1
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Bukiya AN, Dopico AM. Cholesterol antagonism of alcohol inhibition of smooth muscle BK channel requires cell integrity and involves a protein kinase C-dependent mechanism(s). Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1866:158874. [PMID: 33383194 DOI: 10.1016/j.bbalip.2020.158874] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 12/13/2020] [Accepted: 12/22/2020] [Indexed: 10/22/2022]
Abstract
Alcohol constricts cerebral arteries via inhibition of voltage/calcium-gated, large conductance potassium (BK) channels in vascular myocytes. Using a rat model of high-cholesterol (high-CLR) diet and CLR enrichment of cerebral arteries in vitro, we recently showed that CLR protected against alcohol-induced constriction of cerebral arteries. The subcellular mechanism(s) underlying CLR protection against alcohol-induced constriction of the artery is unclear. Here we use a rat model of high-CLR diet and patch-clamp recording of BK channels in inside-out patches from cerebral artery myocytes to demonstrate that this diet antagonizes inhibition of BK currents by 50 mM ethanol. High-CLR-driven protection against alcohol inhibition of BK currents is reversed following CLR depletion in vitro. Similar to CLR accumulation in vivo, pre-incubation of arterial myocytes from normocholesterolemic rats in CLR-enriching media in vitro protects against alcohol-induced inhibition of BK current. However, application of CLR-enriching media to cell-free membrane patches does not protect against the alcohol effect. These different outcomes point to the involvement of cell signaling in CLR-alcohol interaction on BK channels. Incubation of myocytes with the PKC activators phorbol 12-myristate 13-acetate or 1,2-dioctanoyl-sn-glycerol, but not with the PKC inhibitor Gouml 6983, prior to patch excision precludes CLR enrichment from antagonizing alcohol action. Thus, PKC activation either disables the CLR target(s) or competes with elevated CLR. Favoring the latter possibility, 1,2-dioctanoyl-sn-glycerol protects against alcohol-induced inhibition of BK currents in patches from myocytes with naïve CLR. Our findings document that CLR antagonism of alcohol-induced BK channel inhibition requires cell integrity and is enabled by a PKC-dependent mechanism(s).
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Affiliation(s)
- Anna N Bukiya
- Dept. Pharmacology, Addiction Science, and Toxicology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States.
| | - Alex M Dopico
- Dept. Pharmacology, Addiction Science, and Toxicology, College of Medicine, The University of Tennessee Health Science Center, Memphis, TN, United States
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2
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Li H, Shin SE, Seo MS, An JR, Ha KS, Han ET, Hong SH, Choi IW, Lee DS, Yim MJ, Lee JM, Jung ID, Firth AL, Han IY, Park WS. Inhibitory effect of the tricyclic antidepressant amitriptyline on voltage-dependent K + channels in rabbit coronary arterial smooth muscle cells. Clin Exp Pharmacol Physiol 2017; 45:205-212. [PMID: 28945283 DOI: 10.1111/1440-1681.12857] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 09/19/2017] [Accepted: 09/19/2017] [Indexed: 02/03/2023]
Abstract
Amitriptyline, a tricyclic antidepressant (TCA) drug, is widely used in treatment of psychiatric disorders. However, the side effects of amitriptyline on vascular K+ channels remain to be determined. Therefore, we investigated the effect of the tricyclic antidepressant and serotonin reuptake inhibitor amitriptyline on voltage-dependent K+ (Kv) channels in freshly isolated rabbit coronary arterial smooth muscle cells, using the whole-cell patch clamp technique. The Kv current amplitudes were inhibited by amitriptyline in a concentration-dependent manner, with an apparent IC50 value of 2.2 ± 0.14 μmol/L and a Hill coefficient of 0.87 ± 0.03. Amitriptyline shifted the activation curve to a more positive potential, but had no significant effect on the inactivation curve, suggesting that amitriptyline altered the voltage sensitivity of Kv channels. Pretreatment with Kv1.5 and Kv1.2 channel inhibitors did not alter the inhibitory effect of amitriptyline on Kv channels. Additionally, application of train pulses (1 and 2 Hz) did not affect amitriptyline-induced inhibition of Kv currents, which suggested that the action of amitriptyline on Kv channels was not use (state)-dependent. From these results, we concluded that amitriptyline inhibited the channels in a concentration-dependent, but state-independent manner.
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Affiliation(s)
- Hongliang Li
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Sung Eun Shin
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Mi Seon Seo
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Jin Ryeol An
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Seok-Ho Hong
- Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Il-Whan Choi
- Department of Microbiology, College of Medicine, Inje University, Busan, South Korea
| | - Dae-Sung Lee
- Department of Applied Research, National Marine Biodiversity Institute of Korea, Seocheon, South Korea
| | - Mi-Jin Yim
- Department of Applied Research, National Marine Biodiversity Institute of Korea, Seocheon, South Korea
| | - Jeong Min Lee
- Department of Applied Research, National Marine Biodiversity Institute of Korea, Seocheon, South Korea
| | - In Duk Jung
- Department of Immunology, Laboratory of Dendritic Cell Differentiation and Regulation, School of Medicine, Konkuk University, Chungju, South Korea
| | - Amy L Firth
- Department of Pulmonary, Critical Care and Sleep Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Il Yong Han
- Department of Thoracic and Cardiovascular Surgery, Busan Paik Hospital, College of Medicine, Inje University, Busan, South Korea
| | - Won Sun Park
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
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3
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Li H, Shin SE, Seo MS, An JR, Jung WK, Ha KS, Han ET, Hong SH, Bang H, Bae YM, Firth AL, Choi IW, Park WS. The PPARα activator fenofibrate inhibits voltage-dependent K + channels in rabbit coronary arterial smooth muscle cells. Eur J Pharmacol 2017; 812:155-162. [PMID: 28716724 DOI: 10.1016/j.ejphar.2017.07.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 07/03/2017] [Accepted: 07/13/2017] [Indexed: 11/29/2022]
Abstract
We examined the effects of the PPARα activator fenofibrate on voltage-dependent K+ (Kv) channels using a patch clamp technique in native rabbit coronary arterial smooth muscle cells. Kv current was inhibited by application of fenofibrate in a concentration-dependent manner, with an apparent IC50 value of 6.39 ± 0.53μM and a slope value (Hill coefficient) of 1.63 ± 0.10. Fenofibrate accelerated the decay rate of Kv channel inactivation. The rate constants of association and dissociation for fenofibrate were 0.81± 0.05μM-1s-1 and 4.70 ± 0.47s-1, respectively. Although fenofibrate did not affect the steady-state activation curves, fenofibrate shifted the inactivation curves toward a more negative potential. Application of train pulses (1 or 2Hz) progressively increased the fenofibrate-induced inhibition of the Kv channel, and the recovery time constant from inactivation was increased in the presence of fenofibrate, which suggested that the inhibitory effect of fenofibrate is use-dependent. Another PPARα activator, bezafibrate and PPARα inhibitor, GW 6471, did not affect the Kv current and also did not change the inhibitory effect of fenofibrate on the Kv current. From these results, we suggest that fenofibrate inhibited Kv current in a state-, time-, and use-dependent manner, completely independent of PPARα activation.
