1
|
Xiang Y, Fan D, An Q, Zhang T, Wu X, Ding J, Xu X, Yue G, Tang S, Du Q, Xu J, Xie R. Effects of Ion-Transporting Proteins on the Digestive System Under Hypoxia. Front Physiol 2022; 13:870243. [PMID: 36187789 PMCID: PMC9515906 DOI: 10.3389/fphys.2022.870243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
Hypoxia refers to a state of oxygen limitation, which mainly mediates pathological processes in the human body and participates in the regulation of normal physiological processes. In the hypoxic environment, the main regulator of human body homeostasis is the hypoxia-inducible factor family (HIF). HIF can regulate the expression of many hypoxia-induced genes and then participate in various physiological and pathological processes of the human body. Ion-transporting proteins are extremely important types of proteins. Ion-transporting proteins are distributed on cell membranes or organelles and strictly control the inflow or outflow of ions in cells or organelles. Changes in ions in cells are often closely related to extensive physiological and pathological processes in the human body. Numerous studies have confirmed that hypoxia and its regulatory factors can regulate the transcription and expression of ion-transporting protein-related genes. Under hypoxic stress, the regulation and interaction of ion-transporting proteins by hypoxia often leads to diseases of various human systems and even tumors. Using ion-transporting proteins and hypoxia as targets to explore the mechanism of digestive system diseases and targeted therapy is expected to become a new breakthrough point.
Collapse
Affiliation(s)
- Yiwei Xiang
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
| | - Dongdong Fan
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
| | - Qimin An
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
| | - Ting Zhang
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
| | - Xianli Wu
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
| | - Jianhong Ding
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
| | - Xiaolin Xu
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
| | - Gengyu Yue
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
| | - Siqi Tang
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
| | - Qian Du
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
| | - Jingyu Xu
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
- *Correspondence: Jingyu Xu, ; Rui Xie,
| | - Rui Xie
- Department of Gastroenterology, Digestive Disease Hospital, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Collaborative Innovation Center of Tissue Damage Repair and Regeneration Medicine, Zunyi, China
- *Correspondence: Jingyu Xu, ; Rui Xie,
| |
Collapse
|
2
|
Deficiency of the Two-Pore Potassium Channel KCNK9 Impairs Intestinal Epithelial Cell Survival and Aggravates Dextran Sodium Sulfate-Induced Colitis. Cell Mol Gastroenterol Hepatol 2022; 14:1199-1211. [PMID: 35973573 PMCID: PMC9579309 DOI: 10.1016/j.jcmgh.2022.08.003] [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] [Received: 05/03/2021] [Revised: 08/10/2022] [Accepted: 08/10/2022] [Indexed: 01/31/2023]
Abstract
BACKGROUND & AIMS The 2-pore potassium channel subfamily K member 9 (KCNK9) regulates intracellular calcium concentration and thus modulates cell survival and inflammatory signaling pathways. It also was recognized as a risk allele for inflammatory bowel disease. However, it remains unclear whether KCNK9 modulates inflammatory bowel disease via its impact on immune cell function or whether its influence on calcium homeostasis also is relevant in intestinal epithelial cells. METHODS Kcnk9-/- mice were challenged with 3% dextran sulfate sodium (DSS) to induce experimental acute colitis. Primary cultures of intestinal epithelial cells were generated, and expression of potassium channels as well as cytosolic calcium levels and susceptibility to apoptosis were evaluated. Furthermore, we evaluated whether KCNK9 deficiency was compensated by the closely related 2-pore potassium channel KCNK3 in vivo or in vitro. RESULTS Compared with controls, KCNK9 deficiency or its pharmacologic blockade were associated with aggravated DSS-induced colitis compared with wild-type animals. In the absence of KCNK9, intestinal epithelial cells showed increased intracellular calcium levels and were more prone to mitochondrial damage and caspase-9-dependent apoptosis. We found that expression of KCNK3 was increased in Kcnk9-/- mice but did not prevent apoptosis after DSS exposure. Conversely, increased levels of KCNK9 in Kcnk3-/- mice were associated with an ameliorated course of DSS-induced colitis. CONCLUSIONS KCNK9 enhances mitochondrial stability, reduces apoptosis, und thus supports epithelial cell survival after DSS exposure in vivo and in vitro. Conversely, its increased expression in Kcnk3-/- resulted in less mitochondrial damage and apoptosis and was associated with beneficial outcomes in DSS-induced colitis.
