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Shepard BD, Chau J, Kurtz R, Rosenberg AZ, Sarder P, Border SP, Ginley B, Rodriguez O, Albanese C, Knoer G, Greene A, De Souza AMA, Ranjit S, Levi M, Ecelbarger CM. Nascent shifts in renal cellular metabolism, structure, and function due to chronic empagliflozin in prediabetic mice. Am J Physiol Cell Physiol 2024; 326:C1272-C1290. [PMID: 38602847 PMCID: PMC11193535 DOI: 10.1152/ajpcell.00446.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 02/21/2024] [Accepted: 02/21/2024] [Indexed: 04/13/2024]
Abstract
Sodium-glucose cotransporter, type 2 inhibitors (SGLT2i) are emerging as the gold standard for treatment of type 2 diabetes (T2D) with renal protective benefits independent of glucose lowering. We took a high-level approach to evaluate the effects of the SGLT2i, empagliflozin (EMPA) on renal metabolism and function in a prediabetic model of metabolic syndrome. Male and female 12-wk-old TallyHo (TH) mice, and their closest genetic lean strain (Swiss-Webster, SW) were treated with a high-milk-fat diet (HMFD) plus/minus EMPA (@0.01%) for 12-wk. Kidney weights and glomerular filtration rate were slightly increased by EMPA in the TH mice. Glomerular feature analysis by unsupervised clustering revealed sexually dimorphic clustering, and one unique cluster relating to EMPA. Periodic acid Schiff (PAS) positive areas, reflecting basement membranes and mesangium were slightly reduced by EMPA. Phasor-fluorescent life-time imaging (FLIM) of free-to-protein bound NADH in cortex showed a marginally greater reliance on oxidative phosphorylation with EMPA. Overall, net urine sodium, glucose, and albumin were slightly increased by EMPA. In TH, EMPA reduced the sodium phosphate cotransporter, type 2 (NaPi-2), but increased sodium hydrogen exchanger, type 3 (NHE3). These changes were absent or blunted in SW. EMPA led to changes in urine exosomal microRNA profile including, in females, enhanced levels of miRs 27a-3p, 190a-5p, and 196b-5p. Network analysis revealed "cancer pathways" and "FOXO signaling" as the major regulated pathways. Overall, EMPA treatment to prediabetic mice with limited renal disease resulted in modifications in renal metabolism, structure, and transport, which may preclude and underlie protection against kidney disease with developing T2D.NEW & NOTEWORTHY Renal protection afforded by sodium glucose transporter, type 2 inhibitors (SGLT2i), e.g., empagliflozin (EMPA) involves complex intertwined mechanisms. Using a novel mouse model of obesity with insulin resistance, the TallyHo/Jng (TH) mouse on a high-milk-fat diet (HMFD), we found subtle changes in metabolism including altered regulation of sodium transporters that line the renal tubule. New potential epigenetic determinants of metabolic changes relating to FOXO and cancer signaling pathways were elucidated from an altered urine exosomal microRNA signature.
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Affiliation(s)
- Blythe D Shepard
- Department of Human Science, Georgetown University, Washington, District of Columbia, United States
| | - Jennifer Chau
- Department of Medicine,Georgetown University, Washington, District of Columbia, United States
| | - Ryan Kurtz
- Department of Human Science, Georgetown University, Washington, District of Columbia, United States
| | - Avi Z Rosenberg
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland, United States
| | - Pinaki Sarder
- J Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, Florida, United States
| | - Samuel P Border
- J Crayton Pruitt Department of Biomedical Engineering, University of Florida, Gainesville, Florida, United States
| | - Brandon Ginley
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland, United States
- Department of Computational Cell Biology, Anatomy, and Pathology, State University of New York at Buffalo, Buffalo, New York, United States
| | - Olga Rodriguez
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia, United States
- Center for Translational Imaging, Georgetown University, Washington, District of Columbia, United States
| | - Chris Albanese
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, District of Columbia, United States
- Center for Translational Imaging, Georgetown University, Washington, District of Columbia, United States
- Department of Radiology, Georgetown University, Washington, District of Columbia, United States
| | - Grace Knoer
- Center for Translational Imaging, Georgetown University, Washington, District of Columbia, United States
| | - Aarenee Greene
- Department of Medicine,Georgetown University, Washington, District of Columbia, United States
| | - Aline M A De Souza
- Department of Medicine,Georgetown University, Washington, District of Columbia, United States
| | - Suman Ranjit
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, District of Columbia, United States
- Microscopy & Imaging Shared Resources, Georgetown University, Washington, District of Columbia, United States
| | - Moshe Levi
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, District of Columbia, United States
| | - Carolyn M Ecelbarger
- Department of Medicine,Georgetown University, Washington, District of Columbia, United States
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Zinc Laurate Protects against Intestinal Barrier Dysfunction and Inflammation Induced by ETEC in a Mice Model. Nutrients 2022; 15:nu15010054. [PMID: 36615713 PMCID: PMC9824434 DOI: 10.3390/nu15010054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 12/15/2022] [Accepted: 12/20/2022] [Indexed: 12/24/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) infection is one of the most common bacterial causes of diarrhea in children and young farm animals. Medium-chain fatty acids (MCFAs) have been widely used for their antibacterial and immune functions. However, there is limited information regarding the role of MCFAs chelated with Zn in diarrhea induced by ETEC infection. Here, zinc laurate (ZnLa) was used to evaluate its protective effect in a mice diarrhea model induced by ETEC. A total of 45 ICR-weaned female mice were randomly assigned to marginal zinc deficiency (dZn), dZn, and ETEC infection groups (dZn+ETEC); ETEC infection was co-treated with a low, middle, or high dose of ZnLa (ZnLa LOW+ETEC, ZnLa MID+ETEC, and ZnLa HIGH+ETEC), respectively, to explore the effect and its mechanism of ZnLa on diarrhea and intestinal health of mice challenged with ETEC. To further compare the antibacterial efficiency of ZnLa and ZnSO4 in mice with ETEC infection, a total of 36 ICR-weaned female mice were randomly divided into ZnLa, ZnLa+ETEC, ZnSO4, and ZnSO4 and ETEC infection groups (ZnSO4+ETEC); moreover, the growth curve of ETEC also compared ZnLa and ZnSO4 in vitro. Mice pretreated with ZnLa were effectively guarded against body weight losses and increases in diarrhea scores induced by ETEC. ZnLa pretreatment also prevented intestinal barrier damage and ion transport in mice challenged with ETEC, as evidenced by the fact that the intestinal villus height and the ratio of villus height and crypt depth, tight junction protein, and Na+ absorption were higher, whereas intestinal permeability and anion secretion were lower in mice pretreated with ZnLa. In addition, ZnLa conferred effective protection against ETEC-induced intestinal inflammatory responses, as the increases in protein and mRNAs of proinflammatory cytokines were prevented in serum and jejunum, which was likely associated with the TLR4/MYD88/NF-κB signaling pathway. The increase in ETEC shedding and virulence-related gene expression was prevented in mice with ZnLa pretreatment. Finally, the growth of ETEC and virulence-related gene expression were lower in the ZnLa group than in ZnSO4 with an equal concentration of zinc. These findings suggest that ZnLa is a promising prevention strategy to remedy ETEC infection.
