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Nakatsuka R, Kato T, Zhang R, Uemura Y, Sasaki Y, Matsuoka Y, Shirouzu Y, Fujioka T, Yamashita H, Hattori F, Nozaki T, Ogata H, Hitomi H. The Induction of Parathyroid Cell Differentiation from Human Induced Pluripotent Stem Cells Promoted Via TGF-α/EGFR Signaling. Stem Cells Dev 2023; 32:670-680. [PMID: 37639359 DOI: 10.1089/scd.2023.0130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023] Open
Abstract
The parathyroid gland plays an essential role in mineral and bone metabolism. Cultivation of physiological human parathyroid cells has yet to be established and the method by which parathyroid cells differentiate from pluripotent stem cells remains uncertain. Therefore, it has been hard to clarify the mechanisms underlying the onset of parathyroid disorders, such as hyperparathyroidism. In this study, we developed a new method of parathyroid cell differentiation from human induced pluripotent stem (iPS) cells. Parathyroid cell differentiation occurred in accordance with embryologic development. Differentiated cells, which expressed the parathyroid hormone, adopted unique cell aggregation similar to the parathyroid gland. In addition, these differentiated cells were identified as calcium-sensing receptor (CaSR)/epithelial cell adhesion molecule (EpCAM) double-positive cells. Interestingly, stimulation with transforming growth factor-α (TGF-α), which is considered a causative molecule of parathyroid hyperplasia, increased the CaSR/EpCAM double-positive cells, but this effect was suppressed by erlotinib, which is an epidermal growth factor receptor (EGFR) inhibitor. These results suggest that TGF-α/EGFR signaling promotes parathyroid cell differentiation from iPS cells in a similar manner to parathyroid hyperplasia.
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Affiliation(s)
- Ryusuke Nakatsuka
- Department of iPS Stem Cell Regenerative Medicine, Faculty of Medicine, Kansai Medical University, Osaka, Japan
- Department of Pharmacology, Faculty of Dentistry, Osaka Dental University, Osaka, Japan
| | - Tadashi Kato
- Department of iPS Stem Cell Regenerative Medicine, Faculty of Medicine, Kansai Medical University, Osaka, Japan
- Division of Nephrology, Department of Medicine, Showa University, Tokyo, Japan
- Department of Internal Medicine, Showa University Northern Yokohama Hospital, Kanagawa, Japan
| | - Rong Zhang
- Division of Cancer Immunotherapy, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, Chiba, Japan
| | - Yasushi Uemura
- Division of Cancer Immunotherapy, Exploratory Oncology Research and Clinical Trial Center, National Cancer Center, Chiba, Japan
| | - Yuka Sasaki
- Department of Pharmacology, Faculty of Dentistry, Osaka Dental University, Osaka, Japan
| | - Yoshikazu Matsuoka
- Department of iPS Stem Cell Regenerative Medicine, Faculty of Medicine, Kansai Medical University, Osaka, Japan
| | - Yasumasa Shirouzu
- Department of iPS Stem Cell Regenerative Medicine, Faculty of Medicine, Kansai Medical University, Osaka, Japan
| | - Tatsuya Fujioka
- Department of iPS Stem Cell Regenerative Medicine, Faculty of Medicine, Kansai Medical University, Osaka, Japan
| | - Hiromi Yamashita
- Department of iPS Stem Cell Regenerative Medicine, Faculty of Medicine, Kansai Medical University, Osaka, Japan
| | - Fumiyuki Hattori
- Department of iPS Stem Cell Regenerative Medicine, Faculty of Medicine, Kansai Medical University, Osaka, Japan
| | - Tadashige Nozaki
- Department of Pharmacology, Faculty of Dentistry, Osaka Dental University, Osaka, Japan
| | - Hiroaki Ogata
- Department of Internal Medicine, Showa University Northern Yokohama Hospital, Kanagawa, Japan
| | - Hirofumi Hitomi
- Department of iPS Stem Cell Regenerative Medicine, Faculty of Medicine, Kansai Medical University, Osaka, Japan
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Xiang Z, Wang M, Miao C, Jin D, Wang H. Mechanism of calcitriol regulating parathyroid cells in secondary hyperparathyroidism. Front Pharmacol 2022; 13:1020858. [PMID: 36267284 PMCID: PMC9577402 DOI: 10.3389/fphar.2022.1020858] [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: 08/16/2022] [Accepted: 09/15/2022] [Indexed: 12/03/2022] Open
Abstract
A common consequence of chronic renal disease is secondary hyperparathyroidism (SHPT) and is closely related to the mortality and morbidity of uremia patients. Secondary hyperparathyroidism (SHPT) is caused by excessive PTH production and release, as well as parathyroid enlargement. At present, the mechanism of cell proliferation in secondary hyperparathyroidism (SHPT) is not completely clear. Decreased expression of the vitamin D receptor (VDR) and calcium-sensing receptor (CaSR), and 1,25(OH)2D3 insufficiency all lead to a decrease in cell proliferation suppression, and activation of multiple pathways is also involved in cell proliferation in renal hyperparathyroidism. The interaction between the parathormone (PTH) and parathyroid hyperplasia and 1,25(OH)2D3 has received considerable attention. 1,25(OH)2D3 is commonly applied in the therapy of renal hyperparathyroidism. It regulates the production of parathormone (PTH) and parathyroid cell proliferation through transcription and post-transcription mechanisms. This article reviews the role of 1,25(OH)2D3 in parathyroid cells in secondary hyperparathyroidism and its current understanding and potential molecular mechanism.
