1
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Brunerova L, Remes O, Zoubkova V, Votypka P. Case report: Two heterozygous pathogenic variants of CYP24A1: A novel cause of hypercalcemia and nephrocalcinosis in adulthood. Front Med (Lausanne) 2023; 9:1020096. [PMID: 36703897 PMCID: PMC9871448 DOI: 10.3389/fmed.2022.1020096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 12/12/2022] [Indexed: 01/11/2023] Open
Abstract
Background and aims Vitamin D 24-hydroxylase is an enzyme encoded by the CYP24A1 gene, which inhibits the activation of vitamin D to form inactive metabolites. More than 20 currently described pathogenic variants (usually biallelic) of this gene are responsible for idiopathic infantile hypercalcemia manifested typically in childhood (often in newborns) with hypercalcemia, hypercalciuria, and nephrocalcinosis. However, a few patients (mostly with monoallelic heterozygous pathogenic variants) can develop mild symptoms in adulthood. Case description We present the case of a 43-year-old male patient with hypertension and heterozygous Leiden mutation, with mural thrombi in the common iliac artery, who was sent by a nephrologist to endocrinological examination due to hypoparathyroidism, progressive hypercalcemia, hypercalciuria, and CKDG2A1. Complete laboratory and imaging methods (including PET-CT) excluded PTH-related peptide-mediated hypercalcemia and granulomatosis. Finally, the genetic analysis of the CYP24A1 gene revealed the presence of a novel combination of two heterozygous pathogenic variants: CYP24A1: c. 443T>C p.(Leu148Pro) and c.1186C>T p.(Arg396Trp). Conclusion Differential diagnosis of patients with hypercalciuria, nephrocalcinosis, and hypercalcemia related to vitamin D exposure should include the CYP24A1 gene mutation. To the best of our knowledge, this is the first case of the novel combination of two heterozygous pathogenic variants of CYP24A1.
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Affiliation(s)
- Ludmila Brunerova
- Department of Internal Medicine, Faculty Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Charles University, Prague, Czechia,*Correspondence: Ludmila Brunerova ✉
| | - Ondrej Remes
- Department of Internal Medicine, Faculty Hospital Kralovske Vinohrady and 3rd Faculty of Medicine, Charles University, Prague, Czechia,Nefromed, Prague, Czechia
| | - Veronika Zoubkova
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
| | - Pavel Votypka
- Department of Biology and Medical Genetics, 2nd Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czechia
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2
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Sawicki K, Czajka M, Matysiak-Kucharek M, Kurzepa J, Wojtyła-Buciora P, Zygo K, Kruszewski M, Kapka-Skrzypczak L. Chlorpyrifos alters expression of enzymes involved in vitamin D 3 synthesis in skin cells. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2021; 174:104812. [PMID: 33838712 DOI: 10.1016/j.pestbp.2021.104812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 02/11/2021] [Accepted: 02/22/2021] [Indexed: 06/12/2023]
Abstract
Skin acts as a mechanical barrier between human body and environment. Epidermal cells are regularly exposed to many physiological and environmental stressors, such as pesticides, like chlorpyrifos (CPS). It is recognised that CPS may affect metabolism of other exo- and endogenous substances by affecting enzyme activity and expression. This study aims to investigate the effect of CPS on expression of CYP27A1, CYP27B1 and CYP24A1, the enzymes involved in synthesis and metabolism of vitamin D3, in human keratinocytes HaCaT and human fibroblasts BJ. Synthesis of vitamin D3 in cells was initiated by irradiating with UVB. Expression of CYP27A1, CYP27B1 and CYP24A1 was evaluated by RT-qPCR and Western blot. Our experiments revealed that expression of all tested cytochrome P450 isoforms in cells exposed to CPS changed significantly. Exposure of HaCaT keratinocytes to CPS decreased CYP27A1 mRNA levels, but increased CYP27B1 and CYP24A1 mRNA levels. This was confirmed at the protein level, except for the CYP27A1 expression. Outcome for the BJ cells was however less conclusive. Though exposure to CPS decreased CYP27A1 and CYP27B1 mRNA levels, at protein level increasing concentration of CPS and UVB intensity induced expression of CYP27A1 and CYP24A1. The expression of CYP27B1 isoform decreased in line with mRNA level. Nevertheless, it can be concluded that CPS may therefore interrupt vitamin D3 metabolism in skin cells, but further studies are required to better understand such mechanisms.
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Affiliation(s)
- Krzysztof Sawicki
- Department of Molecular Biology and Translational Research, Institute of Rural Health, Lublin, Poland.
| | - Magdalena Czajka
- Department of Molecular Biology and Translational Research, Institute of Rural Health, Lublin, Poland
| | | | - Jacek Kurzepa
- Chair and Department of Medical Chemistry, Medical University, Lublin, Poland
| | | | - Karol Zygo
- Department of Public Health, Medical University, Lublin, Poland
| | - Marcin Kruszewski
- Department of Molecular Biology and Translational Research, Institute of Rural Health, Lublin, Poland; Centre for Radiobiology and Biological Dosimetry, Institute of Nuclear Chemistry and Technology, Warsaw, Poland
| | - Lucyna Kapka-Skrzypczak
- Department of Molecular Biology and Translational Research, Institute of Rural Health, Lublin, Poland.
