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Barenco-Marins TS, Seara FAC, Ponte CG, Nascimento JHM. Pulmonary Circulation Under Pressure: Pathophysiological and Therapeutic Implications of BK Channel. Cardiovasc Drugs Ther 2023:10.1007/s10557-023-07503-7. [PMID: 37624526 DOI: 10.1007/s10557-023-07503-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/10/2023] [Indexed: 08/26/2023]
Abstract
The large-conductance Ca2+-activated K+ (BK) channel is widely expressed in the pulmonary blood vessels and plays a significant role in regulating pulmonary vascular tonus. It opens under membrane depolarization, increased intracellular Ca+2 concentration, and chronic hypoxia, resulting in massive K+ efflux, membrane hyperpolarization, decreased L-type Ca+2 channel opening, and smooth muscle relaxation. Several reports have demonstrated an association between BK channel dysfunction and pulmonary hypertension (PH) development. Decreased BK channel subunit expression and impaired regulation by paracrine hormones result in decreased BK channel opening, increased pulmonary vascular resistance, and pulmonary arterial pressure being the cornerstone of PH. The resulting right ventricular pressure overload ultimately leads to ventricular remodeling and failure. Therefore, it is unsurprising that the BK channel has arisen as a potential target for treating PH. Recently, a series of selective, synthetic BK channel agonists have proven effective in attenuating the pathophysiological progression of PH without adverse effects in animal models.
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Affiliation(s)
- Thais S Barenco-Marins
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Programa de Pós-Graduação Em Cardiologia, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Fernando A C Seara
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
- Instituto de Ciências Biológicas E da Saúde, Universidade Federal Rural Do Rio de Janeiro, Seropédica, RJ, Brazil.
- Programa de Pós-Graduação Multicêntrico Em Ciências Fisiológicas, Sociedade Brasileira de Fisiologia, São Paulo, Brazil.
| | - Cristiano G Ponte
- Instituto Federal de Educação, Ciências e Tecnologia do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Jose H M Nascimento
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Programa de Pós-Graduação Em Cardiologia, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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2
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Här K, Lysenko NN, Dimitrova D, Schlüter T, Zavaritskaya O, Kamkin AG, Mladenov M, Grisk O, Köhler R, Gagov H, Schubert R. Kv2.1 Channels Prevent Vasomotion and Safeguard Myogenic Reactivity in Rat Small Superior Cerebellar Arteries. Cells 2023; 12:1989. [PMID: 37566068 PMCID: PMC10416909 DOI: 10.3390/cells12151989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 07/27/2023] [Accepted: 07/29/2023] [Indexed: 08/12/2023] Open
Abstract
Vascular smooth muscle voltage-gated potassium (Kv) channels have been proposed to contribute to myogenic autoregulation. Surprisingly, in initial experiments, we observed that the Kv2 channel inhibitor stromatoxin induced vasomotion without affecting myogenic tone. Thus, we tested the hypothesis that Kv2 channels contribute to myogenic autoregulation by fine-tuning the myogenic response. Expression of Kv2 channel mRNA was determined using real-time PCR and 'multiplex' single-cell RT-PCR. Potassium currents were measured using the patch-clamp technique. Contractile responses of intact arteries were studied using isobaric myography. Expression of Kv2.1 but not Kv2.2 channels was detected in intact rat superior cerebellar arteries and in single smooth muscle cells. Stromatoxin, a high-affinity inhibitor of Kv2 channels, reduced smooth muscle Kv currents by 61% at saturating concentrations (EC50 36 nmol/L). Further, stromatoxin (10-100 nmol/L) induced pronounced vasomotion in 48% of the vessels studied. In vessels not exhibiting vasomotion, stromatoxin did not affect myogenic reactivity. Notably, in vessels exhibiting stromatoxin-induced vasomotion, pressure increases evoked two effects: First, they facilitated the occurrence of random vasodilations and/or vasoconstrictions, disturbing the myogenic response (24% of the vessels). Second, they modified the vasomotion by decreasing its amplitude and increasing its frequency, thereby destabilizing myogenic tone (76% of the vessels). Our study demonstrates that (i) Kv2.1 channels are the predominantly expressed Kv channels in smooth muscle cells of rat superior cerebellar arteries, and (ii) Kv2.1 channels provide a novel type of negative feedback mechanism in myogenic autoregulation by preventing vasomotion and thereby safeguarding the myogenic response.
