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Ramachandran CD, Gholami K, Lam SK, Hoe SZ. Effects of a high-salt diet on MAP and expression levels of renal ENaCs and aquaporins in SHR. Exp Biol Med (Maywood) 2023; 248:1768-1779. [PMID: 37828834 PMCID: PMC10792424 DOI: 10.1177/15353702231198085] [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: 12/05/2022] [Accepted: 06/05/2023] [Indexed: 10/14/2023] Open
Abstract
An increase in blood pressure by a high-salt (HS) diet may change the expression levels of renal epithelial sodium channels (ENaCs) and aquaporins (AQPs). Spontaneously hypertensive rats (SHRs) and Wistar Kyoto (WKY) rats were exposed to HS and regular-salt (RS) diets for 6 weeks. Mean arterial pressure (MAP) and plasma atrial natriuretic peptide (ANP), angiotensin II (Ang II), aldosterone, and arginine vasopressin (AVP) levels were determined. Expression of mRNA levels of ENaCs and AQPs were quantified by real-time PCR. The MAP was higher in SHRs on the HS diet. Plasma Ang II and aldosterone levels were low while plasma ANP level was high in both strains of rats. Renal expression of mRNA levels of α-, β-, and γ-ENaCs was lowered in SHRs on the HS diet. Meanwhile, renal AQP1, AQP2, and AQP7 mRNA expression levels were lowered in both strains of rats on the HS diet. Suppression of mRNA expression levels of ENaC and AQP subunits suggests that the high-salt-induced increase in the MAP of SHR may not be solely due to renal sodium and water retention.
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Affiliation(s)
| | - Khadijeh Gholami
- Department of Physiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Department of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Sau-Kuen Lam
- Department of Physiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- Department of Pre-Clinical Sciences, Faculty of Medicine & Health Sciences, Universiti Tunku Abdul Rahman, Kajang 43000, Malaysia
| | - See-Ziau Hoe
- Department of Physiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
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2
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Effect of adrenocorticotropin hormone and cortisol on epithelial sodium channels according to delivery route. JOURNAL OF SURGERY AND MEDICINE 2019. [DOI: 10.28982/josam.518414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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(Pro)Renin receptor mediates obesity-induced antinatriuresis and elevated blood pressure via upregulation of the renal epithelial sodium channel. PLoS One 2018; 13:e0202419. [PMID: 30118514 PMCID: PMC6097690 DOI: 10.1371/journal.pone.0202419] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 07/10/2018] [Indexed: 11/21/2022] Open
Abstract
Recent studies have demonstrated that the renal (pro)renin receptor (PRR) regulates expression of the alpha subunit of the epithelial sodium channel (α-ENaC). In this study we hypothesized that the renal PRR mediates high fat diet (HFD)-induced sodium retention and elevated systolic blood pressure (SBP) by enhancing expression of the epithelial sodium channel (α-ENaC). In our study we used a recently developed inducible nephron specific PRR knockout mouse. Mice (n = 6 each group) were allocated to receive regular diet (RD, 12 kcal% fat) or a high-fat diet (HFD, 45 kcal% fat) for 10 weeks. Body weight (BW), SBP, urine volume (UV) and urine sodium (UNaV), as well as renal interstitial Angiotensin II (Ang II), and renal medullary expression of PRR, p-SGK-1, α-ENaC were monitored in RD and HFD mice with or without PRR knockout. At baseline, there were no significant differences in BW, BP, UV or UNaV between different animal groups. At the end of the study, HFD mice had significant increases in SBP, BW, and significant reductions in UV and UNaV. Compared to RD, HFD significantly increased mRNA and protein expression of PRR, α-ENaC, p-SGK-1, and Ang II. Compared to HFD alone, PRR knockout mice on HFD had reduced mRNA and protein expression of PRR, p-SGK-1, and α-ENaC, as well as increased UV, UNaV and significantly reduced SBP. RIF Ang II was significantly increased by HFD and did not change in response to PRR knockout. We conclude that obesity induced sodium retention and elevated SBP are mediated by the PRR-SGK-1- α-ENaC pathway independent of Ang II.
