black Joergensen H, Kamaev D, Hoegh Jensen A, Beck HC, Skryabin BV, Aalkjaer C. A paradoxical increase of force development in saphenous and tail arteries from heterozygous ANO1 knockout mice. Physiol Rep 2020; 8:e14645. [PMID: 33245843 PMCID: PMC7695021 DOI: 10.14814/phy2.14645] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 09/29/2020] [Accepted: 10/18/2020] [Indexed: 12/16/2022] Open
Abstract
A Ca2+‐activated Cl− channel protein, ANO1, is expressed in vascular smooth muscle cells where Cl− current is thought to potentiate contraction by contributing to membrane depolarization. However, there is an inconsistency between previous knockout and knockdown studies on ANO1’s role in small arteries. In this study, we assessed cardiovascular function of heterozygous mice with global deletion of exon 7 in the ANO1 gene. We found decreased expression of ANO1 in aorta, saphenous and tail arteries from heterozygous ANO1 knockout mice in comparison with wild type. Accordingly, ANO1 knockdown reduced the Ca2+‐activated Cl− current in smooth muscle cells. Consistent with conventional hypothesis, the contractility of aorta from ANO1 heterozygous mice was reduced. Surprisingly, we found an enhanced contractility of tail and saphenous arteries from ANO1 heterozygous mice when stimulated with noradrenaline, vasopressin, and K+‐induced depolarization. This difference was endothelium‐independent. The increased contractility of ANO1 downregulated small arteries was due to increased Ca2+ influx. The expression of L‐type Ca2+ channels was not affected but expression of the plasma membrane Ca2+ ATPase 1 and the Piezo1 channel was increased. Expressional analysis of tail arteries further suggested changes of ANO1 knockdown smooth muscle cells toward a pro‐contractile phenotype. We did not find any difference between genotypes in blood pressure, heart rate, pressor response, and vasorelaxation in vivo. Our findings in tail and saphenous arteries contrast with the conventional hypothesis and suggest additional roles for ANO1 as a multifunctional protein in the vascular wall that regulates Ca2+ homeostasis and smooth muscle cell phenotype.
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Affiliation(s)
- Vladimir V Matchkov
- Department of Biomedicine, MEMBRANES, Health, Aarhus University, Aarhus, Denmark
| | | | - Dmitrii Kamaev
- Department of Biomedicine, MEMBRANES, Health, Aarhus University, Aarhus, Denmark
| | - Andreas Hoegh Jensen
- Department of Biomedicine, MEMBRANES, Health, Aarhus University, Aarhus, Denmark
| | - Hans Christian Beck
- Department for Clinical Biochemistry and Pharmacology, University of Southern Denmark, Odense, Denmark
| | - Boris V Skryabin
- Medical Faculty, Core Facility Transgenic Animal and Genetic Engineering Models (TRAM), University of Muenster, Muenster, Germany
| | - Christian Aalkjaer
- Department of Biomedicine, MEMBRANES, Health, Aarhus University, Aarhus, Denmark
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32
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Shelton EL, Yang HC, Zhong J, Salzman MM, Kon V. Renal lymphatic vessel dynamics. Am J Physiol Renal Physiol 2020; 319:F1027-F1036. [PMID: 33103446 DOI: 10.1152/ajprenal.00322.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Similar to other organs, renal lymphatics remove excess fluid, solutes, and macromolecules from the renal interstitium. Given the kidney's unique role in maintaining body fluid homeostasis, renal lymphatics may be critical in this process. However, little is known regarding the pathways involved in renal lymphatic vessel function, and there are no studies on the effects of drugs targeting impaired interstitial clearance, such as diuretics. Using pressure myography, we showed that renal lymphatic collecting vessels are sensitive to changes in transmural pressure and have an optimal range of effective pumping. In addition, they are responsive to vasoactive factors known to regulate tone in other lymphatic vessels including prostaglandin E2 and nitric oxide, and their spontaneous contractility requires Ca2+ and Cl-. We also demonstrated that Na+-K+-2Cl- cotransporter Nkcc1, but not Nkcc2, is expressed in extrarenal lymphatic vessels. Furosemide, a loop diuretic that inhibits Na+-K+-2Cl- cotransporters, induced a dose-dependent dilation in lymphatic vessels and decreased the magnitude and frequency of spontaneous contractions, thereby reducing the ability of these vessels to propel lymph. Ethacrynic acid, another loop diuretic, had no effect on vessel tone. These data represent a significant step forward in our understanding of the mechanisms underlying renal lymphatic vessel function and highlight potential off-target effects of furosemide that may exacerbate fluid accumulation in edema-forming conditions.
