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Li P, Liu Y, You T. CircNRIP1 KNOCKDOWN ALLEVIATES LIPOPOLYSACCHARIDE-INDUCED HUMAN KIDNEY 2 CELL APOPTOSIS AND INFLAMMATION THROUGH miR-339-5p/OXSR1 PATHWAY. Shock 2023; 59:426-433. [PMID: 36609531 DOI: 10.1097/shk.0000000000002057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
ABSTRACT Background: CircRNA regulates sepsis-induced acute kidney injury (AKI). CircNRIP1 is overexpressed in the blood of AKI patients, but its role in septic AKI occurrence remains unknown. Methods: Human kidney 2 (HK2) cells were stimulated using lipopolysaccharide (LPS) to generate a septic AKI cell model. The expression levels of circNRIP1, miR-339-5p, oxidative stress-responsive kinase 1 (OXSR1), B-cell lymphoma-2 (Bcl2), BCL2-associated x protein (Bax), and cleaved-caspase 3 were detected by quantitative real-time polymerase chain reaction or Western blotting analysis. Cell viability and apoptosis were investigated by cell counting kit-8 and flow cytometry analysis. The release of proinflammatory cytokines was monitored using commercial kits. The associations among circNRIP1, miR-339-5p, and OXSR1 were identified by mechanism assays. Results: CircNRIP1 was dramatically upregulated in the blood of septic AKI patients and LPS-induced HK2 cells. CircNRIP1 depletion protected HK2 cells from LPS-induced apoptosis and inflammation. MiR-339-5p expression was downregulated in the blood of septic AKI patients, and miR-339-5p combined with circNRIP1. Moreover, circNRIP1 knockdown-induced effects involved the upregulation of miR-339-5p in LPS-treated HK2 cells. Comparatively, OXSR1 expression was increased in the blood of septic AKI patients. MiR-339-5p bound to OXSR1, and circNRIP1 modulated OXSR1 expression by interacting with miR-339-5p. Further, ectopic expression of OXSR1 relieved circNRIP1 knockdown-mediated effects in LPS-induced HK2 cells. Conclusion: CircNRIP1 depletion ameliorated LPS-induced HK2 cell damage by regulating the miR-339-5p/OXSR1 pathway.
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Affiliation(s)
- Pei Li
- Department of Clinical Laboratory, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang City, Hunan Province, China
| | - Yu Liu
- Department of Emergency, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang City, Hunan Province, China
| | - Ting You
- Department of Emergency, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang City, Hunan Province, China
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2
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Cui H, Ren G, Hu X, Xu B, Li Y, Niu Z, Mu L. Suppression of lncRNA GAS6-AS2 alleviates sepsis-related acute kidney injury through regulating the miR-136-5p/OXSR1 axis in vitro and in vivo. Ren Fail 2022; 44:1070-1082. [PMID: 35793478 PMCID: PMC9272941 DOI: 10.1080/0886022x.2022.2092001] [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] [Indexed: 11/16/2022] Open
Abstract
Acute kidney injury (AKI) is a common complication of sepsis and increase morbidity and mortality. Long non-coding RNA (LncRNA) GAS6-AS2 was related to inflammation and apoptosis in different diseases by regulating miRNAs and downstream genes, but its role in AKI remains unclear. Thus, we speculated that GAS6-AS2 might function in sepsis-related AKI via regulating target genes. Here, LPS or CLP was used to establish in vitro or in vivo sepsis-related AKI model. The interactions between GAS6-AS2 and miR-136-5p, and miR-136-5p and OXSR1, were validated by luciferase reporter assay, RNA pull-down, or RIP assay. Cell apoptosis was determined by flow cytometry, Western blotting, or IHC. The kidney injury was evaluated by H&E staining. The expression of GAS6-AS2, miR-136-5p, and OXSR1 was determined by qRT-PCR or Western blotting. We found that GAS6-AS2 was up-regulated in LPS-treated HK2 cells and the CLP-induced rat model. In vitro, GAS6-AS2 knockdown decreased cleaved caspase-3 and bax expression and increased bcl-2 expression. The levels of TNF-α, IL-1β, and IL-6 were reduced by GAS6-AS2 down-regulation. GAS6-AS2 knockdown ameliorated oxidative stress in the cells, as indicated by the reduced ROS and MDA levels and the elevated SOD level. In vivo, GAS6-AS2 down-regulation decreased urinary NGAL and Kim-1 levels and serum sCr and BUN levels, and H&E proved that the kidney injury was alleviated. GAS6-AS2 knockdown also reduced apoptosis, inflammation, and oxidation induced by CLP in vivo. Mechanically, GAS6-AS2 sponged miR-136-5p which targeted OXSR1. Overall, lncRNA GAS6-AS2 knockdown has the potential to ameliorate sepsis-related AKI, and the mechanism is related to miR-136-5p/OXSR1 axis.
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Affiliation(s)
- Hongrui Cui
- Department of Nephrology, The First Hospital of Hebei Medical University, Shijiazhuang, PR China
| | - Guangwei Ren
- Department of Nephrology, The First Hospital of Hebei Medical University, Shijiazhuang, PR China
| | - Xiuhong Hu
- Department of Nephrology, The First Hospital of Hebei Medical University, Shijiazhuang, PR China
| | - Baozhen Xu
- Department of Nephrology, The First Hospital of Hebei Medical University, Shijiazhuang, PR China
| | - Yuping Li
- Department of Nephrology, The First Hospital of Hebei Medical University, Shijiazhuang, PR China
| | - Zheli Niu
- Department of Nephrology, The First Hospital of Hebei Medical University, Shijiazhuang, PR China
| | - Liqin Mu
- Department of General Practice, The First Hospital of Hebei Medical University, Shijiazhuang, PR China
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Garneau AP, Slimani S, Haydock L, Nsimba-Batomene TR, Préfontaine FCM, Lavoie MM, Tremblay LE, Fiola MJ, Mac-Way F, Isenring P. Molecular mechanisms, physiological roles, and therapeutic implications of ion fluxes in bone cells: Emphasis on the cation-Cl - cotransporters. J Cell Physiol 2022; 237:4356-4368. [PMID: 36125923 PMCID: PMC10087713 DOI: 10.1002/jcp.30879] [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: 05/23/2022] [Revised: 08/25/2022] [Accepted: 09/01/2022] [Indexed: 11/11/2022]
Abstract
Bone turnover diseases are exceptionally prevalent in human and come with a high burden on physical health. While these diseases are associated with a variety of risk factors and causes, they are all characterized by common denominators, that is, abnormalities in the function or number of osteoblasts, osteoclasts, and/or osteocytes. As such, much effort has been deployed in the recent years to understand the signaling mechanisms of bone cell proliferation and differentiation with the objectives of exploiting the intermediates involved as therapeutic preys. Ion transport systems at the external and in the intracellular membranes of osteoblasts and osteoclasts also play an important role in bone turnover by coordinating the movement of Ca2+ , PO4 2- , and H+ ions in and out of the osseous matrix. Even if they sustain the terminal steps of osteoformation and osteoresorption, they have been the object of very little attention in the last several years. Members of the cation-Cl- cotransporter (CCC) family are among the systems at work as they are expressed in bone cells, are known to affect the activity of Ca2+ -, PO4 2- -, and H+ -dependent transport systems and have been linked to bone mass density variation in human. In this review, the roles played by the CCCs in bone remodeling will be discussed in light of recent developments and their potential relevance in the treatment of skeletal disorders.
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Affiliation(s)
- Alexandre P Garneau
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Québec, Canada.,Service de Néphrologie-Transplantation Rénale Adultes, Hôpital Necker-Enfants Malades, AP-HP, Inserm U1151, Université Paris Cité, rue de Sèvres, Paris, France
| | - Samira Slimani
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Québec, Canada
| | - Ludwig Haydock
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Québec, Canada
| | | | | | - Mathilde M Lavoie
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Québec, Canada
| | - Laurence E Tremblay
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Québec, Canada
| | - Marie-Jeanne Fiola
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Québec, Canada
| | - Fabrice Mac-Way
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Québec, Canada
| | - Paul Isenring
- Department of Medicine, Nephrology Research Group, Laval University, Québec, Québec, Canada
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4
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Yang Q, Sun Q, Jin P. Long non‑coding RNA PVT1 regulates LPS‑induced acute kidney injury in an in vitro model of HK‑2 cells by modulating the miR‑27a‑3p/OXSR1 axis. Exp Ther Med 2022; 24:552. [PMID: 35978931 PMCID: PMC9366283 DOI: 10.3892/etm.2022.11490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/18/2020] [Indexed: 11/05/2022] Open
Affiliation(s)
- Qian Yang
- Department of Critical Care Medicine, Jingzhou Central Hospital, The Second Clinical Medical College, Yangtze University, Jingzhou, Hubei 434000, P.R. China
| | - Qi Sun
- Department of Critical Care Medicine, Jingzhou Central Hospital, The Second Clinical Medical College, Yangtze University, Jingzhou, Hubei 434000, P.R. China
| | - Ping Jin
- Department of Critical Care Medicine, Jingzhou Central Hospital, The Second Clinical Medical College, Yangtze University, Jingzhou, Hubei 434000, P.R. China
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Li H, Zhang X, Wang P, Zhou X, Liang H, Li C. Knockdown of circ-FANCA alleviates LPS-induced HK2 cell injury via targeting miR-93-5p/OXSR1 axis in septic acute kidney injury. Diabetol Metab Syndr 2021; 13:7. [PMID: 33468219 PMCID: PMC7816370 DOI: 10.1186/s13098-021-00625-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/06/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Sepsis is life-threatening disease with systemic inflammation and can lead to various diseases, including septic acute kidney injury (AKI). Recently, diverse circular RNAs (circRNAs) are considered to be involved in the development of this disease. In this study, we aimed to elucidate the role of circ-FANCA and the potential action mechanism in sepsis-induced AKI. METHODS HK2 cells were treated with lipopolysaccharide (LPS) to establish septic AKI cell model. The expression of circ-FANCA, microRNA-93-5p (miR-93-5p) and oxidative stress responsive 1 (OXSR1) mRNA was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Cell viability was assessed using cell counting kit-8 (CCK-8) assay. Cell apoptosis and cell cycle distribution were measured by flow cytometry. The inflammatory response was monitored according to the release of pro-inflammatory cytokines via enzyme-linked immunosorbent assay (ELISA). The activities of oxidative indicators were examined using the corresponding kits. Dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were applied to validate the interaction between miR-93-5p and circ-FANCA or OXSR1. Protein analysis was conducted through western blot. RESULTS Circ-FANCA was upregulated in septic AKI serum specimens and LPS-treated HK2 cells. Functionally, circ-FANCA knockdown facilitated cell proliferation and restrained apoptosis, inflammation and oxidative stress in LPS-triggered HK2 cells. Further mechanism analysis revealed that miR-93-5p was a target of circ-FANCA and circ-FANCA modulated LPS-induced cell damage by targeting miR-93-5p. Meanwhile, miR-93-5p overexpression repressed LPS-treated HK2 cell injury by sponging OXSR1. Furthermore, circ-FANCA regulated OXSR1 expression by sponging miR-93-5p. Besides, exosome-derived circ-FANCA was upregulated in LPS-induced HK2 cells, which was downregulated by GW4869. CONCLUSION Circ-FANCA knockdown attenuated LPS-induced HK2 cell injury by regulating OXSR1 expression via targeting miR-93-5p.