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Wang D, Wang Y, Liu FQ, Yuan ZY, Mu JJ. High Salt Diet Affects Renal Sodium Excretion and ERRα Expression. Int J Mol Sci 2016; 17:480. [PMID: 27043552 PMCID: PMC4848936 DOI: 10.3390/ijms17040480] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 03/24/2016] [Accepted: 03/25/2016] [Indexed: 11/18/2022] Open
Abstract
Kidneys regulate the balance of water and sodium and therefore are related to blood pressure. It is unclear whether estrogen-related receptor α (ERRα), an orphan nuclear receptor and transcription factor highly expressed in kidneys, affects the reabsorption of water and sodium. The aim of this study was to determine whether changes in the expressions of ERRα, Na⁺/K⁺-ATPase and epithelial sodium channel (ENaC) proteins affected the reabsorption of water and sodium in kidneys of Dahl salt-sensitive (DS) rats. SS.13BN rats, 98% homologous to the DS rats, were used as a normotensive control group. The 24 h urinary sodium excretion of the DS and SS.13BN rats increased after the 6-week high salt diet intervention, while sodium excretion was increased in DS rats with daidzein (agonist of ERRα) treatment. ERRα expression was decreased, while β- and γ-ENaC mRNA expressions were increased upon high sodium diet treatment in the DS rats. In the chromatin immunoprecipitation (CHIP) assay, positive PCR signals were obtained in samples treated with anti-ERRα antibody. The transcriptional activity of ERRα was decreased upon high salt diet intervention. ERRα reduced the expressions of β- and γ-ENaC by binding to the ENaC promoter, thereby increased Na+ reabsorption. Therefore, ERRα might be one of the factors causing salt-sensitive hypertension.
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Affiliation(s)
- Dan Wang
- Department of Cardiovascular Medicine, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Key Laboratory of Molecular Cardiology, No. 277 Yanta West Road, Xi'an 710061, China.
| | - Yang Wang
- Department of Cardiovascular Medicine, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Key Laboratory of Molecular Cardiology, No. 277 Yanta West Road, Xi'an 710061, China.
| | - Fu-Qiang Liu
- Department of Cardiovascular Medicine, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Key Laboratory of Molecular Cardiology, No. 277 Yanta West Road, Xi'an 710061, China.
| | - Zu-Yi Yuan
- Department of Cardiovascular Medicine, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Key Laboratory of Molecular Cardiology, No. 277 Yanta West Road, Xi'an 710061, China.
| | - Jian-Jun Mu
- Department of Cardiovascular Medicine, First Affiliated Hospital of Medical College of Xi'an Jiaotong University, Key Laboratory of Molecular Cardiology, No. 277 Yanta West Road, Xi'an 710061, China.
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Yamamoto S, Hotta Y, Maeda K, Kataoka T, Maeda Y, Hamakawa T, Sasaki S, Yasui T, Asai K, Kimura K. Mineralocorticoid receptor stimulation induces urinary storage dysfunction via upregulation of epithelial sodium channel expression in the rat urinary bladder epithelium. J Pharmacol Sci 2016; 130:219-25. [DOI: 10.1016/j.jphs.2016.02.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 01/22/2016] [Accepted: 02/14/2016] [Indexed: 12/17/2022] Open
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6
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Shobair M, Dagliyan O, Kota P, Dang YL, He H, Stutts MJ, Dokholyan NV. Gain-of-Function Mutation W493R in the Epithelial Sodium Channel Allosterically Reconfigures Intersubunit Coupling. J Biol Chem 2015; 291:3682-92. [PMID: 26668308 DOI: 10.1074/jbc.m115.678052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Indexed: 12/21/2022] Open
Abstract
Sodium absorption in epithelial cells is rate-limited by the epithelial sodium channel (ENaC) activity in lung, kidney, and the distal colon. Pathophysiological conditions, such as cystic fibrosis and Liddle syndrome, result from water-electrolyte imbalance partly due to malfunction of ENaC regulation. Because the quaternary structure of ENaC is yet undetermined, the bases of pathologically linked mutations in ENaC subunits α, β, and γ are largely unknown. Here, we present a structural model of heterotetrameric ENaC α1βα2γ that is consistent with previous cross-linking results and site-directed mutagenesis experiments. By using this model, we show that the disease-causing mutation αW493R rewires structural dynamics of the intersubunit interfaces α1β and α2γ. Changes in dynamics can allosterically propagate to the channel gate. We demonstrate that cleavage of the γ-subunit, which is critical for full channel activation, does not mediate activation of ENaC by αW493R. Our molecular dynamics simulations led us to identify a channel-activating electrostatic interaction between α2Arg-493 and γGlu-348 at the α2γ interface. By neutralizing a sodium-binding acidic patch at the α1β interface, we reduced ENaC activation of αW493R by more than 2-fold. By combining homology modeling, molecular dynamics, cysteine cross-linking, and voltage clamp experiments, we propose a dynamics-driven model for the gain-of-function in ENaC by αW493R. Our integrated computational and experimental approach advances our understanding of structure, dynamics, and function of ENaC in its disease-causing state.