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Nikolovska K, Seidler UE, Stock C. The Role of Plasma Membrane Sodium/Hydrogen Exchangers in Gastrointestinal Functions: Proliferation and Differentiation, Fluid/Electrolyte Transport and Barrier Integrity. Front Physiol 2022; 13:899286. [PMID: 35665228 PMCID: PMC9159811 DOI: 10.3389/fphys.2022.899286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 04/19/2022] [Indexed: 12/11/2022] Open
Abstract
The five plasma membrane Na+/H+ exchanger (NHE) isoforms in the gastrointestinal tract are characterized by distinct cellular localization, tissue distribution, inhibitor sensitivities, and physiological regulation. NHE1 (Slc9a1) is ubiquitously expressed along the gastrointestinal tract in the basolateral membrane of enterocytes, but so far, an exclusive role for NHE1 in enterocyte physiology has remained elusive. NHE2 (Slc9a2) and NHE8 (Slc9a8) are apically expressed isoforms with ubiquitous distribution along the colonic crypt axis. They are involved in pHi regulation of intestinal epithelial cells. Combined use of a knockout mouse model, intestinal organoid technology, and specific inhibitors revealed previously unrecognized actions of NHE2 and NHE8 in enterocyte proliferation and differentiation. NHE3 (Slc9a3), expressed in the apical membrane of differentiated intestinal epithelial cells, functions as the predominant nutrient-independent Na+ absorptive mechanism in the gut. The new selective NHE3 inhibitor (Tenapanor) allowed discovery of novel pathophysiological and drug-targetable NHE3 functions in cystic-fibrosis associated intestinal obstructions. NHE4, expressed in the basolateral membrane of parietal cells, is essential for parietal cell integrity and acid secretory function, through its role in cell volume regulation. This review focuses on the expression, regulation and activity of the five plasma membrane Na+/H+ exchangers in the gastrointestinal tract, emphasizing their role in maintaining intestinal homeostasis, or their impact on disease pathogenesis. We point to major open questions in identifying NHE interacting partners in central cellular pathways and processes and the necessity of determining their physiological role in a system where their endogenous expression/activity is maintained, such as organoids derived from different parts of the gastrointestinal tract.
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Al-Shamasi AA, Elkaffash R, Mohamed M, Rayan M, Al-Khater D, Gadeau AP, Ahmed R, Hasan A, Eldassouki H, Yalcin HC, Abdul-Ghani M, Mraiche F. Crosstalk between Sodium-Glucose Cotransporter Inhibitors and Sodium-Hydrogen Exchanger 1 and 3 in Cardiometabolic Diseases. Int J Mol Sci 2021; 22:12677. [PMID: 34884494 PMCID: PMC8657861 DOI: 10.3390/ijms222312677] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/08/2021] [Accepted: 11/12/2021] [Indexed: 12/14/2022] Open
Abstract
Abnormality in glucose homeostasis due to hyperglycemia or insulin resistance is the hallmark of type 2 diabetes mellitus (T2DM). These metabolic abnormalities in T2DM lead to cellular dysfunction and the development of diabetic cardiomyopathy leading to heart failure. New antihyperglycemic agents including glucagon-like peptide-1 receptor agonists and the sodium-glucose cotransporter-2 inhibitors (SGLT2i) have been shown to attenuate endothelial dysfunction at the cellular level. In addition, they improved cardiovascular safety by exhibiting cardioprotective effects. The mechanism by which these drugs exert their cardioprotective effects is unknown, although recent studies have shown that cardiovascular homeostasis occurs through the interplay of the sodium-hydrogen exchangers (NHE), specifically NHE1 and NHE3, with SGLT2i. Another theoretical explanation for the cardioprotective effects of SGLT2i is through natriuresis by the kidney. This theory highlights the possible involvement of renal NHE transporters in the management of heart failure. This review outlines the possible mechanisms responsible for causing diabetic cardiomyopathy and discusses the interaction between NHE and SGLT2i in cardiovascular diseases.
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Affiliation(s)
- Al-Anood Al-Shamasi
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha P.O. Box 2713, Qatar; (A.-A.A.-S.); (R.E.); (M.M.); (M.R.); (D.A.-K.)
- Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha P.O. Box 2713, Qatar
| | - Rozina Elkaffash
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha P.O. Box 2713, Qatar; (A.-A.A.-S.); (R.E.); (M.M.); (M.R.); (D.A.-K.)
- Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha P.O. Box 2713, Qatar
| | - Meram Mohamed
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha P.O. Box 2713, Qatar; (A.-A.A.-S.); (R.E.); (M.M.); (M.R.); (D.A.-K.)
- Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha P.O. Box 2713, Qatar
| | - Menatallah Rayan
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha P.O. Box 2713, Qatar; (A.-A.A.-S.); (R.E.); (M.M.); (M.R.); (D.A.-K.)
- Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha P.O. Box 2713, Qatar
| | - Dhabya Al-Khater
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha P.O. Box 2713, Qatar; (A.-A.A.-S.); (R.E.); (M.M.); (M.R.); (D.A.-K.)
- Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha P.O. Box 2713, Qatar
| | - Alain-Pierre Gadeau
- INSERM, Biology of Cardiovascular Disease, University of Bordeaux, U1034 Pessac, France;
| | - Rashid Ahmed
- Department of Mechanical and Chemical Engineering, College of Engineering, Qatar University, Doha P.O. Box 2713, Qatar; (R.A.); (A.H.)
- Biomedical Research Centre (BRC), Qatar University, Doha P.O. Box 2713, Qatar;
| | - Anwarul Hasan
- Department of Mechanical and Chemical Engineering, College of Engineering, Qatar University, Doha P.O. Box 2713, Qatar; (R.A.); (A.H.)
