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Nickerson AJ, Mutchler SM, Sheng S, Cox NA, Ray EC, Kashlan OB, Carattino MD, Marciszyn AL, Winfrey A, Gingras S, Kirabo A, Hughey RP, Kleyman TR. Mice lacking γENaC palmitoylation sites maintain benzamil-sensitive Na+ transport despite reduced channel activity. JCI Insight 2023; 8:e172051. [PMID: 37707951 PMCID: PMC10721255 DOI: 10.1172/jci.insight.172051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 09/12/2023] [Indexed: 09/16/2023] Open
Abstract
Epithelial Na+ channels (ENaCs) control extracellular fluid volume by facilitating Na+ absorption across transporting epithelia. In vitro studies showed that Cys-palmitoylation of the γENaC subunit is a major regulator of channel activity. We tested whether γ subunit palmitoylation sites are necessary for channel function in vivo by generating mice lacking the palmitoylated cysteines (γC33A,C41A) using CRISPR/Cas9 technology. ENaCs in dissected kidney tubules from γC33A,C41A mice had reduced open probability compared with wild-type (WT) littermates maintained on either standard or Na+-deficient diets. Male mutant mice also had higher aldosterone levels than WT littermates following Na+ restriction. However, γC33A,C41A mice did not have reduced amiloride-sensitive Na+ currents in the distal colon or benzamil-induced natriuresis compared to WT mice. We identified a second, larger conductance cation channel in the distal nephron with biophysical properties distinct from ENaC. The activity of this channel was higher in Na+-restricted γC33A,C41A versus WT mice and was blocked by benzamil, providing a possible compensatory mechanism for reduced prototypic ENaC function. We conclude that γ subunit palmitoylation sites are required for prototypic ENaC activity in vivo but are not necessary for amiloride/benzamil-sensitive Na+ transport in the distal nephron or colon.
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Affiliation(s)
| | | | | | | | | | - Ossama B. Kashlan
- Department of Medicine
- Department of Computational and Systems Biology
| | | | | | | | - Sebastien Gingras
- Department of Immunology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Annet Kirabo
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | | | - Thomas R. Kleyman
- Department of Medicine
- Department of Cell Biology, and
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Ehret E, Hummler E. Lessons learned about epithelial sodium channels from transgenic mouse models. Curr Opin Nephrol Hypertens 2022; 31:493-501. [PMID: 35894285 PMCID: PMC10022670 DOI: 10.1097/mnh.0000000000000821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW This review provides an up-to-date understanding about the regulation of epithelial sodium channel (ENaC) expression and function. In particular, we will focus on its implication in renal Na+ and K+ handling and control of blood pressure using transgenic animal models. RECENT FINDINGS In kidney, the highly amiloride-sensitive ENaC maintains whole body Na+ homeostasis by modulating Na+ transport via epithelia. This classical role is mostly confirmed using genetically engineered animal models. Recently identified key signaling pathways that regulate ENaC expression and function unveiled some nonclassical and unexpected channel regulatory processes. If aberrant, these dysregulated mechanisms may also result in the development of salt-dependent hypertension.The purpose of this review is to highlight the most recent findings in renal ENaC regulation and function, in considering data obtained from animal models. SUMMARY Increased ENaC-mediated Na+ transport is a prerequisite for salt-dependent forms of hypertension. To treat salt-sensitive hypertension it is crucial to fully understand the function and regulation of ENaC.
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Affiliation(s)
- Elodie Ehret
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne
| | - Edith Hummler
- Department of Biomedical Sciences, Faculty of Biology and Medicine, University of Lausanne, Lausanne
- National Center of Competence in Research, Kidney.CH, Zurich, Switzerland
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Maternal Heat Stress Alters Expression of Genes Associated with Nutrient Transport Activity and Metabolism in Female Placentae from Mid-Gestating Pigs. Int J Mol Sci 2021; 22:ijms22084147. [PMID: 33923747 PMCID: PMC8073098 DOI: 10.3390/ijms22084147] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 12/22/2022] Open
Abstract
Placental insufficiency is a known consequence of maternal heat stress during gestation in farm animals. The molecular regulation of placentae during the stress response is little known in pigs. This study aims to identify differential gene expression in pig placentae caused by maternal heat exposure during early to mid-gestation. RNA sequencing (RNA-seq) was performed on female placental samples from pregnant pigs exposed to thermoneutral control (CON; constant 20 °C; n = 5) or cyclic heat stress (HS; cyclic 28 to 33 °C; n = 5) conditions between d40 and d60 of gestation. On d60 of gestation, placental efficiency (fetal/placental weight) was decreased (p = 0.023) by maternal HS. A total of 169 genes were differentially expressed (FDR ≤ 0.1) between CON and HS placentae of female fetuses, of which 35 genes were upregulated and 134 genes were downregulated by maternal HS. The current data revealed transport activity (FDR = 0.027), glycoprotein biosynthetic process (FDR = 0.044), and carbohydrate metabolic process (FDR = 0.049) among the terms enriched by the downregulated genes (HS vs. CON). In addition, solute carrier (SLC)-mediated transmembrane transport (FDR = 0.008) and glycosaminoglycan biosynthesis (FDR = 0.027), which modulates placental stroma synthesis, were identified among the pathways enriched by the downregulated genes. These findings provide evidence that heat-stress induced placental inefficiency may be underpinned by altered expression of genes associated with placental nutrient transport capacity and metabolism. A further understanding of the molecular mechanism contributes to the identification of placental gene signatures of summer infertility in pigs.
