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Wagner CA. The basics of phosphate metabolism. Nephrol Dial Transplant 2024; 39:190-201. [PMID: 37660247 PMCID: PMC10828206 DOI: 10.1093/ndt/gfad188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Indexed: 09/04/2023] Open
Abstract
Phosphorus is an essential mineral that is, in the form of inorganic phosphate (Pi), required for building cell membranes, DNA and RNA molecules, energy metabolism, signal transduction and pH buffering. In bone, Pi is essential for bone stability in the form of apatite. Intestinal absorption of dietary Pi depends on its bioavailability and has two distinct modes of active transcellular and passive paracellular absorption. Active transport is transporter mediated and partly regulated, while passive absorption depends mostly on bioavailability. Renal excretion controls systemic Pi levels, depends on transporters in the proximal tubule and is highly regulated. Deposition and release of Pi into and from soft tissues and bone has to be tightly controlled. The endocrine network coordinating intestinal absorption, renal excretion and bone turnover integrates dietary intake and metabolic requirements with renal excretion and is critical for bone stability and cardiovascular health during states of hypophosphataemia or hyperphosphataemia as evident from inborn or acquired diseases. This review provides an integrated overview of the biology of phosphate and Pi in mammals.
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Affiliation(s)
- Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland
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2
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Ramos-Brossier M, Romeo-Guitart D, Lanté F, Boitez V, Mailliet F, Saha S, Rivagorda M, Siopi E, Nemazanyy I, Leroy C, Moriceau S, Beck-Cormier S, Codogno P, Buisson A, Beck L, Friedlander G, Oury F. Slc20a1 and Slc20a2 regulate neuronal plasticity and cognition independently of their phosphate transport ability. Cell Death Dis 2024; 15:20. [PMID: 38195526 PMCID: PMC10776841 DOI: 10.1038/s41419-023-06292-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 11/01/2023] [Accepted: 11/13/2023] [Indexed: 01/11/2024]
Abstract
In recent years, primary familial brain calcification (PFBC), a rare neurological disease characterized by a wide spectrum of cognitive disorders, has been associated to mutations in the sodium (Na)-Phosphate (Pi) co-transporter SLC20A2. However, the functional roles of the Na-Pi co-transporters in the brain remain still largely elusive. Here we show that Slc20a1 (PiT-1) and Slc20a2 (PiT-2) are the most abundant Na-Pi co-transporters expressed in the brain and are involved in the control of hippocampal-dependent learning and memory. We reveal that Slc20a1 and Slc20a2 are differentially distributed in the hippocampus and associated with independent gene clusters, suggesting that they influence cognition by different mechanisms. Accordingly, using a combination of molecular, electrophysiological and behavioral analyses, we show that while PiT-2 favors hippocampal neuronal branching and survival, PiT-1 promotes synaptic plasticity. The latter relies on a likely Otoferlin-dependent regulation of synaptic vesicle trafficking, which impacts the GABAergic system. These results provide the first demonstration that Na-Pi co-transporters play key albeit distinct roles in the hippocampus pertaining to the control of neuronal plasticity and cognition. These findings could provide the foundation for the development of novel effective therapies for PFBC and cognitive disorders.
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Affiliation(s)
- Mariana Ramos-Brossier
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 8, F-75015, Paris, France.
| | - David Romeo-Guitart
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 8, F-75015, Paris, France
| | - Fabien Lanté
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, 38000, Grenoble, France
| | - Valérie Boitez
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 8, F-75015, Paris, France
| | - François Mailliet
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 8, F-75015, Paris, France
| | - Soham Saha
- Institut Pasteur, Perception & Memory Unit, F-75015, Paris, France
- MedInsights, 6 rue de l'église, F-02810, Veuilly la Poterie, France
| | - Manon Rivagorda
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 8, F-75015, Paris, France
| | - Eleni Siopi
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 8, F-75015, Paris, France
| | - Ivan Nemazanyy
- Platform for Metabolic Analyses, Structure Fédérative de Recherche Necker, INSERM US24/CNRS UAR, 3633, Paris, France
| | - Christine Leroy
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 6, F-75015, Paris, France
| | - Stéphanie Moriceau
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 8, F-75015, Paris, France
- Platform for Neurobehavioural and metabolism, Structure Fédérative de Recherche Necker, INSERM, US24/CNRS UAR, 3633, Paris, France
- Institute of Genetic Diseases, Imagine, 75015, Paris, France
| | - Sarah Beck-Cormier
- Nantes Université, CNRS, Inserm, l'Institut du Thorax, F-44000, Nantes, France
| | - Patrice Codogno
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 6, F-75015, Paris, France
| | - Alain Buisson
- Univ. Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, 38000, Grenoble, France
| | - Laurent Beck
- Nantes Université, CNRS, Inserm, l'Institut du Thorax, F-44000, Nantes, France.
| | - Gérard Friedlander
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 6, F-75015, Paris, France.
| | - Franck Oury
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, Team 8, F-75015, Paris, France.
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3
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Wagner CA. Pharmacology of Mammalian Na +-Dependent Transporters of Inorganic Phosphate. Handb Exp Pharmacol 2024; 283:285-317. [PMID: 36592227 DOI: 10.1007/164_2022_633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Inorganic phosphate (Pi) is an essential component of many biologically important molecules such as DNA, RNA, ATP, phospholipids, or apatite. It is required for intracellular phosphorylation signaling events and acts as pH buffer in intra- and extracellular compartments. Intestinal absorption, uptake into cells, and renal reabsorption depend on a set of different phosphate transporters from the SLC20 (PiT transporters) and SLC34 (NaPi transporters) gene families. The physiological relevance of these transporters is evident from rare monogenic disorders in humans affecting SLC20A2 (Fahr's disease, basal ganglia calcification), SLC34A1 (idiopathic infantile hypercalcemia), SLC34A2 (pulmonary alveolar microlithiasis), and SLC34A3 (hereditary hypophosphatemic rickets with hypercalciuria). SLC34 transporters are inhibited by millimolar concentrations of phosphonoformic acid or arsenate while SLC20 are relatively resistant to these compounds. More recently, a series of more specific and potent drugs have been developed to target SLC34A2 to reduce intestinal Pi absorption and to inhibit SLC34A1 and/or SLC34A3 to increase renal Pi excretion in patients with renal disease and incipient hyperphosphatemia. Also, SLC20 inhibitors have been developed with the same intention. Some of these substances are currently undergoing preclinical and clinical testing. Tenapanor, a non-absorbable Na+/H+-exchanger isoform 3 inhibitor, reduces intestinal Pi absorption likely by indirectly acting on the paracellular pathway for Pi and has been tested in several phase III trials for reducing Pi overload in patients with renal insufficiency and dialysis.
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Affiliation(s)
- Carsten A Wagner
- Institute of Physiology, University of Zurich, Zurich, Switzerland.
