1
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Ding M, Heydarpour M, Gomez DH, Aljaibeji H, Parksook WW, Peng L, Pojoga LH, Romero JR, Williams GH. ERAP1 Shows Distinct Regulatory Mechanisms on Blood Pressure Modulation Between Males and Females. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.07.544152. [PMID: 37333240 PMCID: PMC10274870 DOI: 10.1101/2023.06.07.544152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
The authors have withdrawn their manuscript owing to editing error. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.
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2
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Fortner A, Chera A, Tanca A, Bucur O. Apoptosis regulation by the tyrosine-protein kinase CSK. Front Cell Dev Biol 2022; 10:1078180. [PMID: 36578781 PMCID: PMC9792154 DOI: 10.3389/fcell.2022.1078180] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022] Open
Abstract
C-terminal Src kinase (CSK) is a cytosolic tyrosine-protein kinase with an important role in regulating critical cellular decisions, such as cellular apoptosis, survival, proliferation, cytoskeletal organization and many others. Current knowledge on the CSK mechanisms of action, regulation and functions is still at an early stage, most of CSK's known actions and functions being mediated by the negative regulation of the SRC family of tyrosine kinases (SFKs) through phosphorylation. As SFKs play a vital role in apoptosis, cell proliferation and survival regulation, SFK inhibition by CSK has a pro-apoptotic effect, which is mediated by the inhibition of cellular signaling cascades controlled by SFKs, such as the MAPK/ERK, STAT3 and PI3K/AKT signaling pathways. Abnormal functioning of CSK and SFK activation can lead to diseases such as cancer, cardiovascular and neurological manifestations. This review describes apoptosis regulation by CSK, CSK inhibition of the SFKs and further explores the clinical relevance of CSK in important pathologies, such as cancer, autoimmune, autoinflammatory, neurologic diseases, hypertension and HIV/AIDS.
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Affiliation(s)
- Andra Fortner
- Victor Babes National Institute of Pathology, Bucharest, Romania,Medical School, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany
| | - Alexandra Chera
- Victor Babes National Institute of Pathology, Bucharest, Romania,Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania
| | - Antoanela Tanca
- Victor Babes National Institute of Pathology, Bucharest, Romania,Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, Bucharest, Romania,*Correspondence: Octavian Bucur, ; Antoanela Tanca,
| | - Octavian Bucur
- Victor Babes National Institute of Pathology, Bucharest, Romania,Viron Molecular Medicine Institute, Boston, MA, United States,*Correspondence: Octavian Bucur, ; Antoanela Tanca,
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3
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Liu SC, Chen LB, Chen PF, Huang ML, Liu TP, Peng J, Lu XS. PDCD5 inhibits progression of renal cell carcinoma by promoting T cell immunity: with the involvement of the HDAC3/microRNA-195-5p/SGK1. Clin Epigenetics 2022; 14:131. [PMID: 36266728 PMCID: PMC9583501 DOI: 10.1186/s13148-022-01336-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 09/19/2022] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Epigenetics exerts a vital role in the onset and development of renal cell carcinoma (RCC). Mounting evidence has shed light on the significance of human immune system in response to tumor infiltrating T cells. Hereby, we sought to unmask the immunomodulatory role of histone deacetylase 3 (HDAC3) and its potential upstream molecule, programmed cell death 5 (PDCD5) in RCC. METHODS RCC and adjacent non-cancerous tissues were clinically resected from 58 patients, in which the expression profile of microRNA-195-5p (miR-195-5p), PDCD5, HDAC3, and serum glucocorticoid-inducible kinase 1 (SGK1) was determined by RT-qPCR and Western blot analysis. Their relations were investigated by a series of luciferase assays in combination with ChIP and co-IP. RCC cells (A498) were intervened using gain- and loss-of-function approaches, followed by cell proliferation evaluation. After co-culture with CD3+ T cells, flow cytometry and interferon-γ (IFN-γ) determination were performed. A xenograft tumor mouse model was developed for in vivo validation. RESULTS PDCD5 was downregulated in RCC tissues and A498 cells. Upregulation of HDAC3, as well as of SGK1, resulted in suppression of A498 cell proliferation and promotion of T cell activation as evidenced by higher IFN-γ expression. Re-expression of PDCD5 downregulated HDAC3, causing a subsequent upregulation of miR-195-5p, while miR-195-5p could inversely modulate its target gene, SGK1. The regulatory mechanism appeared to be functional in vivo. CONCLUSION Our results highlight the possible manipulation by PDCD5 on RCC cell proliferation and T cell activation, which provides new clues to better understand the immune balance in RCC progression.