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Affiliation(s)
- Heyun Li
- Department of Critical Care Medicine, No. 215 Hospital of Shaanxi Nucler Industry, Xianyang, 712000, China
| | - Xia Zhang
- Department of Rulmonary and Critical Care Medicine, Hanzhong City Central Hospital of Shaanxi Province, Hanzhong, 723000, China
| | - Peng Wang
- Department of Respiratory Medicine, Baoji Central Hospital, Baoji, 721008, China
| | - Xiaoyan Zhou
- Department of Vascular Intervention, Shaanxi Hospital of Traditional Chinese Medicine, Xi'an, 710003, China
| | - Haiying Liang
- Department of Rulmonary and Critical Care Medicine, Shaanxi Hospital of Traditional Chinese Medicine, Xi'an, 710003, China
| | - Caoni Li
- Department of Hematology, Shangluo Central Hospital, No. 148 Beixin Street, Shangluo, 726000, China.
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Caron TJ, Scott KE, Sinha N, Muthupalani S, Baqai M, Ang LH, Li Y, Turner JR, Fox JG, Hagen SJ. Claudin-18 Loss Alters Transcellular Chloride Flux but not Tight Junction Ion Selectivity in Gastric Epithelial Cells. Cell Mol Gastroenterol Hepatol 2020; 11:783-801. [PMID: 33069918 PMCID: PMC7847960 DOI: 10.1016/j.jcmgh.2020.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 10/12/2020] [Accepted: 10/13/2020] [Indexed: 12/15/2022]
Abstract
BACKGROUND & AIMS Tight junctions form a barrier to the paracellular passage of luminal antigens. Although most tight junction proteins reside within the apical tight junction complex, claudin-18 localizes mainly to the basolateral membrane where its contribution to paracellular ion transport is undefined. Claudin-18 loss in mice results in gastric neoplasia development and tumorigenesis that may or may not be due to tight junction dysfunction. The aim here was to investigate paracellular permeability defects in stomach mucosa from claudin-18 knockout (Cldn18-KO) mice. METHODS Stomach tissue from wild-type, heterozygous, or Cldn18-KO mice were stripped of the external muscle layer and mounted in Ussing chambers. Transepithelial resistance, dextran 4 kDa flux, and potential difference (PD) were calculated from the chambered tissues after identifying differences in tissue histopathology that were used to normalize these measurements. Marker expression for claudins and ion transporters were investigated by transcriptomic and immunostaining analysis. RESULTS No paracellular permeability defects were evident in stomach mucosa from Cldn18-KO mice. RNAseq identified changes in 4 claudins from Cldn18-KO mice, particularly the up-regulation of claudin-2. Although claudin-2 localized to tight junctions in cells at the base of gastric glands, its presence did not contribute overall to mucosal permeability. Stomach tissue from Cldn18-KO mice also had no PD versus a lumen-negative PD in tissues from wild-type mice. This difference resulted from changes in transcellular Cl- permeability with the down-regulation of Cl- loading and Cl- secreting anion transporters. CONCLUSIONS Our findings suggest that Cldn18-KO has no effect on tight junction permeability in the stomach from adult mice but rather affects anion permeability. The phenotype in these mice may thus be secondary to transcellular anion transporter expression/function in the absence of claudin-18.
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Affiliation(s)
- Tyler J Caron
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Kathleen E Scott
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Nishita Sinha
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Sureshkumar Muthupalani
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Mahnoor Baqai
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts
| | - Lay-Hong Ang
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts
| | - Yue Li
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts
| | - Jerrold R Turner
- Harvard Medical School, Boston, Massachusetts; Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts
| | - James G Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Susan J Hagen
- Department of Surgery/Division of General Surgery, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts.
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Wang C, Kawakami-Mori F, Kang L, Ayuzawa N, Ogura S, Koid SS, Reheman L, Yeerbolati A, Liu B, Yatomi Y, Chen X, Fujita T, Shimosawa T. Low-dose L-NAME induces salt sensitivity associated with sustained increased blood volume and sodium-chloride cotransporter activity in rodents. Kidney Int 2020; 98:1242-1252. [PMID: 32592815 DOI: 10.1016/j.kint.2020.05.050] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 05/18/2020] [Accepted: 05/21/2020] [Indexed: 12/01/2022]
Abstract
To investigate the cause of salt sensitivity in a normotensive animal model, we treated rats with a low-dose of the nitric oxide synthase inhibitor, L-NAME, that does not elevate blood pressure per se or induce kidney fibrosis. A high salt diet increased the circulating blood volume both in L-NAME-treated and nontreated animals for the first 24 hours. Thereafter, the blood volume increase persisted only in the L-NAME-treated rats. Blood pressure was higher in the L-NAME-treated group from the start of high salt diet exposure. Within the first 24 hours of salt loading, the L-NAME treated animals failed to show vasodilation and maintained high systemic vascular resistance in response to blood volume expansion. After four weeks on the high salt diet, the slope of the pressure-natriuresis curve was blunted in the L-NAME-treated group. An increase in natriuresis was observed after treatment with hydrochlorothiazide, but not amiloride, a change observed in parallel with increased phosphorylated sodium-chloride cotransporter (NCC). In contrast, a change in blood pressure was not observed in L-NAME-treated NCC-deficient mice fed a high salt diet. Moreover, direct L-NAME-induced NCC activation was demonstrated in cells of the mouse distal convoluted tubule. The vasodilatator, sodium nitroprusside, downregulated phosphorylated NCC expression. The effect of L-NAME on phosphorylated NCC was blocked by both the SPAK inhibitor STOCK2S-26016 and the superoxide dismutase mimetic TEMPO which also attenuated salt-induced hypertension. These results suggest that the initiation of salt sensitivity in normotensive rodents could be due to hyporeactivity of the vasculature and that maintaining blood pressure could result in a high circulating volume due to inappropriate NCC activity in the low-dose L-NAME model. Thus, even slightly impaired nitric oxide production may be important in salt sensitivity regulation in healthy rodents.
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Affiliation(s)
- Conghui Wang
- Department of Nephrology, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Chinese PLA General Hospital, Chinese PLA Medical School, Beijing, China; Department of Clinical Laboratory, School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Fumiko Kawakami-Mori
- Department of Clinical Epigenetics, Research Center for Advancing Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Lei Kang
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, China
| | - Nobuhiro Ayuzawa
- Department of Clinical Epigenetics, Research Center for Advancing Science and Technology, The University of Tokyo, Tokyo, Japan
| | - Sayoko Ogura
- Department of Pathology and Microbiology, Division of Laboratory Medicine, School of Medicine, Nihon University, Tokyo, Japan
| | - Suang Suang Koid
- Department of Clinical Laboratory, School of Medicine, The University of Tokyo, Tokyo, Japan; Department of Clinical Laboratory, School of Medicine, International University of Health and Welfare, Chiba, Japan
| | - Latapati Reheman
- Department of Clinical Laboratory, School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Alimila Yeerbolati
- Department of Clinical Laboratory, School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Beibei Liu
- Department of Clinical Laboratory, School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Yutaka Yatomi
- Department of Clinical Laboratory, School of Medicine, The University of Tokyo, Tokyo, Japan
| | - Xiangmei Chen
- Department of Nephrology, Chinese PLA Institute of Nephrology, State Key Laboratory of Kidney Diseases, National Clinical Research Center for Kidney Diseases, Chinese PLA General Hospital, Chinese PLA Medical School, Beijing, China
| | - Toshiro Fujita
- Department of Clinical Epigenetics, Research Center for Advancing Science and Technology, The University of Tokyo, Tokyo, Japan; CREST, Japan Science and Technology Agency, Tokyo, Japan
| | - Tatsuo Shimosawa
- Department of Clinical Laboratory, School of Medicine, International University of Health and Welfare, Chiba, Japan; CREST, Japan Science and Technology Agency, Tokyo, Japan.
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MicroRNA-191-5p diminished sepsis-induced acute kidney injury through targeting oxidative stress responsive 1 in rat models. Biosci Rep 2019; 39:BSR20190548. [PMID: 31362998 PMCID: PMC6692571 DOI: 10.1042/bsr20190548] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 07/18/2019] [Accepted: 07/29/2019] [Indexed: 12/19/2022] Open
Abstract
There is no effective treatment for septic acute kidney injury (AKI), which is considered a major public health concern in today’s world. Here, we studied the functions of miR-191-5p in septic AKI. MiR-191-5p mimic or mimic control was injected into rats from caudal vein before cecal ligation and puncture (CLP) surgery. Part of kidney tissues was stained by Hematoxylin and Eosin (H&E) for histological examination. The levels of serum cytokines were evaluated using enzyme-linked immunosorbent assay (ELISA). For cell transfection, renal cells were isolated from the kidneys of CLP rat model injected with mimic control and miR-191-5p mimic. With TargetScan prediction, serine/threonine-protein kinase OSR1 was identified as a target of miR-191-5p. Oxidative stress responsive 1 (OXSR1) overexpression vector was transfected into renal cells. Cell viability and apoptosis rate were determined by Cell Counting Kit-8 (CCK-8) and flow cytometry, respectively. We additionally measured the phosphorylation levels of p38 and p65. We found that the injection of miR-191-5p mimic could observably inhibit renal injury scores, and inhibit inflammatory cytokine productions and apoptotic protein levels in septic rats. After being transfected with OXSR1, the apoptosis rates and expressions of B-cell lymphoma-2 (Bcl-2), down-regulated Bax and Cleaved caspase-3 (C caspase-3) indicated overexpressed OXSR1 contributed to cell apoptosis. The up-regulated protein levels of p-p38 and p-p65 may suggest the involvement of p38 MAPK/NF-κB signaling pathway in the functions of OXSR1. Our results showed that the protective effects of miR-191-5p on kidney tissues of septic rats may rely on the repression of OXSR1.
