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Chennupati R, Wirth A, Favre J, Li R, Bonnavion R, Jin YJ, Wietelmann A, Schweda F, Wettschureck N, Henrion D, Offermanns S. Myogenic vasoconstriction requires G 12/G 13 and LARG to maintain local and systemic vascular resistance. eLife 2019; 8:49374. [PMID: 31549965 PMCID: PMC6777979 DOI: 10.7554/elife.49374] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Accepted: 09/24/2019] [Indexed: 12/12/2022] Open
Abstract
Myogenic vasoconstriction is an autoregulatory function of small arteries. Recently, G-protein-coupled receptors have been involved in myogenic vasoconstriction, but the downstream signalling mechanisms and the in-vivo-function of this myogenic autoregulation are poorly understood. Here, we show that small arteries from mice with smooth muscle-specific loss of G12/G13 or the Rho guanine nucleotide exchange factor ARHGEF12 have lost myogenic vasoconstriction. This defect was accompanied by loss of RhoA activation, while vessels showed normal increases in intracellular [Ca2+]. In the absence of myogenic vasoconstriction, perfusion of peripheral organs was increased, systemic vascular resistance was reduced and cardiac output and left ventricular mass were increased. In addition, animals with defective myogenic vasoconstriction showed aggravated hypotension in response to endotoxin. We conclude that G12/G13- and Rho-mediated signaling plays a key role in myogenic vasoconstriction and that myogenic tone is required to maintain local and systemic vascular resistance under physiological and pathological condition.
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Affiliation(s)
- Ramesh Chennupati
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Angela Wirth
- Institute of Pharmacology, University of Heidelberg, Heidelberg, Germany
| | - Julie Favre
- Laboratoire MITOVASC, UMR CNRS 6015 - INSERM 1083, Université d'Angers, Angers, France
| | - Rui Li
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Rémy Bonnavion
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Young-June Jin
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Astrid Wietelmann
- Scientific Service Group Nuclear Magnetic Resonance Imaging, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Frank Schweda
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | - Nina Wettschureck
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.,Centre for Molecular Medicine, Medical Faculty, JW Goethe University Frankfurt, Frankfurt, Germany.,German Center for Cardiovascular Research (DZHK), Berlin, Germany
| | - Daniel Henrion
- Laboratoire MITOVASC, UMR CNRS 6015 - INSERM 1083, Université d'Angers, Angers, France
| | - Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany.,Centre for Molecular Medicine, Medical Faculty, JW Goethe University Frankfurt, Frankfurt, Germany.,German Center for Cardiovascular Research (DZHK), Berlin, Germany
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102
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Ottolini M, Hong K, Sonkusare SK. Calcium signals that determine vascular resistance. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2019; 11:e1448. [PMID: 30884210 PMCID: PMC6688910 DOI: 10.1002/wsbm.1448] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 02/07/2019] [Accepted: 02/14/2019] [Indexed: 12/19/2022]
Abstract
Small arteries in the body control vascular resistance, and therefore, blood pressure and blood flow. Endothelial and smooth muscle cells in the arterial walls respond to various stimuli by altering the vascular resistance on a moment to moment basis. Smooth muscle cells can directly influence arterial diameter by contracting or relaxing, whereas endothelial cells that line the inner walls of the arteries modulate the contractile state of surrounding smooth muscle cells. Cytosolic calcium is a key driver of endothelial and smooth muscle cell functions. Cytosolic calcium can be increased either by calcium release from intracellular stores through IP3 or ryanodine receptors, or the influx of extracellular calcium through ion channels at the cell membrane. Depending on the cell type, spatial localization, source of a calcium signal, and the calcium-sensitive target activated, a particular calcium signal can dilate or constrict the arteries. Calcium signals in the vasculature can be classified into several types based on their source, kinetics, and spatial and temporal properties. The calcium signaling mechanisms in smooth muscle and endothelial cells have been extensively studied in the native or freshly isolated cells, therefore, this review is limited to the discussions of studies in native or freshly isolated cells. This article is categorized under: Biological Mechanisms > Cell Signaling Laboratory Methods and Technologies > Imaging Models of Systems Properties and Processes > Mechanistic Models.
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Affiliation(s)
- Matteo Ottolini
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Pharmacology, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
| | - Kwangseok Hong
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Physical Education, Chung-Ang University, Seoul, 06974, South Korea
| | - Swapnil K. Sonkusare
- Robert M. Berne Cardiovascular Research Center, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Pharmacology, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia-School of Medicine, Charlottesville, VA, 22908, USA
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103
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Guan Z, Baty JJ, Zhang S, Remedies CE, Inscho EW. Rho kinase inhibitors reduce voltage-dependent Ca 2+ channel signaling in aortic and renal microvascular smooth muscle cells. Am J Physiol Renal Physiol 2019; 317:F1132-F1141. [PMID: 31432708 DOI: 10.1152/ajprenal.00212.2018] [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] [Indexed: 02/03/2023] Open
Abstract
Voltage-dependent L-type Ca2+ channels (L-VDCCs) and the RhoA/Rho kinase pathway are two predominant intracellular signaling pathways that regulate renal microvascular reactivity. Traditionally, these two pathways have been thought to act independently; however, recent evidence suggests that these pathways could be convergent. We hypothesized that Rho kinase inhibitors can influence L-VDCC signaling. The effects of Rho kinase inhibitors Y-27632 or RKI-1447 on KCl-induced depolarization or the L-VDCC agonist Bay K8644 were assessed in afferent arterioles using an in vitro blood-perfused rat juxtamedullary nephron preparation. Superfusion of KCl (30-90 mM) led to concentration-dependent vasoconstriction of afferent arterioles. Administration of Y-27632 (1, 5, and 10 µM) or RKI-1447 (0.1, 1, and 10 µM) significantly increased the starting diameter by 16-65%. KCl-induced vasoconstriction was markedly attenuated with 5 and 10 µM Y-27632 and with 10 µM RKI-1447 (P < 0.05 vs. KCl alone). Y-27632 (5 µM) also significantly attenuated Bay K8644-induced vasoconstriction (P < 0.05). Changes in intracellular Ca2+ concentration ([Ca2+]i) were estimated by fura-2 fluorescence during KCl-induced depolarization in cultured A7r5 cells and in freshly isolated preglomerular microvascular smooth muscle cells. Administration of 90 mM KCl significantly increased fura-2 fluorescence in both cell types. KCl-mediated elevation of [Ca2+]i in A7r5 cells was suppressed by 1-10 µM Y-27632 (P < 0.05), but 10 µM Y-27632 was required to suppress Ca2+ responses in preglomerular microvascular smooth muscle cells. RKI-1447, however, significantly attenuated KCl-mediated elevation of [Ca2+]i. Y-27632 markedly inhibited Bay K8644-induced elevation of [Ca2+]i in both cell types. The results of the present study indicate that the Rho kinase inhibitors Y-27632 and RKI-1447 can partially inhibit L-VDCC function and participate in L-VDCC signaling.
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Affiliation(s)
- Zhengrong Guan
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Joshua J Baty
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Shali Zhang
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Colton E Remedies
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Edward W Inscho
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
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104
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Activation of Cav1.2 and BKCa is involved in the downregulation of caffeine-induced contraction in mice mesenteric arteries. Life Sci 2019; 231:116555. [DOI: 10.1016/j.lfs.2019.116555] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 06/07/2019] [Accepted: 06/08/2019] [Indexed: 01/05/2023]
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105
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Frösen J, Joutel A. Smooth muscle cells of intracranial vessels: from development to disease. Cardiovasc Res 2019; 114:501-512. [PMID: 29351598 DOI: 10.1093/cvr/cvy002] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 01/12/2018] [Indexed: 02/02/2023] Open
Abstract
Cerebrovascular diseases that cause ischaemic or haemorrhagic stroke with subsequent loss of life or functional capacity due to damage of the brain tissue are among the leading causes of human suffering and economic burden inflicted by diseases in the developed world. Diseases affecting intracranial vessels are significant contributors to ischaemic and haemorrhagic strokes. Brain arteriovenous malformations, which are a collection of abnormal blood vessels connecting arteries to veins, are the most common cause of intracranial haemorrhage in children and young adults. Saccular intracranial aneurysms, which are pathological saccular dilations mainly occurring at bifurcations of the large intracranial arteries near the circle of Willis, are highly prevalent in the middle-aged population, causing significant anxiety and concern; their rupture, although rare, is a significant cause of intracranial haemorrhage in those past middle age that is associated with a very sinister prognosis. Cerebral small-vessel disease, which comprise all pathological processes affecting vessels <500 microns in diameter, account for the majority of intracerebral haemorrhages and ∼25% of ischaemic strokes and 45% of dementias in the elderly. In this review, we summarize the developmental, structural, and functional features of intracranial vessels. We then describe the role of smooth muscle cells in brain arteriovenous malformations, intracranial aneurysms, and small-vessel diseases, and discuss how the peculiar ontogeny, structure, and function of intracranial vessels are related to the development of these diseases.
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Affiliation(s)
- Juhana Frösen
- Hemorrhagic Brain Pathology Research Group, NeuroCenter, Kuopio University Hospital, Kuopio 70029, Finland.,Department of Neurosurgery, Kuopio University Hospital, Kuopio 70029, Finland
| | - Anne Joutel
- Genetics and Pathogenesis of Cerebrovascular Diseases, INSERM, Université Paris Diderot-Paris 7, 10 av de Verdun, Paris 75010, France.,DHU NeuroVasc, Sorbonne Paris Cité, Paris 75010, France
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106
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Paula SM, Couto GK, Fontes MT, Costa SK, Negrão CE, Mill JG, Rossoni LV. Exercise training restores the myogenic response in skeletal muscle resistance arteries and corrects peripheral edema in rats with heart failure. Am J Physiol Heart Circ Physiol 2019; 317:H87-H96. [DOI: 10.1152/ajpheart.00042.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Impairment of the myogenic response can affect capillary hydrostatic pressure and contribute to peripheral edema and exercise intolerance, which are markers of heart failure (HF). The aim of this study was to assess the effects of exercise training (ET) on myogenic response in skeletal muscle resistance arteries and peripheral edema in HF rats, focusing on the potential signaling pathways involved in these adjustments. Male Wistar rats were submitted to either coronary artery occlusion or a sham-operated surgery. After 4 wk, an exercise test was performed, and the rats were divided into the following groups: untrained normal control (UNC) and untrained HF (UHF) and exercise- trained (on treadmill, 50–60% of maximal capacity) NC (TNC) and exercise-trained HF (THF). Caudal tibial artery (CTA) myogenic response was impaired in UHF compared with UNC, and ET restored this response in THF to NC levels and increased it in TNC. Rho kinase (ROCK) inhibitor abolished CTA myogenic response in the untrained and blunted it in exercise-trained groups. CTA-stored calcium (Ca2+) mobilization was higher in exercise-trained rats compared with untrained rats. The paw volume was higher in UHF rats, and ET decreased this response compared with UNC. Myogenic constriction was positively correlated with maximal running distance and negatively correlated with paw volume. The results demonstrate, for the first time, that HF impairs the myogenic response in skeletal muscle arteries, which contributes to peripheral edema in this syndrome. ET restores the myogenic response in skeletal muscle arteries improving Ca2+ sensitization and handling. Additionally, this paradigm also improves peripheral edema and exercise intolerance. NEW & NOTEWORTHY The novel and main finding of the present study is that moderate intensity exercise training restores the impaired myogenic response of skeletal muscle resistance arteries, exercise intolerance and peripheral edema in rats with heart failure. These results also show for the first time to our knowledge that exercise training improving calcium sensitization through the ROCK pathway and enhancing intracellular calcium handling could contribute to restoration of flow autoregulation to skeletal muscle in heart failure.
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Affiliation(s)
- Suliana M. Paula
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Gisele K. Couto
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Milene T. Fontes
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Soraia K. Costa
- Department of Pharmacology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
| | - Carlos E. Negrão
- Heart Institute, Instituto do Coração do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, University of São Paulo, São Paulo, Brazil
- School of Physical Education and Sport, University of São Paulo, São Paulo, Brazil
| | - José G. Mill
- Department of Physiological Sciences, Federal University of Espírito Santo, Espírito Santo, Brazil
| | - Luciana V. Rossoni
- Department of Physiology and Biophysics, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil
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107
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Mishra RC, Rahman MM, Davis MJ, Wulff H, Hill MA, Braun AP. Alpha 1 -adrenergic stimulation selectively enhances endothelium-mediated vasodilation in rat cremaster arteries. Physiol Rep 2019; 6:e13703. [PMID: 29756401 PMCID: PMC5949301 DOI: 10.14814/phy2.13703] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2018] [Revised: 03/19/2018] [Accepted: 04/16/2018] [Indexed: 11/24/2022] Open
Abstract
We have systematically investigated how vascular smooth muscle α1‐adrenoceptor activation impacts endothelium‐mediated vasodilation in isolated, myogenically active, rat cremaster muscle 1A arteries. Cannulated cremaster arteries were pressurized intraluminally to 70 mmHg to induce myogenic tone, and exposed to vasoactive agents via bath superfusion at 34°C. Smooth muscle membrane potential was measured via sharp microelectrode recordings in pressurized, myogenic arteries. The α1‐adrenergic agonist phenylephrine (25–100 nmol/L) produced further constriction of myogenic arteries, but did not alter the vasorelaxant responses to acetylcholine (0.3 μmol/L), SKA‐31 (an activator of endothelial Ca2+‐dependent K+ channels) (3 μmol/L) or sodium nitroprusside (10 μmol/L). Exposure to 0.25–1 μmol/L phenylephrine or 1 μmol/L norepinephrine generated more robust constrictions, and also enhanced the vasodilations evoked by acetylcholine and SKA‐31, but not by sodium nitroprusside. In contrast, the thromboxane receptor agonist U46619 (250 nmol/L) dampened responses to all three vasodilators. Phenylephrine exposure depolarized myogenic arteries, and mimicking this effect with 4‐aminopyridine (1 mmol/L) was sufficient to augment the SKA‐31‐evoked vasodilation. Inhibition of L‐type Ca2+ channels by 1 μmol/L nifedipine decreased myogenic tone, phenylephrine‐induced constriction and prevented α1‐adrenergic enhancement of endothelium‐evoked vasodilation; these latter deficits were overcome by exposure to 3 and 10 μmol/L phenylephrine. Mechanistically, augmentation of ACh‐evoked dilation by phenylephrine was dampened by eNOS inhibition and abolished by blockade of endothelial KCa channels. Collectively, these data suggest that increasing α1‐adrenoceptor activation beyond a threshold level augments endothelium‐evoked vasodilation, likely by triggering transcellular signaling between smooth muscle and the endothelium. Physiologically, this negative feedback process may serve as a “brake” to limit the extent of vasoconstriction in the skeletal microcirculation evoked by the elevated sympathetic tone.
