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Zhai Y, Yu T, Xin S, Ding Y, Cui Y, Nie H. Network pharmacology-based research into the mechanism of ferulic acid on acute lung injury through enhancing transepithelial sodium transport. J Ethnopharmacol 2024:118230. [PMID: 38643862 DOI: 10.1016/j.jep.2024.118230] [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] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/05/2024] [Accepted: 04/18/2024] [Indexed: 04/23/2024]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Ferulic acid (FA) has shown potential therapeutic applications in treating lung diseases. However, the underlying mechanisms by which FA ameliorates acute lung injury (ALI) have not been distinctly elucidated. AIM OF THE STUDY The project aims to observe the therapeutic effects of FA on lipopolysaccharide-induced ALI and to elucidate its specific mechanisms in regulating epithelial sodium channel (ENaC), which majors in alveolar fluid clearance during ALI. MATERIALS AND METHODS In this study, the possible pathways of FA were determined through network pharmacology analyses. The mechanisms of FA in ALI were verified by in vivo mouse model and in vitro studies, including primary alveolar epithelial type 2 cells and three-dimensional alveolar organoid models. RESULTS FA ameliorated ALI by improving lung pathological changes, reducing pulmonary edema, and upregulating the α/γ-ENaC expression in C57BL/J male mice. Simultaneously, FA was observed to augment ENaC levels in both three-dimensional alveolar organoid and alveolar epithelial type 2 cells models. Network pharmacology techniques and experimental data from inhibition or knockdown of IkappaB kinase β (IKKβ) proved that FA reduced the phosphorylation of IKKβ/nuclear factor-kappaB (NF-κB) and eliminated the lipopolysaccharide-inhibited expression of ENaC, which could be regulated by nuclear protein NF-κB p65 directly. CONCLUSIONS FA could enhance the expression of ENaC at least in part by inhibiting the IKKβ/NF-κB signaling pathway, which may potentially pave the way for promising treatment of ALI.
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Affiliation(s)
- Yiman Zhai
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Tong Yu
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Shuning Xin
- 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 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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Kim HK, Choi SH, Kim DH, Jeong YT. Comprehensive mapping of Epithelial Na + channel α expression in the mouse brain. Brain Struct Funct 2024:10.1007/s00429-023-02755-3. [PMID: 38305875 DOI: 10.1007/s00429-023-02755-3] [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: 09/05/2023] [Accepted: 12/29/2023] [Indexed: 02/03/2024]
Abstract
Epithelial sodium channel (ENaC) is responsible for regulating Na+ homeostasis. While its physiological functions have been investigated extensively in peripheral tissues, far fewer studies have explored its functions in the brain. Since our limited knowledge of ENaC's distribution in the brain impedes our understanding of its functions there, we decided to explore the whole-brain expression pattern of the Scnn1a gene, which encodes the core ENaC complex component ENaCα. To visualize Scnn1a expression in the brain, we crossed Scnn1a-Cre mice with Rosa26-lsl-tdTomato mice. Brain sections were subjected to immunofluorescence staining using antibodies against NeuN or Myelin Binding Protein (MBP), followed by the acquisition of confocal images. We observed robust tdTomato fluorescence not only in the soma of cortical layer 4, the thalamus, and a subset of amygdalar nuclei, but also in axonal projections in the hippocampus and striatum. We also observed expression in specific hypothalamic nuclei. Contrary to previous reports, however, we did not detect significant expression in the circumventricular organs, which are known for their role in regulating Na+ balance. Finally, we detected fluorescence in cells lining the ventricles and in the perivascular cells of the median eminence. Our comprehensive mapping of Scnn1a-expressing cells in the brain will provide a solid foundation for further investigations of the physiological roles ENaC plays within the central nervous system.
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Affiliation(s)
- Ha Kyeong Kim
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, Republic of Korea
- Department of Pharmacology, Korea University College of Medicine, Seoul, 02841, Republic of Korea
| | - Sang-Hyun Choi
- Department of Pharmacology, Korea University College of Medicine, Seoul, 02841, Republic of Korea
| | - Dong-Hoon Kim
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, Republic of Korea
- Department of Pharmacology, Korea University College of Medicine, Seoul, 02841, Republic of Korea
| | - Yong Taek Jeong
- BK21 Graduate Program, Department of Biomedical Sciences, Korea University College of Medicine, Seoul, 02841, Republic of Korea.
- Department of Pharmacology, Korea University College of Medicine, Seoul, 02841, Republic of Korea.
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Fu Y, Xue H, Wang T, Ding Y, Cui Y, Nie H. Fibrinolytic system and COVID-19: From an innovative view of epithelial ion transport. Biomed Pharmacother 2023; 163:114863. [PMID: 37172333 PMCID: PMC10169260 DOI: 10.1016/j.biopha.2023.114863] [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: 03/13/2023] [Revised: 05/05/2023] [Accepted: 05/06/2023] [Indexed: 05/14/2023] Open
Abstract
Lifeways of worldwide people have changed dramatically amid the coronavirus disease 2019 (COVID-19) pandemic, and public health is at stake currently. In the early stage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, fibrinolytic system is mostly inhibited, which is responsible for the development of hypofibrinolysis, promoting disseminated intravascular coagulation, hyaline membrane formation, and pulmonary edema. Whereas the common feature and risk factor at advanced stage is a large amount of fibrin degradation products, including D-dimer, the characteristic of hyperfibrinolysis. Plasmin can cleave both SARS-CoV-2 spike protein and γ subunit of epithelial sodium channel (ENaC), a critical element to edematous fluid clearance. In this review, we aim to sort out the role of fibrinolytic system in the pathogenesis of COVID-19, as well as provide the possible guidance in current treating methods. In addition, the abnormal regulation of ENaC in the occurrence of SARS-CoV-2 mediated hypofibrinolysis and hyperfibrinolysis are summarized, with the view of proposing an innovative view of epithelial ion transport in preventing the dysfunction of fibrinolytic system during the progress of COVID-19.
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Affiliation(s)
- Yunmei Fu
- 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
| | - Tingyu Wang
- 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
| | - Yong Cui
- Department of Anesthesiology, the First Hospital of China Medical University, Shenyang 110001, 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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Zheng Q, Wang Y, Zhao R, Han P, Zhao J, Li L, Zhou X, Li P, Mo Y, Pan X, Luo W, Zhou X. Inactivation of epithelial sodium ion channel molecules serves as effective diagnostic biomarkers in clear cell renal cell carcinoma. Genes Genomics 2023:10.1007/s13258-023-01376-8. [PMID: 37133722 DOI: 10.1007/s13258-023-01376-8] [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: 10/09/2022] [Accepted: 03/08/2023] [Indexed: 05/04/2023]
Abstract
BACKGROUND Non-voltage-gated sodium channel, also known as the epithelial sodium channel (ENaC), formed by heteromeric complexes consisting of SCNN1A, SCNN1B, and SCNN1G, is responsible for maintaining sodium ion and body fluid homeostasis in epithelial cells. However, no systematic study of SCNN1 family members has been conducted in renal clear cell carcinoma (ccRCC) to date. OBJECTIVE To investigate the abnormal expression of SCNN1 family in ccRCC and its potential correlation with clinical parameters. METHODS The transcription and protein expression levels of SCNN1 family members in ccRCC were analyzed based on the TCGA database, and were confirmed by quantitative RT-PCR and immunohistochemical staining assays, respectively. The area under curve (AUC) was used to evaluate the diagnostic value of SCNN1 family members for ccRCC patients. RESULTS The mRNA and protein expression of SCNN1 family members was significantly downregulated in ccRCC compared with normal kidney tissues, which might be due to DNA hypermethylation in the promoter region. It is worth noting that the AUC of SCNN1A, SCNN1B, and SCNN1G were 0.965, 0.979, and 0.988 based on the TCGA database (p < 0.0001), respectively. The diagnostic value was even higher when combing these three members together (AUC = 0.997, p < 0.0001). Intriguingly, the mRNA level of SCNN1A was significantly lower in females compared with males, while SCNN1B and SCNN1G were increased with the progression of ccRCC and remarkably associated with a worse outcome for patients. CONCLUSION The aberrantly decrease of SCNN1 family members might serve as valuable biomarkers for the diagnosis of ccRCC.
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Affiliation(s)
- Qian Zheng
- Life Science Institute, Guangxi Medical University, Nanning, China
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Nanning, China
| | - Yifang Wang
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Nanning, China
| | - Ran Zhao
- Life Science Institute, Guangxi Medical University, Nanning, China
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Nanning, China
| | - Peipei Han
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Nanning, China
| | - Jun Zhao
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Nanning, China
| | - Limei Li
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Nanning, China
| | - Xiaohui Zhou
- Life Science Institute, Guangxi Medical University, Nanning, China
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Nanning, China
| | - Ping Li
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Nanning, China
| | - Yingxi Mo
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Nanning, China
| | - Xinli Pan
- Guangxi Key Laboratory of Marine Natural Products and Combinatorial Biosynthesis Chemistry, Guangxi Academy of Sciences, Nanning, China
| | - Wenqi Luo
- Department of Pathology, Affiliated Tumor Hospital of Guangxi Medical University, Guangxi Zhuang Autonomous Region, Nanning, China.
| | - Xiaoying Zhou
- Life Science Institute, Guangxi Medical University, Nanning, China.
- Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor (Guangxi Medical University), Ministry of Education, Guangxi Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumor, Nanning, China.
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Zhou W, Hou Y, Yu T, Wang T, Ding Y, Nie H. Submersion and hypoxia inhibit alveolar epithelial Na + transport through ERK/NF-κB signaling pathway. Respir Res 2023; 24:117. [PMID: 37095538 PMCID: PMC10127099 DOI: 10.1186/s12931-023-02428-z] [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: 10/18/2022] [Accepted: 04/19/2023] [Indexed: 04/26/2023] Open
Abstract
BACKGROUND Hypoxia is associated with many respiratory diseases, partly due to the accumulation of edema fluid and mucus on the surface of alveolar epithelial cell (AEC), which forms oxygen delivery barriers and is responsible for the disruption of ion transport. Epithelial sodium channel (ENaC) on the apical side of AEC plays a crucial role to maintain the electrochemical gradient of Na+ and water reabsorption, thus becomes the key point for edema fluid removal under hypoxia. Here we sought to explore the effects of hypoxia on ENaC expression and the further mechanism related, which may provide a possible treatment strategy in edema related pulmonary diseases. METHODS Excess volume of culture medium was added on the surface of AEC to simulate the hypoxic environment of alveoli in the state of pulmonary edema, supported by the evidence of increased hypoxia-inducible factor-1 expression. The protein/mRNA expressions of ENaC were detected, and extracellular signal-regulated kinase (ERK)/nuclear factor κB (NF-κB) inhibitor was applied to explore the detailed mechanism about the effects of hypoxia on epithelial ion transport in AEC. Meanwhile, mice were placed in chambers with normoxic or hypoxic (8%) condition for 24 h, respectively. The effects of hypoxia and NF-κB were assessed through alveolar fluid clearance and ENaC function by Ussing chamber assay. RESULTS Hypoxia (submersion culture mode) induced the reduction of protein/mRNA expression of ENaC, whereas increased the activation of ERK/NF-κB signaling pathway in parallel experiments using human A549 and mouse alveolar type 2 cells, respectively. Moreover, the inhibition of ERK (PD98059, 10 µM) alleviated the phosphorylation of IκB and p65, implying NF-κB as a downstream pathway involved with ERK regulation. Intriguingly, the expression of α-ENaC could be reversed by either ERK or NF-κB inhibitor (QNZ, 100 nM) under hypoxia. The alleviation of pulmonary edema was evidenced by the administration of NF-κB inhibitor, and enhancement of ENaC function was supported by recording amiloride-sensitive short-circuit currents. CONCLUSIONS The expression of ENaC was downregulated under hypoxia induced by submersion culture, which may be mediated by ERK/NF-κB signaling pathway.
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Affiliation(s)
- Wei Zhou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Yapeng Hou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Tong Yu
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Tingyu Wang
- 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
| | - Hongguang Nie
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, China.
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Zhang L, Wang X, Chen J, Sheng S, Kleyman TR. Extracellular intersubunit interactions modulate epithelial Na + channel gating. J Biol Chem 2023; 299:102914. [PMID: 36649907 PMCID: PMC9975279 DOI: 10.1016/j.jbc.2023.102914] [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: 09/07/2022] [Revised: 12/13/2022] [Accepted: 01/12/2023] [Indexed: 01/15/2023] Open
Abstract
Epithelial Na+ channels (ENaCs) and related channels have large extracellular domains where specific factors interact and induce conformational changes, leading to altered channel activity. However, extracellular structural transitions associated with changes in ENaC activity are not well defined. Using crosslinking and two-electrode voltage clamp in Xenopus oocytes, we identified several pairs of functional intersubunit contacts where mouse ENaC activity was modulated by inducing or breaking a disulfide bond between introduced Cys residues. Specifically, crosslinking E499C in the β-subunit palm domain and N510C in the α-subunit palm domain activated ENaC, whereas crosslinking βE499C with αQ441C in the α-subunit thumb domain inhibited ENaC. We determined that bridging βE499C to αN510C or αQ441C altered the Na+ self-inhibition response via distinct mechanisms. Similar to bridging βE499C and αQ441C, we found that crosslinking palm domain αE557C with thumb domain γQ398C strongly inhibited ENaC activity. In conclusion, we propose that certain residues at specific subunit interfaces form microswitches that convey a conformational wave during ENaC gating and its regulation.
