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Kamalakar A, Washam CL, Akel NS, Allen BJ, Williams DK, Swain FL, Leitzel K, Lipton A, Gaddy D, Suva LJ. PTHrP(12-48) Modulates the Bone Marrow Microenvironment and Suppresses Human Osteoclast Differentiation and Lifespan. J Bone Miner Res 2017; 32:1421-1431. [PMID: 28370412 PMCID: PMC5518789 DOI: 10.1002/jbmr.3142] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 03/09/2017] [Accepted: 03/24/2017] [Indexed: 01/08/2023]
Abstract
Bone is a common site for metastasis in breast cancer patients and is associated with a series of complications that significantly compromise patient survival, partially due to the advanced stage of disease at the time of detection. Currently, no clinically-approved biomarkers can identify or predict the development of bone metastasis. We recently identified a unique peptide fragment of parathyroid hormone-related protein (PTHrP), PTHrP(12-48), as a validated serum biomarker in breast cancer patients that correlates with and predicts the presence of bone metastases. In this study, the biological activity and mode of action of PTHrP(12-48) was investigated. Sequence-based and structure-based bioinformatics techniques predicted that the PTHrP(12-48) fragment formed an alpha helical core followed by an unstructured region after residue 40 or 42. Thereafter, detailed structure alignment and molecular docking simulations predicted a lack of interaction between PTHrP(12-48) and the cognate PTH1 receptor (PTHR1). The in silico prediction was confirmed by the lack of PTHrP(12-48)-stimulated cAMP accumulation in PTHR1-expressing human SaOS2 cells. Using a specific human PTHrP(12-48) antibody that we developed, PTHrP(12-48) was immunolocalized in primary and bone metastatic human breast cancer cells, as well as within human osteoclasts (OCLs) in bone metastasis biopsies, with little or no localization in other resident bone or bone marrow cells. In vitro, PTHrP(12-48) was internalized into cultured primary human OCLs and their precursors within 60 min. Interestingly, PTHrP(12-48) treatment dose-dependently suppressed osteoclastogenesis, via the induction of apoptosis in both OCL precursors as well as in mature OCLs, as measured by the activation of cleaved caspase 3. Collectively, these data suggest that PTHrP(12-48) is a bioactive breast cancer-derived peptide that locally regulates the differentiation of hematopoietic cells and the activity of osteoclasts within the tumor-bone marrow microenvironment, perhaps to facilitate tumor control of bone. © 2017 American Society for Bone and Mineral Research.
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Affiliation(s)
- Archana Kamalakar
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - Charity L Washam
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - Nisreen S Akel
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - Bethany J Allen
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - Diarra K Williams
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA.,Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Frances L Swain
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA
| | - Kim Leitzel
- Department of Medicine, Penn State University, Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Allan Lipton
- Department of Medicine, Penn State University, Milton S. Hershey Medical Center, Hershey, PA, USA
| | - Dana Gaddy
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA.,Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Larry J Suva
- Department of Orthopaedic Surgery, Center for Orthopaedic Research, University of Arkansas for Medical Sciences (UAMS), Little Rock, AR, USA.,Department of Veterinary Physiology and Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
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On JSW, Chow BKC, Lee LTO. Evolution of parathyroid hormone receptor family and their ligands in vertebrate. Front Endocrinol (Lausanne) 2015; 6:28. [PMID: 25806022 PMCID: PMC4354418 DOI: 10.3389/fendo.2015.00028] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 02/17/2015] [Indexed: 11/13/2022] Open
Abstract
The presence of the parathyroid hormones in vertebrates, including PTH, PTH-related peptide (PTHrP), and tuberoinfundibular peptide of 39 residues (TIP39), has been proposed to be the result of two rounds of whole genome duplication in the beginning of vertebrate diversification. Bioinformatics analyses, in particular chromosomal synteny study and the characterization of the PTH ligands and their receptors from various vertebrate species, provide evidence that strongly supports this hypothesis. In this mini-review, we summarize recent advances in studies regarding the molecular evolution and physiology of the PTH ligands and their receptors, with particular focus on non-mammalian vertebrates. In summary, the PTH family of peptides probably predates early vertebrate evolution, indicating a more ancient existence as well as a function of these peptides in invertebrates.
