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Mitsui R, Miwa-Nishimura K, Hashitani H. Roles of endothelial prostaglandin I 2 in maintaining synchronous spontaneous Ca 2+ transients in rectal capillary pericytes. J Physiol 2023; 601:5213-5240. [PMID: 37819628 DOI: 10.1113/jp284284] [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: 12/20/2022] [Accepted: 09/25/2023] [Indexed: 10/13/2023] Open
Abstract
In hollow visceral organs, capillary pericytes appear to drive spontaneous Ca2+ transients in the upstream arterioles. Here, mechanisms underlying the intercellular synchrony of pericyte Ca2+ transients were explored. Ca2+ dynamics in NG2 chondroitin sulphate proteoglycan (NG2)-expressing capillary pericytes were examined using rectal mucosa-submucosa preparations of NG2-GCaMP6 mice. Spontaneous Ca2+ transients arising from endoplasmic reticulum Ca2+ release were synchronously developed amongst capillary pericytes in a gap junction blocker (3 μM carbenoxolone)-sensitive manner and could spread into upstream vascular segments. Spontaneous Ca2+ transients were suppressed by the Ca2+ -activated Cl- channel (CaCC) blocker niflumic acid and their synchrony was diminished by a TMEM16A inhibitor (3 μM Ani9) in accordance with TMEM16A immunoreactivity in pericytes. In capillaries where cyclooxygenase (COX)-2 immunoreactivity was expressed in endothelium but not pericytes, non-selective COX inhibitors (1 μM indomethacin or 10 μM diclofenac) or COX-2 inhibitor (10 μM NS 398) disrupted the synchrony of spontaneous Ca2+ transients and raised the basal Ca2+ level. Subsequent prostaglandin I2 (PGI2 ; 100 nM) or the KATP channel opener levcromakalim restored the synchrony with a reduction in the Ca2+ level. PGI2 receptor antagonist (1 μM RO1138452) also disrupted the synchrony of spontaneous Ca2+ transients and increased the basal Ca2+ level. Subsequent levcromakalim restored the synchrony and reversed the Ca2+ rise. Thus, the synchrony of spontaneous Ca2+ transients in pericytes appears to be developed by the spread of spontaneous transient depolarisations arising from the opening of TMEM16A CaCCs. Endothelial PGI2 may play a role in maintaining the synchrony, presumably by stabilising the resting membrane potential in pericytes. KEY POINTS: Capillary pericytes in the rectal mucosa generate synchronous spontaneous Ca2+ transients that could spread into the upstream vascular segment. Spontaneous Ca2+ release from the endoplasmic reticulum (ER) triggers the opening of Ca2+ -activated Cl- channel TMEM16A and resultant depolarisations that spread amongst pericytes via gap junctions, establishing the synchrony of spontaneous Ca2+ transients in pericytes. Prostaglandin I2 (PGI2 ), which is constitutively produced by the endothelium depending on cyclooxygenase-2, appears to prevent premature ER Ca2+ releases in the pericytes allowing periodic, regenerative Ca2+ releases. Endothelial PGI2 may maintain the synchrony of pericyte activity by stabilising pericyte resting membrane potential by opening of KATP channels.
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Affiliation(s)
- Retsu Mitsui
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Kyoko Miwa-Nishimura
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Hikaru Hashitani
- Department of Cell Physiology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
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Zhang TT, Lei QQ, He J, Guan X, Zhang X, Huang Y, Zhou ZY, Fan RX, Wang T, Li CX, Shang JY, Lin ZM, Peng WL, Xia LK, He YL, Hong CY, Ou JS, Pang RP, Fan XP, Huang H, Zhou JG. Bestrophin3 Deficiency in Vascular Smooth Muscle Cells Activates MEKK2/3-MAPK Signaling to Trigger Spontaneous Aortic Dissection. Circulation 2023; 148:589-606. [PMID: 37203562 DOI: 10.1161/circulationaha.122.063029] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 04/27/2023] [Indexed: 05/20/2023]
Abstract
BACKGROUND Aortic dissection (AD) is a fatal cardiovascular disorder without effective medications due to unclear pathogenic mechanisms. Bestrophin3 (Best3), the predominant isoform of bestrophin family in vessels, has emerged as critical for vascular pathological processes. However, the contribution of Best3 to vascular diseases remains elusive. METHODS Smooth muscle cell-specific and endothelial cell-specific Best3 knockout mice (Best3SMKO and Best3ECKO, respectively) were engineered to investigate the role of Best3 in vascular pathophysiology. Functional studies, single-cell RNA sequencing, proteomics analysis, and coimmunoprecipitation coupled with mass spectrometry were performed to evaluate the function of Best3 in vessels. RESULTS Best3 expression in aortas of human AD samples and mouse AD models was decreased. Best3SMKO but not Best3ECKO mice spontaneously developed AD with age, and the incidence reached 48% at 72 weeks of age. Reanalysis of single-cell transcriptome data revealed that reduction of fibromyocytes, a fibroblast-like smooth muscle cell cluster, was a typical feature of human ascending AD and aneurysm. Consistently, Best3 deficiency in smooth muscle cells decreased the number of fibromyocytes. Mechanistically, Best3 interacted with both MEKK2 and MEKK3, and this interaction inhibited phosphorylation of MEKK2 at serine153 and MEKK3 at serine61. Best3 deficiency induced phosphorylation-dependent inhibition of ubiquitination and protein turnover of MEKK2/3, thereby activating the downstream mitogen-activated protein kinase signaling cascade. Furthermore, restoration of Best3 or inhibition of MEKK2/3 prevented AD progression in angiotensin II-infused Best3SMKO and ApoE-/- mice. CONCLUSIONS These findings unveil a critical role of Best3 in regulating smooth muscle cell phenotypic switch and aortic structural integrity through controlling MEKK2/3 degradation. Best3-MEKK2/3 signaling represents a novel therapeutic target for AD.
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Affiliation(s)
- Ting-Ting Zhang
- Program of Cardiovascular Research, The Eighth Affiliated Hospital (T.-T.Z., H.H., J.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of Cardiology, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China (T.-T.Z., Y.H., H.H.)
| | - Qing-Qing Lei
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jie He
- Department of Cardiovascular Surgery, Guangdong Provincial Hospital of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong, China (J.H., X.-P.F.)
- Division of Vascular Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases (J.H.), NHC Key Laboratory of Assisted Circulation (Sun Yat-Sen University), The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Xin Guan
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Xin Zhang
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Ying Huang
- Department of Cardiology, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China (T.-T.Z., Y.H., H.H.)
| | - Zi-Yue Zhou
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Rui-Xin Fan
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China (R.-X.F., C.-X.L.)
| | - Ting Wang
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Chen-Xi Li
- Department of Cardiac Surgery, Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China (R.-X.F., C.-X.L.)
| | - Jin-Yan Shang
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zhuo-Miao Lin
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Wan-Li Peng
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Li-Kai Xia
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yu-Ling He
- Department of Pharmacology, Cardiac and Cerebrovascular Research Center (T.-T.Z., Q.-Q.L., X.G., X.Z., Z.-Y.Z., T.W., J.-Y.S., Z.-M.L., W.-L.P., L.-K.X., Y.-L.H., Z.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Chuan-Ying Hong
- Department of Physiology, Pain Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China (C.-Y.H., R.-P.P.)
| | - Jing-Song Ou
- Division of Cardiac Surgery, National-Guangdong Joint Engineering Laboratory for Diagnosis and Treatment of Vascular Diseases (J.-S.O.) NHC Key Laboratory of Assisted Circulation (Sun Yat-Sen University), The First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Rui-Ping Pang
- Department of Physiology, Pain Research Center, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, Guangdong, China (C.-Y.H., R.-P.P.)
| | - Xiao-Ping Fan
- Department of Cardiovascular Surgery, Guangdong Provincial Hospital of Chinese Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangdong, China (J.H., X.-P.F.)
| | - Hui Huang
- Program of Cardiovascular Research, The Eighth Affiliated Hospital (T.-T.Z., H.H., J.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Department of Cardiology, The Eighth Affiliated Hospital of Sun Yat-sen University, Shenzhen, Guangdong, China (T.-T.Z., Y.H., H.H.)
| | - Jia-Guo Zhou
- Program of Cardiovascular Research, The Eighth Affiliated Hospital (T.-T.Z., H.H., J.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangdong Province Key Laboratory of Brain Function and Disease (J.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Program of Kidney and Cardiovascular Disease, The Fifth Affiliated Hospital (J.-G.Z.), Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
- Guangzhou Institute of Cardiovascular Disease, Affiliated Guangzhou Women and Children's Hospital, School of Basic Medical Sciences, Guangzhou Medical University, Guangdong, China (J.-G.Z.)