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Boscardin E, Perrier R, Sergi C, Maillard MP, Loffing J, Loffing-Cueni D, Koesters R, Rossier BC, Hummler E. Plasma Potassium Determines NCC Abundance in Adult Kidney-Specific γENaC Knockout. J Am Soc Nephrol 2018; 29:977-990. [PMID: 29371419 DOI: 10.1681/asn.2017030345] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 11/30/2017] [Indexed: 12/18/2022] Open
Abstract
The amiloride-sensitive epithelial sodium channel (ENaC) and the thiazide-sensitive sodium chloride cotransporter (NCC) are key regulators of sodium and potassium and colocalize in the late distal convoluted tubule of the kidney. Loss of the αENaC subunit leads to a perinatal lethal phenotype characterized by sodium loss and hyperkalemia resembling the human syndrome pseudohypoaldosteronism type 1 (PHA-I). In adulthood, inducible nephron-specific deletion of αENaC in mice mimics the lethal phenotype observed in neonates, and as in humans, this phenotype is prevented by a high sodium (HNa+)/low potassium (LK+) rescue diet. Rescue reflects activation of NCC, which is suppressed at baseline by elevated plasma potassium concentration. In this study, we investigated the role of the γENaC subunit in the PHA-I phenotype. Nephron-specific γENaC knockout mice also presented with salt-wasting syndrome and severe hyperkalemia. Unlike mice lacking αENaC or βΕΝaC, an HNa+/LK+ diet did not normalize plasma potassium (K+) concentration or increase NCC activation. However, when K+ was eliminated from the diet at the time that γENaC was deleted, plasma K+ concentration and NCC activity remained normal, and progressive weight loss was prevented. Loss of the late distal convoluted tubule, as well as overall reduced βENaC subunit expression, may be responsible for the more severe hyperkalemia. We conclude that plasma K+ concentration becomes the determining and limiting factor in regulating NCC activity, regardless of Na+ balance in γENaC-deficient mice.
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Affiliation(s)
- Emilie Boscardin
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland.,National Center of Competence in Research "Kidney.Control of Homeostasis," Lausanne and Zurich, Switzerland
| | - Romain Perrier
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Chloé Sergi
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Marc P Maillard
- Service of Nephrology, University Hospital of Lausanne, Lausanne, Switzerland
| | - Johannes Loffing
- National Center of Competence in Research "Kidney.Control of Homeostasis," Lausanne and Zurich, Switzerland.,Institute of Anatomy, University of Zurich, Zurich, Switzerland; and
| | | | - Robert Koesters
- Department of Nephrology, Hôpital Tenon, Université Pierre et Marie Curie, Paris, France
| | - Bernard C Rossier
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Edith Hummler
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland; .,National Center of Competence in Research "Kidney.Control of Homeostasis," Lausanne and Zurich, Switzerland
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Yu D, Saini Y, Chen G, Ghio AJ, Dang H, Burns KA, Wang Y, Davis RM, Randell SH, Esther CR, Paulsen F, Boucher RC. Loss of β Epithelial Sodium Channel Function in Meibomian Glands Produces Pseudohypoaldosteronism 1-Like Ocular Disease in Mice. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:95-110. [PMID: 29107074 PMCID: PMC5745530 DOI: 10.1016/j.ajpath.2017.09.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 08/29/2017] [Accepted: 09/21/2017] [Indexed: 01/14/2023]
Abstract
Human subjects with pseudohypoaldosteronism-1 because of loss-of-function mutations in epithelial sodium channel (ENaC) subunits exhibit meibomian gland (MG) dysfunction. A conditional βENaC MG knockout (KO) mouse model was generated to elucidate the pathogenesis of absent ENaC function in the MG and associated ocular surface disease. βENaC MG KO mice exhibited a striking age-dependent, female-predominant MG dysfunction phenotype, with white toothpaste-like secretions observed obstructing MG orifices at 7 weeks of age. There were compensatory increases in tear production but higher tear sodium and indexes of mucin concentration in βENaC MG KO mice. Histologically, MG acinar atrophy was observed with ductal enlargement and ductal epithelial hyperstratification. Inflammatory cell infiltration was observed in both MG and conjunctiva of βENaC MG KO mice. In older βENaC MG KO mice (5 to 11 months), significant ocular surface pathologies were noted, including corneal opacification, ulceration, neovascularization, and ectasia. Inflammation in MG and conjunctiva was confirmed by increased cytokine gene and protein expression and positive Ly-6B.2 immunostaining. Cell proliferation assays revealed lower proliferation rates of MG cells derived from βENaC MG KO than control mice, suggesting that βENaC plays a role in cell renewal of mouse MG. Loss of βENaC function resulted in MG disease and severe ocular surface damage that phenocopied aspects of human pseudohypoaldosteronism-1 MG disease and was sex dependent.
