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Chen Y, Anderson MT, Payne N, Santori FR, Ivanova NB. Nuclear Receptors and the Hidden Language of the Metabolome. Cells 2024; 13:1284. [PMID: 39120315 PMCID: PMC11311682 DOI: 10.3390/cells13151284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2024] [Revised: 07/16/2024] [Accepted: 07/22/2024] [Indexed: 08/10/2024] Open
Abstract
Nuclear hormone receptors (NHRs) are a family of ligand-regulated transcription factors that control key aspects of development and physiology. The regulation of NHRs by ligands derived from metabolism or diet makes them excellent pharmacological targets, and the mechanistic understanding of how NHRs interact with their ligands to regulate downstream gene networks, along with the identification of ligands for orphan NHRs, could enable innovative approaches for cellular engineering, disease modeling and regenerative medicine. We review recent discoveries in the identification of physiologic ligands for NHRs. We propose new models of ligand-receptor co-evolution, the emergence of hormonal function and models of regulation of NHR specificity and activity via one-ligand and two-ligand models as well as feedback loops. Lastly, we discuss limitations on the processes for the identification of physiologic NHR ligands and emerging new methodologies that could be used to identify the natural ligands for the remaining 17 orphan NHRs in the human genome.
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Affiliation(s)
- Yujie Chen
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA; (Y.C.); (M.T.A.); (N.P.)
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Matthew Tom Anderson
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA; (Y.C.); (M.T.A.); (N.P.)
| | - Nathaniel Payne
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA; (Y.C.); (M.T.A.); (N.P.)
| | - Fabio R. Santori
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA; (Y.C.); (M.T.A.); (N.P.)
| | - Natalia B. Ivanova
- Center for Molecular Medicine, University of Georgia, Athens, GA 30602, USA; (Y.C.); (M.T.A.); (N.P.)
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
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Zillinger LS, Hustedt K, Schnepel N, Hirche F, Schmicke M, Stangl GI, Muscher-Banse AS. Effects of dietary nitrogen and/or phosphorus reduction on mineral homeostasis and regulatory mechanisms in young goats. Front Vet Sci 2024; 11:1375329. [PMID: 38799725 PMCID: PMC11117143 DOI: 10.3389/fvets.2024.1375329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 05/01/2024] [Indexed: 05/29/2024] Open
Abstract
Introduction The reduction of nitrogen (N) and phosphorus (P) in ruminant feed is desirable due to costs and negative environmental impact. Ruminants are able to utilize N and P through endogenous recycling, particularly in times of scarcity. When N and/or P were reduced, changes in mineral homeostasis associated with modulation of renal calcitriol metabolism occurred. The aim of this study was to investigate the potential effects of dietary N- and/or P-reduction on the regulatory mechanisms of mineral transport in the kidney and its hormonal regulation in young goats. Results During N-reduction, calcium (Ca) and magnesium (Mg) concentrations in blood decreased, accompanied by a lower protein expression of cytochrome P450 family 27 subfamily B member 1 (CYP27B1) (p = 0.016). The P-reduced fed goats had low blood phosphate concentrations with simultaneously high Ca and Mg levels. The insulin-like growth factor 1 concentrations decreased significantly with P-reduction. Furthermore, gene expression of CYP27B1 (p < 0.001) and both gene (p = 0.025) and protein (p = 0.016) expression of the fibroblast growth factor receptor 1c isoform in the kidney were also significantly reduced during a P-reduced diet. ERK1/2 activation exhibited a trend toward reduction in P-reduced animals. Interestingly, calcitriol concentrations remained unaffected by either restriction individually, but interacted significantly with N and P (p = 0.014). Additionally, fibroblast growth factor 23 mRNA expression in bone decreased significantly with P-restriction (p < 0.001). Discussion These results shed light on the complex metabolic and regulatory responses of mineral transport of young goats to dietary N and P restriction.
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Affiliation(s)
- Luisa S. Zillinger
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Karin Hustedt
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Nadine Schnepel
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Frank Hirche
- Institute of Agricultural and Nutritional Science, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Marion Schmicke
- Clinic for Cattle, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
| | - Gabriele I. Stangl
- Institute of Agricultural and Nutritional Science, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Alexandra S. Muscher-Banse
- Institute for Physiology and Cell Biology, University of Veterinary Medicine Hannover, Foundation, Hannover, Germany
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Pike JW, Lee SM, Meyer MB. Molecular insights into mineralotropic hormone inter-regulation. Front Endocrinol (Lausanne) 2023; 14:1213361. [PMID: 37441497 PMCID: PMC10334211 DOI: 10.3389/fendo.2023.1213361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 06/13/2023] [Indexed: 07/15/2023] Open
Abstract
The regulation of mineral homeostasis involves the three mineralotropic hormones PTH, FGF23 and 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). Early research efforts focused on PTH and 1,25(OH)2D3 and more recently on FGF23 have revealed that each of these hormones regulates the expression of the other two. Despite early suggestions of transcriptional processes, it has been only recently that research effort have begun to delineate the genomic mechanisms underpinning this regulation for 1,25(OH)2D3 and FGF23; the regulation of PTH by 1,25(OH)2D3, however, remains obscure. We review here our molecular understanding of how PTH induces Cyp27b1 expression, the gene encoding the enzyme responsible for the synthesis of 1,25(OH)2D3. FGF23 and 1,25(OH)2D3, on the other hand, function by suppressing production of 1,25(OH)2D3. PTH stimulates the PKA-induced recruitment of CREB and its coactivator CBP at CREB occupied sites within the kidney-specific regulatory regions of Cyp27b1. PKA activation also promotes the nuclear translocation of SIK bound coactivators such as CRTC2, where it similarly interacts with CREB occupied Cyp27b1 sites. The negative actions of both FGF23 and 1,25(OH)2D3 appear to suppress Cyp27b1 expression by opposing the recruitment of CREB coactivators at this gene. Reciprocal gene actions are seen at Cyp24a1, the gene encoding the enzyme that degrades 1,25(OH)2D3, thereby contributing to the overall regulation of blood levels of 1,25(OH)2D3. Relative to PTH regulation, we summarize what is known of how 1,25(OH)2D3 regulates PTH suppression. These studies suggest that it is not 1,25(OH)2D3 that controls PTH levels in healthy subjects, but rather calcium itself. Finally, we describe current progress using an in vivo approach that furthers our understanding of the regulation of Fgf23 expression by PTH and 1,25(OH)2D3 and provide the first evidence that P may act to induce Fgf23 expression via a complex transcriptional mechanism in bone. It is clear, however, that additional advances will need to be made to further our understanding of the inter-regulation of each of these hormonal genes.
