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Pio-Lopez L, Levin M. Aging as a loss of morphostatic information: A developmental bioelectricity perspective. Ageing Res Rev 2024; 97:102310. [PMID: 38636560 DOI: 10.1016/j.arr.2024.102310] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 02/21/2024] [Accepted: 04/12/2024] [Indexed: 04/20/2024]
Abstract
Maintaining order at the tissue level is crucial throughout the lifespan, as failure can lead to cancer and an accumulation of molecular and cellular disorders. Perhaps, the most consistent and pervasive result of these failures is aging, which is characterized by the progressive loss of function and decline in the ability to maintain anatomical homeostasis and reproduce. This leads to organ malfunction, diseases, and ultimately death. The traditional understanding of aging is that it is caused by the accumulation of molecular and cellular damage. In this article, we propose a complementary view of aging from the perspective of endogenous bioelectricity which has not yet been integrated into aging research. We propose a view of aging as a morphostasis defect, a loss of biophysical prepattern information, encoding anatomical setpoints used for dynamic tissue and organ homeostasis. We hypothesize that this is specifically driven by abrogation of the endogenous bioelectric signaling that normally harnesses individual cell behaviors toward the creation and upkeep of complex multicellular structures in vivo. Herein, we first describe bioelectricity as the physiological software of life, and then identify and discuss the links between bioelectricity and life extension strategies and age-related diseases. We develop a bridge between aging and regeneration via bioelectric signaling that suggests a research program for healthful longevity via morphoceuticals. Finally, we discuss the broader implications of the homologies between development, aging, cancer and regeneration and how morphoceuticals can be developed for aging.
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Affiliation(s)
- Léo Pio-Lopez
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA
| | - Michael Levin
- Allen Discovery Center, Tufts University, Medford, MA 02155, USA; Wyss Institute for Biologically Inspired Engineering, Boston, MA 02115, USA.
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Electrophysiological engineering of heart-derived cells with calcium-dependent potassium channels improves cell therapy efficacy for cardioprotection. Nat Commun 2021; 12:4963. [PMID: 34400625 PMCID: PMC8368210 DOI: 10.1038/s41467-021-25180-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 07/21/2021] [Indexed: 12/30/2022] Open
Abstract
We have shown that calcium-activated potassium (KCa)-channels regulate fundamental progenitor-cell functions, including proliferation, but their contribution to cell-therapy effectiveness is unknown. Here, we test the participation of KCa-channels in human heart explant-derived cell (EDC) physiology and therapeutic potential. TRAM34-sensitive KCa3.1-channels, encoded by the KCNN4 gene, are exclusively expressed in therapeutically bioactive EDC subfractions and maintain a strongly polarized resting potential; whereas therapeutically inert EDCs lack KCa3.1 channels and exhibit depolarized resting potentials. Somatic gene transfer of KCNN4 results in membrane hyperpolarization and increases intracellular [Ca2+], which boosts cell-proliferation and the production of pro-healing cytokines/nanoparticles. Intramyocardial injection of EDCs after KCNN4-gene overexpression markedly increases the salutary effects of EDCs on cardiac function, viable myocardium and peri-infarct neovascularization in a well-established murine model of ischemic cardiomyopathy. Thus, electrophysiological engineering provides a potentially valuable strategy to improve the therapeutic value of progenitor cells for cardioprotection and possibly other indications. Strategies to improve the function of damaged hearts with progenitor cells have stalled. Here, the authors show that gene transfer of a calcium-dependent potassium channel enhances the functional properties and ability of explant-derived cells to improve heart function after a heart attack.
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Henao JC, Grismaldo A, Barreto A, Rodríguez-Pardo VM, Mejía-Cruz CC, Leal-Garcia E, Pérez-Núñez R, Rojas P, Latorre R, Carvacho I, Torres YP. TRPM8 Channel Promotes the Osteogenic Differentiation in Human Bone Marrow Mesenchymal Stem Cells. Front Cell Dev Biol 2021; 9:592946. [PMID: 33614639 PMCID: PMC7890257 DOI: 10.3389/fcell.2021.592946] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 01/05/2021] [Indexed: 11/29/2022] Open
Abstract
Various families of ion channels have been characterized in mesenchymal stem cells (MSCs), including some members of transient receptor potential (TRP) channels family. TRP channels are involved in critical cellular processes as differentiation and cell proliferation. Here, we analyzed the expression of TRPM8 channel in human bone marrow MSCs (hBM-MSCs), and its relation with osteogenic differentiation. Patch-clamp recordings showed that hBM-MSCs expressed outwardly rectifying currents which were increased by exposure to 500 μM menthol and were partially inhibited by 10 μM of BCTC, a TRPM8 channels antagonist. Additionally, we have found the expression of TRPM8 by RT-PCR and western blot. We also explored the TRPM8 localization in hBM-MSCs by immunofluorescence using confocal microscopy. Remarkably, hBM-MSCs treatment with 100 μM of menthol or 10 μM of icilin, TRPM8 agonists, increases osteogenic differentiation. Conversely, 20 μM of BCTC, induced a decrease of osteogenic differentiation. These results suggest that TRPM8 channels are functionally active in hBM-MSCs and have a role in cell differentiation.
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Affiliation(s)
- Juan C Henao
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Adriana Grismaldo
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Alfonso Barreto
- Grupo de Inmunobiología y Biología Celular, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Viviana M Rodríguez-Pardo
- Grupo de Inmunobiología y Biología Celular, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Claudia Camila Mejía-Cruz
- Grupo de Inmunobiología y Biología Celular, Departamento de Microbiología, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
| | - Efrain Leal-Garcia
- Departamento de Ortopedia y Traumatología, Facultad de Medicina, Pontificia Universidad Javeriana, Bogotá, Colombia
| | | | - Patricio Rojas
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Ramón Latorre
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
| | - Ingrid Carvacho
- Department of Biology and Chemistry, Faculty of Basic Sciences, Universidad Católica del Maule, Talca, Chile
| | - Yolima P Torres
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, Colombia
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Andrade S, Morais T, Sandovici I, Seabra AL, Constância M, Monteiro MP. Adipose Tissue Epigenetic Profile in Obesity-Related Dysglycemia - A Systematic Review. Front Endocrinol (Lausanne) 2021; 12:681649. [PMID: 34290669 PMCID: PMC8288106 DOI: 10.3389/fendo.2021.681649] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 05/26/2021] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND Obesity is a major risk factor for dysglycemic disorders, including type 2 diabetes (T2D). However, there is wide phenotypic variation in metabolic profiles. Tissue-specific epigenetic modifications could be partially accountable for the observed phenotypic variability. SCOPE The aim of this systematic review was to summarize the available data on epigenetic signatures in human adipose tissue (AT) that characterize overweight or obesity-related insulin resistance (IR) and dysglycemia states and to identify potential underlying mechanisms through the use of unbiased bioinformatics approaches. METHODS Original data published in the last decade concerning the comparison of epigenetic marks in human AT of individuals with metabolically unhealthy overweight/obesity (MUHO) versus normal weight individuals or individuals with metabolically healthy overweight/obesity (MHO) was assessed. Furthermore, association of these epigenetic marks with IR/dysglycemic traits, including T2D, was compiled. RESULTS We catalogued more than two thousand differentially methylated regions (DMRs; above the cut-off of 5%) in the AT of individuals with MUHO compared to individuals with MHO. These DNA methylation changes were less likely to occur around the promoter regions and were enriched at loci implicated in intracellular signaling (signal transduction mediated by small GTPases, ERK1/2 signaling and intracellular trafficking). We also identified a network of seven transcription factors that may play an important role in targeting DNA methylation changes to specific genes in the AT of subjects with MUHO, contributing to the pathogeny of obesity-related IR/T2D. Furthermore, we found differentially methylated CpG sites at 8 genes that were present in AT and whole blood, suggesting that DMRs in whole blood could be potentially used as accessible biomarkers of MUHO. CONCLUSIONS The overall evidence linking epigenetic alterations in key tissues such AT to metabolic complications in human obesity is still very limited, highlighting the need for further studies, particularly those focusing on epigenetic marks other than DNA methylation. Our initial analysis suggests that DNA methylation patterns can potentially discriminate between MUHO from MHO and provide new clues into why some people with obesity are less susceptible to dysglycemia. Identifying AT-specific epigenetic targets could also lead to novel approaches to modify the progression of individuals with obesity towards metabolic disease. SYSTEMATIC REVIEW REGISTRATION PROSPERO, identifier CRD42021227237.