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Affiliation(s)
- Lei Zhang
- Departments of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China; The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xueqi Wang
- Departments of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China; The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Jingxin Chen
- Departments of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Shaohu Sheng
- Departments of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
| | - Thomas R Kleyman
- Departments of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Cell Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA; Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Azurmendi PJ, Toro AR, Celía AF, Guevara D, Solerno MR, Di Ciano LA, Toledo JE, Ibarra FR, Arrizurieta EE, Oddo EM. Behavior of the renal kallikrein in spontaneously hypertensive rats: Influence of sexual hormones and aldosterone-sensitive distal nephron ion channels. Peptides 2023; 160:170925. [PMID: 36549423 DOI: 10.1016/j.peptides.2022.170925] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 12/01/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022]
Abstract
The renal kallikrein-kinin system (RKKS) has been related to blood pressure control and sodium and water balance. We have previously shown that female spontaneously hypertensive rats (SHR) have high urinary kallikrein activity (UKa) and lower blood pressure (BP) than males whereas ovariectomy stimulates UKa and diminishes BP. We also showed that high K+ intake and prepuberal gonadectomy (Gx) diminish BP with a concomitant increase in UKa and plasma aldosterone levels. Since kallikrein co-localize in the same distal nephron segments of aldosterone effectors, we explored the effect of pharmacological blockage of aldosterone receptor, epithelial Na+ (ENaC) and the rectifying outer medulla K+ (ROMK) channels in different gonad contexts on the gene expression, renal tissue content and urine release of kallikrein. Klk1 gene expression was determined by real-time PCR and enzymatic activity of kallikrein by the amidolytic method. We found that the inhibition of the aldosterone receptor by spironolactone increases kallikrein renal tissue storage and decreases its urinary activity, especially in Gx rats. Moreover, ENaC blockade by benzamil increases the renal content of kallikrein without affecting synthesis or excretion, especially in females and Gx animals, while the inhibition of ROMK by glibenclamide increases the synthesis and renal content of kallikrein only in intact male animals. We concluded that RKKS regulation showed sexual dimorphism and seemed to be modulated by sex hormones throughout a process involving aldosterone and the aldosterone-sensitive ion channels..
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Affiliation(s)
- Pablo Javier Azurmendi
- Universidad de Buenos Aires, Laboratorio de Nefrología Experimental y Bioquímica Molecular, Instituto de Investigaciones Médicas A. Lanari, Buenos Aires, Argentina.
| | - Ayelén Rayen Toro
- Universidad de Buenos Aires, Laboratorio de Nefrología Experimental y Bioquímica Molecular, Instituto de Investigaciones Médicas A. Lanari, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Alejandro Fabián Celía
- Universidad de Buenos Aires, Laboratorio de Nefrología Experimental y Bioquímica Molecular, Instituto de Investigaciones Médicas A. Lanari, Buenos Aires, Argentina
| | - Darío Guevara
- Universidad de Buenos Aires, Laboratorio de Nefrología Experimental y Bioquímica Molecular, Instituto de Investigaciones Médicas A. Lanari, Buenos Aires, Argentina
| | - Martín Rogelio Solerno
- Universidad de Buenos Aires, Laboratorio de Nefrología Experimental y Bioquímica Molecular, Instituto de Investigaciones Médicas A. Lanari, Buenos Aires, Argentina
| | - Luis Alberto Di Ciano
- Universidad de Buenos Aires, Laboratorio de Nefrología Experimental y Bioquímica Molecular, Instituto de Investigaciones Médicas A. Lanari, Buenos Aires, Argentina
| | - Jorge Eduardo Toledo
- Universidad de Buenos Aires, Laboratorio de Nefrología Experimental y Bioquímica Molecular, Instituto de Investigaciones Médicas A. Lanari, Buenos Aires, Argentina
| | - Fernando Raúl Ibarra
- Universidad de Buenos Aires, Laboratorio de Nefrología Experimental y Bioquímica Molecular, Instituto de Investigaciones Médicas A. Lanari, Buenos Aires, Argentina; Universidad de Buenos Aires, Departamento de Ciencias Fisiológicas, Instituto de Fisiología y Biofísica Bernardo Houssay (IFIBIO Houssay)-CONICET, Facultad de Medicina, Buenos Aires, Argentina
| | - Elvira Emilia Arrizurieta
- Universidad de Buenos Aires, Laboratorio de Nefrología Experimental y Bioquímica Molecular, Instituto de Investigaciones Médicas A. Lanari, Buenos Aires, Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Elisabet Mónica Oddo
- Universidad de Buenos Aires, Laboratorio de Nefrología Experimental y Bioquímica Molecular, Instituto de Investigaciones Médicas A. Lanari, Buenos Aires, Argentina
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Cui Y, Sun K, Xiao Y, Li X, Mo S, Yuan Y, Wang P, Yang L, Zhang R, Zhu X. High-salt diet accelerates bone loss accompanied by activation of ion channels related to kidney and bone tissue in ovariectomized rats. Ecotoxicol Environ Saf 2022; 244:114024. [PMID: 36057202 DOI: 10.1016/j.ecoenv.2022.114024] [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] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 08/21/2022] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
Excessive salt intake can induce a variety of diseases, such as hypertension, cardiovascular disease, kidney disease and so on,it is also one of the factors promoting bone resorption. The mechanism of osteoporosis-induced exacerbations of high salt diet is not well-defined. In this study, we used ovariectomized 6-month-old Sprague Dawley rats to construct a high bone turnover model, and then administrated with high sodium chloride diet (2.0% w/w NaCl, 8.0% w/w NaCl) for 12 weeks to observe the effect of high salt diet on bone metabolism. The results showed that high salt diet could lead to the destruction of bone microstructure, promote the excretion of urinary calcium and phosphorus and accelerate the bone turnover, as well as cause the pathologic structural abnormalities in renal tubular. At the same time, it was accompanied by the up-regulated expression of the epithelial sodium channel (ENaCα), voltage-gated chloride channels (ClC)- 3 and the down-regulated expression of Na-Cl cotransporter (NCC), sodium calcium exchanger (NCX1) in femoral tissue and renal tubules. These findings confirm that high salt diet can destroy the microstructure of bone by increasing bone resorption and affect some ion channels of bone tissue and renal tubule in ovariectomized rats.
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Affiliation(s)
- Yan Cui
- The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, PR China; School of Traditional Chinese Medicine, Jinan University, Guangzhou, Guangdong 510630, PR China
| | - Kehuan Sun
- The First Affiliated Hospital of Shenzhen University,Shenzhen Second People's Hospital, Shenzhen, Guangdong 518020, PR China
| | - Yawen Xiao
- School of Traditional Chinese Medicine, Jinan University, Guangzhou, Guangdong 510630, PR China
| | - Xiaoyun Li
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510630, PR China
| | - Shu Mo
- Shenzhen Hospital of Traditional Chinese Medicine, Shenzhen, Guangdong 518000, PR China
| | - Yihan Yuan
- School of Traditional Chinese Medicine, Jinan University, Guangzhou, Guangdong 510630, PR China
| | - Panpan Wang
- The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, PR China; Cancer research Institution, Jinan University, Guangzhou, Guangdong 510630, PR China
| | - Li Yang
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510630, PR China
| | - Ronghua Zhang
- College of Pharmacy, Jinan University, Guangzhou, Guangdong 510630, PR China; Cancer research Institution, Jinan University, Guangzhou, Guangdong 510630, PR China; Guangdong Provincial Key Laboratory of Traditional Chinese Medicine Informatization, Jinan University, Guangzhou, Guangdong 510630, PR China.
| | - Xiaofeng Zhu
- The First Affiliated Hospital of Jinan University, Guangzhou, Guangdong 510630, PR China; School of Traditional Chinese Medicine, Jinan University, Guangzhou, Guangdong 510630, PR China.
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9
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Gao F, Wang D, Liu X, Wu YH, Wang HT, Sun SL. Sodium channel 1 subunit alpha SCNN1A exerts oncogenic function in pancreatic cancer via accelerating cellular growth and metastasis. Arch Biochem Biophys 2022; 727:109323. [PMID: 35714697 DOI: 10.1016/j.abb.2022.109323] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 06/05/2022] [Accepted: 06/10/2022] [Indexed: 11/24/2022]
Abstract
The identification of new diagnostic and therapeutic biomarkers might be helpful to understand molecular mechanism of cancer pathogenesis and develop anti-cancer targets. This study reported the alteration of Sodium channel 1 subunit alpha (SCNN1A) expression, its prognostic significance and biological roles in pancreatic cancer. Bioinformatics database was searched to explore the expression of SCNN1A in pancreatic cancer specimens and analysis results were further validated by qRT-PCR and Western blot assay. The correlation between SCNN1A expression and clinicopathological characteristics and its impact on survival outcome of pancreatic cancer patients were investigated using GEPIA database and Kaplan-Meier plotter. Loss- and gain-of-functional experiments in vitro were done to investigate the biological function of SCNN1A in pancreatic cancer. Bioinformatics analysis and validation experiment showed that SCNN1A was frequently overexpressed in pancreatic cancer specimens and cell lines (P < 0.001), and there were significant relevance between high SCNN1A expression and TP53 mutation (P < 0.05) as well as unfavorable prognosis of pancreatic cancer patients (HR for overall survival: 1.9, P = 0.003 and HR for disease-free survival: 1.7, P = 0.014). The silencing of SCNN1A suppressed cell proliferation, migration and invasion and induced cell apoptosis (P < 0.05), while its overexpression promoted aggressive phenotypes of pancreatic cancer cells in vitro (P < 0.05). SCNN1A possessed oncogenic function and its dysregulation could be implicated in the development and metastasis of pancreatic cancer.
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Affiliation(s)
- Feng Gao
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Dan Wang
- Department of Pancreatic Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Xun Liu
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Yun-Hao Wu
- Department of Pancreatic Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Huai-Tao Wang
- Department of Pancreatic Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China
| | - Shao-Long Sun
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China.
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Jiang YX, Huang ZW. Ulinastatin alleviates pulmonary edema by reducing pulmonary permeability and stimulating alveolar fluid clearance in a rat model of acute lung injury. Iran J Basic Med Sci 2022; 25:1002-1008. [PMID: 36159332 PMCID: PMC9464339 DOI: 10.22038/ijbms.2022.64655.14230] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 07/30/2022] [Indexed: 11/04/2022]
Abstract
Objectives Previous studies have shown that ulinastatin (UTI) alleviates pulmonary edema in acute lung injury (ALI) caused by lipopolysaccharide (LPS), although the mechanism behind this action is uncertain. This research aimed to identify the fundamental mechanism by which UTI alleviates pulmonary edema. Materials and Methods We established a model of acute lung injury (ALI) in rats by using LPS as the inciting agent.The control, LPS, and LPS+UTI groups were each comprised of a specific number of randomly selected Wistar rats. We evaluated lung injury and determined pulmonary edema. The concentrations of TNF-α, IL-1β and IL-6 in BALF and the expression levels of α1Na, k-ATPase, β1Na, K-AtPase, α-ENaC, β-ENaC, γ-ENaC, Zonula occludens (ZO)-1, Occludin, Caludin-5, PI3K, Akt, TLR4, MyD88 and NF-ƘBwere identified in lung tissues. Results The presence of UTI was associated with a reduction in lung pathological alterations, lung injury scores, the lung W/D ratio, and MPO activity, in addition to the improved gas exchange (P<0.01). Furthermore, UTI alleviated EB leakage and stimulated AFC (P<0.01). Importantly, UTI increased the expression of ZO-1, Occludin, Caludin-5, α1Na, K-ATPase, β1Na, K-AtPase, α-ENaC, β-ENaC, and γ-ENaC (P<0.01). Furthermore, UTI inhibited the inflammatory response, enhanced the expression of PI3K and Akt and hindered TLR4, MyD88, and NF-ƘB expression (P<0.01) in lung tissues. Conclusion Our results demonstrated that UTI attenuated pulmonary edema by reducing pulmonary permeability and promoting AFC through inhibiting the inflammatory response, and the mechanism is related to promoting PI3K/Akt signaling pathways and suppressing TLR4/MyD88/NF-ƘB signaling pathways.
