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Reusswig F, Yilmaz M, Brechtenkamp M, Krueger I, Metz LM, Klöcker N, Lammert E, Elvers M. The NMDA receptor regulates integrin activation, ATP release and arterial thrombosis through store-operated Ca 2+ entry in platelets. Front Cardiovasc Med 2023; 10:1171831. [PMID: 37252113 PMCID: PMC10217778 DOI: 10.3389/fcvm.2023.1171831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/27/2023] [Indexed: 05/31/2023] Open
Abstract
Introduction Platelet activation and thrombus formation is crucial for hemostasis, but also trigger arterial thrombosis. Calcium mobilization plays an important role in platelet activation, because many cellular processes depend on the level of intracellular Ca2+ ([Ca2+](i)), such as integrin activation, degranulation, cytoskeletal reorganization. Different modulators of Ca2+ signaling have been implied, such as STIM1, Orai1, CyPA, SGK1, etc. Also, the N-methyl-D-aspartate receptor (NMDAR) was identified to contribute to Ca2+ signaling in platelets. However, the role of the NMDAR in thrombus formation is not well defined. Methods In vitro and in vivo analysis of platelet-specific NMDAR knock-out mice. Results In this study, we analyzed Grin1fl/fl-Pf4-Cre+ mice with a platelet-specific knock-out of the essential GluN1 subunit of the NMDAR. We found reduced store-operated Ca2+ entry (SOCE), but unaltered store release in GluN1-deficient platelets. Defective SOCE resulted in reduced Src and PKC substrate phosphorylation following stimulation of glycoprotein (GP)VI or the thrombin receptor PAR4 followed by decreased integrin activation but unaltered degranulation. Consequently, thrombus formation on collagen under flow conditions was reduced ex vivo, and Grin1fl/fl-Pf4-Cre+ mice were protected against arterial thrombosis. Results from human platelets treated with the NMDAR antagonist MK-801 revealed a crucial role of the NMDAR in integrin activation and Ca2+ homeostasis in human platelets as well. Conclusion NMDAR signaling is important for SOCE in platelets and contributes to platelet activation and arterial thrombosis. Thus, the NMDAR represents a novel target for anti-platelet therapy in cardiovascular disease (CVD).
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Affiliation(s)
- Friedrich Reusswig
- Department of Vascular- and Endovascular Surgery, University Hospital Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany
| | - Münteha Yilmaz
- Department of Vascular- and Endovascular Surgery, University Hospital Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany
| | - Marius Brechtenkamp
- Department of Vascular- and Endovascular Surgery, University Hospital Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany
| | - Irena Krueger
- Department of Vascular- and Endovascular Surgery, University Hospital Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany
| | - Lisa Maria Metz
- Department of Vascular- and Endovascular Surgery, University Hospital Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany
| | - Nikolaj Klöcker
- Institute of Neural and Sensory Physiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany
| | - Eckhard Lammert
- Institute for Vascular and Islet Cell Biology, German Diabetes Center (DDZ), Leibniz Center for Diabetes Research at Heinrich-Heine University, Düsseldorf, Germany
- German Center for Diabetes Research (DZD e.V.), Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Metabolic Physiology, Heinrich Heine University, Düsseldorf, Germany
| | - Margitta Elvers
- Department of Vascular- and Endovascular Surgery, University Hospital Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany
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Glutamate-Gated NMDA Receptors: Insights into the Function and Signaling in the Kidney. Biomolecules 2020; 10:biom10071051. [PMID: 32679780 PMCID: PMC7407907 DOI: 10.3390/biom10071051] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/10/2020] [Accepted: 07/13/2020] [Indexed: 12/21/2022] Open
Abstract
N-Methyl-d-aspartate receptor (NMDAR) is a glutamate-gated ionotropic receptor that intervenes in most of the excitatory synaptic transmission within the central nervous system (CNS). Aside from being broadly distributed in the CNS and having indispensable functions in the brain, NMDAR has predominant roles in many physiological and pathological processes in a wide range of non-neuronal cells and tissues. The present review outlines current knowledge and understanding of the physiological and pathophysiological functions of NMDAR in the kidney, an essential excretory and endocrine organ responsible for the whole-body homeostasis. The review also explores the recent findings regarding signaling pathways involved in NMDAR-mediated responses in the kidney. As established from diverse lines of research reviewed here, basal levels of receptor activation within the kidney are essential for the maintenance of healthy tubular and glomerular function, while a disproportionate activation can lead to a disruption of NMDAR's downstream signaling pathways and a myriad of pathophysiological consequences.