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Affiliation(s)
- Ramesh C Mishra
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Mohammad M Rahman
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Michael J Davis
- Dalton Cardiovascular Research Institute and Dept. of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Heike Wulff
- Department of Pharmacology, University of California Davis, Davis, California
| | - Michael A Hill
- Dalton Cardiovascular Research Institute and Dept. of Medical Pharmacology and Physiology, University of Missouri, Columbia, Missouri
| | - Andrew P Braun
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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108
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Chalacheva P, Kato RM, Shah P, Veluswamy S, Denton CC, Sunwoo J, Thuptimdang W, Wood JC, Detterich JA, Coates TD, Khoo MCK. Sickle Cell Disease Subjects Have a Distinct Abnormal Autonomic Phenotype Characterized by Peripheral Vasoconstriction With Blunted Cardiac Response to Head-Up Tilt. Front Physiol 2019; 10:381. [PMID: 31031633 PMCID: PMC6470196 DOI: 10.3389/fphys.2019.00381] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Accepted: 03/19/2019] [Indexed: 12/26/2022] Open
Abstract
In sickle cell disease (SCD), prolonged capillary transit times, resulting from reduced peripheral blood flow, increase the likelihood of rigid red cells entrapment in the microvasculature, predisposing to vaso-occlusive crisis. Since changes in peripheral flow are mediated by the autonomic nervous system (ANS), we tested the hypothesis that the cardiac and peripheral vascular responses to head-up tilt (HUT) are abnormal in SCD. Heart rate, respiration, non-invasive continuous blood pressure and finger photoplethysmogram (PPG) were monitored before, during, and after HUT in SCD, anemic controls and healthy subjects. Percent increase in heart rate from baseline was used to quantify cardiac ANS response, while percent decrease in PPG amplitude represented degree of peripheral vasoconstriction. After employing cluster analysis to determine threshold levels, the HUT responses were classified into four phenotypes: (CP) increased heart rate and peripheral vasoconstriction; (C) increased heart rate only; (P) peripheral vasoconstriction only; and (ST) subthreshold cardiac and peripheral vascular responses. Multinomial logistic regression (MLR) was used to relate these phenotypic responses to various parameters representing blood properties and baseline cardiovascular activity. The most common phenotypic response, CP, was found in 82% of non-SCD subjects, including those with chronic anemia. In contrast, 70% of SCD subjects responded abnormally to HUT: C-phenotype = 22%, P-phenotype = 37%, or ST-phenotype = 11%. MLR revealed that the HUT phenotypes were significantly associated with baseline cardiac parasympathetic activity, baseline peripheral vascular variability, hemoglobin level and SCD diagnosis. Low parasympathetic activity at baseline dramatically increased the probability of belonging to the P-phenotype in SCD subjects, even after adjusting for hemoglobin level, suggesting a characteristic autonomic dysfunction that is independent of anemia. Further analysis using a mathematical model of heart rate variability revealed that the low parasympathetic activity in P-phenotype SCD subjects was due to impaired respiratory-cardiac coupling rather than reduced cardiac baroreflex sensitivity. By having strong peripheral vasoconstriction without compensatory cardiac responses, P-phenotype subjects may be at increased risk for vaso-occlusive crisis. The classification of autonomic phenotypes based on HUT response may have potential use for guiding therapeutic interventions to alleviate the risk of adverse outcomes in SCD.
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Affiliation(s)
- Patjanaporn Chalacheva
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States
| | - Roberta M Kato
- Divisions of Pulmonology, Children's Hospital Los Angeles, Los Angeles, CA, United States
| | - Payal Shah
- Hematology Section, Children's Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Saranya Veluswamy
- Hematology Section, Children's Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Christopher C Denton
- Hematology Section, Children's Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - John Sunwoo
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States
| | - Wanwara Thuptimdang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States
| | - John C Wood
- Divisions of Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, United States
| | - Jon A Detterich
- Divisions of Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, United States
| | - Thomas D Coates
- Hematology Section, Children's Center for Cancer, Blood Disease and Bone Marrow Transplantation, Children's Hospital Los Angeles, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Michael C K Khoo
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, United States
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109
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Campos R, Claudino MA, de Oliveira MG, Franco-Penteado CF, Del Grossi Ferraz Carvalho F, Zaminelli T, Antunes E, De Nucci G. Amiloride Relaxes Rat Corpus Cavernosum Relaxation In Vitro and Increases Intracavernous Pressure In Vivo. J Sex Med 2019; 16:500-511. [DOI: 10.1016/j.jsxm.2019.01.315] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 01/24/2019] [Accepted: 01/27/2019] [Indexed: 01/30/2023]
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110
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Alaaeddine RA, Mroueh A, Gust S, Eid AH, Plane F, El-Yazbi AF. Impaired cross-talk between NO and hyperpolarization in myoendothelial feedback: a novel therapeutic target in early endothelial dysfunction of metabolic disease. Curr Opin Pharmacol 2019; 45:33-41. [DOI: 10.1016/j.coph.2019.03.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 02/12/2019] [Accepted: 03/15/2019] [Indexed: 12/27/2022]
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111
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Dee RA, Mangum KD, Bai X, Mack CP, Taylor JM. Druggable targets in the Rho pathway and their promise for therapeutic control of blood pressure. Pharmacol Ther 2019; 193:121-134. [PMID: 30189292 PMCID: PMC7235948 DOI: 10.1016/j.pharmthera.2018.09.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The prevalence of high blood pressure (also known as hypertension) has steadily increased over the last few decades. Known as a silent killer, hypertension increases the risk for cardiovascular disease and can lead to stroke, heart attack, kidney failure and associated sequela. While numerous hypertensive therapies are currently available, it is estimated that only half of medicated patients exhibit blood pressure control. This signifies the need for a better understanding of the underlying cause of disease and for more effective therapies. While blood pressure homeostasis is very complex and involves the integrated control of multiple body systems, smooth muscle contractility and arterial resistance are important contributors. Strong evidence from pre-clinical animal models and genome-wide association studies indicate that smooth muscle contraction and BP homeostasis are governed by the small GTPase RhoA and its downstream target, Rho kinase. In this review, we summarize the signaling pathways and regulators that impart tight spatial-temporal control of RhoA activity in smooth muscle cells and discuss current therapeutic strategies to target these RhoA pathway components. We also discuss known allelic variations in the RhoA pathway and consider how these polymorphisms may affect genetic risk for hypertension and its clinical manifestations.
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Affiliation(s)
- Rachel A Dee
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kevin D Mangum
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Xue Bai
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Christopher P Mack
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Joan M Taylor
- Department of Pathology and Laboratory Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; McAllister Heart Institute, University of North Carolina, Chapel Hill, NC 27599, USA.
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112
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Pabbidi MR, Kuppusamy M, Didion SP, Sanapureddy P, Reed JT, Sontakke SP. Sex differences in the vascular function and related mechanisms: role of 17β-estradiol. Am J Physiol Heart Circ Physiol 2018; 315:H1499-H1518. [DOI: 10.1152/ajpheart.00194.2018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The incidence of cardiovascular disease (CVD) is lower in premenopausal women but increases with age and menopause compared with similarly aged men. Based on the prevalence of CVD in postmenopausal women, sex hormone-dependent mechanisms have been postulated to be the primary factors responsible for the protection from CVD in premenopausal women. Recent Women’s Health Initiative studies, Cochrane Review studies, the Early Versus Late Intervention Trial with Estradiol Study, and the Kronos Early Estrogen Prevention Study have suggested that beneficial effects of hormone replacement therapy (HRT) are seen in women of <60 yr of age and if initiated within <10 yr of menopause. In contrast, the beneficial effects of HRT are not seen in women of >60 yr of age and if commenced after 10 yr of menopause. The higher incidence of CVD and the failure of HRT in postmenopausal aged women could be partly associated with fundamental differences in the vascular structure and function between men and women and in between pre- and postmenopausal women, respectively. In this regard, previous studies from human and animal studies have identified several sex differences in vascular function and associated mechanisms. The female sex hormone 17β-estradiol regulates the majority of these mechanisms. In this review, we summarize the sex differences in vascular structure, myogenic properties, endothelium-dependent and -independent mechanisms, and the role of 17β-estradiol in the regulation of vascular function.
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Affiliation(s)
- Mallikarjuna R. Pabbidi
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Maniselvan Kuppusamy
- Division of Endocrinology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Sean P. Didion
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Padmaja Sanapureddy
- Department of Primary Care and Medicine, G. V. (Sonny) Montgomery Veterans Affairs Medical Center, Jackson, Mississippi
| | - Joey T. Reed
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
| | - Sumit P. Sontakke
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, Mississippi
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113
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Hasan R, Jaggar JH. K V channel trafficking and control of vascular tone. Microcirculation 2018; 25. [PMID: 28963858 DOI: 10.1111/micc.12418] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 09/25/2017] [Indexed: 12/21/2022]
Abstract
Membrane potential is a principal regulator of arterial contractility. Arterial smooth muscle cells express several different types of ion channel that control membrane potential, including KV channels. KV channel activation leads to membrane hyperpolarization, resulting in inhibition of voltage-dependent Ca2+ channels, a reduction in [Ca2+ ]i , and vasodilation. In contrast, KV channel inhibition leads to membrane depolarization and vasoconstriction. The ability of KV channels to regulate arterial contractility is dependent upon the number of plasma membrane-resident channels and their open probability. Here, we will discuss mechanisms that alter the surface abundance of KV channel proteins in arterial smooth muscle cells and the functional consequences of such regulation. Cellular processes that will be described include those that modulate KV channel transcription, retrograde and anterograde trafficking, and protein degradation.
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Affiliation(s)
- Raquibul Hasan
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Jonathan H Jaggar
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN, USA
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Koide M, Moshkforoush A, Tsoukias NM, Hill-Eubanks DC, Wellman GC, Nelson MT, Dabertrand F. The yin and yang of K V channels in cerebral small vessel pathologies. Microcirculation 2018; 25. [PMID: 29247493 DOI: 10.1111/micc.12436] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 12/08/2017] [Indexed: 12/14/2022]
Abstract
Cerebral SVDs encompass a group of genetic and sporadic pathological processes leading to brain lesions, cognitive decline, and stroke. There is no specific treatment for SVDs, which progress silently for years before becoming clinically symptomatic. Here, we examine parallels in the functional defects of PAs in CADASIL, a monogenic form of SVD, and in response to SAH, a common type of hemorrhagic stroke that also targets the brain microvasculature. Both animal models exhibit dysregulation of the voltage-gated potassium channel, KV 1, in arteriolar myocytes, an impairment that compromises responses to vasoactive stimuli and impacts CBF autoregulation and local dilatory responses to neuronal activity (NVC). However, the extent to which this channelopathy-like defect ultimately contributes to these pathologies is unknown. Combining experimental data with computational modeling, we describe the role of KV 1 channels in the regulation of myocyte membrane potential at rest and during the modest increase in extracellular potassium associated with NVC. We conclude that PA resting membrane potential and myogenic tone depend strongly on KV 1.2/1.5 channel density, and that reciprocal changes in KV channel density in CADASIL and SAH produce opposite effects on extracellular potassium-mediated dilation during NVC.
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Affiliation(s)
- Masayo Koide
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Arash Moshkforoush
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | - Nikolaos M Tsoukias
- Department of Biomedical Engineering, Florida International University, Miami, FL, USA
| | | | - George C Wellman
- Department of Pharmacology, University of Vermont, Burlington, VT, USA
| | - Mark T Nelson
- Department of Pharmacology, University of Vermont, Burlington, VT, USA.,Institute of Cardiovascular Sciences, University of Manchester, Manchester, UK
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Henrion D. Keeping the Extracellular Matrix Well Structured to Keep Healthy Vessels. Arterioscler Thromb Vasc Biol 2018; 38:2281-2282. [PMID: 30354223 DOI: 10.1161/atvbaha.118.311733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Daniel Henrion
- From the MitoVasc Institute, UMR CNRS 6015-INSERM U1083, University of Angers, France
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116
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Massie F, Mendes de Almeida D, Dreesen P, Thijs I, Vranken J, Klerkx S. An Evaluation of the NightOwl Home Sleep Apnea Testing System. J Clin Sleep Med 2018; 14:1791-1796. [PMID: 30353811 DOI: 10.5664/jcsm.7398] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 08/07/2018] [Indexed: 11/13/2022]
Abstract
STUDY OBJECTIVES The objective of this study was to evaluate the performance of a miniaturized home sleep apnea test, called NightOwl. The system consists of a sensor placed on the fingertip and a cloud-based analytics software. The sensor acquires accelerometer and photoplethysmographic data. The software derives actigraphy from the former, and blood oxygen saturation and peripheral arterial tone, among other features, from the latter. METHODS Data of 101 participants who underwent an in-laboratory polysomnography (PSG), while wearing the NightOwl sensor, were collected. In order to establish an external benchmark, all PSG tests were edited by a somnologist of Younes Medical Technologies Ltd. (YMT) after analysis by the Michele Sleep Scoring System (MSSS). The respiratory event index (REI) derived by NightOwl (NightOwl-REI), the apnea-hypopnea index (AHI) derived by Ziekenhuis Oost-Limburg (ZOL-AHI), and the AHI derived by YMT (MSSS-AHI) were compared. RESULTS The NightOwl-REI had a high correlation with the MSSS-AHI (ρ = .87, P < .001), which was close to the correlation between the ZOL-AHI and MSSS-AHI (ρ = .84, P < .001). The NightOwl-REI and ZOL-AHI had a correlation of .77 (P < .001). After categorization of the AHI, the agreement between the NightOwl-REI and the MSSS-AHI was .812 and the agreement between the ZOL-AHI and MSSS-AHI was .743, after double-labeling near-boundary participants. CONCLUSIONS The NightOwl-REI achieved a close correlation and REI-categorization with the MSSS-AHI, especially in light of the significant inter-scorer variability of the analysis of the PSG.