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Affiliation(s)
- Yuan-xu Jiang
- Department of Anesthesiology, Shenzhen People’s Hospital (The Second Clinical Medical College, Jinan University, The Fist Affiliated Hospital, Southern University of Science and Technology), Shenzhen, Guangdong Province, 518020, P.R. China,Corresponding author: Yuan-xu Jiang. Shenzhen People’s Hospital , no.1017 Dongmen North Road. Shenzhen,Guangdong Province ,518020, P.R China.Tel: 13613051840;
| | - Ze-wei Huang
- Department of Critical Care Medicine, Shenzhen People’s Hospital, Shenzhen, Guangdong Province, 518020, P.R. China
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Hou Y, Li J, Ding Y, Cui Y, Nie H. Luteolin attenuates lipopolysaccharide-induced acute lung injury/acute respiratory distress syndrome by activating alveolar epithelial sodium channels via cGMP/PI3K pathway. J Ethnopharmacol 2022; 282:114654. [PMID: 34537283 DOI: 10.1016/j.jep.2021.114654] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/27/2021] [Accepted: 09/15/2021] [Indexed: 05/10/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Luteolin (Lut) was recently identified as the major active ingredient of Mosla scabra, which was a typical representative traditional Chinese medicine and had been used to treat pulmonary diseases for thousands of years. AIM OF THE STUDY This study was to explore the effects and relative mechanisms of Lut in LPS-induced acute lung injury/acute respiratory distress syndrome (ALI/ARDS). The main characteristic of ALI/ARDS is pulmonary edema, and epithelial sodium channel (ENaC) is a key factor in effective removal of excessive alveolar edematous fluid, which is essential for repairing gas exchange and minimizing damage to the peripheral tissues. However, whether the therapeutic effects of Lut on respiratory diseases are relative with ENaC is still unknown. MATERIALS AND METHODS Alveolar fluid clearance was calculated in BALB/c mice and ENaC function was measured in H441 cells. Moreover, ENaC membrane protein and mRNA were detected by Western blot and real-time PCR, respectively. We also studied the involvement of cGMP/PI3K pathway during the regulation of Lut on ENaC during LPS-induced ALI/ARDS by ELISA method and applying cGMP/PI3K inhibitors/siRNA. RESULTS The beneficial effects of Lut in ALI/ARDS were evidenced by the alleviation of pulmonary edema, and enhancement of both amiloride-sensitive alveolar fluid clearance and short-circuit currents. Lut could alleviate the LPS decreased expression levels of ENaC mRNA and membrane protein in H441 cells and mouse lung. In addition, cGMP concentration was increased after the administration of Lut in ALI/ARDS mice, while the inhibition of cGMP/PI3K pathway could abrogate the enhanced AFC and ENaC protein expression of Lut. CONCLUSION These results implied that Lut could attenuate pulmonary edema via enhancing the abundance of membrane ENaC at least partially through the cGMP/PI3K pathway, which could provide a promising therapeutic strategy for treating ALI/ARDS.
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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.
| | - Jun Li
- Key Laboratory of Medical Electrophysiology, Ministry of Education & Medical Electrophysiological Key Laboratory of Sichuan Province (Collaborative Innovation Center for Prevention of Cardiovascular Diseases), Institute of Cardiovascular Research, Southwest Medical University, Luzhou, 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 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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Jia Q, Yang Y, Chen X, Yao S, Hu Z. Emerging roles of mechanosensitive ion channels in acute lung injury/acute respiratory distress syndrome. Respir Res 2022; 23:366. [PMID: 36539808 PMCID: PMC9764320 DOI: 10.1186/s12931-022-02303-3] [Citation(s) in RCA: 2] [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] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a devastating respiratory disorder with high rates of mortality and morbidity, but the detailed underlying mechanisms of ALI/ARDS remain largely unknown. Mechanosensitive ion channels (MSCs), including epithelial sodium channel (ENaC), Piezo channels, transient receptor potential channels (TRPs), and two-pore domain potassium ion (K2P) channels, are highly expressed in lung tissues, and the activity of these MSCs can be modulated by mechanical forces (e.g., mechanical ventilation) and other stimuli (e.g., LPS, hyperoxia). Dysfunction of MSCs has been found in various types of ALI/ARDS, and MSCs play a key role in regulating alveolar fluid clearance, alveolar epithelial/endothelial barrier function, the inflammatory response and surfactant secretion in ALI/ARDS lungs. Targeting MSCs exerts therapeutic effects in the treatment of ALI/ARDS. In this review, we summarize the structure and functions of several well-recognized MSCs, the role of MSCs in the pathogenesis of ALI/ARDS and recent advances in the pharmacological and molecular modulation of MSCs in the treatment of ALI/ARDS. According to the current literature, targeting MSCs might be a very promising therapeutic approach against ALI/ARDS.
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Affiliation(s)
- Qi Jia
- grid.33199.310000 0004 0368 7223Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yiyi Yang
- grid.33199.310000 0004 0368 7223Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiangdong Chen
- grid.33199.310000 0004 0368 7223Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Shanglong Yao
- grid.33199.310000 0004 0368 7223Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhiqiang Hu
- grid.33199.310000 0004 0368 7223Department of Anesthesiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Noor S, Mohammad T, Ashraf GM, Farhat J, Bilgrami AL, Eapen MS, Sohal SS, Yadav DK, Hassan MI. Mechanistic insights into the role of serum-glucocorticoid kinase 1 in diabetic nephropathy: A systematic review. Int J Biol Macromol 2021; 193:562-573. [PMID: 34715204 DOI: 10.1016/j.ijbiomac.2021.10.165] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 10/21/2021] [Accepted: 10/23/2021] [Indexed: 12/13/2022]
Abstract
Aberrant expression of serum-glucocorticoid kinase 1 (SGK1) contributes to the pathogenesis of multiple disorders, including diabetes, hypertension, obesity, fibrosis, and metabolic syndrome. SGK1 variant is expressed in the presence of insulin and several growth factors, eventually modulating various ion channels, carrier proteins, and transcription factors. SGK1 also regulates the enzymatic activity of Na+ K+ ATPase, glycogen synthase kinase-3, ubiquitin ligase Nedd4-2, and phosphomannose mutase impacting cell cycle regulation, neuroexcitation, and apoptosis. Ample evidence supports the crucial role of aberrant SGK1 expression in hyperglycemia-mediated secondary organ damage. Diabetic nephropathy (DN), a dreadful microvascular complication of diabetes, is the leading cause of end-stage renal failures with high morbidity and mortality rate. The complex pathogenesis of DN encompasses several influencing factors, including transcriptional factors, inflammatory markers, cytokines, epigenetic modulators, and abnormal enzymatic activities. SGK1 plays a pivotal role by controlling various physiological functions associated with the occurrence and progression of DN; therefore, targeting SGK1 may favorably influence the clinical outcome in patients with DN. This review aimed to provide mechanistic insights into SGK1 regulated DN pathogenesis and summarize the evidence supporting the therapeutic potential of SGK1 inhibition and its consequences on human health.
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Affiliation(s)
- Saba Noor
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Taj Mohammad
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Gulam M Ashraf
- Pre-Clinical Research Unit, King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Joviana Farhat
- College of Pharmacy, Al Ain University, Abu Dhabi 112612, United Arab Emirates
| | - Anwar L Bilgrami
- Deanship of Scientific Research, King Abdulaziz University, Jeddah, Saudi Arabia; Department of Entomology, Rutgers University, New Brunswick, NJ 08901, USA
| | - Mathew Suji Eapen
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania, Launceston, TAS, Australia
| | - Sukhwinder Singh Sohal
- Respiratory Translational Research Group, Department of Laboratory Medicine, School of Health Sciences, College of Health and Medicine, University of Tasmania, Launceston, TAS, Australia
| | - Dharmendra Kumar Yadav
- College of Pharmacy, Gachon University of Medicine and Science, Hambakmoeiro, Yeonsu-gu, Incheon City 21924, South Korea.
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
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Xie X, Yu T, Hou Y, Han A, Ding Y, Nie H, Cui Y. Ferulic acid ameliorates lipopolysaccharide-induced tracheal injury via cGMP/PKGII signaling pathway. Respir Res 2021; 22:308. [PMID: 34863181 PMCID: PMC8642995 DOI: 10.1186/s12931-021-01897-4] [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: 06/03/2021] [Accepted: 11/15/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Tracheal injury is a common clinical condition that still lacks an effective therapy at present. Stimulation of epithelial sodium channel (ENaC) increases Na+ transport, which is a driving force to keep tracheal mucosa free edema fluid during tracheal injury. Ferulic acid (FA) has been proved to be effective in many respiratory diseases through exerting anti-oxidant, anti-inflammatory, and anti-thrombotic effects. However, these studies rarely involve the level of ion transport, especially ENaC. METHODS C57BL/J male mice were treated intraperitoneally with normal saline or FA (100 mg/kg) 12 h before, and 12 h after intratracheal administration of lipopolysaccharide (LPS, 5 mg/kg), respectively. The effects of FA on tracheal injury were not only assessed through HE staining, immunofluorescence assay, and protein/mRNA expressions of ENaC located on tracheas, but also evaluated by the function of ENaC in mouse tracheal epithelial cells (MTECs). Besides, to explore the detailed mechanism about FA involved in LPS-induced tracheal injury, the content of cyclic guanosine monophosphate (cGMP) was measured, and Rp-cGMP (cGMP inhibitor) or cGMP-dependent protein kinase II (PKGII)-siRNA (siPKGII) were applied in primary MTECs, respectively. RESULTS Histological examination results demonstrated that tracheal injury was obviously attenuated by pretreatment of FA. Meanwhile, FA could reverse LPS-induced reduction of both protein/mRNA expressions and ENaC activity. ELISA assay verified cGMP content was increased by FA, and administration of Rp-cGMP or transfection of siPKGII could reverse the FA up-regulated ENaC protein expression in MTECs. CONCLUSIONS Ferulic acid can attenuate LPS-induced tracheal injury through up-regulation of ENaC at least partially via the cGMP/PKGII pathway, which may provide a promising new direction for preventive and therapeutic strategy in tracheal injury.
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Affiliation(s)
- Xiaoyong Xie
- Department of Anesthesiology, the First Hospital of China Medical University, Shenyang, 110001, China.,Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, 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
| | - Yapeng Hou
- Department of Stem Cells and Regenerative Medicine, College of Basic Medical Science, China Medical University, Shenyang, 110122, China
| | - Aixin Han
- 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.
| | - Yong Cui
- Department of Anesthesiology, the First Hospital of China Medical University, Shenyang, 110001, China.
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Cerecedo D, Martínez-Vieyra I, López-Villegas EO, Hernández-Cruz A, Loza-Huerta ADC. Heterogeneity of neutrophils in arterial hypertension. Exp Cell Res 2021; 402:112577. [PMID: 33811902 DOI: 10.1016/j.yexcr.2021.112577] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 03/18/2021] [Accepted: 03/20/2021] [Indexed: 01/21/2023]
Abstract
Cellular heterogeneity and diversity are recognized to contribute to the functions of neutrophils under homeostatic and pathological conditions. We previously suggested that the chronic inflammatory responses associated with hypertension (HTN) are related to the participation of different subpopulations of neutrophils. Two populations of neutrophils can be obtained by density gradient centrifugation: normal-density neutrophils (NDN) and low-density neutrophils (LDN). However, the lack of standardized functional protocols has limited phenotypic characterization and functional comparisons of LDN and NDN. Based on their capability to incorporate Na+, maturity and activation stage, we characterized NDN and LDN in blood samples from ten patients with HTN and ten healthy individuals (HI) using flow cytometry. We compared the levels of reactive oxygen species (ROS), generation of neutrophil extracellular traps (NETs) and levels of apoptosis in NDN and LDN. In general, the NDN and LDN subpopulations from patients with HTN exhibited higher levels of sodium influx and ROS, and lower levels of apoptosis than the corresponding NDN and LDN subsets from HI. Transmission electron microscopy revealed NDN and LDN from patients with HTN exhibited alterations to mitochondrial morphology and fewer cytoplasmic granules than the corresponding HI subpopulations. Our results indicate both the NDN and LDN subpopulations enhance the effects of inflammation that contribute to the pathophysiology of HTN. Further detailed studies are required to characterize the events during ontogeny of the myeloid lineage that result in the diverse phenotypic characteristics of each subpopulation of LDN and NDN.
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Fei X, Ziqian Y, Bingwu Y, Min L, Xinmiao X, Zhen M, Lirong G, Song W. Aldosterone alleviates lipopolysaccharide-induced acute lung injury by regulating epithelial sodium channel through PI3K/Akt/SGK1 signaling pathway. Mol Cell Probes 2021; 57:101709. [PMID: 33713776 DOI: 10.1016/j.mcp.2021.101709] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/17/2021] [Accepted: 02/23/2021] [Indexed: 12/14/2022]
Abstract
Reduced alveolar fluid clearance (AFC) is a major pathological feature of acute lung injury (ALI). Epithelial sodium channel (ENaC) plays a key role in regulating the transport of Na+ and clearing alveolar edema fluid effectively. ENaC has been reported to be regulated by aldosterone in the distal collecting tube of the kidney. We hypothesized whether aldosterone regulated ENaC in alveolar epithelium and correspondingly played a role in ALI. In this study we found that the expression of aldosterone synthesis encoding gene, CYP11B2, and ENaC were decreased in the lung tissue of LPS-induced ALI mice. Furthermore, aldosterone alleviated ALI by increasing the expression of ENaC-α and relieving pulmonary edema. Besides, we found that aldosterone upregulated ENaC-α through PI3K/Akt/SGK1 pathway. In conclusion, our study demonstrated that aldosterone attenuated pulmonary edema by upregulating ENaC-α through the PI3K/Akt/SGK1 pathway in LPS-induced ALI, indicating that aldosterone might be a promising adjuvant drug for ALI treatment.