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Adverse effects in kidney function, antioxidant systems and histopathology in rats receiving monosodium glutamate diet. ACTA ACUST UNITED AC 2017; 69:547-556. [DOI: 10.1016/j.etp.2017.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 01/24/2017] [Accepted: 03/21/2017] [Indexed: 12/24/2022]
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Conigrave AD. The Calcium-Sensing Receptor and the Parathyroid: Past, Present, Future. Front Physiol 2016; 7:563. [PMID: 28018229 PMCID: PMC5156698 DOI: 10.3389/fphys.2016.00563] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 11/07/2016] [Indexed: 12/13/2022] Open
Abstract
Parathyroid hormone (PTH) defends the extracellular fluid from hypocalcemia and has powerful and well-documented actions on the skeleton and renal tubular system. To achieve a satisfactory stable plasma calcium level, the secretion of PTH, and the resulting serum PTH level, is titrated carefully to the prevailing plasma ionized Ca2+ concentration via a Ca2+ sensing mechanism that mediates feedback inhibition of PTH secretion. Herein, I consider the properties of the parathyroid Ca2+ sensing mechanism, the identity of the Ca2+ sensor, the intracellular biochemical mechanisms that it controls, the manner of its integration with other components of the PTH secretion control mechanism, and its modulation by other nutrients. Together the well-established, recently elucidated, and yet-to-be discovered elements of the story constitute the past, present, and future of the parathyroid and its calcium-sensing receptor (CaSR).
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Affiliation(s)
- Arthur D Conigrave
- Faculties of Science and Medicine, School of Life and Environmental Sciences, Charles Perkins Centre, University of Sydney Sydney, NSW, Australia
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Qi QQ, Chen FX, Zhao DY, Li LX, Wang P, Li YQ, Zuo XL. Colonic mucosal N-methyl-D-aspartate receptor mediated visceral hypersensitivity in a mouse model of irritable bowel syndrome. J Dig Dis 2016; 17:448-57. [PMID: 27356126 DOI: 10.1111/1751-2980.12374] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 06/11/2016] [Accepted: 06/19/2016] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The aim of this study was to investigate whether colonic mucosal N-methyl-D-aspartate receptor (NMDAR) participates in visceral hypersensitivity in irritable bowel syndrome (IBS). METHODS C57BL/6 mice were administered intrarectally with trinitrobenzenesulfonic acid (TNBS) for the establishment of an IBS-like visceral hypersensitivity model. Those received an equivalent volume of 50% ethanol were regarded as the controls. Abdominal withdrawal reflex (AWR) scores in response to colorectal distention (CRD) were used to assess visceral sensitivity. NMDAR levels in the colonic mucosa were detected by both immunohistochemistry and Western blot. The concentrations of glutamate and ammonia in the feces of the mice were measured. Changes in visceral sensitivity after the intracolonic administration of ammonia or NMDAR antagonist were recorded. RESULTS The established IBS-like mouse model of visceral hypersensitivity showed no evident inflammation in the colon. NMDAR levels in the colonic mucosa of the IBS-like mice were significantly higher compared with the controls, and were positively associated with AWR scores. The glutamate level in the feces of the TNBS-treated mice was similar to that of the controls, although the ammonia level was significantly higher. Intracolonic administration of ammonia induced visceral hypersensitivity in mice, which was repressed by pretreatment with NMDAR antagonist MK801. CONCLUSIONS Overexpressed NMDAR in the colonic mucosa may participate in the pathogenesis of visceral hypersensitivity in IBS. Our study identifies the effect of ammonia in the colonic lumen on NMDAR in the colonic mucosa as a potential novel targeted mechanism for IBS treatment.
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Affiliation(s)
- Qing Qing Qi
- Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, Shandong Province, China
| | - Fei Xue Chen
- Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, Shandong Province, China
| | - Dong Yan Zhao
- Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, Shandong Province, China
| | - Li Xiang Li
- Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, Shandong Province, China
| | - Peng Wang
- Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, Shandong Province, China
| | - Yan Qing Li
- Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, Shandong Province, China
| | - Xiu Li Zuo
- Department of Gastroenterology, Qilu Hospital, Shandong University, Jinan, Shandong Province, China.
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Ding H, Jian Z, Stary CM, Yi W, Xiong X. Molecular Pathogenesis of Anti-NMDAR Encephalitis. BIOMED RESEARCH INTERNATIONAL 2015; 2015:643409. [PMID: 26221602 PMCID: PMC4499418 DOI: 10.1155/2015/643409] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 04/20/2015] [Indexed: 01/17/2023]
Abstract
Anti-NMDAR encephalitis is a recently identified autoimmune disease, described by an immune-mediated loss of NMDA glutamate receptors, resulting in progressive mental deterioration. To date, literature on anti-NMDAR encephalitis has been largely clinically oriented, including descriptions of the clinical presentation and course, diagnostic methods, and potential clinical treatments. However, the underlying molecular mechanisms contributing to the complex immunological cellular transformation that is associated with the progression of anti-NMDAR encephalitis remain to be adequately explored. This review will provide a summary of the current literature on anti-NMDAR encephalitis, including the immunologic molecular mechanisms contributing to disease progression. In particular this review will focus on the effect of anti-NMDAR on GluN2-NMDAR expression and the molecular transformation of B and T leukocytes in the loss of self-tolerance. Further research on the immunologic mechanisms contributing to anti-NMDAR encephalitis may provide an avenue for future novel diagnostic approaches, such as immunologic surveillance, as well as new therapeutic strategies for this recently identified autoimmune disease.