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Wray S, Prendergast C, Arrowsmith S. Calcium-Activated Chloride Channels in Myometrial and Vascular Smooth Muscle. Front Physiol 2021; 12:751008. [PMID: 34867456 PMCID: PMC8637852 DOI: 10.3389/fphys.2021.751008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/24/2021] [Indexed: 11/24/2022] Open
Abstract
In smooth muscle tissues, calcium-activated chloride channels (CaCC) provide the major anionic channel. Opening of these channels leads to chloride efflux and depolarization of the myocyte membrane. In this way, activation of the channels by a rise of intracellular [Ca2+], from a variety of sources, produces increased excitability and can initiate action potentials and contraction or increased tone. We now have a good mechanistic understanding of how the channels are activated and regulated, due to identification of TMEM16A (ANO1) as the molecular entity of the channel, but key questions remain. In reviewing these channels and comparing two distinct smooth muscles, myometrial and vascular, we expose the differences that occur in their activation mechanisms, properties, and control. We find that the myometrium only expresses “classical,” Ca2+-activated, and voltage sensitive channels, whereas both tonic and phasic blood vessels express classical, and non-classical, cGMP-regulated CaCC, which are voltage insensitive. This translates to more complex activation and regulation in vascular smooth muscles, irrespective of whether they are tonic or phasic. We therefore tentatively conclude that although these channels are expressed and functionally important in all smooth muscles, they are probably not part of the mechanisms governing phasic activity. Recent knockdown studies have produced unexpected functional results, e.g. no effects on labour and delivery, and tone increasing in some but decreasing in other vascular beds, strongly suggesting that there is still much to be explored concerning CaCC in smooth muscle.
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Affiliation(s)
- Susan Wray
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Clodagh Prendergast
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Sarah Arrowsmith
- Department of Life Sciences, Manchester Metropolitan University, Manchester, United Kingdom
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4
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Owji AP, Kittredge A, Zhang Y, Yang T. Structure and Function of the Bestrophin family of calcium-activated chloride channels. Channels (Austin) 2021; 15:604-623. [PMID: 34612806 PMCID: PMC8496536 DOI: 10.1080/19336950.2021.1981625] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Bestrophins are a family of calcium-activated chloride channels (CaCCs) with relevance to human physiology and a myriad of eye diseases termed "bestrophinopathies". Since the identification of bestrophins as CaCCs nearly two decades ago, extensive studies from electrophysiological and structural biology perspectives have sought to define their key channel features including calcium sensing, gating, inactivation, and anion selectivity. The initial X-ray crystallography studies on the prokaryotic homolog of Best1, Klebsiella pneumoniae (KpBest), and the Best1 homolog from Gallus gallus (chicken Best1, cBest1), laid the foundational groundwork for establishing the architecture of Best1. Recent progress utilizing single-particle cryogenic electron microscopy has further elucidated the molecular mechanism of gating in cBest1 and, separately, the structure of Best2 from Bos taurus (bovine Best2, bBest2). Meanwhile, whole-cell patch clamp, planar lipid bilayer, and other electrophysiologic analyses using these models as well as the human Best1 (hBest1) have provided ample evidence describing the functional properties of the bestrophin channels. This review seeks to consolidate these structural and functional results to paint a broad picture of the underlying mechanisms comprising the bestrophin family's structure-function relationship.
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Affiliation(s)
- Aaron P Owji
- Department of Pharmacology, Columbia University, NY, USA
| | - Alec Kittredge
- Department of Pharmacology, Columbia University, NY, USA
| | - Yu Zhang
- Department of Ophthalmology, Columbia University, NY, USA
| | - Tingting Yang
- Department of Ophthalmology, Columbia University, NY, USA
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Manoury B, Idres S, Leblais V, Fischmeister R. Ion channels as effectors of cyclic nucleotide pathways: Functional relevance for arterial tone regulation. Pharmacol Ther 2020; 209:107499. [PMID: 32068004 DOI: 10.1016/j.pharmthera.2020.107499] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 02/05/2020] [Indexed: 02/07/2023]
Abstract
Numerous mediators and drugs regulate blood flow or arterial pressure by acting on vascular tone, involving cyclic nucleotide intracellular pathways. These signals lead to regulation of several cellular effectors, including ion channels that tune cell membrane potential, Ca2+ influx and vascular tone. The characterization of these vasocontrictive or vasodilating mechanisms has grown in complexity due to i) the variety of ion channels that are expressed in both vascular endothelial and smooth muscle cells, ii) the heterogeneity of responses among the various vascular beds, and iii) the number of molecular mechanisms involved in cyclic nucleotide signalling in health and disease. This review synthesizes key data from literature that highlight ion channels as physiologically relevant effectors of cyclic nucleotide pathways in the vasculature, including the characterization of the molecular mechanisms involved. In smooth muscle cells, cation influx or chloride efflux through ion channels are associated with vasoconstriction, whereas K+ efflux repolarizes the cell membrane potential and mediates vasodilatation. Both categories of ion currents are under the influence of cAMP and cGMP pathways. Evidence that some ion channels are influenced by CN signalling in endothelial cells will also be presented. Emphasis will also be put on recent data touching a variety of determinants such as phosphodiesterases, EPAC and kinase anchoring, that complicate or even challenge former paradigms.
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Affiliation(s)
- Boris Manoury
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France.
| | - Sarah Idres
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France
| | - Véronique Leblais
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France
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Wang W, Zhang K, Zhang H, Li M, Zhao Y, Wang B, Xin W, Yang W, Zhang J, Yue S, Yang X. Underlying Genes Involved in Atherosclerotic Macrophages: Insights from Microarray Data Mining. Med Sci Monit 2019; 25:9949-9962. [PMID: 31875420 PMCID: PMC6944040 DOI: 10.12659/msm.917068] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Background In an atherosclerotic artery wall, monocyte-derived macrophages are the principal mediators that respond to pathogens and inflammation. The present study aimed to investigate potential genetic changes in gene expression between normal tissue-resident macrophages and atherosclerotic macrophages in the human body. Material/Methods The expression profile data of GSE7074 acquired from the Gene Expression Omnibus (GEO) database, which includes the transcriptome of 4 types of macrophages, was downloaded. Differentially expressed genes (DEGs) were identified using R software, then we performed functional enrichment, protein-protein interaction (PPI) network construction, key node and module analysis, and prediction of microRNAs (miRNAs)/transcription factors (TFs) targeting genes. Results After data processing, 236 DEGs were identified, including 21 upregulated genes and 215 downregulated genes. The DEG set was enriched in 22 significant Gene Ontology (GO) terms and 25 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and the PPI network constructed with these DEGs comprised 6 key nodes with degrees ≥8. Key nodes in the PPI network and simultaneously involved in the prime modules, including rhodopsin (RHO), coagulation factor V (F5), and bestrophin-1 (BEST1), are promising for the prediction of atherosclerotic plaque formation. Furthermore, in the miRNA/TF-target network, hsa-miR-3177-5p might be involved in the pathogenesis of atherosclerosis via regulating BEST1, and the transcription factor early growth response-1 (EGR1) was found to be a potential promoter in atherogenesis. Conclusions The identified key hub genes, predicted miRNAs/TFs, and underlying molecular mechanisms may be involved in atherogenesis, thus potentially contributing to the treatment and diagnosis of patients with atherosclerotic disease.
