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Stott JB, Greenwood IA. G protein βγ regulation of KCNQ-encoded voltage-dependent K channels. Front Physiol 2024; 15:1382904. [PMID: 38655029 PMCID: PMC11035767 DOI: 10.3389/fphys.2024.1382904] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 03/25/2024] [Indexed: 04/26/2024] Open
Abstract
The KCNQ family is comprised of five genes and the expression products form voltage-gated potassium channels (Kv7.1-7.5) that have a major impact upon cellular physiology in many cell types. Each functional Kv7 channel forms as a tetramer that often associates with proteins encoded by the KCNE gene family (KCNE1-5) and is critically reliant upon binding of phosphatidylinositol bisphosphate (PIP2) and calmodulin. Other modulators like A-kinase anchoring proteins, ubiquitin ligases and Ca-calmodulin kinase II alter Kv7 channel function and trafficking in an isoform specific manner. It has now been identified that for Kv7.4, G protein βγ subunits (Gβγ) can be added to the list of key regulators and is paramount for channel activity. This article provides an overview of this nascent field of research, highlighting themes and directions for future study.
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Affiliation(s)
| | - Iain A. Greenwood
- Vascular Biology Research Group, Institute of Molecular and Clinical Sciences, St George’s University of London, London, United Kingdom
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2
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Baldwin SN, Jepps TA, Greenwood IA. Cycling matters: Sex hormone regulation of vascular potassium channels. Channels (Austin) 2023; 17:2217637. [PMID: 37243715 PMCID: PMC10228406 DOI: 10.1080/19336950.2023.2217637] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/07/2023] [Accepted: 05/19/2023] [Indexed: 05/29/2023] Open
Abstract
Sex hormones and the reproductive cycle (estrus in rodents and menstrual in humans) have a known impact on arterial function. In spite of this, sex hormones and the estrus/menstrual cycle are often neglected experimental factors in vascular basic preclinical scientific research. Recent research by our own laboratory indicates that cyclical changes in serum concentrations of sex -hormones across the rat estrus cycle, primary estradiol, have significant consequences for the subcellular trafficking and function of KV. Vascular potassium channels, including KV, are essential components of vascular reactivity. Our study represents a small part of a growing field of literature aimed at determining the role of sex hormones in regulating arterial ion channel function. This review covers key findings describing the current understanding of sex hormone regulation of vascular potassium channels, with a focus on KV channels. Further, we highlight areas of research where the estrus cycle should be considered in future studies to determine the consequences of physiological oscillations in concentrations of sex hormones on vascular potassium channel function.
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Affiliation(s)
- Samuel N Baldwin
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Thomas A Jepps
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Iain A Greenwood
- Vascular Biology Research Centre, Institute of Molecular and Clinical Sciences, St George’s University of London, London, UK
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3
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Lim XR, Bradley E, Griffin CS, Hollywood MA, Sergeant GP, Thornbury KD. Fast voltage-dependent sodium (Na V ) currents are functionally expressed in mouse corpus cavernosum smooth muscle cells. Br J Pharmacol 2021; 179:1082-1101. [PMID: 34767251 DOI: 10.1111/bph.15728] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 10/17/2021] [Accepted: 10/19/2021] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND AND PURPOSE Corpus cavernosum smooth muscle (CCSM) exhibits phasic contractions that are coordinated by ion channels. Mouse models are commonly used to study erectile dysfunction, but there are few published electrophysiological studies of mouse CCSM. We describe, for the first time, voltage-dependent sodium (NaV ) currents in mouse CCSM and investigate their function. EXPERIMENTAL APPROACH Electrophysiological, pharmacological, and immunocytochemical studies on isolated CCSM cells. Tension measurements in whole tissue. KEY RESULTS A fast, voltage-dependent sodium current was induced by depolarising steps. Steady-state activation and inactivation curves revealed a window current between -60 and -30 mV. Two populations of NaV currents, ('TTX-sensitive') and ('TTX-insensitive'), were distinguished. TTX-sensitive current showed 48% block with the NaV -subtype-specific blockers ICA-121431 (NaV 1.1-1.3), PF-05089771 (NaV 1.7), and 4,9-anhydro-TTX (NaV 1.6). TTX-insensitive current was insensitive to A803467, a NaV 1.8 blocker. Immunocytochemistry confirmed the expression of NaV 1.5 and NaV 1.4 in freshly dispersed CCSM cells. Veratridine, a NaV activator, reduced time-dependent inactivation of the current and increased the duration of evoked action potentials. Veratridine induced phasic contractions in CCSM strips. This effect was reversible with TTX and nifedipine but not by KB-R7943. CONCLUSION AND IMPLICATIONS We report, for the first time, a fast voltage-dependent sodium current in mouse CCSM. Stimulation of this current increases the contractility of corpus cavernosum in vitro, suggesting that it may contribute to the mechanisms of detumescence, and potentially serve as a clinically relevant target for pharmaceutical intervention in erectile dysfunction. Further work will be necessary to define its role.
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Affiliation(s)
| | | | | | | | | | - Keith D Thornbury
- Smooth Muscle Research Centre Dundalk Institute of Technology, Dublin, Ireland
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4
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Borgini M, Mondal P, Liu R, Wipf P. Chemical modulation of Kv7 potassium channels. RSC Med Chem 2021; 12:483-537. [PMID: 34046626 PMCID: PMC8128042 DOI: 10.1039/d0md00328j] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 12/01/2020] [Indexed: 01/10/2023] Open
Abstract
The rising interest in Kv7 modulators originates from their ability to evoke fundamental electrophysiological perturbations in a tissue-specific manner. A large number of therapeutic applications are, in part, based on the clinical experience with two broad-spectrum Kv7 agonists, flupirtine and retigabine. Since precise molecular structures of human Kv7 channel subtypes in closed and open states have only very recently started to emerge, computational studies have traditionally been used to analyze binding modes and direct the development of more potent and selective Kv7 modulators with improved safety profiles. Herein, the synthetic and medicinal chemistry of small molecule modulators and the representative biological properties are summarized. Furthermore, new therapeutic applications supported by in vitro and in vivo assay data are suggested.
