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Jaudon F, Cingolani LA. Unlocking mechanosensitivity: integrins in neural adaptation. Trends Cell Biol 2024:S0962-8924(24)00046-1. [PMID: 38514304 DOI: 10.1016/j.tcb.2024.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 03/23/2024]
Abstract
Mechanosensitivity extends beyond sensory cells to encompass most neurons in the brain. Here, we explore recent research on the role of integrins, a diverse family of adhesion molecules, as crucial biomechanical sensors translating mechanical forces into biochemical and electrical signals in the brain. The varied biomechanical properties of neuronal integrins, including their force-dependent conformational states and ligand interactions, dictate their specific functions. We discuss new findings on how integrins regulate filopodia and dendritic spines, shedding light on their contributions to synaptic plasticity, and explore recent discoveries on how they engage with metabotropic receptors and ion channels, highlighting their direct participation in electromechanical transduction. Finally, to facilitate a deeper understanding of these developments, we present molecular and biophysical models of mechanotransduction.
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Affiliation(s)
- Fanny Jaudon
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Lorenzo A Cingolani
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; Center for Synaptic Neuroscience and Technology (NSYN), Fondazione Istituto Italiano di Tecnologia (IIT), 16132 Genoa, Italy.
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2
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Arcangeli A, Iorio J, Duranti C. Targeting the hERG1 and β1 integrin complex for cancer treatment. Expert Opin Ther Targets 2024; 28:145-157. [PMID: 38372580 DOI: 10.1080/14728222.2024.2318449] [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: 10/02/2023] [Accepted: 02/09/2024] [Indexed: 02/20/2024]
Abstract
INTRODUCTION Despite great advances, novel therapeutic targets and strategies are still needed, in particular for some carcinomas in the metastatic stage (breast cancer, colorectal cancer, pancreatic ductal adenocarcinoma and the clear cell renal carcinoma). Ion channels may be considered good cancer biomarkers and targets for antineoplastic therapy. These concepts are particularly relevant considering the hERG1 potassium channel as a novel target for antineoplastic therapy. AREAS COVERED A great deal of evidence demonstrates that hERG1 is aberrantly expressed in human cancers, in particular in aggressive carcinomas. A relevant cornerstone was the discovery that, in cancer cells, the channel is present in a very peculiar conformation, strictly bound to the β1 subunit of integrin receptors. The hERG1/β1 integrin complex does not occur in the heart. Starting from this evidence, we developed a novel single chain bispecific antibody (scDb-hERG1-β1), which specifically targets the hERG1/β1 integrin complex and exerts antineoplastic effects in preclinical experiments. EXPERT OPINION Since hERG1 blockade cannot be pursued for antineoplastic therapy due to the severe cardiac toxic effects (ventricular arrhythmias) that many hERG1 blockers exert, different strategies must be identified to specifically target hERG1 in cancer. The targeting of the hERG1/β1 integrin complex through the bispecific antibody scDb-hERG1-β1 can overcome such hindrances.
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Affiliation(s)
- Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Firenze, Italy
- CSDC (Center for the Study of complex dynamics), University of Florence, Sesto Fiorentino (FI), Italy
- MCK Therapeutics srl, Pistoia (PT), Italy
| | - Jessica Iorio
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Firenze, Italy
| | - Claudia Duranti
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Firenze, Italy
- MCK Therapeutics srl, Pistoia (PT), Italy
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3
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Duranti C, Iorio J, Bagni G, Chioccioli Altadonna G, Fillion T, Lulli M, D'Alessandro FN, Montalbano A, Lastraioli E, Fanelli D, Coppola S, Schmidt T, Piazza F, Becchetti A, Arcangeli A. Integrins regulate hERG1 dynamics by girdin-dependent Gαi3: signaling and modeling in cancer cells. Life Sci Alliance 2024; 7:e202302135. [PMID: 37923359 PMCID: PMC10624597 DOI: 10.26508/lsa.202302135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Revised: 10/22/2023] [Accepted: 10/23/2023] [Indexed: 11/07/2023] Open
Abstract
The hERG1 potassium channel is aberrantly over expressed in tumors and regulates the cancer cell response to integrin-dependent adhesion. We unravel a novel signaling pathway by which integrin engagement by the ECM protein fibronectin promotes hERG1 translocation to the plasma membrane and its association with β1 integrins, by activating girdin-dependent Gαi3 proteins and protein kinase B (Akt). By sequestering hERG1, β1 integrins make it avoid Rab5-mediated endocytosis, where unbound channels are degraded. The cycle of hERG1 expression determines the resting potential (Vrest) oscillations and drives the cortical f-actin dynamics and thus cell motility. To interpret the slow biphasic kinetics of hERG1/β1 integrin interplay, we developed a mathematical model based on a generic balanced inactivation-like module. Integrin-mediated cell adhesion triggers two contrary responses: a rapid stimulation of hERG1/β1 complex formation, followed by a slow inhibition which restores the initial condition. The protracted hERG1/β1 integrin cycle determines the slow time course and cyclic behavior of cell migration in cancer cells.
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Affiliation(s)
- Claudia Duranti
- https://ror.org/04jr1s763 Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Jessica Iorio
- https://ror.org/04jr1s763 Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Giacomo Bagni
- https://ror.org/04jr1s763 Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Ginevra Chioccioli Altadonna
- https://ror.org/04jr1s763 Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Thibault Fillion
- https://ror.org/04jr1s763 Department of Physics, University of Florence, and Florence Section of INFN, Florence, Italy
- Université d'Orléans and Centre de Biophysique Moléculaire (CBM), CNRS UPR 4301, Orléans, France
| | - Matteo Lulli
- https://ror.org/04jr1s763 Department of Experimental and Clinical Biochemical Sciences, Section of General Pathology, University of Florence, Florence, Italy
| | - Franco Nicolas D'Alessandro
- https://ror.org/04jr1s763 Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
- Department of Medical Biotechnologies, University of Siena, Siena, Italy
| | - Alberto Montalbano
- https://ror.org/04jr1s763 Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
| | - Elena Lastraioli
- https://ror.org/04jr1s763 Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
- CSDC (Center for the Study of complex dynamics), University of Florence, Florence, Italy
| | - Duccio Fanelli
- https://ror.org/04jr1s763 Department of Physics, University of Florence, and Florence Section of INFN, Florence, Italy
- CSDC (Center for the Study of complex dynamics), University of Florence, Florence, Italy
| | - Stefano Coppola
- Department of Physics, University of Leiden, Leiden, Netherlands
| | - Thomas Schmidt
- Department of Physics, University of Leiden, Leiden, Netherlands
| | - Francesco Piazza
- https://ror.org/04jr1s763 Department of Physics, University of Florence, and Florence Section of INFN, Florence, Italy
- Université d'Orléans and Centre de Biophysique Moléculaire (CBM), CNRS UPR 4301, Orléans, France
- CSDC (Center for the Study of complex dynamics), University of Florence, Florence, Italy
| | - Andrea Becchetti
- https://ror.org/01ynf4891 Department of Biotechnology and Biosciences, University of Milano Bicocca, Milan, Italy
| | - Annarosa Arcangeli
- https://ror.org/04jr1s763 Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, Florence, Italy
- CSDC (Center for the Study of complex dynamics), University of Florence, Florence, Italy
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4
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Johnson GA, Burghardt RC, Bazer FW, Seo H, Cain JW. Integrins and their potential roles in mammalian pregnancy. J Anim Sci Biotechnol 2023; 14:115. [PMID: 37679778 PMCID: PMC10486019 DOI: 10.1186/s40104-023-00918-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 07/10/2023] [Indexed: 09/09/2023] Open
Abstract
Integrins are a highly complex family of receptors that, when expressed on the surface of cells, can mediate reciprocal cell-to-cell and cell-to-extracellular matrix (ECM) interactions leading to assembly of integrin adhesion complexes (IACs) that initiate many signaling functions both at the membrane and deeper within the cytoplasm to coordinate processes including cell adhesion, migration, proliferation, survival, differentiation, and metabolism. All metazoan organisms possess integrins, and it is generally agreed that integrins were associated with the evolution of multicellularity, being essential for the association of cells with their neighbors and surroundings, during embryonic development and many aspects of cellular and molecular biology. Integrins have important roles in many aspects of embryonic development, normal physiology, and disease processes with a multitude of functions discovered and elucidated for integrins that directly influence many areas of biology and medicine, including mammalian pregnancy, in particular implantation of the blastocyst to the uterine wall, subsequent placentation and conceptus (embryo/fetus and associated placental membranes) development. This review provides a succinct overview of integrin structure, ligand binding, and signaling followed with a concise overview of embryonic development, implantation, and early placentation in pigs, sheep, humans, and mice as an example for rodents. A brief timeline of the initial localization of integrin subunits to the uterine luminal epithelium (LE) and conceptus trophoblast is then presented, followed by sequential summaries of integrin expression and function during gestation in pigs, sheep, humans, and rodents. As appropriate for this journal, summaries of integrin expression and function during gestation in pigs and sheep are in depth, whereas summaries for humans and rodents are brief. Because similar models to those illustrated in Fig. 1, 2, 3, 4, 5 and 6 are present throughout the scientific literature, the illustrations in this manuscript are drafted as Viking imagery for entertainment purposes.
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Affiliation(s)
- Gregory A Johnson
- Department of Veterinary Integrative Biosciences, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4459, USA.
| | - Robert C Burghardt
- Department of Veterinary Integrative Biosciences, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4459, USA
| | - Fuller W Bazer
- Department of Animal Science, College of Agriculture and Life Sciences, Texas A&M University, College Station, TX, 77843-2471, USA
| | - Heewon Seo
- Department of Veterinary Integrative Biosciences, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4459, USA
| | - Joe W Cain
- Department of Veterinary Integrative Biosciences, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843-4459, USA
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5
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Forzisi E, Sesti F. Non-conducting functions of ion channels: The case of integrin-ion channel complexes. Channels (Austin) 2022; 16:185-197. [PMID: 35942524 PMCID: PMC9364710 DOI: 10.1080/19336950.2022.2108565] [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] [Indexed: 11/17/2022] Open
Abstract
Started as an academic curiosity more than two decades ago, the idea that ion channels can regulate cellular processes in ways that do not depend on their conducting properties (non-ionic functions) gained traction and is now a flourishing area of research. Channels can regulate physiological processes including actin cytoskeletal remodeling, cell motility, excitation-contraction coupling, non-associative learning and embryogenesis, just to mention some, through non-ionic functions. When defective, non-ionic functions can give rise to channelopathies involved in cancer, neurodegenerative disease and brain trauma. Ion channels exert their non-ionic functions through a variety of mechanisms that range from physical coupling with other proteins, to possessing enzymatic activity, to assembling with signaling molecules. In this article, we take stock of the field and review recent findings. The concept that emerges, is that one of the most common ways through which channels acquire non-ionic attributes, is by assembling with integrins. These integrin-channel complexes exhibit broad genotypic and phenotypic heterogeneity and reveal a pleiotropic nature, as they appear to be capable of influencing both physiological and pathological processes.