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3
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Svajger BA, Pruss CM, Laverty KJ, Zelt JGE, Jones G, Kaufmann M, Petkovich M, Holden RM, Adams MA. PTH suppression by calcitriol does not predict off-target actions in experimental CKD. Pharmacol Res Perspect 2021; 8:e00605. [PMID: 32519465 PMCID: PMC7283992 DOI: 10.1002/prp2.605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 05/12/2020] [Indexed: 12/28/2022] Open
Abstract
Vitamin D receptor agonist (VDRA) therapy for PTH suppression is a mainstay for patients with severe CKD. Calcitriol (1,25‐(OH)2D3) is a former first‐line VDRA in CKD treatment. However, a consequence of its use in CKD is accelerated vascular calcification (VC). An experimental CKD model was used to determine whether altering the calcitriol delivery profile to obtain different PTH suppression levels could improve vascular health outcomes. High adenine diet (0.25%) was used to generate experimental CKD in rats. CKD rats were treated using different calcitriol dosing strategies: (a) 20 ng/kg SD (n = 8), (b) 80 ng/kg SD (n = 8), (c) 5 ng/kg QID (n = 9), or (d) 20 ng/kg QID (n = 9). Multiple targets of calcitriol were assessed which include arterial calcium and phosphate as well as circulating calcium, phosphate, PTH, FGF‐23, VWF, and vitamin D metabolome. PTH suppression occurred dose‐dependently after 1‐week calcitriol treatment (P < .01), but the suppressive effect was lost over time. Both VC and circulating FGF‐23 increased > 10× in all calcitriol‐treated rats (P < .05 and P < .001, respectively); similarly, circulating VWF increased at all time points (P < .05). Ad‐hoc analysis of CKD morbidities in treated rats indicated no differences in negative outcomes based on PTH suppression level (minimal‐, target‐, and over‐). Comparing different calcitriol dosing strategies revealed the following: (a) despite initial calcitriol‐influenced PTH suppression across all treatments, the ability to continually suppress PTH was markedly reduced by study conclusion and (b) PTH suppression level is not an adequate proxy for improvements in overall CKD morbidity. These findings show (a) a more holistic approach to evaluate CKD treatment efficacy aside from PTH suppression is needed and (b) that other VDRA therapies should be examined in CKD treatment.
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Affiliation(s)
- Bruno A Svajger
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Cynthia M Pruss
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Kimberly J Laverty
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Jason G E Zelt
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,Molecular Function and Imaging Program, The National Cardiac PET Centre, and the Advanced Heart Disease Program, Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute and University of Ottawa, Ottawa, Ontario, Canada
| | - Glenville Jones
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Martin Kaufmann
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Martin Petkovich
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - Rachel M Holden
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada.,Department of Medicine, Queen's University, Kingston, Ontario, Canada
| | - Michael A Adams
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
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4
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Kumar A, Estrada DF. Specificity of the Redox Complex between Cytochrome P450 24A1 and Adrenodoxin Relies on Carbon-25 Hydroxylation of Vitamin-D Substrate. Drug Metab Dispos 2019; 47:974-982. [PMID: 31289106 DOI: 10.1124/dmd.119.087759] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Accepted: 07/01/2019] [Indexed: 11/22/2022] Open
Abstract
Metabolic deactivation of 1,25(OH)2D3 is initiated by modification of the vitamin-D side chain, as carried out by the mitochondrial cytochrome P450 24A1 (CYP24A1). In addition to its role in vitamin-D metabolism, CYP24A1 is involved in catabolism of vitamin-D analogs, thereby reducing their efficacy. CYP24A1 function relies on electron transfer from the soluble ferredoxin protein adrenodoxin (Adx). Recent structural evidence suggests that regioselectivity of the CYP24A1 reaction may correlate with distinct modes of Adx recognition. Here we used nuclear magnetic resonance (NMR) spectroscopy to monitor the structure of 15N-labeled full-length Adx from rat while forming the complex with rat CYP24A1 in the ligand-free state or bound to either 1,25(OH)2D3 or the vitamin-D supplement 1α(OH)D3. Although both vitamin-D ligands were found to induce a reduction in overall NMR peak broadening, thereby suggesting ligand-induced disruption of the complex, a crosslinking analysis suggested that ligand does not have a significant effect on the relative association affinities of the redox complexes. However, a key finding is that, whereas the presence of primary CYP24A1 substrate was found to induce NMR peak broadening focused on the putative recognition site α-helix 3 of rat adrenodoxin, the interaction in the presence of 1α(OH)D3, which is lacking the carbon-25 hydroxyl, results in disruption of the NMR peak broadening pattern, thus indicating a ligand-induced nonspecific protein interaction. These findings provide a structural basis for the poor substrate turnover of side-chain-modified vitamin-D analogs, while also confirming that specificity of the CYP24A1-ligand interaction influences specificity of CYP24A1-Adx recognition. SIGNIFICANCE STATEMENT: Mitochondrial cytochrome P450 enzymes, such as CYP24A1 responsible for catabolizing vitamin-D and its analogs, rely on a protein-protein interaction with a ferredoxin in order to receive delivery of the electrons required for catalysis. In this study, we demonstrate that this protein interaction is influenced by the enzyme-ligand interaction that precedes it. Specifically, vitamin-D missing carbon-25 hydroxylation binds the enzyme active site with high affinity but results in a loss of P450-ferredoxin binding specificity.
