1
|
Harvey BJ, Harvey HM. Sex Differences in Colon Cancer: Genomic and Nongenomic Signalling of Oestrogen. Genes (Basel) 2023; 14:2225. [PMID: 38137047 PMCID: PMC10742859 DOI: 10.3390/genes14122225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/10/2023] [Accepted: 12/14/2023] [Indexed: 12/24/2023] Open
Abstract
Colon cancer (CRC) is a prevalent malignancy that exhibits distinct differences in incidence, prognosis, and treatment responses between males and females. These disparities have long been attributed to hormonal differences, particularly the influence of oestrogen signalling. This review aims to provide a comprehensive analysis of recent advances in our understanding of the molecular mechanisms underlying sex differences in colon cancer and the protective role of membrane and nuclear oestrogen signalling in CRC development, progression, and therapeutic interventions. We discuss the epidemiological and molecular evidence supporting sex differences in colon cancer, followed by an exploration of the impact of oestrogen in CRC through various genomic and nongenomic signalling pathways involving membrane and nuclear oestrogen receptors. Furthermore, we examine the interplay between oestrogen receptors and other signalling pathways, in particular the Wnt/β-catenin proliferative pathway and hypoxia in shaping biological sex differences and oestrogen protective actions in colon cancer. Lastly, we highlight the potential therapeutic implications of targeting oestrogen signalling in the management of colon cancer and propose future research directions to address the current gaps in our understanding of this complex phenomenon.
Collapse
Affiliation(s)
- Brian J. Harvey
- Faculty of Medicine, Royal College of Surgeons in Ireland, RCSI University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland
| | - Harry M. Harvey
- Princess Margaret Cancer Centre, Toronto, ON M5G 1Z5, Canada;
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Barton JR, Londregan AK, Alexander TD, Entezari AA, Covarrubias M, Waldman SA. Enteroendocrine cell regulation of the gut-brain axis. Front Neurosci 2023; 17:1272955. [PMID: 38027512 PMCID: PMC10662325 DOI: 10.3389/fnins.2023.1272955] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Accepted: 10/16/2023] [Indexed: 12/01/2023] Open
Abstract
Enteroendocrine cells (EECs) are an essential interface between the gut and brain that communicate signals about nutrients, pain, and even information from our microbiome. EECs are hormone-producing cells expressed throughout the gastrointestinal epithelium and have been leveraged by pharmaceuticals like semaglutide (Ozempic, Wegovy), terzepatide (Mounjaro), and retatrutide (Phase 2) for diabetes and weight control, and linaclotide (Linzess) to treat irritable bowel syndrome (IBS) and visceral pain. This review focuses on role of intestinal EECs to communicate signals from the gut lumen to the brain. Canonically, EECs communicate information about the intestinal environment through a variety of hormones, dividing EECs into separate classes based on the hormone each cell type secretes. Recent studies have revealed more diverse hormone profiles and communication modalities for EECs including direct synaptic communication with peripheral neurons. EECs known as neuropod cells rapidly relay signals from gut to brain via a direct communication with vagal and primary sensory neurons. Further, this review discusses the complex information processing machinery within EECs, including receptors that transduce intraluminal signals and the ion channel complement that govern initiation and propagation of these signals. Deeper understanding of EEC physiology is necessary to safely treat devastating and pervasive conditions like irritable bowel syndrome and obesity.
Collapse
Affiliation(s)
- Joshua R. Barton
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Annie K. Londregan
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Tyler D. Alexander
- Department of Neurosciences, Thomas Jefferson University, Philadelphia, PA, United States
| | - Ariana A. Entezari
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
| | - Manuel Covarrubias
- Department of Neurosciences, Thomas Jefferson University, Philadelphia, PA, United States
| | - Scott A. Waldman
- Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, PA, United States
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, United States
| |
Collapse
|
4
|
Navarro-Pérez M, Estadella I, Benavente-Garcia A, Orellana-Fernández R, Petit A, Ferreres JC, Felipe A. The Phosphorylation of Kv1.3: A Modulatory Mechanism for a Multifunctional Ion Channel. Cancers (Basel) 2023; 15:2716. [PMID: 37345053 DOI: 10.3390/cancers15102716] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 05/04/2023] [Accepted: 05/09/2023] [Indexed: 06/23/2023] Open
Abstract
The voltage-gated potassium channel Kv1.3 plays a pivotal role in a myriad of biological processes, including cell proliferation, differentiation, and apoptosis. Kv1.3 undergoes fine-tuned regulation, and its altered expression or function correlates with tumorigenesis and cancer progression. Moreover, posttranslational modifications (PTMs), such as phosphorylation, have evolved as rapid switch-like moieties that tightly modulate channel activity. In addition, kinases are promising targets in anticancer therapies. The diverse serine/threonine and tyrosine kinases function on Kv1.3 and the effects of its phosphorylation vary depending on multiple factors. For instance, Kv1.3 regulatory subunits (KCNE4 and Kvβ) can be phosphorylated, increasing the complexity of channel modulation. Scaffold proteins allow the Kv1.3 channelosome and kinase to form protein complexes, thereby favoring the attachment of phosphate groups. This review compiles the network triggers and signaling pathways that culminate in Kv1.3 phosphorylation. Alterations to Kv1.3 expression and its phosphorylation are detailed, emphasizing the importance of this channel as an anticancer target. Overall, further research on Kv1.3 kinase-dependent effects should be addressed to develop effective antineoplastic drugs while minimizing side effects. This promising field encourages basic cancer research while inspiring new therapy development.
Collapse
Affiliation(s)
- María Navarro-Pérez
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain
| | - Irene Estadella
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain
| | - Anna Benavente-Garcia
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain
| | | | - Anna Petit
- Departament de Patologia, Hospital Universitari de Bellvitge, IDIBELL, L'Hospitalet del Llobregat, 08908 Barcelona, Spain
| | - Joan Carles Ferreres
- Servei d'Anatomia Patològica, Parc Taulí Hospital Universitari, Institut d'Investigació i Innovació Parc Taulí (I3PT-CERCA), 08208 Sabadell, Spain
- Departament de Ciències Morfològiques, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain
| | - Antonio Felipe
- Molecular Physiology Laboratory, Departament de Bioquímica i Biomedicina Molecular, Institut de Biomedicina (IBUB), Universitat de Barcelona, Avda. Diagonal 643, 08028 Barcelona, Spain
| |
Collapse
|
5
|
Erlandsdotter LM, Giammarino L, Halili A, Nikesjö J, Gréen H, Odening KE, Liin SI. Long-QT mutations in KCNE1 modulate the 17β-estradiol response of Kv7.1/KCNE1. SCIENCE ADVANCES 2023; 9:eade7109. [PMID: 36921038 PMCID: PMC10017040 DOI: 10.1126/sciadv.ade7109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
Estradiol (17[Formula: see text]-E2) is implicated in higher arrhythmia risk of women with congenital or acquired long-QT syndrome (LQTS) compared to men. However, the underlying mechanisms remain poorly understood, and little is known about the impact of LQTS-associated mutations. We show that 17[Formula: see text]-E2 inhibits the human cardiac Kv7.1/KCNE1 channel expressed in Xenopus oocytes. We find that the 17[Formula: see text]-E2 effect depends on the Kv7.1 to KCNE1 stoichiometry, and we reveal a critical function of the KCNE1 carboxyl terminus for the effect. LQTS-associated mutations in the KCNE1 carboxyl terminus show a range of responses to 17[Formula: see text]-E2, from a wild-type like response to impaired or abolished response. Together, this study increases our understanding of the mechanistic basis for 17[Formula: see text]-E2 inhibition of Kv7.1/KCNE1 and demonstrates mutation-dependent responses to 17[Formula: see text]-E2. These findings suggest that the 17[Formula: see text]-E2 effect on Kv7.1/KCNE1 might contribute to the higher arrhythmia risk of women, particularly in carriers with specific LQTS-associated mutations.