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Dusso AS, Bauerle KT, Bernal-Mizrachi C. Non-classical Vitamin D Actions for Renal Protection. Front Med (Lausanne) 2021; 8:790513. [PMID: 34950686 PMCID: PMC8688743 DOI: 10.3389/fmed.2021.790513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 11/15/2021] [Indexed: 11/17/2022] Open
Abstract
Chronic Kidney Disease (CKD), a disorder that affects 11% of the world's population, is characterized by an acceleration in skeletal, immune, renal, and cardiovascular aging that increases the risk of cardiovascular mortality by 10- to 20-fold, compared to that in individuals with normal renal function. For more than two decades, the progressive impairment in renal capacity to maintain normal circulating levels of the hormonal form of vitamin D (1,25-dihydroxyvitamin D or calcitriol) was considered the main contributor to the reduced survival of CKD patients. Accordingly, calcitriol administration was the treatment of choice to attenuate the progression of secondary hyperparathyroidism (SHPT) and its adverse impact on bone health and vascular calcification. The development of calcitriol analogs, designed to mitigate the resistance to calcitriol suppression of PTH associated with CKD progression, demonstrated survival benefits unrelated to the control of SHPT or skeletal health. The exhaustive search for the pathophysiology behind survival benefits associated with active vitamin D analogs has identified novel anti-inflammatory, anti-hypertensive, anti-aging actions of the vitamin D endocrine system. A major paradigm shift regarding the use of calcitriol or active vitamin D analogs to improve survival in CKD patients emerged upon demonstration of a high prevalence of vitamin D (not calcitriol) deficiency at all stages of CKD and, more significantly, that maintaining serum levels of the calcitriol precursor, 25(OH)vitamin D, above 23 ng/ml delayed CKD progression. The cause of vitamin D deficiency in CKD, however, is unclear since vitamin D bioactivation to 25(OH)D occurs mostly at the liver. Importantly, neither calcitriol nor its analogs can correct vitamin D deficiency. The goals of this chapter are to present our current understanding of the pathogenesis of vitamin D deficiency in CKD and of the causal link between defective vitamin D bioactivation to calcitriol and the onset of molecular pathways that promote CKD progression independently of the degree of SHPT. An understanding of these mechanisms will highlight the need for identification of novel sensitive biomarkers to assess the efficacy of interventions with vitamin D and/or calcitriol(analogs) to ameliorate CKD progression in a PTH-independent manner.