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Affiliation(s)
| | | | - Pauline Dreesen
- Future Health Department, Ziekenhuis Oost-Limburg (Hospital East-Limburg), Genk, Belgium and Mobile Health Unit, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt, Belgium
| | - Inge Thijs
- Future Health Department, Ziekenhuis Oost-Limburg (Hospital East-Limburg), Genk, Belgium and Mobile Health Unit, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt, Belgium
| | - Julie Vranken
- Future Health Department, Ziekenhuis Oost-Limburg (Hospital East-Limburg), Genk, Belgium and Mobile Health Unit, Faculty of Medicine and Life Sciences, Hasselt University, Hasselt, Belgium
| | - Susie Klerkx
- Department of Pneumology, Ziekenhuis Oost-Limburg (Hospital East-Limburg), Genk, Belgium
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Giles AV, Sun J, Femnou AN, Kuzmiak-Glancy S, Taylor JL, Covian R, Murphy E, Balaban RS. Paradoxical arteriole constriction compromises cytosolic and mitochondrial oxygen delivery in the isolated saline-perfused heart. Am J Physiol Heart Circ Physiol 2018; 315:H1791-H1804. [PMID: 30311498 DOI: 10.1152/ajpheart.00493.2018] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The isolated saline-perfused heart is used extensively to study cardiac physiology. Previous isolated heart studies have demonstrated lower tissue oxygenation compared with in vivo hearts based on myoglobin oxygenation and the mitochondrial redox state. These data, consistent with small anoxic regions, suggest that the homeostatic balance between work and oxygen delivery is impaired. We hypothesized that these anoxic regions are caused by inadequate local perfusion due to a paradoxical arteriole constriction generated by a disrupted vasoregulatory network. We tested this hypothesis by applying two exogenous vasodilatory agents, adenosine and cromakalim, to relax vascular tone in an isolated, saline-perfused, working rabbit heart. Oxygenation was monitored using differential optical transmission spectroscopy and full spectral fitting. Increases in coronary flow over control with adenosine (27 ± 4 ml/min) or cromakalim (44 ± 4 ml/min) were associated with proportional spectral changes indicative of myoglobin oxygenation and cytochrome oxidase (COX) oxidation, consistent with a decrease in tissue anoxia. Quantitatively, adenosine decreased deoxymyoglobin optical density (OD) across the wall by 0.053 ± 0.008 OD, whereas the reduced form of COX was decreased by 0.039 ± 0.005 OD. Cromakalim was more potent, decreasing deoxymyoglobin and reducing the level of COX by 0.070 ± 0.019 OD and 0.062 ± 0.019 OD, respectively. These effects were not species specific, as Langendorff-perfused mouse hearts treated with adenosine demonstrated similar changes. These data are consistent with paradoxical arteriole constriction as a major source of regional anoxia during saline heart perfusion. We suggest that the vasoregulatory network is disrupted by the washout of interstitial vasoactive metabolites in vitro. NEW & NOTEWORTHY Regional tissue anoxia is a common finding in the ubiquitous saline-perfused heart but is not found in vivo. Noninvasive optical techniques confirmed the presence of regional anoxia under control conditions and demonstrated that anoxia is diminished using exogenous vasodilators. These data are consistent with active arteriole constriction, occurring despite regional anoxia, generated by a disrupted vasoregulatory network. Washout of interstitial vasoactive metabolites may contribute to the disruption of normal vasoregulatory processes in vitro.
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Affiliation(s)
- Abigail V Giles
- Laboratory of Cardiac Energetics, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland
| | - Junhui Sun
- Laboratory of Cardiac Physiology, Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland
| | - Armel N Femnou
- Laboratory of Cardiac Energetics, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland
| | - Sarah Kuzmiak-Glancy
- Department of Kinesiology, School of Public Health, University of Maryland , College Park, Maryland
| | - Joni L Taylor
- Division of Veterinary Resources, National Institutes of Health , Bethesda, Maryland
| | - Raul Covian
- Laboratory of Cardiac Energetics, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland
| | - Elizabeth Murphy
- Laboratory of Cardiac Physiology, Cardiovascular Branch, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland
| | - Robert S Balaban
- Laboratory of Cardiac Energetics, Systems Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda, Maryland
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Carnevale D, Facchinello N, Iodice D, Bizzotto D, Perrotta M, De Stefani D, Pallante F, Carnevale L, Ricciardi F, Cifelli G, Da Ros F, Casaburo M, Fardella S, Bonaldo P, Innocenzi G, Rizzuto R, Braghetta P, Lembo G, Bressan GM. Loss of EMILIN-1 Enhances Arteriolar Myogenic Tone Through TGF-β (Transforming Growth Factor-β)–Dependent Transactivation of EGFR (Epidermal Growth Factor Receptor) and Is Relevant for Hypertension in Mice and Humans. Arterioscler Thromb Vasc Biol 2018; 38:2484-2497. [DOI: 10.1161/atvbaha.118.311115] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Daniela Carnevale
- From the Department of Molecular Medicine, Sapienza University of Rome, Italy (D.C., M.P., G.L.)
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Nicola Facchinello
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
| | - Daniele Iodice
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Dario Bizzotto
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
| | - Marialuisa Perrotta
- From the Department of Molecular Medicine, Sapienza University of Rome, Italy (D.C., M.P., G.L.)
| | - Diego De Stefani
- Department of Biomedical Sciences (D.D.S., R.R.), University of Padova, Italy
| | - Fabio Pallante
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Lorenzo Carnevale
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Franco Ricciardi
- Department of Neurosurgery (F.R., G.I.), IRCCS Neuromed, Pozzilli, Italy
| | - Giuseppe Cifelli
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Francesco Da Ros
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
| | - Manuel Casaburo
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Stefania Fardella
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Paolo Bonaldo
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
| | | | - Rosario Rizzuto
- Department of Biomedical Sciences (D.D.S., R.R.), University of Padova, Italy
| | - Paola Braghetta
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
| | - Giuseppe Lembo
- From the Department of Molecular Medicine, Sapienza University of Rome, Italy (D.C., M.P., G.L.)
- Department of Angiocardioneurology and Translational Medicine (D.C., D.I., F.P., L.C., G.C., M.C., S.F., G.L.), IRCCS Neuromed, Pozzilli, Italy
| | - Giorgio M. Bressan
- Department of Molecular Medicine (N.F., D.B., F.D.R., P. Bonaldo, P. Braghetta, G.M.B.), University of Padova, Italy
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Nanoscale remodeling of ryanodine receptor cluster size underlies cerebral microvascular dysfunction in Duchenne muscular dystrophy. Proc Natl Acad Sci U S A 2018; 115:E9745-E9752. [PMID: 30181262 PMCID: PMC6187127 DOI: 10.1073/pnas.1804593115] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a hereditary neuromuscular disease that results from mutations in the gene encoding dystrophin. The effects of the disease on cardiac and skeletal muscle have been intensely investigated, but much less is known about how DMD impacts vascular smooth muscle cells (SMCs). Using superresolution nanoscopy, we demonstrate that clusters of ryanodine receptors (RyR2s) on the sarcoplasmic reticulum (SR) of cerebral artery SMCs from the mdx mouse model of DMD are larger compared with controls. Increased RyR2 cluster size is associated with augmented SR Ca2+ release and Ca2+-activated K+ channel activity, resulting in impaired vasoconstriction of cerebral microvessels. Our findings demonstrate that remodeling of RyR2 clusters at the molecular level results in cerebral microvascular dysfunction during DMD. Duchenne muscular dystrophy (DMD) results from mutations in the gene encoding dystrophin which lead to impaired function of skeletal and cardiac muscle, but little is known about the effects of the disease on vascular smooth muscle cells (SMCs). Here we used the mdx mouse model to study the effects of mutant dystrophin on the regulation of cerebral artery and arteriole SMC contractility, focusing on an important Ca2+-signaling pathway composed of type 2 ryanodine receptors (RyR2s) on the sarcoplasmic reticulum (SR) and large-conductance Ca2+-activated K+ (BK) channels on the plasma membrane. Nanoscale superresolution image analysis revealed that RyR2 and BKα were organized into discrete clusters, and that the mean size of RyR2 clusters that colocalized with BKα was larger in SMCs from mdx mice (∼62 RyR2 monomers) than in controls (∼40 RyR2 monomers). We further found that the frequency and signal mass of spontaneous, transient Ca2+-release events through SR RyR2s (“Ca2+ sparks”) were greater in SMCs from mdx mice. Patch-clamp electrophysiological recordings indicated a corresponding increase in Ca2+-dependent BK channel activity. Using pressure myography, we found that cerebral pial arteries and parenchymal arterioles from mdx mice failed to develop appreciable spontaneous myogenic tone. Inhibition of RyRs with tetracaine and blocking of BK channels with paxilline restored myogenic tone to control levels, demonstrating that enhanced RyR and BK channel activity is responsible for the diminished pressure-induced constriction of arteries and arterioles from mdx mice. We conclude that increased size of RyR2 protein clusters in SMCs from mdx mice increases Ca2+ spark and BK channel activity, resulting in cerebral microvascular dysfunction.
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Björling K, Joseph PD, Egebjerg K, Salomonsson M, Hansen JL, Ludvigsen TP, Jensen LJ. Role of age, Rho-kinase 2 expression, and G protein-mediated signaling in the myogenic response in mouse small mesenteric arteries. Physiol Rep 2018; 6:e13863. [PMID: 30198176 PMCID: PMC6129776 DOI: 10.14814/phy2.13863] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 08/21/2018] [Indexed: 12/16/2022] Open
Abstract
The myogenic response (MR) and myogenic tone (MT) in resistance vessels is crucial for maintaining peripheral vascular resistance and blood flow autoregulation. Development of MT involves G protein-coupled receptors, and may be affected by aging. AIMS (1) to estimate the mesenteric blood flow in myogenically active small mesenteric arteries; (2) to investigate the signaling from Gαq/11 and/or Gα12 activation to MT development; (3) to investigate the role of Rho-kinase 2 and aging on MT in mesenteric resistance arteries. METHODS we used pressure myography, quantitative real-time PCR, and immunolocalization to study small (<200 μm) mesenteric arteries (SMA) from young, mature adult, and middle aged mice. RESULTS Poiseuille flow calculations indicated autoregulation of blood flow at 60-120 mm Hg arterial pressure. Gαq/11 and Gα12 were abundantly expressed at the mRNA and protein levels in SMA. The Gαq/11 inhibitor YM-254890 suppressed MT development, and the Phosholipase C inhibitors U73122 and ET-18-OCH3 robustly inhibited it. We found an age-dependent increase in ROCK2 mRNA expression, and in basal MT. The specific ROCK2 inhibitor KD025 robustly inhibited MT in SMAs in all mice with an age-dependent variation in KD025 sensitivity. The inhibitory effect of KD025 was not prevented by the L-type Ca2+ channel activator BayK 8644. KD025 reversibly inhibited MT and endothelin-1 vasoconstriction in small pial arteries from Göttingen minipigs. CONCLUSIONS MT development in SMAs occurs through a Gαq/11 /PLC/Ca2+ -dependent pathway, and is maintained via ROCK2-mediated Ca2+ sensitization. Increased MT at mature adulthood can be explained by increased ROCK2 expression/activity.
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Affiliation(s)
- Karl Björling
- Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CCopenhagenDenmark
| | - Philomeena D. Joseph
- Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CCopenhagenDenmark
| | - Kristian Egebjerg
- Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CCopenhagenDenmark
| | - Max Salomonsson
- Department of Biomedical SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenCopenhagen NDenmark
- Department of Internal MedicineTrelleborg HospitalTrelleborgSweden
| | | | | | - Lars J. Jensen
- Department of Veterinary and Animal SciencesFaculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CCopenhagenDenmark
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Basu S, Barbur I, Calderon A, Banerjee S, Proweller A. Notch signaling regulates arterial vasoreactivity through opposing functions of Jagged1 and Dll4 in the vessel wall. Am J Physiol Heart Circ Physiol 2018; 315:H1835-H1850. [PMID: 30168730 DOI: 10.1152/ajpheart.00293.2018] [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: 02/03/2023]
Abstract
Functional interactions between endothelial cells (ECs) and smooth muscle cells (SMCs) in the arterial wall are necessary for controlling vasoreactivity that underlies vascular resistance and tone. Key signaling pathways converge on the phosphorylation of myosin light chain (p-MLC), the molecular signature of force production in SMCs, through coordinating the relative activities of myosin light chain kinase (MLCK) and myosin phosphatase (MP). Notch signaling in the vessel wall serves critical roles in arterial formation and maturation and has been implicated in arterial vasoregulation. In this report, we hypothesized that Notch signaling through ligands Jagged1 (in SMCs) and delta-like protein-4 (Dll4; in ECs) regulates vasoreactivity via homotypic (SMC-SMC) and heterotypic (EC-SMC) cell interactions. Using ligand induction assays, we demonstrated that Jagged1 selectively induced smooth muscle MLCK gene expression and p-MLC content while inhibiting MP function (i.e., increased Ca2+ sensitization) in a Rho kinase II-dependent manner. Likewise, selective deficiency of smooth muscle Jagged1 in mice resulted in MLCK and p-MLC loss, reduced Ca2+ sensitization, and impaired arterial force generation measured by myography. In contrast, smooth muscle Notch signaling triggered by Dll4 increased expression of MP-targeting subunit 1 (MYPT1; the MP regulatory subunit), whereas arteries from endothelial Dll4-deficient mice featured reduced MYPT1 levels, enhanced force production, and impaired relaxation independent of endothelium-derived nitric oxide signaling. Taken together, this study identifies novel opposing vasoregulatory functions for ligand-specific Notch signaling in the vessel wall, underscoring instructional signaling between ECs and SMCs and suggesting that Notch signals might behave as a "rheostat" in arterial tone control. NEW & NOTEWORTHY The present study unveils novel roles for ligand-specific Notch signaling in arterial function. Smooth muscle Jagged1 and endothelial cell delta-like protein-4 ligands exhibit selective regulation of myosin light chain kinase and myosin phosphatase-targeting subunit 1/myosin phosphatase, respectively, providing a mechanistic link through which Notch signals modulate contractile activities in vascular smooth muscle. These findings may inform vascular derangements observed in human syndromes of Notch signaling deficiency while offering fundamental molecular insights into arterial physiological function.