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Affiliation(s)
- Elaine L Shelton
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Hai-Chun Yang
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, Tennessee
| | - Jianyong Zhong
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, Tennessee
| | - Michele M Salzman
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Valentina Kon
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, Tennessee
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33
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Mitsui R, Hashitani H. Synchrony of spontaneous Ca 2+ activity in microvascular mural cells. J Smooth Muscle Res 2020; 56:1-18. [PMID: 32249242 PMCID: PMC7132055 DOI: 10.1540/jsmr.56.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Spontaneous rhythmic constrictions known as vasomotion are developed in several microvascular beds in vivo. Vasomotion in arterioles is considered to facilitate blood flow, while venular vasomotion would facilitate tissue metabolite drainage. Mechanisms underlying vasomotion periodically generate synchronous Ca2+ transients in vascular smooth muscle cells (VSMCs). In visceral organs, mural cells (pericytes and VSMCs) in arterioles, capillaries and venules exhibit synchronous spontaneous Ca2+ transients. Since sympathetic regulation is rather limited in the intra-organ microvessels, spontaneous activity of mural cells may play an essential role in maintaining tissue perfusion. Synchronous spontaneous Ca2+ transients in precapillary arterioles (PCAs)/capillaries appear to propagate to upstream arterioles to drive their vasomotion, while venules develop their own synchronous Ca2+ transients and associated vasomotion. Spontaneous Ca2+ transients of mural cells primarily arise from IP3 and/or ryanodine receptor-mediated Ca2+ release from sarcoendoplasmic reticulum (SR/ER) Ca2+ stores. The resultant opening of Ca2+-activated Cl- channels (CaCCs) causes a membrane depolarisation that triggers Ca2+ influx via T-type and/or L-type voltage-dependent Ca2+ channels (VDCCs). Mural cells are electrically coupled with each other via gap junctions, and thus allow the sequential spread of CaCC or VDCC-dependent depolarisations to develop the synchrony of Ca2+ transients within their network. Importantly, the synchrony of spontaneous Ca2+ transients also requires a certain range of the resting membrane potential that is maintained by the opening of Kv7 voltage-dependent K+ (Kv7) and inward rectifier K+ (Kir) channels. Thus, a depolarised membrane would evoke asynchronous, 'premature' spontaneous Ca2+ transients, while a hyperpolarised membrane prevents any spontaneous activity.
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Affiliation(s)
- Retsu Mitsui
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, Japan
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, Japan
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PIP 2: A critical regulator of vascular ion channels hiding in plain sight. Proc Natl Acad Sci U S A 2020; 117:20378-20389. [PMID: 32764146 PMCID: PMC7456132 DOI: 10.1073/pnas.2006737117] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The phosphoinositide, phosphatidylinositol 4,5-bisphosphate (PIP2), has long been established as a major contributor to intracellular signaling, primarily by virtue of its role as a substrate for phospholipase C (PLC). Signaling by Gq-protein-coupled receptors triggers PLC-mediated hydrolysis of PIP2 into inositol 1,4,5-trisphosphate and diacylglycerol, which are well known to modulate vascular ion channel activity. Often overlooked, however, is the role PIP2 itself plays in this regulation. Although numerous reports have demonstrated that PIP2 is critical for ion channel regulation, how it impacts vascular function has received scant attention. In this review, we focus on PIP2 as a regulator of ion channels in smooth muscle cells and endothelial cells-the two major classes of vascular cells. We further address the concerted effects of such regulation on vascular function and blood flow control. We close with a consideration of current knowledge regarding disruption of PIP2 regulation of vascular ion channels in disease.
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Wang J, Luo J, Huang W, Liu C, Zeng D, Liu H, Qu X, Liu C, Xiang Y, Qin X. Increased intracellular Cl - concentration by activating FAK promotes airway epithelial BEAS-2B cells proliferation and wound healing. Arch Biochem Biophys 2019; 680:108225. [PMID: 31838119 DOI: 10.1016/j.abb.2019.108225] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/10/2019] [Accepted: 12/10/2019] [Indexed: 11/30/2022]
Abstract
An increase in intracellular Cl- concentration ([Cl-]i) may be a general response of airway epithelial cells to various stimuli and may participate in some basic cellular functions. However, whether the basic functional activities of cells, such as proliferation and wound healing, are related to Cl- activities remains unclear. This study aimed to investigate the effects and potential mechanisms of [Cl-]i on the proliferation and wound healing ability of airway epithelial BEAS-2B cells. BEAS-2B cells were treated with four Cl- channel inhibitors (T16Ainh-A01, CFTRinh-172, CaCCinh-A01, and IAA-94), and the Cl- fluorescence probe N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide was used. Results showed that all Cl- channel inhibitors could increase [Cl-]i in BEAS-2B cells. The increased [Cl-]i induced by Cl- channel inhibitors or clamping [Cl-]i at high levels enhanced the phosphorylation of focal adhesion kinase (FAK) and subsequently promoted the proliferation and wound healing ability of BEAS-2B cells. By contrast, the FAK inhibitor PF573228 abrogated these effects induced by the increased [Cl-]i. FAK also activated the PI3K/AKT signaling pathway. In conclusion, increased [Cl-]i promotes the proliferation and wound healing ability of BEAS-2B cells by activating FAK to activate the PI3K/AKT signaling pathway. Intracellular Cl- may act as a signaling molecule to regulate the proliferation and wound healing ability of airway epithelial cells.
