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Demirci M, Hinton A, Kirabo A. Dendritic cell epithelial sodium channel induced inflammation and salt-sensitive hypertension. Curr Opin Nephrol Hypertens 2024; 33:145-153. [PMID: 38180118 PMCID: PMC10842661 DOI: 10.1097/mnh.0000000000000963] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2024]
Abstract
PURPOSE OF REVIEW Salt sensitivity of blood pressure (SSBP) is an independent risk factor for cardiovascular disease. Epithelial sodium channel (ENaC) plays a critical role in renal electrolyte and volume regulation and has been implicated in the pathogenesis of SSBP. This review describes recent advances regarding the role of ENaC-dependent inflammation in the development of SSBP. RECENT FINDINGS We recently found that sodium enters dendritic cells via ENaC, a process regulated by serum/glucocorticoid-regulated kinase 1 and epoxyeicosatrienoic acid 14,15. Sodium entry activates NADPH oxidase, leading to the production of isolevuglandins (IsoLGs). IsoLGs adduct self-proteins to form neoantigens in dendritic cells that activate T cells and result in the release of cytokines promoting sodium retention, kidney damage, and endothelial dysfunction in SSBP. Additionally, we described a novel mechanistic pathway involving ENaC and IsoLG-dependent NLRP3 inflammasome activation. These findings hold promise for the development of novel diagnostic biomarkers and therapeutic options for SSBP. SUMMARY The exact mechanisms underlying SSBP remain elusive. Recent advances in understanding the extrarenal role of ENaC have opened a new perspective, and further research efforts should focus on understanding the link between ENaC, inflammation, and SSBP.
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Affiliation(s)
- Mert Demirci
- Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center
- Vanderbilt Center for Immunobiology
- Vanderbilt Institute for Infection, Immunology and Inflammation
- Vanderbilt Institute for Global Health, Nashville, Tennessee, USA
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Aufy M, Hussein AM, Stojanovic T, Studenik CR, Kotob MH. Proteolytic Activation of the Epithelial Sodium Channel (ENaC): Its Mechanisms and Implications. Int J Mol Sci 2023; 24:17563. [PMID: 38139392 PMCID: PMC10743461 DOI: 10.3390/ijms242417563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 12/10/2023] [Accepted: 12/14/2023] [Indexed: 12/24/2023] Open
Abstract
Epithelial sodium channel (ENaC) are integral to maintaining salt and water homeostasis in various biological tissues, including the kidney, lung, and colon. They enable the selective reabsorption of sodium ions, which is a process critical for controlling blood pressure, electrolyte balance, and overall fluid volume. ENaC activity is finely controlled through proteolytic activation, a process wherein specific enzymes, or proteases, cleave ENaC subunits, resulting in channel activation and increased sodium reabsorption. This regulatory mechanism plays a pivotal role in adapting sodium transport to different physiological conditions. In this review article, we provide an in-depth exploration of the role of proteolytic activation in regulating ENaC activity. We elucidate the involvement of various proteases, including furin-like convertases, cysteine, and serine proteases, and detail the precise cleavage sites and regulatory mechanisms underlying ENaC activation by these proteases. We also discuss the physiological implications of proteolytic ENaC activation, focusing on its involvement in blood pressure regulation, pulmonary function, and intestinal sodium absorption. Understanding the mechanisms and consequences of ENaC proteolytic activation provides valuable insights into the pathophysiology of various diseases, including hypertension, pulmonary disorders, and various gastrointestinal conditions. Moreover, we discuss the potential therapeutic avenues that emerge from understanding these mechanisms, offering new possibilities for managing diseases associated with ENaC dysfunction. In summary, this review provides a comprehensive discussion of the intricate interplay between proteases and ENaC, emphasizing the significance of proteolytic activation in maintaining sodium and fluid balance in both health and disease.
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Affiliation(s)
- Mohammed Aufy
- Division of Pharmacology and Toxicology, Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (A.M.H.); (M.H.K.)
| | - Ahmed M. Hussein
- Division of Pharmacology and Toxicology, Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (A.M.H.); (M.H.K.)
- Department of Zoology, Faculty of Science, Al-Azhar University, Assiut 71524, Egypt
| | - Tamara Stojanovic
- Programme for Proteomics, Paracelsus Medical University, 5020 Salzburg, Austria;
| | - Christian R. Studenik
- Division of Pharmacology and Toxicology, Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (A.M.H.); (M.H.K.)
| | - Mohamed H. Kotob
- Division of Pharmacology and Toxicology, Department of Pharmaceutical Sciences, University of Vienna, 1090 Vienna, Austria; (A.M.H.); (M.H.K.)
- Department of Pathology, Faculty of Veterinary Medicine, Assiut University, Assiut 71515, Egypt
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Leung PYM, Katerelos M, Choy S, Cook N, Lee M, Paizis K, Abboud A, Manning JA, Mount PF, Power DA. Expression of NEDD4L and ENaC in Urinary Extracellular Vesicles in Pre-eclampsia. Hypertens Pregnancy 2023; 42:2232029. [PMID: 37417251 DOI: 10.1080/10641955.2023.2232029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
OBJECTIVE To assess changes in expression of renal epithelial sodium channel (ENaC) and NEDD4L, a ubiquitin ligase, in urinary extracellular vesicles (UEV) of pre-eclamptic women compared to normal pregnant controls. METHODS Urine was collected from pre-eclamptic women (PE, n = 20) or during normal pregnancy (NP, n = 20). UEV were separated by differential ultracentrifugation. NEDD4L, α-ENaC and γ-ENaC were identified by immunoblotting. RESULTS There was no difference in the expression of NEDD4L (p = 0.17) and α-ENaC (p = 0.10). PE subjects showed increased expression of γ-ENaC by 6.9-fold compared to NP (p < 0.0001). CONCLUSION ENaC expression is upregulated in UEV of pre-eclamptic subjects but was not associated with changes in NEDD4L.
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Affiliation(s)
- P Y M Leung
- Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Australia
- Department of Nephrology, Austin Health, Heidelberg, Australia
- Kidney Laboratory, Institute for Breathing and Sleep, Heidelberg, Australia
| | - M Katerelos
- Department of Nephrology, Austin Health, Heidelberg, Australia
- Kidney Laboratory, Institute for Breathing and Sleep, Heidelberg, Australia
| | - S Choy
- Department of Nephrology, Austin Health, Heidelberg, Australia
| | - N Cook
- Department of Nephrology, Austin Health, Heidelberg, Australia
| | - M Lee
- Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Australia
- Department of Nephrology, Austin Health, Heidelberg, Australia
- Kidney Laboratory, Institute for Breathing and Sleep, Heidelberg, Australia
| | - K Paizis
- Department of Nephrology, Austin Health, Heidelberg, Australia
| | - A Abboud
- Department of Obstetrics & Gynaecology, Mercy Hospital for Women, Heidelberg, Australia
| | - J A Manning
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia
| | - P F Mount
- Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Australia
- Department of Nephrology, Austin Health, Heidelberg, Australia
- Kidney Laboratory, Institute for Breathing and Sleep, Heidelberg, Australia
| | - D A Power
- Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Australia
- Department of Nephrology, Austin Health, Heidelberg, Australia
- Kidney Laboratory, Institute for Breathing and Sleep, Heidelberg, Australia
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Wang S, Ma J, Li X, Xian X, Tan G, Cai H, Yang B, Zhang A, Guo J, Gu G, Meng Z, Fu B. EGR-1 Contributes to Pulmonary Edema by Regulating the Epithelial Sodium Channel in Lipopolysaccharide-Induced Acute Lung Injury. Immunol Invest 2023; 52:925-939. [PMID: 37732637 DOI: 10.1080/08820139.2023.2256778] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
Acute lung injury (ALI) is a common lung disease with increasing morbidity and mortality rates due to the lack of specific drugs. Impaired alveolar fluid clearance (AFC) is a primary pathological feature of ALI. Epithelial sodium channel (ENaC) is a primary determinant in regulating the transport of Na+ and the clearance of alveolar edema fluid. Therefore, ENaC is an important target for the development of drugs for ALI therapy. However, the role of ENaC in the progression of ALI remains unclear. Inhibition of early growth response factor (EGR-1) expression has been reported to induce a protective effect on ALI; therefore, we evaluated whether EGR-1 participates in the progression of ALI by regulating ENaC-α in alveolar epithelium. We investigated the potential mechanism of EGR-1-mediated regulation of ENaC in ALI. We investigated whether EGR-1 aggravates the pulmonary edema response in ALI by regulating ENaC. ALI mouse models were established by intrabronchial injection of lipopolysaccharides (LPS). Lentiviruses with EGR-1 knockdown were transfected into LPS-stimulated A549 cells. We found that EGR-1 expression was upregulated in the lung tissues of ALI mice and in LPS-induced A549 cells, and was negatively correlated with ENaC-α expression. Knockdown of EGR-1 increased ENaC-α expression and relieved cellular edema in ALI. Moreover, EGR-1 regulated ENaC-α expression at the transcriptional level, and correspondingly promoted pulmonary edema and aggravated ALI symptoms. In conclusion, our study demonstrated that EGR-1 could promote pulmonary edema by downregulating ENaC-α at the transcriptional level in ALI. Our study provides a new potential therapeutic strategy for treatment of ALI.
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Affiliation(s)
- Song Wang
- Precision Biomedical Laboratory, Liaocheng People's Hospital, Liaocheng, China
| | - Jing Ma
- Office of Academic Research, Liaocheng People's Hospital, Liaocheng, China
| | - Xin Li
- Department of Clinical Laboratory, Zibo Central Hospital, Zibo, China
| | - Xinmiao Xian
- Precision Biomedical Laboratory, Liaocheng People's Hospital, Liaocheng, China
| | - Guikun Tan
- Pharmacy Department, Liaocheng Woman and Child Health Care Hospital, Liaocheng, China
| | - Hongwei Cai
- Department of Critical Care Medicine, Yantai Affiliated Hospital of Binzhou Medical University, Yantai, China
| | - Bingwu Yang
- Precision Biomedical Laboratory, Liaocheng People's Hospital, Liaocheng, China
| | - Anqi Zhang
- Central Laboratory, Liaocheng People's Hospital, Liaocheng, China
| | - Jianran Guo
- Precision Biomedical Laboratory, Liaocheng People's Hospital, Liaocheng, China
| | - Guohao Gu
- Precision Biomedical Laboratory, Liaocheng People's Hospital, Liaocheng, China
| | - Zhen Meng
- Biomedical Laboratory, Medical School of Liaocheng University, Liaocheng, China
| | - Bo Fu
- Precision Biomedical Laboratory, Liaocheng People's Hospital, Liaocheng, China
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Iwata Y, Deng Q, Kakizoe Y, Nakagawa T, Miyasato Y, Nakagawa M, Nishiguchi K, Nagayoshi Y, Narita Y, Izumi Y, Kuwabara T, Adachi M, Mukoyama M. A Serine Protease Inhibitor, Camostat Mesilate, Suppresses Urinary Plasmin Activity and Alleviates Hypertension and Podocyte Injury in Dahl Salt-Sensitive Rats. Int J Mol Sci 2023; 24:15743. [PMID: 37958726 PMCID: PMC10650472 DOI: 10.3390/ijms242115743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 10/25/2023] [Accepted: 10/28/2023] [Indexed: 11/15/2023] Open
Abstract
In proteinuric renal diseases, the serine protease (SP) plasmin activates the epithelial sodium channel (ENaC) by cleaving its γ subunit. We previously demonstrated that a high-salt (HS) diet provoked hypertension and proteinuria in Dahl salt-sensitive (DS) rats, accompanied by γENaC activation, which were attenuated by camostat mesilate (CM), an SP inhibitor. However, the effects of CM on plasmin activity in DS rats remain unclear. In this study, we investigated the effects of CM on plasmin activity, ENaC activation, and podocyte injury in DS rats. The DS rats were divided into the control diet, HS diet (8.0% NaCl), and HS+CM diet (0.1% CM) groups. After weekly blood pressure measurement and 24-h urine collection, the rats were sacrificed at 5 weeks. The HS group exhibited hypertension, massive proteinuria, increased urinary plasmin, and γENaC activation; CM treatment suppressed these changes. CM prevented plasmin(ogen) attachment to podocytes and mitigated podocyte injury by reducing the number of apoptotic glomerular cells, inhibiting protease-activated receptor-1 activation, and suppressing inflammatory and fibrotic cytokine expression. Our findings highlight the detrimental role of urinary plasmin in the pathogenesis of salt-sensitive hypertension and glomerular injury. Targeting plasmin with SP inhibitors, such as CM, may be a promising therapeutic approach for these conditions.
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Affiliation(s)
- Yasunobu Iwata
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
| | - Qinyuan Deng
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
| | - Yutaka Kakizoe
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
- Comprehensive Clinical Education, Training and Development Center, Kumamoto University Hospital, Kumamoto 860-8556, Japan
| | - Terumasa Nakagawa
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
| | - Yoshikazu Miyasato
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
| | - Miyuki Nakagawa
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
| | - Kayo Nishiguchi
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
| | - Yu Nagayoshi
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
| | - Yuki Narita
- Department of Pharmacy, Kumamoto University Hospital, Kumamoto 860-8556, Japan
| | - Yuichiro Izumi
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
| | - Takashige Kuwabara
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
| | - Masataka Adachi
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
| | - Masashi Mukoyama
- Department of Nephrology, Kumamoto University Graduate School of Medical Sciences, Kumamoto 860-8556, Japan
- Comprehensive Clinical Education, Training and Development Center, Kumamoto University Hospital, Kumamoto 860-8556, Japan
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Chen Y, Yu X, Yan Z, Zhang S, Zhang J, Guo W. Role of epithelial sodium channel-related inflammation in human diseases. Front Immunol 2023; 14:1178410. [PMID: 37559717 PMCID: PMC10407551 DOI: 10.3389/fimmu.2023.1178410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 06/29/2023] [Indexed: 08/11/2023] Open
Abstract
The epithelial sodium channel (ENaC) is a heterotrimer and is widely distributed throughout the kidneys, blood vessels, lungs, colons, and many other organs. The basic role of the ENaC is to mediate the entry of Na+ into cells; the ENaC also has an important regulatory function in blood pressure, airway surface liquid (ASL), and endothelial cell function. Aldosterone, serum/glucocorticoid kinase 1 (SGK1), shear stress, and posttranslational modifications can regulate the activity of the ENaC; some ion channels also interact with the ENaC. In recent years, it has been found that the ENaC can lead to immune cell activation, endothelial cell dysfunction, aggravated inflammation involved in high salt-induced hypertension, cystic fibrosis, pseudohypoaldosteronism (PHA), and tumors; some inflammatory cytokines have been reported to have a regulatory role on the ENaC. The ENaC hyperfunction mediates the increase of intracellular Na+, and the elevated exchange of Na+ with Ca2+ leads to an intracellular calcium overload, which is an important mechanism for ENaC-related inflammation. Some of the research on the ENaC is controversial or unclear; we therefore reviewed the progress of studies on the role of ENaC-related inflammation in human diseases and their mechanisms.
