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Cyclopiazonic acid alters serotonin-induced responses in rat thoracic aorta. Vascul Pharmacol 2014; 61:43-8. [PMID: 24704610 DOI: 10.1016/j.vph.2014.03.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Revised: 02/10/2014] [Accepted: 03/20/2014] [Indexed: 11/20/2022]
Abstract
We previously showed that endothelin A (ETA) receptor antagonist BQ-123 partially inhibited cyclopiazonic acid (CPA)-enhanced endothelin-1 (ET-1)-induced contractions suggesting enhancement of ETA receptor internalization in caveolar structures by sarco/endoplasmic reticulum Ca+2 ATPase (SERCA) blockade. Since serotonin (5-Hydroxytryptamine, 5-HT) receptors are reported to be localized on caveolar membranes, we investigated whether SERCA inhibition affects 5-HT-induced responses and 5-HT receptor antagonism. For this purpose, vascular responses were measured in thoracic aorta segments from male Wistar albino rats using isolated tissue experiments. Data showed that CPA inhibits 5-HT- and PE-induced contractions in intact vessels while potentiating those in endothelium-denuded. Furthermore, non-selective 5-HT receptor blocker methysergide partially inhibited CPA-induced 5-HT contractions. However, α1-adrenergic receptor antagonist prazosin totally inhibited CPA-potentiated PE contractions. We suggest that SERCA inhibition results in 5-HT receptor internalization similar to ETA receptors possibly through protein kinase C activation by increased subsarcolemmal Ca2+ levels, eventually preventing 5-HT receptor antagonism.
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Alonso F, Krattinger N, Mazzolai L, Simon A, Waeber G, Meda P, Haefliger JA. An angiotensin II- and NF-kappaB-dependent mechanism increases connexin 43 in murine arteries targeted by renin-dependent hypertension. Cardiovasc Res 2010; 87:166-76. [PMID: 20110337 PMCID: PMC2883896 DOI: 10.1093/cvr/cvq031] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 01/20/2010] [Accepted: 01/25/2010] [Indexed: 01/17/2023] Open
Abstract
AIMS Connexins (Cxs) play a role in the contractility of the aorta wall. We investigated how connexins of the endothelial cells (ECs; Cx37, Cx40) and smooth muscle cells (SMCs; Cx43, Cx45) of the aorta change during renin-dependent and -independent hypertension. METHODS AND RESULTS We subjected both wild-type (WT) mice and mice lacking Cx40 (Cx40(-/-)), to either a two-kidney, one-clip procedure or to N-nitro-l-arginine-methyl-ester treatment, which induce renin-dependent and -independent hypertension, respectively. All hypertensive mice featured a thickened aortic wall, increased levels of Cx37 and Cx45 in SMC, and of Cx40 in EC (except in Cx40(-/-) mice). Cx43 was up-regulated, with no effect on its S368 phosphorylation, only in the SMCs of renin-dependent models of hypertension. Blockade of the renin-angiotensin system of Cx40(-/-) mice normalized blood pressure and prevented both aortic thickening and Cx alterations. Ex vivo exposure of WT aortas, carotids, and mesenteric arteries to physiologically relevant levels of angiotensin II (AngII) increased the levels of Cx43, but not of other Cx. In the aortic SMC line of A7r5 cells, AngII activated kinase-dependent pathways and induced binding of the nuclear factor-kappa B (NF-kappaB) to the Cx43 gene promoter, increasing Cx43 expression. CONCLUSION In both large and small arteries, hypertension differently regulates Cx expression in SMC and EC layers. Cx43 is selectively increased in renin-dependent hypertension via an AngII activation of the extracellular signal-regulated kinase and NF-kappaB pathways.