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Affiliation(s)
- Hongliang Li
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea
| | - Sung Eun Shin
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea
| | - Mi Seon Seo
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea
| | - Jin Ryeol An
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea
| | - Won-Kyo Jung
- Department of Biomedical Engineering, and Center for Marine-Integrated Biomedical Technology (BK21 Plus) Pukyong National University, Busan 608-737, South Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea
| | - Seok-Ho Hong
- Institute of Medical Sciences, Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea
| | - Hyoweon Bang
- Department of Physiology, College of Medicine, Chung-Ang University, Seoul 06974, South Korea
| | - Young Min Bae
- Department of Physiology, Konkuk University School of Medicine, Chungju 380-701, South Korea
| | - Amy L Firth
- Department of Pulmonary, Critical Care and Sleep Medicine, University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA
| | - Il-Whan Choi
- Department of Microbiology, Inje University College of Medicine, Busan 614-735, South Korea.
| | - Won Sun Park
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea.
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4
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Kim HS, Li H, Kim HW, Shin SE, Jung WK, Ha KS, Han ET, Hong SH, Firth AL, Choi IW, Park WS. The selective serotonin reuptake inhibitor dapoxetine inhibits voltage-dependent K + channels in rabbit coronary arterial smooth muscle cells. Clin Exp Pharmacol Physiol 2017; 44:480-487. [PMID: 28058743 DOI: 10.1111/1440-1681.12723] [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: 10/19/2016] [Revised: 12/18/2016] [Accepted: 12/30/2016] [Indexed: 11/30/2022]
Abstract
We investigated the inhibitory effect of dapoxetine, a selective serotonin reuptake inhibitor (SSRI), on voltage-dependent K+ (Kv) channels using native smooth muscle cells from rabbit coronary arteries. Dapoxetine inhibited Kv channel currents in a concentration-dependent manner, with an IC50 value of 2.68±0.94 μmol/L and a slope value (Hill coefficient) of 0.63±0.11. Application of 10 μmol/L dapoxetine accelerated the rate of inactivation of Kv currents. Although dapoxetine did not modify current activation kinetics, it caused a significant negative shift in the inactivation curves. Application of train step (1 or 2 Hz) progressively increased the inhibitory effect of dapoxetine on Kv channels. In addition, the recovery time constant was extended in its presence, suggesting that the longer recovery time constant from inactivation underlies a use-dependent inhibition of the channel. From these results, we conclude that dapoxetine inhibits Kv channels in a dose-, time-, use-, and state (open)-dependent manner, independent of serotonin reuptake inhibition.
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Affiliation(s)
- Han Sol Kim
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Hongliang Li
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Hye Won Kim
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Sung Eun Shin
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Won-Kyo Jung
- Department of Biomedical Engineering and Center for Marine-Integrated Biomedical Technology (BK21 Plus), Pukyong National University, Busan, South Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Seok-Ho Hong
- Institute of Medical Sciences, Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, South Korea
| | - Amy L Firth
- Department of Pulmonary, Critical Care and Sleep Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Il-Whan Choi
- Department of Microbiology, Inje University College of Medicine, Busan, South Korea
| | - Won Sun Park
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon, South Korea
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5
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Heteromeric complexes of aldo-keto reductase auxiliary K Vβ subunits (AKR6A) regulate sarcolemmal localization of K V1.5 in coronary arterial myocytes. Chem Biol Interact 2017; 276:210-217. [PMID: 28342889 DOI: 10.1016/j.cbi.2017.03.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 03/02/2017] [Accepted: 03/21/2017] [Indexed: 01/20/2023]
Abstract
Redox-sensitive potassium channels consisting of the voltage-gated K+ (KV) channel pore subunit KV1.5 regulate resting membrane potential and thereby contractility of vascular smooth muscle cells. Members of the KV1 family associate with cytosolic auxiliary β subunits, which are members of the aldo-keto reductase (AKR) superfamily (AKR6A subfamily). The Kvβ subunits have been proposed to regulate Kv1 gating via pyridine nucleotide cofactor binding. However, the molecular identity of KVβ subunits that associate with native KV1.5 channels in the vasculature is unknown. Here, we examined mRNA and protein expression of KVβ subunits and tested whether KVβ isoforms interact with KV1.5 channels in murine coronary arteries. We detected KVβ1 (AKR6A3), KVβ2 (AKR6A5) and KVβ3 (AKR6A9) transcripts and KVβ1 and KVβ2 protein in left anterior descending coronary arteries by real time quantitative PCR and Western blot, respectively. In situ proximity ligation assays indicated abundant protein-protein interactions between KV1.5/KVβ1, KV1.5/KVβ2 and KVβ1/β2 in coronary arterial myocytes. Confocal microscopy and membrane fractionation analyses suggest that arterial myocytes from KVβ2-null mice have reduced abundance of sarcolemmal KV1.5. Together, data suggest that in coronary arterial myocytes, KV1.5 channels predominantly associate with KVβ1 and KVβ2 proteins and that KVβ2 performs a chaperone function for KV1.5 channels in arterial myocytes, thereby facilitating Kv1α trafficking and membrane localization.
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6
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Kim HS, Li H, Kim HW, Shin SE, Choi IW, Firth AL, Bang H, Bae YM, Park WS. Selective serotonin reuptake inhibitor sertraline inhibits voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells. J Biosci 2017; 41:659-666. [PMID: 27966486 DOI: 10.1007/s12038-016-9645-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We examined the effects of the selective serotonin reuptake inhibitor (SSRI) sertraline on voltage-dependent K+ (Kv) channels in freshly isolated rabbit coronary arterial smooth muscle cells using the voltage-clamp technique. Sertraline decreased the Kv channel current in a dose-dependent manner, with an IC50 value of 0.18 mu M and a slope value (Hill coefficient) of 0.61. Although the application of 1 mu M sertraline did not affect the steady-state activation curves, sertraline caused a significant, negative shift in the inactivation curves. Pretreatment with another SSRI, paroxetine, had no significant effect on Kv currents and did not alter the inhibitory effects of sertraline on Kv currents. From these results, we concluded that sertraline dose-dependently inhibited Kv currents independently of serotonin reuptake inhibition by shifting inactivation curves to a more negative potential.