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Affiliation(s)
- Matteo Borgini
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Pravat Mondal
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Ruiting Liu
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
| | - Peter Wipf
- Department of Chemistry, University of Pittsburgh Pittsburgh PA 15260 USA
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5
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Baldwin SN, Sandow SL, Mondéjar-Parreño G, Stott JB, Greenwood IA. K V7 Channel Expression and Function Within Rat Mesenteric Endothelial Cells. Front Physiol 2020; 11:598779. [PMID: 33364977 PMCID: PMC7750541 DOI: 10.3389/fphys.2020.598779] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 11/13/2020] [Indexed: 01/04/2023] Open
Abstract
Background and Purpose: Arterial diameter is dictated by the contractile state of the vascular smooth muscle cells (VSMCs), which is modulated by direct and indirect inputs from endothelial cells (ECs). Modulators of KCNQ-encoded kV7 channels have considerable impact on arterial diameter and these channels are known to be expressed in VSMCs but not yet defined in ECs. However, expression of kV7 channels in ECs would add an extra level of vascular control. This study aims to characterize the expression and function of KV7 channels within rat mesenteric artery ECs. Experimental Approach: In rat mesenteric artery, KCNQ transcript and KV7 channel protein expression were determined via RT-qPCR, immunocytochemistry, immunohistochemistry and immunoelectron microscopy. Wire myography was used to determine vascular reactivity. Key Results: KCNQ transcript was identified in isolated ECs and VSMCs. KV7.1, KV7.4 and KV7.5 protein expression was determined in both isolated EC and VSMC and in whole vessels. Removal of ECs attenuated vasorelaxation to two structurally different KV7.2-5 activators S-1 and ML213. KIR2 blockers ML133, and BaCl2 also attenuated S-1 or ML213-mediated vasorelaxation in an endothelium-dependent process. KV7 inhibition attenuated receptor-dependent nitric oxide (NO)-mediated vasorelaxation to carbachol, but had no impact on relaxation to the NO donor, SNP. Conclusion and Implications: In rat mesenteric artery ECs, KV7.4 and KV7.5 channels are expressed, functionally interact with endothelial KIR2.x channels and contribute to endogenous eNOS-mediated relaxation. This study identifies KV7 channels as novel functional channels within rat mesenteric ECs and suggests that these channels are involved in NO release from the endothelium of these vessels.
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Affiliation(s)
- Samuel N Baldwin
- Vascular Biology Research Centre, Institute of Molecular and Clinical Sciences, St George's University of London, London, United Kingdom
| | - Shaun L Sandow
- Biomedical Science, School of Health and Sports Science, University of the Sunshine Coast, Maroochydore, QLD, Australia
| | - Gema Mondéjar-Parreño
- Department of Pharmacology and Toxicology, School of Medicine, Complutense University of Madrid, Madrid, Spain
| | - Jennifer B Stott
- Vascular Biology Research Centre, Institute of Molecular and Clinical Sciences, St George's University of London, London, United Kingdom
| | - Iain A Greenwood
- Vascular Biology Research Centre, Institute of Molecular and Clinical Sciences, St George's University of London, London, United Kingdom
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6
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Hung TY, Huang CW, Wu SN. High ability of zileuton ((±)-1-(1-benzo[b]thien-2-ylethyl)-1-hydroxyurea) to stimulate I K(Ca) but suppress I K(DR) and I K(M) independently of 5-lipoxygenase inhibition. Eur J Pharmacol 2020; 887:173482. [PMID: 32795513 DOI: 10.1016/j.ejphar.2020.173482] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 08/07/2020] [Accepted: 08/08/2020] [Indexed: 12/16/2022]
Abstract
Zileuton (Zyflo®) is regarded to be an inhibitor of 5-lipoxygenase. Although its effect on Ca2+-activated K+ currents has been reported, its overall ionic effects on neurons are uncertain. In whole-cell current recordings, zileuton increased the amplitude of Ca2+-activated K+ currents with an EC50 of 3.2 μM in pituitary GH3 lactotrophs. Furthermore, zileuton decreased the amplitudes of both delayed-rectifier K+ current (IK(DR)) and M-type K+ current (IK(M)). Conversely, no modification of hyperpolarization-activated cation current (Ih) was demonstrated in its presence of zileuton, although the subsequent addition of cilobradine effectively suppressed the current. In inside-out current recordings, the addition of zileuton to the bath increased the probability of large-conductance Ca2+-activated K+ (BKCa) channels; however, the subsequent addition of GAL-021 effectively reversed the stimulation of channel activity. The kinetic analyses showed an evident shortening in the slow component of mean closed time of BKCa channels in the presence of zileuton, with minimal change in mean open time or that in the fast component of mean closed time. The elevation of BKCa channels caused by zileuton was also observed in hippocampal mHippoE-14 neurons, without any modification of single-channel amplitude. In conclusion, except for its suppression of 5-lipoxygenase, our results indicate that zileuton does not exclusively act on BKCa channels, and its inhibitory effects on IK(DR) and IK(M) may combine to exert strong influence on the functional activities of electrically excitable cells in vivo.
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Affiliation(s)
- Te-Yu Hung
- Department of Pediatrics, Chi-Mei Medical Center, Tainan, Taiwan
| | - Chin-Wei Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
| | - Sheng-Nan Wu
- Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan; Institute of Basic Medical Sciences, National Cheng Kung University Medical College, Tainan, Taiwan; Department of Medical Research, China Medical University Hospital, China Medical University, Taichung City, Taiwan.