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Affiliation(s)
- J. Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States
| | - Seong Min Lee
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, United States
| | - Mark B. Meyer
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, United States
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Yasuda K, Nishikawa M, Mano H, Takano M, Kittaka A, Ikushiro S, Sakaki T. Development of In Vitro and In Vivo Evaluation Systems for Vitamin D Derivatives and Their Application to Drug Discovery. Int J Mol Sci 2021; 22:ijms222111839. [PMID: 34769269 PMCID: PMC8584323 DOI: 10.3390/ijms222111839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 12/30/2022] Open
Abstract
We have developed an in vitro system to easily examine the affinity for vitamin D receptor (VDR) and CYP24A1-mediated metabolism as two methods of assessing vitamin D derivatives. Vitamin D derivatives with high VDR affinity and resistance to CYP24A1-mediated metabolism could be good therapeutic agents. This system can effectively select vitamin D derivatives with these useful properties. We have also developed an in vivo system including a Cyp27b1-gene-deficient rat (a type I rickets model), a Vdr-gene-deficient rat (a type II rickets model), and a rat with a mutant Vdr (R270L) (another type II rickets model) using a genome editing method. For Cyp27b1-gene-deficient and Vdr mutant (R270L) rats, amelioration of rickets symptoms can be used as an index of the efficacy of vitamin D derivatives. Vdr-gene-deficient rats can be used to assess the activities of vitamin D derivatives specialized for actions not mediated by VDR. One of our original vitamin D derivatives, which displays high affinity VDR binding and resistance to CYP24A1-dependent metabolism, has shown good therapeutic effects in Vdr (R270L) rats, although further analysis is needed.
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Affiliation(s)
- Kaori Yasuda
- Department of Pharmaceutical Engineering, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu 939-0398, Toyama, Japan; (K.Y.); (H.M.)
| | - Miyu Nishikawa
- Department of Biotechnology, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu 939-0398, Toyama, Japan; (M.N.); (S.I.)
| | - Hiroki Mano
- Department of Pharmaceutical Engineering, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu 939-0398, Toyama, Japan; (K.Y.); (H.M.)
| | - Masashi Takano
- Faculty of Pharmaceutical Sciences, Teikyo University, Tokyo 173-8605, Japan; (M.T.); (A.K.)
| | - Atsushi Kittaka
- Faculty of Pharmaceutical Sciences, Teikyo University, Tokyo 173-8605, Japan; (M.T.); (A.K.)
| | - Shinichi Ikushiro
- Department of Biotechnology, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu 939-0398, Toyama, Japan; (M.N.); (S.I.)
| | - Toshiyuki Sakaki
- Department of Pharmaceutical Engineering, Faculty of Engineering, Toyama Prefectural University, 5180 Kurokawa, Imizu 939-0398, Toyama, Japan; (K.Y.); (H.M.)
- Correspondence:
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Nagata A, Akagi Y, Asano L, Kotake K, Kawagoe F, Mendoza A, Masoud SS, Usuda K, Yasui K, Takemoto Y, Kittaka A, Nagasawa K, Uesugi M. Synthetic Chemical Probes That Dissect Vitamin D Activities. ACS Chem Biol 2019; 14:2851-2858. [PMID: 31618573 DOI: 10.1021/acschembio.9b00718] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Vitamin D3 metabolites are capable of controlling gene expression in mammalian cells through two independent pathways: vitamin D receptor (VDR) and sterol regulatory element-binding protein (SREBP) pathways. In the present study, we dissect the complex biological activity of vitamin D by designing synthetic vitamin D3 analogs specific for VDR or SREBP pathway, i.e., a VDR activator that lacks SREBP inhibitory activity, or an SREBP inhibitor devoid of VDR activity. These synthetic vitamin D probes permitted identification of one of the vitamin D-responsive genes, Soat1, as an SREBP-suppressed gene. The chemical probes developed in the present study may prove useful in dissecting the intricate interplay of vitamin D actions, thereby providing insights into how vitamin D target genes are regulated.
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Affiliation(s)
- Akiko Nagata
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei city, Tokyo 184-8588, Japan
| | - Yusuke Akagi
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei city, Tokyo 184-8588, Japan
| | | | | | - Fumihiro Kawagoe
- Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi, Tokyo 173-8605, Japan
| | | | - Shadi Sedghi Masoud
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei city, Tokyo 184-8588, Japan
| | - Kosuke Usuda
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei city, Tokyo 184-8588, Japan
| | - Koji Yasui
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei city, Tokyo 184-8588, Japan
| | | | - Atsushi Kittaka
- Faculty of Pharmaceutical Sciences, Teikyo University, 2-11-1 Kaga, Itabashi, Tokyo 173-8605, Japan
| | - Kazuo Nagasawa
- Department of Biotechnology and Life Science, Graduate School of Technology, Tokyo University of Agriculture and Technology, 2-24-16, Naka-cho, Koganei city, Tokyo 184-8588, Japan
| | - Motonari Uesugi
- CREST, AMED 1-7-1 Otemachi, Chiyoda-ku, Tokyo 100-0004, Japan
- School of Pharmacy, Fudan University, Shanghai 201203, China
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Meyer MB, Lee SM, Carlson AH, Benkusky NA, Kaufmann M, Jones G, Pike JW. A chromatin-based mechanism controls differential regulation of the cytochrome P450 gene Cyp24a1 in renal and non-renal tissues. J Biol Chem 2019; 294:14467-14481. [PMID: 31439663 DOI: 10.1074/jbc.ra119.010173] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 08/08/2019] [Indexed: 12/18/2022] Open
Abstract
Cytochrome P450 family 27 subfamily B member 1 (CYP27B1) and CYP24A1 function to maintain physiological levels of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) in the kidney. Renal Cyp27b1 and Cyp24a1 expression levels are transcriptionally regulated in a highly reciprocal manner by parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), and 1,25(OH)2D3 In contrast, Cyp24a1 regulation in nonrenal target cells (NRTCs) is limited to induction by 1,25(OH)2D3 Herein, we used ChIP-Seq analyses of mouse tissues to identify regulatory regions within the Cyp24a1 gene locus. We found an extended region downstream of Cyp24a1 containing a cluster of sites, termed C24-DS1, binding PTH-sensitive cAMP-responsive element-binding protein (CREB) and a cluster termed C24-DS2 binding the vitamin D receptor (VDR). VDR-occupied sites were present in both the kidney and NRTCs, but pCREB sites were occupied only in the kidney. We deleted each segment in the mouse and observed that although the overt phenotypes of both cluster deletions were unremarkable, RNA analysis in the C24-DS1-deleted strain revealed a loss of basal renal Cyp24a1 expression, total resistance to FGF23 and PTH regulation, and secondary suppression of renal Cyp27b1; 1,25(OH)2D3 induction remained unaffected in all tissues. In contrast, loss of the VDR cluster in the C24-DS2-deleted strain did not affect 1,25(OH)2D3 induction of renal Cyp24a1 expression yet reduced but did not eliminate Cyp24a1 responses in NRTCs. We conclude that a chromatin-based mechanism differentially regulates Cyp24a1 in the kidney and NRTCs and is essential for the specific functions of Cyp24a1 in these two tissue types.