Collapse
|
3
|
Role of K + and Ca 2+-Permeable Channels in Osteoblast Functions. Int J Mol Sci 2021; 22:ijms221910459. [PMID: 34638799 PMCID: PMC8509041 DOI: 10.3390/ijms221910459] [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: 09/10/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 12/20/2022] Open
Abstract
Bone-forming cells or osteoblasts play an important role in bone modeling and remodeling processes. Osteoblast differentiation or osteoblastogenesis is orchestrated by multiple intracellular signaling pathways (e.g., bone morphogenetic proteins (BMP) and Wnt signaling pathways) and is modulated by the extracellular environment (e.g., parathyroid hormone (PTH), vitamin D, transforming growth factor β (TGF-β), and integrins). The regulation of bone homeostasis depends on the proper differentiation and function of osteoblast lineage cells from osteogenic precursors to osteocytes. Intracellular Ca2+ signaling relies on the control of numerous processes in osteoblast lineage cells, including cell growth, differentiation, migration, and gene expression. In addition, hyperpolarization via the activation of K+ channels indirectly promotes Ca2+ signaling in osteoblast lineage cells. An improved understanding of the fundamental physiological and pathophysiological processes in bone homeostasis requires detailed investigations of osteoblast lineage cells. This review summarizes the current knowledge on the functional impacts of K+ channels and Ca2+-permeable channels, which critically regulate Ca2+ signaling in osteoblast lineage cells to maintain bone homeostasis.
Collapse
|
4
|
Choi SW, Woo J, Park KS, Ko J, Jeon YK, Choi SW, Yoo HY, Kho I, Kim TJ, Kim SJ. Higher expression of KCNK10 (TREK-2) K + channels and their functional upregulation by lipopolysaccharide treatment in mouse peritoneal B1a cells. Pflugers Arch 2021; 473:659-671. [PMID: 33586023 DOI: 10.1007/s00424-021-02526-1] [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: 07/14/2020] [Revised: 01/10/2021] [Accepted: 01/28/2021] [Indexed: 11/24/2022]
Abstract
Innate-like CD5+ B1a cells localized in serous cavities are activated by innate stimuli, such as lipopolysaccharide (LPS), leading to T cell-independent antibody responses. Although ion channels play crucial roles in the homeostasis and activation of immune cells, the electrophysiological properties of B1a cells have not been investigated to date. Previously, in the mouse B cell lymphoma cells, we found that the voltage-independent two-pore-domain potassium (K2P) channels generate a negative membrane potential and drive Ca2+ influx. Here, we newly compared the expression and activities of K2P channels in mouse splenic follicular B (FoB), marginal zone B (MZB), and peritoneal B1a cells. Next-generation sequencing analysis showed higher levels of transcripts for TREK-2 and TWIK-2 in B1a cells than those in FoB or MZB cells. Electrophysiological analysis, using patch clamp technique, revealed higher activity of TREK-2 with the characteristic large unitary conductance (~ 250 pS) in B1a than that in FoB or MZB cells. TREK-2 activity was further increased by LPS treatment (>2 h), which was more prominent in B1a than that in MZB or FoB cells. The cytosolic Ca2+ concentration of B cells was decreased by high-K+-induced depolarization (ΔRKCl (%)), suggesting the basal Ca2+ influx to be driven by negative membrane potential. The LPS treatment significantly increased the ΔRKCl (%) in B1a, though not in FoB and MZB cells. Our study was the first to compare the K2P channels in mouse primary B cell subsets, elucidating the functional upregulation of TREK-2 and augmentation of Ca2+ influx by the stimulation of Toll-like receptor 4 in B1a cells.
Collapse
Affiliation(s)
- Si Won Choi
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Joohan Woo
- Department of Physiology and Ion Channel Disease Research Center, Dongguk University College of Medicine, Seoul, Republic of Korea
| | - Kyung Sun Park
- Wide River Institute of Immunology, Seoul National University College of Medicine, Hongcheon, Republic of Korea
| | - Juyeon Ko
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Young Keul Jeon
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Seong Woo Choi
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea.,Department of Physiology and Ion Channel Disease Research Center, Dongguk University College of Medicine, Seoul, Republic of Korea.,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hae Young Yoo
- Department of Nursing, Chung-Ang University, Seoul, Republic of Korea
| | - Inseong Kho
- Department of Immunology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Tae Jin Kim
- Department of Immunology, Sungkyunkwan University School of Medicine, Suwon, Republic of Korea
| | - Sung Joon Kim
- Department of Physiology, Seoul National University College of Medicine, Seoul, Republic of Korea. .,Wide River Institute of Immunology, Seoul National University College of Medicine, Hongcheon, Republic of Korea. .,Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul, Republic of Korea.