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Affiliation(s)
- Amit Kumar
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Science, University at Buffalo, Buffalo New York
| | - D Fernando Estrada
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Science, University at Buffalo, Buffalo New York
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5
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Jiráčková J, Hyšpler R, Alkanderi S, Pavlíková L, Palicka V, Sayer JA. Novel CYP24A1 Mutation in a Young Male Patient with Nephrolithiasis: Case Report. Kidney Blood Press Res 2019; 44:870-877. [PMID: 31288237 DOI: 10.1159/000500922] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 05/10/2019] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS The CYP24A1 gene encodes the vitamin D 24-hydroxylase enzyme, which hydroxylates active forms of vitamin D into inactive forms. Biallelic mutations in the CYP24A1 gene can lead to elevated levels of active vitamin D metabolites and, consequently, to hypercalcemia, hypercalciuria, nephrocalcinosis, and nephrolithiasis; however, monoallelic mutations have been associated only with milder phenotypes. In the present manuscript, we report the case of a young male patient who presented hypercalcemia and nephrolithiasis, suppressed parathormone, and elevated 1,25 dihydroxy vitamin D levels. METHODS Biochemical analyses were performed on Cobas 8000, F. Hoffmann-La Roche AG, Basel, Switzerland. The proband was initially evaluated for occult malignancies by body imaging, serum electrophoresis, and tumor markers, which did not reveal any pathology. DNA samples of the proband and his sibling were then examined using Sanger sequencing. RESULTS Genetic analysis revealed 2 compound heterozygous CYP24A1 mutations (p.L148P and p.R223*). The novel nonsense CYP24A1 mutation, p.R223*, was also found heterozygously in other family members with a medical history of nephrolithiasis. CONCLUSIONS The identification of this gene mutation causing hypercalcemia, hypercalciuria, and renal stones allows the specific management of endogenous vitamin D production.
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Affiliation(s)
- Jana Jiráčková
- Institute for Clinical Biochemistry and Diagnostics, Department of Clinical Osteology, University Hospital Hradec Králové, Hradec Králové, Czechia, .,Department of Gerontology and Metabolism, University Hospital Hradec Králové, Hradec Králové, Czechia, .,Faculty of Medicine, Charles University, Hradec Králové, Czechia,
| | - Radomir Hyšpler
- Institute for Clinical Biochemistry and Diagnostics, Department of Clinical Osteology, University Hospital Hradec Králové, Hradec Králové, Czechia.,Faculty of Medicine, Charles University, Hradec Králové, Czechia
| | - Sumaya Alkanderi
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Ladislava Pavlíková
- Institute for Clinical Biochemistry and Diagnostics, Department of Clinical Osteology, University Hospital Hradec Králové, Hradec Králové, Czechia.,Faculty of Medicine, Charles University, Hradec Králové, Czechia
| | - Vladimir Palicka
- Institute for Clinical Biochemistry and Diagnostics, Department of Clinical Osteology, University Hospital Hradec Králové, Hradec Králové, Czechia.,Faculty of Medicine, Charles University, Hradec Králové, Czechia
| | - John A Sayer
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom.,Newcastle upon Tyne NHS Hospitals Foundation Trust, Newcastle, United Kingdom.,NIHR Newcastle Biomedical Research Centre, Newcastle, United Kingdom
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6
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Rendic SP, Peter Guengerich F. Human cytochrome P450 enzymes 5-51 as targets of drugs and natural and environmental compounds: mechanisms, induction, and inhibition - toxic effects and benefits. Drug Metab Rev 2019; 50:256-342. [PMID: 30717606 DOI: 10.1080/03602532.2018.1483401] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cytochrome P450 (P450, CYP) enzymes have long been of interest due to their roles in the metabolism of drugs, pesticides, pro-carcinogens, and other xenobiotic chemicals. They have also been of interest due to their very critical roles in the biosynthesis and metabolism of steroids, vitamins, and certain eicosanoids. This review covers the 22 (of the total of 57) human P450s in Families 5-51 and their substrate selectivity. Furthermore, included is information and references regarding inducibility, inhibition, and (in some cases) stimulation by chemicals. We update and discuss important aspects of each of these 22 P450s and questions that remain open.
