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Zhao Y, Pasanen M, Rysä J. Placental ion channels: potential target of chemical exposure. Biol Reprod 2022; 108:41-51. [PMID: 36173899 PMCID: PMC9843680 DOI: 10.1093/biolre/ioac186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 01/21/2023] Open
Abstract
The placenta is an important organ for the exchange of substances between the fetus and the mother, hormone secretion, and fetoplacental immunological defense. Placenta has an organ-specific distribution of ion channels and trophoblasts, and placental vessels express a large number of ion channels. Several placental housekeeping activities and pregnancy complications are at least partly controlled by ion channels, which are playing an important role in regulating hormone secretion, trophoblastic homeostasis, ion transport, and vasomotor activity. The function of several placental ion channels (Na, Ca, and Cl ion channels, cation channel, nicotinic acetylcholine receptors, and aquaporin-1) is known to be influenced by chemical exposure, i.e., their responses to different chemicals have been tested and confirmed in experimental models. Here, we review the possibility that placental ion channels are targets of toxicological concern in terms of placental function, fetal growth, and development.
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Affiliation(s)
- Yi Zhao
- Department of Obstetrics, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China
| | - Markku Pasanen
- School of Pharmacy, University of Eastern Finland, Kuopio, Finland
| | - Jaana Rysä
- Correspondence: School of Pharmacy, University of Eastern Finland, POB 1627, Kuopio 70211, Finland. Tel: +358403552412; E-mail:
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2
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Baldwin SN, Forrester EA, McEwan L, Greenwood IA. Sexual dimorphism in prostacyclin-mimetic responses within rat mesenteric arteries: A novel role for K V 7.1 in shaping IP-receptor mediated relaxation. Br J Pharmacol 2021; 179:1338-1352. [PMID: 34766649 PMCID: PMC9340493 DOI: 10.1111/bph.15722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 09/21/2021] [Accepted: 10/19/2021] [Indexed: 11/29/2022] Open
Abstract
Background and Purpose Prostacyclin mimetics express potent vasoactive effects via prostanoid receptors that are not unequivocally defined, as to date no study has considered sex as a factor. The aim of this study was to determine the contribution of IP and EP3 prostanoid receptors to prostacyclin mimetic iloprost‐mediated responses, whether KV7.1–5 channels represent downstream targets of selective prostacyclin‐IP‐receptor agonist MRE‐269 and the impact of the oestrus cycle on vascular reactivity. Experimental Approach Within second‐order mesenteric arteries from male and female Wistar rats, we determined (1) relative mRNA transcripts for EP1–4 (Ptger1–4), IP (Ptgi) and TXA2 (Tbxa) prostanoid receptors via RT‐qPCR; (2) the effect of iloprost, MRE‐269, isoprenaline and ML277 on precontracted arterial tone in the presence of inhibitors of prostanoid receptors, potassium channels and the molecular interference of KV7.1 via wire‐myograph; (3) oestrus cycle stage via histological changes in cervical cell preparations. Key Results Iloprost evoked a biphasic response in male mesenteric arteries, at concentrations ≤100 nmol·L−1 relaxing, then contracting the vessel at concentration ≥300 nmol·L−1, a process attributed to IP and EP3 receptors respectively. Secondary contraction was absent in the females, which was associated with a reduction in Ptger3. Pharmacological inhibition and molecular interference of KV7.1 significantly attenuated relaxations produced by the selective IP receptor agonist MRE‐269 in male and female Wistar in dioestrus/metoestrus, but not pro‐oestrus/oestrus. Conclusions and Implications Stark sexual dimorphisms in iloprost‐mediated vasoactive responses are present within mesenteric arteries. KV7.1 is implicated in IP receptor‐mediated vasorelaxation and is impaired by the oestrus cycle.