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Affiliation(s)
- Jia Wang
- Department of Physiology, School of Basic Medicine, Central South University, Changsha, 410000, China; Hunan Provincial People's Hospital, The First-affiliated Hospital of Hunan Normal University, Changsha, 410016, China
| | - Jinhua Luo
- Department of Physiology, School of Basic Medicine, Central South University, Changsha, 410000, China
| | - Wenjie Huang
- Department of Physiology, School of Basic Medicine, Central South University, Changsha, 410000, China
| | - Caixia Liu
- College of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha, 410208, China
| | - Dan Zeng
- Department of Physiology, School of Basic Medicine, Central South University, Changsha, 410000, China; Hunan Provincial People's Hospital, The First-affiliated Hospital of Hunan Normal University, Changsha, 410016, China
| | - Huijun Liu
- Department of Physiology, School of Basic Medicine, Central South University, Changsha, 410000, China
| | - Xiangping Qu
- Department of Physiology, School of Basic Medicine, Central South University, Changsha, 410000, China
| | - Chi Liu
- Department of Physiology, School of Basic Medicine, Central South University, Changsha, 410000, China
| | - Yang Xiang
- Department of Physiology, School of Basic Medicine, Central South University, Changsha, 410000, China.
| | - Xiaoqun Qin
- Department of Physiology, School of Basic Medicine, Central South University, Changsha, 410000, China.
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Yarotskyy V, Malysz J, Petkov GV. Extracellular pH and intracellular phosphatidylinositol 4,5-bisphosphate control Cl - currents in guinea pig detrusor smooth muscle cells. Am J Physiol Cell Physiol 2019; 317:C1268-C1277. [PMID: 31577513 DOI: 10.1152/ajpcell.00189.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cl- channels serve as key regulators of excitability and contractility in vascular, intestinal, and airway smooth muscle cells. We recently reported a Cl- conductance in detrusor smooth muscle (DSM) cells. Here, we used the whole cell patch-clamp technique to further characterize biophysical properties and physiological regulators of the Cl- current in freshly isolated guinea pig DSM cells. The Cl- current demonstrated outward rectification arising from voltage-dependent gating of Cl- channels rather than the Cl- transmembrane gradient. An exposure of DSM cells to hypotonic extracellular solution (Δ 165 mOsm challenge) did not increase the Cl- current providing strong evidence that volume-regulated anion channels do not contribute to the Cl- current in DSM cells. The Cl- current was monotonically dependent on extracellular pH, larger and lower in magnitude at acidic (5.0) and basic pH (8.5) values, respectively. Additionally, intracellularly applied phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] analog [PI(4,5)P2-diC8] increased the average Cl- current density by approximately threefold in a voltage-independent manner. The magnitude of the DSM whole cell Cl- current did not depend on the cell surface area (cell capacitance) regardless of the presence or absence of PI(4,5)P2-diC8, an intriguing finding that underscores the complex nature of Cl- channel expression and function in DSM cells. Removal of both extracellular Ca2+ and Mg2+ did not affect the DSM whole cell Cl- current, whereas Gd3+ (1 mM) potentiated the current. Collectively, our recent and present findings strongly suggest that Cl- channels are critical regulators of DSM excitability and are regulated by extracellular pH, Gd3+, and PI(4,5)P2.
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Affiliation(s)
- Viktor Yarotskyy
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
| | - John Malysz
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Georgi V Petkov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, Tennessee
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Ayon RJ, Hawn MB, Aoun J, Wiwchar M, Forrest AS, Cunningham F, Singer CA, Valencik ML, Greenwood IA, Leblanc N. Molecular mechanism of TMEM16A regulation: role of CaMKII and PP1/PP2A. Am J Physiol Cell Physiol 2019; 317:C1093-C1106. [PMID: 31461344 DOI: 10.1152/ajpcell.00059.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
This study explored the mechanism by which Ca2+-activated Cl- channels (CaCCs) encoded by the Tmem16a gene are regulated by calmodulin-dependent protein kinase II (CaMKII) and protein phosphatases 1 (PP1) and 2A (PP2A). Ca2+-activated Cl- currents (IClCa) were recorded from HEK-293 cells expressing mouse TMEM16A. IClCa were evoked using a pipette solution in which free Ca2+ concentration was clamped to 500 nM, in the presence (5 mM) or absence of ATP. With 5 mM ATP, IClCa decayed to <50% of the initial current magnitude within 10 min after seal rupture. IClCa rundown seen with ATP-containing pipette solution was greatly diminished by omitting ATP. IClCa recorded after 20 min of cell dialysis with 0 ATP were more than twofold larger than those recorded with 5 mM ATP. Intracellular application of autocamtide-2-related inhibitory peptide (5 µM) or KN-93 (10 µM), two specific CaMKII inhibitors, produced a similar attenuation of TMEM16A rundown. In contrast, internal application of okadaic acid (30 nM) or cantharidin (100 nM), two nonselective PP1 and PP2A blockers, promoted the rundown of TMEM16A in cells dialyzed with 0 ATP. Mutating serine 528 of TMEM16A to an alanine led to a similar inhibition of TMEM16A rundown to that exerted by either one of the two CaMKII inhibitors tested, which was not observed for three putative CaMKII consensus sites for phosphorylation (T273, T622, and S730). Our results suggest that TMEM16A-mediated CaCCs are regulated by CaMKII and PP1/PP2A. Our data also suggest that serine 528 of TMEM16A is an important contributor to the regulation of IClCa by CaMKII.