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7
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Mondéjar-Parreño G, Barreira B, Callejo M, Morales-Cano D, Barrese V, Esquivel-Ruiz S, Olivencia MA, Macías M, Moreno L, Greenwood IA, Perez-Vizcaino F, Cogolludo A. Uncovered Contribution of Kv7 Channels to Pulmonary Vascular Tone in Pulmonary Arterial Hypertension. Hypertension 2020; 76:1134-1146. [DOI: 10.1161/hypertensionaha.120.15221] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
K
+
channels play a fundamental role regulating membrane potential of pulmonary artery (PA) smooth muscle cells and their impairment is a common feature in pulmonary arterial hypertension (PAH). K
+
voltage-gated channel subfamily Q (
KCNQ1-5
) or Kv7 channels and their regulatory subunits subfamily E (KCNE) regulatory subunits are known to regulate vascular tone, but whether Kv7 channel function is impaired in PAH and how this can affect the rationale for targeting Kv7 channels in PAH remains unknown. Here, we have studied the role of Kv7/KCNE subunits in rat PA and their possible alteration in PAH. Using the patch-clamp technique, we found that the total K
+
current is reduced in PA smooth muscle cells from pulmonary hypertension animals (SU5416 plus hypoxia) and Kv7 currents made a higher contribution to the net K
+
current. Likewise, enhanced vascular responses to Kv7 channel modulators were found in pulmonary hypertension rats. Accordingly, KCNE4 subunit was highly upregulated in lungs from pulmonary hypertension animals and patients. Additionally, Kv7 channel activity was enhanced in the presence of Kv1.5 and TASK-1 channel inhibitors and this was associated with an increased KCNE4 membrane abundance. Compared with systemic arteries, PA showed a poor response to Kv7 channel modulators which was associated with reduced expression and membrane abundance of Kv7.4 and KCNE4. Our data indicate that Kv7 channel function is preserved and KCNE4 is upregulated in PAH. Therefore, compared with other downregulated channels, the contribution of Kv7 channels is increased in PAH resulting in an enhanced sensitivity to Kv7 channel modulators. This study provides insight into the potential usefulness of targeting Kv7 channels in PAH.
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Affiliation(s)
- Gema Mondéjar-Parreño
- From the Departamento de Farmacología y Toxicología. Facultad de Medicina, Universidad Complutense de Madrid, Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Ciber Enfermedades Respiratorias (Ciberes), Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM) (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
| | - Bianca Barreira
- From the Departamento de Farmacología y Toxicología. Facultad de Medicina, Universidad Complutense de Madrid, Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Ciber Enfermedades Respiratorias (Ciberes), Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM) (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
| | - María Callejo
- From the Departamento de Farmacología y Toxicología. Facultad de Medicina, Universidad Complutense de Madrid, Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Ciber Enfermedades Respiratorias (Ciberes), Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM) (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
| | - Daniel Morales-Cano
- Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain (D.M.-C.)
| | - Vincenzo Barrese
- Vascular Biology Research Centre, Institute of Molecular and Clinical Sciences, St George’s University of London, United Kingdom (V.B., I.A.G.)
- Department of Neuroscience, Reproductive Sciences and Dentistry, University of Naples Federico II, Naples, Italy (V.B.)
| | - Sergio Esquivel-Ruiz
- From the Departamento de Farmacología y Toxicología. Facultad de Medicina, Universidad Complutense de Madrid, Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Ciber Enfermedades Respiratorias (Ciberes), Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM) (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
| | - Miguel A. Olivencia
- From the Departamento de Farmacología y Toxicología. Facultad de Medicina, Universidad Complutense de Madrid, Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Ciber Enfermedades Respiratorias (Ciberes), Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM) (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
| | - Miguel Macías
- From the Departamento de Farmacología y Toxicología. Facultad de Medicina, Universidad Complutense de Madrid, Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Ciber Enfermedades Respiratorias (Ciberes), Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM) (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
| | - Laura Moreno
- From the Departamento de Farmacología y Toxicología. Facultad de Medicina, Universidad Complutense de Madrid, Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Ciber Enfermedades Respiratorias (Ciberes), Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM) (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
| | - Iain A. Greenwood
- Vascular Biology Research Centre, Institute of Molecular and Clinical Sciences, St George’s University of London, United Kingdom (V.B., I.A.G.)
| | - Francisco Perez-Vizcaino
- From the Departamento de Farmacología y Toxicología. Facultad de Medicina, Universidad Complutense de Madrid, Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Ciber Enfermedades Respiratorias (Ciberes), Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM) (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
| | - Angel Cogolludo
- From the Departamento de Farmacología y Toxicología. Facultad de Medicina, Universidad Complutense de Madrid, Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Ciber Enfermedades Respiratorias (Ciberes), Spain (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
- Instituto de Investigación Sanitaria Gregorio Marañón (IISGM) (G.M.-P., B.B., M.C., S.E.-R., M.A.O., M.M., L.M., F.P.-V., A.C.)
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8
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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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9
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Diniz AFA, Ferreira RC, de Souza ILL, da Silva BA. Ionic Channels as Potential Therapeutic Targets for Erectile Dysfunction: A Review. Front Pharmacol 2020; 11:1120. [PMID: 32848741 PMCID: PMC7396897 DOI: 10.3389/fphar.2020.01120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/10/2020] [Indexed: 12/12/2022] Open
Abstract
Erectile dysfunction (ED) is a prevalent condition, especially in men over 40 years old, characterized by the inability to obtain and/or maintain penile erection sufficient for satisfactory sexual intercourse. Several psychological and/or organic factors are involved in the etiopathogenesis of ED. In this context, we gathered evidence of the involvement of Large-conductance, Ca2+-activated K+ channels (BKCa), Small-conductance, Ca2+-activated K+ channels (SKCa), KCNQ-encoded voltage-dependent K+ channels (KV7), Transient Receptor Potential channels (TRP), and Calcium-activated Chloride channels (CaCC) dysfunctions on ED. In addition, the use of modulating agents of these channels are involved in relaxation of the cavernous smooth muscle cell and, consequent penile erection, suggesting that these channels are promising therapeutic targets for the treatment of erectile dysfunction.
