1
|
Burns D, Berlinguer-Palmini R, Werner A. XPR1: a regulator of cellular phosphate homeostasis rather than a Pi exporter. Pflugers Arch 2024; 476:861-869. [PMID: 38507112 PMCID: PMC11033234 DOI: 10.1007/s00424-024-02941-0] [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: 12/19/2023] [Revised: 02/19/2024] [Accepted: 03/04/2024] [Indexed: 03/22/2024]
Abstract
Phosphate (Pi) is an essential nutrient, and its plasma levels are under tight hormonal control. Uphill transport of Pi into cells is mediated by the two Na-dependent Pi transporter families SLC34 and SLC20. The molecular identity of a potential Pi export pathway is controversial, though XPR1 has recently been suggested by Giovannini and coworkers to mediate Pi export. We expressed XPR1 in Xenopus oocytes to determine its functional characteristics. Xenopus isoforms of proteins were used to avoid species incompatibility. Protein tagging confirmed the localization of XPR1 at the plasma membrane. Efflux experiments, however, failed to detect translocation of Pi attributable to XPR1. We tested various counter ions and export medium compositions (pH, plasma) as well as potential protein co-factors that could stimulate the activity of XPR1, though without success. Expression of truncated XPR1 constructs and individual domains of XPR1 (SPX, transmembrane core, C-terminus) demonstrated downregulation of the uptake of Pi mediated by the C-terminal domain of XPR1. Tethering the C-terminus to the transmembrane core changed the kinetics of the inhibition and the presence of the SPX domain blunted the inhibitory effect. Our observations suggest a regulatory role of XPR1 in cellular Pi handling rather than a function as Pi exporter. Accordingly, XPR1 senses intracellular Pi levels via its SPX domain and downregulates cellular Pi uptake via the C-terminal domain. The molecular identity of a potential Pi export protein remains therefore elusive.
Collapse
Affiliation(s)
- David Burns
- Biosciences Institute, Newcastle University, Framlington Place, Newcastle Upon Tyne, NE2 4HH, UK
| | | | - Andreas Werner
- Biosciences Institute, Newcastle University, Framlington Place, Newcastle Upon Tyne, NE2 4HH, UK.
| |
Collapse
|
2
|
Siva Sankari G, James R, Payva F, Sivaramakrishnan V, Vineeth Kumar TV, Kanchi S, Santhy KS. Computational analysis of sodium-dependent phosphate transporter SLC20A1/PiT1 gene identifies missense variations C573F, and T58A as high-risk deleterious SNPs. J Biomol Struct Dyn 2024; 42:4072-4086. [PMID: 37286379 DOI: 10.1080/07391102.2023.2218939] [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: 10/17/2022] [Accepted: 05/21/2023] [Indexed: 06/09/2023]
Abstract
SLC20A1/PiT1 is a sodium-dependent inorganic phosphate transporter, initially recognized as the retroviral receptor for Gibbon Ape Leukemia Virus in humans. SNPs in SLC20A1 is associated with Combined Pituitary Hormone Deficiency and Sodium Lithium Counter transport. Using in silico techniques, we have screened the nsSNPs for their deleterious effect on the structure and function of SLC20A1. Screening with sequence and structure-based tools on 430 nsSNPs, filtered 17 nsSNPs which are deleterious. To evaluate the role of these SNPs, protein modeling and MD simulations were performed. A comparative analysis of model generated with SWISS-MODEL and AlphaFold shows that many residues are in the disallowed region of Ramachandran plot. Since SWISS-MODEL structure has a 25-residue deletion, the AlphaFold structure was used to perform MD simulation for equilibration and structure refinement. Further, to understand perturbation of energetics, we performed in silico mutagenesis and ΔΔG calculation using FoldX on MD refined structures, which yielded SNPs that are neutral (3), destabilizing (12) and stabilizing (2) on protein structure. Furthermore, to elucidate the impact of SNPs on structure, we performed MD simulations to discern the changes in RMSD, Rg, RMSF and LigPlot of interacting residues. RMSF profiles of representative SNPs revealed that A114V (neutral) and T58A (positive) were more flexible & C573F (negative) was more rigid compared to wild type, which is also reflected in the changes in number of local interacting residues in LigPlot and ΔΔG. Taken together, our results show that SNPs can lead to structural perturbations and impact the function of SLC20A1 with potential implications for disease.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- G Siva Sankari
- Centre for Wildlife Studies, Kerala Veterinary and Animal Sciences University, Wayanad, Kerala, India
| | - Remya James
- St. Joseph's College for Women, Alappuzha, Kerala, India
- Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, India
| | - Febby Payva
- St. Joseph's College for Women, Alappuzha, Kerala, India
- Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, India
| | - Venketesh Sivaramakrishnan
- Disease Biology Lab, Department of Biosciences, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Puttaparthi, Andhra Pradesh, India
| | | | - Subbarao Kanchi
- Department of Physics, Sri Sathya Sai Institute of Higher Learning, Prasanthi Nilayam, Puttaparthi, Andhra Pradesh, India
| | - K S Santhy
- Avinashilingam Institute for Home Science and Higher Education for Women, Coimbatore, Tamil Nadu, India
| |
Collapse
|
3
|
Mottaghinia S, Stenzel S, Tsangaras K, Nikolaidis N, Laue M, Müller K, Hölscher H, Löber U, McEwen GK, Donnellan SC, Rowe KC, Aplin KP, Goffinet C, Greenwood AD. A recent gibbon ape leukemia virus germline integration in a rodent from New Guinea. Proc Natl Acad Sci U S A 2024; 121:e2220392121. [PMID: 38305758 PMCID: PMC10861895 DOI: 10.1073/pnas.2220392121] [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: 12/09/2022] [Accepted: 11/30/2023] [Indexed: 02/03/2024] Open
Abstract
Germline colonization by retroviruses results in the formation of endogenous retroviruses (ERVs). Most colonization's occurred millions of years ago. However, in the Australo-Papuan region (Australia and New Guinea), several recent germline colonization events have been discovered. The Wallace Line separates much of Southeast Asia from the Australo-Papuan region restricting faunal and pathogen dispersion. West of the Wallace Line, gibbon ape leukemia viruses (GALVs) have been isolated from captive gibbons. Two microbat species from China appear to have been infected naturally. East of Wallace's Line, the woolly monkey virus (a GALV) and the closely related koala retrovirus (KoRV) have been detected in eutherians and marsupials in the Australo-Papuan region, often vertically transmitted. The detected vertically transmitted GALV-like viruses in Australo-Papuan fauna compared to sporadic horizontal transmission in Southeast Asia and China suggest the GALV-KoRV clade originates in the former region and further models of early-stage genome colonization may be found. We screened 278 samples, seven bat and one rodent family endemic to the Australo-Papuan region and bat and rodent species found on both sides of the Wallace Line. We identified two rodents (Melomys) from Australia and Papua New Guinea and no bat species harboring GALV-like retroviruses. Melomys leucogaster from New Guinea harbored a genomically complete replication-competent retrovirus with a shared integration site among individuals. The integration was only present in some individuals of the species indicating this retrovirus is at the earliest stages of germline colonization of the Melomys genome, providing a new small wild mammal model of early-stage genome colonization.
Collapse
Affiliation(s)
- Saba Mottaghinia
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin10315, Germany
- Centre International de Recherche en Infectiologie, Université de Lyon, Inserm, U1111, Université Claude Bernard Lyon 1, CNRS, UMR5308, École Nationale Supérieure de Lyon, LyonF-69007, France
| | - Saskia Stenzel
- Institute of Virology Charité–Universitätsmedizin Berlin, BerlinD-10117, Germany
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, LiverpoolL3 5QA, United Kingdom
| | - Kyriakos Tsangaras
- Department of Life and Health Sciences, University of Nicosia, NicosiaCY-2417, Cyprus
| | - Nikolas Nikolaidis
- Department of Biological Science, Center for Applied Biotechnology Studies, and Center for Computational and Applied Mathematics, College of Natural Sciences and Mathematics, California State University Fullerton, Fullerton, CA92834-6850
| | - Michael Laue
- Advanced Light and Electron Microscopy (ZBS 4), Centre for Biological Threats and Special Pathogens, Robert Koch Institute, BerlinD-13353, Germany
| | - Karin Müller
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin10315, Germany
| | - Henriette Hölscher
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin10315, Germany
| | - Ulrike Löber
- Max-Delbrük Center for Molecular Medicine Helmholtz Association, Berlin13125, Germany
| | - Gayle K. McEwen
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin10315, Germany
| | | | - Kevin C. Rowe
- Sciences Department, Museums Victoria, Melbourne, VIC3001, Australia
| | - Ken P. Aplin
- South Australian Museum, North Terrace, Adelaide SA5000, Australia
| | - Christine Goffinet
- Institute of Virology Charité–Universitätsmedizin Berlin, BerlinD-10117, Germany
- Department of Tropical Disease Biology, Liverpool School of Tropical Medicine, LiverpoolL3 5QA, United Kingdom
| | - Alex D. Greenwood
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin10315, Germany
- School of Veterinary Medicine, Freie Universität Berlin, Berlin14163, Germany
| |
Collapse
|
4
|
Liu Y, Xu Y, Li X, Chen M, Wang X, Zhang N, Zhang H, Zhang Z. Towards precision oncology discovery: four less known genes and their unknown interactions as highest-performed biomarkers for colorectal cancer. NPJ Precis Oncol 2024; 8:13. [PMID: 38243058 PMCID: PMC10799029 DOI: 10.1038/s41698-024-00512-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 01/05/2024] [Indexed: 01/21/2024] Open
Abstract
The goal of this study was to use a new interpretable machine-learning framework based on max-logistic competing risk factor models to identify a parsimonious set of differentially expressed genes (DEGs) that play a pivotal role in the development of colorectal cancer (CRC). Transcriptome data from nine public datasets were analyzed, and a new Chinese cohort was collected to validate the findings. The study discovered a set of four critical DEGs - CXCL8, PSMC2, APP, and SLC20A1 - that exhibit the highest accuracy in detecting CRC in diverse populations and ethnicities. Notably, PSMC2 and CXCL8 appear to play a central role in CRC, and CXCL8 alone could potentially serve as an early-stage marker for CRC. This work represents a pioneering effort in applying the max-logistic competing risk factor model to identify critical genes for human malignancies, and the interpretability and reproducibility of the results across diverse populations suggests that the four DEGs identified can provide a comprehensive description of the transcriptomic features of CRC. The practical implications of this research include the potential for personalized risk assessment and precision diagnosis and tailored treatment plans for patients.
Collapse
Affiliation(s)
- Yongjun Liu
- Department of Laboratory Medicine and Pathology, University of Washington Medical Center, Seattle, WA, USA
| | - Yuqing Xu
- Department of Statistics, University of Wisconsin-Madison, Madison, WI, USA
| | - Xiaoxing Li
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China.
| | - Mengke Chen
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China
| | - Xueqin Wang
- Department of Statistics and Finance, University of Science and Technology of China, Hefei, China
| | - Ning Zhang
- Department of Gastroenterology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Heping Zhang
- Yale School of Public Health, Yale University, New Haven, CT, USA
| | - Zhengjun Zhang
- Department of Statistics, University of Wisconsin-Madison, Madison, WI, USA.
- Department of Biostatistics and Medical Informatics, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.
- School of Economics and Management, and MOE Social Science Laboratory of Digital Economic Forecasts and Policy Simulation, University of Chinese Academy of Sciences, Center for Forecasting Sciences, Chinese Academy of Sciences, Beijing, China.
| |
Collapse
|
5
|
Correia-Branco A, Mei A, Pillai S, Jayaraman N, Sharma R, Paquette AG, Neradugomma NK, Benson C, Chavkin NW, Mao Q, Wallingford MC. SLC20a1/PiT-1 is required for chorioallantoic placental morphogenesis. VASCULAR BIOLOGY (BRISTOL, ENGLAND) 2023; 5:e220018. [PMID: 36795703 PMCID: PMC10160536 DOI: 10.1530/vb-22-0018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 02/16/2023] [Indexed: 02/17/2023]
Abstract
The placenta mediates the transport of nutrients, such as inorganic phosphate (Pi), between the maternal and fetal circulatory systems. The placenta itself also requires high levels of nutrient uptake as it develops to provide critical support for fetal development. This study aimed to determine placental Pi transport mechanisms using in vitro and in vivo models. We observed that Pi (P33) uptake in BeWo cells is sodium dependent and that SLC20A1/Slc20a1 is the most highly expressed placental sodium-dependent transporter in mouse (microarray), human cell line (RT-PCR) and term placenta (RNA-seq), supporting that normal growth and maintenance of the mouse and human placenta requires SLC20A1/Slc20a1. Slc20a1 wild-type (Slc20a1+/+) and knockout (Slc20a1-/-) mice were produced through timed intercrosses and displayed yolk sac angiogenesis failure as expected at E10.5. E9.5 tissues were analyzed to test whether placental morphogenesis requires Slc20a1. At E9.5, the developing placenta was reduced in size in Slc20a1-/-. Multiple structural abnormalities were also observed in the Slc20a1-/-chorioallantois. We determined that monocarboxylate transporter 1 protein (MCT1+) cells were reduced in developing Slc20a1-/-placenta, confirming that Slc20a1 loss reduced trophoblast syncytiotrophoblast 1 (SynT-I) coverage. Next, we examined the cell type-specific Slc20a1 expression and SynT molecular pathways in silico and identified Notch/Wnt as a pathway of interest that regulates trophoblast differentiation. We further observed that specific trophoblast lineages express Notch/Wnt genes that associate with endothelial cell tip-and-stalk cell markers. In conclusion, our findings support that Slc20a1 mediates the symport of Pi into SynT cells, providing critical support for their differentiation and angiogenic mimicry function at the developing maternal-fetal interface.