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Affiliation(s)
| | - F Peter Guengerich
- b Department of Biochemistry , Vanderbilt University School of Medicine , Nashville , TN , USA
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7
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Kaufmann M, Martineau C, Arabian A, Traynor M, St-Arnaud R, Jones G. Calcioic acid: In vivo detection and quantification of the terminal C24-oxidation product of 25-hydroxyvitamin D 3 and related intermediates in serum of mice treated with 24,25-dihydroxyvitamin D 3. J Steroid Biochem Mol Biol 2019; 188:23-28. [PMID: 30553931 PMCID: PMC9703456 DOI: 10.1016/j.jsbmb.2018.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/26/2018] [Accepted: 12/06/2018] [Indexed: 11/21/2022]
Abstract
Calcitroic acid, the excretory form of vitamin D, is the terminal product of a 5-step pathway catalyzed by CYP24A1, commencing with C24-hydroxylation of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3). Catabolism of 25-hydroxyvitamin D3 (25-OH-D3) proceeds via analogous steps culminating in calcioic acid; however this C23-truncated acid has not been reported in the circulation. It has recently been shown that 24,25-dihydroxyvitamin D3 (24,25-(OH)2D3) is an important factor in optimal bone fracture healing acting via an effector molecule FAM57B2 to produce lactosylceramide. Administration of 24,25-(OH)2D3 was found to restore normal fracture repair in Cyp24a1-/- mice devoid of 24,25-(OH)2D3. We set out to study the multi-step catabolism of D3 metabolites in vivo using LC-MS/MS methods in vehicle or 24,25-(OH)2D3-treated mice. Vehicle-treated Cyp24a1+/- mice possessed normal levels of serum 24,25-(OH)2D3 (7 ng/mL) and 25-OH-D3-26,23-lactone (4 ng/mL). We also detected 24-oxo-25-OH-D3 (3 ng/mL) and 24-oxo-23,25-(OH)2D3 (0.4 ng/mL); which were not detectable in vehicle-treated Cyp24a1-/- mice. In 24,25-(OH)2D3-treated Cyp24a1+/- mice, serum 24,25-(OH)2D3 rose to 200 ng/mL while 25-OH-D3-26,23-lactone remained unchanged in comparison to vehicle-treated Cyp24a1+/- mice Concentration of serum 24-oxo-25-OH-D3 and 24-oxo-23,25-(OH)2D3 rose by 10-fold, when Cyp24a1+/- mice were treated with 24,25-(OH)2D3 Calcioic acid was increased to 0.030 ng/mL for 24,25-(OH)2D3-treated Cyp24a1+/- mice. In 24,25-(OH)2D3-treated Cyp24a1-/- mice, serum 24,25-(OH)2D3 rose further to a striking 830 ng/mL due to lack of catabolism of the 24,25-(OH)2D3 dose. Serum 1,25-(OH)2D3 levels were suppressed in 24,25-(OH)2D3-treated Cyp24a1+/- and Cyp24a1-/- mice. Circulating 1,24,25-(OH)3D3 rose from 73 pg/mL to 106 pg/mL when Cyp24a1+/- mice were treated with 24,25-(OH)2D3. While undetectable in vehicle-treated Cyp24a1-/- mice, 1,24,25-(OH)3D3 rose unexpectedly to 153 pg/mL in 24,25-(OH)2D3-treated nulls suggesting conversion of 24,25-(OH)2D3 to 1,24,25-(OH)3D3 via 1-hydroxylation. Taken together, amplification of 24,25-(OH)2D3 catabolism by exogenous doses of this metabolite have enabled detection of downstream C24-oxidation pathway products in vivo, including calcioic acid; and provides a platform for studying alternative routes of vitamin D metabolism that may occur in pathological states including hypervitaminosis D and idiopathic infantile hypercalcemia caused by mutations of CYP24A1.
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Affiliation(s)
- Martin Kaufmann
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada; Department of Surgery, Queen's University, Kingston, ON, Canada
| | - Corine Martineau
- Research Centre - Shriners Hospitals for Children - Canada, Montreal, PQ, Canada
| | - Alice Arabian
- Research Centre - Shriners Hospitals for Children - Canada, Montreal, PQ, Canada
| | - Mary Traynor
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada
| | - René St-Arnaud
- Research Centre - Shriners Hospitals for Children - Canada, Montreal, PQ, Canada; Department of Human Genetics, and Department of Surgery, McGill University, Montréal, PQ, Canada
| | - Glenville Jones
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada.