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Affiliation(s)
- Weihan Wang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Tianjin Neurological Institute, Key Laboratory of Post-Trauma Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, China (mainland)
| | - Kai Zhang
- Department of Gynecology and Obstetrics, Tianjin Medical University General Hospital, Tianjin, China (mainland)
| | - Hao Zhang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Tianjin Neurological Institute, Key Laboratory of Post-Trauma Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, China (mainland)
| | - Mengqi Li
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Tianjin Neurological Institute, Key Laboratory of Post-Trauma Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, China (mainland)
| | - Yan Zhao
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China (mainland)
| | - Bangyue Wang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China (mainland)
| | - Wenqiang Xin
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Tianjin Neurological Institute, Key Laboratory of Post-Trauma Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, China (mainland)
| | - Weidong Yang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Tianjin Neurological Institute, Key Laboratory of Post-Trauma Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, China (mainland)
| | - Jianning Zhang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Tianjin Neurological Institute, Key Laboratory of Post-Trauma Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, China (mainland)
| | - Shuyuan Yue
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Tianjin Neurological Institute, Key Laboratory of Post-Trauma Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, China (mainland)
| | - Xinyu Yang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China (mainland).,Tianjin Neurological Institute, Key Laboratory of Post-Trauma Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education, Tianjin Key Laboratory of Injuries, Variations and Regeneration of Nervous System, Tianjin, China (mainland)
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Targeted sequencing identifies a missense variant in the BEST3 gene associated with antihypertensive response to hydrochlorothiazide. Pharmacogenet Genomics 2019; 28:251-255. [PMID: 30289819 DOI: 10.1097/fpc.0000000000000353] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Chromosome 12q15 was identified in Genetic Epidemiology of Response Assessment (GERA) and replicated in Pharmacogenomic Evaluation of Antihypertensive Responses (PEAR) for its association with blood pressure (BP) response to hydrochlorothiazide (HCTZ). However, the functional variant is unknown and we aimed to identify the likely functional variants through targeted sequencing. The chromosome 12q15 region was sequenced in 397 best and worst responders to HCTZ in PEAR (N=199) and GERA (N=198) hypertensive study participants. Logistic regression was used for the association analysis adjusting for age, sex, race, and principal components 1 and 2. For validation, the significant single nucleotide polymorphism was tested for association with the change in systolic (ΔSBP) and diastolic BP (ΔDBP) post-treatment in the entire PEAR (N=370) and GERA (N=570) cohorts. A novel missense polymorphism (G>A, Pro383Leu) in BEST3, rs61747221, was significantly associated with better HCTZ response (P=0.0021, odds ratio=2.05). It was validated in the entire cohort of PEAR (ΔSBP: P=0.021, β=-1.60, ΔDBP: P=0.023, β=-1.08) and GERA (ΔSBP: P=0.028, β=-1.95, ΔDBP: P=0.032, β=-1.28). BEST3 encodes the calcium sensitive chloride channel in the vascular smooth muscle implicated in the regulation of BP, especially in response to vasoconstrictors like angiotensin II. These results suggest that BEST3 is involved in the chronic BP lowering mechanism of thiazides and highlight its importance as a genetic predictor of the BP response to thiazide diuretics.
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8
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Cellular and Ionic Mechanisms of Arterial Vasomotion. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1124:297-312. [DOI: 10.1007/978-981-13-5895-1_12] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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9
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Hald BO, Sørensen RB, Sørensen PG, Sørensen CM, Jacobsen JCB. Stimulation history affects vasomotor responses in rat mesenteric arterioles. Pflugers Arch 2018; 471:271-283. [PMID: 30219946 DOI: 10.1007/s00424-018-2206-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/06/2018] [Indexed: 11/25/2022]
Abstract
Resistance vessels regulate blood flow by continuously adjusting activity of the wall smooth muscle cells. These cells integrate a variety of stimuli from blood, endothelium, autonomic nerves, and surrounding tissues. Each stimulus elicits an intracellular signaling cascade that eventually influences activation of the contractile machinery. The characteristic time scale of each cascade and the sharing of specific reactions between cascades provide for complex behavior when a vessel receives multiple stimuli. Here, we apply sequential stimulation with invariant concentrations of vasoconstrictor (norepinephrine/methoxamine) and vasodilator (SNAP/carbacol) to rat mesenteric vessels in the wire myograph to show that (1) time elapsed between addition of two vasoactive drugs and (2) the sequence of addition may significantly affect final force development. Furthermore, force oscillations (vasomotion) often appear upon norepinephrine administration. Using computational modeling in combination with nitric oxide (NO) inhibition/NO addition experiments, we show that (3) amplitude and number of oscillating vessels increase over time, (4) the ability of NO to induce vasomotion depends on whether it is applied before or after norepinephrine, and (5) emergence of vasomotion depends on the prior dynamical state of the system; in simulations, this phenomenon appears as "hysteresis." These findings underscore the time-dependent nature of vascular tone generation which must be considered when evaluating the vasomotor effects of multiple, simultaneous stimuli in vitro or in vivo.
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Affiliation(s)
- Bjørn Olav Hald
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.
| | - Rasmus B Sørensen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Preben G Sørensen
- Department of Chemistry, University of Copenhagen, Copenhagen, Denmark
| | - Charlotte M Sørensen
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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10
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Fonseca DA, Antunes PE, Antunes MJ, Cotrim MD. Vasomotion as an oscillatory sign of functional impairment in the human internal thoracic artery: A study based on risk factors and vessel reactivity. Exp Physiol 2018; 103:1030-1038. [PMID: 29714043 DOI: 10.1113/ep087002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2018] [Accepted: 04/24/2018] [Indexed: 01/14/2023]
Abstract
NEW FINDINGS What is the central question of this study? Vasomotion has been viewed as a rhythmic oscillation of the vascular tone that is physiologically important for optimal tissue perfusion. Also, it has been studied primarily in the microcirculation. However, the precise underlying mechanisms and the physiological significance remain unknown. What is the main finding and its importance? Vasomotion is not specific to the microcirculation, as shown by our findings. In human arteries from patients undergoing cardiac surgery, an increased incidence was associated with endothelial dysfunction settings. Therefore, this oscillatory behaviour might be a signal of functional impairment and not of integrity. ABSTRACT Vasomotion has been defined as the rhythmic oscillation of the vascular tone, involved in the control of the blood flow and subsequent tissue perfusion. Our aims were to study the incidence of vasomotion in the human internal thoracic artery and the correlation of this phenomenon with the clinical profile and parameters of vascular reactivity. In our study, vasomotion was elicited with a single-dose contractile stimulation of noradrenaline (10 μm) in internal thoracic artery segments, from patients undergoing coronary artery bypass grafting, mounted in tissue organ bath chambers. The incidence was 29.1%. Vessel samples with vasomotion presented significantly higher contractility in response to both potassium chloride (maximal response or Emax of 7.65 ± 5.81 mN versus 4.52 ± 3.73 mN in control vessels, P = 0.024) and noradrenaline (Emax of 7.60 ± 5.93 mN versus 2.96 ± 4.41 mN in control vessels, P < 0.001). Predictive modelling through multivariable logistic regression analysis showed that female sex (odds ratio = 9.82) and increasing maximal response to noradrenaline (odds ratio = 1.19, per 1 mN increase) were associated with a higher probability of the occurrence of vasomotion, whereas increasing kidney function (expressed as estimated glomerular filtration rate) was associated with a lower probability (odds ratio = 0.97, per 1 ml min-1 (1.73 m)-2 ]. Our results provide a characterization of the phenomenon of vasomotion in the internal thoracic artery and suggest that vasomotion might be associated with endothelial dysfunction settings, as determined by a multivariable analysis approach. Considering the associations observed in our results, vasomotion might be a signal of functional impairment and not of integrity.