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Affiliation(s)
- Hao Ding
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Zhihong Jian
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Creed M. Stary
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Wei Yi
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
| | - Xiaoxing Xiong
- Department of Neurosurgery, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan, Hubei 430060, China
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Abstract
INTRODUCTION NMDA receptor (NMDAR) is an ionotropic glutamate receptor with a high permeability to calcium and a unique feature of controlling numerous calcium-dependent processes. Apart from being widely distributed in the CNS, the presence of NMDAR and its potential significance in a variety of non-neuronal cells and tissues has become an interesting research topic. AREAS COVERED The current review summarizes prevailing knowledge on the role of NMDARs in the kidney, bone and parathyroid gland, three main organs responsible for calcium homeostasis, as well as in the heart, an organ whose function is highly dependable on balanced intracellular calcium concentrations. The review also examines studies that have advanced our understanding of the therapeutic potential of NMDAR agonists and antagonists in renal, cardiovascular and bone pathologies. EXPERT OPINION NMDARs have a preeminent role in many physiological and pathological processes outside the CNS. In certain organs and/or disease conditions, activating the NMDAR leads to beneficial effects for the target organ, whereas in other diseases cell signaling downstream of NMDAR activation can exacerbate their pathology. Therefore, targeting NMDARs therapeutically is rather intricate work, and surely requires more extensive investigation in order to properly tune up the diverse NMDAR's actions translating them into beneficial cellular responses.
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Affiliation(s)
- Milica Bozic
- Institute for Biomedical Research (IRB Lleida), Nephrology Research Department , Edificio Biomedicina 1. Lab B1-10, Lleida , Spain +34 973 003 650 ; +34 973 702 213 ;
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Valcheva P, Cardus A, Panizo S, Parisi E, Bozic M, Lopez Novoa JM, Dusso A, Fernández E, Valdivielso JM. Lack of vitamin D receptor causes stress-induced premature senescence in vascular smooth muscle cells through enhanced local angiotensin-II signals. Atherosclerosis 2014; 235:247-55. [PMID: 24880896 DOI: 10.1016/j.atherosclerosis.2014.05.911] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 04/09/2014] [Accepted: 05/01/2014] [Indexed: 12/20/2022]
Abstract
OBJECTIVES The inhibition of the renal renin-angiotensin system by the active form of vitamin D contributes to the cardiovascular health benefits of a normal vitamin D status. Local production of angiotensin-II in the vascular wall is a potent mediator of oxidative stress, prompting premature senescence. Herein, our objective was to examine the impact of defective vitamin D signalling on local angiotensin-II levels and arterial health. METHODS Primary cultures of aortic vascular smooth muscle cells (VSMC) from wild-type and vitamin D receptor-knockout (VDRKO) mice were used for the assessment of cell growth, angiotensin-II and superoxide anion production and expression levels of cathepsin D, angiotensin-II type 1 receptor and p57(Kip2). The in vitro findings were confirmed histologically in aortas from wild-type and VDRKO mice. RESULTS VSMC from VDRKO mice produced more angiotensin-II in culture, and elicited higher levels of cathepsin D, an enzyme with renin-like activity, and angiotensin-II type 1 receptor, than wild-type mice. Accordingly, VDRKO VSMC showed higher intracellular superoxide anion production, which could be suppressed by cathepsin D, angiotensin-II type 1 receptor or NADPH oxidase antagonists. VDRKO cells presented higher levels of p57(Kip2), impaired proliferation and premature senescence, all of them blunted upon inhibition of angiotensin-II signalling. In vivo studies confirmed higher levels of cathepsin D, angiotensin-II type 1 receptor and p57(Kip2) in aortas from VDRKO mice. CONCLUSION The beneficial effects of active vitamin D in vascular health could be a result of the attenuation of local production of angiotensin-II and downstream free radicals, thus preventing the premature senescence of VSMC.