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Affiliation(s)
- Adriana S. Dusso
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
| | - Kevin T. Bauerle
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
- Department of Medicine, VA Medical Center, St. Louis, MO, United States
| | - Carlos Bernal-Mizrachi
- Division of Endocrinology, Metabolism and Lipid Research, Department of Medicine, Washington University School of Medicine, St. Louis, MO, United States
- Department of Medicine, VA Medical Center, St. Louis, MO, United States
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO, United States
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Mizobuchi M, Ogata H, Koiwa F. Secondary Hyperparathyroidism: Pathogenesis and Latest Treatment. Ther Apher Dial 2018; 23:309-318. [PMID: 30411503 DOI: 10.1111/1744-9987.12772] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 10/23/2018] [Accepted: 11/02/2018] [Indexed: 01/02/2023]
Abstract
The classic pathogenesis of secondary hyperparathyroidism (SHPT) began with the trade-off hypothesis based on parathyroid hormone hypersecretion brought about by renal failure resulting from a physiological response to correct metabolic disorder of calcium, phosphorus, and vitamin D. In dialysis patients with failed renal function, physiological mineral balance control by parathyroid hormone through the kidney fails and hyperparathyroidism progresses. In this process, many significant genetic findings have been established. Abnormalities of Ca-sensing receptor and vitamin D receptor are associated with the pathogenesis of SHPT, and fibroblast growth factor 23 has also been shown to be involved in the pathogenesis. Vitamin D receptor activators (VDRAs) are widely used for treatment of SHPT. However, VDRAs have calcemic and phosphatemic effects that limit their use to a subset of patients, and calcimimetics have been developed as alternative drugs for SHPT. Hyperphosphatemia also affects progression of SHPT, and control of hyperphosphatemia is, therefore, thought to be fundamental for control of SHPT. Currently, a combination of a VDRA and a calcimimetic is recognized as the optimal strategy for SHPT, and for other outcomes such as reduced cardiovascular disease and improved survival. The latest findings on the pathogenesis and treatment of SHPT are summarized in this review.
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Affiliation(s)
- Masahide Mizobuchi
- Division of Nephrology, Department of Medicine, Showa University School of Medicine, Tokyo, Japan
| | - Hiroaki Ogata
- Department of Medicine, Showa University Northern Yokohama Hospital, Yokohama, Japan
| | - Fumihiko Koiwa
- Division of Nephrology, Department of Medicine, Showa University Fujigaoka Hospital, Yokohama, Japan
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Cozzolino M, Pasho S, Fallabrino G, Olivi L, Gallieni M, Brancaccio D. Pathogenesis of Secondary Hyperparathyroidism. Int J Artif Organs 2018; 32:75-80. [DOI: 10.1177/039139880903200203] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chronic renal failure is the primary cause of secondary hyperparathyroidism (SHPT). Patients with mineral metabolism disorders commonly present with low serum calcium levels, hyperphosphatemia, and calcitriol deficiency. In normal renal function subjects, parathyroid cells have a low turnover and rarely undergo mitoses. In uremic conditions, however, parathyroid glands become hyperplasic and leave quiescence. During the last ten years, new molecular mechanisms have been investigated to better understand the pathogenesis of SHPT: the emerging role of the Calcium Sensing Receptor (CaSR); the importance of the parathyroid expression of the Vitamin D receptor (VDR); the growing evidence on the central role of the Fibroblast Growth Factor 23 (FGF-23). In contrast, the discovery of a parathyroid phosphate sensor or receptor has yet to be made.
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Affiliation(s)
- Mario Cozzolino
- Renal Division, San Paolo Hospital, University of Milan, Milan - Italy
| | - Sabina Pasho
- Renal Division, San Paolo Hospital, University of Milan, Milan - Italy
| | | | - Laura Olivi
- Renal Division, San Paolo Hospital, University of Milan, Milan - Italy
| | - Maurizio Gallieni
- Renal Division, San Paolo Hospital, University of Milan, Milan - Italy
| | - Diego Brancaccio
- Renal Division, San Paolo Hospital, University of Milan, Milan - Italy
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Volovelsky O, Cohen G, Kenig A, Wasserman G, Dreazen A, Meyuhas O, Silver J, Naveh-Many T. Phosphorylation of Ribosomal Protein S6 Mediates Mammalian Target of Rapamycin Complex 1-Induced Parathyroid Cell Proliferation in Secondary Hyperparathyroidism. J Am Soc Nephrol 2015; 27:1091-101. [PMID: 26283674 DOI: 10.1681/asn.2015040339] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Accepted: 06/30/2015] [Indexed: 01/03/2023] Open
Abstract
Secondary hyperparathyroidism is characterized by increased serum parathyroid hormone (PTH) level and parathyroid cell proliferation. However, the molecular pathways mediating the increased parathyroid cell proliferation remain undefined. Here, we found that the mTOR pathway was activated in the parathyroid of rats with secondary hyperparathyroidism induced by either chronic hypocalcemia or uremia, which was measured by increased phosphorylation of ribosomal protein S6 (rpS6), a downstream target of the mTOR pathway. This activation correlated with increased parathyroid cell proliferation. Inhibition of mTOR complex 1 by rapamycin decreased or prevented parathyroid cell proliferation in secondary hyperparathyroidism rats and in vitro in uremic rat parathyroid glands in organ culture. Knockin rpS6(p-/-) mice, in which rpS6 cannot be phosphorylated because of substitution of all five phosphorylatable serines with alanines, had impaired PTH secretion after experimental uremia- or folic acid-induced AKI. Uremic rpS6(p-/-) mice had no increase in parathyroid cell proliferation compared with a marked increase in uremic wild-type mice. These results underscore the importance of mTOR activation and rpS6 phosphorylation for the pathogenesis of secondary hyperparathyroidism and indicate that mTORC1 is a significant regulator of parathyroid cell proliferation through rpS6.