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Affiliation(s)
- Ramon J Ayon
- Division of Translational and Regenerative Medicine, Department of Medicine, College of Medicine, The University of Arizona College of Medicine, Arizona Health Sciences Center, Tucson, Arizona
| | - Matthew B Hawn
- Department of Pharmacology, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada.,The Center for Cardiovascular Research, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Joydeep Aoun
- Department of Pharmacology, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada.,The Center for Cardiovascular Research, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Michael Wiwchar
- Department of Pharmacology, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Abigail S Forrest
- Department of Pharmacology, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Fiona Cunningham
- Department of Pharmacology, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Cherie A Singer
- Department of Pharmacology, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Maria L Valencik
- Department of Pharmacology, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
| | - Iain A Greenwood
- Institute of Molecular and Clinical Sciences, St. George's University of London, London, United Kingdom
| | - Normand Leblanc
- Department of Pharmacology, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada.,The Center for Cardiovascular Research, Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, Nevada
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38
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Feng M, Wang Z, Liu Z, Liu D, Zheng K, Lu P, Liu C, Zhang M, Li J. The RyR–Cl
Ca
–VDCC axis contributes to spontaneous tone in urethral smooth muscle. J Cell Physiol 2019; 234:23256-23267. [PMID: 31161632 DOI: 10.1002/jcp.28892] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 05/13/2019] [Accepted: 05/14/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Mei Feng
- Central Laboratory Shandong Provincial Hospital Affiliated to Shandong University Jinan China
- Department of Microbiology and Physiological Systems University of Massachusetts Medical School Worcester Massachusetts
- Central Laboratory Shandong Provincial Hospital Affiliated to Shandong First Medical University Jinan China
| | - Zhaoyang Wang
- Operating Room Jinan Central Hospital Affiliated to Shandong University Jinan China
| | - Zheng Liu
- Department of Urology Shandong Provincial Hospital Affiliated to Shandong University Jinan China
| | - Donghai Liu
- Department of Microbiology and Physiological Systems University of Massachusetts Medical School Worcester Massachusetts
| | - Kaizhi Zheng
- Department of Microbiology and Physiological Systems University of Massachusetts Medical School Worcester Massachusetts
| | - Ping Lu
- Department of Microbiology and Physiological Systems University of Massachusetts Medical School Worcester Massachusetts
| | - Chuanyong Liu
- Department of Physiology, School of Basic Medicine, Cheeloo College of Medicine Shandong University Jinan China
| | - Min Zhang
- Arts and Science Department University of Toronto Toronto Canada
| | - Jingxin Li
- Department of Physiology, School of Basic Medicine, Cheeloo College of Medicine Shandong University Jinan China
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39
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Yarotskyy V, Malysz J, Petkov GV. Properties of single-channel and whole cell Cl - currents in guinea pig detrusor smooth muscle cells. Am J Physiol Cell Physiol 2019; 316:C698-C710. [PMID: 30566392 DOI: 10.1152/ajpcell.00327.2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Multiple types of Cl- channels regulate smooth muscle excitability and contractility in vascular, gastrointestinal, and airway smooth muscle cells. However, little is known about Cl- channels in detrusor smooth muscle (DSM) cells. Here, we used inside-out single channel and whole cell patch-clamp recordings for detailed biophysical and pharmacological characterizations of Cl- channels in freshly isolated guinea pig DSM cells. The recorded single Cl- channels displayed unique gating with multiple subconductive states, a fully opened single-channel conductance of 164 pS, and a reversal potential of -41.5 mV, which is close to the ECl of -65 mV, confirming preferential permeability to Cl-. The Cl- channel demonstrated strong voltage dependence of activation (half-maximum of mean open probability, V0.5, ~-20 mV) and robust prolonged openings at depolarizing voltages. The channel displayed similar gating when exposed intracellularly to solutions containing Ca2+-free or 1 mM Ca2+. In whole cell patch-clamp recordings, macroscopic current demonstrated outward rectification, inhibitions by 4,4'-diisothiocyano-2,2'-stilbenedisulfonic acid (DIDS) and niflumic acid, and insensitivity to chlorotoxin. The outward current was reversibly reduced by 94% replacement of extracellular Cl- with I-, Br-, or methanesulfonate (MsO-), resulting in anionic permeability sequence: Cl->Br->I->MsO-. While intracellular Ca2+ levels (0, 300 nM, and 1 mM) did not affect the amplitude of Cl- current and outward rectification, high Ca2+ slowed voltage-step current activation at depolarizing voltages. In conclusion, our data reveal for the first time the presence of a Ca2+-independent DIDS and niflumic acid-sensitive, voltage-dependent Cl- channel in the plasma membrane of DSM cells. This channel may be a key regulator of DSM excitability.