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Affiliation(s)
- Han Sol Kim
- Department of Physiology, Kangwon National University School of Medicine Chuncheon 200-701, South Korea
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7
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Kim HW, Li H, Kim HS, Shin SE, Jung WK, Ha KS, Han ET, Hong SH, Choi IW, Park WS. Cisapride, a selective serotonin 5-HT4-receptor agonist, inhibits voltage-dependent K(+) channels in rabbit coronary arterial smooth muscle cells. Biochem Biophys Res Commun 2016; 478:1423-8. [PMID: 27569285 DOI: 10.1016/j.bbrc.2016.08.140] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 08/24/2016] [Indexed: 10/21/2022]
Abstract
We investigated the effect of cisapride, a selective serotonin 5-HT4-receptor agonist, on voltage-dependent K(+) (Kv) channels using freshly isolated smooth muscle cells from the coronary arteries of rabbits. The amplitude of Kv currents was reduced by cisapride in a concentration-dependent manner, with an IC50 value of 6.77 ± 6.01 μM and a Hill coefficient of 0.51 ± 0.18. The application of cisapride shifted the steady-state inactivation curve toward a more negative potential, but had no significant effect on the steady-state activation curve. This suggested that cisapride inhibited the Kv channel in a closed state by changing the voltage sensitivity of Kv channels. The application of another selective serotonin 5-HT4-receptor agonist, prucalopride, did not affect the basal Kv current and did not alter the inhibitory effect of cisapride on Kv channels. From these results, we concluded that cisapride inhibited vascular Kv current in a concentration-dependent manner by shifting the steady-state inactivation curve, independent of its own function as a selective serotonin 5-HT4-receptor agonist.
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Affiliation(s)
- Hye Won Kim
- Department of Physiology, Kangwon National University, School of Medicine, Chuncheon, 200-701, South Korea
| | - Hongliang Li
- Department of Physiology, Kangwon National University, School of Medicine, Chuncheon, 200-701, South Korea
| | - Han Sol Kim
- Department of Physiology, Kangwon National University, School of Medicine, Chuncheon, 200-701, South Korea
| | - Sung Eun Shin
- Department of Physiology, Kangwon National University, School of Medicine, Chuncheon, 200-701, South Korea
| | - Won-Kyo Jung
- Department of Biomedical Engineering, and Center for Marine-Integrated Biomedical Technology (BK21 Plus), Pukyong National University, Busan, 608-737, South Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, Kangwon National University, School of Medicine, Chuncheon, 200-701, South Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University, School of Medicine, Chuncheon, 200-701, South Korea
| | - Seok-Ho Hong
- Department of Internal Medicine, Kangwon National University, School of Medicine, Chuncheon, 200-701, South Korea
| | - Il-Whan Choi
- Department of Microbiology, Inje University, College of Medicine, Busan, 614-735, South Korea.
| | - Won Sun Park
- Department of Physiology, Kangwon National University, School of Medicine, Chuncheon, 200-701, South Korea.
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8
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Li H, Kim HS, Kim HW, Shin SE, Jung WK, Ha KS, Han ET, Hong SH, Firth AL, Bae YM, Choi IW, Park WS. The class III anti-arrhythmic agent, amiodarone, inhibits voltage-dependent K(+) channels in rabbit coronary arterial smooth muscle cells. Naunyn Schmiedebergs Arch Pharmacol 2016; 389:713-21. [PMID: 27030392 DOI: 10.1007/s00210-016-1232-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 03/16/2016] [Indexed: 01/06/2023]
Abstract
We examined the inhibitory effect of amiodarone, a class III anti-arrhythmic agent, on voltage-dependent K(+) (Kv) currents in freshly isolated rabbit coronary arterial smooth muscle cells, using a whole-cell patch clamp technique. Amiodarone inhibited Kv currents in a concentration-dependent manner, with a half-maximal inhibitory concentration (IC50) value of 3.9 ± 1.44 μM and a Hill coefficient of 0.45 ± 0.14. Amiodarone did not have a significant effect on the steady-state activation of Kv channels, but shifted the inactivation current toward a more negative potential. Application of consecutive pulses progressively augmented the amiodarone-induced Kv channel inhibition. Another class III anti-arrhythmic agent, dofetilide, did not inhibit the Kv current or change the inhibitory effect of amiodarone on Kv channels. Therefore, these results strongly suggest that amiodarone inhibits Kv currents in a concentration- and state-dependent manner.
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Affiliation(s)
- Hongliang Li
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, 1 Kangwondaehak-gil, Chuncheon, 200-701, South Korea
| | - Han Sol Kim
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, 1 Kangwondaehak-gil, Chuncheon, 200-701, South Korea
| | - Hye Won Kim
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, 1 Kangwondaehak-gil, Chuncheon, 200-701, South Korea
| | - Sung Eun Shin
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, 1 Kangwondaehak-gil, Chuncheon, 200-701, South Korea
| | - Won-Kyo Jung
- Department of Biomedical Engineering, and Center for Marine-Integrated Biomedical Technology (BK21 Plus), Pukyong National University, Busan, 608-737, South Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon, 200-701, South Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon, 200-701, South Korea
| | - Seok-Ho Hong
- Institute of Medical Sciences, Department of Internal Medicine, Kangwon National University School of Medicine, Chuncheon, 200-701, South Korea
| | - Amy L Firth
- Department of Pulmonary, Critical Care and Sleep Medicine, University of Southern California, Keck School of Medicine, Los Angeles, CA, 90033, USA
| | - Young Min Bae
- Department of Physiology, Konkuk University School of Medicine, Chungju, 380-701, South Korea
| | - Il-Whan Choi
- Department of Microbiology, Inje University College of Medicine, Busan, 614-735, South Korea.
| | - Won Sun Park
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, 1 Kangwondaehak-gil, Chuncheon, 200-701, South Korea.