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4
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Kulesza T, Typiak M, Rachubik P, Rogacka D, Audzeyenka I, Saleem MA, Piwkowska A. Pit 1 transporter (SLC20A1) as a key factor in the NPP1-mediated inhibition of insulin signaling in human podocytes. J Cell Physiol 2023; 238:1921-1936. [PMID: 37269459 DOI: 10.1002/jcp.31051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/12/2023] [Accepted: 05/16/2023] [Indexed: 06/05/2023]
Abstract
Podocytes are crucially involved in blood filtration in the glomerulus. Their proper function relies on efficient insulin responsiveness. The insulin resistance of podocytes, defined as a reduction of cell sensitivity to this hormone, is the earliest pathomechanism of microalbuminuria that is observed in metabolic syndrome and diabetic nephropathy. In many tissues, this alteration is mediated by the phosphate homeostasis-controlling enzyme nucleotide pyrophosphatase/phosphodiesterase 1 (NPP1). By binding to the insulin receptor (IR), NPP1 inhibits downstream cellular signaling. Our previous research found that hyperglycemic conditions affect another protein that is involved in phosphate balance, type III sodium-dependent phosphate transporter 1 (Pit 1). In the present study, we evaluated the insulin resistance of podocytes after 24 h of incubation under hyperinsulinemic conditions. Thereafter, insulin signaling was inhibited. The formation of NPP1/IR complexes was observed at that time. A novel finding in the present study was our observation of an interaction between NPP1 and Pit 1 after the 24 h stimulation of podocytes with insulin. After downregulation of the SLC20A1 gene, which encodes Pit 1, we established insulin resistance in podocytes that were cultured under native conditions, manifested as a lack of intracellular insulin signaling and the inhibition of glucose uptake via the glucose transporter type 4. These findings suggest that Pit 1 might be a major factor that participates in the NPP1-mediated inhibition of insulin signaling.
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Affiliation(s)
- Tomasz Kulesza
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
| | - Marlena Typiak
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Gdansk, Poland
| | - Patrycja Rachubik
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
| | - Dorota Rogacka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
- Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
| | - Irena Audzeyenka
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
- Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
| | | | - Agnieszka Piwkowska
- Laboratory of Molecular and Cellular Nephrology, Mossakowski Medical Research Institute, Polish Academy of Sciences, Gdansk, Poland
- Department of Molecular Biotechnology, Faculty of Chemistry, University of Gdansk, Gdansk, Poland
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5
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Jin Z, Dou M, Peng W, Xiao B, Liu J, Meng W, Liu W. Identification of distinct immune infiltration and potential biomarkers in patients with liver ischemia-reperfusion injury. Life Sci 2023:121726. [PMID: 37105441 DOI: 10.1016/j.lfs.2023.121726] [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: 02/18/2023] [Revised: 04/10/2023] [Accepted: 04/20/2023] [Indexed: 04/29/2023]
Abstract
AIMS To identify alterations of specific gene expression, immune infiltration components, and potential biomarkers in liver ischemia-reperfusion injury (IRI) following liver transplantation (LT). MATERIALS AND METHODS GSE23649 and GSE151648 datasets were obtained from the Gene Expression Omnibus (GEO) database. To determine the differentially expressed genes (DEGs), we utilized the R package "limma". We also identify the infiltration of different immune cells through single-sample gene-set enrichment analysis (ssGSEA). Furthermore, we utilized LASSO logistic regression to select feature genes and Spearman's rank correlation analysis to determine the correlation between these genes and infiltrating immune cells. Finally, the significance of these feature genes was confirmed using a mouse model of hepatic IRI. KEY FINDINGS A total of 17 DEGs were acquired, most of which were associated with inflammation, apoptosis, cell proliferation, immune disorders, stress response, and angiogenesis. 28 immune cell types were determined using ssGSEA. 5 feature genes (ADM, KLF6, SERPINE1, SLC20A1, and HBB) were screened using LASSO analysis, but the HBB gene was ultimately excluded due to the lack of statistical significance in the GSE151648 dataset. These 4 feature genes were predominantly related to immune cells. Finally, 15 significantly distinctive types of immune cells between the control and IRI groups were verified. SIGNIFICANCE We unveiled that macrophages, dendritic cells (DCs), neutrophils, CD4 T cells, and other immune cells infiltrated the IRI that occurred after LT. Moreover, we identified ADM, KLF6, SERPINE1, and SLC20A1 as potential biological biomarkers underlying IRI post-transplant, which may improve the diagnosis and prognosis of this condition.
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Affiliation(s)
- Zhangliu Jin
- Department of General Surgery, Division of Biliopancreatic and Metabolic Surgery, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Meng Dou
- Department of Kidney Transplantation, Hospital of Nephropathy, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shangxi 710000, China
| | - Weihui Peng
- Department of General Surgery, Division of Biliopancreatic and Metabolic Surgery, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Boen Xiao
- Department of General Surgery, Division of Biliopancreatic and Metabolic Surgery, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Jinjin Liu
- Department of General Surgery, Division of Biliopancreatic and Metabolic Surgery, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Wen Meng
- National Clinical Research Center for Metabolic Diseases, Key Laboratory of Cardiometabolic Medicine of Hunan Province, Metabolic Syndrome Research Center, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China
| | - Wei Liu
- Department of General Surgery, Division of Biliopancreatic and Metabolic Surgery, The Second Xiangya Hospital of Central South University, Changsha 410011, Hunan, China.
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6
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Brazier F, Courbebaisse M, David A, Bergerat D, Leroy C, Lindner M, Maruani G, Saint Jacques C, Letavernier E, Hureaux M, Vargas-Poussou R, Prié D. Relationship between clinical phenotype and in vitro analysis of 13 NPT2c/SCL34A3 mutants. Sci Rep 2023; 13:85. [PMID: 36596813 PMCID: PMC9810644 DOI: 10.1038/s41598-022-25995-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 12/07/2022] [Indexed: 01/04/2023] Open
Abstract
Biallelic pathogenic variants in the SLC34A3 gene, encoding for the NPT2c cotransporter, cause Hereditary Hypophosphatemic Rickets with Hypercalciuria (HHRH). However, the associated phenotype is highly variable. In addition, mice deleted for Slc34a3 exhibit a different phenotype compared to humans, without urinary phosphate leakage. The mechanisms by which SLC34A3 variants disrupt phosphate/calcium metabolism are un-completely understood. In this study we explored these mechanisms in vitro using SLC34A3 variants identified in patients with urinary phosphate leakage. We analyzed the consequences of these variants on NPT2c function and the link with the phenotype of the patients. We studied 20 patients with recurrent nephrolithiasis and low serum phosphate concentration harboring variants in the SLC34A3 gene. Half of the patients carried homozygous or composite heterozygous variants. Three patients had in addition variants in SLC34A1 and SLC9A3R1 genes. All these patients benefited from a precise analysis of their phenotype. We generated 13 of these mutants by site-directed mutagenesis. Then we carried out transient transfections of these mutants in HEK cells and measured their phosphate uptake capacity under different conditions. Among the 20 patients included, 3 had not only mutations in NPT2c but also in NPT2a or NHERF1 genes. Phosphate uptake was decreased in 8 NPT2c mutants studied and normal for 5. Four variants were initially categorized as variants of uncertain significance. Expression of the corresponding mutants showed that one did not modify phosphate transport, two reduced it moderately and one abolished it. Co-transfection of the NPT2c mutants with the wild-type plasmid of NPT2c or NPT2a did not reveal dominant negative effect of the mutants on NPT2c-mediated phosphate transport. A detailed analysis of patient phenotypes did not find a link between the severity of the disorder and the level of phosphate transport impairment. NPT2c mutations classified as ACMG3 identified in patients with renal phosphate leak should be characterized by in vitro study to check if they alter NPT2c-mediated phosphate transport since phosphate uptake capacity may not be affected. In addition, research for mutations in NHERF1 and NPT2a genes should always be associated to NPT2c sequencing.