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Affiliation(s)
- Sara Andrade
- Endocrine and Metabolic Research, Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, Porto, Portugal
- Department of Anatomy, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Tiago Morais
- Endocrine and Metabolic Research, Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, Porto, Portugal
- Department of Anatomy, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Ionel Sandovici
- University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrookes Hospital, Cambridge, United Kingdom
- Department of Obstetrics and Gynaecology and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
| | - Alexandre L. Seabra
- Endocrine and Metabolic Research, Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, Porto, Portugal
- Department of Anatomy, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
| | - Miguel Constância
- University of Cambridge Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Institute of Metabolic Science, Addenbrookes Hospital, Cambridge, United Kingdom
- Department of Obstetrics and Gynaecology and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge, United Kingdom
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
- National Institute of Health Research, Cambridge Biomedical Research Centre, Cambridge, United Kingdom
| | - Mariana P. Monteiro
- Endocrine and Metabolic Research, Unit for Multidisciplinary Research in Biomedicine (UMIB), University of Porto, Porto, Portugal
- Department of Anatomy, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- *Correspondence: Mariana P. Monteiro,
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Tajti G, Wai DCC, Panyi G, Norton RS. The voltage-gated potassium channel K V1.3 as a therapeutic target for venom-derived peptides. Biochem Pharmacol 2020; 181:114146. [PMID: 32653588 DOI: 10.1016/j.bcp.2020.114146] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/05/2020] [Accepted: 07/07/2020] [Indexed: 02/07/2023]
Abstract
The voltage-gated potassium channel KV1.3 is a well-established therapeutic target for a range of autoimmune diseases, in addition to being the site of action of many venom-derived peptides. Numerous studies have documented the efficacy of venom peptides that target KV1.3, in particular from sea anemones and scorpions, in animal models of autoimmune diseases such as rheumatoid arthritis, psoriasis and multiple sclerosis. Moreover, an analogue of the sea anemone peptide ShK (known as dalazatide) has successfully completed Phase 1 clinical trials in mild-to-moderate plaque psoriasis. In this article we consider other potential therapeutic applications of inhibitors of KV1.3, including in inflammatory bowel disease and neuroinflammatory conditions such as Alzheimer's and Parkinson's diseases, as well as fibrotic diseases. We also summarise strategies for facilitating the entry of peptides to the central nervous system, given that this will be a pre-requisite for the treatment of most neuroinflammatory diseases. Venom-derived peptides that have been reported recently to target KV1.3 are also described. The increasing number of autoimmune and other conditions in which KV1.3 is upregulated and is therefore a potential therapeutic target, combined with the fact that many venom-derived peptides are potent inhibitors of KV1.3, suggests that venoms are likely to continue to serve as a rich source of new pharmacological tools and therapeutic leads targeting this channel.
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Affiliation(s)
- Gabor Tajti
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary
| | - Dorothy C C Wai
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
| | - Raymond S Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia; ARC Centre for Fragment-Based Design, Monash University, Parkville, VIC 3052, Australia.
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Dettlaff-Pokora A. Adipocyte differentiation impairment as well as lipid metabolism and transport problems – major causes of genetic lipodystrophies. POSTEP HIG MED DOSW 2019. [DOI: 10.5604/01.3001.0013.6553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Lipodystrophies are heterogenic group of adipose tissue disorders with its general or partial atrophy. In case of congenital lipodystrophies disturbances of adipogenesis or/and alterations of adipocyte differentiation often occur leading to thermogenic adipocytes formation. Basic adipocyte functions can be perturbed, including improper synthesis of triacylglycerols and phospholipids of lipid droplet, but also impaired fatty acids release and intracellular lipid traffic. Lipodystrophy can result from weakening of adipose tissue structure, but also from improper function of both cytoskeleton and nuclear lamina leading to cell dysfunction. Lack of adipose tissue leads to a) increased plasma triacylglycerols level and ectopic fat accumulation in other tissues; b) total plasma cholesterol increase; c) plasma HDL-cholesterol decrease. Ectopic fat accumulation in liver can cause fatty liver and with time can lead to hepatomegaly and liver cirrhosis. Dysfunctions are proportional to the extent of fat tissue loss with generalized lipodystrophies patients developing complications at early ages. Diabetes and insulin resistance are common comorbidities. Improvement of diagnostic methods of medical genetics allows precise determination of their genotypes and correct diagnosis of patients suffering from lipodystrophy. For that reason number of described cases increased in recent years, also in Poland. New lipodystrophy types were described. Therefore there is a need to bring lipodystrophy syndromes for the attention of primary care physicians, pediatricians and endocrinologists.
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Silva HB, Rodrigues DC, Andrade R, Teixeira GHGSF, Stelling MP, Ponte CG, Nascimento JHM, Campos de Carvalho AC, Medei E. Expression of potassium channels is relevant for cell survival and migration in a murine bone marrow stromal cell line. J Cell Physiol 2019; 234:18086-18097. [PMID: 30887515 DOI: 10.1002/jcp.28441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 02/07/2019] [Accepted: 02/14/2019] [Indexed: 02/05/2023]
Abstract
S17 is a clonogenic bone marrow stromal (BMS) cell line derived from mouse that has been extensively used to assess both human and murine hematopoiesis support capacity. However, very little is known about the expression of potassium ion channels and their function in cell survival and migration in these cells. Thus, the present study was designed to characterize potassium ion channels using electrophysiological and molecular biological approaches in S17 BMS cells. The whole-cell configuration of the patch clamp technique has been applied to identify potassium ion currents and reverse transcription polymerase chain reaction (RT-PCR) used to determine their molecular identities. Based on gating kinetics and pharmacological modulation of the macroscopic currents we found the presence of four functional potassium ion channels in S17 BMS cells. These include a current rapidly activated and inactivated, tetraethylammonium-sensitive, (IKV ) in most (50%) cells; a fast activated and rapidly inactivating A-type K + current (IK A -like); a delayed rectifier K + current (IK DR ) and an inward rectifier potassium current (IK IR ), found in, respectively 4.5%, 26% and 24% of these cells. RT-PCR confirmed the presence of mRNA transcripts for the alpha subunit of the corresponding functional ion channels. Additionally, functional assays were performed to investigate the importance of potassium currents in cell survival and migration. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide analyses revealed a reduction in cell viability, while wound healing assays revealed reduced migration potential in cells incubated with different potassium channel blockers. In conclusion, our data suggested that potassium currents might play a role in the maintenance of overall S17 cell ionic homeostasis directly affecting cell survival and migration.