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Kocyigit I, Taheri S, Eroglu E, Zararsiz G, Sener EF, Uzun I, Imamoglu H, Mehmetbeyoglu E, Unal A, Korkmaz K, Sipahioglu MH, Oymak O, Tokgoz B. Association of OSR-1 With Vascular Dysfunction and Hypertension in Polycystic Kidney Disease. Ther Apher Dial 2019; 24:64-71. [PMID: 31020807 DOI: 10.1111/1744-9987.12814] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 03/22/2019] [Accepted: 04/23/2019] [Indexed: 11/30/2022]
Abstract
Autosomal-dominant polycystic kidney disease (ADPKD) is associated with oxidative stress and hypertension development before renal function decline and cardiovascular disease development. Oxidative stress-responsive kinase-1 (OSR-1) participates in the signaling regulating Na+ transport during oxidative stress and also plays a role in the regulation of cell volume and blood pressure. Therefore, we aimed to investigate the potential role of OSR-1 in ADPKD patients. Eighty ADPKD patients, 80 healthy controls, and 80 non-ADPKD patients with hypertension were enrolled in this cross-sectional study. Twenty-four-hour ambulatory blood pressure monitoring was conducted in all participants. Blood samples were taken after 12-h fasting for the measurement of biochemical parameters and OSR-1 gene expression. Vascular dysfunction was assessed using ischemia-induced forearm flow-mediated vasodilation (FMD). Briefly, of the 80 ADPKD patients, 41(51%) were male, and 53(66%) of them were hypertensive. The mean age of the 80 controls was 35.3 ± 12.6 years, and 37(46%) of them were male. The mean age of the 80 non-ADPKD patients with hypertension was 44.6 ± 11.9 years, and 38(47.5) of them were male. There were significant differences in serum OSR-1 gene expression between the ADPKD patients and the control subjects. Serum OSR-1 gene expression was also significantly increased in hypertensive ADPKD patients in comparison with both normotensive ADPKD counterparts and non-ADPKD hypertensive subjects. Serum OSR-1 gene expression was increased in patients with ADPKD than healthy subjects. Low estimated glomerular filtration rate (eGFR), OSR-1 gene expression, total kidney volume (TKV), and high-density lipoprotein (HDL) were also independently associated with hypertension in ADPKD patients.
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Affiliation(s)
- Ismail Kocyigit
- Department of Internal Medicine, Division of Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Serpil Taheri
- Department of Medical Biology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Eray Eroglu
- Department of Internal Medicine, Division of Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Gokmen Zararsiz
- Department of Biostatistics, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Elif Funda Sener
- Department of Medical Biology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Ilknur Uzun
- Department of Internal Medicine, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Hakan Imamoglu
- Department of Radiology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Ecmel Mehmetbeyoglu
- Betul-Ziya Eren Genome and Stem Cell Center, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Aydin Unal
- Department of Internal Medicine, Division of Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Keziban Korkmaz
- Betul-Ziya Eren Genome and Stem Cell Center, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Murat Hayri Sipahioglu
- Department of Internal Medicine, Division of Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Oktay Oymak
- Department of Internal Medicine, Division of Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey
| | - Bulent Tokgoz
- Department of Internal Medicine, Division of Nephrology, Erciyes University Medical Faculty, Kayseri, Turkey
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Rashmi P, Colussi G, Ng M, Wu X, Kidwai A, Pearce D. Glucocorticoid-induced leucine zipper protein regulates sodium and potassium balance in the distal nephron. Kidney Int 2017; 91:1159-1177. [PMID: 28094030 DOI: 10.1016/j.kint.2016.10.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 10/06/2016] [Accepted: 10/27/2016] [Indexed: 01/21/2023]
Abstract
Glucocorticoid induced leucine zipper protein (GILZ) is an aldosterone-regulated protein that controls sodium transport in cultured kidney epithelial cells. Mice lacking GILZ have been reported previously to have electrolyte abnormalities. However, the mechanistic basis has not been explored. Here we provide evidence supporting a role for GILZ in modulating the balance of renal sodium and potassium excretion by regulating the sodium-chloride cotransporter (NCC) activity in the distal nephron. Gilz-/- mice have a higher plasma potassium concentration and lower fractional excretion of potassium than wild type mice. Furthermore, knockout mice are more sensitive to NCC inhibition by thiazides than are the wild type mice, and their phosphorylated NCC expression is higher. Despite increased NCC activity, knockout mice do not have higher blood pressure than wild type mice. However, during sodium deprivation, knockout mice come into sodium balance more quickly, than do the wild type, without a significant increase in plasma renin activity. Upon prolonged sodium restriction, knockout mice develop frank hyperkalemia. Finally, in HEK293T cells, exogenous GILZ inhibits NCC activity at least in part by inhibiting SPAK phosphorylation. Thus, GILZ promotes potassium secretion by inhibiting NCC and enhancing distal sodium delivery to the epithelial sodium channel. Additionally, Gilz-/- mice have features resembling familial hyperkalemic hypertension, a human disorder that manifests with hyperkalemia associated variably with hypertension.
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Affiliation(s)
- Priyanka Rashmi
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California, USA
| | - GianLuca Colussi
- Department of Experimental and Clinical Medical Sciences, University of Udine, Udine, Italy
| | - Michael Ng
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California, USA
| | - Xinhao Wu
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California, USA
| | - Atif Kidwai
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California, USA
| | - David Pearce
- Division of Nephrology, Department of Medicine, University of California, San Francisco, California, USA.
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11
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Jung J, Lee M. Effects of interaction betweenSLC12A3polymorphism, salt-sensitive gene, and sodium intake on risk of child obesity. ACTA ACUST UNITED AC 2017. [DOI: 10.4163/jnh.2017.50.1.32] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- Joohyun Jung
- Department of Food and Nutrition, Sungshin Women's University, Seoul 01133, Korea
| | - Myoungsook Lee
- Department of Food and Nutrition, Sungshin Women's University, Seoul 01133, Korea
- Research Institute of obesity Sciences, Sungshin Women's University, Seoul 01133, Korea
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12
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Fezai M, Elvira B, Warsi J, Ben-Attia M, Hosseinzadeh Z, Lang F. Up-Regulation of Intestinal Phosphate Transporter NaPi-IIb (SLC34A2) by the Kinases SPAK and OSR1. Kidney Blood Press Res 2015; 40:555-64. [PMID: 26506223 DOI: 10.1159/000368531] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS SPAK (SPS1-related proline/alanine-rich kinase) and OSR1 (oxidative stress-responsive kinase 1), kinases controlled by WNK (with-no-K[Lys] kinase), are powerful regulators of cellular ion transport and blood pressure. Observations in gene-targeted mice disclosed an impact of SPAK/OSR1 on phosphate metabolism. The present study thus tested whether SPAK and/or OSR1 contributes to the regulation of the intestinal Na(+)-coupled phosphate co-transporter NaPi-IIb (SLC34A2). METHODS cRNA encoding NaPi-IIb was injected into Xenopus laevis oocytes without or with additional injection of cRNA encoding wild-type SPAK, constitutively active (T233E)SPAK, WNK insensitive (T233A)SPAK, catalytically inactive (D212A)SPAK, wild-type OSR1, constitutively active (T185E)OSR1, WNK insensitive (T185A)OSR1 or catalytically inactive (D164A)OSR1. The phosphate (1 mM)-induced inward current (I(Pi)) was taken as measure of phosphate transport. RESULTS I(Pi) was observed in NaPi-IIb expressing oocytes but not in water injected oocytes, and was significantly increased by co-expression of SPAK, (T233E)SPAK, OSR1, (T185E)OSR1 or SPAK+OSR1, but not by co-expression of (T233A)SPAK, (D212A)SPAK, (T185A)OSR1, or (D164A)OSR1. SPAK and OSR1 both increased the maximal transport rate of the carrier. CONCLUSIONS SPAK and OSR1 are powerful stimulators of the intestinal Na+-coupled phosphate co-transporter NaPi-IIb.
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Affiliation(s)
- Myriam Fezai
- Department of Physiology I, University of Tx00FC;bingen, Tx00FC;bingen, Germany
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13
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Abstract
Submucosal glands contribute to airway surface liquid (ASL), a film that protects all airway surfaces. Glandular mucus comprises electrolytes, water, the gel-forming mucin MUC5B, and hundreds of different proteins with diverse protective functions. Gland volume per unit area of mucosal surface correlates positively with impaction rate of inhaled particles. In human main bronchi, the volume of the glands is ∼ 50 times that of surface goblet cells, but the glands diminish in size and frequency distally. ASL and its trapped particles are removed from the airways by mucociliary transport. Airway glands have a tubuloacinar structure, with a single terminal duct, a nonciliated collecting duct, then branching secretory tubules lined with mucous cells and ending in serous acini. They allow for a massive increase in numbers of mucus-producing cells without replacing surface ciliated cells. Active secretion of Cl(-) and HCO3 (-) by serous cells produces most of the fluid of gland secretions. Glands are densely innervated by tonically active, mutually excitatory airway intrinsic neurons. Most gland mucus is secreted constitutively in vivo, with large, transient increases produced by emergency reflex drive from the vagus. Elevations of [cAMP]i and [Ca(2+)]i coordinate electrolyte and macromolecular secretion and probably occur together for baseline activity in vivo, with cholinergic elevation of [Ca(2+)]i being mainly responsive for transient increases in secretion. Altered submucosal gland function contributes to the pathology of all obstructive diseases, but is an early stage of pathogenesis only in cystic fibrosis.