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Affiliation(s)
- François Brazier
- Université de Paris Cité, Faculté de Médecine, INSERM U1151, Paris, France.,Département de Physiologie, hôpital Necker Assistance Publique Hôpitaux de Paris, Paris, France
| | - Marie Courbebaisse
- Université de Paris Cité, Faculté de Médecine, INSERM U1151, Paris, France.,Service de Physiologie, hôpital européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Amandine David
- Université de Paris Cité, Faculté de Médecine, INSERM U1151, Paris, France
| | - David Bergerat
- Université de Paris Cité, Faculté de Médecine, INSERM U1151, Paris, France
| | - Christine Leroy
- Université de Paris Cité, Faculté de Médecine, INSERM U1151, Paris, France
| | - Marta Lindner
- Université de Paris Cité, Faculté de Médecine, INSERM U1151, Paris, France
| | - Gérard Maruani
- Département de Physiologie, hôpital Necker Assistance Publique Hôpitaux de Paris, Paris, France.,Service de Physiologie, hôpital européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, Paris, France
| | - Camille Saint Jacques
- Service d'Explorations fonctionnelles multidisciplinaires, hôpital Tenon, Assistance Publique Hôpitaux de Paris, Paris, France.,Université Paris Sorbonne, Paris, France
| | - Emmanuel Letavernier
- Service d'Explorations fonctionnelles multidisciplinaires, hôpital Tenon, Assistance Publique Hôpitaux de Paris, Paris, France.,Université Paris Sorbonne, Paris, France
| | - Marguerite Hureaux
- Service de Génétique, hôpital européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, 75015, Paris, France.,Université de Paris Cité, Faculté de médecine, INSERM U970, Paris, France
| | - Rosa Vargas-Poussou
- Service de Génétique, hôpital européen Georges Pompidou, Assistance Publique Hôpitaux de Paris, 75015, Paris, France
| | - Dominique Prié
- Université de Paris Cité, Faculté de Médecine, INSERM U1151, Paris, France. .,Département de Physiologie, hôpital Necker Assistance Publique Hôpitaux de Paris, Paris, France.
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7
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Frangi G, Guicheteau M, Jacquot F, Pyka G, Kerckhofs G, Feyeux M, Veziers J, Guihard P, Halgand B, Sourice S, Guicheux J, Prieur X, Beck L, Beck-Cormier S. PiT2 deficiency prevents increase of bone marrow adipose tissue during skeletal maturation but not in OVX-induced osteoporosis. Front Endocrinol (Lausanne) 2022; 13:921073. [PMID: 36465661 PMCID: PMC9708882 DOI: 10.3389/fendo.2022.921073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 10/24/2022] [Indexed: 11/17/2022] Open
Abstract
The common cellular origin between bone marrow adipocytes (BMAds) and osteoblasts contributes to the intimate link between bone marrow adipose tissue (BMAT) and skeletal health. An imbalance between the differentiation ability of BMSCs towards one of the two lineages occurs in conditions like aging or osteoporosis, where bone mass is decreased. Recently, we showed that the sodium-phosphate co-transporter PiT2/SLC20A2 is an important determinant for bone mineralization, strength and quality. Since bone mass is reduced in homozygous mutant mice, we investigated in this study whether the BMAT was also affected in PiT2-/- mice by assessing the effect of the absence of PiT2 on BMAT volume between 3 and 16 weeks, as well as in an ovariectomy-induced bone loss model. Here we show that the absence of PiT2 in juveniles leads to an increase in the BMAT that does not originate from an increased adipogenic differentiation of bone marrow stromal cells. We show that although PiT2-/- mice have higher BMAT volume than control PiT2+/+ mice at 3 weeks of age, BMAT volume do not increase from 3 to 16 weeks of age, leading to a lower BMAT volume in 16-week-old PiT2-/- compared to PiT2+/+ mice. In contrast, the absence of PiT2 does not prevent the increase in BMAT volume in a model of ovariectomy-induced bone loss. Our data identify SLC20a2/PiT2 as a novel gene essential for the maintenance of the BMAd pool in adult mice, involving mechanisms of action that remain to be elucidated, but which appear to be independent of the balance between osteoblastic and adipogenic differentiation of BMSCs.
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Affiliation(s)
- Giulia Frangi
- Nantes Université, Oniris, CHU Nantes, Inserm, Regenerative Medicine and Skeleton, RMeS, UMR 1229, SFR Bonamy, Nantes, France
| | - Marie Guicheteau
- Nantes Université, Oniris, CHU Nantes, Inserm, Regenerative Medicine and Skeleton, RMeS, UMR 1229, SFR Bonamy, Nantes, France
| | - Frederic Jacquot
- Nantes Université, CHU Nantes, Inserm, CNRS, CRCI2NA, Nantes, France
| | - Grzegorz Pyka
- Biomechanics lab, Institute of Mechanics, Materials, and Civil Engineering, UC Louvain, Louvain-la-Neuve, Belgium
- Department of Materials Engineering, KU Leuven, Leuven, Belgium
| | - Greet Kerckhofs
- Biomechanics lab, Institute of Mechanics, Materials, and Civil Engineering, UC Louvain, Louvain-la-Neuve, Belgium
- Department of Materials Engineering, KU Leuven, Leuven, Belgium
- IREC, Institute of Experimental and Clinical Research, UC Louvain, Woluwé-Saint-Lambert, Belgium
- Prometheus, Division of Skeletal Tissue Engineering, KU Leuven, Leuven, Belgium
| | - Magalie Feyeux
- Nantes Université, CHU Nantes, CNRS, Inserm, BioCore, US16, SFR Bonamy, Nantes, France
| | - Joëlle Veziers
- Nantes Université, Oniris, CHU Nantes, Inserm, Regenerative Medicine and Skeleton, RMeS, UMR 1229, SFR Bonamy, Nantes, France
| | - Pierre Guihard
- Nantes Université, Oniris, CHU Nantes, Inserm, Regenerative Medicine and Skeleton, RMeS, UMR 1229, SFR Bonamy, Nantes, France
| | - Boris Halgand
- Nantes Université, Oniris, CHU Nantes, Inserm, Regenerative Medicine and Skeleton, RMeS, UMR 1229, SFR Bonamy, Nantes, France
| | - Sophie Sourice
- Nantes Université, Oniris, CHU Nantes, Inserm, Regenerative Medicine and Skeleton, RMeS, UMR 1229, SFR Bonamy, Nantes, France
| | - Jérôme Guicheux
- Nantes Université, Oniris, CHU Nantes, Inserm, Regenerative Medicine and Skeleton, RMeS, UMR 1229, SFR Bonamy, Nantes, France
| | - Xavier Prieur
- Nantes Université, CNRS, Inserm, l’Institut du Thorax, Nantes, France
| | - Laurent Beck
- Nantes Université, Oniris, CHU Nantes, Inserm, Regenerative Medicine and Skeleton, RMeS, UMR 1229, SFR Bonamy, Nantes, France
| | - Sarah Beck-Cormier
- Nantes Université, Oniris, CHU Nantes, Inserm, Regenerative Medicine and Skeleton, RMeS, UMR 1229, SFR Bonamy, Nantes, France
- *Correspondence: Sarah Beck-Cormier,
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8
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Chen J, Li G, Lian J, Ma N, Huang Z, Li J, Wen Z, Zhang W, Zhang Y. Slc20a1b is essential for hematopoietic stem/progenitor cell expansion in zebrafish. SCIENCE CHINA. LIFE SCIENCES 2021; 64:2186-2201. [PMID: 33751369 DOI: 10.1007/s11427-020-1878-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 01/05/2021] [Indexed: 10/21/2022]
Abstract
Hematopoietic stem and progenitor cells (HSPCs) are able to self-renew and can give rise to all blood lineages throughout their lifetime, yet the mechanisms regulating HSPC development have yet to be discovered. In this study, we characterized a hematopoiesis defective zebrafish mutant line named smu07, which was obtained from our previous forward genetic screening, and found the HSPC expansion deficiency in the mutant. Positional cloning identified that slc20a1b, which encodes a sodium phosphate cotransporter, contributed to the smu07 blood phenotype. Further analysis demonstrated that mutation of slc20a1b affects HSPC expansion through cell cycle arrest at G2/M phases in a cell-autonomous manner. Our study shows that slc20a1b is a vital regulator for HSPC proliferation in zebrafish early hematopoiesis and provides valuable insights into HSPC development.