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Affiliation(s)
- Elena Forzisi
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, NJ, USA
| | - Federico Sesti
- Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers University, NJ, USA
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Chioccioli Altadonna G, Montalbano A, Iorio J, Becchetti A, Arcangeli A, Duranti C. The Interaction between hERG1 and β1 Integrins Modulates hERG1 Current in Different Pathological Cell Models. MEMBRANES 2022; 12:1162. [PMID: 36422154 PMCID: PMC9698864 DOI: 10.3390/membranes12111162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 11/13/2022] [Accepted: 11/16/2022] [Indexed: 06/16/2023]
Abstract
Ion channels are implicated in various diseases, including cancer, in which they modulate different aspects of cancer progression. In particular, potassium channels are often aberrantly expressed in cancers, a major example being provided by hERG1. The latter is generally complexed with β1 integrin in tumour cells, and such a molecular complex represents a new druggable hub. The present study focuses on the characterization of the functional consequences of the interaction between hERG1 and β1 integrins on different substrates over time. To this purpose, we studied the interplay alteration on the plasma membrane through patch clamp techniques in a cellular model consisting of human embryonic kidney (HEK) cells stably transfected with hERG1 and in a cancer cell model consisting of SH-SY5Y neuroblastoma cells, endogenously expressing the channel. Cells were seeded on different substrates known to stimulate β1 integrins, such as fibronectin (FN) for HEK-hERG1 and laminin (LMN) for SH-SY5Y. In HEK cells stably overexpressing hERG1, we observed a hERG1 current density increase accompanied by Vrest hyperpolarization after cell seeding onto FN. Notably, a similar behaviour was shown by SH-SY5Y neuroblastoma cells plated onto LMN. Interestingly, we did not observe this phenomenon when plating the cells on substrates such as Bovine Serum Albumin (BSA) or Polylysine (PL), thus suggesting a crucial involvement of ECM proteins as well as of β1 integrin activation.
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Affiliation(s)
| | - Alberto Montalbano
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Jessica Iorio
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Claudia Duranti
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
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7
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Iorio J, Antonuzzo L, Scarpi E, D’Amico M, Duranti C, Messerini L, Sparano C, Caputo D, Lavacchi D, Borzomati D, Antonelli A, Nibid L, Perrone G, Coppola A, Coppola R, di Costanzo F, Lastraioli E, Arcangeli A. Prognostic role of hERG1 Potassium Channels in Neuroendocrine Tumours of the Ileum and Pancreas. Int J Mol Sci 2022; 23:ijms231810623. [PMID: 36142530 PMCID: PMC9504580 DOI: 10.3390/ijms231810623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/08/2022] [Accepted: 09/10/2022] [Indexed: 11/16/2022] Open
Abstract
hERG1 potassium channels are widely expressed in human cancers of different origins, where they affect several key aspects of cellular behaviour. The present study was designed to evaluate the expression and clinical relevance of hERG1 protein in cancer tissues from patients suffering from neuroendocrine tumours (NETs) of ileal (iNETs) and pancreatic (pNETs) origin, with available clinicopathological history and follow-up. The study was carried out by immunohistochemistry with an anti-hERG1 monoclonal antibody. In a subset of samples, a different antibody directed against the hERG1/β1 integrin complex was also used. The analysis showed for the first time that hERG1 is expressed in human NETs originating from either the ileum or the pancreas. hERG1 turned out to have a prognostic value in NETs, showing (i) a statistically significant positive impact on OS of patients affected by ileal NETs, regardless the TNM stage; (ii) a statistically significant positive impact on OS of patients affected by aggressive (TNM stage IV) disease, either ileal or pancreatic; (iii) a trend to a negative impact on OS of patients affected by less aggressive (TNM stage I-III) disease, either ileal or pancreatic. Moreover, in order to evaluate whether ERG1 was functionally expressed in a cellular model of pNET, the INS1E rat insulinoma cell line was used, and it emerged that blocking ERG1 with a specific inhibitor of the channel (E4031) turned out in a significant reduction in cell proliferation.
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Affiliation(s)
- Jessica Iorio
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Lorenzo Antonuzzo
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
- Medical Oncology, Azienda Ospedaliero-Universitaria Careggi, 50134 Florence, Italy
| | - Emanuela Scarpi
- Unit of Biostatistics and Clinical Trials, IRCCS Istituto Romagnolo per lo Studio dei tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy
| | | | - Claudia Duranti
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Luca Messerini
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Clotilde Sparano
- Endocrinology Unit, Department of Experimental and Clinical Biomedical Sciences “Mario Serio”, University of Florence, 50134 Florence, Italy
| | - Damiano Caputo
- General Surgery, Campus Bio-Medico University, 00128 Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
| | - Daniele Lavacchi
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
- Medical Oncology, Azienda Ospedaliero-Universitaria Careggi, 50134 Florence, Italy
| | - Domenico Borzomati
- General Surgery, Campus Bio-Medico University, 00128 Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
| | - Alice Antonelli
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
- Medical Oncology, Azienda Ospedaliero-Universitaria Careggi, 50134 Florence, Italy
| | - Lorenzo Nibid
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
- Pathology Unit, Campus Bio-Medico University, 00128 Rome, Italy
| | - Giuseppe Perrone
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
- Pathology Unit, Campus Bio-Medico University, 00128 Rome, Italy
| | - Alessandro Coppola
- General Surgery, Campus Bio-Medico University, 00128 Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
| | - Roberto Coppola
- General Surgery, Campus Bio-Medico University, 00128 Rome, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
| | | | - Elena Lastraioli
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
- Complex Dynamics Study Centre (CSDC), University of Florence, 50100 Florence, Italy
- Correspondence: ; Tel.: +39-(0)5-5275-1319
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
- Complex Dynamics Study Centre (CSDC), University of Florence, 50100 Florence, Italy
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Becchetti A, Duranti C, Arcangeli A. Dynamics and physiological meaning of complexes between ion channels and integrin receptors: the case of Kv11.1. Am J Physiol Cell Physiol 2022; 322:C1138-C1150. [PMID: 35442831 DOI: 10.1152/ajpcell.00107.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The cellular functions are regulated by a complex interplay of diffuse and local signals. Experimental work in cell physiology has led to recognize that understanding a cell's dynamics requires a deep comprehension of local fluctuations of cytosolic regulators. Macromolecular complexes are major determinants of local signaling. Multi-enzyme assemblies limit the diffusion restriction to reaction kinetics by direct exchange of metabolites. Likewise, close coupling of ion channels and transporters modulate the ion concentration around a channel mouth or transporter binding site. Extreme signal locality is brought about by conformational coupling between membrane proteins, as is typical of mechanotransduction. A paradigmatic case is integrin-mediated cell adhesion. Sensing the extracellular microenvironment and providing an appropriate response is essential in growth and development and has innumerable pathological implications. The process involves bidirectional signal transduction by complex supra-molecular structures that link integrin receptors to ion channels and transporters, growth factor receptors, cytoskeletal elements and other regulatory elements. The dynamics of such complexes is only beginning to be understood. A thoroughly studied example is the association between integrin receptors and the voltage-gated K+ channels Kv11.1. These channels are widely expressed in early embryos, where their physiological roles are poorly understood and apparently different from the shaping of action potential firing in the adult. Hints about these roles come from studies in cancer cells, where Kv11.1 is often overexpressed and appears to re-assume functions, such as controlling cell proliferation/differentiation, apoptosis and migration. Kv11.1 is implicated in these processes through its linking to integrin subunits.
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Affiliation(s)
- Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milano, Italy
| | - Claudia Duranti
- Department of Experimental and Clinical Medicine. University of Florence, Firenze, Italy
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine. University of Florence, Firenze, Italy
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9
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Bachmann M, Li W, Edwards MJ, Ahmad SA, Patel S, Szabo I, Gulbins E. Voltage-Gated Potassium Channels as Regulators of Cell Death. Front Cell Dev Biol 2020; 8:611853. [PMID: 33381507 PMCID: PMC7767978 DOI: 10.3389/fcell.2020.611853] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 11/23/2020] [Indexed: 12/11/2022] Open
Abstract
Ion channels allow the flux of specific ions across biological membranes, thereby determining ion homeostasis within the cells. Voltage-gated potassium-selective ion channels crucially contribute to the setting of the plasma membrane potential, to volume regulation and to the physiologically relevant modulation of intracellular potassium concentration. In turn, these factors affect cell cycle progression, proliferation and apoptosis. The present review summarizes our current knowledge about the involvement of various voltage-gated channels of the Kv family in the above processes and discusses the possibility of their pharmacological targeting in the context of cancer with special emphasis on Kv1.1, Kv1.3, Kv1.5, Kv2.1, Kv10.1, and Kv11.1.
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Affiliation(s)
- Magdalena Bachmann
- Department of Biology, University of Padova, Padua, Italy.,Department of Surgery, Medical School, University of Cincinnati, Cincinnati, OH, United States
| | - Weiwei Li
- Department of Surgery, Medical School, University of Cincinnati, Cincinnati, OH, United States
| | - Michael J Edwards
- Department of Surgery, Medical School, University of Cincinnati, Cincinnati, OH, United States
| | - Syed A Ahmad
- Department of Surgery, Medical School, University of Cincinnati, Cincinnati, OH, United States
| | - Sameer Patel
- Department of Surgery, Medical School, University of Cincinnati, Cincinnati, OH, United States
| | - Ildiko Szabo
- Department of Biology, University of Padova, Padua, Italy.,Consiglio Nazionale delle Ricerche Institute of Neuroscience, Padua, Italy
| | - Erich Gulbins
- Department of Surgery, Medical School, University of Cincinnati, Cincinnati, OH, United States.,Department of Molecular Biology, University of Duisburg-Essen, Essen, Germany
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10
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Muttaqin A, Syukur S, Yulkifli Y, Alimuddin T. Direct-current electric field effect on the viability of HeLa cell line. Electromagn Biol Med 2020; 40:41-48. [PMID: 33183075 DOI: 10.1080/15368378.2020.1846193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Electric fields affect cell life, cancer cells are not spared. Research on the effectiveness of electric fields on the life of cancer cells is carried out using HeLa cells as target cells receiving an electric-field treatment for 24 h. This study is a laboratory experimental study of the viability of cancer cells (HeLa cells), measured by employing the MTT assay method. Experiments are carried out by administering a low direct-current electric field utilizing a couple of aluminum electrode plates on the HeLa cell line, planted in a micro-culture plate with voltages ranging from 46.67 V/m to 600.00 V/m. The dcEF was found to have a profound inhibitory effect on HeLa cell line viability, except at dcEF 93.33 V/m which shows anomalies, in the form of increased viability over control viability (115%). The mortality index reaches almost 100% when induced by dcEF>300.00 V/m. It was observed that the HeLa cell size is larger after dcEF induction was applied.