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Affiliation(s)
- Diogo A Fonseca
- Laboratory of Pharmacology and Pharmaceutical Care, Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal.,Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.iCBR, University of Coimbra, Coimbra, Portugal
| | - Pedro E Antunes
- Centre of Cardiothoracic Surgery, University Hospital and Faculty of Medicine of Coimbra, Coimbra, Portugal
| | - Manuel J Antunes
- Centre of Cardiothoracic Surgery, University Hospital and Faculty of Medicine of Coimbra, Coimbra, Portugal
| | - Maria Dulce Cotrim
- Laboratory of Pharmacology and Pharmaceutical Care, Faculty of Pharmacy, University of Coimbra, Coimbra, Portugal.,Coimbra Institute for Clinical and Biomedical Research (iCBR), Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,CNC.iCBR, University of Coimbra, Coimbra, Portugal
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11
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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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12
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Nyvad J, Mazur A, Postnov DD, Straarup MS, Soendergaard AM, Staehr C, Brøndum E, Aalkjaer C, Matchkov VV. Intravital investigation of rat mesenteric small artery tone and blood flow. J Physiol 2017; 595:5037-5053. [PMID: 28568894 DOI: 10.1113/jp274604] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 05/24/2017] [Indexed: 01/07/2023] Open
Abstract
KEY POINTS Substantial information on rat mesenteric small artery physiology and pharmacology based on in vitro experiments is available. Little is known about the relevance of this for artery function in vivo. We here present an intravital model where rat mesenteric small artery diameters are studied under isolated and controlled conditions in situ with simultaneous measurement of blood flow. The responses of the isolated arteries vary with the anaesthetic used, and they are quantitatively but not qualitatively different from the responses seen in vitro. ABSTRACT Functional characteristics of rat mesenteric small arteries (internal diameter ∼150-200 μm) have been extensively studied in vitro using isometric and isobaric myographs. In vivo, precapillary arterioles (internal diameter < 50 μm) have been studied, but only a few studies have investigated the function of mesenteric small arteries. We here present a novel approach for intravital studies of rat mesenteric small artery segments (∼5 mm long) isolated in a chamber. The agonist-induced changes in arterial diameter and blood flow were studied using video imaging and laser speckle analysis in rats anaesthetized by isoflurane, pentobarbital, ketamine-xylazine, or by a combination of fentanyl, fluanison and midazolam (rodent mixture). The arteries had spontaneous tone. Noradrenaline added to the chamber constricted the artery in the chamber but not the downstream arteries in the intestinal wall. The constriction was smaller when rats were anaesthetized by rodent mixture in comparison with other anaesthetics, where responses were qualitatively similar to those reported in vitro. The contraction was associated with reduction of blood flow, but no flow reduction was seen in the downstream arteries in the intestinal wall. The magnitude of different endothelium-dependent relaxation pathways was dependent on the anaesthesia. Vasomotion was present under all forms of anaesthesia with characteristics similar to in vitro. We have established an intravital method for studying the tone and flow in rat mesenteric arteries. The reactivity of the arteries was qualitatively similar to the responses previously obtained under in vitro conditions, but the choice of anaesthetic affects the magnitude of responses.
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Affiliation(s)
- Jakob Nyvad
- Department of Biomedicine, Membranes, Aarhus University, Aarhus, Denmark
| | - Aleksandra Mazur
- Department of Biomedicine, Membranes, Aarhus University, Aarhus, Denmark
| | - Dmitry D Postnov
- Department of Biomedical Sciences, University of Copenhagen, Denmark
| | | | | | - Christian Staehr
- Department of Biomedicine, Membranes, Aarhus University, Aarhus, Denmark
| | - Emil Brøndum
- Department of Oto-Rhino-Laryngology, Aarhus University Hospital, Denmark
| | - Christian Aalkjaer
- Department of Biomedicine, Membranes, Aarhus University, Aarhus, Denmark.,Department of Biomedical Sciences, University of Copenhagen, Denmark
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13
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Hangaard L, Bouzinova EV, Staehr C, Dam VS, Kim S, Xie Z, Aalkjaer C, Matchkov VV. Na-K-ATPase regulates intercellular communication in the vascular wall via cSrc kinase-dependent connexin43 phosphorylation. Am J Physiol Cell Physiol 2017; 312:C385-C397. [DOI: 10.1152/ajpcell.00347.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/10/2017] [Accepted: 01/14/2017] [Indexed: 12/23/2022]
Abstract
Communication between vascular smooth muscle cells (VSMCs) is dependent on gap junctions and is regulated by the Na-K-ATPase. The Na-K-ATPase is therefore important for synchronized VSMC oscillatory activity, i.e., vasomotion. The signaling between the Na-K-ATPase and gap junctions is unknown. We tested here the hypothesis that this signaling involves cSrc kinase. Intercellular communication was assessed by membrane capacitance measurements of electrically coupled VSMCs. Vasomotion in isometric myograph, input resistance, and synchronized [Ca2+]i transients were used as readout for intercellular coupling in rat mesenteric small arteries in vitro. Phosphorylation of cSrc kinase and connexin43 (Cx43) were semiquantified by Western blotting. Micromole concentration of ouabain reduced the amplitude of norepinephrine-induced vasomotion and desynchronized Ca2+ transients in VSMC in the arterial wall. Ouabain also increased input resistance in the arterial wall. These effects of ouabain were antagonized by inhibition of tyrosine phosphorylation with genistein, PP2, and by an inhibitor of the Na-K-ATPase-dependent cSrc activation, pNaKtide. Moreover, inhibition of cSrc phosphorylation increased vasomotion amplitude and decreased the resistance between cells in the vascular wall. Ouabain inhibited the electrical coupling between A7r5 cells, but pNaKtide restored the electrical coupling. Ouabain increased cSrc autophosphorylation of tyrosine 418 (Y418) required for full catalytic activity whereas pNaKtide antagonized it. This cSrc activation was associated with Cx43 phosphorylation of tyrosine 265 (Y265). Our findings demonstrate that Na-K-ATPase regulates intercellular communication in the vascular wall via cSrc-dependent Cx43 tyrosine phosphorylation.
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Affiliation(s)
- Lise Hangaard
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | | | - Vibeke S. Dam
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Sukhan Kim
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Zijian Xie
- Marshall Institute for Interdisciplinary Research, Marshall University, Huntington, West Virginia
| | - Christian Aalkjaer
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
- Department of Biomedicine, University of Copenhagen, Copenhagen, Denmark; and
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14
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Boedtkjer E, Matchkov VV, Boedtkjer DMB, Aalkjaer C. Negative News: Cl− and HCO3− in the Vascular Wall. Physiology (Bethesda) 2016; 31:370-83. [DOI: 10.1152/physiol.00001.2016] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Cl− and HCO3− are the most prevalent membrane-permeable anions in the intra- and extracellular spaces of the vascular wall. Outwardly directed electrochemical gradients for Cl− and HCO3− permit anion channel opening to depolarize vascular smooth muscle and endothelial cells. Transporters and channels for Cl− and HCO3− also modify vascular contractility and structure independently of membrane potential. Transport of HCO3− regulates intracellular pH and thereby modifies the activity of enzymes, ion channels, and receptors. There is also evidence that Cl− and HCO3− transport proteins affect gene expression and protein trafficking. Considering the extensive implications of Cl− and HCO3− in the vascular wall, it is critical to understand how these ions are transported under physiological conditions and how disturbances in their transport can contribute to disease development. Recently, sensing mechanisms for Cl− and HCO3− have been identified in the vascular wall where they modify ion transport and vasomotor function, for instance, during metabolic disturbances. This review discusses current evidence that transport (e.g., via NKCC1, NBCn1, Ca2+-activated Cl− channels, volume-regulated anion channels, and CFTR) and sensing (e.g., via WNK and RPTPγ) of Cl− and HCO3− influence cardiovascular health and disease.