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Affiliation(s)
- Viktor Yarotskyy
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center , Memphis, Tennessee
| | - John Malysz
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center , Memphis, Tennessee
| | - Georgi V Petkov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center , Memphis, Tennessee
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40
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Acid-Base Disturbances in Patients with Asthma: A Literature Review and Comments on Their Pathophysiology. J Clin Med 2019; 8:jcm8040563. [PMID: 31027265 PMCID: PMC6518237 DOI: 10.3390/jcm8040563] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 04/19/2019] [Accepted: 04/23/2019] [Indexed: 01/19/2023] Open
Abstract
Asthma is a common illness throughout the world that affects the respiratory system function, i.e., a system whose operational adequacy determines the respiratory gases exchange. It is therefore expected that acute severe asthma will be associated with respiratory acid-base disorders. In addition, the resulting hypoxemia along with the circulatory compromise due to heart–lung interactions can reduce tissue oxygenation, with a particular impact on respiratory muscles that have increased energy needs due to the increased workload. Thus, anaerobic metabolism may ensue, leading to lactic acidosis. Additionally, chronic hypocapnia in asthma can cause a compensatory drop in plasma bicarbonate concentration, resulting in non-anion gap acidosis. Indeed, studies have shown that in acute severe asthma, metabolic acid-base disorders may occur, i.e., high anion gap or non-anion gap metabolic acidosis. This review briefly presents studies that have investigated acid-base disorders in asthma, with comments on their underlying pathophysiology.
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41
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Yan H, Zhang MZ, Wong G, Liu L, Kwok YSS, Kuang SJ, Yang H, Rao F, Li X, Mai LP, Lin QX, Yang M, Zhang QH, Deng CY. Mechanisms of U46619-induced contraction in mouse intrarenal artery. Clin Exp Pharmacol Physiol 2019; 46:643-651. [PMID: 30907443 DOI: 10.1111/1440-1681.13087] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 03/15/2019] [Accepted: 03/19/2019] [Indexed: 11/27/2022]
Abstract
Thromboxane A2 (TXA2 ) has been implicated in the pathogenesis of vascular complications, but the underlying mechanism remains unclear. The contraction of renal arterial rings in mice was measured by a Multi Myograph System. The intracellular calcium concentration ([Ca2+ ]i ) in vascular smooth muscle cells (VSMCs) was obtained by using a fluo-4/AM dye and a confocal laser scanning microscopy. The results show that the U46619-induced vasoconstriction of renal artery was completely blocked by a TXA2 receptor antagonist GR32191, significantly inhibited by a selective phospholipase C (PI-PLC) inhibitor U73122 at 10 μmol/L and partially inhibited by a Phosphatidylcholine - specific phospholipase C (PC-PLC) inhibitor D609 at 50 μmol/L. Moreover, the U46619-induced vasoconstriction was inhibited by a general protein kinase C (PKC) inhibitor chelerythrine at 10 μmol/L, and a selective PKCδ inhibitor rottlerin at 10 μmol/L. In addition, the PKC-induced vasoconstriction was partially inhibited by a Rho-kinase inhibitor Y-27632 at 10 μmol/L and was further completely inhibited together with a putative IP3 receptor antagonist and store-operated Ca2+ (SOC) entry inhibitor 2-APB at 100 μmol/L. On the other hand, U46619-induced vasoconstriction was partially inhibited by L-type calcium channel (Cav1.2) inhibitor nifedipine at 1 μmol/L and 2-APB at 50 and 100 μmol/L. Last, U46619-induced vasoconstriction was partially inhibited by a cell membrane Ca2+ activated C1- channel blocker 5-Nitro-2-(3-phenylpropylamino) benzoic acid (NPPB) at 50 and 100 μmol/L. Our results suggest that the U46619-induced contraction of mouse intrarenal arteries is mediated by Cav1.2 and SOC channel, through the activation of thromboxane-prostanoid receptors and its downstream signaling pathway.
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Affiliation(s)
- Hong Yan
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Meng-Zhen Zhang
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Gordon Wong
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Lin Liu
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Yat Sze Shelia Kwok
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Su-Juan Kuang
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Hui Yang
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Fang Rao
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Xin Li
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Li-Ping Mai
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Qiu-Xiong Lin
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Min Yang
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Qian-Huan Zhang
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
| | - Chun-Yu Deng
- Department of Cardiology, Guangdong Cardiovascular Institute, Guangzhou, China.,Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China.,Guangdong Provincial Key Laboratory of Clinical Pharmacology, Guangdong Academy of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou, China
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Koumangoye R, Omer S, Delpire E. A dileucine motif in the COOH-terminal domain of NKCC1 targets the cotransporter to the plasma membrane. Am J Physiol Cell Physiol 2019; 316:C545-C558. [PMID: 30865516 DOI: 10.1152/ajpcell.00023.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Na+-K+-2Cl- cotransporter-1 (NKCC1) mediates the electroneutral transport of Na+, K+, and Cl- and is normally localized to the basolateral membrane of polarized epithelial cells. We recently reported the first known solute carrier family 12 member 2 ( SLC12A2) mutation (we call NKCC1-DFX) that causes epithelial dysfunction in an undiagnosed disease program case. The heterozygous mutation leads to truncation of the COOH-terminal tail of the cotransporter, resulting in both mutant and wild-type cotransporters being mistrafficked to the apical membrane of polarized epithelial cells. Here we demonstrate by using consecutive truncations and site-directed mutagenesis of the COOH-terminal domain of NKCC1 that truncation of NKCC1 COOH domain uncouples the cotransporter from the lateral membrane. We identify a dileucine motif that, when mutated, leads to cotransporter accumulation in the cytoplasm and mistrafficking to the apical/subapical region of epithelial cells, thereby recapitulating the phenotype observed with the patient mutation. We show that truncation deletion and LL substitution mutants are trafficked out of the endoplasmic reticulum and trans-Golgi network but accumulate in early and late endosomes where they are degraded.