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Affiliation(s)
- Samuel N Baldwin
- Molecular and clinical sciences research institute, St George's university, Cranmer terrace, London
| | - Elizabeth A Forrester
- Molecular and clinical sciences research institute, St George's university, Cranmer terrace, London
| | - Lauren McEwan
- Molecular and clinical sciences research institute, St George's university, Cranmer terrace, London
| | - Iain A Greenwood
- Molecular and clinical sciences research institute, St George's university, Cranmer terrace, London
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3
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Kasak L, Rull K, Yang T, Roden DM, Laan M. Recurrent Pregnancy Loss and Concealed Long-QT Syndrome. J Am Heart Assoc 2021; 10:e021236. [PMID: 34398675 PMCID: PMC8649249 DOI: 10.1161/jaha.121.021236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background Recurrent pregnancy loss affects 1% to 2% of couples attempting childbirth. A large fraction of all cases remains idiopathic, which warrants research into monogenic causes of this distressing disorder. Methods and Results We investigated a nonconsanguineous Estonian family who had experienced 5 live births, intersected by 3 early pregnancy losses, and 6 fetal deaths, 3 of which occurred during the second trimester. No fetal malformations were described at the autopsies performed in 3 of 6 cases of fetal death. Parental and fetal chromosomal abnormalities (including submicroscopic) and maternal risk factors were excluded. Material for genetic testing was available from 4 miscarried cases (gestational weeks 11, 14, 17, and 18). Exome sequencing in 3 pregnancy losses and the mother identified no rare variants explicitly shared by the miscarried conceptuses. However, the mother and 2 pregnancy losses carried a heterozygous nonsynonymous variant, resulting in p.Val173Asp (rs199472695) in the ion channel gene KCNQ1. It is expressed not only in heart, where mutations cause type 1 long‐QT syndrome, but also in other tissues, including uterus. The p.Val173Asp variant has been previously identified in a patient with type 1 long‐QT syndrome, but not reported in the Genome Aggregation Database. With heterologous expression in CHO cells, our in vitro electrophysiologic studies indicated that the mutant slowly activating voltage‐gated K+ channel (IKs) is dysfunctional. It showed reduced total activating and deactivating currents (P<0.01), with dramatically positive shift of voltage dependence of activation by ≈10 mV (P<0.05). Conclusions The current study uncovered concealed maternal type 1 long‐QT syndrome as a potential novel cause behind recurrent fetal loss.
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Affiliation(s)
- Laura Kasak
- Institute of Biomedicine and Translational Medicine University of Tartu Estonia
| | - Kristiina Rull
- Institute of Biomedicine and Translational Medicine University of Tartu Estonia.,Women's Clinic Tartu University Hospital Tartu Estonia.,Institute of Clinical Medicine University of Tartu Estonia
| | - Tao Yang
- Departments of Medicine, Pharmacology and Biomedical Informatics Vanderbilt University Medical Center Nashville TN
| | - Dan M Roden
- Departments of Medicine, Pharmacology and Biomedical Informatics Vanderbilt University Medical Center Nashville TN
| | - Maris Laan
- Institute of Biomedicine and Translational Medicine University of Tartu Estonia
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Jepps TA. Kv7 channel trafficking by the microtubule network in vascular smooth muscle. Acta Physiol (Oxf) 2021; 232:e13692. [PMID: 34021973 PMCID: PMC8365713 DOI: 10.1111/apha.13692] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/17/2021] [Accepted: 05/19/2021] [Indexed: 12/17/2022]
Abstract
In arterial smooth muscle cells, changes in availability of integral membrane proteins influence the regulation of blood flow and blood pressure, which is critical for human health. However, the mechanisms that coordinate the trafficking and membrane expression of specific receptors and ion channels in vascular smooth muscle are poorly understood. In the vasculature, very little is known about microtubules, which form a road network upon which proteins can be transported to and from the cell membrane. This review article summarizes the impact of the microtubule network on arterial contractility, highlighting the importance of the network, with an emphasis on our recent findings regarding the trafficking of the voltage‐dependent Kv7 channels.