Collapse
Affiliation(s)
| | - Lucilla Giammarino
- Translational Cardiology, Department of Cardiology, Inselspital, University Hospital Bern and Department of Physiology, University of Bern, Bern, Switzerland
| | - Azemine Halili
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Johan Nikesjö
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| | - Henrik Gréen
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
- Department of Forensic Genetics and Forensic Toxicology, National Board of Forensic Medicine, Linköping, Sweden
| | - Katja E. Odening
- Translational Cardiology, Department of Cardiology, Inselspital, University Hospital Bern and Department of Physiology, University of Bern, Bern, Switzerland
| | - Sara I. Liin
- Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
| |
Collapse
|
6
|
Baldwin SN, Forrester EA, Homer NZM, Andrew R, Barrese V, Stott JB, Isakson BE, Albert AP, Greenwood IA. Marked oestrous cycle-dependent regulation of rat arterial K V 7.4 channels driven by GPER1. Br J Pharmacol 2023; 180:174-193. [PMID: 36085551 PMCID: PMC10091994 DOI: 10.1111/bph.15947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 06/21/2022] [Accepted: 07/20/2022] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Kcnq-encoded KV 7 channels (termed KV 7.1-5) regulate vascular smooth muscle cell (VSMC) contractility at rest and as targets of receptor-mediated responses. However, the current data are mostly derived from males. Considering the known effects of sex, the oestrous cycle and sex hormones on vascular reactivity, here we have characterised the molecular and functional properties of KV 7 channels from renal and mesenteric arteries from female Wistar rats separated into di-oestrus and met-oestrus (F-D/M) and pro-oestrus and oestrus (F-P/E). EXPERIMENTAL APPROACH RT-qPCR, immunocytochemistry, proximity ligation assay and wire myography were performed in renal and mesenteric arteries. Circulating sex hormone concentrations were determined by liquid chromatography-tandem mass spectrometry. Whole-cell electrophysiology was undertaken on cells expressing KV 7.4 channels in association with G-protein-coupled oestrogen receptor 1 (GPER1). KEY RESULTS The KV 7.2-5 activators S-1 and ML213 and the pan-KV 7 inhibitor linopirdine were more effective in arteries from F-D/M compared with F-P/E animals. In VSMCs isolated from F-P/E rats, exploratory evidence indicates reduced membrane abundance of KV 7.4 but not KV 7.1, KV 7.5 and Kcne4 when compared with cells from F-D/M. Plasma oestradiol was higher in F-P/E compared with F-D/M, and progesterone showed the converse pattern. Oestradiol/GPER1 agonist G-1 diminished KV 7.4 encoded currents and ML213 relaxations and reduced the membrane abundance of KV 7.4 and interaction between KV 7.4 and heat shock protein 90 (HSP90), in arteries from F-D/M but not F-P/E. CONCLUSIONS AND IMPLICATIONS GPER1 signalling decreased KV 7.4 membrane abundance in conjunction with diminished interaction with HSP90, giving rise to a 'pro-contractile state'.
Collapse
Affiliation(s)
- Samuel N. Baldwin
- Vascular Biology Research Centre, Institute of Molecular and Clinical SciencesSt George's University of LondonLondonUK
| | - Elizabeth A. Forrester
- Vascular Biology Research Centre, Institute of Molecular and Clinical SciencesSt George's University of LondonLondonUK
| | - Natalie Z. M. Homer
- Mass Spectrometry Core Laboratory, Edinburgh Clinical Research Facility, Queen's Medical Research InstituteUniversity of EdinburghEdinburghUK
| | - Ruth Andrew
- Mass Spectrometry Core Laboratory, Edinburgh Clinical Research Facility, Queen's Medical Research InstituteUniversity of EdinburghEdinburghUK
- BHF Centre for Cardiovascular Science, Queen's Medical Research InstituteUniversity of EdinburghEdinburghUK
| | - Vincenzo Barrese
- Department of Neuroscience, Reproductive Sciences and DentistryUniversity of Naples Federico IINaplesItaly
| | - Jennifer B. Stott
- Vascular Biology Research Centre, Institute of Molecular and Clinical SciencesSt George's University of LondonLondonUK
| | - Brant E. Isakson
- Department of Molecular Physiology and Biophysics, Robert M. Berne Cardiovascular Research CentreUniversity of Virginia School of MedicineCharlottesvilleVirginiaUSA
| | - Anthony P. Albert
- Vascular Biology Research Centre, Institute of Molecular and Clinical SciencesSt George's University of LondonLondonUK
| | - Iain A. Greenwood
- Vascular Biology Research Centre, Institute of Molecular and Clinical SciencesSt George's University of LondonLondonUK
| |
Collapse
|
7
|
Refaat B, Aslam A, Idris S, Almalki AH, Alkhaldi MY, Asiri HA, Almaimani RA, Mujalli A, Minshawi F, Alamri SA, AlHussain MI, Baltow BA, Alqasmi MH, Basfar GT, Alosaimi OM, Muhayya IA. Profiling estrogen, progesterone, and androgen receptors in colorectal cancer in relation to gender, menopausal status, clinical stage, and tumour sidedness. Front Endocrinol (Lausanne) 2023; 14:1187259. [PMID: 37206439 PMCID: PMC10190606 DOI: 10.3389/fendo.2023.1187259] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 04/12/2023] [Indexed: 05/21/2023] Open
Abstract
Background Although estrogen (ERα/ERβ), progesterone (PGR), and androgen (AR) receptors are pathologically altered in colorectal cancer (CRC), their simultaneous expression within the same cohort of patients was not previously measured. Methods ERα/ERβ/PGR/AR proteins were measured in archived paired normal and malignant colon specimens (n =120 patients) by immunohistochemistry, and results were analyzed by gender, age (≤50 vs. ≥60 years), clinical stages (early-stage I/II vs. late-stage III/IV), and anatomical location (right; RSCs vs. left; LSCs). Effects of 17β-estradiol (E2), progesterone (P4), and testosterone alone or combined with the specific blockers of ERα (MPP dihydrochloride), ERβ (PHTPP), PGR (mifepristone), and AR (bicalutamide) on cell cycle and apoptosis were also measured in the SW480 male and HT29 female CRC cell lines. Results ERα and AR proteins increased, whilst ERβ and PGR declined markedly in malignant specimens. Moreover, male neoplastic tissues showed highest AR expression, whilst ERβ and PGR weakest alongside ERα strongest expression was seen in cancerous tissues from women aged ≥60 years. Late-stage neoplasms also revealed maximal alterations in the expression of sex steroid receptors. By tumor location, LSCs disclosed significant elevations in ERα with marked declines in PGR compared with RSCs, and ERα strongest alongside PGR weakest expression was detected in advanced LSCs from women aged ≥60 years. Late-stage LSCs from females aged ≥60 years also showed weakest ERβ and strongest AR expression. In contrast, male RSC and LSC tissues exhibited equal ERβ and AR expression in all clinical stages. ERα and AR proteins also correlated positively, whereas ERβ and PGR inversely, with tumor characteristics. Concomitantly, E2 and P4 monotherapies triggered cell cycle arrest and apoptosis in the SW480 and HT29 cells, and while pre-treatment with ERα-blocker enhanced the effects of E2, ERβ-blocker and PGR-blocker suppressed the E2 and P4 anti-cancer actions, respectively. In contrast, treatment with the AR-blocker induced apoptosis, whilst co-treatment with testosterone hindered the effects. Conclusions This study advocates that protein expression of sex steroid receptors in malignant tissues could represent prognostic markers, as well as hormonal therapy could provide an alternative strategy against CRC, and their efficacies could be dependent on gender, clinical stage, and tumor location.