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Affiliation(s)
- Shu-Cheng Liu
- The First Affiliated Hospital, Department of Urology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Li-Bo Chen
- The First Affiliated Hospital, Department of Urology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Ping-Feng Chen
- The First Affiliated Hospital, Department of Urology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Meng-Long Huang
- The First Affiliated Hospital, Department of Urology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Tian-Pei Liu
- The First Affiliated Hospital, Department of Urology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Jun Peng
- The First Affiliated Hospital, Department of Neurology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Xin-Sheng Lu
- The First Affiliated Hospital, Department of Urology, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
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4
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The electrogenic sodium bicarbonate cotransporter and its roles in the myocardial ischemia-reperfusion induced cardiac diseases. Life Sci 2021; 270:119153. [PMID: 33539911 DOI: 10.1016/j.lfs.2021.119153] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 01/06/2021] [Accepted: 01/22/2021] [Indexed: 12/19/2022]
Abstract
Cardiac tissue ischemia/hypoxia increases glycolysis and lactic acid accumulation in cardiomyocytes, leading to intracellular metabolic acidosis. Sodium bicarbonate cotransporters (NBCs) play a vital role in modulating intracellular pH and maintaining sodium ion concentrations in cardiomyocytes. Cardiomyocytes mainly express electrogenic sodium bicarbonate cotransporter (NBCe1), which has been demonstrated to participate in myocardial ischemia/reperfusion (I/R) injury. This review outlines the structural and functional properties of NBCe1, summarizes the signaling pathways and factors that may regulate the activity of NBCe1, and reviews the roles of NBCe1 in the pathogenesis of I/R-induced cardiac diseases. Further studies revealing the regulatory mechanisms of NBCe1 activity should provide novel therapeutic targets for preventing I/R-induced cardiac diseases.
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5
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Pina AF, Borges DO, Meneses MJ, Branco P, Birne R, Vilasi A, Macedo MP. Insulin: Trigger and Target of Renal Functions. Front Cell Dev Biol 2020; 8:519. [PMID: 32850773 PMCID: PMC7403206 DOI: 10.3389/fcell.2020.00519] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 06/02/2020] [Indexed: 12/16/2022] Open
Abstract
Kidney function in metabolism is often underestimated. Although the word “clearance” is associated to “degradation”, at nephron level, proper balance between what is truly degraded and what is redirected to de novo utilization is crucial for the maintenance of electrolytic and acid–basic balance and energy conservation. Insulin is probably one of the best examples of how diverse and heterogeneous kidney response can be. Kidney has a primary role in the degradation of insulin released in the bloodstream, but it is also incredibly susceptible to insulin action throughout the nephron. Fluctuations in insulin levels during fast and fed state add another layer of complexity in the understanding of kidney fine-tuning. This review aims at revisiting renal insulin actions and clearance and to address the association of kidney dysmetabolism with hyperinsulinemia and insulin resistance, both highly prevalent phenomena in modern society.