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Affiliation(s)
- Mahmoud Shobair
- From the Program in Molecular and Cellular Biophysics, Curriculum in Bioinformatics and Computational Biology, Department of Biochemistry and Biophysics, and
| | - Onur Dagliyan
- From the Program in Molecular and Cellular Biophysics, Department of Biochemistry and Biophysics, and
| | - Pradeep Kota
- From the Program in Molecular and Cellular Biophysics, Department of Biochemistry and Biophysics, and
| | - Yan L Dang
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Hong He
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - M Jackson Stutts
- Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
| | - Nikolay V Dokholyan
- From the Program in Molecular and Cellular Biophysics, Curriculum in Bioinformatics and Computational Biology, Department of Biochemistry and Biophysics, and Cystic Fibrosis and Pulmonary Diseases Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599
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Ravi S, Schilder RJ, Kimball SR. Role of precursor mRNA splicing in nutrient-induced alterations in gene expression and metabolism. J Nutr 2015; 145:841-6. [PMID: 25761502 PMCID: PMC4408736 DOI: 10.3945/jn.114.203216] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Precursor mRNA (pre-mRNA) splicing is a critical step in gene expression that results in the removal of intronic sequences from immature mRNA, leading to the production of mature mRNA that can be translated into protein. Alternative pre-mRNA splicing is the process whereby alternative exons and/or introns are selectively included or excluded, generating mature mRNAs that encode proteins that may differ in function. The resulting alterations in the pattern of protein isoform expression can result in changes in protein-protein interaction, subcellular localization, and flux through metabolic pathways. Although basic mechanisms of pre-mRNA splicing of introns and exons are reasonably well characterized, how these mechanisms are regulated remains poorly understood. The goal of this review is to highlight selected recent advances in our understanding of the regulation of pre-mRNA splicing by nutrients and modulation of nutrient metabolism that result from changes in pre-mRNA splicing.
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Affiliation(s)
- Suhana Ravi
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA; and
| | - Rudolf J Schilder
- Departments of Entomology and Biology, The Pennsylvania State University, State College, PA
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA; and
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Associations of epithelial sodium channel genes with blood pressure: the GenSalt study. J Hum Hypertens 2014; 29:224-8. [PMID: 25231509 PMCID: PMC4357546 DOI: 10.1038/jhh.2014.78] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 06/25/2014] [Accepted: 07/18/2014] [Indexed: 01/19/2023]
Abstract
In order to investigate associations of SCNN1A, SCNN1G and SCNN1B genes with blood pressure (BP) in Han Chinese population, we included 2 880 participants did not use antihypertensive medication in the month prior to the baseline survey in the current analysis. Forty-four tag-SNPs in epithelial sodium channel (ENaC) genes were selected and genotyped and nine BP measurements were obtained during 3-day examination. In single-marker analyses, we identified significant associations of SCNN1A marker rs13306613 with diastolic BP (DBP) and SCNN1B marker rs12447134 with systolic BP (SBP) under codominant model after Bonferroni correction (P= 2.82×10−5 and 4.63×10−4, respectively). In addition, 5 SNPs in SCNN1G and 4 SNPs in SCNN1B achieved nominal significance for SBP, DBP or mean arterial pressure (MAP) under the additive model. For example, the minor C allele of rs5735 in SCNN1G gene was associated with decreased SBP, DBP and MAP (P=0.016, 5.41×10−3, and 4.36×10−3, respectively). Gene-based results showed significant associations of SCNN1G and SCNN1Bwith BP levels. This study suggested that ENaC genes play important roles in BP regulation in the Han Chinese population. Future studies are warranted to replicate these findings and functional studies are needed to identify true causal variants in ENaC genes.