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Affiliation(s)
- Dongfang Yu
- Marsico Lung Institute/University of North Carolina Cystic Fibrosis Research Center, School of Medicine, Chapel Hill, North Carolina; Department of Pathology, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Yogesh Saini
- Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
| | - Gang Chen
- Marsico Lung Institute/University of North Carolina Cystic Fibrosis Research Center, School of Medicine, Chapel Hill, North Carolina
| | - Andrew J Ghio
- National Health and Environmental Effects Research Laboratory, Environmental Protection Agency, Chapel Hill, North Carolina
| | - Hong Dang
- Marsico Lung Institute/University of North Carolina Cystic Fibrosis Research Center, School of Medicine, Chapel Hill, North Carolina
| | - Kimberlie A Burns
- Marsico Lung Institute/University of North Carolina Cystic Fibrosis Research Center, School of Medicine, Chapel Hill, North Carolina
| | - Yang Wang
- Marsico Lung Institute/University of North Carolina Cystic Fibrosis Research Center, School of Medicine, Chapel Hill, North Carolina
| | - Richard M Davis
- Department of Ophthalmology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Scott H Randell
- Marsico Lung Institute/University of North Carolina Cystic Fibrosis Research Center, School of Medicine, Chapel Hill, North Carolina
| | - Charles R Esther
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Friedrich Paulsen
- Department of Anatomy II, Friedrich Alexander University Erlangen Nürnberg, Erlangen, Germany
| | - Richard C Boucher
- Marsico Lung Institute/University of North Carolina Cystic Fibrosis Research Center, School of Medicine, Chapel Hill, North Carolina.
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Boscardin E, Perrier R, Sergi C, Maillard M, Loffing J, Loffing-Cueni D, Koesters R, Rossier BC, Hummler E. Severe hyperkalemia is rescued by low-potassium diet in renal βENaC-deficient mice. Pflugers Arch 2017; 469:1387-1399. [DOI: 10.1007/s00424-017-1990-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 04/07/2017] [Accepted: 04/26/2017] [Indexed: 12/31/2022]
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Altered Prostasin (CAP1/Prss8) Expression Favors Inflammation and Tissue Remodeling in DSS-induced Colitis. Inflamm Bowel Dis 2016; 22:2824-2839. [PMID: 27755216 DOI: 10.1097/mib.0000000000000940] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Inflammatory bowel diseases (IBD) including ulcerative colitis and Crohn's disease are diseases with impaired epithelial barrier function. We aimed to investigate whether mutated prostasin and thus, reduced colonic epithelial sodium channel activity predisposes to develop an experimentally dextran sodium sulfate (DSS)-induced colitis. METHODS Wildtype, heterozygous (fr/+), and homozygous (fr/fr) prostasin-mutant rats were treated 7 days with DSS followed by 7 days of recovery and analyzed with respect to histology, clinicopathological parameters, inflammatory marker mRNA transcript expression, and sodium transporter protein expression. RESULTS In this study, a more detailed analysis on rat fr/fr colons revealed reduced numbers of crypt and goblet cells, and local angiodysplasia, as compared with heterozygous (fr/+) and wildtype littermates. Following 2% DSS treatment for 7 days followed by 7 days recovery, fr/fr animals lost body weight, and reached maximal diarrhea score and highest disease activity after only 3 days, and strongly increased cytokine levels. The histology score significantly increased in all groups, but fr/fr colons further displayed pronounced histological alterations with near absence of goblet cells, rearrangement of the lamina propria, and presence of neutrophils, eosinophils, and macrophages. Additionally, fr/fr colons showed ulcerations and edemas that were absent in fr/+ and wildtype littermates. Following recovery, fr/fr rats reached, although significantly delayed, near-normal diarrhea score and disease activity, but exhibited severe architectural remodeling, despite unchanged sodium transporter protein expression. CONCLUSIONS In summary, our results demonstrate a protective role of colonic prostasin expression against experimental colitis, and thus represent a susceptibility gene in the development of inflammatory bowel disease.