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Affiliation(s)
- Yabin Chen
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- National Organ Transplantation (Liver &Kidney Transplantation) Physician Training Centre, Zhengzhou, China
- National Regional Medical Treatment Centre of Henan Organ Transplantation, Zhengzhou, China
| | - Xiao Yu
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- National Organ Transplantation (Liver &Kidney Transplantation) Physician Training Centre, Zhengzhou, China
- National Regional Medical Treatment Centre of Henan Organ Transplantation, Zhengzhou, China
| | - Zhiping Yan
- Henan Organ Transplantation Centre, Zhengzhou, China
- Henan Engineering and Research Center for Diagnosis and Treatment of Hepatobiliary and Pancreatic Surgical Diseases, Zhengzhou, China
| | - Shuijun Zhang
- Henan Research Centre for Organ Transplantation, Zhengzhou, China
| | - Jiacheng Zhang
- Henan Key Laboratory for Digestive Organ Transplantation, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Wenzhi Guo
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Open and Key Laboratory for Hepatobiliary and Pancreatic Surgery and Digestive Organ Transplantation at Henan Universities, Zhengzhou, China
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Chen L, Yu T, Zhai Y, Nie H, Li X, Ding Y. Luteolin Enhances Transepithelial Sodium Transport in the Lung Alveolar Model: Integrating Network Pharmacology and Mechanism Study. Int J Mol Sci 2023; 24:10122. [PMID: 37373270 DOI: 10.3390/ijms241210122] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 06/07/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023] Open
Abstract
Luteolin (Lut), a natural flavonoid compound existing in Perilla frutescens (L.) Britton, has been proven to play a protective role in the following biological aspects: inflammatory, viral, oxidant, and tumor-related. Lut can alleviate acute lung injury (ALI), manifested mainly by preventing the accumulation of inflammation-rich edematous fluid, while the protective actions of Lut on transepithelial ion transport in ALI were seldom researched. We found that Lut could improve the lung appearance/pathological structure in lipopolysaccharide (LPS)-induced mouse ALI models and reduce the wet/dry weight ratio, bronchoalveolar protein, and inflammatory cytokines. Meanwhile, Lut upregulated the expression level of the epithelial sodium channel (ENaC) in both the primary alveolar epithelial type 2 (AT2) cells and three-dimensional (3D) alveolar epithelial organoid model that recapitulated essential structural and functional aspects of the lung. Finally, by analyzing the 84 interaction genes between Lut and ALI/acute respiratory distress syndrome using GO and KEGG enrichment of network pharmacology, we found that the JAK/STAT signaling pathway might be involved in the network. Experimental data by knocking down STAT3 proved that Lut could reduce the phosphorylation of JAK/STAT and enhance the level of SOCS3, which abrogated the inhibition of ENaC expression induced by LPS accordingly. The evidence supported that Lut could attenuate inflammation-related ALI by enhancing transepithelial sodium transport, at least partially, via the JAK/STAT pathway, which may offer a promising therapeutic strategy for edematous lung diseases.
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Affiliation(s)
- Lei Chen
- Department of Pharmacology, School of Pharmacy, China Medical University, Shenyang 110122, China
| | - Tong Yu
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang 110122, China
| | - Yiman Zhai
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang 110122, China
| | - Hongguang Nie
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang 110122, China
| | - Xin Li
- Department of Chemistry, School of Forensic Medicine, China Medical University, Shenyang 110122, China
- Liaoning Province Key Laboratory of Forensic Bio-Evidence Sciences, Shenyang 110122, China
- Center of Forensic Investigation, China Medical University, Shenyang 110122, China
| | - Yan Ding
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang 110122, China
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Saha B, Shabbir W, Takagi E, Duan XP, Leite Dellova DCA, Demko J, Manis A, Loffing-Cueni D, Loffing J, Sørensen MV, Wang WH, Pearce D. Potassium Activates mTORC2-dependent SGK1 Phosphorylation to Stimulate Epithelial Sodium Channel: Role in Rapid Renal Responses to Dietary Potassium. J Am Soc Nephrol 2023; 34:1019-1038. [PMID: 36890646 PMCID: PMC10278851 DOI: 10.1681/asn.0000000000000109] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 02/06/2023] [Indexed: 03/10/2023] Open
Abstract
SIGNIFICANCE STATEMENT Rapid renal responses to ingested potassium are essential to prevent hyperkalemia and also play a central role in blood pressure regulation. Although local extracellular K + concentration in kidney tissue is increasingly recognized as an important regulator of K + secretion, the underlying mechanisms that are relevant in vivo remain controversial. To assess the role of the signaling kinase mTOR complex-2 (mTORC2), the authors compared the effects of K + administered by gavage in wild-type mice and knockout mice with kidney tubule-specific inactivation of mTORC2. They found that mTORC2 is rapidly activated to trigger K + secretion and maintain electrolyte homeostasis. Downstream targets of mTORC2 implicated in epithelial sodium channel regulation (SGK1 and Nedd4-2) were concomitantly phosphorylated in wild-type, but not knockout, mice. These findings offer insight into electrolyte physiologic and regulatory mechanisms. BACKGROUND Increasing evidence implicates the signaling kinase mTOR complex-2 (mTORC2) in rapid renal responses to changes in plasma potassium concentration [K + ]. However, the underlying cellular and molecular mechanisms that are relevant in vivo for these responses remain controversial. METHODS We used Cre-Lox-mediated knockout of rapamycin-insensitive companion of TOR (Rictor) to inactivate mTORC2 in kidney tubule cells of mice. In a series of time-course experiments in wild-type and knockout mice, we assessed urinary and blood parameters and renal expression and activity of signaling molecules and transport proteins after a K + load by gavage. RESULTS A K + load rapidly stimulated epithelial sodium channel (ENaC) processing, plasma membrane localization, and activity in wild-type, but not in knockout, mice. Downstream targets of mTORC2 implicated in ENaC regulation (SGK1 and Nedd4-2) were concomitantly phosphorylated in wild-type, but not knockout, mice. We observed differences in urine electrolytes within 60 minutes, and plasma [K + ] was greater in knockout mice within 3 hours of gavage. Renal outer medullary potassium (ROMK) channels were not acutely stimulated in wild-type or knockout mice, nor were phosphorylation of other mTORC2 substrates (PKC and Akt). CONCLUSIONS The mTORC2-SGK1-Nedd4-2-ENaC signaling axis is a key mediator of rapid tubule cell responses to increased plasma [K + ] in vivo . The effects of K + on this signaling module are specific, in that other downstream mTORC2 targets, such as PKC and Akt, are not acutely affected, and ROMK and Large-conductance K + (BK) channels are not activated. These findings provide new insight into the signaling network and ion transport systems that underlie renal responses to K +in vivo .
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Affiliation(s)
- Bidisha Saha
- Department of Medicine, Division of Nephrology, Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California
| | - Waheed Shabbir
- Department of Medicine, Division of Nephrology, Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California
| | - Enzo Takagi
- Department of Medicine, Division of Nephrology, Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California
| | - Xin-Peng Duan
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - Deise Carla Almeida Leite Dellova
- Department of Medicine, Division of Nephrology, Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California
- Current address: Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga, Sao Paulo, Brazil
| | - John Demko
- Department of Medicine, Division of Nephrology, Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California
| | - Anna Manis
- Department of Medicine, Division of Nephrology, Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California
| | | | | | - Mads Vaarby Sørensen
- Department of Biomedicine, Unit of Physiology, Aarhus University, Aarhus, Denmark
| | - Wen-Hui Wang
- Department of Pharmacology, New York Medical College, Valhalla, New York
| | - David Pearce
- Department of Medicine, Division of Nephrology, Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, California
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Ellison DH, McCormick JA. mTORC2, a Novel " Twist " on the Epithelial Sodium Channel (ENaC). J Am Soc Nephrol 2023; 34:937-938. [PMID: 37052952 PMCID: PMC10278834 DOI: 10.1681/asn.0000000000000131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/14/2023] Open
Affiliation(s)
- David H. Ellison
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
- Oregon Clinical and Translational Research Institute, Oregon Health and Science University, Portland, Oregon
- VA Portland Health Care System, Portland, Oregon
| | - James A. McCormick
- Division of Nephrology and Hypertension, Department of Medicine, Oregon Health and Science University, Portland, Oregon
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10
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Lemmens-Gruber R, Tzotzos S. The Epithelial Sodium Channel-An Underestimated Drug Target. Int J Mol Sci 2023; 24:ijms24097775. [PMID: 37175488 PMCID: PMC10178586 DOI: 10.3390/ijms24097775] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/14/2023] [Accepted: 04/15/2023] [Indexed: 05/15/2023] Open
Abstract
Epithelial sodium channels (ENaC) are part of a complex network of interacting biochemical pathways and as such are involved in several disease states. Dependent on site and type of mutation, gain- or loss-of-function generated symptoms occur which span from asymptomatic to life-threatening disorders such as Liddle syndrome, cystic fibrosis or generalized pseudohypoaldosteronism type 1. Variants of ENaC which are implicated in disease assist further understanding of their molecular mechanisms in order to create models for specific pharmacological targeting. Identification and characterization of ENaC modifiers not only furthers our basic understanding of how these regulatory processes interact, but also enables discovery of new therapeutic targets for the disease conditions caused by ENaC dysfunction. Numerous test compounds have revealed encouraging results in vitro and in animal models but less in clinical settings. The EMA- and FDA-designated orphan drug solnatide is currently being tested in phase 2 clinical trials in the setting of acute respiratory distress syndrome, and the NOX1/ NOX4 inhibitor setanaxib is undergoing clinical phase 2 and 3 trials for therapy of primary biliary cholangitis, liver stiffness, and carcinoma. The established ENaC blocker amiloride is mainly used as an add-on drug in the therapy of resistant hypertension and is being studied in ongoing clinical phase 3 and 4 trials for special applications. This review focuses on discussing some recent developments in the search for novel therapeutic agents.
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Affiliation(s)
- Rosa Lemmens-Gruber
- Department of Pharmaceutical Sciences, Division of Pharmacology and Toxicology, University of Vienna, A-1090 Vienna, Austria
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Obayashi N, Sakayori N, Kawaguchi H, Sugita M. Effect of irinotecan administration on amiloride-sensitive sodium taste responses in mice. Eur J Oral Sci 2023; 131:e12922. [PMID: 36852977 DOI: 10.1111/eos.12922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 01/25/2023] [Indexed: 03/01/2023]
Abstract
Taste alteration is a frequently reported side effect in patients receiving the chemotherapeutic agent, irinotecan. However, the way in which irinotecan causes taste disturbance and the type of taste impairment that is affected remain elusive. Here, we used the two-bottle preference test to characterize behavioral taste responses and employed immunohistochemical analyses to clarify the types and mechanisms of taste alteration induced, in mice, by irinotecan administration. Irinotecan administration resulted in a reduced intake of sodium taste solution but had no effect on sweet taste responses, as determined in the two-bottle preference test. In the presence of amiloride, which inhibits the function of the epithelial sodium channel (ENaC) in the periphery, the intake of sodium taste solution was comparable between the irinotecan-treated and control groups. Immunohistochemical analyses revealed that α-ENaC immunoreactivity detected in taste bud cells decreased slowly after irinotecan administration, and that administration of irinotecan had little effect on the number of cells expressing the cellular proliferation marker, Ki67, within or around taste buds. Our results imply that irinotecan administration may be responsible for altered behavioral sodium taste responses originating from ENaC function in the periphery, while being accompanied by the reduction of α-ENaC expression at the apical membrane of taste receptor cells without disturbing taste cell renewal.
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Affiliation(s)
- Nami Obayashi
- Department of Physiology and Oral Physiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
- Department of General Dentistry, Hiroshima University Hospital, Hiroshima, Japan
| | - Nobuyuki Sakayori
- Department of Physiology and Oral Physiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
| | - Hiroyuki Kawaguchi
- Department of General Dentistry, Hiroshima University Hospital, Hiroshima, Japan
| | - Makoto Sugita
- Department of Physiology and Oral Physiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan
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Wang T, Zhai Y, Xue H, Zhou W, Ding Y, Nie H. Regulation of Epithelial Sodium Transport by SARS-CoV-2 Is Closely Related with Fibrinolytic System-Associated Proteins. Biomolecules 2023; 13:biom13040578. [PMID: 37189326 DOI: 10.3390/biom13040578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/08/2023] [Accepted: 03/21/2023] [Indexed: 05/17/2023] Open
Abstract
Dyspnea and progressive hypoxemia are the main clinical features of patients with coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Pulmonary pathology shows diffuse alveolar damage with edema, hemorrhage, and the deposition of fibrinogens in the alveolar space, which are consistent with the Berlin Acute Respiratory Distress Syndrome Criteria. The epithelial sodium channel (ENaC) is a key channel protein in alveolar ion transport and the rate-limiting step for pulmonary edema fluid clearance, the dysregulation of which is associated with acute lung injury/acute respiratory distress syndrome. The main protein of the fibrinolysis system, plasmin, can bind to the furin site of γ-ENaC and induce it to an activation state, facilitating pulmonary fluid reabsorption. Intriguingly, the unique feature of SARS-CoV-2 from other β-coronaviruses is that the spike protein of the former has the same furin site (RRAR) with ENaC, suggesting that a potential competition exists between SARS-CoV-2 and ENaC for the cleavage by plasmin. Extensive pulmonary microthrombosis caused by disorders of the coagulation and fibrinolysis system has also been seen in COVID-19 patients. To some extent, high plasmin (ogen) is a common risk factor for SARS-CoV-2 infection since an increased cleavage by plasmin accelerates virus invasion. This review elaborates on the closely related relationship between SARS-CoV-2 and ENaC for fibrinolysis system-related proteins, aiming to clarify the regulation of ENaC under SARS-CoV-2 infection and provide a novel reference for the treatment of COVID-19 from the view of sodium transport regulation in the lung epithelium.
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Affiliation(s)
- Tingyu Wang
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang 110122, China
| | - Yiman Zhai
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang 110122, China
| | - Hao Xue
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang 110122, China
| | - Wei Zhou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang 110122, China
| | - Yan Ding
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang 110122, China
| | - Hongguang Nie
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang 110122, China
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Fu Z, Zheng H, Kaewsaro K, Lambert J, Chen Y, Yang T. Mutagenesis of the cleavage site of (pro)renin receptor abrogates aldosterone-salt-induced hypertension and renal injury in mice. Am J Physiol Renal Physiol 2023; 324:F1-F11. [PMID: 36302140 PMCID: PMC9762973 DOI: 10.1152/ajprenal.00088.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 09/29/2022] [Accepted: 10/17/2022] [Indexed: 02/04/2023] Open
Abstract
Soluble (pro)renin receptor (sPRR), the extracellular domain of (pro)renin receptor (PRR), is primarily generated by site-1 protease and furin. It has been reported that sPRR functions as an important regulator of intrarenal renin contributing to angiotensin II (ANG II)-induced hypertension. Relatively, less is known for the function of sPRR in ANG II-independent hypertension such as mineralocorticoid excess. In the present study, we used a novel mouse model with mutagenesis of the cleavage site in PRR (termed as PRRR279V/L282V or mutant) to examine the phenotype during aldosterone (Aldo)-salt treatment. The hypertensive response of mutant mice to Aldo-salt treatment was blunted in parallel with the attenuated response of plasma volume expansion and renal medullary α-epithelial Na+ channel expression. Moreover, Aldo-salt-induced hypertrophy in the heart and kidney as well as proteinuria were improved, accompanied by blunted polydipsia and polyuria. Together, these results represent strong evidence favoring endogenous sPRR as a mediator of Aldo-salt-induced hypertension and renal injury.NEW & NOTEWORTHY We used a novel mouse model with mutagenesis of the cleavage site of PRR to support soluble PRR as an essential mediator of aldosterone-salt-induced hypertension and also as a potential therapeutic target for patients with mineralocorticoid excess. We firstly report that soluble PRR-dependent pathway medicates the Na+-retaining action of aldosterone in the distal nephron, which opens up a new area for a better understanding of the molecular basis of renal handling of Na+ balance and blood pressure.