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8
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Meyer MB, Benkusky NA, Kaufmann M, Lee SM, Onal M, Jones G, Pike JW. A kidney-specific genetic control module in mice governs endocrine regulation of the cytochrome P450 gene Cyp27b1 essential for vitamin D 3 activation. J Biol Chem 2017; 292:17541-17558. [PMID: 28808057 DOI: 10.1074/jbc.m117.806901] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 08/10/2017] [Indexed: 01/08/2023] Open
Abstract
The vitamin D endocrine system regulates mineral homeostasis through its activities in the intestine, kidney, and bone. Terminal activation of vitamin D3 to its hormonal form, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3), occurs in the kidney via the cytochrome P450 enzyme CYP27B1. Despite its importance in vitamin D metabolism, the molecular mechanisms underlying the regulation of the gene for this enzyme, Cyp27b1, are unknown. Here, we identified a kidney-specific control module governed by a renal cell-specific chromatin structure located distal to Cyp27b1 that mediates unique basal and parathyroid hormone (PTH)-, fibroblast growth factor 23 (FGF23)-, and 1,25(OH)2D3-mediated regulation of Cyp27b1 expression. Selective genomic deletion of key components within this module in mice resulted in loss of either PTH induction or FGF23 and 1,25(OH)2D3 suppression of Cyp27b1 gene expression; the former loss caused a debilitating skeletal phenotype, whereas the latter conferred a quasi-normal bone mineral phenotype through compensatory homeostatic mechanisms involving Cyp24a1 We found that Cyp27b1 is also expressed at low levels in non-renal cells, in which transcription was modulated exclusively by inflammatory factors via a process that was unaffected by deletion of the kidney-specific module. These results reveal that differential regulation of Cyp27b1 expression represents a mechanism whereby 1,25(OH)2D3 can fulfill separate functional roles, first in the kidney to control mineral homeostasis and second in extra-renal cells to regulate target genes linked to specific biological responses. Furthermore, we conclude that these mouse models open new avenues for the study of vitamin D metabolism and its involvement in therapeutic strategies for human health and disease.
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Affiliation(s)
- Mark B Meyer
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
| | - Nancy A Benkusky
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
| | - Martin Kaufmann
- the Department of Biomedical and Molecular Sciences, Queen's University Kingston, Kingston, Ontario K7L 3N6, Canada
| | - Seong Min Lee
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
| | - Melda Onal
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
| | - Glenville Jones
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
| | - J Wesley Pike
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
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9
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Hawkes CP, Li D, Hakonarson H, Meyers KE, Thummel KE, Levine MA. CYP3A4 Induction by Rifampin: An Alternative Pathway for Vitamin D Inactivation in Patients With CYP24A1 Mutations. J Clin Endocrinol Metab 2017; 102:1440-1446. [PMID: 28324001 PMCID: PMC5443336 DOI: 10.1210/jc.2016-4048] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 02/28/2017] [Indexed: 11/19/2022]
Abstract
Context The P450 enzyme CYP24A1 is the principal inactivator of vitamin D metabolites. Biallelic loss-of-function mutations in CYP24A1 are associated with elevated serum levels of 1,25-dihydroxyvitamin D3 with consequent hypercalcemia and hypercalciuria and represent the most common form of idiopathic infantile hypercalcemia (IIH). Current management strategies for this condition include a low-calcium diet, reduced dietary vitamin D intake, and limited sunlight exposure. CYP3A4 is a P450 enzyme that inactivates many drugs and xenobiotics and may represent an alternative pathway for inactivation of vitamin D metabolites. Objective Our goal was to determine if rifampin, a potent inducer of CYP3A4, can normalize mineral metabolism in patients with IIH due to mutations in CYP24A1. Methods We treated two patients with IIH with daily rifampin (10 mg/kg/d, up to a maximum of 600 mg). Serum calcium, phosphorus, parathyroid hormone (PTH), liver, and adrenal function and vitamin D metabolites, as well as urinary calcium excretion, were monitored during treatment of up to 13 months. Results Prior to treatment, both patients had hypercalcemia, hypercalciuria, and nephrocalcinosis with elevated serum 1,25-dihydroxyvitamin D3 and suppressed serum PTH. Daily treatment with rifampin was well tolerated and led to normalization or improvement in all clinical and biochemical parameters. Conclusion These observations suggest that rifampin-induced overexpression of CYP3A4 provides an alternative pathway for inactivation of vitamin D metabolites in patients who lack CYP24A1 function.