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Affiliation(s)
- Thomas A Jepps
- Vascular Biology Group Department of Biomedical Sciences University of Copenhagen Blegdamsvej 3 2200 Copenhagen N Denmark
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5
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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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6
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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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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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8
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Clinical Importance of the Human Umbilical Artery Potassium Channels. Cells 2020; 9:cells9091956. [PMID: 32854241 PMCID: PMC7565333 DOI: 10.3390/cells9091956] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 02/06/2023] Open
Abstract
Potassium (K+) channels are usually predominant in the membranes of vascular smooth muscle cells (SMCs). These channels play an important role in regulating the membrane potential and vessel contractility-a role that depends on the vascular bed. Thus, the activity of K+ channels represents one of the main mechanisms regulating the vascular tone in physiological and pathophysiological conditions. Briefly, the activation of K+ channels in SMC leads to hyperpolarization and vasorelaxation, while its inhibition induces depolarization and consequent vascular contraction. Currently, there are four different types of K+ channels described in SMCs: voltage-dependent K+ (KV) channels, calcium-activated K+ (KCa) channels, inward rectifier K+ (Kir) channels, and 2-pore domain K+ (K2P) channels. Due to the fundamental role of K+ channels in excitable cells, these channels are promising therapeutic targets in clinical practice. Therefore, this review discusses the basic properties of the various types of K+ channels, including structure, cellular mechanisms that regulate their activity, and new advances in the development of activators and blockers of these channels. The vascular functions of these channels will be discussed with a focus on vascular SMCs of the human umbilical artery. Then, the clinical importance of K+ channels in the treatment and prevention of cardiovascular diseases during pregnancy, such as gestational hypertension and preeclampsia, will be explored.
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9
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Dreier R, Abdolalizadeh B, Asferg CL, Hölmich LR, Buus NH, Forman JL, Andersen UB, Egfjord M, Sheykhzade M, Jeppesen JL. Effect of increased potassium intake on the renin-angiotensin-aldosterone system and subcutaneous resistance arteries: a randomized crossover study. Nephrol Dial Transplant 2020; 36:gfaa114. [PMID: 32596729 DOI: 10.1093/ndt/gfaa114] [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: 01/14/2020] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Increased potassium intake lowers blood pressure (BP) in hypertensive patients. The underlying mechanism is not fully understood but must be complex because increased potassium intake elevates circulating concentrations of the BP-raising hormone aldosterone. METHODS In a randomized placebo-controlled crossover study in 25 normotensive men, we investigated the effect of 4 weeks of potassium supplement (90 mmol/day) compared with 4 weeks of placebo on the renin-angiotensin-aldosterone system (RAAS), urine composition and 24-h ambulatory BP. Vascular function was also assessed through wire myograph experiments on subcutaneous resistance arteries from gluteal fat biopsies. RESULTS Higher potassium intake increased urinary potassium excretion (144.7 ± 28.7 versus 67.5 ± 25.5 mmol/24-h; P < 0.0001) and plasma concentrations of potassium (4.3 ± 0.2 versus 4.0 ± 0.2 mmol/L; P = 0.0002), renin {mean 16 [95% confidence interval (CI) 12-23] versus 11 [5-16] mIU/L; P = 0.0047}, angiotensin II [mean 10.0 (95% CI 6.2-13.0) versus 6.1 (4.0-10.0) pmol/L; P = 0.0025] and aldosterone [mean 440 (95% CI 336-521) versus 237 (173-386) pmol/L; P < 0.0001]. Despite RAAS activation, systolic BP (117.6 ± 5.8 versus 118.2 ± 5.2 mmHg; P = 0.48) and diastolic BP (70.8 ± 6.2 versus 70.8 ± 6.3 mmHg; P = 0.97) were unchanged. In the wire myograph experiments, higher potassium intake did not affect endothelial function as assessed by acetylcholine [logarithmically transformed half maximal effective concentration (pEC50): 7.66 ± 0.95 versus 7.59 ± 0.85; P = 0.86] and substance P (pEC50: 8.42 ± 0.77 versus 8.41 ± 0.89; P = 0.97) or vascular smooth muscle cell reactivity as assessed by angiotensin II (pEC50: 9.01 ± 0.86 versus 9.02 ± 0.59; P = 0.93) and sodium nitroprusside (pEC50: 7.85 ± 1.07 versus 8.25 ± 1.32; P = 0.25) but attenuated the vasodilatory response of retigabine (pEC50: 7.47 ± 1.16 versus 8.14 ± 0.90; P = 0.0084), an activator of Kv7 channels. CONCLUSIONS Four weeks of increased potassium intake activates the RAAS in normotensive men without changing BP and this is not explained by improved vasodilatory responses ex vivo.