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Affiliation(s)
- Jiakui Chen
- Department of Developmental Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Gaofei Li
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou, 510006, China
| | - Junwei Lian
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou, 510006, China
| | - Ning Ma
- Department of Developmental Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Zhibin Huang
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou, 510006, China
| | - Jianchao Li
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou, 510006, China
| | - Zilong Wen
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Hong Kong, China
| | - Wenqing Zhang
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou, 510006, China.
| | - Yiyue Zhang
- Department of Developmental Biology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
- Division of Cell, Developmental and Integrative Biology, School of Medicine, South China University of Technology, Guangzhou, 510006, China.
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9
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Ding M, Zhang Q, Zhang M, Jiang X, Wang M, Ni L, Gong W, Huang B, Chen J. Phosphate Overload Stimulates Inflammatory Reaction via PiT-1 and Induces Vascular Calcification in Uremia. J Ren Nutr 2021; 32:178-188. [PMID: 34688540 DOI: 10.1053/j.jrn.2021.03.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 01/27/2021] [Accepted: 03/20/2021] [Indexed: 11/11/2022] Open
Abstract
OBJECTIVE Vascular calcification (VC) is an important risk factor for cardiovascular disease in maintenance hemodialysis (MHD) patients. Hyperphosphatemia and microinflammation statement are known major contributors to the development of VC; however, the mechanisms are unknown. The aims of this study were to explore the risk factors of VC in MHD patients and to explore whether high phosphate could increase the secretion of inflammatory cytokines via PiT-1 in monocytes. METHODS A cross-sectional study was conducted on 65 MHD patients to assess the relevance of coronary artery calcification (CAC), inflammatory factors, serum phosphate, and sodium-dependent phosphate cotransporter (NPT) mRNA expression of peripheral blood mononuclear cells (PBMCs). Multivariate logistic regression analysis was used to analyze the predictors of CAC. The calcification effects of high phosphate (HP), TNF-α, and supernatants of healthy human monocytes treated with HP were further evaluated in cultured HASMCs. RESULTS Diabetes, longer dialysis vintage, higher serum TNF-α levels, and PiT-1 mRNA expression of PBMCs) were independent risk factors of CAC in MHD patients. The mRNA levels of PiT-1 in PBMCs were positively correlated with serum phosphate, CAC scores, and Pit-2 mRNA levels of PBMCs. The expressions of TNF-α, IL-6, and PiT-1 in human monocytes were significantly increased in a dose-dependent manner after treatment with HP, which was subsequently inhibited by NPT antagonist phosphonoformic acid. Neither TNF-α alone nor supernatants of monocytes stimulated with HP promoted the expression of osteopontin and Runt-related transcription factor 2 (Runx2) or caused mineralization in human aortic smooth muscle cells, but combined with HP intervention, the calcification effects were markedly increased in human aortic smooth muscle cells and ameliorated by phosphonoformic acid treatment. CONCLUSION Hyperphosphatemia directly increased the synthesis and secretion of TNF-α by monocytes may via PiT-1 pathway, resulting in elevated systemic inflammatory response, which may further aggravate VC induced by phosphate overload in MHD patients.
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Affiliation(s)
- Minwen Ding
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Qian Zhang
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Minmin Zhang
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Xinxin Jiang
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Mengjing Wang
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Li Ni
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Wen Gong
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Bihong Huang
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Jing Chen
- Division of Nephrology, National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China.
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10
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Machado A, Pouzolles M, Gailhac S, Fritz V, Craveiro M, López-Sánchez U, Kondo T, Pala F, Bosticardo M, Notarangelo LD, Petit V, Taylor N, Zimmermann VS. Phosphate Transporter Profiles in Murine and Human Thymi Identify Thymocytes at Distinct Stages of Differentiation. Front Immunol 2020; 11:1562. [PMID: 32793218 PMCID: PMC7387685 DOI: 10.3389/fimmu.2020.01562] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/15/2020] [Indexed: 12/22/2022] Open
Abstract
Thymocyte differentiation is dependent on the availability and transport of metabolites in the thymus niche. As expression of metabolite transporters is a rate-limiting step in nutrient utilization, cell surface transporter levels generally reflect the cell's metabolic state. The GLUT1 glucose transporter is upregulated on actively dividing thymocytes, identifying thymocytes with an increased metabolism. However, it is not clear whether transporters of essential elements such as phosphate are modulated during thymocyte differentiation. While PiT1 and PiT2 are both phosphate transporters in the SLC20 family, we show here that they exhibit distinct expression profiles on both murine and human thymocytes. PiT2 expression distinguishes thymocytes with high metabolic activity, identifying immature murine double negative (CD4−CD8−) DN3b and DN4 thymocyte blasts as well as immature single positive (ISP) CD8 thymocytes. Notably, the absence of PiT2 expression on RAG2-deficient thymocytes, blocked at the DN3a stage, strongly suggests that high PiT2 expression is restricted to thymocytes having undergone a productive TCRβ rearrangement at the DN3a/DN3b transition. Similarly, in the human thymus, PiT2 was upregulated on early post-β selection CD4+ISP and TCRαβ−CD4hiDP thymocytes co-expressing the CD71 transferrin receptor, a marker of metabolic activity. In marked contrast, expression of the PiT1 phosphate importer was detected on mature CD3+ murine and human thymocytes. Notably, PiT1 expression on CD3+DN thymocytes was identified as a biomarker of an aging thymus, increasing from 8.4 ± 1.5% to 42.4 ± 9.4% by 1 year of age (p < 0.0001). We identified these cells as TCRγδ and, most significantly, NKT, representing 77 ± 9% of PiT1+DN thymocytes by 1 year of age (p < 0.001). Thus, metabolic activity and thymic aging are associated with distinct expression profiles of the PiT1 and PiT2 phosphate transporters.