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Affiliation(s)
- Oded Volovelsky
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Gili Cohen
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Ariel Kenig
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Gilad Wasserman
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Avigail Dreazen
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Oded Meyuhas
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Justin Silver
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
| | - Tally Naveh-Many
- Department of Nephrology, Hadassah-Hebrew University Medical Center, and
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Magnabosco FF, Tavares MR, Montenegro FLDM. [Surgical treatment of secondary hyperparathyroidism: a systematic review of the literature]. ACTA ACUST UNITED AC 2015; 58:562-71. [PMID: 25166048 DOI: 10.1590/0004-2730000003372] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 05/12/2014] [Indexed: 11/22/2022]
Abstract
Secondary hyperparathyroidism (HPT) has a high prevalence in renal patients. Secondary HPT results from disturbances in mineral homeostasis, particularly calcium, which stimulates the parathyroid glands, increasing the secretion of parathyroid hormone (PTH). Prolonged stimulation can lead to autonomy in parathyroid function. Initial treatment is clinical, but parathyroidectomy (PTx) may be required. PTx can be subtotal or total followed or not followed by parathyroid tissue autograft. We compared the indications and results of these strategies as shown in the literature through a systematic literature review on surgical treatment of secondary HPT presented in MedLine and LILACS from January 2008 to March 2014. The search terms were: hyperparathyroidism; secondary hyperparathyroidism; parathyroidectomy and parathyroid glands, restricted to research only in humans, articles available in electronic media, published in Portuguese, Spanish, English or French. We selected 49 articles. Subtotal and total PTx followed by parathyroid tissue autograft were the most used techniques, without consensus on the most effective surgical procedure, although there was a preference for the latter. The choice depends on surgeon's experience. There was consensus on the need to identify all parathyroid glands and cryopreservation of parathyroid tissue whenever possible to graft if hypoparathyroidism arise. Imaging studies may be useful, especially in recurrences. Alternative treatments of secondary HPT, both interventional and conservative, require further study.
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Affiliation(s)
| | - Marcos Roberto Tavares
- Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brasil
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Arcidiacono MV, Yang J, Fernandez E, Dusso A. Parathyroid-specific epidermal growth factor-receptor inactivation prevents uremia-induced parathyroid hyperplasia in mice. Nephrol Dial Transplant 2014; 30:434-40. [PMID: 25324357 DOI: 10.1093/ndt/gfu318] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND In chronic kidney disease (CKD), parathyroid hyperplasia contributes to high serum parathyroid hormone (PTH) and also to an impaired suppression of secondary hyperparathyroidism by calcium, vitamin D and fibroblast growth factor 23 (FGF23). In rats, systemic inhibition of epidermal growth factor receptor (EGFR) activation markedly attenuated uremia-induced parathyroid hyperplasia and vitamin D receptor (VDR) loss, hence restoring the response to vitamin D. Therefore, we propose that parathyroid-specific EGFR inactivation should prevent CKD-induced parathyroid hyperplasia. METHODS A dominant-negative human EGFR mutant, which forms non-functional heterodimers with full-length endogenous EGFR, was successfully targeted to the parathyroid glands (PTGs) of FVB/N mice, using the 5' regulatory sequence of the PTH promoter. The parathyroid phenotype and serum chemistries of wild-type (WT) and transgenic mice were examined after 14 weeks of either sham operation or 75% renal mass reduction (NX). RESULTS Both genotypes had similar morphology and body weight, and NX-induction enhanced similarly serum blood urea nitrogen compared with sham-operated controls. However, despite similar serum calcium, phosphate and FGF23 levels in NX mice of both genotypes, parathyroid EGFR inactivation sufficed to completely prevent the marked increases in PTG enlargement, serum PTH and in parathyroid levels of transforming growth factor-α, a powerful EGFR-activator, and the VDR reductions observed in WT mice. CONCLUSION In CKD, parathyroid EGFR activation is essential for parathyroid hyperplasia and VDR loss, rendering this transgenic mouse a unique tool to scrutinize the pathogenesis of parathyroid and multiple organ dysfunction of CKD progression unrelated to parathyroid hyperplasia.