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Affiliation(s)
- Ziwei Fu
- Division of Nephrology and Hypertension, University of Utah, Salt Lake City, Utah
| | - Huaqing Zheng
- Division of Nephrology and Hypertension, University of Utah, Salt Lake City, Utah
- Renal Section, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
| | - Kannaree Kaewsaro
- Division of Nephrology and Hypertension, University of Utah, Salt Lake City, Utah
| | - Jacob Lambert
- Division of Nephrology and Hypertension, University of Utah, Salt Lake City, Utah
| | - Yanting Chen
- Division of Nephrology and Hypertension, University of Utah, Salt Lake City, Utah
| | - Tianxin Yang
- Division of Nephrology and Hypertension, University of Utah, Salt Lake City, Utah
- Renal Section, Veterans Affairs Salt Lake City Health Care System, Salt Lake City, Utah
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Mareš Š, Filipovský J. Liddle syndrome. Vnitr Lek 2022; 68:8-11. [PMID: 36575060 DOI: 10.36290/vnl.2022.115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Liddle syndrome is an inherited form of arterial hypertension with autosomal dominant pattern of inheritance. It is caused by activating mutation of genes coding of the epithelial sodium channel in distal nephron. Mutation leads to excessive reabsorbtion of sodium ions and volume expansion resulting in arterial hypertension. Antoher typical laboratory findings are hypokalaemia, low levels of serum aldosteron and metabolic alkalosis. Phenotypic variability makes it difficult to identify patients with Liddle syndrome, often resulting in misdiagnosis and severe complications at early age. Genetic studies should be done to confirm the diagnosis. Therapy of Liddle syndrome is based on administration of epithelial sodium channel blocker amilorid.
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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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Matsumoto T, Doi S, Nakashima A, Ike T, Sasaki K, Masaki T. Upregulation of Mineralocorticoid Receptor Contributes to Development of Salt-Sensitive Hypertension after Ischemia-Reperfusion Injury in Rats. Int J Mol Sci 2022; 23:7831. [PMID: 35887178 DOI: 10.3390/ijms23147831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/08/2022] [Accepted: 07/15/2022] [Indexed: 02/06/2023] Open
Abstract
The ischemia-reperfusion injury (IRI) of rat kidneys is used as a model of acute kidney injury. Salt-sensitive hypertension occurs in rats after IRI, and the distal nephrons play important roles in the development of this condition. We investigated the role of the mineralocorticoid receptor (MR) in the progression of IRI-induced salt-sensitive hypertension in rats. Fourteen days after right-side nephrectomy, IRI was induced by clamping the left renal artery, with sham surgery performed as a control. IRI rats were provided with normal water or water with 1.0% NaCl (IRI/NaCl), or they were implanted with an osmotic mini-pump to infuse vehicle or aldosterone (IRI/Aldo). Esaxerenone, a non-steroidal MR blocker (MRB), was administered to IRI/NaCl and IRI/Aldo rats for 6 weeks. MR expression increased by day 7 post-IRI. Blood pressure and urinary protein excretion increased in IRI/NaCl and IRI/Aldo rats over the 6-week period, but these effects were negated by MRB administration. The MRB attenuated the expression of the gamma-epithelial sodium channel (ENaC) and renal damage. The ENaC inhibitor, amiloride, ameliorated hypertension and renal damage in IRI/NaCl and IRI/Aldo rats. Our findings thus showed that MR upregulation may play a pivotal role in ENaC-mediated sodium uptake in rats after IRI, resulting in the development of salt-sensitive hypertension in response to salt overload or the activation of the renin-angiotensin-aldosterone system.
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Deng W, Qi D, Tang XM, Deng XY, He J, Wang DX. THE WNK4/SPAK PATHWAY STIMULATES ALVEOLAR FLUID CLEARANCE BY UPREGULATION OF EPITHELIAL SODIUM CHANNEL IN MICE WITH LIPOPOLYSACCHARIDE-INDUCED ACUTE RESPIRATORY DISTRESS SYNDROME. Shock 2022; 58:68-77. [PMID: 35670456 PMCID: PMC9415224 DOI: 10.1097/shk.0000000000001945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/01/2022] [Accepted: 04/15/2022] [Indexed: 11/25/2022]
Abstract
ABSTRACT With-No lysine Kinases (WNKs) have been newly implicated in alveolar fluid clearance (AFC). Epithelial sodium channels (ENaCs) serve a vital role in AFC. The potential protective effect of WNK4 in acute respiratory distress syndrome (ARDS), mediated by ENaC-associated AFC was investigated in the study. A model of lipopolysaccharide (LPS)-induced ARDS was established in C57BL/6 mice. WNK4, Sterile 20-related proline-alanine-rich kinase (SPAK), small interfering RNA (siRNA)-WNK4 or siRNA-SPAK were transfected into mouse lung or primary alveolar epithelial type II (ATII) cells. AFC, bronchoalveolar lavage fluid and lung histomorphology were determined. The expression of ENaC was determined to investigate the regulation of AFC by WNK4-SPAK signaling pathway. Activation of WNK4-SPAK signaling improved lung injury and survival rate, with enhanced AFC and reduced pulmonary edema via the upregulation of ENaC in ARDS. In primary rat ATII cells, gene-silencing by siRNA transfection reduced ENaC expression and the level of WNK4-associated SPAK phosphorylation. Immunoprecipitation revealed that the level of neural precursor cell-expressed developmentally downregulated gene 4 (Nedd4-2) binding to ENaC was decreased as a result of WNK4-SPAK signaling. The present study demonstrated that the WNK4/SPAK pathway improved AFC during LPS-induced ARDS, which is mainly dependent on the upregulation of ENaC with Nedd4-2-mediated ubiquitination.
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Affiliation(s)
- Wang Deng
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Medical Research Center for Respiratory and Critical Care Medicine, Chongqing, China
| | - Di Qi
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Medical Research Center for Respiratory and Critical Care Medicine, Chongqing, China
| | - Xu-Mao Tang
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Medical Research Center for Respiratory and Critical Care Medicine, Chongqing, China
| | - Xin-Yu Deng
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Medical Research Center for Respiratory and Critical Care Medicine, Chongqing, China
| | - Jing He
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Medical Research Center for Respiratory and Critical Care Medicine, Chongqing, China
| | - Dao-Xin Wang
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Medical Research Center for Respiratory and Critical Care Medicine, Chongqing, China
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Chen L, Hou Y, Du D, Cui Y, Nie H, Ding Y. MiR-199a-3p in mouse bone marrow mesenchymal stem cell exosomes increases epithelial sodium channel expression in lung injury. Fundam Clin Pharmacol 2022; 36:1011-1019. [PMID: 35667855 DOI: 10.1111/fcp.12807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 05/18/2022] [Accepted: 06/05/2022] [Indexed: 11/28/2022]
Abstract
Acute lung injury (ALI) causes significant morbidity and mortality in critically ill patients, which often presents with extensive accumulation of activated inflammatory cells and diffused alveolar damage accompanied by oxidative stress. Exosomes are nanovesicles, which have notable anti-inflammatory and repair properties, thus alleviating the symptoms of ALI. Epithelial sodium channel (ENaC) is essential for the transepithelial absorption of Na+ and fluid from alveolar spaces. We studied the effects of bone marrow mesenchymal stem cell exosomes (BMSC-exo) on the apoptosis and protein expression of ENaC in primary mouse alveolar epithelial type 2 cells (AT 2 cells). Moreover, the change of miR-199a-3p in AT 2 cells was detected by qRT-PCR, and we studied the regulation of miR-199a-3p on ENaC protein expression. Our results demonstrated that BMSC-exo could not only improve viability and reduce apoptosis in AT 2 cells, but also enhance the expression of ENaC protein and miR-199a-3p. Meanwhile, the upregulation of miR-199a-3p resulted in increased expression of ENaC protein. In summary, the BMSC-exo could participate in the regulation of ENaC through miR-199a-3p originated from BMSC-exo, thereby providing a new pharmacological tool for the treatment of ALI.
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Affiliation(s)
- Lei Chen
- China Medical University, Shenyang, China
| | - Yapeng Hou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Danni Du
- Department of Anesthesiology, The First Hospital of China Medical University, Shenyang, China
| | - Yong Cui
- Department of Anesthesiology, The First Hospital of China Medical University, Shenyang, China
| | - Hongguang Nie
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yan Ding
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
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Mernea M, Ulăreanu RȘ, Cucu D, Al-Saedi JH, Pop CE, Fendrihan S, Anghelescu GDC, Mihăilescu DF. Epithelial Sodium Channel Inhibition by Amiloride Addressed with THz Spectroscopy and Molecular Modeling. Molecules 2022; 27:3271. [PMID: 35630748 PMCID: PMC9144217 DOI: 10.3390/molecules27103271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 05/08/2022] [Accepted: 05/18/2022] [Indexed: 11/16/2022] Open
Abstract
THz spectroscopy is important for the study of ion channels because it directly addresses the low frequency collective motions relevant for their function. Here we used THz spectroscopy to investigate the inhibition of the epithelial sodium channel (ENaC) by its specific blocker, amiloride. Experiments were performed on A6 cells' suspensions, which are cells overexpressing ENaC derived from Xenopus laevis kidney. THz spectra were investigated with or without amiloride. When ENaC was inhibited by amiloride, a substantial increase in THz absorption was noticed. Molecular modeling methods were used to explain the observed spectroscopic differences. THz spectra were simulated using the structural models of ENaC and ENaC-amiloride complexes built here. The agreement between the experiment and the simulations allowed us to validate the structural models and to describe the amiloride dynamics inside the channel pore. The amiloride binding site validated using THz spectroscopy agrees with previous mutagenesis studies. Altogether, our results show that THz spectroscopy can be successfully used to discriminate between native and inhibited ENaC channels and to characterize the dynamics of channels in the presence of their specific antagonist.
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Affiliation(s)
- Maria Mernea
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
| | - Roxana Ștefania Ulăreanu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
| | - Dana Cucu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
| | - Jasim Hafedh Al-Saedi
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
| | - Cristian-Emilian Pop
- Department of Biochemistry and Molecular Biology, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania;
- Non-Governmental Research Organization Biologic, 14 Schitului Str., 032044 Bucharest, Romania;
| | - Sergiu Fendrihan
- Non-Governmental Research Organization Biologic, 14 Schitului Str., 032044 Bucharest, Romania;
- Faculty of Medicine, University “Vasile Goldis”, Bulevardul Revoluției 94, 310025 Arad, Romania
| | - Giorgiana Diana Carmen Anghelescu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
| | - Dan Florin Mihăilescu
- Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, 91–95 Splaiul Independenței Str., 050095 Bucharest, Romania; (M.M.); (R.Ș.U.); (J.H.A.-S.); (G.D.C.A.); (D.F.M.)
- Biometric Psychiatric Genetics Research Unit, Alexandru Obregia Psychiatric Hospital, 10 Șoseaua Berceni Str., 041914 Bucharest, Romania
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Abstract
Proteases are fundamental for a plethora of biological processes, including signalling and tissue remodelling, and dysregulated proteolytic activity can result in pathogenesis. In this review, we focus on a subclass of membrane‐bound and soluble proteases that are defined as channel‐activating proteases (CAPs), since they induce Na+ ion transport through an autocrine mechanism when co‐expressed with the highly amiloride‐sensitive epithelial sodium channel (ENaC) in Xenopus oocytes. These experiments first identified CAP1 (channel‐activating protease 1, prostasin) followed by CAP2 (channel‐activating protease 2, TMPRSS4) and CAP3 (channel‐activating protease 3, matriptase) as in vitro mediators of ENaC current. Since then, more serine‐, cysteine‐ and metalloproteases were confirmed as in vitro CAPs that potentially cleave and regulate ENaC, and thus this nomenclature was not further followed, but is accepted as functional term or alias. The precise mechanism of ENaC modulation by proteases has not been fully elucidated. Studies in organ‐specific protease knockout models revealed evidence for their role in increasing ENaC activity, although the proteases responsible for ENaC activation are yet to be identified. We summarize recent findings in animal models of these CAPs with respect to their implication in ENaC activation. We discuss the consequences of dysregulated CAPs underlying epithelial phenotypes in pathophysiological conditions, and the role of selected protease inhibitors. We believe that these proteases may present interesting therapeutic targets for diseases with aberrant sodium homoeostasis.
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Affiliation(s)
- Deepika Anand
- Department of Biomedical Sciences University of Lausanne Lausanne Switzerland
- National Center of Competence in Research, Kidney.CH Lausanne Switzerland
| | - Edith Hummler
- Department of Biomedical Sciences University of Lausanne Lausanne Switzerland
- National Center of Competence in Research, Kidney.CH Lausanne Switzerland
| | - Olivia J. Rickman
- Department of Biomedical Sciences University of Lausanne Lausanne Switzerland
- National Center of Competence in Research, Kidney.CH Lausanne Switzerland
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Sure F, Bertog M, Afonso S, Diakov A, Rinke R, Madej MG, Wittmann S, Gramberg T, Korbmacher C, Ilyaskin AV. Transmembrane serine protease 2 (TMPRSS2) proteolytically activates the epithelial sodium channel (ENaC) by cleaving the channel's γ-subunit. J Biol Chem 2022; 298:102004. [PMID: 35504352 PMCID: PMC9163703 DOI: 10.1016/j.jbc.2022.102004] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 04/21/2022] [Accepted: 04/27/2022] [Indexed: 01/09/2023] Open
Abstract
The epithelial sodium channel (ENaC) is a heterotrimer consisting of α-, β-, and γ-subunits. Channel activation requires proteolytic release of inhibitory tracts from the extracellular domains of α-ENaC and γ-ENaC; however, the proteases involved in the removal of the γ-inhibitory tract remain unclear. In several epithelial tissues, ENaC is coexpressed with the transmembrane serine protease 2 (TMPRSS2). Here, we explored the effect of human TMPRSS2 on human αβγ-ENaC heterologously expressed in Xenopus laevis oocytes. We found that coexpression of TMPRSS2 stimulated ENaC-mediated whole-cell currents by approximately threefold, likely because of an increase in average channel open probability. Furthermore, TMPRSS2-dependent ENaC stimulation was not observed using a catalytically inactive TMPRSS2 mutant and was associated with fully cleaved γ-ENaC in the intracellular and cell surface protein fractions. This stimulatory effect of TMPRSS2 on ENaC was partially preserved when inhibiting its proteolytic activity at the cell surface using aprotinin but was abolished when the γ-inhibitory tract remained attached to its binding site following introduction of two cysteine residues (S155C–Q426C) to form a disulfide bridge. In addition, computer simulations and site-directed mutagenesis experiments indicated that TMPRSS2 can cleave γ-ENaC at sites both proximal and distal to the γ-inhibitory tract. This suggests a dual role of TMPRSS2 in the proteolytic release of the γ-inhibitory tract. Finally, we demonstrated that TMPRSS2 knockdown in cultured human airway epithelial cells (H441) reduced baseline proteolytic activation of endogenously expressed ENaC. Thus, we conclude that TMPRSS2 is likely to contribute to proteolytic ENaC activation in epithelial tissues in vivo.