- Biomedical Research Centre (BRC), Qatar University, Doha P.O. Box 2713, Qatar;
| | - Hussein Eldassouki
- College of Kinesiology, University of Saskatchewan, Saskatoon, SK S7N 5B5, Canada;
| | | | - Muhammad Abdul-Ghani
- Division of Diabetes, University of Texas Health Science Center at San Antonio, Floyd Curl Drive, San Antonio, TX 7703, USA;
| | - Fatima Mraiche
- Department of Pharmaceutical Sciences, College of Pharmacy, QU Health, Qatar University, Doha P.O. Box 2713, Qatar; (A.-A.A.-S.); (R.E.); (M.M.); (M.R.); (D.A.-K.)
- Biomedical and Pharmaceutical Research Unit, QU Health, Qatar University, Doha P.O. Box 2713, Qatar
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Jorge ARC, Marinho AD, Silveira JADM, Nogueira Junior FA, de Aquino PEA, Alves APNN, Jorge RJB, Ferreira Junior RS, Monteiro HSA. Phosphodiesterase-5 inhibitor sildenafil attenuates kidney injury induced by Bothrops alternatus snake venom. Toxicon 2021; 202:46-52. [PMID: 34516995 DOI: 10.1016/j.toxicon.2021.08.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 08/12/2021] [Accepted: 08/30/2021] [Indexed: 10/20/2022]
Abstract
Acute kidney injury pathogenesis in envenoming by snakes is multifactorial and involves immunologic reactions, hemodynamic disturbances, and direct nephrotoxicity. Sildenafil (SFC), a phosphodiesterase 5 inhibitor, has been reported to protect against pathological kidney changes. OBJECTIVE This study aimed to investigate the protective effect of sildenafil against Bothrops alternatus snake venom (BaV)-induced nephrotoxicity. METHODS Kidneys from Wistar rats (n = 6, weighing 260-300 g) were isolated and divided into four groups: (1) perfused with a modified Krebs-Henseleit solution (MKHS) containing 6 g% of bovine serum albumin; (2) administered 3 μg/mL SFC; (3) perfused with 3 μg/mL BaV; and (4) administered SFC + BaV, both at 3 μg/mL. Subsequently, the perfusion pressure (PP), renal vascular resistance (RVR), urinary flow (UF), glomerular filtration rate (GFR), and percentage of electrolyte tubular sodium and chloride transport (%TNa+, %TCl-, respectively) were evaluated. The cyclic guanosine monophosphate (cGMP) levels were analyzed in the perfusate, and the kidneys were removed to perform oxidative stress and histopathological analyses. RESULTS All renal parameters evaluated were reduced with BaV. In the SFC + BaV group, SFC restored PP to normal values and promoted a significant increase in %TNa+ and %TCl-. cGMP levels were increased in the SFC + BaV group. The oxidative stress biomarkers, malondialdehyde (MDA) and glutathione (GSH), were reduced by BaV. In the SFC + BaV group, a decrease in MDA without an increase in GSH was observed. These findings were confirmed by histological analysis, which showed improvement mainly in tubulis. CONCLUSION Our data suggest the involvement of phosphodiesterase-5 and cGMP in BaV-induced nephrotoxicity since its effects were attenuated by the administration of SFC.
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Affiliation(s)
- Antônio Rafael Coelho Jorge
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| | - Aline Diogo Marinho
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil.
| | - João Alison de Moraes Silveira
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| | - Francisco Assis Nogueira Junior
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| | - Pedro Everson Alexandre de Aquino
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| | - Ana Paula Negreiros Nunes Alves
- Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil; Department of Dental Clinic, School of Pharmacy, Dentistry and Nursing, Federal University of Ceara, Monsenhor Furtado St., 60.430-350, Fortaleza, CE, Brazil
| | - Roberta Jeane Bezerra Jorge
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
| | - Rui Seabra Ferreira Junior
- Center for the Study of Venoms and Venomous Animals, Fazenda Experimental Lageado, São Paulo State University, José Barbosa de Barros St. 1780, 18610-307, Botucatu, SP, Brazil
| | - Helena Serra Azul Monteiro
- Department of Physiology and Pharmacology, School of Medicine, Federal University of Ceara, Coronel Nunes de Melo St., 1127, 60.430-275, Fortaleza, CE, Brazil; Drug Research and Development Center (NPDM), Federal University of Ceara, Coronel Nunes de Melo St., 1000, 60.430-275, Fortaleza, CE, Brazil
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Yang Y, Yu Q, Song H, Ran L, Wang K, Xie L, Huang S, Niu Z, Zhang Y, Kan Z, Yan T, Song Z. Decreased NHE3 activity and trafficking in TGEV-infected IPEC-J2 cells via the SGLT1-mediated P38 MAPK/AKt2 pathway. Virus Res 2020; 280:197901. [PMID: 32070687 PMCID: PMC7114662 DOI: 10.1016/j.virusres.2020.197901] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 01/09/2020] [Accepted: 02/14/2020] [Indexed: 02/03/2023]
Abstract
Decreased of apical of NHE3 protein expression and Na+/H+ exchange activity after TGEV infected IPEC-J2. SGLT1 can regulation the trafficking of NHE3 by p38MAPK/AKt2 singal pathway and show a corporate relationship. TGEV infection causes an increase in the expression of total SGLT1 protein. TGEV infection attenuates the translocation and exchange activity of NHE3 via the p38MAPK/AKt2 signaling pathway.
Transmissible gastroenteritis virus (TGEV) primarily replicates in intestinal epithelial cells and causes severe damage to host cells, resulting in diarrhea. Surface NHE3 serves as the key regulatory site controlling electroneutral Na+ absorption. In this study, our results showed that the surface NHE3 content was significantly reduced following TGEV infection, whereas the total level of protein expression was not significantly changed, and NHE3 activity gradually decreased with prolonged infection time. We then inhibited SGLT1 expression by lentiviral interference and drug inhibition, respectively. Inhibition studies showed that the level of phosphorylation of the downstream key proteins, MAPKAPK-2 and EZRIN, in the SGLT1-mediated p38MAPK/AKt2 signaling pathway was significantly increased. The surface NHE3 expression was also significantly increased, and NHE3 activity was also significantly enhanced. These results demonstrate that a TGEV infection can inhibit NHE3 translocation and attenuates sodium-hydrogen exchange activity via the SGLT1-mediated p38MAPK/AKt2 signaling pathway, affecting cellular electrolyte absorption leading to diarrhea.