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Affiliation(s)
- Maria Vittoria Arcidiacono
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA Division of Experimental Nephrology, IRB Lleida, Lleida, Spain Renal Division, Hospital Universitari Arnau de Vilanova, Universidad de Lleida, Lleida, Spain
| | - Jing Yang
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA
| | - Elvira Fernandez
- Division of Experimental Nephrology, IRB Lleida, Lleida, Spain Renal Division, Hospital Universitari Arnau de Vilanova, Universidad de Lleida, Lleida, Spain
| | - Adriana Dusso
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA Division of Experimental Nephrology, IRB Lleida, Lleida, Spain Renal Division, Hospital Universitari Arnau de Vilanova, Universidad de Lleida, Lleida, Spain
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Arcidiacono MV, Yang J, Fernandez E, Dusso A. The induction of C/EBPβ contributes to vitamin D inhibition of ADAM17 expression and parathyroid hyperplasia in kidney disease. Nephrol Dial Transplant 2014; 30:423-33. [PMID: 25294851 DOI: 10.1093/ndt/gfu311] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND In secondary hyperparathyroidism (SHPT), enhanced parathyroid levels of transforming growth factor-α (TGFα) increase EGF receptor (EGFR) activation causing parathyroid hyperplasia, high parathyroid hormone (PTH) and also reductions in vitamin D receptor (VDR) that limit vitamin D suppression of SHPT. Since anti-EGFR therapy is not an option in human SHPT, we evaluated ADAM17 as a therapeutic target to suppress parathyroid hyperplasia because ADAM17 is required to release mature TGFα, the most potent EGFR-activating ligand. METHODS Computer analysis of the ADAM17 promoter identified TGFα and C/EBPβ as potential regulators of the ADAM17 gene. Their regulation of ADAM17 expression, TGFα/EGFR-driven growth and parathyroid gland (PTG) enlargement were assessed in promoter-reporter assays in A431 cells and corroborated in rat and human SHPT, using erlotinib as anti-EGFR therapy to suppress TGFα signals, active vitamin D to induce C/EBPβ or the combination. RESULTS While TGFα induced ADAM17-promoter activity by 2.2-fold exacerbating TGFα/EGFR-driven growth, ectopic C/EBPβ expression completely prevented this vicious synergy. Accordingly, in advanced human SHPT, parathyroid ADAM17 levels correlated directly with TGFα and inversely with C/EBPβ. Furthermore, combined erlotinib + calcitriol treatment suppressed TGFα/EGFR-cell growth and PTG enlargement more potently than erlotinib in part through calcitriol induction of C/EBPβ to inhibit ADAM17-promoter activity, mRNA and protein. Importantly, in rat SHPT, the correction of vitamin D deficiency effectively reversed the resistance to paricalcitol induction of C/EBPβ to suppress ADAM17 expression and PTG enlargement, reducing PTH by 50%. CONCLUSION In SHPT, correction of vitamin D and calcitriol deficiency induces parathyroid C/EBPβ to efficaciously attenuate the severe ADAM17/TGFα synergy, which drives PTG enlargement and high PTH.