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Affiliation(s)
- Anderson Fellyp Avelino Diniz
- Programa de Pós-Graduação em Produtos Naturais e Sintéticos Bioativos, Universidade Federal da Paraíba, João Pessoa, Brazil
| | - Rafael Carlos Ferreira
- Programa de Pós-Graduação em Produtos Naturais e Sintéticos Bioativos, Universidade Federal da Paraíba, João Pessoa, Brazil
| | - Iara Leão Luna de Souza
- Departamento de Ciências Biológicas e da Saúde, Universidade Estadual de Roraima, Boa Vista, Brazil
| | - Bagnólia Araújo da Silva
- Programa de Pós-Graduação em Produtos Naturais e Sintéticos Bioativos, Universidade Federal da Paraíba, João Pessoa, Brazil
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10
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van der Horst J, Greenwood IA, Jepps TA. Cyclic AMP-Dependent Regulation of Kv7 Voltage-Gated Potassium Channels. Front Physiol 2020; 11:727. [PMID: 32695022 PMCID: PMC7338754 DOI: 10.3389/fphys.2020.00727] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/04/2020] [Indexed: 01/08/2023] Open
Abstract
Voltage-gated Kv7 potassium channels, encoded by KCNQ genes, have major physiological impacts cardiac myocytes, neurons, epithelial cells, and smooth muscle cells. Cyclic adenosine monophosphate (cAMP), a well-known intracellular secondary messenger, can activate numerous downstream effector proteins, generating downstream signaling pathways that regulate many functions in cells. A role for cAMP in ion channel regulation has been established, and recent findings show that cAMP signaling plays a role in Kv7 channel regulation. Although cAMP signaling is recognized to regulate Kv7 channels, the precise molecular mechanism behind the cAMP-dependent regulation of Kv7 channels is complex. This review will summarize recent research findings that support the mechanisms of cAMP-dependent regulation of Kv7 channels.
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Affiliation(s)
- Jennifer van der Horst
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Iain A Greenwood
- Molecular and Clinical Sciences Institute, St. George's University of London, London, United Kingdom
| | - Thomas A Jepps
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
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11
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Ding F, Shan C, Li H, Zhang Y, Guo C, Zhou Z, Zheng J, Shen W, Dai Q, Ouyang Q, Wu X. Simvastatin alleviated diabetes mellitus-induced erectile dysfunction in rats by enhancing AMPK pathway-induced autophagy. Andrology 2020; 8:780-792. [PMID: 31955524 DOI: 10.1111/andr.12758] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 01/09/2020] [Accepted: 01/14/2020] [Indexed: 12/25/2022]
Abstract
BACKGROUND Diabetes mellitus-induced erectile dysfunction is a common diabetic complication, and new therapeutics and the pathogenesis of diabetes mellitus-induced erectile dysfunction need to be investigated. OBJECTIVES The aim was to investigate the pathogenesis of diabetes mellitus-induced erectile dysfunction and the pharmacological mechanism of simvastatin treatment in diabetes mellitus-induced erectile dysfunction model rats. MATERIALS AND METHODS A total of 86 male Sprague Dawley rats aged 8 weeks old were used in this study. The rats were divided into three groups: control (normal), diabetes mellitus-induced erectile dysfunction (streptozotocin-injected), and diabetes mellitus-induced erectile dysfunction + simvastatin (sim). Each group was subdivided into two subgroups for in vitro and in vivo analyses. A bioinformatics method was used to detect differences in gene expression in the corpus cavernosum between normal and diabetes mellitus-induced erectile dysfunction rats. Erectile function was measured by a cavernous nerve electrostimulation test. Corpus cavernosum fibrosis was assessed by Masson staining and Western blotting. Immunofluorescence and Western blotting were performed to explore the differential expression of autophagy-related genes and the AMPK-SKP2-CARM1 pathway genes in rat cavernous smooth muscle cells and the corpus cavernosum. The autophagosomes of the corpus cavernosum tissue were observed by transmission electron microscopy. RESULTS Autophagy-related genes and pathways (the AMPK and FoxO pathway) were identified by bioinformatics analysis and confirmed at the protein level. Simvastatin, an AMPK agonist, was used to treat diabetes mellitus-induced erectile dysfunction rats for 8 weeks, demonstrating that erectile function was improved for 80.5% (P < .05) of rats. Corpus cavernosum fibrosis was alleviated (P < .05), and autophagy was further enhanced (P < .05); these results might be partially caused by AMPK-SKP2-CARM1 pathway activation (P < .05). DISCUSSION AND CONCLUSION Simvastatin could enhance protective autophagy by activating the AMPK-SKP2-CARM1 pathway to improve erectile function in diabetes mellitus-induced erectile dysfunction rats.
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Affiliation(s)
- Fan Ding
- Institute of Urinary Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Changyu Shan
- Department of Pharmaceutical Chemistry, Third Military Medical University, Chongqing, China
| | - Hongwei Li
- Department of Pharmaceutical Chemistry, Third Military Medical University, Chongqing, China
| | - Yuping Zhang
- Department of Pharmaceutical Chemistry, Third Military Medical University, Chongqing, China
| | - Chunling Guo
- Department of Pharmaceutical Chemistry, Third Military Medical University, Chongqing, China
| | - Zhansong Zhou
- Institute of Urinary Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Ji Zheng
- Institute of Urinary Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Wenhao Shen
- Institute of Urinary Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Qiang Dai
- Institute of Urinary Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China
| | - Qin Ouyang
- Department of Pharmaceutical Chemistry, Third Military Medical University, Chongqing, China
| | - Xiaojun Wu
- Institute of Urinary Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China
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12
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Characterization and functional roles of KCNQ-encoded voltage-gated potassium (Kv7) channels in human corpus cavernosum smooth muscle. Pflugers Arch 2020; 472:89-102. [PMID: 31919767 DOI: 10.1007/s00424-019-02343-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 12/12/2019] [Accepted: 12/26/2019] [Indexed: 12/23/2022]
Abstract
The group of KCNQ-encoded voltage-gated potassium (Kv7) channels includes five family members (Kv7.1-7.5). We examined the molecular expression and functional roles of Kv7 channels in corporal smooth muscle (CSM). Isolated rabbit CSM strips were mounted in an organ bath system to characterize Kv7 channels during CSM relaxation. Intracellular Ca2+ levels were measured in the CSM using the Ca2+ dye Fluo-4 AM. The expression of the KCNQ1-5 (the encoding genes for Kv7.1-7.5) and KCNE1-5 subtypes was determined by quantitative real-time PCR. Electrophysiological recordings and an in situ proximity ligation assay (PLA) were also performed. ML213 (a Kv7.2/7.4/7.5 activator) exhibited the most potent relaxation effect. XE911 (a Kv7.1-7.5 blocker) significantly inhibited the relaxation caused by ML213. Removal of the endothelium from the CSM did not affect the relaxation effect of ML213. H-89 (a protein kinase A inhibitor) and ESI-09 (an exchange protein directly activated by cAMP inhibitor) significantly inhibited ML213-induced relaxation (H-89: 31.3%; ESI-09: 52.7%). XE991 significantly increased basal [Ca2+]i in hCSM cells. KCNQ4 (the Kv7.4-encoding gene) and KCNE4 in CSM were the most abundantly expressed subtypes in humans and rats, respectively. KCNQ4 and KCNE4 expression was significantly decreased in diabetes mellitus rats. ML213 significantly increased the outward current amplitude. XE991 inhibited the ML213-induced outward currents. ML213 hyperpolarized the hCSM cell membrane potential. Subsequent addition of XE991 completely reversed the ML213-induced hyperpolarizing effects. A combination of Kv7.4 and Kv7.5 antibodies generated a strong PLA signal. We found that the Kv7.4 channel is a potential target for ED treatment.