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Affiliation(s)
| | | | - Donna M. B. Boedtkjer
- Department of Biomedicine, Aarhus University, Denmark
- Department of Clinical Medicine, Aarhus University, Denmark; and
| | - Christian Aalkjaer
- Department of Biomedicine, Aarhus University, Denmark
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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15
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Schepelmann M, Yarova PL, Lopez-Fernandez I, Davies TS, Brennan SC, Edwards PJ, Aggarwal A, Graça J, Rietdorf K, Matchkov V, Fenton RA, Chang W, Krssak M, Stewart A, Broadley KJ, Ward DT, Price SA, Edwards DH, Kemp PJ, Riccardi D. The vascular Ca2+-sensing receptor regulates blood vessel tone and blood pressure. Am J Physiol Cell Physiol 2015; 310:C193-204. [PMID: 26538090 DOI: 10.1152/ajpcell.00248.2015] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 10/29/2015] [Indexed: 12/28/2022]
Abstract
The extracellular calcium-sensing receptor CaSR is expressed in blood vessels where its role is not completely understood. In this study, we tested the hypothesis that the CaSR expressed in vascular smooth muscle cells (VSMC) is directly involved in regulation of blood pressure and blood vessel tone. Mice with targeted CaSR gene ablation from vascular smooth muscle cells (VSMC) were generated by breeding exon 7 LoxP-CaSR mice with animals in which Cre recombinase is driven by a SM22α promoter (SM22α-Cre). Wire myography performed on Cre-negative [wild-type (WT)] and Cre-positive (SM22α)CaSR(Δflox/Δflox) [knockout (KO)] mice showed an endothelium-independent reduction in aorta and mesenteric artery contractility of KO compared with WT mice in response to KCl and to phenylephrine. Increasing extracellular calcium ion (Ca(2+)) concentrations (1-5 mM) evoked contraction in WT but only relaxation in KO aortas. Accordingly, diastolic and mean arterial blood pressures of KO animals were significantly reduced compared with WT, as measured by both tail cuff and radiotelemetry. This hypotension was mostly pronounced during the animals' active phase and was not rescued by either nitric oxide-synthase inhibition with nitro-l-arginine methyl ester or by a high-salt-supplemented diet. KO animals also exhibited cardiac remodeling, bradycardia, and reduced spontaneous activity in isolated hearts and cardiomyocyte-like cells. Our findings demonstrate a role for CaSR in the cardiovascular system and suggest that physiologically relevant changes in extracellular Ca(2+) concentrations could contribute to setting blood vessel tone levels and heart rate by directly acting on the cardiovascular CaSR.
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Affiliation(s)
- M Schepelmann
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - P L Yarova
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - I Lopez-Fernandez
- School of Biosciences, Cardiff University, Cardiff, United Kingdom; Faculty of Pharmacy, Université de Picardie Jules Verne, Amiens, France
| | - T S Davies
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - S C Brennan
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - P J Edwards
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - A Aggarwal
- Department of Pathophysiology and Allergy Research, Medical University of Vienna, Vienna, Austria
| | - J Graça
- School of Biosciences, Cardiff University, Cardiff, United Kingdom; Pathology Sciences, AstraZeneca, Macclesfield, Cheshire, United Kingdom
| | - K Rietdorf
- Faculty of Science, Department for Life, Health and Chemical Sciences, The Open University, Milton Keynes, United Kingdom
| | - V Matchkov
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - R A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - W Chang
- Endocrine Research Unit, Department of Veteran Affairs Medical Center, Department of Medicine, University of California, San Francisco, Califonia
| | - M Krssak
- Division of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Vienna, Austria
| | - A Stewart
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - K J Broadley
- School of Pharmacy and Pharmaceutical Sciences, Division of Pharmacology, Cardiff University, Cardiff, United Kingdom
| | - D T Ward
- Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom; and
| | - S A Price
- Pathology Sciences, AstraZeneca, Macclesfield, Cheshire, United Kingdom
| | - D H Edwards
- Cardiff University, Wales Heart Research Institute, Cardiff, United Kingdom
| | - P J Kemp
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - D Riccardi
- School of Biosciences, Cardiff University, Cardiff, United Kingdom;
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16
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Dam VS, Boedtkjer DMB, Aalkjaer C, Matchkov V. The bestrophin- and TMEM16A-associated Ca(2+)- activated Cl(–) channels in vascular smooth muscles. Channels (Austin) 2015; 8:361-9. [PMID: 25478625 PMCID: PMC4203738 DOI: 10.4161/chan.29531] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The presence of Ca2+-activated Cl– currents (ICl(Ca)) in vascular smooth muscle cells (VSMCs) is well established. ICl(Ca) are supposedly important for arterial contraction by linking changes in [Ca2+]i and membrane depolarization. Bestrophins and some members of the TMEM16 protein family were recently associated with ICl(Ca). Two distinct ICl(Ca) are characterized in VSMCs; the cGMP-dependent ICl(Ca) dependent upon bestrophin expression and the ‘classical’ Ca2+-activated Cl– current, which is bestrophin-independent. Interestingly, TMEM16A is essential for both the cGMP-dependent and the classical ICl(Ca). Furthermore, TMEM16A has a role in arterial contraction while bestrophins do not. TMEM16A’s role in the contractile response cannot be explained however only by a simple suppression of the depolarization by Cl– channels. It is suggested that TMEM16A expression modulates voltage-gated Ca2+ influx in a voltage-independent manner and recent studies also demonstrate a complex role of TMEM16A in modulating other membrane proteins.
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17
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Leblanc N, Forrest AS, Ayon RJ, Wiwchar M, Angermann JE, Pritchard HAT, Singer CA, Valencik ML, Britton F, Greenwood IA. Molecular and functional significance of Ca(2+)-activated Cl(-) channels in pulmonary arterial smooth muscle. Pulm Circ 2015; 5:244-68. [PMID: 26064450 DOI: 10.1086/680189] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Accepted: 07/22/2014] [Indexed: 12/31/2022] Open
Abstract
Increased peripheral resistance of small distal pulmonary arteries is a hallmark signature of pulmonary hypertension (PH) and is believed to be the consequence of enhanced vasoconstriction to agonists, thickening of the arterial wall due to remodeling, and increased thrombosis. The elevation in arterial tone in PH is attributable, at least in part, to smooth muscle cells of PH patients being more depolarized and displaying higher intracellular Ca(2+) levels than cells from normal subjects. It is now clear that downregulation of voltage-dependent K(+) channels (e.g., Kv1.5) and increased expression and activity of voltage-dependent (Cav1.2) and voltage-independent (e.g., canonical and vanilloid transient receptor potential [TRPC and TRPV]) Ca(2+) channels play an important role in the functional remodeling of pulmonary arteries in PH. This review focuses on an anion-permeable channel that is now considered a novel excitatory mechanism in the systemic and pulmonary circulations. It is permeable to Cl(-) and is activated by a rise in intracellular Ca(2+) concentration (Ca(2+)-activated Cl(-) channel, or CaCC). The first section outlines the biophysical and pharmacological properties of the channel and ends with a description of the molecular candidate genes postulated to encode for CaCCs, with particular emphasis on the bestrophin and the newly discovered TMEM16 and anoctamin families of genes. The second section provides a review of the various sources of Ca(2+) activating CaCCs, which include stimulation by mobilization from intracellular Ca(2+) stores and Ca(2+) entry through voltage-dependent and voltage-independent Ca(2+) channels. The third and final section summarizes recent findings that suggest a potentially important role for CaCCs and the gene TMEM16A in PH.
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Affiliation(s)
- Normand Leblanc
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Abigail S Forrest
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Ramon J Ayon
- Department of Medicine, University of Illinois, Chicago, Illinois, USA
| | - Michael Wiwchar
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Jeff E Angermann
- School of Community Health Sciences, University of Nevada, Reno, Nevada, USA
| | - Harry A T Pritchard
- Vascular Biology Research Centre, Institute of Cardiovascular and Cell Sciences, St. George's University of London, London, United Kingdom
| | - Cherie A Singer
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Maria L Valencik
- Department of Biochemistry and Molecular Biology, University of Nevada School of Medicine, Reno, Nevada, USA
| | - Fiona Britton
- Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Iain A Greenwood
- Vascular Biology Research Centre, Institute of Cardiovascular and Cell Sciences, St. George's University of London, London, United Kingdom
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18
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Mijušković A, Kokić AN, Dušić ZO, Slavić M, Spasić MB, Blagojević D. Chloride channels mediate sodium sulphide-induced relaxation in rat uteri. Br J Pharmacol 2015; 172:3671-86. [PMID: 25857480 DOI: 10.1111/bph.13161] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 03/23/2015] [Accepted: 03/30/2015] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND AND PURPOSE Hydrogen sulphide reduces uterine contractility and is of potential interest as a treatment for uterine disorders. The aim of this study was to explore the mechanism of sodium sulphide (Na2 S)-induced relaxation of rat uterus, investigate the importance of redox effects and ion channel-mediated mechanisms, and any interactions between these two mechanisms. EXPERIMENTAL APPROACH Organ bath studies were employed to assess the pharmacological effects of Na2 S in uterine strips by exposing them to Na2 S with or without Cl(-) channel blockers (DIDS, NFA, IAA-94, T16Ainh-A01, TA), raised KCl (15 and 75 mM), K(+) channel inhibitors (glibenclamide, TEA, 4-AP), L-type Ca(2+) channel activator (S-Bay K 8644), propranolol and methylene blue. The activities of antioxidant enzymes were measured in homogenates of treated uteri. The expression of bestrophin channel 1 (BEST-1) was determined by Western blotting and RT-PCR. KEY RESULTS Na2 S caused concentration-dependent reversible relaxation of spontaneously active and calcium-treated uteri, affecting both amplitude and frequency of contractions. Uteri exposed to 75 mM KCl were less sensitive to Na2 S compared with uteri in 15 mM KCl. Na2 S-induced relaxations were abolished by DIDS, but unaffected by other modulators or by the absence of extracellular HCO3 (-) , suggesting the involvement of chloride ion channels. Na2 S in combination with different modulators provoked specific changes in the anti-oxidant profiles of uteri. The expression of BEST-1, both mRNA and protein, was demonstrated in rat uteri. CONCLUSIONS AND IMPLICATIONS The relaxant effects of Na2 S in rat uteri are mediated mainly via a DIDS-sensitive Cl(-) -pathway. Components of the relaxation are redox- and Ca(2+) -dependent.