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Affiliation(s)
- Maria Vittoria Arcidiacono
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA Division of Experimental Nephrology, IRB Lleida, Lleida, Spain
| | - Jing Yang
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA
| | - Elvira Fernandez
- Division of Experimental Nephrology, IRB Lleida, Lleida, Spain Renal Division, Hospital Universitari Arnau de Vilanova, Universidad de Lleida, Lleida, Spain
| | - Adriana Dusso
- Renal Division, Washington University School of Medicine, St. Louis, MO, USA Division of Experimental Nephrology, IRB Lleida, Lleida, Spain
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Li H, Sheridan R, Williams T. Analysis of TFAP2A mutations in Branchio-Oculo-Facial Syndrome indicates functional complexity within the AP-2α DNA-binding domain. Hum Mol Genet 2013; 22:3195-206. [PMID: 23578821 DOI: 10.1093/hmg/ddt173] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Multiple lines of evidence indicate that the AP-2 transcription factor family has an important regulatory function in human craniofacial development. Notably, mutations in TFAP2A, the gene encoding AP-2α, have been identified in patients with Branchio-Oculo-Facial Syndrome (BOFS). BOFS is an autosomal-dominant trait that commonly presents with facial clefting, eye defects and branchial skin anomalies. Examination of multiple cases has suggested either simple haploinsufficiency or more complex genetic causes for BOFS, especially as the clinical manifestations are variable, with no clear genotype-phenotype correlation. Mutations occur throughout TFAP2A, but mostly within conserved sequences within the DNA contact domain of AP-2α. However, the consequences of the various mutations for AP-2α protein function have not been evaluated. Therefore, it remains unclear if all BOFS mutations result in similar changes to the AP-2α protein or if they each produce specific alterations that underlie the spectrum of phenotypes. Here, we have investigated the molecular consequences of the mutations that localize to the DNA-binding region. We show that although individual mutations have different effects on DNA binding, they all demonstrate significantly reduced transcriptional activities. Moreover, all mutant derivatives have an altered nuclear:cytoplasmic distribution compared with the predominantly nuclear localization of wild-type AP-2α and several can exert a dominant-negative activity on the wild-type AP-2α protein. Overall, our data suggest that the individual TFAP2A BOFS mutations can generate null, hypomorphic or antimorphic alleles and that these differences in activity, combined with a role for AP-2α in epigenetic events, may influence the resultant pathology and the phenotypic variability.
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Affiliation(s)
- Hong Li
- Department of Craniofacial Biology and Cell and Developmental Biology, University of Colorado Denver, Aurora, CO 80045, USA
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Bienaimé F, Prié D, Friedlander G, Souberbielle JC. Vitamin D metabolism and activity in the parathyroid gland. Mol Cell Endocrinol 2011; 347:30-41. [PMID: 21664247 DOI: 10.1016/j.mce.2011.05.031] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 05/05/2011] [Accepted: 05/06/2011] [Indexed: 12/21/2022]
Abstract
Parathormone (PTH) and vitamin D are two critical hormonal regulators of calcium homeostasis. An important cross-talk exists between the PTH and vitamin D hormonal systems. PTH enhances vitamin D hydroxylation on carbon 1 in kidney cells thereby allowing the systemic release of 1-25-dihydroxy-vitamin D, which represents the fully active hormone. Conversely, parathyroid gland represents a direct target for vitamin D. Parathyroid cells express the vitamin D receptor and the 1-α-hydroxylase enzyme, which allows the local formation of 1-25-dihydroxy-vitamin D. Because of its potential implication in several diseases, including osteoporosis or chronic kidney disease, the interplay between PTH and vitamin D has received considerable attention these last two decades. The aim of this review is to summarize our current understanding of the molecular basis of vitamin D action and metabolism in parathyroid cells. The potential clinical implications of the recent advances made in this field will also be discussed.
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Affiliation(s)
- Frank Bienaimé
- Service de Physiologie - Explorations Fonctionnelles, Hôpital Necker Enfants Malades, 149 Rue de Sèvres, 75015 Paris, France
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Shiizaki K, Hatamura I, Mato M, Nakazawa E, Saji F, Onishi A, Ogura M, Watanabe Y, Kusano E. Development and prevention of morphologic and ultrastructural changes in uremia-induced hyperplastic parathyroid gland. Ultrastruct Pathol 2011; 35:230-8. [PMID: 21867406 DOI: 10.3109/01913123.2011.601406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The detailed ultrastructural changes of uremia-induced hyperplastic parathyroid gland and the effects of current medical treatments for secondary hyperparathyroidism were investigated. Marked enlargement of parathyroid cell with accumulation of mitochondria and lipids and a significant increase in the thickness of the pericapillary area with increased fibrosis and appearance of fibroblast like cells were noted in the hyperplastic gland caused by uremia and phosphate retention. These ultrastructural changes and biochemical findings indicating hyperparathyroidism were significantly suppressed by all of the treatment using phosphate restriction, calcitriol, and cinacalcet. The characteristic ultrastructural changes, including the morphologic evidence of nodule formation, were indicated.