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13
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KCNQ5 activation is a unifying molecular mechanism shared by genetically and culturally diverse botanical hypotensive folk medicines. Proc Natl Acad Sci U S A 2019; 116:21236-21245. [PMID: 31570602 DOI: 10.1073/pnas.1907511116] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Botanical folk medicines have been used throughout human history to treat common disorders such as hypertension, often with unknown underlying mechanisms. Here, we discovered that hypotensive folk medicines from a genetically diverse range of plant species each selectively activated the vascular-expressed KCNQ5 potassium channel, a feature lacking in the modern synthetic pharmacopeia, whereas nonhypotensive plant extracts did not. Analyzing constituents of the hypotensive Sophora flavescens root, we found that the quinolizidine alkaloid aloperine is a KCNQ-dependent vasorelaxant that potently and isoform-selectively activates KCNQ5 by binding near the foot of the channel voltage sensor. Our findings reveal that KCNQ5-selective activation is a defining molecular mechanistic signature of genetically diverse traditional botanical hypotensives, transcending plant genus and human cultural boundaries. Discovery of botanical KCNQ5-selective potassium channel openers may enable future targeted therapies for diseases including hypertension and KCNQ5 loss-of-function encephalopathy.
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14
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Mondéjar-Parreño G, Moral-Sanz J, Barreira B, De la Cruz A, Gonzalez T, Callejo M, Esquivel-Ruiz S, Morales-Cano D, Moreno L, Valenzuela C, Perez-Vizcaino F, Cogolludo A. Activation of K v 7 channels as a novel mechanism for NO/cGMP-induced pulmonary vasodilation. Br J Pharmacol 2019; 176:2131-2145. [PMID: 30883701 DOI: 10.1111/bph.14662] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 02/08/2019] [Accepted: 02/13/2019] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND AND PURPOSE The NO/cGMP pathway represents a major physiological signalling controlling tone in pulmonary arteries (PA), and drugs activating this pathway are used to treat pulmonary arterial hypertension. Kv channels expressed in PA smooth muscle cells (PASMCs) are key determinants of vascular tone. We aimed to analyse the contribution of Kv 1.5 and Kv 7 channels in the electrophysiological and vasodilating effects evoked by NO donors and the GC stimulator riociguat in PA. EXPERIMENTAL APPROACH Kv currents were recorded in isolated rat PASMCs using the patch-clamp technique. Vascular reactivity was assessed in a wire myograph. KEY RESULTS The NO donors diethylamine NONOate diethylammonium (DEA-NO) and sodium nitroprusside hyperpolarized the membrane potential and induced a bimodal effect on Kv currents (augmenting the current between -40 and -10 mV and decreasing it at more depolarized potentials). The hyperpolarization and the enhancement of the current were suppressed by Kv 7 channel inhibitors and by the GC inhibitor ODQ but preserved when Kv 1.5 channels were inhibited. Additionally, DEA-NO enhanced Kv 7.5 currents in COS7 cells expressing the KCNQ5 gene. Riociguat increased Kv currents at all potentials ≥-40 mV and induced membrane hyperpolarization. Both effects were prevented by Kv 7 inhibition. Likewise, PA relaxation induced by NO donors and riociguat was attenuated by Kv 7 inhibitors. CONCLUSIONS AND IMPLICATIONS NO donors and riociguat enhance Kv 7 currents, leading to PASMC hyperpolarization. This mechanism contributes to NO/cGMP-induced PA vasodilation. Our study identifies Kv 7 channels as a novel mechanism of action of vasodilator drugs used in the treatment of pulmonary arterial hypertension.
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Affiliation(s)
- Gema Mondéjar-Parreño
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Ciber Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Javier Moral-Sanz
- Centres for Discovery Brain Sciences and Cardiovascular Science, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh, UK
| | - Bianca Barreira
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Ciber Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Alicia De la Cruz
- Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC-UAM, Madrid, Spain.,CIBER Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Teresa Gonzalez
- Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC-UAM, Madrid, Spain.,CIBER Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain.,Department of Biochemistry, School of Medicine, Universidad Autónoma de Madrid, Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain
| | - Maria Callejo
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Ciber Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Sergio Esquivel-Ruiz
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Ciber Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Daniel Morales-Cano
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Ciber Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Laura Moreno
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Ciber Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Carmen Valenzuela
- Instituto de Investigaciones Biomédicas "Alberto Sols" CSIC-UAM, Madrid, Spain.,CIBER Enfermedades Cardiovasculares (CIBERCV), Madrid, Spain
| | - Francisco Perez-Vizcaino
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Ciber Enfermedades Respiratorias (CIBERES), Madrid, Spain
| | - Angel Cogolludo
- Department of Pharmacology and Toxicology, School of Medicine, University Complutense of Madrid, Instituto de Investigación Sanitaria Gregorio Marañón (IiSGM), Madrid, Spain.,Ciber Enfermedades Respiratorias (CIBERES), Madrid, Spain
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15
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Thornbury KD, Hollywood MA, Sergeant GP. Ion Channels and Intracellular Calcium Signalling in Corpus Cavernosum. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1124:171-194. [PMID: 31183827 DOI: 10.1007/978-981-13-5895-1_7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The corpus cavernosum smooth muscle is important for both erection of the penis and for maintaining penile flaccidity. Most of the time, the smooth muscle cells are in a contracted state, which limits filling of the corpus sinuses with blood. Occasionally, however, they relax in a co-ordinated manner, allowing filling to occur. This results in an erection. When contractions of the corpus cavernosum are measured, it can be deduced that the muscle cells work together in a syncytium, for not only do they spontaneously contract in a co-ordinated manner, but they also synchronously relax. It is challenging to understand how they achieve this.In this review we will attempt to explain the activity of the corpus cavernosum, firstly by summarising current knowledge regarding the role of ion channels and how they influence tone, and secondly by presenting data on the intracellular Ca2+ signals that interact with the ion channels. We propose that spontaneous Ca2+ waves act as a primary event, driving transient depolarisation by activating Ca2+-activated Cl- channels. Depolarisation then facilitates Ca2+ influx via L-type voltage-dependent Ca2+ channels. We propose that the spontaneous Ca2+ oscillations depend on Ca2+ release from both ryanodine- and inositol trisphosphate (IP3)-sensitive stores and that modulation by signalling molecules is achieved mainly by interactions with the IP3-sensitive mechanism. This pacemaker mechanism is inhibited by nitric oxide (acting through cyclic GMP) and enhanced by noradrenaline. By understanding these mechanisms better, it might be possible to design new treatments for erectile dysfunction.