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Affiliation(s)
- Afdhal Muttaqin
- Program Studi Ilmu Biomedik, Fakultas Kedokteran, Universitas Andalas Indonesia , Padang, Indonesia
| | - Sumaryati Syukur
- Program Studi Ilmu Biomedik, Fakultas Kedokteran, Universitas Andalas Indonesia , Padang, Indonesia
| | - Yulkifli Yulkifli
- Program Studi Ilmu Biomedik, Fakultas Kedokteran, Universitas Andalas Indonesia , Padang, Indonesia
| | - Tofrizal Alimuddin
- Program Studi Ilmu Biomedik, Fakultas Kedokteran, Universitas Andalas Indonesia , Padang, Indonesia
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11
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Pethő Z, Najder K, Carvalho T, McMorrow R, Todesca LM, Rugi M, Bulk E, Chan A, Löwik CWGM, Reshkin SJ, Schwab A. pH-Channeling in Cancer: How pH-Dependence of Cation Channels Shapes Cancer Pathophysiology. Cancers (Basel) 2020; 12:E2484. [PMID: 32887220 PMCID: PMC7565548 DOI: 10.3390/cancers12092484] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 12/20/2022] Open
Abstract
Tissue acidosis plays a pivotal role in tumor progression: in particular, interstitial acidosis promotes tumor cell invasion, and is a major contributor to the dysregulation of tumor immunity and tumor stromal cells. The cell membrane and integral membrane proteins commonly act as important sensors and transducers of altered pH. Cell adhesion molecules and cation channels are prominent membrane proteins, the majority of which is regulated by protons. The pathophysiological consequences of proton-sensitive ion channel function in cancer, however, are scarcely considered in the literature. Thus, the main focus of this review is to highlight possible events in tumor progression and tumor immunity where the pH sensitivity of cation channels could be of great importance.
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Affiliation(s)
- Zoltán Pethő
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Karolina Najder
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Tiago Carvalho
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 90126 Bari, Italy; (T.C.); (S.J.R.)
| | - Roisin McMorrow
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, 3035 GD Rotterdam, The Netherlands; (R.M.); (C.W.G.M.L.)
| | - Luca Matteo Todesca
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Micol Rugi
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Etmar Bulk
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
| | - Alan Chan
- Percuros B.V., 2333 CL Leiden, The Netherlands;
| | - Clemens W. G. M. Löwik
- Department of Radiology and Nuclear Medicine, Erasmus Medical Center, 3035 GD Rotterdam, The Netherlands; (R.M.); (C.W.G.M.L.)
- Department of Oncology CHUV, UNIL and Ludwig Cancer Center, 1011 Lausanne, Switzerland
| | - Stephan J. Reshkin
- Department of Biosciences, Biotechnologies, and Biopharmaceutics, University of Bari, 90126 Bari, Italy; (T.C.); (S.J.R.)
| | - Albrecht Schwab
- Institute of Physiology II, University Münster, 48147 Münster, Germany; (K.N.); (L.M.T.); (M.R.); (E.B.); (A.S.)
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12
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Wong KK, Banham AH, Yaacob NS, Nur Husna SM. The oncogenic roles of TRPM ion channels in cancer. J Cell Physiol 2019; 234:14556-14573. [PMID: 30710353 DOI: 10.1002/jcp.28168] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 01/10/2019] [Indexed: 01/24/2023]
Abstract
Transient receptor potential (TRP) proteins are a diverse family of ion channels present in multiple types of tissues. They function as gatekeepers for responses to sensory stimuli including temperature, vision, taste, and pain through their activities in conducting ion fluxes. The TRPM (melastatin) subfamily consists of eight members (i.e., TRPM1-8), which collectively regulate fluxes of various types of cations such as K+ , Na+ , Ca2+ , and Mg2+ . Growing evidence in the past two decades indicates that TRPM ion channels, their isoforms, or long noncoding RNAs encoded within the locus may be oncogenes involved in the regulation of cancer cell growth, proliferation, autophagy, invasion, and epithelial-mesenchymal transition, and their significant association with poor clinical outcomes of cancer patients. In this review, we describe and discuss recent findings implicating TRPM channels in different malignancies, their functions, mechanisms, and signaling pathways involved in cancers, as well as summarizing their normal physiological functions and the availability of ion channel pharmacological inhibitors.
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Affiliation(s)
- Kah Keng Wong
- Department of Immunology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Alison H Banham
- Nuffield Division of Clinical Laboratory Sciences, Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Nik Soriani Yaacob
- Department of Chemical Pathology, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, Kubang Kerian, Kelantan, Malaysia
| | - Siti Muhamad Nur Husna
- Department of Immunology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
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13
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Becchetti A, Petroni G, Arcangeli A. Ion Channel Conformations Regulate Integrin-Dependent Signaling. Trends Cell Biol 2019; 29:298-307. [PMID: 30635161 DOI: 10.1016/j.tcb.2018.12.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 12/16/2018] [Accepted: 12/18/2018] [Indexed: 01/12/2023]
Abstract
Cell-matrix adhesion determines the choice between different cell fates and is accompanied by substantial changes in ion transport. The greatest evidence is the bidirectional interplay occurring between integrin receptors and K+ channels. These proteins can form signaling hubs that regulate cell proliferation, differentiation, and migration in normal and neoplastic tissue. Recent results show that the physical interaction with integrins determines the balance of the open and closed K+ channel states, and individual channel conformations regulate distinct downstream pathways. We propose a model of how these mechanisms regulate proliferation and metastasis in cancer cells. In particular, we suggest that the neoplastic progression could be modulated by targeting specific ion channel conformations.
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Affiliation(s)
- Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milano, Italy.
| | - Giulia Petroni
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Firenze, Italy
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, University of Florence, 50134 Firenze, Italy
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14
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Modulation of the inwardly rectifying potassium channel Kir4.1 by the pro-invasive miR-5096 in glioblastoma cells. Oncotarget 2018; 8:37681-37693. [PMID: 28445150 PMCID: PMC5514940 DOI: 10.18632/oncotarget.16949] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/22/2017] [Indexed: 12/19/2022] Open
Abstract
Inwardly rectifying potassium channels (Kir), and especially the barium-sensitive Kir4.1 encoded by KCNJ10, are key regulators of glial functions. A lower expression or mislocation of Kir4.1 is detected in human brain tumors. MicroRNAs participate in the regulation of ionic channels and associated neurologic disorders. Here, we analyze effects of miR-5096 on the Kir4.1 expression and function in two glioblastoma cell lines, U87 and U251. Using whole-cell patch-clamp and western-blot analysis, we show that cell loading with miR-5096 decreases the Kir4.1 protein level and associated K+ current. Cell treatment with barium, a Kir4.1 blocker, or cell loading of miR-5096 both increase the outgrowth of filopodia in glioma cells, as observed by time-lapse microscopy. Knocking-down Kir4.1 expression by siRNA transfection similarly increased both filopodia formation and invasiveness of glioma cells as observed in Boyden chamber assay. MiR-5096 also promotes the release of extracellular vesicles by which it increases its own transfer to surrounding cells, in a Kir4.1-dependent manner in U251 but not in U87. Altogether, our results validate Kir4.1 as a miR-5096 target to promote invasion of glioblastoma cells. Our data highlight the complexity of microRNA effects and the role of K+ channels in cancer.
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15
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Urner S, Kelly-Goss M, Peirce SM, Lammert E. Mechanotransduction in Blood and Lymphatic Vascular Development and Disease. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 2017; 81:155-208. [PMID: 29310798 DOI: 10.1016/bs.apha.2017.08.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The blood and lymphatic vasculatures are hierarchical networks of vessels, which constantly transport fluids and, therefore, are exposed to a variety of mechanical forces. Considering the role of mechanotransduction is key for fully understanding how these vascular systems develop, function, and how vascular pathologies evolve. During embryonic development, for example, initiation of blood flow is essential for early vascular remodeling, and increased interstitial fluid pressure as well as initiation of lymph flow is needed for proper development and maturation of the lymphatic vasculature. In this review, we introduce specific mechanical forces that affect both the blood and lymphatic vasculatures, including longitudinal and circumferential stretch, as well as shear stress. In addition, we provide an overview of the role of mechanotransduction during atherosclerosis and secondary lymphedema, which both trigger tissue fibrosis.
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Affiliation(s)
- Sofia Urner
- Institute of Metabolic Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Molly Kelly-Goss
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States
| | - Shayn M Peirce
- Department of Biomedical Engineering, University of Virginia, Charlottesville, VA, United States
| | - Eckhard Lammert
- Institute of Metabolic Physiology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany; Institute for Beta Cell Biology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany.
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16
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Becchetti A, Crescioli S, Zanieri F, Petroni G, Mercatelli R, Coppola S, Gasparoli L, D'Amico M, Pillozzi S, Crociani O, Stefanini M, Fiore A, Carraresi L, Morello V, Manoli S, Brizzi MF, Ricci D, Rinaldi M, Masi A, Schmidt T, Quercioli F, Defilippi P, Arcangeli A. The conformational state of hERG1 channels determines integrin association, downstream signaling, and cancer progression. Sci Signal 2017; 10:10/473/eaaf3236. [PMID: 28377405 DOI: 10.1126/scisignal.aaf3236] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ion channels regulate cell proliferation, differentiation, and migration in normal and neoplastic cells through cell-cell and cell-extracellular matrix (ECM) transmembrane receptors called integrins. K+ flux through the human ether-à-go-go-related gene 1 (hERG1) channel shapes action potential firing in excitable cells such as cardiomyocytes. Its abundance is often aberrantly high in tumors, where it modulates integrin-mediated signaling. We found that hERG1 interacted with the β1 integrin subunit at the plasma membrane of human cancer cells. This interaction was not detected in cardiomyocytes because of the presence of the hERG1 auxiliary subunit KCNE1 (potassium voltage-gated channel subfamily E regulatory subunit 1), which blocked the β1 integrin-hERG1 interaction. Although open hERG1 channels did not interact as strongly with β1 integrins as did closed channels, current flow through hERG1 channels was necessary to activate the integrin-dependent phosphorylation of Tyr397 in focal adhesion kinase (FAK) in both normal and cancer cells. In immunodeficient mice, proliferation was inhibited in breast cancer cells expressing forms of hERG1 with impaired K+ flow, whereas metastasis of breast cancer cells was reduced when the hERG1/β1 integrin interaction was disrupted. We conclude that the interaction of β1 integrins with hERG1 channels in cancer cells stimulated distinct signaling pathways that depended on the conformational state of hERG1 and affected different aspects of tumor progression.
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Affiliation(s)
- Andrea Becchetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy
| | - Silvia Crescioli
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Francesca Zanieri
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Giulia Petroni
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Raffaella Mercatelli
- Consiglio Nazionale delle Ricerche-Istituto Nazionale di Ottica, Via N. Carrara 1, 50019 Sesto Fiorentino, Italy
| | - Stefano Coppola
- Physics of Life Processes, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, Netherlands
| | - Luca Gasparoli
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Massimo D'Amico
- Di.V.A.L. Toscana SRL, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
| | - Serena Pillozzi
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Olivia Crociani
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Matteo Stefanini
- Di.V.A.L. Toscana SRL, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
| | - Antonella Fiore
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Laura Carraresi
- Di.V.A.L. Toscana SRL, Via Madonna del Piano 6, 50019 Sesto Fiorentino, Italy
| | - Virginia Morello
- Department of Molecular Biotechnology and Health Sciences, University of Torino, Via Nizza 52, 10126 Torino, Italy
| | - Sagar Manoli
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Maria Felice Brizzi
- Department of Medical Sciences, University of Torino, Corso Dogliotti 14, 10126 Torino, Italy
| | - Davide Ricci
- Department of Surgical Sciences, University of Torino, Corso Dogliotti 14, 10126 Torino, Italy
| | - Mauro Rinaldi
- Department of Surgical Sciences, University of Torino, Corso Dogliotti 14, 10126 Torino, Italy
| | - Alessio Masi
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy
| | - Thomas Schmidt
- Physics of Life Processes, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, Netherlands
| | - Franco Quercioli
- Consiglio Nazionale delle Ricerche-Istituto Nazionale di Ottica, Via N. Carrara 1, 50019 Sesto Fiorentino, Italy
| | - Paola Defilippi
- Physics of Life Processes, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, Netherlands
| | - Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, University of Firenze, Viale G.B. Morgagni 50, 50134 Firenze, Italy.