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Affiliation(s)
- Henrique B Silva
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
- Center for Neuroscience and Cell Biology, University of Coimbra Rua Larga, Faculty of Medicine, Coimbra, Portugal
| | - Deivid C Rodrigues
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Raiana Andrade
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Gabriel H G S F Teixeira
- Federal Institute of Education, Science and Technology of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Mariana P Stelling
- Federal Institute of Education, Science and Technology of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Cristiano G Ponte
- Federal Institute of Education, Science and Technology of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - José H M Nascimento
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | | | - Emiliano Medei
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Tian JJ, Lei CX, Ji H, Zhou JS, Yu HB, Li Y, Yu EM, Xie J. Dietary arachidonic acid decreases the expression of transcripts related to adipocyte development and chronic inflammation in the adipose tissue of juvenile grass carp, Ctenopharyngodon idella. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2019; 30:122-132. [DOI: 10.1016/j.cbd.2019.02.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 02/18/2019] [Accepted: 02/20/2019] [Indexed: 12/30/2022]
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Pérez-Verdaguer M, Capera J, Ortego-Domínguez M, Bielanska J, Comes N, Montoro RJ, Camps M, Felipe A. Caveolar targeting links Kv1.3 with the insulin-dependent adipocyte physiology. Cell Mol Life Sci 2018; 75:4059-4075. [PMID: 29947924 PMCID: PMC11105548 DOI: 10.1007/s00018-018-2851-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 05/14/2018] [Accepted: 06/05/2018] [Indexed: 12/23/2022]
Abstract
The voltage-dependent potassium channel Kv1.3 participates in peripheral insulin sensitivity. Genetic ablation of Kv1.3 triggers resistance to diet-induced weight gain, thereby pointing to this protein as a pharmacological target for obesity and associated type II diabetes. However, this role is under intense debate because Kv1.3 expression in adipose tissue raises controversy. We demonstrated that Kv1.3 is expressed in white adipose tissue from humans and rodents. Moreover, other channels, such as Kv1.1, Kv1.2, Kv1.4 and especially Kv1.5, from the same Shaker family are also present. Although elevated insulin levels and adipogenesis remodel the Kv phenotype, which could lead to multiple heteromeric complexes, Kv1.3 markedly participates in the insulin-dependent regulation of glucose uptake in mature adipocytes. Adipocyte differentiation increased the expression of Kv1.3, which is targeted to caveolae by molecular interactions with caveolin 1. Using a caveolin 1-deficient 3T3-L1 adipocyte cell line, we demonstrated that the localization of Kv1.3 in caveolar raft structures is important for proper insulin signaling. Insulin-dependent phosphorylation of the channel occurs at the onset of insulin-mediated signaling. However, when Kv1.3 was spatially outside of these lipid microdomains, impaired phosphorylation was exhibited. Our data shed light on the putative role of Kv1.3 in weight gain and insulin-dependent responses contributing to knowledge about adipocyte physiology.
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Affiliation(s)
- Mireia Pérez-Verdaguer
- Molecular Physiology Laboratory, Dpt. de Bioquímica i Biomedicina Molecular, Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - Jesusa Capera
- Molecular Physiology Laboratory, Dpt. de Bioquímica i Biomedicina Molecular, Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - María Ortego-Domínguez
- Dpto. de Fisiología Médica y Biofísica, Universidad de Sevilla, Av. Dr. Fedriani, s/n., 41009, Seville, Spain
| | - Joanna Bielanska
- Molecular Physiology Laboratory, Dpt. de Bioquímica i Biomedicina Molecular, Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
- Max-Planck-Institute of Experimental Medicine, Molecular Biology of Neuronal Signals, AG Oncophysiology, Hermann-Rein-Str. 3, 37075, Göttingen, Germany
| | - Núria Comes
- Molecular Physiology Laboratory, Dpt. de Bioquímica i Biomedicina Molecular, Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - Rafael J Montoro
- Dpto. de Fisiología Médica y Biofísica, Universidad de Sevilla, Av. Dr. Fedriani, s/n., 41009, Seville, Spain
| | - Marta Camps
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain
| | - Antonio Felipe
- Molecular Physiology Laboratory, Dpt. de Bioquímica i Biomedicina Molecular, Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain.
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Av. Diagonal 643, 08028, Barcelona, Spain.
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Jayaram DT, Luo Q, Thourson SB, Finlay AH, Payne CK. Controlling the Resting Membrane Potential of Cells with Conducting Polymer Microwires. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2017; 13:10.1002/smll.201700789. [PMID: 28556571 PMCID: PMC5560653 DOI: 10.1002/smll.201700789] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 04/11/2017] [Indexed: 05/11/2023]
Abstract
All cells have a resting membrane potential resulting from an ion gradient across the plasma membrane. The resting membrane potential of cells is tightly coupled to regeneration and differentiation. The ability to control this parameter provides the opportunity for both biomedical advances and the probing of fundamental bioelectric pathways. The use of poly(3,4-ethylenedioxythiophene): polystyrene sulfonate (PEDOT:PSS) conducting polymer microwires to depolarize cells is tested using E. coli cells loaded with a fluorescent dye that is pumped out of the cells in response to depolarization; a more positive membrane potential. Fluorescence imaging of the cells in response to a conducting-polymer-microwire applied voltage confirms depolarization and shows that the rate of depolarization is a function of the applied voltage and frequency. Microwire activity does not damage the cells, demonstrated with a propidium iodide assay of membrane integrity. The conducting polymer microwires do not penetrate the cell, or even come into contact with the cell; they only need to generate a minimum electric field, controlled by the placement of the wires. It is expected that these microwires will provide a new, noninvasive, cellular-scale tool for the control of resting membrane potential with high spatial precision.
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Affiliation(s)
- Dhanya T Jayaram
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Qingjie Luo
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Scott B Thourson
- Interdisciplinary Program in BioEngineering and George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Adam H Finlay
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Christine K Payne
- School of Chemistry and Biochemistry and Petit Institute for Bioengineering and Biosciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
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Choi SY, Kim HR, Ryu PD, Lee SY. Regulation of voltage-gated potassium channels attenuates resistance of side-population cells to gefitinib in the human lung cancer cell line NCI-H460. BMC Pharmacol Toxicol 2017. [DOI: 10.1186/s40360-017-0118-9 order by 25532--] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Choi SY, Kim HR, Ryu PD, Lee SY. Regulation of voltage-gated potassium channels attenuates resistance of side-population cells to gefitinib in the human lung cancer cell line NCI-H460. BMC Pharmacol Toxicol 2017; 18:14. [PMID: 28219421 PMCID: PMC5319158 DOI: 10.1186/s40360-017-0118-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 01/28/2017] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Side-population (SP) cells that exclude anti-cancer drugs have been found in various tumor cell lines. Moreover, SP cells have a higher proliferative potential and drug resistance than main population cells (Non-SP cells). Also, several ion channels are responsible for the drug resistance and proliferation of SP cells in cancer. METHODS To confirm the expression and function of voltage-gated potassium (Kv) channels of SP cells, these cells, as well as highly expressed ATP-binding cassette (ABC) transporters and stemness genes, were isolated from a gefitinib-resistant human lung adenocarcinoma cell line (NCI-H460), using Hoechst 33342 efflux. RESULTS In the present study, we found that mRNA expression of Kv channels in SP cells was different compared to Non-SP cells, and the resistance of SP cells to gefitinib was weakened with a combination treatment of gefitinib and Kv channel blockers or a Kv7 opener, compared to single-treatment gefitinib, through inhibition of the Ras-Raf signaling pathway. CONCLUSIONS The findings indicate that Kv channels in SP cells could be new targets for reducing the resistance to gefitinib.
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Affiliation(s)
- Seon Young Choi
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Hang-Rae Kim
- Department of Anatomy and Cell Biology, and Biomedical Sciences, College of Medicine, Seoul National University, Seoul, Korea
| | - Pan Dong Ryu
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - So Yeong Lee
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea.
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Choi SY, Kim HR, Ryu PD, Lee SY. Regulation of voltage-gated potassium channels attenuates resistance of side-population cells to gefitinib in the human lung cancer cell line NCI-H460. BMC Pharmacol Toxicol 2017. [DOI: 10.1186/s40360-017-0118-9 order by 21742--] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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14
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Yang JE, Song MS, Shen Y, Ryu PD, Lee SY. The Role of KV7.3 in Regulating Osteoblast Maturation and Mineralization. Int J Mol Sci 2016; 17:407. [PMID: 26999128 PMCID: PMC4813262 DOI: 10.3390/ijms17030407] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 03/02/2016] [Accepted: 03/10/2016] [Indexed: 11/19/2022] Open
Abstract
KCNQ (KV7) channels are voltage-gated potassium (KV) channels, and the function of KV7 channels in muscles, neurons, and sensory cells is well established. We confirmed that overall blockade of KV channels with tetraethylammonium augmented the mineralization of bone-marrow-derived human mesenchymal stem cells during osteogenic differentiation, and we determined that KV7.3 was expressed in MG-63 and Saos-2 cells at the mRNA and protein levels. In addition, functional KV7 currents were detected in MG-63 cells. Inhibition of KV7.3 by linopirdine or XE991 increased the matrix mineralization during osteoblast differentiation. This was confirmed by alkaline phosphatase, osteocalcin, and osterix in MG-63 cells, whereas the expression of Runx2 showed no significant change. The extracellular glutamate secreted by osteoblasts was also measured to investigate its effect on MG-63 osteoblast differentiation. Blockade of KV7.3 promoted the release of glutamate via the phosphorylation of extracellular signal-regulated kinase 1/2-mediated upregulation of synapsin, and induced the deposition of type 1 collagen. However, activation of KV7.3 by flupirtine did not produce notable changes in matrix mineralization during osteoblast differentiation. These results suggest that KV7.3 could be a novel regulator in osteoblast differentiation.