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Affiliation(s)
- Petya Valcheva
- Experimental Nephrology Laboratory, Department of Experimental Medicine, Biomedical Research Institute of Lleida (IRBLLEIDA), Lleida, Spain
| | - Anna Cardus
- Experimental Nephrology Laboratory, Department of Experimental Medicine, Biomedical Research Institute of Lleida (IRBLLEIDA), Lleida, Spain
| | - Sara Panizo
- Experimental Nephrology Laboratory, Department of Experimental Medicine, Biomedical Research Institute of Lleida (IRBLLEIDA), Lleida, Spain
| | - Eva Parisi
- Experimental Nephrology Laboratory, Department of Experimental Medicine, Biomedical Research Institute of Lleida (IRBLLEIDA), Lleida, Spain
| | - Milica Bozic
- Experimental Nephrology Laboratory, Department of Experimental Medicine, Biomedical Research Institute of Lleida (IRBLLEIDA), Lleida, Spain
| | - Jose M Lopez Novoa
- Department of Physiology and Pharmacology, University of Salamanca, Salamanca, Spain
| | - Adriana Dusso
- Experimental Nephrology Laboratory, Department of Experimental Medicine, Biomedical Research Institute of Lleida (IRBLLEIDA), Lleida, Spain
| | - Elvira Fernández
- Nephrology Service and UDETMA, University Hospital Arnau de Vilanova, Lleida, Spain
| | - Jose M Valdivielso
- Experimental Nephrology Laboratory, Department of Experimental Medicine, Biomedical Research Institute of Lleida (IRBLLEIDA), Lleida, Spain.
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Nemoto K, Ikeda A, Tanaka T, Inoue K, Yoshida M, Nishikawa A, Gamou T, Habano W, Ozawa S, Degawa M. Change in the gene expression of the N-methyl-D-aspartate receptor 2C subunit by dietary β-naphthoflavone, indole-3-carbinol, or acetaminophen in the rat liver. J Toxicol Sci 2013; 38:611-7. [PMID: 23824016 DOI: 10.2131/jts.38.611] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We have previously demonstrated super-induced expression of the Grin2c gene encoding the N-methyl-D-aspartate receptor 2C subunit during the process of liver enlargement induced by phenobarbital, clofibrate, piperonyl butoxide, or lead nitrate. In the present study, hepatic Grin2c gene expression levels were assessed by real-time RT-PCR in male F344 rats fed for 3 days, 4 weeks, and 13 weeks a diet containing either β-naphthoflavone (BNF) (5,000 ppm), indole-3-carbinol (I3C) (2,000 ppm), or acetaminophen (AA) (12,500 ppm until the first 14 days; 10,000 ppm from 15 days on), each of which is capable of inducing hepatocellular hypertrophy. Especially, either the 4-week or the 13-week treatment with each chemical, except for BNF, resulted in a drastic increase in the expression level of the Grin2c gene. DNA microarray analysis using RNAs of 13-week-treated rats showed that in the I3C- and AA-treated rats, the fold-increase rates of the Grin2c gene ranked second and first, respectively, among the genes analyzed. Histopathological analyses indicated that the slight hepatocellular hypertrophy in the periportal area and the hepatocellular necrosis in a portion of the centrilobular area developed in the BNF-treated and AA-treated rats, respectively. In addition, relative liver weight was significantly higher in the rats treated with BNF and I3C than in the control rats. The present findings suggest the possibility that the induction of Grin2c gene expression is not necessarily dependent on only the development of liver enlargement, although the significance of this induction remains unclear.
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Affiliation(s)
- Kiyomitsu Nemoto
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Japan.
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Nemoto K, Ikeda A, Hikida T, Kojima M, Degawa M. Induced expression of hepatic N-methyl-D-aspartate receptor 2C subunit gene during liver enlargement induced by lead nitrate, a hepatocellular mitogen. J Toxicol Sci 2013; 38:127-9. [PMID: 23358146 DOI: 10.2131/jts.38.127] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We previously demonstrated the super-induced expression of the Grin2c gene encoding the N-methyl-D-aspartate receptor 2C subunit during the development of liver enlargement with hepatocellular hypertrophy induced by phenobarbital, clofibrate, or piperonyl butoxide. In the present study, we assessed whether or not Grin2c gene expression was induced during the development of chemically induced liver enlargement with hyperplasia. Male Sprague-Dawley (SD) rats, stroke-prone spontaneously hypertensive rats (SHRSPs), and SHRSP's normotensive control, Wistar-Kyoto (WKY) rats, were administered lead nitrate (LN) (0.1 mmol/kg, single i.v.), a direct inducer of liver hyperplasia, and changes in the level of Grin2c mRNA in the liver were assessed by real-time RT-PCR. The level of hepatic Grin2c mRNA was significantly higher 6-48 hr after the injection in SD rats (about 30~40- and 70-fold over the control at 6~24 hr and 48 hr, respectively) and in WKY rats (about 20-fold over the control only at 12 hr), but was not significantly higher in SHRSPs. Such differences in LN-induced levels of Grin2c mRNA among SD rats, WKY rats, and SHRSPs were closely correlated with those in the previously reported increase in liver weight 48 hr after LN administration. The present findings suggest that the increase in the level of hepatic Grin2c mRNA relates to development of chemically induced liver enlargement with hyperplasia.
