1
|
Dymowska AK, Schultz AG, Blair SD, Chamot D, Goss GG. Acid-sensing ion channels are involved in epithelial Na+ uptake in the rainbow trout Oncorhynchus mykiss. Am J Physiol Cell Physiol 2014; 307:C255-65. [PMID: 24898589 DOI: 10.1152/ajpcell.00398.2013] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A role for acid-sensing ion channels (ASICs) to serve as epithelial channels for Na(+) uptake by the gill of freshwater rainbow trout was investigated. We found that the ASIC inhibitors 4',6-diamidino-2-phenylindole and diminazene decreased Na(+) uptake in adult rainbow trout in a dose-dependent manner, with IC50 values of 0.12 and 0.96 μM, respectively. Furthermore, we cloned the trout ASIC1 and ASIC4 homologs and demonstrated that they are expressed differentially in the tissues of the rainbow trout, including gills and isolated mitochondrion-rich cells. Immunohistochemical analysis using custom-made anti-zASIC4.2 antibody and the Na(+)-K(+)-ATPase (α5-subunit) antibody demonstrated that the trout ASIC localizes to Na(+)/K(+)-ATPase-rich cells in the gill. Moreover, three-dimensional rendering of confocal micrographs demonstrated that ASIC is found in the apical region of mitochondrion-rich cells. We present a revised model whereby ASIC4 is proposed as one mechanism for Na(+) uptake from dilute freshwater in the gill of rainbow trout.
Collapse
Affiliation(s)
- Agnieszka K Dymowska
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Aaron G Schultz
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Salvatore D Blair
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Danuta Chamot
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Greg G Goss
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
3
|
Blanchard MG, Rash LD, Kellenberger S. Inhibition of voltage-gated Na(+) currents in sensory neurones by the sea anemone toxin APETx2. Br J Pharmacol 2012; 165:2167-77. [PMID: 21943094 PMCID: PMC3413854 DOI: 10.1111/j.1476-5381.2011.01674.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 09/07/2011] [Accepted: 09/08/2011] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE APETx2, a toxin from the sea anemone Anthropleura elegantissima, inhibits acid-sensing ion channel 3 (ASIC3)-containing homo- and heterotrimeric channels with IC(50) values < 100 nM and 0.1-2 µM respectively. ASIC3 channels mediate acute acid-induced and inflammatory pain response and APETx2 has been used as a selective pharmacological tool in animal studies. Toxins from sea anemones also modulate voltage-gated Na(+) channel (Na(v) ) function. Here we tested the effects of APETx2 on Na(v) function in sensory neurones. EXPERIMENTAL APPROACH Effects of APETx2 on Na(v) function were studied in rat dorsal root ganglion (DRG) neurones by whole-cell patch clamp. KEY RESULTS APETx2 inhibited the tetrodotoxin (TTX)-resistant Na(v) 1.8 currents of DRG neurones (IC(50) , 2.6 µM). TTX-sensitive currents were less inhibited. The inhibition of Na(v) 1.8 currents was due to a rightward shift in the voltage dependence of activation and a reduction of the maximal macroscopic conductance. The inhibition of Na(v) 1.8 currents by APETx2 was confirmed with cloned channels expressed in Xenopus oocytes. In current-clamp experiments in DRG neurones, the number of action potentials induced by injection of a current ramp was reduced by APETx2. CONCLUSIONS AND IMPLICATIONS APETx2 inhibited Na(v) 1.8 channels, in addition to ASIC3 channels, at concentrations used in in vivo studies. The limited specificity of this toxin should be taken into account when using APETx2 as a pharmacological tool. Its dual action will be an advantage for the use of APETx2 or its derivatives as analgesic drugs.
Collapse
Affiliation(s)
- Maxime G Blanchard
- Département de Pharmacologie et Toxicologie, Université de LausanneLausanne, Switzerland
| | - Lachlan D Rash
- Institute for Molecular Bioscience, The University of QueenslandSt Lucia, Queensland, Australia
| | - Stephan Kellenberger
- Département de Pharmacologie et Toxicologie, Université de LausanneLausanne, Switzerland
| |
Collapse
|
4
|
Calvo A, Yameen B, Williams FJ, Soler-Illia GJ, Azzaroni O. Mesoporous Films and Polymer Brushes Helping Each Other To Modulate Ionic Transport in Nanoconfined Environments. An Interesting Example of Synergism in Functional Hybrid Assemblies. J Am Chem Soc 2009; 131:10866-8. [DOI: 10.1021/ja9031067] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alejandra Calvo
- Gerencia de Química, CNEA, Centro Atómico Constituyentes, Av. Gral. Paz 1499, San Martín B1650KNA, Argentina, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, Departamento de Química de Superficies y Recubrimientos, TENARIS, Simini 250, B2804MHA Campana, Argentina, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)-CONICET, Universidad Nacional de La Plata, CC 16 Sucursal 4 (1900) La Plata, Argentina
| | - Basit Yameen
- Gerencia de Química, CNEA, Centro Atómico Constituyentes, Av. Gral. Paz 1499, San Martín B1650KNA, Argentina, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, Departamento de Química de Superficies y Recubrimientos, TENARIS, Simini 250, B2804MHA Campana, Argentina, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)-CONICET, Universidad Nacional de La Plata, CC 16 Sucursal 4 (1900) La Plata, Argentina
| | - Federico J. Williams
- Gerencia de Química, CNEA, Centro Atómico Constituyentes, Av. Gral. Paz 1499, San Martín B1650KNA, Argentina, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, Departamento de Química de Superficies y Recubrimientos, TENARIS, Simini 250, B2804MHA Campana, Argentina, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)-CONICET, Universidad Nacional de La Plata, CC 16 Sucursal 4 (1900) La Plata, Argentina
| | - Galo J.A.A. Soler-Illia
- Gerencia de Química, CNEA, Centro Atómico Constituyentes, Av. Gral. Paz 1499, San Martín B1650KNA, Argentina, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, Departamento de Química de Superficies y Recubrimientos, TENARIS, Simini 250, B2804MHA Campana, Argentina, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)-CONICET, Universidad Nacional de La Plata, CC 16 Sucursal 4 (1900) La Plata, Argentina
| | - Omar Azzaroni
- Gerencia de Química, CNEA, Centro Atómico Constituyentes, Av. Gral. Paz 1499, San Martín B1650KNA, Argentina, Max-Planck-Institut für Polymerforschung, Ackermannweg 10, 55128 Mainz, Germany, Departamento de Química de Superficies y Recubrimientos, TENARIS, Simini 250, B2804MHA Campana, Argentina, and Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)-CONICET, Universidad Nacional de La Plata, CC 16 Sucursal 4 (1900) La Plata, Argentina
| |
Collapse
|