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Affiliation(s)
- Sanchita Basu
- Department of Medicine, Case Cardiovascular Research Institute and University Hospitals Harrington Heart and Vascular Institute, Case Western Reserve University , Cleveland, Ohio
| | - Iulia Barbur
- Department of Medicine, Case Cardiovascular Research Institute and University Hospitals Harrington Heart and Vascular Institute, Case Western Reserve University , Cleveland, Ohio
| | - Alexander Calderon
- Department of Medicine, Case Cardiovascular Research Institute and University Hospitals Harrington Heart and Vascular Institute, Case Western Reserve University , Cleveland, Ohio
| | - Suhanti Banerjee
- Department of Medicine, Case Cardiovascular Research Institute and University Hospitals Harrington Heart and Vascular Institute, Case Western Reserve University , Cleveland, Ohio
| | - Aaron Proweller
- Department of Medicine, Case Cardiovascular Research Institute and University Hospitals Harrington Heart and Vascular Institute, Case Western Reserve University , Cleveland, Ohio
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Nunes DO, Marques VB, Almenara CCP, Marcarini WD, Ribeiro Júnior RF, Padilha AS. Linoleic acid reduces vascular reactivity and improves the vascular dysfunction of the small mesentery in hypertension. J Nutr Biochem 2018; 62:18-27. [PMID: 30218979 DOI: 10.1016/j.jnutbio.2018.07.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2018] [Revised: 07/24/2018] [Accepted: 07/25/2018] [Indexed: 02/07/2023]
Abstract
We aimed to investigate the effect of linoleic acid (LA) treatment on the blood pressure and function of mesenteric resistance arteries (MRA) in spontaneous hypertensive rats (SHR). Male SHR were treated daily with LA (15 mg/kg) or vehicle (control) for 15 days. Compared with controls, LA treatment decreased blood pressure and showed the following in MRA: (1) increased lumen and external diameter, (2) decreased wall:lumen ratio and wall thickness, (3) decreased stiffness and (4) less collagen deposition. LA treatment reduced the contractile response to phenylephrine, although there were no changes observed in MRA in regard to the acetylcholine or sodium nitroprusside responses. Incubation with L-NAME left-shifted the reactivity to phenylephrine only in the MRA treated group, suggesting that LA treatment can improve NO bioavailability. This result was accompanied by an increase "in situ" NO production. Incubation with tiron decreased vascular reactivity to phenylephrine in MRA in LA rats, which was accompanied by decreased superoxide anion production. Moreover, incubation with indomethacin (non-selective COX inhibitor, 10 μM), NS 398 (COX-2 specific inhibitor, 1 μM), furegrelate (TXA2 synthase inhibitor, 1 μM), SQ 29.548 (TP receptor antagonist, 1 μM) and SC 19220 (EP1 receptor antagonist, 10 μM) reduced the vasoconstrictor responses to phenylephrine in MRA in the treated group. These results were accompanied by a reduction in COX-2 protein expression. In conclusion, these findings show that LA treatment decreases blood pressure. In addition, the improvement of endothelial dysfunction and structural changes in this hypertension model may be responsible for the reduction in blood pressure.
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Affiliation(s)
- Dieli Oliveira Nunes
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, ES, Brazil
| | | | | | - Wena Dantas Marcarini
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitoria, ES, Brazil
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Isolation and differential transcriptome of vascular smooth muscle cells and mid-capillary pericytes from the rat brain. Sci Rep 2018; 8:12272. [PMID: 30116021 PMCID: PMC6095852 DOI: 10.1038/s41598-018-30739-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 07/20/2018] [Indexed: 12/20/2022] Open
Abstract
Brain mural cells form a heterogeneous family which significantly contributes to the maintenance of the blood-brain barrier and regulation of the cerebral blood flow. Current procedures to isolate them cannot specifically separate their distinct subtypes, in particular vascular smooth muscle cells (VSMCs) and mid-capillary pericytes (mcPCs), which differ among others by their expression of smooth muscle actin (SMA). We herein describe an innovative method allowing SMA+ VSMCs and SMA− mcPCs to be freshly isolated from the rat cerebral cortex. Using differential RNA-Seq analysis, we then reveal the specific gene expression profile of each subtype. Our results refine the current description of the role of VSMCs in parenchymal cortical arterioles at the molecular level and provide a unique platform to identify the molecular mechanisms underlying the specific functions of mcPCs in the brain vasculature.
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Yip KP, Balasubramanian L, Kan C, Wang L, Liu R, Ribeiro-Silva L, Sham JSK. Intraluminal pressure triggers myogenic response via activation of calcium spark and calcium-activated chloride channel in rat renal afferent arteriole. Am J Physiol Renal Physiol 2018; 315:F1592-F1600. [PMID: 30089032 DOI: 10.1152/ajprenal.00239.2018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Myogenic contraction of renal arterioles is an important regulatory mechanism for renal blood flow autoregulation. We have previously demonstrated that integrin-mediated mechanical force increases the occurrence of Ca2+ sparks in freshly isolated renal vascular smooth muscle cells (VSMCs). To further test whether the generation of Ca2+ sparks is a downstream signal of mechanotransduction in pressure-induced myogenic constriction, the relationship between Ca2+ sparks and transmural perfusion pressure was investigated in intact VSMCs of pressurized rat afferent arterioles. Spontaneous Ca2+ sparks were found in VSMCs when afferent arterioles were perfused at 80 mmHg. The spark frequency was significantly increased when perfusion pressure was increased to 120 mmHg. A similar increase of spark frequency was also observed in arterioles stimulated with β1-integrin-activating antibody. Moreover, spark frequency was significantly higher in arterioles of spontaneous hypertensive rats at 80 and 120 mmHg. Spontaneous membrane current recorded using whole cell perforated patch in renal VSMCs showed predominant activity of spontaneous transient inward currents instead of spontaneous transient outward currents when holding potential was set close to physiological resting membrane potential. Real-time PCR and immunohistochemistry confirmed the expression of Ca2+-activated Cl- channel (ClCa) TMEM16A in renal VSMCs. Inhibition of TMEM16A with T16Ainh-A01 impaired the pressure-induced myogenic contraction in perfused afferent arterioles. Our study, for the first time to our knowledge, detected Ca2+ sparks in VSMCs of intact afferent arterioles, and their frequencies were positively modulated by the perfusion pressure. Our results suggest that Ca2+ sparks may couple to ClCa channels and trigger pressure-induced myogenic constriction via membrane depolarization.
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Affiliation(s)
- Kay-Pong Yip
- Department of Molecular Pharmacology and Physiology, University of South Florida , Tampa, Florida
| | - Lavanya Balasubramanian
- Department of Molecular Pharmacology and Physiology, University of South Florida , Tampa, Florida
| | - Chen Kan
- Department of Industrial, Manufacturing, and System Engineering, University of Texas at Arlington , Arlington, Texas
| | - Lei Wang
- Department of Molecular Pharmacology and Physiology, University of South Florida , Tampa, Florida
| | - Ruisheng Liu
- Department of Molecular Pharmacology and Physiology, University of South Florida , Tampa, Florida
| | - Luisa Ribeiro-Silva
- Department of Molecular Pharmacology and Physiology, University of South Florida , Tampa, Florida
| | - James S K Sham
- Division of Pulmonary and Critical Care Medicine, Johns Hopkins University School of Medicine , Baltimore, Maryland
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125
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Morra S, Roubille F. Obstructive sleep apnoea: from respiratory events to coronary microvascular dysfunction. Acta Cardiol 2018; 73:319-324. [PMID: 28990847 DOI: 10.1080/00015385.2017.1384183] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Obstructive sleep apnoea (OSA) is an emerging and independent risk factor for cardiovascular diseases; coronary artery disease (CAD) is higher in OSA patients, even in the absence of other traditional cardiovascular risk factors. There is little evidence to show abnormalities in coronary blood flow (CBF) and disorders in coronary vascular resistance (CVR), occurring during the obstructive respiratory event, suggesting coronary microvascular dysfunction (CMD) as a potential mechanism of ischaemic heart disease (IHD) OSA-as a related consequence.
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Affiliation(s)
- Sofia Morra
- Department of Cardiology, University Hospital of Montpellier, Montpellier, France
- Department of Cardiac, Thoracic and Cardiovascular Sciences, University of Padua Medical School, Padua, Italy
| | - François Roubille
- Department of Cardiology, University Hospital of Montpellier, Montpellier, France
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126
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Abstract
The myogenic response is a key autoregulatory mechanism in the mammalian kidney. Triggered by blood pressure perturbations, it is well established that the myogenic response is initiated in the renal afferent arteriole and mediated by alterations in muscle tone and vascular diameter that counterbalance hemodynamic perturbations. The entire process involves several subcellular, cellular, and vascular mechanisms whose interactions remain poorly understood. Here, we model and investigate the myogenic response of a multicellular segment of an afferent arteriole. Extending existing work, we focus on providing an accurate—but still computationally tractable—representation of the coupling among the involved levels. For individual muscle cells, we include detailed Ca2+ signaling, transmembrane transport of ions, kinetics of myosin light chain phosphorylation, and contraction mechanics. Intercellular interactions are mediated by gap junctions between muscle or endothelial cells. Additional interactions are mediated by hemodynamics. Simulations of time-independent pressure changes reveal regular vasoresponses throughout the model segment and stabilization of a physiological range of blood pressures (80–180 mmHg) in agreement with other modeling and experimental studies that assess steady autoregulation. Simulations of time-dependent perturbations reveal irregular vasoresponses and complex dynamics that may contribute to the complexity of dynamic autoregulation observed in vivo. The ability of the developed model to represent the myogenic response in a multiscale and realistic fashion, under feasible computational load, suggests that it can be incorporated as a key component into larger models of integrated renal hemodynamic regulation.
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127
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Evanson KW, Goldsmith JA, Ghosh P, Delp MD. The G protein-coupled estrogen receptor agonist, G-1, attenuates BK channel activation in cerebral arterial smooth muscle cells. Pharmacol Res Perspect 2018; 6:e00409. [PMID: 29938113 PMCID: PMC6011940 DOI: 10.1002/prp2.409] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 05/22/2018] [Indexed: 11/07/2022] Open
Abstract
The G protein-coupled estrogen receptor (GPER) is a significant modulator of arterial contractility and blood flow. The GPER-specific activator, G-1, has been widely used to characterize GPER function in a variety of tissue types. Large conductance, calcium (Ca2+)-activated K+ (BK) channels are sensitive to 17β-estradiol (17β-E2) and estrogenic compounds (e.g., tamoxifen, ICI 182 780) that target estrogen receptors. The purpose of this study was to investigate the effects of G-1 on BK channel activation and function in cerebral arterial myocytes. Inside-out and perforated patch clamp were utilized to assess the effects of G-1 (50 nmol·L-1-5 μmol·L-1) on BK channel activation and currents in cerebral arterial myocytes. Pressurized artery myography was used to investigate the effects of G-1 on vasodilatory response and BK channel function of cerebral resistance size arteries. G-1 reduced BK channel activation in cerebral arterial myocytes through elevations in BK channel mean close times. Depressed BK channel activation following G-1 application resulted in attenuated physiological BK currents (transient BK currents). G-1 elicited vasodilation, but reduced BK channel function, in pressurized, endothelium-denuded cerebral arteries. These data suggest that G-1 directly suppresses BK channel activation and currents in cerebral arterial myocytes, BK channels being critically important in the regulation of myocyte membrane potential and arterial contractility. Thus, GPER-mediated vasodilation using G-1 to activate the receptor may underestimate the physiological function and relevance of GPER in the cardiovascular system.
