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Sulgin AA, Sidorova TN, Sidorov VY. GROWTH AND CHARACTERIZATION OF A TISSUE-ENGINEERED CONSTRUCT FROM HUMAN CORONARY ARTERY SMOOTH MUSCLE CELLS. ACTA ACUST UNITED AC 2020; 19:85-95. [PMID: 32863830 DOI: 10.20538/1682-0363-2020-2-85-95] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Objective To optimize a bioengineered «I-Wire» platform to grow tissue-engineered constructs (TCs) derived from coronary artery smooth muscle cells and characterize the mechano-elastic properties of the grown TCs. Materials and Methods A fibrinogen-based cell mixture was pipetted in a casting mold having two parallel titanium anchoring wires inserted in the grooves on opposite ends of the mold to support the TC. The casting mold was 3 mm in depth, 2 mm in width and 12 mm in length. To measure TC deformation, a flexible probe with a diameter of 365 mk and a length of 42 mm was utilized. The deflection of the probe tip at various tensile forces applied to the TC was recorded using an inverted microscope optical recording system. The elasticity modulus was calculated based on a stretch-stress diagram reconstructed for each TC. The mechano-elastic properties of control TCs and TCs under the influence of isoproterenol (Iso), acetylcholine (ACh), blebbistatin (Bb) and cytochalasin D (Cyto-D) were evaluated. Immunohistochemical staining of smooth muscle α-actin, desmin and the cell nucleus was implemented for the structural characterization of the TCs. Results The TCs formed on day 5-6 of incubation. Subsequent measurements during the following 7 days did not reveal significant changes in elasticity. Values of the elastic modulus were 7.4 ± 1.5 kPa at the first day, 7.9 ± 1.4 kPa on the third day, and 7.8 ± 1.9 kPa on the seventh day of culturing after TC formation. Changes in the mechano-elastic properties of the TCs in response to the subsequent application of Bb and Cyto-D had a two-phase pattern, indicating a possible separation of active and passive elements of the TC elasticity. The application of 1 μM of Iso led to an increase in the value of the elastic modulus from 7.9 ± 1.5 kPa to 10.2 ± 2.1 kPa (p<0.05, n = 6). ACh did not cause a significant change in elasticity. Conclusion The system allows quantification of the mechano-elastic properties of TCs in response to pharmacological stimuli and can be useful to model pathological changes in vascular smooth muscle cells.
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Affiliation(s)
- A A Sulgin
- Siberian State Medical University, Moskovsky tract, Tomsk, 634050, Russia
| | - T N Sidorova
- Division of Allergy, Pulmonary and Critical Care Medicine, Vanderbilt University Medical Center, 1211 Medical Center Dr, Nashville, 37232, TN, USA
| | - V Y Sidorov
- Department of Biomedical Engineering, Vanderbilt University, 1221 Stevenson Center Ln., Nashville, 37240, TN, USA
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2
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Manoury B, Idres S, Leblais V, Fischmeister R. Ion channels as effectors of cyclic nucleotide pathways: Functional relevance for arterial tone regulation. Pharmacol Ther 2020; 209:107499. [PMID: 32068004 DOI: 10.1016/j.pharmthera.2020.107499] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Accepted: 02/05/2020] [Indexed: 02/07/2023]
Abstract
Numerous mediators and drugs regulate blood flow or arterial pressure by acting on vascular tone, involving cyclic nucleotide intracellular pathways. These signals lead to regulation of several cellular effectors, including ion channels that tune cell membrane potential, Ca2+ influx and vascular tone. The characterization of these vasocontrictive or vasodilating mechanisms has grown in complexity due to i) the variety of ion channels that are expressed in both vascular endothelial and smooth muscle cells, ii) the heterogeneity of responses among the various vascular beds, and iii) the number of molecular mechanisms involved in cyclic nucleotide signalling in health and disease. This review synthesizes key data from literature that highlight ion channels as physiologically relevant effectors of cyclic nucleotide pathways in the vasculature, including the characterization of the molecular mechanisms involved. In smooth muscle cells, cation influx or chloride efflux through ion channels are associated with vasoconstriction, whereas K+ efflux repolarizes the cell membrane potential and mediates vasodilatation. Both categories of ion currents are under the influence of cAMP and cGMP pathways. Evidence that some ion channels are influenced by CN signalling in endothelial cells will also be presented. Emphasis will also be put on recent data touching a variety of determinants such as phosphodiesterases, EPAC and kinase anchoring, that complicate or even challenge former paradigms.