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Affiliation(s)
- Xiu Fei
- Department of Blood Transfusion, Liaocheng People's Hospital, #67 Dongchangxi Road, Liaocheng, 252000, China
| | - Yu Ziqian
- Department of Clinical Laboratory, Liaocheng Veterans Hospital, #2 Gaodong Street, Liaocheng, 252000, China
| | - Yang Bingwu
- Procesion Biomedical Lab, Liaocheng People's Hospital, Medical College of Liaocheng University, #67 Dongchangxi Road, Liaocheng, 252000, China
| | - Li Min
- Procesion Biomedical Lab, Liaocheng People's Hospital, Medical College of Liaocheng University, #67 Dongchangxi Road, Liaocheng, 252000, China
| | - Xian Xinmiao
- Procesion Biomedical Lab, Liaocheng People's Hospital, Medical College of Liaocheng University, #67 Dongchangxi Road, Liaocheng, 252000, China
| | - Meng Zhen
- Procesion Biomedical Lab, Liaocheng People's Hospital, Medical College of Liaocheng University, #67 Dongchangxi Road, Liaocheng, 252000, China
| | - Guo Lirong
- Nursing School of Jilin University, Changchun, Jilin, 130021, China.
| | - Wang Song
- Procesion Biomedical Lab, Liaocheng People's Hospital, Medical College of Liaocheng University, #67 Dongchangxi Road, Liaocheng, 252000, China.
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Zhang H, Ding Y, Hou Y, Liu Y, Zhou Z, Nie H. Bone marrow mesenchymal stem cells derived miRNA-130b enhances epithelial sodium channel by targeting PTEN. Respir Res 2020; 21:329. [PMID: 33308227 DOI: 10.1186/s12931-020-01595-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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: 09/15/2020] [Accepted: 12/01/2020] [Indexed: 12/13/2022] Open
Abstract
Aims Acute lung injury (ALI) is a clinical syndrome with high morbidity and mortality, and severe pulmonary edema is one of the characteristics. Epithelial sodium channel (ENaC) located on the apical side of alveolar type 2 epithelial (AT2) cells is the primary rate limiting segment in alveolar fluid clearance. Many preclinical studies have revealed that mesenchymal stem cells (MSCs) based therapy has great therapeutic potential for ALI, while the role of ENaC in this process is rarely known. Methods We studied the effects of bone marrow-derived MSCs (BMSCs) on the protein/mRNA expression and activity of ENaC in primary mouse AT2 and human H441 cells by co-culture with them, respectively. Moreover, the changes of miRNA-130b in AT2 cells were detected by qRT-PCR, and we studied the involvement of phosphatase and tensin homolog deleted on chromosome ten (PTEN) and the downstream PI3K/AKT pathway in the miRNA-130b regulation of ENaC. Results Our results demonstrated that BMSCs could increase ENaC protein expression and function, as well as the expression level of miRNA-130b. The dual luciferase target gene assay verified that PTEN was one of the target genes of miR-130b, which showed adverse effects on the protein expression of α/γ-ENaC and PTEN in AT2 cells. Upregulating miR-130b and/or knocking down PTEN resulted in the increase of α/γ-ENaC protein level, and the protein expression of p-AKT/AKT was enhanced by miR-130b. Both α and γ-ENaC protein expressions were increased after AT2 cells were transfected with siPTEN, which could be reversed by the co-administration of PI3K/AKT inhibitor LY294002. Conclusion In summary, miRNA-130b in BMSCs can enhance ENaC at least partially by targeting PTEN and activating PI3K/AKT pathway, which may provide a promising new direction for therapeutic strategy in ALI.
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Obendorf J, Fabian C, Thome UH, Laube M. Paracrine stimulation of perinatal lung functional and structural maturation by mesenchymal stem cells. Stem Cell Res Ther 2020; 11:525. [PMID: 33298180 PMCID: PMC7724458 DOI: 10.1186/s13287-020-02028-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 08/20/2020] [Accepted: 11/13/2020] [Indexed: 12/14/2022] Open
Abstract
Background Mesenchymal stem cells (MSCs) were shown to harbor therapeutic potential in models of respiratory diseases, such as bronchopulmonary dysplasia (BPD), the most common sequel of preterm birth. In these studies, cells or animals were challenged with hyperoxia or other injury-inducing agents. However, little is known about the effect of MSCs on immature fetal lungs and whether MSCs are able to improve lung maturity, which may alleviate lung developmental arrest in BPD. Methods We aimed to determine if the conditioned medium (CM) of MSCs stimulates functional and structural lung maturation. As a measure of functional maturation, Na+ transport in primary fetal distal lung epithelial cells (FDLE) was studied in Ussing chambers. Na+ transporter and surfactant protein mRNA expression was determined by qRT-PCR. Structural maturation was assessed by microscopy in fetal rat lung explants. Results MSC-CM strongly increased the activity of the epithelial Na+ channel (ENaC) and the Na,K-ATPase as well as their mRNA expression. Branching and growth of fetal lung explants and surfactant protein mRNA expression were enhanced by MSC-CM. Epithelial integrity and metabolic activity of FDLE cells were not influenced by MSC-CM. Since MSC’s actions are mainly attributed to paracrine signaling, prominent lung growth factors were blocked. None of the tested growth factors (VEGF, BMP, PDGF, EGF, TGF-β, FGF, HGF) contributed to the MSC-induced increase of Na+ transport. In contrast, inhibition of PI3-K/AKT and Rac1 signaling reduced MSC-CM efficacy, suggesting an involvement of these pathways in the MSC-CM-induced Na+ transport. Conclusion The results demonstrate that MSC-CM strongly stimulated functional and structural maturation of the fetal lungs. These effects were at least partially mediated by the PI3-K/AKT and Rac1 signaling pathway. Thus, MSCs not only repair a deleterious tissue environment, but also target lung cellular immaturity itself.
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Affiliation(s)
- Janine Obendorf
- Center for Pediatric Research Leipzig, Department of Pediatrics, Division of Neonatology, University of Leipzig, Liebigstrasse 19, 04103, Leipzig, Germany
| | - Claire Fabian
- Fraunhofer Institute for Cell Therapy and Immunology, Perlickstrasse 1, 04103, Leipzig, Germany
| | - Ulrich H Thome
- Center for Pediatric Research Leipzig, Department of Pediatrics, Division of Neonatology, University of Leipzig, Liebigstrasse 19, 04103, Leipzig, Germany
| | - Mandy Laube
- Center for Pediatric Research Leipzig, Department of Pediatrics, Division of Neonatology, University of Leipzig, Liebigstrasse 19, 04103, Leipzig, Germany.
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Malmberg MH, Mose FH, Pedersen EB, Bech JN. Urine concentration ability is reduced to the same degree in adult dominant polycystic kidney disease compared with other chronic kidney diseases in the same CKD-stage and lower THAN in healthy control subjects - a CASE control study. BMC Nephrol 2020; 21:379. [PMID: 32867720 DOI: 10.1186/s12882-020-02043-w] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/23/2020] [Indexed: 01/20/2023] Open
Abstract
Background Concentration of the urine is primarily regulated via vasopressin dependent aquaporin-2 water channels in the apical membrane of kidney principal cells. It is unclear whether urine concentration ability in ADPKD differs from other patients with similar degree of impaired renal function (non-ADPKD patients). The purpose of this case control study was to measure urine concentration ability in ADPKD patients compared to non-ADPKD patients and healthy controls. Methods A seventeen hour long water deprivation test was carried out in 17 ADPKD patients (CKD I-IV), 16 non-ADPKD patients (CKD I-IV), and 18 healthy controls. Urine was collected in 4 consecutive periods during water deprivation (12 h, 1 h, 2 h and 2 h, respectively) and analyzed for osmolality (u-Osm), output (UO), fractional excretion of sodium (FENa), aquaporin2 (u-AQP2) and ENaC (u-ENaC). Blood samples were drawn trice (after 13-, 15-, and 17 h after water deprivation) for analyses of osmolality (p-Osm), vasopressin (p-AVP), and aldosterone (p-Aldo). Results U-Osm was significantly lower and FENa significantly higher in both ADPKD patients and non-ADPKD patients compared to healthy controls during the last three periods of water deprivation. During the same periods, UO was higher and secretion rates of u-AQP2 and u-ENaC were lower and at the same level in the two groups of patients compared to controls. P-AVP and p-Osm did not differ significantly between the three groups. P-Aldo was higher in both groups of patients than in controls. Conclusions Urine concentration ability was reduced to the same extent in patients with ADPKD and other chronic kidney diseases with the same level of renal function compared to healthy controls. The lower urine excretion of AQP2 and ENaC suggests that the underlying mechanism may be a reduced tubular response to vasopressin and aldosterone. Trial registration Current Controlled Trial NCT04363554, date of registration: 20.08.2017.
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Deng J, Wang DX, Tang J, Liang AL, He ZL, Xiang DK, Yan TG. An increase in alveolar fluid clearance induced by hyperinsulinemia in obese rats with LPS-induced acute lung injury. Respir Physiol Neurobiol 2020; 279:103470. [PMID: 32474115 DOI: 10.1016/j.resp.2020.103470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 05/07/2020] [Accepted: 05/25/2020] [Indexed: 01/11/2023]
Abstract
A lower mortality rate is observed in obese patients with acute lung injury (ALI), which is referred to as the obesity paradox, in several studies and recent meta-analyses. Hyperinsulinemia is characterized as the primary effect of obesity, and exogenous insulin attenuates LPS-induced pulmonary edema. The detailed mechanism responsible for the effect of hyperinsulinemia on pulmonary edema and alveolar filling needs to be elucidated. SD rats were fed with a high-fat diet (HFD) for a total of 14 weeks. SD rats were anesthetized and intraperitoneally injected with 10 mg/kg lipopolysaccharide (LPS), while control rats received only saline vehicle. Insulin receptor antagonist S961 (20 nmol/kg) was given by the tail vein and serum, and glucocorticoid-induced protein kinase-1 (SGK-1) inhibitor EMD638683 (20 mg/kg) was administrated intragastrically prior to LPS exposure. The lungs were isolated for the measurement of alveolar fluid clearance. The protein expression of epithelial sodium channel (ENaC) was detected by Western blot. Insulin level in serum was significantly higher in HFD rats compared with normal diet rats in the presence or absence of LPS pretreatment. Hyperinsulinemia induced by high fat feeding increased alveolar fluid clearance and the abundance of α-ENaC, β-ENaC, and γ-ENaC in both normal rats and ALI rats. Moreover, these effects were reversed in response to S961. EMD638683 prevented the simulation of alveolar fluid clearance and protein expression of ENaC in HFD rats with ALI. These findings suggest that hyperinsulinemia induced by obesity results in the stimulation of alveolar fluid clearance via the upregulation of the abundance of ENaC in clinical acute lung injury, whereas theses effects are prevented by an SGK-1 inhibitor.
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Aggarwal S, Lazrak A, Ahmad I, Yu Z, Bryant A, Mobley JA, Ford DA, Matalon S. Reactive species generated by heme impair alveolar epithelial sodium channel function in acute respiratory distress syndrome. Redox Biol 2020; 36:101592. [PMID: 32506040 DOI: 10.1016/j.redox.2020.101592] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 03/25/2020] [Revised: 05/08/2020] [Accepted: 05/20/2020] [Indexed: 12/19/2022] Open
Abstract
We previously reported that the highly reactive cell-free heme (CFH) is increased in the plasma of patients with chronic lung injury and causes pulmonary edema in animal model of acute respiratory distress syndrome (ARDS) post inhalation of halogen gas. However, the mechanisms by which CFH causes pulmonary edema are unclear. Herein we report for the first time that CFH and chlorinated lipids (formed by the interaction of halogen gas, Cl2, with plasmalogens) are increased in the plasma of patients exposed to Cl2 gas. Ex vivo incubation of red blood cells (RBC) with halogenated lipids caused oxidative damage to RBC cytoskeletal protein spectrin, resulting in hemolysis and release of CFH. Patch clamp and short circuit current measurements revealed that CFH inhibited the activity of amiloride-sensitive epithelial Na+ channel (ENaC) and cation sodium (Na+) channels in mouse alveolar cells and trans-epithelial Na+ transport across human airway cells with EC50 of 125 nM and 500 nM, respectively. Molecular modeling identified 22 putative heme-docking sites on ENaC (energy of binding range: 86-1563 kJ/mol) with at least 2 sites within its narrow transmembrane pore, potentially capable of blocking Na+ transport across the channel. A single intramuscular injection of the heme-scavenging protein, hemopexin (4 μg/kg body weight), one hour post halogen gas exposure, decreased plasma CFH and improved lung ENaC activity in mice. In conclusion, results suggested that CFH mediated inhibition of ENaC activity may be responsible for pulmonary edema post inhalation injury.