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Affiliation(s)
- Jonathan H Widdicombe
- Department of Physiology and Membrane Biology, University of California-Davis, Davis, California; and Department of Psychology and Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California
| | - Jeffrey J Wine
- Department of Physiology and Membrane Biology, University of California-Davis, Davis, California; and Department of Psychology and Cystic Fibrosis Research Laboratory, Stanford University, Stanford, California
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14
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Abousaab A, Warsi J, Elvira B, Alesutan I, Hoseinzadeh Z, Lang F. Down-Regulation of Excitatory Amino Acid Transporters EAAT1 and EAAT2 by the Kinases SPAK and OSR1. J Membr Biol 2015; 248:1107-19. [PMID: 26233565 DOI: 10.1007/s00232-015-9826-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/24/2015] [Indexed: 11/27/2022]
Abstract
SPAK (SPS1-related proline/alanine-rich kinase) and OSR1 (oxidative stress-responsive kinase 1) are cell volume-sensitive kinases regulated by WNK (with-no-K[Lys]) kinases. SPAK/OSR1 regulate several channels and carriers. SPAK/OSR1 sensitive functions include neuronal excitability. Orchestration of neuronal excitation involves the excitatory glutamate transporters EAAT1 and EAAT2. Sensitivity of those carriers to SPAK/OSR1 has never been shown. The present study thus explored whether SPAK and/or OSR1 contribute to the regulation of EAAT1 and/or EAAT2. To this end, cRNA encoding EAAT1 or EAAT2 was injected into Xenopus oocytes without or with additional injection of cRNA encoding wild-type SPAK or wild-type OSR1, constitutively active (T233E)SPAK, WNK insensitive (T233A)SPAK, catalytically inactive (D212A)SPAK, constitutively active (T185E)OSR1, WNK insensitive (T185A)OSR1 or catalytically inactive (D164A)OSR1. The glutamate (2 mM)-induced inward current (I Glu) was taken as a measure of glutamate transport. As a result, I Glu was observed in EAAT1- and in EAAT2-expressing oocytes but not in water-injected oocytes, and was significantly decreased by coexpression of SPAK and OSR1. As shown for EAAT2, SPAK, and OSR1 decreased significantly the maximal transport rate but significantly enhanced the affinity of the carrier. The effect of wild-type SPAK/OSR1 on EAAT1 and EAAT2 was mimicked by (T233E)SPAK and (T185E)OSR1, but not by (T233A)SPAK, (D212A)SPAK, (T185A)OSR1, or (D164A)OSR1. Coexpression of either SPAK or OSR1 decreased the EAAT2 protein abundance in the cell membrane of EAAT2-expressing oocytes. In conclusion, SPAK and OSR1 are powerful negative regulators of the excitatory glutamate transporters EAAT1 and EAAT2.
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Affiliation(s)
- Abeer Abousaab
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Jamshed Warsi
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Bernat Elvira
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Ioana Alesutan
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Zohreh Hoseinzadeh
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
| | - Florian Lang
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany.
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15
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Borrás J, Salker MS, Elvira B, Warsi J, Fezai M, Hoseinzadeh Z, Lang F. SPAK and OSR1 Sensitivity of Excitatory Amino Acid Transporter EAAT3. Nephron Clin Pract 2015; 130:221-8. [PMID: 26112741 DOI: 10.1159/000433567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/20/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Kinases involved in the regulation of epithelial transport include SPAK (SPS1-related proline/alanine-rich kinase) and OSR1 (oxidative stress-responsive kinase 1). SPAK and OSR1 are both regulated by WNK (with-no-K(Lys)) kinases. The present study explored whether SPAK and/or OSR1 influence the excitatory amino acid transporter EAAT3, which accomplishes glutamate and aspartate transport in kidney, intestine and brain. METHODS cRNA encoding EAAT3 was injected into Xenopus laevis oocytes with or without additional injection of cRNA encoding wild-type SPAK, constitutively active (T233E)SPAK, WNK insensitive (T233A)SPAK, catalytically inactive (D212A)SPAK, wild-type OSR1, constitutively active (T185E)OSR1, WNK insensitive (T185A)OSR1 and catalytically inactive (D164A)OSR1. Glutamate-induced current was taken as measure of electrogenic glutamate transport and was quantified utilizing dual electrode voltage clamp. Furthermore, Ussing chamber was employed to determine glutamate transport in the intestine from gene-targeted mice carrying WNK insensitive SPAK (spak(tg/tg)) and from corresponding wild-type mice (spak(+/+)). RESULTS EAAT3 activity was significantly decreased by wild-type SPAK and (T233E)SPAK, but not by (T233A)SPAK and (D212A)SPAK. SPAK decreased maximal transport rate without affecting significantly affinity of the carrier. Similarly, EAAT3 activity was significantly downregulated by wild-type OSR1 and (T185E)OSR1, but not by (T185A)OSR1 and (D164A)OSR1. Again OSR1 decreased maximal transport rate without affecting significantly affinity of the carrier. Intestinal electrogenic glutamate transport was significantly lower in spak(+/+) than in spak(tg/tg) mice. CONCLUSION Both, SPAK and OSR1 are negative regulators of EAAT3 activity.
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Affiliation(s)
- José Borrás
- Department of Physiology I, University of Tübingen, Tubingen, Germany
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16
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Warsi J, Elvira B, Bissinger R, Shumilina E, Hosseinzadeh Z, Lang F. Downregulation of peptide transporters PEPT1 and PEPT2 by oxidative stress responsive kinase OSR1. Kidney Blood Press Res 2014; 39:591-9. [PMID: 25531100 DOI: 10.1159/000368469] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/27/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS OSR1 (oxidative-stress-responsive kinase 1) participates in the regulation of renal tubular ion transport, cell volume and blood pressure. Whether OSR1 contributes to the regulation of organic solute transport remained; however, elusive. The present study thus explored the OSR1 sensitivity of the peptide transporters PEPT1 and PEPT2. METHODS cRNA encoding PEPT1 or PEPT2 were injected into Xenopus oocytes without or with additional injection of cRNA encoding wild-type OSR1, WNK1 insensitive inactive (T185A)OSR1, constitutively active (T185E)OSR1, and catalytically inactive (D164A)OSR1. Electrogenic peptide (glycine-glycine) transport was determined by dual electrode voltage clamp, the abundance of hemagglutinin-tagged PEPT2 (PEPT2-HA) by chemiluminescence. RESULTS In Xenopus oocytes injected with cRNA encoding PEPT1 or PEPT2, but not in oocytes injected with water, the dipeptide gly-gly (2 mM) generated an appreciable inward current (I(gly-gly)). Coexpression of OSR1 significantly decreased Igly-gly in both PEPT1 and PEPT2 expressing oocytes. The effect of OSR1 coexpression on Igly-gly in PEPT1 expressing oocytes was mimicked by coexpression of (T185E)OSR1, but not of (D164A)OSR1 or (T185A)OSR1. Kinetic analysis revealed that coexpression of OSR1 decreased maximal Igly-gly. OSR1 further decreased the PEPT2-HA protein abundance in the cell membrane. CONCLUSION OSR1 has the capacity to downregulate the peptide transporters PEPT1 and PEPT2 by decreasing the carrier protein abundance in the cell membrane.
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Affiliation(s)
- Jamshed Warsi
- Department of Physiology I, University of Tübingen, Tübingen, Germany
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17
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Fezai M, Elvira B, Borras J, Ben-Attia M, Hoseinzadeh Z, Lang F. Negative regulation of the creatine transporter SLC6A8 by SPAK and OSR1. Kidney Blood Press Res 2014; 39:546-54. [PMID: 25531585 DOI: 10.1159/000368465] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Transport regulation involves several kinases including SPAK (SPS1-related proline/alanine-rich kinase) and OSR1 (oxidative stress-responsive kinase 1), which are under control of WNK (with-no-K[Lys]) kinases. The present study explored whether SPAK and/or OSR1 participate in the regulation of the creatine transporter CreaT (SLC6A8), which accomplishes Na+ coupled cellular uptake of creatine in several tissues including kidney, intestine, heart, skeletal muscle and brain. METHODS cRNA encoding SLC6A8 was injected into Xenopus laevis oocytes with or without additional injection of cRNA encoding wild-type SPAK, constitutively active (T233E)SPAK, WNK insensitive (T233A)SPAK, catalytically inactive (D212A)SPAK, wild-type OSR1, constitutively active (T185E)OSR1, WNK insensitive (T185A)OSR1 and catalytically inactive (D164A)OSR1. Transporter activity was determined from creatine (1 mM) induced current utilizing dual electrode voltage clamp. RESULTS Coexpression of wild-type SPAK and of (T233E)SPAK, but not of (T233A)SPAK or of (D212A)SPAK was followed by a significant decrease of creatine induced current in SLC6A8 expressing oocytes. Coexpression of SPAK significantly decreased maximal transport rate. Coexpression of wild-type OSR1, (T185E)OSR1 and (T185A)OSR1 but not of (D164A)OSR1 significantly negatively regulated SLC6A8 activity. OSR1 again decreased significantly maximal transport rate. CONCLUSIONS Both, SPAK and OSR1, are negative regulators of the creatine transporter SLC6A8.
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Affiliation(s)
- Myriam Fezai
- Department of Physiology I, University of Tübingen, Tübingen, Germany
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18
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Cheng CJ, Yoon J, Baum M, Huang CL. STE20/SPS1-related proline/alanine-rich kinase (SPAK) is critical for sodium reabsorption in isolated, perfused thick ascending limb. Am J Physiol Renal Physiol 2014; 308:F437-43. [PMID: 25477470 DOI: 10.1152/ajprenal.00493.2013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
SPAK [STE20 (sterile 20)/SPS1-related proline/alanine-rich kinase] kinase consists of a full-length (FL-) and an alternatively spliced kidney-specific (KS-) isoform. SPAK regulates the NaCl cotransporter (NCC) in the distal convoluted tubule (DCT). The relative abundance and role of FL- vs. KS-SPAK in regulating Na(+)-K(+)-2Cl(-) cotransporter (NKCC2) in thick ascending limb (TAL) are not completely understood. Here, we report that FL-SPAK mRNA was the most abundant in medullary TAL (mTAL), followed by cortical TAL (cTAL) and DCT. KS-SPAK mRNA abundance was relatively lower than FL-SPAK. The ratios of FL-SPAK to KS-SPAK in mTAL, cTAL, and DCT were 12.3, 12.5, and 10.2, respectively. To examine the role of SPAK in the regulation of sodium transport in TAL, we used in vitro microperfusion of mTAL and cTAL isolated from wild-type (WT) and SPAK knockout mice (SPAK-KO) that lack both FL- and KS-SPAK. The rates of sodium absorption in cTAL and mTAL of SPAK-KO mice were 34.5 and 12.5% of WT tubules, respectively. The mRNA levels of related OSR1 kinase and SPAK protease Dnpep in SPAK-KO tubules were not significantly different from WT tubules. We next examined the role of SPAK in the regulation of sodium reabsorption by vasopressin in TAL. Vasopressin increased sodium reabsorption by ∼80% in both mTAL and cTAL from WT mice. While baseline sodium reabsorption was lower in SPAK-KO tubules, vasopressin increased sodium reabsorption over twofold. In conclusion, the combined net effect of SPAK isoforms on sodium reabsorption in TAL is stimulatory. SPAK is not essential for vasopressin stimulation of sodium reabsorption in TAL.