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MESH Headings
- Adolescent
- Calcitriol/blood
- Calcium/blood
- Calcium/urine
- Child
- Cytochrome P-450 CYP3A Inducers/therapeutic use
- Female
- Humans
- Hypercalcemia/blood
- Hypercalcemia/complications
- Hypercalcemia/drug therapy
- Hypercalcemia/genetics
- Hypercalciuria/etiology
- Infant, Newborn, Diseases/blood
- Infant, Newborn, Diseases/drug therapy
- Infant, Newborn, Diseases/genetics
- Male
- Metabolism, Inborn Errors/blood
- Metabolism, Inborn Errors/complications
- Metabolism, Inborn Errors/drug therapy
- Metabolism, Inborn Errors/genetics
- Mutation
- Nephrocalcinosis/etiology
- Parathyroid Hormone/blood
- Phosphorus/blood
- Rifampin/therapeutic use
- Treatment Outcome
- Vitamin D/blood
- Vitamin D3 24-Hydroxylase/genetics
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Affiliation(s)
- Colin Patrick Hawkes
- Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
- National Children’s Research Centre, Crumlin, Dublin, D12 V004, Ireland
| | - Dong Li
- Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
| | - Hakon Hakonarson
- Center for Applied Genomics, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
| | - Kevin E. Meyers
- Division of Nephrology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Kenneth E. Thummel
- Department of Pharmaceutics, University of Washington School of Pharmacy, Seattle, Washington 98155
| | - Michael A. Levine
- Division of Endocrinology and Diabetes, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania 19104
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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10
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Jones G, Kaufmann M. Vitamin D metabolite profiling using liquid chromatography-tandem mass spectrometry (LC-MS/MS). J Steroid Biochem Mol Biol 2016; 164:110-114. [PMID: 26409684 DOI: 10.1016/j.jsbmb.2015.09.026] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Revised: 07/30/2015] [Accepted: 09/14/2015] [Indexed: 11/26/2022]
Abstract
Liquid chromatography tandem mass spectrometry (LC-MS/MS) has emerged as the latest technology to be used to assay the metabolites of vitamin D. The method uses molecular mass as a detection technique after straightforward extraction and chromatography steps. LC-MS/MS assay provides a level of accuracy and reproducibility not seen before with other methods and is beginning to rival antibody-based methods in terms of sensitivity and convenience. Methods for detection of underivatized and DMEQ-TAD derivatized vitamin D metabolites are evaluated. Sensitivity is improved by 10-100 fold with derivatization and allows for the simultaneous assay of multiple vitamin D metabolites, a process termed vitamin D metabolite profiling. Clinical and research applications of vitamin D metabolite profiling are discussed.
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Affiliation(s)
- Glenville Jones
- Department of Biomedical & Molecular Sciences, Queen's University, Kingston, Ontario K7L3N6, Canada
| | - Martin Kaufmann
- Department of Biomedical & Molecular Sciences, Queen's University, Kingston, Ontario K7L3N6, Canada.
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Kaufmann M, Lee SM, Pike JW, Jones G. A High-Calcium and Phosphate Rescue Diet and VDR-Expressing Transgenes Normalize Serum Vitamin D Metabolite Profiles and Renal Cyp27b1 and Cyp24a1 Expression in VDR Null Mice. Endocrinology 2015; 156:4388-97. [PMID: 26441239 PMCID: PMC4655220 DOI: 10.1210/en.2015-1664] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Vitamin D receptor (VDR)-mediated 1,25-dihydroxyvitamin D3 (1,25(OH)2D3)-dependent gene expression is compromised in the VDR null mouse. The biological consequences include: hypocalcemia, hypophosphatemia, elevated parathyroid hormone (PTH) and 1,25(OH)2D3, and consequential skeletal abnormalities. CYP24A1 is a cytochrome P450 enzyme that is involved in the side chain oxidation and destruction of both 1,25(OH)2D3 and 25-hydroxyvitamin D3 (25-OH-D3). In the current studies, we used liquid chromatography-tandem mass spectrometry technology to compare the metabolic profiles of VDR null mice fed either a normal or a calcium and phosphate-enriched rescue diet and to assess the consequence of transgenic expression of either mouse or human VDR genes in the same background. Serum 1,25(OH)2D3 levels in VDR null mice on normal chow were highly elevated (>3000 pg/mL) coincident with undetectable levels of catabolites such as 24,25-(OH)2D3 and 25-OH-D3-26,23-lactone normally observed in wild-type mice. The rescue diet corrected serum Ca(++), PTH, and 1,25(OH)2D3 values and restored basal expression of Cyp24a1 as evidenced by both renal expression of Cyp24a1 and detection of 24,25-(OH)2D3 and the 25-OH-D3-26,23-lactone. Unexpectedly, this diet also resulted in supranormal levels of 3-epi-24,25-(OH)2D3 and 3-epi-25-OH-D3-26,23-lactone. The reappearance of serum 24,25-(OH)2D3 and renal Cyp24a1 expression after rescue suggests that basal levels of Cyp24a1 may be repressed by high PTH. Introduction of transgenes for either mouse or human VDR also normalized vitamin D metabolism in VDR null mice, whereas this metabolic pattern was unaffected by a transgene encoding a ligand binding-deficient mutant (L233S) human VDR. We conclude that liquid chromatography-tandem mass spectrometry-based metabolic profiling is an ideal analytical method to study mouse models with alterations in calcium/phosphate homeostasis.