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Affiliation(s)
- Yang Yang
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Qiuhan Yu
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Han Song
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Ling Ran
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Kai Wang
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Luyi Xie
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Shilei Huang
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Zheng Niu
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Yilin Zhang
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Zifei Kan
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Tao Yan
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China
| | - Zhenhui Song
- Department of Veterinary Medicine Southwest University Chongqing People's Republic of China, Chongqing 402460, China.
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Pedersen SF, Counillon L. The SLC9A-C Mammalian Na +/H + Exchanger Family: Molecules, Mechanisms, and Physiology. Physiol Rev 2019; 99:2015-2113. [PMID: 31507243 DOI: 10.1152/physrev.00028.2018] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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Sitprija V, Sitprija S. Marine toxins and nephrotoxicity:Mechanism of injury. Toxicon 2019; 161:44-49. [PMID: 30826470 DOI: 10.1016/j.toxicon.2019.02.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 02/21/2019] [Accepted: 02/24/2019] [Indexed: 02/06/2023]
Abstract
Marine toxins are known among several causes of toxin induced renal injury. Enzymatic mechanism by phospholipase A2 is responsible for acute kidney injury (AKI) in sea snake envenoming without any change in cardiac output and systemic vascular resistance. Cnidarian toxins form pores in the cell membrane with Ca influx storm resulting in cell death. Among plankton toxins domoic acid, palytoxin and maitotoxin cause renal injury by ion transport into the cell through ion channels resulting in renal cell swelling and lysis. Okadaic acid, calyculin A, microcystin LR and nodularin cause AKI by serine threonine phosphatase inhibition and hyperphosphorylation with increased activity of Ca2+/calmodulin - dependent protein kinase II, increased cytosolic Ca2+, reactive oxygen species, caspase and P53. Renal injury by plankons is mostly subclinical and requires sensitive biomarker for diagnosis. In this respect repeated consumption of plankton toxin contaminated seafood is a risk of developing chronic renal disease. The subject deserves more clinical study and scientific attention.
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Affiliation(s)
- Visith Sitprija
- Queen Saovabha Memorial Institute, Thai Red Cross Society, Rama 4 Road, Bangkok, 10330, Thailand.
| | - Siravit Sitprija
- Department of Biology, Mahidol University, Rama 6 Road, Bangkok, 10400, Thailand.
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9
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Lang F, Guelinckx I, Lemetais G, Melander O. Two Liters a Day Keep the Doctor Away? Considerations on the Pathophysiology of Suboptimal Fluid Intake in the Common Population. Kidney Blood Press Res 2017; 42:483-494. [PMID: 28787716 DOI: 10.1159/000479640] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 04/19/2017] [Indexed: 11/19/2022] Open
Abstract
Suboptimal fluid intake may require enhanced release of antidiuretic hormone (ADH) or vasopressin for the maintenance of adequate hydration. Enhanced copeptin levels (reflecting enhanced vasopressin levels) in 25% of the common population are associated with enhanced risk of metabolic syndrome with abdominal obesity, type 2 diabetes, hypertension, coronary artery disease, heart failure, vascular dementia, cognitive impairment, microalbuminuria, chronic kidney disease, inflammatory bowel disease, cancer, and premature mortality. Vasopressin stimulates the release of glucocorticoids which in turn up-regulate the serum- and glucocorticoid-inducible kinase 1 (SGK1). Moreover, dehydration upregulates the transcription factor NFAT5, which in turn stimulates SGK1 expression. SGK1 is activated by insulin, growth factors and oxidative stress via phosphatidylinositide-3-kinase, 3-phosphoinositide-dependent kinase PDK1 and mTOR. SGK1 is a powerful stimulator of Na+/K+-ATPase, carriers (e.g. the Na+,K+,2Cl- cotransporter NKCC, the NaCl cotransporter NCC, the Na+/H+ exchanger NHE3, and the Na+ coupled glucose transporter SGLT1), and ion channels (e.g. the epithelial Na+ channel ENaC, the Ca2+ release activated Ca2+ channel Orai1 with its stimulator STIM1, and diverse K+ channels). SGK1 further participates in the regulation of the transcription factors nuclear factor kappa-B NFκB, p53, cAMP responsive element binding protein (CREB), activator protein-1, and forkhead transcription factor FKHR-L1 (FOXO3a). Enhanced SGK1 activity fosters the development of hypertension, obesity, diabetes, thrombosis, stroke, inflammation including inflammatory bowel disease and autoimmune disease, cardiac fibrosis, proteinuria, renal failure as well as tumor growth. The present brief review makes the case that suboptimal fluid intake in the common population may enhance vasopressin and glucocorticoid levels thus up-regulating SGK1 expression and favouring the development of SGK1 related pathologies.
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Affiliation(s)
- Florian Lang
- Department of Physiology I, University of Tuebingen, Tuebingen, Germany
| | | | | | - Olle Melander
- Department of Clinical Sciences, Lund University, Malmö, Sweden
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10
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Sitprija V, Sitprija S. Animal toxins and renal ion transport: Another dimension in tropical nephrology. Nephrology (Carlton) 2017; 21:355-62. [PMID: 26421422 DOI: 10.1111/nep.12633] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 09/10/2015] [Accepted: 09/24/2015] [Indexed: 12/31/2022]
Abstract
Renal vascular and tubular ion channels and transporters involved in toxin injury are reviewed. Vascular ion channels modulated by animal toxins, which result in haemodynamic alterations and changes in blood pressure, include ENaC/Degenerin/ASIC, ATP sensitive K channels (KATP ), Ca activated K channels (Kca) and voltage gated Ca channels, mostly L-type. Renal tubular Na channels and K channels are also targeted by animal toxins. NHE3 and ENaC are two important targets. NCC and NKCC may be involved indirectly by vasoactive mediators induced by inflammation. Most renal tubular K channels including voltage gated K channels (Kv1), KATP , ROMK1, BK and SK are blocked by scorpion toxins. Few are inhibited by bee, wasp and spider venoms. Due to small envenoming, incomplete block and several compensatory mechanisms in renal tubules, serum electrolyte charges are not apparent. Changes in serum electrolytes are observed in injury by large amount of venom when several channels or transporters are targeted. Envenomings by scorpions and bees are examples of toxins targeting multiple ion channels and transporters.