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Affiliation(s)
- Rasmus Dreier
- Department of Medicine, Amager Hvidovre Hospital in Glostrup, University of Copenhagen, Glostrup, Denmark
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
| | - Bahareh Abdolalizadeh
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Camilla L Asferg
- Department of Medicine, Amager Hvidovre Hospital in Glostrup, University of Copenhagen, Glostrup, Denmark
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
| | - Lisbet R Hölmich
- Department of Plastic Surgery, Herlev Gentofte Hospital, University of Copenhagen, Herlev, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Niels H Buus
- Department of Renal Medicine, Aarhus University Hospital, Aarhus, Denmark
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Julie L Forman
- Department of Public Health, Section of Biostatistics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ulrik B Andersen
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
| | - Martin Egfjord
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Nephrology, Rigshospitalet Blegdamsvej, University of Copenhagen, Copenhagen, Denmark
| | - Majid Sheykhzade
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jørgen L Jeppesen
- Department of Medicine, Amager Hvidovre Hospital in Glostrup, University of Copenhagen, Glostrup, Denmark
- Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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Tsuchida N, Kojima J, Fukuda A, Oda M, Kawasaki T, Ito H, Kuji N, Isaka K, Nishi H, Umezawa A, Akutsu H. Transcriptomic features of trophoblast lineage cells derived from human induced pluripotent stem cells treated with BMP 4. Placenta 2019; 89:20-32. [PMID: 31675487 DOI: 10.1016/j.placenta.2019.10.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 08/31/2019] [Accepted: 10/07/2019] [Indexed: 01/08/2023]
Abstract
INTRODUCTION Early development of the human placenta remains poorly understood due to the lack of proper model systems. Previous reports have demonstrated that human induced pluripotent stem cells (hiPSCs) treated with bone morphogenetic protein 4 (BMP4) can differentiate into extraembryonic tissues as useful models of the early stage of trophoblast (TB) differentiation. In our previous study, we optimized the culture conditions of hiPSC-derived TB lineages, but the differentiated cells were heterogeneous. METHODS In order to characterize the hiPSC-derived TB lineage cells, four types of hiPSCs were treated with 50 ng/mL of BMP4 for 10 days. Subsequently, cells that were positive for the pan-TB marker keratin 7(KRT7) were purified from the differentiated cells using flow cytometry and identified with a DNA microarray. RESULTS Comparisons of our microarray data with the human transcriptome in a previous large-scale analysis showed that the gene expression patterns of KRT7+ cells were similar to the placenta. In total, 259 upregulated genes were commonly expressed in all four KRT7+ groups, including well-known TB markers. Among these upregulated genes, several with poorly investigated expression patterns and functions were confirmed as expressed in the primary placenta. While only XAGE2 and KCNQ2 were expressed in TB layers, XAGE2 was expressed throughout pregnancy and KCNQ2 was expressed only in cytotrophoblasts of the first trimester placenta. CONCLUSION BMP4-treated KRT7+ cells were in the course of the human placental development. In addition, this approach allowed the identification of new genes that might be involved in placentation. However, further studies are needed to confirm their functions.
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Affiliation(s)
- Nanae Tsuchida
- Department of Obstetrics and Gynecology, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku, Tokyo, 160-0023, Japan; Center for Regenerative Medicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo, 157-8535, Japan
| | - Junya Kojima
- Department of Obstetrics and Gynecology, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku, Tokyo, 160-0023, Japan
| | - Atsushi Fukuda
- Center for Regenerative Medicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo, 157-8535, Japan
| | - Mayumi Oda
- Department of Systems Medicine, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan
| | - Tomoyuki Kawasaki
- Center for Regenerative Medicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo, 157-8535, Japan
| | - Hiroe Ito
- Department of Obstetrics and Gynecology, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku, Tokyo, 160-0023, Japan
| | - Naoaki Kuji
- Department of Obstetrics and Gynecology, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku, Tokyo, 160-0023, Japan
| | - Keiichi Isaka
- Department of Obstetrics and Gynecology, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku, Tokyo, 160-0023, Japan
| | - Hirotaka Nishi
- Department of Obstetrics and Gynecology, Tokyo Medical University, 6-7-1 Nishi-Shinjuku, Shinjuku, Tokyo, 160-0023, Japan
| | - Akihiro Umezawa
- Center for Regenerative Medicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo, 157-8535, Japan
| | - Hidenori Akutsu
- Center for Regenerative Medicine, National Research Institute for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo, 157-8535, Japan.