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Li L, Wang F, Wei X, Liang Y, Cui Y, Gao F, Zhong J, Pu Y, Zhao Y, Yan Z, Arendshorst WJ, Nilius B, Chen J, Liu D, Zhu Z. Transient receptor potential vanilloid 1 activation by dietary capsaicin promotes urinary sodium excretion by inhibiting epithelial sodium channel α subunit-mediated sodium reabsorption. Hypertension 2014; 64:397-404. [PMID: 24890824 DOI: 10.1161/hypertensionaha.114.03105] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
High salt (HS) intake contributes to the development of hypertension. Epithelial sodium channels play crucial roles in regulating renal sodium reabsorption and blood pressure. The renal transient receptor potential vanilloid 1 (TRPV1) cation channel can be activated by its agonist capsaicin. However, it is unknown whether dietary factors can act on urinary sodium excretion and renal epithelial sodium channel (ENaC) function. Here, we report that TRPV1 activation by dietary capsaicin increased urinary sodium excretion through reducing sodium reabsorption in wild-type (WT) mice on a HS diet but not in TRPV1(-/-) mice. The effect of capsaicin on urinary sodium excretion was involved in inhibiting αENaC and its related with-no-lysine kinase 1/serum- and glucocorticoid-inducible protein kinase 1 pathway in renal cortical collecting ducts of WT mice. Dietary capsaicin further reduced the increased αENaC activity in WT mice attributed to the HS diet. In contrast, this capsaicin effect was absent in TRPV1(-/-) mice. Immunoprecipitation study indicated αENaC specifically coexpressed and functionally interact with TRPV1 in renal cortical collecting ducts of WT mice. Additionally, ENaC activity and expression were suppressed by capsaicin-mediated TRPV1 activation in cultured M1-cortical collecting duct cells. Long-term dietary capsaicin prevented the development of high blood pressure in WT mice on a HS diet. It concludes that TRPV1 activation in the cortical collecting ducts by capsaicin increases urinary sodium excretion and avoids HS diet-induced hypertension through antagonizing αENaC-mediated urinary sodium reabsorption. Dietary capsaicin may represent a promising lifestyle intervention in populations exposed to a high dietary salt intake.
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Affiliation(s)
- Li Li
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Fei Wang
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Xing Wei
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Yi Liang
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Yuanting Cui
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Feng Gao
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Jian Zhong
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Yunfei Pu
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Yu Zhao
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Zhencheng Yan
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - William J Arendshorst
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Bernd Nilius
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Jing Chen
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Daoyan Liu
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.)
| | - Zhiming Zhu
- From the Department of Hypertension and Endocrinology, Center for Hypertension and Metabolic Diseases, Daping Hospital, Third Military Medical University, Chongqing Institute of Hypertension, Chongqing, China (L.L., F.W., X.W., Y.L., Y.C., F.G., J.Z., Y.P., Y.Z., Z.Y., J.C., D.L., Z.Z.); Department of Cell Biology and Physiology, School of Medicine, University of North Carolina at Chapel Hill (W.J.A.); and Department of Cell Molecular Medicine, Laboratory Ion Channel Research, Campus Gasthuisberg, Leuven, Belgium (B.N.).
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Wang H, D'Ambrosio MA, Garvin JL, Ren Y, Carretero OA. Connecting tubule glomerular feedback in hypertension. Hypertension 2013; 62:738-45. [PMID: 23959547 DOI: 10.1161/hypertensionaha.113.01846] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In Dahl salt-sensitive rats (Dahl SS), glomerular capillary pressure increases in response to high salt intake and this is accompanied by significant glomerular injury compared with spontaneously hypertensive rats with similar blood pressure. Glomerular capillary pressure is controlled mainly by afferent arteriolar resistance, which is regulated by the vasoconstrictor tubule glomerular feedback (TGF) and the vasodilator connecting TGF (CTGF). We hypothesized that Dahl SS have a decreased TGF response and enhanced TGF resetting compared with spontaneously hypertensive rats, and that these differences are attributable in part to an increase in CTGF. In vivo, using micropuncture we measured stop-flow pressure (a surrogate of glomerular capillary pressure). TGF was calculated as the maximal decrease in stop-flow pressure caused by increasing nephron perfusion, TGF resetting as the attenuation in TGF induced by high salt diet, and CTGF as the difference in TGF response before and during CTGF inhibition with benzamil. Compared with spontaneously hypertensive rats, Dahl SS had (1) lower TGF responses in normal (6.6±0.1 versus 11.0±0.2 mm Hg; P<0.001) and high-salt diets (3.3±0.1 versus 10.1±0.3 mm Hg; P<0.001), (2) greater TGF resetting (3.3±0.1 versus 1.0±0.3 mm Hg; P<0.001), and (3) greater CTGF (3.4±0.4 versus 1.2±0.1 mm Hg; P<0.001). We conclude that Dahl SS have lower TGF and greater CTGF than spontaneously hypertensive rats, and that CTGF antagonizes TGF. Furthermore, CTGF is enhanced by a high-salt diet and contributes significantly to TGF resetting. Our findings may explain in part the increase in vasodilatation, glomerular capillary pressure, and glomerular damage in SS hypertension during high salt intake.