Collapse
Affiliation(s)
- Ana Correia-Branco
- Mother Infant Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Ariel Mei
- Mother Infant Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Sreehari Pillai
- Mother Infant Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Nirmala Jayaraman
- Mother Infant Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Radhika Sharma
- Mother Infant Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| | - Alison G Paquette
- University of Washington, Department of Pediatrics, Seattle, Washington, USA
| | - Naveen K Neradugomma
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Ciara Benson
- Department of Bioengineering, University of Washington, Seattle, Washington, USA
| | - Nicholas W Chavkin
- Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Qingcheng Mao
- Department of Pharmaceutics, School of Pharmacy, University of Washington, Seattle, Washington, USA
| | - Mary C Wallingford
- Mother Infant Research Institute, Tufts Medical Center, Boston, Massachusetts, USA
| |
Collapse
|
6
|
Jennings ML. Role of transporters in regulating mammalian intracellular inorganic phosphate. Front Pharmacol 2023; 14:1163442. [PMID: 37063296 PMCID: PMC10097972 DOI: 10.3389/fphar.2023.1163442] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 03/17/2023] [Indexed: 03/31/2023] Open
Abstract
This review summarizes the current understanding of the role of plasma membrane transporters in regulating intracellular inorganic phosphate ([Pi]In) in mammals. Pi influx is mediated by SLC34 and SLC20 Na+-Pi cotransporters. In non-epithelial cells other than erythrocytes, Pi influx via SLC20 transporters PiT1 and/or PiT2 is balanced by efflux through XPR1 (xenotropic and polytropic retrovirus receptor 1). Two new pathways for mammalian Pi transport regulation have been described recently: 1) in the presence of adequate Pi, cells continuously internalize and degrade PiT1. Pi starvation causes recycling of PiT1 from early endosomes to the plasma membrane and thereby increases the capacity for Pi influx; and 2) binding of inositol pyrophosphate InsP8 to the SPX domain of XPR1 increases Pi efflux. InsP8 is degraded by a phosphatase that is strongly inhibited by Pi. Therefore, an increase in [Pi]In decreases InsP8 degradation, increases InsP8 binding to SPX, and increases Pi efflux, completing a feedback loop for [Pi]In homeostasis. Published data on [Pi]In by magnetic resonance spectroscopy indicate that the steady state [Pi]In of skeletal muscle, heart, and brain is normally in the range of 1–5 mM, but it is not yet known whether PiT1 recycling or XPR1 activation by InsP8 contributes to Pi homeostasis in these organs. Data on [Pi]In in cultured cells are variable and suggest that some cells can regulate [Pi] better than others, following a change in [Pi]Ex. More measurements of [Pi]In, influx, and efflux are needed to determine how closely, and how rapidly, mammalian [Pi]In is regulated during either hyper- or hypophosphatemia.
Collapse
|
7
|
Onaga C, Tamori S, Matsuoka I, Ozaki A, Motomura H, Nagashima Y, Sato T, Sato K, Tahata K, Xiong Y, Nakano Y, Mano Y, Miyazaki S, Sasaki K, Ohno S, Akimoto K. High SLC20A1 Expression Is Associated With Poor Prognosis for Radiotherapy of Estrogen Receptor-positive Breast Cancer. CANCER DIAGNOSIS & PROGNOSIS 2022; 2:429-442. [PMID: 35813014 PMCID: PMC9254097 DOI: 10.21873/cdp.10126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND/AIM Radiotherapy is one of the main treatments for estrogen receptor-positive (ER+) breast cancer. However, in some ER+ breast cancer cases, radiotherapy is insufficient to inhibit progression and there is a lack of markers to predict radiotherapy insensitivity. Solute carrier family 20 member 1 (SLC20A1) is a sodium/inorganic phosphate symporter, which has been proposed to be a viable prognostic marker for luminal A and B types of ER+ breast cancer. The present study examined the possibility of SLC20A1 as a novel biomarker for the prediction of radiotherapy efficiency. PATIENTS AND METHODS The Molecular Taxonomy of Breast Cancer International Consortium dataset was downloaded from cBioportal and the prognosis of patients with high SLC20A1 expression (SLC20A1 high ) was compared with that of patients with low SLC20A1 expression, without or with radiotherapy and tumor stages I, II, and III, using the Kaplan-Meier method and multivariate Cox regression analyses of disease-specific and relapse-free survival. RESULTS Patients in the SLC20A1 high group with radiotherapy showed poor clinical outcomes in both luminal A and luminal B breast cancers. Furthermore, in luminal A breast cancer at tumor stage I, patients in the SLC20A1 high group with radiotherapy also showed poor clinical outcomes. Therefore, these results suggest that radiotherapy is insufficient for patients in the SLC20A1 high group for both luminal A and B types, and especially for the luminal A type at tumor stage I. CONCLUSION SLC20A1 can be used as a prognostic marker for the prediction of the efficacy of radiotherapy for luminal A and luminal B breast cancers.
Collapse
Affiliation(s)
- Chotaro Onaga
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Shoma Tamori
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Izumi Matsuoka
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Ayaka Ozaki
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Hitomi Motomura
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Yuka Nagashima
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Tsugumichi Sato
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Keiko Sato
- Department of Information Sciences, Faculty of Science and Technology, Tokyo University of Science, Chiba, Japan
| | - Kouji Tahata
- Department of Information Sciences, Faculty of Science and Technology, Tokyo University of Science, Chiba, Japan
| | - Yuyun Xiong
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Yoshio Nakano
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Yasunari Mano
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Satoru Miyazaki
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Kazunori Sasaki
- Laboratory of Cancer Biology, Institute for Diseases of Old Age, Juntendo University School of Medicine, Tokyo, Japan
| | - Shigeo Ohno
- Laboratory of Cancer Biology, Institute for Diseases of Old Age, Juntendo University School of Medicine, Tokyo, Japan
| | - Kazunori Akimoto
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| |
Collapse
|
8
|
Zechner C, Henne WM, Sathe AA, Xing C, Hernandez G, Sun S, Cheong MC. Cellular abundance of sodium phosphate cotransporter SLC20A1/PiT1 and phosphate uptake are controlled post-transcriptionally by ESCRT. J Biol Chem 2022; 298:101945. [PMID: 35447110 PMCID: PMC9123275 DOI: 10.1016/j.jbc.2022.101945] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/09/2022] [Accepted: 04/12/2022] [Indexed: 11/30/2022] Open
Abstract
Inorganic phosphate is essential for human life. The widely expressed mammalian sodium/phosphate cotransporter SLC20A1/PiT1 mediates phosphate uptake into most cell types; however, while SLC20A1 is required for development, and elevated SLC20A1 expression is associated with vascular calcification and aggressive tumor growth, the mechanisms regulating SLC20A1 protein abundance are unknown. Here, we found that SLC20A1 protein expression is low in phosphate-replete cultured cells but is strikingly induced following phosphate starvation, whereas mRNA expression is high in phosphate-replete cells and only mildly increased by phosphate starvation. To identify regulators of SLC20A1 protein levels, we performed a genome-wide CRISPR-based loss-of-function genetic screen in phosphate-replete cells using SLC20A1 protein induction as readout. Our screen revealed that endosomal sorting complexes required for transport (ESCRT) machinery was essential for proper SLC20A1 protein downregulation in phosphate-replete cells. We show that SLC20A1 colocalizes with ESCRT and that ESCRT deficiency increases SLC20A1 protein and phosphate uptake into cells. We also found numerous additional candidate regulators of mammalian phosphate homeostasis, including genes modifying protein ubiquitination and the Krebs cycle and oxidative phosphorylation pathways. Many of these targets have not been previously implicated in this process. We present here a model in which SLC20A1 protein abundance and phosphate uptake are tonically negatively regulated post-transcriptionally in phosphate-replete cells through direct ESCRT-mediated SLC20A1 degradation. Moreover, our screening results provide a comprehensive resource for future studies to elucidate the mechanisms governing cellular phosphate homeostasis. We conclude that genome-wide CRISPR-based genetic screening is a powerful tool to discover proteins and pathways relevant to physiological processes.
Collapse
Affiliation(s)
- Christoph Zechner
- Division of Endocrinology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Charles and Jane Pak Center for Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
| | - W Mike Henne
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Adwait A Sathe
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Chao Xing
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Population and Data Sciences, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Genaro Hernandez
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Shengyi Sun
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan, USA
| | - Mi Cheong Cheong
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| |
Collapse
|
9
|
Onaga C, Tamori S, Matsuoka I, Ozaki A, Motomura H, Nagashima Y, Sato T, Sato K, Xiong Y, Sasaki K, Ohno S, Akimoto K. High expression of SLC20A1 is less effective for endocrine therapy and predicts late recurrence in ER-positive breast cancer. PLoS One 2022; 17:e0268799. [PMID: 35605014 PMCID: PMC9126382 DOI: 10.1371/journal.pone.0268799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 05/08/2022] [Indexed: 12/02/2022] Open
Abstract
Estrogen receptor-positive (ER+) breast cancer intrinsically confers satisfactory clinical outcomes in response to endocrine therapy. However, a significant proportion of patients with ER+ breast cancer do not respond well to this treatment. Therefore, to evaluate the effects of endocrine therapy, there is a need for identification of novel markers that can be used at the time of diagnosis for predicting clinical outcomes, especially for early-stage and late recurrence. Solute carrier family 20 member 1 (SLC20A1) is a sodium/inorganic phosphate symporter that has been proposed to be a viable prognostic marker for the luminal A and luminal B types of ER+ breast cancer. In the present study, we examined the possible association of SLC20A1 expression with tumor staging, endocrine therapy and chemotherapy in the luminal A and luminal B subtypes of breast cancer. In addition, we analyzed the relationship between SLC20A1 expression and late recurrence in patients with luminal A and luminal B breast cancer following endocrine therapy. We showed that patients with higher levels of SLC20A1 expression (SLC20A1high) exhibited poorer clinical outcomes in those with tumor stage I luminal A breast cancer. In addition, this SLC20A1high subgroup of patients exhibited less responses to endocrine therapy, specifically in those with the luminal A and luminal B subtypes of breast cancer. However, patients with SLC20A1high showed good clinical outcomes following chemotherapy. Patients tested to be in the SLC20A1high group at the time of diagnosis also showed a higher incidence of recurrence compared with those with lower expression levels of SLC20A1, at >15 years for luminal A breast cancer and at 10–15 years for luminal B breast cancer. Therefore, we conclude that SLC20A1high can be used as a prognostic biomarker for predicting the efficacy of endocrine therapy and late recurrence for ER+ breast cancer.