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Affiliation(s)
- Kristina Här
- European Center of Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Natalia N. Lysenko
- European Center of Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
- Department of Physiology, N. I. Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Daniela Dimitrova
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria
| | - Torsten Schlüter
- Institute of Physiology, Universitätsmedizin Greifswald, 17475 Greifswald, Germany
| | - Olga Zavaritskaya
- European Center of Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
| | - Andrej G. Kamkin
- Department of Physiology, N. I. Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Mitko Mladenov
- Department of Physiology, N. I. Pirogov Russian National Research Medical University, 117997 Moscow, Russia
- Institute of Biology, Faculty of Natural Sciences and Mathematics, University of Ss. Cyril and Methodius, 1000 Skopje, North Macedonia
| | - Olaf Grisk
- Institute of Physiology, Brandenburg Medical School Theodor Fontane, 16816 Neuruppin, Germany
| | - Ralf Köhler
- ARAID-IACS, UIT University Hospital Miguel Servet, 50009 Zaragoza, Spain
| | - Hristo Gagov
- Department of Animal and Human Physiology, Faculty of Biology, Sofia University ‘St. Kliment Ohridski’, 1164 Sofia, Bulgaria
| | - Rudolf Schubert
- European Center of Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, 68167 Mannheim, Germany
- Physiology, Institute of Theoretical Medicine, Faculty of Medicine, University of Augsburg, Universitätsstrasse 2, 86159 Augsburg, Germany
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3
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Villegas-Esguevillas M, Cho S, Vera-Zambrano A, Kwon JW, Barreira B, Telli G, Navarro-Dorado J, Morales-Cano D, de Olaiz B, Moreno L, Greenwood I, Pérez-Vizcaíno F, Kim SJ, Climent B, Cogolludo A. The novel K V7 channel activator URO-K10 exerts enhanced pulmonary vascular effects independent of the KCNE4 regulatory subunit. Biomed Pharmacother 2023; 164:114952. [PMID: 37295249 DOI: 10.1016/j.biopha.2023.114952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 05/23/2023] [Accepted: 05/27/2023] [Indexed: 06/12/2023] Open
Abstract
KV7 channels exert a pivotal role regulating vascular tone in several vascular beds. In this context, KV7 channel agonists represent an attractive strategy for the treatment of pulmonary arterial hypertension (PAH). Therefore, in this study, we have explored the pulmonary vascular effects of the novel KV7 channel agonist URO-K10. Consequently, the vasodilator and electrophysiological effects of URO-K10 were tested in rat and human pulmonary arteries (PA) and PA smooth muscle cells (PASMC) using myography and patch-clamp techniques. Protein expression was also determined by Western blot. Morpholino-induced knockdown of KCNE4 was assessed in isolated PA. PASMC proliferation was measured by BrdU incorporation assay. In summary, our data show that URO-K10 is a more effective relaxant of PA than the classical KV7 activators retigabine and flupirtine. URO-K10 enhanced KV currents in PASMC and its electrophysiological and relaxant effects were inhibited by the KV7 channel blocker XE991. The effects of URO-K10 were confirmed in human PA. URO-K10 also exhibited antiproliferative effects in human PASMC. Unlike retigabine and flupirtine, URO-K10-induced pulmonary vasodilation was not affected by morpholino-induced knockdown of the KCNE4 regulatory subunit. Noteworthy, the pulmonary vasodilator efficacy of this compound was considerably increased under conditions mimicking the ionic remodelling (as an in vitro model of PAH) and in PA from monocrotaline-induced pulmonary hypertensive rats. Taking all together, URO-K10 behaves as a KCNE4-independent KV7 channel activator with much increased pulmonary vascular effects compared to classical KV7 channel activators. Our study identifies a promising new drug in the context of PAH.