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Affiliation(s)
- Keith D Thornbury
- Smooth Muscle Research Centre, Regional Development Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland.
| | - Mark A Hollywood
- Smooth Muscle Research Centre, Regional Development Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland
| | - Gerard P Sergeant
- Smooth Muscle Research Centre, Regional Development Centre, Dundalk Institute of Technology, Dundalk, Co. Louth, Ireland
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16
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Nieves-Cintrón M, Syed AU, Nystoriak MA, Navedo MF. Regulation of voltage-gated potassium channels in vascular smooth muscle during hypertension and metabolic disorders. Microcirculation 2018; 25. [PMID: 29044853 DOI: 10.1111/micc.12423] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 10/11/2017] [Indexed: 12/12/2022]
Abstract
Voltage-gated potassium (KV ) channels are key regulators of vascular smooth muscle contractility and vascular tone, and thus have major influence on the microcirculation. KV channels are important determinants of vascular smooth muscle membrane potential (Em ). A number of KV subunits are expressed in the plasma membrane of smooth muscle cells. Each subunit confers distinct kinetics and regulatory properties that allow for fine control of Em to orchestrate vascular tone. Modifications in KV subunit expression and/or channel activity can contribute to changes in vascular smooth muscle contractility in response to different stimuli and in diverse pathological conditions. Consistent with this, a number of studies suggest alterations in KV subunit expression and/or function as underlying contributing mechanisms for small resistance artery dysfunction in pathologies such as hypertension and metabolic disorders, including diabetes. Here, we review our current knowledge on the effects of these pathologies on KV channel expression and function in vascular smooth muscle cells, and the repercussions on (micro)vascular function.
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Affiliation(s)
| | - Arsalan U Syed
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Matthew A Nystoriak
- Diabetes and Obesity Center, Department of Medicine, University of Louisville, Louisville, KY, USA
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA, USA
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17
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Byron KL, Brueggemann LI. Kv7 potassium channels as signal transduction intermediates in the control of microvascular tone. Microcirculation 2018; 25. [PMID: 28976052 DOI: 10.1111/micc.12419] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 09/27/2017] [Indexed: 12/18/2022]
Abstract
Potassium channels are recognized as important regulators of cellular functions in most, if not all cell types. These cellular proteins assemble to form gated pores in the plasma membrane, which serve to regulate the flow of potassium ions (K+ ) from the cytosol to the extracellular space. In VSMCs, the open state of potassium channels enables the efflux of K+ and thereby establishes a negative resting voltage across the plasma membrane that inhibits the opening of VSCCs. Under these conditions, cytosolic Ca2+ concentrations are relatively low and Ca2+ -dependent contraction is inhibited. Recent research has identified Kv7 family potassium channels as important contributors to resting membrane voltage in VSMCs, with much of the research focusing on the effects of drugs that specifically activate or block these channels to produce corresponding effects on VSMC contraction and vascular tone. Increasingly, evidence is emerging that these channels are not just good drug targets-they are also essential intermediates in vascular signal transduction, mediating vasoconstrictor or vasodilator responses to a variety of physiological stimuli. This review will summarize recent research findings that support a crucial function of Kv7 channels in both positive (vasoconstrictive) and negative (vasorelaxant) regulation of microvascular tone.
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Affiliation(s)
- Kenneth L Byron
- Department of Molecular Pharmacology & Therapeutics, Loyola University Chicago, Maywood, IL, USA
| | - Lyubov I Brueggemann
- Department of Molecular Pharmacology & Therapeutics, Loyola University Chicago, Maywood, IL, USA
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18
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Wei X, Zhang Y, Yin B, Wen J, Cheng J, Fu X. The expression and function of KCNQ potassium channels in human chorionic plate arteries from women with normal pregnancies and pre-eclampsia. PLoS One 2018; 13:e0192122. [PMID: 29579054 PMCID: PMC5868761 DOI: 10.1371/journal.pone.0192122] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 01/18/2018] [Indexed: 11/25/2022] Open
Abstract
Pre-eclampsia is associated with altered maternal and placental vascular reactivity. Kv7 channels (encoded by KCNQ 1–5 genes) are a potential contributor to the regulation of vascular tone in CPAs (chorionic plate arteries) during normal pregnancy. The aim of this study is to establish the expression profile of KCNQ subunits in CPAs taken from women with preeclampsia or normotensive women and to examine the functional relevance of the Kv7 channels on an altered expression profile of KCNQ subunits. The effects of Kv7 channel modulators on CPAs were investigated by tension measurement. Quantitative PCR experiments were used to analyze the expression of KCNQ genes. Western blotting and immunofluorescence were both used to analyze the protein expression of Kv7 channels. Finally, in CPAs from normotensive women, the Kv7 channel blocker XE991 increased arterial basal tone and U46619-induced contraction, and pre-contracted CPAs (10−7 M U46619) exhibited significant relaxation following treatment with Retigabine(Kv7.2–7.5 activator) and BMS-204352(Kv7.2–7.5 activator). However, ICA-27243(selective KCNQ2 and KCNQ3 activator) and ML277(selective KV7.1 activator) had no significant effect on tension in the pre-contracted CPAs. Conversely, compared with CPAs from normotensive women, the effects of XE991 on basal tone and agonist (U46619)-induced contractions in CPAs from women with preeclampsia were markedly attenuated. Moreover, the relaxation effects of Retigabine and BMS-204352 on pre-contracted CPA vessels from women with pre-eclampsia were also markedly down-regulated. Interestingly, the relaxation ability of ICA-27243 in pre-contracted CPA vessels in women with pre-eclampsia was enhanced. The mRNA of KCNQ3 was specifically up-regulated, whereas those for KCNQ4 and KCNQ5 were down-regulated in CPAs from women with pre-eclampsia compared with those in normotensive women. Similar observations were found in a subsequent analysis of protein expression of KCNQ genes 3–5. Thus, down-regulated Kv7 channel function in tension regulation of CPAs in women with pre-eclampsia could be associated with considerably altered expression profiles of Kv7 subunits.