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Affiliation(s)
- Visith Sitprija
- Queen Saovabha Memorial Institute, Mahidol University, Bangkok, Thailand
| | - Siravit Sitprija
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, Thailand
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Lou Y, Zhang F, Luo Y, Wang L, Huang S, Jin F. Serum and Glucocorticoid Regulated Kinase 1 in Sodium Homeostasis. Int J Mol Sci 2016; 17:ijms17081307. [PMID: 27517916 PMCID: PMC5000704 DOI: 10.3390/ijms17081307] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/02/2016] [Accepted: 08/03/2016] [Indexed: 12/13/2022] Open
Abstract
The ubiquitously expressed serum and glucocorticoid regulated kinase 1 (SGK1) is tightly regulated by osmotic and hormonal signals, including glucocorticoids and mineralocorticoids. Recently, SGK1 has been implicated as a signal hub for the regulation of sodium transport. SGK1 modulates the activities of multiple ion channels and carriers, such as epithelial sodium channel (ENaC), voltage-gated sodium channel (Nav1.5), sodium hydrogen exchangers 1 and 3 (NHE1 and NHE3), sodium-chloride symporter (NCC), and sodium-potassium-chloride cotransporter 2 (NKCC2); as well as the sodium-potassium adenosine triphosphatase (Na+/K+-ATPase) and type A natriuretic peptide receptor (NPR-A). Accordingly, SGK1 is implicated in the physiology and pathophysiology of Na+ homeostasis. Here, we focus particularly on recent findings of SGK1’s involvement in Na+ transport in renal sodium reabsorption, hormone-stimulated salt appetite and fluid balance and discuss the abnormal SGK1-mediated Na+ reabsorption in hypertension, heart disease, edema with diabetes, and embryo implantation failure.
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Affiliation(s)
- Yiyun Lou
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
- Department of Gynaecology, Hangzhou Hospital of Traditional Chinese Medicine, Hangzhou 310007, Zhejiang, China.
| | - Fan Zhang
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Yuqin Luo
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Liya Wang
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Shisi Huang
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
| | - Fan Jin
- Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou 310006, Zhejiang, China.
- Key Laboratory of Reproductive Genetics, National Ministry of Education (Zhejiang University), Women's Reproductive Healthy Laboratory of Zhejiang Province, Hangzhou 310058, Zhejiang, China.
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12
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Effects of diuretics on sodium-dependent glucose cotransporter 2 inhibitor-induced changes in blood pressure in obese rats suffering from the metabolic syndrome. J Hypertens 2016; 34:893-906. [DOI: 10.1097/hjh.0000000000000871] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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13
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Abstract
The H(+) concentration in human blood is kept within very narrow limits, ~40 nmol/L, despite the fact that dietary metabolism generates acid and base loads that are added to the systemic circulation throughout the life of mammals. One of the primary functions of the kidney is to maintain the constancy of systemic acid-base chemistry. The kidney has evolved the capacity to regulate blood acidity by performing three key functions: (i) reabsorb HCO3(-) that is filtered through the glomeruli to prevent its excretion in the urine; (ii) generate a sufficient quantity of new HCO3(-) to compensate for the loss of HCO3(-) resulting from dietary metabolic H(+) loads and loss of HCO3(-) in the urea cycle; and (iii) excrete HCO3(-) (or metabolizable organic anions) following a systemic base load. The ability of the kidney to perform these functions requires that various cell types throughout the nephron respond to changes in acid-base chemistry by modulating specific ion transport and/or metabolic processes in a coordinated fashion such that the urine and renal vein chemistry is altered appropriately. The purpose of the article is to provide the interested reader with a broad review of a field that began historically ~60 years ago with whole animal studies, and has evolved to where we are currently addressing questions related to kidney acid-base regulation at the single protein structure/function level.
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Affiliation(s)
- Ira Kurtz
- Division of Nephrology, David Geffen School of Medicine, Los Angeles, CA; Brain Research Institute, UCLA, Los Angeles, CA
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Crajoinas RO, Pessoa TD, Rodrigues MV, Malnic G, Girardi ACC. Changes in the activity and expression of protein phosphatase-1 accompany the differential regulation of NHE3 before and after the onset of hypertension in spontaneously hypertensive rats. Acta Physiol (Oxf) 2014; 211:395-408. [PMID: 24666699 DOI: 10.1111/apha.12288] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Revised: 11/18/2013] [Accepted: 03/18/2014] [Indexed: 12/14/2022]
Abstract
AIM The Na(+) /H(+) exchanger NHE3 activity decreases in the proximal tubule of spontaneously hypertensive rats (SHRs) as blood pressure increases, and this reduction is correlated with higher NHE3 phosphorylation levels at the PKA consensus site serine 552. This study tested the hypothesis that this lowered NHE3 activity is associated with an increase in PKA activity and expression, and/or a decrease in protein phosphatase-1 (PP1) activity and expression. METHODS Proximal tubule NHE3 activity was measured as the rate of bicarbonate reabsorption by stationary microperfusion. NHE3 phosphorylation and protein expression were determined by immunoblotting. PKA and PP1 activities were determined using specific substrates under optimal enzymatic conditions. RESULTS The PKA activator, 6-MB-cAMP, increased the phosphorylation levels of NHE3 at serine 552 in the renal cortex; this increase happens to a much greater extent in young pre-hypertensive SHRs (Y-SHRs) compared to adult SHRs with established hypertension (A-SHRs). Likewise, the inhibitory effect of 6-MB-cAMP on NHE3 transport activity was much more pronounced in the proximal tubules of Y-SHRs than in those of A-SHRs. Renal cortical activity of PKA was not significantly different between Y-SHRs and A-SHRs. On the other hand, Y-SHRs exhibited higher protein phosphatase 1 (PP1) activity, and their expression of the PP1 catalytic subunit PP1α in the renal cortex was also higher than in A-SHRs. CONCLUSION Collectively, these results support the idea that the lower NHE3 transport activity and higher phosphorylation occurring after the development of hypertension in SHRs are due, at least in part, to reduced PP1-mediated dephosphorylation of NHE3 at serine 552.