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Affiliation(s)
- Marta Villegas-Esguevillas
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Institute of Health Research Gregorio Marañón (IiSGM), Madrid, Spain; CIBER Enfermedades Respiratorias (Ciberes), Madrid, Spain
| | - Suhan Cho
- Department of Physiology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Alba Vera-Zambrano
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Institute of Health Research Gregorio Marañón (IiSGM), Madrid, Spain; CIBER Enfermedades Respiratorias (Ciberes), Madrid, Spain
| | - Jae Won Kwon
- Institute of Health Research Gregorio Marañón (IiSGM), Madrid, Spain
| | - Bianca Barreira
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Institute of Health Research Gregorio Marañón (IiSGM), Madrid, Spain; CIBER Enfermedades Respiratorias (Ciberes), Madrid, Spain
| | - Göcken Telli
- Department of Pharmacology, Faculty of Pharmacy, Hacettepe University, Ankara, Turkey
| | - Jorge Navarro-Dorado
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
| | - Daniel Morales-Cano
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Institute of Health Research Gregorio Marañón (IiSGM), Madrid, Spain; CIBER Enfermedades Respiratorias (Ciberes), Madrid, Spain
| | - Beatriz de Olaiz
- Department of Thoracic Surgery, Hospital Universitario de Getafe, Getafe, Spain
| | - Laura Moreno
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Institute of Health Research Gregorio Marañón (IiSGM), Madrid, Spain; CIBER Enfermedades Respiratorias (Ciberes), Madrid, Spain
| | - Iain Greenwood
- Vascular Biology Research Centre, Institute of Molecular and Clinical Sciences, St George's University of London, United Kingdom
| | - Francisco Pérez-Vizcaíno
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Institute of Health Research Gregorio Marañón (IiSGM), Madrid, Spain; CIBER Enfermedades Respiratorias (Ciberes), Madrid, Spain
| | - Sung Joon Kim
- Department of Physiology, College of Medicine, Seoul National University, Seoul, South Korea
| | - Belén Climent
- Departamento de Fisiología, Facultad de Farmacia, Universidad Complutense, Madrid, Spain.
| | - Angel Cogolludo
- Departamento de Farmacología, Facultad de Medicina, Universidad Complutense, Madrid, Spain; Institute of Health Research Gregorio Marañón (IiSGM), Madrid, Spain; CIBER Enfermedades Respiratorias (Ciberes), Madrid, Spain
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4
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Gao J, Yin H, Dong Y, Wang X, Liu Y, Wang K. A Novel Role of Uricosuric Agent Benzbromarone in BK Channel Activation and Reduction of Airway Smooth Muscle Contraction. Mol Pharmacol 2023; 103:241-254. [PMID: 36669879 DOI: 10.1124/molpharm.122.000638] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/28/2022] [Accepted: 12/19/2022] [Indexed: 01/21/2023] Open
Abstract
The uricosuric drug benzbromarone, widely used for treatment of gout, hyperpolarizes the membrane potential of airway smooth muscle cells, but how it works remains unknown. Here we show a novel role of benzbromarone in activation of large conductance calcium-activated K+ channels. Benzbromarone results in dose-dependent activation of macroscopic big potassium (BK) currents about 1.7- to 14.5-fold with an EC50 of 111 μM and shifts the voltage-dependent channel activation to a more hyperpolarizing direction about 10 to 54 mV in whole-cell patch clamp recordings. In single-channel recordings, benzbromarone decreases single BKα channel closed dwell time and increases the channel open probability. Coexpressing β1 subunit also enhances BK activation by benzbromarone with an EC50 of 67 μM and a leftward shift of conductance-voltage (G-V) curve about 44 to 138 mV. Site-directed mutagenesis reveals that a motif of three amino acids 329RKK331 in the cytoplasmic linker between S6 and C-terminal regulator of potassium conductance (RCK) gating ring mediates the pharmacological activation of BK channels by benzbromarone. Further ex vivo assay shows that benzbromarone causes reduction of tracheal strip contraction. Taken together, our findings demonstrate that uricosuric benzbromarone activates BK channels through molecular mechanism of action involving the channel RKK motif of S6-RCK linker. Pharmacological activation of BK channel by benzbromarone causes reduction of tracheal strip contraction, holding a repurposing potential for asthma and pulmonary arterial hypertension or BK channelopathies. SIGNIFICANCE STATEMENT: We describe a novel role of uricosuric agent benzbromarone in big potassium (BK) channel activation and relaxation of airway smooth muscle contraction. In this study, we find that benzbromarone is an activator of the large-conductance Ca2+- and voltage-activated K+ channel (BK channel), which serves numerous cellular functions, including control of smooth muscle contraction. Pharmacological activation of BK channel by the FDA-approved drug benzbromarone may hold repurposing potential for treatment of asthma and pulmonary arterial hypertension or BK channelopathies.