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Affiliation(s)
- Kirk W. Evanson
- Department of Nutrition, Food, and Exercise SciencesFlorida State UniversityTallahasseeFlorida
| | - Jacob A. Goldsmith
- Department of Nutrition, Food, and Exercise SciencesFlorida State UniversityTallahasseeFlorida
| | - Payal Ghosh
- Department of Nutrition, Food, and Exercise SciencesFlorida State UniversityTallahasseeFlorida
| | - Michael D. Delp
- Department of Nutrition, Food, and Exercise SciencesFlorida State UniversityTallahasseeFlorida
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128
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Brinton M, Mandel Y, Schachar I, Palanker D. Mechanisms of electrical vasoconstriction. J Neuroeng Rehabil 2018; 15:43. [PMID: 29843762 PMCID: PMC5975571 DOI: 10.1186/s12984-018-0390-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/22/2018] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Electrical vasoconstriction is a promising approach to control blood pressure or restrict bleeding in non-compressible wounds. We explore the neural and non-neural pathways of electrical vasoconstriction in-vivo. METHODS Charge-balanced, asymmetric pulses were delivered through a pair of metal disc electrodes. Vasoconstriction was assessed by measuring the diameter of rat saphenous vessels stimulated with low-voltage (20 V, 1 ms) and high-voltage (150 V, 10 μs) stimuli at 10 Hz for 5 min. Activation pathways were explored by topical application of a specific neural agonist (phenylephrine, alpha-1 receptor), a non-specific agonist (KCl) and neural inhibitors (phenoxybenzamine, 25 mg/ml; guanethidine, 1 mg/ml). Acute tissue damage was assessed with a membrane permeability (live-dead) fluorescent assay. The Joule heating in tissue was estimated using COMSOL Multiphysics modeling. RESULTS During stimulation, arteries constricted to 41 ± 8% and 37 ± 6% of their pre-stimulus diameter with low- and high-voltage stimuli, while veins constricted to 80 ± 18% and 40 ± 11%, respectively. In arteries, despite similar extent of constriction, the recovery time was very different: about 30 s for low-voltage and 10 min for high-voltage stimuli. Neural inhibitors significantly reduced low-voltage arterial constriction, but did not affect high-voltage arterial or venous constriction, indicating that high-voltage stimuli activate non-neural vasoconstriction pathways. Adrenergic pathways predominantly controlled low-voltage arterial but not venous constriction, which may involve a purinergic pathway. Viability staining confirmed that stimuli were below the electroporation threshold. Modeling indicates that heating of the blood vessels during stimulation (< 0.2 °C) is too low to cause vasoconstriction. CONCLUSIONS We demonstrate that low-voltage stimuli induce reversible vasoconstriction through neural pathways, while high-voltage stimuli activate non-neural pathways, likely in addition to neural stimulation. Different stimuli providing precise control over the extent of arterial and venous constriction as well as relaxation rate could be used to control bleeding, perfusion or blood pressure.
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Affiliation(s)
- Mark Brinton
- Department of Bioengineering, University of Utah, 20 S. 2030 E., Salt Lake City, UT, 84112, USA.
| | - Yossi Mandel
- Faculty of Life Sciences, Bar Ilan University, 5290002, Ramat-Gan, Israel
| | - Ira Schachar
- Department of Ophthalmology, Stanford University, 2452 Watson Court Palo Alto, Stanford, CA, 94303, USA
| | - Daniel Palanker
- Department of Ophthalmology, Stanford University, 2452 Watson Court Palo Alto, Stanford, CA, 94303, USA.,Hansen Experimental Physics Laboratory, Stanford University, 452 Lomita Mall, Stanford, CA, 94305, USA
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129
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Jadeja RN, Thounaojam MC, Bartoli M, Khurana S. Deoxycholylglycine, a conjugated secondary bile acid, reduces vascular tone by attenuating Ca 2+ sensitivity via rho kinase pathway. Toxicol Appl Pharmacol 2018; 348:14-21. [PMID: 29660437 DOI: 10.1016/j.taap.2018.04.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 04/02/2018] [Accepted: 04/10/2018] [Indexed: 01/25/2023]
Abstract
Patients with cirrhosis have reduced systemic vascular resistance and elevated circulating bile acids (BAs). Previously, we showed that secondary conjugated BAs impair vascular tone by reducing vascular smooth muscle cell (VSMC) Ca2+ influx. In this study, we investigated the effect of deoxycholylglycine (DCG), on Ca2+ sensitivity in reducing vascular tone. First, we evaluated the effects of DCG on U46619- and phorbol-myristate-acetate (PMA)-induced vasoconstriction. DCG reduced U46619-induced vascular tone but failed to reduce PMA-induced vasoconstriction. Then, by utilizing varied combinations of diltiazem (voltage-dependent Ca2+ channel [VDCC] inhibitor), Y27632 (RhoA kinase [ROCK] inhibitor) and chelerythrine (PKC inhibitor) for the effect of DCG on U46619-induced vasoconstriction, we ascertained that DCG inhibits VDCC and ROCK pathway with no effect on PKC. We further assessed the effect of DCG on ROCK pathway. In β-escin-permeabilized arteries, DCG reduced high-dose Ca2+- and GTPγS (a ROCK activator)-induced vasoconstriction. In rat vascular smooth muscle cells (VSMCs), DCG reduced U46619-induced phosphorylation of myosin light chain subunit (MLC20) and myosin phosphatase target subunit-1 (MYPT1). In permeabilized VSMCs, DCG reduced Ca2+- and GTPγS-mediated MLC20 and MYPT1 phosphorylation, and further, reduced GTPγS-mediated membrane translocation of RhoA. In VSMCs, long-term treatment with DCG had no effect on ROCK2 and RhoA expression. In conclusion, DCG attenuates vascular Ca2+ sensitivity and tone via inhibiting ROCK pathway. These results enhance our understanding of BAs-mediated regulation of vascular tone and provide a platform to develop new treatment strategies to reduce arterial dysfunction in cirrhosis.
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Affiliation(s)
- Ravirajsinh N Jadeja
- Digestive Health Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Menaka C Thounaojam
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Manuela Bartoli
- Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Sandeep Khurana
- Digestive Health Center, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA.
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Soluble TNFα Signaling within the Spinal Cord Contributes to the Development of Autonomic Dysreflexia and Ensuing Vascular and Immune Dysfunction after Spinal Cord Injury. J Neurosci 2018; 38:4146-4162. [PMID: 29610439 DOI: 10.1523/jneurosci.2376-17.2018] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 03/08/2018] [Accepted: 03/14/2018] [Indexed: 12/15/2022] Open
Abstract
Cardiovascular disease and susceptibility to infection are leading causes of morbidity and mortality for individuals with spinal cord injury (SCI). A major contributor to these is autonomic dysreflexia (AD), an amplified reaction of the autonomic nervous system (hallmarked by severe hypertension) in response to sensory stimuli below the injury. Maladaptive plasticity of the spinal sympathetic reflex circuit below the SCI results in AD intensification over time. Mechanisms underlying this maladaptive plasticity are poorly understood, restricting the identification of treatments. Thus, no preventative treatments are currently available. Neuroinflammation has been implicated in other pathologies associated with hyperexcitable neural circuits. Specifically, the soluble form of TNFα (sTNFα) is known to play a role in neuroplasticity. We hypothesize that persistent expression of sTNFα in spinal cord underlies AD exacerbation. To test this, we intrathecally administered XPro1595, a biologic that renders sTNFα nonfunctional, after complete, high-level SCI in female rats. This dramatically attenuated the intensification of colorectal distension-induced and naturally occurring AD events. This improvement is mediated via decreased sprouting of nociceptive primary afferents and activation of the spinal sympathetic reflex circuit. We also examined peripheral vascular function using ex vivo pressurized arterial preparations and immune function via flow cytometric analysis of splenocytes. Diminishing AD via pharmacological inhibition of sTNFα mitigated ensuing vascular hypersensitivity and immune dysfunction. This is the first demonstration that neuroinflammation-induced sTNFα is critical for altering the spinal sympathetic reflex circuit, elucidating a novel mechanism for AD. Importantly, we identify the first potential pharmacological, prophylactic treatment for this life-threatening syndrome.SIGNIFICANCE STATEMENT Autonomic dysreflexia (AD), a disorder that develops after spinal cord injury (SCI) and is hallmarked by sudden, extreme hypertension, contributes to cardiovascular disease and susceptibility to infection, respectively, two leading causes of mortality and morbidity in SCI patients. We demonstrate that neuroinflammation-induced expression of soluble TNFα plays a critical role in AD, elucidating a novel underlying mechanism. We found that intrathecal administration after SCI of a biologic that inhibits soluble TNFα signaling dramatically attenuates AD and significantly reduces AD-associated peripheral vascular and immune dysfunction. We identified mechanisms behind diminished plasticity of neuronal populations within the spinal sympathetic reflex circuit. This study is the first to pinpoint a potential pharmacological, prophylactic strategy to attenuate AD and ensuing cardiovascular and immune dysfunction.
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131
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Coucha M, Abdelsaid M, Ward R, Abdul Y, Ergul A. Impact of Metabolic Diseases on Cerebral Circulation: Structural and Functional Consequences. Compr Physiol 2018; 8:773-799. [PMID: 29687902 DOI: 10.1002/cphy.c170019] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Metabolic diseases including obesity, insulin resistance, and diabetes have profound effects on cerebral circulation. These diseases not only affect the architecture of cerebral blood arteries causing adverse remodeling, pathological neovascularization, and vasoregression but also alter the physiology of blood vessels resulting in compromised myogenic reactivity, neurovascular uncoupling, and endothelial dysfunction. Coupled with the disruption of blood brain barrier (BBB) integrity, changes in blood flow and microbleeds into the brain rapidly occur. This overview is organized into sections describing cerebrovascular architecture, physiology, and BBB in these diseases. In each section, we review these properties starting with larger arteries moving into smaller vessels. Where information is available, we review in the order of obesity, insulin resistance, and diabetes. We also tried to include information on biological variables such as the sex of the animal models noted since most of the information summarized was obtained using male animals. © 2018 American Physiological Society. Compr Physiol 8:773-799, 2018.
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Affiliation(s)
- Maha Coucha
- South University, School of Pharmacy, Savannah, Georgia, USA
| | | | - Rebecca Ward
- Department of Neuroscience & Regenerative Medicine, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Yasir Abdul
- Charlie Norwood VA Medical Center, Augusta, Georgia, USA.,Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
| | - Adviye Ergul
- Charlie Norwood VA Medical Center, Augusta, Georgia, USA.,Department of Physiology, Medical College of Georgia, Augusta University, Augusta, Georgia, USA
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132
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Zhang J, Yin J, Wang Y, Li B, Zeng X. Apelin impairs myogenic response to induce diabetic nephropathy in mice. FASEB J 2018. [PMID: 29522374 DOI: 10.1096/fj.201701257r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The cause of the invalid reaction of smooth muscle cells to mechanical stimulation that results in a dysfunctional myogenic response that mediates the disruption of renal blood flow (RBF) in patients with diabetes is debatable. The present study revealed that increased apelin concentration in serum of diabetic mice neutralized the myogenic response mediated by apelin receptor (APJ) and resulted in increased RBF, which promoted the progression of diabetic nephropathy. The results showed that apelin concentration, RBF, and albuminuria:creatinine ratio were all increased in kkAy mice, and increased RBF correlated positively with serum apelin both in C57 and diabetic mice. The increased RBF was accompanied by decreased phosphorylation of myosin light chain (MLC), β-arrestin, and increased endothelial NOS in glomeruli. Meanwhile, calcium, phosphorylation of MLC, and β-arrestin were decreased by high glucose and apelin treatment in cultured smooth muscle cells, as well. eNOS was increased by high glucose and increased by apelin in cultured endothelial cells (ECs). Knockdown of β-arrestin expression in smooth muscle cells cancelled phosphorylation of MLC induced by apelin. Therefore, apelin may induce the progression of diabetic nephropathy by counteracting the myogenic response in smooth muscle cells.-Zhang, J., Yin, J., Wang, Y., Li, B., Zeng, X. Apelin impairs myogenic response to induce diabetic nephropathy in mice.
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Affiliation(s)
- Jia Zhang
- Department of Pathophysiology, Capital Medical University, Beijing, China
| | - Jiming Yin
- Beijing Institute of Hepatology, Beijing You An Hospital, Capital Medical University, Beijing, China
| | - Yangjia Wang
- Department of Pathophysiology, Capital Medical University, Beijing, China
| | - Bin Li
- Department of Pathophysiology, Capital Medical University, Beijing, China
| | - Xiangjun Zeng
- Department of Pathophysiology, Capital Medical University, Beijing, China
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Holmberg J, Bhattachariya A, Alajbegovic A, Rippe C, Ekman M, Dahan D, Hien TT, Boettger T, Braun T, Swärd K, Hellstrand P, Albinsson S. Loss of Vascular Myogenic Tone in miR-143/145 Knockout Mice Is Associated With Hypertension-Induced Vascular Lesions in Small Mesenteric Arteries. Arterioscler Thromb Vasc Biol 2018; 38:414-424. [PMID: 29217510 DOI: 10.1161/atvbaha.117.310499] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 11/21/2017] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Pressure-induced myogenic tone is involved in autoregulation of local blood flow and confers protection against excessive pressure levels in small arteries and capillaries. Myogenic tone is dependent on smooth muscle microRNAs (miRNAs), but the identity of these miRNAs is unclear. Furthermore, the consequences of altered myogenic tone for hypertension-induced damage to small arteries are not well understood. APPROACH AND RESULTS The importance of smooth muscle-enriched microRNAs, miR-143/145, for myogenic tone was evaluated in miR-143/145 knockout mice. Furthermore, hypertension-induced vascular injury was evaluated in mesenteric arteries in vivo after angiotensin II infusion. Myogenic tone was abolished in miR-143/145 knockout mesenteric arteries, whereas contraction in response to calyculin A and potassium chloride was reduced by ≈30%. Furthermore, myogenic responsiveness was potentiated by angiotensin II in wild-type but not in knockout mice. Angiotensin II administration in vivo elevated systemic blood pressure in both genotypes. Hypertensive knockout mice developed severe vascular lesions characterized by vascular inflammation, adventitial fibrosis, and neointimal hyperplasia in small mesenteric arteries. This was associated with depolymerization of actin filaments and fragmentation of the elastic laminae at the sites of vascular lesions. CONCLUSIONS This study demonstrates that miR-143/145 expression is essential for myogenic responsiveness. During hypertension, loss of myogenic tone results in potentially damaging levels of mechanical stress and detrimental effects on small arteries. The results presented herein provide novel insights into the pathogenesis of vascular disease and emphasize the importance of controlling mechanical factors to maintain structural integrity of the vascular wall.
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Affiliation(s)
- Johan Holmberg
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Anirban Bhattachariya
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Azra Alajbegovic
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Catarina Rippe
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Mari Ekman
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Diana Dahan
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Tran Thi Hien
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Thomas Boettger
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Thomas Braun
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Karl Swärd
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Per Hellstrand
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun)
| | - Sebastian Albinsson
- From the Department of Experimental Medical Science, Lund University, Sweden (J.H., A.B., A.A., C.R., M.E., D.D., T.T.H., K.S., P.H., S.A.); and Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany (T. Boettger, T. Braun).
