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Morrissette-McAlmon J, Xu WR, Teuben R, Boheler KR, Tung L. Adipocyte-mediated electrophysiological remodeling of human stem cell - derived cardiomyocytes. J Mol Cell Cardiol 2024; 189:52-65. [PMID: 38346641 DOI: 10.1016/j.yjmcc.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/20/2024] [Accepted: 02/06/2024] [Indexed: 03/02/2024]
Abstract
Adipocytes normally accumulate in the epicardial and pericardial layers around the human heart, but their infiltration into the myocardium can be proarrhythmic. METHODS AND RESULTS: Human adipose derived stem/stromal cells and human induced pluripotent stem cells (hiPSC) were differentiated, respectively into predominantly white fat-like adipocytes (hAdip) and ventricular cardiomyocytes (CMs). Adipocytes cultured in CM maintenance medium (CM medium) maintained their morphology, continued to express adipogenic markers, and retained clusters of intracellular lipid droplets. In contrast, hiPSC-CMs cultivated in adipogenic growth medium displayed abnormal cell morphologies and more clustering across the monolayer. Pre-plated hiPSC-CMs co-cultured in direct contact with hAdips in CM medium displayed prolonged action potential durations, increased triangulation, slowed conduction velocity, increased conduction velocity heterogeneity, and prolonged calcium transients. When hAdip-conditioned medium was added to monolayer cultures of hiPSC-CMs, results similar to those recorded with direct co-cultures were observed. Both co-culture and conditioned medium experiments resulted in increases in transcript abundance of SCN10A, CACNA1C, SLC8A1, and RYR2, with a decrease in KCNJ2. Human adipokine immunoblots revealed the presence of cytokines that were elevated in adipocyte-conditioned medium, including MCP-1, IL-6, IL-8 and CFD that could induce electrophysiological changes in cultured hiPSC-CMs. CONCLUSIONS: Co-culture of hiPSC-CMs with hAdips reveals a potentially pathogenic role of infiltrating human adipocytes on myocardial tissue. In the absence of structural changes, hAdip paracrine release alone is sufficient to cause CM electrophysiological dysfunction mirroring the co-culture conditions. These effects, mediated largely by paracrine mechanisms, could promote arrhythmias in the heart.
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Affiliation(s)
| | - William R Xu
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Roald Teuben
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Kenneth R Boheler
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA; Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Leslie Tung
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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2
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Simon-Chica A, Wülfers EM, Kohl P. Nonmyocytes as electrophysiological contributors to cardiac excitation and conduction. Am J Physiol Heart Circ Physiol 2023; 325:H475-H491. [PMID: 37417876 PMCID: PMC10538996 DOI: 10.1152/ajpheart.00184.2023] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/22/2023] [Accepted: 06/29/2023] [Indexed: 07/08/2023]
Abstract
Although cardiac action potential (AP) generation and propagation have traditionally been attributed exclusively to cardiomyocytes (CM), other cell types in the heart are also capable of forming electrically conducting junctions. Interactions between CM and nonmyocytes (NM) enable and modulate each other's activity. This review provides an overview of the current understanding of heterocellular electrical communication in the heart. Although cardiac fibroblasts were initially thought to be electrical insulators, recent studies have demonstrated that they form functional electrical connections with CM in situ. Other NM, such as macrophages, have also been recognized as contributing to cardiac electrophysiology and arrhythmogenesis. Novel experimental tools have enabled the investigation of cell-specific activity patterns in native cardiac tissue, which is expected to yield exciting new insights into the development of novel or improved diagnostic and therapeutic strategies.