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Affiliation(s)
- Boris Manoury
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France.
| | - Sarah Idres
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France
| | - Véronique Leblais
- Inserm, Umr-S 1180, Université Paris-Saclay, Châtenay-Malabry, France
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3
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Potentiation of carbachol-induced detrusor smooth muscle contractions by beta-adrenoceptor activation. Eur J Pharmacol 2009; 606:191-8. [PMID: 19374847 DOI: 10.1016/j.ejphar.2009.01.034] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 12/22/2008] [Accepted: 01/19/2009] [Indexed: 01/16/2023]
Abstract
In strips of rabbit bladder free of urothelium, the beta-adrenoceptor agonist, isoproterenol, significantly reduced basal detrusor smooth muscle tone and inhibited contractions produced by low concentrations of the muscarinic receptor agonist, carbachol. During a carbachol concentration-response curve, instead of inhibiting, isoproterenol strengthened contractions produced by high carbachol concentrations. Thus, the carbachol concentration-response curve was shifted by isoproterenol from a shallow, graded relationship, to a steep, switch-like relationship. The tyrosine kinase inhibitor, genistein, inhibited carbachol-induced contractions only in the presence of isoproterenol. Contraction produced by a single high carbachol concentration (1 microM) displayed 1 fast and 1 slow peak. In the presence of isoproterenol, the slow peak was not strengthened, but was delayed, and U-0126 (mitogen-activated protein kinase kinase inhibitor) selectively inhibited this delay concomitantly with inhibition of extracellular signal-regulated kinase (ERK) phosphorylation. Isoproterenol reduced ERK phosphorylation only in the absence of carbachol. These data support the concept that, by inhibiting weak contractions, potentiating strong contractions, and producing a more switch-like concentration-response curve, beta-adrenoceptor stimulation enhanced the effectiveness of muscarinic receptor-induced detrusor smooth muscle contraction. Moreover, beta-adrenoceptor stimulation changed the cellular mechanism by which carbachol produced contraction. The potential significance of multi-receptor and multi-cell crosstalk is discussed.
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4
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Shibata EF, Brown TLY, Washburn ZW, Bai J, Revak TJ, Butters CA. Autonomic Regulation of Voltage-Gated Cardiac Ion Channels. J Cardiovasc Electrophysiol 2006; 17 Suppl 1:S34-S42. [PMID: 16686680 DOI: 10.1111/j.1540-8167.2006.00387.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Altering voltage-gated ion channel currents, by changing channel number or voltage-dependent kinetics, regulates the propagation of action potentials along the plasma membrane of individual cells and from one cell to its neighbors. Functional increases in the number of cardiac sodium channels (Na(V)1.5) at the myocardial sarcolemma are accomplished by the regulation of caveolae by beta adrenergically stimulated G-proteins. We demonstrate that Na(V)1.5, Ca(V)1.2a, and K(V)1.5 channels specifically localize to isolated caveolar membranes, and to punctate regions of the sarcolemma labeled with caveolin-3. In addition, we show that Na(V)1.5, Ca(V)1.2a, and K(V)1.5 channel antibodies label the same subpopulation of isolated caveolae. Plasma membrane sheet assays demonstrate that Na(V)1.5, Ca(V)1.2a, and K(V)1.5 cluster with caveolin-3. This may have interesting implications for the way in which adrenergic pathways alter the cardiac action potential morphology and the velocity of the excitatory wave.
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Affiliation(s)
- Erwin F Shibata
- Department of Physiology and Biophysics, The University of Iowa, Iowa City, Iowa 52242-1109, USA.