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Affiliation(s)
- Hong Wang
- Hypertension and Vascular Research Division, Department of Internal Medicine, Henry Ford Hospital, 2799 West Grand Blvd, Detroit, MI 48202.
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Oztekin O, Akyol M, Kalay S, Tezel G, Akcakus M, Oygur N. Investigation of the serum glucocorticoid kinase 1 gene in patients with transient tachypnea of the newborn. J Matern Fetal Neonatal Med 2013; 26:990-4. [PMID: 23339546 DOI: 10.3109/14767058.2013.766709] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE The aim of this study was to investigate whether there is a role of the serum glucocorticoid kinase (SGK) 1 gene, which has an effect on the control of the epithelial sodium channels. MATERIALS AND METHOD This study included patients who were diagnosed with transient tachypnea of the newborn (TTN) with more than 37 weeks of gestation. As the control group, healthy newborns of the same gestational age were included. From each group, within the first 5 d of their lives, 2 cc of whole blood was taken in EDTA tubes, and stored at -80 °C. The DNA extraction was performed. RESULTS There were 32 patients in the TTN, and also 32 patients in the control group. The heterozygous allele rs1057293 (3/28) and rs1743966 (8/28) were located in the encoder region of the SGK 1 gene. In addition, in encoding region of the SGK 1 gene, the Arg97Ile (1/28), which causes the amino acid changes, had a genotype frequency of 0.0357, and a mutation was identified in Arg97Ile. DISCUSSION We have defined polymorphisms rs1057293 and rs1743966 in the SGK 1 gene, and the Arg97Ile mutation, for the first time in patients with TTN. This pilot study gave us some clues about a genetic basis of TTN phenotype, next to the lack of the pulmonary maturation.
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Affiliation(s)
- Osman Oztekin
- Department of Pediatrics, Division of Neonatology, Akdeniz University Medical School, Antalya, Turkey
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12
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Investigation on genetic heterogeneity of α-subunit of the epithelial sodium channel in rat renal cortex. Bull Exp Biol Med 2012; 151:709-12. [PMID: 22485214 DOI: 10.1007/s10517-011-1422-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Genotypic variability of αENaC mRNA in adult rat kidney caused by deletion at the 3'-end of α-subunit DNA was studied by real-time PCR using specific probes with a fluorescent dye (TaqMan). It was found that mRNA deletion forms (a and b), products of alternative splicing of aENaC gene, are absent in the cortex of adult rat kidney.
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13
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Abstract
The epithelial Na(+) channel (ENaC) and acid-sensitive ion channel (ASIC) branches of the ENaC/degenerin superfamily of cation channels have drawn increasing attention as potential therapeutic targets in a variety of diseases and conditions. Originally thought to be solely expressed in fluid absorptive epithelia and in neurons, it has become apparent that members of this family exhibit nearly ubiquitous expression. Therapeutic opportunities range from hypertension, due to the role of ENaC in maintaining whole body salt and water homeostasis, to anxiety disorders and pain associated with ASIC activity. As a physiologist intrigued by the fundamental mechanics of salt and water transport, it was natural that Dale Benos, to whom this series of reviews is dedicated, should have been at the forefront of research into the amiloride-sensitive sodium channel. The cloning of ENaC and subsequently the ASIC channels has revealed a far wider role for this channel family than was previously imagined. In this review, we will discuss the known and potential roles of ENaC and ASIC subunits in the wide variety of pathologies in which these channels have been implicated. Some of these, such as the role of ENaC in Liddle's syndrome are well established, others less so; however, all are related in that the fundamental defect is due to inappropriate channel activity.