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Affiliation(s)
- Mark B Meyer
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Seong Min Lee
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Alex H Carlson
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Nancy A Benkusky
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Martin Kaufmann
- Department of Biomedical and Molecular Sciences, Queens University, Kingston, Ontario K7L 3N6, Canada.,Department of Surgery, Queens University, Kingston, Ontario K7L 3N6, Canada
| | - Glenville Jones
- Department of Biomedical and Molecular Sciences, Queens University, Kingston, Ontario K7L 3N6, Canada
| | - J Wesley Pike
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
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Vieira WA, Wells KM, Milgrom R, McCusker CD. Exogenous Vitamin D signaling alters skeletal patterning, differentiation, and tissue integration during limb regeneration in the axolotl. Mech Dev 2018; 153:1-9. [PMID: 30096415 PMCID: PMC6727847 DOI: 10.1016/j.mod.2018.08.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2017] [Revised: 03/22/2018] [Accepted: 08/06/2018] [Indexed: 12/19/2022]
Abstract
Urodele amphibians such as the axolotl regenerate complete limbs as adults, and understanding how the "blueprint", or pattern, of the regenerate is established and manipulated are areas of intense interest. Nutrient signaling plays an important role in pattern formation during regeneration. Retinoic acid signaling is the most characterized pathway during this process. Exogenous retinoic acid (RA) reprograms the pattern information in regenerating cells to a more posterior, ventral, and proximal identity. Vitamin D signaling shares several molecular similarities with RA and has been shown to alter pattern formation during zebrafish pectoral fin regeneration. To determine if exogenous Vitamin D signaling is capable of reprograming pattern in the axolotl limb blastema, we treated regenerating limbs with a potent Vitamin D agonist. Under the studied conditions, exogenous Vitamin D did not act in a manner similar to RA and failed to proximalize the pattern of the resulting regenerates. The Vitamin D treatment did result in several skeletal defects during regeneration, including carpal fusions along the A/P axis; failure to integrate the newly regenerated tissue with the existing tissue, formation of ectopic nodules of cartilage at the site of amputation, and altered bone morphology in uninjured skeletal tissue.
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Affiliation(s)
- Warren A Vieira
- Department of Biology, University of Massachusetts Boston, Boston, MA, USA
| | - Kaylee M Wells
- Department of Biology, University of Massachusetts Boston, Boston, MA, USA
| | - Roni Milgrom
- Department of Biology, University of Massachusetts Boston, Boston, MA, USA
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Lu M, Taylor BV, Körner H. Genomic Effects of the Vitamin D Receptor: Potentially the Link between Vitamin D, Immune Cells, and Multiple Sclerosis. Front Immunol 2018; 9:477. [PMID: 29593729 PMCID: PMC5857605 DOI: 10.3389/fimmu.2018.00477] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/22/2018] [Indexed: 12/12/2022] Open
Abstract
Vitamin D has a plethora of functions that are important for the maintenance of general health and in particular, the functional integrity of the immune system, such as promoting an anti-inflammatory cytokine profile and reducing the Treg/Th17 ratio. Multiple sclerosis (MS) is a chronic, inflammatory, and neurodegenerative central nervous system (CNS) disorder of probable autoimmune origin. MS is characterized by recurring or progressive demyelination and degeneration of the CNS due in part to a misguided immune response to as yet undefined (CNS) antigens, potentially including myelin basic protein and proteolipid protein. MS has also been shown to be associated significantly with environmental factors such as the lack of vitamin D. The role of vitamin D in the pathogenesis and progression of MS is complex. Recent genetic studies have shown that various common MS-associated risk-single-nucleotide polymorphisms (SNPs) are located within or in the vicinity of genes associated with the complex metabolism of vitamin D. The functional aspects of these genetic associations may be explained either by a direct SNP-associated loss- or gain-of-function in a vitamin D-associated gene or due to a change in the regulation of gene expression in certain immune cell types. The development of new genetic tools using next-generation sequencing: e.g., chromatin immunoprecipitation sequencing (ChIP-seq) and the accompanying rapid progress of epigenomics has made it possible to recognize that the association between vitamin D and MS could be based on the extensive and characteristic genomic binding of the vitamin D receptor (VDR). Therefore, it is important to analyze comprehensively the spatiotemporal VDR binding patterns that have been identified using ChIP-seq in multiple immune cell types to reveal an integral profile of genomic VDR interaction. In summary, the aim of this review is to connect genomic effects vitamin D has on immune cells with MS and thus, to contribute to a better understanding of the influence of vitamin D on the etiology and the pathogenesis of this complex autoimmune disease.
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Affiliation(s)
- Ming Lu
- Menzies Institute for Medical Research Tasmania, Hobart, TAS, Australia
| | - Bruce V. Taylor
- Menzies Institute for Medical Research Tasmania, Hobart, TAS, Australia
| | - Heinrich Körner
- Menzies Institute for Medical Research Tasmania, Hobart, TAS, Australia
- Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immunopharmacology, Ministry of Education, Engineering Technology Research Center of Anti-inflammatory and Immunodrugs in Anhui Province, Hefei, China
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Abstract
The central role of hormonal 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] is to regulate calcium and phosphorus homeostasis via actions in intestine, kidney, and bone. These and other actions in many cell types not involved in mineral metabolism are mediated by the vitamin D receptor. Recent studies using genome-wide scale techniques have extended fundamental ideas regarding vitamin D-mediated control of gene expression while simultaneously revealing a series of new concepts. This article summarizes the current view of the biological actions of the vitamin D hormone and focuses on new concepts that drive the understanding of the mechanisms through which vitamin D operates.
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Affiliation(s)
- J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Biochem Addition, Room 543D, 433 Babcock Drive, Madison, WI 53706, USA.
| | - Sylvia Christakos
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
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OWENS DANIELJ, TANG JONATHANCY, BRADLEY WARRENJ, SPARKS ANDYS, FRASER WILLIAMD, MORTON JAMESP, CLOSE GRAEMEL. Efficacy of High-Dose Vitamin D Supplements for Elite Athletes. Med Sci Sports Exerc 2017; 49:349-356. [DOI: 10.1249/mss.0000000000001105] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Jin D, Zhang YG, Wu S, Lu R, Lin Z, Zheng Y, Chen H, Cs-Szabo G, Sun J. Vitamin D receptor is a novel transcriptional regulator for Axin1. J Steroid Biochem Mol Biol 2017; 165:430-437. [PMID: 27601169 PMCID: PMC5180453 DOI: 10.1016/j.jsbmb.2016.09.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Axin1 is a scaffold protein in the β-catenin destruction complex, which, if disrupted, contributes to pathogenesis of various human diseases, including colorectal carcinogenesis and inflammatory bowel diseases (IBD). We have previously demonstrated that Salmonella infection promotes the degradation and plasma sequestration of Axin1, leading to bacterial invasiveness and inflammatory responses. Vitamin D and the vitamin D receptor (VDR) appear to be important regulators of IBD and colon cancer. Although VDR and Axin1 are all involved in intestinal inflammation, it remains unclear whether these processes are related or function independently. In the current study, we hypothesize that VDR is an important regulator for the maintenance of physiological level of Axin1. METHODS Using the intestinal epithelial conditional VDR knockout mouse model (VDRΔIEC) and cultured cell lines, influences of VDR status on the expression of Axin1 was evaluated by Western blots and real-time PCR. Loss- and gain-of-function assays were used to investigate the regulation of VDR on Axin1 at the transcriptional and translational levels. Cells were treated with cycloheximide or actinomycin for molecular mechanistic studies. Candidate genomic VDR binding sites for Axin1 were tested by chromatin immunoprecipitation (ChIP) assay. Physical interactions among VDR, Axin1, and β-catenin were tested by immunoprecipitation. Cellular localization of Axin1 with different VDR status was determined by fractionation and immunohistochemistry. RESULTS We found that VDR deletion led to lower protein and mRNA levels of Axin1, whereas knockdown of Axin1 did not change the expression level of VDR protein. Immunoprecipitation data did not support physical interaction between VDR and Axin1. The VDR regulation of Axin1 was through a VDR genomic binding site for Axin1 gene on the regulatory region. Fractionation data showed that cytosolic Axin1 was significantly reduced due to VDR deletion, leaving the nuclear fraction unchanged. In ileum, Axin1 was distributed in the cytosol of apical epithelium and crypts. CONCLUSION VDR is important for the maintenance of physiological level of Axin1. The discovery of Axin1 as a VDR target gene provides novel and fundamental insights into the interactions between the VDR and β-catenin signaling pathways.