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Affiliation(s)
- Jian Gao
- Department of Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, China (J.G., X.W.); Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (H.Y., Y.D., Y.L., K.W.); and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
| | - Hao Yin
- Department of Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, China (J.G., X.W.); Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (H.Y., Y.D., Y.L., K.W.); and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
| | - Yanqun Dong
- Department of Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, China (J.G., X.W.); Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (H.Y., Y.D., Y.L., K.W.); and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
| | - Xintong Wang
- Department of Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, China (J.G., X.W.); Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (H.Y., Y.D., Y.L., K.W.); and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
| | - Yani Liu
- Department of Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, China (J.G., X.W.); Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (H.Y., Y.D., Y.L., K.W.); and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
| | - KeWei Wang
- Department of Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, China (J.G., X.W.); Department of Pharmacology, School of Pharmacy, Qingdao University Medical College, Qingdao, China (H.Y., Y.D., Y.L., K.W.); and Institute of Innovative Drugs, Qingdao University, Qingdao, China (Y.L., K.W.)
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5
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Schubert R, Gaynullina D, Shvetsova A, Tarasova OS. Myography of isolated blood vessels: Considerations for experimental design and combination with supplementary techniques. Front Physiol 2023; 14:1176748. [PMID: 37168231 PMCID: PMC10165122 DOI: 10.3389/fphys.2023.1176748] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 04/11/2023] [Indexed: 05/13/2023] Open
Abstract
The study of the mechanisms of regulation of vascular tone is an urgent task of modern science, since diseases of the cardiovascular system remain the main cause of reduction in the quality of life and mortality of the population. Myography (isometric and isobaric) of isolated blood vessels is one of the most physiologically relevant approaches to study the function of cells in the vessel wall. On the one hand, cell-cell interactions as well as mechanical stretch of the vessel wall remain preserved in myography studies, in contrast to studies on isolated cells, e.g., cell culture. On the other hand, in vitro studies in isolated vessels allow control of numerous parameters that are difficult to control in vivo. The aim of this review was to 1) discuss the specifics of experimental design and interpretation of data obtained by myography and 2) highlight the importance of the combined use of myography with various complementary techniques necessary for a deep understanding of vascular physiology.
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Affiliation(s)
- Rudolf Schubert
- Physiology, Institute of Theoretical Medicine, Faculty of Medicine, University of Augsburg, Augsburg, Germany
- *Correspondence: Rudolf Schubert,
| | - Dina Gaynullina
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | | | - Olga S. Tarasova
- Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
- State Research Center of the Russian Federation, Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
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6
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Nagasawa Y, Shimoda A, Shiratori H, Morishita T, Sakuma K, Chiba T, Cao X, Kawakami S, Aimoto M, Miyazaki C, Sato S, Takahashi M, Shimizu K, Shirai K, Takahara A. Analysis of effects of acute hypovolemia on arterial stiffness in rabbits monitored with cardio-ankle vascular index. J Pharmacol Sci 2022; 148:331-336. [DOI: 10.1016/j.jphs.2022.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/06/2022] [Accepted: 01/17/2022] [Indexed: 12/01/2022] Open
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7
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Wang Y, Yildiz F, Struve A, Kassmann M, Markó L, Köhler MB, Luft FC, Gollasch M, Tsvetkov D. Aging Affects K V7 Channels and Perivascular Adipose Tissue-Mediated Vascular Tone. Front Physiol 2021; 12:749709. [PMID: 34899382 PMCID: PMC8662361 DOI: 10.3389/fphys.2021.749709] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 10/26/2021] [Indexed: 12/04/2022] Open
Abstract
Aging is an independent risk factor for hypertension, cardiovascular morbidity, and mortality. However, detailed mechanisms linking aging to cardiovascular disease are unclear. We studied the aging effects on the role of perivascular adipose tissue and downstream vasoconstriction targets, voltage-dependent KV7 channels, and their pharmacological modulators (flupirtine, retigabine, QO58, and QO58-lysine) in a murine model. We assessed vascular function of young and old mesenteric arteries in vitro using wire myography and membrane potential measurements with sharp electrodes. We also performed bulk RNA sequencing and quantitative reverse transcription-polymerase chain reaction tests in mesenteric arteries and perivascular adipose tissue to elucidate molecular underpinnings of age-related phenotypes. Results revealed impaired perivascular adipose tissue-mediated control of vascular tone particularly via KV7.3–5 channels with increased age through metabolic and inflammatory processes and release of perivascular adipose tissue-derived relaxation factors. Moreover, QO58 was identified as novel pharmacological vasodilator to activate XE991-sensitive KCNQ channels in old mesenteric arteries. Our data suggest that targeting inflammation and metabolism in perivascular adipose tissue could represent novel approaches to restore vascular function during aging. Furthermore, KV7.3–5 channels represent a promising target in cardiovascular aging.