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Affiliation(s)
- Ana Simon-Chica
- Novel Arrhythmogenic Mechanisms Program, Centro Nacional de Investigaciones Cardiovasculares, Madrid, Spain
| | - Eike M Wülfers
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Department of Physics and Astronomy, Faculty of Sciences, Ghent University, Gent, Belgium
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg-Bad Krozingen, Faculty of Medicine, University of Freiburg, Freiburg, Germany
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3
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Silic MR, Zhang G. Bioelectricity in Developmental Patterning and Size Control: Evidence and Genetically Encoded Tools in the Zebrafish Model. Cells 2023; 12:cells12081148. [PMID: 37190057 DOI: 10.3390/cells12081148] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 04/03/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023] Open
Abstract
Developmental patterning is essential for regulating cellular events such as axial patterning, segmentation, tissue formation, and organ size determination during embryogenesis. Understanding the patterning mechanisms remains a central challenge and fundamental interest in developmental biology. Ion-channel-regulated bioelectric signals have emerged as a player of the patterning mechanism, which may interact with morphogens. Evidence from multiple model organisms reveals the roles of bioelectricity in embryonic development, regeneration, and cancers. The Zebrafish model is the second most used vertebrate model, next to the mouse model. The zebrafish model has great potential for elucidating the functions of bioelectricity due to many advantages such as external development, transparent early embryogenesis, and tractable genetics. Here, we review genetic evidence from zebrafish mutants with fin-size and pigment changes related to ion channels and bioelectricity. In addition, we review the cell membrane voltage reporting and chemogenetic tools that have already been used or have great potential to be implemented in zebrafish models. Finally, new perspectives and opportunities for bioelectricity research with zebrafish are discussed.
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Affiliation(s)
- Martin R Silic
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
| | - GuangJun Zhang
- Department of Comparative Pathobiology, Purdue University, West Lafayette, IN 47907, USA
- Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute for Inflammation, Immunology and Infectious Diseases (PI4D), Purdue University, West Lafayette, IN 47907, USA
- Purdue Institute for Integrative Neuroscience, Purdue University, 625 Harrison Street, West Lafayette, IN 47907, USA
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4
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Akaniro-Ejim NE, Smith PA. Intracellular Ca 2+ in Mouse White Fat Adipocytes: Effects of Extracellular Anions, Growth Hormone, and Their Interaction with Ca 2+ Influx. Bioelectricity 2021. [DOI: 10.1089/bioe.2021.0020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - Paul A. Smith
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
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5
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Modulation of Cardiac Arrhythmogenesis by Epicardial Adipose Tissue: JACC State-of-the-Art Review. J Am Coll Cardiol 2021; 78:1730-1745. [PMID: 34674819 DOI: 10.1016/j.jacc.2021.08.037] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 08/06/2021] [Accepted: 08/25/2021] [Indexed: 01/04/2023]
Abstract
Obesity is a significant risk factor for arrhythmic cardiovascular death. Interactions between epicardial adipose tissue (EAT) and myocytes are thought to play a key role in the development of arrhythmias. In this review, the authors investigate the influence of EAT on arrhythmogenesis. First, they summarize electrocardiographic evidence showing the association between increased EAT volume and atrial and ventricular conduction delay. Second, they detail the structural cross talk between EAT and the heart and its arrhythmogenicity. Adipose tissue infiltration within the myocardium constitutes an anatomical obstacle to cardiac excitation. It causes activation delay and increases the risk of arrhythmias. Intercellular electrical coupling between cardiomyocytes and EAT can further slow conduction and increase the risk of block, favoring re-entry and arrhythmias. Finally, EAT secretes multiple substances that influence cardiomyocyte electrophysiology either by modulating ion currents and electrical coupling or by stimulating fibrosis. Thus, structural and paracrine cross talk between EAT and cardiomyocytes facilitates arrhythmias.