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Keppner A, Andreasen D, Mérillat AM, Bapst J, Ansermet C, Wang Q, Maillard M, Malsure S, Nobile A, Hummler E. Epithelial Sodium Channel-Mediated Sodium Transport Is Not Dependent on the Membrane-Bound Serine Protease CAP2/Tmprss4. PLoS One 2015; 10:e0135224. [PMID: 26309024 PMCID: PMC4550455 DOI: 10.1371/journal.pone.0135224] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 07/20/2015] [Indexed: 01/27/2023] Open
Abstract
The membrane-bound serine protease CAP2/Tmprss4 has been previously identified in vitro as a positive regulator of the epithelial sodium channel (ENaC). To study its in vivo implication in ENaC-mediated sodium absorption, we generated a knockout mouse model for CAP2/Tmprss4. Mice deficient in CAP2/Tmprss4 were viable, fertile, and did not show any obvious histological abnormalities. Unexpectedly, when challenged with sodium-deficient diet, these mice did not develop any impairment in renal sodium handling as evidenced by normal plasma and urinary sodium and potassium electrolytes, as well as normal aldosterone levels. Despite minor alterations in ENaC mRNA expression, we found no evidence for altered proteolytic cleavage of ENaC subunits. In consequence, ENaC activity, as monitored by the amiloride-sensitive rectal potential difference (ΔPD), was not altered even under dietary sodium restriction. In summary, ENaC-mediated sodium balance is not affected by lack of CAP2/Tmprss4 expression and thus, does not seem to directly control ENaC expression and activity in vivo.
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Affiliation(s)
- Anna Keppner
- Department of Pharmacology & Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Ditte Andreasen
- Department of Pharmacology & Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Anne-Marie Mérillat
- Department of Pharmacology & Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Julie Bapst
- Department of Pharmacology & Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Camille Ansermet
- Department of Pharmacology & Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Qing Wang
- Department of Medicine/Division of Nephrology and Hypertension, Lausanne University Hospital (CHUV), Lausanne, Switzerland
- Department of Medicine/Physiology, University of Fribourg, Fribourg, Switzerland
| | - Marc Maillard
- Department of Medicine/Division of Nephrology and Hypertension, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Sumedha Malsure
- Department of Pharmacology & Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Antoine Nobile
- Institut Universitaire de Pathologie, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Edith Hummler
- Department of Pharmacology & Toxicology, University of Lausanne, Lausanne, Switzerland
- * E-mail:
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Sachse G, Faulhaber J, Seniuk A, Ehmke H, Pongs O. Smooth muscle BK channel activity influences blood pressure independent of vascular tone in mice. J Physiol 2014; 592:2563-74. [PMID: 24687584 DOI: 10.1113/jphysiol.2014.272880] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The large conductance voltage- and Ca(2+)-activated K(+) (BK) channel is an important determinant of vascular tone and contributes to blood pressure regulation. Both activities depend on the ancillary BKβ1 subunit. To determine the significance of smooth muscle BK channel activity for blood pressure regulation, we investigated the potential link between changes in arterial tone and altered blood pressure in BKβ1 knockout (BKβ1(-/-)) mice from three different genetically defined strains. While vascular tone was consistently increased in all BKβ1(-/-) mice independent of genetic background, BKβ1(-/-) strains exhibited increased (strain A), unaltered (strain B) or decreased (strain C) mean arterial blood pressures compared to their corresponding BKβ1(+/+) controls. In agreement with previous data on aldosterone regulation by renal/adrenal BK channel function, BKβ1(-/-) strain A mice have increased plasma aldosterone and increased blood pressure. Consistently, blockade of mineralocorticoid receptors by spironolactone treatment reversibly restored the elevated blood pressure to the BKβ1(+/+) strain A level. In contrast, loss of BKβ1 did not affect plasma aldosterone in strain C mice. Smooth muscle-restricted restoration of BKβ1 expression increased blood pressure in BKβ1(-/-) strain C mice, implying that impaired smooth muscle BK channel activity lowers blood pressure in these animals. We conclude that BK channel activity directly affects vascular tone but influences blood pressure independent of this effect via different pathways.