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Affiliation(s)
- Alice Machado
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health (NIH), Bethesda, MD, United States.,Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Marie Pouzolles
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Sarah Gailhac
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Vanessa Fritz
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Marco Craveiro
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Uriel López-Sánchez
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Taisuke Kondo
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Francesca Pala
- Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, United States
| | - Marita Bosticardo
- Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, United States
| | - Luigi D Notarangelo
- Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD, United States
| | | | - Naomi Taylor
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health (NIH), Bethesda, MD, United States.,Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | - Valérie S Zimmermann
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health (NIH), Bethesda, MD, United States.,Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
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11
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Novel function of PiT1/SLC20A1 in LPS-related inflammation and wound healing. Sci Rep 2019; 9:1808. [PMID: 30755642 PMCID: PMC6372663 DOI: 10.1038/s41598-018-37551-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 11/27/2018] [Indexed: 12/17/2022] Open
Abstract
PiT1/SLC20A1 is an inorganic phosphate transporter with additional functions including the regulation of TNFα-induced apoptosis, erythropoiesis, cell proliferation and insulin signaling. Recent data suggest a relationship between PiT1 and NF-κB-dependent inflammation: (i) Pit1 mRNA is up-regulated in the context of NF-κB pathway activation; (ii) NF-κB target gene transcription is decreased in PiT1-deficient conditions. This led us to investigate the role of PiT1 in lipopolysaccharide (LPS)-induced inflammation. MCP-1 and IL-6 concentrations were impaired in PiT1-deficient bone marrow derived macrophages (BMDMs) upon LPS stimulation. Lower MCP-1 and IL-6 serum levels were observed in Mx1-Cre; Pit1lox/lox mice dosed intraperitoneally with LPS. Lower PiT1 expression correlated with decreased in vitro wound healing and lower reactive oxygen species levels. Reduced IκB degradation and lower p65 nuclear translocation were observed in PiT1-deficient cells stimulated with LPS. Conversely, PiT1 expression was induced in vitro upon LPS stimulation. Addition of an NF-κB inhibitor abolished LPS-induced PiT1 expression. Furthermore, we showed that p65 expression activated Pit1 promoter activity. Finally, ChIP assays demonstrated that p65 directly binds to the mPit1 promoter in response to LPS. These data demonstrate a completely novel function of PiT1 in the response to LPS and provide mechanistic insights into the regulation of PiT1 expression by NF-κB.
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12
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Couasnay G, Bon N, Devignes CS, Sourice S, Bianchi A, Véziers J, Weiss P, Elefteriou F, Provot S, Guicheux J, Beck-Cormier S, Beck L. PiT1/Slc20a1 Is Required for Endoplasmic Reticulum Homeostasis, Chondrocyte Survival, and Skeletal Development. J Bone Miner Res 2019; 34:387-398. [PMID: 30347511 DOI: 10.1002/jbmr.3609] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Revised: 09/26/2018] [Accepted: 10/22/2018] [Indexed: 01/09/2023]
Abstract
During skeletal mineralization, the sodium-phosphate co-transporter PiT1Slc20a1 is assumed to meet the phosphate requirements of bone-forming cells, although evidence is missing. Here, we used a conditional gene deletion approach to determine the role of PiT1 in growth plate chondrocytes. We show that PiT1 ablation shortly after birth generates a rapid and massive cell death in the center of the growth plate, together with an uncompensated endoplasmic reticulum (ER) stress, characterized by morphological changes and increased Chop, Atf4, and Bip expression. PiT1 expression in chondrocytes was not found at the cell membrane but co-localized with the ER marker ERp46, and was upregulated by the unfolded protein response cascade. In addition, we identified the protein disulfide isomerase (Pdi) ER chaperone as a PiT1 binding partner and showed that PiT1 ablation impaired Pdi reductase activity. The ER stress induced by PiT1 deficiency in chondrocytes was associated with intracellular retention of aggrecan and vascular endothelial growth factor A (Vegf-A), which was rescued by overexpressing a phosphate transport-deficient mutant of PiT1. Our data thus reveal a novel, Pi-transport independent function of PiT1, as a critical modulator of ER homeostasis and chondrocyte survival during endochondral ossification. © 2018 American Society for Bone and Mineral Research.
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Affiliation(s)
- Greig Couasnay
- INSERM, Unité mixte de Recherche (UMR) 1229, Regenerative Medicine and Skeleton (RMeS), Nantes-Atlantic National College of Veterinary Medicine, Food Science and Engineering, ONIRIS, Université de Nantes, Nantes, France.,Faculty of Dental Surgery of Nantes (UFR Odontologie), Université de Nantes, Nantes, France.,Department of Molecular and Human Genetics and Orthopedic Surgery, Baylor College of Medicine, Houston, TX, USA
| | - Nina Bon
- INSERM, Unité mixte de Recherche (UMR) 1229, Regenerative Medicine and Skeleton (RMeS), Nantes-Atlantic National College of Veterinary Medicine, Food Science and Engineering, ONIRIS, Université de Nantes, Nantes, France.,Faculty of Dental Surgery of Nantes (UFR Odontologie), Université de Nantes, Nantes, France
| | - Claire-Sophie Devignes
- INSERM, UMR 1132, Centre Viggo Petersen-Hôpital Lariboisière, Paris, France.,Université Paris Diderot, Sorbonne Paris-Cité, Paris, France
| | - Sophie Sourice
- INSERM, Unité mixte de Recherche (UMR) 1229, Regenerative Medicine and Skeleton (RMeS), Nantes-Atlantic National College of Veterinary Medicine, Food Science and Engineering, ONIRIS, Université de Nantes, Nantes, France.,Faculty of Dental Surgery of Nantes (UFR Odontologie), Université de Nantes, Nantes, France
| | - Arnaud Bianchi
- National Center for Scientific Research (CNRS), UMR 7365, IMoPA, Vandœuvre-lès-Nancy, France.,Faculté de Médecine, Université de Lorraine, Vandœuvre-lès-Nancy, France
| | - Joëlle Véziers
- INSERM, Unité mixte de Recherche (UMR) 1229, Regenerative Medicine and Skeleton (RMeS), Nantes-Atlantic National College of Veterinary Medicine, Food Science and Engineering, ONIRIS, Université de Nantes, Nantes, France.,Faculty of Dental Surgery of Nantes (UFR Odontologie), Université de Nantes, Nantes, France.,PHU 4 Odontologie, Neurochirurgie, Neurotraumatologie (OTONN), CHU de Nantes University Hospital Center, Nantes, France
| | - Pierre Weiss
- INSERM, Unité mixte de Recherche (UMR) 1229, Regenerative Medicine and Skeleton (RMeS), Nantes-Atlantic National College of Veterinary Medicine, Food Science and Engineering, ONIRIS, Université de Nantes, Nantes, France.,Faculty of Dental Surgery of Nantes (UFR Odontologie), Université de Nantes, Nantes, France.,PHU 4 Odontologie, Neurochirurgie, Neurotraumatologie (OTONN), CHU de Nantes University Hospital Center, Nantes, France
| | - Florent Elefteriou
- Department of Molecular and Human Genetics and Orthopedic Surgery, Baylor College of Medicine, Houston, TX, USA
| | - Sylvain Provot
- INSERM, UMR 1132, Centre Viggo Petersen-Hôpital Lariboisière, Paris, France.,Université Paris Diderot, Sorbonne Paris-Cité, Paris, France
| | - Jérôme Guicheux
- INSERM, Unité mixte de Recherche (UMR) 1229, Regenerative Medicine and Skeleton (RMeS), Nantes-Atlantic National College of Veterinary Medicine, Food Science and Engineering, ONIRIS, Université de Nantes, Nantes, France.,Faculty of Dental Surgery of Nantes (UFR Odontologie), Université de Nantes, Nantes, France.,PHU 4 Odontologie, Neurochirurgie, Neurotraumatologie (OTONN), CHU de Nantes University Hospital Center, Nantes, France
| | - Sarah Beck-Cormier
- INSERM, Unité mixte de Recherche (UMR) 1229, Regenerative Medicine and Skeleton (RMeS), Nantes-Atlantic National College of Veterinary Medicine, Food Science and Engineering, ONIRIS, Université de Nantes, Nantes, France.,Faculty of Dental Surgery of Nantes (UFR Odontologie), Université de Nantes, Nantes, France
| | - Laurent Beck
- INSERM, Unité mixte de Recherche (UMR) 1229, Regenerative Medicine and Skeleton (RMeS), Nantes-Atlantic National College of Veterinary Medicine, Food Science and Engineering, ONIRIS, Université de Nantes, Nantes, France.,Faculty of Dental Surgery of Nantes (UFR Odontologie), Université de Nantes, Nantes, France
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13
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Michigami T, Kawai M, Yamazaki M, Ozono K. Phosphate as a Signaling Molecule and Its Sensing Mechanism. Physiol Rev 2018; 98:2317-2348. [DOI: 10.1152/physrev.00022.2017] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
In mammals, phosphate balance is maintained by influx and efflux via the intestines, kidneys, bone, and soft tissue, which involves multiple sodium/phosphate (Na+/Pi) cotransporters, as well as regulation by several hormones. Alterations in the levels of extracellular phosphate exert effects on both skeletal and extra-skeletal tissues, and accumulating evidence has suggested that phosphate itself evokes signal transduction to regulate gene expression and cell behavior. Several in vitro studies have demonstrated that an elevation in extracellular Piactivates fibroblast growth factor receptor, Raf/MEK (mitogen-activated protein kinase/ERK kinase)/ERK (extracellular signal-regulated kinase) pathway and Akt pathway, which might involve the type III Na+/Picotransporter PiT-1. Excessive phosphate loading can lead to various harmful effects by accelerating ectopic calcification, enhancing oxidative stress, and dysregulating signal transduction. The responsiveness of mammalian cells to altered extracellular phosphate levels suggests that they may sense and adapt to phosphate availability, although the precise mechanism for phosphate sensing in mammals remains unclear. Unicellular organisms, such as bacteria and yeast, use some types of Pitransporters and other molecules, such as kinases, to sense the environmental Piavailability. Multicellular animals may need to integrate signals from various organs to sense the phosphate levels as a whole organism, similarly to higher plants. Clarification of the phosphate-sensing mechanism in humans may lead to the development of new therapeutic strategies to prevent and treat diseases caused by phosphate imbalance.