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5
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Sperelakis N, Sunagawa M, Yokoshiki H, Seki T, Nakamura M. Regulation of ion channels in myocardial cells and protection of ischemic myocardium. Heart Fail Rev 2005; 5:139-66. [PMID: 16228141 DOI: 10.1023/a:1009832804103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- N Sperelakis
- Department of Molecular and Cellular Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0576, USA
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6
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Petkov GV, Nelson MT. Differential regulation of Ca2+-activated K+ channels by beta-adrenoceptors in guinea pig urinary bladder smooth muscle. Am J Physiol Cell Physiol 2005; 288:C1255-63. [PMID: 15677377 DOI: 10.1152/ajpcell.00381.2004] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Stimulation of beta-adrenoceptors contributes to the relaxation of urinary bladder smooth muscle (UBSM) through activation of large-conductance Ca(2+)-activated K(+) (BK) channels. We examined the mechanisms by which beta-adrenoceptor stimulation leads to an elevation of the activity of BK channels in UBSM. Depolarization from -70 to +10 mV evokes an inward L-type dihydropyridine-sensitive voltage-dependent Ca(2+) channel (VDCC) current, followed by outward steady-state and transient BK current. In the presence of ryanodine, which blocks the transient BK currents, isoproterenol, a nonselective beta-adrenoceptor agonist, increased the VDCC current by approximately 25% and the steady-state BK current by approximately 30%. In the presence of the BK channel inhibitor iberiotoxin, isoproterenol did not cause activation of the remaining steady-state K(+) current component. Decreasing Ca(2+) influx through VDCC by nifedipine or depolarization to +80 mV suppressed the isoproterenol-induced activation of the steady-state BK current. Unlike forskolin, isoproterenol did not change significantly the open probability of single BK channels in the absence of Ca(2+) sparks and with VDCC inhibited by nifedipine. Isoproterenol elevated Ca(2+) spark (local intracellular Ca(2+) release through ryanodine receptors of the sarcoplasmic reticulum) frequency and associated transient BK currents by approximately 1.4-fold. The data support the concept that in UBSM beta-adrenoceptor stimulation activates BK channels by elevating Ca(2+) influx through VDCC and by increasing Ca(2+) sparks, but not through a Ca(2+)-independent mechanism. This study reveals key regulatory molecular and cellular mechanisms of beta-adrenergic regulation of BK channels in UBSM that could provide new targets for drugs in the treatment of bladder dysfunction.
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Affiliation(s)
- Georgi V Petkov
- Department of Pharmacology, University of Vermont, College of Medicine, Given Bldg., Rm. B-331, 89 Beaumont Ave., Burlington, VT 05405-0068, USA.
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7
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Kobayashi H, Miwa T, Nagao T, Adachi-Akahane S. Negative modulation of L-type Ca2+ channels via beta-adrenoceptor stimulation in guinea-pig detrusor smooth muscle cells. Eur J Pharmacol 2003; 470:9-15. [PMID: 12787825 DOI: 10.1016/s0014-2999(03)01762-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
beta-Adrenergic stimulation enhances the activity of L-type Ca(2+) channels through mechanisms mediated by adenosine 3'5'-cyclic monophosphate (cAMP) and protein kinase A in cardiac myocytes. However, in smooth muscle cells, the effect of beta-adrenoceptor stimulation on the L-type Ca(2+) channel activity has been controversial, and the exact mechanism is still unclear. The present study was aimed at elucidating the effect of beta-adrenergic stimulation upon the activity of L-type Ca(2+) channels in guinea-pig detrusor smooth muscle cells. Isoproterenol (0.1-1 microM) inhibited Ba(2+) currents through L-type Ca(2+) channels (I(Ba)). Isoproterenol (0.1 microM) shifted the steady-state inactivation curve to negative voltages by 11 mV without affecting activation curves. The stimulation of cAMP-mediated signal transduction pathway by forskolin, 8-bromoadenosine 3'5'-cyclic monophosphate (8-Br-cAMP), or the intracellular application of cAMP also mimicked the effects of isoproterenol on I(Ba), which was blocked by the inhibition of protein kinase A. These results indicate that, in detrusor smooth muscles, the stimulation of beta-adrenoceptors exerts negative modulation of L-type Ca(2+) channels via cAMP/protein kinase A-dependent mechanism.