Collapse
Affiliation(s)
- Bassem Refaat
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
- *Correspondence: Bassem Refaat, ;
| | - Akhmed Aslam
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Shakir Idris
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Ahmed H. Almalki
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
- Regional Laboratory and Central Blood Bank, Ministry of Health, Jizan, Saudi Arabia
| | - Mofareh Y. Alkhaldi
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
- Laboratory And Blood Bank Department, Asir Central Hospital, Abha, Saudi Arabia
| | - Hassan A. Asiri
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
- Forensic Medicine Department, Health Affairs General Directorate in Assir, Abha, Saudi Arabia
| | - Riyad A. Almaimani
- Biochemistry Department, Faculty of Medicine, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Abdulrahman Mujalli
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Faisal Minshawi
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Sara A. Alamri
- Histopathology Department, King Abdullah Medical City, Makkah, Saudi Arabia
| | - Mona I. AlHussain
- Histopathology Department, King Abdullah Medical City, Makkah, Saudi Arabia
| | - Badee A. Baltow
- Histopathology Department, King Abdullah Medical City, Makkah, Saudi Arabia
| | - Mansour H. Alqasmi
- Clinical Laboratories, Al-Noor Specialist Hospital, Makkah, Saudi Arabia
| | - Ghaiyda T. Basfar
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
- Clinical Laboratories, Al-Noor Specialist Hospital, Makkah, Saudi Arabia
| | - Ohoud M. Alosaimi
- Laboratory Medicine Department, Faculty of Applied Medical Sciences, Umm Al-Qura University, Makkah, Saudi Arabia
- Clinical Laboratories, Eradah and Mental Health Complex, Ministry of Health, Taif, Saudi Arabia
| | - Ibrahim A. Muhayya
- Laboratory And Blood Bank Department, Asir Central Hospital, Abha, Saudi Arabia
| |
Collapse
|
8
|
Keely SJ, Barrett KE. Intestinal secretory mechanisms and diarrhea. Am J Physiol Gastrointest Liver Physiol 2022; 322:G405-G420. [PMID: 35170355 PMCID: PMC8917926 DOI: 10.1152/ajpgi.00316.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 01/31/2023]
Abstract
One of the primary functions of the intestinal epithelium is to transport fluid and electrolytes to and from the luminal contents. Under normal circumstances, absorptive and secretory processes are tightly regulated such that absorption predominates, thereby enabling conservation of the large volumes of water that pass through the intestine each day. However, in conditions of secretory diarrhea, this balance becomes dysregulated, so that fluid secretion, driven primarily by Cl- secretion, overwhelms absorptive capacity, leading to increased loss of water in the stool. Secretory diarrheas are common and include those induced by pathogenic bacteria and viruses, allergens, and disruptions to bile acid homeostasis, or as a side effect of many drugs. Here, we review the cellular and molecular mechanisms by which Cl- and fluid secretion in the intestine are regulated, how these mechanisms become dysregulated in conditions of secretory diarrhea, currently available and emerging therapeutic approaches, and how new strategies to exploit intestinal secretory mechanisms are successfully being used in the treatment of constipation.
Collapse
Affiliation(s)
- Stephen J Keely
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Kim E Barrett
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, California
| |
Collapse
|
9
|
Acconcia F, Fiocchetti M, Busonero C, Fernandez VS, Montalesi E, Cipolletti M, Pallottini V, Marino M. The extra-nuclear interactome of the estrogen receptors: implications for physiological functions. Mol Cell Endocrinol 2021; 538:111452. [PMID: 34500041 DOI: 10.1016/j.mce.2021.111452] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/19/2021] [Accepted: 09/02/2021] [Indexed: 02/07/2023]
Abstract
Over the last decades, a great body of evidence has defined a novel view of the cellular mechanism of action of the steroid hormone 17β-estradiol (E2) through its estrogen receptors (i.e., ERα and ERβ). It is now clear that the E2-activated ERs work both as transcription factors and extra-nuclear plasma membrane-localized receptors. The activation of a plethora of signal transduction cascades follows the E2-dependent engagement of plasma membrane-localized ERs and is required for the coordination of gene expression, which ultimately controls the occurrence of the pleiotropic effects of E2. The definition of the molecular mechanisms by which the ERs locate at the cell surface (i.e., palmitoylation and protein association) determined the quest for understanding the specificity of the extra-nuclear E2 signaling. The use of mice models lacking the plasma membrane ERα localization unveiled that the extra-nuclear E2 signaling is operational in vivo but tissue-specific. However, the underlying molecular details for such ERs signaling diversity in the perspective of the E2 physiological functions in the different cellular contexts are still not understood. Therefore, to gain insights into the tissue specificity of the extra-nuclear E2 signaling to physiological functions, here we reviewed the known ERs extra-nuclear interactors and tried to extrapolate from available databases the ERα and ERβ extra-nuclear interactomes. Based on literature data, it is possible to conclude that by specifically binding to extra-nuclear localized proteins in different sub-cellular compartments, the ERs fine-tune their molecular activities. Moreover, we report that the context-dependent diversity of the ERs-mediated extra-nuclear E2 actions can be ascribed to the great flexibility of the physical structures of ERs and the spatial-temporal organization of the logistics of the cells (i.e., the endocytic compartments). Finally, we provide lists of proteins belonging to the potential ERα and ERβ extra-nuclear interactomes and propose that the systematic experimental definition of the ERs extra-nuclear interactomes in different tissues represents the next step for the research in the ERs field. Such characterization will be fundamental for the identification of novel druggable targets for the innovative treatment of ERs-related diseases.
Collapse
Affiliation(s)
- Filippo Acconcia
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146, Rome, Italy.
| | - Marco Fiocchetti
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146, Rome, Italy
| | - Claudia Busonero
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146, Rome, Italy
| | - Virginia Solar Fernandez
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146, Rome, Italy
| | - Emiliano Montalesi
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146, Rome, Italy
| | - Manuela Cipolletti
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146, Rome, Italy
| | - Valentina Pallottini
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146, Rome, Italy
| | - Maria Marino
- Department of Sciences, Section Biomedical Sciences, and Technology, University Roma Tre, Viale Guglielmo Marconi, 446, I-00146, Rome, Italy.
