1
|
Li H, Zhou Y, Yang Y, Zha Y, Ye B, Mun SY, Zhuang W, Liang J, Park WS. Encainide, a class Ic anti-arrhythmic agent, blocks voltage-dependent potassium channels in coronary artery smooth muscle cells. Korean J Physiol Pharmacol 2023; 27:399-406. [PMID: 37386837 DOI: 10.4196/kjpp.2023.27.4.399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/24/2023] [Accepted: 05/18/2023] [Indexed: 07/01/2023]
Abstract
Voltage-dependent K+ (Kv) channels are widely expressed on vascular smooth muscle cells and regulate vascular tone. Here, we explored the inhibitory effect of encainide, a class Ic anti-arrhythmic agent, on Kv channels of vascular smooth muscle from rabbit coronary arteries. Encainide inhibited Kv channels in a concentration-dependent manner with an IC50 value of 8.91 ± 1.75 μM and Hill coefficient of 0.72 ± 0.06. The application of encainide shifted the activation curve toward a more positive potential without modifying the inactivation curve, suggesting that encainide inhibited Kv channels by altering the gating property of channel activation. The inhibition by encainide was not significantly affected by train pulses (1 and 2 Hz), indicating that the inhibition is not use (state)-dependent. The inhibitory effect of encainide was reduced by pretreatment with the Kv1.5 subtype inhibitor. However, pretreatment with the Kv2.1 subtype inhibitor did not alter the inhibitory effects of encainide on Kv currents. Based on these results, encainide inhibits vascular Kv channels in a concentration-dependent and use (state)-independent manner by altering the voltage sensor of the channels. Furthermore, Kv1.5 is the main Kv subtype involved in the effect of encainide.
Collapse
Affiliation(s)
- Hongliang Li
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225001, China
- Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment for Senile Diseases, Yangzhou University, Yangzhou 225001, China
| | - Yue Zhou
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225001, China
| | - Yongqi Yang
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225001, China
| | - Yiwen Zha
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225001, China
| | - Bingqian Ye
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225001, China
| | - Seo-Yeong Mun
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Wenwen Zhuang
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Jingyan Liang
- Institute of Translational Medicine, Medical College, Yangzhou University, Yangzhou 225001, China
| | - Won Sun Park
- Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| |
Collapse
|
2
|
Kang M, Heo R, Park S, Mun SY, Park M, Han ET, Han JH, Chun W, Ha KS, Park H, Jung WK, Choi IW, Park WS. Inhibitory effects of the atypical antipsychotic, clozapine, on voltage-dependent K + channels in rabbit coronary arterial smooth muscle cells. Korean J Physiol Pharmacol 2022; 26:277-285. [PMID: 35766005 PMCID: PMC9247706 DOI: 10.4196/kjpp.2022.26.4.277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 05/10/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
To investigate the adverse effects of clozapine on cardiovascular ion channels, we examined the inhibitory effect of clozapine on voltage-dependent K+ (Kv) channels in rabbit coronary arterial smooth muscle cells. Clozapine-induced inhibition of Kv channels occurred in a concentration-dependent manner with an half-inhibitory concentration value of 7.84 ± 4.86 µM and a Hill coefficient of 0.47 ± 0.06. Clozapine did not shift the steady-state activation or inactivation curves, suggesting that it inhibited Kv channels regardless of gating properties. Application of train pulses (1 and 2 Hz) progressively augmented the clozapine-induced inhibition of Kv channels in the presence of the drug. Furthermore, the recovery time constant from inactivation was increased in the presence of clozapine, suggesting that clozapine-induced inhibition of Kv channels is use (state)-dependent. Pretreatment of a Kv1.5 subtype inhibitor decreased the Kv current amplitudes, but additional application of clozapine did not further inhibit the Kv current. Pretreatment with Kv2.1 or Kv7 subtype inhibitors partially blocked the inhibitory effect of clozapine. Based on these results, we conclude that clozapine inhibits arterial Kv channels in a concentrationand use (state)-dependent manner. Kv1.5 is the major subtype involved in clozapine-induced inhibition of Kv channels, and Kv2.1 and Kv7 subtypes are partially involved.