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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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135
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Ronconi KDS, Stefanon I, Ribeiro Junior RF. Tributyltin and Vascular Dysfunction: The Role of Oxidative Stress. Front Endocrinol (Lausanne) 2018; 9:354. [PMID: 30050498 PMCID: PMC6052083 DOI: 10.3389/fendo.2018.00354] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/13/2018] [Indexed: 01/18/2023] Open
Abstract
The organotin compounds (OT) are used as fungicides, stabilizers in plastics, miticides, manufacturing and agricultural biocides, wood preservatives and antifouling agents. Tributyltin (TBT) is an OT that was first used for antifouling because it was the most effective agent to prevent undesirable accumulation of marine organisms on solid surfaces, such as ships' hulls or mechanical components, immersed in saltwater. TBT can be easily absorbed by mammals through ingestion, and its cytotoxic effects have become a major concern since their discovery in the 1970s. Recently, it has been demonstrated that TBT exposure is detrimental to the cardiovascular system. TBT is a membrane active substance and its action seems to depend on the OT lipophilicity. As a result, TBT crosses the cell membrane and damages the endothelium and the smooth muscle cells. TBT exposure induces vascular dysfunction, most likely due to endothelial dysfunction and morphological changes in the vascular wall. In an experimental rodent model, small doses of TBT (100 and 500 ng/kg/bw/day for 15 days) modified the vascular reactivity in aorta, mesenteric and coronary arteries followed by smooth muscle cell atrophy, increased collagen deposition and fibrin accumulation. TBT exposure increases oxidative stress by inducing vascular superoxide anion production derived from NADPH oxidase and decreases nitric oxide (NO) production as well as eNOS protein expression. The goal of this review is to summarize the current state of the art regarding the mechanisms involved in the vascular and endothelial dysfunction induced by TBT.
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Affiliation(s)
| | - Ivanita Stefanon
- Department of Physiological Sciences, Federal University of Espírito Santo, Vitória, Brazil
| | - Rogerio F. Ribeiro Junior
- Department of Physiological Sciences, Federal University of Espírito Santo, Vitória, Brazil
- Department of Pharmacology, University of California, Davis, Davis, CA, United States
- *Correspondence: Rogerio F. Ribeiro Junior
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136
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Zhang LF, Hargens AR. Spaceflight-Induced Intracranial Hypertension and Visual Impairment: Pathophysiology and Countermeasures. Physiol Rev 2017; 98:59-87. [PMID: 29167331 DOI: 10.1152/physrev.00017.2016] [Citation(s) in RCA: 129] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 05/25/2017] [Accepted: 05/26/2017] [Indexed: 12/21/2022] Open
Abstract
Visual impairment intracranial pressure (VIIP) syndrome is considered an unexplained major risk for future long-duration spaceflight. NASA recently redefined this syndrome as Spaceflight-Associated Neuro-ocular Syndrome (SANS). Evidence thus reviewed supports that chronic, mildly elevated intracranial pressure (ICP) in space (as opposed to more variable ICP with posture and activity on Earth) is largely accounted for by loss of hydrostatic pressures and altered hemodynamics in the intracranial circulation and the cerebrospinal fluid system. In space, an elevated pressure gradient across the lamina cribrosa, caused by a chronic but mildly elevated ICP, likely elicits adaptations of multiple structures and fluid systems in the eye which manifest themselves as the VIIP syndrome. A chronic mismatch between ICP and intraocular pressure (IOP) in space may acclimate the optic nerve head, lamina cribrosa, and optic nerve subarachnoid space to a condition that is maladaptive to Earth, all contributing to the pathogenesis of space VIIP syndrome. Relevant findings help to evaluate whether artificial gravity is an appropriate countermeasure to prevent this seemingly adverse effect of long-duration spaceflight.
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Affiliation(s)
- Li-Fan Zhang
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China; and Department of Orthopaedic Surgery, University of California, San Diego, California
| | - Alan R Hargens
- Department of Aerospace Physiology, Fourth Military Medical University, Xi'an, China; and Department of Orthopaedic Surgery, University of California, San Diego, California
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137
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Estañol B, Rivera AL, Martínez Memije R, Fossion R, Gómez F, Bernal K, Murúa Beltrán S, Delgado-García G, Frank A. From supine to standing: in vivo segregation of myogenic and baroreceptor vasoconstriction in humans. Physiol Rep 2017; 4:4/24/e13053. [PMID: 28039403 PMCID: PMC5210387 DOI: 10.14814/phy2.13053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 10/30/2016] [Indexed: 11/24/2022] Open
Abstract
Myogenic vascular response is a form of systemic and regional vasoconstriction produced increasing the intra‐arterial pressure by gravity. Here, the vasoconstriction due to the myogenic response, induced by the gravitational action in a dependent limb, is separated from that caused by the baroreceptor reflex. Regional changes of skin blood flow (SBF), total blood volume of the finger (TBVF), pulse pressure (PP), heart rate (HR), systolic, and diastolic blood pressure (BP) were analyzed in 10 healthy young subjects in supine and upright positions. By lowering the arm in supine position, SBF decreased compared to its basal measurement, PR increased, and PP contracted, indicating arterial vasoconstriction that rise BP. TBVF increased, demonstrating an increment in venous volume. HR did not change, reflecting no action of the baroreceptor reflex. In upright position with lowered arm, there was an additional increase in BP variables, demonstrating vasoconstriction. Moreover, BP and HR showed oscillations at 0.1 Hz reflecting the entrance of the baroreceptor reflex. The action of gravity in a dependent limb in supine position induces a regional vasoconstriction and an increase of BP due to activation of the myogenic response, while the baroreceptor reflex or other neural factors do not appear to operate. In the upright position with the arm dependent, there is a further increase in regional vasoconstriction and BP with reciprocal changes in HR, indicating the entrance of the baroreceptor superimposed to the myogenic response. This study demonstrates that the myogenic and baroreceptor vasoconstriction can be separated in vivo.
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Affiliation(s)
- Bruno Estañol
- Laboratorio de Neurofisiología Clínica, Departamento de Neurología y Psiquiatría, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México City, México.,Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, México City, México
| | - Ana Leonor Rivera
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, México City, México .,Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México City, México
| | - Raúl Martínez Memije
- Departamento de Instrumentación Electromecánica, Instituto Nacional de Cardiología, México City, México
| | - Ruben Fossion
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, México City, México.,Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México City, México
| | - Fermín Gómez
- Laboratorio de Neurofisiología Clínica, Departamento de Neurología y Psiquiatría, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México City, México
| | - Katherine Bernal
- Laboratorio de Neurofisiología Clínica, Departamento de Neurología y Psiquiatría, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México City, México
| | - Sofía Murúa Beltrán
- Laboratorio de Neurofisiología Clínica, Departamento de Neurología y Psiquiatría, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México City, México
| | - Guillermo Delgado-García
- Laboratorio de Neurofisiología Clínica, Departamento de Neurología y Psiquiatría, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, México City, México .,Departamento de Medicina Interna, Hospital Universitario "Dr. José Eleuterio González", Universidad Autónoma de Nuevo León, Monterrey, México
| | - Alejandro Frank
- Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, México City, México.,Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, México City, México.,Colegio Nacional, México City, México
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138
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Owens EA, Jie L, Reyes BA, Van Bockstaele EJ, Osei-Owusu P. Elastin insufficiency causes hypertension, structural defects and abnormal remodeling of renal vascular signaling. Kidney Int 2017; 92:1100-1118. [DOI: 10.1016/j.kint.2017.04.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 03/29/2017] [Accepted: 04/13/2017] [Indexed: 01/24/2023]
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139
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Khaddaj Mallat R, Mathew John C, Kendrick DJ, Braun AP. The vascular endothelium: A regulator of arterial tone and interface for the immune system. Crit Rev Clin Lab Sci 2017; 54:458-470. [PMID: 29084470 DOI: 10.1080/10408363.2017.1394267] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
As the primary interface between the blood and various tissues of the body, the vascular endothelium exhibits a diverse range of roles and activities, all of which contribute to the overall health and function of the cardiovascular system. In this focused review, we discuss several key aspects of endothelial function, how this may be compromised and subsequent consequences. Specifically, we examine the dynamic regulation of arterial contractility and distribution of blood flow through the generation of chemical and electrical signaling events that impinge upon vascular smooth muscle. The endothelium can generate a diverse range of vasoactive compounds and signals, most of which act locally to adjust blood flow in a dynamic fashion to match tissue metabolism. Disruption of these vascular signaling processes (e.g. reduced nitric oxide bioavailability) is typically referred to as endothelial dysfunction, which is a recognized risk factor for cardiovascular disease in patients and occurs early in the development and progression of hypertension, atherosclerosis and tissue ischemia. Endothelial dysfunction is also associated with type-2 Diabetes and aging and increased mechanistic knowledge of the cellular changes contributing to these effects may provide important clues for interventional strategies. The endothelium also serves as the initial site of interaction for immune cells entering tissues in response to damage and acts to facilitate the actions of both the innate and acquired immune systems to interact with the vascular wall. In addition to representing the main cell type responsible for the formation of new blood vessels (i.e. angiogenesis) within the vasculature, the endothelium is also emerging as a source of extracellular vesicle or microparticles for the transport of signaling molecules and other cellular materials to nearby, or remote, sites in the body. The characteristics of released microparticles appear to change with the functional status of the endothelium; thus, these microparticles may represent novel biomarkers of endothelial health and more serious cardiovascular disease.
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Affiliation(s)
- Rayan Khaddaj Mallat
- a Department of Physiology and Pharmacology, Cumming School of Medicine , University of Calgary, and Libin Cardiovascular Institute of Alberta , Calgary , Canada
| | - Cini Mathew John
- a Department of Physiology and Pharmacology, Cumming School of Medicine , University of Calgary, and Libin Cardiovascular Institute of Alberta , Calgary , Canada
| | - Dylan J Kendrick
- a Department of Physiology and Pharmacology, Cumming School of Medicine , University of Calgary, and Libin Cardiovascular Institute of Alberta , Calgary , Canada
| | - Andrew P Braun
- a Department of Physiology and Pharmacology, Cumming School of Medicine , University of Calgary, and Libin Cardiovascular Institute of Alberta , Calgary , Canada
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140
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Hong K, Li M, Nourian Z, Meininger GA, Hill MA. Angiotensin II Type 1 Receptor Mechanoactivation Involves RGS5 (Regulator of G Protein Signaling 5) in Skeletal Muscle Arteries: Impaired Trafficking of RGS5 in Hypertension. Hypertension 2017; 70:1264-1272. [PMID: 29061726 DOI: 10.1161/hypertensionaha.117.09757] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 06/11/2017] [Accepted: 09/20/2017] [Indexed: 01/07/2023]
Abstract
Studies suggest that arteriolar pressure-induced vasoconstriction can be initiated by GPCRs (G protein-coupled receptors), including the AT1R (angiotensin II type 1 receptor). This raises the question, are such mechanisms regulated by negative feedback? The present studies examined whether RGS (regulators of G protein signaling) proteins in vascular smooth muscle cells are colocalized with the AT1R when activated by mechanical stress or angiotensin II and whether this modulates AT1R-mediated vasoconstriction. To determine whether activation of the AT1R recruits RGS5, an in situ proximity ligation assay was performed in primary cultures of cremaster muscle arteriolar vascular smooth muscle cells treated with angiotensin II or hypotonic solution in the absence or presence of candesartan (an AT1R blocker). Proximity ligation assay results revealed a concentration-dependent increase in trafficking/translocation of RGS5 toward the activated AT1R, which was attenuated by candesartan. In intact arterioles, knockdown of RGS5 enhanced constriction to angiotensin II and augmented myogenic responses to increased intraluminal pressure. Myogenic constriction was attenuated to a higher degree by candesartan in RGS5 siRNA-transfected arterioles, consistent with RGS5 contributing to downregulation of AT1R-mediated signaling. Further, translocation of RGS5 was impaired in vascular smooth muscle cells of spontaneously hypertensive rats. This is consistent with dysregulated (RGS5-mediated) AT1R signaling that could contribute to excessive vasoconstriction in hypertension. In intact vessels, candesartan reduced myogenic vasoconstriction to a greater extent in spontaneously hypertensive rats compared with controls. Collectively, these findings suggest that AT1R activation results in translocation of RGS5 toward the plasma membrane, limiting AT1R-mediated vasoconstriction through its role in Gq/11 protein-dependent signaling.
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Affiliation(s)
- Kwangseok Hong
- From the Department of Medical Pharmacology and Physiology (K.H., M.L., G.A.M., M.A.H.) and Dalton Cardiovascular Research Center (K.H., Z.N., G.A.M., M.A.H.), University of Missouri, Columbia; and Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville (K.H.)
| | - Min Li
- From the Department of Medical Pharmacology and Physiology (K.H., M.L., G.A.M., M.A.H.) and Dalton Cardiovascular Research Center (K.H., Z.N., G.A.M., M.A.H.), University of Missouri, Columbia; and Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville (K.H.)
| | - Zahra Nourian
- From the Department of Medical Pharmacology and Physiology (K.H., M.L., G.A.M., M.A.H.) and Dalton Cardiovascular Research Center (K.H., Z.N., G.A.M., M.A.H.), University of Missouri, Columbia; and Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville (K.H.)
| | - Gerald A Meininger
- From the Department of Medical Pharmacology and Physiology (K.H., M.L., G.A.M., M.A.H.) and Dalton Cardiovascular Research Center (K.H., Z.N., G.A.M., M.A.H.), University of Missouri, Columbia; and Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville (K.H.)
| | - Michael A Hill
- From the Department of Medical Pharmacology and Physiology (K.H., M.L., G.A.M., M.A.H.) and Dalton Cardiovascular Research Center (K.H., Z.N., G.A.M., M.A.H.), University of Missouri, Columbia; and Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville (K.H.).