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Mustafa SB, Hernandez TF, Johnson-Pais TL, Kumar PA, Petershack JA, Henson BM, Seidner SR. IL-1 promotes α- epithelial Sodium Channel (α-ENaC) expression in murine lung epithelial cells: involvement of NF-κB. J Cell Commun Signal 2019; 14:303-314. [PMID: 31659629 DOI: 10.1007/s12079-019-00533-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [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: 01/17/2019] [Accepted: 10/09/2019] [Indexed: 01/13/2023] Open
Abstract
Intra-amniotic exposure to proinflammatory cytokines such as interleukin-1 (IL-1) correlates with a decreased incidence of respiratory distress syndrome (RDS) in infants following premature birth. At birth, inadequate absorption of fluid from the fetal lung contributes to the onset RDS. Lung fluid clearance is coupled to Na+ transport via epithelial sodium channels (ENaC). In this study, we assessed the effects of IL-1 on the expression of ENaC, particularly the α-subunit which is critical for fetal lung fluid clearance at birth. Cultured mouse lung epithelial (MLE-12) cells were treated with either IL-1α or IL-1β to determine their effects on α-ENaC expression. Changes in IL-1-induced α-ENaC levels in the presence of IL-1 receptor antagonist (IL-1ra), cycloheximide, NF-κB inhibitor, and MAP kinase inhibitors were investigated. IL-1α and IL-1β independently induced a significant increase of α-ENaC mRNA and protein after 24 h compared to untreated cells. IL-1-dependent increases in α-ENaC protein were mitigated by IL-1ra and cycloheximide. IL-1 exposure induced NF-κB binding activity. Attenuation of IL-1-induced NF-κB activation by its inhibitor SN50 decreased α-ENaC protein abundance. Inhibition of ERK 1,2 MAPK significantly decreased both IL-1α and β-induced α-ENaC protein expression whereas inhibition of p38 MAPK only blocked IL-1β-induced α-ENaC protein levels. In contrast, IL-1-induced α-ENaC protein levels were unaffected by a c-Jun N-terminal kinase (JNK) inhibitor. Our results suggest that in MLE-12 cells, IL-1-induced elevation of α-ENaC is mediated via NF-κB activation and in part involves stimulation of the ERK 1,2 and p38 MAPK signaling pathways.
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Affiliation(s)
- Shamimunisa B Mustafa
- Department of Pediatrics/Division of Neonatology, University of Texas Health Science Center, 7703 Floyd Curl Drive, MSC 7812, San Antonio, TX, 78229-3900, USA.
| | - Tania F Hernandez
- Department of Pediatrics/Division of Neonatology, University of Texas Health Science Center, 7703 Floyd Curl Drive, MSC 7812, San Antonio, TX, 78229-3900, USA
| | - Teresa L Johnson-Pais
- Department of Urology, University of Texas Health Science Center, 7703 Floyd Curl Drive, MSC 7812, San Antonio, TX, 78229-3900, USA
| | - Pratap A Kumar
- Department of Urology, University of Texas Health Science Center, 7703 Floyd Curl Drive, MSC 7812, San Antonio, TX, 78229-3900, USA
| | - Jean A Petershack
- Department of Pediatrics/Division of Neonatology, University of Texas Health Science Center, 7703 Floyd Curl Drive, MSC 7812, San Antonio, TX, 78229-3900, USA
| | - Barbara M Henson
- Department of Pediatrics/Division of Neonatology, University of Texas Health Science Center, 7703 Floyd Curl Drive, MSC 7812, San Antonio, TX, 78229-3900, USA
| | - Steven R Seidner
- Department of Pediatrics/Division of Neonatology, University of Texas Health Science Center, 7703 Floyd Curl Drive, MSC 7812, San Antonio, TX, 78229-3900, USA
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Zhang L, Xing YZ, Ye HB, Shi HB. [The expression and function of acid-sensing ion channels in auditory system and vestibular system]. Zhonghua Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2019; 54:708-11. [PMID: 31550769 DOI: 10.3760/cma.j.issn.1673-0860.2019.09.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Acid-sensing ion channels are a class of extracellular H(+) activated cation channels, belonging to the amiloride-sensitive epithelial Na(+) channel/degenerin (ENaC/DEG) superfamily. During extracellular acidification, the channels are activated and produce corresponding action potential. Acid-sensing ion channels are extensively expressed in the peripheral and central nervous system. It plays an important in synaptic plasticity, mechanical sensation, injury sensation related to acidosis of local tissues, acid reception and retinal regulation. This article reviews the expression, biological characteristics and functions of acid-sensing ion channels in cochlea, vestibular tissue and auditory center, so as to improve the understanding of physiology and pathophysiology of auditory system.
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Gupta A, Li X, DiCicco-Bloom E, Bello NT. Altered salt taste response and increased tongue epithelium Scnna1 expression in adult Engrailed-2 null mice. Physiol Behav 2018; 194:410-419. [PMID: 29953887 DOI: 10.1016/j.physbeh.2018.06.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 12/27/2017] [Revised: 06/19/2018] [Accepted: 06/20/2018] [Indexed: 02/06/2023]
Abstract
Sensory impairments are critical for diagnosing and characterizing neurodevelopmental disorders. Taste is a sensory modality often not well characterized. Engrailed-2 (En2) is a transcription factor critical for neural development, and mice lacking En2 (En2-/-) display signs of impaired social interaction, cognitive processes (e.g., learning and memory, conditioned fear), and neurodevelopmental alterations. As such, En2-/- mice display the behavioral deficits and neural impairments characteristic of the core symptoms associated with autism spectrum disorder (ASD). The objective of this study was to characterize the taste function in En2-/- compared with En2+/+ in adult male mice. Measuring taste responsiveness by an automated gustometer, En2 null mice had decreased lick responses for 1.6 M fructose, whereas they demonstrated an increased taste responsivity (i.e., relative to water) at 0.3 M sodium chloride and 1 M monosodium glutamate. In a separate cohort of mice, En2-/- mice had an increased preference for sodium chloride over a range of concentrations (0.032-0.3 M) compared with En2+/+ mice. Regional gene expression of the tongue epithelium demonstrated an increase in Scnn1a, T2R140, T1R3, and Trpm5 and a decrease in Pkd1l3 in En2 null mice. Taken together, such data indicate that deficits in En2 can produce sensory impairments that can have a measurable impact on taste, particularly salt taste.
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Affiliation(s)
- Ankita Gupta
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Xinyi Li
- Nutritional Sciences Graduate Program, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA
| | - Emanuel DiCicco-Bloom
- Department of Neuroscience and Cell Biology/Pediatrics, Rutgers Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ, USA
| | - Nicholas T Bello
- Department of Animal Sciences, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA; Nutritional Sciences Graduate Program, School of Environmental and Biological Sciences, Rutgers, The State University of New Jersey, New Brunswick, NJ, USA.
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Yamaguchi E, Yoshikawa K, Nakaya I, Kato K, Miyasato Y, Nakagawa T, Kakizoe Y, Mukoyama M, Soma J. Liddle's-like syndrome associated with nephrotic syndrome secondary to membranous nephropathy: the first case report. BMC Nephrol 2018; 19:122. [PMID: 29792170 PMCID: PMC5966895 DOI: 10.1186/s12882-018-0916-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 03/14/2017] [Accepted: 05/11/2018] [Indexed: 12/20/2022] Open
Abstract
Background Liddle’s syndrome is a rare monogenic form of hypertension caused by truncating or missense mutations in the C termini of the epithelial sodium channel (ENaC) β or γ subunits. Patients with this syndrome present with early onset of hypertension, hypokalemia, metabolic alkalosis, hyporeninemia and hypoaldosteronism, and a potassium-sparing diuretics (triamterene or amiloride) can drastically improves the disease condition. Although elderly patients having these characteristics were considered to have Liddle’s syndrome or Liddle’s-like syndrome, no previous report has indicated that Liddle’s-like syndrome could be caused by nephrotic syndrome of primary glomerular disease, which is characterized by urinary excretion of > 3 g of protein/day plus edema and hypoalbuminemia, or has explained how the activity function of ENaC could be affected in the setting of high proteinuria. Case presentation A 65-year-old Japanese man presented with nephrotic syndrome. He had no remarkable family history, but had a medical history of hypertension and hyperlipidemia. On admission, hypertension, spironolactone-resistant hypokalemia (2.43 mEq/l), hyporeninemic hypoaldosteronism, and metabolic alkalosis, which suggested Liddle’s syndrome, were observed. Treatment with triamterene together with a steroid for nephrotic syndrome resulted in rapid and remarkable effective on improvements of hypertension, hypokalemia, and edema of the lower extremities. Renal biopsy revealed membranous nephropathy (MN) as the cause of nephrotic syndrome, and advanced gastric cancer was identified on screening examination for cancers that could be associated with the development of MN. After total gastrectomy, triamterene was not required and proteinuria decreased. A mutation in the β or γ subunits of the ENaC gene was not identified. Conclusion We reported for the first time a case of Liddle’s-like syndrome associated with nephrotic syndrome secondary to MN. Aberrant activation of ENaC was suggested transient during the period of high proteinuria, and the activation was reversible with a decrease in proteinuria.
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Affiliation(s)
- Eriko Yamaguchi
- Department of Nephrology and Rheumatology, Iwate Prefectural Central Hospital, 1-4-1, Morioka, 020-0066, Japan
| | - Kazuhiro Yoshikawa
- Department of Nephrology and Rheumatology, Iwate Prefectural Central Hospital, 1-4-1, Morioka, 020-0066, Japan
| | - Izaya Nakaya
- Department of Nephrology and Rheumatology, Iwate Prefectural Central Hospital, 1-4-1, Morioka, 020-0066, Japan
| | - Karen Kato
- Department of Nephrology and Rheumatology, Iwate Prefectural Central Hospital, 1-4-1, Morioka, 020-0066, Japan
| | - Yoshikazu Miyasato
- Department of Nephrology, Kumamoto University School of Medicine, Honjyo 1-1-1, Chuo-Ku, Kumamoto, 860-8556, Japan
| | - Terumasa Nakagawa
- Department of Nephrology, Kumamoto University School of Medicine, Honjyo 1-1-1, Chuo-Ku, Kumamoto, 860-8556, Japan
| | - Yutaka Kakizoe
- Department of Nephrology, Kumamoto University School of Medicine, Honjyo 1-1-1, Chuo-Ku, Kumamoto, 860-8556, Japan
| | - Masashi Mukoyama
- Department of Nephrology, Kumamoto University School of Medicine, Honjyo 1-1-1, Chuo-Ku, Kumamoto, 860-8556, Japan
| | - Jun Soma
- Department of Nephrology and Rheumatology, Iwate Prefectural Central Hospital, 1-4-1, Morioka, 020-0066, Japan.
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Schragenheim J, Bellner L, Cao J, Singh SP, Bamshad D, McClung JA, Maayan O, Meissner A, Grant I, Stier CT, Abraham NG. EET enhances renal function in obese mice resulting in restoration of HO-1-Mfn1/2 signaling, and decrease in hypertension through inhibition of sodium chloride co-transporter. Prostaglandins Other Lipid Mediat 2018; 137:30-39. [PMID: 29787809 DOI: 10.1016/j.prostaglandins.2018.05.008] [Citation(s) in RCA: 14] [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: 11/21/2017] [Revised: 04/12/2018] [Accepted: 05/14/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND We have previously reported that epoxyeicosatrienoic acid (EET) has multiple beneficial effects on renal and adipose tissue function, in addition to its vasodilatory action; it increases insulin sensitivity and inhibits inflammation. In an examination of the signaling mechanisms by which EET reduces renal and peri-renal fat function, we hypothesized that EET ameliorates obesity-induced renal dysfunction by improving sodium excretion, reducing the sodium-chloride cotransporter NCC, lowering blood pressure, and enhancing mitochondrial and thermogenic gene levels in PGC-1α dependent mice. METHODS EET-agonist treatment normalized glucose metabolism, renal ENaC and NCC protein expression, urinary sodium excretion and blood pressure in obese (db/db) mice. A marked improvement in mitochondrial integrity, thermogenic genes, and PGC-1α-HO-1-adiponectin signaling occurred. Knockout of PGC-1α in EET-treated mice resulted in a reversal of these beneficial effects including a decrease in sodium excretion, elevation of blood pressure and an increase in the pro-inflammatory adipokine nephroblastoma overexpressed gene (NOV). In the elucidation of the effects of EET on peri-renal adipose tissue, EET increased adiponectin, mitochondrial integrity, thermogenic genes and decreased NOV, i.e. "Browning' peri-renal adipose phenotype that occurs under high fat diets. Taken together, these data demonstrate a critical role of an EET agonist in the restoration of healthy adipose tissue with reduced release of inflammatory molecules, such as AngII and NOV, thereby preventing their detrimental impact on sodium absorption and NCC levels and the development of obesity-induced renal dysfunction.
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Affiliation(s)
- Joseph Schragenheim
- Department of Pharmacology, New York Medical College, Valhalla, NY, 10595, United States
| | - Lars Bellner
- Department of Pharmacology, New York Medical College, Valhalla, NY, 10595, United States
| | - Jian Cao
- Chinese PLA General Hospital, Beijing, 100853, China
| | - Shailendra P Singh
- Department of Pharmacology, New York Medical College, Valhalla, NY, 10595, United States
| | - David Bamshad
- Department of Medicine, New York Medical College, Valhalla, NY, 10595, United States
| | - John A McClung
- Department of Medicine, New York Medical College, Valhalla, NY, 10595, United States
| | - Omri Maayan
- Department of Pharmacology, New York Medical College, Valhalla, NY, 10595, United States
| | - Aliza Meissner
- Department of Medicine, New York Medical College, Valhalla, NY, 10595, United States
| | - Ilana Grant
- Department of Medicine, New York Medical College, Valhalla, NY, 10595, United States
| | - Charles T Stier
- Department of Pharmacology, New York Medical College, Valhalla, NY, 10595, United States.
| | - Nader G Abraham
- Department of Pharmacology, New York Medical College, Valhalla, NY, 10595, United States; Department of Medicine, New York Medical College, Valhalla, NY, 10595, United States; Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, 25701, United States.