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Affiliation(s)
- Rainelli Koumangoye
- Department of Anesthesiology, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Salma Omer
- Department of Anesthesiology, Vanderbilt University School of Medicine , Nashville, Tennessee
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine , Nashville, Tennessee
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Dayal A, Ng SFJ, Grabner M. Ca 2+-activated Cl - channel TMEM16A/ANO1 identified in zebrafish skeletal muscle is crucial for action potential acceleration. Nat Commun 2019; 10:115. [PMID: 30631052 PMCID: PMC6328546 DOI: 10.1038/s41467-018-07918-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 12/03/2018] [Indexed: 01/16/2023] Open
Abstract
The Ca2+-activated Cl− channel (CaCC) TMEM16A/Anoctamin 1 (ANO1) is expressed in gastrointestinal epithelia and smooth muscle cells where it mediates secretion and intestinal motility. However, ANO1 Cl− conductance has never been reported to play a role in skeletal muscle. Here we show that ANO1 is robustly expressed in the highly evolved skeletal musculature of the euteleost species zebrafish. We characterised ANO1 as bonafide CaCC which is activated close to maximum by Ca2+ ions released from the SR during excitation-contraction (EC) coupling. Consequently, our study addressed the question about the physiological advantage of implementation of ANO1 into the euteleost skeletal-muscle EC coupling machinery. Our results reveal that Cl− influx through ANO1 plays an essential role in restricting the width of skeletal-muscle action potentials (APs) by accelerating the repolarisation phase. Resulting slimmer APs enable higher AP-frequencies and apparently tighter controlled, faster and stronger muscle contractions, crucial for high speed movements. The Ca2+-activated Cl- channel TMEM16A/Anoctamin 1 (ANO1) mediates secretion and intestinal motility in gastrointestinal epithelia and smooth muscle cells. Here, the authors show a role for ANO1 in zebrafish skeletal muscle which is activated by SR Ca2+ release during excitation-contraction coupling.
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Affiliation(s)
- Anamika Dayal
- Department of Medical Genetics, Molecular and Clinical Pharmacology, Division of Biochemical Pharmacology, Medical University of Innsbruck, Peter Mayr Strasse 1, A-6020, Innsbruck, Austria.
| | - Shu Fun J Ng
- Department of Medical Genetics, Molecular and Clinical Pharmacology, Division of Biochemical Pharmacology, Medical University of Innsbruck, Peter Mayr Strasse 1, A-6020, Innsbruck, Austria
| | - Manfred Grabner
- Department of Medical Genetics, Molecular and Clinical Pharmacology, Division of Biochemical Pharmacology, Medical University of Innsbruck, Peter Mayr Strasse 1, A-6020, Innsbruck, Austria.
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Rorsman NJG, Ta CM, Garnett H, Swietach P, Tammaro P. Defining the ionic mechanisms of optogenetic control of vascular tone by channelrhodopsin-2. Br J Pharmacol 2018; 175:2028-2045. [PMID: 29486056 PMCID: PMC5979753 DOI: 10.1111/bph.14183] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 01/16/2018] [Accepted: 02/14/2018] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Optogenetic control of electromechanical coupling in vascular smooth muscle cells (VSMCs) is emerging as a powerful research tool with potential applications in drug discovery and therapeutics. However, the precise ionic mechanisms involved in this control remain unclear. EXPERIMENTAL APPROACH Cell imaging, patch-clamp electrophysiology and muscle tension recordings were used to define these mechanisms over a wide range of light stimulations. KEY RESULTS Transgenic mice expressing a channelrhodopsin-2 variant [ChR2(H134R)] selectively in VSMCs were generated. Isolated VSMCs obtained from these mice demonstrated blue light-induced depolarizing whole-cell currents. Fine control of artery tone was attained by varying the intensity of the light stimulus. This arterial response was sufficient to overcome the endogenous, melanopsin-mediated, light-evoked, arterial relaxation observed in the presence of contractile agonists. Ca2+ entry through voltage-gated Ca2+ channels, and opening of plasmalemmal depolarizing channels (TMEM16A and TRPM) and intracellular IP3 receptors were involved in the ChR2(H134R)-dependent arterial response to blue light at intensities lower than ~0.1 mW·mm-2 . Light stimuli of greater intensity evoked a significant Ca2+ influx directly through ChR2(H134R) and produced marked intracellular alkalinization of VSMCs. CONCLUSIONS AND IMPLICATIONS We identified the range of light intensity allowing optical control of arterial tone, primarily by means of endogenous channels and without substantial alteration to intracellular pH. Within this range, mice expressing ChR2(H134R) in VSMCs are a powerful experimental model for achieving accurate and tuneable optical voltage-clamp of VSMCs and finely graded control of arterial tone, offering new approaches to the discovery of vasorelaxant drugs.