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Affiliation(s)
- Martin Kaufmann
- Department of Biomedical and Molecular Sciences (M.K., G.J.), Queen's University, Kingston, Ontario, Canada K7L3N6; and Department of Biochemistry (S.M.L., J.W.P.), University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Seong Min Lee
- Department of Biomedical and Molecular Sciences (M.K., G.J.), Queen's University, Kingston, Ontario, Canada K7L3N6; and Department of Biochemistry (S.M.L., J.W.P.), University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - J Wesley Pike
- Department of Biomedical and Molecular Sciences (M.K., G.J.), Queen's University, Kingston, Ontario, Canada K7L3N6; and Department of Biochemistry (S.M.L., J.W.P.), University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Glenville Jones
- Department of Biomedical and Molecular Sciences (M.K., G.J.), Queen's University, Kingston, Ontario, Canada K7L3N6; and Department of Biochemistry (S.M.L., J.W.P.), University of Wisconsin-Madison, Madison, Wisconsin 53706
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Hartfield KA, Stout CD, Annalora AJ. The novel purification and biochemical characterization of a reversible CYP24A1:adrenodoxin complex. J Steroid Biochem Mol Biol 2013; 136:47-53. [PMID: 23165146 DOI: 10.1016/j.jsbmb.2012.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2012] [Revised: 11/02/2012] [Accepted: 11/04/2012] [Indexed: 11/29/2022]
Abstract
Novel paradigms for CYP24A1 inhibitor development are needed to circumvent existing efficacy and toxicity issues related to human therapeutics in this class. We hypothesize that improved structural knowledge of CYP24A1 in complex with natural substrates, inhibitors and/or its redox partner protein, adrenodoxin (Adx) is required to facilitate the next generation of CYP24A1 inhibitor design. To this end, we have developed truncated expression constructs for both rat CYP24A1 (Δ51) and bovine Adx (Δ108), which allow us to purify a stable and reversible state of the CYP24A1:Adx complex, for use in ongoing X-ray crystallographic studies. Spectral characterization of the reversible complex revealed that Adx binding enhanced the stability of the enzyme-substrate complex, despite lowering the ligand binding affinity of the free enzyme, for 1,25(OH)2D2, over 9-fold. Truncation of CYP24A1's flexible N-terminus (Δ51) improved the enzyme's ability to recruit substrate, without altering Adx's ability to stabilize the ligand-bound form. We also found that several common crystallization detergents, including CHAPS, inhibit ligand binding to the CYP24A1:Adx complex at concentrations well below their reported critical micelle concentration (CMC) values. Ultimately, this research provides a useful platform and framework for the study of conformationally complex, membrane-protein complexes, in the ligand-bound state.
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Affiliation(s)
- Kimberly A Hartfield
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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13
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Abstract
The vitamin D signal transduction system involves a series of cytochrome P450-containing sterol hydroxylases to generate and degrade the active hormone, 1α,25-dihydroxyvitamin D3, which serves as a ligand for the vitamin D receptor-mediated transcriptional gene expression described in companion articles in this review series. This review updates our current knowledge of the specific anabolic cytochrome P450s involved in 25- and 1α-hydroxylation, as well as the catabolic cytochrome P450 involved in 24- and 23-hydroxylation steps, which are believed to initiate inactivation of the vitamin D molecule. We focus on the biochemical properties of these enzymes; key residues in their active sites derived from crystal structures and mutagenesis studies; the physiological roles of these enzymes as determined by animal knockout studies and human genetic diseases; and the regulation of these different cytochrome P450s by extracellular ions and peptide modulators. We highlight the importance of these cytochrome P450s in the pathogenesis of kidney disease, metabolic bone disease, and hyperproliferative diseases, such as psoriasis and cancer; as well as explore potential future developments in the field.
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Affiliation(s)
- Glenville Jones
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
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Nesterova G, Malicdan MC, Yasuda K, Sakaki T, Vilboux T, Ciccone C, Horst R, Huang Y, Golas G, Introne W, Huizing M, Adams D, Boerkoel CF, Collins MT, Gahl WA. 1,25-(OH)2D-24 Hydroxylase (CYP24A1) Deficiency as a Cause of Nephrolithiasis. Clin J Am Soc Nephrol 2013; 8:649-57. [PMID: 23293122 DOI: 10.2215/cjn.05360512] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND AND OBJECTIVES Elevated serum vitamin D with hypercalciuria can result in nephrocalcinosis and nephrolithiasis. This study evaluated the cause of excess 1,25-dihydroxycholecalciferol (1α,25(OH)2D3) in the development of those disorders in two individuals. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Two patients with elevated vitamin D levels and nephrocalcinosis or nephrolithiasis were investigated at the National Institutes of Health (NIH) Clinical Center and the NIH Undiagnosed Diseases Program, by measuring calcium, phosphate, and vitamin D metabolites, and by performing CYP24A1 mutation analysis. RESULTS Both patients exhibited hypercalciuria, hypercalcemia, low parathyroid hormone, elevated vitamin D (1α,25(OH)2D3), normal 25-OHD3, decreased 24,25(OH)2D, and undetectable activity of 1,25(OH)2D-24-hydroxylase (CYP24A1), the enzyme that inactivates 1α,25(OH)2D3. Both patients had bi-allelic mutations in CYP24A1 leading to loss of function of this enzyme. On the basis of dbSNP data, the frequency of predicted deleterious bi-allelic CYP24A1 variants in the general population is estimated to be as high as 4%-20%. CONCLUSIONS The results of this study show that 1,25(OH)2D-24-hydroxylase deficiency due to bi-allelic mutations in CYP24A1 causes elevated serum vitamin D, hypercalciuria, nephrocalcinosis, and renal stones.