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Affiliation(s)
- R. O. Crajoinas
- Laboratory of Genetics and Molecular Cardiology; Heart Institute (InCor); University of São Paulo Medical School; São Paulo Brazil
| | - T. D. Pessoa
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo Brazil
| | - M. V. Rodrigues
- Laboratory of Genetics and Molecular Cardiology; Heart Institute (InCor); University of São Paulo Medical School; São Paulo Brazil
| | - G. Malnic
- Department of Physiology and Biophysics; Institute of Biomedical Sciences; University of São Paulo; São Paulo Brazil
| | - A. C. C. Girardi
- Laboratory of Genetics and Molecular Cardiology; Heart Institute (InCor); University of São Paulo Medical School; São Paulo Brazil
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Xie P, Joladarashi D, Dudeja P, Sun L, Kanwar YS. Modulation of angiotensin II-induced inflammatory cytokines by the Epac1-Rap1A-NHE3 pathway: implications in renal tubular pathobiology. Am J Physiol Renal Physiol 2014; 306:F1260-74. [PMID: 24553435 DOI: 10.1152/ajprenal.00069.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Besides the glomerulus, the tubulointerstitium is often concomitantly affected in certain diseases, e.g., diabetic nephropathy, and activation of the renin-angiotensin system, to a certain extent, worsens its outcome because of perturbations in hemodynamics and possibly tubuloglomerular feedback. Certain studies suggest that pathobiology of the tubulointerstitium is influenced by small GTPases, e.g., Rap1. We investigated the effect of ANG II on inflammatory cytokines, while at the same time focusing on upstream effector of Rap1, i.e., Epac1, and some of the downstream tubular transport molecules, i.e., Na/H exchanger 3 (NHE3). ANG II treatment of LLC-PK1 cells decreased Rap1a GTPase activity in a time- and dose-dependent manner. ANG II treatment led to an increased membrane translocation of NHE3, which was reduced with Epac1 and PKA activators. ANG II-induced NHE3 translocation was notably reduced with the transfection of Rap1a dominant positive mutants, i.e., Rap1a-G12V or Rap1a-T35A. Transfection of cells with dominant negative Rap1a mutants, i.e., Rap1a-S17A, or Epac1 mutant, i.e., EPAC-ΔcAMP, normalized ANG II-induced translocation of NHE3. In addition, ANG II treatment led to an increased expression of inflammatory cytokines, i.e., IL-1β, IL-6, IL-8, and TNF-α, which was reduced with Rap1a-G12V or Rap1a-T35A transfection, while it reverted to previous comparable levels following transfection of Rap1a-S17A or EPAC-ΔcAMP. ANG II-induced expression of cytokines was reduced with the treatment with NHE3 inhibitor S3226 or with Epac1 and PKA activators. These data suggest that this novel Epac1-Rap1a-NHE3 pathway conceivably modulates ANG II-induced expression of inflammatory cytokines, and this information may yield the impetus for developing strategies to reduce tubulointertstitial inflammation in various renal diseases.
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Affiliation(s)
- Ping Xie
- Departments of Pathology and Medicine, Northwestern University, Chicago, Illinois; and
| | | | - Pradeep Dudeja
- Department of Medicine, University of Illinois, Chicago, Illinois
| | - Lin Sun
- Departments of Pathology and Medicine, Northwestern University, Chicago, Illinois; and
| | - Yashpal S Kanwar
- Departments of Pathology and Medicine, Northwestern University, Chicago, Illinois; and
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Lang F, Stournaras C, Alesutan I. Regulation of transport across cell membranes by the serum- and glucocorticoid-inducible kinase SGK1. Mol Membr Biol 2014; 31:29-36. [PMID: 24417516 DOI: 10.3109/09687688.2013.874598] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The serum- and glucocorticoid-inducible kinase 1 (SGK1) is genomically upregulated by cell stress including energy depletion and hyperosmotic shock as well as a variety of hormones including glucocorticoids, mineralocorticoids and TGFβ. SGK1 is activated by insulin, growth factors and oxidative stress via phosphatidylinositide-3-kinase, 3-phosphoinositide-dependent kinase PDK1 and mTOR. SGK1 is a powerful stimulator of Na(+)/K(+)-ATPase, carriers (e.g., NCC, NKCC, NHE1, NHE3, SGLT1, several amino acid transporters) and ion channels (e.g., ENaC, SCN5A, TRPV4-6, ORAI1/STIM1, ROMK, KCNE1/KCNQ1, GluR6, CFTR). Mechanisms employed by SGK1 in transport regulation include direct phosphorylation of target transport proteins, phosphorylation and thus activation of other transport regulating kinases, stabilization of membrane proteins by phosphorylation and thus inactivation of the ubiquitin ligase NEDD4-2, as well as stimulation of transport protein expression by upregulation transcription factors (e.g., nuclear factor kappa-B [NFκB]) and by fostering of protein translation. SGK1 sensitivity of pump, carrier and channel activities participate in the regulation of epithelial transport, cardiac and neuronal excitability, degranulation, platelet function, migration, cell proliferation and apoptosis. SGK1-sensitive functions do not require the presence of SGK1 but are markedly upregulated by SGK1. Accordingly, the phenotype of SGK1 knockout mice is mild. The mice are, however, less sensitive to excessive activation of transport by glucocorticoids, mineralocorticoids, insulin and inflammation. Moreover, excessive SGK1 activity contributes to the pathophysiology of hypertension, obesity, diabetes, thrombosis, stroke, inflammation, autoimmune disease, fibrosis and tumor growth.
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Affiliation(s)
- Florian Lang
- Department of Physiology, University of Tübingen , Germany and
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17
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Hendus-Altenburger R, Kragelund BB, Pedersen SF. Structural dynamics and regulation of the mammalian SLC9A family of Na⁺/H⁺ exchangers. CURRENT TOPICS IN MEMBRANES 2014; 73:69-148. [PMID: 24745981 DOI: 10.1016/b978-0-12-800223-0.00002-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mammalian Na⁺/H⁺ exchangers of the SLC9A family are widely expressed and involved in numerous essential physiological processes. Their primary function is to mediate the 1:1 exchange of Na⁺ for H⁺ across the membrane in which they reside, and they play central roles in regulation of body, cellular, and organellar pH. Their function is tightly regulated through mechanisms involving interactions with multiple protein and lipid-binding partners, phosphorylations, and other posttranslational modifications. Biochemical and mutational analyses indicate that the SLC9As have a short intracellular N-terminus, 12 transmembrane (TM) helices necessary and sufficient for ion transport, and a C-terminal cytoplasmic tail region with essential regulatory roles. No high-resolution structures of the SLC9As exist; however, models based on crystal structures of the bacterial NhaAs support the 12 TM organization and suggest that TMIV and XI may form a central part of the ion-translocation pathway, whereas pH sensing may involve TMII, TMIX, and several intracellular loops. Similar to most ion transporters studied, SLC9As likely exist as coupled dimers in the membrane, and this appears to be important for the well-studied cooperativity of H⁺ binding. The aim of this work is to summarize and critically discuss the currently available evidence on the structural dynamics, regulation, and binding partner interactions of SLC9As, focusing in particular on the most widely studied isoform, SLC9A1/NHE1. Further, novel bioinformatic and structural analyses are provided that to some extent challenge the existing paradigm on how ions are transported by mammalian SLC9As.