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Affiliation(s)
- Dapeng Jin
- Department of Biochemistry, Rush University, Chicago, IL, 60612, USA
| | - Yong-Guo Zhang
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Shaoping Wu
- Department of Biochemistry, Rush University, Chicago, IL, 60612, USA
| | - Rong Lu
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Zhijie Lin
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Yuanyuan Zheng
- Department of Biochemistry, Rush University, Chicago, IL, 60612, USA
| | - Honglei Chen
- Department of Biochemistry, Rush University, Chicago, IL, 60612, USA
| | | | - Jun Sun
- Department of Biochemistry, Rush University, Chicago, IL, 60612, USA; Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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Díaz L, Díaz-Muñoz M, García-Gaytán AC, Méndez I. Mechanistic Effects of Calcitriol in Cancer Biology. Nutrients 2015; 7:5020-50. [PMID: 26102214 PMCID: PMC4488829 DOI: 10.3390/nu7065020] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 06/09/2015] [Accepted: 06/12/2015] [Indexed: 02/05/2023] Open
Abstract
Besides its classical biological effects on calcium and phosphorus homeostasis, calcitriol, the active vitamin D metabolite, has a broad variety of actions including anticancer effects that are mediated either transcriptionally and/or via non-genomic pathways. In the context of cancer, calcitriol regulates the cell cycle, induces apoptosis, promotes cell differentiation and acts as anti-inflammatory factor within the tumor microenvironment. In this review, we address the different mechanisms of action involved in the antineoplastic effects of calcitriol.
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Affiliation(s)
- Lorenza Díaz
- Departamento de Biología de la Reproducción, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga No. 15, Tlalpan, Mexico City 14000, Mexico.
| | - Mauricio Díaz-Muñoz
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, Blvd. Juriquilla 3001, Querétaro 76230, Mexico.
| | - Ana Cristina García-Gaytán
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, Blvd. Juriquilla 3001, Querétaro 76230, Mexico.
| | - Isabel Méndez
- Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, Blvd. Juriquilla 3001, Querétaro 76230, Mexico.
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13
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Pike JW, Meyer MB. Fundamentals of vitamin D hormone-regulated gene expression. J Steroid Biochem Mol Biol 2014; 144 Pt A:5-11. [PMID: 24239506 PMCID: PMC4144817 DOI: 10.1016/j.jsbmb.2013.11.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Revised: 10/24/2013] [Accepted: 11/05/2013] [Indexed: 12/20/2022]
Abstract
Initial research focused upon several known genetic targets provided early insight into the mechanism of action of the vitamin D hormone (1,25-dihydroxyvitamin D3 (1,25(OH)2D3)). Recently, however, a series of technical advances involving the coupling of chromatin immunoprecipitation (ChIP) to unbiased methodologies that initially involved tiled DNA microarrays (ChIP-chip analysis) and now Next Generation DNA Sequencing techniques (ChIP-seq analysis) has opened new avenues of research into the mechanisms through which 1,25(OH)2D3 regulates gene expression. In this review, we summarize briefly the results of this early work and then focus on more recent studies in which ChIP-chip and ChIP-seq analyses have been used to explore the mechanisms of 1,25(OH)2D3 action on a genome-wide scale providing specific target genes as examples. The results of this work have advanced our understanding of the mechanisms involved at both genetic and epigenetic levels and have revealed a series of new principles through which the vitamin D hormone functions to control the expression of genes. This article is part of a Special Issue entitled '16th Vitamin D Workshop'.
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Affiliation(s)
- J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States.
| | - Mark B Meyer
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
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14
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Abstract
The vitamin D endocrine system in now recognized as subserving a wide range of fundamental biological functions in cell differentiation, inhibition of cell growth as well as immunomodulation. Both forms of immunity, namely adaptive and innate, are regulated by 1,25(OH)2D3. The immune-modulatory properties of vitamin D suggest that it could play a potential therapeutic role in prevention of type 1 diabetes mellitus (T1DM). It is postulated that large doses of vitamin D supplementation may influence the pattern of immune regulation and subsequent progression to T1DM in a genetically susceptible individual. More studies are required to substantiate the relation between T1DM and vitamin D/vitamin D analogues in the pattern of immune regulations in susceptible individuals. In type 2 diabetes mellitus (T2DM), vitamin D may influence both insulin secretion and sensitivity. An inverse relationship between T2DM and vitamin D is postulated from cross-sectional and prospective studies, though conclusive proof is as yet lacking. Available studies differ in their design and in the recommended daily allowances (RDA) of vitamin D in non-skeletal diseases and β-cell function. Large, well designed, controlled, randomized interventional studies on the potential role of vitamin D and calcium in prevention and management of T2DM are required to clarify the relationship between vitamin D and glucose homeostasis in T2DM.
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Affiliation(s)
- Chittari Venkata Harinarayan
- Institute of Endocrinology, Diabetes, Thyroid and Osteoporosis Disorders, Sakra World Hospitals, Bangalore, India
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15
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Lin R, Taylor BV, Simpson S, Charlesworth J, Ponsonby AL, Pittas F, Dwyer T, van der Mei I. Association between multiple sclerosis risk-associated SNPs and relapse and disability--a prospective cohort study. Mult Scler 2013; 20:313-21. [PMID: 23886828 DOI: 10.1177/1352458513496882] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND The modulating effects of the multiple sclerosis (MS) risk-associated single-nucleotide polymorphisms (SNPs) on MS clinical course are not well established. OBJECTIVES The objective of this paper is to investigate whether known MS risk-associated SNPs were associated with clinical course, and whether these SNPs modified the 25(OH)D-relapse association. METHODS Using a prospective cohort of 141 participants with relapsing-remitting MS and genotype data followed between 2002 and 2005, genotype-vitamin D interactions and the genetic predictors of relapse were assessed using survival analysis, and genetic predictors of 25(OH)D and disability progression were evaluated by multilevel mixed-effects linear regression. RESULTS While no SNP reached statistical significance after multiple testing, five SNPs were associated with relapse, with significant cumulative genotype risk effects and two demonstrated significant allele dose-response. Two SNPs altered the 25(OH)D-relapse association with significant allele dose-response. Five SNPs modified levels of 25(OH)D, with significant cumulative genotype 'risk' effect, and three demonstrated significant allele dose-response. We found no consistent evidence for an association between any SNPs and disability. CONCLUSIONS Our study provides evidence for an association between known MS risk-associated SNPs and relapse. Our findings indicate gene-environment interactions may be an important mechanism on MS clinical course, and provide support for the role of vitamin D in MS relapse.