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Affiliation(s)
- Ana F Pina
- Centro de Estudos de Doenças Crónicas, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.,ProRegeM Ph.D. Programme, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.,Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Diego O Borges
- Centro de Estudos de Doenças Crónicas, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.,Molecular Biosciences Ph.D. Programme, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Maria João Meneses
- Centro de Estudos de Doenças Crónicas, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.,ProRegeM Ph.D. Programme, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal
| | - Patrícia Branco
- Department of Nephrology, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal.,Portuguese Diabetes Association - Education and Research Center (APDP-ERC), Lisbon, Portugal
| | - Rita Birne
- Department of Nephrology, Centro Hospitalar Lisboa Ocidental, Lisbon, Portugal.,Portuguese Diabetes Association - Education and Research Center (APDP-ERC), Lisbon, Portugal
| | - Antonio Vilasi
- Institute of Clinical Physiology - National Research Council, Reggio Calabria Unit1, Reggio Calabria, Italy
| | - Maria Paula Macedo
- Centro de Estudos de Doenças Crónicas, NOVA Medical School/Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisbon, Portugal.,Department of Medical Sciences, University of Aveiro, Aveiro, Portugal.,Portuguese Diabetes Association - Education and Research Center (APDP-ERC), Lisbon, Portugal
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6
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Marunaka R, Marunaka Y. Interactive Actions of Aldosterone and Insulin on Epithelial Na + Channel Trafficking. Int J Mol Sci 2020; 21:ijms21103407. [PMID: 32408487 PMCID: PMC7279156 DOI: 10.3390/ijms21103407] [Citation(s) in RCA: 4] [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: 04/14/2020] [Revised: 05/08/2020] [Accepted: 05/09/2020] [Indexed: 11/29/2022] Open
Abstract
Epithelial Na+ channel (ENaC) participates in renal epithelial Na+ reabsorption, controlling blood pressure. Aldosterone and insulin elevate blood pressure by increasing the ENaC-mediated Na+ reabsorption. However, little information is available on the interactive action of aldosterone and insulin on the ENaC-mediated Na+ reabsorption. In the present study, we tried to clarify if insulin would modify the aldosterone action on the ENaC-mediated Na+ reabsorption from a viewpoint of intracellular ENaC trafficking. We measured the ENaC-mediated Na+ transport as short-circuit currents using a four-state mathematical ENaC trafficking model in renal A6 epithelial cells with or without aldosterone treatment under the insulin-stimulated and -unstimulated conditions. We found that: (A) under the insulin-stimulated condition, aldosterone treatment (1 µM for 20 h) significantly elevated the ENaC insertion rate to the apical membrane (kI) 3.3-fold and the ENaC recycling rate (kR) 2.0-fold, but diminished the ENaC degradation rate (kD) 0.7-fold without any significant effect on the ENaC endocytotic rate (kE); (B) under the insulin-unstimulated condition, aldosterone treatment decreased kE 0.5-fold and increased kR 1.4-fold, without any significant effect on kI or kD. Thus, the present study indicates that: (1) insulin masks the well-known inhibitory action of aldosterone on the ENaC endocytotic rate; (2) insulin induces a stimulatory action of aldosterone on ENaC apical insertion and an inhibitory action of aldosterone on ENaC degradation; (3) insulin enhances the aldosterone action on ENaC recycling; (4) insulin has a more effective action on diminution of ENaC endocytosis than aldosterone.