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9
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The calmodulin inhibitor CGS 9343B inhibits voltage-dependent K + channels in rabbit coronary arterial smooth muscle cells. Toxicol Appl Pharmacol 2015; 285:207-13. [DOI: 10.1016/j.taap.2015.03.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Revised: 03/05/2015] [Accepted: 03/10/2015] [Indexed: 11/18/2022]
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10
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Li H, Choi IW, Hong DH, Son YK, Na SH, Jung WK, Firth AL, Jung ID, Park YM, Park WS. W-7 inhibits voltage-dependent K(+) channels independent of calmodulin activity in rabbit coronary arterial smooth muscle cells. Eur J Pharmacol 2015; 750:14-9. [PMID: 25617796 DOI: 10.1016/j.ejphar.2014.12.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 12/02/2014] [Accepted: 12/20/2014] [Indexed: 10/24/2022]
Abstract
We investigated the effect of W-7, a calmodulin inhibitor, on voltage-dependent K(+) (Kv) channels in freshly isolated coronary arterial smooth muscle cells using the whole-cell patch clamp technique. The amplitude of Kv currents was inhibited by W-7 in a concentration-dependent manner, with an IC50 value of 3.38±0.47μM and a Hill coefficient of 0.84±0.10. W-7 shifted the activation curve to a more positive potential but had no significant effect on the inactivation curve, which indicated that W-7 inhibited the Kv current in a closed state of the Kv channel. Another calmodulin inhibitor, W-13, had no significant effect on Kv currents and did not change the inhibitory effect of W-7 on Kv channels. From these results, we conclude that W-7 inhibited the Kv current in a dose-dependent manner, but this inhibition occurred independent of calmodulin activity and in a closed (inactivated) state of the Kv channels.
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Affiliation(s)
- Hongliang Li
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea
| | - Il-Whan Choi
- Department of Microbiology, Inje University College of Medicine, Busan 614-735, South Korea
| | - Da Hye Hong
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea
| | - Youn Kyoung Son
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea
| | - Sung Hun Na
- Institute of Medical Sciences, Department of Obstetrics and Gynecology, Kangwon National University Hospital, School of Medicine, Kangwon National University, Chuncheon 200-701, South Korea
| | - Won-Kyo Jung
- Department of Biomedical Engineering, and Center for Marine-Integrated Biomedical Technology (BK21 Plus) Pukyong National University, Busan 608-737, South Korea
| | - Amy L Firth
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA 92037, USA
| | - In Duk Jung
- Department of Immunology, Lab of Dendritic Cell Differentiation and Regulation, College of Medicine, Konkuk University, Chungju 380-701, South Korea
| | - Yeong-Min Park
- Department of Immunology, Lab of Dendritic Cell Differentiation and Regulation, College of Medicine, Konkuk University, Chungju 380-701, South Korea.
| | - Won Sun Park
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 200-701, South Korea.
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11
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Hong DH, Li H, Kim HS, Kim HW, Shin SE, Jung WK, Na SH, Choi IW, Firth AL, Park WS, Kim DJ. The Effects of the Selective Serotonin Reuptake Inhibitor Fluvoxamine on Voltage-Dependent K + Channels in Rabbit Coronary Arterial Smooth Muscle Cells. Biol Pharm Bull 2015; 38:1208-13. [DOI: 10.1248/bpb.b15-00207] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Da Hye Hong
- Department of Physiology, Kangwon National University School of Medicine
| | - Hongliang Li
- Department of Physiology, Kangwon National University School of Medicine
| | - Han Sol Kim
- Department of Physiology, Kangwon National University School of Medicine
| | - Hye Won Kim
- Department of Physiology, Kangwon National University School of Medicine
| | - Sung Eun Shin
- Department of Physiology, Kangwon National University School of Medicine
| | - Won-Kyo Jung
- Department of Biomedical Engineering, Center for Marine-Integrated Biomedical Technology (BK21 Plus) Pukyong National University
| | - Sung Hun Na
- Department of Obstetrics and Gynecology, Kangwon National University Hospital, School of Medicine, Kangwon National University
| | - Il-Whan Choi
- Department of Microbiology, Inje University College of Medicine
| | | | - Won Sun Park
- Department of Physiology, Kangwon National University School of Medicine
| | - Dae-Joong Kim
- Department of Anatomy and Cell Biology, Kangwon National University School of Medicine
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12
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Son YK, Hong DH, Li H, Kim DJ, Na SH, Park H, Jung WK, Choi IW, Park WS. Ca2+ channel inhibitor NNC 55-0396 inhibits voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells. J Pharmacol Sci 2014; 125:312-9. [PMID: 24989838 DOI: 10.1254/jphs.14054fp] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
We demonstrated the inhibitory effect of NNC 55-0396, a T-type Ca(2+) channel inhibitor, on voltage-dependent K(+) (K(V)) channels in freshly isolated rabbit coronary arterial smooth muscle cells. NNC 55-0396 decreased the amplitude of K(V) currents in a concentration-dependent manner, with an IC(50) of 0.080 μM and a Hill coefficient of 0.76.NNC 55-0396 did not affect steady-state activation and inactivation curves, indicating that the compound does not affect the voltage sensitivity of K(V) channel gating. Both the K(V) currents and the inhibitory effect of NNC 55-0396 on K(V) channels were not altered by depletion of extracellular Ca(2+) or intracellular ATP, suggesting that the inhibitory effect of NNC 55-0396 is independent of Ca(2+)-channel activity and phosphorylation-dependent signaling cascades. From these results, we concluded that NNC 55-0396 dosedependently inhibits K(V) currents, independently of Ca(2+)-channel activity and intracellular signaling cascades.
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Affiliation(s)
- Youn Kyoung Son
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Korea
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Hydrogen peroxide induces vasorelaxation by enhancing 4-aminopyridine-sensitive Kv currents through S-glutathionylation. Pflugers Arch 2014; 467:285-97. [PMID: 24756196 PMCID: PMC4293500 DOI: 10.1007/s00424-014-1513-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 01/04/2014] [Accepted: 04/02/2014] [Indexed: 12/04/2022]
Abstract
Hydrogen peroxide (H2O2) is an endothelium-derived hyperpolarizing factor. Since opposing vasoactive effects have been reported for H2O2 depending on the vascular bed and experimental conditions, this study was performed to assess whether H2O2 acts as a vasodilator in the rat mesenteric artery and, if so, to determine the underlying mechanisms. H2O2 elicited concentration-dependent relaxation in mesenteric arteries precontracted with norepinephrine. The vasodilatory effect of H2O2 was reversed by treatment with dithiothreitol. H2O2-elicited vasodilation was significantly reduced by blocking 4-aminopyridine (4-AP)-sensitive Kv channels, but it was resistant to blockers of big-conductance Ca2+-activated K+ channels and inward rectifier K+ channels. A patch-clamp study in mesenteric arterial smooth muscle cells (MASMCs) showed that H2O2 increased Kv currents in a concentration-dependent manner. H2O2 speeded up Kv channel activation and shifted steady state activation to hyperpolarizing potentials. Similar channel activation was seen with oxidized glutathione (GSSG). The H2O2-mediated channel activation was prevented by glutathione reductase. Consistent with S-glutathionylation, streptavidin pull-down assays with biotinylated glutathione ethyl ester showed incorporation of glutathione (GSH) in the Kv channel proteins in the presence of H2O2. Interestingly, conditions of increased oxidative stress within MASMCs impaired the capacity of H2O2 to stimulate Kv channels. Not only was the H2O2 stimulatory effect much weaker, but the inhibitory effect of H2O2 was unmasked. These data suggest that H2O2 activates 4-AP-sensitive Kv channels, possibly through S-glutathionylation, which elicits smooth muscle relaxation in rat mesenteric arteries. Furthermore, our results support the idea that the basal redox status of MASMCs determines the response of Kv currents to H2O2.