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Affiliation(s)
- Nils J G Rorsman
- Department of PharmacologyUniversity of OxfordOxfordUK
- OXION Initiative in Ion Channels and DiseaseUniversity of OxfordOxfordUK
| | - Chau M Ta
- Department of PharmacologyUniversity of OxfordOxfordUK
| | | | - Pawel Swietach
- Department of Physiology, Anatomy and GeneticsUniversity of OxfordOxfordUK
| | - Paolo Tammaro
- Department of PharmacologyUniversity of OxfordOxfordUK
- OXION Initiative in Ion Channels and DiseaseUniversity of OxfordOxfordUK
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Jensen AB, Joergensen HB, Dam VS, Kamaev D, Boedtkjer D, Füchtbauer EM, Aalkjaer C, Matchkov VV. Variable Contribution of TMEM16A to Tone in Murine Arterial Vasculature. Basic Clin Pharmacol Toxicol 2018; 123:30-41. [DOI: 10.1111/bcpt.12984] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 01/31/2018] [Indexed: 01/02/2023]
Affiliation(s)
| | | | | | - Dmitrii Kamaev
- Department of Biomedicine; Aarhus University; Aarhus Denmark
| | - Donna Boedtkjer
- Department of Biomedicine; Aarhus University; Aarhus Denmark
- Department of Clinical Medicine; Aarhus University; Aarhus Denmark
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46
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Ocampo Daza D, Larhammar D. Evolution of the receptors for growth hormone, prolactin, erythropoietin and thrombopoietin in relation to the vertebrate tetraploidizations. Gen Comp Endocrinol 2018; 257:143-160. [PMID: 28652136 DOI: 10.1016/j.ygcen.2017.06.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 06/16/2017] [Accepted: 06/22/2017] [Indexed: 12/19/2022]
Abstract
The receptors for the pituitary hormones growth hormone (GH), prolactin (PRL) and somatolactin (SL), and the hematopoietic hormones erythropoietin (EPO) and thrombopoietin (TPO), comprise a structurally related family in the superfamily of cytokine class-I receptors. GH, PRL and SL receptors have a wide variety of effects in development, osmoregulation, metabolism and stimulation of growth, while EPO and TPO receptors guide the production and differentiation of erythrocytes and thrombocytes, respectively. The evolution of the receptors for GH, PRL and SL has been partially investigated by previous reports suggesting different time points for the hormone and receptor gene duplications. This raises questions about how hormone-receptor partnerships have emerged and evolved. Therefore, we have investigated in detail the expansion of this receptor family, especially in relation to the basal vertebrate (1R, 2R) and teleost (3R) tetraploidizations. Receptor family genes were identified in a broad range of vertebrate genomes and investigated using a combination of sequence-based phylogenetic analyses and comparative genomic analyses of synteny. We found that 1R most likely generated EPOR/TPOR and GHR/PRLR ancestors; following this, 2R resulted in EPOR and TPOR genes. No GHR/PRLR duplicate seems to have survived after 2R. Instead the single GHR/PRLR underwent a local duplication sometime after 2R, generating separate syntenic genes for GHR and PRLR. Subsequently, 3R duplicated the gene pair in teleosts, resulting in two GHR and two PRLR genes, but no EPOR or TPOR duplicates. These analyses help illuminate the evolution of the regulatory mechanisms for somatic growth, metabolism, osmoregulation and hematopoiesis in vertebrates.
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Affiliation(s)
- Daniel Ocampo Daza
- Department of Neuroscience, Science for Life Laboratory, Uppsala University, Box 593, SE-75124 Uppsala, Sweden.
| | - Dan Larhammar
- Department of Neuroscience, Science for Life Laboratory, Uppsala University, Box 593, SE-75124 Uppsala, Sweden
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47
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Regional Heterogeneity in the Regulation of Vasoconstriction in Arteries and Its Role in Vascular Mechanics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1097:105-128. [PMID: 30315542 DOI: 10.1007/978-3-319-96445-4_6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Vasoconstriction and vasodilation play important roles in the circulatory system and can be regulated through different pathways that depend on myriad biomolecules. These different pathways reflect the various functions of smooth muscle cell (SMC) contractility within the different regions of the arterial tree and how they contribute to both the mechanics and the mechanobiology. Here, we review the primary regulatory pathways involved in SMC contractility and highlight their regional differences in elastic, muscular, and resistance arteries. In this way, one can begin to assess how these properties affect important biomechanical and mechanobiological functions in the circulatory system in health and disease.