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Affiliation(s)
- Rui Lin
- Menzies Research Institute Tasmania, University of Tasmania, Australia
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16
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Zhang Q, Kanterewicz B, Shoemaker S, Hu Q, Liu S, Atwood K, Hershberger P. Differential response to 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) in non-small cell lung cancer cells with distinct oncogene mutations. J Steroid Biochem Mol Biol 2013; 136:264-70. [PMID: 23026510 PMCID: PMC3674199 DOI: 10.1016/j.jsbmb.2012.09.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/17/2012] [Accepted: 09/20/2012] [Indexed: 01/08/2023]
Abstract
We previously demonstrated that non-small cell lung cancer (NSCLC) cells and primary human lung tumors aberrantly express the vitamin D3-catabolizing enzyme, CYP24, and that CYP24 restricts transcriptional regulation and growth control by 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3) in NSCLC cells. To ascertain the basis for CYP24 dysregulation, we assembled a panel of cell lines that represent distinct molecular classes of lung cancer: cell lines were selected which harbored mutually exclusive mutations in either the K-ras or the Epidermal Growth Factor Receptor (EGFR) genes. We observed that K-ras mutant lines displayed a basal vitamin D receptor (VDR)(low)CYP24(high) phenotype, whereas EGFR mutant lines had a VDR(high)CYP24(low) phenotype. A mutation-associated difference in CYP24 expression was also observed in clinical specimens. Specifically, K-ras mutation was associated with a median 4.2-fold increase in CYP24 mRNA expression (p=4.8×10(-7)) compared to EGFR mutation in a series of 147 primary lung adenocarcinoma cases. Because of their differential basal expression of VDR and CYP24, we hypothesized that NSCLC cells with an EGFR mutation would be more responsive to 1,25(OH)2D3 treatment than those with a K-ras mutation. To test this, we measured the ability of 1,25(OH)2D3 to increase reporter gene activity, induce transcription of endogenous target genes, and suppress colony formation. In each assay, the extent of 1,25(OH)2D3 response was greater in EGFR mutation-positive HCC827 and H1975 cells than in K-ras mutation-positive A549 and 128.88T cells. We subsequently examined the effect of combining 1,25(OH)2D3 with erlotinib, which is used clinically in the treatment of EGFR mutation-positive NSCLC. 1,25(OH)2D3/erlotinib combination resulted in significantly greater growth inhibition than either single agent in both the erlotinib-sensitive HCC827 cell line and the erlotinib-resistant H1975 cell line. These data are the first to suggest that EGFR mutations may identify a lung cancer subset which remains responsive to and is likely to benefit from 1,25(OH)2D3 administration. This article is part of a Special Issue entitled 'Vitamin D Workshop'.
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Affiliation(s)
- Qiuhong Zhang
- University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213, United States
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17
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Kongsbak M, Levring TB, Geisler C, von Essen MR. The vitamin d receptor and T cell function. Front Immunol 2013; 4:148. [PMID: 23785369 PMCID: PMC3684798 DOI: 10.3389/fimmu.2013.00148] [Citation(s) in RCA: 194] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/29/2013] [Indexed: 12/14/2022] Open
Abstract
The vitamin D receptor (VDR) is a nuclear, ligand-dependent transcription factor that in complex with hormonally active vitamin D, 1,25(OH)2D3, regulates the expression of more than 900 genes involved in a wide array of physiological functions. The impact of 1,25(OH)2D3-VDR signaling on immune function has been the focus of many recent studies as a link between 1,25(OH)2D3 and susceptibility to various infections and to development of a variety of inflammatory diseases has been suggested. It is also becoming increasingly clear that microbes slow down immune reactivity by dysregulating the VDR ultimately to increase their chance of survival. Immune modulatory therapies that enhance VDR expression and activity are therefore considered in the clinic today to a greater extent. As T cells are of great importance for both protective immunity and development of inflammatory diseases a variety of studies have been engaged investigating the impact of VDR expression in T cells and found that VDR expression and activity plays an important role in both T cell development, differentiation and effector function. In this review we will analyze current knowledge of VDR regulation and function in T cells and discuss its importance for immune activity.
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Affiliation(s)
- Martin Kongsbak
- Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
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18
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Kopic S, Geibel JP. Gastric acid, calcium absorption, and their impact on bone health. Physiol Rev 2013; 93:189-268. [PMID: 23303909 DOI: 10.1152/physrev.00015.2012] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Calcium balance is essential for a multitude of physiological processes, ranging from cell signaling to maintenance of bone health. Adequate intestinal absorption of calcium is a major factor for maintaining systemic calcium homeostasis. Recent observations indicate that a reduction of gastric acidity may impair effective calcium uptake through the intestine. This article reviews the physiology of gastric acid secretion, intestinal calcium absorption, and their respective neuroendocrine regulation and explores the physiological basis of a potential link between these individual systems.
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Affiliation(s)
- Sascha Kopic
- Department of Surgery and Cellular and Molecular Physiology, Yale School of Medicine, New Haven, Connecticut, USA
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19
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Zhang Q, Kanterewicz B, Buch S, Petkovich M, Parise R, Beumer J, Lin Y, Diergaarde B, Hershberger PA. CYP24 inhibition preserves 1α,25-dihydroxyvitamin D(3) anti-proliferative signaling in lung cancer cells. Mol Cell Endocrinol 2012; 355:153-61. [PMID: 22386975 PMCID: PMC3312998 DOI: 10.1016/j.mce.2012.02.006] [Citation(s) in RCA: 36] [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: 09/16/2011] [Revised: 01/09/2012] [Accepted: 02/07/2012] [Indexed: 01/08/2023]
Abstract
Human lung tumors aberrantly express the 1α,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3))-catabolizing enzyme, CYP24. We hypothesized that CYP24 reduces 1,25(OH)(2)D(3)-mediated transcription and allows lung cancer cells to escape its growth-inhibitory action. To test this, H292 lung cancer cells and the CYP24-selective inhibitor CTA091 were utilized. In H292 cells, CTA091 reduces 1,25(OH)(2)D(3) catabolism, significantly increases 1,25(OH)(2)D(3)-mediated growth inhibition, and increases 1,25(OH)(2)D(3) effects on induced and repressed genes in gene expression profiling studies. Pathway mapping of repressed genes uncovered cell cycle as a predominant 1,25(OH)(2)D(3) target. In H292 cells, 1,25(OH)(2)D(3) significantly decreases cyclin E2 levels and induces G(0)/G(1) arrest. A broader set of cyclins is down-regulated when 1,25(OH)(2)D(3) is combined with CTA091, and cell cycle arrest further increases. Effects of CTA091 on 1,25(OH)(2)D(3) signaling are vitamin D receptor-dependent. These data provide evidence that CYP24 limits 1,25(OH)(2)D(3) anti-proliferative signaling in cancer cells, and suggest that CTA091 may be beneficial in preserving 1,25(OH)(2)D(3) action in lung cancer.
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Affiliation(s)
- Qiuhong Zhang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, PA, USA
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20
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Pike JW, Meyer MB. The vitamin D receptor: new paradigms for the regulation of gene expression by 1,25-dihydroxyvitamin D3. Rheum Dis Clin North Am 2012; 38:13-27. [PMID: 22525840 DOI: 10.1016/j.rdc.2012.03.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This article represents a summary of what is known of the VDR protein and its molecular mechanism of action at target genes. New methodologies now used, such as ChIP-chip and ChIP-seq, as well as novel reporter studies using large BAC clones stably transfected into culture cells or introduced as transgenes in mice, are providing new insights into how 1,25(OH)2D3-activated VDR modulates the expression of genes at single gene loci and at the level of gene networks. Many of these insights are unexpected and suggest that gene regulation is even more complex than previously appreciated. These studies also highlight new technologies and their central role in establishing fundamental biologic principles.