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Affiliation(s)
- Florian Sure
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
| | - Marko Bertog
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
| | - Sara Afonso
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
| | - Alexei Diakov
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
| | - Ralf Rinke
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
| | - M Gregor Madej
- Department of Biophysics II/Structural Biology, University of Regensburg, Regensburg, Germany
| | - Sabine Wittmann
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsklinikum Erlangen, Institute of Clinical and Molecular Virology, Erlangen, Germany
| | - Thomas Gramberg
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsklinikum Erlangen, Institute of Clinical and Molecular Virology, Erlangen, Germany
| | - Christoph Korbmacher
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany.
| | - Alexandr V Ilyaskin
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Cellular and Molecular Physiology, Erlangen, Germany
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22
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Lucas R, Hadizamani Y, Enkhbaatar P, Csanyi G, Caldwell RW, Hundsberger H, Sridhar S, Lever AA, Hudel M, Ash D, Ushio-Fukai M, Fukai T, Chakraborty T, Verin A, Eaton DC, Romero M, Hamacher J. Dichotomous Role of Tumor Necrosis Factor in Pulmonary Barrier Function and Alveolar Fluid Clearance. Front Physiol 2022; 12:793251. [PMID: 35264975 PMCID: PMC8899333 DOI: 10.3389/fphys.2021.793251] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 11/30/2021] [Indexed: 02/04/2023] Open
Abstract
Alveolar-capillary leak is a hallmark of the acute respiratory distress syndrome (ARDS), a potentially lethal complication of severe sepsis, trauma and pneumonia, including COVID-19. Apart from barrier dysfunction, ARDS is characterized by hyper-inflammation and impaired alveolar fluid clearance (AFC), which foster the development of pulmonary permeability edema and hamper gas exchange. Tumor Necrosis Factor (TNF) is an evolutionarily conserved pleiotropic cytokine, involved in host immune defense against pathogens and cancer. TNF exists in both membrane-bound and soluble form and its mainly -but not exclusively- pro-inflammatory and cytolytic actions are mediated by partially overlapping TNFR1 and TNFR2 binding sites situated at the interface between neighboring subunits in the homo-trimer. Whereas TNFR1 signaling can mediate hyper-inflammation and impaired barrier function and AFC in the lungs, ligand stimulation of TNFR2 can protect from ventilation-induced lung injury. Spatially distinct from the TNFR binding sites, TNF harbors within its structure a lectin-like domain that rather protects lung function in ARDS. The lectin-like domain of TNF -mimicked by the 17 residue TIP peptide- represents a physiological mediator of alveolar-capillary barrier protection. and increases AFC in both hydrostatic and permeability pulmonary edema animal models. The TIP peptide directly activates the epithelial sodium channel (ENaC) -a key mediator of fluid and blood pressure control- upon binding to its α subunit, which is also a part of the non-selective cation channel (NSC). Activity of the lectin-like domain of TNF is preserved in complexes between TNF and its soluble TNFRs and can be physiologically relevant in pneumonia. Antibody- and soluble TNFR-based therapeutic strategies show considerable success in diseases such as rheumatoid arthritis, psoriasis and inflammatory bowel disease, but their chronic use can increase susceptibility to infection. Since the lectin-like domain of TNF does not interfere with TNF's anti-bacterial actions, while exerting protective actions in the alveolar-capillary compartments, it is currently evaluated in clinical trials in ARDS and COVID-19. A more comprehensive knowledge of the precise role of the TNFR binding sites versus the lectin-like domain of TNF in lung injury, tissue hypoxia, repair and remodeling may foster the development of novel therapeutics for ARDS.
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Affiliation(s)
- Rudolf Lucas
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States,*Correspondence: Rudolf Lucas,
| | - Yalda Hadizamani
- Lungen-und Atmungsstiftung Bern, Bern, Switzerland,Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, Bern, Switzerland
| | - Perenlei Enkhbaatar
- Department of Anesthesiology, University of Texas Medical Branch, Galveston, TX, United States
| | - Gabor Csanyi
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States
| | - Robert W. Caldwell
- Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States
| | - Harald Hundsberger
- Department of Medical Biotechnology, University of Applied Sciences, Krems, Austria,Department of Dermatology, University Hospital of the Paracelsus Medical University, Salzburg, Austria
| | - Supriya Sridhar
- Vascular Biology Center, Augusta University, Augusta, GA, United States
| | - Alice Ann Lever
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Martina Hudel
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Dipankar Ash
- Vascular Biology Center, Augusta University, Augusta, GA, United States
| | - Masuko Ushio-Fukai
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Tohru Fukai
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States,Charlie Norwood Veterans Affairs Medical Center, Augusta, GA, United States
| | - Trinad Chakraborty
- Institute for Medical Microbiology, Justus-Liebig University, Giessen, Germany
| | - Alexander Verin
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Douglas C. Eaton
- Department of Medicine, School of Medicine, Emory University, Atlanta, GA, United States
| | - Maritza Romero
- Vascular Biology Center, Augusta University, Augusta, GA, United States,Department of Pharmacology and Toxicology, Augusta University, Augusta, GA, United States,Department of Anesthesiology and Perioperative Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Jürg Hamacher
- Lungen-und Atmungsstiftung Bern, Bern, Switzerland,Pneumology, Clinic for General Internal Medicine, Lindenhofspital Bern, Bern, Switzerland,Medical Clinic V-Pneumology, Allergology, Intensive Care Medicine, and Environmental Medicine, Faculty of Medicine, University Medical Centre of the Saarland, Saarland University, Homburg, Germany,Institute for Clinical & Experimental Surgery, Faculty of Medicine, Saarland University, Homburg, Germany,Jürg Hamacher,
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23
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Wörner S, Bohnert BN, Wörn M, Xiao M, Janessa A, Birkenfeld AL, Amann K, Daniel C, Artunc F. Renal effects of the serine protease inhibitor aprotinin in healthy conscious mice. Acta Pharmacol Sin 2022; 43:111-120. [PMID: 33758357 PMCID: PMC8724274 DOI: 10.1038/s41401-021-00628-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 02/12/2021] [Indexed: 12/31/2022] Open
Abstract
Treatment with aprotinin, a broad-spectrum serine protease inhibitor with a molecular weight of 6512 Da, was associated with acute kidney injury, which was one of the reasons for withdrawal from the market in 2007. Inhibition of renal serine proteases regulating the epithelial sodium channel ENaC could be a possible mechanism. Herein, we studied the effect of aprotinin in wild-type 129S1/SvImJ mice on sodium handling, tubular function, and integrity under a control and low-salt diet. Mice were studied in metabolic cages, and aprotinin was delivered by subcutaneously implanted sustained release pellets (2 mg/day over 10 days). Mean urinary aprotinin concentration ranged between 642 ± 135 (day 2) and 127 ± 16 (day 8) µg/mL . Aprotinin caused impaired sodium preservation under a low-salt diet while stimulating excessive hyperaldosteronism and unexpectedly, proteolytic activation of ENaC. Aprotinin inhibited proximal tubular function leading to glucosuria and proteinuria. Plasma urea and cystatin C concentration increased significantly under aprotinin treatment. Kidney tissues from aprotinin-treated mice showed accumulation of intracellular aprotinin and expression of the kidney injury molecule 1 (KIM-1). In electron microscopy, electron-dense deposits were observed. There was no evidence for kidney injury in mice treated with a lower aprotinin dose (0.5 mg/day). In conclusion, high doses of aprotinin exert nephrotoxic effects by accumulation in the tubular system of healthy mice, leading to inhibition of proximal tubular function and counterregulatory stimulation of ENaC-mediated sodium transport.
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24
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Yin S, Ding M, Fan L, Yu X, Liang Z, Wu L, Gao Z, Lin L, Chen Y. Inhibition of Inflammation and Regulation of AQPs/ENaCs/Na +-K +-ATPase Mediated Alveolar Fluid Transport by Total Flavonoids Extracted From Nervilia fordii in Lipopolysaccharide-induced Acute Lung Injury. Front Pharmacol 2021; 12:603863. [PMID: 34887746 PMCID: PMC8650715 DOI: 10.3389/fphar.2021.603863] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/07/2021] [Indexed: 11/13/2022] Open
Abstract
Aims: The occurrence of vascular permeability pulmonary edema in acute lung injury (ALI) is related to the imbalance of alveolar fluid transport. Regulating the active transport of alveolar fluid by aquaporins (AQPs), epithelial sodium channels (ENaCs), and Na+-K+-ATPase can effectively reduce the edema fluid in the alveolar cavity and protect against ALI. We evaluated the therapeutic effects of total flavonoids, extracted from Nervilia fordii (TFENF), and investigated its potential mechanisms of alveolar fluid transport in a rat ALI model. Materials and methods: A model of lipopolysaccharide (LPS, 5 mg/kg)-induced ALI was established in Sprague-Dawley (SD) rats through the arteriae dorsalis penis. SD rats were divided into six groups, including the vehicle, LPS model, TFENF (6 mg/kg, 12 mg/kg, 24 mg/kg), and dexamethasone group (DEX group, 5 mg/kg). The wet-to-dry (W/D) lung weight ratio, oxygenation index, and histopathological observation were used to evaluate the therapeutic effect of TFENF. The mRNA expression of AQPs, ENaCs, and pro-inflammatory cytokines was determined using real-time polymerase chain reaction, whereas protein expression was determined using immunohistochemistry. The Na + -K + -ATPase activity was assessed using enzyme-linked immunosorbent assay. Results: LPS significantly stimulated the production of inflammatory mediators including tumor necrosis factor (TNF)-α and interleukin (IL)-1β, and disrupted the water transport balance in the alveolar cavity by inhibiting AQPs/ENaCs/Na + -K + -ATPase. Pretreatment with TFENF reduced the pathological damage and W/D ratio of the lungs and ameliorated the arterial blood oxygen partial pressure (PaO2) and oxygenation index. TFENF further decreased the mRNA level of TNF-α and IL-1β; increased the expression of AQP-1, AQP-5, αENaC, and βENaC; and increased Na + -K + -ATPase activity. Moreover, the regulation of AQPs, βENaC, and Na + -K + -ATPase and the inhibition of TNF-α and IL-1β by TFENF were found to be dose dependent. Conclusion: TFENF protects against LPS-induced ALI, at least in part, through the suppression of inflammatory cytokines and regulation of the active transport capacity of AQPs/ENaCs/Na + -K + -ATPase. These findings suggest the therapeutic potential of TFENF as phytomedicine to treat inflammation and pulmonary edema in ALI.
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Affiliation(s)
- Shuomiao Yin
- Department of Intensive Care Unit, The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China
| | - Meizhu Ding
- Department of Respiratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine and Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Long Fan
- Department of Respiratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine and Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Xuhua Yu
- Department of Respiratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine and Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Ziyao Liang
- Department of Respiratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine and Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China
| | - Lei Wu
- Department of Respiratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine and Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.,Guangdong-Hong Kong-Macau Joint Lab on Chinese Medicine and Immune Disease Research, Guangzhou, China
| | - Zhiling Gao
- Department of Intensive Care Unit, The First Affiliated Hospital of Anhui University of Chinese Medicine, Hefei, China
| | - Lin Lin
- Department of Respiratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine and Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.,Guangdong-Hong Kong-Macau Joint Lab on Chinese Medicine and Immune Disease Research, Guangzhou, China
| | - Yuanbin Chen
- Department of Respiratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, The Second Clinical College of Guangzhou University of Chinese Medicine and Guangdong Provincial Hospital of Chinese Medicine, Guangzhou, China.,Guangdong-Hong Kong-Macau Joint Lab on Chinese Medicine and Immune Disease Research, Guangzhou, China
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25
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Karacan Küçükali G, Çetinkaya S, Tunç G, Oğuz MM, Çelik N, Akkaş KY, Şenel S, Güleray Lafcı N, Savaş Erdeve Ş. Clinical Management in Systemic Type Pseudohypoaldosteronism Due to SCNN1B Variant and Literature Review. J Clin Res Pediatr Endocrinol 2021; 13:446-451. [PMID: 32840096 PMCID: PMC8638636 DOI: 10.4274/jcrpe.galenos.2020.2020.0107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Systemic pseudohypoaldosteronism (PHA) is a rare, salt-wasting syndrome that is caused by inactivating variants in genes encoding epithelial sodium channel subunits. Hyponatremia, hyperkalemia, metabolic acidosis, increased aldosterone and renin levels are expected findings in PHA. Clinical management is challenging due to high dose oral replacement therapy. Furthermore, patients with systemic PHA require life-long therapy. Here we report a patient with systemic PHA due to SCNN1B variant whose hyponatremia and hyperkalemia was detected at the 24th hour of life. Hyperkalemia did not improve with conventional treatments and dialysis was required. He also developed myocarditis and hypertension in follow-up. Challenges for diagnosis and treatment in this patient are discussed herein. In addition, published evidence concerning common features of patients with SCNN1B variant are reviewed.
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Affiliation(s)
- Gülin Karacan Küçükali
- University of Health Sciences Turkey, Dr. Sami Ulus Maternity, Child Health and Diseases Training and Research Hospital, Clinic of Pediatric Endocrinology, Ankara, Turkey,* Address for Correspondence: University of Health Sciences Turkey, Dr. Sami Ulus Maternity, Child Health and Diseases Training and Research Hospital, Clinic of Pediatric Endocrinology, Ankara, Turkey Phone: +90 533 764 84 26 E-mail:
| | - Semra Çetinkaya
- University of Health Sciences Turkey, Dr. Sami Ulus Maternity, Child Health and Diseases Training and Research Hospital, Clinic of Pediatric Endocrinology, Ankara, Turkey
| | - Gaffari Tunç
- Sivas Cumhuriyet University Faculty of Medicine, Department of Child Health and Diseases, Division of Neonatalogy, Sivas, Turkey
| | - M. Melek Oğuz
- University of Health Sciences Turkey, Dr. Sami Ulus Maternity, Child Health and Diseases Training and Research Hospital, Clinic of Pediatric, Ankara, Turkey
| | - Nurullah Çelik
- Sivas Cumhuriyet University Faculty of Medicine, Department of Child Health and Diseases, Division of Pediatric Endocrinology, Sivas, Turkey
| | - Kardelen Yağmur Akkaş
- University of Health Sciences Turkey, Dr. Sami Ulus Maternity, Child Health and Diseases Training and Research Hospital, Clinic of Pediatric, Ankara, Turkey
| | - Saliha Şenel
- University of Health Sciences Turkey, Dr. Sami Ulus Maternity, Child Health and Diseases Training and Research Hospital, Clinic of Pediatric, Ankara, Turkey
| | - Naz Güleray Lafcı
- University of Health Sciences Turkey, Dr. Sami Ulus Maternity, Child Health and Diseases Training and Research Hospital, Clinic of Medical Genetics, Ankara, Turkey
| | - Şenay Savaş Erdeve
- University of Health Sciences Turkey, Dr. Sami Ulus Maternity, Child Health and Diseases Training and Research Hospital, Clinic of Pediatric Endocrinology, Ankara, Turkey
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26
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Ding Y, Cui Y, Hou Y, Nie H. Bone marrow mesenchymal stem cell-conditioned medium facilitates fluid resolution via miR-214-activating epithelial sodium channels. MedComm (Beijing) 2021; 1:376-385. [PMID: 34766129 PMCID: PMC8491198 DOI: 10.1002/mco2.40] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 10/20/2020] [Accepted: 10/21/2020] [Indexed: 01/08/2023] Open
Abstract
Acute lung injury (ALI) is featured with severe lung edema at the early exudative phase, resulting from the imbalance of alveolar fluid turnover and clearance. Mesenchymal stem cells (MSCs) belong to multipotent stem cells, which have shown potential therapeutic effects during ALI. Of note, MSC‐conditioned medium (MSC‐CM) improved alveolar fluid clearance (AFC) in vivo, whereas the involvement of miRNAs is seldom known. We thus aim to explore the roles of miR‐214 in facilitating MSC‐CM mediated fluid resolution of impaired AFC. In this study, AFC was increased significantly by intratracheally administrated MSC‐CM in lipopolysaccharide‐treated mice. MSC‐CM augmented amiloride‐sensitive currents in intact H441 monolayers, and increased α‐epithelial sodium channel (α‐ENaC) expression level in H441 and mouse alveolar type 2 epithelial cells. Meanwhile, MSC‐CM increased the expression of miR‐214, which may participate in regulating ENaC expression and function. Our results suggested that MSC‐CM enhanced AFC in ALI mice in vivo through a novel mechanism, involving miR‐214 regulation of ENaC.