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141
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Zhao T, Zhang H, Jin C, Qiu F, Wu Y, Shi L. Melatonin mediates vasodilation through both direct and indirect activation of BK Ca channels. J Mol Endocrinol 2017; 59:219-233. [PMID: 28676563 DOI: 10.1530/jme-17-0028] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 07/03/2017] [Indexed: 01/14/2023]
Abstract
Melatonin, synthesized primarily by the pineal gland, is a neuroendocrine hormone with high membrane permeability. The vascular effects of melatonin, including vasoconstriction and vasodilation, have been demonstrated in numerous studies. However, the mechanisms underlying these effects are not fully understood. Large-conductance Ca2+-activated K+ (BKCa) channels are expressed broadly on smooth muscle cells and play an important role in vascular tone regulation. This study explored the mechanisms of myocyte BKCa channels and endothelial factors underlying the action of melatonin on the mesenteric arteries (MAs). Vascular contractility and patch-clamp studies were performed on myocytes of MAs from Wistar rats. Melatonin induced significant vasodilation on MAs. In the presence of Nω-nitro-l-arginine methyl ester (l-NAME), a potent endothelial oxide synthase (eNOS) inhibitor, melatonin elicited concentration-dependent relaxation, with lowered pIC50 The effect of melatonin was significantly attenuated in the presence of BKCa channel blocker iberiotoxin or MT1/MT2 receptor antagonist luzindole in both (+) l-NAME and (-) l-NAME groups. In the (+) l-NAME group, iberiotoxin caused a parallel rightward shift of the melatonin concentration-relaxation curve, with pIC50 lower than that of luzindole. Both inside-out and cell-attached patch-clamp recordings showed that melatonin significantly increased the open probability, mean open time and voltage sensitivity of BKCa channels. In a cell-attached patch-clamp configuration, the melatonin-induced enhancement of BKCa channel activity was significantly suppressed by luzindole. These findings indicate that in addition to the activation of eNOS, melatonin-induced vasorelaxation of MAs is partially attributable to its direct (passing through the cell membrane) and indirect (via MT1/MT2 receptors) activation of the BKCa channels on mesenteric arterial myocytes.
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MESH Headings
- Animals
- Gene Expression
- Ion Channel Gating/drug effects
- Large-Conductance Calcium-Activated Potassium Channel alpha Subunits/agonists
- Large-Conductance Calcium-Activated Potassium Channel alpha Subunits/genetics
- Large-Conductance Calcium-Activated Potassium Channel alpha Subunits/metabolism
- Male
- Melatonin/metabolism
- Melatonin/pharmacology
- Muscle, Smooth, Vascular/cytology
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Rats
- Receptor, Melatonin, MT1/genetics
- Receptor, Melatonin, MT1/metabolism
- Receptor, Melatonin, MT2/genetics
- Receptor, Melatonin, MT2/metabolism
- Vasodilation/drug effects
- Vasodilation/genetics
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Affiliation(s)
- T Zhao
- Department of Exercise PhysiologyBeijing Sport University, Beijing, China
| | - H Zhang
- Department of Exercise PhysiologyBeijing Sport University, Beijing, China
| | - C Jin
- Department of Exercise PhysiologyBeijing Sport University, Beijing, China
| | - F Qiu
- Department of Exercise PhysiologyBeijing Sport University, Beijing, China
| | - Y Wu
- Department of Exercise PhysiologyBeijing Sport University, Beijing, China
| | - L Shi
- Department of Exercise PhysiologyBeijing Sport University, Beijing, China
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142
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Kang LS, Masilamani S, Boegehold MA. Juvenile growth reduces the influence of epithelial sodium channels on myogenic tone in skeletal muscle arterioles. Clin Exp Pharmacol Physiol 2017; 43:1199-1207. [PMID: 27560463 DOI: 10.1111/1440-1681.12664] [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: 10/26/2015] [Revised: 06/21/2016] [Accepted: 07/14/2016] [Indexed: 02/05/2023]
Abstract
Previous studies have documented that rapid juvenile growth is accompanied by functional changes in the arteriolar endothelium, but much less is known about functional changes in arteriolar smooth muscle over this period. In this study, we investigate the possible contribution of epithelial sodium channels (ENaC) to the myogenic behaviour of arterioles at two stages of juvenile growth. The effects of the ENaC inhibitor benzamil on different levels of myogenic tone were studied in isolated gracilis muscle arterioles from rats aged 21-28 days ("weanlings") and 42-49 days ("juveniles"). ENaC subunit expression in the arteriolar wall was also determined, and the interaction between ENaC and nitric oxide (NO) in regulating vascular tone was explored by combined use of benzamil and NG -monomethyl-l-arginine (l-NMMA). At physiological pressures, both steady-state myogenic tone and the dynamic adjustments in this tone triggered by acute pressure changes were less in juvenile arterioles than in weanling arterioles. α, β and γ ENaC protein was present in arterioles at both ages, but benzamil only had an effect on myogenic tone in weanling arterioles. In these vessels, benzamil increased, rather than decreased, myogenic tone, and this effect was prevented by l-NMMA or endothelial removal. These findings suggest that although ENaC is present in gracilis muscle arterioles of both weanling and juvenile rats, it is not obligatory for the genesis of myogenic activity in these vessels at either age. However, ENaC activity can significantly modulate the level of myogenic tone through stimulation of endothelial NO release at an early stage of growth.
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Affiliation(s)
- Lori S Kang
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA
| | - Shyama Masilamani
- Department of Internal Medicine/Division of Nephrology, Virginia Commonwealth University Medical Center, Richmond, VA, USA
| | - Matthew A Boegehold
- Department of Physiology and Pharmacology, West Virginia University School of Medicine, Morgantown, WV, USA
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143
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Soni H, Peixoto-Neves D, Matthews AT, Adebiyi A. TRPV4 channels contribute to renal myogenic autoregulation in neonatal pigs. Am J Physiol Renal Physiol 2017; 313:F1136-F1148. [PMID: 28768667 DOI: 10.1152/ajprenal.00300.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/20/2017] [Accepted: 07/26/2017] [Indexed: 12/20/2022] Open
Abstract
Myogenic response, a phenomenon in which resistance size arteries and arterioles swiftly constrict or dilate in response to an acute elevation or reduction, respectively, in intravascular pressure is a key component of renal autoregulation mechanisms. Although it is well established that the renal system is functionally immature in neonates, mechanisms that regulate neonatal renal blood flow (RBF) remain poorly understood. In this study, we investigated the hypothesis that members of the transient receptor potential vanilloid (TRPV) channels are molecular components of renal myogenic constriction in newborns. We show that unlike TRPV1-3, TRPV4 channels are predominantly expressed in neonatal pig preglomerular vascular smooth muscle cells (SMCs). Intracellular Ca2+ concentration ([Ca2+]i) elevation induced by osmotic cell swelling was attenuated by TRPV4, L-type Ca2+, and stretch-activated Ca2+ channel blockers but not phospholipase A2 inhibitor. Blockade of TRPV4 channels reversed steady-state myogenic tone and inhibited pressure-induced membrane depolarization, [Ca2+]i elevation, and constriction in distal interlobular arteries. A step increase in arterial pressure induced efficient autoregulation of renal cortical perfusion and total RBF in anesthetized and mechanically ventilated neonatal pigs. Moreover, intrarenal arterial infusion of the TRPV4 channel blockers HC 067047 and RN 1734 attenuated renal autoregulation in the pigs. These data suggest that renal myogenic autoregulation is functional in neonates. Our findings also indicate that TRPV4 channels are mechanosensors in neonatal pig preglomerular vascular SMCs and contribute to renal myogenic autoregulation.
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Affiliation(s)
- Hitesh Soni
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Dieniffer Peixoto-Neves
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Anberitha T Matthews
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Adebowale Adebiyi
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee
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144
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Pires PW, Ko E, Pritchard HA, Rudokas M, Yamasaki E, Earley S. The angiotensin II receptor type 1b is the primary sensor of intraluminal pressure in cerebral artery smooth muscle cells. J Physiol 2017; 595:4735-4753. [PMID: 28475214 PMCID: PMC5509855 DOI: 10.1113/jp274310] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/03/2017] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS The angiotensin II receptor type 1b (AT1 Rb ) is the primary sensor of intraluminal pressure in cerebral arteries. Pressure or membrane-stretch induced stimulation of AT1 Rb activates the TRPM4 channel and results in inward transient cation currents that depolarize smooth muscle cells, leading to vasoconstriction. Activation of either AT1 Ra or AT1 Rb with angiotensin II stimulates TRPM4 currents in cerebral artery myocytes and vasoconstriction of cerebral arteries. The expression of AT1 Rb mRNA is ∼30-fold higher than AT1 Ra in whole cerebral arteries and ∼45-fold higher in isolated cerebral artery smooth muscle cells. Higher levels of expression are likely to account for the obligatory role of AT1 Rb for pressure-induced vasoconstriction. ABSTRACT: Myogenic vasoconstriction, which reflects the intrinsic ability of smooth muscle cells to contract in response to increases in intraluminal pressure, is critically important for the autoregulation of blood flow. In smooth muscle cells from cerebral arteries, increasing intraluminal pressure engages a signalling cascade that stimulates cation influx through transient receptor potential (TRP) melastatin 4 (TRPM4) channels to cause membrane depolarization and vasoconstriction. Substantial evidence indicates that the angiotensin II receptor type 1 (AT1 R) is inherently mechanosensitive and initiates this signalling pathway. Rodents express two types of AT1 R - AT1 Ra and AT1 Rb - and conflicting studies provide support for either isoform as the primary sensor of intraluminal pressure in peripheral arteries. We hypothesized that mechanical activation of AT1 Ra increases TRPM4 currents to induce myogenic constriction of cerebral arteries. However, we found that development of myogenic tone was greater in arteries from AT1 Ra knockout animals compared with controls. In patch-clamp experiments using native cerebral arterial myocytes, membrane stretch-induced cation currents were blocked by the TRPM4 inhibitor 9-phenanthrol in both groups. Further, the AT1 R blocker losartan (1 μm) diminished myogenic tone and blocked stretch-induced cation currents in cerebral arteries from both groups. Activation of AT1 R with angiotensin II (30 nm) also increased TRPM4 currents in smooth muscle cells and constricted cerebral arteries from both groups. Expression of AT1 Rb mRNA was ∼30-fold greater than AT1 Ra in cerebral arteries, and knockdown of AT1 Rb selectively diminished myogenic constriction. We conclude that AT1 Rb , acting upstream of TRPM4 channels, is the primary sensor of intraluminal pressure in cerebral artery smooth muscle cells.
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Affiliation(s)
- Paulo W. Pires
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Eun‐A. Ko
- Department of Physiology and Cell Biology, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Harry A.T. Pritchard
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Michael Rudokas
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Evan Yamasaki
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
| | - Scott Earley
- Department of Pharmacology, Center for Cardiovascular Research, University of NevadaReno School of MedicineRenoNV89557‐0318USA
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145
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Ortner NJ, Bock G, Dougalis A, Kharitonova M, Duda J, Hess S, Tuluc P, Pomberger T, Stefanova N, Pitterl F, Ciossek T, Oberacher H, Draheim HJ, Kloppenburg P, Liss B, Striessnig J. Lower Affinity of Isradipine for L-Type Ca 2+ Channels during Substantia Nigra Dopamine Neuron-Like Activity: Implications for Neuroprotection in Parkinson's Disease. J Neurosci 2017; 37:6761-6777. [PMID: 28592699 PMCID: PMC6596555 DOI: 10.1523/jneurosci.2946-16.2017] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 05/08/2017] [Accepted: 05/13/2017] [Indexed: 12/21/2022] Open
Abstract
Ca2+-influx through L-type Ca2+-channels (LTCCs) is associated with activity-related stressful oscillations of Ca2+ levels within dopaminergic (DA) neurons in the substantia nigra (SN), which may contribute to their selective degeneration in Parkinson's disease (PD). LTCC blockers were neuroprotective in mouse neurotoxin models of PD, and isradipine is currently undergoing testing in a phase III clinical trial in early PD. We report no evidence for neuroprotection by in vivo pretreatment with therapeutically relevant isradipine plasma levels, or Cav1.3 LTCC deficiency in 6-OHDA-treated male mice. To explain this finding, we investigated the pharmacological properties of human LTCCs during SN DA-like and arterial smooth muscle (aSM)-like activity patterns using whole-cell patch-clamp recordings in HEK293 cells (Cav1.2 α1-subunit, long and short Cav1.3 α1-subunit splice variants; β3/α2δ1). During SN DA-like pacemaking, only Cav1.3 variants conducted Ca2+ current (ICa) at subthreshold potentials between action potentials. SN DA-like burst activity increased integrated ICa during (Cav1.2 plus Cav1.3) and after (Cav1.3) the burst. Isradipine inhibition was splice variant and isoform dependent, with a 5- to 11-fold lower sensitivity to Cav1.3 variants during SN DA-like pacemaking compared with Cav1.2 during aSM-like activity. Supratherapeutic isradipine concentrations reduced the pacemaker precision of adult mouse SN DA neurons but did not affect their somatic Ca2+ oscillations. Our data predict that Cav1.2 and Cav1.3 splice variants contribute differentially to Ca2+ load in SN DA neurons, with prominent Cav1.3-mediated ICa between action potentials and after bursts. The failure of therapeutically relevant isradipine levels to protect SN DA neurons can be explained by weaker state-dependent inhibition of SN DA LTCCs compared with aSM Cav1.2.SIGNIFICANCE STATEMENT The high vulnerability of dopamine (DA) neurons in the substantia nigra (SN) to neurodegenerative stressors causes Parkinson's disease (PD). Ca2+ influx through voltage-gated L-type Ca2+ channels (LTCCs), in particular Cav1.3, appears to contribute to this vulnerability, and the LTCC inhibitor isradipine is currently being tested as a neuroprotective agent for PD in a phase III clinical trial. However, in our study isradipine plasma concentrations approved for therapy were not neuroprotective in a PD mouse model. We provide an explanation for this observation by demonstrating that during SN DA-like neuronal activity LTCCs are less sensitive to isradipine than Cav1.2 LTCCs in resistance blood vessels (mediating dose-limiting vasodilating effects) and even at supratherapeutic concentrations isradipine fails to reduce somatic Ca2+ oscillations of SN DA neurons.