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Affiliation(s)
- Galina Nesterova
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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15
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Höbaus J, Thiem U, Hummel DM, Kallay E. Role of calcium, vitamin D, and the extrarenal vitamin D hydroxylases in carcinogenesis. Anticancer Agents Med Chem 2013; 13:20-35. [PMID: 23094918 PMCID: PMC3826118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2012] [Revised: 05/05/2012] [Accepted: 05/16/2012] [Indexed: 06/01/2023]
Abstract
Vitamin D deficiency and low calcium intake are considered risk factors for several cancers. Vitamin D, synthesized in the skin or ingested through the diet, is transformed through two hydroxylation steps to the active metabolite, 1α,25-dihydroxyvitamin D3 (1,25-D3). 25-hydroxylases in the liver are responsible for the first hydroxylation step. The ultimate activation is performed by the renal 25-hydroxyvitamin D 1α-hydroxylase (CYP27B1), while the 1,25-dihydroxyvitamin D 24-hydroxylase (CYP24A1) in the kidneys degrades the active metabolite. These two renal vitamin D hydroxylases control the endocrine serum 1,25-D3 levels, and are responsible for maintaining mineral homeostasis. In addition, the active vitamin D hormone 1,25-D3 regulates cellular proliferation, differentiation, and apoptosis in multiple tissues in a paracrine/autocrine manner. Interestingly, it is the low serum level of the precursor 25- hydroxyvitamin D3 (25-D3) that predisposes to numerous cancers and other chronic diseases, and not the serum concentration of the active vitamin D hormone. The extra-renal autocrine/paracrine vitamin D system is able to synthesize and degrade locally the active 1,25- D3 necessary to maintain normal cell growth and to counteract mitogenic stimuli. Thus, vitamin D hydroxylases play a prominent role in this process. The present review describes the role of the vitamin D hydroxylases in cancer pathogenesis and the cross-talk between the extra-renal autocrine/paracrine vitamin D system and calcium in cancer prevention.
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Affiliation(s)
- Julia Höbaus
- Department of Pathophysiology and Allergy Research
| | - Ursula Thiem
- Department of Pathophysiology and Allergy Research
- Division of Nephrology and Dialysis, Medical University of Vienna
| | | | - Enikö Kallay
- Department of Pathophysiology and Allergy Research
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Jones G, Prosser DE, Kaufmann M. 25-Hydroxyvitamin D-24-hydroxylase (CYP24A1): its important role in the degradation of vitamin D. Arch Biochem Biophys 2011; 523:9-18. [PMID: 22100522 DOI: 10.1016/j.abb.2011.11.003] [Citation(s) in RCA: 332] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/19/2011] [Accepted: 11/01/2011] [Indexed: 01/08/2023]
Abstract
CYP24A1 is the cytochrome P450 component of the 25-hydroxyvitamin D(3)-24-hydroxylase enzyme that catalyzes the conversion of 25-hydroxyvitamin D(3) (25-OH-D(3)) and 1,25-dihydroxyvitamin D(3) (1,25-(OH)(2)D(3)) into 24-hydroxylated products, which constitute the degradation of the vitamin D molecule. This review focuses on recent data in the CYP24A1 field, including biochemical, physiological and clinical developments. Notable among these are: the first crystal structure for rat CYP24A1; mutagenesis studies which change the regioselectivity of the enzyme; and the finding that natural inactivating mutations of CYP24A1 cause the genetic disease idiopathic infantile hypercalcemia (IIH). The review also discusses the emerging correlation between rising serum phosphate/FGF-23 levels and increased CYP24A1 expression in chronic kidney disease, which in turn underlies accelerated degradation of both serum 25-OH-D(3) and 1,25-(OH)(2)D(3) in this condition. This review concludes by evaluating the potential clinical utility of blocking this enzyme with CYP24A1 inhibitors in various disease states.
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Affiliation(s)
- Glenville Jones
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, ON, Canada K7L 3N6.
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