Collapse
Affiliation(s)
- Minji Kang
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Ryeon Heo
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Seojin Park
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Seo-Yeong Mun
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Minju Park
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Jin-Hee Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Wanjoo Chun
- Department of Pharmacology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Hongzoo Park
- Institute of Medical Sciences, Department of Urology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| | - Won-Kyo Jung
- Department of Biomedical Engineering and Center for Marine-Integrated Biomedical Technology (BK21 Plus), Pukyong National University, Busan 48513, Korea
| | - Il-Whan Choi
- Department of Microbiology, College of Medicine, Inje University, Busan 48516, Korea
| | - Won Sun Park
- Institute of Medical Sciences, Department of Physiology, Kangwon National University School of Medicine, Chuncheon 24341, Korea
| |
Collapse
|
3
|
Altamirano F, Schiattarella GG, French KM, Kim SY, Engelberger F, Kyrychenko S, Villalobos E, Tong D, Schneider JW, Ramirez-Sarmiento CA, Lavandero S, Gillette TG, Hill JA. Polycystin-1 Assembles With Kv Channels to Govern Cardiomyocyte Repolarization and Contractility. Circulation 2019; 140:921-936. [PMID: 31220931 DOI: 10.1161/circulationaha.118.034731] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
BACKGROUND Polycystin-1 (PC1) is a transmembrane protein originally identified in autosomal dominant polycystic kidney disease where it regulates the calcium-permeant cation channel polycystin-2. Autosomal dominant polycystic kidney disease patients develop renal failure, hypertension, left ventricular hypertrophy, and diastolic dysfunction, among other cardiovascular disorders. These individuals harbor PC1 loss-of-function mutations in their cardiomyocytes, but the functional consequences are unknown. PC1 is ubiquitously expressed, and its experimental ablation in cardiomyocyte-specific knockout mice reduces contractile function. Here, we set out to determine the pathophysiological role of PC1 in cardiomyocytes. METHODS Wild-type and cardiomyocyte-specific PC1 knockout mice were analyzed by echocardiography. Excitation-contraction coupling was assessed in isolated cardiomyocytes and human embryonic stem cell-derived cardiomyocytes, and functional consequences were explored in heterologous expression systems. Protein-protein interactions were analyzed biochemically and by means of ab initio calculations. RESULTS PC1 ablation reduced action potential duration in cardiomyocytes, decreased Ca2+ transients, and myocyte contractility. PC1-deficient cardiomyocytes manifested a reduction in sarcoendoplasmic reticulum Ca2+ stores attributable to a reduced action potential duration and sarcoendoplasmic reticulum Ca2+ ATPase (SERCA) activity. An increase in outward K+ currents decreased action potential duration in cardiomyocytes lacking PC1. Overexpression of full-length PC1 in HEK293 cells significantly reduced the current density of heterologously expressed Kv4.3, Kv1.5 and Kv2.1 potassium channels. PC1 C terminus inhibited Kv4.3 currents to the same degree as full-length PC1. Additionally, PC1 coimmunoprecipitated with Kv4.3, and a modeled PC1 C-terminal structure suggested the existence of 2 docking sites for PC1 within the N terminus of Kv4.3, supporting a physical interaction. Finally, a naturally occurring human mutant PC1R4228X manifested no suppressive effects on Kv4.3 channel activity. CONCLUSIONS Our findings uncover a role for PC1 in regulating multiple Kv channels, governing membrane repolarization and alterations in SERCA activity that reduce cardiomyocyte contractility.
Collapse
Affiliation(s)
- Francisco Altamirano
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas
| | - Gabriele G Schiattarella
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas.,Department of Advanced Biomedical Sciences, Federico II University, Naples, Italy (G.G.S.)
| | - Kristin M French
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas
| | - Soo Young Kim
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas
| | - Felipe Engelberger
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine, and Biological Sciences, Pontificia Universidad Catolica de Chile, Santiago, Chile (F.E., C.A.R.S.)
| | - Sergii Kyrychenko
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas
| | - Elisa Villalobos
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas
| | - Dan Tong
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas
| | - Jay W Schneider
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas
| | - Cesar A Ramirez-Sarmiento
- Institute for Biological and Medical Engineering, Schools of Engineering, Medicine, and Biological Sciences, Pontificia Universidad Catolica de Chile, Santiago, Chile (F.E., C.A.R.S.)
| | - Sergio Lavandero
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas.,Advanced Center for Chronic Diseases (ACCDiS), Facultad de Ciencias Químicas y Farmacéuticas & Facultad de Medicina, Universidad de Chile, Santiago, Chile (S.L.).,Corporación Centro de Estudios Científicos de las Enfermedades Crónicas (CECEC), Santiago, Chile (S.L.)