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Balasuriya GK, Nugapitiya SS, Hill-Yardin EL, Bornstein JC. Nitric Oxide Regulates Estrus Cycle Dependent Colonic Motility in Mice. Front Neurosci 2021; 15:647555. [PMID: 34658750 PMCID: PMC8511480 DOI: 10.3389/fnins.2021.647555] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Accepted: 08/12/2021] [Indexed: 11/23/2022] Open
Abstract
Women are more susceptible to functional bowel disorders than men and the severity of their symptoms such as diarrhea, constipation, abdominal pain and bloating changes over the menstrual cycle, suggesting a role for sex hormones in gastrointestinal function. Nitric oxide (NO) is a major inhibitory neurotransmitter in the gut and blockade of nitric oxide synthase (NOS; responsible for NO synthesis) increases colonic motility in male mice ex vivo. We assessed the effects of NOS inhibition on colonic motility in female mice using video imaging analysis of colonic motor complexes (CMCs). To understand interactions between NO and estrogen in the gut, we also quantified neuronal NOS and estrogen receptor alpha (ERα)-expressing myenteric neurons in estrus and proestrus female mice using immunofluorescence. Mice in estrus had fewer CMCs under control conditions (6 ± 1 per 15 min, n = 22) compared to proestrus (8 ± 1 per 15 min, n = 22, One-way ANOVA, p = 0.041). During proestrus, the NOS antagonist N-nitro-L-arginine (NOLA) increased CMC numbers compared to controls (189 ± 46%). In contrast, NOLA had no significant effect on CMC numbers during estrus. During estrus, we observed more NOS-expressing myenteric neurons (48 ± 2%) than during proestrus (39 ± 1%, n = 3, p = 0.035). Increased nuclear expression of ERα was observed in estrus which coincided with an altered motility response to NOLA in contrast with proestrus when ERα was largely cytoplasmic. In conclusion, we confirm a cyclic and sexually dimorphic effect of NOS activity in female mouse colon, which could be due to genomic effects of estrogens via ERα.
Collapse
Affiliation(s)
- Gayathri K Balasuriya
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia.,School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Saseema S Nugapitiya
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia.,Faculty of Medicine, The University of Queensland, Herston, QLD, Australia
| | - Elisa L Hill-Yardin
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia.,School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia
| | - Joel C Bornstein
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia
| |
Collapse
|
12
|
Control of Biophysical and Pharmacological Properties of Potassium Channels by Ancillary Subunits. Handb Exp Pharmacol 2021; 267:445-480. [PMID: 34247280 DOI: 10.1007/164_2021_512] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Potassium channels facilitate and regulate physiological processes as diverse as electrical signaling, ion, solute and hormone secretion, fluid homeostasis, hearing, pain sensation, muscular contraction, and the heartbeat. Potassium channels are each formed by either a tetramer or dimer of pore-forming α subunits that co-assemble to create a multimer with a K+-selective pore that in most cases is capable of functioning as a discrete unit to pass K+ ions across the cell membrane. The reality in vivo, however, is that the potassium channel α subunit multimers co-assemble with ancillary subunits to serve specific physiological functions. The ancillary subunits impart specific physiological properties that are often required for a particular activity in vivo; in addition, ancillary subunit interaction often alters the pharmacology of the resultant complex. In this chapter the modes of action of ancillary subunits on K+ channel physiology and pharmacology are described and categorized into various mechanistic classes.
Collapse
|
13
|
Fluorescence Fluctuation Spectroscopy enables quantification of potassium channel subunit dynamics and stoichiometry. Sci Rep 2021; 11:10719. [PMID: 34021177 PMCID: PMC8140153 DOI: 10.1038/s41598-021-90002-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 04/15/2021] [Indexed: 11/08/2022] Open
Abstract
Voltage-gated potassium (Kv) channels are a family of membrane proteins that facilitate K+ ion diffusion across the plasma membrane, regulating both resting and action potentials. Kv channels comprise four pore-forming α subunits, each with a voltage sensing domain, and they are regulated by interaction with β subunits such as those belonging to the KCNE family. Here we conducted a comprehensive biophysical characterization of stoichiometry and protein diffusion across the plasma membrane of the epithelial KCNQ1-KCNE2 complex, combining total internal reflection fluorescence (TIRF) microscopy and a series of complementary Fluorescence Fluctuation Spectroscopy (FFS) techniques. Using this approach, we found that KCNQ1-KCNE2 has a predominant 4:4 stoichiometry, while non-bound KCNE2 subunits are mostly present as dimers in the plasma membrane. At the same time, we identified unique spatio-temporal diffusion modalities and nano-environment organization for each channel subunit. These findings improve our understanding of KCNQ1-KCNE2 channel function and suggest strategies for elucidating the subunit stoichiometry and forces directing localization and diffusion of ion channel complexes in general.
Collapse
|
14
|
Cosme D, Estevinho MM, Rieder F, Magro F. Potassium channels in intestinal epithelial cells and their pharmacological modulation: a systematic review. Am J Physiol Cell Physiol 2020; 320:C520-C546. [PMID: 33326312 DOI: 10.1152/ajpcell.00393.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Several potassium channels (KCs) have been described throughout the gastrointestinal tract. Notwithstanding, their contribution to both physiologic and pathophysiologic conditions, as inflammatory bowel disease (IBD), remains underexplored. Therefore, we aim to systematically review, for the first time, the evidence on the characteristics and modulation of KCs in intestinal epithelial cells (IECs). PubMed, Scopus, and Web of Science were searched to identify studies focusing on KCs and their modulation in IECs. The included studies were assessed using a reporting inclusiveness checklist. From the 745 identified records, 73 met the inclusion criteria; their reporting inclusiveness was moderate-high. Some studies described the physiological role of KCs, while others explored their importance in pathological settings. Globally, in IBD animal models, apical KCa1.1 channels, responsible for luminal secretion, were upregulated. In human colonocytes, basolateral KCa3.1 channels were downregulated. The pharmacological inhibition of K2P and Kv influenced intestinal barrier function, promoting inflammation. Evidence suggests a strong association between KCs expression and secretory mechanisms in human and animal IECs. Further research is warranted to explore the usefulness of KC pharmacological modulation as a therapeutic target.
Collapse
Affiliation(s)
- Dina Cosme
- Department of Biomedicine, Unit of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, Porto, Portugal.,MedInUP, Center for Drug Discovery and Innovative Medicines, Porto, Portugal
| | - Maria Manuela Estevinho
- Department of Biomedicine, Unit of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, Porto, Portugal.,Department of Gastroenterology, Centro Hospitalar Vila Nova de Gaia/Espinho, Vila Nova de Gaia, Portugal
| | - Florian Rieder
- Department of Gastroenterology, Hepatology and Nutrition, Digestive Diseases, and Surgery Institute, Cleveland Clinic Foundation, Cleveland, Ohio.,Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Fernando Magro
- Department of Biomedicine, Unit of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, Porto, Portugal.,MedInUP, Center for Drug Discovery and Innovative Medicines, Porto, Portugal.,Department of Gastroenterology, Centro Hospitalar São João, Porto, Portugal
| |
Collapse
|
15
|
Abancens M, Bustos V, Harvey H, McBryan J, Harvey BJ. Sexual Dimorphism in Colon Cancer. Front Oncol 2020; 10:607909. [PMID: 33363037 PMCID: PMC7759153 DOI: 10.3389/fonc.2020.607909] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 11/09/2020] [Indexed: 12/12/2022] Open
Abstract
A higher incidence of colorectal cancer (CRC) is found in males compared to females. Young women (18-44 years) with CRC have a better survival outcome compared to men of the same age or compared to older women (over 50 years), indicating a global incidence of sexual dimorphism in CRC rates and survival. This suggests a protective role for the sex steroid hormone estrogen in CRC development. Key proliferative pathways in CRC tumorigenesis exhibit sexual dimorphism, which confer better survival in females through estrogen regulated genes and cell signaling. Estrogen regulates the activity of a class of Kv channels (KCNQ1:KCNE3), which control fundamental ion transport functions of the colon and epithelial mesenchymal transition through bi-directional interactions with the Wnt/β-catenin signalling pathway. Estrogen also modulates CRC proliferative responses in hypoxia via the novel membrane estrogen receptor GPER and HIF1A and VEGF signaling. Here we critically review recent clinical and molecular insights into sexual dimorphism of CRC biology modulated by the tumor microenvironment, estrogen, Wnt/β-catenin signalling, ion channels, and X-linked genes.