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Affiliation(s)
- Jason S. W. On
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Billy K. C. Chow
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
| | - Leo T. O. Lee
- School of Biological Sciences, The University of Hong Kong, Hong Kong, China
- *Correspondence: Leo T. O. Lee, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China e-mail:
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Pellicelli M, Taheri M, St-Louis M, Bériault V, Desgroseillers L, Boileau G, Moreau A. PTHrP(1-34)-mediated repression of the PHEX gene in osteoblastic cells involves the transcriptional repressor E4BP4. J Cell Physiol 2012; 227:2378-87. [DOI: 10.1002/jcp.22973] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Parathyroid hormone related protein (PTHrP) in tumor progression. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 720:145-60. [PMID: 21901625 DOI: 10.1007/978-1-4614-0254-1_12] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Parathyroid hormone-related protein (PTHrP) is widely expressed in fetal and adult tissues and is a key regulator for cellular calcium transport and smooth muscle cell contractility, as well as a crucial control factor in cell proliferation, development and differentiation. PTHrP stimulates or inhibits apoptosis in an autocrine/paracrine and intracrine fashion, and is particularly important for hair follicle and bone development, mammary epithelial development and tooth eruption. PTHrP's dysregulated expression has traditionally been associated with oncogenic pathologies as the major causative agent of malignancy-associated hypercalcemia, but recent evidence revealed a driving role in skeletal metastasis progression. Here, we demonstrate that PTHrP is also closely involved in breast cancer initiation, growth and metastasis through mechanisms separate from its bone turnover action, and we suggest that PTHrP as a facilitator of oncogenes would be a novel target for therapeutic purposes.
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Pioszak AA, Xu HE. Molecular recognition of parathyroid hormone by its G protein-coupled receptor. Proc Natl Acad Sci U S A 2008; 105:5034-9. [PMID: 18375760 PMCID: PMC2278174 DOI: 10.1073/pnas.0801027105] [Citation(s) in RCA: 211] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2007] [Indexed: 11/18/2022] Open
Abstract
Parathyroid hormone (PTH) is central to calcium homeostasis and bone maintenance in vertebrates, and as such it has been used for treating osteoporosis. It acts primarily by binding to its receptor, PTH1R, a member of the class B G protein-coupled receptor (GPCR) family that also includes receptors for glucagon, calcitonin, and other therapeutically important peptide hormones. Despite considerable interest and much research, determining the structure of the receptor-hormone complex has been hindered by difficulties in purifying the receptor and obtaining diffraction-quality crystals. Here, we present a method for expression and purification of the extracellular domain (ECD) of human PTH1R engineered as a maltose-binding protein (MBP) fusion that readily crystallizes. The 1.95-A structure of PTH bound to the MBP-PTH1R-ECD fusion reveals that PTH docks as an amphipathic helix into a central hydrophobic groove formed by a three-layer alpha-beta-betaalpha fold of the PTH1R ECD, resembling a hot dog in a bun. Conservation in the ECD scaffold and the helical structure of peptide hormones emphasizes this hot dog model as a general mechanism of hormone recognition common to class B GPCRs. Our findings reveal critical insights into PTH actions and provide a rational template for drug design that targets this hormone signaling pathway.
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MESH Headings
- Amino Acid Sequence
- Animals
- Cattle
- Conserved Sequence
- Crystallography, X-Ray
- Gene Expression
- Humans
- Models, Molecular
- Molecular Sequence Data
- Parathyroid Hormone/chemistry
- Parathyroid Hormone/metabolism
- Protein Binding
- Protein Structure, Quaternary
- Receptor, Parathyroid Hormone, Type 1/chemistry
- Receptor, Parathyroid Hormone, Type 1/genetics
- Receptor, Parathyroid Hormone, Type 1/isolation & purification
- Receptor, Parathyroid Hormone, Type 1/metabolism
- Sensitivity and Specificity
- Sequence Alignment
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Affiliation(s)
- Augen A. Pioszak
- Laboratory of Structural Sciences, Van Andel Research Institute, 333 Bostwick Avenue, N.E., Grand Rapids, MI 49503
| | - H. Eric Xu
- Laboratory of Structural Sciences, Van Andel Research Institute, 333 Bostwick Avenue, N.E., Grand Rapids, MI 49503
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Vargas MA, St-Louis M, Desgroseillers L, Charli JL, Boileau G. Parathyroid hormone-related protein(1-34) regulates Phex expression in osteoblasts through the protein kinase A pathway. Endocrinology 2003; 144:4876-85. [PMID: 12960044 DOI: 10.1210/en.2003-0253] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Phex (a phosphate-regulating gene with homologies to endopeptidases on the X chromosome) is expressed predominantly in bone in which it has been implicated in the mineralization process. Multiple factors and hormones, including PTHrP, regulate formation, development, and/or homeostasis of bone. The purpose of the present study was to determine whether PTHrP(1-34) regulates Phex expression and identify the signaling pathway used. Phex mRNA and protein levels were analyzed by RT-PCR and immunoblotting, respectively. In UMR-106 cells, PTHrP(1-34) caused a time- and concentration-dependent decrease in Phex expression. Forskolin, an adenylate cyclase activator, had the same effect. Dibutiryl cAMP also decreased Phex expression, and its effect was blocked by H89, a protein kinase A (PKA) inhibitor. In contrast, 12-O-tetradecanoyl phorbol-13-acetate, a protein kinase C (PKC) activator, increased Phex expression in a time- and dose-dependent manner. This effect was reversed by bisindolylmaleimide Iota, a PKC inhibitor. Bovine PTH(3-34), which activates PKC but not PKA, had no effect. On the contrary, human PTH(1-31), which activates PKA but not PKC, decreased Phex expression. H89 but not bisindolylmaleimide Iota blocked the effect of PTHrP(1-34). PTHrP(1-34) also decreased Phex expression in cultures of fetal rat calvaria cells at d 7 of culture but not at later stages. These data demonstrate that PTHrP(1-34), through PKA, down-regulates Phex expression in osteoblasts.