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MESH Headings
- Angiotensin II/metabolism
- Angiotensin II Type 1 Receptor Blockers/pharmacology
- Angiotensin-Converting Enzyme Inhibitors/pharmacology
- Animals
- Antihypertensive Agents/pharmacology
- Aorta/drug effects
- Aorta/metabolism
- Aorta/physiopathology
- Binding Sites
- Blood Pressure
- Carotid Arteries/metabolism
- Carotid Arteries/physiopathology
- Cell Line
- Connexin 43/genetics
- Connexin 43/metabolism
- Connexins/deficiency
- Connexins/genetics
- Disease Models, Animal
- Endothelial Cells/metabolism
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Genes, Reporter
- Hypertension, Renovascular/drug therapy
- Hypertension, Renovascular/etiology
- Hypertension, Renovascular/metabolism
- Hypertension, Renovascular/physiopathology
- Mesenteric Arteries/metabolism
- Mesenteric Arteries/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Myocytes, Smooth Muscle/metabolism
- NF-kappa B/metabolism
- NG-Nitroarginine Methyl Ester
- Nephrectomy
- Phosphorylation
- Promoter Regions, Genetic
- Rats
- Renin/blood
- Time Factors
- Transfection
- Up-Regulation
- Gap Junction alpha-5 Protein
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Affiliation(s)
- Florian Alonso
- Service of Internal Medicine, Laboratory of Experimental Medicine 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
| | - Nathalie Krattinger
- Service of Internal Medicine, Laboratory of Experimental Medicine 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
| | - Lucia Mazzolai
- Service of Internal Medicine, Laboratory of Experimental Medicine 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
| | - Alexander Simon
- Department of Physiology, College of Medicine, University of Arizona, Tucson, AZ, USA
| | - Gérard Waeber
- Service of Internal Medicine, Laboratory of Experimental Medicine 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
| | - Paolo Meda
- Department of Cell Physiology and Metabolism, University of Geneva, School of Medicine, CMU, 1211 Genève 4, Switzerland
| | - Jacques-Antoine Haefliger
- Service of Internal Medicine, Laboratory of Experimental Medicine 19-135S, University Hospital, CHUV-1011 Lausanne, Switzerland
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Tosun M, Erac Y, Selli C, Karakaya N. Sarcoplasmic-endoplasmic reticulum Ca2+-ATPase inhibition prevents endothelin A receptor antagonism in rat aorta. Am J Physiol Heart Circ Physiol 2006; 292:H1961-6. [PMID: 17172280 DOI: 10.1152/ajpheart.00298.2006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study tested whether sarcoplasmic-endoplasmic reticulum Ca(2+)-ATPase regulates the ability of endothelin receptor antagonist to inhibit the endothelin-1 constriction. The endothelin A receptor antagonist BQ-123 (1 microM) completely relaxed constriction to 10 nM endothelin-1 in endothelium-denuded rat aorta. Challenge with cyclopiazonic acid (10 microM), a sarcoplasmic-endoplasmic reticulum Ca(2+)-ATPase inhibitor, during the plateau of endothelin-1 constriction enhanced the constriction by approximately 30%. BQ-123 relaxed the endothelin-1 plus cyclopiazonic acid constriction by only approximately 10%. In contrast, prazosin (1 microM), an alpha-adrenergic receptor antagonist, still completely relaxed the 0.3 muM phenylephrine constriction in the presence of cyclopiazonic acid. Verapamil relaxed the endothelin-1 plus cyclopiazonic acid constriction by approximately 30%, whereas Ni(2+) and 2-aminoethoxydiphenyl borate, nonselective cation channel and store-operated channel blockers, respectively, completely relaxed the constriction. These results suggest that lowered sarcoplasmic-endoplasmic reticulum Ca(2+)-ATPase activity selectively decreases the ability of endothelin receptor antagonist to inhibit the endothelin A receptor. The decreased antagonism may be related to the opening of store-operated channels and subsequent greater internalization of endothelin A receptor.
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Affiliation(s)
- M Tosun
- Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Turkey.
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4
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Potocnik SJ, Hill MA. Pharmacological evidence for capacitative Ca(2+) entry in cannulated and pressurized skeletal muscle arterioles. Br J Pharmacol 2001; 134:247-56. [PMID: 11564642 PMCID: PMC1572963 DOI: 10.1038/sj.bjp.0704270] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Arteriolar myogenic tone shows a marked dependency on extracellular Ca(2+). The contribution played by mechanisms such as intracellular Ca(2+) release and capacitative entry, however, are less certain. The present studies aimed to demonstrate functional evidence for involvement of such mechanisms in myogenic tone and reactivity. Single cremaster arterioles were denuded of endothelium, pressurized under no-flow conditions and loaded with fura 2-AM for measurement of changes in intracellular Ca(2+) [Ca(2+)](i). The cell permeable, putative, IP(3) receptor antagonist 2APB (2 aminoethoxydiphenyl borate) was used to determine the possible role of IP(3) receptor-mediated mechanisms in arteriolar myogenic tone and reactivity. Arterioles dilated in response to increasing concentrations of 2APB (1 - 300 microM) without a concomitant change in global [Ca(2+)](i). Also 2APB (50 microM) completely inhibited the myogenic constriction in response to a step change in luminal pressure (50 - 120 mmHg) with no apparent effect on pressure-mediated increases in [Ca(2+)](i). 2APB markedly attenuated the constrictor response and [Ca(2+)](i) increase stimulated by phenylephrine but not KCl. Capacitative Ca(2+) influx in arterioles was demonstrated either by re-addition of extracellular [Ca(2+)] following pre-treatment with 1 or 10 microM nifedipine in Ca(2+) free buffer or exposure of vessels to thapsigargin (1 microM) to induce store depletion. In both cases 2APB inhibited the increase in [Ca(2+)](i). Capacitative Ca(2+) entry showed an inverse relationship with intraluminal pressure over the range 10 - 120 mmHg. Consistent with an effect on a Ca(2+) entry pathway, 2APB had no effect on intracellular (caffeine releasable) Ca(2+) stores while decreasing the rate of Mn(2+) quench of fura 2 fluorescence. The results provide functional evidence for capacitative Ca(2+) entry in intact arteriolar smooth muscle. The effectiveness of 2APB in inhibiting both non-voltage gated Ca(2+) entry and responsiveness to an acute pressure step is consistent with the involvement of an axis involving IP(3)-mediated and or capacitative Ca(2+) entry mechanisms in myogenic reactivity. Given the lack of effect of 2APB on pressure-induced changes in global [Ca(2+)](i) it is suggested that such mechanisms participate on a localized level to couple the myogenic stimulus to contraction.