Collapse
Affiliation(s)
- Maria Abancens
- Department of Molecular Medicine, RCSI University of Medicine and Health Sciences, Beaumont Hospital, Dublin, Ireland
- Department of Surgery, RCSI University of Medicine and Health Sciences, Beaumont Hospital, Dublin, Ireland
| | - Viviana Bustos
- Departamento de Acuicultura y Recursos Agroalimentarios, Programa Fitogen, Universidad de Los Lagos, Osorno, Chile
| | - Harry Harvey
- Department of Medical Oncology, Cork University Hospital, Cork, Ireland
| | - Jean McBryan
- Department of Molecular Medicine, RCSI University of Medicine and Health Sciences, Beaumont Hospital, Dublin, Ireland
- Department of Surgery, RCSI University of Medicine and Health Sciences, Beaumont Hospital, Dublin, Ireland
| | - Brian J. Harvey
- Department of Molecular Medicine, RCSI University of Medicine and Health Sciences, Beaumont Hospital, Dublin, Ireland
- Centro de Estudios Cientificos CECs, Valdivia, Chile
| |
Collapse
|
16
|
Abstract
Kv7 channels (Kv7.1-7.5) are voltage-gated K+ channels that can be modulated by five β-subunits (KCNE1-5). Kv7.1-KCNE1 channels produce the slow-delayed rectifying K+ current, IKs, which is important during the repolarization phase of the cardiac action potential. Kv7.2-7.5 are predominantly neuronally expressed and constitute the muscarinic M-current and control the resting membrane potential in neurons. Kv7.1 produces drastically different currents as a result of modulation by KCNE subunits. This flexibility allows the Kv7.1 channel to have many roles depending on location and assembly partners. The pharmacological sensitivity of Kv7.1 channels differs from that of Kv7.2-7.5 and is largely dependent upon the number of β-subunits present in the channel complex. As a result, the development of pharmaceuticals targeting Kv7.1 is problematic. This review discusses the roles and the mechanisms by which different signaling pathways affect Kv7.1 and KCNE channels and could potentially provide different ways of targeting the channel.
Collapse
Affiliation(s)
- Emely Thompson
- Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada;
| | - Jodene Eldstrom
- Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada;
| | - David Fedida
- Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada;
| |
Collapse
|
17
|
Hynes D, Harvey BJ. Dexamethasone reduces airway epithelial Cl - secretion by rapid non-genomic inhibition of KCNQ1, KCNN4 and KATP K + channels. Steroids 2019; 151:108459. [PMID: 31330137 DOI: 10.1016/j.steroids.2019.108459] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/05/2019] [Accepted: 07/07/2019] [Indexed: 11/26/2022]
Abstract
Basolateral membrane K+ channels play a key role in basal and agonist stimulated Cl- transport across airway epithelial cells by generating a favourable electrical driving force for Cl- efflux. The K+ channel sub-types and molecular mechanisms of regulation by hormones and secretagoues are still poorly understood. Here we have identified the type of K+ channels involved in cAMP and Ca2+ stimulated Cl- secretion and uncovered a novel anti-secretory effect of dexamethasone mediated by inhibition of basolateral membrane K+ channels in a human airway cell model of 16HBE14o- cells commonly used for ion transport studies. Dexamethasone produced a rapid inhibition of transepithelial chloride ion secretion under steady state conditions and after stimulation with cAMP agonist (forskolin) or a Ca2+ mobilizing agonist (ATP). Our results show three different types of K+ channels are targeted by dexamethasone to reduce airway secretion, namely Ca2+-activated secretion via KCNN4 (KCa3.1) channels and cAMP-activated secretion via KCNQ1 (Kv7.1) and KATP (Kir6.1,6.2) channels. The down-regulation of KCNN4 and KCNQ1 channel activities by dexamethasone involves rapid non-genomic activation of PKCα and PKA signalling pathways, respectively. Dexamethasone signal transduction for PKC and PKA activation was demonstrated to occur through a rapid non-genomic pathway that did not implicate the classical nuclear receptors for glucocorticoids or mineralocorticoids but occurred via a novel signalling cascade involving sequentially a Gi-protein coupled receptor, PKC, adenylyl cyclase Type IV, cAMP, PKA and ERK1/2 activation. The rapid, non-genomic, effects of dexamethasone on airway epithelial ion transport and cell signalling introduces a new paradigm for glucocorticoid actions in lung epithelia which may serve to augment the anti-inflammatory activity of the steroid and enhance its therapeutic potential in treating airway hypersecretion in asthma and COPD.
Collapse
Affiliation(s)
- Darina Hynes
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin 9, Ireland
| | - Brian J Harvey
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Beaumont Hospital, Dublin 9, Ireland; Centro di Estudios Cientificos CECs, Valdivia, Chile.
| |
Collapse
|
18
|
Zhou L, Köhncke C, Hu Z, Roepke TK, Abbott GW. The KCNE2 potassium channel β subunit is required for normal lung function and resilience to ischemia and reperfusion injury. FASEB J 2019; 33:9762-9774. [PMID: 31162977 DOI: 10.1096/fj.201802519r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The KCNE2 single transmembrane-spanning voltage-gated potassium (Kv) channel β subunit is ubiquitously expressed and essential for normal function of a variety of cell types, often via regulation of the KCNQ1 Kv channel. A polymorphism upstream of KCNE2 is associated with reduced lung function in human populations, but the pulmonary consequences of KCNE2 gene disruption are unknown. Here, germline deletion of mouse Kcne2 reduced pulmonary expression of potassium channel α subunits Kcnq1 and Kcnb1 but did not alter expression of other Kcne genes. Kcne2 colocalized and coimmunoprecipitated with Kcnq1 in mouse lungs, suggesting the formation of pulmonary Kcnq1-Kcne2 potassium channel complexes. Kcne2 deletion reduced blood O2, increased CO2, increased pulmonary apoptosis, and increased inflammatory mediators TNF-α, IL-6, and leukocytes in bronchoalveolar lavage (BAL) fluids. Consistent with increased pulmonary vascular leakage, Kcne2 deletion increased plasma, BAL albumin, and the BAL:plasma albumin concentration ratio. Kcne2-/- mouse lungs exhibited baseline induction of the reperfusion injury salvage kinase pathway but were less able to respond via this pathway to imposed pulmonary ischemia/reperfusion injury (IRI). We conclude that KCNE2 regulates KCNQ1 in the lungs and is required for normal lung function and resistance to pulmonary IRI. Our data support a causal relationship between KCNE2 gene disruption and lung dysfunction.-Zhou, L., Köhncke, C., Hu, Z., Roepke, T. K., Abbott, G. W. The KCNE2 potassium channel β subunit is required for normal lung function and resilience to ischemia and reperfusion injury.