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Affiliation(s)
- Gregor Sachse
- Institut für Neurale Signalverarbeitung, Zentrum für Molekulare Neurobiologie, Falkenried 94, D-20251, Hamburg, Germany Department of Physiology, Anatomy and Genetics, South Parks Road, Oxford, OX1 3QX, UK
| | - Jörg Faulhaber
- Institut für Zelluläre und Integrative Physiologie, UKE, Martinistr. 52, D-20246, Hamburg, Germany
| | - Anika Seniuk
- Institut für Zelluläre und Integrative Physiologie, UKE, Martinistr. 52, D-20246, Hamburg, Germany
| | - Heimo Ehmke
- Institut für Zelluläre und Integrative Physiologie, UKE, Martinistr. 52, D-20246, Hamburg, Germany
| | - Olaf Pongs
- Institut für Neurale Signalverarbeitung, Zentrum für Molekulare Neurobiologie, Falkenried 94, D-20251, Hamburg, Germany Institut für Physiologie (Geb 56), Universität des Saarlandes, 66421, Homburg/Saar, Germany
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Raouf R, Rugiero F, Kiesewetter H, Hatch R, Hummler E, Nassar MA, Wang F, Wood JN. Sodium channels and mammalian sensory mechanotransduction. Mol Pain 2012; 8:21. [PMID: 22449024 PMCID: PMC3378430 DOI: 10.1186/1744-8069-8-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 03/26/2012] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Members of the degenerin/epithelial (DEG/ENaC) sodium channel family are mechanosensors in C elegans, and Nav1.7 and Nav1.8 voltage-gated sodium channel knockout mice have major deficits in mechanosensation. β and γENaC sodium channel subunits are present with acid sensing ion channels (ASICs) in mammalian sensory neurons of the dorsal root ganglia (DRG). The extent to which epithelial or voltage-gated sodium channels are involved in transduction of mechanical stimuli is unclear. RESULTS Here we show that deleting β and γENaC sodium channels in sensory neurons does not result in mechanosensory behavioural deficits. We had shown previously that Nav1.7/Nav1.8 double knockout mice have major deficits in behavioural responses to noxious mechanical pressure. However, all classes of mechanically activated currents in DRG neurons are unaffected by deletion of the two sodium channels. In contrast, the ability of Nav1.7/Nav1.8 knockout DRG neurons to generate action potentials is compromised with 50% of the small diameter sensory neurons unable to respond to electrical stimulation in vitro. CONCLUSION Behavioural deficits in Nav1.7/Nav1.8 knockout mice reflects a failure of action potential propagation in a mechanosensitive set of sensory neurons rather than a loss of primary transduction currents. DEG/ENaC sodium channels are not mechanosensors in mouse sensory neurons.
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Affiliation(s)
- Ramin Raouf
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
- Pfizer KCL Pain Lab, Wolfson Centre for Age-Related Diseases, King's College London, London, UK
| | - Francois Rugiero
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Hannes Kiesewetter
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Rachel Hatch
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
| | - Edith Hummler
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne 1005, Switzerland
| | - Mohammed A Nassar
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
- Biomedical Science University of Sheffield, Sheffield S10 2TN, UK
| | - Fan Wang
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - John N Wood
- Molecular Nociception Group, Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, UK
- DMMBPS, Seoul National University, Seoul 151-742, Korea
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Aydin IT, Hummler E, Smit NPM, Beermann F. Coat color dilution in mice because of inactivation of the melanoma antigen MART-1. Pigment Cell Melanoma Res 2011; 25:37-46. [PMID: 21943097 DOI: 10.1111/j.1755-148x.2011.00910.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Melanoma antigen recognized by T cells 1 (MART-1) is a melanoma-specific antigen, which has been thoroughly studied in the context of immunotherapy against malignant melanoma and which is found only in the pigment cell lineage. However, its exact function and involvement in pigmentation is not clearly understood. Melanoma antigen recognized by T cells 1 has been shown to interact with the melanosomal proteins Pmel17 and OA1. To understand the function of MART-1 in pigmentation, we developed a new knockout mouse model. Mice deficient in MART-1 are viable, but loss of MART-1 leads to a coat color phenotype, with a reduction in total melanin content of the skin and hair. Lack of MART-1 did not affect localization of melanocyte-specific proteins nor maturation of Pmel17. Melanosomes of hair follicle melanocytes in MART-1 knockout mice displayed morphological abnormalities, which were exclusive to stage III and IV melanosomes. In conclusion, our results suggest that MART-1 is a pigmentation gene that is required for melanosome biogenesis and/or maintenance.
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Affiliation(s)
- Iraz T Aydin
- Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
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