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Abstract
The highly structurally similar drugs flupirtine and retigabine have been regarded as safe and effective for many years but lately they turned out to exert intolerable side effects. While the twin molecules share the mode of action, both stabilize the open state of voltage-gated potassium channels, the form and severity of adverse effects is different. The analgesic flupirtine caused drug-induced liver injury in rare but fatal cases, whereas prolonged use of the antiepileptic retigabine led to blue tissue discoloration. Because the adverse effects seem unrelated to the mode of action, it is likely, that both drugs that occupied important therapeutic niches, could be replaced. Reasons for the clinically relevant toxicity will be clarified and future substitutes for these drugs presented in this review.
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Namgoong H, Cho C, Lee S. The Kv7 channel activator, retigabine, induces vasorelaxation via an endothelial-independent pathway in male mouse aorta. J Exerc Nutrition Biochem 2018; 22:51-55. [PMID: 30343562 PMCID: PMC6199484 DOI: 10.20463/jenb.2018.0024] [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: 09/03/2018] [Accepted: 09/27/2018] [Indexed: 11/22/2022] Open
Abstract
PURPOSE Previous studies have indicated that Kv7 channels have an important role in the regulation of blood vessel reactivity, including in the coronary, renal, and cerebral arteries. The present studies examined whether Kv7 channels regulated vascular reactivity in the mouse aorta and investigated the mechanisms involved in the reactivity. METHODS Wild-type (WT) male C57BL/6 mice, between 10 and 15 weeks old, were used in this study. The vascular function of the aorta in WT male mice was assessed by using a pin myography system (Model 620; DMT, Denmark). RESULTS Vasorelaxation by an endothelial-dependent vasodilator, acetylcholine (ACh, 1 nM - 10 μM) and an endothelial-independent vasodilator, sodium nitroprusside (SNP, 1 nM - 10 μM) was induced in the aorta in a dose-dependent manner. Pre-incubation with the nitric oxide synthase inhibitor, L-NAME (100 μM, 20 min), completely abolished ACh-induced vasorelaxation, but did not block retigabine-induced vasorelaxation, which suggested that retigabine caused vasorelaxation in the aorta via smooth muscle activation rather than via endothelial cells. Pre-application of the Kv7 channel blocker, linopirdine (10 μM), resulted in a greater contractile response compared with that induced by vehicle in the aorta. In addition, pre-incubation with linopirdine (10 μM, 20 min) reduced retigabine-induced vasorelaxation (1-50 μM). CONCLUSION This study has provided evidence that Kv7 channels may play a role in the regulation of aortic blood flow via smooth muscle activation.
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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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Abbott GW, Jepps TA. Kcne4 Deletion Sex-Dependently Alters Vascular Reactivity. J Vasc Res 2016; 53:138-148. [PMID: 27710966 DOI: 10.1159/000449060] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 08/10/2016] [Indexed: 01/06/2023] Open
Abstract
Voltage-gated potassium (Kv) channels formed by Kv7 (KCNQ) α-subunits are recognized as crucial for vascular smooth muscle function, in addition to their established roles in the heart (Kv7.1) and the brain (Kv7.2-5). In vivo, Kv7 α-subunits are often regulated by KCNE subfamily ancillary (β) subunits. We investigated the effects of targeted germline Kcne4 deletion on mesenteric artery reactivity in adult male and female mice. Kcne4 deletion increased mesenteric artery contractility in response to α-adrenoceptor agonist methoxamine, and decreased responses to Kv7.2-7.5 channel activator ML213, in male but not female mice. In contrast, Kcne4 deletion markedly decreased vasorelaxation in response to isoprenaline in both male and female mice. Kcne4 expression was 2-fold lower in the female versus the male mouse mesenteric artery, and Kcne4 deletion elicited only moderate changes of other Kcne transcripts, with no striking sex-specific differences. However, Kv7.4 protein expression in females was twice that in males, and was reduced in both sexes by Kcne4 deletion. Our findings confirm a crucial role for KCNE4 in regulation of Kv7 channel activity to modulate vascular tone, and provide the first known molecular mechanism for sex-specificity of this modulation that has important implications for vascular reactivity and may underlie sex-specific susceptibility to cardiovascular diseases.