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Affiliation(s)
- Hiroyuki Kobayashi
- Laboratory of Pharmacology and Toxicology, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka 812-8582, Japan
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8
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Heloire F, Hittinger L, Champagne S, Suto Y, Houel R, Ennezat PV, Sambin L, Crozatier B, Su JB. Different effects of mibefradil and amlodipine on coronary vessels and during beta-adrenergic stimulation in conscious dogs. J Cardiovasc Pharmacol 2002; 40:898-906. [PMID: 12451323 DOI: 10.1097/00005344-200212000-00011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Coronary effects of Ca -channel blockers mibefradil and amlodipine were compared in conscious dogs. Ten dogs were instrumented for measurement of aortic and left ventricular pressures, circumflex coronary blood flow velocity (CBFv), and coronary diameter (CD). A permanent catheter was implanted in the circumflex coronary artery. At doses having no systemic effects (7.5-150 micro g/kg), mibefradil and amlodipine increased CBFv and CD dose dependently. At the same dose, mibefradil increased less CBFv than amlodipine. However, for a similar increase in CBFv induced by amlodipine, mibefradil increased CD more. BAY K8644, an L-type Ca -channel agonist, prevented the CBFv and CD responses to amlodipine, but minimally affected the coronary responses to mibefradil. Intracoronary isoproterenol (6 ng/kg) increased LV dP/dt max, CBFv, and CD. Amlodipine markedly altered these responses, while mibefradil did not affect LV inotropic response and slightly altered CBFv response to isoproterenol. Thus, in conscious dogs, both mibefradil and amlodipine exert coronary vasodilation, with different patterns on coronary conductance and resistance vessels and during beta-adrenergic stimulation. These differences could be related to their actions on different Ca channels.
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9
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Keef KD, Hume JR, Zhong J. Regulation of cardiac and smooth muscle Ca(2+) channels (Ca(V)1.2a,b) by protein kinases. Am J Physiol Cell Physiol 2001; 281:C1743-56. [PMID: 11698232 DOI: 10.1152/ajpcell.2001.281.6.c1743] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
High voltage-activated Ca(2+) channels of the Ca(V)1.2 class (L-type) are crucial for excitation-contraction coupling in both cardiac and smooth muscle. These channels are regulated by a variety of second messenger pathways that ultimately serve to modulate the level of contractile force in the tissue. The specific focus of this review is on the most recent advances in our understanding of how cardiac Ca(V)1.2a and smooth muscle Ca(V)1.2b channels are regulated by different kinases, including cGMP-dependent protein kinase, cAMP-dependent protein kinase, and protein kinase C. This review also discusses recent evidence regarding the regulation of these channels by protein tyrosine kinase, calmodulin-dependent kinase, purified G protein subunits, and identification of possible amino acid residues of the channel responsible for kinase regulation.
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Affiliation(s)
- K D Keef
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, Nevada 89557, USA.
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10
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Viard P, Macrez N, Coussin F, Morel JL, Mironneau J. Beta-3 adrenergic stimulation of L-type Ca(2+) channels in rat portal vein myocytes. Br J Pharmacol 2000; 129:1497-505. [PMID: 10742307 PMCID: PMC1571970 DOI: 10.1038/sj.bjp.0703187] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1. The effects of beta(3)-adrenergic stimulation were studied on the L-type Ca(2+) channel in single myocytes from rat portal vein using the whole-cell mode of the patch-clamp technique. 2. Reverse transcription-polymerase chain reaction showed that beta(1)-, beta(2)- and beta(3)-adrenoceptor subtypes were expressed in rat portal vein myocytes. Application of both propranolol (a non-selective beta(1)- and beta(2)-adrenoceptor antagonist) and SR59230A (a beta(3)-adrenoceptor antagonist) were needed to inhibit the isoprenaline-induced increase in L-type Ca(2+) channel current. 3. L-type Ca(2+) channels were stimulated by CGP12177A (a beta(3)-adrenoceptor agonist with potent beta(1)- and beta(2)-adrenoceptor antagonist property) in a manner similar to that of isoprenaline. The CGP12177A-induced stimulation of Ca(2+) channel current was blocked by SR59230A, cyclic AMP-dependent protein kinase inhibitors, H-89 and Rp 8-Br-cyclic AMPs, but was unaffected by protein kinase C inhibitors, GF109203X and 19-31 peptide. This stimulation was mimicked by forskolin and 8-Br-cyclic AMP. In the presence of okadaic acid (a phosphatase inhibitor), the beta(3)-adrenoceptor-induced stimulation was maintained after withdrawal of the agonist. 4. The beta(3)-adrenoceptor stimulation of L-type Ca(2+) channels was blocked by a pretreatment with cholera toxin and by the intracellular application of an anti-Galpha(s) antibody. This stimulation was unaffected by intracellular infusion of an anti-Gbeta(com) antibody and a betaARK(1) peptide. 5. These results show that activation of beta(3)-adrenoceptors stimulates L-type Ca(2+) channels in vascular myocytes through a Galpha(s)-induced stimulation of the cyclic AMP/protein kinase A pathway and the subsequent phosphorylation of the channels.