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Affiliation(s)
- Chih-Jen Cheng
- Department of Medicine, Division of Nephrology, UT Southwestern Medical Center, Dallas, Texas; Department of Medicine, Division of Nephrology, Tri-Service General Hospital, National Defense Medical Center, Taipei 114, Taiwan
| | - Joonho Yoon
- Department of Medicine, Division of Nephrology, UT Southwestern Medical Center, Dallas, Texas
| | - Michel Baum
- Department of Medicine, Division of Nephrology, UT Southwestern Medical Center, Dallas, Texas; Department of Pediatrics, UT Southwestern Medical Center, Dallas, Texas; and
| | - Chou-Long Huang
- Department of Medicine, Division of Nephrology, UT Southwestern Medical Center, Dallas, Texas
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Warsi J, Dong L, Elvira B, Salker MS, Shumilina E, Hosseinzadeh Z, Lang F. SPAK dependent regulation of peptide transporters PEPT1 and PEPT2. Kidney Blood Press Res 2014; 39:388-98. [PMID: 25376088 DOI: 10.1159/000368451] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS SPAK (STE20-related proline/alanine-rich kinase) is a powerful regulator of renal tubular ion transport and blood pressure. Moreover, SPAK contributes to the regulation of cell volume. Little is known, however, about a role of SPAK in the regulation or organic solutes. The present study thus addressed the influence of SPAK on the peptide transporters PEPT1 and PEPT2. METHODS To this end, cRNA encoding PEPT1 or PEPT2 were injected into Xenopus laevis oocytes without or with additional injection of cRNA encoding wild-type, SPAK, WNK1 insensitive inactive (T233A)SPAK, constitutively active (T233E)SPAK, and catalytically inactive (D212A)SPAK. Electrogenic peptide (glycine-glycine) transport was determined by dual electrode voltage clamp and PEPT2 protein abundance in the cell membrane by chemiluminescence. Intestinal electrogenic peptide transport was estimated from peptide induced current in Ussing chamber experiments of jejunal segments isolated from gene targeted mice expressing SPAK resistant to WNK-dependent activation (spak(tg/tg)) and respective wild-type mice (spak(+/+)). RESULTS In PEPT1 and in PEPT2 expressing oocytes, but not in oocytes injected with water, the dipeptide gly-gly (2 mM) generated an inward current, which was significantly decreased following coexpression of SPAK. The effect of SPAK on PEPT1 was mimicked by (T233E)SPAK, but not by (D212A)SPAK or (T233A)SPAK. SPAK decreased maximal peptide induced current of PEPT1. Moreover, SPAK decreased carrier protein abundance in the cell membrane of PEPT2 expressing oocytes. In intestinal segments gly-gly generated a current, which was significantly higher in spak(tg/tg) than in spak(+/+) mice. CONCLUSION SPAK is a powerful regulator of peptide transporters PEPT1 and PEPT2.
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Affiliation(s)
- Jamshed Warsi
- Department of Physiology I, University of Tübingen, Gmelinstr. 5, 70276 Tübingen, Germany
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20
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Elvira B, Warsi J, Munoz C, Lang F. SPAK and OSR1 sensitivity of voltage-gated K+ channel Kv1.5. J Membr Biol 2014; 248:59-66. [PMID: 25315612 DOI: 10.1007/s00232-014-9741-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 09/30/2014] [Indexed: 12/11/2022]
Abstract
SPS1-related proline/alanine-rich kinase (SPAK) and oxidative stress-responsive kinase 1 (OSR1) are potent regulators of several transporters and ion channels. The kinases are under regulation of with-no-K(Lys) (WNK) kinases. The present study explored whether SPAK and/or OSR1 modify the expression and/or activity of the voltage-gated K(+) channel Kv1.5, which participates in the regulation of diverse functions including atrial cardiac action potential and tumor cell proliferation. cRNA encoding Kv1.5 was injected into Xenopus oocytes with or without additional injection of cRNA encoding wild-type SPAK, constitutively active (T233E)SPAK, WNK insensitive (T233A)SPAK, catalytically inactive (D212A)SPAK, wild-type OSR1, constitutively active (T185E)OSR1, WNK insensitive (T185A)OSR1, and catalytically inactive (D164A)OSR1. Voltage-gated K(+) channel activity was quantified utilizing dual electrode voltage clamp and Kv1.5 channel protein abundance in the cell membrane utilizing chemiluminescence of Kv1.5 containing an extracellular hemagglutinin epitope (Kv1.5-HA). Kv1.5 activity and Kv1.5-HA protein abundance were significantly decreased by wild-type SPAK and (T233E)SPAK, but not by (T233A)SPAK and (D212A)SPAK. Similarly, Kv1.5 activity and Kv1.5-HA protein abundance were significantly down-regulated by wild-type OSR1 and (T185E)OSR1, but not by (T185A)OSR1 and (D164A)OSR1. Both, SPAK and OSR1 decrease cell membrane Kv1.5 protein abundance and activity.
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Affiliation(s)
- Bernat Elvira
- Department of Physiology, University of Tübingen, Gmelinstr. 5, 72076, Tübingen, Germany
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21
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Warsi J, Hosseinzadeh Z, Elvira B, Bissinger R, Shumilina E, Lang F. Regulation of ClC-2 Activity by SPAK and OSR1. Kidney Blood Press Res 2014; 39:378-87. [DOI: 10.1159/000355816] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/23/2014] [Indexed: 11/19/2022] Open
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Elvira B, Munoz C, Borras J, Chen H, Warsi J, Ajay SS, Shumilina E, Lang F. SPAK and OSR1 dependent down-regulation of murine renal outer medullary K channel ROMK1. Kidney Blood Press Res 2014; 39:353-60. [PMID: 25322850 DOI: 10.1159/000355812] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/17/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The kinases SPAK (SPS1-related proline/alanine-rich kinase) and OSR1 (oxidative stress-responsive kinase 1) participate in the regulation of the NaCl cotransporter NCC and the Na+, K+, 2Cl- cotransporter NKCC2. The kinases are regulated by WNK (with-no-K[Lys]) kinases. Mutations of genes encoding WNK kinases underly Gordon's syndrome, a monogenic disease leading to hypertension and hyperkalemia. WNK kinases further regulate the renal outer medullary K+ channel ROMK1. The present study explored, whether SPAK and/or OSR1 have similarly the potential to modify the activity of ROMK1. METHODS ROMK1 was expressed in Xenopus oocytes with or without additional expression of wild-type SPAK, constitutively active (T233E)SPAK, catalytically inactive (D212A)SPAK, wild-type OSR1, constitutively active (T185E)OSR1 and catalytically inactive (D164A)OSR1. Channel activity was determined utilizing dual electrode voltage clamp and ROMK1 protein abundance in the cell membrane utilizing chemiluminescence of ROMK1 containing an extracellular hemagglutinin epitope (ROMK1-HA). RESULTS ROMK1 activity and ROMK1-HA protein abundance were significantly down-regulated by wild-type SPAK and (T233E)SPAK, but not by (D212A)SPAK. Similarly, ROMK1 activity and ROMK1-HA protein abundance were significantly down-regulated by wild-type OSR1 and (T185E)OSR1, but not by (D164A)OSR1. CONCLUSION ROMK1 protein abundance and activity are down-regulated by SPAK and OSR1.
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Affiliation(s)
- Bernat Elvira
- Department of Physiology I, University of Tübingen, Tübingen, Germany
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23
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SPAK-sensitive regulation of glucose transporter SGLT1. J Membr Biol 2014; 247:1191-7. [PMID: 25161031 DOI: 10.1007/s00232-014-9719-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 08/07/2014] [Indexed: 01/07/2023]
Abstract
The WNK-dependent STE20/SPS1-related proline/alanine-rich kinase SPAK is a powerful regulator of ion transport. The study explored whether SPAK similarly regulates nutrient transporters, such as the Na(+)-coupled glucose transporter SGLT1 (SLC5A1). To this end, SGLT1 was expressed in Xenopus oocytes with or without additional expression of wild-type SPAK, constitutively active (T233E)SPAK, WNK-insensitive (T233A)SPAK or catalytically inactive (D212A)SPAK, and electrogenic glucose transport determined by dual-electrode voltage-clamp experiments. Moreover, Ussing chamber was employed to determine the electrogenic glucose transport in intestine from wild-type mice (spak(wt/wt)) and from gene-targeted mice carrying WNK-insensitive SPAK (spak(tg/tg)). In SGLT1-expressing oocytes, but not in water-injected oocytes, the glucose-dependent current (I(g)) was significantly decreased following coexpression of wild-type SPAK and (T233E)SPAK, but not by coexpression of (T233A)SPAK or (D212A)SPAK. Kinetic analysis revealed that SPAK decreased maximal I(g) without significantly modifying the glucose concentration required for halfmaximal I(g) (K(m)). According to the chemiluminescence experiments, wild-type SPAK but not (D212A)SPAK decreased SGLT1 protein abundance in the cell membrane. Inhibition of SGLT1 insertion by brefeldin A (5 μM) resulted in a decline of I(g), which was similar in the absence and presence of SPAK, suggesting that SPAK did not accelerate the retrieval of SGLT1 protein from the cell membrane but rather down-regulated carrier insertion into the cell membrane. Intestinal electrogenic glucose transport was significantly lower in spak(wt/wt) than in spak(tg/tg) mice. In conclusion, SPAK is a powerful negative regulator of SGLT1 protein abundance in the cell membrane and thus of electrogenic glucose transport.