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Affiliation(s)
- J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
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21
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Beumer JH, Parise RA, Kanterewicz B, Petkovich M, D’Argenio DZ, A. Hershberger P. A local effect of CYP24 inhibition on lung tumor xenograft exposure to 1,25-dihydroxyvitamin D(3) is revealed using a novel LC-MS/MS assay. Steroids 2012; 77:477-83. [PMID: 22285938 PMCID: PMC3303948 DOI: 10.1016/j.steroids.2012.01.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Revised: 01/09/2012] [Accepted: 01/10/2012] [Indexed: 01/08/2023]
Abstract
The vitamin D(3) catabolizing enzyme, CYP24, is frequently over-expressed in tumors, where it may support proliferation by eliminating the growth suppressive effects of 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)). However, the impact of CYP24 expression in tumors or consequence of CYP24 inhibition on tumor levels of 1,25(OH)(2)D(3)in vivo has not been studied due to the lack of a suitable quantitative method. To address this need, an LC-MS/MS assay that permits absolute quantitation of 1,25(OH)(2)D(3) in plasma and tumor was developed. We applied this assay to the H292 lung tumor xenograft model: H292 cells eliminate 1,25(OH)(2)D(3) by a CYP24-dependent process in vitro, and 1,25(OH)(2)D(3) rapidly induces CYP24 expression in H292 cells in vivo. In tumor-bearing mice, plasma and tumor concentrations of 1,25(OH)(2)D(3) reached a maximum of 21.6 and 1.70ng/mL, respectively, following intraperitoneal dosing (20μg/kg 1,25(OH)(2)D(3)). When co-administered with the CYP24 selective inhibitor CTA091 (250μg/kg), 1,25(OH)(2)D(3) plasma levels increased 1.6-fold, and tumor levels increased 2.6-fold. The tumor/plasma ratio of 1,25(OH)(2)D(3) AUC was increased 1.7-fold by CTA091, suggesting that the inhibitor increased the tumor concentrations of 1,25(OH)(2)D(3) independent of its effects on plasma disposition. Compartmental modeling of 1,25(OH)(2)D(3) concentration versus time data confirmed that: 1,25(OH)(2)D(3) was eliminated from plasma and tumor; CTA091 reduced the elimination from both compartments; and that the effect of CTA091 on tumor exposure was greater than its effect on plasma. These results provide evidence that CYP24-expressing lung tumors eliminate 1,25(OH)(2)D(3) by a CYP24-dependent process in vivo and that CTA091 administration represents a feasible approach to increase tumor exposure to 1,25(OH)(2)D(3).
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Affiliation(s)
- Jan H. Beumer
- Molecular Therapeutics/Drug Discovery Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213
- Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, PA 15213
| | - Robert A. Parise
- Molecular Therapeutics/Drug Discovery Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213
- Department of Pharmaceutical Sciences, University of Pittsburgh School of Pharmacy, Pittsburgh, PA 15213
| | - Beatriz Kanterewicz
- Lung and Thoracic Malignancies Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213
| | - Martin Petkovich
- Cytochroma, Markham, Ontario and Cancer Research Institute, Queen's University, Kingston
| | - David Z. D’Argenio
- Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089
| | - Pamela A. Hershberger
- Lung and Thoracic Malignancies Program, University of Pittsburgh Cancer Institute, Pittsburgh, PA 15213
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15213
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22
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Pike JW, Meyer MB. Regulation of mouse Cyp24a1 expression via promoter-proximal and downstream-distal enhancers highlights new concepts of 1,25-dihydroxyvitamin D(3) action. Arch Biochem Biophys 2011; 523:2-8. [PMID: 22179019 DOI: 10.1016/j.abb.2011.12.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Revised: 11/29/2011] [Accepted: 12/02/2011] [Indexed: 12/19/2022]
Abstract
CYP24A1 functions in vitamin D target tissues to degrade 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)). Thus, the concentration of this enzyme and the regulation of its expression is a primary determinant of the overall biological activity of 1,25(OH)(2)D(3) within cells. The principle regulator of CYP24A1 expression is 1,25(OH)(2)D(3) itself, which functions through the vitamin D receptor to upregulate the transcriptional activity of the Cyp24a1 gene. In this report, we explore the mechanism of this regulation using recently developed ChIP-chip and ChIP-seq techniques that permit an unbiased search for enhancer elements that participate in this transcriptional control. Our studies both confirm a regulatory region defined earlier and located proximal to the transcriptional start site (TSS) of mouse Cyp24a1 (-160 and -265nt) and identify a novel intergenic region located downstream of the transcription unit that contains two enhancers (+35 and +37kb) that facilitate 1,25(OH)(2)D(3)-dependent upregulation of Cyp24a1 expression. Interestingly, while C/EBPβ also binds under basal conditions to a site located immediately upstream of the Cyp24a1 promoter (-345nt), occupancy by this factor is strikingly increased following 1,25(OH)(2)D(3) treatment. The locations and activities of these regulatory regions that mediate 1,25(OH)(2)D(3) actions were confirmed in mice in vivo. We conclude that the mechanism through which 1,25(OH)(2)D(3) induces the CYP24A1 enzyme, thereby autoregulating its own destruction, involves both promoter-proximal as well as downstream-distal enhancers. These findings highlight new concepts regarding the molecular mechanism of action of 1,25(OH)(2)D(3) and other hormonal regulators.
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Affiliation(s)
- J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
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23
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Pike JW. Genome-wide principles of gene regulation by the vitamin D receptor and its activating ligand. Mol Cell Endocrinol 2011; 347:3-10. [PMID: 21664239 PMCID: PMC3179550 DOI: 10.1016/j.mce.2011.05.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 05/09/2011] [Accepted: 05/10/2011] [Indexed: 12/22/2022]
Abstract
The vitamin D receptor (VDR) mediates virtually all of the known biological actions of the hormonal ligand 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)). These actions are directed toward the nucleus, where the VDR binds to the regulatory regions of target genes and modulates their transcriptional output. Recent technological advances have enabled the study of transcription factor binding on a genome-wide scale in cells and tissues that are major targets of vitamin D action. In this review, the results of several of these studies are discussed wherein overarching principles of gene regulation by the vitamin D hormone are beginning to emerge. In addition, several specific genes that are regulated by 1,25(OH)(2)D(3) and which provide new insight into the increasingly complex mechanism whereby the receptor functions to modulate gene expression are considered. These studies suggest that while many of the principles that are now accepted regarding the regulation of gene expression by hormones and other regulatory factors are well grounded, others require extensive modification.
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Affiliation(s)
- J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States.