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Affiliation(s)
- Yibin Wang
- Charité Medical Faculty, Experimental and Clinical Research Center (ECRC), Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Fatima Yildiz
- Faculty of Medicine, Istanbul Medeniyet University, Istanbul, Turkey
| | - Andrey Struve
- Department of Ear, Throat and Nose Diseases, I.M. Sechenov First Moscow State Medical University, Moscow, Russia
| | - Mario Kassmann
- Charité Medical Faculty, Experimental and Clinical Research Center (ECRC), Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.,Department of Internal Medicine and Geriatrics, University Medicine Greifswald, Greifswald, Germany
| | - Lajos Markó
- Charité Medical Faculty, Experimental and Clinical Research Center (ECRC), Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - May-Britt Köhler
- Charité Medical Faculty, Experimental and Clinical Research Center (ECRC), Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Friedrich C Luft
- Charité Medical Faculty, Experimental and Clinical Research Center (ECRC), Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Maik Gollasch
- Charité Medical Faculty, Experimental and Clinical Research Center (ECRC), Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.,Department of Internal Medicine and Geriatrics, University Medicine Greifswald, Greifswald, Germany
| | - Dmitry Tsvetkov
- Charité Medical Faculty, Experimental and Clinical Research Center (ECRC), Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany.,Department of Internal Medicine and Geriatrics, University Medicine Greifswald, Greifswald, Germany
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8
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Zhang D, Krause BM, Schmalz HG, Wohlfart P, Yard BA, Schubert R. ET-CORM Mediated Vasorelaxation of Small Mesenteric Arteries: Involvement of Kv7 Potassium Channels. Front Pharmacol 2021; 12:702392. [PMID: 34552483 PMCID: PMC8451721 DOI: 10.3389/fphar.2021.702392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 08/24/2021] [Indexed: 11/18/2022] Open
Abstract
Although the vasoactive properties of carbon monoxide (CO) have been extensively studied, the mechanism by which CO mediates vasodilation is not completely understood. Through-out published studies on CO mediated vasodilation there is inconsistency on the type of K+-channels that are activated by CO releasing molecules (CORMs). Since the vasorelaxation properties of enzyme triggered CORMs (ET-CORMs) have not been studied thus far, we first assessed if ET-CORMs can mediate vasodilation of small mesenteric arteries and subsequently addressed the role of soluble guanylate cyclase (sGC) and that of K-channels herein. To this end, 3 different types of ET-CORMs that either contain acetate (rac-1 and rac-4) or pivalate (rac-8) as ester functionality, were tested ex vivo on methoxamine pre-contracted small rat mesenteric arteries in a myograph setting. Pre-contracted mesenteric arteries strongly dilated upon treatment with both types of acetate containing ET-CORMs (rac-1 and rac-4), while treatment with the pivalate containing ET-CORM (rac-8) resulted in no vasodilation. Pre-treatment of mesenteric arteries with the sGC inhibitor ODQ abolished rac-4 mediated vasodilation, similar as for the known sGC activator SNP. Likewise, rac-4 mediated vasodilation did not occur in KCL pretreated mesenteric arteries. Although mesenteric arteries abundantly expressed a variety of K+-channels only Kv7 channels were found to be of functional relevance for rac-4 mediated vasodilation. In conclusion the current results identified Kv7 channels as the main channel by which rac-4 mediates vasodilation. In keeping with the central role of Kv7 in the control of vascular tone and peripheral resistance these promising ex-vivo data warrant further in vivo studies, particularly in models of primary hypertension or cardiac diseases, to assess the potential use of ET-CORMs in these diseases.