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Affiliation(s)
- Ji Eun Yang
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
| | - Min Seok Song
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
| | - Yiming Shen
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
| | - Pan Dong Ryu
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
| | - So Yeong Lee
- Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul 151-742, Korea.
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15
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Sun W, Uchida K, Suzuki Y, Zhou Y, Kim M, Takayama Y, Takahashi N, Goto T, Wakabayashi S, Kawada T, Iwata Y, Tominaga M. Lack of TRPV2 impairs thermogenesis in mouse brown adipose tissue. EMBO Rep 2016; 17:383-99. [PMID: 26882545 DOI: 10.15252/embr.201540819] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 01/13/2016] [Indexed: 11/09/2022] Open
Abstract
Brown adipose tissue (BAT), a major site for mammalian non-shivering thermogenesis, could be a target for prevention and treatment of human obesity. Transient receptor potential vanilloid 2 (TRPV2), a Ca(2+)-permeable non-selective cation channel, plays vital roles in the regulation of various cellular functions. Here, we show that TRPV2 is expressed in brown adipocytes and that mRNA levels of thermogenic genes are reduced in both cultured brown adipocytes and BAT from TRPV2 knockout (TRPV2KO) mice. The induction of thermogenic genes in response to β-adrenergic receptor stimulation is also decreased in TRPV2KO brown adipocytes and suppressed by reduced intracellular Ca(2+) concentrations in wild-type brown adipocytes. In addition, TRPV2KO mice have more white adipose tissue and larger brown adipocytes and show cold intolerance, and lower BAT temperature increases in response to β-adrenergic receptor stimulation. Furthermore, TRPV2KO mice have increased body weight and fat upon high-fat-diet treatment. Based on these findings, we conclude that TRPV2 has a role in BAT thermogenesis and could be a target for human obesity therapy.
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Affiliation(s)
- Wuping Sun
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), Okazaki, Japan Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Kunitoshi Uchida
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), Okazaki, Japan Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Yoshiro Suzuki
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), Okazaki, Japan Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Yiming Zhou
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), Okazaki, Japan
| | - Minji Kim
- Division of Food Science and Biotechnology, Graduate School of Agriculture Kyoto University, Uji, Japan
| | - Yasunori Takayama
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), Okazaki, Japan Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
| | - Nobuyuki Takahashi
- Division of Food Science and Biotechnology, Graduate School of Agriculture Kyoto University, Uji, Japan
| | - Tsuyoshi Goto
- Division of Food Science and Biotechnology, Graduate School of Agriculture Kyoto University, Uji, Japan
| | - Shigeo Wakabayashi
- Department of Molecular Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Teruo Kawada
- Division of Food Science and Biotechnology, Graduate School of Agriculture Kyoto University, Uji, Japan
| | - Yuko Iwata
- Department of Molecular Physiology, National Cerebral and Cardiovascular Center Research Institute, Suita, Osaka, Japan
| | - Makoto Tominaga
- Division of Cell Signaling, Okazaki Institute for Integrative Bioscience (National Institute for Physiological Sciences), Okazaki, Japan Department of Physiological Sciences, SOKENDAI (The Graduate University for Advanced Studies), Okazaki, Japan
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16
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Voltage-Gated K+ Channel, Kv3.3 Is Involved in Hemin-Induced K562 Differentiation. PLoS One 2016; 11:e0148633. [PMID: 26849432 PMCID: PMC4743930 DOI: 10.1371/journal.pone.0148633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 01/20/2016] [Indexed: 12/31/2022] Open
Abstract
Voltage-gated K+ (Kv) channels are well known to be involved in cell proliferation. However, even though cell proliferation is closely related to cell differentiation, the relationship between Kv channels and cell differentiation remains poorly investigated. This study demonstrates that Kv3.3 is involved in K562 cell erythroid differentiation. Down-regulation of Kv3.3 using siRNA-Kv3.3 increased hemin-induced K562 erythroid differentiation through decreased activation of signal molecules such as p38, cAMP response element-binding protein, and c-fos. Down-regulation of Kv3.3 also enhanced cell adhesion by increasing integrin β3 and this effect was amplified when the cells were cultured with fibronectin. The Kv channels, or at least Kv3.3, appear to be associated with cell differentiation; therefore, understanding the mechanisms of Kv channel regulation of cell differentiation would provide important information regarding vital cellular processes.
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17
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Bocksteins E. Kv5, Kv6, Kv8, and Kv9 subunits: No simple silent bystanders. J Gen Physiol 2016; 147:105-25. [PMID: 26755771 PMCID: PMC4727947 DOI: 10.1085/jgp.201511507] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 12/11/2015] [Indexed: 12/19/2022] Open
Abstract
Members of the electrically silent voltage-gated K(+) (Kv) subfamilies (Kv5, Kv6, Kv8, and Kv9, collectively identified as electrically silent voltage-gated K(+) channel [KvS] subunits) do not form functional homotetrameric channels but assemble with Kv2 subunits into heterotetrameric Kv2/KvS channels with unique biophysical properties. Unlike the ubiquitously expressed Kv2 subunits, KvS subunits show a more restricted expression. This raises the possibility that Kv2/KvS heterotetramers have tissue-specific functions, making them potential targets for the development of novel therapeutic strategies. Here, I provide an overview of the expression of KvS subunits in different tissues and discuss their proposed role in various physiological and pathophysiological processes. This overview demonstrates the importance of KvS subunits and Kv2/KvS heterotetramers in vivo and the importance of considering KvS subunits and Kv2/KvS heterotetramers in the development of novel treatments.
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Affiliation(s)
- Elke Bocksteins
- Laboratory for Molecular Biophysics, Physiology, and Pharmacology, Department for Biomedical Sciences, University of Antwerp, 2610 Antwerp, Belgium
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18
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Lucia U, Ponzetto A, Deisboeck TS. Constructal approach to cell membranes transport: Amending the 'Norton-Simon' hypothesis for cancer treatment. Sci Rep 2016; 6:19451. [PMID: 26822208 PMCID: PMC4731791 DOI: 10.1038/srep19451] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 12/14/2015] [Indexed: 12/27/2022] Open
Abstract
To investigate biosystems, we propose a new thermodynamic concept that analyses ion, mass and energy flows across the cell membrane. This paradigm-shifting approach has a wide applicability to medically relevant topics including advancing cancer treatment. To support this claim, we revisit ‘Norton-Simon’ and evolving it from an already important anti-cancer hypothesis to a thermodynamic theorem in medicine. We confirm that an increase in proliferation and a reduction in apoptosis trigger a maximum of ATP consumption by the tumor cell. Moreover, we find that positive, membrane-crossing ions lead to a decrease in the energy used by the tumor, supporting the notion of their growth inhibitory effect while negative ions apparently increase the cancer’s consumption of energy hence reflecting a growth promoting impact. Our results not only represent a thermodynamic proof of the original Norton-Simon hypothesis but, more concretely, they also advance the clinically intriguing and experimentally testable, diagnostic hypothesis that observing an increase in negative ions inside a cell in vitro, and inside a diseased tissue in vivo, may indicate growth or recurrence of a tumor. We conclude with providing theoretical evidence that applying electromagnetic field therapy early on in the treatment cycle may maximize its anti-cancer efficacy.