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Affiliation(s)
- Xiaohong Wei
- Department of Gynecology and Obstetrics, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Yujiao Zhang
- Department of Gynecology and Obstetrics, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Benlan Yin
- Department of Gynecology and Obstetrics, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Jing Wen
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China
| | - Jun Cheng
- Key Laboratory of Medical Electrophysiology of Ministry of Education, Collaborative Innovation Center for Prevention and Treatment of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan, China
| | - Xiaodong Fu
- Department of Gynecology and Obstetrics, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
- * E-mail:
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19
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Barrese V, Stott JB, Greenwood IA. KCNQ-Encoded Potassium Channels as Therapeutic Targets. Annu Rev Pharmacol Toxicol 2018; 58:625-648. [DOI: 10.1146/annurev-pharmtox-010617-052912] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | | | - Iain A. Greenwood
- Vascular Biology Research Centre, Molecular and Clinical Sciences Institute, St George's, University of London, London, SW17 0RE, United Kingdom;, ,
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20
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Comerma-Steffensen SG, Carvacho I, Hedegaard ER, Simonsen U. Small and Intermediate Calcium-Activated Potassium Channel Openers Improve Rat Endothelial and Erectile Function. Front Pharmacol 2017; 8:660. [PMID: 28993731 PMCID: PMC5619997 DOI: 10.3389/fphar.2017.00660] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 09/05/2017] [Indexed: 12/13/2022] Open
Abstract
Modulation of endothelial calcium-activated potassium (KCa) channels has been proposed as an approach to restore endothelial function. The present study investigated whether novel openers of KCa channels with small (KCa2.x) and intermediate (KCa3.1) conductance, NS309 and NS4591, improve endothelium-dependent relaxation and erectile function. Rat corpus cavernosum (CC) strips were mounted for isometric tension recording and processed for immunoblotting. Mean arterial pressure (MAP), intracavernosal pressure (ICP), and electrocardiographic (ECG) measurements were conducted in anesthetized rats. Immunoblotting revealed the presence of KCa2.3 and large KCa conductance (KCa1.1) channels in the corpus cavernosum. NS309 and NS4591 increased current in CC endothelial cells in whole cell patch clamp experiments. Relaxation induced by NS309 (<1 μM) was inhibited by endothelial cell removal and high extracellular potassium. An inhibitor of nitric oxide (NO) synthase, and blockers of KCa2.x and KCa1.1 channels, apamin and iberiotoxin also inhibited NS309 relaxation. Incubation with NS309 (0.5 μM) markedly enhanced acetylcholine relaxation. Basal erectile function (ICP/MAP) increased during administration of NS309. Increases in ICP/MAP after cavernous nerve stimulation with NS309 were unchanged, whereas NS4591 significantly improved erectile function. Administration of NS309 and NS4591 caused small changes in the electrocardiogram, but neither arrhythmic events nor prolongation of the QTc interval were observed. The present study suggests that openers of KCa2.x and KCa3.1 channels improve endothelial and erectile function. The effects of NS309 and NS4591 on heart rate and ECG are small, but will require additional safety studies before evaluating whether activation of KCa2.3 channels has a potential for treatment of erectile dysfunction.
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Affiliation(s)
- Simon G. Comerma-Steffensen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus UniversityAarhus, Denmark
- Animal Physiology, Department of Biomedical Sciences, Veterinary Sciences Faculty, Central University of VenezuelaMaracay, Venezuela
| | - Ingrid Carvacho
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus UniversityAarhus, Denmark
- Department of Biology and Chemistry, Faculty of Basic Sciences, Universidad Católica del MauleTalca, Chile
| | - Elise R. Hedegaard
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus UniversityAarhus, Denmark
| | - Ulf Simonsen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus UniversityAarhus, Denmark
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21
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Senbel AM, Abd Elmoneim HM, Sharabi FM, Mohy El-Din MM. Neuronal Voltage Gated Potassium Channels May Modulate Nitric Oxide Synthesis in Corpus Cavernosum. Front Pharmacol 2017; 8:297. [PMID: 28603495 PMCID: PMC5445172 DOI: 10.3389/fphar.2017.00297] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Accepted: 05/10/2017] [Indexed: 11/24/2022] Open
Abstract
Potassium channels (K+Ch) in corpus cavernosum play an important role in the regulation of erection. Nitric oxide (NO) acts through opening of K+Ch leading to hyperpolarization and relaxation. Aim : This study aims to update knowledge about the role of voltage-gated K+Ch (KV) channels in erectile machinery and investigate their role in the control of NO action &/or synthesis in the corpus cavernosum. Methods : Tension studies using isolated rabbit corpus cavernosum (CC) strips and rat anococcygeus muscle were conducted. Results are expressed as mean ± SEM. Results : Electric field stimulation (EFS, 2–16 Hz) evoked frequency-dependent relaxations of the PE (phenylephrine)-precontracted CC strips. At 2 Hz, EFS-induced relaxation amounted to 73.17 ± 2.55% in presence 4-AP (10−3 M) compared to 41.98 ± 1.45% as control. None of the other selective K+Ch blockers tested inhibited EFS-induced relaxation. 4-AP (10−3M) significantly attenuated ACh-induced relaxation of rabbit CC where dose-response curve was clearly shifted upward, and attenuated SNP- induced relaxation, for example, to 49.28 ± 4.52% compared to 65.53 ± 3.01% as control at 10−6 M SNP. The potentiatory effect of 4-AP on EFS was abolished or reversed in presence of NG-nitro-L-arginine (L-NNA, non-selective nitric oxide synthase inhibitor, 10−5M, and 2 × 10−4M). Same results were observed in rat anococcygeus muscle which is a part of the erectile machinery in rats. Conclusion : This study provides evidence for the presence of prejunctional voltage-gated K+Ch in CC, the blockade of which may increase the neuronal synthesis of NO.