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17
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Baameur F, Singhmar P, Zhou Y, Hancock JF, Cheng X, Heijnen CJ, Kavelaars A. Epac1 interacts with importin β1 and controls neurite outgrowth independently of cAMP and Rap1. Sci Rep 2016; 6:36370. [PMID: 27808165 PMCID: PMC5093460 DOI: 10.1038/srep36370] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 10/14/2016] [Indexed: 01/23/2023] Open
Abstract
Exchange protein directly activated by cAMP-1 (Epac1) is a cAMP sensor that regulates multiple cellular functions including cellular migration, proliferation and differentiation. Classically, Epac1 is thought to exert its effects through binding of cAMP leading to a conformational change in Epac1 and its accumulation at the plasma membrane (PM) where it activates Rap1. In search for regulators of Epac1 activity, we show here that importin β1 (impβ1) is an Epac1 binding partner that prevents PM accumulation of Epac1. We demonstrate that in the absence of impβ1, endogenous as well as overexpressed Epac1 accumulate at the PM. Moreover, agonist-induced PM translocation of Epac1 leads to dissociation of Epac1 from impβ1. Localization of Epac1 at the PM in the absence of impβ1, requires residue R82 in its DEP domain. Notably, the PM accumulation of Epac1 in the absence of impβ1 does not require binding of cAMP to Epac1 and does not result in Rap1 activation. Functionally, PM accumulation of Epac1, an Epac1 mutant deficient in cAMP binding, or an Epac1 mutant tethered to the PM, is sufficient to inhibit neurite outgrowth. In conclusion, we uncover a cAMP-independent function of Epac1 at the PM and demonstrate that impβ1 controls subcellular localization of Epac1.
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Affiliation(s)
- Faiza Baameur
- Laboratory of Neuroimmunology, Department of Symptom Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Pooja Singhmar
- Laboratory of Neuroimmunology, Department of Symptom Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Yong Zhou
- Department of Integrative Biology and Pharmacology and Texas Therapeutics Institute, The University of Texas Health Science Center, Houston, TX 77030, USA
| | - John F Hancock
- Department of Integrative Biology and Pharmacology and Texas Therapeutics Institute, The University of Texas Health Science Center, Houston, TX 77030, USA
| | - Xiaodong Cheng
- Department of Integrative Biology and Pharmacology and Texas Therapeutics Institute, The University of Texas Health Science Center, Houston, TX 77030, USA
| | - Cobi J Heijnen
- Laboratory of Neuroimmunology, Department of Symptom Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Annemieke Kavelaars
- Laboratory of Neuroimmunology, Department of Symptom Research, Division of Internal Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
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18
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Pharmacological targeting of ion channels for cancer therapy: In vivo evidences. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1385-97. [DOI: 10.1016/j.bbamcr.2015.11.032] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 11/25/2015] [Accepted: 11/26/2015] [Indexed: 12/29/2022]
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19
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Cancer (stem) cell differentiation: An inherent or acquired property? Med Hypotheses 2015; 85:1012-8. [PMID: 26347071 DOI: 10.1016/j.mehy.2015.08.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2014] [Accepted: 08/23/2015] [Indexed: 02/08/2023]
Abstract
There is a growing list of data indicating that cancer (stem) cells could functionally adapt foreign tissue features, such as endothelial-like cells or neuroendocrine cells, express lineage markers or could differentiate into various lineages in response to appropriate differentiation criteria. The finding that cancer (stem) cells may possess some kind of differentiation capacity poses the question whether this might be an inherent or acquired property. Cancer stem cells share stem cell characteristics and may thus possess an inherent differentiation capacity enabling the cells to respond to various differentiation stimuli. Considering the plasticity of cancer (stem) cells, even non-tumorigenic (and putatively non-differentiable) tumor cells could give rise to tumorigenic tumor stem cells, exhibiting stem cell characteristics including an inherent differentiation capacity. On the contrary, cancer (stem) cells may have acquired differentiation capacity as a consequence of a previous cell fusion event with cell types exhibiting differentiation potential and being fusogenic, such as macrophages or stem cells. Of pivotal interest in a tumor context are macrophages, which chiefly foster the chronically inflamed tumor microenvironment. Because chronically inflamed tissue is a well-known trigger for cell fusion and both macrophages and stem cells are highly fusogenic we conclude that cell fusion events between these cell types and cancer (stem) cells should frequently occur, thereby giving rise to hybrid cells exhibiting not only novel properties, like an enhanced metastatogenic phenotype, but also parental characteristics, such as differentiation capacity. Conceivably, the combination of both properties might be advantageous for metastasizing cancer (stem) cells to adapt better and faster to a foreign organ tissue environment.
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20
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Rooj AK, Liu Z, McNicholas CM, Fuller CM. Physical and functional interactions between a glioma cation channel and integrin-β1 require α-actinin. Am J Physiol Cell Physiol 2015; 309:C308-19. [PMID: 26108662 DOI: 10.1152/ajpcell.00036.2015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 06/17/2015] [Indexed: 11/22/2022]
Abstract
Major plasma membrane components of the tumor cell, ion channels, and integrins play crucial roles in metastasis. Glioma cells express an amiloride-sensitive nonselective cation channel composed of acid-sensing ion channel (ASIC)-1 and epithelial Na(+) channel (ENaC) α- and γ-subunits. Inhibition of this channel is associated with reduced cell migration and proliferation. Using the ASIC-1 subunit as a reporter for the channel complex, we found a physical and functional interaction between this channel and integrin-β1. Short hairpin RNA knockdown of integrin-β1 attenuated the amiloride-sensitive current, which was due to loss of surface expression of ASIC-1. In contrast, upregulation of membrane expression of integrin-β1 increased the surface expression of ASIC-1. The link between the amiloride-sensitive channel and integrin-β1 was mediated by α-actinin. Downregulation of α-actinin-1 or -4 attenuated the amiloride-sensitive current. Mutation of the putative binding site for α-actinin on the COOH terminus of ASIC-1 reduced the membrane localization of ASIC-1 and also resulted in attenuation of the amiloride-sensitive current. Our data suggest a novel interaction between the amiloride-sensitive glioma cation channel and integrin-β1, mediated by α-actinin. This interaction may form a mechanism by which channel activity can regulate glioma cell proliferation and migration.
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Affiliation(s)
- Arun K Rooj
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Zhiyong Liu
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Carmel M McNicholas
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Catherine M Fuller
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
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21
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Litan A, Langhans SA. Cancer as a channelopathy: ion channels and pumps in tumor development and progression. Front Cell Neurosci 2015; 9:86. [PMID: 25852478 PMCID: PMC4362317 DOI: 10.3389/fncel.2015.00086] [Citation(s) in RCA: 198] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 02/23/2015] [Indexed: 12/23/2022] Open
Abstract
Increasing evidence suggests that ion channels and pumps not only regulate membrane potential, ion homeostasis, and electric signaling in excitable cells but also play important roles in cell proliferation, migration, apoptosis and differentiation. Consistent with a role in cell signaling, channel proteins and ion pumps can form macromolecular complexes with growth factors, and cell adhesion and other signaling molecules. And while cancer is still not being cataloged as a channelopathy, as the non-traditional roles of ion pumps and channels are being recognized, it is increasingly being suggested that ion channels and ion pumps contribute to cancer progression. Cancer cell migration requires the regulation of adhesion complexes between migrating cells and surrounding extracellular matrix (ECM) proteins. Cell movement along solid surfaces requires a sequence of cell protrusions and retractions that mainly depend on regulation of the actin cytoskeleton along with contribution of microtubules and molecular motor proteins such as mysoin. This process is triggered and modulated by a combination of environmental signals, which are sensed and integrated by membrane receptors, including integrins and cadherins. Membrane receptors transduce these signals into downstream signaling pathways, often involving the Rho GTPase protein family. These pathways regulate the cytoskeletal rearrangements necessary for proper timing of adhesion, contraction and detachment of cells in order to find their way through extracellular spaces. Migration and adhesion involve continuous modulation of cell motility, shape and volume, in which ion channels and pumps play major roles. Research on cancer cells suggests that certain ion channels may be involved in aberrant tumor growth and channel inhibitors often lead to growth arrest. This review will describe recent research into the role of ion pumps and ion channels in cell migration and adhesion, and how they may contribute to tumor development.
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Affiliation(s)
- Alisa Litan
- Nemours Center for Childhood Cancer Research, Alfred I. duPont Hospital for Children Wilmington, DE, USA
| | - Sigrid A Langhans
- Nemours Center for Childhood Cancer Research, Alfred I. duPont Hospital for Children Wilmington, DE, USA
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22
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Tang DY, Yu Y, Zhao XJ, Schachner M, Zhao WJ. Single chain fragment variable antibodies developed by using as target the 3rd fibronectin type III homologous repeat fragment of human neural cell adhesion molecule L1 promote cell migration and neuritogenesis. Exp Cell Res 2015; 330:336-345. [PMID: 25447207 DOI: 10.1016/j.yexcr.2014.10.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 10/24/2014] [Accepted: 10/27/2014] [Indexed: 02/05/2023]
Abstract
L1CAM plays important roles during ontogeny, including promotion of neuronal cell migration and neuritogenesis, and stimulation of axonal outgrowth, fasciculation and myelination. These functions are at least partially exerted through a 16-mer amino acid sequence in the third fibronectin type III-like repeat of L1, which associates with several interaction partners, including integrins, other adhesion molecules and growth factor receptors. Here, using the Tomlinson I library for phage display, we obtained two single-chain variable fragment antibodies (scFvs) against this peptide sequence of human L1, hereafter called H3 peptide. Both scFvs recognize the H3 peptide and the extracellular domain of L1, as tested by enzyme-linked immunosorbent assay (ELISA), Western blot analysis and immunofluorescence staining of L1 expresssing cells. Furthermore, both scFvs reduce U-87 MG cell adhesion to fibronectin, while stimulating cell migration. Application of scFvs to human neuroblastoma SK-N-SH cells promote process outgrowth. Similar to triggering of endogenous L1 functions at the cell surface, both scFvs activate the signal transducers Erk and Src in these cells. Our results indicate that scFvs against a functionally pivotal domain in L1 trigger its regeneration-beneficial functions in vitro, encouraging thoughts on therapy of neurodegenerative diseases in the hope to ameliorate human nervous system diseases.
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Affiliation(s)
- Dan-Yang Tang
- Center for Neuroscience, Shantou University Medical College, 22 Xin Ling Road, Jinping District, Shantou, Guangdong 515041, People׳s Republic of China
| | - Yang Yu
- Center for Neuroscience, Shantou University Medical College, 22 Xin Ling Road, Jinping District, Shantou, Guangdong 515041, People׳s Republic of China
| | - Xuan-Jun Zhao
- Center for Neuroscience, Shantou University Medical College, 22 Xin Ling Road, Jinping District, Shantou, Guangdong 515041, People׳s Republic of China
| | - Melitta Schachner
- Center for Neuroscience, Shantou University Medical College, 22 Xin Ling Road, Jinping District, Shantou, Guangdong 515041, People׳s Republic of China.
| | - Wei-Jiang Zhao
- Center for Neuroscience, Shantou University Medical College, 22 Xin Ling Road, Jinping District, Shantou, Guangdong 515041, People׳s Republic of China.