Collapse
Affiliation(s)
- Chotaro Onaga
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Shoma Tamori
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Izumi Matsuoka
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Ayaka Ozaki
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Hitomi Motomura
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Yuka Nagashima
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Tsugumichi Sato
- Department of Pharmacy, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Keiko Sato
- Department of Information Sciences, Faculty of Sciences and Technology, Tokyo University of Science, Chiba, Japan
| | - Yuyun Xiong
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
| | - Kazunori Sasaki
- Laboratory of Cancer Biology, Institute for Diseases of Old Age, Juntendo University School of Medicine, Tokyo, Japan
| | - Shigeo Ohno
- Laboratory of Cancer Biology, Institute for Diseases of Old Age, Juntendo University School of Medicine, Tokyo, Japan
| | - Kazunori Akimoto
- Department of Medicinal and Life Sciences, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Chiba, Japan
- * E-mail:
| |
Collapse
|
10
|
Nguyen NT, Nguyen TT, Park KS. Oxidative Stress Related to Plasmalemmal and Mitochondrial Phosphate Transporters in Vascular Calcification. Antioxidants (Basel) 2022; 11:antiox11030494. [PMID: 35326144 PMCID: PMC8944874 DOI: 10.3390/antiox11030494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 02/26/2022] [Accepted: 02/28/2022] [Indexed: 12/04/2022] Open
Abstract
Inorganic phosphate (Pi) is essential for maintaining cellular function but excess of Pi leads to serious complications, including vascular calcification. Accumulating evidence suggests that oxidative stress contributes to the pathogenic progression of calcific changes. However, the molecular mechanism underlying Pi-induced reactive oxygen species (ROS) generation and its detrimental consequences remain unclear. Type III Na+-dependent Pi cotransporter, PiT-1/-2, play a significant role in Pi uptake of vascular smooth muscle cells. Pi influx via PiT-1/-2 increases the abundance of PiT-1/-2 and depolarization-activated Ca2+ entry due to its electrogenic properties, which may lead to Ca2+ and Pi overload and oxidative stress. At least four mitochondrial Pi transporters are suggested, among which the phosphate carrier (PiC) is known to be mainly involved in mitochondrial Pi uptake. Pi transport via PiC may induce hyperpolarization and superoxide generation, which may lead to mitochondrial dysfunction and endoplasmic reticulum stress, together with generation of cytosolic ROS. Increase in net influx of Ca2+ and Pi and their accumulation in the cytosol and mitochondrial matrix synergistically increases oxidative stress and osteogenic differentiation, which could be prevented by suppressing either Ca2+ or Pi overload. Therapeutic strategies targeting plasmalemmal and mitochondrial Pi transports can protect against Pi-induced oxidative stress and vascular calcification.
Collapse
Affiliation(s)
- Nhung Thi Nguyen
- Department of Physiology, Wonju College of Medicine, Yonsei University, Wonju 26426, Korea;
- Mitohormesis Research Center, Wonju College of Medicine, Yonsei University, Wonju 26426, Korea
- Medical Doctor Program, College of Health Sciences, VinUniversity, Hanoi 12406, Vietnam
| | - Tuyet Thi Nguyen
- Department of Physiology, Wonju College of Medicine, Yonsei University, Wonju 26426, Korea;
- Internal Medicine Residency Program, College of Health Sciences, VinUniversity, Hanoi 12406, Vietnam
- Correspondence: (T.T.N.); (K.-S.P.); Tel.: +84-247-108-9779 (T.T.N.); +82-33-741-0294 (K.-S.P.)
| | - Kyu-Sang Park
- Department of Physiology, Wonju College of Medicine, Yonsei University, Wonju 26426, Korea;
- Mitohormesis Research Center, Wonju College of Medicine, Yonsei University, Wonju 26426, Korea
- Correspondence: (T.T.N.); (K.-S.P.); Tel.: +84-247-108-9779 (T.T.N.); +82-33-741-0294 (K.-S.P.)
| |
Collapse
|
11
|
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.
Collapse
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,
| |
Collapse
|
12
|
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.
Collapse
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.
| |
Collapse
|
13
|
Yamazaki M, Kawai M, Kinoshita S, Tachikawa K, Nakanishi T, Ozono K, Michigami T. Clonal osteoblastic cell lines with CRISPR/Cas9-mediated ablation of Pit1 or Pit2 show enhanced mineralization despite reduced osteogenic gene expression. Bone 2021; 151:116036. [PMID: 34118444 DOI: 10.1016/j.bone.2021.116036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 06/02/2021] [Accepted: 06/04/2021] [Indexed: 12/12/2022]
Abstract
Multiple actions of extracellular Pi on the skeletal cells are likely to be partly mediated by type III sodium/phosphate (Na+/Pi) cotransporters Pit1 and Pit2, although the details are not fully understood. In the current study, to determine the roles of Pit1 and Pit2 in osteoblasts, we generated Pit1-knockout (KO) and Pit2-KO osteoblastic cells by applying CRISPR/Cas9 genome editing to an osteoblastic cell line MC3T3-E1 subclone 4. The extracellular Pi level was increased in the Pit1-KO and Pit2-KO clones due to the reduced Pi uptake. Interestingly, in vitro mineralization was accelerated in the Pit1-KO and Pit2-KO clones, although the induction of the expression of osteogenic marker genes was suppressed. In the cells before mineralization, extracellular levels of pyrophosphate (PPi) and adenosine triphosphate (ATP) were increased in the Pit1-KO and Pit2-KO clones, which might be attributable to the reduced expression and activity of tissue-nonspecific alkaline phosphatase (TNSALP). A 24-h treatment with high Pi reduced the expression and activity of TNSALP, suggesting that the suppression of TNSALP in the Pit1-KO and Pit2-KO clones was caused by the increased availability of extracellular Pi. Lentiviral gene transfer of Pit1 and Pit2 restored the changes observed in Pit1-KO and Pit2-KO clones, respectively. The expressions of P2Y2 and P2X7 which encode receptors for extracellular ATP were altered in the Pit1-KO and Pit2-KO clones, suggesting an influence on purinergic signaling. In mineralized cells after long-term culture, intracellular levels of PPi and ATP were higher in the Pit1-KO and Pit2-KO clones. Taken together, ablation of Pit1 or Pit2 in this osteoblastic cell model led to accelerated mineralization, suppressed TNSALP and altered the levels of extracellular and intracellular PPi and ATP, which might be partly mediated by changes in the availability of extracellular Pi.
Collapse
Affiliation(s)
- Miwa Yamazaki
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan
| | - Masanobu Kawai
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan
| | - Saori Kinoshita
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan
| | - Kanako Tachikawa
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan
| | - Tatsuro Nakanishi
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan; Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan
| | - Toshimi Michigami
- Department of Bone and Mineral Research, Research Institute, Osaka Women's and Children's Hospital, Osaka Prefectural Hospital Organization, Izumi, Osaka 594-1101, Japan.
| |
Collapse
|
14
|
Figueres L, Beck-Cormier S, Beck L, Marks J. The Complexities of Organ Crosstalk in Phosphate Homeostasis: Time to Put Phosphate Sensing Back in the Limelight. Int J Mol Sci 2021; 22:5701. [PMID: 34071837 PMCID: PMC8199323 DOI: 10.3390/ijms22115701] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 05/13/2021] [Accepted: 05/21/2021] [Indexed: 12/16/2022] Open
Abstract
Phosphate homeostasis is essential for health and is achieved via interaction between the bone, kidney, small intestine, and parathyroid glands and via intricate processes involving phosphate transporters, phosphate sensors, and circulating hormones. Numerous genetic and acquired disorders are associated with disruption in these processes and can lead to significant morbidity and mortality. The role of the kidney in phosphate homeostasis is well known, although it is recognized that the cellular mechanisms in murine models and humans are different. Intestinal phosphate transport also appears to differ in humans and rodents, with recent studies demonstrating a dominant role for the paracellular pathway. The existence of phosphate sensing has been acknowledged for decades; however, the underlying molecular mechanisms are poorly understood. At least three phosphate sensors have emerged. PiT2 and FGFR1c both act as phosphate sensors controlling Fibroblast Growth Factor 23 secretion in bone, whereas the calcium-sensing receptor controls parathyroid hormone secretion in response to extracellular phosphate. All three of the proposed sensors are expressed in the kidney and intestine but their exact function in these organs is unknown. Understanding organ interactions and the mechanisms involved in phosphate sensing requires significant research to develop novel approaches for the treatment of phosphate homeostasis disorders.
Collapse
Affiliation(s)
- Lucile Figueres
- Department of Neuroscience, Physiology and Pharmacology, Royal Free Campus, University College London, London NW3 2PF, UK;
- CHU de Nantes, Université de Nantes, F-44042 Nantes, France
| | - Sarah Beck-Cormier
- Inserm, UMR 1229, RMeS Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, F-44042 Nantes, France; (S.B.-C.); (L.B.)
| | - Laurent Beck
- Inserm, UMR 1229, RMeS Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, F-44042 Nantes, France; (S.B.-C.); (L.B.)
| | - Joanne Marks
- Department of Neuroscience, Physiology and Pharmacology, Royal Free Campus, University College London, London NW3 2PF, UK;
| |
Collapse
|
15
|
Ribet ABP, Ng PY, Pavlos NJ. Membrane Transport Proteins in Osteoclasts: The Ins and Outs. Front Cell Dev Biol 2021; 9:644986. [PMID: 33718388 PMCID: PMC7952445 DOI: 10.3389/fcell.2021.644986] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/09/2021] [Indexed: 12/12/2022] Open
Abstract
During bone resorption, the osteoclast must sustain an extraordinarily low pH environment, withstand immense ionic pressures, and coordinate nutrient and waste exchange across its membrane to sustain its unique structural and functional polarity. To achieve this, osteoclasts are equipped with an elaborate set of membrane transport proteins (pumps, transporters and channels) that serve as molecular ‘gatekeepers’ to regulate the bilateral exchange of ions, amino acids, metabolites and macromolecules across the ruffled border and basolateral domains. Whereas the importance of the vacuolar-ATPase proton pump and chloride voltage-gated channel 7 in osteoclasts has long been established, comparatively little is known about the contributions of other membrane transport proteins, including those categorized as secondary active transporters. In this Special Issue review, we provide a contemporary update on the ‘ins and outs’ of membrane transport proteins implicated in osteoclast differentiation, function and bone homeostasis and discuss their therapeutic potential for the treatment of metabolic bone diseases.
Collapse
Affiliation(s)
- Amy B P Ribet
- Bone Biology and Disease Laboratory, School of Biomedical Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Pei Ying Ng
- Bone Biology and Disease Laboratory, School of Biomedical Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Nathan J Pavlos
- Bone Biology and Disease Laboratory, School of Biomedical Sciences, The University of Western Australia, Nedlands, WA, Australia
| |
Collapse
|
16
|
Stenhouse C, Halloran KM, Newton MG, Gaddy D, Suva LJ, Bazer FW. Novel mineral regulatory pathways in ovine pregnancy: I. phosphate, klotho signaling, and sodium-dependent phosphate transporters. Biol Reprod 2021; 104:1084-1096. [PMID: 33624764 DOI: 10.1093/biolre/ioab028] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 01/25/2021] [Accepted: 02/12/2021] [Indexed: 12/30/2022] Open
Abstract
Appropriate mineralization of the fetal skeleton requires an excess of phosphate in the fetus compared to the mother. However, mechanisms for placental phosphate transport are poorly understood. This study aimed to identify phosphate regulatory pathways in ovine endometria and placentae throughout gestation. Suffolk ewes were bred with fertile rams upon visual detection of estrus (Day 0). On Days 9, 12, 17, 30, 70, 90, 110, and 125 of pregnancy (n = 3-14/Day), ewes were euthanized and hysterectomized. Phosphate abundance varied across gestational days in uterine flushings, allantoic fluid, and homogenized endometria and placentae (P < 0.05). The expression of mRNAs for sodium-dependent phosphate transporters (SLC20A1 and SLC20A2) and klotho signaling mediators (FGF7, FGF21, FGF23, FGFR1-4, KL, KLB, ADAM10, and ADAM17) were quantified by qPCR. Day 17 conceptus tissue expressed SLC20A1, SLC20A2, KLB, FGF7, FGF21, FGF23, FGFR1, and FGFR2 mRNAs. Both sodium-dependent phosphate transporters and klotho signaling mediators were expressed in endometria and placentae throughout gestation. Gestational day influenced the expression of SLC20A1, ADAM10, ADAM17, FGF21, FGFR1, and FGFR3 mRNAs in both endometria and placentae (P < 0.05). Gestational day influenced endometrial expression of FGF7 (P < 0.001), and placental expression of FGF23 (P < 0.05). Immunohistochemistry confirmed that both FGF23 and KL proteins were expressed in endometria and placentae throughout gestation. The observed spatiotemporal profile of KL-FGF signaling suggests a potential role in the establishment of pregnancy and regulation of fetal growth. This study provides a platform for further mechanistic investigation into the role for KL-FGF signaling in the regulation of phosphate transport at the ovine maternal-conceptus interface.