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Affiliation(s)
- Danfeng Zhang
- Department of Nephrology, Endocrinology and Rheumatology, Fifth Medical Department of Medicine, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.,Department of Nephrology, the Second Hospital of Anhui Medical University, Hefei, China
| | | | | | - Paulus Wohlfart
- Diabetes Research, Sanofi Aventis Deutschland GmbH, Frankfurt, Germany
| | - Benito A Yard
- Department of Nephrology, Endocrinology and Rheumatology, Fifth Medical Department of Medicine, Medical Faculty Mannheim, University of Heidelberg, Mannheim, Germany.,European Center of Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Frankfurt, Germany
| | - Rudolf Schubert
- European Center of Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Frankfurt, Germany.,Physiology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany
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9
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Ivanova IV, Melnyk MI, Dryn DO, Prokhorov VV, Zholos AV, Soloviev AI. Electrophysiological characterization of the activating action of a novel liposomal nitric oxide carrier on Maxi-K channels in pulmonary artery smooth muscle cells. J Liposome Res 2021; 31:399-408. [PMID: 33319630 DOI: 10.1080/08982104.2020.1863424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The aim of this study was to establish the mechanisms of action of a novel liposomal nitric oxide (NO) carrier on large-conductance Ca2+-activated channels (BKCa or Maxi-K) expressed in vascular smooth muscle cells (VSMCs) isolated from the rat main pulmonary artery (MPA). Experimental design comprised of both whole-cell and cell-attached single-channel recordings using the patch-clamp techniques. The liposomal form of NO, Lip(NO), increased whole-cell outward K+ currents in a dose dependent manner while shifting the activation curve negatively by about 50 mV with respect to unstimulated cells with the EC50 value of 0.55 ± 0.17 µM. At the single channel level, Lip(NO) increased the probability of the open state (Po) of Maxi-K channels from 0.0020 ± 0.0008 to 0.74 ± 0.02 with half-maximal activation occurring at 4.91 ± 0.01 μM, while sub-maximal activation was achieved at 10-5 M Lip(NO). Channel activation was mainly due to significant decrease in the mean closed dwell time (about 500-fold), rather than an increase in the mean open dwell time, which was comparatively modest (about twofold). There was also a slight decrease in the amplitude of the elementary Maxi-K currents (approximately 15%) accompanied by an increase in current noise, which might indicate some non-specific effects of Lip(NO) on the plasma membrane itself and/or on the phospholipids environment of the channels. In conclusion, the activating action of Lip(NO) on the Maxi-K channel is due to the destabilization of the closed conformation of the channel protein, which causes its more frequent openings and, accordingly, increases the probability of channel transition to its open state.
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Affiliation(s)
- Irina V Ivanova
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine
| | - Mariia I Melnyk
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine.,A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine.,Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Dariia O Dryn
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine.,A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine.,Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | | | - Alexander V Zholos
- Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Anatoly I Soloviev
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine
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10
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Abstract
Potassium channels are the most diverse and ubiquitous family of ion channels found in cells. The Ca2+ and voltage gated members form a subfamily that play a variety of roles in both excitable and non-excitable cells and are further classified on the basis of their single channel conductance to form the small conductance (SK), intermediate conductance (IK) and big conductance (BK) K+ channels.In this chapter, we will focus on the mechanisms underlying the gating of BK channels, whose function is modified in different tissues by different splice variants as well as the expanding array of regulatory accessory subunits including β, γ and LINGO subunits. We will examine how BK channels are modified by these regulatory subunits and describe how the channel gating is altered by voltage and Ca2+ whilst setting this in context with the recently published structures of the BK channel. Finally, we will discuss how BK and other calcium-activated channels are modulated by novel ion channel modulators and describe some of the challenges associated with trying to develop compounds with sufficient efficacy, potency and selectivity to be of therapeutic benefit.