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23
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Involvement of potassium channels in the progression of cancer to a more malignant phenotype. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:2477-92. [PMID: 25517985 DOI: 10.1016/j.bbamem.2014.12.008] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 12/01/2014] [Accepted: 12/08/2014] [Indexed: 12/22/2022]
Abstract
Potassium channels are a diverse group of pore-forming transmembrane proteins that selectively facilitate potassium flow through an electrochemical gradient. They participate in the control of the membrane potential and cell excitability in addition to different cell functions such as cell volume regulation, proliferation, cell migration, angiogenesis as well as apoptosis. Because these physiological processes are essential for the correct cell function, K+ channels have been associated with a growing number of diseases including cancer. In fact, different K+ channel families such as the voltage-gated K+ channels, the ether à-go-go K+ channels, the two pore domain K+ channels and the Ca2+-activated K+ channels have been associated to tumor biology. Potassium channels have a role in neoplastic cell-cycle progression and their expression has been found abnormal in many types of tumors and cancer cells. In addition, the expression and activity of specific K+ channels have shown a significant correlation with the tumor malignancy grade. The aim of this overview is to summarize published data on K+ channels that exhibit oncogenic properties and have been linked to a more malignant cancer phenotype. This article is part of a Special Issue entitled: Membrane channels and transporters in cancers.
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24
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Yun JS, Kim SY. Antihistamines modulate the integrin signaling pathway in h9c2 rat cardiomyocytes: Possible association with cardiotoxicity. Hum Exp Toxicol 2014; 34:796-807. [PMID: 25425550 DOI: 10.1177/0960327114559988] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The identification of biomarkers for toxicity prediction is crucial for drug development and safety evaluation. The selective and specific biomarkers for antihistamines-induced cardiotoxicity is not well identified yet. In order to evaluate the mechanism of the life-threatening effects caused by antihistamines, we used DNA microarrays to analyze genomic profiles in H9C2 rat cardiomyocytes that were treated with antihistamines. The gene expression profiles from drug-treated cells revealed changes in the integrin signaling pathway, suggesting that cardiac arrhythmias induced by antihistamine treatment may be mediated by changes in integrin-mediated signaling. It has been reported that integrin plays a role in QT prolongation that may induce cardiac arrhythmia. These results indicate that the integrin-mediated signaling pathway induced by antihistamines is involved in various biological mechanisms that lead to cardiac QT prolongation. Therefore, we suggest that genomic profiling of antihistamine-treated cardiomyocytes has the potential to reveal the mechanism of adverse drug reactions, and this signal pathway is applicable to prediction of in vitro cardiotoxicity induced by antihistamines as a biomarker candidate.
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Affiliation(s)
- J S Yun
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong-eup, Chungcheongbuk-do, Republic of Korea
| | - S Y Kim
- National Institute of Drug and Safety Evaluation, Ministry of Food and Drug Safety, Osong-eup, Chungcheongbuk-do, Republic of Korea
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Russo L, Sgambato A, Lecchi M, Pastori V, Raspanti M, Natalello A, Doglia SM, Nicotra F, Cipolla L. Neoglucosylated collagen matrices drive neuronal cells to differentiate. ACS Chem Neurosci 2014; 5:261-5. [PMID: 24625037 DOI: 10.1021/cn400222s] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Despite the relevance of carbohydrates as cues in eliciting specific biological responses, glycans have been rarely exploited in the study of neuronal physiology. We report thereby the study of the effect of neoglucosylated collagen matrices on neuroblastoma F11 cell line behavior. Morphological and functional analysis clearly showed that neoglucosylated collagen matrices were able to drive cells to differentiate. These data show for the first time that F11 cells can be driven from proliferation to differentiation without the use of chemical differentiating agents. Our work may offer to cell biologists new opportunities to study neuronal cell differentiation mechanisms in a cell environment closer to physiological conditions.
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Affiliation(s)
- Laura Russo
- Department of Biotechnology and Biosciences, University of Milano-Bicocca , P.zza della Scienza 2, I-20126 Milano, Italy
| | - Antonella Sgambato
- Department of Biotechnology and Biosciences, University of Milano-Bicocca , P.zza della Scienza 2, I-20126 Milano, Italy
| | - Marzia Lecchi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca , P.zza della Scienza 2, I-20126 Milano, Italy
| | - Valentina Pastori
- Department of Biotechnology and Biosciences, University of Milano-Bicocca , P.zza della Scienza 2, I-20126 Milano, Italy
| | - Mario Raspanti
- Department of Human Morphology, Human Morphology Laboratory, University of Insubria Via Monte Generoso 71, I- 21100 Varese, Italy
| | - Antonino Natalello
- Department of Biotechnology and Biosciences, University of Milano-Bicocca , P.zza della Scienza 2, I-20126 Milano, Italy
| | - Silvia M. Doglia
- Department of Biotechnology and Biosciences, University of Milano-Bicocca , P.zza della Scienza 2, I-20126 Milano, Italy
| | - Francesco Nicotra
- Department of Biotechnology and Biosciences, University of Milano-Bicocca , P.zza della Scienza 2, I-20126 Milano, Italy
| | - Laura Cipolla
- Department of Biotechnology and Biosciences, University of Milano-Bicocca , P.zza della Scienza 2, I-20126 Milano, Italy
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Arcangeli A, Crociani O, Bencini L. Interaction of tumour cells with their microenvironment: ion channels and cell adhesion molecules. A focus on pancreatic cancer. Philos Trans R Soc Lond B Biol Sci 2014; 369:20130101. [PMID: 24493749 DOI: 10.1098/rstb.2013.0101] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cancer must be viewed as a 'tissue', constituted of both transformed cells and a heterogeneous microenvironment, the 'tumour microenvironment' (TME). The TME undergoes a complex remodelling during the course of multistep tumourigenesis, hence strongly contributing to tumour progression. Ion channels and transporters (ICTs), being expressed on both tumour cells and in the different cellular components of the TME, are in a strategic position to sense and mediate signals arising from the TME. Often, this transmission is mediated by integrin adhesion receptors, which are the main cellular receptors capable of mediating cell-to-cell and cell-to-matrix bidirectional signalling. Integrins can often operate in conjunction with ICT because they can behave as functional partners of ICT proteins. The role of integrin receptors in the crosstalk between tumour cells and the TME is particularly relevant in the context of pancreatic cancer (PC), characterized by an overwhelming TME which actively contributes to therapy resistance. We discuss the possibility that this occurs through integrins and ICTs, which could be exploited as targets to overcome chemoresistance in PC.
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Affiliation(s)
- Annarosa Arcangeli
- Department of Experimental and Clinical Medicine, Section of Internal Medicine, University of Florence, , Viale G.B. Morgagni, 50, 50134 Firenze, Italy
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hERG1 channels modulate integrin signaling to trigger angiogenesis and tumor progression in colorectal cancer. Sci Rep 2013; 3:3308. [PMID: 24270902 PMCID: PMC3839040 DOI: 10.1038/srep03308] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Accepted: 11/05/2013] [Indexed: 12/12/2022] Open
Abstract
Angiogenesis is a potential target for cancer therapy. We identified a novel signaling pathway that sustains angiogenesis and progression in colorectal cancer (CRC). This pathway is triggered by β1 integrin-mediated adhesion and leads to VEGF-A secretion. The effect is modulated by the human ether-à-go-go related gene 1 (hERG1) K+ channel. hERG1 recruits and activates PI3K and Akt. This in turn increases the Hypoxia Inducible Factor (HIF)-dependent transcription of VEGF-A and other tumour progression genes. This signaling pathway has novel features in that the integrin- and hERG1-dependent activation of HIF (i) is triggered in normoxia, especially after CRC cells have experienced a hypoxic stage, (ii) involves NF-kB and (iii) is counteracted by an active p53. Blocking hERG1 switches this pathway off also in vivo, by inhibiting cell growth, angiogenesis and metastatic spread. This suggests that non-cardiotoxic anti-hERG1 drugs might be a fruitful therapeutic strategy to prevent the failure of anti-VEGF therapy.
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Stock C, Ludwig FT, Hanley PJ, Schwab A. Roles of ion transport in control of cell motility. Compr Physiol 2013; 3:59-119. [PMID: 23720281 DOI: 10.1002/cphy.c110056] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell motility is an essential feature of life. It is essential for reproduction, propagation, embryonic development, and healing processes such as wound closure and a successful immune defense. If out of control, cell motility can become life-threatening as, for example, in metastasis or autoimmune diseases. Regardless of whether ciliary/flagellar or amoeboid movement, controlled motility always requires a concerted action of ion channels and transporters, cytoskeletal elements, and signaling cascades. Ion transport across the plasma membrane contributes to cell motility by affecting the membrane potential and voltage-sensitive ion channels, by inducing local volume changes with the help of aquaporins and by modulating cytosolic Ca(2+) and H(+) concentrations. Voltage-sensitive ion channels serve as voltage detectors in electric fields thus enabling galvanotaxis; local swelling facilitates the outgrowth of protrusions at the leading edge while local shrinkage accompanies the retraction of the cell rear; the cytosolic Ca(2+) concentration exerts its main effect on cytoskeletal dynamics via motor proteins such as myosin or dynein; and both, the intracellular and the extracellular H(+) concentration modulate cell migration and adhesion by tuning the activity of enzymes and signaling molecules in the cytosol as well as the activation state of adhesion molecules at the cell surface. In addition to the actual process of ion transport, both, channels and transporters contribute to cell migration by being part of focal adhesion complexes and/or physically interacting with components of the cytoskeleton. The present article provides an overview of how the numerous ion-transport mechanisms contribute to the various modes of cell motility.
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Affiliation(s)
- Christian Stock
- Institute of Physiology II, University of Münster, Münster, Germany.
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Schwab A, Fabian A, Hanley PJ, Stock C. Role of ion channels and transporters in cell migration. Physiol Rev 2013; 92:1865-913. [PMID: 23073633 DOI: 10.1152/physrev.00018.2011] [Citation(s) in RCA: 311] [Impact Index Per Article: 28.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cell motility is central to tissue homeostasis in health and disease, and there is hardly any cell in the body that is not motile at a given point in its life cycle. Important physiological processes intimately related to the ability of the respective cells to migrate include embryogenesis, immune defense, angiogenesis, and wound healing. On the other side, migration is associated with life-threatening pathologies such as tumor metastases and atherosclerosis. Research from the last ≈ 15 years revealed that ion channels and transporters are indispensable components of the cellular migration apparatus. After presenting general principles by which transport proteins affect cell migration, we will discuss systematically the role of channels and transporters involved in cell migration.