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Affiliation(s)
- Toshimi Michigami
- Department of Bone and Mineral Research, Research Institute, Osaka Women’s and Children’s Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka, Japan; and Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Masanobu Kawai
- Department of Bone and Mineral Research, Research Institute, Osaka Women’s and Children’s Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka, Japan; and Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Miwa Yamazaki
- Department of Bone and Mineral Research, Research Institute, Osaka Women’s and Children’s Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka, Japan; and Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
| | - Keiichi Ozono
- Department of Bone and Mineral Research, Research Institute, Osaka Women’s and Children’s Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka, Japan; and Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
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14
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Bon N, Couasnay G, Bourgine A, Sourice S, Beck-Cormier S, Guicheux J, Beck L. Phosphate (P i)-regulated heterodimerization of the high-affinity sodium-dependent P i transporters PiT1/Slc20a1 and PiT2/Slc20a2 underlies extracellular P i sensing independently of P i uptake. J Biol Chem 2017; 293:2102-2114. [PMID: 29233890 DOI: 10.1074/jbc.m117.807339] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 11/16/2017] [Indexed: 12/24/2022] Open
Abstract
Extracellular phosphate (Pi) can act as a signaling molecule that directly alters gene expression and cellular physiology. The ability of cells or organisms to detect changes in extracellular Pi levels implies the existence of a Pi-sensing mechanism that signals to the body or individual cell. However, unlike in prokaryotes, yeasts, and plants, the molecular players involved in Pi sensing in mammals remain unknown. In this study, we investigated the involvement of the high-affinity, sodium-dependent Pi transporters PiT1 and PiT2 in mediating Pi signaling in skeletal cells. We found that deletion of PiT1 or PiT2 blunted the Pi-dependent ERK1/2-mediated phosphorylation and subsequent gene up-regulation of the mineralization inhibitors matrix Gla protein and osteopontin. This result suggested that both PiTs are necessary for Pi signaling. Moreover, the ERK1/2 phosphorylation could be rescued by overexpressing Pi transport-deficient PiT mutants. Using cross-linking and bioluminescence resonance energy transfer approaches, we found that PiT1 and PiT2 form high-abundance homodimers and Pi-regulated low-abundance heterodimers. Interestingly, in the absence of sodium-dependent Pi transport activity, the PiT1-PiT2 heterodimerization was still regulated by extracellular Pi levels. Of note, when two putative Pi-binding residues, Ser-128 (in PiT1) and Ser-113 (in PiT2), were substituted with alanine, the PiT1-PiT2 heterodimerization was no longer regulated by extracellular Pi These observations suggested that Pi binding rather than Pi uptake may be the key factor in mediating Pi signaling through the PiT proteins. Taken together, these results demonstrate that Pi-regulated PiT1-PiT2 heterodimerization mediates Pi sensing independently of Pi uptake.
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Affiliation(s)
- Nina Bon
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
| | - Greig Couasnay
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
| | - Annabelle Bourgine
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
| | - Sophie Sourice
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
| | - Sarah Beck-Cormier
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
| | - Jérôme Guicheux
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and.,CHU Nantes, PHU 4 OTONN, Nantes F-44042, France
| | - Laurent Beck
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France, .,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
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15
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Park S, Han CR, Park JW, Zhao L, Zhu X, Willingham M, Bodine DM, Cheng SY. Defective erythropoiesis caused by mutations of the thyroid hormone receptor α gene. PLoS Genet 2017; 13:e1006991. [PMID: 28910278 PMCID: PMC5621702 DOI: 10.1371/journal.pgen.1006991] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 09/29/2017] [Accepted: 08/21/2017] [Indexed: 12/12/2022] Open
Abstract
Patients with mutations of the THRA gene exhibit classical features of hypothyroidism, including erythroid disorders. We previously created a mutant mouse expressing a mutated TRα1 (denoted as PV; Thra1PV/+ mouse) that faithfully reproduces the classical hypothyroidism seen in patients. Using Thra1PV/+ mice, we explored how the TRα1PV mutant acted to cause abnormalities in erythropoiesis. Thra1PV/+ mice exhibited abnormal red blood cell indices similarly as reported for patients. The total bone marrow cells and erythrocytic progenitors were markedly reduced in the bone marrow of Thra1PV/+ mice. In vitro terminal differentiation assays showed a significant reduction of mature erythrocytes in Thra1PV/+ mice. In wild-type mice, the clonogenic potential of progenitors in the erythrocytic lineage was stimulated by thyroid hormone (T3), suggesting that T3 could directly accelerate the differentiation of progenitors to mature erythrocytes. Analysis of gene expression profiles showed that the key regulator of erythropoiesis, the Gata-1 gene, and its regulated genes, such as the Klf1, β-globin, dematin genes, CAII, band3 and eALAS genes, involved in the maturation of erythrocytes, was decreased in the bone marrow cells of Thra1PV/+ mice. We further elucidated that the Gata-1 gene was a T3-directly regulated gene and that TRα1PV could impair erythropoiesis via repression of the Gata-1 gene and its regulated genes. These results provide new insights into how TRα1 mutants acted to cause erythroid abnormalities in patients with mutations of the THRA gene. Importantly, the Thra1PV/+ mouse could serve as a preclinical mouse model to identify novel molecular targets for treatment of erythroid disorders. Patients with mutations of the THRA gene exhibit erythroid disorders. The molecular pathogenesis underlying erythroid abnormalities is poorly understood. In Thra1PV/+ mice expressing a dominant negative mutant TRα1PV, we found abnormal red blood cell indices similar to patients. Total bone marrow cells, the clonogenic potential of erythrocytic progenitors, and terminal differentiation of erythrocytes were markedly decreased in Thra1PV/+ mice. We elucidated that Gata-1, a key erythroid gene, was directly positively regulated by TRα1. The erythroid defects in Thra1PV/+ mice were due, at least partly, to the TRα1PV-mediated suppression of the Gata-1 gene and its down-stream target genes. Over-expression of Gata-1 rescued impaired terminal differentiation. Our studies elucidated molecular mechanisms by which TRα1 mutants caused erythroid disorders in patients. The present study suggests that therapies aimed at GATA1 could be tested as a potential target in treating erythroid abnormalities in patients.