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Affiliation(s)
- Yan Ding
- Department of Stem Cells and Regenerative Medicine College of Basic Medical Science China Medical University Shenyang China
| | - Yong Cui
- Department of Anesthesiology the First Affiliated Hospital of China Medical University Shenyang China
| | - Yapeng Hou
- Department of Stem Cells and Regenerative Medicine College of Basic Medical Science China Medical University Shenyang China
| | - Hongguang Nie
- Department of Stem Cells and Regenerative Medicine College of Basic Medical Science China Medical University Shenyang China
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27
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Yan Y, Wang J, Yu L, Cui B, Wang H, Xiao X, Zhang Y, Zheng J, Wang J, Hui R, Wang Y. ANKRD36 Is Involved in Hypertension by Altering Expression of ENaC Genes. Circ Res 2021; 129:1067-1081. [PMID: 34615377 DOI: 10.1161/circresaha.121.319883] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Yupeng Yan
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (Y.Y., Jin'e Wang, L.Y., B.C., H.W., X.X., Y.Z., R.H., Y.W.)
| | - Jin'e Wang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (Y.Y., Jin'e Wang, L.Y., B.C., H.W., X.X., Y.Z., R.H., Y.W.)
| | - Liang Yu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (Y.Y., Jin'e Wang, L.Y., B.C., H.W., X.X., Y.Z., R.H., Y.W.)
| | - Bing Cui
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (Y.Y., Jin'e Wang, L.Y., B.C., H.W., X.X., Y.Z., R.H., Y.W.)
| | - Hongrui Wang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (Y.Y., Jin'e Wang, L.Y., B.C., H.W., X.X., Y.Z., R.H., Y.W.)
| | - Xiao Xiao
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (Y.Y., Jin'e Wang, L.Y., B.C., H.W., X.X., Y.Z., R.H., Y.W.)
| | - Yu Zhang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (Y.Y., Jin'e Wang, L.Y., B.C., H.W., X.X., Y.Z., R.H., Y.W.)
| | - Jun Zheng
- Rizhao Port Hospital, Shandong, China (J.Z., Jingjun Wang)
| | - Jingjun Wang
- Rizhao Port Hospital, Shandong, China (J.Z., Jingjun Wang)
| | - Rutai Hui
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (Y.Y., Jin'e Wang, L.Y., B.C., H.W., X.X., Y.Z., R.H., Y.W.)
| | - Yibo Wang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (Y.Y., Jin'e Wang, L.Y., B.C., H.W., X.X., Y.Z., R.H., Y.W.)
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28
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Vallée C, Howlin B, Lewis R. Ion Selectivity in the ENaC/DEG Family: A Systematic Review with Supporting Analysis. Int J Mol Sci 2021; 22:ijms222010998. [PMID: 34681656 PMCID: PMC8536179 DOI: 10.3390/ijms222010998] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 12/16/2022] Open
Abstract
The Epithelial Sodium Channel/Degenerin (ENaC/DEG) family is a superfamily of sodium-selective channels that play diverse and important physiological roles in a wide variety of animal species. Despite their differences, they share a high homology in the pore region in which the ion discrimination takes place. Although ion selectivity has been studied for decades, the mechanisms underlying this selectivity for trimeric channels, and particularly for the ENaC/DEG family, are still poorly understood. This systematic review follows PRISMA guidelines and aims to determine the main components that govern ion selectivity in the ENaC/DEG family. In total, 27 papers from three online databases were included according to specific exclusion and inclusion criteria. It was found that the G/SxS selectivity filter (glycine/serine, non-conserved residue, serine) and other well conserved residues play a crucial role in ion selectivity. Depending on the ion type, residues with different properties are involved in ion permeability. For lithium against sodium, aromatic residues upstream of the selectivity filter seem to be important, whereas for sodium against potassium, negatively charged residues downstream of the selectivity filter seem to be important. This review provides new perspectives for further studies to unravel the mechanisms of ion selectivity.
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Affiliation(s)
- Cédric Vallée
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford GU2 5XH, UK; (C.V.); (B.H.)
- Department of Chemistry, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7AL, UK
| | - Brendan Howlin
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford GU2 5XH, UK; (C.V.); (B.H.)
- Department of Chemistry, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
| | - Rebecca Lewis
- Leverhulme Quantum Biology Doctoral Training Centre, University of Surrey, Guildford GU2 5XH, UK; (C.V.); (B.H.)
- School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7AL, UK
- Correspondence:
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Soares AG, Contreras J, Archer CR, Mironova E, Berdeaux R, Stockand JD, Abd El-Aziz TM. Stimulation of the Epithelial Na + Channel in Renal Principal Cells by Gs-Coupled Designer Receptors Exclusively Activated by Designer Drugs. Front Physiol 2021; 12:725782. [PMID: 34512393 PMCID: PMC8425396 DOI: 10.3389/fphys.2021.725782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/28/2021] [Indexed: 11/29/2022] Open
Abstract
The activity of the Epithelial Na+ Channel (ENaC) in renal principal cells (PC) fine-tunes sodium excretion and consequently, affects blood pressure. The Gs-adenylyl cyclase-cAMP signal transduction pathway is believed to play a central role in the normal control of ENaC activity in PCs. The current study quantifies the importance of this signaling pathway to the regulation of ENaC activity in vivo using a knock-in mouse that has conditional expression of Gs-DREADD (designer receptors exclusively activated by designer drugs; GsD) in renal PCs. The GsD mouse also contains a cAMP response element-luciferase reporter transgene for non-invasive bioluminescence monitoring of cAMP signaling. Clozapine N-oxide (CNO) was used to selectively and temporally stimulate GsD. Treatment with CNO significantly increased luciferase bioluminescence in the kidneys of PC-specific GsD but not control mice. CNO also significantly increased the activity of ENaC in principal cells in PC-specific GsD mice compared to untreated knock-in mice and CNO treated littermate controls. The cell permeable cAMP analog, 8-(4-chlorophenylthio)adenosine 3′,5′-cyclic monophosphate, significantly increased the activity and expression in the plasma membrane of recombinant ENaC expressed in CHO and COS-7 cells, respectively. Treatment of PC-specific GsD mice with CNO rapidly and significantly decreased urinary Na+ excretion compared to untreated PC-specific GsD mice and treated littermate controls. This decrease in Na+ excretion in response to CNO in PC-specific GsD mice was similar in magnitude and timing as that induced by the selective vasopressin receptor 2 agonist, desmopressin, in wild type mice. These findings demonstrate for the first time that targeted activation of Gs signaling exclusively in PCs is sufficient to increase ENaC activity and decrease dependent urinary Na+ excretion in live animals.
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Affiliation(s)
- Antonio G Soares
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Jorge Contreras
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Crystal R Archer
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Elena Mironova
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Rebecca Berdeaux
- Department of Integrative Biology and Pharmacology, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - James D Stockand
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Tarek Mohamed Abd El-Aziz
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.,Zoology Department, Faculty of Science, Minia University, Minya, Egypt
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30
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Gettings SM, Maxeiner S, Tzika M, Cobain MRD, Ruf I, Benseler F, Brose N, Krasteva-Christ G, Vande Velde G, Schönberger M, Althaus M. Two functional epithelial sodium channel isoforms are present in rodents despite pronounced evolutionary pseudogenisation and exon fusion. Mol Biol Evol 2021; 38:5704-5725. [PMID: 34491346 PMCID: PMC8662647 DOI: 10.1093/molbev/msab271] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The epithelial sodium channel (ENaC) plays a key role in salt and water homeostasis in
tetrapod vertebrates. There are four ENaC subunits (α, β, γ, δ), forming heterotrimeric
αβγ- or δβγ-ENaCs. Although the physiology of αβγ-ENaC is well understood, for decades the
field has stalled with respect to δβγ-ENaC due to the lack of mammalian model organisms.
The SCNN1D gene coding for δ-ENaC was previously believed to be absent in
rodents, hindering studies using standard laboratory animals. We analyzed all currently
available rodent genomes and discovered that SCNN1D is present in rodents
but was independently lost in five rodent lineages, including the Muridae (mice and rats).
The independent loss of SCNN1D in rodent lineages may be constrained by
phylogeny and taxon-specific adaptation to dry habitats, however habitat aridity does not
provide a selection pressure for maintenance of SCNN1D across Rodentia. A
fusion of two exons coding for a structurally flexible region in the extracellular domain
of δ-ENaC appeared in the Hystricognathi (a group that includes guinea pigs). This
conserved pattern evolved at least 41 Ma and represents a new autapomorphic feature for
this clade. Exon fusion does not impair functionality of guinea pig (Cavia
porcellus) δβγ-ENaC expressed in Xenopus oocytes.
Electrophysiological characterization at the whole-cell and single-channel level revealed
conserved biophysical features and mechanisms controlling guinea pig αβγ- and δβγ-ENaC
function as compared with human orthologs. Guinea pigs therefore represent commercially
available mammalian model animals that will help shed light on the physiological function
of δ-ENaC.
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Affiliation(s)
- Sean M Gettings
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom.,Biomedical Imaging, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Belgium
| | - Stephan Maxeiner
- Institute for Anatomy and Cell Biology, Saarland University School of Medicine, Homburg, Germany
| | - Maria Tzika
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Matthew R D Cobain
- School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Irina Ruf
- Division of Messel Research and Mammalogy, Senckenberg Research Institute and Natural History Museum Frankfurt, Frankfurt am Main, Germany
| | - Fritz Benseler
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Gabriela Krasteva-Christ
- Institute for Anatomy and Cell Biology, Saarland University School of Medicine, Homburg, Germany
| | - Greetje Vande Velde
- Biomedical Imaging, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Belgium
| | - Matthias Schönberger
- Biomedical Imaging, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven, Belgium
| | - Mike Althaus
- Institute for Functional Gene Analytics, Department of Natural Sciences, Bonn-Rhein-Sieg University of Applied Sciences, Rheinbach, Germany
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31
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Deng W, He J, Tang XM, Li CY, Tong J, Qi D, Wang DX. Alcohol inhibits alveolar fluid clearance through the epithelial sodium channel via the A2 adenosine receptor in acute lung injury. Mol Med Rep 2021; 24:725. [PMID: 34396442 PMCID: PMC8404097 DOI: 10.3892/mmr.2021.12364] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/26/2021] [Indexed: 12/16/2022] Open
Abstract
Chronic alcohol abuse increases the risk of mortality and poor outcomes in patients with acute respiratory distress syndrome. However, the underlying mechanisms remain to be elucidated. The present study aimed to investigate the effects of chronic alcohol consumption on lung injury and clarify the signaling pathways involved in the inhibition of alveolar fluid clearance (AFC). In order to produce rodent models with chronic alcohol consumption, wild‑type C57BL/6 mice were treated with alcohol. A2a adenosine receptor (AR) small interfering (si)RNA or A2bAR siRNA were transfected into the lung tissue of mice and primary rat alveolar type II (ATII) cells. The rate of AFC in lung tissue was measured during exposure to lipopolysaccharide (LPS). Epithelial sodium channel (ENaC) expression was determined to investigate the mechanisms underlying alcohol‑induced regulation of AFC. In the present study, exposure to alcohol reduced AFC, exacerbated pulmonary edema and worsened LPS‑induced lung injury. Alcohol caused a decrease in cyclic adenosine monophosphate (cAMP) levels and inhibited α‑ENaC, β‑ENaC and γ‑ENaC expression levels in the lung tissue of mice and ATII cells. Furthermore, alcohol decreased α‑ENaC, β‑ENaC and γ‑ENaC expression levels via the A2aAR or A2bAR‑cAMP signaling pathways in vitro. In conclusion, the results of the present study demonstrated that chronic alcohol consumption worsened lung injury by aggravating pulmonary edema and impairing AFC. An alcohol‑induced decrease of α‑ENaC, β‑ENaC and γ‑ENaC expression levels by the A2AR‑mediated cAMP pathway may be responsible for the exacerbated effects of chronic alcohol consumption in lung injury.
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Affiliation(s)
- Wang Deng
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Jing He
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Xu-Mao Tang
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Chang-Yi Li
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Jin Tong
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Di Qi
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
| | - Dao-Xin Wang
- Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, P.R. China
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32
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Barros Lamus ER, Carotti V, de Vries CRS, Witsel F, Arntz OJ, van de Loo FAJ, Carvajal CA, Bindels RJM, Hoenderop JGJ, Rigalli JP. Extracellular vesicles regulate purinergic signaling and epithelial sodium channel expression in renal collecting duct cells. FASEB J 2021; 35:e21506. [PMID: 33811695 DOI: 10.1096/fj.202002559r] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 02/04/2021] [Accepted: 02/22/2021] [Indexed: 12/12/2022]
Abstract
Purinergic signaling regulates several renal physiological and pathophysiological processes. Extracellular vesicles (EVs) are nanoparticles released by most cell types, which, in non-renal tissues, modulate purinergic signaling. The aim of this study was to investigate the effect of EVs from renal proximal tubule (HK2) and collecting duct cells (HCD) on intra- and intersegment modulation of extracellular ATP levels, the underlying molecular mechanisms, and the impact on the expression of the alpha subunit of the epithelial sodium channel (αENaC). HK2 cells were exposed to HK2 EVs, while HCD cells were exposed to HK2 and HCD EVs. Extracellular ATP levels and αENaC expression were measured by chemiluminescence and qRT-PCR, respectively. ATPases in EV populations were identified by mass spectrometry. The effect of aldosterone was assessed using EVs from aldosterone-treated cells and urinary EVs (uEVs) from primary aldosteronism (PA) patients. HK2 EVs downregulated ectonucleoside-triphosphate-diphosphohydrolase-1 (ENTPD1) expression, increased extracellular ATP and downregulated αENaC expression in HCD cells. ENTPD1 downregulation could be attributed to increased miR-205-3p and miR-505 levels. Conversely, HCD EVs decreased extracellular ATP levels and upregulated αENaC expression in HCD cells, probably due to enrichment of 14-3-3 isoforms with ATPase activity. Pretreatment of donor cells with aldosterone or exposure to uEVs from PA patients enhanced the effects on extracellular ATP and αENaC expression. We demonstrated inter- and intrasegment modulation of renal purinergic signaling by EVs. Our findings postulate EVs as carriers of information along the renal tubules, whereby processes affecting EV release and/or cargo may impact on purinergically regulated processes.