Collapse
Affiliation(s)
- Claire Stenhouse
- Departments of Animal Science, Texas A&M University, College Station, Texas, USA
| | - Katherine M Halloran
- Departments of Animal Science, Texas A&M University, College Station, Texas, USA
| | - Makenzie G Newton
- Departments of Animal Science, Texas A&M University, College Station, Texas, USA
| | - Dana Gaddy
- Veterinary Integrative Biosciences, Texas A&M University, College Station, Texas, USA
| | - Larry J Suva
- Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas, USA
| | - Fuller W Bazer
- Departments of Animal Science, Texas A&M University, College Station, Texas, USA
| |
Collapse
|
17
|
Sellars KB, Ryan BA, Hartery SA, Kirby BJ, Kovacs CS. Murine Fetal Serum Phosphorus is Set Independent of FGF23 and PTH, Except in the Presence of Maternal Phosphate Loading. Endocrinology 2021; 162:5956315. [PMID: 33150413 PMCID: PMC7737482 DOI: 10.1210/endocr/bqaa202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Indexed: 01/03/2023]
Abstract
Fibroblast growth factor 23 (FGF23) appears to play no role until after birth, given unaltered phosphate and bone metabolism in Fgf23- and Klotho-null fetuses. However, in those studies maternal serum phosphorus was normal. We studied whether maternal phosphate loading alters fetal serum phosphorus and invokes a fetal FGF23 or parathyroid hormone (PTH) response. C57BL/6 wild-type (WT) female mice received low (0.3%), normal (0.7%), or high (1.65%) phosphate diets beginning 1 week prior to mating to WT males. Fgf23+/- female mice received the normal or high-phosphate diets 1 week before mating to Fgf23+/- males. One day before expected birth, we harvested maternal and fetal blood, intact fetuses, placentas, and fetal kidneys. Increasing phosphate intake in WT resulted in progressively higher maternal serum phosphorus and FGF23 during pregnancy, while PTH remained undetectable. Fetal serum phosphorus was independent of the maternal phosphorus and PTH remained low, but FGF23 showed a small nonsignificant increase with high maternal serum phosphorus. There were no differences in fetal ash weight and mineral content, or placental gene expression. High phosphate intake in Fgf23+/- mice also increased maternal serum phosphorus and FGF23, but there was no change in PTH. WT fetuses remained unaffected by maternal high-phosphate intake, while Fgf23-null fetuses became hyperphosphatemic but had no change in PTH, skeletal ash weight or mineral content. In conclusion, fetal phosphate metabolism is generally regulated independently of maternal serum phosphorus and fetal FGF23 or PTH. However, maternal phosphate loading reveals that fetal FGF23 can defend against the development of fetal hyperphosphatemia.
Collapse
Affiliation(s)
- K Berit Sellars
- Faculty of Medicine – Endocrinology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Brittany A Ryan
- Faculty of Medicine – Endocrinology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Sarah A Hartery
- Faculty of Medicine – Endocrinology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Beth J Kirby
- Faculty of Medicine – Endocrinology, Memorial University of Newfoundland, St. John’s, NL, Canada
| | - Christopher S Kovacs
- Faculty of Medicine – Endocrinology, Memorial University of Newfoundland, St. John’s, NL, Canada
- Correspondence: Dr Christopher Kovacs, Health Sciences Centre, 300 Prince Philip Drive, St. John’s, Newfoundland, A1B 3V6, Canada. E-mail:
| |
Collapse
|
18
|
Isolation and Characterization of Three Sodium-Phosphate Cotransporter Genes and Their Transcriptional Regulation in the Grass Carp Ctenopharyngodon idella. Int J Mol Sci 2020; 21:ijms21218228. [PMID: 33153158 PMCID: PMC7662828 DOI: 10.3390/ijms21218228] [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: 09/23/2020] [Revised: 10/31/2020] [Accepted: 11/02/2020] [Indexed: 12/20/2022] Open
Abstract
It is important to explore the regulatory mechanism of phosphorus homeostasis in fish, which help avoid the risk of P toxicity and prevent P pollution in aquatic environment. The present study obtained the full-length cDNA sequences and the promoters of three SLC20 members (slc20a1a, slc20a1b and slc20a2) from grass carp Ctenopharyngodon idella, and explored their responses to inorganic phosphorus (Pi). Grass carp SLC20s proteins possessed conservative domains and amino acid sites relevant with phosphorus transport. The mRNAs of three slc20s appeared in the nine tissues, but their expression levels were tissue-dependent. The binding sites of three transcription factors (SREBP1, NRF2 and VDR) were predicted on the slc20s promoters. The mutation and EMSA analysis indicated that: (1) SREBP1 binding site (−783/−771 bp) negatively but VDR (−260/−253 bp) binding site positively regulated the activities of slc20a1a promoter; (2) SREBP1 (−1187/−1178 bp), NRF2 (−572/−561 bp) and VDR(615/−609 bp) binding sites positively regulated the activities of slc20a1b promoter; (3) SREBP1 (−987/−977 bp), NRF2 (−1469/−1459 bp) and VDR (−1124/−1117 bp) binding sites positively regulated the activities of the slc20a2 promoter. Moreover, Pi incubation significantly reduced the activities of three slc20s promoters, and Pi-induced transcriptional inactivation of slc20s promoters abolished after the mutation of the VDR element but not SREBP1 and NRF2 elements. Pi incubation down-regulated the mRNA levels of three slc20s. For the first time, our study elucidated the transcriptional regulatory mechanisms of SLC20s and their responses to Pi, which offered new insights into the Pi homeostatic regulation and provided the basis for reducing phosphorus discharge into the waters.
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Beck-Cormier S, Beck L. The Need of a Paradigm Shift to Better Understand PiT1 and PiT2 Biology: Response to "Why Is There No PiT1/SLC20A1 Pathogenic Variants Yet Linked to Primary Familial Brain Calcification?". J Bone Miner Res 2020; 35:825-826. [PMID: 32049372 DOI: 10.1002/jbmr.3969] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/03/2020] [Accepted: 01/08/2020] [Indexed: 01/11/2023]
Affiliation(s)
| | - Laurent Beck
- Université de Nantes, INSERM, UMR 1229, RMeS, ONIRIS, Nantes, France
| |
Collapse
|
21
|
Dos Santos-Junior EF, de Oliveira JRM. Why Is There No PiT1/SLC20A1 Pathogenic Variants Yet Linked to Primary Familial Brain Calcification? J Bone Miner Res 2020; 35:823-824. [PMID: 32045498 DOI: 10.1002/jbmr.3973] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 10/24/2019] [Accepted: 11/29/2019] [Indexed: 11/08/2022]
|
22
|
Chande S, Caballero D, Ho BB, Fetene J, Serna J, Pesta D, Nasiri A, Jurczak M, Chavkin NW, Hernando N, Giachelli CM, Wagner CA, Zeiss C, Shulman GI, Bergwitz C. Slc20a1/Pit1 and Slc20a2/Pit2 are essential for normal skeletal myofiber function and survival. Sci Rep 2020; 10:3069. [PMID: 32080237 PMCID: PMC7033257 DOI: 10.1038/s41598-020-59430-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Accepted: 01/29/2020] [Indexed: 01/25/2023] Open
Abstract
Low blood phosphate (Pi) reduces muscle function in hypophosphatemic disorders. Which Pi transporters are required and whether hormonal changes due to hypophosphatemia contribute to muscle function is unknown. To address these questions we generated a series of conditional knockout mice lacking one or both house-keeping Pi transporters Pit1 and Pit2 in skeletal muscle (sm), using the postnatally expressed human skeletal actin-cre. Simultaneous conditional deletion of both transporters caused skeletal muscle atrophy, resulting in death by postnatal day P13. smPit1-/-, smPit2-/- and three allele mutants are fertile and have normal body weights, suggesting a high degree of redundance for the two transporters in skeletal muscle. However, these mice show a gene-dose dependent reduction in running activity also seen in another hypophosphatemic model (Hyp mice). In contrast to Hyp mice, grip strength is preserved. Further evaluation of the mechanism shows reduced ERK1/2 activation and stimulation of AMP kinase in skeletal muscle from smPit1-/-; smPit2-/- mice consistent with energy-stress. Similarly, C2C12 myoblasts show a reduced oxygen consumption rate mediated by Pi transport-dependent and ERK1/2-dependent metabolic Pi sensing pathways. In conclusion, we here show that Pit1 and Pit2 are essential for normal myofiber function and survival, insights which may improve management of hypophosphatemic myopathy.
Collapse
Affiliation(s)
- Sampada Chande
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Daniel Caballero
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Bryan B Ho
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Jonathan Fetene
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Juan Serna
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
| | - Dominik Pesta
- Department of Cellular&Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
- German Diabetes Center, Düsseldorf, Germany, University of Washington, Box 355061, Foege Hall Seattle, WA, 98195, USA
| | - Ali Nasiri
- Department of Cellular&Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Michael Jurczak
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
- Department of Medicine, Division of Endocrinology, University of Pittsburgh, University of Washington, Box 355061, Foege Hall Seattle, WA, 98195, USA
| | - Nicholas W Chavkin
- Department of Bioengineering, University of Washington, Box 355061, Foege Hall Seattle, WA, 98195, USA
| | - Nati Hernando
- Institute of Physiology, University of Zürich, Switzerland and National Center of Competence in Research NCCR Kidney.CH, Zürich, Switzerland
| | - Cecilia M Giachelli
- Department of Bioengineering, University of Washington, Box 355061, Foege Hall Seattle, WA, 98195, USA
| | - Carsten A Wagner
- Institute of Physiology, University of Zürich, Switzerland and National Center of Competence in Research NCCR Kidney.CH, Zürich, Switzerland
| | - Caroline Zeiss
- Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA
- Department of Cellular&Molecular Physiology, Yale University School of Medicine, New Haven, CT, USA
| | - Clemens Bergwitz
- Department of Internal Medicine, Section Endocrinology, Yale University School of Medicine, New Haven, CT, USA.
| |
Collapse
|
23
|
Xu X, Li X, Sun H, Cao Z, Gao R, Niu T, Wang Y, Ma T, Chen R, Wang C, Yang Z, Liu JY. Murine Placental-Fetal Phosphate Dyshomeostasis Caused by an Xpr1 Deficiency Accelerates Placental Calcification and Restricts Fetal Growth in Late Gestation. J Bone Miner Res 2020; 35:116-129. [PMID: 31498925 DOI: 10.1002/jbmr.3866] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 08/23/2019] [Accepted: 08/27/2019] [Indexed: 11/09/2022]
Abstract
Phosphorus is a necessary component of all living organisms. This nutrient is mainly transported from the maternal blood to the fetus via the placenta, and insufficient phosphorus availability via the placenta disturbs the normal development of the fetus, especially fetal bone formation in late gestation. Key proteins (phosphate transporters and exporters) that are responsible for the maintenance of placental-fetal phosphorus homeostasis have been identified. A deficiency in the phosphate transporter Pit2 has been shown to result in placental calcification and the retardation of fetal development in mice. What roles does XPR1 (the only known phosphate exporter) play in maintaining placental-fetal phosphorus homeostasis? In this study, we found that Xpr1 expression is strong in the murine placenta and increases with age during gestation. We generated a global Xpr1 knockout mouse and found that heterozygous (Xpr1+/- ) and homozygous (Xpr1-/- ) fetuses have lower inorganic phosphate (Pi) levels in amniotic fluid and serum and a decreased skeletal mineral content. Xpr1-deficient placentas show abnormal Pi exchange during gestation. Therefore, Xpr1 deficiency in the placenta disrupts placental-fetal Pi homeostasis. We also discovered that the placentas of the Xpr1+/- and Xpr1-/- embryos are severely calcified. Mendelian inheritance statistics for offspring outcomes indicated that Xpr1-deficient embryos are significantly reduced in late gestation. In addition, Xpr1-/- mice die perinatally and a small proportion of Xpr1+/- mice die neonatally. RNA sequence (RNA-Seq) analysis of placental mRNA revealed that many of the transcripts are significantly differentially expressed due to Xpr1 deficiency and are linked to dysfunction of the placenta. This study is the first to reveal that XPR1 plays an important role in maintaining placental-fetal Pi homeostasis, disruption of which causes severe placental calcification, delays normal placental function, and restricts fetal growth. © 2019 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Xuan Xu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Xiunan Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Hao Sun
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Zhijian Cao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Ruixi Gao
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Tingting Niu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Yanli Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Tingbin Ma
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Rui Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Cheng Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| | - Zhengang Yang
- State Key Laboratory of Medical Neurobiology, Department of Neurology, Institutes of Brain Science, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Jing Yu Liu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, China
| |
Collapse
|
24
|
Chande S, Ho B, Fetene J, Bergwitz C. Transgenic mouse model for conditional expression of influenza hemagglutinin-tagged human SLC20A1/PIT1. PLoS One 2019; 14:e0223052. [PMID: 31613887 PMCID: PMC6793878 DOI: 10.1371/journal.pone.0223052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2019] [Accepted: 09/12/2019] [Indexed: 11/19/2022] Open
Abstract
To further investigate the role of the phosphate (Pi) transporter PIT1 in Pi homeostasis and tissue mineralization, we developed a transgenic mouse expressing the C-terminal influenza hemagglutinin (HA) epitope-tagged human PIT1 transporter under control of the cytomegalovirus/chicken beta actin/rabbit beta-globin gene (CAG) promotor and a loxP-stop-loxP (LSL) cassette permitting conditional activation of transgene expression (LSL-HA-hPITtg/+). For an initial characterization of this conditional mouse model, germline excision of the LSL cassette was performed to induce expression of the transgene in all mouse tissues (HA-hPIT1tg/+). Recombination was confirmed using genomic DNA obtained from blood samples of these mice. Furthermore, expression of HA-hPIT1 was found to be at least 10-fold above endogenous mouse Pit1 in total RNA isolated from multiple tissues and from cultured primary calvaria osteoblasts (PCOB) estimated by semi-quantitative RT-PCR. Robust expression of the HA-hPIT1 protein was also observed upon immunoblot analysis in most tissues and permits HA-mediated immunoprecipitation of the transporter. Characterization of the phenotype of HA-hPIT1tg/+ mice at 80 days of age when fed a standard chow (0.7% Pi and 1% calcium) showed elevated plasma Pi, but normal plasma iPTH, iFGF23, serum calcium, BUN, 1,25-dihydroxy vitamin D levels and urine Pi, calcium and protein excretion when compared to WT littermates. Likewise, no change in bone mineral density was observed upon uCT analysis of the distal femur obtained from these mice. In conclusion, heterozygous overexpression of HA-hPIT1 is compatible with life and causes hyperphosphatemia while bone and mineral metabolism of these mice are otherwise normal.