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MESH Headings
- 1-Propanol/pharmacology
- 8-Bromo Cyclic Adenosine Monophosphate/pharmacology
- Adrenergic beta-Agonists/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Animals
- Barium/pharmacology
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/metabolism
- Cells, Cultured
- Cholera Toxin/pharmacology
- Colforsin/pharmacology
- Dose-Response Relationship, Drug
- Electric Stimulation
- Isoproterenol/pharmacology
- Isoquinolines/pharmacology
- Membrane Potentials/drug effects
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/physiology
- Phorbol 12,13-Dibutyrate/pharmacology
- Portal Vein/cytology
- Portal Vein/drug effects
- Portal Vein/physiology
- Propanolamines/pharmacology
- RNA, Messenger/genetics
- Rats
- Receptors, Adrenergic, beta/drug effects
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/physiology
- Receptors, Adrenergic, beta-3
- Reverse Transcriptase Polymerase Chain Reaction
- Signal Transduction
- Sulfonamides
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Affiliation(s)
- Patricia Viard
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS UMR 5017, Université de Bordeaux II, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Nathalie Macrez
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS UMR 5017, Université de Bordeaux II, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Frédéric Coussin
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS UMR 5017, Université de Bordeaux II, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Jean-Luc Morel
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS UMR 5017, Université de Bordeaux II, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Jean Mironneau
- Laboratoire de Physiologie Cellulaire et Pharmacologie Moléculaire, CNRS UMR 5017, Université de Bordeaux II, 146 rue Léo Saignat, 33076 Bordeaux Cedex, France
- Author for correspondence:
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Zhong J, Dessauer CW, Keef KD, Hume JR. Regulation of L-type Ca2+ channels in rabbit portal vein by G protein alphas and betagamma subunits. J Physiol 1999; 517 ( Pt 1):109-20. [PMID: 10226153 PMCID: PMC2269331 DOI: 10.1111/j.1469-7793.1999.0109z.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
1. The effect of purified G protein subunits alphas and betagamma on L-type Ca2+ channels in vascular smooth muscle and the possible pathways involved were investigated using freshly isolated smooth muscle cells from rabbit portal vein and the whole-cell patch clamp technique. 2. Cells dialysed with either Galphas or Gbetagamma exhibited significant increases in peak Ba2+ current (IBa) density (148 % and 131 %, respectively) compared with control cells. The combination of Galphas and Gbetagamma further increased peak IBa density (181 %). Inactive Galphas and Gbetagamma did not have any effect on Ca2+ channels. 3. The stimulatory effect of Galphas on peak IBa was entirely abolished by the protein kinase A inhibitor Rp-8-Br-cAMPS, or the adenylyl cyclase inhibitor SQ 22536. On the other hand, the stimulatory response of Ca2+ channels to Gbetagamma was not affected by the protein kinase A inhibitors Rp-8-Br-cAMPS and KT 5720, or by the Ca2+-dependent protein kinase C inhibitor bisindolylmaleimide 1, but was completely blocked by the protein kinase C inhibitor calphostin C. Pretreatment of cells with phorbol 12-myristate 13-acetate for over 18 h prevented the stimulatory effect of Gbetagamma on peak IBa. In addition, acute application of phorbol 12,13-dibutyrate enhanced peak IBa density in control cells, which could be entirely blocked by calphostin C. 4. These data indicate that enhancement of Ba2+ currents by Galphas and Gbetagamma can be attributed to increased activity of protein kinase A and protein kinase C, respectively. No direct membrane-delimited pathway for Ca2+ channel regulation by activated Gs proteins could be detected in vascular smooth muscle cells.