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Affiliation(s)
- Ruth Hendus-Altenburger
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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18
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Lang F, Voelkl J. Therapeutic potential of serum and glucocorticoid inducible kinase inhibition. Expert Opin Investig Drugs 2013; 22:701-14. [PMID: 23506284 DOI: 10.1517/13543784.2013.778971] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
INTRODUCTION Expression of serum-and-glucocorticoid-inducible kinase-1 (SGK1) is low in most cells, but dramatically increases under certain pathophysiological conditions, such as glucocorticoid or mineralocorticoid excess, inflammation with TGFβ release, hyperglycemia, cell shrinkage and ischemia. SGK1 is activated by insulin and growth factors via phosphatidylinositide-3-kinase, 3-phosphoinositide-dependent kinase and mammalian target of rapamycin. SGK1 sensitive functions include activation of ion channels (including epithelial Na(+) channel ENaC, voltage gated Na(+) channel SCN5A transient receptor potential channels TRPV4 - 6, Ca(2+) release activated Ca(2+) channel Orai1/STIM1, renal outer medullary K(+) channel ROMK, voltage gated K(+) channels KCNE1/KCNQ1, kainate receptor GluR6, cystic fibrosis transmembrane regulator CFTR), carriers (including Na(+),Cl(-) symport NCC, Na(+),K(+),2Cl(-) symport NKCC, Na(+)/H(+) exchangers NHE1 and NHE3, Na(+), glucose symport SGLT1, several amino acid transporters), and Na(+)/K(+)-ATPase. SGK1 regulates several enzymes (e.g., glycogen synthase kinase-3, ubiquitin-ligase Nedd4-2) and transcription factors (e.g., forkhead transcription factor 3a, β-catenin, nuclear factor kappa B). AREAS COVERED The phenotype of SGK1 knockout mice is mild and SGK1 is apparently dispensible for basic functions. Excessive SGK1 expression and activity, however, contributes to the pathophysiology of several disorders, including hypertension, obesity, diabetes, thrombosis, stroke, fibrosing disease, infertility and tumor growth. A SGK1 gene variant (prevalence ∼ 3 - 5% in Caucasians and ∼ 10% in Africans) is associated with hypertension, stroke, obesity and type 2 diabetes. SGK1 inhibitors have been developed and shown to reduce blood pressure of hyperinsulinemic mice and to counteract tumor cell survival. EXPERT OPINION Targeting SGK1 may be a therapeutic option in several clinical conditions, including metabolic syndrome and tumor growth.
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Affiliation(s)
- Florian Lang
- University of Tuebingen, Department of Physiology, Tuebingen, Germany.
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Liu T, Jose PA. Gastrin induces sodium-hydrogen exchanger 3 phosphorylation and mTOR activation via a phosphoinositide 3-kinase-/protein kinase C-dependent but AKT-independent pathway in renal proximal tubule cells derived from a normotensive male human. Endocrinology 2013; 154:865-75. [PMID: 23275470 PMCID: PMC3548178 DOI: 10.1210/en.2012-1813] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gastrin is natriuretic, but its renal molecular targets and signal transduction pathways are not fully known. In this study, we confirmed the existence of CCKBR (a gastrin receptor) in male human renal proximal tubule cells and discovered that gastrin induced S6 phosphorylation, a downstream component of the phosphatidylinositol 3 kinase (PI3 kinase)-mammalian target of rapamycin pathway. Gastrin also increased the phosphorylation of sodium-hydrogen exchanger 3 (NHE3) at serine 552, caused its internalization, and decreased its expression at the cell surface and NHE activity. The phosphorylation of NHE3 and S6 was dependent on PI3 kinases because it was blocked by 2 different PI3-kinase inhibitors, wortmannin and LY294,002. The phosphorylation of NHE3 and S6 was not affected by the protein kinase A inhibitor H-89 but was blocked by a pan-PKC (chelerythrine) and a conventional PKC (cPKC) inhibitor (Gö6976) (10 μM) and an intracellular calcium chelator, 1,2-bis-(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, tetra(acetoxymethyl)-ester, suggesting the importance of cPKC and intracellular calcium in the gastrin signaling pathway. The cPKC involved was probably PKCα because it was phosphorylated by gastrin. The gastrin-mediated phosphorylation of NHE3, S6, and PKCα was via phospholipase C because it was blocked by a phospholipase C inhibitor, U73122 (10 μM). The phosphorylation (activation) of AKT, which is usually upstream of mammalian target of rapamycin in the classic PI3 kinase-AKT-p70S6K signaling pathway, was not affected, suggesting that the gastrin-induced phosphorylation of NHE3 and S6 is dependent on both PI3 kinase and PKCα but not AKT.
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Affiliation(s)
- Tianbing Liu
- Center for Molecular Physiology Research, Children's Research Institute, Children's National Medical Center, 111 Michigan Avenue, Washington, DC 20010, USA.
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Carvalho JG, Leite ADL, Peres-Buzalaf C, Salvato F, Labate CA, Everett ET, Whitford GM, Buzalaf MAR. Renal proteome in mice with different susceptibilities to fluorosis. PLoS One 2013; 8:e53261. [PMID: 23308176 PMCID: PMC3537663 DOI: 10.1371/journal.pone.0053261] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2012] [Accepted: 11/27/2012] [Indexed: 11/19/2022] Open
Abstract
A/J and 129P3/J mouse strains have different susceptibilities to dental fluorosis due to their genetic backgrounds. They also differ with respect to several features of fluoride (F) metabolism and metabolic handling of water. This study was done to determine whether differences in F metabolism could be explained by diversities in the profile of protein expression in kidneys. Weanling, male A/J mice (susceptible to dental fluorosis, n = 18) and 129P3/J mice (resistant, n = 18) were housed in pairs and assigned to three groups given low-F food and drinking water containing 0, 10 or 50 ppm [F] for 7 weeks. Renal proteome profiles were examined using 2D-PAGE and LC-MS/MS. Quantitative intensity analysis detected between A/J and 129P3/J strains 122, 126 and 134 spots differentially expressed in the groups receiving 0, 10 and 50 ppmF, respectively. From these, 25, 30 and 32, respectively, were successfully identified. Most of the proteins were related to metabolic and cellular processes, followed by response to stimuli, development and regulation of cellular processes. In F-treated groups, PDZK-1, a protein involved in the regulation of renal tubular reabsorption capacity was down-modulated in the kidney of 129P3/J mice. A/J and 129P3/J mice exhibited 11 and 3 exclusive proteins, respectively, regardless of F exposure. In conclusion, proteomic analysis was able to identify proteins potentially involved in metabolic handling of F and water that are differentially expressed or even not expressed in the strains evaluated. This can contribute to understanding the molecular mechanisms underlying genetic susceptibility to dental fluorosis, by indicating key-proteins that should be better addressed in future studies.