Collapse
Affiliation(s)
- Sampada Chande
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT, United States of America
| | - Bryan Ho
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT, United States of America
| | - Jonathan Fetene
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT, United States of America
| | - Clemens Bergwitz
- Section of Endocrinology and Metabolism, Yale University School of Medicine, New Haven, CT, United States of America
- * E-mail:
| |
Collapse
|
25
|
Beck‐Cormier S, Lelliott CJ, Logan JG, Lafont DT, Merametdjian L, Leitch VD, Butterfield NC, Protheroe HJ, Croucher PI, Baldock PA, Gaultier‐Lintia A, Maugars Y, Nicolas G, Banse C, Normant S, Magne N, Gérardin E, Bon N, Sourice S, Guicheux J, Beck L, Williams GR, Bassett JHD. Slc20a2, Encoding the Phosphate Transporter PiT2, Is an Important Genetic Determinant of Bone Quality and Strength. J Bone Miner Res 2019; 34:1101-1114. [PMID: 30721528 PMCID: PMC6618161 DOI: 10.1002/jbmr.3691] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 01/22/2019] [Accepted: 01/26/2019] [Indexed: 12/25/2022]
Abstract
Osteoporosis is characterized by low bone mineral density (BMD) and fragility fracture and affects over 200 million people worldwide. Bone quality describes the material properties that contribute to strength independently of BMD, and its quantitative analysis is a major priority in osteoporosis research. Tissue mineralization is a fundamental process requiring calcium and phosphate transporters. Here we identify impaired bone quality and strength in Slc20a2-/- mice lacking the phosphate transporter SLC20A2. Juveniles had abnormal endochondral and intramembranous ossification, decreased mineral accrual, and short stature. Adults exhibited only small reductions in bone mass and mineralization but a profound impairment of bone strength. Bone quality was severely impaired in Slc20a2-/- mice: yield load (-2.3 SD), maximum load (-1.7 SD), and stiffness (-2.7 SD) were all below values predicted from their bone mineral content as determined in a cohort of 320 wild-type controls. These studies identify Slc20a2 as a physiological regulator of tissue mineralization and highlight its critical role in the determination of bone quality and strength. © 2019 The Authors. Journal of Bone and Mineral Research Published by Wiley Periodicals Inc.
Collapse
Affiliation(s)
- Sarah Beck‐Cormier
- INSERM, UMR 1229, Regenerative Medicine and Skeleton (RMeS), Université de Nantes, École Nationale Vétérinaire, Agroalimentaire et de l'AlimentationNantes‐Atlantique (ONIRIS)NantesFrance
- Université de NantesUnité de Formation et de Recherche (UFR) OdontologieNantesFrance
| | | | - John G Logan
- Molecular Endocrinology LaboratoryDepartment of MedicineImperial College LondonLondonUK
| | | | - Laure Merametdjian
- INSERM, UMR 1229, Regenerative Medicine and Skeleton (RMeS), Université de Nantes, École Nationale Vétérinaire, Agroalimentaire et de l'AlimentationNantes‐Atlantique (ONIRIS)NantesFrance
- Université de NantesUnité de Formation et de Recherche (UFR) OdontologieNantesFrance
- Centre Hospitalier Universitaire (CHU) NantesPôles Hospitalo‐Universitaires (PHU4) ‐ Ostéo‐articulaire ‐ Tête et Cou ‐ Odontologie ‐ Neurochirurgie ‐ Neuro‐traumatologie (OTONN)NantesFrance
| | - Victoria D Leitch
- Molecular Endocrinology LaboratoryDepartment of MedicineImperial College LondonLondonUK
| | - Natalie C Butterfield
- Molecular Endocrinology LaboratoryDepartment of MedicineImperial College LondonLondonUK
| | - Hayley J Protheroe
- Molecular Endocrinology LaboratoryDepartment of MedicineImperial College LondonLondonUK
| | - Peter I Croucher
- The Garvan Institute of Medical ResearchSydneyNSWAustralia
- St Vincent's Clinical School, Faculty of MedicineUniversity of New South Wales (UNSW) AustraliaSydneyNSWAustralia
| | - Paul A Baldock
- The Garvan Institute of Medical ResearchSydneyNSWAustralia
- St Vincent's Clinical School, Faculty of MedicineUniversity of New South Wales (UNSW) AustraliaSydneyNSWAustralia
| | | | - Yves Maugars
- INSERM, UMR 1229, Regenerative Medicine and Skeleton (RMeS), Université de Nantes, École Nationale Vétérinaire, Agroalimentaire et de l'AlimentationNantes‐Atlantique (ONIRIS)NantesFrance
- Centre Hospitalier Universitaire (CHU) NantesPôles Hospitalo‐Universitaires (PHU4) ‐ Ostéo‐articulaire ‐ Tête et Cou ‐ Odontologie ‐ Neurochirurgie ‐ Neuro‐traumatologie (OTONN)NantesFrance
| | - Gael Nicolas
- INSERM U1245Université de Rouen Normandie (UNIROUEN)RouenFrance
- Department of GeneticsRouen University HospitalRouenFrance
- Centre National de Référence pour les Malades Alzheimer Jeunes (CNR‐MAJ)Normandy Center for Genomic and Personalized MedicineRouenFrance
| | | | | | - Nicolas Magne
- Department of NeuroradiologyRouen University HospitalRouenFrance
| | | | - Nina Bon
- INSERM, UMR 1229, Regenerative Medicine and Skeleton (RMeS), Université de Nantes, École Nationale Vétérinaire, Agroalimentaire et de l'AlimentationNantes‐Atlantique (ONIRIS)NantesFrance
- Université de NantesUnité de Formation et de Recherche (UFR) OdontologieNantesFrance
| | - Sophie Sourice
- INSERM, UMR 1229, Regenerative Medicine and Skeleton (RMeS), Université de Nantes, École Nationale Vétérinaire, Agroalimentaire et de l'AlimentationNantes‐Atlantique (ONIRIS)NantesFrance
- Université de NantesUnité de Formation et de Recherche (UFR) OdontologieNantesFrance
| | - Jérôme Guicheux
- INSERM, UMR 1229, Regenerative Medicine and Skeleton (RMeS), Université de Nantes, École Nationale Vétérinaire, Agroalimentaire et de l'AlimentationNantes‐Atlantique (ONIRIS)NantesFrance
- Université de NantesUnité de Formation et de Recherche (UFR) OdontologieNantesFrance
- Centre Hospitalier Universitaire (CHU) NantesPôles Hospitalo‐Universitaires (PHU4) ‐ Ostéo‐articulaire ‐ Tête et Cou ‐ Odontologie ‐ Neurochirurgie ‐ Neuro‐traumatologie (OTONN)NantesFrance
| | - Laurent Beck
- INSERM, UMR 1229, Regenerative Medicine and Skeleton (RMeS), Université de Nantes, École Nationale Vétérinaire, Agroalimentaire et de l'AlimentationNantes‐Atlantique (ONIRIS)NantesFrance
- Université de NantesUnité de Formation et de Recherche (UFR) OdontologieNantesFrance
| | - Graham R Williams
- Molecular Endocrinology LaboratoryDepartment of MedicineImperial College LondonLondonUK
| | - J H Duncan Bassett
- Molecular Endocrinology LaboratoryDepartment of MedicineImperial College LondonLondonUK
| |
Collapse
|
26
|
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.
Collapse
|
27
|
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.
Collapse
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
| |
Collapse
|
28
|
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.
Collapse
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
| |
Collapse
|
29
|
Mice Knocked Out for the Primary Brain Calcification–Associated Gene Slc20a2 Show Unimpaired Prenatal Survival but Retarded Growth and Nodules in the Brain that Grow and Calcify Over Time. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:1865-1881. [DOI: 10.1016/j.ajpath.2018.04.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 03/30/2018] [Accepted: 04/19/2018] [Indexed: 12/17/2022]
|
30
|
Bon N, Frangi G, Sourice S, Guicheux J, Beck-Cormier S, Beck L. Phosphate-dependent FGF23 secretion is modulated by PiT2/Slc20a2. Mol Metab 2018; 11:197-204. [PMID: 29551636 PMCID: PMC6001877 DOI: 10.1016/j.molmet.2018.02.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 02/12/2018] [Accepted: 02/15/2018] [Indexed: 12/19/2022] Open
Abstract
OBJECTIVE The canonical role of the bone-derived fibroblast growth factor 23 (Fgf23) is to regulate the serum inorganic phosphate (Pi) level. As part of a feedback loop, serum Pi levels control Fgf23 secretion through undefined mechanisms. We recently showed in vitro that the two high-affinity Na+-Pi co-transporters PiT1/Slc20a1 and PiT2/Slc20a2 were required for mediating Pi-dependent signaling. Here, we addressed the contribution of PiT1 and PiT2 to the regulation of Fgf23 secretion. METHODS To this aim, we used PiT2 KO and DMP1Cre; PiT1lox/lox fed Pi-modified diets, as well as ex vivo isolated long bone shafts. Fgf23 secretion and expression of Pi homeostasis-related genes were assessed. RESULTS In vivo, PiT2 KO mice responded inappropriately to low-Pi diets, displaying abnormally normal serum levels of intact Fgf23. Despite the high iFgf23 level, serum Pi levels remained unaffected, an effect that may relate to lower αKlotho expression in the kidney. Moreover, consistent with a role of PiT2 as a possible endocrine Pi sensor, the iFGF23/cFGF23 ratios were suppressed in PiT2 KO mice, irrespective of the Pi loads. While deletion of PiT1 in osteocytes using the DMP1-Cre mice was inefficient, adenovirus-mediated deletion of PiT1 in isolated long bone shafts suggested that PiT1 does not contribute to Pi-dependent regulation of Fgf23 secretion. In contrast, using isolated bone shafts from PiT2 KO mice, we showed that PiT2 was necessary for the appropriate Pi-dependent secretion of Fgf23, independently from possible endocrine regulatory loops. CONCLUSIONS Our data provide initial mechanistic insights underlying the Pi-dependent regulation of Fgf23 secretion in identifying PiT2 as a potential player in this process, at least in high Pi conditions. Targeting PiT2, therefore, could improve excess FGF23 in hyperphosphatemic conditions such as chronic kidney disease.
Collapse
Affiliation(s)
- Nina Bon
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France
| | - Giulia Frangi
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France
| | - Sophie Sourice
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France
| | - Jérôme Guicheux
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France; CHU Nantes, PHU 4 OTONN, Nantes, F-44042, France
| | - Sarah Beck-Cormier
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France
| | - Laurent Beck
- Inserm, UMR 1229, RMeS, Regenerative Medicine and Skeleton, Université de Nantes, ONIRIS, Nantes, F-44042, France; Université de Nantes, UFR Odontologie, Nantes, F-44042, France.
| |
Collapse
|
31
|
Insights into phytase-containing transgenic Lemna minor (L.) as a novel feed additive. Transgenic Res 2018; 27:211-224. [DOI: 10.1007/s11248-018-0068-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 03/16/2018] [Indexed: 10/17/2022]
|
32
|
Greenwood AD, Ishida Y, O'Brien SP, Roca AL, Eiden MV. Transmission, Evolution, and Endogenization: Lessons Learned from Recent Retroviral Invasions. Microbiol Mol Biol Rev 2018; 82:e00044-17. [PMID: 29237726 PMCID: PMC5813887 DOI: 10.1128/mmbr.00044-17] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Viruses of the subfamily Orthoretrovirinae are defined by the ability to reverse transcribe an RNA genome into DNA that integrates into the host cell genome during the intracellular virus life cycle. Exogenous retroviruses (XRVs) are horizontally transmitted between host individuals, with disease outcome depending on interactions between the retrovirus and the host organism. When retroviruses infect germ line cells of the host, they may become endogenous retroviruses (ERVs), which are permanent elements in the host germ line that are subject to vertical transmission. These ERVs sometimes remain infectious and can themselves give rise to XRVs. This review integrates recent developments in the phylogenetic classification of retroviruses and the identification of retroviral receptors to elucidate the origins and evolution of XRVs and ERVs. We consider whether ERVs may recurrently pressure XRVs to shift receptor usage to sidestep ERV interference. We discuss how related retroviruses undergo alternative fates in different host lineages after endogenization, with koala retrovirus (KoRV) receiving notable interest as a recent invader of its host germ line. KoRV is heritable but also infectious, which provides insights into the early stages of germ line invasions as well as XRV generation from ERVs. The relationship of KoRV to primate and other retroviruses is placed in the context of host biogeography and the potential role of bats and rodents as vectors for interspecies viral transmission. Combining studies of extant XRVs and "fossil" endogenous retroviruses in koalas and other Australasian species has broadened our understanding of the evolution of retroviruses and host-retrovirus interactions.