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Affiliation(s)
- Amira M Senbel
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt
| | - Heba M Abd Elmoneim
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt
| | - Fouad M Sharabi
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt
| | - Mahmoud M Mohy El-Din
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Alexandria UniversityAlexandria, Egypt
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22
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Stott JB, Barrese V, Greenwood IA. Kv7 Channel Activation Underpins EPAC-Dependent Relaxations of Rat Arteries. Arterioscler Thromb Vasc Biol 2016; 36:2404-2411. [PMID: 27789473 DOI: 10.1161/atvbaha.116.308517] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 10/11/2016] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To establish the role of Kv7 channels in EPAC (exchange protein directly activated by cAMP)-dependent relaxations of the rat vasculature and to investigate whether this contributes to β-adrenoceptor-mediated vasorelaxations. APPROACH AND RESULTS Isolated rat renal and mesenteric arteries (RA and MA, respectively) were used for isometric tension recording to study the relaxant effects of a specific EPAC activator and the β-adrenoceptor agonist isoproterenol in the presence of potassium channel inhibitors and cell signaling modulators. Isolated myocytes were used in proximity ligation assay studies to detect localization of signaling intermediaries with Kv7.4 before and after cell stimulation. Our studies showed that the EPAC activator (8-pCPT-2Me-cAMP-AM) produced relaxations and enhanced currents of MA and RA that were sensitive to linopirdine (Kv7 inhibitor). Linopirdine also inhibited isoproterenol-mediated relaxations in both RA and MA. In the MA, isoproterenol relaxations were sensitive to EPAC inhibition, but not protein kinase A inhibition. In contrast, isoproterenol relaxations in RA were attenuated by protein kinase A but not by EPAC inhibition. Proximity ligation assay showed a localization of Kv7.4 with A-kinase anchoring protein in both vessels in the basal state, which increased only in the RA with isoproterenol stimulation. In the MA, but not the RA, a localization of Kv7.4 with both Rap1a and Rap2 (downstream of EPAC) increased with isoproterenol stimulation. CONCLUSIONS EPAC-dependent vasorelaxations occur in part via activation of Kv7 channels. This contributes to the isoproterenol-mediated relaxation in mesenteric, but not renal, arteries.
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Affiliation(s)
- Jennifer B Stott
- From the Vascular Biology Research Group, Institute for Cardiovascular and Cell Sciences, St George's University of London, UK
| | - Vincenzo Barrese
- From the Vascular Biology Research Group, Institute for Cardiovascular and Cell Sciences, St George's University of London, UK
| | - Iain A Greenwood
- From the Vascular Biology Research Group, Institute for Cardiovascular and Cell Sciences, St George's University of London, UK.
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Jepps TA, Olesen SP, Greenwood IA, Dalsgaard T. Molecular and functional characterization of Kv 7 channels in penile arteries and corpus cavernosum of healthy and metabolic syndrome rats. Br J Pharmacol 2016; 173:1478-90. [PMID: 26802314 DOI: 10.1111/bph.13444] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Revised: 01/13/2016] [Accepted: 01/15/2016] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND AND PURPOSE KCNQ-encoded voltage-dependent potassium channels (Kv 7) are involved in the regulation of vascular tone. In this study we evaluated the influence of Kv 7 channel activation on smooth muscle relaxation in rat penile arteries and corpus cavernosum from normal and spontaneously hypertensive, heart failure-prone (SHHF) rats - a rat model of human metabolic syndrome. EXPERIMENTAL APPROACH Quantitative PCR and immunohistochemistry were used to determine the expression of KCNQ isoforms in penile tissue. Isometric tension was measured in intracavernous arterial rings and corpus cavernosum strips isolated from normal and SHHF rats. KEY RESULTS Transcripts for KCNQ3, KCNQ4 and KCNQ5 were detected in penile arteries and corpus cavernosum. KCNQ1 was only found in corpus cavernosum. Immunofluorescence signals to Kv 7.4 and Kv 7.5 were found in penile arteries, penile veins and corpus cavernosum. The Kv 7.2-7.5 activators, ML213 and BMS204352, relaxed pre-contracted penile arteries and corpus cavernosum independently of nitric oxide synthase or endothelium-derived hyperpolarization. Relaxations to sildenafil, a PDE5 inhibitor, and sodium nitroprusside (SNP), an nitric oxide donor, were reduced by blocking Kv 7 channels with linopirdine in penile arteries and corpus cavernosum. In SHHF rat penile arteries and corpus cavernosum, relaxations to ML213 and BMS204352 were attenuated, and the blocking effect of linopirdine on sildenafil-induced and SNP-induced relaxations reduced. KCNQ3, KCNQ4 and KCNQ5 were down-regulated, and KCNQ1 was up-regulated in corpus cavernosum from SHHF rats. KCNQ1-5 transcripts remained unchanged in penile arteries from SHHF rats. CONCLUSIONS AND IMPLICATIONS These data suggest that Kv 7 channels play a role in erectile function and contribute to the pathophysiology of erectile dysfunction, an early indicator of cardiovascular disease.
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Affiliation(s)
- T A Jepps
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - S P Olesen
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - I A Greenwood
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,The Vascular Biology Research Centre, Institute of Cardiovascular and Cell Sciences, St George's, London, UK
| | - T Dalsgaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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