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Affiliation(s)
- Umberto Lucia
- Dipartimento Energia, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino, Italy
| | - Antonio Ponzetto
- Department of Medical Sciences, University of Torino, Corso A.M. Dogliotti 14, 10126 Torino, Italy
| | - Thomas S Deisboeck
- Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129, USA.,ThinkMotu LLC, Wellesley, MA 02481, USA
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19
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Vasopressin-induced Ca(2+) signals in human adipose-derived stem cells. Cell Calcium 2016; 59:135-9. [PMID: 26830970 DOI: 10.1016/j.ceca.2015.12.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/25/2015] [Accepted: 12/31/2015] [Indexed: 12/12/2022]
Abstract
Intracellular Ca(2+) signals are essential for stem cell differentiation due to their ability to control signaling pathways involved in this process. Arginine vasopression (AVP) is a neurohypophyseal hormone that increases intracellular Ca(2+) concentration during adipogenesis via V1a receptors, Gq-proteins and the PLC-IP3 pathway in human adipose-derived stromal/stem cells (hASCs). These Ca(2+) signals originate through calcium release from pools within the endoplasmic reticulum and the extracellular space. AVP supplementation to the adipogenic media inhibits adipogenesis and key adipocyte marker genes. This review focuses on the intersection between AVP, Ca(2+) signals and ASC differentiation.
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20
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Pérez-Verdaguer M, Capera J, Serrano-Novillo C, Estadella I, Sastre D, Felipe A. The voltage-gated potassium channel Kv1.3 is a promising multitherapeutic target against human pathologies. Expert Opin Ther Targets 2015; 20:577-91. [DOI: 10.1517/14728222.2016.1112792] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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21
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Pezzulo G, Levin M. Re-membering the body: applications of computational neuroscience to the top-down control of regeneration of limbs and other complex organs. Integr Biol (Camb) 2015; 7:1487-517. [PMID: 26571046 DOI: 10.1039/c5ib00221d] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
A major goal of regenerative medicine and bioengineering is the regeneration of complex organs, such as limbs, and the capability to create artificial constructs (so-called biobots) with defined morphologies and robust self-repair capabilities. Developmental biology presents remarkable examples of systems that self-assemble and regenerate complex structures toward their correct shape despite significant perturbations. A fundamental challenge is to translate progress in molecular genetics into control of large-scale organismal anatomy, and the field is still searching for an appropriate theoretical paradigm for facilitating control of pattern homeostasis. However, computational neuroscience provides many examples in which cell networks - brains - store memories (e.g., of geometric configurations, rules, and patterns) and coordinate their activity towards proximal and distant goals. In this Perspective, we propose that programming large-scale morphogenesis requires exploiting the information processing by which cellular structures work toward specific shapes. In non-neural cells, as in the brain, bioelectric signaling implements information processing, decision-making, and memory in regulating pattern and its remodeling. Thus, approaches used in computational neuroscience to understand goal-seeking neural systems offer a toolbox of techniques to model and control regenerative pattern formation. Here, we review recent data on developmental bioelectricity as a regulator of patterning, and propose that target morphology could be encoded within tissues as a kind of memory, using the same molecular mechanisms and algorithms so successfully exploited by the brain. We highlight the next steps of an unconventional research program, which may allow top-down control of growth and form for numerous applications in regenerative medicine and synthetic bioengineering.
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Affiliation(s)
- G Pezzulo
- Institute of Cognitive Sciences and Technologies, National Research Council, Rome, Italy
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22
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Lobikin M, Lobo D, Blackiston DJ, Martyniuk CJ, Tkachenko E, Levin M. Serotonergic regulation of melanocyte conversion: A bioelectrically regulated network for stochastic all-or-none hyperpigmentation. Sci Signal 2015; 8:ra99. [PMID: 26443706 DOI: 10.1126/scisignal.aac6609] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Experimentally induced depolarization of resting membrane potential in "instructor cells" in Xenopus laevis embryos causes hyperpigmentation in an all-or-none fashion in some tadpoles due to excess proliferation and migration of melanocytes. We showed that this stochastic process involved serotonin signaling, adenosine 3',5'-monophosphate (cAMP), and the transcription factors cAMP response element-binding protein (CREB), Sox10, and Slug. Transcriptional microarray analysis of embryos taken at stage 15 (early neurula) and stage 45 (free-swimming tadpole) revealed changes in the abundance of 45 and 517 transcripts, respectively, between control embryos and embryos exposed to the instructor cell-depolarizing agent ivermectin. Bioinformatic analysis revealed that the human homologs of some of the differentially regulated genes were associated with cancer, consistent with the induced arborization and invasive behavior of converted melanocytes. We identified a physiological circuit that uses serotonergic signaling between instructor cells, melanotrope cells of the pituitary, and melanocytes to control the proliferation, cell shape, and migration properties of the pigment cell pool. To understand the stochasticity and properties of this multiscale signaling system, we applied a computational machine-learning method that iteratively explored network models to reverse-engineer a stochastic dynamic model that recapitulated the frequency of the all-or-none hyperpigmentation phenotype produced in response to various pharmacological and molecular genetic manipulations. This computational approach may provide insight into stochastic cellular decision-making that occurs during normal development and pathological conditions, such as cancer.
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Affiliation(s)
- Maria Lobikin
- Biology Department and Center for Regenerative and Developmental Biology, Tufts University, Medford, MA 02155, USA
| | - Daniel Lobo
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Douglas J Blackiston
- Biology Department and Center for Regenerative and Developmental Biology, Tufts University, Medford, MA 02155, USA
| | - Christopher J Martyniuk
- Center for Environmental and Human Toxicology and Department of Physiological Sciences, UF Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Elizabeth Tkachenko
- Biology Department and Center for Regenerative and Developmental Biology, Tufts University, Medford, MA 02155, USA
| | - Michael Levin
- Biology Department and Center for Regenerative and Developmental Biology, Tufts University, Medford, MA 02155, USA.
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23
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Yu Y, Wang J, Kang R, Dong J, Zhang Y, Liu F, Yan Y, Zhu R, Xia L, Peng X, Zhang L, He D, Gaisano HY, Herbert G, Chen Z, He Y. Association of KCNB1 polymorphisms with lipid metabolisms and insulin resistance: a case-control design of population-based cross-sectional study in Chinese Han population. Lipids Health Dis 2015; 14:112. [PMID: 26377690 PMCID: PMC4574025 DOI: 10.1186/s12944-015-0115-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 09/04/2015] [Indexed: 12/12/2022] Open
Abstract
Background In our previous study, we had assessed in the Chinese Han population the association of KCNB1 rs1051295 with metabolic traits indicating metabolic syndrome, and showed that KCNB1 rs1051295 genotype TT was associated with increase of waist to hip ratio (WHR), fasting insulin (FINS), triglycerides (TG) and decreased insulin sensitivity at basal condition. Here, we aimed at detecting whether there were associations between other tag SNPs of KCNB1 and favorable or unfavorable metabolic traits. Methods We conducted a case–control design of population-based cross-sectional study to investigate the association between each of the 22 candidates tag SNPs of KCNB1 and metabolic traits in a population of 733 Chinese Han individuals. The association was assessed by multiple linear regression analysis or unconditional logistic regression analysis. Results We found that among the 22 selected tag SNPs, four were associated with an increase (rs3331, rs16994565) or decrease (rs237460, rs802950) in serum cholesterol levels; two of these (rs237460, rs802590) further associated or were associated with reduced serum LDL-cholesterol. Two novel tag SNPs (rs926672, rs1051295) were associated with increased serum TG levels. We also showed that KCNB1 rs926672 associated with insulin resistance by a case–control study, and two tag SNPs (rs2057077and rs4810952) of KCNB1 were associated with the measure of insulin resistance (HOMA-IR) in a cross-section study. Conclusion These results indicate that KCNB1 is likely associated with metabolic traits that may either predispose or protect from progression to metabolic syndrome. This study provides initial evidence that the gene variants of KCNB1, encoding Kv2.1 channel, is associated with perturbation of lipid metabolism and insulin resistance in Chinese Han population.