| |
Collapse
|
5
|
Ohya S, Matsui M, Kajikuri J, Endo K, Kito H. Increased Interleukin-10 Expression by the Inhibition of Ca 2+-Activated K + Channel K Ca3.1 in CD4 +CD25 + Regulatory T Cells in the Recovery Phase in an Inflammatory Bowel Disease Mouse Model. J Pharmacol Exp Ther 2021; 377:75-85. [PMID: 33504590 DOI: 10.1124/jpet.120.000395] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 01/22/2021] [Indexed: 12/13/2022] Open
Abstract
Inflammatory bowel diseases (IBD) are chronic inflammatory diseases of the gastrointestinal tract arising from abnormal responses of the innate and adaptative immune systems. Interleukin (IL)-10-producing CD4+CD25+ regulatory T (Treg) cells play a protective role in the recovery phase of IBD. In the present study, the effects of the administration of the selective Ca2+-activated K+ channel KCa3.1 inhibitor TRAM-34 on disease activities were examined in chemically induced IBD model mice. IBD disease severity, as assessed by diarrhea, visible fecal blood, inflammation, and crypt damage in the colon, was significantly lower in mice administered 1 mg/kg TRAM-34 than in vehicle-administered mice. Quantitative real-time polymerase chain reaction examinations showed that IL-10 expression levels in the recovery phase were markedly increased by the inhibition of KCa3.1 in mesenteric lymph node (mLN) Treg cells of IBD model mice compared with vehicle-administered mice. Among several positive and negative transcriptional regulators (TRs) for IL-10, three positive TRs-E4BP4, KLF4, and Blimp1-were upregulated by the inhibition of KCa3.1 in the mLN Treg cells of IBD model mice. In mouse peripheral CD4+CD25+ Treg cells induced by lectin stimulation, IL-10 expression and secretion were enhanced by the treatment with TRAM-34, together with the upregulation of E4BP4, KLF4, and Blimp1. Collectively, the present results demonstrated that the pharmacological inhibition of KCa3.1 decreased IBD symptoms in the IBD model by increasing IL-10 production in peripheral Treg cells and that IL-10high Treg cells produced by the treatment with KCa3.1 inhibitor may contribute to efficient Treg therapy for chronic inflammatory disorders, including IBD. SIGNIFICANCE STATEMENT: Pharmacological inhibition of Ca2+-activated K+ channel KCa3.1 increased IL-10 expression in peripheral Treg cells, together with the upregulation of the transcriptional regulators of IL-10: Krüppel-like factor 4, E4 promoter-binding protein 4, and/or B lymphocyte-induced maturation protein 1. The manipulation of IL-10high-producing Treg cells by the pharmacological inhibition of KCa3.1 may be beneficial in the treatment of chronic inflammatory diseases such as inflammatory bowel disease.
Collapse
Affiliation(s)
- Susumu Ohya
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Miki Matsui
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Junko Kajikuri
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Kyoko Endo
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| | - Hiroaki Kito
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya, Japan
| |
Collapse
|
6
|
Fernández-Orth J, Rolfes L, Gola L, Bittner S, Andronic J, Sukhorukov VL, Sisario D, Landgraf P, Dieterich DC, Cerina M, Smalla KH, Kähne T, Budde T, Kovac S, Ruck T, Sauer M, Meuth SG. A role for TASK2 channels in the human immunological synapse. Eur J Immunol 2020; 51:342-353. [PMID: 33169379 DOI: 10.1002/eji.201948269] [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: 06/07/2019] [Revised: 08/30/2020] [Accepted: 11/05/2019] [Indexed: 12/29/2022]
Abstract
The immunological synapse is a transient junction that occurs when the plasma membrane of a T cell comes in close contact with an APC after recognizing a peptide from the antigen-MHC. The interaction starts when CRAC channels embedded in the T cell membrane open, flowing calcium ions into the cell. To counterbalance the ion influx and subsequent depolarization, Kv 1.3 and KCa3.1 channels are recruited to the immunological synapse, increasing the extracellular K+ concentration. These processes are crucial as they initiate gene expression that drives T cell activation and proliferation. The T cell-specific function of the K2P channel family member TASK2 channels and their role in autoimmune processes remains unclear. Using mass spectrometry analysis together with epifluorescence and super-resolution single-molecule localization microscopy, we identified TASK2 channels as novel players recruited to the immunological synapse upon stimulation. TASK2 localizes at the immunological synapse, upon stimulation with CD3 antibodies, likely interacting with these molecules. Our findings suggest that, together with Kv 1.3 and KCa3.1 channels, TASK2 channels contribute to the proper functioning of the immunological synapse, and represent an interesting treatment target for T cell-mediated autoimmune disorders.