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Affiliation(s)
- Kazuhiro Shiizaki
- Division of Nephrology, Department of Internal Medicine, Jichi Medical University, Shimotsuke, Japan.
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Komaba H, Shiizaki K, Fukagawa M. Pharmacotherapy and interventional treatments for secondary hyperparathyroidism: current therapy and future challenges. Expert Opin Biol Ther 2010; 10:1729-42. [DOI: 10.1517/14712598.2010.518614] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Carrillo-López N, Román-García P, Fernández-Martín JL, Cannata-Andía JB. Parathyroid gland regulation: contribution of thein vivoandin vitromodels. Expert Opin Drug Discov 2010; 5:265-75. [DOI: 10.1517/17460441003615170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Natalia Carrillo-López
- Hospital Universitario Central de Asturias, Bone and Mineral Research Unit, Instituto Reina Sofía de Investigación, REDinREN del ISCIII, Universidad de Oviedo, C/Julián Clavería s/n, Oviedo 33006, Asturias, Spain +34 985106137 ; +34 985106142 ;
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Current world literature. Curr Opin Endocrinol Diabetes Obes 2009; 16:470-80. [PMID: 19858911 DOI: 10.1097/med.0b013e3283339a46] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Canalejo A, Canalejo R, Rodriguez ME, Martinez-Moreno JM, Felsenfeld AJ, Rodríguez M, Almaden Y. Development of parathyroid gland hyperplasia without uremia: role of dietary calcium and phosphate. Nephrol Dial Transplant 2009; 25:1087-97. [PMID: 19934096 DOI: 10.1093/ndt/gfp616] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background. Many experimental studies have demonstrated that parathyroid cell proliferation is induced by uremia and further aggravated by hypocalcemia, phosphorus retention and vitamin D deficiency. However, these factors may also promote parathyroid growth without uremia. In the present study, we examined the onset and progression of parathyroid hyperplasia regardless of the uremic setting, a situation that might occur soon during the early renal disease. Thus, the novelty of this work resides in the close examination of the time course for the expected changes in proliferation rates and their association with parathyroid hormone (PTH) release in normal rats under the physiological demands of a high-phosphate diet (HPD) or a low-calcium diet (LCD). Methods. We evaluated the functional response of the parathyroid glands in normal rats to different physiological demands an HPD 0.6% Ca, 1.2% P) and LCD 0.2% Ca, 0.6% P) and compared it with that of uremic rats. Furthermore, we also evaluated the time course for the reversal of high-P and low-Ca-induced parathyroid cell growth and PTH upon normalization of dietary Ca and P intake (0.6% Ca, 0.6% P). Proliferation was measured by flow cytometry and calcium receptor (CaR) and vitamin D receptor (VDR) expression were assessed by qRT-PCR. Results. The pattern in the development of parathyroid hyperplasia by the two dietary models was different. The HPD produced a stronger stimulus than the number of proliferating cells doubled after only 1 day, while the LCD required 5 days to induce an increase; the elevated calcitriol might be a mitigating factor. The increase in cell proliferation was accompanied by a transient down-regulation of VDR expression (higher in the HPD); the expression of CaR was not affected by either diet. Cell proliferation and VDR mRNA levels were restored to control values by Day 15; it is as though the gland had attained a sufficient level of hyperplasia to respond to the PTH challenge. Compared to normal rats, the response of uremic rats to the HPD showed sustained and much higher rates of PTH secretion and cell proliferation and sustained down-regulation of both VDR mRNA and CaR mRNA. Finally, the recovery from the HPD or LCD to a control diet resulted in a rapid restoration of PTH values (1 to 2 days), but the reduction in cell proliferation was delayed (3 to 5 days). Conclusions. Regardless of uremia, a physiological demand to increase the PTH secretion driven either by a high P or a low Ca intake is able to induce a different pattern of parathyroid hyperplasia, which might be aggravated by the down-regulation of VDR expression. The recovery from the HPD or LCD to a control diet results in a more rapid reduction in PTH than in cell proliferation.
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Affiliation(s)
- Antonio Canalejo
- Department of Environmental Biology and Public Health, University of Huelva, Huelva, Spain
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