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Affiliation(s)
- Rie Marunaka
- Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto 604-8472, Japan;
- Okamura Dental Clinic, Chuo-ku, Osaka 541-0041, Japan
| | - Yoshinori Marunaka
- Research Institute for Clinical Physiology, Kyoto Industrial Health Association, Kyoto 604-8472, Japan;
- Research Center for Drug Discovery and Pharmaceutical Development Science, Research Organization of Science and Technology, Ritsumeikan University, Kusatsu 525-8577, Japan
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto 602-8566, Japan
- Correspondence: ; Tel.: +81-75-802-0135
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7
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Lee D, Hong JH. The Fundamental Role of Bicarbonate Transporters and Associated Carbonic Anhydrase Enzymes in Maintaining Ion and pH Homeostasis in Non-Secretory Organs. Int J Mol Sci 2020; 21:ijms21010339. [PMID: 31947992 PMCID: PMC6981687 DOI: 10.3390/ijms21010339] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 01/02/2020] [Accepted: 01/03/2020] [Indexed: 12/18/2022] Open
Abstract
The bicarbonate ion has a fundamental role in vital systems. Impaired bicarbonate transport leads to various diseases, including immune disorders, cystic fibrosis, tumorigenesis, kidney diseases, brain dysfunction, tooth fracture, ischemic reperfusion injury, hypertension, impaired reproductive system, and systemic acidosis. Carbonic anhydrases are involved in the mechanism of bicarbonate movement and consist of complex of bicarbonate transport systems including bicarbonate transporters. This review focused on the convergent regulation of ion homeostasis through various ion transporters including bicarbonate transporters, their regulatory enzymes, such as carbonic anhydrases, pH regulatory role, and the expression pattern of ion transporters in non-secretory systems throughout the body. Understanding the correlation between these systems will be helpful in order to obtain new insights and design potential therapeutic strategies for the treatment of pH-related disorders. In this review, we have discussed the broad prospects and challenges that remain in elucidation of bicarbonate-transport-related biological and developmental systems.
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Affiliation(s)
| | - Jeong Hee Hong
- Correspondence: ; Tel.: +82-32-899-6682; Fax: +82-32-899-6039
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8
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Yang S, Zhang Y, Shen F, Ma X, Zhang M, Hou Y, Bai G. The flavonoid baicalin improves glucose metabolism by targeting the PH domain of AKT and activating AKT/GSK3β phosphorylation. FEBS Lett 2018; 593:175-186. [PMID: 30489635 DOI: 10.1002/1873-3468.13305] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 10/26/2018] [Accepted: 11/13/2018] [Indexed: 01/21/2023]
Abstract
Baicalin is one of the main flavonoids of the dried root of Scutellaria baicalensis Georgi and is reported to exert beneficial effects on the regulation of glucose/lipid metabolism. However, understanding its specific target and unique mechanism for improving glucose utilization is a challenge. In this paper, target fishing with a baicalin probe reveals that baicalin interacts with AKT. An immunofluorescence assay further demonstrates the colocalization of baicalin with AKT in the cytoplasm. A competitive test and virtual docking show that baicalin might bind to the pleckstrin homology domain of AKT. This specific binding hampers AKT membrane translocation, activates the phosphorylation of AKT on Ser473, induces the downstream glycogen synthase kinase 3β activation, and affects glycogen synthesis.
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Affiliation(s)
- Shengnan Yang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Yuan Zhang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Fukui Shen
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Xiaoyao Ma
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Man Zhang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Yuanyuan Hou
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
| | - Gang Bai
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, China
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9
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Nizar JM, Shepard BD, Vo VT, Bhalla V. Renal tubule insulin receptor modestly promotes elevated blood pressure and markedly stimulates glucose reabsorption. JCI Insight 2018; 3:95107. [PMID: 30135311 DOI: 10.1172/jci.insight.95107] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 07/03/2018] [Indexed: 12/25/2022] Open
Abstract
Although the cause of hypertension among individuals with obesity and insulin resistance is unknown, increased plasma insulin, acting in the kidney to increase sodium reabsorption, has been proposed as a potential mechanism. Insulin may also stimulate glucose uptake, but the contributions of tubular insulin signaling to sodium or glucose transport in the setting of insulin resistance is unknown. To directly study the role of insulin signaling in the kidney, we generated inducible renal tubule-specific insulin receptor-KO mice and used high-fat feeding and mineralocorticoids to model obesity and insulin resistance. Insulin receptor deletion did not alter blood pressure or sodium excretion in mice on a high-fat diet alone, but it mildly attenuated the increase in blood pressure with mineralocorticoid supplementation. Under these conditions, KO mice developed profound glucosuria. Insulin receptor deletion significantly reduced SGLT2 expression and increased urinary glucose excretion and urine flow. These data demonstrate a direct role for insulin receptor-stimulated sodium and glucose transport and a functional interaction of insulin signaling with mineralocorticoids in vivo. These studies uncover a potential mechanistic link between preserved insulin sensitivity and renal glucose handling in obesity and insulin resistance.