Collapse
Affiliation(s)
| | - Leoni Rolfes
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| | - Lukas Gola
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| | - Stefan Bittner
- Department of Neurology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Joseph Andronic
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Vladimir L Sukhorukov
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Dmitri Sisario
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Peter Landgraf
- Neural Plasticity and Communication, Institute for Pharmacology and Toxicology, Otto-von-Guericke-University, Magdeburg, Germany
| | - Daniela C Dieterich
- Neural Plasticity and Communication, Institute for Pharmacology and Toxicology, Otto-von-Guericke-University, Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Manuela Cerina
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| | - Karl-Heinz Smalla
- Special Lab Molecular Biological Techniques, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Thilo Kähne
- Institute of Experimental Internal Medicine, Medical Faculty, Otto-von-Guericke-University, Magdeburg, Germany
| | - Thomas Budde
- Institute of Physiology I, Westfälische Wilhelms-Universität, Münster, Germany
| | - Stjepana Kovac
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| | - Tobias Ruck
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Sven G Meuth
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| |
Collapse
|
7
|
Endo K, Kito H, Tanaka R, Kajikuri J, Tanaka S, Elboray EE, Suzuki T, Ohya S. Possible Contribution of Inflammation-Associated Hypoxia to Increased K 2P5.1 K + Channel Expression in CD4 + T cells of the Mouse Model for Inflammatory Bowel Disease. Int J Mol Sci 2019; 21:ijms21010038. [PMID: 31861667 PMCID: PMC6981474 DOI: 10.3390/ijms21010038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Revised: 12/10/2019] [Accepted: 12/17/2019] [Indexed: 01/03/2023] Open
Abstract
Previous studies have reported the up-regulation of the two-pore domain K+ channel K2P5.1 in the CD4+ T cells of patients with multiple sclerosis (MS) and rheumatoid arthritis (RA), as well as in a mouse model of inflammatory bowel disease (IBD). However, the mechanisms underlying this up-regulation remain unclear. Inflammation-associated hypoxia is involved in the pathogenesis of autoimmune diseases, such as IBD, MS, and RA, and T cells are exposed to a hypoxic environment during their recruitment from inflamed tissues to secondary lymphoid tissues. We herein investigated whether inflammation-associated hypoxia is attributable to the increased expression and activity of K2P5.1 in the splenic CD4+ T cells of chemically-induced IBD model mice. Significant increases in hypoxia-inducible factor (HIF)-1α transcripts and proteins were found in the splenic CD4+ T cells of the IBD model. In the activated splenic CD4+ T cells, hypoxia (1.5% O2) increased K2P5.1 expression and activity, whereas a treatment with the HIF inhibitor FM19G11 but not the selective HIF-2 inhibitor exerted the opposite effect. Hypoxia-exposed K2P5.1 up-regulation was also detected in stimulated thymocytes and the mouse T-cell line. The class III histone deacetylase sirtuin-1 (SIRT1) is a downstream molecule of HIF-1α signaling. We examined the effects of the SIRT1 inhibitor NCO-01 on K2P5.1 transcription in activated CD4+ T cells, and we found no significant effects on the K2P5.1 transcription. No acute compensatory responses of K2P3.1–K2P5.1 up-regulation were found in the CD4+ T cells of the IBD model and the hypoxia-exposed T cells. Collectively, these results suggest a mechanism for K2P5.1 up-regulation via HIF-1 in the CD4+ T cells of the IBD model.
Collapse
Affiliation(s)
- Kyoko Endo
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan; (K.E.); (R.T.); (S.T.)