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Affiliation(s)
- Yuncui Yu
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Jing Wang
- Departments of Emergency, Beijing Xuanwu Hospital, Capital Medical University, No.45Changchun Street, Xuanwu District, Beijing, 100053, Beijing, PR China.
| | - Ruiying Kang
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Jing Dong
- Departments of Emergency, Beijing Xuanwu Hospital, Capital Medical University, No.45Changchun Street, Xuanwu District, Beijing, 100053, Beijing, PR China.
| | - Yuxiang Zhang
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Fen Liu
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Yuxiang Yan
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Rong Zhu
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Lili Xia
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Xiaoxia Peng
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Ling Zhang
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Dian He
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Herbert Y Gaisano
- Departments of Medicine and Physiology, University of Toronto, 315 Bloor Street West, Toronto, Ontario, Canada.
| | | | - Zhenwen Chen
- School of Basic Medicine, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
| | - Yan He
- School of Public Health, Capital Medical University, No.10 Xitoutiao, Youanmen, Fengtai District, Beijing, 100069, PR China.
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24
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Levin M. Molecular bioelectricity: how endogenous voltage potentials control cell behavior and instruct pattern regulation in vivo. Mol Biol Cell 2015; 25:3835-50. [PMID: 25425556 PMCID: PMC4244194 DOI: 10.1091/mbc.e13-12-0708] [Citation(s) in RCA: 221] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In addition to biochemical gradients and transcriptional networks, cell behavior is regulated by endogenous bioelectrical cues originating in the activity of ion channels and pumps, operating in a wide variety of cell types. Instructive signals mediated by changes in resting potential control proliferation, differentiation, cell shape, and apoptosis of stem, progenitor, and somatic cells. Of importance, however, cells are regulated not only by their own Vmem but also by the Vmem of their neighbors, forming networks via electrical synapses known as gap junctions. Spatiotemporal changes in Vmem distribution among nonneural somatic tissues regulate pattern formation and serve as signals that trigger limb regeneration, induce eye formation, set polarity of whole-body anatomical axes, and orchestrate craniofacial patterning. New tools for tracking and functionally altering Vmem gradients in vivo have identified novel roles for bioelectrical signaling and revealed the molecular pathways by which Vmem changes are transduced into cascades of downstream gene expression. Because channels and gap junctions are gated posttranslationally, bioelectrical networks have their own characteristic dynamics that do not reduce to molecular profiling of channel expression (although they couple functionally to transcriptional networks). The recent data provide an exciting opportunity to crack the bioelectric code, and learn to program cellular activity at the level of organs, not only cell types. The understanding of how patterning information is encoded in bioelectrical networks, which may require concepts from computational neuroscience, will have transformative implications for embryogenesis, regeneration, cancer, and synthetic bioengineering.
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Affiliation(s)
- Michael Levin
- Biology Department, Center for Regenerative and Developmental Biology, Tufts University, Medford, MA 02155-4243
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25
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Masotti A, Uva P, Davis-Keppen L, Basel-Vanagaite L, Cohen L, Pisaneschi E, Celluzzi A, Bencivenga P, Fang M, Tian M, Xu X, Cappa M, Dallapiccola B. Keppen-Lubinsky syndrome is caused by mutations in the inwardly rectifying K+ channel encoded by KCNJ6. Am J Hum Genet 2015; 96:295-300. [PMID: 25620207 DOI: 10.1016/j.ajhg.2014.12.011] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 12/10/2014] [Indexed: 12/30/2022] Open
Abstract
Keppen-Lubinsky syndrome (KPLBS) is a rare disease mainly characterized by severe developmental delay and intellectual disability, microcephaly, large prominent eyes, a narrow nasal bridge, a tented upper lip, a high palate, an open mouth, tightly adherent skin, an aged appearance, and severe generalized lipodystrophy. We sequenced the exomes of three unrelated individuals affected by KPLBS and found de novo heterozygous mutations in KCNJ6 (GIRK2), which encodes an inwardly rectifying potassium channel and maps to the Down syndrome critical region between DIRK1A and DSCR4. In particular, two individuals shared an in-frame heterozygous deletion of three nucleotides (c.455_457del) leading to the loss of one amino acid (p.Thr152del). The third individual was heterozygous for a missense mutation (c.460G>A) which introduces an amino acid change from glycine to serine (p.Gly154Ser). In agreement with animal models, the present data suggest that these mutations severely impair the correct functioning of this potassium channel. Overall, these results establish KPLBS as a channelopathy and suggest that KCNJ6 (GIRK2) could also be a candidate gene for other lipodystrophies. We hope that these results will prompt investigations in this unexplored class of inwardly rectifying K(+) channels.
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Affiliation(s)
- Andrea Masotti
- Bambino Gesù Children's Hospital, Istituto di Ricovero e Cura a Carattere Scientifico, 00165 Rome, Italy.
| | - Paolo Uva
- CRS4 Bioinformatics Laboratory, Parco Scientifico e Tecnologico POLARIS, 09010 Pula, Cagliari, Italy
| | - Laura Davis-Keppen
- Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57105, USA
| | - Lina Basel-Vanagaite
- Pediatric Genetics Unit, Schneider Children's Medical Center of Israel, Petah Tikva 49202, Israel; Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva 49100, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 69978, Israel; Felsenstein Medical Research Center, Rabin Medical Center, Petah Tikva 49100, Israel
| | - Lior Cohen
- Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva 49100, Israel
| | - Elisa Pisaneschi
- Bambino Gesù Children's Hospital, Istituto di Ricovero e Cura a Carattere Scientifico, 00165 Rome, Italy
| | - Antonella Celluzzi
- Bambino Gesù Children's Hospital, Istituto di Ricovero e Cura a Carattere Scientifico, 00165 Rome, Italy
| | - Paola Bencivenga
- Bambino Gesù Children's Hospital, Istituto di Ricovero e Cura a Carattere Scientifico, 00165 Rome, Italy
| | | | | | - Xun Xu
- BGI Shenzhen, Shenzhen 518083, China.
| | - Marco Cappa
- Bambino Gesù Children's Hospital, Istituto di Ricovero e Cura a Carattere Scientifico, 00165 Rome, Italy
| | - Bruno Dallapiccola
- Bambino Gesù Children's Hospital, Istituto di Ricovero e Cura a Carattere Scientifico, 00165 Rome, Italy
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26
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Nishizuka M, Hayashi T, Asano M, Osada S, Imagawa M. KCNK10, a tandem pore domain potassium channel, is a regulator of mitotic clonal expansion during the early stage of adipocyte differentiation. Int J Mol Sci 2014; 15:22743-56. [PMID: 25501330 PMCID: PMC4284734 DOI: 10.3390/ijms151222743] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 11/10/2014] [Accepted: 11/26/2014] [Indexed: 01/13/2023] Open
Abstract
KCNK10, a member of tandem pore domain potassium channel family, gives rise to leak K+ currents. It plays important roles in stabilizing the negative resting membrane potential and in counterbalancing depolarization. We previously demonstrated that kcnk10 expression is quickly elevated during the early stage of adipogenesis of 3T3-L1 cells and that reduction of kcnk10 expression inhibits adipocyte differentiation. However, the molecular mechanism of KCNK10 in adipocyte differentiation remains unclear. Here we revealed that kcnk10 is induced by 3-isobutyl-1-methylxanthine, a cyclic nucleotide phosphodiesterase inhibitor and a potent inducer of adipogenesis, during the early stage of adipocyte differentiation. We also demonstrated that KCNK10 functions as a positive regulator of mitotic clonal expansion (MCE), a necessary process for terminal differentiation. The reduction of kcnk10 expression repressed the expression levels of CCAAT/enhancer-binding protein β (C/EBPβ) and C/EBPδ as well as the phosphorylation level of Akt during the early phase of adipogenesis. In addition, knockdown of kcnk10 expression suppressed insulin-induced Akt phosphorylation. These results indicate that KCNK10 contributes to the regulation of MCE through the control of C/EBPβ and C/EBPδ expression and insulin signaling.