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mTORC1 maintains renal tubular homeostasis and is essential in response to ischemic stress. Proc Natl Acad Sci U S A 2014; 111:E2817-26. [PMID: 24958889 DOI: 10.1073/pnas.1402352111] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Mammalian target of rapamycin complex 1 (mTORC1) is a key regulator of cell metabolism and autophagy. Despite widespread clinical use of mTORC1 inhibitors, the role of mTORC1 in renal tubular function and kidney homeostasis remains elusive. By using constitutive and inducible deletion of conditional Raptor alleles in renal tubular epithelial cells, we discovered that mTORC1 deficiency caused a marked concentrating defect, loss of tubular cells, and slowly progressive renal fibrosis. Transcriptional profiling revealed that mTORC1 maintains renal tubular homeostasis by controlling mitochondrial metabolism and biogenesis as well as transcellular transport processes involved in countercurrent multiplication and urine concentration. Although mTORC2 partially compensated for the loss of mTORC1, exposure to ischemia and reperfusion injury exaggerated the tubular damage in mTORC1-deficient mice and caused pronounced apoptosis, diminished proliferation rates, and delayed recovery. These findings identify mTORC1 as an important regulator of tubular energy metabolism and as a crucial component of ischemic stress responses.
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Tarone G, Balligand JL, Bauersachs J, Clerk A, De Windt L, Heymans S, Hilfiker-Kleiner D, Hirsch E, Iaccarino G, Knöll R, Leite-Moreira AF, Lourenço AP, Mayr M, Thum T, Tocchetti CG. Targeting myocardial remodelling to develop novel therapies for heart failure. Eur J Heart Fail 2014; 16:494-508. [DOI: 10.1002/ejhf.62] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Revised: 01/02/2014] [Accepted: 01/18/2014] [Indexed: 02/04/2023] Open
Affiliation(s)
- Guido Tarone
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute; Università di Torino; Torino Italy
| | - Jean-Luc Balligand
- Institut de Recherche Expérimentale et Clinique (IREC), Pole de Pharmacologie et Thérapeutique (UCL-FATH) and Department of Medicine, Cliniques Saint-Luc; Université catholique de Louvain; Bruxelles Belgium
| | - Johann Bauersachs
- Department of Cardiology and Angiology; Medizinische Hochschule-Hannover; Hannover Germany
| | - Angela Clerk
- School of Biological Sciences; University of Reading; Reading UK
| | - Leon De Windt
- Department of Cardiology, CARIM School for Cardiovascular Diseases; Maastricht University; Maastricht The Netherlands
| | - Stephane Heymans
- Center for Heart Failure Research, Cardiovascular Research Institute Maastricht (CARIM); Maastricht University; The Netherlands
| | - Denise Hilfiker-Kleiner
- Molecular Cardiology, Department of Cardiology and Angiology; Medizinische Hochschule-Hannover; Hannover Germany
| | - Emilio Hirsch
- Dipartimento di Biotecnologie Molecolari e Scienze per la Salute; Università di Torino; Torino Italy
| | - Guido Iaccarino
- Facoltà di Medicina; Università di Salerno; Salerno Italy
- IRCCS ‘Multimedica’; Milano Italy
| | - Ralph Knöll
- National Heart & Lung Institute; Imperial College London; London UK
| | - Adelino F. Leite-Moreira
- Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine; University of Porto; Porto Portugal
| | - André P. Lourenço
- Department of Physiology and Cardiothoracic Surgery, Faculty of Medicine; University of Porto; Porto Portugal
| | - Manuel Mayr
- King's British Heart Foundation Centre; King's College London; London UK
| | - Thomas Thum
- National Heart & Lung Institute; Imperial College London; London UK
- Institute of Molecular and Translational Therapeutic Strategies; Hannover Medical School; Hannover Germany
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Ponsuksili S, Murani E, Trakooljul N, Schwerin M, Wimmers K. Discovery of candidate genes for muscle traits based on GWAS supported by eQTL-analysis. Int J Biol Sci 2014; 10:327-37. [PMID: 24643240 PMCID: PMC3957088 DOI: 10.7150/ijbs.8134] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 01/22/2014] [Indexed: 12/12/2022] Open
Abstract
Biochemical and biophysical processes that take place in muscle under relaxed and stressed conditions depend on the abundance and activity of gene products of metabolic and structural pathways. In livestock at post-mortem, these muscle properties determine aspects of meat quality and are measurable. The conversion of muscle to meat mimics pathological processes associated with muscle ischemia, injury or damage in humans and it is an economic factor in pork production. Linkage, association, and expression analyses independently contributed to the identification of trait-associated molecular pathways and genes. We aim at providing multiple evidences for the role of specific genes in meat quality by integrating a genome-wide association study (GWAS) for meat quality traits and the detection of eQTL based on trait-correlated expressed genes and trait-associated markers. The GWAS revealed 51 and 200 SNPs significantly associated with meat quality in a crossbred Pietrain×(German Landrace×Large White) (Pi×(GL×LW)) and a purebred German Landrace (GL) population, respectively. Most significant SNPs in Pi×(GL×LW) were located on chromosomes (SSC) 4 and 6. The data of 47,836 eQTLs at a significance level of p<10-5 were used to scale down the number candidate genes located in these regions. These SNPs on SSC4 showed association with expression levels of ZNF704, IMPA1, and OXSR1; SSC6 SNPs were associated with expression of SIGLEC10 and PIH1D1. Most significant SNPs in GL were located on SSC6 and associated with expression levels of PIH1D1, SIGLEC10, TBCB, LOC100518735, KIF1B, LOC100514845, and two unknown genes. The abundance of transcripts of these genes in muscle, in turn, is significantly correlated with meat quality traits. We identified several genes with evidence for their candidacy for meat quality arising from the integrative approach of a genome-wide association study and eQTL analysis.
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Affiliation(s)
- Siriluck Ponsuksili
- 1. Research Group 'Functional Genome Analyses', Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Eduard Murani
- 2. Research Unit 'Molecular Biology', Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Nares Trakooljul
- 2. Research Unit 'Molecular Biology', Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Manfred Schwerin
- 1. Research Group 'Functional Genome Analyses', Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Klaus Wimmers
- 2. Research Unit 'Molecular Biology', Leibniz Institute for Farm Animal Biology (FBN), Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
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Olden M, Corre T, Hayward C, Toniolo D, Ulivi S, Gasparini P, Pistis G, Hwang SJ, Bergmann S, Campbell H, Cocca M, Gandin I, Girotto G, Glaudemans B, Hastie ND, Loffing J, Polasek O, Rampoldi L, Rudan I, Sala C, Traglia M, Vollenweider P, Vuckovic D, Youhanna S, Weber J, Wright AF, Kutalik Z, Bochud M, Fox CS, Devuyst O. Common variants in UMOD associate with urinary uromodulin levels: a meta-analysis. J Am Soc Nephrol 2014; 25:1869-82. [PMID: 24578125 DOI: 10.1681/asn.2013070781] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Uromodulin is expressed exclusively in the thick ascending limb and is the most abundant protein excreted in normal urine. Variants in UMOD, which encodes uromodulin, are associated with renal function, and urinary uromodulin levels may be a biomarker for kidney disease. However, the genetic factors regulating uromodulin excretion are unknown. We conducted a meta-analysis of urinary uromodulin levels to identify associated common genetic variants in the general population. We included 10,884 individuals of European descent from three genetic isolates and three urban cohorts. Each study measured uromodulin indexed to creatinine and conducted linear regression analysis of approximately 2.5 million single nucleotide polymorphisms using an additive model. We also tested whether variants in genes expressed in the thick ascending limb associate with uromodulin levels. rs12917707, located near UMOD and previously associated with renal function and CKD, had the strongest association with urinary uromodulin levels (P<0.001). In all cohorts, carriers of a G allele of this variant had higher uromodulin levels than noncarriers did (geometric means 10.24, 14.05, and 17.67 μg/g creatinine for zero, one, or two copies of the G allele). rs12446492 in the adjacent gene PDILT (protein disulfide isomerase-like, testis expressed) also reached genome-wide significance (P<0.001). Regarding genes expressed in the thick ascending limb, variants in KCNJ1, SORL1, and CAB39 associated with urinary uromodulin levels. These data indicate that common variants in the UMOD promoter region may influence urinary uromodulin levels. They also provide insights into uromodulin biology and the association of UMOD variants with renal function.