Collapse
Affiliation(s)
- Leng Zhou
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Clemens Köhncke
- Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Zhaoyang Hu
- Laboratory of Anesthesiology and Critical Care Medicine, Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu, China
| | - Torsten K Roepke
- Experimental and Clinical Research Center, Max Delbrück Center for Molecular Medicine, Berlin, Germany.,Clinic for Cardiology and Angiology, Charité-Berlin University of Medicine Campus Mitte, Berlin, Germany.,Clinic for Internal Medicine and Cardiology Klinikum Niederlausitz, Senftenberg, Germany
| | - Geoffrey W Abbott
- Bioelectricity Laboratory, Department of Physiology and Biophysics, School of Medicine, University of California-Irvine, Irvine, California, USA
| |
Collapse
|
19
|
Yang X, Guo Y, He J, Zhang F, Sun X, Yang S, Dong H. Estrogen and estrogen receptors in the modulation of gastrointestinal epithelial secretion. Oncotarget 2017; 8:97683-97692. [PMID: 29228643 PMCID: PMC5722595 DOI: 10.18632/oncotarget.18313] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Accepted: 05/22/2017] [Indexed: 12/24/2022] Open
Abstract
Gastrointestinal (GI) epithelial ion transport is physiologically important in many aspects of humans, such as in maintaining fluid balance of whole body, and also plays a role in the development and progression of common GI disease. Estrogen and estrogen receptors have been shown to modulate the activity of epithelial ion secretion in GI tract. This review aims to address the current state of knowledge about the role of estrogen and estrogen receptors in modulation of GI epithelial secretion and to elucidate the underlying mechanisms. We highlight the recent findings regarding the importance of estrogen and estrogen receptors in GI epithelia protection and body fluid balance by modulation of gastrointestinal epithelial HCO3- and Cl- secretion, especially current information about the regulatory mechanisms of duodenal HCO3- secretion based on our study in this field. Since there are no reviews on this topic but only few papers to address the main issues, we hope to timely provide new perspectives for the association between estrogen and GI disease.
Collapse
Affiliation(s)
- Xin Yang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
| | - Yanjun Guo
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
| | - Jialin He
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
| | - Fenglian Zhang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
| | - Xuemei Sun
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
| | - Shiming Yang
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China
| | - Hui Dong
- Department of Gastroenterology, Xinqiao Hospital, Third Military Medical University, Chongqing, P.R. China.,Division of Gastroenterology, Department of Medicine, School of Medicine, University of California, San Diego, California, USA
| |
Collapse
|
20
|
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.
Collapse
Affiliation(s)
- Geoffrey W Abbott
- Bioelectricity Laboratory, Departments of Pharmacology and Physiology and Biophysics, School of Medicine, University of California, Irvine, Calif., USA
| | | |
Collapse
|
21
|
Kroncke BM, Van Horn WD, Smith J, Kang C, Welch RC, Song Y, Nannemann DP, Taylor KC, Sisco NJ, George AL, Meiler J, Vanoye CG, Sanders CR. Structural basis for KCNE3 modulation of potassium recycling in epithelia. SCIENCE ADVANCES 2016; 2:e1501228. [PMID: 27626070 PMCID: PMC5017827 DOI: 10.1126/sciadv.1501228] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 08/10/2016] [Indexed: 05/25/2023]
Abstract
The single-span membrane protein KCNE3 modulates a variety of voltage-gated ion channels in diverse biological contexts. In epithelial cells, KCNE3 regulates the function of the KCNQ1 potassium ion (K(+)) channel to enable K(+) recycling coupled to transepithelial chloride ion (Cl(-)) secretion, a physiologically critical cellular transport process in various organs and whose malfunction causes diseases, such as cystic fibrosis (CF), cholera, and pulmonary edema. Structural, computational, biochemical, and electrophysiological studies lead to an atomically explicit integrative structural model of the KCNE3-KCNQ1 complex that explains how KCNE3 induces the constitutive activation of KCNQ1 channel activity, a crucial component in K(+) recycling. Central to this mechanism are direct interactions of KCNE3 residues at both ends of its transmembrane domain with residues on the intra- and extracellular ends of the KCNQ1 voltage-sensing domain S4 helix. These interactions appear to stabilize the activated "up" state configuration of S4, a prerequisite for full opening of the KCNQ1 channel gate. In addition, the integrative structural model was used to guide electrophysiological studies that illuminate the molecular basis for how estrogen exacerbates CF lung disease in female patients, a phenomenon known as the "CF gender gap."
Collapse
Affiliation(s)
- Brett M. Kroncke
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37240, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Wade D. Van Horn
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37240, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
- Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
- Center for Personalized Diagnostics, Arizona State University, Tempe, AZ 85287, USA
| | - Jarrod Smith
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37240, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - CongBao Kang
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37240, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Experimental Therapeutics Centre, Agency for Science Technology and Research, Singapore, Singapore
| | - Richard C. Welch
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| | - Yuanli Song
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37240, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - David P. Nannemann
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Keenan C. Taylor
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37240, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Nicholas J. Sisco
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA
- Biodesign Institute, Arizona State University, Tempe, AZ 85287, USA
- Center for Personalized Diagnostics, Arizona State University, Tempe, AZ 85287, USA
| | - Alfred L. George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Jens Meiler
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Carlos G. Vanoye
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Charles R. Sanders
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37240, USA
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37240, USA
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN 37240, USA
| |
Collapse
|
22
|
Balasuriya GK, Hill-Yardin EL, Gershon MD, Bornstein JC. A sexually dimorphic effect of cholera toxin: rapid changes in colonic motility mediated via a 5-HT3 receptor-dependent pathway in female C57Bl/6 mice. J Physiol 2016; 594:4325-38. [PMID: 26990461 DOI: 10.1113/jp272071] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 03/11/2016] [Indexed: 12/19/2022] Open
Abstract
KEY POINTS Cholera causes more than 100,000 deaths each year as a result of severe diarrhoea, vomiting and dehydration due to the actions of cholera toxin; more females than males are affected. Cholera toxin induces hypersecretion via release of mucosal serotonin and over-activation of enteric neurons, but its effects on gastrointestinal motility are not well characterized. We found that cholera toxin rapidly and reversibly reduces colonic motility in female mice in oestrus, but not in males or females in prooestrus, an effect mediated by 5-HT in the colonic mucosa and by 5-HT3 receptors. We show that the number of mucosal enterochromaffin cells containing 5-HT changes with the oestrous cycle in mice. These findings indicate that cholera toxin's effects on motility are rapid and depend on the oestrous cycle and therefore can help us better understand differences in responses in males and female patients. ABSTRACT Extensive studies of the mechanisms responsible for the hypersecretion produced by cholera toxin (CT) have shown that this toxin produces a massive over-activation of enteric neural secretomotor circuits. The effects of CT on gastrointestinal motility, however, have not been adequately characterized. We investigated effects of luminal CT on neurally mediated motor activity in ex vivo male and female mouse full length colon preparations. We used video recording and spatiotemporal maps of contractile activity to quantify colonic migrating motor complexes (CMMCs) and resting colonic diameter. We compared effects of CT in female colon from wild-type and mice lacking tryptophan hydroxylase (TPH1KO). We also compared CMMCs in colons of female mice in oestrus with those in prooestrus. In female (but not male) colon, CT rapidly, reversibly and concentration-dependently inhibits CMMC frequency and induces a tonic constriction. These effects were blocked by granisetron (5-HT3 antagonist) and were absent from TPH1KO females. CT effects were prominent at oestrus but absent at prooestrus. The number of EC cells containing immunohistochemically demonstrable serotonin (5-HT) was 30% greater in female mice during oestrus than during prooestrus or in males. We conclude that CT inhibits CMMCs via release of mucosal 5-HT, which activates an inhibitory pathway involving 5-HT3 receptors. This effect is sex- and oestrous cycle-dependent and is probably due to an oestrous cycle-dependent change in the number of 5-HT-containing EC cells in the colonic mucosa.