Collapse
Affiliation(s)
- Alex D Greenwood
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research (IZW) in the Forschungsverbund Berlin e.V., Berlin, Germany
| | - Yasuko Ishida
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Sean P O'Brien
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, USA
| | - Alfred L Roca
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Maribeth V Eiden
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research (IZW) in the Forschungsverbund Berlin e.V., Berlin, Germany
| |
Collapse
|
33
|
Simm F, Griesbeck A, Choukair D, Weiß B, Paramasivam N, Klammt J, Schlesner M, Wiemann S, Martinez C, Hoffmann GF, Pfäffle RW, Bettendorf M, Rappold GA. Identification of SLC20A1 and SLC15A4 among other genes as potential risk factors for combined pituitary hormone deficiency. Genet Med 2017; 20:728-736. [DOI: 10.1038/gim.2017.165] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 08/14/2017] [Indexed: 12/25/2022] Open
|
34
|
Merametdjian L, Beck-Cormier S, Bon N, Couasnay G, Sourice S, Guicheux J, Gaucher C, Beck L. Expression of Phosphate Transporters during Dental Mineralization. J Dent Res 2017; 97:209-217. [PMID: 28892649 DOI: 10.1177/0022034517729811] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The importance of phosphate (Pi) as an essential component of hydroxyapatite crystals suggests a key role for membrane proteins controlling Pi uptake during mineralization in the tooth. To clarify the involvement of the currently known Pi transporters (Slc17a1, Slc34a1, Slc34a2, Slc34a3, Slc20a1, Slc20a2, and Xpr1) during tooth development and mineralization, we determined their spatiotemporal expression in murine tooth germs from embryonic day 14.5 to postnatal day 15 and in human dental samples from Nolla stages 6 to 9. Using real-time polymerase chain reaction, in situ hybridization, immunohistochemistry, and X-gal staining, we showed that the expression of Slc17a1, Slc34a1, and Slc34a3 in tooth germs from C57BL/6 mice were very low. In contrast, Slc34a2, Slc20a1, Slc20a2, and Xpr1 were highly expressed, mostly during the postnatal stages. The expression of Slc20a2 was 2- to 10-fold higher than the other transporters. Comparable results were obtained in human tooth germs. In mice, Slc34a2 and Slc20a1 were predominantly expressed in ameloblasts but not odontoblasts, while Slc20a2 was detected neither in ameloblasts nor in odontoblasts. Rather, Slc20a2 was highly expressed in the stratum intermedium and the subodontoblastic cell layer. Although Slc20a2 knockout mice did not show enamel defects, mutant mice showed a disrupted dentin mineralization, displaying unmerged calcospherites at the mineralization front. This latter phenotypical finding raises the possibility that Slc20a2 may play an indirect role in regulating the extracellular Pi availability for mineralizing cells rather than a direct role in mediating Pi transport through mineralizing plasma cell membranes. By documenting the spatiotemporal expression of Pi transporters in the tooth, our data support the possibility that the currently known Pi transporters may be dispensable for the initiation of dental mineralization and may rather be involved later during the tooth mineralization scheme.
Collapse
Affiliation(s)
- L Merametdjian
- 1 INSERM, U1229, RMeS, Nantes, France.,2 Université de Nantes, UMR_S1229, UFR Odontologie, Nantes, France.,3 CHU Nantes, PHU 4 OTONN, Nantes, France
| | - S Beck-Cormier
- 1 INSERM, U1229, RMeS, Nantes, France.,2 Université de Nantes, UMR_S1229, UFR Odontologie, Nantes, France
| | - N Bon
- 1 INSERM, U1229, RMeS, Nantes, France.,2 Université de Nantes, UMR_S1229, UFR Odontologie, Nantes, France
| | - G Couasnay
- 1 INSERM, U1229, RMeS, Nantes, France.,2 Université de Nantes, UMR_S1229, UFR Odontologie, Nantes, France
| | - S Sourice
- 1 INSERM, U1229, RMeS, Nantes, France.,2 Université de Nantes, UMR_S1229, UFR Odontologie, Nantes, France
| | - J Guicheux
- 1 INSERM, U1229, RMeS, Nantes, France.,2 Université de Nantes, UMR_S1229, UFR Odontologie, Nantes, France.,3 CHU Nantes, PHU 4 OTONN, Nantes, France
| | - C Gaucher
- 4 Dental School, University Paris Descartes, PRES Sorbonne Paris Cité, Montrouge, France.,5 AP-HP, Odontology Department, Hôpital Albert Chenevier, GHHM, Créteil, France
| | - L Beck
- 1 INSERM, U1229, RMeS, Nantes, France.,2 Université de Nantes, UMR_S1229, UFR Odontologie, Nantes, France
| |
Collapse
|
35
|
Lacruz RS, Habelitz S, Wright JT, Paine ML. DENTAL ENAMEL FORMATION AND IMPLICATIONS FOR ORAL HEALTH AND DISEASE. Physiol Rev 2017; 97:939-993. [PMID: 28468833 DOI: 10.1152/physrev.00030.2016] [Citation(s) in RCA: 214] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 01/10/2017] [Accepted: 01/10/2017] [Indexed: 12/16/2022] Open
Abstract
Dental enamel is the hardest and most mineralized tissue in extinct and extant vertebrate species and provides maximum durability that allows teeth to function as weapons and/or tools as well as for food processing. Enamel development and mineralization is an intricate process tightly regulated by cells of the enamel organ called ameloblasts. These heavily polarized cells form a monolayer around the developing enamel tissue and move as a single forming front in specified directions as they lay down a proteinaceous matrix that serves as a template for crystal growth. Ameloblasts maintain intercellular connections creating a semi-permeable barrier that at one end (basal/proximal) receives nutrients and ions from blood vessels, and at the opposite end (secretory/apical/distal) forms extracellular crystals within specified pH conditions. In this unique environment, ameloblasts orchestrate crystal growth via multiple cellular activities including modulating the transport of minerals and ions, pH regulation, proteolysis, and endocytosis. In many vertebrates, the bulk of the enamel tissue volume is first formed and subsequently mineralized by these same cells as they retransform their morphology and function. Cell death by apoptosis and regression are the fates of many ameloblasts following enamel maturation, and what cells remain of the enamel organ are shed during tooth eruption, or are incorporated into the tooth's epithelial attachment to the oral gingiva. In this review, we examine key aspects of dental enamel formation, from its developmental genesis to the ever-increasing wealth of data on the mechanisms mediating ionic transport, as well as the clinical outcomes resulting from abnormal ameloblast function.
Collapse
Affiliation(s)
- Rodrigo S Lacruz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - Stefan Habelitz
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - J Timothy Wright
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| | - Michael L Paine
- Department of Basic Science and Craniofacial Biology, College of Dentistry, New York University, New York, New York; Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, San Francisco, California; Department of Pediatric Dentistry, School of Dentistry, University of North Carolina, Chapel Hill, North Carolina; Herman Ostrow School of Dentistry, Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California
| |
Collapse
|
36
|
Castella B, Kopecka J, Sciancalepore P, Mandili G, Foglietta M, Mitro N, Caruso D, Novelli F, Riganti C, Massaia M. The ATP-binding cassette transporter A1 regulates phosphoantigen release and Vγ9Vδ2 T cell activation by dendritic cells. Nat Commun 2017; 8:15663. [PMID: 28580927 PMCID: PMC5465356 DOI: 10.1038/ncomms15663] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 04/19/2017] [Indexed: 12/21/2022] Open
Abstract
Vγ9Vδ2 T cells are activated by phosphoantigens, such as isopentenyl pyrophosphate (IPP), which is generated in the mevalonate pathway of antigen-presenting cells. IPP is released in the extracellular microenvironment via unknown mechanisms. Here we show that the ATP-binding cassette transporter A1 (ABCA1) mediates extracellular IPP release from dendritic cells (DC) in cooperation with apolipoprotein A-I (apoA-I) and butyrophilin-3A1. IPP concentrations in the supernatants are sufficient to induce Vγ9Vδ2 T cell proliferation after DC mevalonate pathway inhibition with zoledronic acid (ZA). ZA treatment increases ABCA1 and apoA-I expression via IPP-dependent LXRα nuclear translocation and PI3K/Akt/mTOR pathway inhibition. These results close the mechanistic gap in our understanding of extracellular IPP release from DC and provide a framework to fine-tune Vγ9Vδ2 T cell activation via mevalonate and PI3K/Akt/mTOR pathway modulation. γδT cells are activated by phosphoantigens, and ABCA1 is involved in cholesterol transport. Here the authors link these ideas to show that ABCA1, apoA-I and BTN3A1 regulate extracellular phosphoantigen release by dendritic cells, and implicate ABCA1 in mevalonate-mediated activation of Vγ9Vδ2 T cells.
Collapse
Affiliation(s)
- Barbara Castella
- Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Università degli Studi di Torino, Via Nizza 52, Torino 10126, Italy.,Centro di Ricerca in Medicina Sperimentale (CeRMS), AOU Città della Salute e della Scienza di Torino, Via Santena 5, Torino 10126, Italy
| | - Joanna Kopecka
- Dipartimento di Oncologia, Università degli Studi di Torino, Via Santena 5/bis, Torino 10126, Italy
| | - Patrizia Sciancalepore
- Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Università degli Studi di Torino, Via Nizza 52, Torino 10126, Italy.,Centro di Ricerca in Medicina Sperimentale (CeRMS), AOU Città della Salute e della Scienza di Torino, Via Santena 5, Torino 10126, Italy
| | - Giorgia Mandili
- Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Università degli Studi di Torino, Via Nizza 52, Torino 10126, Italy.,Centro Interdipartimentale di Ricerca per le Biotecnologie Molecolari (CIRBM), Via Nizza 52, Torino 10126, Italy
| | - Myriam Foglietta
- Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Università degli Studi di Torino, Via Nizza 52, Torino 10126, Italy.,Centro di Ricerca in Medicina Sperimentale (CeRMS), AOU Città della Salute e della Scienza di Torino, Via Santena 5, Torino 10126, Italy
| | - Nico Mitro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Via Balzaretti 9, Milano 20133, Italy
| | - Donatella Caruso
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Via Balzaretti 9, Milano 20133, Italy
| | - Francesco Novelli
- Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Università degli Studi di Torino, Via Nizza 52, Torino 10126, Italy.,Centro Interdipartimentale di Ricerca per le Biotecnologie Molecolari (CIRBM), Via Nizza 52, Torino 10126, Italy
| | - Chiara Riganti
- Centro di Ricerca in Medicina Sperimentale (CeRMS), AOU Città della Salute e della Scienza di Torino, Via Santena 5, Torino 10126, Italy.,Dipartimento di Oncologia, Università degli Studi di Torino, Via Santena 5/bis, Torino 10126, Italy
| | - Massimo Massaia
- Dipartimento di Biotecnologie Molecolari e Scienze della Salute, Università degli Studi di Torino, Via Nizza 52, Torino 10126, Italy.,Centro di Ricerca in Medicina Sperimentale (CeRMS), AOU Città della Salute e della Scienza di Torino, Via Santena 5, Torino 10126, Italy.,Centro Interdipartimentale di Ricerca per le Biotecnologie Molecolari (CIRBM), Via Nizza 52, Torino 10126, Italy.,SC. Ematologia, AO S. Croce e Carle, Via Michele Coppino 26, Cuneo 12100, Italy
| |
Collapse
|
37
|
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
|
38
|
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.