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6
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Jiang J, Smith P, van Rossum MCW. Electro-physiology Models of Cells with Spherical Geometry with Non-conducting Center. Bull Math Biol 2020; 82:147. [PMID: 33211192 PMCID: PMC7677290 DOI: 10.1007/s11538-020-00828-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 10/30/2020] [Indexed: 11/28/2022]
Abstract
We study the flow of electrical currents in spherical cells with a non-conducting core, so that current flow is restricted to a thin shell below the cell's membrane. Examples of such cells are fat storing cells (adipocytes). We derive the relation between current and voltage in the passive regime and examine the conditions under which the cell is electro-tonically compact. We compare our results to the well-studied case of electrical current flow in cylinder structures, such as neurons, described by the cable equation. In contrast to the cable, we find that for the sphere geometry (1) the voltage profile across the cell depends critically on the electrode geometry, and (2) the charging and discharging can be much faster than the membrane time constant; however, (3) voltage clamp experiments will incur similar distortion as in the cable case. We discuss the relevance for adipocyte function and experimental electro-physiology.
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Affiliation(s)
- Jiamu Jiang
- School of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Paul Smith
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Mark C W van Rossum
- School of Mathematical Sciences, University of Nottingham, Nottingham, NG7 2RD, UK. .,School of Psychology, University of Nottingham, Nottingham, NG7 2RD, UK.
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7
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Cavanagh RJ, Smith PA, Stolnik S. Exposure to a Nonionic Surfactant Induces a Response Akin to Heat-Shock Apoptosis in Intestinal Epithelial Cells: Implications for Excipients Safety. Mol Pharm 2019; 16:618-631. [PMID: 30608696 DOI: 10.1021/acs.molpharmaceut.8b00934] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Amphipathic, nonionic, surfactants are widely used in pharmaceutical, food, and agricultural industry to enhance product features; as pharmaceutical excipients, they are also aimed at increasing cell membrane permeability and consequently improving oral drugs absorption. Here, we report on the concentration- and time-dependent succession of events occurring throughout and subsequent exposure of Caco-2 epithelium to a "typical" nonionic surfactant (Kolliphor HS15) to provide a molecular explanation for nonionic surfactant cytotoxicity. The study shows that the conditions of surfactant exposure, which increase plasma membrane fluidity and permeability, produced rapid (within 5 min) redox and mitochondrial effects. Apoptosis was triggered early during exposure (within 10 min) and relied upon an initial mitochondrial membrane hyperpolarization (5-10 min) as a crucial step, leading to its subsequent depolarization and caspase-3/7 activation (60 min). The apoptotic pathway appears to be triggered prior to substantial surfactant-induced membrane damage (observed ≥60 min). We hence propose that the cellular response to the model nonionic surfactant is triggered via surfactant-induced increase in plasma membrane fluidity, a phenomenon akin to the stress response to membrane fluidization induced by heat shock, and consequent apoptosis. Therefore, the fluidization effect that confers surfactants the ability to enhance drug permeability may also be intrinsically linked to the propagation of their cytotoxicity. The reported observations have important implications for the safety of a multitude of nonionic surfactants used in drug delivery formulations and to other permeability enhancing compounds with similar plasma membrane fluidizing mechanisms.