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Ma D, Gaynullina D, Schmidt N, Mladenov M, Schubert R. The Functional Availability of Arterial Kv7 Channels Is Suppressed Considerably by Large-Conductance Calcium-Activated Potassium Channels in 2- to 3-Month Old but Not in 10- to 15-Day Old Rats. Front Physiol 2020; 11:597395. [PMID: 33384611 PMCID: PMC7770149 DOI: 10.3389/fphys.2020.597395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 11/24/2020] [Indexed: 01/26/2023] Open
Abstract
Background Voltage-gated potassium (Kv) channels, especially Kv7 channels, are major potassium channels identified in vascular smooth muscle cells with a great, albeit differential functional impact in various vessels. Vascular smooth muscle Kv7 channels always coexist with other K channels, in particular with BK channels. BK channels differ in the extent to which they influence vascular contractility. Whether this difference also causes the variability in the functional impact of Kv7 channels is unknown. Therefore, this study addressed the hypothesis that the functional impact of Kv7 channels depends on BK channels. Experimental Approach Experiments were performed on young and adult rat gracilis and saphenous arteries using real-time PCR as well as pressure and wire myography. Key Results Several subfamily members of Kv7 (KCNQ) and BK channels were expressed in saphenous and gracilis arteries: the highest expression was observed for BKα, BKβ1 and KCNQ4. Arterial contractility was assessed with methoxamine-induced contractions and pressure-induced myogenic responses. In vessels of adult rats, inhibition of Kv7 channels or BK channels by XE991 or IBTX, respectively enhanced arterial contractility to a similar degree, whereas activation of Kv7 channels or BK channels by retigabine or NS19504, respectively reduced arterial contractility to a similar degree. Further, IBTX increased both the contractile effect of XE991 and the anticontractile effect of retigabine, whereas NS19504 reduced the effect of retigabine and impaired the effect of XE991. In vessels of young rats, inhibition of Kv7 channels by XE991 enhanced arterial contractility much stronger than inhibition of BK channels by IBTX, whereas activation of Kv7 by retigabine reduced arterial contractility to a greater extent than activation of BK channels by NS19504. Further, IBTX increased the anticontractile effect of retigabine but not the contractile effect of XE991, whereas NS19504 reduced the effect of retigabine and impaired the effect of XE991. Conclusion Kv7 and BK channels are expressed in young and adult rat arteries and function as negative feedback modulators in the regulation of contractility of these arteries. Importantly, BK channels govern the extent of functional impact of Kv7 channels. This effect depends on the relationship between the functional activities of BK and Kv7 channels.
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Affiliation(s)
- Dongyu Ma
- European Center for Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Department of Cardiology, The First Affiliated Hospital of Anhui Medical University, Anhui, China
| | - Dina Gaynullina
- European Center for Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Nadine Schmidt
- European Center for Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Mitko Mladenov
- Department of Fundamental and Applied Physiology, Russian National Research Medical University, Moscow, Russia.,Institute of Biology, Faculty of Natural Sciences and Mathematics, Ss Cyril and Methodius University, Skopje, Macedonia
| | - Rudolf Schubert
- European Center for Angioscience (ECAS), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Department of Physiology, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany
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12
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Malysz J, Petkov GV. Detrusor Smooth Muscle K V7 Channels: Emerging New Regulators of Urinary Bladder Function. Front Physiol 2020; 11:1004. [PMID: 33041840 PMCID: PMC7526500 DOI: 10.3389/fphys.2020.01004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 07/23/2020] [Indexed: 01/21/2023] Open
Abstract
Relaxation and contraction of the urinary bladder smooth muscle, also known as the detrusor smooth muscle (DSM), facilitate the micturition cycle. DSM contractility depends on cell excitability, which is established by the synchronized activity of multiple diverse ion channels. K+ channels, the largest family of channels, control DSM excitability by maintaining the resting membrane potential and shaping the action potentials that cause the phasic contractions. Among the members of the voltage-gated K+ (KV) channel superfamily, KV type 7 (KV7) channels - KV7.1-KV7.5 members encoded by KCNQ1-KCNQ5 genes - have been recently identified as functional regulators in various cell types including vascular, cardiac, and neuronal cells. Their regulatory roles in DSM, however, are just now emerging and remain to be elucidated. To address this gap, our research group has initiated the systematic investigation of human DSM KV7 channels in collaboration with clinical urologists. In this comprehensive review, we summarize the current understanding of DSM Kv7 channels and highlight recent discoveries in the field. We describe KV7 channel expression profiles at the mRNA and protein levels, and further elaborate on functional effects of KV7 channel selective modulators on DSM excitability, contractility, and intracellular Ca2+ dynamics in animal species along with in vivo studies and the limited data on human DSM. Within each topic, we highlight the main observations, current gaps in knowledge, and most pressing questions and concepts in need of resolution. We emphasize the lack of systematic studies on human DSM KV7 channels that are now actively ongoing in our laboratory.