Collapse
|
39
|
Linking Gene Expression in the Intestine to Production of Gametes Through the Phosphate Transporter PITR-1 in Caenorhabditis elegans. Genetics 2016; 204:153-62. [PMID: 27449055 PMCID: PMC5012382 DOI: 10.1534/genetics.116.188532] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 07/12/2016] [Indexed: 12/31/2022] Open
Abstract
Inorganic phosphate is an essential mineral for both prokaryotic and eukaryotic cell metabolism and structure. Its uptake into the cell is mediated by membrane-bound transporters and coupled to Na+ transport. Mammalian sodium-dependent Pi cotransporters have been grouped into three families NaPi-I, NaPi-II, and NaPi-III. Despite being discovered more than two decades ago, very little is known about requirements for NaPi-III transporters in vivo, in the context of intact animal models. Here we find that impaired function of the Caenorhabditis elegans NaPi-III transporter, pitr-1, results in decreased brood size and dramatically increased expression of vitellogenin by the worm intestine. Unexpectedly, we found that the effects of pitr-1 mutation on vitellogenin expression in the intestine could only be rescued by expression of pitr-1 in the germline, and not by expression of pitr-1 in the intestine itself. Our results indicate the existence of a signal from the germline that regulates gene expression in the intestine, perhaps linking nutrient export from the intestine to production of gametes by the germline.
Collapse
|
40
|
Pesta DH, Tsirigotis DN, Befroy DE, Caballero D, Jurczak MJ, Rahimi Y, Cline GW, Dufour S, Birkenfeld AL, Rothman DL, Carpenter TO, Insogna K, Petersen KF, Bergwitz C, Shulman GI. Hypophosphatemia promotes lower rates of muscle ATP synthesis. FASEB J 2016; 30:3378-3387. [PMID: 27338702 PMCID: PMC5024687 DOI: 10.1096/fj.201600473r] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 06/14/2016] [Indexed: 12/13/2022]
Abstract
Hypophosphatemia can lead to muscle weakness and respiratory and heart failure, but the mechanism is unknown. To address this question, we noninvasively assessed rates of muscle ATP synthesis in hypophosphatemic mice by using in vivo saturation transfer [31P]-magnetic resonance spectroscopy. By using this approach, we found that basal and insulin-stimulated rates of muscle ATP synthetic flux (VATP) and plasma inorganic phosphate (Pi) were reduced by 50% in mice with diet-induced hypophosphatemia as well as in sodium-dependent Pi transporter solute carrier family 34, member 1 (NaPi2a)-knockout (NaPi2a-/-) mice compared with their wild-type littermate controls. Rates of VATP normalized in both hypophosphatemic groups after restoring plasma Pi concentrations. Furthermore, VATP was directly related to cellular and mitochondrial Pi uptake in L6 and RC13 rodent myocytes and isolated muscle mitochondria. Similar findings were observed in a patient with chronic hypophosphatemia as a result of a mutation in SLC34A3 who had a 50% reduction in both serum Pi content and muscle VATP After oral Pi repletion and normalization of serum Pi levels, muscle VATP completely normalized in the patient. Taken together, these data support the hypothesis that decreased muscle ATP synthesis, in part, may be caused by low blood Pi concentrations, which may explain some aspects of muscle weakness observed in patients with hypophosphatemia.-Pesta, D. H., Tsirigotis, D. N., Befroy, D. E., Caballero, D., Jurczak, M. J., Rahimi, Y., Cline, G. W., Dufour, S., Birkenfeld, A. L., Rothman, D. L., Carpenter, T. O., Insogna, K., Petersen, K. F., Bergwitz, C., Shulman, G. I. Hypophosphatemia promotes lower rates of muscle ATP synthesis.
Collapse
Affiliation(s)
- Dominik H Pesta
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Dimitrios N Tsirigotis
- Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Douglas E Befroy
- Department of Radiology and Biomedical Engineering, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Daniel Caballero
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Michael J Jurczak
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Yasmeen Rahimi
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Gary W Cline
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Sylvie Dufour
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Andreas L Birkenfeld
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Douglas L Rothman
- Department of Radiology and Biomedical Engineering, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Thomas O Carpenter
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut, USA; and
| | - Karl Insogna
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Kitt Falk Petersen
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Clemens Bergwitz
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Gerald I Shulman
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA; Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA; Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA; Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
41
|
Yadav MC, Bottini M, Cory E, Bhattacharya K, Kuss P, Narisawa S, Sah RL, Beck L, Fadeel B, Farquharson C, Millán JL. Skeletal Mineralization Deficits and Impaired Biogenesis and Function of Chondrocyte-Derived Matrix Vesicles in Phospho1(-/-) and Phospho1/Pi t1 Double-Knockout Mice. J Bone Miner Res 2016; 31:1275-86. [PMID: 26773408 PMCID: PMC4891278 DOI: 10.1002/jbmr.2790] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 01/05/2016] [Accepted: 01/13/2016] [Indexed: 11/10/2022]
Abstract
We have previously shown that ablation of either the Phospho1 or Alpl gene, encoding PHOSPHO1 and tissue-nonspecific alkaline phosphatase (TNAP) respectively, lead to hyperosteoidosis, but that their chondrocyte-derived and osteoblast-derived matrix vesicles (MVs) are able to initiate mineralization. In contrast, the double ablation of Phospho1 and Alpl completely abolish initiation and progression of skeletal mineralization. We argued that MVs initiate mineralization by a dual mechanism: PHOSPHO1-mediated intravesicular generation of inorganic phosphate (Pi ) and phosphate transporter-mediated influx of Pi . To test this hypothesis, we generated mice with col2a1-driven Cre-mediated ablation of Slc20a1, hereafter referred to as Pi t1, alone or in combination with a Phospho1 gene deletion. Pi t1(col2/col2) mice did not show any major phenotypic abnormalities, whereas severe skeletal deformities were observed in the [Phospho1(-/-) ; Pi t1(col2/col2) ] double knockout mice that were more pronounced than those observed in the Phospho1(-/-) mice. Histological analysis of [Phospho1(-/-) ; Pi t1(col2/col2) ] bones showed growth plate abnormalities with a shorter hypertrophic chondrocyte zone and extensive hyperosteoidosis. The [Phospho1(-/-) ; Pi t1(col2/col2) ] skeleton displayed significant decreases in BV/TV%, trabecular number, and bone mineral density, as well as decreased stiffness, decreased strength, and increased postyield deflection compared to Phospho1(-/-) mice. Using atomic force microscopy we found that ∼80% of [Phospho1(-/-) ; Pi t1(col2/col2) ] MVs were devoid of mineral in comparison to ∼50% for the Phospho1(-/-) MVs and ∼25% for the WT and Pi t1(col2/col2) MVs. We also found a significant decrease in the number of MVs produced by both Phospho1(-/-) and [Phospho1(-/-) ; Pi t1(col2/col2) ] chondrocytes. These data support the involvement of phosphate transporter 1, hereafter referred to as Pi T-1, in the initiation of skeletal mineralization and provide compelling evidence that PHOSPHO1 function is involved in MV biogenesis. © 2016 American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Manisha C Yadav
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Massimo Bottini
- Department of Experimental Medicine and Surgery, University of Rome Tor Vergata, Rome, Italy.,Inflammatory and Infectious Disease Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Esther Cory
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Kunal Bhattacharya
- Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Pia Kuss
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Sonoko Narisawa
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Robert L Sah
- Department of Bioengineering, University of California San Diego, La Jolla, CA, USA
| | - Laurent Beck
- INSERM U791, Centre for Osteoarticular and Dental Tissue Engineering (LIOAD), Nantes, Cedex, France
| | - Bengt Fadeel
- Division of Molecular Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Colin Farquharson
- The Roslin Institute, The University of Edinburgh, Midlothian, Scotland, UK
| | - José Luis Millán
- Sanford Children's Health Research Center, Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| |
Collapse
|
42
|
Keasey MP, Lemos RR, Hagg T, Oliveira JRM. Vitamin-D receptor agonist calcitriol reduces calcification in vitro through selective upregulation of SLC20A2 but not SLC20A1 or XPR1. Sci Rep 2016; 6:25802. [PMID: 27184385 PMCID: PMC4868979 DOI: 10.1038/srep25802] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 04/21/2016] [Indexed: 01/30/2023] Open
Abstract
Vitamin D deficiency (hypovitaminosis D) causes osteomalacia and poor long bone mineralization. In apparent contrast, hypovitaminosis D has been reported in patients with primary brain calcifications (“Fahr’s disease”). We evaluated the expression of two phosphate transporters which we have found to be associated with primary brain calcification (SLC20A2, whose promoter has a predicted vitamin D receptor binding site, and XPR1), and one unassociated (SLC20A1), in an in vitro model of calcification. Expression of all three genes was significantly decreased in calcifying human bone osteosarcoma (SaOs-2) cells. Further, we confirmed that vitamin D (calcitriol) reduced calcification as measured by Alizarin Red staining. Cells incubated with calcitriol under calcifying conditions specifically maintained expression of the phosphate transporter SLC20A2 at higher levels relative to controls, by RT-qPCR. Neither SLC20A1 nor XPR1 were affected by calcitriol treatment and remained suppressed. Critically, knockdown of SLC20A2 gene and protein with CRISPR technology in SaOs2 cells significantly ablated vitamin D mediated inhibition of calcification. This study elucidates the mechanistic importance of SLC20A2 in suppressing the calcification process. It also suggests that vitamin D might be used to regulate SLC20A2 gene expression, as well as reduce brain calcification which occurs in Fahr’s disease and normal aging.
Collapse
Affiliation(s)
- M P Keasey
- Department of Biomedical Sciences - Quillen College of Medicine, East Tennessee State University, Johnson City, USA.,Keizo Asami Laboratory - Federal University of Pernambuco, Recife-PE, Brazil
| | - R R Lemos
- Keizo Asami Laboratory - Federal University of Pernambuco, Recife-PE, Brazil
| | - T Hagg
- Department of Biomedical Sciences - Quillen College of Medicine, East Tennessee State University, Johnson City, USA
| | - J R M Oliveira
- Keizo Asami Laboratory - Federal University of Pernambuco, Recife-PE, Brazil.,Neuropsychiatry Department - Federal University of Pernambuco, Recife-PE, Brazil
| |
Collapse
|
43
|
Wallingford MC, Gammill HS, Giachelli CM. Slc20a2 deficiency results in fetal growth restriction and placental calcification associated with thickened basement membranes and novel CD13 and lamininα1 expressing cells. Reprod Biol 2016; 16:13-26. [PMID: 26952749 DOI: 10.1016/j.repbio.2015.12.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 12/28/2015] [Accepted: 12/29/2015] [Indexed: 10/22/2022]
Abstract
The essential nutrient phosphorus must be taken up by the mammalian embryo during gestation. The mechanism(s) and key proteins responsible for maternal to fetal phosphate transport have not been identified. Established parameters for placental phosphate transport match those of the type III phosphate transporters, Slc20a1 and Slc20a2. Both members are expressed in human placenta, and their altered expression is linked to preeclampsia. In this study, we tested the hypothesis that Slc20a2 is required for placental function. Indeed, complete deficiency of Slc20a2 in either the maternal or embryonic placental compartment results in fetal growth restriction. We found that Slc20a2 null mice can reproduce, but are subviable; ∼50% are lost prior to weaning age. We also observed that 23% of Slc20a2 deficient females develop pregnancy complications at full term, with tremors and placental abnormalities including abnormal vascular structure, increased basement membrane deposition, abundant calcification, and accumulation of novel CD13 and lamininα1 positive cells. Together these data support that Slc20a2 deficiency impacts both maternal and neonatal health, and Slc20a2 is required for normal placental function. In humans, decreased levels of placental Slc20a1 and Slc20a2 have been correlated with early onset preeclampsia, a disorder that can manifest from placental dysfunction. In addition, preterm placental calcification has been associated with poor pregnancy outcomes. We surveyed placental calcification in human preeclamptic placenta samples, and detected basement membrane-associated placental calcification as well as a comparable lamininα1 positive cell type, indicating that similar mechanisms may underlie both human and mouse placental calcification.
Collapse
Affiliation(s)
- Mary C Wallingford
- University of Washington, Department of Bioengineering, 3720 15th Ave NE, Seattle, WA 98195, USA.
| | - Hilary S Gammill
- University of Washington, Department of Obstetrics and Gynecology, Seattle, WA 98195, USA.
| | - Cecilia M Giachelli
- University of Washington, Department of Bioengineering, 3720 15th Ave NE, Seattle, WA 98195, USA.
| |
Collapse
|
44
|
Villa-Bellosta R. Vascular Calcification Revisited: A New Perspective for Phosphate Transport. Curr Cardiol Rev 2015; 11:341-351. [PMID: 26242187 PMCID: PMC4774640 DOI: 10.2174/1573403x11666150805120505] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 03/10/2015] [Accepted: 03/11/2015] [Indexed: 12/30/2022] Open
Abstract
Elevated serum phosphorus has emerged as a key risk factor for pathologic calcification of
cardiovascular structures, or vascular calcification (VC). To prevent the formation of calciumphosphate
deposits (CPD), the body uses adenosine-5’-triphosphate (ATP) to synthesize inhibitors of
calcification, including proteins and inhibitors of low molecular weight. Extracellular pyrophosphate
(PPi) is a potent inhibitor of VC, which is produced during extracellular hydrolysis of ATP. Loss of
function in the enzymes and transporters that are involved in the cycle of extracellular ATP, including
Pi transporters, leads to excessive deposition of calcium-phosphate salts. Treatment of hyperphosphatemia
with Pi-binders and Injection of exogenous PPi are the effective treatments to prevent CPD
in the aortic wall. The role of sodium phosphate cotransporters in ectopic calcification is contradictory and not well defined,
but their important role in the control of intracellular Pi levels and the synthesis of ATP make them an important
target to study.