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Affiliation(s)
- Robert J Cavanagh
- Division of Molecular Therapeutics and Formulation, School of Pharmacy , University of Nottingham , Nottingham NG7 2RD , United Kingdom
| | - Paul A Smith
- School of Life Science , University of Nottingham , Nottingham NG7 2RD , United Kingdom
| | - Snow Stolnik
- Division of Molecular Therapeutics and Formulation, School of Pharmacy , University of Nottingham , Nottingham NG7 2RD , United Kingdom
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8
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Bederman I, DiScenna A, Henderson L, Perez A, Klavanian J, Kovtun D, Collins O, Dunn J, Erokwu B, Flask CA, Drumm ML. Small adipose stores in cystic fibrosis mice are characterized by reduced cell volume, not cell number. Am J Physiol Gastrointest Liver Physiol 2018; 315:G943-G953. [PMID: 30188751 PMCID: PMC6336944 DOI: 10.1152/ajpgi.00096.2017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Cystic fibrosis (CF) is a lethal genetic disorder that affects many organ systems of the body, including various endocrine and exocrine tissues. Health and survival positively associate with body mass, and as a consequence, CF clinical care includes high-fat, high-calorie diets to maintain and increase adipose tissue stores. Such strategies have been implemented without a clear understanding of the cause and effect relationship between body mass and patients' health. Here, we used CF mouse models, which display small adipose stores, to begin examining body fat as a prelude into mechanistic studies of low body growth in CF, so that optimal therapeutic strategies could be developed. We reasoned that low adiposity must result from reduced number and/or volume of adipocytes. To determine relative contribution of either mechanism, we quantified volume of intraperitoneal and subcutaneous adipocytes. We found smaller, but not fewer, adipocytes in CF compared with wild-type (WT) animals. Specifically, intraperitoneal CF adipocytes were one-half the volume of WT cells, whereas subcutaneous cells were less affected by the Cftr genotype. No differences were found in cell types between CF and WT adipose tissues. Adipose tissue CFTR mRNA was detected, and we found greater CFTR expression in intraperitoneal depots as compared with subcutaneous samples. RNA sequencing revealed that CF adipose tissue exhibited lower expression of several key genes of adipocyte function ( Lep, Pck1, Fas, Jun), consistent with low triglyceride storage. The data indicate that CF adipocytes contain fewer triglycerides than WT cells, and a role for CFTR in these cells is proposed. NEW & NOTEWORTHY Adipocytes in cystic fibrosis mice exhibit smaller size due to low triglyceride storage. Adipocyte cell number per fat pad is similar, implying triglyceride storage problem. The absence of CFTR function in adipose tissue has been proposed as a direct link to low triglyceride storage in cystic fibrosis.
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Affiliation(s)
- Ilya Bederman
- 1Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio
| | - Alex DiScenna
- 1Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio
| | - Leigh Henderson
- 2Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio
| | - Aura Perez
- 1Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio
| | - Jeannie Klavanian
- 2Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio
| | - Daniel Kovtun
- 1Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio
| | - Olivia Collins
- 1Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio
| | - John Dunn
- 1Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio
| | - Bernadette Erokwu
- 3Department of Radiology, School of Medicine, Case Western Reserve University, Cleveland, Ohio
| | - Christopher A. Flask
- 3Department of Radiology, School of Medicine, Case Western Reserve University, Cleveland, Ohio,4Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Mitchell L. Drumm
- 1Department of Pediatrics, Case Western Reserve University, Cleveland, Ohio,2Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, Ohio
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9
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El Hachmane MF, Olofsson CS. A mechanically activated TRPC1-like current in white adipocytes. Biochem Biophys Res Commun 2018. [PMID: 29524421 DOI: 10.1016/j.bbrc.2018.03.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Ca2+ impacts a large array of cellular processes in every known cell type. In the white adipocyte, Ca2+ is involved in regulation of metabolic processes such as lipolysis, glucose uptake and hormone secretion. Although the importance of Ca2+ in control of white adipocyte function is clear, knowledge is still lacking regarding the control of dynamic Ca2+ alterations within adipocytes and mechanisms inducing intracellular Ca2+ changes remain elusive. Own work has recently demonstrated the existence of store-operated Ca2+ entry (SOCE) in lipid filled adipocytes. We defined stromal interaction molecule 1 (STIM1) and the calcium release-activated calcium channel protein 1 (ORAI1) as the key players involved in this process and we showed that the transient receptor potential (TRP) channel TRPC1 contributed to SOCE. Here we have aimed to further characterised SOCE in the white adipocyte by use of single cell whole-cell patch clamp recordings. The electrophysiological measurements show the existence of a seemingly constitutively active current that is inhibited by known store-operated Ca2+ channel (SOCC) blockers. We demonstrate that the mechanical force applied to the plasma membrane upon patching leads to an elevation of the cytoplasmic Ca2+ concentration and that this elevation can be reversed by SOCC antagonists. We conclude that a mechanically activated current with properties similar to TRPC1 is present in white adipocytes. Activation of TRPC1 by membrane tension/stretch may be specifically important for the function of this cell type, since adipocytes can rapidly increase or decrease in size.