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Hong DH, Son YK, Li H, Jung ID, Park YM, Jung WK, Kim HS, Choi IW, Park WS. The calmodulin inhibitor and antipsychotic drug trifluoperazine inhibits voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells. Biochem Biophys Res Commun 2014; 443:321-5. [DOI: 10.1016/j.bbrc.2013.11.115] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 11/26/2013] [Indexed: 10/25/2022]
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Park WS, Heo SC, Jeon ES, Hong DH, Son YK, Ko JH, Kim HK, Lee SY, Kim JH, Han J. Functional expression of smooth muscle-specific ion channels in TGF-β(1)-treated human adipose-derived mesenchymal stem cells. Am J Physiol Cell Physiol 2013; 305:C377-91. [PMID: 23761629 DOI: 10.1152/ajpcell.00404.2012] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Human adipose tissue-derived mesenchymal stem cells (hASCs) have the power to differentiate into various cell types including chondrocytes, osteocytes, adipocytes, neurons, cardiomyocytes, and smooth muscle cells. We characterized the functional expression of ion channels after transforming growth factor-β1 (TGF-β1)-induced differentiation of hASCs, providing insights into the differentiation of vascular smooth muscle cells. The treatment of hASCs with TGF-β1 dramatically increased the contraction of a collagen-gel lattice and the expression levels of specific genes for smooth muscle including α-smooth muscle actin, calponin, smooth mucle-myosin heavy chain, smoothelin-B, myocardin, and h-caldesmon. We observed Ca(2+), big-conductance Ca(2+)-activated K(+) (BKCa), and voltage-dependent K(+) (Kv) currents in TGF-β1-induced, differentiated hASCs and not in undifferentiated hASCs. The currents share the characteristics of vascular smooth muscle cells (SMCs). RT-PCR and Western blotting revealed that the L-type (Cav1.2) and T-type (Cav3.1, 3.2, and 3.3), known to be expressed in vascular SMCs, dramatically increased along with the Cavβ1 and Cavβ3 subtypes in TGF-β1-induced, differentiated hASCs. Although the expression-level changes of the β-subtype BKCa channels varied, the major α-subtype BKCa channel (KCa1.1) clearly increased in the TGF-β1-induced, differentiated hASCs. Most of the Kv subtypes, also known to be expressed in vascular SMCs, dramatically increased in the TGF-β1-induced, differentiated hASCs. Our results suggest that TGF-β1 induces the increased expression of vascular SMC-like ion channels and the differentiation of hASCs into contractile vascular SMCs.
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Affiliation(s)
- Won Sun Park
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, Korea
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Hong DH, Choi IW, Son YK, Kim DJ, Na SH, Jung WK, Yoon YW, Park WS. The effect of PI3 kinase inhibitor LY294002 on voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells. Life Sci 2013; 92:916-22. [DOI: 10.1016/j.lfs.2013.03.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 02/21/2013] [Accepted: 03/15/2013] [Indexed: 10/27/2022]
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Chen H, Zhang D, Chao SP, Ren JH, Xu L, Jiang XJ, Wang SM. Comparison of the effects of antiarrhythmic drugs flecainide and verapamil on fKv1.4ΔN channel currents in Xenopus oocytes. Acta Pharmacol Sin 2013. [PMID: 23202797 DOI: 10.1038/aps.2012.157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
AIM To study the effects of Na(+) channel blocker flecainide and L-type Ca(2+) channel antagonist verapamil on the voltage-gated fKv1.4ΔN channel, an N-terminal-deleted mutant of the ferret Kv1.4 K(+) channel. METHODS fKv1.4ΔN channels were stably expressed in Xenopus oocytes. The K(+) currents were recorded using a two-electrode voltage-clamp technique. The drugs were administered through superfusion. RESULTS fKv1.4ΔN currents displayed slow inactivation, with a half-inactivation potential of -41.74 mV and a slow recovery from inactivation (τ=1.90 s at -90 mV). Flecainide and verapamil blocked the currents with IC(50) values of 512.29 ± 56.92 and 260.71 ± 18.50 μmol/L, respectively. The blocking action of the drugs showed opposite voltage-dependence: it was enhanced with depolarization for flecainide, and was attenuated with depolarization for verapamil. Both the drugs exerted state-dependent blockade on fKv1.4ΔN currents, but verapamil showed a stronger use-dependent blockage compared with flecainide. Flecainide accelerated the C-type inactivation rate without affecting the recovery kinetics and the steady-state activation. Verapamil also accelerated the inactivation kinetics of the currents, but unlike flecainide, it affected both the recovery and the steady-state activation, causing slower recovery of fKv1.4ΔN channel and a depolarizing shift of the steady-state activation curve. CONCLUSION The results demonstrate that widely used antiarrhythmic drugs flecainide and verapamil substantially inhibit fKv1.4ΔN channels expressed in Xenopus oocytes by binding to the open state of the channels. Therefore, caution should be taken when these drugs are administered in combination with K(+) channel blockers to treat arrhythmia.
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Hong DH, Son YK, Choi IW, Park WS. The inhibitory effect of curcumin on voltage-dependent K⁺ channels in rabbit coronary arterial smooth muscle cells. Biochem Biophys Res Commun 2012; 430:307-12. [PMID: 23146635 DOI: 10.1016/j.bbrc.2012.10.132] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Accepted: 10/31/2012] [Indexed: 11/19/2022]
Abstract
We investigated the effects of curcumin, the principal active compound of turmeric, on voltage-dependent K(+) (Kv) channels in freshly isolated rabbit coronary arterial smooth muscle cells using the voltage-clamp technique. Curcumin reduced the Kv current in a dose-dependent manner with an apparent K(d) value of 1.07 ± 0.03 μM. Although curcumin did not alter the kinetics of Kv current activation, it predominantly accelerated the decay rate of channel inactivation. The association and dissociation rate constants of curcumin were 1.35 ± 0.05 μM(-1)s(-1) and 1.47 ± 0.17s(-1), respectively. Curcumin did not alter the steady-state activation or inactivation curves. Application of train pulses (1 or 2 Hz) increased curcumin-induced blockade of the Kv current, and the recovery time constant also increased in the presence of curcumin suggesting, that the inhibitory action of Kv currents by curcumin was use-dependent. From these results, we concluded that curcumin inhibited vascular Kv current in a state-, time-, and use-dependent manner.