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Affiliation(s)
- Jonathan M Nizar
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Blythe D Shepard
- Department of Human Science, Georgetown University, Washington, DC
| | - Vianna T Vo
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
| | - Vivek Bhalla
- Division of Nephrology, Department of Medicine, Stanford University School of Medicine, Stanford, California, USA
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10
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(Pro)Renin receptor mediates obesity-induced antinatriuresis and elevated blood pressure via upregulation of the renal epithelial sodium channel. PLoS One 2018; 13:e0202419. [PMID: 30118514 PMCID: PMC6097690 DOI: 10.1371/journal.pone.0202419] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 07/10/2018] [Indexed: 11/21/2022] Open
Abstract
Recent studies have demonstrated that the renal (pro)renin receptor (PRR) regulates expression of the alpha subunit of the epithelial sodium channel (α-ENaC). In this study we hypothesized that the renal PRR mediates high fat diet (HFD)-induced sodium retention and elevated systolic blood pressure (SBP) by enhancing expression of the epithelial sodium channel (α-ENaC). In our study we used a recently developed inducible nephron specific PRR knockout mouse. Mice (n = 6 each group) were allocated to receive regular diet (RD, 12 kcal% fat) or a high-fat diet (HFD, 45 kcal% fat) for 10 weeks. Body weight (BW), SBP, urine volume (UV) and urine sodium (UNaV), as well as renal interstitial Angiotensin II (Ang II), and renal medullary expression of PRR, p-SGK-1, α-ENaC were monitored in RD and HFD mice with or without PRR knockout. At baseline, there were no significant differences in BW, BP, UV or UNaV between different animal groups. At the end of the study, HFD mice had significant increases in SBP, BW, and significant reductions in UV and UNaV. Compared to RD, HFD significantly increased mRNA and protein expression of PRR, α-ENaC, p-SGK-1, and Ang II. Compared to HFD alone, PRR knockout mice on HFD had reduced mRNA and protein expression of PRR, p-SGK-1, and α-ENaC, as well as increased UV, UNaV and significantly reduced SBP. RIF Ang II was significantly increased by HFD and did not change in response to PRR knockout. We conclude that obesity induced sodium retention and elevated SBP are mediated by the PRR-SGK-1- α-ENaC pathway independent of Ang II.
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11
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Lee JJ, Plain A, Beggs MR, Dimke H, Alexander RT. Effects of phospho- and calciotropic hormones on electrolyte transport in the proximal tubule. F1000Res 2017; 6:1797. [PMID: 29043081 PMCID: PMC5627579 DOI: 10.12688/f1000research.12097.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/04/2017] [Indexed: 12/17/2022] Open
Abstract
Calcium and phosphate are critical for a myriad of physiological and cellular processes within the organism. Consequently, plasma levels of calcium and phosphate are tightly regulated. This occurs through the combined effects of the phospho- and calciotropic hormones, parathyroid hormone (PTH), active vitamin D
3, and fibroblast growth factor 23 (FGF23). The organs central to this are the kidneys, intestine, and bone. In the kidney, the proximal tubule reabsorbs the majority of filtered calcium and phosphate, which amounts to more than 60% and 90%, respectively. The basic molecular mechanisms responsible for phosphate reclamation are well described, and emerging work is delineating the molecular identity of the paracellular shunt wherein calcium permeates the proximal tubular epithelium. Significant experimental work has delineated the molecular effects of PTH and FGF23 on these processes as well as their regulation of active vitamin D
3 synthesis in this nephron segment. The integrative effects of both phospho- and calciotropic hormones on proximal tubular solute transport and subsequently whole body calcium-phosphate balance thus have been further complicated. Here, we first review the molecular mechanisms of calcium and phosphate reabsorption from the proximal tubule and how they are influenced by the phospho- and calciotropic hormones acting on this segment and then consider the implications on both renal calcium and phosphate handling as well as whole body mineral balance.