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Affiliation(s)
- Eric R Barros Lamus
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Endocrinology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Valentina Carotti
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Christine R S de Vries
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Femke Witsel
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Onno J Arntz
- Department of Rheumatology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Fons A J van de Loo
- Department of Rheumatology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Cristian A Carvajal
- Department of Endocrinology, School of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - René J M Bindels
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Joost G J Hoenderop
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Juan P Rigalli
- Department of Physiology, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
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33
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Grant GJ, Mimche PN, Paine R, Liou TG, Qian WJ, Helms MN. Enhanced epithelial sodium channel activity in neonatal Scnn1b mouse lung attenuates high oxygen-induced lung injury. Am J Physiol Lung Cell Mol Physiol 2021; 321:L29-L41. [PMID: 33949206 PMCID: PMC8321857 DOI: 10.1152/ajplung.00538.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 04/26/2021] [Accepted: 04/27/2021] [Indexed: 11/22/2022] Open
Abstract
Prolonged oxygen therapy leads to oxidative stress, epithelial dysfunction, and acute lung injury in preterm infants and adults. Heterozygous Scnn1b mice, which overexpress lung epithelial sodium channels (ENaC), and their wild-type (WT) C57Bl6 littermates were utilized to study the pathogenesis of high fraction inspired oxygen ([Formula: see text])-induced lung injury. Exposure to high [Formula: see text] from birth to postnatal (PN) day 11 was used to model oxidative stress. Chronic exposure of newborn pups to 85% O2 increased glutathione disulfide (GSSG) and elevated the GSH/GSSG redox potential (Eh) of bronchoalveolar lavage fluid (BALF). Longitudinal X-ray imaging and Evans blue-labeled-albumin assays showed that chronic 85% O2 and acute GSSG (400 µM) exposures decreased alveolar fluid clearance (AFC) in the WT lung. Morphometric analysis of WT pups insufflated with GSSG (400 µM) or amiloride (1 µM) showed a reduction in alveologenesis and increased lung injury compared with age-matched control pups. The Scnn1b mouse lung phenotype was not further aggravated by chronic 85% O2 exposure. These outcomes support the hypothesis that exposure to hyperoxia increases GSSG, resulting in reduced lung fluid reabsorption due to inhibition of amiloride-sensitive ENaC. Flavin adenine dinucleotide (FADH2; 10 µM) was effective in recycling GSSG in vivo and promoted alveologenesis, but did not impact AFC nor attenuate fibrosis following high [Formula: see text] exposure. In conclusion, the data indicate that FADH2 may be pivotal for normal lung development, and show that ENaC is a key factor in promoting alveologenesis, sustaining AFC, and attenuating fibrotic lung injury caused by prolonged oxygen therapy in WT mice.
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Affiliation(s)
- Garett J Grant
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Patrice N Mimche
- Division of Microbiology and Immunology, Department of Pathology, University of Utah, Salt Lake City, Utah
| | - Robert Paine
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Theodore G Liou
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Wei-Jun Qian
- Biological Science Division, Pacific Northwest National Laboratory, Richland, Washington
| | - My N Helms
- Division of Respiratory, Critical Care and Occupational Pulmonary Medicine, Department of Internal Medicine, University of Utah, Salt Lake City, Utah
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34
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Corrêa JWN, Boaro KR, Sene LB, Polidoro JZ, Salles TA, Martins FL, Bendhack LM, Girardi ACC. Antiproteinuric and Hyperkalemic Mechanisms Activated by Dual Versus Single Blockade of the RAS in Renovascular Hypertensive Rats. Front Physiol 2021; 12:656460. [PMID: 34177612 PMCID: PMC8221266 DOI: 10.3389/fphys.2021.656460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/09/2021] [Indexed: 11/24/2022] Open
Abstract
This study aimed to investigate the antiproteinuric and hyperkalemic mechanisms activated by dual renin-angiotensin system (RAS) blockade in renovascular hypertensive rats (2-kidney 1-clip model [2K-1C]). Six weeks after clipping the left renal artery or sham operation (2K), rats were treated with losartan, enalapril, or both drugs for two weeks. We found that 2K-1C rats displayed higher tail-cuff blood pressure (BP), increased non-clipped kidney Ang II concentration, and more pronounced urinary albumin excretion than 2K. BP was decreased by the treatment with either enalapril or losartan, and the combination of both drugs promoted an additional antihypertensive effect in 2K-1C rats. Renal Ang II content and albuminuria were reduced by either enalapril or losartan in monotherapy and restored to control levels by dual RAS blockade. Albuminuria in 2K-1C rats was accompanied by downregulation of the glomerular slit protein podocin, reduction of the endocytic receptors megalin and cubilin, and a marked decrease in the expression of the ClC-5 chloride channel, compared to 2K animals. Treatment with losartan and enalapril in monotherapy or combination increased the expression of podocin, cubilin, and ClC-5. However, only the combined therapy normalized podocin, cubilin, and ClC-5 protein abundance in the non-clipped kidney of 2K-1C rats. Renovascular hypertensive 2K-1C rats had a lower concentration of plasma potassium compared to 2K rats. Single RAS blockade normalized potassium plasma concentration, whereas 2K-1C rats treated with dual RAS blockade exhibited hyperkalemia. Hypokalemia in 2K-1C rats was accompanied by an increase in the cleaved activated forms of α-ENaC and γ-ENaC and the expression of β-ENaC. Combined RAS blockade but not monotherapy significantly reduced the expression of these ENaC subunits in 2K-1C rats. Indeed, double RAS blockade reduced the abundance of cleaved-α-ENaC to levels lower than those of 2K rats. Collectively, these results demonstrate that the antiproteinuric effect of dual RAS blockade in 2K-1C rats is associated with the restored abundance of podocin and cubilin, and ClC-5. Moreover, double RAS blockade-induced hyperkalemia may be due, at least partially, to an exaggerated downregulation of cleaved α-ENaC in the non-clipped kidney of renovascular hypertensive rats.
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Affiliation(s)
- José Wilson N Corrêa
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor) University of São Paulo Medical School, São Paulo, Brazil.,Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Amazonas, Manaus, Brazil
| | - Karoline R Boaro
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor) University of São Paulo Medical School, São Paulo, Brazil
| | - Letícia B Sene
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor) University of São Paulo Medical School, São Paulo, Brazil
| | - Juliano Z Polidoro
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor) University of São Paulo Medical School, São Paulo, Brazil
| | - Thiago A Salles
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor) University of São Paulo Medical School, São Paulo, Brazil
| | - Flavia L Martins
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor) University of São Paulo Medical School, São Paulo, Brazil
| | - Lusiane M Bendhack
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Adriana C C Girardi
- Laboratory of Genetics and Molecular Cardiology, Heart Institute (InCor) University of São Paulo Medical School, São Paulo, Brazil
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35
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Wang QS, Liang C, Jiang S, Zhu D, Sun Y, Niu N, Yang X, Yang YC, Dong BH, Yao J, Yu CJ, Lou J, Tang LL, Wu MM, Zhang ZR, Ma HP. NaHS or Lovastatin Attenuates Cyclosporine A-Induced Hypertension in Rats by Inhibiting Epithelial Sodium Channels. Front Pharmacol 2021; 12:665111. [PMID: 34122084 PMCID: PMC8187945 DOI: 10.3389/fphar.2021.665111] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 04/19/2021] [Indexed: 12/01/2022] Open
Abstract
The use of cyclosporine A (CsA) in transplant recipients is limited due to its side effects of causing severe hypertension. We have previously shown that CsA increases the activity of the epithelial sodium channel (ENaC) in cultured distal nephron cells. However, it remains unknown whether ENaC mediates CsA-induced hypertension and how we could prevent hypertension. Our data show that the open probability of ENaC in principal cells of split-open cortical collecting ducts was significantly increased after treatment of rats with CsA; the increase was attenuated by lovastatin. Moreover, CsA also elevated the levels of intracellular cholesterol (Cho), intracellular reactive oxygen species (ROS) via activation of NADPH oxidase p47phox, serum- and glucocorticoid-induced kinase isoform 1 (Sgk1), and phosphorylated neural precursor cell–expressed developmentally downregulated protein 4–2 (p-Nedd4-2) in the kidney cortex. Lovastatin also abolished CsA-induced elevation of α-, ß-, and γ-ENaC expressions. CsA elevated systolic blood pressure in rats; the elevation was completely reversed by lovastatin (an inhibitor of cholesterol synthesis), NaHS (a donor of H2S which ameliorated CsA-induced elevation of reactive oxygen species), or amiloride (a potent ENaC blocker). These results suggest that CsA elevates blood pressure by increasing ENaC activity via a signaling cascade associated with elevation of intracellular ROS, activation of Sgk1, and inactivation of Nedd4-2 in an intracellular cholesterol-dependent manner. Our data also show that NaHS ameliorates CsA-induced hypertension by inhibition of oxidative stress.
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Affiliation(s)
- Qiu-Shi Wang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China.,Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
| | - Chen Liang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Shuai Jiang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Di Zhu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Yu Sun
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Na Niu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Xu Yang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Yan-Chao Yang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Bi-Han Dong
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Jie Yao
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Chang-Jiang Yu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Jie Lou
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Liang-Liang Tang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Ming-Ming Wu
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - Zhi-Ren Zhang
- Departments of Pharmacy and Cardiology, Harbin Medical University Cancer Hospital, Institute of Metabolic Disease, Heilongjiang Academy of Medical Science, Heilongjiang key laboratory for Metabolic disorder & cancer related cardiovascular diseases, NHC Key Laboratory of Cell Transplantation, Harbin Medical University & Key Laboratories of Education Ministry for Myocardial Ischemia Mechanism and Treatment, Harbin, China
| | - He-Ping Ma
- Department of Physiology, Emory University School of Medicine, Atlanta, GA, United States
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36
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Abstract
Salt taste is one of the 5 basic taste qualities. Depending on the concentration, table salt is perceived either as appetitive or aversive, suggesting the contribution of several mechanisms to salt taste, distinguishable by their sensitivity to the epithelial sodium channel (ENaC) blocker amiloride. A taste-specific knockout of the α-subunit of the ENaC revealed the relevance of this polypeptide for low-salt transduction, whereas the response to other taste qualities remained normal. The fully functional ENaC is composed of α-, β-, and γ-subunits. In taste tissue, however, the precise constitution of the channel and the cell population responsible for detecting table salt remain uncertain. In order to examine the cells and subunits building the ENaC, we generated mice carrying modified alleles allowing the synthesis of green and red fluorescent proteins in cells expressing the α- and β-subunit, respectively. Fluorescence signals were detected in all types of taste papillae and in taste buds of the soft palate and naso-incisor duct. However, the lingual expression patterns of the reporters differed depending on tongue topography. Additionally, immunohistochemistry for the γ-subunit of the ENaC revealed a lack of overlap between all potential subunits. The data suggest that amiloride-sensitive recognition of table salt is unlikely to depend on the classical ENaCs formed by α-, β-, and γ-subunits and ask for a careful investigation of the channel composition.
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Affiliation(s)
- Kristina Lossow
- Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee, Nuthetal, Germany
| | - Irm Hermans-Borgmeyer
- Transgenic Animal Unit, University Medical Center Hamburg-Eppendorf (ZMNH), Hamburg, Germany
| | - Wolfgang Meyerhof
- Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee, Nuthetal, Germany
| | - Maik Behrens
- Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke, Arthur-Scheunert-Allee, Nuthetal, Germany
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Essigke D, Ilyaskin AV, Wörn M, Bohnert BN, Xiao M, Daniel C, Amann K, Birkenfeld AL, Szabo R, Bugge TH, Korbmacher C, Artunc F. Zymogen-locked mutant prostasin (Prss8) leads to incomplete proteolytic activation of the epithelial sodium channel (ENaC) and severely compromises triamterene tolerance in mice. Acta Physiol (Oxf) 2021; 232:e13640. [PMID: 33650216 DOI: 10.1111/apha.13640] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 02/15/2021] [Accepted: 02/26/2021] [Indexed: 02/06/2023]
Abstract
AIM The serine protease prostasin (Prss8) is expressed in the distal tubule and stimulates proteolytic activation of the epithelial sodium channel (ENaC) in co-expression experiments in vitro. The aim of this study was to explore the role of prostasin in proteolytic ENaC activation in the kidney in vivo. METHODS We used genetically modified knockin mice carrying a Prss8 mutation abolishing proteolytic activity (Prss8-S238A) or a mutation leading to a zymogen-locked state (Prss8-R44Q). Mice were challenged with low sodium diet and diuretics. Regulation of ENaC activity by Prss8-S238A and Prss8-R44Q was studied in vitro using the Xenopus laevis oocyte expression system. RESULTS Co-expression of murine ENaC with Prss8-wt or Prss8-S238A in oocytes caused maximal proteolytic ENaC activation, whereas ENaC was activated only partially in oocytes co-expressing Prss8-R44Q. This was paralleled by a reduced proteolytic activity at the cell surface of Prss8-R44Q expressing oocytes. Sodium conservation under low sodium diet was preserved in Prss8-S238A and Prss8-R44Q mice but with higher plasma aldosterone concentrations in Prss8-R44Q mice. Treatment with the ENaC inhibitor triamterene over four days was tolerated in Prss8-wt and Prss8-S238A mice, whereas Prss8-R44Q mice developed salt wasting and severe weight loss associated with hyperkalemia and acidosis consistent with impaired ENaC function and renal failure. CONCLUSION Unlike proteolytically inactive Prss8-S238A, zymogen-locked Prss8-R44Q produces incomplete proteolytic ENaC activation in vitro and causes a severe renal phenotype in mice treated with the ENaC inhibitor triamterene. This indicates that Prss8 plays a role in proteolytic ENaC activation and renal function independent of its proteolytic activity.
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Affiliation(s)
- Daniel Essigke
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tuebingen Germany
| | - Alexandr V. Ilyaskin
- Institute of Cellular and Molecular Physiology Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Erlangen Germany
| | - Matthias Wörn
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tuebingen Germany
| | - Bernhard N. Bohnert
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tuebingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tuebingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tuebingen Germany
| | - Mengyun Xiao
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tuebingen Germany
| | - Christoph Daniel
- Institute of Pathology Department of Nephropathology Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Erlangen Germany
| | - Kerstin Amann
- Institute of Pathology Department of Nephropathology Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Erlangen Germany
| | - Andreas L. Birkenfeld
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tuebingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tuebingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tuebingen Germany
| | - Roman Szabo
- Proteases and Tissue Remodeling Section National Institute of Dental and Craniofacial ResearchNational Institutes of Health Bethesda MD USA
| | - Thomas H. Bugge
- Proteases and Tissue Remodeling Section National Institute of Dental and Craniofacial ResearchNational Institutes of Health Bethesda MD USA
| | - Christoph Korbmacher
- Institute of Cellular and Molecular Physiology Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Erlangen Germany
| | - Ferruh Artunc
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tuebingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tuebingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tuebingen Germany
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Pierandrei S, Truglio G, Ceci F, Del Porto P, Bruno SM, Castellani S, Conese M, Ascenzioni F, Lucarelli M. DNA Methylation Patterns Correlate with the Expression of SCNN1A, SCNN1B, and SCNN1G ( Epithelial Sodium Channel, ENaC) Genes. Int J Mol Sci 2021; 22:ijms22073754. [PMID: 33916525 PMCID: PMC8038451 DOI: 10.3390/ijms22073754] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/12/2021] [Accepted: 03/23/2021] [Indexed: 12/17/2022] Open
Abstract
The interplay between the cystic fibrosis transmembrane conductance regulator (CFTR) and the epithelial sodium channel (ENaC) in respiratory epithelia has a crucial role in the pathogenesis of cystic fibrosis (CF). The comprehension of the mechanisms of transcriptional regulation of ENaC genes is pivotal to better detail the pathogenic mechanism and the genotype-phenotype relationship in CF, as well as to realize therapeutic approaches based on the transcriptional downregulation of ENaC genes. Since we aimed to study the epigenetic transcriptional control of ENaC genes, an assessment of their expression and DNA methylation patterns in different human cell lines, nasal brushing samples, and leucocytes was performed. The mRNA expression of CFTR and ENaC subunits α, β and γ (respectively SCNN1A, SCNN1B, and SCNN1G genes) was studied by real time PCR. DNA methylation of 5'-flanking region of SCNN1A, SCNN1B, and SCNN1G genes was studied by HpaII/PCR. The levels of expression and DNA methylation of ENaC genes in the different cell lines, brushing samples, and leukocytes were very variable. The DNA regions studied of each ENaC gene showed different methylation patterns. A general inverse correlation between expression and DNA methylation was evidenced. Leukocytes showed very low expression of all the 3 ENaC genes corresponding to a DNA methylated pattern. The SCNN1A gene resulted to be the most expressed in some cell lines that, accordingly, showed a completely demethylated pattern. Coherently, a heavy and moderate methylated pattern of, respectively, SCNN1B and SCNN1G genes corresponded to low levels of expression. As exceptions, we found that dexamethasone treatment appeared to stimulate the expression of all the 3 ENaC genes, without an evident modulation of the DNA methylation pattern, and that in nasal brushing a considerable expression of all the 3 ENaC genes were found despite an apparent methylated pattern. At least part of the expression modulation of ENaC genes seems to depend on the DNA methylation patterns of specific DNA regions. This points to epigenetics as a controlling mechanism of ENaC function and as a possible therapeutic approach for CF.