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Affiliation(s)
- Da Hye Hong
- Department of Physiology, Kangwon National University School of Medicine, 1 Kangwondaehak-gil, Chuncheon 200-701, South Korea
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Son YK, Hong DH, Choi TH, Choi SW, Shin DH, Kim SJ, Jung ID, Park YM, Jung WK, Kim DJ, Choi IW, Park WS. The inhibitory effect of BIM (I) on L-type Ca²⁺ channels in rat ventricular cells. Biochem Biophys Res Commun 2012; 423:110-5. [PMID: 22634012 DOI: 10.1016/j.bbrc.2012.05.091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 05/16/2012] [Indexed: 02/04/2023]
Abstract
We investigated the effect of a specific protein kinase C (PKC) inhibitor, bisindolylmaleimide I [BIM (I)], on L-type Ca(2+) channels in rat ventricular myocytes. BIM (I) alone inhibited the L-type Ca(2+) current in a concentration-dependent manner, with a K(d) value of 3.31 ± 0.25 μM, and a Hill coefficient of 2.34 ± 0.23. Inhibition was immediate after applying BIM (I) in the bath solution and then it partially washed out. The steady-state activation curve was not altered by applying 3μ M BIM (I), but the steady-state inactivation curve shifted to a more negative potential with a change in the slope factor. Other PKC inhibitors, PKC-IP and chelerythrine, showed no significant effects either on the L-type Ca(2+) current or on the inhibitory effect of BIM (I) on the L-type Ca(2+) current. The results suggest that the inhibitory effect of BIM (I) on the L-type Ca(2+) current is independent of the PKC pathway. Thus, our results should be considered in studies using BIM (I) to inhibit PKC activity and ion channel modulation.
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Affiliation(s)
- Youn Kyoung Son
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon, Republic of Korea
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Hong DH, Yang D, Choi IW, Son YK, Jung WK, Kim DJ, Han J, Na SH, Park WS. The T-type Ca2+ Channel Inhibitor Mibefradil Inhibits Voltage-Dependent K+ Channels in Rabbit Coronary Arterial Smooth Muscle Cells. J Pharmacol Sci 2012; 120:196-205. [DOI: 10.1254/jphs.12104fp] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
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Son YK, Hong DH, Kim DJ, Firth AL, Park WS. Direct effect of protein kinase C inhibitors on cardiovascular ion channels. BMB Rep 2011; 44:559-65. [DOI: 10.5483/bmbrep.2011.44.9.559] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Harmati G, Papp F, Szentandrássy N, Bárándi L, Ruzsnavszky F, Horváth B, Bányász T, Magyar J, Panyi G, Krasznai Z, Nánási PP. Effects of the PKC inhibitors chelerythrine and bisindolylmaleimide I (GF 109203X) on delayed rectifier K+ currents. Naunyn Schmiedebergs Arch Pharmacol 2010; 383:141-8. [PMID: 21120453 DOI: 10.1007/s00210-010-0584-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 11/19/2010] [Indexed: 11/30/2022]
Abstract
Protein kinase C (PKC) inhibitors are useful tools for studying PKC-dependent regulation of ion channels. For this purpose, high PKC specificity is a basic requirement excluding any direct interaction between the PKC inhibitor and the ion channel. In the present study, the effects of two frequently applied PKC inhibitors, chelerythine and bisindolylmaleimide I, were studied on the rapid and slow components of the delayed rectifier K(+) current (I(Kr) and I(Ks)) in canine ventricular cardiomyocytes and on the human ether-à-go-go-related gene (hERG) channels expressed in human embryonic kidney (HEK) cells. The whole cell version of the patch clamp technique was used in all experiments. Chelerythrine and bisindolylmaleimide I (both 1 μM) suppressed I(Kr) in canine ventricular cells. This inhibition developed rapidly, suggesting a direct drug-channel interaction. In HEK cells heterologously expressing hERG channels, chelerythrine and bisindolylmaleimide I blocked hERG current in a concentration-dependent manner, having EC(50) values of 0.11 ± 0.01 and 0.76 ± 0.04 μM, respectively. Both chelerythrine and bisindolylmaleimide I strongly modified gating kinetics of hERG--voltage dependence of activation was shifted towards more negative voltages and activation was accelerated. Deactivation was slowed by bisindolylmaleimide I but not by chelerythrine. I(Ks) was not significantly altered by bisindolylmaleimide I and chelerythrine. No significant effect of 0.1 μM bisindolylmaleimide I or 0.1 μM PMA (PKC activator) was observed on I(Kr) arguing against significant contribution of PKC to regulation of I(Kr). It is concluded that neither chelerythrine nor bisindolylmaleimide I is suitable for selective PKC blockade due to their direct blocking actions on the hERG channel.
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Affiliation(s)
- Gábor Harmati
- Department of Physiology, University of Debrecen, 4012, Debrecen, P.O. Box 22, Hungary
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Park WS, Ko JH, Ko EA, Son YK, Hong DH, Jung ID, Park YM, Choi TH, Kim N, Han J. The guanylyl cyclase activator YC-1 directly inhibits the voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells. J Pharmacol Sci 2010; 112:64-72. [PMID: 20093789 DOI: 10.1254/jphs.09228fp] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
We investigated the effects of YC-1, an activator of soluble guanylyl cyclase (sGC), on voltage-dependent K+ (Kv) channels in smooth muscle cells from freshly isolated rabbit coronary arteries by using the whole-cell patch clamp technique. YC-1 inhibited the Kv current in a dose-dependent fashion with an apparent K(d) of 9.67 microM. It accelerated the decay rate of Kv channel inactivation without altering the kinetics of current activation. The rate constants of association and dissociation for YC-1 were 0.36 +/- 0.01 microM(-1) x s(-1) and 3.44 +/- 0.22 s(-1), respectively. YC-1 did not have a significant effect on the steady-state activation and inactivation curves. The recovery time constant from inactivation was decreased in the presence of YC-1, and application of train pulses (1 or 2 Hz) caused a progressive increase in the YC-1 blockade, indicating that YC-1-induced inhibition of Kv currents is use-dependent. Pretreatment with Bay 41-2272 (also a sGC activator), ODQ (a sGC inhibitor), or Rp-8-Br-PET-cGMPs (a protein kinase G inhibitor) did not affect the basal Kv current and also did not significantly alter the inhibitory effect of YC-1. From these results, we suggest that YC-1 directly inhibits the Kv current independently of sGC activation and in a state-, time-, and use-dependent fashion.