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8601, Japan; (H.K.); (J.K.)
| | - Hiroaki Kito
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8601, Japan; (H.K.); (J.K.)
| | - Ryo Tanaka
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan; (K.E.); (R.T.); (S.T.)
| | - Junko Kajikuri
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8601, Japan; (H.K.); (J.K.)
| | - Satoshi Tanaka
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan; (K.E.); (R.T.); (S.T.)
| | - Elghareeb E. Elboray
- Department of Complex Molecular Chemistry, The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan; (E.E.E.); (T.S.)
- Faculty of Science, South Valley University, Qena 83523, Egypt
| | - Takayoshi Suzuki
- Department of Complex Molecular Chemistry, The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan; (E.E.E.); (T.S.)
| | - Susumu Ohya
- Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya 467-8601, Japan; (H.K.); (J.K.)
- Correspondence: ; Tel.: +81-52-853-8149
| |
Collapse
|
8
|
Legrand JMD, Roy E, Baz B, Mukhopadhyay P, Wong HY, Ram R, Morahan G, Walker G, Khosrotehrani K. Genetic variation in the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway affects contact hypersensitivity responses. J Allergy Clin Immunol 2018; 142:981-984.e7. [PMID: 29753814 DOI: 10.1016/j.jaci.2018.04.028] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 01/17/2018] [Accepted: 04/20/2018] [Indexed: 12/31/2022]
Affiliation(s)
- Julien M D Legrand
- UQ Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, Australia
| | - Edwige Roy
- UQ Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, Australia
| | - Batoul Baz
- UQ Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, Australia
| | | | - Ho Yi Wong
- UQ Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, Australia
| | - Ramesh Ram
- Centre for Diabetes Research, Harry Perkins Institute of Medical Research, Perth, Australia
| | - Grant Morahan
- Centre for Diabetes Research, Harry Perkins Institute of Medical Research, Perth, Australia
| | - Graeme Walker
- QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Kiarash Khosrotehrani
- UQ Diamantina Institute, Translational Research Institute, University of Queensland, Brisbane, Australia.
| |
Collapse
|
9
|
Phosphatidylinositol (4,5)-bisphosphate dynamically regulates the K 2P background K + channel TASK-2. Sci Rep 2017; 7:45407. [PMID: 28358046 PMCID: PMC5371824 DOI: 10.1038/srep45407] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 02/23/2017] [Indexed: 12/22/2022] Open
Abstract
Two-pore domain K2P K+ channels responsible for the background K+ conductance and the resting membrane potential, are also finely regulated by a variety of chemical, physical and physiological stimuli. Hormones and transmitters acting through Gq protein-coupled receptors (GqPCRs) modulate the activity of various K2P channels but the signalling involved has remained elusive, in particular whether dynamic regulation by membrane PI(4,5)P2, common among other classes of K+ channels, affects K2P channels is controversial. Here we show that K2P K+ channel TASK-2 requires PI(4,5)P2 for activity, a dependence that accounts for its run down in the absence of intracellular ATP and its full recovery by addition of exogenous PI(4,5)P2, its inhibition by low concentrations of polycation PI scavengers, and inhibition by PI(4,5)P2 depletion from the membrane. Comprehensive mutagenesis suggests that PI(4,5)P2 interaction with TASK-2 takes place at C-terminus where three basic aminoacids are identified as being part of a putative binding site.
Collapse
|
10
|
Khatun A, Fujimoto M, Kito H, Niwa S, Suzuki T, Ohya S. Down-Regulation of Ca 2+-Activated K⁺ Channel K Ca1.1 in Human Breast Cancer MDA-MB-453 Cells Treated with Vitamin D Receptor Agonists. Int J Mol Sci 2016; 17:ijms17122083. [PMID: 27973439 PMCID: PMC5187883 DOI: 10.3390/ijms17122083] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Revised: 12/01/2016] [Accepted: 12/08/2016] [Indexed: 12/15/2022] Open
Abstract
Vitamin D (VD) reduces the risk of breast cancer and improves disease prognoses. Potential VD analogs are being developed as therapeutic agents for breast cancer treatments. The large-conductance Ca2+-activated K+ channel KCa1.1 regulates intracellular Ca2+ signaling pathways and is associated with high grade tumors and poor prognoses. In the present study, we examined the effects of treatments with VD receptor (VDR) agonists on the expression and activity of KCa1.1 in human breast cancer MDA-MB-453 cells using real-time PCR, Western blotting, flow cytometry, and voltage-sensitive dye imaging. Treatments with VDR agonists for 72 h markedly decreased the expression levels of KCa1.1 transcripts and proteins in MDA-MB-453 cells, resulting in the significant inhibition of depolarization responses induced by paxilline, a specific KCa1.1 blocker. The specific proteasome inhibitor MG132 suppressed VDR agonist-induced decreases in KCa1.1 protein expression. These results suggest that KCa1.1 is a new downstream target of VDR signaling and the down-regulation of KCa1.1 through the transcriptional repression of KCa1.1 and enhancement of KCa1.1 protein degradation contribute, at least partly, to the antiproliferative effects of VDR agonists in breast cancer cells.