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Elias SO, Sofola OA, Jaja SI. Epithelial sodium channel blockade and new β-ENaC polymorphisms among normotensive and hypertensive adult Nigerians. Clin Exp Hypertens 2018; 41:144-151. [PMID: 29580127 DOI: 10.1080/10641963.2018.1451538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We sought to determine the effect of amiloride on blood pressure (BP) and the presence of polymorphisms of the β-subunit of the epithelial sodium channel (ENaC) among normotensive (NT) and hypertensive (HT) Nigerians. Healthy volunteers-47 NT and 53 age-matched HT were recruited after giving informed consent. Subjects were salt-loaded with 200 mmol of NaCl daily for 5 days. Following a week washout period, salt-loading was repeated in addition to the administration of 5 mg amiloride daily for five days. Blood pressure, plasma and urine electrolytes were measured at baseline, after salt-loading and after salt-loading plus amiloride. PCR amplicons were sequenced for β-ENaC polymorphisms. Salt-loading led to a significant increase (p < 0.05) in SBP among NT and HT and in DBP (p < 0.001) only among HT. Amiloride reduced SBP and DBP to below baseline levels in NT (p < 0.05) and HT (p < 0.001) subjects. Five of the subjects had the β-T594M polymorphism, HT 3/53; NT 2/47 (p = 0.75). Four previously unreported β-ENaC mutations were recorded: E632V and E636V, respectively, among two HT subjects, D638Y in another HT and L628Q in one NT subject. We showed the presence of β-ENaC polymorphisms among our populace and the possible usefulness of amiloride as a single antihypertensive among Nigerians.
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Affiliation(s)
- Simiat O Elias
- Department of Physiology, Lagos State University College of Medicine, Lagos, Nigeria
| | - Olusoga A Sofola
- Department of Physiology, College of Medicine University of Lagos, Lagos, Nigeria
| | - Smith I Jaja
- Department of Physiology, College of Medicine University of Lagos, Lagos, Nigeria
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Ji P, Chen L, Gong J, Yuan Y, Li M, Zhao Y, Zhang H. Co-expression of vasoactive intestinal peptide and protein gene product 9.5 surrounding the lumen of human Schlemm's canal. Exp Eye Res 2018; 170:1-7. [PMID: 29432726 DOI: 10.1016/j.exer.2018.02.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [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: 10/26/2016] [Revised: 02/08/2018] [Accepted: 02/08/2018] [Indexed: 01/20/2023]
Abstract
Previous studies of aqueous humor outflow have focused primarily on resistance at the trabecular meshwork (TM), and little is known about the function of Schlemm's canal (SC). Here, we aimed to investigate whether SC is innervated by the peripheral nervous system. Ten eye specimens from eight donors were processed for histological analysis. CD31 was used to identify SC, after which we used protein gene product (PGP) 9.5 as a marker to detect nerve fibers around SC. We then characterized the nerves by double staining for PGP9.5 and sympathetic nerve markers, such as tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DβH), or the parasympathetic marker vasoactive intestinal peptide (VIP), as well as sensory nerve marker calcitonin gene-related peptide (CGRP) and vesicular glutamate transporter 2 (VGLUT2). Immunohistochemistry and immunofluorescence were also performed to detect the expression of γ-epithelial Na+ channel (γ-ENaC) in SC. We found that different markers were expressed in the anterior chamber angle, with the luminal surface of SC were only positive stained for PGP9.5, VIP, and γ-ENaC. CGRP and VGLUT2 were expressed in TM and scleral spur (SS), whereas TH and DβH were absent in both TM and SC. Furthermore, PGP9.5 was co-expressed with VIP and γ-ENaC in the region surrounding the SC as well as in SS. Our findings indicate that the peripheral nerves anatomically spread in the tissues around the SC and the local nerve fibers may be parasympathetic or sensory rather than sympathetic.
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Affiliation(s)
- Pingting Ji
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, PR China
| | - Liwen Chen
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, PR China
| | - Jieling Gong
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, PR China
| | - Yuxiang Yuan
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, PR China
| | - Mu Li
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, PR China
| | - Yin Zhao
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, PR China.
| | - Hong Zhang
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan 430030, PR China.
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29
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Jia G, Habibi J, Aroor AR, Hill MA, DeMarco VG, Lee LE, Ma L, Barron BJ, Whaley-Connell A, Sowers JR. Enhanced endothelium epithelial sodium channel signaling prompts left ventricular diastolic dysfunction in obese female mice. Metabolism 2018; 78:69-79. [PMID: 28920862 DOI: 10.1016/j.metabol.2017.08.008] [Citation(s) in RCA: 36] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 07/21/2017] [Accepted: 08/25/2017] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Enhanced activation of cell specific mineralocorticoid receptors (MRs) in obesity plays a key role in the development of cardiovascular disease including cardiac diastolic dysfunction as a critical prognosticator. Our previous investigations demonstrated that selective endothelium MR activation promotes a maladaptive inflammatory response and fibrosis in cardiovascular tissue in female mice fed a western diet (WD), and this was associated with expression and activation of the epithelial sodium channel on the surface of endothelial cells (EnNaC). However, the specific role of EnNaC signaling in the development of cardiac stiffness and diastolic dysfunction has not been examined. We hypothesized that targeted inhibition of EnNaC with low dose amiloride would prevent WD-induced diastolic dysfunction by suppressing abnormal endothelial permeability, inflammation and oxidative stress, and myocardial fibrosis. MATERIALS/METHODS Four week-old female C57BL6/J mice were fed a WD with or without a low dose of amiloride (1mg/kg/day) for 16weeks. Left ventricular cardiac function was evaluated by magnetic resonance imaging. In addition, we examined coronary vessel and cardiac remodeling, fibrosis, macrophage infiltration using immunohistochemistry, western blot and real time PCR. RESULTS Amiloride, an antagonist of EnNaC, attenuated WD-induced impairment of left ventricular initial filling rate and relaxation time. Cardiac diastolic dysfunction was associated with increases in coronary endothelium remodeling and permeability that paralleled WD-induced increases in F-actin and fibronectin, decreased expression of claudin-5 and occludin, and increased macrophage recruitment, M1 polarization, cardiac oxidative stress, fibrosis and maladaptive remodeling. CONCLUSION Our data support the concept that EnNaC activation mediates endothelium permeability which, in turn, promotes macrophage infiltration, M1 polarization, and oxidative stress, resulting in cardiac fibrosis and diastolic dysfunction in females with diet induced obesity.
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Affiliation(s)
- Guanghong Jia
- Diabetes and Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA.
| | - Javad Habibi
- Diabetes and Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA
| | - Annayya R Aroor
- Diabetes and Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA
| | - Michael A Hill
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO 65212, USA; Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65212, USA
| | - Vincent G DeMarco
- Diabetes and Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA; Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO 65212, USA
| | - Li E Lee
- Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA; Department of Radiology, University of Missouri school of Medicine, Columbia, MO 65212, USA
| | - Lixin Ma
- Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA; Department of Radiology, University of Missouri school of Medicine, Columbia, MO 65212, USA
| | - Brady J Barron
- Diabetes and Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA
| | - Adam Whaley-Connell
- Diabetes and Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA
| | - James R Sowers
- Diabetes and Cardiovascular Research Center, University of Missouri School of Medicine, Columbia, MO 65212, USA; Research Service, Harry S Truman Memorial Veterans Hospital, 800 Hospital Dr, Columbia, MO 65201, USA; Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO 65212, USA; Dalton Cardiovascular Research Center, University of Missouri, Columbia, MO 65212, USA.
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Hołyńska-Iwan I, Dziembowska I, Smyk P, Lampka M, Olszewska-Słonina D. Capsaicin Used on Skin Influences Ion Transport Pathways: An in vitro Study. Skin Pharmacol Physiol 2017; 31:19-27. [PMID: 29131139 DOI: 10.1159/000481689] [Citation(s) in RCA: 5] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 09/15/2017] [Indexed: 01/07/2023]
Abstract
Acute, adverse skin effects to capsaicin can be activated by inhibition of sodium transport not only in nociceptive neurons, but also in keratinocytes. The aim of the current study was to describe and compare immediate (15 s) and prolonged (30 min) effects of capsaicin on epidermal (not neural) sodium transport using a rabbit skin model. Skin fragments (n = 169) were incubated in 4 conditions: undisturbed ion transport (U; n = 48); inhibited sodium transport (INa; n = 34) with amiloride used as sodium transport blocker; long-term irritation by capsaicin with undisturbed ion transport (CAPSA-U; n = 43) and with inhibited sodium transport (CAPSA-INa; n = 35). After 30 min of incubation, a solution of capsaicin was applied directly to the skin fragments. The study demonstrated that sodium transport inhibition eliminated the effects of both immediate and prolonged capsaicin application. The results could be the basis for future research considering selective sodium transport inhibitors for human skin to reduce the side effects of capsaicin, related to activation of sodium channels in keratinocytes.
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Affiliation(s)
- Iga Hołyńska-Iwan
- Department of Pathobiochemistry and Clinical Chemistry, Faculty of Pharmacy, Collegium Medicum in Bydgoszcz Nicolaus Copernicus University in Torun, Bydgoszcz, Poland
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Yamamoto S, Hotta Y, Maeda K, Kataoka T, Maeda Y, Hamakawa T, Shibata Y, Sasaki S, Ugawa S, Yasui T, Kimura K. High salt loading induces urinary storage dysfunction via upregulation of epithelial sodium channel alpha in the bladder epithelium in Dahl salt-sensitive rats. J Pharmacol Sci 2017; 135:121-125. [PMID: 29129584 DOI: 10.1016/j.jphs.2017.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [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: 04/24/2017] [Revised: 09/28/2017] [Accepted: 10/03/2017] [Indexed: 12/21/2022] Open
Abstract
We aimed to investigate whether high salt intake affects bladder function via epithelial sodium channel (ENaC) by using Dahl salt-resistant (DR) and salt-sensitive (DS) rats. Bladder weight of DR + high-salt diet (HS, 8% NaCl) and DS + HS groups were significantly higher than those of DR + normal-salt diet (NS, 0.3% NaCl) and DS + NS groups after one week treatment. We thereafter used only DR + HS and DS + HS group. Systolic and diastolic blood pressures were significantly higher in DS + HS group than in DR + HS group after the treatment period. Cystometrogram showed the intercontraction intervals (ICI) were significantly shorter in DS + HS group than in DR + HS group during infusion of saline. Subsequent infusion of amiloride significantly prolonged ICI in DS + HS group, while no intra-group difference in ICI was observed in DR + HS group. No intra- or inter-group differences in maximum intravesical pressure were observed. Protein expression levels of ENaCα in the bladder were significantly higher in DS + HS group than in DR + HS group. ENaCα protein was localized at bladder epithelium in both groups. In conclusion, high salt intake is considered to cause urinary storage dysfunction via upregulation of ENaC in the bladder epithelium with salt-sensitive hypertension, suggesting that ENaC might be a candidate for therapeutic target for urinary storage dysfunction.
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Affiliation(s)
- Seiji Yamamoto
- Department of Hospital Pharmacy, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe do-ri, Mizuho-ku, Nagoya 467-8603, Japan
| | - Yuji Hotta
- Department of Hospital Pharmacy, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe do-ri, Mizuho-ku, Nagoya 467-8603, Japan
| | - Kotomi Maeda
- Department of Hospital Pharmacy, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe do-ri, Mizuho-ku, Nagoya 467-8603, Japan
| | - Tomoya Kataoka
- Department of Clinical Pharmaceutics, Graduate School of Medical Sciences, Nagoya City University, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Yasuhiro Maeda
- Department of Hospital Pharmacy, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe do-ri, Mizuho-ku, Nagoya 467-8603, Japan
| | - Takashi Hamakawa
- Department of Nephro-urology, Graduate School of Medical Sciences, Nagoya City University, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Yasuhiro Shibata
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Nagoya City University, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Shoichi Sasaki
- Department of Nephro-urology, Graduate School of Medical Sciences, Nagoya City University, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Shinya Ugawa
- Department of Anatomy and Neuroscience, Graduate School of Medical Sciences, Nagoya City University, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Takahiro Yasui
- Department of Nephro-urology, Graduate School of Medical Sciences, Nagoya City University, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan
| | - Kazunori Kimura
- Department of Hospital Pharmacy, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe do-ri, Mizuho-ku, Nagoya 467-8603, Japan; Department of Clinical Pharmaceutics, Graduate School of Medical Sciences, Nagoya City University, 1-Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan.