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Affiliation(s)
- John Malysz
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Georgi V. Petkov
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN, United States
- Department of Pharmacology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States
- Department of Urology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, United States
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13
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Zavaritskaya O, Dudem S, Ma D, Rabab KE, Albrecht S, Tsvetkov D, Kassmann M, Thornbury K, Mladenov M, Kammermeier C, Sergeant G, Mullins N, Wouappi O, Wurm H, Kannt A, Gollasch M, Hollywood MA, Schubert R. Vasodilation of rat skeletal muscle arteries by the novel BK channel opener GoSlo is mediated by the simultaneous activation of BK and K v 7 channels. Br J Pharmacol 2020; 177:1164-1186. [PMID: 31658366 PMCID: PMC7042121 DOI: 10.1111/bph.14910] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 09/27/2019] [Accepted: 10/01/2019] [Indexed: 01/17/2023] Open
Abstract
Background and Purpose BK channels play important roles in various physiological and pathophysiological processes and thus have been the target of several drug development programmes focused on creating new efficacious BK channel openers, such as the GoSlo‐SR compounds. However, the effect of GoSlo‐SR compounds on vascular smooth muscle has not been studied. Therefore, we tested the hypothesis that GoSlo‐SR compounds dilate arteries exclusively by activating BK channels. Experimental Approach Experiments were performed on rat Gracilis muscle, saphenous, mesenteric and tail arteries using isobaric and isometric myography, sharp microelectrodes, digital droplet PCR and the patch‐clamp technique. Key Results GoSlo‐SR compounds dilated isobaric and relaxed and hyperpolarised isometric vessel preparations and their effects were abolished after (a) functionally eliminating K+ channels by pre‐constriction with 50 mM KCl or (b) blocking all K+ channels known to be expressed in vascular smooth muscle. However, these effects were not blocked when BK channels were inhibited. Surprisingly, the Kv7 channel inhibitor XE991 reduced their effects considerably, but neither Kv1 nor Kv2 channel blockers altered the inhibitory effects of GoSlo‐SR. However, the combined blockade of BK and Kv7 channels abolished the GoSlo‐SR‐induced relaxation. GoSlo‐SR compounds also activated Kv7.4 and Kv7.5 channels expressed in HEK 293 cells. Conclusion and Implications This study shows that GoSlo‐SR compounds are effective relaxants in vascular smooth muscle and mediate their effects by a combined activation of BK and Kv7.4/Kv7.5 channels. Activation of Kv1, Kv2 or Kv7.1 channels or other vasodilator pathways seems not to be involved.
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Affiliation(s)
- Olga Zavaritskaya
- Centre for Biomedicine and Medical Technology Mannheim (CBTM), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Srikanth Dudem
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Dongyu Ma
- Centre for Biomedicine and Medical Technology Mannheim (CBTM), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Department of Cardiology, The First Affiliated Hospital of Anhui Medical University, Anhui, China
| | - Kaneez E Rabab
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Sarah Albrecht
- Centre for Biomedicine and Medical Technology Mannheim (CBTM), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Dmitry Tsvetkov
- Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Mario Kassmann
- Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Keith Thornbury
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland.,Ion Channel Biotechnology Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Mitko Mladenov
- Centre for Biomedicine and Medical Technology Mannheim (CBTM), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Institute of Biology, Faculty of Natural Sciences and Mathematics, Sts. Cyril and Methodius, University of Skopje, Skopje, Macedonia.,Department of Fundamental and Applied Physiology, Russian National Research Medical University, Moscow, Russia
| | - Claire Kammermeier
- Sanofi Diabetes Research, Industriepark Hoechst, Frankfurt am Main, Germany
| | - Gerard Sergeant
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland.,Ion Channel Biotechnology Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Nicholas Mullins
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Ornella Wouappi
- Centre for Biomedicine and Medical Technology Mannheim (CBTM), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Hannah Wurm
- Centre for Biomedicine and Medical Technology Mannheim (CBTM), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Aimo Kannt
- Sanofi Diabetes Research, Industriepark Hoechst, Frankfurt am Main, Germany.,Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Maik Gollasch
- Experimental and Clinical Research Center (ECRC), a joint cooperation between the Charité Medical Faculty and the Max Delbrück Center for Molecular Medicine (MDC), Berlin, Germany
| | - Mark A Hollywood
- Smooth Muscle Research Centre, Dundalk Institute of Technology, Dundalk, Ireland.,Ion Channel Biotechnology Centre, Dundalk Institute of Technology, Dundalk, Ireland
| | - Rudolf Schubert
- Centre for Biomedicine and Medical Technology Mannheim (CBTM), Research Division Cardiovascular Physiology, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.,Faculty of Medicine, Department of Physiology, Augsburg University, Augsburg, Germany
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