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Affiliation(s)
- Justin J Lee
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada
| | - Allein Plain
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada
| | - Megan R Beggs
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada
| | - Henrik Dimke
- Department of Cardiovascular and Renal Research, Institute of Molecular Medicine, University of Southern Denmark, Odense, Denmark
| | - R Todd Alexander
- Department of Physiology, University of Alberta, Edmonton, Canada.,The Women and Children's Health Research Institute, Edmonton, Canada.,Department of Pediatrics, Edmonton Clinic Health Academy, University of Alberta, Edmonton, Canada
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12
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Chen F, Hu Q, Huang H, Chen B, Xia Y, Liu W. Follistatin-like protein 1 increases transepithelial resistance in kidney epithelial cells through Akt signaling. Mol Med Rep 2017; 16:4341-4347. [PMID: 28765894 DOI: 10.3892/mmr.2017.7113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 05/24/2017] [Indexed: 11/06/2022] Open
Abstract
Tight junctions are intercellular junctional structures that control paracellular permeability across epithelial cell sheets, and serve as a barrier to the intramembranic diffusion of components between apical and basolateral cell membrane domains. Follistatin‑like protein 1 (FSTL1) has been reported to promote cellular metabolism and survival. FSTL1 has been revealed to be highly expressed in adult kidney tissues, and high FSTL1 levels have been reported in mouse and human serum samples; however, the roles of FSTL1 in the regulation of kidney function remain to be elucidated. In the present study, FSTL1 was demonstrated to increase the transepithelial electrical resistance in mouse inner medullary collecting duct (mIMCD3) cells. The molecular mechanisms underlying the effects of FSTL1 were also investigated and the results suggested that FSTL1 may exert its actions through the modulation of Akt signaling. In addition, FSTL1 was revealed to produce no effect on the migratory capabilities of mIMCD3 cells. The results of the present study suggested that FSTL1 may facilitate the formation of tight junctions and regulate their function in renal tubular epithelia.
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Affiliation(s)
- Fei Chen
- Department of Nephrology, The First People's Hospital of Yunnan, Kunming University of Sciences and Technology, Kunming, Yunnan 650032, P.R. China
| | - Qiang Hu
- Department of Emergency Medicine, The Second Affiliated Hospital, Kunming Medical University, Kunming, Yunnan 650101, P.R. China
| | - Huihui Huang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Binbin Chen
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Yin Xia
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, P.R. China
| | - Wenjing Liu
- School of Medicine, Yunnan University, Kunming, Yunnan 650091, P.R. China
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13
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Zhou X, Packialakshmi B, Xiao Y, Nurmukhambetova S, Lees JR. Progression of experimental autoimmune encephalomyelitis is associated with up-regulation of major sodium transporters in the mouse kidney cortex under a normal salt diet. Cell Immunol 2017; 317:18-25. [PMID: 28438314 DOI: 10.1016/j.cellimm.2017.04.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Revised: 04/13/2017] [Accepted: 04/13/2017] [Indexed: 01/11/2023]
Abstract
Recent demonstrations of exacerbation of experimental autoimmune encephalomyelitis (EAE) by high salt diets prompted us to study whether EAE stimulated Na absorption by the renal cortex, a primary regulatory site for Na balance, even under a normal NaCl diet. We found that as EAE progressed from mild to severe symptoms, there were parallel increases in the protein abundance of NHE3 and αENaC and the Na,K-ATPase activity with an affiliated elevation of its β1-subunit protein. These effects are associated with increases in the protein levels of the well-known regulators SGK1 and scaffold NHERF2, and phosphorylation of ERK1/2. These effects of EAE could not be explained by reduction in water or food intake. We conclude that EAE progression is associated with up-regulation of major Na transporters, which is most likely driven by increased expression of SGK1 and NHERF2 and activation of ERK1/2. These data suggest that EAE progression increases Na absorption by the renal cortex.