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Affiliation(s)
- Miguel Angel Vargas
- Département de Biochimie, Faculté de Médecine, Université de Montréal, Montréal, Québec, Canada H3C 3J7
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Usdin TB, Wang T, Hoare SR, Mezey E, Palkovits M. New members of the parathyroid hormone/parathyroid hormone receptor family: the parathyroid hormone 2 receptor and tuberoinfundibular peptide of 39 residues. Front Neuroendocrinol 2000; 21:349-83. [PMID: 11013069 DOI: 10.1006/frne.2000.0203] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The parathyroid hormone (PTH) family currently includes three peptides and three receptors. PTH regulates calcium homeostasis through bone and kidney PTH1 receptors. PTH-related peptide, probably also through PTH1 receptors, regulates skeletal, pancreatic, epidermal, and mammary gland differentiation and bladder and vascular smooth muscle relaxation and has a CNS role that is under investigation. Tuberoinfundibular peptide of 39 residues (TIP39) was recently purified from bovine hypothalamus based on selective PTH2 receptor activation. PTH2 receptor expression is greatest in the CNS, where it is concentrated in limbic, hypothalamic, and sensory areas, especially hypothalamic periventricular neurons, nerve terminals in the median eminence, superficial layers of the spinal cord dorsal horn, and the caudal part of the sensory trigeminal nucleus. It is also present in a number of endocrine cells. Thus TIP39 and PTH2 receptor-influenced functions may range from pituitary and pancreatic hormone release to pain perception. A third PTH-recognizing receptor has been found in zebrafish.
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Affiliation(s)
- T B Usdin
- Laboratory of Genetics, National Institute of Mental Health, Bethesda, Maryland 20892-4094, USA.
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Jin L, Briggs SL, Chandrasekhar S, Chirgadze NY, Clawson DK, Schevitz RW, Smiley DL, Tashjian AH, Zhang F. Crystal Structure of Human Parathyroid Hormone 1–34 at 0.9-Å Resolution. J Biol Chem 2000. [DOI: 10.1016/s0021-9258(19)61502-4] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Weidler M, Marx UC, Seidel G, Schäfer W, Hoffmann E, Esswein A, Rösch P. The structure of human parathyroid hormone-related protein(1-34) in near-physiological solution. FEBS Lett 1999; 444:239-44. [PMID: 10050767 DOI: 10.1016/s0014-5793(98)01658-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Parathyroid hormone-related protein plays a major role in the pathogenesis of humoral hypercalcemia of malignancy. Under normal physiological conditions, parathyroid hormone-related protein is produced in a wide variety of tissues and acts in an autocrine or paracrine fashion. Parathyroid hormone-related protein and parathyroid hormone bind to and activate the same G-protein-coupled receptor. Here we present the structure of the biologically active NH2-terminal domain of human parathyroid hormone-related protein(1-34) in near-physiological solution in the absence of crowding reagents as determined by two-dimensional proton magnetic resonance spectroscopy. An improved strategy for structure calculation revealed the presence of two helices, His-5-Leu-8 and Gln-16-Leu-27, connected by a flexible linker. The parathyroid hormone-related protein(1-34) structure and the structure of human parathyroid hormone(1-37) as well as human parathyroid hormone(1-34) are highly similar, except for the well defined turn, His-14-Ser-17, present in parathyroid hormone. Thus, the similarity of the binding affinities of parathyroid hormone and parathyroid hormone-related protein to their common receptor may be based on their structural similarity.