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Affiliation(s)
- Kiyomitsu Nemoto
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, Japan.
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Kim EY, Anderson M, Dryer SE. Sustained activation of N-methyl-D-aspartate receptors in podoctyes leads to oxidative stress, mobilization of transient receptor potential canonical 6 channels, nuclear factor of activated T cells activation, and apoptotic cell death. Mol Pharmacol 2012; 82:728-37. [PMID: 22828802 DOI: 10.1124/mol.112.079376] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Atypical N-methyl-D-aspartate (NMDA) receptors are expressed in podocytes. Sustained (≥24 h) application of 50 to100 μM NMDA to immortalized mouse podocytes evoked a marked increase in the production of reactive oxygen species(ROS) such as H₂O₂. This effect of NMDA was associated with increased cell-surface expression of p47(phox), a cytosolic regulatory subunit of the NADPH oxidase NOX2. NMDA-evoked generation of ROS drove an increase in steady-state surface expression of transient receptor potential canonical (TRPC) 6 channels, which was blocked by the NMDA antagonist dizocilpine(MK-801) and by a membrane-permeable scavenger of ROS. The effect of NMDA on TRPC6 was observed using cell surface biotinylation assays and also with whole-cell recordings made under conditions designed to facilitate detection of current through TRPC6. NMDA mobilization of TRPC6 channels was blocked by concurrent treatment with the NMDA antagonist MK-801 and by a membrane-permeable scavenger ofROS. Mobilization of TRPC6 was also evoked by L-homocysteic acid. NMDA treatment also increased nuclear localization of endogenous nuclear factor of activated T cells, which could be blocked by MK-801, by scavenging ROS, by the calcineurin inhibitor cyclosporine, and by the TRPC channel inhibitor 1-[2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl)propoxy]ethyl]imidazole (SKF-96365). NMDA treatment also evoked robust activation of Rho but not Rac,consistent with previous studies of downstream effectors of TRPC6 activation. Exposing cells to NMDA for 24 h reduced total and cell surface expression of the podocyte markers nephrin and podocin, but there was no loss of cells. With longer NMDA exposure (72 h), we observed loss of cells associated with nuclear fragmentation and increased expression of caspase-3, caspase-6, and Bax, suggesting an apoptotic process.
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Affiliation(s)
- Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Houston, Texas, USA
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Román-García P, Carrillo-López N, Naves-Díaz M, Rodríguez I, Ortiz A, Cannata-Andía JB. Dual-specificity phosphatases are implicated in severe hyperplasia and lack of response to FGF23 of uremic parathyroid glands from rats. Endocrinology 2012; 153:1627-37. [PMID: 22334717 DOI: 10.1210/en.2011-1770] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Phosphate load accelerates the progression of secondary hyperparathyroidism (sHPT). In advanced stages of sHPT, there is a marked hyperplasia and resistance to classical regulatory endocrine factors such as calcium, calcitriol, or fibroblast growth factor 23 (FGF23), which suppresses PTH secretion by an ERK-dependent mechanism. Nephrectomized rats were fed with a high- or normal-phosphorus diet for different periods of time to induce sHPT. Biochemical parameters, parathyroid gland microarrays, quantitative real-time PCR, and immunohistochemistry (ERK/phospho-ERK) were performed. To test the role of dual-specificity phosphatases (Dusp) on parathyroid gland regulation, normal parathyroid glands were cultured with FGF23 and Dusp. Uremic rats fed with a high-phosphorus diet showed more severe sHPT, higher serum FGF23 levels and mortality, and decreased parathyroid Klotho gene expression. In all stages of sHPT, parathyroid microarrays displayed a widespread gene expression down-regulation; only a few genes were overexpressed, among them, Dusp5 and -6. In very severe sHPT, a significant reduction in phospho-ERK (the target of Dusp) and a significant increase of Dusp5 and -6 gene expression were observed. In ex vivo experiments with parathyroid glands, Dusp partially blocked the effect of FGF23 on PTH secretion, suggesting that Dusp might play a role in parathyroid regulation. The overexpression of Dusp and the inactivation of ERK found in the in vivo studies together with the ex vivo results might be indicative of the defense mechanism triggered to counteract hyperplasia, a mechanism that can also contribute to the resistance to the effect of FGF23 on parathyroid gland observed in advanced forms of chronic kidney disease.