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Affiliation(s)
- Xiaoming Zhou
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States.
| | - Balamurugan Packialakshmi
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Yao Xiao
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Saule Nurmukhambetova
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Jason R Lees
- Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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14
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Khachab M, Kanaan A, Awad D, Deeba E, Osman S, Nassar CF. Colectomy induces an aldosterone-mediated increase in jejunal glucose uptake in rats. Life Sci 2017; 174:43-49. [PMID: 28254387 DOI: 10.1016/j.lfs.2017.02.012] [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: 11/24/2016] [Revised: 02/15/2017] [Accepted: 02/24/2017] [Indexed: 11/25/2022]
Abstract
AIMS The main function of the colon is water and electrolyte absorption. Total colectomy eliminates this colonic function and may alter the absorptive capacity of the small intestine for nutrients. This study examines the effect of total colectomy on jejunal glucose absorption and investigates the potential role of aldosterone in mediating the alterations in glucose uptake post-colectomy using the aldosterone antagonist spironolactone. MAIN METHODS Total colectomy with ileo-rectal anastomosis was performed on anesthetized rats. Sham rats were identically handled without colon resection. Two days post-surgery, groups of colectomized rats were injected with either a daily subcutaneous dose of spironolactone or sesame oil for 12days. Body weight changes and food and water intake were measured in all experimental groups. Glucose absorption was measured by in-vivo single pass perfusion in the rat jejunum of control, sham, colectomized, colectomized with spironolactone, and colectomized with sesame oil treatment. Na/K ATPase, SGK1, SGLT1 and GLUT2 expressions were determined in jejunal mucosa in control, colectomized and colectomized/spironolactone injected rats by Western blot analysis. Histological assessment was performed on jejunal sections in control and colectomized groups. KEY FINDINGS Glucose absorption significantly increased in colectomized rats with an observed increase in Na/K ATPase and SGK1 expression. No significant expression change in SGLT1 and GLUT2 was detected in the jejunum in colectomized rats. Spironolactone, however, significantly decreased the glucose uptake post-colectomy and normalized Na/K ATPase and SGK1 expression. SIGNIFICANCE Our results suggest that jejunal glucose uptake increases post-colectomy as a possible consequence of an aldosterone-mediated function.
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Affiliation(s)
- Maha Khachab
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, El-Kurah, Lebanon.
| | - Amjad Kanaan
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, El-Kurah, Lebanon
| | - Dania Awad
- Faculty of Health Sciences, Lebanese University, Tripoli, Lebanon
| | - Elie Deeba
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, El-Kurah, Lebanon
| | - Samira Osman
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, El-Kurah, Lebanon
| | - Camille F Nassar
- Department of Biomedical Sciences, Faculty of Medicine and Medical Sciences, University of Balamand, El-Kurah, Lebanon
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15
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Andrukhova O, Streicher C, Zeitz U, Erben RG. Fgf23 and parathyroid hormone signaling interact in kidney and bone. Mol Cell Endocrinol 2016; 436:224-39. [PMID: 27498418 DOI: 10.1016/j.mce.2016.07.035] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Revised: 07/26/2016] [Accepted: 07/26/2016] [Indexed: 12/19/2022]
Abstract