| | - Thomas G Gillette
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas
| | - Joseph A Hill
- Department of Internal Medicine, Cardiology Division (F.A., G.G.S., K.M.F., S.Y.K., S.K., E.V., D.T., J.W.S., S.L., T.G.G., J.A.H.), University of Texas Southwestern Medical Center, Dallas.,Department of Molecular Biology (J.A.H.), University of Texas Southwestern Medical Center, Dallas
| |
Collapse
|
4
|
Wu J, Chen Z, Liu Q, Zeng W, Wu X, Lin B. Silencing of Kv1.5 Gene Inhibits Proliferation and Induces Apoptosis of Osteosarcoma Cells. Int J Mol Sci 2015; 16:26914-26. [PMID: 26569226 DOI: 10.3390/ijms161126002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 09/08/2015] [Accepted: 10/30/2015] [Indexed: 11/17/2022] Open
Abstract
Kv1.5 (also known as KCNA5) is a protein encoded by the KCNA5 gene, which belongs to the voltage-gated potassium channel, shaker-related subfamily. Recently, a number of studies have suggested that Kv1.5 is overexpressed in numerous cancers and plays crucial roles in cancer development. However, until now, the expression and functions of Kv1.5 in osteosarcoma are still unclear. To characterize the potential biological functions of Kv1.5 in osteosarcoma, herein, we examined the expression levels of Kv1.5 in osteosarcoma cells and tissues using quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and immunohistochemistry assays. Four short hairpin RNAs (shRNAs) targeting Kv1.5 were designed and homologous recombination technology was used to construct pGeneSil-Kv1.5 vectors. In addition, the vectors were transfected into osteosarcoma MG63 cells and Kv1.5 mRNA level was measured by qRT-PCR and the Kv1.5 protein level was examined by western blot. We also examined the effects of Kv1.5 silencing on proliferation, cell cycle and apoptosis of the osteosarcoma cells using CCK-8, colony formation, flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assays. Our results showed that Kv1.5 was aberrantly expressed in osteosarcoma and that the synthesized shRNA targeting Kv1.5 reduced Kv1.5 mRNA and protein expression effectively. Silencing Kv1.5 expression in the osteosarcoma cells significantly inhibited the proliferation of osteosarcoma cells, induced cell cycle arrest at G0/G1 phase, and induced cell apoptosis through up-regulation of p21, p27, Bax, Bcl-XL and caspase-3 and down-regulation of cyclins A, cyclins D1, cyclins E, Bcl-2 and Bik. In summary, our results indicate that Kv1.5 silencing could suppress osteosarcoma progression through multiple signaling pathways and suggest that Kv1.5 may be a novel target for osteosarcoma therapeutics.
Collapse
|
5
|
Schumacher-Bass SM, Vesely ED, Zhang L, Ryland KE, McEwen DP, Chan PJ, Frasier CR, McIntyre JC, Shaw RM, Martens JR. Role for myosin-V motor proteins in the selective delivery of Kv channel isoforms to the membrane surface of cardiac myocytes. Circ Res 2014; 114:982-92. [PMID: 24508725 DOI: 10.1161/circresaha.114.302711] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Kv1.5 (KCNA5) mediates the ultra-rapid delayed rectifier current that controls atrial action potential duration. Given its atrial-specific expression and alterations in human atrial fibrillation, Kv1.5 has emerged as a promising target for the treatment of atrial fibrillation. A necessary step in the development of novel agents that selectively modulate trafficking pathways is the identification of the cellular machinery controlling Kv1.5 surface density, of which little is yet known. OBJECTIVE To investigate the role of the unconventional myosin-V (MYO5A and MYO5B) motors in determining the cell surface density of Kv1.5. METHODS AND RESULTS Western blot analysis showed MYO5A and MYO5B expression in the heart, whereas disruption of endogenous motors selectively reduced IKur current in adult rat cardiomyocytes. Dominant negative constructs and short hairpin RNA silencing demonstrated a role for MYO5A and MYO5B in the surface trafficking of Kv1.5 and connexin-43 but not potassium voltage-gated channel, subfamily H (eag-related), member 2 (KCNH2). Live-cell imaging of Kv1.5-GFP and retrospective labeling of phalloidin demonstrated motility of Kv1.5 vesicles on actin tracts. MYO5A participated in anterograde trafficking, whereas MYO5B regulated postendocytic recycling. Overexpression of mutant motors revealed a selective role for Rab11 in coupling MYO5B to Kv1.5 recycling. CONCLUSIONS MYO5A and MYO5B control functionally distinct steps in the surface trafficking of Kv1.5. These isoform-specific trafficking pathways determine Kv1.5-encoded IKur in myocytes to regulate repolarizing current and, consequently, cardiac excitability. Therapeutic strategies that manipulate Kv1.5 selective trafficking pathways may prove useful in the treatment of arrhythmias.
Collapse
Affiliation(s)
- Sarah M Schumacher-Bass
- From the Department of Pharmacology, University of Michigan, Ann Arbor (S.M.S.-B., E.D.V., L.Z., K.E.R., D.P.M., C.R.F., J.C.M., J.R.M.); Cardiovascular Research Institute Robin Shaw, Department of Medicine, University of California, San Francisco (P.J.C.); and Cedars-Sinai Medical Center, Los Angeles, CA (R.M.S.)
| | | | | | | | | | | | | | | | | | | |
Collapse
|