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Affiliation(s)
- J Zhong
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV 89557, USA
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12
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Smith LM, Kajioka S, Brading AF, Nakayama S. Effects of phosphorylation-related drugs on slow Ca2+ tail current in guinea-pig detrusor cells. Eur J Pharmacol 1999; 370:187-93. [PMID: 10323268 DOI: 10.1016/s0014-2999(99)00119-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In isolated guinea-pig detrusor cells, large conditioning depolarizations evoke slowly deactivating Ca2+ tail currents, considered to represent the second open state. The possible involvement of channel phosphorylation in this open state was examined. Application of isoprenaline caused a marginal increase in Ca2+ channel current evoked by simple depolarization, while forskolin did not. During application of either drug, slow-tail currents were never observed after simple depolarizations. The conditions necessary to induce slow-tail currents were not changed, even when cyclic AMP, ATP-gamma-S (adenosine 5'-O-(3-thiotriphosphate)), GDP-beta-S (guanosine 5'-O-(2-thiodiphosphate)) (in the pipette) or H-7 (1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride) (to the bathing solution) was applied. The frequent depolarization protocol, known to facilitate Ca2+ current via Ca2+ and cyclic AMP-dependent phosphorylation mechanism(s) in cardiac myocytes, did not induce slow-tail currents. These results suggest that the transition of Ca2+ channels to the second open state during large depolarization is not a result of (voltage-operated) channel phosphorylation itself. Possible underlying mechanisms are discussed.
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Affiliation(s)
- L M Smith
- Department of Physiology, School of Medicine, Nagoya University, Japan
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13
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Ohya Y, Tsuchihashi T, Kagiyama S, Abe I, Fujishima M. Single L-type calcium channels in smooth muscle cells from resistance arteries of spontaneously hypertensive rats. Hypertension 1998; 31:1125-9. [PMID: 9576124 DOI: 10.1161/01.hyp.31.5.1125] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The amplitude of the whole-cell L-type Ca2+ channel current recorded from vascular smooth muscle cells is reportedly greater in spontaneously hypertensive rats (SHR) than in Wistar-Kyoto rats (WKY). However, no study has examined properties of single Ca2+ channels in arterial cells from these strains. To further test the hypothesis that activation of L-type Ca2+ channels in arterial smooth muscle cells would be enhanced in SHR, we recorded single Ca2+ channel currents in resistance mesenteric artery cells from SHR and WKY (8 to 9 weeks of age) using a cell-attached patch clamp technique. With 50 mmol/L Ba2+ in the recording pipette, the depolarizing pulse from a holding potential of -40 mV evoked the single L-type Ca2+ channel current. Opening of the single channels was more frequent in cells from SHR than from WKY. Single-channel conductance (20 pS) and open time (1 ms at 0 mV) did not differ in the two strains. The results suggest that an increased amplitude of the whole-cell current can be attributed to the enhanced opening of single Ca2+ channels in the arterial smooth muscle cells from SHR compared with WKY.
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Affiliation(s)
- Y Ohya
- Second Department of Internal Medicine, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
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14
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Role of cAMP, cGMP, and protein kinase C in regulation of calcium current through the L-type calcium channels in the electroexcitable membrane of smooth muscle cells. NEUROPHYSIOLOGY+ 1998. [DOI: 10.1007/bf02463053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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15
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Roullet JB, Luft UC, Xue H, Chapman J, Bychkov R, Roullet CM, Luft FC, Haller H, McCarron DA. Farnesol inhibits L-type Ca2+ channels in vascular smooth muscle cells. J Biol Chem 1997; 272:32240-6. [PMID: 9405427 DOI: 10.1074/jbc.272.51.32240] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Earlier experiments with animal and human arteries have shown that farnesol, a natural 15-carbon (C15) isoprenoid, is an inhibitor of vasoconstriction (Roullet, J.-B., Xue, H., Chapman, J., McDougal, P., Roullet, C. M., and McCarron, D. A. (1996) J. Clin. Invest. 97, 2384-2390). We report here that farnesol reduced KCl- and norepinephrine-dependent cytosolic Ca2+ transients in fura-2-loaded intact arteries. An effect on Ca2+ signaling was also observed in cultured aortic smooth muscle cells (A10 cells). In these cells, farnesol reduced KCl-induced [Ca2+]i transients and mimicked the inhibitory effect of Ca2+-free medium on the [Ca2+]i response to both 12,13-phorbol myristate acetate, a protein kinase C activator, and thapsigargin, a specific endoplasmic reticulum ATPase inhibitor. Perforated patch-clamp experiments further showed in two vascular smooth muscle cell lines (A10 and A7r5), a reversible, dose-dependent inhibitory effect of farnesol on L-type Ca2+ currents (IC50 = 2.2 microM). Shorter (C10, geraniol) and longer (C20, geranylgeraniol) isoprenols were inactive. L-type Ca2+ channel blockade also occurred under tight (gigaohm) seal configuration using cell-attached, single-channel analysis, thus suggesting a possible action of farnesol from within the intracellular space. We finally demonstrated that farnesol did not affect Ca2+-sensitive pathways implicated in smooth muscle contraction, as tested with alpha-toxin permeabilized arteries. Altogether, our results indicate that farnesol is an inhibitor of vascular smooth muscle Ca2+ signaling with plasma membrane Ca2+ channel blocker properties. The data have implications for the endogenous and pharmacological regulation of vascular tone by farnesol or farnesol analogues.