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Affiliation(s)
- Sunmi Park
- Laboratory of Molecular Biology, the Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Cho Rong Han
- Laboratory of Molecular Biology, the Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Jeong Won Park
- Laboratory of Molecular Biology, the Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Li Zhao
- Laboratory of Molecular Biology, the Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Xuguang Zhu
- Laboratory of Molecular Biology, the Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America
| | - Mark Willingham
- Laboratory of Molecular Biology, the Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America
| | - David M. Bodine
- Hematopoiesis Section, National Human Geneome Research Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Sheue-yann Cheng
- Laboratory of Molecular Biology, the Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America
- * E-mail:
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16
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Forand A. PiT1 : du transport de phosphate à la signalisation insulinique. Med Sci (Paris) 2017; 33:480-483. [DOI: 10.1051/medsci/20173305007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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17
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Disruption of the Phosphate Transporter Pit1 in Hepatocytes Improves Glucose Metabolism and Insulin Signaling by Modulating the USP7/IRS1 Interaction. Cell Rep 2016; 16:2736-2748. [PMID: 27568561 DOI: 10.1016/j.celrep.2016.08.012] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 06/02/2016] [Accepted: 08/03/2016] [Indexed: 01/07/2023] Open
Abstract
The liver plays a central role in whole-body lipid and glucose homeostasis. Increasing dietary fat intake results in increased hepatic fat deposition, which is associated with a risk for development of insulin resistance and type 2 diabetes. In this study, we demonstrate a role for the phosphate inorganic transporter 1 (PiT1/SLC20A1) in regulating metabolism. Specific knockout of Pit1 in hepatocytes significantly improved glucose tolerance and insulin sensitivity, enhanced insulin signaling, and decreased hepatic lipogenesis. We identified USP7 as a PiT1 binding partner and demonstrated that Pit1 deletion inhibited USP7/IRS1 dissociation upon insulin stimulation. This prevented IRS1 ubiquitination and its subsequent proteasomal degradation. As a consequence, delayed insulin negative feedback loop and sustained insulin signaling were observed. Moreover, PiT1-deficient mice were protected against high-fat-diet-induced obesity and diabetes. Our findings indicate that PiT1 has potential as a therapeutic target in the context of metabolic syndrome, obesity, and diabetes.
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Kadri Z, Lefevre C, Goupille O, Penglong T, Granger-Locatelli M, Fucharoen S, Maouche-Chretien L, Leboulch P, Chretien S. Erythropoietin and IGF-1 signaling synchronize cell proliferation and maturation during erythropoiesis. Genes Dev 2016; 29:2603-16. [PMID: 26680303 PMCID: PMC4699388 DOI: 10.1101/gad.267633.115] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Kadri et al. show that erythropoietin activates AKT, which phosphorylates GATA-1 at Ser310, thereby increasing GATA-1 affinity for FOG-1. In turn, FOG-1 displaces pRb/E2F-2 from GATA-1, ultimately releasing free, proproliferative E2F-2. Mice bearing a GATA-1S310A mutation suffer from fatal anemia when a compensatory pathway for E2F-2 production involving IGF-1 signaling is simultaneously abolished. Tight coordination of cell proliferation and differentiation is central to red blood cell formation. Erythropoietin controls the proliferation and survival of red blood cell precursors, while variations in GATA-1/FOG-1 complex composition and concentrations drive their maturation. However, clear evidence of cross-talk between molecular pathways is lacking. Here, we show that erythropoietin activates AKT, which phosphorylates GATA-1 at Ser310, thereby increasing GATA-1 affinity for FOG-1. In turn, FOG-1 displaces pRb/E2F-2 from GATA-1, ultimately releasing free, proproliferative E2F-2. Mice bearing a Gata-1S310A mutation suffer from fatal anemia when a compensatory pathway for E2F-2 production involving insulin-like growth factor-1 (IGF-1) signaling is simultaneously abolished. In the context of the GATA-1V205G mutation resulting in lethal anemia, we show that the Ser310 cannot be phosphorylated and that constitutive phosphorylation at this position restores partial erythroid differentiation. This study sheds light on the GATA-1 pathways that synchronize cell proliferation and differentiation for tissue homeostasis.
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Affiliation(s)
- Zahra Kadri
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France
| | - Carine Lefevre
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France
| | - Olivier Goupille
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France
| | - Tipparat Penglong
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France; Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, 73170 Nakhon Pathom, Thailand
| | - Marine Granger-Locatelli
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France
| | - Suthat Fucharoen
- Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, 73170 Nakhon Pathom, Thailand
| | - Leila Maouche-Chretien
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France; Institut National de la Santé et de la Recherche Médicale, 75013 Paris, France
| | - Philippe Leboulch
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France; Thalassemia Research Center, Institute of Molecular Biosciences, Mahidol University, 73170 Nakhon Pathom, Thailand; Genetics Division, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02215, USA
| | - Stany Chretien
- Commissariat à l'Energie Atomique et aux Énergies Alternatives, Institute of Emerging Diseases and Innovative Therapies (iMETI), 92265 Fontenay-aux-Roses, France; UMR-E 007, Université Paris-Saclay, 91400 Orsay, France; Institut National de la Santé et de la Recherche Médicale, 75013 Paris, France
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Wallingford MC, Giachelli CM. Loss of PiT-1 results in abnormal endocytosis in the yolk sac visceral endoderm. Mech Dev 2014; 133:189-202. [PMID: 25138534 DOI: 10.1016/j.mod.2014.08.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 08/06/2014] [Accepted: 08/07/2014] [Indexed: 10/24/2022]
Abstract
PiT-1 protein is a transmembrane sodium-dependent phosphate (Pi) transporter. PiT-1 knock out (KO) embryos die from largely unknown causes by embryonic day (E) 12.5. We tested the hypothesis that PiT-1 is required for endocytosis in the embryonic yolk sac (YS) visceral endoderm (VE). Here we present data supporting that PiT-1 KO results in a YS remodeling defect and decreased endocytosis in the YS VE. The remodeling defect is not due to an upstream cardiomyocyte requirement for PiT-1, as SM22αCre-specific KO of PiT-1 in the developing heart and the YS mesodermal layer (ME) does not recapitulate the PiT-1 global KO phenotype. Furthermore, we find that high levels of PiT-1 protein localize to the YS VE apical membrane. Together these data support that PiT-1 is likely required in YS VE. During normal development maternal immunoglobulin (IgG) is endocytosed into YS VE and accumulates in the apical side of the VE in a specialized lysosome termed the apical vacuole (AV). We have identified a reduction in PiT-1 KO VE cell height and a striking loss of IgG accumulation in the PiT-1 KO VE. The endocytosis genes Tfeb, Lamtor2 and Snx2 are increased at the RNA level. Lysotracker Red staining reveals a loss of distinct AVs, and yolk sacs incubated ex vivo with phRODO Green Dextran for Endocytosis demonstrate a functional loss of endocytosis. As yolk sac endocytosis is controlled in part by microautophagy, but expression of LC3 had not been examined, we investigated LC3 expression during yolk sac development and found stage-specific LC3 RNA expression that is predominantly from the YS VE layer at E9.5. Normalized LC3-II protein levels are decreased in the PiT-1 KO YS, supporting a requirement for PiT-1 in autophagy in the YS. Therefore, we propose the novel idea that PiT-1 is central to the regulation of endocytosis and autophagy in the YS VE.