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Affiliation(s)
- Makoto Nishizuka
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
| | - Takahiro Hayashi
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
| | - Mami Asano
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
| | - Shigehiro Osada
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
| | - Masayoshi Imagawa
- Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
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Ngala RA, Zaibi MS, Langlands K, Stocker CJ, Arch JRS, Cawthorne MA. Stimulation of glucose uptake in murine soleus muscle and adipocytes by 5-(4-phenoxybutoxy)psoralen (PAP-1) may be mediated by Kv1.5 rather than Kv1.3. PeerJ 2014. [PMID: 25320682 DOI: 10.7717/peerj.614.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Kv1 channels are shaker-related potassium channels that influence insulin sensitivity. Kv1.3(-/-) mice are protected from diet-induced insulin resistance and some studies suggest that Kv1.3 inhibitors provide similar protection. However, it is unclear whether blockade of Kv1.3 in adipocytes or skeletal muscle increases glucose uptake. There is no evidence that the related channel Kv1.5 has any influence on insulin sensitivity and its expression in adipose tissue has not been reported. PAP-1 is a selective inhibitor of Kv1.3, with 23-fold, 32-fold and 125-fold lower potencies as an inhibitor of Kv1.5, Kv1.1 and Kv1.2 respectively. Soleus muscles from wild-type and genetically obese ob/ob mice were incubated with 2-deoxy[1-(14)C]-glucose for 45 min and formation of 2-deoxy[1-(14)C]-glucose-6-phosphate was measured. White adipocytes were incubated with D-[U-(14)C]-glucose for 1 h. TNFα and Il-6 secretion from white adipose tissue pieces were measured by enzyme-linked-immunoassay. In the absence of insulin, a high concentration (3 µM) of PAP-1 stimulated 2-deoxy[1-14C]-glucose uptake in soleus muscle of wild-type and obese mice by 30% and 40% respectively, and in adipocytes by 20% and 50% respectively. PAP-1 also stimulated glucose uptake by adipocytes at the lower concentration of 1 µM, but at 300 nM, which is still 150-fold higher than its EC50 value for inhibition of the Kv1.3 channel, it had no effect. In the presence of insulin, PAP-1 (3 µM) had a significant effect only in adipocytes from obese mice. PAP-1 (3 µM) reduced the secretion of TNFα by adipose tissue but had no effect on the secretion of IL-6. Expression of Kv1.1, Kv1.2, Kv1.3 and Kv1.5 was determined by RT-PCR. Kv1.3 and Kv1.5 mRNA were detected in liver, gastrocnemius muscle, soleus muscle and white adipose tissue from wild-type and ob/ob mice, except that Kv1.3 could not be detected in gastrocnemius muscle, nor Kv1.5 in liver, of wild-type mice. Expression of both genes was generally higher in liver and muscle of ob/ob mice compared to wild-type mice. Kv1.5 appeared to be expressed more highly than Kv1.3 in soleus muscle, adipose tissue and adipocytes of wild-type mice. Expression of Kv1.2 appeared to be similar to that of Kv1.3 in soleus muscle and adipose tissue, but Kv1.2 was undetectable in adipocytes. Kv1.1 could not be detected in soleus muscle, adipose tissue or adipocytes. We conclude that inhibition of Kv1 channels by PAP-1 stimulates glucose uptake by adipocytes and soleus muscle of wild-type and ob/ob mice, and reduces the secretion of TNFα by adipose tissue. However, these effects are more likely due to inhibition of Kv1.5 than to inhibition of Kv1.3 channels.
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Affiliation(s)
- Robert A Ngala
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Mohamed S Zaibi
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Kenneth Langlands
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Claire J Stocker
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Jonathan R S Arch
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Michael A Cawthorne
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
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28
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Ngala RA, Zaibi MS, Langlands K, Stocker CJ, Arch JRS, Cawthorne MA. Stimulation of glucose uptake in murine soleus muscle and adipocytes by 5-(4-phenoxybutoxy)psoralen (PAP-1) may be mediated by Kv1.5 rather than Kv1.3. PeerJ 2014; 2:e614. [PMID: 25320682 PMCID: PMC4193404 DOI: 10.7717/peerj.614] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 09/17/2014] [Indexed: 01/08/2023] Open
Abstract
Kv1 channels are shaker-related potassium channels that influence insulin sensitivity. Kv1.3−/− mice are protected from diet-induced insulin resistance and some studies suggest that Kv1.3 inhibitors provide similar protection. However, it is unclear whether blockade of Kv1.3 in adipocytes or skeletal muscle increases glucose uptake. There is no evidence that the related channel Kv1.5 has any influence on insulin sensitivity and its expression in adipose tissue has not been reported. PAP-1 is a selective inhibitor of Kv1.3, with 23-fold, 32-fold and 125-fold lower potencies as an inhibitor of Kv1.5, Kv1.1 and Kv1.2 respectively. Soleus muscles from wild-type and genetically obese ob/ob mice were incubated with 2-deoxy[1-14C]-glucose for 45 min and formation of 2-deoxy[1-14C]-glucose-6-phosphate was measured. White adipocytes were incubated with D-[U-14C]-glucose for 1 h. TNFα and Il-6 secretion from white adipose tissue pieces were measured by enzyme-linked-immunoassay. In the absence of insulin, a high concentration (3 µM) of PAP-1 stimulated 2-deoxy[1-14C]-glucose uptake in soleus muscle of wild-type and obese mice by 30% and 40% respectively, and in adipocytes by 20% and 50% respectively. PAP-1 also stimulated glucose uptake by adipocytes at the lower concentration of 1 µM, but at 300 nM, which is still 150-fold higher than its EC50 value for inhibition of the Kv1.3 channel, it had no effect. In the presence of insulin, PAP-1 (3 µM) had a significant effect only in adipocytes from obese mice. PAP-1 (3 µM) reduced the secretion of TNFα by adipose tissue but had no effect on the secretion of IL-6. Expression of Kv1.1, Kv1.2, Kv1.3 and Kv1.5 was determined by RT-PCR. Kv1.3 and Kv1.5 mRNA were detected in liver, gastrocnemius muscle, soleus muscle and white adipose tissue from wild-type and ob/ob mice, except that Kv1.3 could not be detected in gastrocnemius muscle, nor Kv1.5 in liver, of wild-type mice. Expression of both genes was generally higher in liver and muscle of ob/ob mice compared to wild-type mice. Kv1.5 appeared to be expressed more highly than Kv1.3 in soleus muscle, adipose tissue and adipocytes of wild-type mice. Expression of Kv1.2 appeared to be similar to that of Kv1.3 in soleus muscle and adipose tissue, but Kv1.2 was undetectable in adipocytes. Kv1.1 could not be detected in soleus muscle, adipose tissue or adipocytes. We conclude that inhibition of Kv1 channels by PAP-1 stimulates glucose uptake by adipocytes and soleus muscle of wild-type and ob/ob mice, and reduces the secretion of TNFα by adipose tissue. However, these effects are more likely due to inhibition of Kv1.5 than to inhibition of Kv1.3 channels.
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Affiliation(s)
- Robert A Ngala
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Mohamed S Zaibi
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Kenneth Langlands
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Claire J Stocker
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Jonathan R S Arch
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
| | - Michael A Cawthorne
- Clore Laboratory, Buckingham Institute for Translational Medicine, University of Buckingham , Buckingham , UK
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Bartok A, Toth A, Somodi S, Szanto TG, Hajdu P, Panyi G, Varga Z. Margatoxin is a non-selective inhibitor of human Kv1.3 K+ channels. Toxicon 2014; 87:6-16. [PMID: 24878374 DOI: 10.1016/j.toxicon.2014.05.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Revised: 05/07/2014] [Accepted: 05/12/2014] [Indexed: 11/28/2022]
Abstract
Margatoxin (MgTx), an alpha-KTx scorpion toxin, is considered a selective inhibitor of the Kv1.3K + channel. This peptide is widely used in ion channel research; however, a comprehensive study of its selectivity with electrophysiological methods has not been published yet. The lack of selectivity might lead to undesired side effects upon therapeutic application or may lead to incorrect conclusion regarding the role of a particular ion channel in a physiological or pathophysiological response either in vitro or in vivo. Using the patch-clamp technique we characterized the selectivity profile of MgTx using L929 cells expressing mKv1.1 channels, human peripheral lymphocytes expressing Kv1.3 channels and transiently transfected tsA201 cells expressing hKv1.1, hKv1.2, hKv1.3, hKv1.4-IR, hKv1.5, hKv1.6, hKv1.7, rKv2.1, Shaker-IR, hERG, hKCa1.1, hKCa3.1 and hNav1.5 channels. MgTx is indeed a high affinity inhibitor of Kv1.3 (Kd = 11.7 pM) but is not selective, it inhibits the Kv1.2 channel with similar affinity (Kd = 6.4 pM) and Kv1.1 in the nanomolar range (Kd = 4.2 nM). Based on our comprehensive data MgTX has to be considered a non-selective Kv1.3 inhibitor, and thus, experiments aiming at elucidating the significance of Kv1.3 in in vitro or in vivo physiological responses have to be carefully evaluated.