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Affiliation(s)
- Silvia Pierandrei
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Roma, Italy; (S.P.); (G.T.); (F.C.); (S.M.B.)
| | - Gessica Truglio
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Roma, Italy; (S.P.); (G.T.); (F.C.); (S.M.B.)
| | - Fabrizio Ceci
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Roma, Italy; (S.P.); (G.T.); (F.C.); (S.M.B.)
| | - Paola Del Porto
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, Via dei Sardi 70, 00185 Roma, Italy;
| | - Sabina Maria Bruno
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Roma, Italy; (S.P.); (G.T.); (F.C.); (S.M.B.)
| | - Stefano Castellani
- Department of Biomedical Sciences and Human Oncology, University of Bari, Piazza Giulio Cesare 11, 70124 Bari, Italy;
| | - Massimo Conese
- Department of Medical and Surgical Sciences, University of Foggia, Via Napoli 121, 71122 Foggia, Italy;
| | - Fiorentina Ascenzioni
- Department of Biology and Biotechnology “Charles Darwin”, Sapienza University of Rome, Via dei Sardi 70, 00185 Roma, Italy;
- Correspondence: (F.A.); (M.L.)
| | - Marco Lucarelli
- Department of Experimental Medicine, Sapienza University of Rome, Viale Regina Elena 324, 00161 Roma, Italy; (S.P.); (G.T.); (F.C.); (S.M.B.)
- Pasteur Institute, Cenci Bolognetti Foundation, Sapienza University of Rome, Viale Regina Elena 291, 00161 Roma, Italy
- Correspondence: (F.A.); (M.L.)
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Hou Y, Zhou Z, Liu H, Zhang H, Ding Y, Cui Y, Nie H. Mesenchymal Stem Cell-Conditioned Medium Rescues LPS-Impaired ENaC Activity in Mouse Trachea via WNK4 Pathway. Curr Pharm Des 2021; 26:3601-3607. [PMID: 32003683 DOI: 10.2174/1381612826666200131141732] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 01/28/2020] [Indexed: 02/07/2023]
Abstract
BACKGROUND Airway epithelium plays an essential role in maintaining the homeostasis and function of respiratory system as the first line of host defense. Of note, epithelial sodium channel (ENaC) is one of the victims of LPS-induced airway injury. Regarding the great promise held by mesenchymal stem cells (MSCs) for regenerative medicine in the field of airway injury and the limitations of cell-based MSCs therapy, we focused on the therapeutic effect of MSCs conditioned medium (MSCs-CM) on the ENaC activity in mouse tracheal epithelial cells. METHODS Ussing chamber apparatus was applied to record the short-circuit currents in primary cultured mouse tracheal epithelial cells, which reflects the ENaC activity. Expressions of α and γ ENaC were measured at the protein and mRNA levels by western blot and real-time PCR, respectively. The expression of with-no-lysinekinase- 4 (WNK4) and ERK1/2 were measured at protein levels, and the relationship between WNK4 and ERK1/2 was determined by WNK4 knockdown. RESULTS MSCs-CM restored the LPS-impaired ENaC activity, as well as enhanced the mRNA and protein expressions of ENaC in primary cultured mouse tracheal epithelial cells. Meanwhile, WNK4 and ERK1/2, both negative-regulators of ENaC, were suppressed accordingly after the administration of MSCs-CM in LPS-induced airway injury. After WNK4 gene was knocked down by siRNA, the level of ERK1/2 phosphorylation decreased. CONCLUSION In light of the key role of ENaC in fluid reabsorption and the beneficial effects of MSCs-CM in the injury of airway epithelium, our results suggest that MSCs-CM is effective in alleviating LPS-induced ENaC dysfunction through WNK4-ERK1/2 pathway, which will provide a potent direction for the therapy of airway injury.
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Affiliation(s)
- Yapeng Hou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Zhiyu Zhou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Hongfei Liu
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Honglei Zhang
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yan Ding
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yong Cui
- Department of Anesthesiology, the First Affiliated Hospital of China Medical University, Shenyang, China
| | - Hongguang Nie
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
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Lu C, Yang W, Zhou J, Zhang Z, Gong Y, Hu F, Yu W, Dong X. Inhibition of Pre-B Cell Colony Enhancing Factor Reduces Lung Injury in Rats Receiving Cardiopulmonary Bypass. Drug Des Devel Ther 2021; 15:51-60. [PMID: 33442236 PMCID: PMC7800440 DOI: 10.2147/dddt.s281554] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 12/17/2020] [Indexed: 11/30/2022]
Abstract
Objective Pre-B cell colony enhancing factor (PBEF) is an important proinflammatory cytokine involved in acute lung injury. However, whether PBEF participates in lung injury caused by cardiopulmonary bypass (CPB) is still unknown. This study aimed to investigate the effects of silencing PBEF on lung injury and the sodium and water transport system in rats receiving CPB. Methods Morphological changes in lung tissues were evaluated using hematoxylin and eosin (H&E) staining. PBEF was detected using immunohistochemistry. The sodium and water transport system-related proteins and cellular signaling pathways were detected by Western blotting. Results Rats receiving CPB (model group) had more severe alveolar wall damage and higher expression of PBEF in free form than the control rats. Western blotting showed that the expression of PBEF, surfactant protein D (SP), aquaporin (AQP) 1, AQP5, and epithelial sodium channel (ENaC) was significantly higher in the lung tissue of CPB rats than control rats. By contrast, adenovirus-encoding sh-PBEF significantly reduced the expression of PBEF, SP, AQP1, AQP5, and ENaC in the lung tissues of rats treated with CPB. The phosphorylation levels of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), protein kinase B (AKT), and p38 mitogen-activated protein kinase (MAPK) were significantly increased in the lung tissue of rats that received CPB, and were downregulated by adenovirus-encoding sh-PBEF. Conclusion Adenovirus-encoding sh-PBEF could reduce lung injury and repair the sodium–water transport system in rats receiving CPB, likely through reducing MAPK, ERK1/2, and Akt signaling pathways.
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Affiliation(s)
- Chao Lu
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, People's Republic of China
| | - Wei Yang
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, People's Republic of China
| | - Jianliang Zhou
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, People's Republic of China
| | - Zulei Zhang
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, People's Republic of China
| | - Yi Gong
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, People's Republic of China
| | - Fajia Hu
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, People's Republic of China
| | - Wenpeng Yu
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, People's Republic of China
| | - Xiao Dong
- Department of Cardiovascular Surgery, The Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, People's Republic of China
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Xiao M, Bohnert BN, Aypek H, Kretz O, Grahammer F, Aukschun U, Wörn M, Janessa A, Essigke D, Daniel C, Amann K, Huber TB, Plow EF, Birkenfeld AL, Artunc F. Plasminogen deficiency does not prevent sodium retention in a genetic mouse model of experimental nephrotic syndrome. Acta Physiol (Oxf) 2021; 231:e13512. [PMID: 32455507 DOI: 10.1111/apha.13512] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/15/2020] [Accepted: 05/19/2020] [Indexed: 12/19/2022]
Abstract
AIM Sodium retention is the hallmark of nephrotic syndrome (NS) and mediated by the proteolytic activation of the epithelial sodium channel (ENaC) by aberrantly filtered serine proteases. Plasmin is highly abundant in nephrotic urine and has been proposed to be the principal serine protease responsible for ENaC activation in NS. However, a proof of the essential role of plasmin in experimental NS is lacking. METHODS We used a genetic mouse model of NS based on an inducible podocin knockout (Bl6-Nphs2tm3.1Antc *Tg(Nphs1-rtTA*3G)8Jhm *Tg(tetO-cre)1Jaw or nphs2Δipod ). These mice were crossed with plasminogen deficient mice (Bl6-Plgtm1Jld or plg-/- ) to generate double knockout mice (nphs2Δipod *plg-/- ). NS was induced after oral doxycycline treatment for 14 days and mice were followed for subsequent 14 days. RESULTS Uninduced nphs2Δipod *plg-/- mice had normal kidney function and sodium handling. After induction, proteinuria increased similarly in both nphs2Δipod *plg+/+ and nphs2Δipod *plg-/- mice. Western blot revealed the urinary excretion of plasminogen and plasmin in nphs2Δipod *plg+/+ mice which were absent in nphs2Δipod *plg-/- mice. After the onset of proteinuria, amiloride-sensitive natriuresis was increased compared to the uninduced state in both genotypes. Subsequently, urinary sodium excretion dropped in both genotypes leading to an increase in body weight and development of ascites. Treatment with the serine protease inhibitor aprotinin prevented sodium retention in both genotypes. CONCLUSIONS This study shows that mice lacking urinary plasminogen are not protected from ENaC-mediated sodium retention in experimental NS. This points to an essential role of other urinary serine proteases in the absence of plasminogen.
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Affiliation(s)
- Mengyun Xiao
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tübingen Germany
| | - Bernhard N. Bohnert
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
| | - Hande Aypek
- III. Department of Medicine University Medical Center Hamburg‐Eppendorf Hamburg Germany
| | - Oliver Kretz
- III. Department of Medicine University Medical Center Hamburg‐Eppendorf Hamburg Germany
| | - Florian Grahammer
- III. Department of Medicine University Medical Center Hamburg‐Eppendorf Hamburg Germany
| | - Ute Aukschun
- IV. Department of Medicine, Faculty and University Medical Center Freiburg Freiburg Germany
| | - Matthias Wörn
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tübingen Germany
| | - Andrea Janessa
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tübingen Germany
| | - Daniel Essigke
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tübingen Germany
| | - Christoph Daniel
- Institute of Nephropathology Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Erlangen Germany
| | - Kerstin Amann
- Institute of Nephropathology Friedrich‐Alexander University Erlangen‐Nürnberg (FAU) Erlangen Germany
| | - Tobias B. Huber
- III. Department of Medicine University Medical Center Hamburg‐Eppendorf Hamburg Germany
| | - Edward F. Plow
- Lerner Research InstituteCleveland Clinic Cleveland OH USA
| | - Andreas L. Birkenfeld
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
| | - Ferruh Artunc
- Department of Internal Medicine Division of Endocrinology, Diabetology and Nephrology University Hospital Tübingen Tübingen Germany
- Institute of Diabetes Research and Metabolic Diseases (IDM) of the Helmholtz Center Munich at the University Tübingen Tübingen Germany
- German Center for Diabetes Research (DZD) at the University Tübingen Tübingen Germany
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Li J, Liu L, Zhou X, Lu X, Liu X, Li G, Long J. Melatonin Attenuates Sepsis-Induced Acute Lung Injury Through Improvement of Epithelial Sodium Channel-Mediated Alveolar Fluid Clearance Via Activation of SIRT1/SGK1/Nedd4-2 Signaling Pathway. Front Pharmacol 2020; 11:590652. [PMID: 33362546 PMCID: PMC7759566 DOI: 10.3389/fphar.2020.590652] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 11/04/2020] [Indexed: 02/06/2023] Open
Abstract
Acute lung injury is characterized by alveolar vascular barrier injury, and protein-rich pulmonary oedema. Alveolar fluid clearance is closely related to the prognosis of patients with acute lung injury. Melatonin has been shown to have a protective effect on multiple organ injury induced by sepsis. In this study we investigated the effect of melatonin on alveolar fluid clearance (AFC) and explored its potential mechanisms in sepsis-induced acute lung injury. The cecal ligation and puncture was adopted to establish mouse sepsis model. Morphological changes of lung tissues with the hematoxylin staining were observed. AFC and lung wet/dry weight ratio were measured to assess pulmonary edema. Inflammatory mediators in bronchoalveolar lavage fluid were analyzed via enzyme-linked immunosorbent assay. NAD+/NADH and SIRT1 activity were measured by colorimetric assay kit. The protein expressions of epithelial sodium channel (ENaC), silent information regulator1 (SIRT1), SGK1 and Nedd4-2 were immunoblotted by western blot in vivo and in vitro. The distribution of α-ENaC and SIRT1 was detected by immunofluorescence. We found that melatonin attenuated sepsis induced lung injury, improved survival rate, enhanced alveolar fluid clearance, improved SIRT1 activity, increased protein expressions of SIRT1 and ENaC, and activated SGK1/Nedd4-2 pathway. Furthermore, SIRT1 inhibitor EX527 counteracted the effects of melatonin on alveolar fluid clearance and ENaC. These results revealed that melatonin enhanced ENaC-mediated AFC via the SIRT1/SGK1/Nedd4-2 signaling pathway. Our study demonstrated that melatonin might provide a novel therapeutic strategy for sepsis-induced acute lung injury.
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Affiliation(s)
- Jing Li
- Department of Endocrinology, Affiliated Nanhua Hospital, University of South China, Hengyang, China
| | - Longfei Liu
- Department of Hepatobiliary Surgery, Affiliated Nanhua Hospital, University of South China, Hengyang, China
| | - Xiaojun Zhou
- Department of Hepatobiliary Surgery, Affiliated Nanhua Hospital, University of South China, Hengyang, China
| | - Xianzhou Lu
- Department of Hepatobiliary Surgery, Affiliated Nanhua Hospital, University of South China, Hengyang, China
| | - Xianrong Liu
- Department of Hepatobiliary Surgery, Affiliated Nanhua Hospital, University of South China, Hengyang, China
| | - Guojuan Li
- Department of Endocrinology, Affiliated Nanhua Hospital, University of South China, Hengyang, China
| | - Jianwu Long
- Department of Hepatobiliary Surgery, Affiliated Nanhua Hospital, University of South China, Hengyang, China
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Abstract
Vascular epithelial sodium channels (ENaCs) made up of canonical α, β, and γ subunits have attracted more attention recently owing to their physiological role in vascular health and disease. A fourth subunit, δ-ENaC, is expressed in various mammalian species, except mice and rats, which are common animal models for cardiovascular research. Accordingly, δ-ENaC is the least understood subunit. However, the recent discovery of δ subunit in human vascular cells indicates that this subunit may play a significant role in normal/pathological vascular physiology in humans. Channels containing the δ subunit have different biophysical and pharmacological properties compared with channels containing the α subunit, with the potential to alter the vascular function of ENaC in health and disease. Hence, it is important to investigate the expression and function of δ-ENaC in the vasculature to identify whether δ-ENaC is a potential new drug target for the treatment of cardiovascular disease. In this review, we will focus on the existing knowledge of δ-ENaC and implications for vascular physiology and pathophysiology in humans.