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Affiliation(s)
- Won Sun Park
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, FIRST Mitochondrial Research Group, Biomarker Medical Research Center, Inje University, Korea
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Ko EA, Park WS, Firth AL, Kim N, Yuan JXJ, Han J. Pathophysiology of voltage-gated K+ channels in vascular smooth muscle cells: Modulation by protein kinases. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2010; 103:95-101. [DOI: 10.1016/j.pbiomolbio.2009.10.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Accepted: 10/07/2009] [Indexed: 10/20/2022]
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De Marinis YZ, Zhang E, Amisten S, Taneera J, Renström E, Rorsman P, Eliasson L. Enhancement of glucagon secretion in mouse and human pancreatic alpha cells by protein kinase C (PKC) involves intracellular trafficking of PKCalpha and PKCdelta. Diabetologia 2010; 53:717-29. [PMID: 20020096 DOI: 10.1007/s00125-009-1635-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2009] [Accepted: 11/19/2009] [Indexed: 10/20/2022]
Abstract
AIMS/HYPOTHESIS Protein kinase C (PKC) regulates exocytosis in various secretory cells. Here we studied intracellular translocation of the PKC isoenzymes PKCalpha and PKCdelta, and investigated how activation of PKC influences glucagon secretion in mouse and human pancreatic alpha cells. METHODS Glucagon release from intact islets was measured in static incubations, and the amounts released were determined by RIA. Exocytosis was monitored as increases in membrane capacitance using the patch-clamp technique. The expression of genes encoding PKC isoforms was analysed by real-time PCR. Intracellular PKC distribution was assessed by confocal microscopy. RESULTS The PKC activator phorbol 12-myristate 13-acetate (PMA) stimulated glucagon secretion from mouse and human islets about fivefold (p < 0.01). This stimulation was abolished by the PKC inhibitor bisindolylmaleimide (BIM). Whereas PMA potentiated exocytosis more than threefold (p < 0.001), BIM inhibited alpha cell exocytosis by 60% (p < 0.05). In mouse islets, the PKC isoenzymes, PKCalpha and PKCbeta1, were highly abundant, while in human islets PKCeta, PKCepsilon and PKCzeta were the dominant variants. PMA stimulation of human alpha cells correlated with the translocation of PKCalpha and PKCdelta from the cytosol to the cell periphery. In the mouse alpha cells, PKCdelta was similarly affected by PMA, whereas PKCalpha was already present at the cell membrane in the absence of PMA. This association of PKCalpha in alpha cells was principally dependent on Ca(2+) influx through the L-type Ca(2+) channel. CONCLUSIONS/INTERPRETATION PKC activation augments glucagon secretion in mouse and human alpha cells. This effect involves translocation of PKCalpha and PKCdelta to the plasma membrane, culminating in increased Ca(2+)-dependent exocytosis. In addition, we demonstrated that PKCalpha translocation and exocytosis exhibit differential Ca(2+) channel dependence.
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Affiliation(s)
- Y Z De Marinis
- Lund University Diabetes Centre, Department of Clinical Sciences, Clinical Research Centre, Lund University, CRC 91-11, UMAS entrance 72, SE-20502 Malmö, Sweden.
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Ko EA, Park WS, Son YK, Ko JH, Choi TH, Jung ID, Park YM, Hong DH, Kim N, Han J. Calcium Channel Inhibitor, Verapamil, Inhibits the Voltage-Dependent K+ Channels in Rabbit Coronary Smooth Muscle Cells. Biol Pharm Bull 2010; 33:47-52. [DOI: 10.1248/bpb.33.47] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Eun A Ko
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, Biomarker Medical Research Center, FIRST Mitochondrial Research Group, Inje University
| | - Won Sun Park
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, Biomarker Medical Research Center, FIRST Mitochondrial Research Group, Inje University
| | | | - Jae-Hong Ko
- Department of Physiology, Chung-Ang University
| | - Tae-Hoon Choi
- Department of Physical Education, Andong Science College
| | - In Duk Jung
- Department of Microbiology and Immunology and National Research Laboratory of Dendritic Cell Differentiation & Regulation, Medical Research Institute, Pusan National University, College of Medicine
| | - Yeong-Min Park
- Department of Microbiology and Immunology and National Research Laboratory of Dendritic Cell Differentiation & Regulation, Medical Research Institute, Pusan National University, College of Medicine
| | - Da Hye Hong
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, Biomarker Medical Research Center, FIRST Mitochondrial Research Group, Inje University
| | - Nari Kim
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, Biomarker Medical Research Center, FIRST Mitochondrial Research Group, Inje University
| | - Jin Han
- National Research Laboratory for Mitochondrial Signaling, Department of Physiology, College of Medicine, Cardiovascular and Metabolic Disease Center, Biomarker Medical Research Center, FIRST Mitochondrial Research Group, Inje University
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Ko EA, Park WS, Son YK, Kim DH, Kim N, Kim HK, Choi TH, Jung ID, Park YM, Han J. The effect of tyrosine kinase inhibitor genistein on voltage-dependent K+ channels in rabbit coronary arterial smooth muscle cells. Vascul Pharmacol 2008; 50:51-6. [PMID: 18952004 DOI: 10.1016/j.vph.2008.09.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 09/04/2008] [Accepted: 09/25/2008] [Indexed: 11/15/2022]
Abstract
We examined the effect of the protein tyrosine kinase (PTK) inhibitor, genistein on voltage-dependent K+ (Kv) channels in freshly isolated rabbit coronary arterial smooth muscle cells, using whole-cell patch clamp techniques. The amplitude of the Kv current was inhibited by genistein in a dose-dependent manner, with a Kd value of 7.51 microM. Genistein had no effect on the steady-state activation or inactivation of Kv channels. The applications of trains of pulses at 1 or 2 Hz caused a progressive increase in the genistein-blockade. Genistein produced use-dependent inhibition of the Kv currents, consistent with a slow recovery from inactivation in the presence of genistein. Daidzein and genistin, two inactive analogs of genistein, showed an inhibitory effect similar to that of genistein on Kv channels. Moreover, the absence of ATP inside the pipette did not influence the blocking effect of genistein. We suggest that genistein directly inhibited the Kv current, independently of PTK inhibition.