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Chernet B, Levin M. Endogenous Voltage Potentials and the Microenvironment: Bioelectric Signals that Reveal, Induce and Normalize Cancer. JOURNAL OF CLINICAL & EXPERIMENTAL ONCOLOGY 2013; Suppl 1:S1-002. [PMID: 25525610 PMCID: PMC4267524 DOI: 10.4172/2324-9110.s1-002] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cancer may be a disease of geometry: a misregulation of the field of information that orchestrates individual cells' activities towards normal anatomy. Recent work identified molecular mechanisms underlying a novel system of developmental control: bioelectric gradients. Endogenous spatio-temporal differences in resting potential of non-neural cells provide instructive cues for cell regulation and complex patterning during embryogenesis and regeneration. It is now appreciated that these cues are an important layer of the dysregulation of cell: cell interactions that leads to cancer. Abnormal depolarization of resting potential (Vmem) is a convenient marker for neoplasia and activates a metastatic phenotype in genetically-normal cells in vivo. Moreover, oncogene expression depolarizes cells that form tumor-like structures, but is unable to form tumors if this depolarization is artificially prevented by misexpression of hyperpolarizing ion channels. Vmem triggers metastatic behaviors at considerable distance, mediated by transcriptional and epigenetic effects of electrically-modulated flows of serotonin and butyrate. While in vivo data on voltages in carcinogenesis comes mainly from the amphibian model, unbiased genetic screens and network profiling in rodents and human tissues reveal several ion channel proteins as bona fide oncogene and promising targets for cancer drug development. However, we propose that a focus on specific channel genes is just the tip of the iceberg. Bioelectric state is determined by post-translational gating of ion channels, not only from genetically-specified complements of ion translocators. A better model is a statistical dynamics view of spatial Vmem gradients. Cancer may not originate at the single cell level, since gap junctional coupling results in multi-cellular physiological networks with multiple stable attractors in bioelectrical state space. New medical applications await a detailed understanding of the mechanisms by which organ target morphology stored in real-time patterns of ion flows is perceived or mis-perceived by cells. Mastery of somatic voltage gradients will lead to cancer normalization or rebooting strategies, such as those that occur in regenerating and embryonic organs, resulting in transformative advances in basic biology and oncology.
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Affiliation(s)
| | - Michael Levin
- Corresponding author: Michael Levin, Department of Biology, Tufts Center for Regenerative and Developmental Biology, Tufts University, 200 Boston Ave., Suite 4600, Medford, MA 02155, USA, Tel: (617) 627-6161; Fax:(617) 627- 6121;
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Arcangeli A. Ion channels and transporters in cancer. 3. Ion channels in the tumor cell-microenvironment cross talk. Am J Physiol Cell Physiol 2011; 301:C762-71. [DOI: 10.1152/ajpcell.00113.2011] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The traditional view of cancer as a collection of proliferating cells must be reconsidered, and cancer must be viewed as a “tissue” constituted by both transformed cells and a heterogeneous microenvironment, that tumor cells construct and remodel during multistep tumorigenesis. The “tumor microenvironment” (TM) is formed by mesenchymal, endothelial, and immune cells immersed in a network of extracellular matrix (ECM) proteins and soluble factors. The TM strongly contributes to tumor progression, through long distance, cell-to-cell or cell-to-matrix signals, which influence different aspects of tumor cell behavior. Understanding the relationships among the different components of the cancer tissue is crucial to design and develop new therapeutic strategies. Ion channels are emerging as relevant players in the cross talk between tumor cells and their TM. Ion channels are expressed on tumor cells, as well as in the different cellular components of the TM. In all these cells, ion channels are in a strategic position to sense and transmit extracellular signals into the intracellular machinery. Often, this transmission is mediated by integrin adhesion receptors, which can be functional partners of ion channels since they form molecular complexes with the channel protein in the context of the plasma membrane. The same relevant role is exerted by ion transporters, which also contribute to determine two facets of the cancer tissue: hypoxia and the acidic extracellular pH. On the whole, it is conceivable to prospect the targeting of ion channels for new therapeutic strategies aimed at better controlling the malignant progression of the cancer tissue.
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Affiliation(s)
- Annarosa Arcangeli
- Department of Experimental Pathology and Oncology, University of Firenze, and Istituto Toscano Tumori, Firenze, Italy
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32
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New insights into the regulation of ion channels by integrins. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2010; 279:135-90. [PMID: 20797679 DOI: 10.1016/s1937-6448(10)79005-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
By controlling cell adhesion to the extracellular matrix, integrin receptors regulate processes as diverse as cell migration, proliferation, differentiation, apoptosis, and synaptic stability. Because the underlying mechanisms are generally accompanied by changes in transmembrane ion flow, a complex interplay occurs between integrins, ion channels, and other membrane transporters. This reciprocal interaction regulates bidirectional signal transduction across the cell surface and may take place at all levels of control, from transcription to direct conformational coupling. In particular, it is becoming increasingly clear that integrin receptors form macromolecular complexes with ion channels. Besides contributing to the membrane localization of the channel protein, the integrin/channel complex can regulate a variety of downstream signaling pathways, centered on regulatory proteins like tyrosine kinases and small GTPases. In turn, the channel protein usually controls integrin activation and expression. We review some recent advances in the field, with special emphasis on hematology and neuroscience. Some oncological implications are also discussed.
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Physical and Functional Interaction between Integrins and hERG1 Channels in Cancer Cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 674:55-67. [DOI: 10.1007/978-1-4419-6066-5_6] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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34
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Integrin structure and functional relation with ion channels. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 674:1-7. [PMID: 20549935 DOI: 10.1007/978-1-4419-6066-5_1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Physical and functional link between cell adhesion molecules and ion channels provide a rapid connection between extracellular environment and cell physiology. Growing evidence does shows that frequent cross talk occurs between these classes of membrane proteins. These interactions are being addressed in ever increasing molecular detail. Recent advances have given X-ray resolved structure of the extracellular domains of integrin receptors. Such a level of resolution is still not available for the transmembrane and intracellular domains. Nonetheless, current molecular biological work is unraveling an intricate network connecting the cytoplasmic integrin domains with the cytoskeleton, ion channels and variety of cellular messengers. Overall, these studies show that integrins and ion channels both present bidirectional signaling features. Extracellular signals are usually transduced by integrins to trigger cellular responses that may involve ion fluxes, which can offer further relay. Intracellular processes and ion channel engagement can in turn affect integrin activation and expression and thus cell adhesion to the extracellular matrix. Moreover, ion channels themselves can communicate extracellular messages to both the cytoplasmic environment and integrin themselves. These interactions appear to often depend on formation of multiprotein membrane complexes that can recruit other elements, such as growth factor receptors and cytoplasmic signaling proteins. This chapter provides a general introduction to the field by giving a brief historical introduction and summarizing the main features of integrin structure and link to the cytoplasmic proteins. In addition, it outlines the main cellular processes inwhich channel-integrin interplay is known to exert clear physiological and pathological roles.
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35
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Erg K+ currents modulate excitability in mouse mitral/tufted neurons. Pflugers Arch 2009; 459:55-70. [DOI: 10.1007/s00424-009-0709-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 06/13/2009] [Accepted: 07/30/2009] [Indexed: 10/20/2022]
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36
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Hong HK, Jo SH. Block of HERG k channel by classic histamine h(1) receptor antagonist chlorpheniramine. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2009; 13:215-20. [PMID: 19885040 DOI: 10.4196/kjpp.2009.13.3.215] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2009] [Revised: 06/08/2009] [Accepted: 06/19/2009] [Indexed: 11/15/2022]
Abstract
Chlorpheniramine is a potent first-generation histamine H(1) receptor antagonist that can increase action potential duration and induce QT prolongation in several animal models. Since block of cardiac human ether-a-go-go-related gene (hERG) channels is one of leading causes of acquired long QT syndrome, we investigated the acute effects of chlorpheniramine on hERG channels to determine the electrophysiological basis for its proarrhythmic potential. We examined the effects of chlorpheniramine on the hERG channels expressed in Xenopus oocytes using two-microelectrode voltage-clamp techniques. Chlorpheniramine induced a concentration-dependent decrease of the current amplitude at the end of the voltage steps and hERG tail currents. The IC(50) of chlorpheniramine-dependent hERG block in Xenopus oocytes decreased progressively relative to the degree of depolarization. Chlorpheniramine affected the channels in the activated and inactivated states but not in the closed states. The S6 domain mutations Y652A and F656A partially attenuated (Y652A) or abolished (F656A) the hERG current block. These results suggest that the H(1) antihistamine, chlorpheniramine is a blocker of the hERG channels, providing a molecular mechanism for the drug-induced arrhythmogenic side effects.
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Affiliation(s)
- Hee-Kyung Hong
- Department of Physiology, Institute of Bioscience and Biotechnology, Kangwon National University College of Medicine, Chuncheon 200-701, Korea
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37
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Varghese M, Olstorn H, Sandberg C, Vik-Mo EO, Noordhuis P, Nistér M, Berg-Johnsen J, Moe MC, Langmoen IA. A comparison between stem cells from the adult human brain and from brain tumors. Neurosurgery 2009; 63:1022-33; discussion 1033-4. [PMID: 19057315 DOI: 10.1227/01.neu.0000335792.85142.b0] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE To directly compare stem cells from the normal adult human brain (adult human neural stem cells [AHNSC]), Grade II astrocytomas (AC II), and glioblastoma multiforme (GBM), with respect to proliferative and tumor-forming capacity and differentiation potential. METHODS Cells were isolated from tissue obtained during epilepsy surgery (AHNSCs) or tumor surgery (glioma stem cells [GSC]). They were cultured and investigated in vitro or after transplantation in immunodeficient mice. RESULTS Under identical experimental conditions, the following were found: 1) GBM stem cells formed tumors after orthotopic transplantation; AHNSCs showed no sign of tumor formation; 2) GSCs showed a significantly higher growth rate and self-renewal capacity; 3) both the growth rate and telomerase expression were high in GSCs and correlated with malignancy grade (GBM higher than AC II); AHNSCs had low telomerase expression; 4) GSCs invaded normal neurospheres, not vice versa; 5) both AHNSCs and stem cells from AC II and GBM responded to differentiation cues with a dramatic decrease in the proliferation index (Ki-67); 6) GSCs differentiated faster than AHNSCs; 7) upon differentiation, AHNSCs produced normal glia and neurons; GSCs produced morphologically aberrant cells often expressing both glial and neuronal antigens; and 8) differentiation of AHNSCs resulted in 2 typical functional phenotypes: neurons (high electrical membrane resistance, ability to generate action potentials) and glial cells (low membrane resistance, no action potentials). In contrast, GSCs resulted in only 1 functional phenotype: cells with high electrical resistance and active membrane properties capable of generating action potentials. CONCLUSION AHNSCs and stem cells from AC II and GBM differ with respect to proliferation, tumor-forming capacity, and rate and pattern of differentiation.
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Affiliation(s)
- Mercy Varghese
- Vilhelm Magnus Laboratory, Institute for Surgical Research, University of Oslo, Oslo, Norway.