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Affiliation(s)
- Puja Paudel
- Department of Physiology, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
| | - Fiona J McDonald
- Department of Physiology, University of Otago, Dunedin, New Zealand
| | - Martin Fronius
- Department of Physiology, University of Otago, Dunedin, New Zealand.,HeartOtago, University of Otago, Dunedin, New Zealand
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Skyberg R, Sun C, Hill DL. Selective Removal of Sodium Salt Taste Disrupts the Maintenance of Dendritic Architecture of Gustatory Relay Neurons in the Mouse Nucleus of the Solitary Tract. eNeuro 2020; 7:ENEURO. [PMID: 32817119 DOI: 10.1523/ENEURO.0140-20.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 07/20/2020] [Accepted: 07/27/2020] [Indexed: 11/21/2022] Open
Abstract
Neuronal activity plays critical roles in the development of sensory circuits in the mammalian brain. Experimental procedures are now available to alter the function of specific taste transduction pathways and have been especially useful in studying how stimulus-specific taste activity influences the development of central gustatory circuits. We previously used a mouse knock-out (KO) model in which the transduction channel necessary for sodium taste is removed from taste bud cells throughout life. In these KO mice, the terminal fields that carry taste information from taste buds into the nucleus of the solitary tract (NST) fail to mature, suggesting that sodium-elicited taste activity is important for the proper development of central gustatory circuits. Here, we tested the hypothesis that the development and maintenance of the dendritic architecture of NST relay cells, the primary postsynaptic partner of gustatory nerve terminal fields, are similarly dependent on sodium-elicited taste activity. The dendritic fields of NST relay cells, from adult male and female mice in which the α-subunit of the epithelial sodium channel (αENaC) was conditionally deleted in taste bud cells throughout life, were up to 2.4× larger and more complex than that of age-matched control mice. Interestingly, these differences in dendritic architecture did not appear until after the age when terminal fields begin “pruning,” after postnatal day (P)20. Overall, our results suggest that ENaC-mediated sodium taste activity is necessary for the maintenance of dendritic fields of relay cells in the gustatory NST.
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Eisenhut M, Shin JI. Pathways in the Pathophysiology of Coronavirus 19 Lung Disease Accessible to Prevention and Treatment. Front Physiol 2020; 11:872. [PMID: 32922301 PMCID: PMC7457053 DOI: 10.3389/fphys.2020.00872] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 06/29/2020] [Indexed: 12/12/2022] Open
Abstract
Background: In COVID 19 related lung disease, which is a leading cause of death from this disease, cytokines like tumor necrosis factor-alpha (TNF alpha) may be pivotal in the pathogenesis. TNF alpha reduces fluid absorption due to impairment of sodium and chloride transport required for building an osmotic gradient across epithelial cells, which in the airways maintains airway surface liquid helping to keep airways open and enabling bacterial clearance and aids water absorption from the alveolar spaces. TNF alpha can, through Rho-kinase, disintegrate the endothelial and epithelial cytoskeleton, and thus break up intercellular tight junctional proteins, breaching the intercellular barrier, which prevents flooding of the interstitial and alveolar spaces with fluid. Hypotheses: (1) Preservation and restoration of airway and alveolar epithelial sodium and chloride transport and the cytoskeleton dependent integrity of the cell barriers within the lung can prevent and treat COVID 19 lung disease. (2) TNF alpha is the key mediator of pulmonary edema in COVID 19 lung disease. Confirmation of hypothesis and implications: The role of a reduction in the function of epithelial sodium and chloride transport could with regards to chloride transport be tested by analysis of chloride levels in exhaled breath condensate and levels correlated with TNF alpha concentrations. Reduced levels would indicate a reduction of the function of the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel and a correlation with TNF alpha levels indicative of its involvement. Anti-TNF alpha treatment with antibodies is already available and needs to be tested in randomized controlled trials of COVID 19 lung disease. TNF alpha levels could also be reduced by statins, aspirin, and curcumin. Chloride transport could be facilitated by CFTR activators, including curcumin and phosphodiesterase-5 inhibitors. Sodium and chloride transport could be further regulated to prevent accumulation of alveolar fluid by use of Na(+)/K(+)/2Cl(-) cotransporter type 1 inhibitors, which have been associated with improved outcome in adults ventilated for acute respiratory distress syndrome (ARDS) in randomized controlled trials. Primary prevention of coronavirus infection and TNF alpha release in response to it could be improved by induction of antimicrobial peptides LL-37 and human beta defensin-2 and reduction of TNF alpha production by vitamin D prophylaxis for the population as a whole.
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Affiliation(s)
- Michael Eisenhut
- Children's & Adolescent Services, Luton & Dunstable University Hospital NHS Foundation Trust, Luton, United Kingdom
| | - Jae Il Shin
- Department of Pediatrics, Yonsei University College of Medicine, Seoul, South Korea
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Ozbaki-Yagan N, Liu X, Bodnar AJ, Ho J, Butterworth MB. Aldosterone-induced microRNAs act as feedback regulators of mineralocorticoid receptor signaling in kidney epithelia. FASEB J 2020; 34:11714-11728. [PMID: 32652691 DOI: 10.1096/fj.201902254rr] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 06/17/2020] [Accepted: 06/17/2020] [Indexed: 12/12/2022]
Abstract
The final steps in the Renin-Angiotensin-Aldosterone signaling System (RAAS) involve binding of the corticosteroid hormone, aldosterone to its mineralocorticoid receptor (MR). The bound MR interacts with response elements to induce or repress the transcription of aldosterone-regulated genes. A well characterized aldosterone-induced gene is the serum and glucocorticoid-induced kinase (SGK1), which acts downstream to increase sodium transport in distal kidney nephron epithelial cells. The role of microRNAs (miRs) induced by extended aldosterone stimulation in regulating MR and SGK1 has not been reported. In these studies, miRs predicted to bind to the 3'-UTR of mouse MR were profiled by qRT-PCR after aldosterone stimulation. The miR-466a/b/c/e family was upregulated in mouse kidney cortical collecting duct epithelial cells. A luciferase reporter assay confirmed miR-466 binding to both MR and SGK1 3'-UTRs. Inhibition of miR-466 increased MR and SGK1 mRNA and protein levels. Inhibiting miR-466b and preventing its upregulation after aldosterone stimulation increased amiloride-sensitive sodium transport and sensitivity to aldosterone stimulation. In vivo upregulation of miR-466 was confirmed in distal nephrons of mice on low Na+ diets. Repression of MR and SGK1 by aldosterone-induced miRs may represent a negative feedback loop that contributes to a form of aldosterone escape in vivo.
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Affiliation(s)
- Nejla Ozbaki-Yagan
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Xiaoning Liu
- Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Andrew J Bodnar
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jacqueline Ho
- Division of Nephrology, Department of Pediatrics, University of Pittsburgh, Pittsburgh, PA, USA
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Yoder N, Gouaux E. The His-Gly motif of acid-sensing ion channels resides in a reentrant 'loop' implicated in gating and ion selectivity. eLife 2020; 9:e56527. [PMID: 32496192 PMCID: PMC7308080 DOI: 10.7554/elife.56527] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 06/03/2020] [Indexed: 12/18/2022] Open
Abstract
Acid-sensing ion channels (ASICs) are proton-gated members of the epithelial sodium channel/degenerin (ENaC/DEG) superfamily of ion channels and are expressed throughout the central and peripheral nervous systems. The homotrimeric splice variant ASIC1a has been implicated in nociception, fear memory, mood disorders and ischemia. Here, we extract full-length chicken ASIC1 (cASIC1) from cell membranes using styrene maleic acid (SMA) copolymer, elucidating structures of ASIC1 channels in both high pH resting and low pH desensitized conformations by single-particle cryo-electron microscopy (cryo-EM). The structures of resting and desensitized channels reveal a reentrant loop at the amino terminus of ASIC1 that includes the highly conserved 'His-Gly' (HG) motif. The reentrant loop lines the lower ion permeation pathway and buttresses the 'Gly-Ala-Ser' (GAS) constriction, thus providing a structural explanation for the role of the His-Gly dipeptide in the structure and function of ASICs.
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Affiliation(s)
- Nate Yoder
- Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
| | - Eric Gouaux
- Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
- Howard Hughes Medical Institute, Oregon Health & Science UniversityPortlandUnited States
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Ishigami T, Kino T, Minegishi S, Araki N, Umemura M, Ushio H, Saigoh S, Sugiyama M. Regulators of Epithelial Sodium Channels in Aldosterone-Sensitive Distal Nephrons (ASDN): Critical Roles of Nedd4L/Nedd4-2 and Salt-Sensitive Hypertension. Int J Mol Sci 2020; 21:ijms21113871. [PMID: 32485919 PMCID: PMC7312533 DOI: 10.3390/ijms21113871] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 05/21/2020] [Accepted: 05/27/2020] [Indexed: 01/12/2023] Open
Abstract
Ubiquitination is a representative, reversible biological process of the post-translational modification of various proteins with multiple catalytic reaction sequences, including ubiquitin itself, in addition to E1 ubiquitin activating enzymes, E2 ubiquitin conjugating enzymes, E3 ubiquitin ligase, deubiquitinating enzymes, and proteasome degradation. The ubiquitin–proteasome system is known to play a pivotal role in various molecular life phenomena, including the cell cycle, protein quality, and cell surface expressions of ion-transporters. As such, the failure of this system can lead to cancer, neurodegenerative diseases, cardiovascular diseases, and hypertension. This review article discusses Nedd4-2/NEDD4L, an E3-ubiquitin ligase involved in salt-sensitive hypertension, drawing from detailed genetic dissection analysis and the development of genetically engineered mice model. Based on our analyses, targeting therapeutic regulations of ubiquitination in the fields of cardio-vascular medicine might be a promising strategy in future. Although the clinical applications of this strategy are limited, compared to those of kinase systems, many compounds with a high pharmacological activity were identified at the basic research level. Therefore, future development could be expected.
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Lossow K, Meyerhof W, Behrens M. Sodium Imbalance in Mice Results Primarily in Compensatory Gene Regulatory Responses in Kidney and Colon, but Not in Taste Tissue. Nutrients 2020; 12:E995. [PMID: 32260115 DOI: 10.3390/nu12040995] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 12/12/2022] Open
Abstract
Renal excretion and sodium appetite provide the basis for sodium homeostasis. In both the kidney and tongue, the epithelial sodium channel (ENaC) is involved in sodium uptake and sensing. The diuretic drug amiloride is known to block ENaC, producing a mild natriuresis. However, amiloride is further reported to induce salt appetite in rodents after prolonged exposure as well as bitter taste impressions in humans. To examine how dietary sodium content and amiloride impact on sodium appetite, mice were subjected to dietary salt and amiloride intervention and subsequently analyzed for ENaC expression and taste reactivity. We observed substantial changes of ENaC expression in the colon and kidney confirming the role of these tissues for sodium homeostasis, whereas effects on lingual ENaC expression and taste preferences were negligible. In comparison, prolonged exposure to amiloride-containing drinking water affected β- and αENaC expression in fungiform and posterior taste papillae, respectively, next to changes in salt taste. However, amiloride did not only change salt taste sensation but also perception of sucrose, glutamate, and citric acid, which might be explained by the fact that amiloride itself activates bitter taste receptors in mice. Accordingly, exposure to amiloride generally affects taste impression and should be evaluated with care.
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Sassi A, Wang Y, Chassot A, Komarynets O, Roth I, Olivier V, Crambert G, Dizin E, Boscardin E, Hummler E, Feraille E. Interaction between Epithelial Sodium Channel γ-Subunit and Claudin-8 Modulates Paracellular Sodium Permeability in Renal Collecting Duct. J Am Soc Nephrol 2020; 31:1009-1023. [PMID: 32245797 DOI: 10.1681/asn.2019080790] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 02/15/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Water and solute transport across epithelia can occur via the transcellular or paracellular pathways. Tight junctions play a key role in mediating paracellular ion reabsorption in the kidney. In the renal collecting duct, which is a typical absorptive tight epithelium, coordination between transcellular sodium reabsorption and paracellular permeability may prevent the backflow of reabsorbed sodium to the tubular lumen along a steep electrochemical gradient. METHODS To investigate whether transcellular sodium transport controls tight-junction composition and paracellular permeability via modulating expression of the transmembrane protein claudin-8, we used cultured mouse cortical collecting duct cells to see how overexpression or silencing of epithelial sodium channel (ENaC) subunits and claudin-8 affect paracellular permeability. We also used conditional kidney tubule-specific knockout mice lacking ENaC subunits to assess the ENaC's effect on claudin-8 expression. RESULTS Overexpression or silencing of the ENaC γ-subunit was associated with parallel and specific changes in claudin-8 abundance. Increased claudin-8 abundance was associated with a reduction in paracellular permeability to sodium, whereas decreased claudin-8 abundance was associated with the opposite effect. Claudin-8 overexpression and silencing reproduced these functional effects on paracellular ion permeability. Conditional kidney tubule-specific ENaC γ-subunit knockout mice displayed decreased claudin-8 expression, confirming the cell culture experiments' findings. Importantly, ENaC β-subunit or α-subunit silencing or kidney tubule-specific β-ENaC or α-ENaC knockout mice did not alter claudin-8 abundance. CONCLUSIONS Our data reveal the specific coupling between ENaC γ-subunit and claudin-8 expression. This coupling may play an important role in preventing the backflow of reabsorbed solutes and water to the tubular lumen, as well as in coupling paracellular and transcellular sodium permeability.
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Affiliation(s)
- Ali Sassi
- Department of Cellular Physiology and Metabolism, University of Geneva, University Medical Center, Geneva, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (Kidney.CH), Zurich, Switzerland
| | - Yubao Wang
- Department of Cellular Physiology and Metabolism, University of Geneva, University Medical Center, Geneva, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (Kidney.CH), Zurich, Switzerland
| | - Alexandra Chassot
- Department of Cellular Physiology and Metabolism, University of Geneva, University Medical Center, Geneva, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (Kidney.CH), Zurich, Switzerland
| | - Olga Komarynets
- Department of Cellular Physiology and Metabolism, University of Geneva, University Medical Center, Geneva, Switzerland
| | - Isabelle Roth
- Department of Cellular Physiology and Metabolism, University of Geneva, University Medical Center, Geneva, Switzerland
| | - Valérie Olivier
- Department of Cellular Physiology and Metabolism, University of Geneva, University Medical Center, Geneva, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (Kidney.CH), Zurich, Switzerland
| | - Gilles Crambert
- Sorbonne University, Unité Mixte de Recherche (UMR) S1138, Cordeliers Research Center, Paris, France
| | - Eva Dizin
- Department of Cellular Physiology and Metabolism, University of Geneva, University Medical Center, Geneva, Switzerland.,National Center of Competence in Research Kidney Control of Homeostasis (Kidney.CH), Zurich, Switzerland
| | - Emilie Boscardin
- National Center of Competence in Research Kidney Control of Homeostasis (Kidney.CH), Zurich, Switzerland.,Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Edith Hummler
- National Center of Competence in Research Kidney Control of Homeostasis (Kidney.CH), Zurich, Switzerland.,Department of Biomedical Sciences, University of Lausanne, Lausanne, Switzerland
| | - Eric Feraille
- Department of Cellular Physiology and Metabolism, University of Geneva, University Medical Center, Geneva, Switzerland .,National Center of Competence in Research Kidney Control of Homeostasis (Kidney.CH), Zurich, Switzerland
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