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Affiliation(s)
- Matthias Olden
- National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts; Department of Genetic Epidemiology, Institute of Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany
| | - Tanguy Corre
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland; Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Caroline Hayward
- Institute of Genetics and Molecular Medicine, Western General Hospital, and
| | - Daniela Toniolo
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milano, Italy; Institute of Molecular Genetics, National Research Council, Pavia, Italy
| | - Sheila Ulivi
- Institute for Maternal and Child Health, Burlo Garofolo Pediatric Institute Trieste, Italy
| | - Paolo Gasparini
- Institute for Maternal and Child Health, Burlo Garofolo Pediatric Institute Trieste, Italy; Department of Medical Sciences, University of Trieste, Trieste, Italy
| | - Giorgio Pistis
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milano, Italy
| | - Shih-Jen Hwang
- National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts
| | - Sven Bergmann
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland; Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Harry Campbell
- Dulbecco Telethon Institute, San Raffaele Scientific Institute, Milan, Italy
| | - Massimiliano Cocca
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milano, Italy
| | - Ilaria Gandin
- Institute for Maternal and Child Health, Burlo Garofolo Pediatric Institute Trieste, Italy; Department of Medical Sciences, University of Trieste, Trieste, Italy
| | - Giorgia Girotto
- Institute for Maternal and Child Health, Burlo Garofolo Pediatric Institute Trieste, Italy; Department of Medical Sciences, University of Trieste, Trieste, Italy
| | - Bob Glaudemans
- Institute of Physiology, Zurich Center for Integrative Human Physiology, and
| | - Nicholas D Hastie
- Institute of Genetics and Molecular Medicine, Western General Hospital, and
| | | | - Ozren Polasek
- Department of Public Health, Faculty of Medicine, University of Split, Croatia
| | - Luca Rampoldi
- Dulbecco Telethon Institute, San Raffaele Scientific Institute, Milan, Italy
| | - Igor Rudan
- Department of Genetic Epidemiology, Institute of Epidemiology and Preventive Medicine, University of Regensburg, Regensburg, Germany
| | - Cinzia Sala
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milano, Italy
| | - Michela Traglia
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milano, Italy
| | | | - Dragana Vuckovic
- Institute for Maternal and Child Health, Burlo Garofolo Pediatric Institute Trieste, Italy; Department of Medical Sciences, University of Trieste, Trieste, Italy
| | - Sonia Youhanna
- Institute of Physiology, Zurich Center for Integrative Human Physiology, and Division of Nephrology, Catholic University of Louvain Medical School, Brussels, Belgium
| | - Julien Weber
- Institute of Physiology, Zurich Center for Integrative Human Physiology, and Division of Nephrology, Catholic University of Louvain Medical School, Brussels, Belgium
| | - Alan F Wright
- Institute of Genetics and Molecular Medicine, Western General Hospital, and
| | - Zoltán Kutalik
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland; Swiss Institute of Bioinformatics, Lausanne, Switzerland; Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland; and
| | - Murielle Bochud
- Institute of Social and Preventive Medicine, Lausanne University Hospital, Lausanne, Switzerland; and
| | - Caroline S Fox
- National Heart, Lung, and Blood Institute's Framingham Heart Study, Framingham, Massachusetts; Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts
| | - Olivier Devuyst
- Institute of Physiology, Zurich Center for Integrative Human Physiology, and Division of Nephrology, Catholic University of Louvain Medical School, Brussels, Belgium;
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Denton JS, Pao AC, Maduke M. Novel diuretic targets. Am J Physiol Renal Physiol 2013; 305:F931-42. [PMID: 23863472 PMCID: PMC3798746 DOI: 10.1152/ajprenal.00230.2013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 07/12/2013] [Indexed: 01/11/2023] Open
Abstract
As the molecular revolution continues to inform a deeper understanding of disease mechanisms and pathways, there exist unprecedented opportunities for translating discoveries at the bench into novel therapies for improving human health. Despite the availability of several different classes of antihypertensive medications, only about half of the 67 million Americans with hypertension manage their blood pressure appropriately. A broader selection of structurally diverse antihypertensive drugs acting through different mechanisms would provide clinicians with greater flexibility in developing effective treatment regimens for an increasingly diverse and aging patient population. An emerging body of physiological, genetic, and pharmacological evidence has implicated several renal ion-transport proteins, or regulators thereof, as novel, yet clinically unexploited, diuretic targets. These include the renal outer medullary potassium channel, ROMK (Kir1.1), Kir4.1/5.1 potassium channels, ClC-Ka/b chloride channels, UTA/B urea transporters, the chloride/bicarbonate exchanger pendrin, and the STE20/SPS1-related proline/alanine-rich kinase (SPAK). The molecular pharmacology of these putative targets is poorly developed or lacking altogether; however, recent efforts by a few academic and pharmaceutical laboratories have begun to lessen this critical barrier. Here, we review the evidence in support of the aforementioned proteins as novel diuretic targets and highlight examples where progress toward developing small-molecule pharmacology has been made.
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Affiliation(s)
- Jerod S Denton
- T4208 Medical Center North, 1161 21st Ave. South, Nashville, TN 37232.
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Frizzell RA, Hanrahan JW. Physiology of epithelial chloride and fluid secretion. Cold Spring Harb Perspect Med 2013; 2:a009563. [PMID: 22675668 DOI: 10.1101/cshperspect.a009563] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Epithelial salt and water secretion serves a variety of functions in different organ systems, such as the airways, intestines, pancreas, and salivary glands. In cystic fibrosis (CF), the volume and/or composition of secreted luminal fluids are compromised owing to mutations in the gene encoding CFTR, the apical membrane anion channel that is responsible for salt secretion in response to cAMP/PKA stimulation. This article examines CFTR and related cellular transport processes that underlie epithelial anion and fluid secretion, their regulation, and how these processes are altered in CF disease to account for organ-specific secretory phenotypes.
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Affiliation(s)
- Raymond A Frizzell
- Department of Cell Biology and Physiology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.
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Choe KP. Physiological and molecular mechanisms of salt and water homeostasis in the nematode Caenorhabditis elegans. Am J Physiol Regul Integr Comp Physiol 2013; 305:R175-86. [PMID: 23739341 DOI: 10.1152/ajpregu.00109.2013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Intracellular salt and water homeostasis is essential for all cellular life. Extracellular salt and water homeostasis is also important for multicellular organisms. Many fundamental mechanisms of compensation for osmotic perturbations are well defined and conserved. Alternatively, molecular mechanisms of detecting salt and water imbalances and regulating compensatory responses are generally poorly defined for animals. Throughout the last century, researchers studying vertebrates and vertebrate cells made critical contributions to our understanding of osmoregulation, especially mechanisms of salt and water transport and organic osmolyte accumulation. Researchers have more recently started using invertebrate model organisms with defined genomes and well-established methods of genetic manipulation to begin defining the genes and integrated regulatory networks that respond to osmotic stress. The nematode Caenorhabditis elegans is well suited to these studies. Here, I introduce osmoregulatory mechanisms in this model, discuss experimental advantages and limitations, and review important findings. Key discoveries include defining genetic mechanisms of osmolarity sensing in neurons, identifying protein damage as a sensor and principle determinant of hypertonic stress resistance, and identification of a putative sensor for hypertonic stress associated with the extracellular matrix. Many of these processes and pathways are conserved and, therefore, provide new insights into salt and water homeostasis in other animals, including mammals.
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Affiliation(s)
- Keith P Choe
- Department of Biology and Genetics Institute, University of Florida, Gainesville, FL 32611, USA.
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Sorensen MV, Grossmann S, Roesinger M, Gresko N, Todkar AP, Barmettler G, Ziegler U, Odermatt A, Loffing-Cueni D, Loffing J. Rapid dephosphorylation of the renal sodium chloride cotransporter in response to oral potassium intake in mice. Kidney Int 2013; 83:811-24. [DOI: 10.1038/ki.2013.14] [Citation(s) in RCA: 241] [Impact Index Per Article: 21.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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An inducible transgenic mouse model for familial hypertension with hyperkalaemia (Gordon's syndrome or pseudohypoaldosteronism type II). Clin Sci (Lond) 2013; 124:701-8. [PMID: 23336180 DOI: 10.1042/cs20120430] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mutations in the novel serine/threonine WNK [With No lysine (=K)] kinases WNK1 and WNK4 cause PHAII (pseudohypoaldosteronism type II or Gordon's syndrome), a rare monogenic syndrome which causes hypertension and hyperkalaemia on a background of a normal glomerular filtration rate. Current animal models for PHAII recapitulate some aspects of the disease phenotype, but give no clues to how rapidly the phenotype emerges or whether it is reversible. To this end we have created an inducible PHAII transgenic animal model that expresses a human disease-causing WNK4 mutation, WNK4 Q565E, under the control of the Tet-On system. Several PHAII inducible transgenic mouse lines were created, each with differing TG (transgene) copy numbers and displaying varying degrees of TG expression (low, medium and high). Each of these transgenic lines demonstrated similar elevations of BP (blood pressure) and plasma potassium after 4 weeks of TG induction. Withdrawal of doxycycline switched off mutant TG expression and the disappearance of the PHAII phenotype. Western blotting of microdissected kidney nephron segments confirmed that expression of the thiazide-sensitive NCC (Na⁺-Cl⁻ co-transporter) was increased, as expected, in the distal convoluted tubule when transgenic mice were induced with doxycycline. The kidneys of these mice also do not show the morphological changes seen in the previous transgenic model expressing the same mutant form of WNK4. This inducible model shows, for the first time, that in vivo expression of a mutant WNK4 protein is sufficient to cause the rapid and reversible appearance of a PHAII disease phenotype in mice.
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Ding J, Ponce-Coria J, Delpire E. A trafficking-deficient mutant of KCC3 reveals dominant-negative effects on K-Cl cotransport function. PLoS One 2013; 8:e61112. [PMID: 23593405 PMCID: PMC3617232 DOI: 10.1371/journal.pone.0061112] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Accepted: 03/06/2013] [Indexed: 12/27/2022] Open
Abstract
The K-Cl cotransporter (KCC) functions in maintaining chloride and volume homeostasis in a variety of cells. In the process of cloning the mouse KCC3 cDNA, we came across a cloning mutation (E289G) that rendered the cotransporter inactive in functional assays in Xenopus laevis oocytes. Through biochemical studies, we demonstrate that the mutant E289G cotransporter is glycosylation-deficient, does not move beyond the endoplasmic reticulum or the early Golgi, and thus fails to reach the plasma membrane. We establish through co-immunoprecipitation experiments that both wild-type and mutant KCC3 with KCC2 results in the formation of hetero-dimers. We further demonstrate that formation of these hetero-dimers prevents the proper trafficking of the cotransporter to the plasma membrane, resulting in a significant decrease in cotransporter function. This effect is due to interaction between the K-Cl cotransporter isoforms, as this was not observed when KCC3-E289G was co-expressed with NKCC1. Our studies also reveal that the glutamic acid residue is essential to K-Cl cotransporter function, as the corresponding mutation in KCC2 also leads to an absence of function. Interestingly, mutation of this conserved glutamic acid residue in the Na(+)-dependent cation-chloride cotransporters had no effect on NKCC1 function in isosmotic conditions, but diminished cotransporter activity under hypertonicity. Together, our data show that the glutamic acid residue (E289) is essential for proper trafficking and function of KCCs and that expression of a non-functional but full-length K-Cl cotransporter might results in dominant-negative effects on other K-Cl cotransporters.