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Growth-inhibiting extracellular matrix proteins also inhibit electrical activity by reducing calcium and increasing potassium conductances. Neuroscience 2009; 158:592-601. [DOI: 10.1016/j.neuroscience.2008.10.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Revised: 09/30/2008] [Accepted: 10/07/2008] [Indexed: 11/22/2022]
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Feigenspan A, Trümpler J, Dirks P, Weiler R. Ether-à-gogo-related gene (erg1) potassium channels shape the dark response of horizontal cells in the mammalian retina. Pflugers Arch 2008; 458:359-77. [PMID: 18998156 DOI: 10.1007/s00424-008-0609-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2008] [Revised: 09/19/2008] [Accepted: 10/22/2008] [Indexed: 12/11/2022]
Abstract
Postsynaptic to photoreceptors, horizontal cells face prolonged exposure to glutamate in the dark. Therefore, efficient hyperpolarizing mechanisms are crucial to keep horizontal cells within an operating range and to reduce glutamate-induced excitotoxicity. Combining electrophysiology, single-cell reverse transcriptase polymerase chain reaction, and immunocytochemistry, we found that horizontal cell bodies but not their axon terminals express the ether-à-gogo-related gene isoform 1 (erg1) K(+) channel. Erg1-mediated outward currents displayed voltage-dependent activation and C-type inactivation. Recovery from inactivation involved a transient open state. Gating of erg1 channels kept the voltage response to glutamate brief and at physiological amplitudes. With erg1 channels blocked, the response of horizontal cells to the onset of darkness was significantly enhanced. These results indicate a functional dichotomy between horizontal cell bodies and axon terminals in the processing of photoreceptor signals. The dark response thus reflects a finely tuned balance determined by the successive gating of ionotropic glutamate receptors and erg1 channels.
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Affiliation(s)
- Andreas Feigenspan
- Institute of Biology, University of Oldenburg, 26111 Oldenburg, Germany.
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Wu X, Yang Y, Gui P, Sohma Y, Meininger GA, Davis GE, Braun AP, Davis MJ. Potentiation of large conductance, Ca2+-activated K+ (BK) channels by alpha5beta1 integrin activation in arteriolar smooth muscle. J Physiol 2008; 586:1699-713. [PMID: 18218680 DOI: 10.1113/jphysiol.2007.149500] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Injury/degradation of the extracellular matrix (ECM) is associated with vascular wall remodelling and impaired reactivity, a process in which altered ECM-integrin interactions play key roles. Previously, we found that peptides containing the RGD integrin-binding sequence produce sustained vasodilatation of rat skeletal muscle arterioles. Here, we tested the hypothesis that RGD ligands work through alpha5beta1 integrin to modulate the activity of large conductance, Ca(2+)-activated K(+) (BK) channels in arteriolar smooth muscle. K(+) currents were recorded in single arteriolar myocytes using whole-cell and single-channel patch clamp methods. Activation of alpha5beta1 integrin by an appropriate, insoluble alpha5beta1 antibody resulted in a 30-50% increase in the amplitude of iberiotoxin (IBTX)-sensitive, whole-cell K(+) current. Current potentiation occurred 1-8 min after bead-antibody application to the cell surface. Similarly, the endogenous alpha5beta1 integrin ligand fibronectin (FN) potentiated IBTX-sensitive K(+) current by 26%. Current potentiation was blocked by the c-Src inhibitor PP2 but not by PP3 (0.1-1 mum). In cell-attached patches, number of open channels x open probability (NP(o)) of a 230-250 pS K(+) channel was significantly increased after FN application locally to the external surface of cell-attached patches through the recording pipette. In excised, inside-out patches, the same method of FN application led to large, significant increases in NP(o) and caused a leftward shift in the NP(o)-voltage relationship at constant [Ca(2+)]. PP2 (but not PP3) nearly abolished the effect of FN on channel activity, suggesting that signalling between the integrin and channel involved an increase in Ca(2+)sensitivity of the channel via a membrane-delimited pathway. The effects of alpha5beta1 integrin activation on both whole-cell and single-channel BK currents could be reproduced in HEK 293 cells expressing the BK channel alpha-subunit. This is the first demonstration at the single-channel level that integrin signalling can regulate an ion channel. Our results show that alpha5beta1 integrin activation potentiates BK channel activity in vascular smooth muscle through both Ca(2+)- and c-Src-dependent mechanisms. This mechanism is likely to play a role in the arteriolar dilatation and impaired vascular reactivity associated with ECM degradation.
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Affiliation(s)
- Xin Wu
- Department of Medical Pharmacology & Physiology, University of Missouri School of Medicine, 1 Hospital Dr, Rm M451, Columbia, MO 65212, USA.
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Hernandez L, Park KH, Cai SQ, Qin L, Partridge N, Sesti F. The antiproliferative role of ERG K+ channels in rat osteoblastic cells. Cell Biochem Biophys 2007; 47:199-208. [PMID: 17652772 DOI: 10.1007/s12013-007-0006-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 10/23/2022]
Abstract
We report on the role of K+ currents in the mechanisms regulating the proliferation of UMR 106-01 osteoblastic osteosarcoma cells. Electrophysiological analysis showed that UMR 106-01 cells produce robust K+ currents that can be pharmacologically separated into two major components: a E-4031-susceptible current, I E-4031, and a tetraethylammonium (TEA)-susceptible component, I TEA. Western blot and RT-PCR analysis showed that I E-4031 is produced by ether a go-go (eag)-related channels (ERG). Incubation of the cells with E-4031 enhanced their proliferation by 80%. Application of E-4031 in the bath solution did not induce instantaneous changes in the membrane resting potential or in the level of cytosolic calcium; however, the cells were slightly depolarized and the calcium content was significantly increased upon prolonged incubation with the compound. Taken together these findings indicate that ERG channels can impair cell proliferation. This is a novel finding that underscores new modes of regulation of mitosis by voltage-gated K+ channels and provides an unexpected insight into the current view of the mechanisms governing bone tissue proliferation.
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Affiliation(s)
- Leonardo Hernandez
- Department of Physiology and Biophysics, UMDNJ-Robert Wood Johnson Medical School, 683 Hoes Lane, Piscataway, NJ 08854, USA
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Wanke E, Restano-Cassulini R. Toxins interacting with ether-à-go-go-related gene voltage-dependent potassium channels. Toxicon 2007; 49:239-48. [PMID: 17097705 DOI: 10.1016/j.toxicon.2006.09.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The critical role that ether-à-go-go-related gene (erg) K(+) channels play in mating in Caenorhabditis elegans, neuronal seizures in Drosophila and cardiac action potential repolarization in humans has been well documented. Three erg genes (erg1, erg2 and erg3) have been identified and characterized. A structurally diverse number of compounds block these channels, but do not display specificity among the different channel isoforms. In this review we describe the blocking properties of several peptides, purified from scorpion, sea anemone and spider venoms, which are selective for certain members of the ERG family of channels. These peptides do not behave as classical pore blockers and appear to modify the gating properties of the channel. Genomic studies predict the existence of many other novel peptides with the potential of being more selective for ERG channels than those discussed here.
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Affiliation(s)
- Enzo Wanke
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, Piazza della Scienza 2, 20126 Milano, Italy.
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Neusch C, Bähr M, Schneider-Gold C. Glia cells in amyotrophic lateral sclerosis: New clues to understanding an old disease? Muscle Nerve 2007; 35:712-24. [PMID: 17373702 DOI: 10.1002/mus.20768] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In classic neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), the pathogenic concept of a cell-autonomous disease of motor neurons has been challenged increasingly in recent years. Macro- and microglial cells have come to the forefront for their role in multistep degenerative processes in ALS and respective disease models. The activation of astroglial and microglial cells occurs early in the pathogenesis of the disease and seems to greatly influence disease onset and promotion. The role of oligodendrocytes and Schwann cells remains elusive. In this review we highlight the impact of nonneuronal cells in ALS pathology. We discuss diverse glial membrane proteins that are necessary to control neuronal activity and neuronal cell survival, and summarize the contribution of these proteins to motor neuron death in ALS. We also describe recently discovered glial mechanisms that promote motor neuron degeneration using state-of-the-art genetic mouse technology. Finally, we provide an outlook on the extent to which these new pathomechanistic insights may offer novel therapeutic approaches.
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Affiliation(s)
- Clemens Neusch
- Department of Neurology, University of Göttingen, Robert-Koch-Str. 40, 37075 Göttingen, Germany.
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44
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Franco R, Bortner CD, Cidlowski JA. Potential Roles of Electrogenic Ion Transport and Plasma Membrane Depolarization in Apoptosis. J Membr Biol 2006; 209:43-58. [PMID: 16685600 DOI: 10.1007/s00232-005-0837-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2005] [Indexed: 12/15/2022]
Abstract
Apoptosis is characterized by the programmed activation of specific biochemical pathways leading to the organized demise of cells. To date, aspects of the intracellular signaling machinery involved in this phenomenon have been extensively dissected and characterized. However, recent studies have elucidated a novel role for changes in the intracellular milieu of the cells as important modulators of the cell death program. Specially, intracellular ionic homeostasis has been reported to be a determinant in both the activation and progression of the apoptotic cascade. Several apoptotic insults trigger specific changes in ionic gradients across the plasma membrane leading to depolarization of the plasma membrane potential (PMP). These changes lead to ionic imbalance early during apoptosis. Several studies have also suggested the activation and/or modulation of specific ionic transport mechanisms including ion channels, transporters and ATPases, as mediators of altered intracellular ionic homeostasis leading to PMP depolarization during apoptosis. However, the role of PMP depolarization and of the changes in ionic homeostasis during the progression of apoptosis are still unclear. This review summarizes the current knowledge regarding the causes and consequences of PMP depolarization during apoptosis. We also review the potential electrogenic ion transport mechanisms associated with this event, including the net influx/efflux of cations and anions. An understanding of these mechamisms could lead to the generation of new therapeutic approaches for a variety of diseases involving apoptosis.
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Affiliation(s)
- R Franco
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
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45
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Subramanian A, Lin HY. Crosslinked chitosan: Its physical properties and the effects of matrix stiffness on chondrocyte cell morphology and proliferation. J Biomed Mater Res A 2005; 75:742-53. [PMID: 16110496 DOI: 10.1002/jbm.a.30489] [Citation(s) in RCA: 123] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Chitosan [beta(1-4)-2 amino-2-deoxy-D-glucose], the natural polyaminosaccharide derived from N-deacetylation of chitin [beta(1-4)-2 acetamide-2-deoxy-D-glucose], has been shown to possess attractive biological and cell interactive properties. Recently chitosan and chitosan analogs have also been shown to support the growth and continued function of chondrocytes. In the present study, chitosan substrates are crosslinked with a functional diepoxide (1,4 butanediol diglycidyl ether) to alter its mechanical property, and the viability and proliferation of the canine articular chondrocytes seeded on the crosslinked surface are further assayed. Of interest is the impact of substrate stiffness on the growth and proliferation of articular canine chondrocytes. Crosslinked scaffolds were also subjected to degradation by chitosanase to examine the impact of crosslinking on enzyme-assisted degradation. The hydrophilicity and compression modulus of the crosslinked surfaces were measured via contact-angle measurements and compression tests, respectively. Scanning electron microscopy (SEM) and fluorescent staining were used to observe the proliferation and morphology of chondrocyte cells on noncrosslinked and crosslinked surfaces. The crosslinked chitosan was found to be nontoxic to chondrocytes and more hydrophilic. Its compression modulus and stiffness increased, which may improve the scaffold resistance to wear and in vivo shrinkage once implanted. The increased stiffness also seemed to serve as an additional mechanical stimulus to promote chondrocyte growth and proliferation. The cell morphology on crosslinked scaffolds seen by SEM and fluorescent stain was the typical chondrocytic rounded shape. The method proposed provides a nontoxic way to increase the mechanical strength of the chitosan scaffolds.
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Affiliation(s)
- Anuradha Subramanian
- Department of Chemical Engineering, 207 Othmer Hall, University of Nebraska, Lincoln, NE 68588, USA.