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Affiliation(s)
- Geoffrey W Abbott
- Bioelectricity Laboratory, Departments of Pharmacology and Physiology and Biophysics, School of Medicine, University of California, Irvine, Calif., USA
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Haick JM, Byron KL. Novel treatment strategies for smooth muscle disorders: Targeting Kv7 potassium channels. Pharmacol Ther 2016; 165:14-25. [PMID: 27179745 DOI: 10.1016/j.pharmthera.2016.05.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Smooth muscle cells provide crucial contractile functions in visceral, vascular, and lung tissues. The contractile state of smooth muscle is largely determined by their electrical excitability, which is in turn influenced by the activity of potassium channels. The activity of potassium channels sustains smooth muscle cell membrane hyperpolarization, reducing cellular excitability and thereby promoting smooth muscle relaxation. Research over the past decade has indicated an important role for Kv7 (KCNQ) voltage-gated potassium channels in the regulation of the excitability of smooth muscle cells. Expression of multiple Kv7 channel subtypes has been demonstrated in smooth muscle cells from viscera (gastrointestinal, bladder, myometrial), from the systemic and pulmonary vasculature, and from the airways of the lung, from multiple species, including humans. A number of clinically used drugs, some of which were developed to target Kv7 channels in other tissues, have been found to exert robust effects on smooth muscle Kv7 channels. Functional studies have indicated that Kv7 channel activators and inhibitors have the ability to relax and contact smooth muscle preparations, respectively, suggesting a wide range of novel applications for the pharmacological tool set. This review summarizes recent findings regarding the physiological functions of Kv7 channels in smooth muscle, and highlights potential therapeutic applications based on pharmacological targeting of smooth muscle Kv7 channels throughout the body.
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Affiliation(s)
- Jennifer M Haick
- Department of Molecular Pharmacology & Therapeutics, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Kenneth L Byron
- Department of Molecular Pharmacology & Therapeutics, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA.
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Hayward CE, Lean S, Sibley CP, Jones RL, Wareing M, Greenwood SL, Dilworth MR. Placental Adaptation: What Can We Learn from Birthweight:Placental Weight Ratio? Front Physiol 2016; 7:28. [PMID: 26903878 PMCID: PMC4742558 DOI: 10.3389/fphys.2016.00028] [Citation(s) in RCA: 170] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/18/2016] [Indexed: 11/17/2022] Open
Abstract
Appropriate fetal growth relies upon adequate placental nutrient transfer. Birthweight:placental weight ratio (BW:PW ratio) is often used as a proxy for placental efficiency, defined as the grams of fetus produced per gram placenta. An elevated BW:PW ratio in an appropriately grown fetus (small placenta) is assumed to be due to up-regulated placental nutrient transfer capacity i.e., a higher nutrient net flux per gram placenta. In fetal growth restriction (FGR), where a fetus fails to achieve its genetically pre-determined growth potential, placental weight and BW:PW ratio are often reduced which may indicate a placenta that fails to adapt its nutrient transfer capacity to compensate for its small size. This review considers the literature on BW:PW ratio in both large cohort studies of normal pregnancies and those studies offering insight into the relationship between BW:PW ratio and outcome measures including stillbirth, FGR, and subsequent postnatal consequences. The core of this review is the question of whether BW:PW ratio is truly indicative of altered placental efficiency, and whether changes in BW:PW ratio reflect those placentas which adapt their nutrient transfer according to their size. We consider this question using data from mice and humans, focusing upon studies that have measured the activity of the well characterized placental system A amino acid transporter, both in uncomplicated pregnancies and in FGR. Evidence suggests that BW:PW ratio is reduced both in FGR and in pregnancies resulting in a small for gestational age (SGA, birthweight < 10th centile) infant but this effect is more pronounced earlier in gestation (<28 weeks). In mice, there is a clear association between increased BW:PW ratio and increased placental system A activity. Additionally, there is good evidence in wild-type mice that small placentas upregulate placental nutrient transfer to prevent fetal undergrowth. In humans, this association between BW:PW ratio and placental system A activity is less clear and is worthy of further consideration, both in terms of system A and other placental nutrient transfer processes. This knowledge would help decide the value of measuring BW:PW ratio in terms of determining the risk of poor health outcomes, both in the neonatal period and long term.
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Affiliation(s)
- Christina E Hayward
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Samantha Lean
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Colin P Sibley
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Rebecca L Jones
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Mark Wareing
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Susan L Greenwood
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Mark R Dilworth
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
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