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Affiliation(s)
- Juliane Guimarães Carvalho
- Department of Biological Sciences, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil
| | - Aline de Lima Leite
- Department of Biological Sciences, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil
| | - Camila Peres-Buzalaf
- Department of Biological Sciences, Bauru Dental School, University of São Paulo, Bauru, São Paulo, Brazil
| | - Fernanda Salvato
- Department of Genetics, Escola Superior de Agricultura “Luiz de Queiros”, University of São Paulo, Piracicaba, São Paulo, Brazil
| | - Carlos Alberto Labate
- Department of Genetics, Escola Superior de Agricultura “Luiz de Queiros”, University of São Paulo, Piracicaba, São Paulo, Brazil
| | - Eric T. Everett
- Department of Pediatric Dentistry, School of Dentistry, The Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Gary Milton Whitford
- Department of Oral Biology, School of Dentistry, The Medical College of Georgia, Augusta, Georgia, United States of America
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Inoue BH, dos Santos L, Pessoa TD, Antonio EL, Pacheco BPM, Savignano FA, Carraro-Lacroix LR, Tucci PJF, Malnic G, Girardi ACC. Increased NHE3 abundance and transport activity in renal proximal tubule of rats with heart failure. Am J Physiol Regul Integr Comp Physiol 2012; 302:R166-74. [DOI: 10.1152/ajpregu.00127.2011] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Heart failure (HF) is associated with a reduced effective circulating volume that drives sodium and water retention and extracellular volume expansion. We therefore hypothesized that Na+/H+ exchanger isoform 3 (NHE3), the major apical transcellular pathway for sodium reabsorption in the proximal tubule, is upregulated in an experimental model of HF. HF was induced in male rats by left ventricle radiofrequency ablation. Sham-operated rats (sham) were used as controls. At 6 wk after surgery, HF rats exhibited cardiac dysfunction with a dramatic increase in left ventricular end-diastolic pressure. By means of stationary in vivo microperfusion and pH-dependent sodium uptake, we demonstrated that NHE3 transport activity was significantly higher in the proximal tubule of HF compared with sham rats. Increased NHE3 activity was paralleled by increased renal cortical NHE3 expression at both protein and mRNA levels. In addition, the baseline PKA-dependent NHE3 phosphorylation at serine 552 was reduced in renal cortical membranes of rats with HF. Collectively, these results suggest that NHE3 is upregulated in the proximal tubule of HF rats by transcriptional, translational, and posttranslational mechanisms. Enhanced NHE3-mediated sodium reabsorption in the proximal tubule may contribute to extracellular volume expansion and edema, the hallmark feature of HF. Moreover, our study emphasizes the importance of undertaking a cardiorenal approach to contain progression of cardiac disease.
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Affiliation(s)
- Bruna H. Inoue
- Heart Institute (InCor), University of São Paulo Medical School
| | - Leonardo dos Santos
- Heart Institute (InCor), University of São Paulo Medical School
- Department of Physiological Sciences, Federal University of Espírito Santo, Vitória, ES
| | - Thaissa D. Pessoa
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo; and
| | - Ednei L. Antonio
- Department of Physiology, Federal University of São Paulo, São Paulo, Brazil
| | | | | | | | - Paulo J. F. Tucci
- Department of Physiology, Federal University of São Paulo, São Paulo, Brazil
| | - Gerhard Malnic
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo; and
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Mohan S, Tse CM, Gabelli SB, Sarker R, Cha B, Fahie K, Nadella M, Zachos NC, Tu-Sekine B, Raben D, Amzel LM, Donowitz M. NHE3 activity is dependent on direct phosphoinositide binding at the N terminus of its intracellular cytosolic region. J Biol Chem 2010; 285:34566-78. [PMID: 20736165 DOI: 10.1074/jbc.m110.165712] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The small intestinal BB Na(+)/H(+) antiporter NHE3 accounts for the majority of intestinal sodium and water absorption. It is highly regulated with both postprandial inhibition and stimulation sequentially occurring. Phosphatidylinositide 4,5-bisphosphate (PI(4,5)P(2)) and phosphatidylinositide 3,4,5-trisphosphate (PI(3,4,5)P(3)) binding is involved with regulation of multiple transporters. We tested the hypothesis that phosphoinositides bind NHE3 under basal conditions and are necessary for its acute regulation. His(6) proteins were made from the NHE3 C-terminal region divided into four parts as follows: F1 (amino acids 475-589), F2 (amino acids 590-667), F3 (amino acids 668-747), and F4 (amino acids 748-832) and purified by a nickel column. Mutations were made in the F1 region of NHE3 and cloned in pet30a and pcDNA3.1 vectors. PI(4,5)P(2) and PI(3,4,5)P(3) bound only to the NHE3 F1 fusion protein (amino acids 475-589) on liposomal pulldown assays. Mutations were made in the putative lipid binding region of the F1 domain and studied for alterations in lipid binding and Na(+)/H(+) exchange as follows: Y501A/R503A/K505A; F509A/R511A/R512A; R511L/R512L; R520/FR527F; and R551L/R552L. Our results indicate the following. 1) The F1 domain of the NHE3 C terminus has phosphoinositide binding regions. 2) Mutations of these regions alter PI(4,5)P(2) and PI(3,4,5)P(3) binding and basal NHE3 activity. 3) The magnitude of serum stimulation of NHE3 correlates with PI(4,5)P(2) and PI(3,4,5)P(3) binding of NHE3. 4) Wortmannin inhibition of PI3K did not correlate with PI(4,5)P(2) or PI(3,4,5)P(3) binding of NHE3. Two functionally distinct phosphoinositide binding regions (Tyr(501)-Arg(512) and Arg(520)-Arg(552)) are present in the NHE3 F1 domain; both regions are important for serum stimulation, but they display differences in phosphoinositide binding, and the latter but not the former alters NHE3 surface expression.
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Affiliation(s)
- Sachin Mohan
- Department of Physiology and Medicine, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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