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Affiliation(s)
- Nadine J Ortner
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Gabriella Bock
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Antonios Dougalis
- Institute of Applied Physiology, University of Ulm, 89081 Ulm, Germany
| | - Maria Kharitonova
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Johanna Duda
- Institute of Applied Physiology, University of Ulm, 89081 Ulm, Germany
| | - Simon Hess
- Biocenter, Institute for Zoology, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50674 Cologne, Germany
| | - Petronel Tuluc
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Thomas Pomberger
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | | | - Florian Pitterl
- Institute of Legal Medicine and Core Facility Metabolomics, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Thomas Ciossek
- Boehringer Ingelheim Pharma GmbH & Co KG, CNS Research, 88400 Biberach an der Riss, Germany, and
| | - Herbert Oberacher
- Institute of Legal Medicine and Core Facility Metabolomics, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Henning J Draheim
- Boehringer Ingelheim Pharma GmbH & Co KG, CNS Research, 88400 Biberach an der Riss, Germany, and
| | - Peter Kloppenburg
- Biocenter, Institute for Zoology, and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50674 Cologne, Germany
| | - Birgit Liss
- Institute of Applied Physiology, University of Ulm, 89081 Ulm, Germany
| | - Jörg Striessnig
- Department of Pharmacology and Toxicology, Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria,
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146
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Jackson WF, Boerman EM. Regional heterogeneity in the mechanisms of myogenic tone in hamster arterioles. Am J Physiol Heart Circ Physiol 2017; 313:H667-H675. [PMID: 28667050 DOI: 10.1152/ajpheart.00183.2017] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 06/07/2017] [Accepted: 06/26/2017] [Indexed: 01/30/2023]
Abstract
Myogenic tone is an important feature of arterioles and resistance arteries, but the mechanisms responsible for this hallmark characteristic remain unclear. We used pharmacological inhibitors to compare the roles played by phospholipase C (PLC; 10 μM U73122), inositol 1,4,5-trisphosphate receptors (IP3Rs; 100 μM 2-aminoethoxydiphenylborane), protein kinase C (10 μM bisindolylmaleimide I), angiotensin II type 1 receptors (1 μM losartan), Rho kinase (10 nM-30 μM Y27632 or 300 nM H1152), stretch-activated ion channels (10 nM-1 μM Gd3+ or 5 μM spider venom toxin GsMTx-4) and L-type voltage-gated Ca2+ channels (0.3-100 μM diltiazem) in myogenic tone of cannulated, pressurized (80 cmH2O), second-order hamster cremaster or cheek pouch arterioles. Effective inhibition of either PLC or IP3Rs dilated cremaster arterioles, inhibited Ca2+ waves, and reduced global Ca2+ levels. In contrast, cheek pouch arterioles did not display Ca2+ waves and inhibition of PLC or IP3Rs had no effect on myogenic tone or intracellular Ca2+ levels. Inhibition of Rho kinase dilated both cheek pouch and cremaster arterioles with equal efficacy and potency but also reduced intracellular Ca2+ signals in both arterioles. Similarly, inhibition of mechanosensitive ion channels with Gd2+ or GsMTx-4 produced comparable dilation in both arterioles. Inhibition of L-type Ca2+ channels with diltiazem was more effective in dilating cremaster (86 ± 5% dilation, n = 4) than cheek pouch arterioles (54 ± 4% dilation, n = 6, P < 0.05). Thus, there are substantial differences in the mechanisms underlying myogenic tone in hamster cremaster and cheek pouch arterioles. Regional heterogeneity in myogenic mechanisms could provide new targets for drug development to improve regional blood flow in a tissue-specific manner.NEW & NOTEWORTHY Regional heterogeneity in the mechanisms of pressure-induced myogenic tone implies that resistance vessels may be able to alter myogenic signaling pathways to adapt to their environment. A better understanding of the spectrum of myogenic mechanisms could provide new targets to treat diseases that affect resistance artery and arteriolar function.
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Affiliation(s)
- William F Jackson
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
| | - Erika M Boerman
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan
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147
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Importance of Altered Levels of SERCA, IP 3R, and RyR in Vascular Smooth Muscle Cell. Biophys J 2017; 112:265-287. [PMID: 28122214 DOI: 10.1016/j.bpj.2016.11.3206] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/26/2016] [Accepted: 11/21/2016] [Indexed: 11/23/2022] Open
Abstract
Calcium cycling between the sarcoplasmic reticulum (SR) and the cytosol via the sarco-/endoplasmic reticulum Ca-ATPase (SERCA) pump, inositol-1,4,5-triphosphate receptor (IP3R), and Ryanodine receptor (RyR), plays a major role in agonist-induced intracellular calcium ([Ca2+]cyt) dynamics in vascular smooth muscle cells (VSMC). Levels of these calcium handling proteins in SR get altered under disease conditions. We have developed a mathematical model to understand the significance of altered levels of SERCA, IP3R, and RyR on the intracellular calcium dynamics of VSMC and to understand how variation in protein levels that arise due to diabetes contribute to different VSMC behavior and thus vascular disease. SR is modeled as a single continuous entity with homogeneous intra-SR calcium. Model results show that agonist-induced intracellular calcium dynamics can be modified by changing the levels of SERCA, IP3R, and/or RyR. Lowering SERCA level will enable intracellular calcium oscillations at low agonist concentrations whereas lowered levels of IP3R and RyR need higher agonist concentration for intracellular calcium oscillations. This research suggests that reduced SERCA level is the main factor responsible for the reduced intracellular calcium transients and contractility in VSMCs.
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148
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Hulls CM, Lentle RG, King QM, Reynolds GW, Chambers JP. Spatiotemporal analysis of spontaneous myogenic contractions in the urinary bladder of the rabbit: timing and patterns reflect reported electrophysiology. Am J Physiol Renal Physiol 2017; 313:F687-F698. [PMID: 28539334 DOI: 10.1152/ajprenal.00156.2017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 05/22/2017] [Accepted: 05/22/2017] [Indexed: 11/22/2022] Open
Abstract
The dynamics of propagating myogenic contractions in the wall of the resting ex vivo urinary bladder of the rabbit were characterized by spatiotemporal maps and related to cyclic variation in intravesical pressure (Pves). Patches of propagating contractions (PPCs) enlarged and involuted in near synchrony with peaks in Pves [mean 3.85 ± 0.3 cycles per minute (cpm)] and were preceded by regions of stretch. The maximum area of the bladder undergoing contraction (55.28 ± 2.65%) and the sizes of individual PPCs (42.61 ± 1.65 mm2) coincided with the peak in Pves PPCs originated and propagated within temporary patch domains (TPDs) and comprised groups of nearly synchronous cyclic propagating individual contractions (PICs). The TPDs were located principally along the vertical axis of the anterior surface of the bladder. The sites of origin of PICs within PPCs were inconsistent, consecutive contractions often propagating in opposite directions along linear maps of strain rate. Similar patterns of movement occurred in areas of the anterior bladder wall that had been stripped of mucosa. Pves varied cyclically with area of contraction and with the indices of aggregation of PPCs, indicating that they grew by peripheral enlargement and collision without annihilation. The synchronization of PICs within PPCs was sometimes lost, uncoordinated PICs then occurring irregularly (between 4 and 20 cpm) having little effect on Pves We postulate that the formation and involution of PPCs within a TPD resulted from cyclic variation in excitation that increased the incidence and distance over which component PICs propagated.
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Affiliation(s)
- C M Hulls
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
| | - R G Lentle
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand;
| | - Q M King
- Division of Urology, Palmerston North Hospital, Palmerston North, New Zealand; and
| | - G W Reynolds
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
| | - J P Chambers
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
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149
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Chalacheva P, Khaleel M, Sunwoo J, Shah P, Detterich JA, Kato RM, Thuptimdang W, Meiselman HJ, Sposto R, Tsao J, Wood JC, Zeltzer L, Coates TD, Khoo MCK. Biophysical markers of the peripheral vasoconstriction response to pain in sickle cell disease. PLoS One 2017; 12:e0178353. [PMID: 28542469 PMCID: PMC5443571 DOI: 10.1371/journal.pone.0178353] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 05/11/2017] [Indexed: 02/07/2023] Open
Abstract
Painful vaso-occlusive crisis (VOC), a complication of sickle cell disease (SCD), occurs when sickled red blood cells obstruct flow in the microvasculature. We postulated that exaggerated sympathetically mediated vasoconstriction, endothelial dysfunction and the synergistic interaction between these two factors act together to reduce microvascular flow, promoting regional vaso-occlusions, setting the stage for VOC. We previously found that SCD subjects had stronger vasoconstriction response to pulses of heat-induced pain compared to controls but the relative degrees to which autonomic dysregulation, peripheral vascular dysfunction and their interaction are present in SCD remain unknown. In the present study, we employed a mathematical model to decompose the total vasoconstriction response to pain into: 1) the neurogenic component, 2) the vascular response to blood pressure, 3) respiratory coupling and 4) neurogenic-vascular interaction. The model allowed us to quantify the contribution of each component to the total vasoconstriction response. The most salient features of the components were extracted to represent biophysical markers of autonomic and vascular impairment in SCD and controls. These markers provide a means of phenotyping severity of disease in sickle-cell anemia that is based more on underlying physiology than on genotype. The marker of the vascular component (BMv) showed stronger contribution to vasoconstriction in SCD than controls (p = 0.0409), suggesting a dominant myogenic response in the SCD subjects as a consequence of endothelial dysfunction. The marker of neurogenic-vascular interaction (BMn-v) revealed that the interaction reinforced vasoconstriction in SCD but produced vasodilatory response in controls (p = 0.0167). This marked difference in BMn-v suggests that it is the most sensitive marker for quantifying combined alterations in autonomic and vascular function in SCD in response to heat-induced pain.
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Affiliation(s)
- Patjanaporn Chalacheva
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
- * E-mail:
| | - Maha Khaleel
- Division of Hematology, Oncology and Blood & Marrow Transplantation, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California, United States of America
| | - John Sunwoo
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
| | - Payal Shah
- Division of Hematology, Oncology and Blood & Marrow Transplantation, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California, United States of America
| | - Jon A. Detterich
- Division of Cardiology, Children’s Hospital Los Angeles, Los Angeles, California, United States of America
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Roberta M. Kato
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
- Division of Pulmonology, Children’s Hospital Los Angeles, Los Angeles, California, United States of America
| | - Wanwara Thuptimdang
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
| | - Herbert J. Meiselman
- Department of Physiology and Biophysics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Richard Sposto
- Division of Hematology, Oncology and Blood & Marrow Transplantation, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California, United States of America
- Department of Preventative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Jennie Tsao
- Pediatric Pain Program, David Geffen School of Medicine, University of California at Los Angeles, California, United States of America
| | - John C. Wood
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
- Division of Cardiology, Children’s Hospital Los Angeles, Los Angeles, California, United States of America
| | - Lonnie Zeltzer
- Pediatric Pain Program, David Geffen School of Medicine, University of California at Los Angeles, California, United States of America
| | - Thomas D. Coates
- Division of Hematology, Oncology and Blood & Marrow Transplantation, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, Los Angeles, California, United States of America
- Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, California, United States of America
| | - Michael C. K. Khoo
- Department of Biomedical Engineering, University of Southern California, Los Angeles, California, United States of America
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150
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Ismail B, deKemp RA, Croteau E, Hadizad T, Burns KD, Beanlands RS, DaSilva JN. Treatment with enalapril and not diltiazem ameliorated progression of chronic kidney disease in rats, and normalized renal AT1 receptor expression as measured with PET imaging. PLoS One 2017; 12:e0177451. [PMID: 28542215 PMCID: PMC5438116 DOI: 10.1371/journal.pone.0177451] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 04/27/2017] [Indexed: 12/23/2022] Open
Abstract
ACE inhibitors are considered first line of treatment in patients with many forms of chronic kidney disease (CKD). Other antihypertensives such as calcium channel blockers achieve similar therapeutic effectiveness in attenuating hypertension-related renal damage progression. Our objective was to explore the value of positron emission tomography (PET) imaging of renal AT1 receptor (AT1R) to guide therapy in the 5/6 subtotal-nephrectomy (Nx) rat model of CKD. Ten weeks after Nx, Sprague-Dawley rats were administered 10mg/kg/d enalapril (NxE), 30mg/kg/d diltiazem (NxD) or left untreated (Nx) for an additional 8-10 weeks. Kidney AT1R expression was assessed using in vivo [18F]fluoropyridine-losartan PET and in vitro autoradiography. Compared to shams, Nx rats exhibited higher systolic blood pressure that was reduced by both enalapril and diltiazem. At 18-20 weeks, plasma creatinine and albuminuria were significantly increased in Nx, reduced to sham levels in NxE, but enhanced in NxD rats. Enalapril treatment decreased kidney angiotensin II whereas diltiazem induced significant elevations in plasma and kidney levels. Reduced PET renal AT1R levels in Nx were normalized by enalapril but not diltiazem, and results were supported by autoradiography. Reduction of renal blood flow in Nx was restored by enalapril, while no difference was observed in myocardial blood flow amongst groups. Enhanced left ventricle mass in Nx was not reversed by enalapril but was augmented with diltiazem. Stroke volume was diminished in untreated Nx compared to shams and restored with both therapies. [18F]Fluoropyridine-Losartan PET allowed in vivo quantification of kidney AT1R changes associated with progression of CKD and with various pharmacotherapies.
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Affiliation(s)
- Basma Ismail
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Rob A. deKemp
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Etienne Croteau
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Tayebeh Hadizad
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Kevin D. Burns
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ontario, Canada
| | - Rob S. Beanlands
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Jean N. DaSilva
- Cardiac PET Centre, Department of Medicine (Division of Cardiology), University of Ottawa Heart Institute, Ottawa, ON, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
- Department of Radiology, Radio-Oncology and Nuclear Medicine, University of Montreal; University of Montreal Hospital Research Centre (CRCHUM), Montréal, Québec, Canada
- * E-mail:
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