Collapse
Affiliation(s)
| | - Elisa L Hill-Yardin
- Department of Physiology, University of Melbourne, Parkville Vic, 3010, Australia
| | - Michael D Gershon
- Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, NY, 10032, USA
| | - Joel C Bornstein
- Department of Physiology, University of Melbourne, Parkville Vic, 3010, Australia
| |
Collapse
|
23
|
Itoh H, Berthet M, Fressart V, Denjoy I, Maugenre S, Klug D, Mizusawa Y, Makiyama T, Hofman N, Stallmeyer B, Zumhagen S, Shimizu W, Wilde AAM, Schulze-Bahr E, Horie M, Tezenas du Montcel S, Guicheney P. Asymmetry of parental origin in long QT syndrome: preferential maternal transmission of KCNQ1 variants linked to channel dysfunction. Eur J Hum Genet 2015; 24:1160-6. [PMID: 26669661 DOI: 10.1038/ejhg.2015.257] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Revised: 10/30/2015] [Accepted: 11/15/2015] [Indexed: 11/09/2022] Open
Abstract
Transmission distortion of disease-causing alleles in long QT syndrome (LQTS) has been reported, suggesting a potential role of KCNQ1 and KCNH2 in reproduction. This study sought to investigate parental transmission in LQTS families according to ethnicity, gene loci (LQT1-3: KCNQ1, KCNH2, and SCN5A) or severity of channel dysfunction. We studied 3782 genotyped members from 679 European and Japanese LQTS families (2748 carriers). We determined grandparental and parental origins of variant alleles in 1903 children and 624 grandchildren, and the grandparental origin of normal alleles in healthy children from 44 three-generation control families. LQTS alleles were more of maternal than paternal origin (61 vs 39%, P<0.001). The ratio of maternally transmitted alleles in LQT1 (66%) was higher than in LQT2 (56%, P<0.001) and LQT3 (57%, P=0.03). Unlike the Mendelian distribution of grandparental alleles seen in control families, variant grandparental LQT1 and LQT2 alleles in grandchildren showed an excess of maternally transmitted grandmother alleles. For LQT1, maternal transmission differs according to the variant level of dysfunction with 68% of maternal transmission for dominant negative or unknown functional consequence variants vs 58% for non-dominant negative and variants leading to haploinsufficiency, P<0.01; however, for LQT2 or LQT3 this association was not significant. An excess of disease-causing alleles of maternal origin, most pronounced in LQT1, was consistently found across ethnic groups. This observation does not seem to be linked to an imbalance in transmission of the LQTS subtype-specific grandparental allele, but to the potential degree of potassium channel dysfunction.
Collapse
Affiliation(s)
- Hideki Itoh
- INSERM, UMR S1166, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, UMR S1166, Paris, France.,Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan
| | - Myriam Berthet
- INSERM, UMR S1166, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, UMR S1166, Paris, France.,Institute of Cardiometabolism and Nutrition, ICAN, Pitié-Salpêtrière Hospital, Paris, France
| | - Véronique Fressart
- INSERM, UMR S1166, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, UMR S1166, Paris, France.,Institute of Cardiometabolism and Nutrition, ICAN, Pitié-Salpêtrière Hospital, Paris, France.,AP-HP, Groupe Hospitalier Pitié-Salpétrière, Service de Biochimie Métabolique, UF Cardiogénétique et Myogénétique Moléculaire et Cellulaire, Paris, France
| | - Isabelle Denjoy
- INSERM, UMR S1166, Paris, France.,Cardiology Department, AP-HP, Hôpital Bichat, Paris, France
| | - Svetlana Maugenre
- INSERM, UMR S1166, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, UMR S1166, Paris, France.,Institute of Cardiometabolism and Nutrition, ICAN, Pitié-Salpêtrière Hospital, Paris, France
| | - Didier Klug
- Hôpital Cardiologique de Lille, CHRU, Service de cardiologie A, Lille, France
| | - Yuka Mizusawa
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Takeru Makiyama
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Nynke Hofman
- Department of Clinical Genetics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Birgit Stallmeyer
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Sven Zumhagen
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Wataru Shimizu
- Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan.,Division of Cardiology, Department of Internal Medicine, Nippon Medical School, Tokyo, Japan
| | - Arthur A M Wilde
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Eric Schulze-Bahr
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany.,Interdisciplinary Centre for Clinical Research (IZKF) of the University of Münster, Münster, Germany
| | - Minoru Horie
- Department of Cardiovascular and Respiratory Medicine, Shiga University of Medical Science, Otsu, Japan
| | - Sophie Tezenas du Montcel
- Biostatistics Unit, AP-HP, Groupe Hospitalier Pitié-Salpêtrière Charles-Foix, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, INSERM, Institut Pierre Louis d'Epidémiologie et de Santé Publique (IPLESP UMRS 1136), Paris, France
| | - Pascale Guicheney
- INSERM, UMR S1166, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, UMR S1166, Paris, France.,Institute of Cardiometabolism and Nutrition, ICAN, Pitié-Salpêtrière Hospital, Paris, France
| |
Collapse
|
24
|
Abbott GW. KCNE1 and KCNE3: The yin and yang of voltage-gated K(+) channel regulation. Gene 2015; 576:1-13. [PMID: 26410412 DOI: 10.1016/j.gene.2015.09.059] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 09/03/2015] [Accepted: 09/22/2015] [Indexed: 12/20/2022]
Abstract
The human KCNE gene family comprises five genes encoding single transmembrane-spanning ion channel regulatory subunits. The primary function of KCNE subunits appears to be regulation of voltage-gated potassium (Kv) channels, and the best-understood KCNE complexes are with the KCNQ1 Kv α subunit. Here, we review the often opposite effects of KCNE1 and KCNE3 on Kv channel biology, with an emphasis on regulation of KCNQ1. Slow-activating IKs channel complexes formed by KCNQ1 and KCNE1 are essential for human ventricular myocyte repolarization, while constitutively active KCNQ1-KCNE3 channels are important in the intestine. Inherited sequence variants in human KCNE1 and KCNE3 cause cardiac arrhythmias but by different mechanisms, and each is important for hearing in unique ways. Because of their contrasting effects on KCNQ1 function, KCNE1 and KCNE3 have proved invaluable tools in the mechanistic understanding of how channel gating can be manipulated, and each may also provide a window into novel insights and new therapeutic opportunities in K(+) channel pharmacology. Finally, findings from studies of Kcne1(-/-) and Kcne3(-/-) mouse lines serve to illustrate the complexity of KCNE biology and KCNE-linked disease states.
Collapse
Affiliation(s)
- Geoffrey W Abbott
- Bioelectricity Laboratory, Dept. of Pharmacology and Dept. of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA; 360 Medical Surge II, Dept. of Pharmacology, School of Medicine, University of California, Irvine, CA 92697, USA.
| |
Collapse
|
25
|
Hill M, Dušková M, Stárka L. Dehydroepiandrosterone, its metabolites and ion channels. J Steroid Biochem Mol Biol 2015; 145:293-314. [PMID: 24846830 DOI: 10.1016/j.jsbmb.2014.05.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 05/06/2014] [Accepted: 05/11/2014] [Indexed: 11/20/2022]
Abstract
This review is focused on the physiological and pathophysiological relevance of steroids influencing the activities of the central and peripheral nervous systems with regard to their concentrations in body fluids and tissues in various stages of human life like the fetal development or pregnancy. The data summarized in this review shows that DHEA and its unconjugated and sulfated metabolites are physiologically and pathophysiologically relevant in modulating numerous ion channels and participate in vital functions of the human organism. DHEA and its unconjugated and sulfated metabolites including 5α/β-reduced androstane steroids participate in various physiological and pathophysiological processes like the management of GnRH cyclic release, regulation of glandular and neurotransmitter secretions, maintenance of glucose homeostasis on one hand and insulin insensitivity on the other hand, control of skeletal muscle and smooth muscle activities including vasoregulation, promotion of tolerance to ischemia and other neuroprotective effects. In respect of prevalence of steroid sulfates over unconjugated steroids in the periphery and the opposite situation in the CNS, the sulfated androgens and androgen metabolites reach relevance in peripheral organs. The unconjugated androgens and estrogens are relevant in periphery and so much the more in the CNS due to higher concentrations of most unconjugated steroids in the CNS tissues than in circulation and peripheral organs. This article is part of a Special Issue entitled "Essential role of DHEA".