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48
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Zhang YJ, Zheng HQ, Chen BY, Sun L, Ma MM, Wang GL, Guan YY. WNK1 is required for proliferation induced by hypotonic challenge in rat vascular smooth muscle cells. Acta Pharmacol Sin 2018; 39:35-47. [PMID: 28770829 DOI: 10.1038/aps.2017.56] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 04/07/2017] [Indexed: 12/20/2022] Open
Abstract
Hypotonic challenge evoked vascular cell proliferation through activation of volume-regulated Cl- channel (VRCC), leading to a decrease in the intracellular Cl- concentration ([Cl-]i). We hypothesize that the decrease in [Cl-]i may activate one or several Cl--sensitive kinases, resulting in a subsequent signaling cascade. In this study we demonstrated that WNK1, a Cl--sensitive kinase, was involved in VRCC-induced proliferative signaling pathway in A10 vascular smooth muscle cells in vitro. A10 cells were exposed to a hypotonic challenge (225 mosmol·kg-1·H20), which caused significantly increase in WNK1 phosphorylation without altering WNK1 protein expression. WNK1 overexpression significantly increased hypotonic-induced A10 cell proliferation, whereas silencing of WNK1 caused an opposite action. WNK1 mutation did not affect hypotonic-induced WNK1 phosphorylation and cell proliferation. Silencing of WNK1 caused cell cycle arrest at G0/G1 phase and prevented transition from G1 to S phase, whereas the WNK1 overexpression accelerated cell cycle transition from G1 to S phase. Silencing of WNK1 significantly inhibited cyclin D1/cyclin E1 expression and increased p27kip/p21cip expression. WNK1 overexpression significantly increased cyclin D1/cyclin E1 expression and reduced p27KIP/p21CIP expression. In addition, WNK1 knockdown or overexpression significantly attenuated or increased the hypotonic-induced phosphorylation of Akt and PI3K respectively.In conclusion, the reduction in [Cl-]i caused by hypotonic challenge-induced VRCC opening evokes WNK1 phosphorylation in A10 VSMCs, which mediates cell cycle transition from G0/G1 to S phase and proliferation through the PI3K-Akt signaling pathway.
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Lidington D, Kroetsch JT, Bolz SS. Cerebral artery myogenic reactivity: The next frontier in developing effective interventions for subarachnoid hemorrhage. J Cereb Blood Flow Metab 2018; 38:17-37. [PMID: 29135346 PMCID: PMC5757446 DOI: 10.1177/0271678x17742548] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Aneurysmal subarachnoid hemorrhage (SAH) is a devastating cerebral event that kills or debilitates the majority of those afflicted. The blood that spills into the subarachnoid space stimulates profound cerebral artery vasoconstriction and consequently, cerebral ischemia. Thus, once the initial bleeding in SAH is appropriately managed, the clinical focus shifts to maintaining/improving cerebral perfusion. However, current therapeutic interventions largely fail to improve clinical outcome, because they do not effectively restore normal cerebral artery function. This review discusses emerging evidence that perturbed cerebrovascular "myogenic reactivity," a crucial microvascular process that potently dictates cerebral perfusion, is the critical element underlying cerebral ischemia in SAH. In fact, the myogenic mechanism could be the reason why many therapeutic interventions, including "Triple H" therapy, fail to deliver benefit to patients. Understanding the molecular basis for myogenic reactivity changes in SAH holds the key to develop more effective therapeutic interventions; indeed, promising recent advancements fuel optimism that vascular dysfunction in SAH can be corrected to improve outcome.
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Affiliation(s)
- Darcy Lidington
- 1 Department of Physiology, University of Toronto, Toronto, Canada.,2 Toronto Centre for Microvascular Medicine at TBEP, University of Toronto, Toronto, Canada
| | - Jeffrey T Kroetsch
- 1 Department of Physiology, University of Toronto, Toronto, Canada.,2 Toronto Centre for Microvascular Medicine at TBEP, University of Toronto, Toronto, Canada
| | - Steffen-Sebastian Bolz
- 1 Department of Physiology, University of Toronto, Toronto, Canada.,2 Toronto Centre for Microvascular Medicine at TBEP, University of Toronto, Toronto, Canada.,3 Heart & Stroke/Richard Lewar Centre of Excellence for Cardiovascular Research, University of Toronto, Toronto, Canada
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50
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Marunaka Y. The Mechanistic Links between Insulin and Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) Cl - Channel. Int J Mol Sci 2017; 18:ijms18081767. [PMID: 28805732 PMCID: PMC5578156 DOI: 10.3390/ijms18081767] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 07/31/2017] [Accepted: 08/10/2017] [Indexed: 12/30/2022] Open
Abstract
The cystic fibrosis transmembrane conductance regulator (CFTR) Cl− channel belongs to the ATP-binding cassette (ABC) transporter superfamily and regulates Cl− secretion in epithelial cells for water secretion. Loss-of-function mutations to the CFTR gene cause dehydrated mucus on the apical side of epithelial cells and increase the susceptibility of bacterial infection, especially in the airway and pulmonary tissues. Therefore, research on the molecular properties of CFTR, such as its gating mechanism and subcellular trafficking, have been intensively pursued. Dysregulated CFTR trafficking is one of the major pathological hallmarks in cystic fibrosis (CF) patients bearing missense mutations in the CFTR gene. Hormones that activate cAMP signaling, such as catecholamine, have been found to regulate the intracellular trafficking of CFTR. Insulin is one of the hormones that regulate cAMP production and promote trafficking of transmembrane proteins to the plasma membrane. The functional interactions between insulin and CFTR have not yet been clearly defined. In this review article, I review the roles of CFTR in epithelial cells, its regulatory role in insulin secretion, and a mechanism of CFTR regulation by insulin.
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Affiliation(s)
- Yoshinori Marunaka
- Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
- Department of Bio-Ionomics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan.
- Japan Institute for Food Education and Health, St. Agnes' University, Kyoto 602-8013, Japan.
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