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Affiliation(s)
- Adam Bartok
- Department of Biophysics and Cell Biology, University of Debrecen, Faculty of Medicine, 98 Nagyerdei krt., Debrecen 4032, Hungary.
| | - Agnes Toth
- Department of Biophysics and Cell Biology, University of Debrecen, Faculty of Medicine, 98 Nagyerdei krt., Debrecen 4032, Hungary.
| | - Sandor Somodi
- Division of Metabolic Diseases, Department of Internal Medicine, University of Debrecen, 98 Nagyerdei krt., Debrecen 4032, Hungary.
| | - Tibor G Szanto
- Department of Biophysics and Cell Biology, University of Debrecen, Faculty of Medicine, 98 Nagyerdei krt., Debrecen 4032, Hungary.
| | - Peter Hajdu
- Department of Biophysics and Cell Biology, University of Debrecen, Faculty of Dentistry, 98 Nagyerdei krt., Debrecen 4032, Hungary.
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, University of Debrecen, Faculty of Medicine, 98 Nagyerdei krt., Debrecen 4032, Hungary; MTA-DE Cell Biology and Signaling Research Group, 4032 Debrecen, Egyetem tér 1, Hungary. http://biophys.med.unideb.hu/en/node/311
| | - Zoltan Varga
- Department of Biophysics and Cell Biology, University of Debrecen, Faculty of Medicine, 98 Nagyerdei krt., Debrecen 4032, Hungary.
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30
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Sesti F, Wu X, Liu S. Oxidation of KCNB1 K(+) channels in central nervous system and beyond. World J Biol Chem 2014; 5:85-92. [PMID: 24921000 PMCID: PMC4050120 DOI: 10.4331/wjbc.v5.i2.85] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 01/26/2014] [Accepted: 03/03/2014] [Indexed: 02/05/2023] Open
Abstract
KCNB1, a voltage-gated potassium (K(+)) channel that conducts a major delayed rectifier current in the brain, pancreas and cardiovascular system is a key player in apoptotic programs associated with oxidative stress. As a result, this protein represents a bona fide drug target for limiting the toxic effects of oxygen radicals. Until recently the consensus view was that reactive oxygen species trigger a pro-apoptotic surge in KCNB1 current via phosphorylation and SNARE-dependent incorporation of KCNB1 channels into the plasma membrane. However, new evidence shows that KCNB1 can be modified by oxidants and that oxidized KCNB1 channels can directly activate pro-apoptotic signaling pathways. Hence, a more articulated picture of the pro-apoptotic role of KCNB1 is emerging in which the protein induces cell's death through distinct molecular mechanisms and activation of multiple pathways. In this review article we discuss the diverse functional, toxic and protective roles that KCNB1 channels play in the major organs where they are expressed.
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31
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Sayed M, Drummond CA, Evans KL, Haller ST, Liu J, Xie Z, Tian J. Effects of Na/K-ATPase and its ligands on bone marrow stromal cell differentiation. Stem Cell Res 2014; 13:12-23. [PMID: 24793006 DOI: 10.1016/j.scr.2014.04.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 03/21/2014] [Accepted: 04/05/2014] [Indexed: 12/16/2022] Open
Abstract
Endogenous ligands of Na/K-ATPase have been demonstrated to increase in kidney dysfunction and heart failure. It is also reported that Na/K-ATPase signaling function effects stem cell differentiation. This study evaluated whether Na/K-ATPase activation through its ligands and associated signaling functions affect bone marrow stromal cells (BMSCs, also known as bone marrow-derived mesenchymal stem cells) differentiation capacity. BMSCs were isolated from male Sprague-Dawley rats and cultured in minimal essential medium alpha (MEM-α) supplemented with 15% Fetal Bovine serum (FBS). The results showed that marinobufagenin (MBG), a specific Na/K-ATPase ligand, potentiated rosiglitazone-induced adipogenesis in these BMSCs. Meanwhile, it attenuated BMSC osteogenesis. Mechanistically, MBG increased CCAAT/enhancer binding protein alpha (C/EBPα) protein expression through activation of an extracellular regulated kinase (ERK) signaling pathway, which leads to enhanced rosiglitazone-induced adipogenesis. Inhibition of ERK activation by U0126 blocks the effect of MBG on C/EBPα expression and on rosiglitazone-induced adipogenesis. Reciprocally, MBG reduced runt-related transcription factor 2 (RunX2) expression, which resulted in the inhibition of osteogenesis induced by β-glycerophosphate/ascorbic acid. MBG also potentiated rosiglitazone-induced adipogenesis in 3T3-L1 cells and in mouse BMSCs. These results suggest that Na/K-ATPase and its signaling functions are involved in the regulation of BMSCs differentiation.
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Affiliation(s)
- Moustafa Sayed
- Department of Medicine, University of Toledo, Toledo, OH, USA
| | | | - Kaleigh L Evans
- Department of Medicine, University of Toledo, Toledo, OH, USA
| | - Steven T Haller
- Department of Medicine, University of Toledo, Toledo, OH, USA
| | - Jiang Liu
- Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, USA
| | - Zijian Xie
- Department of Medicine, University of Toledo, Toledo, OH, USA
| | - Jiang Tian
- Department of Medicine, University of Toledo, Toledo, OH, USA.
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32
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Levin M. Reprogramming cells and tissue patterning via bioelectrical pathways: molecular mechanisms and biomedical opportunities. WILEY INTERDISCIPLINARY REVIEWS. SYSTEMS BIOLOGY AND MEDICINE 2013; 5:657-76. [PMID: 23897652 PMCID: PMC3841289 DOI: 10.1002/wsbm.1236] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 05/16/2013] [Accepted: 06/21/2013] [Indexed: 12/17/2022]
Abstract
Transformative impact in regenerative medicine requires more than the reprogramming of individual cells: advances in repair strategies for birth defects or injuries, tumor normalization, and the construction of bioengineered organs and tissues all require the ability to control large-scale anatomical shape. Much recent work has focused on the transcriptional and biochemical regulation of cell behavior and morphogenesis. However, exciting new data reveal that bioelectrical properties of cells and their microenvironment exert a profound influence on cell differentiation, proliferation, and migration. Ion channels and pumps expressed in all cells, not just excitable nerve and muscle, establish resting potentials that vary across tissues and change with significant developmental events. Most importantly, the spatiotemporal gradients of these endogenous transmembrane voltage potentials (Vmem ) serve as instructive patterning cues for large-scale anatomy, providing organ identity, positional information, and prepattern template cues for morphogenesis. New genetic and pharmacological techniques for molecular modulation of bioelectric gradients in vivo have revealed the ability to initiate complex organogenesis, change tissue identity, and trigger regeneration of whole vertebrate appendages. A large segment of the spatial information processing that orchestrates individual cells' programs toward the anatomical needs of the host organism is electrical; this blurs the line between memory and decision-making in neural networks and morphogenesis in nonneural tissues. Advances in cracking this bioelectric code will enable the rational reprogramming of shape in whole tissues and organs, revolutionizing regenerative medicine, developmental biology, and synthetic bioengineering.
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Affiliation(s)
- Michael Levin
- Tufts University, Department of Biology and Tufts Center for Regenerative and Developmental Biology, 200 Boston Ave., Suite 4600, Medford, MA 02155
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