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Affiliation(s)
- Yawar J Qadri
- Department of Physiology and Biophysics, University of Alabama at Birmingham, AL 35294, USA
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14
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Zhao Q, Gu D, Hixson JE, Liu DP, Rao DC, Jaquish CE, Kelly TN, Lu F, Ma J, Mu J, Shimmin LC, Chen J, Mei H, Hamm LL, He J. Common Variants in Epithelial Sodium Channel Genes Contribute to Salt Sensitivity of Blood Pressure. ACTA ACUST UNITED AC 2011; 4:375-80. [DOI: 10.1161/circgenetics.110.958629] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Rare mutations of the epithelial sodium channel (ENaC) lead to mendelian forms of salt-sensitive hypertension or salt-wasting hypotension. We aimed to examine the association between common variants in the ENaC genes and salt sensitivity of blood pressure (BP).
Methods and Results—
A total of 1906 Han Chinese participated in the Genetic Epidemiology Network of Salt Sensitivity (GenSalt) study, which includes a 7-day low-sodium intake (51.3 mmol sodium/d) followed by a 7-day high-sodium intake (307.8 mmol sodium/d). Nine BP measurements were obtained at baseline and each intervention period using a random-zero sphygmomanometer. Single-nucleotide polymorphisms, both tagging and functional, from the 3 ENaC subunits, α, β, and γ (
SCNN1A, SCNN1B
, and
SCNN1G
), were genotyped. Multiple common single-nucleotide polymorphisms in
SCNN1G
were significantly associated with BP response to low-sodium intervention (rs4073930,
P
=1.7×10
−5
; rs4073291,
P
=1.1×10
−5
; rs7404408,
P
=1.9×10
−5
; rs5735,
P
=3.0×10
−4
; rs4299163,
P
=0.004; and rs4499238,
P
=0.002) even after correcting for multiple testing. For example, under an additive model, the minor allele G of SNP rs4073291 was associated with 1.33 mm Hg lower systolic BP reduction during low-sodium intervention.
Conclusions—
This large dietary sodium intervention study indicates that common variants of ENaC subunits may contribute to the variation of BP response to dietary sodium intake. Future studies are warranted to confirm these findings in an independent population and to identify functional variants for salt sensitivity.
Clinical Trial Registration—
URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00721721.
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Affiliation(s)
- Qi Zhao
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Dongfeng Gu
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - James E. Hixson
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - De-Pei Liu
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Dabeeru C. Rao
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Cashell E. Jaquish
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Tanika N. Kelly
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Fanghong Lu
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Jixiang Ma
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Jianjun Mu
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Lawrence C. Shimmin
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Jichun Chen
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Hao Mei
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - L. Lee Hamm
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
| | - Jiang He
- From the Department of Epidemiology (Q.Z., T.N.K., H.M., J.H.), Tulane University School of Public Health and Tropical Medicine, and the Department of Medicine (L.L.H., J.H.), Tulane University School of Medicine, New Orleans, LA; the Division of Population Genetics and Prevention, Cardiovascular Institute and Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College and National Center for Cardiovascular Diseases, Beijing, China (D.G., J.C.); Human Genetics Center,
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15
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Shehata MF. Article Commentary: The Alternatively Spliced Form “b” of the Epithelial Sodium Channel α subunit (α ENaC): Any Prior Evidence of its Existence? CLINICAL MEDICINE INSIGHTS: CARDIOLOGY 2010; 4:73-5. [PMID: 20842211 PMCID: PMC2937307 DOI: 10.4137/cmc.s5270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The epithelial sodium channel (ENaC) is critical in maintaining sodium balance across aldosterone-responsive epithelia. ENaC is a combined channel formed of three subunits (αβγ) with α ENaC subunit being the most critical for channel functionality. In a previous report, we have demonstrated the existence and mRNA expression levels of four alternatively spliced forms of the α ENaC subunit denoted by -a, -b, -c and -d in kidney cortex of Dahl S and R rats. Of the four alternatively spliced forms presently identified, α ENaC-b is considered the most interesting for the following reasons: Aside from being a salt-sensitive transcript, α ENaC-b mRNA expression is ∼32 fold higher than α ENaC wildtype in kidney cortex of Dahl rats. Additionally, the splice site used to generate α ENaC-b is conserved across species. Finally, α ENaC-b mRNA expression is significantly higher in salt-resistant Dahl R rats versus salt-sensitive Dahl S rats. As such, this commentary aims to highlight some of the previously published research articles that described the existence of an additional protein band on α ENaC western blots that could account for α ENaC-b in other rat species.
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Affiliation(s)
- Marlene F. Shehata
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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