Fibroblast growth factor-23 (FGF23) is a bone-derived hormone, suppressing renal phosphate reabsorption and vitamin D hormone synthesis in proximal tubules, and stimulating calcium reabsorption in distal tubules of the kidney. Here, we analyzed the long term sequelae of deficient Fgf23 signaling on bone and mineral metabolism in 9-month-old mice lacking both Fgf23 or Klotho and a functioning vitamin D receptor (VDR). To prevent hypocalcemia in VDR deficient mice, all mice were kept on a rescue diet enriched with calcium, phosphate, and lactose. VDR mutants were normocalcemic and normophosphatemic, and had normal tibial bone mineral density. Relative to VDR mutants, Fgf23/VDR and Klotho/VDR compound mutants were characterized by hypocalcemia, hyperphosphatemia, and very high serum parathyroid hormone (PTH). Despite ∼10-fold higher serum PTH levels in compound mutants, urinary excretion of phosphate and calcium as well as osteoclast numbers in bone remained unchanged relative to VDR mutants. The increase in plasma cAMP after hPTH(1-34) injection was similar in all genotypes. However, a 5-day infusion of hPTH(1-34) via osmotic minipumps resulted in reduced phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) in bone and kidney of Fgf23/VDR and Klotho/VDR compound mutants, relative to VDR and WT controls. Similarly, the PTH-mediated ERK1/2 phosphorylation was reduced in primary osteoblasts isolated from Fgf23 and Klotho deficient mice, but was restored by concomitant treatment with recombinant FGF23. Collectively, our data indicate that the phosphaturic, calcium-conserving, and bone resorption-stimulating actions of PTH are blunted by Fgf23 or Klotho deficiency. Hence, FGF23 may be an important modulator of PTH signaling in bone and kidney.
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Affiliation(s)
- Olena Andrukhova
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Carmen Streicher
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Ute Zeitz
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria
| | - Reinhold G Erben
- Department of Biomedical Sciences, University of Veterinary Medicine, 1210, Vienna, Austria.
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16
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Marunaka Y, Marunaka R, Sun H, Yamamoto T, Kanamura N, Taruno A. Na + homeostasis by epithelial Na + channel (ENaC) and Na x channel (Na x): cooperation of ENaC and Na x. ANNALS OF TRANSLATIONAL MEDICINE 2016; 4:S11. [PMID: 27867979 DOI: 10.21037/atm.2016.10.42] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Yoshinori Marunaka
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto 602-8566, Japan;; Department of Bio-Ionomics, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto 602-8566, Japan;; Japan Institute for Food Education and Health, St. Agnes' University, Kyoto 602-8013, Japan
| | - Rie Marunaka
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto 602-8566, Japan;; Department of Dental Medicine, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto 602-8566, Japan
| | - Hongxin Sun
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto 602-8566, Japan
| | - Toshiro Yamamoto
- Department of Dental Medicine, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto 602-8566, Japan
| | - Narisato Kanamura
- Department of Dental Medicine, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto 602-8566, Japan
| | - Akiyuki Taruno
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine Graduate School of Medical Science, Kyoto 602-8566, Japan
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17
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Dbouk HA, Huang CL, Cobb MH. Hypertension: the missing WNKs. Am J Physiol Renal Physiol 2016; 311:F16-27. [PMID: 27009339 PMCID: PMC4967160 DOI: 10.1152/ajprenal.00358.2015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 03/16/2016] [Indexed: 12/23/2022] Open
Abstract
The With no Lysine [K] (WNK) family of enzymes are central in the regulation of blood pressure. WNKs have been implicated in hereditary hypertension disorders, mainly through control of the activity and levels of ion cotransporters and channels. Actions of WNKs in the kidney have been heavily investigated, and recent studies have provided insight into not only the regulation of these enzymes but also how mutations in WNKs and their interacting partners contribute to hypertensive disorders. Defining the roles of WNKs in the cardiovascular system will provide clues about additional mechanisms by which WNKs can regulate blood pressure. This review summarizes recent developments in the regulation of the WNK signaling cascade and its role in regulation of blood pressure.
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Affiliation(s)
- Hashem A Dbouk
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas; and
| | - Chou-Long Huang
- Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Melanie H Cobb
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas; and
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