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Oxlund C, Kurt B, Schwarzensteiner I, Hansen MR, Stæhr M, Svenningsen P, Jacobsen IA, Hansen PB, Thuesen AD, Toft A, Hinrichs GR, Bistrup C, Jensen BL. Albuminuria is associated with an increased prostasin in urine while aldosterone has no direct effect on urine and kidney tissue abundance of prostasin. Pflugers Arch 2017; 469:655-667. [PMID: 28233126 DOI: 10.1007/s00424-017-1938-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [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: 11/17/2016] [Revised: 01/11/2017] [Accepted: 01/16/2017] [Indexed: 01/29/2023]
Abstract
The proteinase prostasin is a candidate mediator for aldosterone-driven proteolytic activation of the epithelial sodium channel (ENaC). It was hypothesized that the aldosterone-mineralocorticoid receptor (MR) pathway stimulates prostasin abundance in kidney and urine. Prostasin was measured in plasma and urine from type 2 diabetic patients with resistant hypertension (n = 112) randomized to spironolactone/placebo in a clinical trial. Prostasin protein level was assessed by immunoblotting in (1) human and rat urines with/without nephrotic syndrome, (2) human nephrectomy tissue, (3) urine and kidney from aldosterone synthase-deficient (AS-/-) mice and ANGII- and aldosterone-infused mice, and in (4) kidney from adrenalectomized rats. Serum aldosterone concentration related to prostasin concentration in urine but not in plasma. Plasma prostasin concentration increased significantly after spironolactone compared to control. Urinary prostasin and albumin related directly and were reduced by spironolactone. In patients with nephrotic syndrome, urinary prostasin protein was elevated compared to controls. In rat nephrosis, proteinuria coincided with increased urinary prostasin, unchanged kidney tissue prostasin, and decreased plasma prostasin while plasma aldosterone was suppressed. Prostasin protein abundance in human nephrectomy tissue was similar across gender and ANGII inhibition regimens. Prostasin urine abundance was not different in AS-/- and aldosterone-infused mice. Prostasin kidney level was not different from control in adrenalectomized rats and AS-/- mice. We found no evidence for a direct relationship between mineralocorticoid receptor signaling and kidney and urine prostasin abundance. The reduction of urinary prostasin in spironolactone-treated patients is most likely the result of an improved glomerular filtration barrier function and generally reduced proteinuria.
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Affiliation(s)
- Christina Oxlund
- Research Unit for Cardiovascular and Metabolic Prevention, Department of Endocrinology, Odense University Hospital, Sdr. Boulevard 29, DK-5000, Odense C, Denmark.
| | - Birgül Kurt
- Institute of Physiology, University of Regensburg, Regensburg, Germany
| | | | - Mie R Hansen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Mette Stæhr
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Per Svenningsen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Ib A Jacobsen
- Research Unit for Cardiovascular and Metabolic Prevention, Department of Endocrinology, Odense University Hospital, Sdr. Boulevard 29, DK-5000, Odense C, Denmark
| | - Pernille B Hansen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Anne D Thuesen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Anja Toft
- Department of Urology, Odense University Hospital, Odense, Denmark
| | - Gitte R Hinrichs
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - Claus Bistrup
- Department of Nephrology, Odense University Hospital, Odense, Denmark
| | - Boye L Jensen
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
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Xu W, Huang Y, Li L, Sun Z, Shen Y, Xing J, Li M, Su D, Liang X. Hyperuricemia induces hypertension through activation of renal epithelial sodium channel (ENaC). Metabolism 2016; 65:73-83. [PMID: 26892518 DOI: 10.1016/j.metabol.2015.10.026] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 10/19/2015] [Accepted: 10/21/2015] [Indexed: 11/24/2022]
Abstract
OBJECTIVES The mechanisms leading to hypertension associated with hyperuricemia are still unclear. The activity of the distal nephron epithelial sodium channel (ENaC) is an important determinant of sodium balance and blood pressure. Our aim was to investigate whether the effect of hyperuricemia on blood pressure is related to ENaC activation. METHODS A hyperuricemic model was induced in rats by 2% oxonic acid and 6 mg/dl uric acid (UA). The hyperuricemic rats were co-treated with either 10mg/kg/d benzbromarone (Ben) or 1 mg/kg/d amiloride (Ami). Blood pressure was monitored using a tail-cuff, and blood, urine, and kidney samples were taken. Western blotting and immunohistochemical staining were performed to determine the expressions of ENaC subunits and components of the ENaC Regulatory Complex (ERC) in kidney tissue or mCCD cells. RESULTS Serum uric acid (SUA) was increased 2.5-3.5 times above normal in hyperuricemic rats after 3 weeks and remained at these high levels until 6 weeks. The in vivo rise in SUA was followed by elevated blood pressure, renal tubulointerstitial injury, and increased expressions of ENaC subunits, SGK1, and GILZ1, which were prevented by Ben treatment. The decrease in urinary Na(+) excretion in hyperuricemic rats was blunted by Ami. UA induced the expression of all three ENaC subunits, SGK1, and GILZ1, and increased Na(+) transport in mCCD cells. Phosphorylation of ERK was significantly decreased in both UA-treated mCCD cells and hyperuricemic rat kidney; this effect was prevented by Ben co-treatment. CONCLUSION Our findings suggest that elevated serum uric acid could induce hypertension by activation of ENaC and regulation of ERC expression.
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Affiliation(s)
- Weifeng Xu
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China; Zhuji people Hospital, Zhuji, Zhejiang Province, China
| | - Yujie Huang
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Lei Li
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Zhen Sun
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Yachen Shen
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Jing Xing
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Min Li
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Dongming Su
- Department of Pathology, Nanjing Medical University, Nanjing, Jiangsu Province, China; State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu Province, China
| | - Xiubin Liang
- Department of Pathophysiology, Nanjing Medical University, Nanjing, Jiangsu Province, China; State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing, Jiangsu Province, China.
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Reddy BG, Dai Q, McNicholas CM, Fuller CM, Kappes JC, DeLucas LJ. Expression and purification of the alpha subunit of the epithelial sodium channel, ENaC. Protein Expr Purif 2015; 117:67-75. [PMID: 26394093 DOI: 10.1016/j.pep.2015.09.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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: 07/14/2015] [Revised: 09/05/2015] [Accepted: 09/11/2015] [Indexed: 01/19/2023]
Abstract
The epithelial sodium channel (ENaC) plays a critical role in maintaining Na(+) homeostasis in various tissues throughout the body. An understanding of the structure of the ENaC subunits has been developed from homology modeling based on the related acid sensing ion channel 1 (ASIC1) protein structure, as well as electrophysiological approaches. However, ENaC has several notable functional differences compared to ASIC1, thereby providing justification for determination of its three-dimensional structure. Unfortunately, this goal remains elusive due to several experimental challenges. Of the subunits that comprise a physiological hetero-trimeric αβγENaC, the α-subunit is unique in that it is capable of forming a homo-trimeric structure that conducts Na(+) ions. Despite functional and structural interest in αENaC, a key factor complicating structural studies has been its interaction with multiple other proteins, disrupting its homogeneity. In order to address this issue, a novel protocol was used to reduce the number of proteins that associate and co-purify with αENaC. In this study, we describe a novel expression system coupled with a two-step affinity purification approach using NiNTA, followed by a GFP antibody column as a rapid procedure to improve the purity and yield of rat αENaC.
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Affiliation(s)
- Bharat G Reddy
- Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Qun Dai
- Dept. of Biochemistry, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Dept. of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Carmel M McNicholas
- Dept. of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Catherine M Fuller
- Dept. of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - John C Kappes
- Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Dept. of Biochemistry, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Dept. of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Birmingham Veterans Affairs Medical Center, Research Service, Birmingham, AL 35233, United States
| | - Lawrence J DeLucas
- Dept. of Optometry, University of Alabama at Birmingham, Birmingham, AL 35294, United States; Center for Biophysical Sciences and Engineering, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
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Chen R, Sun W, Gu H, Cheng Y. Aldosterone-induced expression of ENaC-α is associated with activity of p65/p50 in renal epithelial cells. J Nephrol 2017; 30:73-9. [PMID: 26385798 DOI: 10.1007/s40620-015-0231-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 08/29/2015] [Indexed: 10/23/2022]
Abstract
The amiloride-sensitive epithelial sodium channel (ENaC), located in the apical membrane in the cortical collecting duct of the kidney, mediates the fine-tuned regulation of external Na+ balance. Expression of the alpha-subunit of ENaC (ENaC-α) is regulated by a number of factors in the lung, including transcription factor nuclear factor kappa B (NF-κB). In the present study, we examined the effect of IKKβ/p65/p50 on ENaC-α in a murine cortical collecting duct cell line that endogenously expresses ENaC, mpkCCDc14 (CCD) cells. Aldosterone exposure led to up-regulation of ENaC-α and IKKβ, and nuclear p65 and p50. Knockdown of IKKβ or p65 exhibited >60 % reduction of aldosterone-induced ENaC-α mRNA levels. Chromatin immunoprecipitation and electrophoretic mobility shift assays demonstrated a specific interaction between p65/p50 and ENaC-α gene promoter, which was further confirmed using luciferase reporter-gene vectors transiently transfected into CCD cells. Taken together these data support an important role for p65/p50 in the direct regulation of ENaC-α transcription and have important implications for understanding the role of NF-κB in the regulation of renal function.
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Perniss A, Wolf A, Wichmann L, Schönberger M, Althaus M. Evans Blue is not a suitable inhibitor of the epithelial sodium channel δ-subunit. Biochem Biophys Res Commun 2015; 466:468-74. [PMID: 26365349 DOI: 10.1016/j.bbrc.2015.09.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 09/07/2015] [Accepted: 09/09/2015] [Indexed: 01/06/2023]
Abstract
The Epithelial Sodium Channel (ENaC) is a heterotrimeric ion channel which can be either formed by assembly of its α-, β- and γ-subunits or, alternatively, its δ-, β- and γ-subunits. The physiological function of αβγ-ENaC is well established, but the function of δβγ-ENaC remains elusive. The azo-dye Evans Blue (EvB) has been routinely used to discriminate between the two channel isoforms by decreasing transmembrane currents and amiloride-sensitive current fractions of δβγ-ENaC expressing Xenopus oocytes. Even though these results could be reproduced, it was found by precipitation experiments and spectroscopic methods that the cationic amiloride and the anionic EvB directly interact in solution, forming a strong complex. Thereby a large amount of pharmacologically available amiloride is removed from physiological buffer solutions and the effective amiloride concentration is reduced. This interaction did not occur in the presence of albumin. In microelectrode recordings, EvB was able to abrogate the block of δβγ-ENaC by amiloride or its derivative benzamil. In sum, EvB reduces amiloride-sensitive ion current fractions in electrophysiological experiments. This is not a result of a specific inhibition of δβγ-ENaC but rather represents a pharmacological artefact. EvB should therefore not be used as an inhibitor of δ-ENaC.
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Affiliation(s)
- Alexander Perniss
- Institute for Animal Physiology, Justus-Liebig-University, Heinrich-Buff-Ring 26, D-35392 Giessen, Germany
| | - Annemarie Wolf
- Institute for Animal Physiology, Justus-Liebig-University, Heinrich-Buff-Ring 26, D-35392 Giessen, Germany
| | - Lukas Wichmann
- Institute for Animal Physiology, Justus-Liebig-University, Heinrich-Buff-Ring 26, D-35392 Giessen, Germany
| | - Matthias Schönberger
- Department of Chemistry, Stanford University, 337 Campus Drive, Stanford, CA 94305-4401337, USA; Institute for Radiochemistry and Molecular Imaging, University Clinic Cologne, Kerpener Strasse 62, 50931 Cologne, Germany.
| | - Mike Althaus
- Institute for Animal Physiology, Justus-Liebig-University, Heinrich-Buff-Ring 26, D-35392 Giessen, Germany.
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Zhang W. Epigenetics of epithelial Na + channel-dependent sodium uptake and blood pressure regulation. World J Nephrol 2015; 4:363-366. [PMID: 26167459 PMCID: PMC4491926 DOI: 10.5527/wjn.v4.i3.363] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 12/08/2014] [Accepted: 05/18/2015] [Indexed: 02/06/2023] Open
Abstract
The epithelial Na+ channel (ENaC) consists of α, β, γ subunits. Its expression and function are regulated by aldosterone at multiple levels including transcription. ENaC plays a key role in Na+ homeostasis and blood pressure. Mutations in ENaC subunit genes result in hypertension or hypotension, depending on the nature of the mutations. Transcription of αENaC is considered as the rate-limiting step in the formation of functional ENaC. As an aldosterone target gene, αENaC is activated upon aldosterone- mineralocorticoid receptor binding to the cis-elements in the αENaC promoter, which is packed into chromatin. However, how aldosterone alters chromatin structure to induce changes in transcription is poorly understood. Studies by others and us suggest that Dot1a-Af9 complex represses αENaC by directly binding and regulating targeted histone H3 K79 hypermethylation at the specific subregions of αENaC promoter. Aldosterone decreases Dot1a-Af9 formation by impairing expression of Dot1a and Af9 and by inducing Sgk1, which, in turn, phosphorylates Af9 at S435 to weaken Dot1a-Af9 interaction. MR attenuates Dot1a-Af9 effect by competing with Dot1a for binding Af9. Af17 relieves repression by interfering with Dot1a-Af9 interaction and promoting Dot1a nuclear export. Af17-/- mice exhibit defects in ENaC expression, renal Na+ retention, and blood pressure control. This review gives a brief summary of these novel findings.