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Affiliation(s)
- J B Roullet
- Department of Nephrology, Hypertension and Clinical Pharmacology, Oregon Sciences Health University, Portland, Oregon 97201, USA.
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Prakash YS, van der Heijden HF, Kannan MS, Sieck GC. Effects of salbutamol on intracellular calcium oscillations in porcine airway smooth muscle. J Appl Physiol (1985) 1997; 82:1836-43. [PMID: 9173948 DOI: 10.1152/jappl.1997.82.6.1836] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Relaxation of airway smooth muscle (ASM) by beta-adrenoceptor agonists involves reduction of intracellular Ca2+ concentration ([Ca2+]i). In porcine ASM cells, acetylcholine induces [Ca2+]i oscillations that display frequency modulation by agonist concentration and basal [Ca2+]i. We used real-time confocal microscopy to examine the effect of salbutamol (1 nM to 1 microM), a beta 2-adrenoceptor agonist, on [Ca2+]i oscillations in freshly dissociated porcine ASM cells. Salbutamol decreased the frequency of [Ca2+]i oscillations in a concentration-dependent fashion, completely inhibiting the oscillations at 1 microM. These effects were mimicked by a cell-permeant analog of adenosine 3',5'-cyclic monophosphate. The inhibitory effect of salbutamol was partially reversed by BAY K 8644. Salbutamol reduced [Ca2+]i even when sarcoplasmic reticulum (SR) Ca2+ reuptake and Ca2+ influx were blocked. Lanthanum blockade of Ca2+ efflux attenuated the inhibitory effect of salbutamol on [Ca2+]i. The [Ca2+]i response to caffeine was unaffected by salbutamol. On the basis of these results, we conclude that beta 2-adrenoceptor agonists have little effect on SR Ca2+ release in ASM cells but reduce [Ca2+]i by inhibiting Ca2+ influx through voltage-gated channels and by enhancing Ca2+ efflux.
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Affiliation(s)
- Y S Prakash
- Department of Anesthesiology, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA
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Beech DJ. Actions of neurotransmitters and other messengers on Ca2+ channels and K+ channels in smooth muscle cells. Pharmacol Ther 1997; 73:91-119. [PMID: 9131720 DOI: 10.1016/s0163-7258(97)87271-3] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Ion channels play key roles in determining smooth muscle tone by setting the membrane potential and allowing Ca2+ influx. Perhaps not surprisingly, therefore, they also provide targets for neurotransmitters and other messengers that act on smooth muscle. Application of patch-clamp and molecular biology techniques and the use of selective pharmacology has started to provide a wealth of information on the ion channel systems of smooth muscle cells, revealing complexity and functional significance. Reviewed are the actions of messengers (e.g., noradrenaline, acetylcholine, endothelin, angiotensin II, neuropeptide Y, 5-hydroxytryptamine, histamine, adenosine, calcitonin gene-related peptide, substance P, prostacyclin, nitric oxide and oxygen) on specific types of ion channel in smooth muscle, the L-type calcium channel, and the large conductance Ca(2+)-activated, ATP-sensitive, delayed rectifier and apamin-sensitive K+ channels.