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Affiliation(s)
- Ana Mijušković
- Department of Physiology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Belgrade, Serbia
| | - Aleksandra Nikolić Kokić
- Department of Physiology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Belgrade, Serbia
| | - Zorana Oreščanin Dušić
- Department of Physiology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Belgrade, Serbia
| | - Marija Slavić
- Department of Physiology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Belgrade, Serbia
| | - Mihajlo B Spasić
- Department of Physiology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Belgrade, Serbia
| | - Duško Blagojević
- Department of Physiology, Institute for Biological Research 'Siniša Stanković', University of Belgrade, Belgrade, Serbia
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19
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Matchkov VV, Boedtkjer DM, Aalkjaer C. The role of Ca2+ activated Cl− channels in blood pressure control. Curr Opin Pharmacol 2015; 21:127-37. [DOI: 10.1016/j.coph.2015.02.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/02/2015] [Accepted: 02/04/2015] [Indexed: 12/17/2022]
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20
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Abstract
Intrarenal autoregulatory mechanisms maintain renal blood flow (RBF) and glomerular filtration rate (GFR) independent of renal perfusion pressure (RPP) over a defined range (80-180 mmHg). Such autoregulation is mediated largely by the myogenic and the macula densa-tubuloglomerular feedback (MD-TGF) responses that regulate preglomerular vasomotor tone primarily of the afferent arteriole. Differences in response times allow separation of these mechanisms in the time and frequency domains. Mechanotransduction initiating the myogenic response requires a sensing mechanism activated by stretch of vascular smooth muscle cells (VSMCs) and coupled to intracellular signaling pathways eliciting plasma membrane depolarization and a rise in cytosolic free calcium concentration ([Ca(2+)]i). Proposed mechanosensors include epithelial sodium channels (ENaC), integrins, and/or transient receptor potential (TRP) channels. Increased [Ca(2+)]i occurs predominantly by Ca(2+) influx through L-type voltage-operated Ca(2+) channels (VOCC). Increased [Ca(2+)]i activates inositol trisphosphate receptors (IP3R) and ryanodine receptors (RyR) to mobilize Ca(2+) from sarcoplasmic reticular stores. Myogenic vasoconstriction is sustained by increased Ca(2+) sensitivity, mediated by protein kinase C and Rho/Rho-kinase that favors a positive balance between myosin light-chain kinase and phosphatase. Increased RPP activates MD-TGF by transducing a signal of epithelial MD salt reabsorption to adjust afferent arteriolar vasoconstriction. A combination of vascular and tubular mechanisms, novel to the kidney, provides for high autoregulatory efficiency that maintains RBF and GFR, stabilizes sodium excretion, and buffers transmission of RPP to sensitive glomerular capillaries, thereby protecting against hypertensive barotrauma. A unique aspect of the myogenic response in the renal vasculature is modulation of its strength and speed by the MD-TGF and by a connecting tubule glomerular feedback (CT-GF) mechanism. Reactive oxygen species and nitric oxide are modulators of myogenic and MD-TGF mechanisms. Attenuated renal autoregulation contributes to renal damage in many, but not all, models of renal, diabetic, and hypertensive diseases. This review provides a summary of our current knowledge regarding underlying mechanisms enabling renal autoregulation in health and disease and methods used for its study.
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Affiliation(s)
- Mattias Carlström
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Christopher S Wilcox
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - William J Arendshorst
- Department of Medicine, Division of Nephrology and Hypertension and Hypertension, Kidney and Vascular Research Center, Georgetown University, Washington, District of Columbia; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; and Department of Cell Biology and Physiology, UNC Kidney Center, and McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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21
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Hübner CA, Schroeder BC, Ehmke H. Regulation of vascular tone and arterial blood pressure: role of chloride transport in vascular smooth muscle. Pflugers Arch 2015; 467:605-14. [DOI: 10.1007/s00424-014-1684-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 12/24/2014] [Accepted: 12/29/2014] [Indexed: 01/01/2023]
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22
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Bulley S, Jaggar JH. Cl⁻ channels in smooth muscle cells. Pflugers Arch 2014; 466:861-72. [PMID: 24077695 DOI: 10.1007/s00424-013-1357-2] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 09/09/2013] [Accepted: 09/09/2013] [Indexed: 10/26/2022]
Abstract
In smooth muscle cells (SMCs), the intracellular chloride ion (Cl−) concentration is high due to accumulation by Cl−/HCO3− exchange and Na+–K+–Cl− cotransportation. The equilibrium potential for Cl− (ECl) is more positive than physiological membrane potentials (Em), with Cl− efflux inducing membrane depolarization. Early studies used electrophysiology and nonspecific antagonists to study the physiological relevance of Cl− channels in SMCs. More recent reports have incorporated molecular biological approaches to identify and determine the functional significance of several different Cl− channels. Both "classic" and cGMP-dependent calcium (Ca2+)-activated (ClCa) channels and volume-sensitive Cl− channels are present, with TMEM16A/ANO1, bestrophins, and ClC-3, respectively, proposed as molecular candidates for these channels. The cystic fibrosis transmembrane conductance regulator (CFTR) has also been described in SMCs. This review will focus on discussing recent progress made in identifying each of these Cl− channels in SMCs, their physiological functions, and contribution to diseases that modify contraction, apoptosis, and cell proliferation.
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Song W, Yang Z, He B. Bestrophin 3 ameliorates TNFα-induced inflammation by inhibiting NF-κB activation in endothelial cells. PLoS One 2014; 9:e111093. [PMID: 25329324 PMCID: PMC4203846 DOI: 10.1371/journal.pone.0111093] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 09/22/2014] [Indexed: 01/20/2023] Open
Abstract
Increasing evidences have suggested vascular endothelial inflammatory processes are the initiator of atherosclerosis. Bestrophin 3 (Best-3) is involved in the regulation of cell proliferation, apoptosis and differentiation of a variety of physiological functions, but its function in cardiovascular system remains unclear. In this study, we investigated the effect of Best-3 on endothelial inflammation. We first demonstrated that Best-3 is expressed in endothelial cells and decreased after tumor necrosis factor-α (TNFα) challenge. Overexpression of Best-3 significantly attenuated TNFα-induced expression of adhesion molecules and chemokines, and subsequently inhibited the adhesion of monocytes to human umbilical vein endothelial cells (HUVECs). Conversely, knockdown of Best-3 with siRNA resulted in an enhancement on TNFα-induced expression of adhesion molecules and chemokines and adhesion of monocytes to HUVECs. Furthermore, overexpression of Best-3 with adenovirus dramatically ameliorated inflammatory response in TNFα-injected mice. Mechanistically, we found up-regulation of Best-3 inhibited TNFα-induced IKKβ and IκBα phosphorylation, IκBα degradation and NF-κB translocation. Our results demonstrated that Best-3 is an endogenous inhibitor of NF-κB signaling pathway in endothelial cells, suggesting that forced Best-3 expression may be a novel approach for the treatment of vascular inflammatory diseases.