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Affiliation(s)
- Pablo Román-García
- Servicio de Metabolismo Óseo y Mineral, Instituto Reina Sofía de Investigaciones Nefrológicas, Hospital Universitario Central de Asturias, 33006 Oviedo, Asturias, Spain
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Peery HE, Day GS, Dunn S, Fritzler MJ, Prüss H, De Souza C, Doja A, Mossman K, Resch L, Xia C, Sakic B, Belbeck L, Foster WG. Anti-NMDA receptor encephalitis. The disorder, the diagnosis and the immunobiology. Autoimmun Rev 2012; 11:863-72. [PMID: 22440397 DOI: 10.1016/j.autrev.2012.03.001] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Accepted: 03/07/2012] [Indexed: 12/21/2022]
Abstract
Anti-NMDAR encephalitis is a newly characterized syndrome with a progressive, predictable clinical course and the possibility of effective treatment. Accurate and timely diagnosis is critical to selection and implementation of treatments, and optimal patient outcomes. Outcomes are improved with early diagnosis via indirect immunofluorescence or cell-based assays, and the rapid and appropriate administration of immunosuppressant and anti-psychotic therapies. Three possible scenarios accounting for the immunopathogenesis of anti-NMDAR encephalitis are presented, with the most probable one being that of paraneoplastic autoimmunity. Future efforts in this disorder should focus on elucidating the mechanisms that contribute to initiation of this antibody response, as well as exploring the role of tumors, infectious triggers and immune-reactivation. Finally, accessible tools need to be developed that allow for reliable identification of specific antibody markers against synaptic proteins.
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Affiliation(s)
- Harry E Peery
- Department of Obstetrics and Gynecology, Division of Reproductive Biology, McMaster University, 1200 Main Street West, Hamilton, Ontario, Canada L8N 3Z5.
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Cowan RW, Seidlitz EP, Singh G. Glutamate signaling in healthy and diseased bone. Front Endocrinol (Lausanne) 2012; 3:89. [PMID: 22833735 PMCID: PMC3400067 DOI: 10.3389/fendo.2012.00089] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Accepted: 06/30/2012] [Indexed: 01/22/2023] Open
Abstract
Bone relies on multiple extracellular signaling systems to maintain homeostasis of its normal structure and functions. The amino acid glutamate is a fundamental extracellular messenger molecule in many tissues, and is used in bone for both neural and non-neural signaling. This review focuses on the non-neural interactions, and examines the evolutionarily ancient glutamate signaling system in the context of its application to normal bone functioning and discusses recent findings on the role of glutamate signaling as they pertain to maintaining healthy bone structure. The underlying mechanisms of glutamate signaling and the many roles glutamate plays in modulating bone physiology are featured, including those involved in osteoclast and osteoblast differentiation and mature cell functions. Moreover, the relevance of glutamate signaling systems in diseases that affect bone, such as cancer and rheumatoid arthritis, is discussed, and will highlight how the glutamate system may be exploited as a viable therapeutic target. We will identify novel areas of research where knowledge of glutamate communication mechanisms may aid in our understanding of the complex nature of bone homeostasis. By uncovering the contributions of glutamate in maintaining healthy bone, the reader will discover how this complex molecular signaling system may advance our capacity to treat bone pathologies.
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Affiliation(s)
- Robert W. Cowan
- Department of Pathology and Molecular Medicine, McMaster UniversityHamilton, ON, Canada
| | - Eric P. Seidlitz
- Department of Pathology and Molecular Medicine, McMaster UniversityHamilton, ON, Canada
| | - Gurmit Singh
- Department of Pathology and Molecular Medicine, McMaster UniversityHamilton, ON, Canada
- *Correspondence: Gurmit Singh, Juravinski Cancer Centre, Room 4-225, 699 Concession Street, Hamilton, ON, Canada L8V 5C2. e-mail:
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15
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Bozic M, Valdivielso JM. Calcium signaling in renal tubular cells. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:933-44. [PMID: 22453977 DOI: 10.1007/978-94-007-2888-2_42] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The kidney handles calcium by filtration and reabsorption. About 60% of the plasma calcium is filterable, and 99% is reabsorbed in the tubule. In the proximal tubule, the reabsorption is passive and paracellular, but in the distal tubule is active and transcellular. Thus, renal tubular cells are exposed to very high concentrations of calcium in both, the extracellular and the intracellular compartments. Extracellular calcium signaling is transmitted by the calcium sensing receptor, located both in the luminal and basolateral sides of tubular cells. This receptor is able to control levels of extracellular calcium and acts in consequence to maintain calcium homeostasis. Furthermore, renal tubular cells possess several calcium channels that regulate some of the cell functions. Among those, voltage gated calcium channels, transient receptor potential channels and N-methyl-D-aspartate receptor channels have been reported to control several functions. Those functions include survival, apoptosis, differentiation, epithelial-mesenchymal transition, and active vitamin D and renin synthesis.
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Affiliation(s)
- Milica Bozic
- Nephrology Research Laboratory, IRB Lleida, University Hospital Arnau de Vilanova, Rovira Roure 80, Planta 1, 25198 Lleida, Spain.