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24
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Lisse TS, Liu T, Irmler M, Beckers J, Chen H, Adams JS, Hewison M. Gene targeting by the vitamin D response element binding protein reveals a role for vitamin D in osteoblast mTOR signaling. FASEB J 2010; 25:937-47. [PMID: 21123297 DOI: 10.1096/fj.10-172577] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Transcriptional regulation by hormonal 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] involves occupancy of vitamin D response elements (VDREs) by the VDRE binding protein (VDRE-BP) or 1,25(OH)(2)D(3)-bound vitamin D receptor (VDR). This relationship is disrupted by elevated VDRE-BP, causing a form of hereditary vitamin D-resistant rickets (HVDRR). DNA array analysis showed that of 114 genes regulated by 1,25(OH)(2)D(3) in control cells, almost all (113) were rendered insensitive to the hormone in VDRE-BP-overexpressing HVDRR cells. Among these was the gene for DNA-damage-inducible transcript 4 (DDIT4), an inhibitor of mammalian target of rapamycin (mTOR) signaling. Chromatin immunoprecipitation PCR using 1,25(OH)(2)D(3)-treated osteoblasts confirmed that VDR and VDRE-BP compete for binding to the DDIT4 gene promoter. Expression of DDIT4 mRNA in these cells was induced (1.6-6 fold) by 1,25(OH)(2)D(3) (10-100 nM), and Western blot and flow cytometry analysis showed that this response involved suppression of phosphorylated S6K1(T389) (a downstream target of mTOR) similar to rapamycin treatment. siRNA knockdown of DDIT4 completely abrogated antiproliferative responses to 1,25(OH)(2)D(3), whereas overexpression of VDRE-BP exerted a dominant-negative effect on transcription of 1,25(OH)(2)D(3)-target genes. DDIT4, an inhibitor of mTOR signaling, is a direct target for 1,25(OH)(2)D(3) and VDRE-BP, and functions to suppress cell proliferation in response to vitamin D.
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Affiliation(s)
- Thomas S Lisse
- Orthopaedic Hospital Research Center, University of California-Los Angeles, 615 Charles E. Young Dr., South Los Angeles, CA 90095, USA
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25
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Pike JW, Meyer MB. The vitamin D receptor: new paradigms for the regulation of gene expression by 1,25-dihydroxyvitamin D(3). Endocrinol Metab Clin North Am 2010; 39:255-69, table of contents. [PMID: 20511050 PMCID: PMC2879406 DOI: 10.1016/j.ecl.2010.02.007] [Citation(s) in RCA: 248] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The actions of the vitamin D hormone 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) are mediated by the vitamin D receptor (VDR), a ligand-activated transcription factor that functions to control gene expression. After ligand activation, the VDR binds directly to specific sequences located near promoters and recruits a variety of coregulatory complexes that perform the additional functions required to modify transcriptional output. Recent advances in transcriptional regulation, which permit the unbiased identification of the regulatory regions of genes, are providing new insight into how genes are regulated. Surprisingly, gene regulation requires the orchestrated efforts of multiple modular enhancers often located many kilobases upstream, downstream, or within the transcription units themselves. These studies are transforming our understanding of how 1,25(OH)(2)D(3) regulates gene transcription.
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Affiliation(s)
- J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA.
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26
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Bikle DD. Vitamin D: newly discovered actions require reconsideration of physiologic requirements. Trends Endocrinol Metab 2010; 21:375-84. [PMID: 20149679 PMCID: PMC2880203 DOI: 10.1016/j.tem.2010.01.003] [Citation(s) in RCA: 114] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2009] [Revised: 01/07/2010] [Accepted: 01/07/2010] [Indexed: 01/08/2023]
Abstract
Vitamin D is not just for preventing rickets and osteomalacia. Recent findings in animal experiments, epidemiologic studies and clinical trials indicate that adequate vitamin D levels are important for cancer prevention, controlling hormone levels and regulating the immune response. Although 25 hydroxyvitamin D (25OHD) levels >10 ng/ml can prevent rickets and osteomalacia, these levels are not sufficient to provide these more recently discovered clinical benefits. Rather, levels of 25OHD >30 ng/ml are generally recommended. Determining optimal levels of 25OHD and the amount of vitamin D supplementation required to achieve those levels for the numerous actions of vitamin D will only be established with additional trials. In this review, these newer applications are summarized and therapeutic considerations are provided.
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Affiliation(s)
- Daniel D Bikle
- Veterans Affairs Medical Center and University of California, San Francisco, CA 94121, USA.
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27
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Bao BY, Ting HJ, Hsu JW, Yasmin-Karim S, Messing E, Lee YF. Down-regulation of NF-kappaB signals is involved in loss of 1alpha,25-dihydroxyvitamin D3 responsiveness. J Steroid Biochem Mol Biol 2010; 120:11-21. [PMID: 20206692 DOI: 10.1016/j.jsbmb.2010.02.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 02/11/2010] [Accepted: 02/14/2010] [Indexed: 01/02/2023]
Abstract
Vitamin D anti-tumor effect is often found reduced in the late stages of cancer. To uncover vitamin D resistance mechanism, we established a vitamin D-resistant human prostate cancer LNCaP cell line, LNCaP-R, by chronic exposure of cells to 1alpha,25-dihydroxyvitamin D(3) (1,25-VD). The vitamin D receptor (VDR)-mediated transcriptional activity was reduced in LNCaP-R, whereas VDR expression level and DNA-binding capacity were similar compared to parental cells (LNCaP-P). The expressions of the key factors involved in VDR transactivity, including CYP24A1 and VDR-associated proteins are all increased in LNCaP-R cells, and yet treatment with ketoconazole, P450 enzymes inhibitor, as well as trichostatin A (TSA), a histone deacetylase inhibitor, did not sensitize LNCaP-R cells response to vitamin D, suggesting that neither a local 1,25-VD availability, nor VDR-associated proteins are responsible for the vitamin D resistance. Interestingly, nuclear factor-kappaB (NF-kappaB) signaling, which is critical for 1,25-VD/VDR activity was found reduced in LNCaP-R cells, thereby treatment with NF-kappaB activator, 12-O-tetradecanoylphorbol-13-acetate (TPA), can sensitize LNCaP-R vitamin D response. Together, we conclude that NF-kappaB signaling is critical for vitamin D sensitivity, and dysregulation of this pathway would result in vitamin D resistance and disease progression.
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Affiliation(s)
- Bo-Ying Bao
- Department of Urology and Pathology & Laboratory Medicine, Rochester, NY 14642, USA
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Meyer MB, Goetsch PD, Pike JW. A downstream intergenic cluster of regulatory enhancers contributes to the induction of CYP24A1 expression by 1alpha,25-dihydroxyvitamin D3. J Biol Chem 2010; 285:15599-15610. [PMID: 20236932 DOI: 10.1074/jbc.m110.119958] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
CYP24A1 expression is up-regulated by 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) via a vitamin D receptor (VDR)/retinoid X receptor (RXR) heterodimer that binds to two vitamin D response elements (VDREs) located near the proximal promoter. Interestingly, although 1,25(OH)(2)D(3) induced VDR/RXR binding to the VDRE-containing proximal promoter, the VDR/RXR heterodimer also localized to a cluster of at least four potential enhancers located in intergenic regions 50-69 kb downstream of the human CYP24A1 gene and 35-45 kb downstream of the mouse Cyp24a1 gene as revealed by ChIP-chip and ChIP-seq analyses. To address whether this downstream region and potential VDREs located within mediated CYP24A1 induction, we constructed recombinant wild-type and mutant bacterial artificial chromosome clones that spanned mouse and human loci and contained luciferase reporters inserted into their 3'-untranslated regions. The activity of these clones in stably transfected cells revealed that both the proximal and the putative downstream elements contributed to CYP24A1 up-regulation by 1,25(OH)(2)D(3). Further analysis using transfected enhancer fragments led to the identification of contributing regulatory elements in several of these downstream regions. Additional studies of coregulator recruitment using ChIP-chip analysis revealed both similarities and differences between the region located proximal to and those located downstream of the promoter. Recruitment of these coregulators was likely responsible for the increase in RNA polymerase II and histone H4 acetylation, which was also observed in response to 1,25(OH)(2)D(3) at the enhancer sites across the locus. We conclude that a more complex mechanism is responsible for the striking CYP24A1 up-regulation induced by the vitamin D hormone in target cells.