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Affiliation(s)
- Wei Song
- Department of Cardiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Zhen Yang
- Department of Hypertension and Vascular Disease, the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Ben He
- Department of Cardiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
- * E-mail:
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Kudryavtseva O, Herum KM, Dam VS, Straarup MS, Kamaev D, Briggs Boedtkjer DM, Matchkov VV, Aalkjær C. Downregulation of L-type Ca2+ channel in rat mesenteric arteries leads to loss of smooth muscle contractile phenotype and inward hypertrophic remodeling. Am J Physiol Heart Circ Physiol 2014; 306:H1287-301. [DOI: 10.1152/ajpheart.00503.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
L-type Ca2+ channels (LTCCs) are important for vascular smooth muscle cell (VSMC) contraction, as well as VSMC differentiation, as indicated by loss of LTCCs during VSMC dedifferentiation. However, it is not clear whether loss of LTCCs is a primary event underlying phenotypic modulation or whether loss of LTCCs has significance for vascular structure. We used small interference RNA (siRNA) transfection in vivo to investigate the role of LTCCs in VSMC phenotypic expression and structure of rat mesenteric arteries. siRNA reduced LTCC mRNA and protein expression in rat mesenteric arteries 3 days after siRNA transfection to 12.7 ± 0.7% and 47.3 ± 13%, respectively: this was associated with an increased resting intracellular Ca2+ concentration ([Ca2+]i). Despite the high [Ca2+]i, the contractility was reduced (tension development to norepinephrine was 3.5 ± 0.2 N/m and 0.8 ± 0.2 N/m for sham-transfected and downregulated arteries respectively; P < 0.05). Expression of contractile phenotype marker genes was reduced in arteries downregulated for LTCCs. Phenotypic changes were associated with a 45% increase in number of VSMCs and a consequent increase of media thickness and media area. Ten days after siRNA transfection arterial structure was again normalized. The contractile responses of LTCC-siRNA transfected arteries were elevated in comparison with matched controls 10 days after transfection. The study provides strong evidence for causal relationships between LTCC expression and VSMC contractile phenotype, as well as novel data addressing the complex relationship between VSMC contractility, phenotype, and vascular structure. These findings are relevant for understanding diseases, associated with phenotype changes of VSMC and vascular remodeling, such as atherosclerosis and hypertension.
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Affiliation(s)
- Olga Kudryavtseva
- Department of Biomedicine, Membranes, Aarhus University, Aarhus C, Denmark; and
| | - Kate Møller Herum
- Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, Oslo, Norway
| | - Vibeke Secher Dam
- Department of Biomedicine, Membranes, Aarhus University, Aarhus C, Denmark; and
| | | | - Dmitry Kamaev
- Department of Biomedicine, Membranes, Aarhus University, Aarhus C, Denmark; and
| | | | | | - Christian Aalkjær
- Department of Biomedicine, Membranes, Aarhus University, Aarhus C, Denmark; and
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Abstract
Ca(2+)-activated Cl(-) channels (CaCCs) are plasma membrane proteins involved in various important physiological processes. In epithelial cells, CaCC activity mediates the secretion of Cl(-) and of other anions, such as bicarbonate and thiocyanate. In smooth muscle and excitable cells of the nervous system, CaCCs have an excitatory role coupling intracellular Ca(2+) elevation to membrane depolarization. Recent studies indicate that TMEM16A (transmembrane protein 16 A or anoctamin 1) and TMEM16B (transmembrane protein 16 B or anoctamin 2) are CaCC-forming proteins. Induced expression of TMEM16A and B in null cells by transfection causes the appearance of Ca(2+)-activated Cl(-) currents similar to those described in native tissues. Furthermore, silencing of TMEM16A by RNAi causes disappearance of CaCC activity in cells from airway epithelium, biliary ducts, salivary glands, and blood vessel smooth muscle. Mice devoid of TMEM16A expression have impaired Ca(2+)-dependent Cl(-) secretion in the epithelial cells of the airways, intestine, and salivary glands. These animals also show a loss of gastrointestinal motility, a finding consistent with an important function of TMEM16A in the electrical activity of gut pacemaker cells, that is, the interstitial cells of Cajal. Identification of TMEM16 proteins will help to elucidate the molecular basis of Cl(-) transport.
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Affiliation(s)
- Loretta Ferrera
- Laboratory of Molecular Genetics, Istituto Giannina Gaslini, Genova, Italy
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Dam VS, Boedtkjer DMB, Nyvad J, Aalkjaer C, Matchkov V. TMEM16A knockdown abrogates two different Ca(2+)-activated Cl (-) currents and contractility of smooth muscle in rat mesenteric small arteries. Pflugers Arch 2013; 466:1391-409. [PMID: 24162234 PMCID: PMC4062836 DOI: 10.1007/s00424-013-1382-1] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 10/10/2013] [Accepted: 10/10/2013] [Indexed: 12/30/2022]
Abstract
The presence of Ca2+-activated Cl− channels (CaCCs) in vascular smooth muscle cells (SMCs) is well established. Their molecular identity is, however, elusive. Two distinct Ca2+-activated Cl− currents (ICl(Ca)) were previously characterized in SMCs. We have shown that the cGMP-dependent ICl(Ca) depends on bestrophin expression, while the “classical” ICl(Ca) is not. Downregulation of bestrophins did not affect arterial contraction but inhibited the rhythmic contractions, vasomotion. In this study, we have used in vivo siRNA transfection of rat mesenteric small arteries to investigate the role of a putative CaCC, TMEM16A. Isometric force, [Ca2+]i, and SMC membrane potential were measured in isolated arterial segments. ICl(Ca) and GTPγS-induced nonselective cation current were measured in isolated SMCs. Downregulation of TMEM16A resulted in inhibition of both the cGMP-dependent ICl(Ca) and the “classical” ICl(Ca) in SMCs. TMEM16A downregulation also reduced expression of bestrophins. TMEM16A downregulation suppressed vasomotion both in vivo and in vitro. Downregulation of TMEM16A reduced agonist (noradrenaline and vasopressin) and K+-induced contractions. In accordance with the depolarizing role of CaCCs, TMEM16A downregulation suppressed agonist-induced depolarization and elevation in [Ca2+]i. Surprisingly, K+-induced depolarization was unchanged but Ca2+ entry was reduced. We suggested that this is due to reduced expression of the L-type Ca2+ channels, as observed at the mRNA level. Thus, the importance of TMEM16A for contraction is, at least in part, independent from membrane potential. This study demonstrates the significance of TMEM16A for two SMCs ICl(Ca) and vascular function and suggests an interaction between TMEM16A and L-type Ca2+ channels.
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Affiliation(s)
- Vibeke Secher Dam
- Department of Biomedicine, MEMBRANES, Aarhus University, Ole Worms Alle bygn.4, 1163, Aarhus, C 8000, Denmark
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Mitochondria dependent pathway is involved in the protective effect of bestrophin-3 on hydrogen peroxide-induced apoptosis in basilar artery smooth muscle cells. Apoptosis 2013; 18:556-65. [DOI: 10.1007/s10495-013-0828-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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28
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Matchkov VV, Secher Dam V, Bødtkjer DMB, Aalkjær C. Transport and Function of Chloride in Vascular Smooth Muscles. J Vasc Res 2013; 50:69-87. [DOI: 10.1159/000345242] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Accepted: 10/16/2012] [Indexed: 12/12/2022] Open
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Nagaraja S, Kapela A, Tsoukias NM. Intercellular communication in the vascular wall: a modeling perspective. Microcirculation 2012; 19:391-402. [PMID: 22340204 DOI: 10.1111/j.1549-8719.2012.00171.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Movement of ions (Ca(2+) , K(+) , Na(+) , and Cl(-) ) and second messenger molecules like inositol 1, 4, 5-trisphosphate inside and in between different cells is the basis of many signaling mechanisms in the microcirculation. In spite of the vast experimental efforts directed toward evaluation of these fluxes, it has been a challenge to establish their roles in many essential microcirculatory phenomena. Recently, detailed theoretical models of calcium dynamics and plasma membrane electrophysiology have emerged to assist in the quantification of these intra and intercellular fluxes and enhance understanding of their physiological importance. This perspective reviews selected models relevant to estimation of such intra and intercellular ionic and second messenger fluxes and prediction of their relative significance to a variety of vascular phenomena, such as myoendothelial feedback, conducted responses, and vasomotion.