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Affiliation(s)
- Eun A Ko
- National Research Laboratory for Mitochondrial Signaling, FIRST Mitochondria Research Group, Department of Physiology and Biophysics, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Republic of Korea
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Ko EA, Han J, Jung ID, Park WS. Physiological roles of K + channels in vascular smooth muscle cells. J Smooth Muscle Res 2008; 44:65-81. [DOI: 10.1540/jsmr.44.65] [Citation(s) in RCA: 317] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Eun A Ko
- National Research Laboratory for Mitochondrial Signaling, FIRST Mitochondria Research Group, Department of Physiology and Biophysics, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University
| | - Jin Han
- National Research Laboratory for Mitochondrial Signaling, FIRST Mitochondria Research Group, Department of Physiology and Biophysics, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University
| | - In Duk Jung
- Department of Microbiology and Immunology and National Research Laboratory of Dentritic, Cell Differentiation and Regulation, Pusan National University, College of Medicine
| | - Won Sun Park
- National Research Laboratory for Mitochondrial Signaling, FIRST Mitochondria Research Group, Department of Physiology and Biophysics, College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University
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Ko JH, Park WS, Kim SJ, Earm YE. Slowing of the inactivation of voltage-dependent sodium channels by staurosporine, the protein kinase C inhibitor, in rabbit atrial myocytes. Eur J Pharmacol 2006; 534:48-54. [PMID: 16488408 DOI: 10.1016/j.ejphar.2006.01.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2005] [Revised: 01/09/2006] [Accepted: 01/11/2006] [Indexed: 11/25/2022]
Abstract
In this study, the effect of staurosporine, a potent protein kinase C (PKC) inhibitor, on Na+ current (I(Na)) was examined by whole-cell patch recording in rabbit atrial myocytes. The most prominent staurosporine effect was a slowing of I(Na) inactivation and 1 microM staurosporine reduced amplitude of I(Na) about 33%. Staurosporine decreased I(Na) at all potentials and slowed the I(Na) inactivation in a dose-dependent manner, with a Kd value of 1.107+/-0.162 microM. Staurosporine did not change the recovery kinetics and show use dependence. However, the activation and the steady-state inactivation curves were shifted toward more negative potentials (-5.5 and -5.1 mV, respectively). Two other PKC inhibitors, GF 109203X (1 microM) and chelerythrine (3 microM), did not show a slowing effect on I(Na) inactivation. In conclusion, our results indicate that the slowing of I(Na) inactivation by staurosporine seems not to be through blockade of PKC rather to act directly on the Na+ channels, and the direct blocking effects of staurosporine on the Na+ channel should be taken into consideration when staurosporine is used in functional studies of ion channel modulation by protein phosphorylation.
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Affiliation(s)
- Jae Hong Ko
- Department of Physiology and National Research Laboratory for Cellular Signaling, Seoul National University College of Medicine, Seoul 110-799, South Korea
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Son YK, Park WS, Kim SJ, Earm YE, Kim N, Youm JB, Warda M, Kim E, Han J. Direct inhibition of a PKA inhibitor, H-89 on KV channels in rabbit coronary arterial smooth muscle cells. Biochem Biophys Res Commun 2006; 341:931-7. [PMID: 16455049 DOI: 10.1016/j.bbrc.2006.01.053] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2006] [Accepted: 01/17/2006] [Indexed: 11/20/2022]
Abstract
We examined the effects of the protein kinase A (PKA) inhibitor H-89 on voltage-dependent K(+) (K(V)) currents in freshly isolated rabbit coronary arterial smooth muscle cells, using a whole-cell patch clamp technique. H-89 inhibited the K(V) current in a concentration-dependent manner, with a K(d) value of 1.02 microM. However, the PKA inhibitors KT 5720 and Rp-8-CPT-cAMPS did not significantly alter the K(V) current or the inhibitory effects of H-89 on the K(V) current. Moreover, H-85, a structurally similar but inactive analog of H-89, showed similar inhibitory effects on the K(V) channel. H-89 had no effect on the voltage-dependency of activation or inactivation, or on recovery kinetics. These results suggest that in rabbit coronary arterial smooth muscle cells, H-89 inhibits the K(V) current directly by blocking the pore cavity, an effect independent of PKA inhibition.
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Affiliation(s)
- Youn Kyoung Son
- Department of Physiology and National Research Laboratory for Cellular Signaling, Seoul National University College of Medicine, Seoul, Republic of Korea
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Park WS, Kim N, Youm JB, Warda M, Ko JH, Kim SJ, Earm YE, Han J. Angiotensin II inhibits inward rectifier K+ channels in rabbit coronary arterial smooth muscle cells through protein kinase Calpha. Biochem Biophys Res Commun 2006; 341:728-35. [PMID: 16442501 DOI: 10.1016/j.bbrc.2006.01.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2006] [Accepted: 01/10/2006] [Indexed: 11/25/2022]
Abstract
We investigated the effects of the vasoconstrictor angiotensin (Ang) II on the whole cell inward rectifier K(+) (Kir) current enzymatically isolated from small-diameter (<100 microm) coronary arterial smooth muscle cells (CASMCs). Ang II inhibited the Kir current in a dose-dependent manner (half inhibition value: 154 nM). Pretreatment with phospholipase C inhibitor and protein kinase C (PKC) inhibitors prevented the Ang II-induced inhibition of the Kir current. The PKC activator reduced the Kir currents. The inhibitory effect of Ang II was reduced by intracellular and extracellular Ca(2+) free condition and by Gö6976, which inhibits Ca(2+)-dependent PKC isoforms alpha and beta. However, the inhibitory effect of Ang II was unaffected by a peptide that selectively inhibits the translocation of the epsilon isoform of PKC. Western blot analysis confirmed that PKCalpha, and not PKCbeta, was expressed in small-diameter CASMCs. The Ang II type 1 (AT(1))-receptor antagonist CV-11974 prevented the Ang II-induced inhibition of the Kir current. From these results, we conclude that Ang II inhibits Kir channels through AT(1) receptors by the activation of PKCalpha.
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MESH Headings
- Angiotensin II/pharmacology
- Animals
- Calcium/chemistry
- Calcium/metabolism
- Cations, Divalent/chemistry
- Cells, Cultured
- Electrophysiology
- Female
- Isoenzymes/antagonists & inhibitors
- Isoenzymes/classification
- Isoenzymes/metabolism
- Male
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Patch-Clamp Techniques
- Potassium Channels, Inwardly Rectifying/metabolism
- Protein Kinase C-alpha/antagonists & inhibitors
- Protein Kinase C-alpha/metabolism
- Protein Kinase Inhibitors/pharmacology
- Rabbits
- Receptor, Angiotensin, Type 1/metabolism
- Type C Phospholipases/antagonists & inhibitors
- Type C Phospholipases/metabolism
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Affiliation(s)
- Won Sun Park
- Mitochondrial Signaling Laboratory, Department of Physiology and Biophysics, College of Medicine, Biohealth Products Research Center, Cardiovascular and Metabolic Disease Center, Inje University, Busan, Republic of Korea
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