Collapse
Affiliation(s)
- M Hill
- Steroid Hormone Unit, Institute of Endocrinology, Národní třída 8, Prague 116 94, Praha 1, CZ 116 94, Czech Republic.
| | - M Dušková
- Steroid Hormone Unit, Institute of Endocrinology, Národní třída 8, Prague 116 94, Praha 1, CZ 116 94, Czech Republic.
| | - L Stárka
- Steroid Hormone Unit, Institute of Endocrinology, Národní třída 8, Prague 116 94, Praha 1, CZ 116 94, Czech Republic.
| |
Collapse
|
26
|
Abstract
Ion channels are essential for basic cellular function and for processes including sensory perception and intercellular communication in multicellular organisms. Voltage-gated potassium (Kv) channels facilitate dynamic cellular repolarization during an action potential, opening in response to membrane depolarization to facilitate K+ efflux. In both excitable and nonexcitable cells other, constitutively active, K+ channels provide a relatively constant repolarizing force to control membrane potential, ion homeostasis, and secretory processes. Of the forty known human Kv channel pore-forming α subunits that coassemble in various combinations to form the fundamental tetrameric channel pore and voltage sensor module, KCNQ1 is unique. KCNQ1 stands alone in having the capacity to form either channels that are voltage-dependent and require membrane depolarization for activation, or constitutively active channels. In mammals, KCNQ1 regulates processes including gastric acid secretion, thyroid hormone biosynthesis, salt and glucose homeostasis, and cell volume and in some species is required for rhythmic beating of the heart. In this review, the author discusses the unique functional properties, regulation, cell biology, diverse physiological roles, and involvement in human disease states of this chameleonic K+ channel.
Collapse
|
27
|
Rapetti-Mauss R, O'Mahony F, Sepulveda FV, Urbach V, Harvey BJ. Oestrogen promotes KCNQ1 potassium channel endocytosis and postendocytic trafficking in colonic epithelium. J Physiol 2013; 591:2813-31. [PMID: 23529131 PMCID: PMC3690688 DOI: 10.1113/jphysiol.2013.251678] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Accepted: 03/19/2013] [Indexed: 12/23/2022] Open
Abstract
The cAMP-regulated potassium channel KCNQ1:KCNE3 plays an essential role in transepithelial Cl(-) secretion. Recycling of K(+) across the basolateral membrane provides the driving force necessary to maintain apical Cl(-) secretion. The steroid hormone oestrogen (17β-oestradiol; E2), produces a female-specific antisecretory response in rat distal colon through the inhibition of the KCNQ1:KCNE3 channel. It has previously been shown that rapid inhibition of the channel conductance results from E2-induced uncoupling of the KCNE3 regulatory subunit from the KCNQ1 channel pore complex. The purpose of this study was to determine the mechanism required for sustained inhibition of the channel function. We found that E2 plays a role in regulation of KCNQ1 cell membrane abundance by endocytosis. Ussing chamber experiments have shown that E2 inhibits both Cl(-) secretion and KCNQ1 current in a colonic cell line, HT29cl.19A, when cultured as a confluent epithelium. Following E2 treatment, KCNQ1 was retrieved from the plasma membrane by a clathrin-mediated endocytosis, which involved the association between KCNQ1 and the clathrin adaptor, AP-2. Following endocytosis, KCNQ1 was accumulated in early endosomes. Following E2-induced endocytosis, rather than being degraded, KCNQ1 was recycled by a biphasic mechanism involving Rab4 and Rab11. Protein kinase Cδ and AMP-dependent kinase were rapidly phosphorylated in response to E2 on their activating phosphorylation sites, Ser643 and Thr172, respectively (as previously shown). Both kinases are necessary for the E2-induced endocytosis, because E2 failed to induce KCNQ1 internalization following pretreatment with specific inhibitors of both protein kinase Cδ and AMP-dependent kinase. The ubiquitin ligase Nedd4.2 binds KCNQ1 in response to E2 to induce channel internalization. This study has provided the first demonstration of hormonal regulation of KCNQ1 trafficking. In conclusion, we propose that internalization of KCNQ1 is a key event in the sustained antisecretory response to oestrogen.
Collapse
Affiliation(s)
- Raphael Rapetti-Mauss
- Department of Molecular Medicine, RCSI-ERC, Beaumont Hospital, PO Box 9063, Dublin 9, Ireland
| | | | | | | | | |
Collapse
|
28
|
Kampa M, Pelekanou V, Notas G, Stathopoulos EN, Castanas E. The estrogen receptor: two or more molecules, multiple variants, diverse localizations, signaling and functions. Are we undergoing a paradigm-shift as regards their significance in breast cancer? Hormones (Athens) 2013; 12:69-85. [PMID: 23624133 DOI: 10.1007/bf03401288] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Marilena Kampa
- Department of Experimental Endocrinology, University of Crete, School of Medicine, Heraklion, Crete, Greece
| | | | | | | | | |
Collapse
|
29
|
Saint-Criq V, Rapetti-Mauss R, Yusef YR, Harvey BJ. Estrogen regulation of epithelial ion transport: Implications in health and disease. Steroids 2012; 77:918-23. [PMID: 22410439 DOI: 10.1016/j.steroids.2012.02.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 01/29/2012] [Accepted: 02/23/2012] [Indexed: 02/02/2023]
Abstract
Estrogen, 17β-estradiol (E2), has been shown to modulate the activity of ion channels in a diverse range of epithelial tissues. The channel activation or inhibition responses to E2 are often rapid, occurring in seconds to minutes, independent of protein synthesis and gene transcription ('non-genomic' response). These rapid effects of E2 require activation of specific protein kinases or changes in intracellular calcium and pH which in turn modulate the conductance, open probability or number of channels in the plasmamembrane. Estrogen has also been shown to affect the expression of ion transporters over days ('genotropic' response) causing long-term sustained changes in transepithelial ion transport. It is now accepted that so called non-genomic responses are not stand-alone events and are necessary to prime the latent genomic response and even be critical for the full latent response to occur. In a number of epithelia the non-genomic and genotropic responses to estrogen are sex-specific and variable in potency and sensitivity to E2 depending on the stage of the estrous cycle. Of increasing interest is the effect these rapid and latent actions of E2 on ion transporters have on the physiological functions of epithelia. For example, estrogen regulation of a class of voltage-gated K(+) channels (KCNQ1) can determine the rate of Cl(-) secretion in the intestine. In whole-body terms, the combined effects of estrogen on a variety of ion channels which control fluid and electrolyte transport in the kidney, intestine and lung may be necessary for endometrial expansion and implantation of the blastocyte.
Collapse
Affiliation(s)
- Vinciane Saint-Criq
- Department of Molecular Medicine, Royal College of Surgeons in Ireland, Education & Research Centre, Beaumont Hospital, Dublin 9, Ireland
| | | | | | | |
Collapse
|
30
|
Affiliation(s)
- Michael E Duffey
- Physiology & Biophysics, Centre for Cellular and Systems Electrophysiology, 124 Sherman Hall, State University of New York at Buffalo, Buffalo, NY 14214, USA.
| | | |
Collapse
|