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Affiliation(s)
- M Weidler
- Lehrstuhl für Biopolymere, Universität Bayreuth, Germany
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Ingleton PM, Danks JA. Distribution and functions of parathyroid hormone-related protein in vertebrate cells. INTERNATIONAL REVIEW OF CYTOLOGY 1996; 166:231-80. [PMID: 8881777 DOI: 10.1016/s0074-7696(08)62510-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Parathyroid hormone-related protein (PTHrP) was isolated from tumors and identified as the agent of humoral hypercalcemia of malignancy (HHM) in 1987. Since then its gene structure in several mammalian and an avian species has been analyzed and its gene expression demonstrated in many adult and embryonic tissues derived from all three germ layers. The composition and structure of PTHrP peptide depends on both differential gene splicing and posttranslational processing, which result in a range of peptides of potentially diverse functions. This chapter describes the distribution of PTHrP in both normal and neoplastic adult and embryonic tissues. PTHrP is of fundamental importance to cell survival because the absence of the gene is fatal; this aspect of PTHrP function in cell physiology becomes overwhelmingly important in neoplasia. Intracrine or paracrine actions for PTHrP seem to be most likely in mammalian and avian physiology, but in fishes high circulating levels suggest classic endocrine functions as well. Much remains to be learned of the biology of this fascinating protein.
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Affiliation(s)
- P M Ingleton
- Institute of Endocrinology, Sheffield University Medical School, United Kingdom
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Usdin TB, Gruber C, Bonner TI. Identification and functional expression of a receptor selectively recognizing parathyroid hormone, the PTH2 receptor. J Biol Chem 1995; 270:15455-8. [PMID: 7797535 DOI: 10.1074/jbc.270.26.15455] [Citation(s) in RCA: 310] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We have identified a G-protein-coupled receptor specifically activated by parathyroid hormone, which we refer to as the PTH2 receptor. Parathyroid hormone (PTH) and parathyroid hormone-related peptide (PTHrP, hypercalcemia of malignancy factor) activate a previously identified PTH/PTHrP receptor, which has a widespread tissue distribution. The PTH2 receptor is much more selective in ligand recognition and appears to have a more specific tissue distribution. It is activated by PTH and not by PTHrP and is particularly abundant in the brain and pancreas.
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Affiliation(s)
- T B Usdin
- Laboratory of Cell Biology, National Institute of Mental Health, Bethesda, Maryland 20892-4090, USA
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Abstract
The discovery of PTHrP was the result of research on the mechanisms by which some cancers cause hypercalcemia (humoral hypercalcemia of malignancy) without necessarily metastasizing to bone. PTHrP is also present in various normal adult and fetal tissues. Its concentration is normally very low (picomolar) in blood, but it is more abundant in milk (nanomolar concentration). PTHrP seems able to exert autocrine/paracrine as well as endocrine effects on bone metabolism. A major role for PTHrP in regulation of fetal bone metabolism has been demonstrated in mice. Homologous recombination has been used in these rodents to remove the major coding exon from one copy of the mouse PTHrP gene in embryonic stem cells. Subsequently generated chimeric mice transmit the mutant PTHrP allele through the germline. Homozygous mutants died immediately after birth and had a multitude of skeletal abnormalities. So PTHrP seems necessary to embryonic development of the skeleton. PTHrP (1-34), like PTH (1-34) fragments, might be responsible for both bone resorption and formation. Although the effects of the carboxyl-terminal fragments are still controversial, PTHrP (107-111) fragment seems able to inhibit osteoclast activity. PTHrP (1-34), whose 8 of the first 13 amino-acids are identical with those in PTH (1-34), acts through the same receptor as PTH on osteoblasts and renal cells membrane. The PTHrP/PTH receptor sequence is now well established. PTHrP-receptor coupling is mediated by cyclic AMP and/or inositols-phosphate. The consequent activation of protein kinase A and intracellular calcium or protein kinase C, respectively, locally induces growth factors or cytokines secretion, responsible for the observed effects. The role of PTHrP appears important during pregnancy and lactation, when it stimulates fetal bone growth by increasing calcium transport from the dam to its fetus and maternal bone resorption allowing calcium supply for milk production, respectively. Such a role would be particularly important in domestic ruminants, which are often simultaneously pregnant and lactating. The role of PTHrP during aging (especially in post-menopausal women in which bone loss may induce osteoporosis) remains unknown and might be of peculiar interest since PTHrP (1-34) and (107-111) are able to restore bone loss induced by ovariectomy in rats.
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Affiliation(s)
- J Rouffet
- Laboratoire Croissance et Métabolismes des Herbivores, INRA Theix, St Genès-Champanelle
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Blind E. Humoral hypercalcemia of malignancy: role of parathyroid hormone-related protein. Recent Results Cancer Res 1994; 137:20-43. [PMID: 7878294 DOI: 10.1007/978-3-642-85073-8_2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- E Blind
- Department of Internal Medicine I-Endocrinology and Metabolism, University of Heidelberg, Germany
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