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Affiliation(s)
- Mickaël F El Hachmane
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden
| | - Charlotta S Olofsson
- Department of Physiology/Metabolic Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Medicinaregatan 11, SE-405 30, Göteborg, Sweden.
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10
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Extracellular ATP activates store-operated Ca 2+ entry in white adipocytes: functional evidence for STIM1 and ORAI1. Biochem J 2018; 475:691-704. [PMID: 29335300 PMCID: PMC5813502 DOI: 10.1042/bcj20170484] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 01/05/2018] [Accepted: 01/13/2018] [Indexed: 12/26/2022]
Abstract
In the present study, we have applied ratiometric measurements of intracellular Ca2+ concentrations ([Ca2+]i) to show that extracellularly applied ATP (adenosine triphosphate) (100 µM) stimulates store-operated Ca2+ entry (SOCE) in 3T3-L1 adipocytes. ATP produced a rapid increase in [Ca2+]i consisting of an initial transient elevation followed by a sustained elevated phase that could be observed only in the presence of extracellular Ca2+. Gene expression data and [Ca2+]i recordings with uridine-5′-triphosphate or with the phospholipase C (PLC) inhibitor U73122 demonstrated the involvement of purinergic P2Y2 receptors and the PLC/inositol trisphosphate pathway. The [Ca2+]i elevation produced by reintroduction of a Ca2+-containing intracellular solution to adipocytes exposed to ATP in the absence of Ca2+ was diminished by known SOCE antagonists. The chief molecular components of SOCE, the stromal interaction molecule 1 (STIM1) and the calcium release-activated calcium channel protein 1 (ORAI1), were detected at the mRNA and protein level. Moreover, SOCE was largely diminished in cells where STIM1 and/or ORAI1 had been silenced by small interfering (si)RNA. We conclude that extracellular ATP activates SOCE in white adipocytes, an effect predominantly mediated by STIM1 and ORAI1.
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11
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Crosstalk between KCNK3-Mediated Ion Current and Adrenergic Signaling Regulates Adipose Thermogenesis and Obesity. Cell 2017; 171:836-848.e13. [PMID: 28988768 DOI: 10.1016/j.cell.2017.09.015] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 06/10/2017] [Accepted: 09/08/2017] [Indexed: 01/13/2023]
Abstract
Adrenergic stimulation promotes lipid mobilization and oxidation in brown and beige adipocytes, where the harnessed energy is dissipated as heat in a process known as adaptive thermogenesis. The signaling cascades and energy-dissipating pathways that facilitate thermogenesis have been extensively described, yet little is known about the counterbalancing negative regulatory mechanisms. Here, we identify a two-pore-domain potassium channel, KCNK3, as a built-in rheostat negatively regulating thermogenesis. Kcnk3 is transcriptionally wired into the thermogenic program by PRDM16, a master regulator of thermogenesis. KCNK3 antagonizes norepinephrine-induced membrane depolarization by promoting potassium efflux in brown adipocytes. This limits calcium influx through voltage-dependent calcium channels and dampens adrenergic signaling, thereby attenuating lipolysis and thermogenic respiration. Adipose-specific Kcnk3 knockout mice display increased energy expenditure and are resistant to hypothermia and obesity. These findings uncover a critical K+-Ca2+-adrenergic signaling axis that acts to dampen thermogenesis, maintain tissue homeostasis, and reveal an electrophysiological regulatory mechanism of adipocyte function.