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Affiliation(s)
- Simon J Potocnik
- Microvascular Biology Group, School of Medical Sciences, Division of Biosciences, RMIT University, Plenty Road, Bundoora, Victoria 3083, Australia
| | - Michael A Hill
- Microvascular Biology Group, School of Medical Sciences, Division of Biosciences, RMIT University, Plenty Road, Bundoora, Victoria 3083, Australia
- Author for correspondence:
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5
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Gardner JD, Benoit JN. Effects of capacitative calcium entry on agonist-induced calcium transients in A7r5 vascular smooth muscle cells. J Biomed Sci 2000; 7:304-10. [PMID: 10895053 DOI: 10.1007/bf02253249] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
OBJECTIVE The purpose of this study was to evaluate the contribution of capacitative calcium influx to intracellular calcium levels during agonist-induced stimulation of vascular smooth muscle cells. METHODS Aortic vascular smooth muscle cells (A7r5) were loaded with Indo-1 and intracellular calcium transients were measured. Cells were challenged with either arginine vasopressin (0. 5 microM) or thapsigargin (1 microM). Lanthanum (1 mM) was used to block capacitative calcium influx through store-operated channels. Calcium traces were analyzed for basal, peak and plateau responses. Recordings were derivatized and integrated to gain additional information. Nonlinear regression provided a time constant that describes restoration of ionic equilibrium involving both sequestration and extrusion pathways. RESULTS Stimulation of cells with thapsigargin produced a non-L-type calcium influx that was attenuated by lanthanum. Cells excited with vasopressin exhibited a rapid calcium increase followed by a gradual decrease to a plateau level. Lanthanum pretreatment prior to stimulation caused no significant change in baseline, peak or plateau calcium levels as compared to control. Lanthanum caused no significant change in maximal calcium release rate, calcium integrals or time constant as compared to control. CONCLUSIONS Capacitative calcium entry can occur in vascular smooth muscle cells, but does not appear to contribute significantly to the vasopressin response.
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Affiliation(s)
- J D Gardner
- Department of Physiology, University of South Alabama, Mobile, AL 36688USA
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Fellner SK, Arendshorst WJ. Capacitative calcium entry in smooth muscle cells from preglomerular vessels. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:F533-42. [PMID: 10516277 DOI: 10.1152/ajprenal.1999.277.4.f533] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Calcium entry via voltage-gated L-type channels is responsible for at least half of the increase in cytosolic calcium ([Ca(2+)](i)) in afferent arterioles following agonist stimulation. We sought the presence of capacitative calcium entry in fresh vascular smooth muscle cells (VSMC) derived from rat preglomerular vessels. [Ca(2+)](i) was measured using fura-2 ratiometric fluorescence. Vasopressin V1 receptor agonist (V1R) (10(-7) M) increased [Ca(2+)](i) by approximately 100 nM. A calcium channel blocker (CCB), nifedipine or verapamil (10(-7) M), inhibited the response by approximately 50%. V1R in the presence of CCB increased [Ca(2+)](i) from 106 to 176 nM, confirming that calcium mobilization and/or entry may occur independent of voltage-gated channels. In nominally Ca(2+)-free buffer, V1R increased [Ca(2+)](i) from 94 to 129 nM, denoting mobilization; addition of CaCl(2) (1 mM) further elevated [Ca(2+)](i) to 176 nM, indicating a secondary phase of Ca(2+) entry. Similar responses were obtained when CCB was present in calcium-free buffer or when EGTA was present. In nominally Ca(2+)-free medium, the sarcoplasmic reticulum Ca(2+)-ATPase inhibitors (SRCAI), thapsigargin and cyclopiazonic acid (CPA), increased [Ca(2+)](i) from 97 to 128 and 143 nM, respectively, and to 214 and 220 nM, respectively, when 1 mM extracellular Ca(2+) was added. In the presence of verapamil, the results with CPA acid were nearly identical. In Ca(2+)-free buffer, the stimulatory effect of V1R or SRCAI on the Ca(2+)/fura signal was quenched by the addition of Mn(2+) (1 mM), demonstrating divalent cation entry. These studies provide evidence for capacitative (store- operated) calcium entry in VSMC freshly isolated from rat preglomerular arterioles.