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Affiliation(s)
- Mary C Wallingford
- Department of Bioengineering, University of Washington, Seattle, WA 91895, USA.
| | - Cecilia M Giachelli
- Department of Bioengineering, University of Washington, Seattle, WA 91895, USA.
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Kongsfelt IB, Byskov K, Pedersen LE, Pedersen L. High levels of the type III inorganic phosphate transporter PiT1 (SLC20A1) can confer faster cell adhesion. Exp Cell Res 2014; 326:57-67. [PMID: 24880124 DOI: 10.1016/j.yexcr.2014.05.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2013] [Revised: 05/18/2014] [Accepted: 05/20/2014] [Indexed: 01/16/2023]
Abstract
The inorganic phosphate transporter PiT1 (SLC20A1) is ubiquitously expressed in mammalian cells. We recently showed that overexpression of human PiT1 was sufficient to increase proliferation of two strict density-inhibited cell lines, murine fibroblastic NIH3T3 and pre-osteoblastic MC3T3-E1 cells, and allowed the cultures to grow to higher cell densities. In addition, upon transformation NIH3T3 cells showed increased ability to form colonies in soft agar. The cellular regulation of PiT1 expression supports that cells utilize the PiT1 levels to control proliferation, with non-proliferating cells showing the lowest PiT1 mRNA levels. The mechanism behind the role of PiT1 in increased cell proliferation is not known. We, however, found that compared to control cells, cultures of NIH3T3 cells overexpressing PiT1 upon seeding showed increased cell number after 24h and had shifted more cells from G0/G1 to S+G2/M within 12h, suggesting that an early event may play a role. We here show that expression of human PiT1 in NIH3T3 cells led to faster cell adhesion; this effect was not cell type specific in that it was also observed when expressing human PiT1 in MC3T3-E1 cells. We also show for NIH3T3 that PiT1 overexpression led to faster cell spreading. The final total numbers of attached cells did, however, not differ between cultures of PiT1 overexpressing cells and control cells of neither cell type. We suggest that the PiT1-mediated fast adhesion potentials allow the cells to go faster out of G0/G1 and thereby contribute to their proliferative advantage within the first 24h after seeding.
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Affiliation(s)
| | - Kristina Byskov
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | - Lene Pedersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Hematology, Aarhus University Hospital, Aarhus, Denmark.
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Rare and low-frequency coding variants in CXCR2 and other genes are associated with hematological traits. Nat Genet 2014; 46:629-34. [PMID: 24777453 PMCID: PMC4050975 DOI: 10.1038/ng.2962] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 03/31/2014] [Indexed: 12/15/2022]
Abstract
Hematological traits are important clinical parameters. To test the effects of rare and low-frequency coding variants on hematological traits, we analyzed hemoglobin concentration, hematocrit levels, white blood cell (WBC) counts and platelet counts in 31,340 individuals genotyped on an exome array. We identified several missense variants in CXCR2 associated with reduced WBC count (gene-based P = 2.6 × 10(-13)). In a separate family-based resequencing study, we identified a CXCR2 frameshift mutation in a pedigree with congenital neutropenia that abolished ligand-induced CXCR2 signal transduction and chemotaxis. We also identified missense or splice-site variants in key hematopoiesis regulators (EPO, TFR2, HBB, TUBB1 and SH2B3) associated with blood cell traits. Finally, we were able to detect associations between a rare somatic JAK2 mutation (encoding p.Val617Phe) and platelet count (P = 3.9 × 10(-22)) as well as hemoglobin concentration (P = 0.002), hematocrit levels (P = 9.5 × 10(-7)) and WBC count (P = 3.1 × 10(-5)). In conclusion, exome arrays complement genome-wide association studies in identifying new variants that contribute to complex human traits.
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Crouthamel MH, Lau WL, Leaf EM, Chavkin NW, Wallingford MC, Peterson DF, Li X, Liu Y, Chin MT, Levi M, Giachelli CM. Sodium-dependent phosphate cotransporters and phosphate-induced calcification of vascular smooth muscle cells: redundant roles for PiT-1 and PiT-2. Arterioscler Thromb Vasc Biol 2013; 33:2625-32. [PMID: 23968976 DOI: 10.1161/atvbaha.113.302249] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Elevated serum phosphate has emerged as a major risk factor for vascular calcification. The sodium-dependent phosphate cotransporter, PiT-1, was previously shown to be required for phosphate-induced osteogenic differentiation and calcification of cultured human vascular smooth muscle cells (VSMCs), but its importance in vascular calcification in vivo and the potential role of its homologue, PiT-2, have not been determined. We investigated the in vivo requirement for PiT-1 in vascular calcification using a mouse model of chronic kidney disease and the potential compensatory role of PiT-2 using in vitro knockdown and overexpression strategies. APPROACH AND RESULTS Mice with targeted deletion of PiT-1 in VSMCs were generated (PiT-1(Δsm)). PiT-1 mRNA levels were undetectable, whereas PiT-2 mRNA levels were increased 2-fold in the vascular aortic media of PiT-1(Δsm) compared with PiT-1(flox/flox) control. When arterial medial calcification was induced in PiT-1(Δsm) and PiT-1(flox/flox) by chronic kidney disease followed by dietary phosphate loading, the degree of aortic calcification was not different between genotypes, suggesting compensation by PiT-2. Consistent with this possibility, VSMCs isolated from PiT-1(Δsm) mice had no PiT-1 mRNA expression, increased PiT-2 mRNA levels, and no difference in sodium-dependent phosphate uptake or phosphate-induced matrix calcification compared with PiT-1(flox/flox) VSMCs. Knockdown of PiT-2 decreased phosphate uptake and phosphate-induced calcification of PiT-1(Δsm) VSMCs. Furthermore, overexpression of PiT-2 restored these parameters in human PiT-1-deficient VSMCs. CONCLUSIONS PiT-2 can mediate phosphate uptake and calcification of VSMCs in the absence of PiT-1. Mechanistically, PiT-1 and PiT-2 seem to serve redundant roles in phosphate-induced calcification of VSMCs.
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Affiliation(s)
- Matthew H Crouthamel
- From the Departments of Bioengineering (M.H.C., E.M.L., N.W.C., M.C.W., D.F.P., X.L., C.M.G.), Nephrology (W.L.L.), and Cardiology (Y.L., M.T.C.), University of Washington, Seattle; and Department of Medicine, University of Colorado, Denver (M.L.)
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Baron MH, Vacaru A, Nieves J. Erythroid development in the mammalian embryo. Blood Cells Mol Dis 2013; 51:213-9. [PMID: 23932234 DOI: 10.1016/j.bcmd.2013.07.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 06/25/2013] [Indexed: 12/22/2022]
Abstract
Erythropoiesis is the process by which progenitors for red blood cells are produced and terminally differentiate. In all vertebrates, two morphologically distinct erythroid lineages (primitive, embryonic, and definitive, fetal/adult) form successively within the yolk sac, fetal liver, and marrow and are essential for normal development. Red blood cells have evolved highly specialized functions in oxygen transport, defense against oxidation, and vascular remodeling. Here we review key features of the ontogeny of red blood cell development in mammals, highlight similarities and differences revealed by genetic and gene expression profiling studies, and discuss methods for identifying erythroid cells at different stages of development and differentiation.
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Affiliation(s)
- Margaret H Baron
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Department of The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; The Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA; Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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