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16
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Sanchez-Niño MD, Bozic M, Córdoba-Lanús E, Valcheva P, Gracia O, Ibarz M, Fernandez E, Navarro-Gonzalez JF, Ortiz A, Valdivielso JM. Beyond proteinuria: VDR activation reduces renal inflammation in experimental diabetic nephropathy. Am J Physiol Renal Physiol 2011; 302:F647-57. [PMID: 22169009 DOI: 10.1152/ajprenal.00090.2011] [Citation(s) in RCA: 122] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Local inflammation is thought to contribute to the progression of diabetic nephropathy. The vitamin D receptor (VDR) activator paricalcitol has an antiproteinuric effect in human diabetic nephropathy at high doses. We have explored potential anti-inflammatory effects of VDR activator doses that do not modulate proteinuria in an experimental model of diabetic nephropathy to gain insights into potential benefits of VDR activators in those patients whose proteinuria is not decreased by this therapy. The effect of calcitriol and paricalcitol on renal function, albuminuria, and renal inflammation was explored in a rat experimental model of diabetes induced by streptozotocin. Modulation of the expression of mediators of inflammation by these drugs was explored in cultured podocytes. At the doses used, neither calcitriol nor paricalcitol significantly modified renal function or reduced albuminuria in experimental diabetes. However, both drugs reduced the total kidney mRNA expression of IL-6, monocyte chemoattractant protein (MCP)-1, and IL-18. Immunohistochemistry showed that calcitriol and paricalcitol reduced MCP-1 and IL-6 in podocytes and tubular cells as well as glomerular infiltration by macrophages, glomerular cell NF-κB activation, apoptosis, and extracellular matrix deposition. In cultured podocytes, paricalcitol and calcitriol at concentrations in the physiological and clinically significant range prevented the increase in MCP-1, IL-6, renin, and fibronectin mRNA expression and the secretion of MCP-1 to the culture media induced by high glucose. In conclusion, in experimental diabetic nephropathy VDR activation has local renal anti-inflammatory effects that can be observed even when proteinuria is not decreased. This may be ascribed to decreased inflammatory responses of intrinsic renal cells, including podocytes, to high glucose.
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Affiliation(s)
- Maria-Dolores Sanchez-Niño
- Research Laboratory and Nephrology Department, Hospital Universitari Arnau de Vilanova, IRBLLEIDA, Lleida, Spain
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17
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Bozic M, de Rooij J, Parisi E, Ortega MR, Fernandez E, Valdivielso JM. Glutamatergic signaling maintains the epithelial phenotype of proximal tubular cells. J Am Soc Nephrol 2011; 22:1099-111. [PMID: 21597037 DOI: 10.1681/asn.2010070701] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Epithelial-mesenchymal transition (EMT) contributes to the progression of renal tubulointerstitial fibrosis. The N-methyl-d-aspartate receptor (NMDAR), which is present in proximal tubular epithelium, is a glutamate receptor that acts as a calcium channel. Activation of NMDAR induces actin rearrangement in cells of the central nervous system, but whether it helps maintain the epithelial phenotype of the proximal tubule is unknown. Here, knockdown of NMDAR1 in a proximal tubule cell line (HK-2) induced changes in cell morphology, reduced E-cadherin expression, and increased α-SMA expression. Induction of EMT with TGF-β1 led to downregulation of both E-cadherin and membrane-associated β-catenin, reorganization of F-actin, expression of mesenchymal markers de novo, upregulation of Snail1, and increased cell migration; co-treatment with NMDA attenuated all of these changes. Furthermore, NMDA reduced TGF-β1-induced phosphorylation of Erk1/2 and Akt and the activation of Ras, suggesting that NMDA antagonizes TGF-β1-induced EMT by inhibiting the Ras-MEK pathway. In the unilateral ureteral obstruction model, treatment with NMDA blunted obstruction-induced upregulation of α-SMA, FSP1, and collagen I and downregulation of E-cadherin. Taken together, these results suggest that NMDAR plays a critical role in preserving the normal epithelial phenotype and modulating tubular EMT.