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Ray EC, Rondon-Berrios H, Boyd CR, Kleyman TR. Sodium retention and volume expansion in nephrotic syndrome: implications for hypertension. Adv Chronic Kidney Dis 2015; 22:179-84. [PMID: 25908466 DOI: 10.1053/j.ackd.2014.11.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Revised: 11/11/2014] [Accepted: 11/20/2014] [Indexed: 01/09/2023]
Abstract
Sodium retention is a major clinical feature of nephrotic syndrome. The mechanisms responsible for sodium retention in this setting have been a subject of debate for years. Excessive sodium retention occurs in some individuals with nephrotic syndrome in the absence of activation of the renin-angiotensin-aldosterone system, suggesting an intrinsic defect in sodium excretion by the kidney. Recent studies have provided new insights regarding mechanisms by which sodium transporters are activated by factors present in nephrotic urine. These mechanisms likely have a role in the development of hypertension in nephrotic syndrome, where hypertension may be difficult to control, and provide new therapeutic options for the management of blood pressure and edema in the setting of nephrotic syndrome.
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Abstract
Aldosterone is a major regulator of Na(+) absorption and acts primarily by controlling the epithelial Na(+) channel (ENaC) function at multiple levels including transcription. ENaC consists of α, β, and γ subunits. In the classical model, aldosterone enhances transcription primarily by activating mineralocorticoid receptor (MR). However, how aldosterone induces chromatin alternation and thus leads to gene activation or repression remains largely unknown. Emerging evidence suggests that Dot1a-Af9 complex plays an important role in repression of αENaC by directly binding and modulating targeted histone H3 K79 hypermethylation at the specific subregions of αENaC promoter. Aldosterone impairs Dot1a-Af9 formation by decreasing expression of Dot1a and Af9 and by inducing Sgk1, which, in turn, phosphorylates Af9 at S435 to weaken Dot1a-Af9 interaction. MR counterbalances Dot1a-Af9 action by competing with Dot1a for binding Af9. Af17 derepresses αENaC by competitively interacting with Dot1a and facilitating Dot1a nuclear export. Consistently, MR(-/-) mice have impaired ENaC expression at day 5 after birth, which may contribute to progressive development of pseudohypoaldosteronism type 1 in a later stage. Af17(-/-) mice have decreased ENaC expression, renal Na(+) retention, and blood pressure. In contrast, Dot1l(AC) mice have increased αENaC expression, despite a 20% reduction of the principal cells. This chapter reviews these findings linking aldosterone action to ENaC transcription through chromatin modification. Future direction toward the understanding the role of Dot1a-Af9 complex beyond ENaC regulation, in particular, in renal fibrosis is also briefly discussed.
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Affiliation(s)
- Lihe Chen
- Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas, USA; Division of Renal Diseases and Hypertension, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas, USA
| | - Xi Zhang
- Division of Renal Diseases and Hypertension, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas, USA
| | - Wenzheng Zhang
- Graduate School of Biomedical Sciences, The University of Texas Health Science Center at Houston, Houston, Texas, USA; Division of Renal Diseases and Hypertension, Department of Internal Medicine, University of Texas Medical School at Houston, Houston, Texas, USA.
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Jiang Y, Xu J, Chen Y, Shi J, Zhang C, Li J. Expression and distribution of epithelial sodium channel in nasal polyp and nasal mucosa. Eur Arch Otorhinolaryngol 2015; 272:3361-6. [PMID: 25559464 DOI: 10.1007/s00405-014-3477-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 12/23/2014] [Indexed: 10/24/2022]
Abstract
To evaluate the expression and location of epithelial sodium channels (ENaCs) in human nasal polyp and normal nasal mucosa, and to characterize the relevance of ENaCs to the development of NPs. Nasal polyp tissue from 17 patients and nasal mucosa from ten patients were obtained through endoscopic sinus surgery. The mRNA concentrations of ENaC-α, β, and γ were detected by real-time polymerase chain reaction. The expression of ENaC-α was detected using western blot and immunofluorescence techniques. The distribution of ENaC-α in mucosal tissue was observed using a laser scanning confocal microscope. The transcriptional expression of three subunits of ENaC was in the following order: α > β > γ, in both groups. The transcriptional expression of α, β, and γ subunits of ENaC was elevated in nasal polyp compared to nasal mucosa (p < 0.01). ENaC-α expression was higher in nasal polyp than in nasal mucosa (p < 0.05). Immunofluorescent staining indicated that ENaC-α protein was distributed in the epithelial cell apical membrane. The expression of ENaC is upregulated in human nasal polyp, which might in turn facilitate the formation and development of nasal polyp.
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Abstract
Nephrotic syndrome and liver cirrhosis are common clinical manifestations, and are associated with avid sodium retention leading to the development of edema and ascites. However, the mechanism for the sodium retention is still incompletely understood and the molecular basis remains undefined. We examined the changes of sodium (co)transporters and epithelial sodium channels (ENaCs) in the kidneys of experimental nephrotic syndrome and liver cirrhosis. The results demonstrated that puromycin- or HgCl2-induced nephrotic syndrome was associated with 1) sodium retention, decreased urinary sodium excretion, development of ascites, and increased plasma aldosterone level; 2) increased apical targeting of ENaC subunits in connecting tubule and collecting duct segments; and 3) decreased protein abundance of type 2 11β-hydroxysteroid dehydrogenase (11βHSD2). Experimental liver cirrhosis was induced in rats by CCl4 treatment or common bile duct ligation. An increased apical targeting of alpha-, beta-, and gamma-ENaC subunits in connecting tubule, and cortical and medullary collecting duct segments in sodium retaining phase of liver cirhosis but not in escape phase of sodium retention. Immunolabeling intensity of 11βHSD2 in the connecting tubule and cortical collecting duct was significantly reduced in sodium retaining phase of liver cirrhosis, and this was confirmed by immunoblotting. These observations therefore strongly support the view that the renal sodium retention associated with nephrotic syndrome and liver cirrhosis is caused by increased sodium reabsorption in the aldosterone sensitive distal nephron including the connecting tubule and collecting duct, and increased apical targeting of ENaC subunits plays a role in the development of sodium retention in nephrotic syndrome and liver cirrhosis.
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Affiliation(s)
- Soo Wan Kim
- Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea
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Abstract
Aldosterone regulates blood pressure through its effects on the kidney and the cardiovascular system. Dysregulation of aldosterone signalling can result in hypertension which in turn can lead to chronic pathologies of the kidney such as renal fibrosis and nephropathy. Aldosterone acts by binding to the mineralocorticoid receptor (MR), which acts as a ligand-dependent transcription factor in target tissues such as segments of the distal nephron including the connecting tubule and cortical collecting duct (CCD). Aldosterone also promotes the activation of protein kinase signalling cascades that are coupled to growth factor receptors and act directly on specific substrates in the cell membrane or cytoplasm. The rapid actions of aldosterone can also modulate gene expression through the phosphorylation of transcription factors. Aldosterone is a key regulator of Na(+) conservation in the distal nephron, largely through multiple mechanisms that modulate the activity of the epithelial Na(+) channel (ENaC). Aldosterone transcriptionally up-regulates the ENaCα subunit and also up regulates serum and glucocorticoid-regulated kinase-1 (SGK1) that indirectly regulates the ubiquitination of ENaC subunits. Aldosterone promotes the activation of protein kinase D1 (PKD1) which can modify the activity of ENaC and other transporters through effects on sub-cellular trafficking. In M1-CCD cells, early sub-cellular trafficking causes the redistribution of ENaC subunits within minutes of treatment with aldosterone. ENaC subunits can also interact directly with phosphatidylinositide signalling intermediates in the membrane and the mechanism by which PKD isoforms regulate protein trafficking is through the control of vesicle fission from the trans Golgi network by activation of phosphatidylinositol 4-kinaseIIIβ (PI4KIIIβ).
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Affiliation(s)
- Sinéad Quinn
- Molecular Medicine Laboratories, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland
| | - Brian J Harvey
- Molecular Medicine Laboratories, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland
| | - Warren Thomas
- Molecular Medicine Laboratories, Royal College of Surgeons in Ireland, Education and Research Centre, Beaumont Hospital, Dublin 9, Ireland.
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43
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Abstract
Neurons regulate ionic fluxes across their plasma membrane to maintain their excitable properties under varying environmental conditions. However, the mechanisms that regulate ion channels abundance remain poorly understood. Here we show that pickpocket 29 (ppk29), a gene that encodes a Drosophila degenerin/epithelial sodium channel (DEG/ENaC), regulates neuronal excitability via a protein-independent mechanism. We demonstrate that the mRNA 3′UTR of ppk29 affects neuronal firing rates and associated heat-induced seizures by acting as a natural antisense transcript (NAT) that regulates the neuronal mRNA levels of seizure (sei), the Drosophila homolog of the human Ether-à-go-go Related Gene (hERG) potassium channel. We find that the regulatory impact of ppk29 mRNA on sei is independent of the sodium channel it encodes. Thus, our studies reveal a novel mRNA dependent mechanism for the regulation of neuronal excitability that is independent of protein-coding capacity. DOI:http://dx.doi.org/10.7554/eLife.01849.001 Neurons communicate with one another via electrical signals known as action potentials. These signals are generated when a stimulus causes sodium and potassium ion channels in the cell membrane to open, leading to an influx of sodium ions, followed by an efflux of potassium ions. Changes in temperature affect the rate at which ion channels open and close, and thus affect how easy it is for a stimulus to trigger an action potential. In response to a sudden rise in temperature, neurons must adjust the number of ion channels in their membranes to ensure that they do not become hyperexcitable, which could result in epilepsy. Now, Zheng et al. have revealed one possible mechanism for how neurons do this. In the fruit fly, Drosophila, a gene for a potassium channel is found on the same chromosomal location as a gene for a sodium channel, and some of the genetic elements that regulate the expression of these two genes even overlap. However, the genes are on opposite strands of the DNA double helix. This means that when the genes are transcribed to produce molecules of messenger RNA (mRNA), which is usually single stranded, some of the mRNA molecules will pair up to form double-stranded mRNA molecules. This is significant because such RNA ‘duplexes’ have been shown to inhibit the translation of conventional single-stranded mRNA molecules into proteins, or to lead to their complete degradation. Zheng et al. found that flies with mutations in the potassium channel gene display seizures in response to sudden changes in temperature. However, insects with mutations in the sodium channel gene are not affected because, surprisingly, they have a higher than expected number of potassium channels. It turns out that the mutant sodium channel mRNA molecules are unable to form RNA duplexes with potassium channel mRNA molecules: these duplexes would normally limit the number of potassium channels so, in their absence, the number of potassium channels increases, and this protects the flies from seizures. Zheng et al. also uncovered a novel mechanism by which mRNA molecules can regulate gene expression independent of their role as templates for proteins. Further work is required to determine whether this mechanism is also present in other organisms, including humans. DOI:http://dx.doi.org/10.7554/eLife.01849.002
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Affiliation(s)
- Xingguo Zheng
- Department of Biology, Washington University in St. Louis, St. Louis, United States
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Miller RL, Loewy AD. ENaC γ-expressing astrocytes in the circumventricular organs, white matter, and ventral medullary surface: sites for Na+ regulation by glial cells. J Chem Neuroanat 2013; 53:72-80. [PMID: 24145067 DOI: 10.1016/j.jchemneu.2013.10.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 10/02/2013] [Indexed: 12/19/2022]
Abstract
Using a double immunofluorescence procedure, we report the discovery of a novel group of fibrous astrocytes that co-express epithelial sodium channel (ENaC) γ-subunit protein along with glial acidic fibrillary protein (GFAP). These cells are concentrated along the borders of the sensory circumventricular organs (CVOs), embedded in the white matter (e.g., optic nerve/chiasm, anterior commissure, corpus callosum, pyramidal tract) and are components of the pia mater. In the CVOs, a compact collection of ENaC γ-immunoreactive glial fibers form the lamina terminalis immediately rostral to the organum vasculosum of the lamina terminalis (OVLT). Astrocyte processes can be traced into the median preoptic nucleus - a region implicated in regulation of sodium homeostasis. In the subfornical organ (SFO), ENaC γ-GFAP astrocytes lie in its lateral border, but not in the ventromedial core. In the area postrema (AP), a dense ENaC γ-GFAP glial fibers form the interface between the AP and nucleus tractus solitarius; this area is termed the subpostremal region. Antibodies against the ENaC α- or β-subunit proteins do not immunostain these regions. In contrast, the antibodies against the ENaC γ-subunit protein react weakly with neuronal cell bodies in the CVOs. Besides affecting glial-neural functions in the CVOs, the astrocytes found in the white matter may affect saltatory nerve conduction, serving as a sodium buffer. The ENaC γ-expressing astrocytes of the ventral medulla send processes into the raphe pallidus which intermingle with the serotoninergic (5-HT) neurons found in this region as well as with the other nearby 5-HT neurons distributed along ventral medullary surface.
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