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12
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Forostyak O, Butenko O, Anderova M, Forostyak S, Sykova E, Verkhratsky A, Dayanithi G. Specific profiles of ion channels and ionotropic receptors define adipose- and bone marrow derived stromal cells. Stem Cell Res 2016; 16:622-34. [PMID: 27062357 DOI: 10.1016/j.scr.2016.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 03/21/2016] [Accepted: 03/23/2016] [Indexed: 01/09/2023] Open
Abstract
Adherent, fibroblastic cells from different tissues are thought to contain subsets of tissue-specific stem/progenitor cells (often called mesenchymal stem cells). These cells display similar cell surface characteristics based on their fibroblastic nature, but also exhibit differences in molecular phenotype, growth rate, and their ability to differentiate into various cell phenotypes. The mechanisms underlying these differences remain poorly understood. We analyzed Ca(2+) signals and membrane properties in rat adipose-derived stromal cells (ADSCs) and bone marrow stromal cells (BMSCs) in basal conditions, and then following a switch into medium that contains factors known to modify their character. Modified ADSCs (mADSCs) expressed L-type Ca(2+) channels whereas both L- and P/Q- channels were operational in mBMSCs. Both mADSCs and mBMSCs possessed functional endoplasmic reticulum Ca(2+) stores, expressed ryanodine receptor-1 and -3, and exhibited spontaneous [Ca(2+)]i oscillations. The mBMSCs expressed P2X7 purinoceptors; the mADSCs expressed both P2X (but not P2X7) and P2Y (but not P2Y1) receptors. Both types of stromal cells exhibited [Ca(2+)]i responses to vasopressin (AVP) and expressed V1 type receptors. Functional oxytocin (OT) receptors were, in contrast, expressed only in modified ADSCs and BMSCs. AVP and OT-induced [Ca(2+)]i responses were dose-dependent and were blocked by their respective specific receptor antagonists. Electrophysiological data revealed that passive ion currents dominated the membrane conductance in ADSCs and BMSCs. Medium modification led to a significant shift in the reversal potential of passive currents from -40 to -50mV in cells in basal to -80mV in modified cells. Hence membrane conductance was mediated by non-selective channels in cells in basal conditions, whereas in modified medium conditions, it was associated with K(+)-selective channels. Our results indicate that modification of ADSCs and BMSCs by alteration in medium formulation is associated with significant changes in their Ca(2+) signaling and membrane properties.
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Affiliation(s)
- Oksana Forostyak
- Department of Molecular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Videnska 1083, Prague 14220, Czech Republic; Department of Neuroscience, Charles University, Second Faculty of Medicine, V Uvalu 84, Prague 15006, Czech Republic
| | - Olena Butenko
- Department of Cellular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Videnska 1083, Prague 14220, Czech Republic.
| | - Miroslava Anderova
- Department of Neuroscience, Charles University, Second Faculty of Medicine, V Uvalu 84, Prague 15006, Czech Republic; Department of Cellular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Videnska 1083, Prague 14220, Czech Republic
| | - Serhiy Forostyak
- Department of Neuroscience, Charles University, Second Faculty of Medicine, V Uvalu 84, Prague 15006, Czech Republic; Department of Neuroscience, Institute of Experimental Medicine, Czech Academy of Sciences, Videnska 1083, Prague 14220, Czech Republic
| | - Eva Sykova
- Department of Neuroscience, Charles University, Second Faculty of Medicine, V Uvalu 84, Prague 15006, Czech Republic; Department of Neuroscience, Institute of Experimental Medicine, Czech Academy of Sciences, Videnska 1083, Prague 14220, Czech Republic
| | - Alexei Verkhratsky
- University of Manchester, School of Biological Sciences, D.4417 Michael Smith Building, Oxford Road, Manchester M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain; University of Nizhny Novgorod, Nizhny Novgorod 603022, Russia
| | - Govindan Dayanithi
- Department of Molecular Neurophysiology, Institute of Experimental Medicine, Czech Academy of Sciences, Videnska 1083, Prague 14220, Czech Republic; Institut National de la Santé et de la Recherche Médicale-U1198, Université Montpellier, Montpellier 34095, France; Ecole Pratique des Hautes Etudes-Sorbonne, Les Patios Saint-Jacques, 4-14 rue Ferrus, 75014 Paris, France.
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