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Affiliation(s)
- D J Beech
- Department of Pharmacology, University of Leeds, England
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Sperelakis N, Katsube Y, Yokoshiki H, Sada H, Sumii K. Regulation of the slow Ca++ channels of myocardial cells. Mol Cell Biochem 1996; 163-164:85-98. [PMID: 8974043 DOI: 10.1007/bf00408644] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Contraction of the heart is regulated by a number of mechanisms, such as neurotransmitters, hormones, autacoids, pH, intracellular ATP, and Ca++ ions. These actions are mediated, at least in part, by actions on the sarcolemmal slow (L-type) Ca++ channels, exerted directly or indirectly. The major mechanisms for the regulation of the slow Ca++ channels of myocardial cells includes the following. cAMP/PK-A phosphorylation stimulates the slow Ca++ channel activity, whereas cGMP/PK-G phosphorylation inhibits. DAG/PK-C phosphorylation and tyrosine kinase phosphorylation are suggested to stimulate the slow Ca++ channel activity. Intracellular application of Gs alpha protein increases the slow Ca++ currents (ICa(L)). Lowering of intracellular ATP inhibits ICa(L). Acidosis and increase in [Ca]i inhibits ICa(L). A number of changes in the Ca++ channels also occur during development and aging. Thus, it appears that the slow Ca++ channel is a complex structure, including perhaps several associated regulatory proteins, which can be regulated by a number of extrinsic and intrinsic factors, and thereby control can be exercised over the force of contraction of the heart.
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Shuttleworth CW, Keef KD. Roles of peptides in enteric neuromuscular transmission. REGULATORY PEPTIDES 1995; 56:101-20. [PMID: 7544470 DOI: 10.1016/0167-0115(95)00013-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Sperelakis N, Xiong Z, Haddad G, Masuda H. Regulation of slow calcium channels of myocardial cells and vascular smooth muscle cells by cyclic nucleotides and phosphorylation. Mol Cell Biochem 1994; 140:103-17. [PMID: 7898483 DOI: 10.1007/bf00926749] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The slow Ca2+ channels (L-type) of the heart are stimulated by cAMP. Elevation of cAMP produces a very rapid increase in number of slow channels available for voltage activation during excitation. The probability of a Ca2+ channel opening and the mean open time of the channel are increased. Therefore, any agent that increases the cAMP level of the myocardial cell will tend to potentiate ICa, Ca2+ influx, and contraction. The action of cAMP is mediated by PK-A and phosphorylation of the slow Ca2+ channel protein or an associated regulatory protein (stimulatory type). The myocardial slow Ca2+ channels are also regulated by cGMP, in a manner that is opposite or antagonistic to that of cAMP. We have demonstrated this at both the macroscopic level (whole-cell voltage clamp) and the single-channel level. The effect of cGMP is mediated by PK-G and phosphorylation of a protein, as for example, a regulatory protein (inhibitory-type) associated with the Ca2+ channel. Introduction of PK-G intracellularly causes a relatively rapid inhibition of ICa(L) in both chick and rat heart cells. Such inhibition occurs for both the basal and stimulated ICa(L). In addition, the cGMP/PK-G system was reported to stimulate a phosphatase that dephosphorylates the Ca2+ channel. In addition to the slower indirect pathway--exerted via cAMP/PK-A--there is a faster more-direct pathway for ICa(L) stimulation by the beta-adrenergic receptor. This latter pathway involves direct modulation of the channel activity by the alpha subunit (alpha s*) of the Gs-protein. In vascular smooth muscle cells the two pathways (direct and indirect) also appear to be present, although the indirect pathway produces inhibition of ICa(L). PK-C and calmodulin-PK also may play roles in regulation of the myocardial slow Ca2+ channels. Both of these protein kinases stimulate the activity of these channels. Thus, it appears that the slow Ca2+ channel is a complex structure, including perhaps several associated regulatory proteins, which can be regulated by a number of factors intrinsic and extrinsic to the cell, and thereby control can be exercised over the force of contraction of the heart.
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Affiliation(s)
- N Sperelakis
- Department of Physiology and Biophysics, University of Cincinnati, OH 45267-0576
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