Collapse
|
45
|
Peric D, Barragan I, Giraud-Triboult K, Egesipe AL, Meyniel-Schicklin L, Cousin C, Lotteau V, Petit V, Touhami J, Battini JL, Sitbon M, Pinset C, Ingelman-Sundberg M, Laustriat D, Peschanski M. Cytostatic Effect of Repeated Exposure to Simvastatin: A Mechanism for Chronic Myotoxicity Revealed by the Use of Mesodermal Progenitors Derived from Human Pluripotent Stem Cells. Stem Cells 2015; 33:2936-48. [DOI: 10.1002/stem.2107] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 06/06/2015] [Indexed: 12/13/2022]
Affiliation(s)
- Delphine Peric
- INSERM U861; I-Stem, Evry Cedex Paris France
- UEVE U861; I-Stem, Evry Cedex Paris France
| | - Isabel Barragan
- Department of Physiology and Pharmacology; Karolinska Institute; Stockholm Sweden
| | | | - Anne-Laure Egesipe
- INSERM U861; I-Stem, Evry Cedex Paris France
- UEVE U861; I-Stem, Evry Cedex Paris France
| | - Laurène Meyniel-Schicklin
- CIRI, International Center for Infectiology Research; Université de Lyon; Lyon France
- INSERM U1111; Lyon France
| | | | - Vincent Lotteau
- CIRI, International Center for Infectiology Research; Université de Lyon; Lyon France
- INSERM U1111; Lyon France
| | | | - Jawida Touhami
- Institut de Génétique Moléculaire de Montpellier, CNRS, UMR5535; Université de Montpellier; Montpellier France
| | - Jean-Luc Battini
- Institut de Génétique Moléculaire de Montpellier, CNRS, UMR5535; Université de Montpellier; Montpellier France
| | - Marc Sitbon
- Institut de Génétique Moléculaire de Montpellier, CNRS, UMR5535; Université de Montpellier; Montpellier France
| | - Christian Pinset
- INSERM U861; I-Stem, Evry Cedex Paris France
- UEVE U861; I-Stem, Evry Cedex Paris France
| | | | | | - Marc Peschanski
- INSERM U861; I-Stem, Evry Cedex Paris France
- UEVE U861; I-Stem, Evry Cedex Paris France
| |
Collapse
|
46
|
Purfield DC, Bradley DG, Evans RD, Kearney FJ, Berry DP. Genome-wide association study for calving performance using high-density genotypes in dairy and beef cattle. Genet Sel Evol 2015; 47:47. [PMID: 26065883 PMCID: PMC4464877 DOI: 10.1186/s12711-015-0126-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 05/18/2015] [Indexed: 12/02/2022] Open
Abstract
Background Calving difficulty and perinatal mortality are prevalent in modern-day cattle production systems. It is well-established that there is a genetic component to both traits, yet little is known about their underlying genomic architecture, particularly in beef breeds. Therefore, we performed a genome-wide association study using high-density genotypes to elucidate the genomic architecture of these traits and to identify regions of the bovine genome associated with them. Results Genomic regions associated with calving difficulty (direct and maternal) and perinatal mortality were detected using two statistical approaches: (1) single-SNP (single nucleotide polymorphism) regression and (2) a Bayesian approach. Data included high-density genotypes on 770 Holstein-Friesian, 927 Charolais and 963 Limousin bulls. Several novel or previously identified genomic regions were detected but associations differed by breed. For example, two genomic associations, one each on chromosomes 18 and 2 explained 2.49 % and 3.13 % of the genetic variance in direct calving difficulty in the Holstein-Friesian and Charolais populations, respectively. Imputed Holstein-Friesian sequence data was used to refine the genomic regions responsible for significant associations. Several candidate genes on chromosome 18 were identified and four highly significant missense variants were detected within three of these genes (SIGLEC12, CTU1, and ZNF615). Nevertheless, only CTU1 contained a missense variant with a putative impact on direct calving difficulty based on SIFT (0.06) and Polyphen (0.95) scores. Using imputed sequence data, we refined a genomic region on chromosome 4 associated with maternal calving difficulty in the Holstein-Friesian population and found the strongest association with an intronic variant in the PCLO gene. A meta-analysis was performed across the three breeds for each calving performance trait to identify common variants associated with these traits in the three breeds. Our results suggest that a portion of the genetic variation in calving performance is common to all three breeds. Conclusion The genomic architecture of calving performance is complex and mainly influenced by many polymorphisms of small effect. We identified several associations of moderate effect size but the majority were breed-specific, indicating that breed-specific alleles exist for calving performance or that the linkage phase between genotyped allele and causal mutation varies between breeds. Electronic supplementary material The online version of this article (doi:10.1186/s12711-015-0126-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Deirdre C Purfield
- Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Ireland. .,Animal & Grassland Research and Innovation Center, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland.
| | - Daniel G Bradley
- Smurfit Institute of Genetics, University of Dublin, Trinity College, Dublin 2, Ireland.
| | - Ross D Evans
- Irish Cattle Breeding Federation, Bandon, Co. Cork, Ireland.
| | | | - Donagh P Berry
- Animal & Grassland Research and Innovation Center, Teagasc, Moorepark, Fermoy, Co. Cork, Ireland.
| |
Collapse
|
47
|
Sodium-dependent phosphate transporters in osteoclast differentiation and function. PLoS One 2015; 10:e0125104. [PMID: 25910236 PMCID: PMC4409223 DOI: 10.1371/journal.pone.0125104] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/20/2015] [Indexed: 11/19/2022] Open
Abstract
Osteoclasts are multinucleated bone degrading cells. Phosphate is an important constituent of mineralized bone and released in significant quantities during bone resorption. Molecular contributors to phosphate transport during the resorptive activity of osteoclasts have been controversially discussed. This study aimed at deciphering the role of sodium-dependent phosphate transporters during osteoclast differentiation and bone resorption. Our studies reveal RANKL-induced differential expression of sodium-dependent phosphate transport protein IIa (NaPi-IIa) transcript and protein during osteoclast development, but no expression of the closely related NaPi-IIb and NaPi-IIc SLC34 family isoforms. In vitro studies employing NaPi-IIa-deficient osteoclast precursors and mature osteoclasts reveal that NaPi-IIa is dispensable for bone resorption and osteoclast differentiation. These results are supported by the analysis of structural bone parameters by high-resolution microcomputed tomography that yielded no differences between adult NaPi-IIa WT and KO mice. By contrast, both type III sodium-dependent phosphate transporters Pit-1 and Pit-2 were abundantly expressed throughout osteoclast differentiation, indicating that they are the relevant sodium-dependent phosphate transporters in osteoclasts and osteoclast precursors. We conclude that phosphate transporters of the SLC34 family have no role in osteoclast differentiation and function and propose that Pit-dependent phosphate transport could be pivotal for bone resorption and should be addressed in further studies.
Collapse
|
48
|
Abstract
Phosphate is essential for growth and maintenance of the skeleton and for generating high-energy phosphate compounds. Evolutionary adaptation to high dietary phosphorous in humans and other terrestrial vertebrates involves regulated mechanisms assuring the efficient renal elimination of excess phosphate. These mechanisms prominently include PTH, FGF23, and Vitamin D, which directly and indirectly regulate phosphate transport. Disordered phosphate homeostasis is associated with pathologies ranging from kidney stones to kidney failure. Chronic kidney disease results in hyperphosphatemia, an elevated calcium×phosphate product with considerable morbidity and mortality, mostly associated with adverse cardiovascular events. This chapter highlights recent findings and insights regarding the hormonal regulation of renal phosphate transport along with imbalances of phosphate balance due to acquired or inherited diseases states.
Collapse
|
49
|
Chavkin NW, Chia JJ, Crouthamel MH, Giachelli CM. Phosphate uptake-independent signaling functions of the type III sodium-dependent phosphate transporter, PiT-1, in vascular smooth muscle cells. Exp Cell Res 2015; 333:39-48. [PMID: 25684711 DOI: 10.1016/j.yexcr.2015.02.002] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 01/06/2015] [Accepted: 02/06/2015] [Indexed: 12/26/2022]
Abstract
Vascular calcification (VC) is prevalent in chronic kidney disease and elevated serum inorganic phosphate (Pi) is a recognized risk factor. The type III sodium-dependent phosphate transporter, PiT-1, is required for elevated Pi-induced osteochondrogenic differentiation and matrix mineralization in vascular smooth muscle cells (VSMCs). However, the molecular mechanism(s) by which PiT-1 promotes these processes is unclear. In the present study, we confirmed that the Pi concentration required to induce osteochondrogenic differentiation and matrix mineralization of mouse VSMCs was well above that required for maximal Pi uptake, suggesting a signaling function of PiT-1 that was independent of Pi transport. Elevated Pi-induced signaling via ERK1/2 phosphorylation was abrogated in PiT-1 deficient VSMCs, but could be rescued by wild-type (WT) and a Pi transport-deficient PiT-1 mutant. Furthermore, both WT and transport-deficient PiT-1 mutants promoted osteochondrogenic differentiation as measured by decreased SM22α and increased osteopontin mRNA expression. Finally, compared to vector alone, expression of transport-deficient PiT-1 mutants promoted VSMC matrix mineralization, but not to the extent observed with PiT-1 WT. These data suggest that both Pi uptake-dependent and -independent functions of PiT-1 are important for VSMC processes mediating vascular calcification.
Collapse
Affiliation(s)
- Nicholas W Chavkin
- Department of Bioengineering, University of Washington, Box 355061, Foege Hall Seattle, WA 98195, USA
| | - Jia Jun Chia
- Department of Bioengineering, University of Washington, Box 355061, Foege Hall Seattle, WA 98195, USA
| | - Matthew H Crouthamel
- Department of Bioengineering, University of Washington, Box 355061, Foege Hall Seattle, WA 98195, USA
| | - Cecilia M Giachelli
- Department of Bioengineering, University of Washington, Box 355061, Foege Hall Seattle, WA 98195, USA.
| |
Collapse
|
50
|
Yang H, Kim TH, Lee GS, Hong EJ, Jeung EB. Comparing the expression patterns of placental magnesium/phosphorus-transporting channels between healthy and preeclamptic pregnancies. Mol Reprod Dev 2014; 81:851-60. [PMID: 25155868 DOI: 10.1002/mrd.22353] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 06/13/2014] [Indexed: 11/08/2022]
Abstract
Preeclampsia is a pregnancy-specific disorder characterized by de novo development of concurrent hypertension, proteinuria, and placental oxidative stress. During the last trimester of gestation, maternal-to-fetal transport of minerals is dramatically increased and becomes tightly mediated by ion channels that are highly permeable to various divalent cations, such as Ca(2+) , Mg(2+) , and Zn(2+) . The regulation of magnesium/inorganic phosphorus ion-channel transport in the placenta, however, is not incompletely understood. In the present study, we examined the regulation of magnesium/inorganic phosphorus channels (MPCs) in the placenta of pregnant women suffering from preeclampsia as well as in primary human placental cells subjected to oxidative stress. The expression of MPC genes (TRPM6, TRPM7, PiT-1, and PiT-2) was down-regulated in preeclamptic placenta tissues during preterm labor, and generally remained lower at term labor-although TRPM7 expression in the central placenta or PiT-2 expression in whole placenta was unchanged or up-regulated. Consistent with this association, expression of MPC genes in the primary placental cells was reduced under hypoxic conditions. TRPM6, TRPM7, and PiT-1 channels were predominantly detected in the syncytiotrophoblast layers of the placenta. In contrast, PiT-2 was abundant in the placental intravillous connective tissues. Taken together, our findings indicated that placental MPC expression is down-regulated in cases of preeclampsia and under hypoxia. This relationship may contribute to a better understanding of the interrelationship between magnesium/inorganic phosphorus imbalances and preeclampsia development during preterm or term labor.
Collapse
Affiliation(s)
- Hyun Yang
- Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | | | | | | | | |
Collapse
|