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MESH Headings
- Animals
- Arterioles/cytology
- Arterioles/drug effects
- Arterioles/metabolism
- Arterioles/physiology
- Calcium/metabolism
- Calcium/physiology
- Calcium Channel Blockers/pharmacology
- Calcium-Transporting ATPases/antagonists & inhibitors
- Electric Conductivity
- Enzyme Inhibitors/pharmacology
- Indoles/pharmacology
- Intracellular Membranes/metabolism
- Kidney Glomerulus/blood supply
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/physiology
- Osmolar Concentration
- Rats
- Rats, Inbred WKY
- Receptors, Vasopressin/agonists
- Sarcoplasmic Reticulum/enzymology
- Thapsigargin/pharmacology
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Affiliation(s)
- S K Fellner
- Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7545, USA.
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7
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Golovina VA. Cell proliferation is associated with enhanced capacitative Ca(2+) entry in human arterial myocytes. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:C343-9. [PMID: 10444411 DOI: 10.1152/ajpcell.1999.277.2.c343] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Depletion of Ca(2+) stores in the sarcoplasmic reticulum (SR) activates extracellular Ca(2+) influx via capacitative Ca(2+) entry (CCE). Here, CCE levels in proliferating and growth-arrested human pulmonary artery smooth muscle cells (PASMCs) were compared by digital imaging fluorescence microscopy. Resting cytosolic free Ca(2+) concentration ([Ca(2+)](cyt)) in proliferating PASMCs was twofold higher than that in growth-arrested cells. Cyclopiazonic acid (CPA; 10 microM), which inhibits SR Ca(2+)-ATPase and depletes inositol 1,4,5-trisphosphate-sensitive Ca(2+) stores, transiently increased [Ca(2+)](cyt) in the absence of extracellular Ca(2+). The addition of 1.8 mM Ca(2+) to the extracellular solution in the presence of CPA induced large increases in [Ca(2+)](cyt), indicative of CCE. The CPA-induced SR Ca(2+) release in proliferating PASMCs was twofold higher than that in growth-arrested cells, whereas the transient rise of [Ca(2+)](cyt) due to CCE was fivefold greater in proliferating cells. CCE was insensitive to nifedipine but was significantly inhibited by 50 mM K(+), which reduces the driving force for Ca(2+) influx, and by 0.5 mM Ni(2+), a putative blocker of store-operated Ca(2+) channels. These data show that augmented CCE is associated with proliferation of human PASMCs and may be involved in stimulating and maintaining cell growth.
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Affiliation(s)
- V A Golovina
- Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
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Abstract
The vascular myogenic response refers to the acute reaction of a blood vessel to a change in transmural pressure. This response is critically important for the development of resting vascular tone, upon which other control mechanisms exert vasodilator and vasoconstrictor influences. The purpose of this review is to summarize and synthesize information regarding the cellular mechanism(s) underlying the myogenic response in blood vessels, with particular emphasis on arterioles. When necessary, experiments performed on larger blood vessels, visceral smooth muscle, and even striated muscle are cited. Mechanical aspects of myogenic behavior are discussed first, followed by electromechanical coupling mechanisms. Next, mechanotransduction by membrane-bound enzymes and involvement of second messengers, including calcium, are discussed. After this, the roles of the extracellular matrix, integrins, and the smooth muscle cytoskeleton are reviewed, with emphasis on short-term signaling mechanisms. Finally, suggestions are offered for possible future studies.
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Affiliation(s)
- M J Davis
- Department of Medical Physiology, Microcirculation Research Institute, Texas A&M University, College Station, Texas, USA
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