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46
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Neusch C, Papadopoulos N, Müller M, Maletzki I, Winter SM, Hirrlinger J, Handschuh M, Bähr M, Richter DW, Kirchhoff F, Hülsmann S. Lack of the Kir4.1 channel subunit abolishes K+ buffering properties of astrocytes in the ventral respiratory group: impact on extracellular K+ regulation. J Neurophysiol 2005; 95:1843-52. [PMID: 16306174 DOI: 10.1152/jn.00996.2005] [Citation(s) in RCA: 146] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ongoing rhythmic neuronal activity in the ventral respiratory group (VRG) of the brain stem results in periodic changes of extracellular K+. To estimate the involvement of the weakly inwardly rectifying K+ channel Kir4.1 (KCNJ10) in extracellular K+ clearance, we examined its functional expression in astrocytes of the respiratory network. Kir4.1 was expressed in astroglial cells of the VRG, predominantly in fine astrocytic processes surrounding capillaries and in close proximity to VRG neurons. Kir4.1 expression was up-regulated during early postnatal development. The physiological role of astrocytic Kir4.1 was studied using mice with a null mutation in the Kir4.1 channel gene that were interbred with transgenic mice expressing the enhanced green fluorescent protein in their astrocytes. The membrane potential was depolarized in astrocytes of Kir4.1-/- mice, and Ba2+-sensitive inward K+ currents were diminished. Brain slices from Kir4.1-/- mice, containing the pre-Bötzinger complex, which generates a respiratory rhythm, did not show any obvious differences in rhythmic bursting activity compared with wild-type controls, indicating that the lack of Kir4.1 channels alone does not impair respiratory network activity. Extracellular K+ measurements revealed that Kir4.1 channels contribute to extracellular K+ regulation. Kir4.1 channels reduce baseline K+ levels, and they compensate for the K+ undershoot. Our data indicate that Kir4.1 channels 1) are expressed in perineuronal processes of astrocytes, 2) constitute the major part of the astrocytic Kir conductance, and 3) contribute to regulation of extracellular K+ in the respiratory network.
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Affiliation(s)
- Clemens Neusch
- Dept. of Neurology, Georg-August-Univ. Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
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McBride SM. Prion protein: a pattern recognition receptor for viral components and uric acid responsible for the induction of innate and adaptive immunity. Med Hypotheses 2005; 65:570-7. [PMID: 15913900 DOI: 10.1016/j.mehy.2005.02.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Accepted: 02/23/2005] [Indexed: 10/25/2022]
Abstract
Prion protein, known as Prp(c), is a GPI-anchored membrane bound glycoprotein ubiquitously expressed in the body. To date, the precise nature of its physiological role remains a mystery. The prion protein's presence on neurons and immune effector cells suggests a dual neurological and immunological function. Some consensus exists regarding the proposed involvement of Prp(c) in neurodevelopment, where it would serve to mediate interactions between the extra-cellular matrix (ECM) and the neuron. There is also evidence that Prp plays a part in immunity, although the exact nature of the role remains unclear. Interestingly, a role in both immunity and development is a functional division seen in other types of receptors, most notably the Toll Receptor. In mammals, toll-like receptors (TLRs) are partly responsible for both innate and adaptive immune activity. However, recently several TLR independent pathways have been identified that initiate such responses. Unfortunately, receptors for such pathways remain unidentified. But based upon its functional homology to Toll Receptors, its known interactions with several viruses, and its possible downstream effector proteins, it is proposed that Prp(c) represents a new type of pattern recognition receptor responsible for TLR-independent induction of myeloid dendritic cell and macrophage maturation and later T-cell activation. From what is known of the ligands for the prion protein, it is proposed that this response would be initiated via the binding of uric acid, viral RNA, or viral structural proteins to Prp(c). It will further be proposed that Prp(c)'s ability to interact with viral components stems from its evolutionary origin as a horizontally transferred gene from an early RNA virus. Finally, Prp(c)'s functional role in immunity will be related to the pathophysiology of TSEs, with observations made concerning immune response to infection and agent composition.
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Affiliation(s)
- Sean M McBride
- Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
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Furlan F, Guasti L, Avossa D, Becchetti A, Cilia E, Ballerini L, Arcangeli A. Interneurons transiently express the ERG K+ channels during development of mouse spinal networks in vitro. Neuroscience 2005; 135:1179-92. [PMID: 16165280 DOI: 10.1016/j.neuroscience.2005.06.040] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Revised: 06/06/2005] [Accepted: 06/16/2005] [Indexed: 11/15/2022]
Abstract
During spinal cord maturation neuronal excitability gradually differentiates to meet different functional demands. Spontaneous activity, appearing early during spinal development, is regulated by the expression pattern of ion channels in individual neurons. While emerging excitability of embryonic motoneurons has been widely investigated, little is known about that of spinal interneurons. Voltage-dependent K+ channels are a heterogeneous class of ion channels that accomplish several functions. Recently voltage-dependent K+ channels encoded by erg subfamily genes (ERG channels) were shown to modulate excitability in immature neurons of mouse and quail. We investigated the expression of ERG channels in immature spinal interneurons, using organotypic embryonic cultures of mouse spinal cord after 1 and 2 weeks of development in vitro. We report here that all the genes of the erg family known so far (erg1a, erg1b, erg2, erg3) are expressed in embryonic spinal cultures. We demonstrate for the first time that three ERG proteins (ERG1A, ERG2 and ERG3) are co-expressed in the same neuronal population, and display a spatio-temporal distribution in the spinal slices. ERG immuno-positive cells, representing mainly GABAergic interneurons, were present in large numbers at early stages of development, while declining later, with a ventral to dorsal gradient. Patch clamp recordings confirmed these data, showing that ventral interneurons expressed functional ERG currents only transiently. Similar expression of the erg genes was observed at comparable ages in vivo. The role of ERG currents in regulating neuronal excitability during the earliest phases of spinal circuitry development will be examined in future studies.
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Affiliation(s)
- F Furlan
- Physiology and Pathology Department, Center for Neuroscience B.R.A.I.N., Psychology Faculty, University of Trieste, via Sant'Anastasio 12, 34134, Trieste, Italy
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Cherubini A, Hofmann G, Pillozzi S, Guasti L, Crociani O, Cilia E, Di Stefano P, Degani S, Balzi M, Olivotto M, Wanke E, Becchetti A, Defilippi P, Wymore R, Arcangeli A. Human ether-a-go-go-related gene 1 channels are physically linked to beta1 integrins and modulate adhesion-dependent signaling. Mol Biol Cell 2005; 16:2972-83. [PMID: 15800067 PMCID: PMC1142440 DOI: 10.1091/mbc.e04-10-0940] [Citation(s) in RCA: 120] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Adhesive receptors of the integrin family are primarily involved in cell-extracellular matrix adhesion. Additionally, integrins trigger multiple signaling pathways that are involved in cell migration, proliferation, survival, and differentiation. We previously demonstrated that the activation of integrins containing the beta(1) subunit leads to a selective increase in potassium currents carried by the human ether-a-go-go-related gene (hERG) channels in neuroblastoma and leukemia cells; this current activation modulates adhesion-dependent differentiation in these cells. We hypothesized that the cross-talk between integrins and hERG channels could be traced back to the assembly of a macromolecular signaling complex comprising the two proteins. We tested this hypothesis in both SH-SY5Y neuroblastoma cells and in human embryonic kidney 293 cells stably transfected with hERG1 and, therefore, expressing only the full-length hERG1 protein on the plasma membrane. The beta(1) integrin and hERG1 coprecipitate in these cells and colocalize in both intracellular and surface membrane compartments. The two proteins also coprecipitate with caveolin-1, suggesting the localization of the complex in lipid rafts/caveolae. hERG1-transfected cells undergo an activation of hERG currents after beta(1) integrin-mediated adhesion to fibronectin; concomitant with this activation, the focal adhesion kinase associates with the hERG1 protein and becomes tyrosine phosphorylated. Using hERG1-specific inhibitors, we show that the tyrosine phosphorylation of focal adhesion kinase is strictly dependent on hERG channel activity. Similarly, the activity of the small GTPase Rac1 turned out to be dependent on hERG currents. On the whole, these data indicate that the hERG1 protein associates with beta(1) integrins and modulates adhesion receptor signaling.
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Affiliation(s)
- Alessia Cherubini
- Department of Experimental Pathology and Oncology, University of Firenze, 50134 Firenze, Italy
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50
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Hirdes W, Schweizer M, Schuricht KS, Guddat SS, Wulfsen I, Bauer CK, Schwarz JR. Fast erg K+ currents in rat embryonic serotonergic neurones. J Physiol 2005; 564:33-49. [PMID: 15677682 PMCID: PMC1456054 DOI: 10.1113/jphysiol.2004.082123] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Ether-á-go-go-related gene (erg) channels form one subfamily of the ether-á-go-go (EAG) K(+) channels and all three erg channels (erg1-3) are expressed in the brain. In the present study we characterize a fast erg current in neurones in primary culture derived from the median part of rat embryonic rhombencephala (E15-16). The relatively uniform erg current was regularly found in large multipolar serotonergic neurones, and occurred also in other less well characterized neurones. The erg current was blocked by the antiarrhythmic substance E-4031. Single-cell RT-PCR revealed the expression of erg1a, erg1b, erg2 and erg3 mRNA in different combinations in large multipolar neurones. These cells also contained neuronal tryptophan hydroxylase, a key enzyme for serotonin production. To characterize the molecular properties of the channels mediating the native erg current, we compared the voltage and time dependence of activation and deactivation of the neuronal erg current to erg1a, erg1b, erg2 and erg3 currents heterologously expressed in CHO cells. The biophysical properties of the neuronal erg current were well within the range displayed by the different heterologously expressed erg currents. Activation and deactivation kinetics of the neuronal erg current were fast and resembled those of erg3 currents. Our data suggest that the erg channels in rat embryonic rhombencephalon neurones are heteromultimers formed by different erg channel subunits.
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Affiliation(s)
- Wiebke Hirdes
- Institute of Applied Physiology, University Hospital Hamburg-Eppendorf, University of HamburgMartinistr. 52, D-20246 Hamburg, Germany
| | - Michaela Schweizer
- Center for Molecular Neurobiology, ZMNH, University of HamburgFalkenried 94, D-20251 Hamburg, Germany
| | - Kristina S Schuricht
- Institute of Applied Physiology, University Hospital Hamburg-Eppendorf, University of HamburgMartinistr. 52, D-20246 Hamburg, Germany
| | - Saskia S Guddat
- Institute of Applied Physiology, University Hospital Hamburg-Eppendorf, University of HamburgMartinistr. 52, D-20246 Hamburg, Germany
| | - Iris Wulfsen
- Institute of Applied Physiology, University Hospital Hamburg-Eppendorf, University of HamburgMartinistr. 52, D-20246 Hamburg, Germany
| | - Christiane K Bauer
- Institute of Applied Physiology, University Hospital Hamburg-Eppendorf, University of HamburgMartinistr. 52, D-20246 Hamburg, Germany
| | - Jürgen R Schwarz
- Institute of Applied Physiology, University Hospital Hamburg-Eppendorf, University of HamburgMartinistr. 52, D-20246 Hamburg, Germany
- Corresponding author J. R. Schwarz: Institute of Applied Physiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany.
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