Collapse
Affiliation(s)
- Anowara Khatun
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Mayu Fujimoto
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Hiroaki Kito
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Satomi Niwa
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| | - Takayoshi Suzuki
- Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto 403-8334, Japan.
| | - Susumu Ohya
- Department of Pharmacology, Division of Pathological Sciences, Kyoto Pharmaceutical University, Kyoto 607-8414, Japan.
| |
Collapse
|
11
|
Fernández-Orth J, Ehling P, Ruck T, Pankratz S, Hofmann MS, Landgraf P, Dieterich DC, Smalla KH, Kähne T, Seebohm G, Budde T, Wiendl H, Bittner S, Meuth SG. 14-3-3 Proteins regulate K 2P 5.1 surface expression on T lymphocytes. Traffic 2016; 18:29-43. [PMID: 27743426 DOI: 10.1111/tra.12455] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 10/12/2016] [Accepted: 10/12/2016] [Indexed: 01/10/2023]
Abstract
K2P 5.1 channels (also called TASK-2 or Kcnk5) have already been shown to be relevant in the pathophysiology of autoimmune disease because they are known to be upregulated on peripheral and central T lymphocytes of multiple sclerosis (MS) patients. Moreover, overexpression of K2P 5.1 channels in vitro provokes enhanced T-cell effector functions. However, the molecular mechanisms regulating intracellular K2P 5.1 channel trafficking are unknown so far. Thus, the aim of the study is to elucidate the trafficking of K2P 5.1 channels on T lymphocytes. Using mass spectrometry analysis, we have identified 14-3-3 proteins as novel binding partners of K2P 5.1 channels. We show that a non-classical 14-3-3 consensus motif (R-X-X-pT/S-x) at the channel's C-terminus allows the binding between K2P 5.1 and 14-3-3. The mutant K2P 5.1/S266A diminishes the protein-protein interaction and reduces the amplitude of membrane currents. Application of a non-peptidic 14-3-3 inhibitor (BV02) significantly reduces the number of wild-type channels in the plasma membrane, whereas the drug has no effect on the trafficking of the mutated channel. Furthermore, blocker application reduces T-cell effector functions. Taken together, we demonstrate that 14-3-3 interacts with K2P 5.1 and plays an important role in channel trafficking.
Collapse
Affiliation(s)
| | - Petra Ehling
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| | - Tobias Ruck
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| | - Susann Pankratz
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| | | | - Peter Landgraf
- Neural Plasticity and Communication, Institute for Pharmacology and Toxicology, Otto von-Guericke-University, Magdeburg, Germany
| | - Daniela C Dieterich
- Neural Plasticity and Communication, Institute for Pharmacology and Toxicology, Otto von-Guericke-University, Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Otto von-Guericke-University, Magdeburg, Germany
| | - Karl-Heinz Smalla
- Special Lab Molecular Biological Techniques, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Thilo Kähne
- Institute of Experimental Internal Medicine, Medical Faculty, Otto-von-Guericke-University, Magdeburg, Germany
| | - Guiscard Seebohm
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Diseases (IfGH), University Hospital Münster, Münster, Germany
| | - Thomas Budde
- Institute for Physiology I, Westfälische Wilhelms-Universität, Münster, Germany
| | - Heinz Wiendl
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| | - Stefan Bittner
- Department of Neurology, University Medical Center, Johannes Gutenberg-University, Mainz, Germany
| | - Sven G Meuth
- Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany
| |
Collapse
|
12
|
Tagishi K, Shimizu A, Endo K, Kito H, Niwa S, Fujii M, Ohya S. Defective splicing of the background K+ channel K2P5.1 by the pre-mRNA splicing inhibitor, pladienolide B in lectin-activated mouse splenic CD4+ T cells. J Pharmacol Sci 2016; 132:205-209. [DOI: 10.1016/j.jphs.2016.10.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 10/20/2016] [Accepted: 10/23/2016] [Indexed: 11/24/2022] Open
|