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Affiliation(s)
- Sridevi Nagaraja
- Department of Biomedical Engineering, Florida International University, Miami, Florida 33174, USA
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C-terminal membrane association of Bestrophin 3 and its activation as a chloride channel. J Membr Biol 2012; 246:177-82. [PMID: 23124946 DOI: 10.1007/s00232-012-9514-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 10/15/2012] [Indexed: 11/27/2022]
Abstract
Bestrophin 3 (Best3), a member of the bestrophin Cl(-) channel family, is a candidate of cGMP-sensitive, Ca(2+)-activated Cl(-) channel in vascular smooth muscle cells. The Best3 channel was recently found to play an important role in vasomotion. However, the mechanism for its activation has not been clarified. In previous studies, we found that a Best3 C-terminal sequence (amino acids 353-404) was associated with the cellular membrane. The sequence includes an autoinhibitory domain ((356)IPSFLGS(362)) and a downstream basic residue domain (amino acids 384-397). In this study, we found that the sequence (368-383) between the two domains is actually a determinant for Best3 C-terminal membrane associability. Deletion of the sequence almost abolished the membrane association but did not activate the Best3 channel. Treatment of Best3-expressing HEK293 cells with the PI3Kα inhibitor IV (a Best3 activator) could not abolish but weakened the Best3 membrane association. The result supports the assumption that the positively charged basic residues in the Best3 C terminus are likely associated with the membranous negatively charged phospholipids, which plays a role in the regulation of Best3 activation. But the relationship between membrane associability and Best3 activation seems more complicated than expected.
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Kapela A, Parikh J, Tsoukias NM. Multiple factors influence calcium synchronization in arterial vasomotion. Biophys J 2012; 102:211-20. [PMID: 22339857 DOI: 10.1016/j.bpj.2011.12.032] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Revised: 10/26/2011] [Accepted: 12/05/2011] [Indexed: 10/14/2022] Open
Abstract
The intercellular synchronization of spontaneous calcium (Ca(2+)) oscillations in individual smooth muscle cells is a prerequisite for vasomotion. A detailed mathematical model of Ca(2+) dynamics in rat mesenteric arteries shows that a number of synchronizing and desynchronizing pathways may be involved. In particular, Ca(2+)-dependent phospholipase C, the intercellular diffusion of inositol trisphosphate (IP(3), and to a lesser extent Ca(2+)), IP(3) receptors, diacylglycerol-activated nonselective cation channels, and Ca(2+)-activated chloride channels can contribute to synchronization, whereas large-conductance Ca(2+)-activated potassium channels have a desynchronizing effect. Depending on the contractile state and agonist concentrations, different pathways become predominant, and can be revealed by carefully inhibiting the oscillatory component of their total activity. The phase shift between the Ca(2+) and membrane potential oscillations can change, and thus electrical coupling through gap junctions can mediate either synchronization or desynchronization. The effect of the endothelium is highly variable because it can simultaneously enhance the intercellular coupling and affect multiple smooth muscle cell components. Here, we outline a system of increased complexity and propose potential synchronization mechanisms that need to be experimentally tested.
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Affiliation(s)
- Adam Kapela
- Department of Biomedical Engineering, Florida International University, Miami, Florida, USA
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Matchkov VV, Moeller-Nielsen N, Dam VS, Nourian Z, Briggs Boedtkjer DM, Aalkjaer C. The α2 isoform of the Na,K-pump is important for intercellular communication, agonist-induced contraction, and EDHF-like response in rat mesenteric arteries. Am J Physiol Heart Circ Physiol 2012; 303:H36-46. [PMID: 22561302 DOI: 10.1152/ajpheart.00673.2011] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The specific role of different isoforms of the Na,K-pump in the vascular wall is still under debate. We have previously suggested that the α(2) isoform of the Na,K-pump (α(2)), Na(+), Ca(2+)-exchange (NCX), and connexin43 form a regulatory microdomain in smooth muscle cells (SMCs), which controls intercellular communication and contractile properties of the vascular wall. We have tested this hypothesis by downregulating α(2) in cultured SMCs and in small arteries with siRNA in vivo. Intercellular communication was assessed by using membrane capacitance measurements. Arteries transfected in vivo were tested for isometric and isobaric force development in vitro; [Ca(2+)](i) was measured simultaneously. Cultured rat SMCs were well-coupled electrically, but 10 μM ouabain uncoupled them. Downregulation of α(2) reduced electrical coupling between SMCs and made them insensitive to ouabain. Downregulation of α(2) in small arteries was accompanied with significant reduction in NCX expression. Acetylcholine-induced relaxation was not different between the groups, but the endothelium-dependent hyperpolarizing factor-like component of the response was significantly diminished in α(2)-downregulated arteries. Micromolar ouabain reduced in a concentration-dependent manner the amplitude of norepinephrine (NE)-induced vasomotion. Sixty percent of the α(2)-downregulated arteries did not have vasomotion, and vasomotion in the remaining 40% was ouabain insensitive. Although ouabain increased the sensitivity to NE in the control arteries, it had no effect on α(2)-downregulated arteries. In the presence of a low NE concentration the α(2)-downregulated arteries had higher [Ca(2+)](i) and tone. However, the NE EC50 was reduced under isometric conditions, and maximal contraction was reduced under isometric and isobaric conditions. The latter was caused by a reduced Ca(2+)-sensitivity. The α(2)-downregulated arteries also had reduced contraction to vasopressin, whereas the contractile response to high K(+) was not affected. Our results demonstrate the importance of α(2) for intercellular coupling in the vascular wall and its involvement in the regulation of vascular tone.
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Chronic mild stress-induced depression-like symptoms in rats and abnormalities in catecholamine uptake in small arteries. Psychosom Med 2012; 74:278-87. [PMID: 22408132 DOI: 10.1097/psy.0b013e31824c40a9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Major depression and cardiovascular diseases have a strong comorbidity; however, the reason for this is unknown. In the chronic mild stress (CMS) model of depression, only a fraction of rats develop a major feature of depression-anhedonia-like behavior, whereas other rats are stress resilient. Previous studies suggested that CMS rats also have increased total peripheral vascular resistance. METHODS On the basis of CMS-induced changes of sucrose intake, a reliable measure for anhedonia, rats were divided into "resilient" and "anhedonic" groups. An interaction between hedonic status and vascular function was studied after 4 and 8 weeks of CMS exposure in vitro in wire myograph on saphenous arteries and mesenteric small arteries (MSAs) from these rats. RESULTS When comparing the different experimental rat groups, arterial sensitivities to noradrenaline (NA) were similar under control conditions, but in the presence of the neuronal reuptake inhibitor cocaine, arteries from anhedonic rats were more sensitive to NA. No change in perivascular innervation was found, but elevated expression of neuronal NA transporter was detected. Inhibition of extraneuronal uptake with corticosterone (1 μM) suggests that this transport is diminished in MSAs after CMS. The corticosterone-sensitive transporter organic cation cotransporter 2 was shown to be reduced in MSAs after CMS. No CMS-induced changes in the corticosterone-sensitive transport were found in saphenous arteries. CONCLUSIONS Our results indicate that CMS-induced depression-like symptoms in rats are associated with changes in catecholamine uptake pathways in the vascular wall, which potentially modulates the effect of sympathetic innervation of resistance arteries.
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Abstract
This minireview discusses vasomotion, which is the oscillation in tone of blood vessels leading to flowmotion. We will briefly discuss the prevalence of vasomotion and its potential physiological and pathophysiological relevance. We will also discuss the models that have been suggested to explain how a coordinated oscillatory activity of the smooth muscle tone can occur and emphasize the role of the endothelium, the handling of intracellular Ca(2+) and the role of smooth muscle cell ion conductances. It is concluded that vasomotion is likely to enhance tissue dialysis, although this concept still requires more experimental verification, and that an understanding at the molecular level for the pathways leading to vasomotion is beginning to emerge.
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Affiliation(s)
- C Aalkjær
- Department of Physiology and Biophysics, The Water and Salt Centre, Aarhus University, Denmark.
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