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Affiliation(s)
- Milica Bozic
- Nephrology Research Laboratory, IRB LLEIDA, University Hospital Arnau de Vilanova, Lleida, Spain
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18
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Nemoto K, Tanaka T, Ikeda A, Ito S, Mizukami M, Hikida T, Gamou T, Habano W, Ozawa S, Inoue K, Yoshida M, Nishikawa A, Degawa M. Super-induced gene expression of the N-methyl-D-aspartate receptor 2C subunit in chemical-induced hypertrophic liver in rats. J Toxicol Sci 2011; 36:507-14. [DOI: 10.2131/jts.36.507] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Kiyomitsu Nemoto
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka
| | - Takahiro Tanaka
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka
| | - Ayaka Ikeda
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka
| | - Sei Ito
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka
| | - Masanori Mizukami
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka
| | - Tokihiro Hikida
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka
| | - Toshie Gamou
- Department of Pharmacodynamics and Molecular Genetics, School of Pharmacy, Iwate Medical University
| | - Wataru Habano
- Department of Pharmacodynamics and Molecular Genetics, School of Pharmacy, Iwate Medical University
| | - Shogo Ozawa
- Department of Pharmacodynamics and Molecular Genetics, School of Pharmacy, Iwate Medical University
| | - Kaoru Inoue
- Division of Pathology, National Institute of Health Sciences
| | - Midori Yoshida
- Division of Pathology, National Institute of Health Sciences
| | | | - Masakuni Degawa
- Department of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka
- Global Center of Excellence (COE) Program, University of Shizuoka
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19
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Parisi E, Bozic M, Ibarz M, Panizo S, Valcheva P, Coll B, Fernández E, Valdivielso JM. Sustained activation of renal N-methyl-D-aspartate receptors decreases vitamin D synthesis: a possible role for glutamate on the onset of secondary HPT. Am J Physiol Endocrinol Metab 2010; 299:E825-31. [PMID: 20823451 PMCID: PMC2980358 DOI: 10.1152/ajpendo.00428.2010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 09/07/2010] [Indexed: 01/16/2023]
Abstract
N-methyl-D-aspartate (NMDA) receptors (NMDAR) are tetrameric amino acid receptors that act as membrane calcium channels. The presence of the receptor has been detected in the principal organs responsible for calcium homeostasis (kidney, bone, and parathyroid gland), pointing to a possible role in mineral metabolism. The aim of this study was to test the effect of NMDAR activation in the kidney and on 1,25(OH)₂D₃ synthesis. We determined the presence of NMDAR subunits in HK-2 (human kidney cells) cells and proved its functionality. NMDA treatment for 4 days induced a decrease in 1α-hydroxylase levels and 1,25(OH)₂D₃ synthesis through the activation of the MAPK/ERK pathway in HK-2 cells. In vivo administration of NMDA for 4 days also caused a decrease in blood 1,25(OH)₂D₃ levels in healthy animals and an increase in blood PTH levels. This increase in PTH induced a decrease in the urinary excretion of calcium and an increase in urinary excretion of phosphorous and sodium as well as in diuresis. Bone turnover markers also increased. Animals with 5/6 nephrectomy showed low levels of renal 1α-hydroxylase as well as high levels of renal glutamate compared with healthy animals. In conclusion, NMDAR activation in the kidney causes a decrease in 1,25(OH)₂D₃ synthesis, which induces an increase on PTH synthesis and release. In animals with chronic kidney disease, high renal levels of glutamate could be involved in the downregulation of 1α-hydroxylase expression.
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Affiliation(s)
- Eva Parisi
- Institut de Recerca Biomèdica de Lleida, Spain
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20
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Anderson M, Suh JM, Kim EY, Dryer SE. Functional NMDA receptors with atypical properties are expressed in podocytes. Am J Physiol Cell Physiol 2010; 300:C22-32. [PMID: 20739624 DOI: 10.1152/ajpcell.00268.2010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
N-methyl-D-aspartate (NMDA) receptors are essential for normal nervous system function, but their excessive activation can lead to neuronal degeneration. NMDA receptors are also expressed in peripheral tissues, where their properties and significance are not well understood. Here we show that functional NMDA receptors are expressed in podocytes, polarized cells that form an essential component of the glomerular filtration apparatus. Application of NMDA to podocyte cell lines or primary cultures of mouse podocytes evoked macroscopic currents mediated by cation channels, with significant permeability to Ca²(+). Podocyte NMDA receptors do not desensitize with prolonged exposure to NMDA. They are blocked by supraphysiological concentrations of external or internal Mg²(+) and, also, by the prototype antagonists MK-801 and D-2-aminophosphonovaleric acid. NMDA responses in podocytes were strongly potentiated by D-serine, but not by glycine, even at high concentrations. D-Aspartate and L-homocysteate are effective agonists of podocyte NMDA receptors. Surprisingly, L-glutamate and L-aspartate did not evoke robust ionic currents in podocytes, regardless of the concentration or membrane potential at which these amino acids were tested. NMDA application for 2 h caused activation of secondary signals through Erk and Akt pathways and, at higher concentrations, caused activation of RhoA. Exposure to NMDA for 6 h did not cause loss of cultured podocytes but did lead to a reduction in nephrin expression. NMDA receptors that respond to circulating ligands may play a role in regulation of glomerular function or dysfunction, but they are unlikely to be components of a local glutamate signaling system in glomeruli.
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Affiliation(s)
- Marc Anderson
- Department of Biology and Biochemistry, University of Houston, TX 77204-5001, USA
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