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Affiliation(s)
- Jinlong Ding
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Molecular Physiology and Biophysics Graduate Program Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - José Ponce-Coria
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
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Smith L, Litman P, Liedtke CM. COMMD1 interacts with the COOH terminus of NKCC1 in Calu-3 airway epithelial cells to modulate NKCC1 ubiquitination. Am J Physiol Cell Physiol 2013; 305:C133-46. [PMID: 23515529 DOI: 10.1152/ajpcell.00394.2012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Mice deficient in Na-K-2Cl cotransporter (NKCC1) have been generated by targeted disruption of the gene encoding NKCC1 involving the carboxy terminus (CT-NKCC1) but not the amino terminus. We hypothesize that the resulting physiological defects are due to loss of proteins interacting with CT-NKCC1. Using a yeast two-hybrid approach, adaptor protein COMMD1 was found to bind to CT-NKCC1 (aa 1,040-1,212). Binding was verified in a yeast-independent system using GST-COMMD1 and myc-CT-NKCC1. Truncated COMMD1 and CT-NKCC1 peptides were used in binding assays to identify the site of interaction. The results demonstrate concentration-dependent binding of COMMD1 (aa 1-47) to CT-NKCC1 (aa 1,040-1,134). Endogenous COMMD1 was detected in pull downs using recombinant FLAG-CT-NKCC1; this co-pull down was blocked by COMMD1 (aa 1-47). CT-NKCC1 (aa 1,040-1,137) decreased basolateral membrane expression of NKCC1, and COMMD1 (aa 1-47) increased NKCC1 membrane expression. Downregulation of COMMD1 using silencing (si)RNA led to a transient loss of endogenous COMMD1 but did not affect activation of NKCC1 by hyperosmotic sucrose. Hyperosmolarity caused a transient increase in NKCC1 membrane expression, indicating regulated trafficking of NKCC1; downregulation of COMMD1 using siRNA reduced baseline (unstimulated) NKCC1 expression and blunted a transient elevation in NKCC1 membrane expression caused by hyperosmolarity. Constitutive downregulation of COMMD1 in HT29 engineered cells exhibited loss of COMMD1 and decreased NKCC1 membrane expression with no effect on activation of NKCC1. Loss of COMMD1 in Calu-3 cells and in HT29 cells led to reduced ubiquitinated NKCC1. The results indicate a role for COMMD1 in the regulation of NKCC1 membrane expression and ubiquitination.
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Affiliation(s)
- Laura Smith
- Willard Alan Bernbaum, Center for Cystic Fibrosis Research, Departments of Pediatrics at Rainbow Babies and Children Hospital and Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio, USA
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Pasham V, Pathare G, Fajol A, Rexhepaj R, Michael D, Pakladok T, Alesutan I, Rotte A, Föller M, Lang F. OSR1-sensitive small intestinal Na+ transport. Am J Physiol Gastrointest Liver Physiol 2012; 303:G1212-9. [PMID: 23019198 DOI: 10.1152/ajpgi.00367.2011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The oxidative stress responsive kinase 1 (OSR1) contributes to WNK (with no K)-dependent regulation of renal tubular salt transport, renal salt excretion, and blood pressure. Little is known, however, about a role of OSR1 in the regulation of intestinal salt transport. The present study thus explored whether OSR1 is expressed in intestinal tissue and whether small intestinal Na(+)/H(+) exchanger (NHE), small intestinal Na(+)-glucose cotransport (SGLT1), and/or colonic epithelium Na(+) channel (ENaC) differ between knockin mice carrying one allele of WNK-resistant OSR1 (osr1(+/KI)) and wild-type mice (osr1(+/+)). OSR1 protein abundance was determined by Western blotting, cytosolic pH from BCECF fluorescence, NHE activity from Na(+)-dependent realkalinization following an ammonium pulse, SGLT1 activity from glucose-induced current, and colonic ENaC activity from amiloride-sensitive transepithelial current in Ussing chamber experiments. As a result, OSR1 protein was expressed in small intestine of both osr1(+/KI) mice and osr1(+/+) mice. Daily fecal Na(+), K(+), and H(2)O excretion and jejunal SGLT1 activity were lower, whereas small intestinal NHE activity and colonic ENaC activity were higher in osr1(+/KI) mice than in osr1(+/+) mice. NHE3 inhibitor S-3226 significantly reduced NHE activity in both genotypes but did not abrogate the difference between the genotypes. Plasma osmolarity, serum antidiuretic hormone, plasma aldosterone, and plasma corticosterone concentrations were similar in both genotypes. Small intestinal NHE3 and colonic α-ENaC protein abundance were not significantly different between genotypes, but colonic phospho-β-ENaC (ser633) was significantly higher in osr1(+/KI) mice. In conclusion, OSR1 is expressed in intestine and partial WNK insensitivity of OSR1 increases intestinal NHE activity and colonic ENaC activity.
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Affiliation(s)
- Venkanna Pasham
- Department of Physiology, University of Tübingen, Gmelinstr. 5, D-72076 Tübingen, Germany
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Lee DH, Maunsbach AB, Riquier-Brison AD, Nguyen MTX, Fenton RA, Bachmann S, Yu AS, McDonough AA. Effects of ACE inhibition and ANG II stimulation on renal Na-Cl cotransporter distribution, phosphorylation, and membrane complex properties. Am J Physiol Cell Physiol 2012; 304:C147-63. [PMID: 23114965 DOI: 10.1152/ajpcell.00287.2012] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The renal distal tubule Na-Cl cotransporter (NCC) reabsorbs <10% of the filtered Na(+) but is a key control point for blood pressure regulation by angiotensin II (ANG II), angiotensin-converting enzyme inhibitors (ACEI), and thiazide diuretics. This study aimed to determine whether NCC phosphorylation (NCCp) was regulated by acute (20-30 min) treatment with the ACEI captopril (12 μg/min × 20 min) or by a sub-pressor dose of ANG II (20 ng·kg(-1)·min(-1)) in Inactin-anesthetized rats. By immuno-EM, NCCp was detected exclusively in or adjacent to apical plama membranes (APM) in controls and after ACEI or ANG II treatment, while NCC total was detected in both APM and subapical cytoplasmic vesicles (SCV) in all conditions. In renal homogenates, neither ACEI nor ANG II treatment altered NCCp abundance, assayed by immunoblot. However, by density gradient fractionation we identified a pool of low-density APM in which NCCp decreased 50% in response to captopril and was restored during ANG II infusion, and another pool of higher-density APM that responded reciprocally, indicative of regulated redistribution between two APM pools. In both pools, NCCp was preferentially localized to Triton-soluble membranes. Blue Native gel electrophoresis established that APM NCCp localized to ~700 kDa complexes (containing γ-adducin) while unphosphorylated NCC in intracellular membranes primarily localized to ~400 kDa complexes: there was no evidence for native monomeric or dimeric NCC or NCCp. In summary, this study demonstrates that phosphorylated NCC, localized to multimeric complexes in the APM, redistributes in a regulated manner within the APM in response to ACEI and ANG II.
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Affiliation(s)
- Donna H Lee
- Department of Cell and Neurobiology, Keck School of Medicine of University of Southern California, Los Angeles, CA 90033, USA
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Abstract
Germinal center kinases (GCKs) participate in a variety of signaling pathways needed to regulate cellular functions including apoptosis, cell proliferation, polarity and migration. Recent studies have shown that GCKs are participants in both adaptive and innate immune regulation. However, the differential activation and regulatory mechanisms of GCKs, as well as upstream and downstream signaling molecules, remain to be fully defined. It remains unresolved whether and how GCKs may cross-talk with existing signaling pathways. This review stresses the progresses in research of GCKs relevant to the immune system.
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Current world literature. Curr Opin Nephrol Hypertens 2012; 21:557-66. [PMID: 22874470 DOI: 10.1097/mnh.0b013e3283574c3b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Chen D, Coffman TM. The Kidney and Hypertension: Lessons From Mouse Models. Can J Cardiol 2012; 28:305-10. [DOI: 10.1016/j.cjca.2012.01.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2011] [Revised: 01/04/2012] [Accepted: 01/04/2012] [Indexed: 11/28/2022] Open
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Nguyen MTX, Yang LE, Fletcher NK, Lee DH, Kocinsky H, Bachmann S, Delpire E, McDonough AA. Effects of K+-deficient diets with and without NaCl supplementation on Na+, K+, and H2O transporters' abundance along the nephron. Am J Physiol Renal Physiol 2012; 303:F92-104. [PMID: 22496411 DOI: 10.1152/ajprenal.00032.2012] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Dietary potassium (K(+)) restriction and hypokalemia have been reported to change the abundance of most renal Na(+) and K(+) transporters and aquaporin-2 isoform, but results have not been consistent. The aim of this study was to reexamine Na(+), K(+) and H(2)O transporters' pool size regulation in response to removing K(+) from a diet containing 0.74% NaCl, as well as from a diet containing 2% NaCl (as found in American diets) to blunt reducing total diet electrolytes. Sprague-Dawley rats (n = 5-6) were fed for 6 days with one of these diets: 2% KCl, 0.74% NaCl (2K1Na, control chow) compared with 0.03% KCl, 0.74% NaCl (0K1Na); or 2% KCl, 2%NaCl (2K2Na) compared with 0.03% KCl, 2% NaCl (0K2Na, Na(+) replete). In both 0K1Na and 0K2Na there were significant decreases in: 1) plasma [K(+)] (<2.5 mM); 2) urinary K(+) excretion (<5% of control); 3) urine osmolality and plasma [aldosterone], as well as 4) an increase in urine volume and medullary hypertrophy. The 0K2Na group had the lowest [aldosterone] (172.0 ± 17.4 pg/ml) and lower blood pressure (93.2 ± 4.9 vs. 112.0 ± 3.1 mmHg in 2K2Na). Transporter pool size regulation was determined by quantitative immunoblotting of renal cortex and medulla homogenates. The only differences measured in both 0K1Na and 0K2Na groups were a 20-30% decrease in cortical β-ENaC, 30-40% increases in kidney-specific Ste20/SPS1-related proline/alanine-rich kinase, and a 40% increase in medullary sodium pump abundance. The following proteins were not significantly changed in both the 0 K groups: Na(+)/H(+) exchanger isoform 3; Na(+)-K(+)-Cl(-) cotransporter; Na(+)-Cl(-) cotransporter, oxidative stress response kinase-1; renal outer medullary K(+) channel; autosomal recessive hypercholesterolemia; c-Src, aquaporin 2 isoform; or renin. Thus, despite profound hypokalemia and renal K(+) conservation, we did not confirm many of the changes that were previously reported. We predict that changes in transporter distribution and activity are likely more important for conserving K(+) than changes in total abundance.
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Affiliation(s)
- Mien T X Nguyen
- Department of Cell and Neurobiology, Keck School of Medicine of University of Southern California, Los Angeles, California, USA
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Pathare G, Föller M, Michael D, Walker B, Hierlmeier M, Mannheim JG, Pichler BJ, Lang F. Enhanced FGF23 Serum Concentrations and Phosphaturia in Gene Targeted Mice Expressing WNK-Resistant Spak. ACTA ACUST UNITED AC 2012; 36:355-64. [DOI: 10.1159/000343393] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2012] [Indexed: 12/20/2022]
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