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Affiliation(s)
- Mark B Meyer
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - Paul D Goetsch
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706
| | - J Wesley Pike
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706.
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Beildeck ME, Islam M, Shah S, Welsh J, Byers SW. Control of TCF-4 expression by VDR and vitamin D in the mouse mammary gland and colorectal cancer cell lines. PLoS One 2009; 4:e7872. [PMID: 19924301 PMCID: PMC2774944 DOI: 10.1371/journal.pone.0007872] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Accepted: 10/14/2009] [Indexed: 11/18/2022] Open
Abstract
Background The vitamin D receptor (VDR) pathway is important in the prevention and potentially in the treatment of many cancers. One important mechanism of VDR action is related to its interaction with the Wnt/β-catenin pathway. Agonist-bound VDR inhibits the oncogenic Wnt/β-catenin/TCF pathway by interacting directly with β-catenin and in some cells by increasing cadherin expression which, in turn, recruits β-catenin to the membrane. Here we identify TCF-4, a transcriptional regulator and β-catenin binding partner as an indirect target of the VDR pathway. Methodology/Principal Findings In this work, we show that TCF-4 (gene name TCF7L2) is decreased in the mammary gland of the VDR knockout mouse as compared to the wild-type mouse. Furthermore, we show 1,25(OH)2D3 increases TCF-4 at the RNA and protein levels in several human colorectal cancer cell lines, the effect of which is completely dependent on the VDR. In silico analysis of the human and mouse TCF7L2 promoters identified several putative VDR binding elements. Although TCF7L2 promoter reporters responded to exogenous VDR, and 1,25(OH)2D3, mutation analysis and chromatin immunoprecipitation assays, showed that the increase in TCF7L2 did not require recruitment of the VDR to the identified elements and indicates that the regulation by VDR is indirect. This is further confirmed by the requirement of de novo protein synthesis for this up-regulation. Conclusions/Significance Although it is generally assumed that binding of β-catenin to members of the TCF/LEF family is cancer-promoting, recent studies have indicated that TCF-4 functions instead as a transcriptional repressor that restricts breast and colorectal cancer cell growth. Consequently, we conclude that the 1,25(OH)2D3/VDR-mediated increase in TCF-4 may have a protective role in colon cancer as well as diabetes and Crohn's disease.
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Affiliation(s)
- Marcy E. Beildeck
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University School of Medicine, Washington, D. C., United States of America
| | - Md Islam
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University School of Medicine, Washington, D. C., United States of America
| | - Salimuddin Shah
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University School of Medicine, Washington, D. C., United States of America
| | - JoEllen Welsh
- GenNYsis Center for Excellence in Cancer Genomics, SUNY at Albany, Rensselaer, New York, United States of America
| | - Stephen W. Byers
- Lombardi Comprehensive Cancer Center, Department of Oncology, Georgetown University School of Medicine, Washington, D. C., United States of America
- * E-mail:
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Miyauchi Y, Sakaguchi N, Okada T, Makishima M, Ozono K, Michigami T. Oncogenic nucleoporin CAN/Nup214 interacts with vitamin D receptor and modulates its function. J Cell Biochem 2009; 106:1090-101. [DOI: 10.1002/jcb.22101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nakagawa K, Okano T, Ozono K, Kato S, Kubodera N, Ohba S, Itoh Y, Mikami K. Catalytic asymmetric synthesis and anticancer effects of the novel non-calcemic analog of vitamin D, 2α-fluoro-19-nor-22-oxa-1α,25-dihydroxyvitamin D3 in metastatic lung carcinoma. J Fluor Chem 2007. [DOI: 10.1016/j.jfluchem.2007.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Wang X, Wang TT, White JH, Studzinski GP. Expression of human kinase suppressor of Ras 2 (hKSR-2) gene in HL60 leukemia cells is directly upregulated by 1,25-dihydroxyvitamin D(3) and is required for optimal cell differentiation. Exp Cell Res 2007; 313:3034-45. [PMID: 17599832 PMCID: PMC3351793 DOI: 10.1016/j.yexcr.2007.05.021] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 05/15/2007] [Accepted: 05/22/2007] [Indexed: 11/24/2022]
Abstract
Induction of terminal differentiation of neoplastic cells offers potential for a novel approach to cancer therapy. One of the agents being investigated for this purpose in preclinical studies is 1,25-dihydroxyvitamin D(3) (1,25D), which can convert myeloid leukemia cells into normal monocyte-like cells, but the molecular mechanisms underlying this process are not fully understood. Here, we report that 1,25D upregulates the expression of hKSR-2, a new member of a small family of proteins that exhibit evolutionarily conserved function of potentiating ras signaling. The upregulation of hKSR-2 is direct, as it occurs in the presence of cycloheximide, and occurs primarily at the transcriptional level, via activation of vitamin D receptor, which acts as a ligand-activated transcription factor. Two VDRE-type motifs identified in the hKSR-2 gene bind VDR-RXR alpha heterodimers present in nuclear extracts of 1,25D-treated HL60 cells, and chromatin immunoprecipitation assays show that these VDRE motifs bind VDR in 1,25D-dependent manner in intact cells, coincident with the recruitment of RNA polymerase II to these motifs. Treatment of the cells with siRNA to hKSR-2 reduced the proportion of the most highly differentiated cells in 1,25D-treated cultures. These results demonstrate that hKSR-2 is a direct target of 1,25D in HL60 cells, and is required for optimal monocytic differentiation.
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Affiliation(s)
- Xuening Wang
- Department of Pathology and Laboratory Medicine, UMDNJ-New Jersey Medical School, Newark, New Jersey 07103, USA
| | - Tian-Tian Wang
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - John H. White
- Department of Physiology, McGill University, Montreal, Quebec, Canada
| | - George P. Studzinski
- Department of Pathology and Laboratory Medicine, UMDNJ-New Jersey Medical School, Newark, New Jersey 07103, USA
- Correspondence to: George P. Studzinski, M.D., Ph.D., Department of Pathology and Laboratory Medicine, UMDNJ-New Jersey Medical School, 185 South Orange Avenue, C-543, Newark, NJ 07103, USA, Tel: (973) 972-5869, Fax: (973) 973-972-7293,
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Bär M, Domaschke D, Meye A, Lehmann B, Meurer M. Wavelength-Dependent Induction of CYP24A1-mRNA after UVB-Triggered Calcitriol Synthesis in Cultured Human Keratinocytes. J Invest Dermatol 2007; 127:206-13. [PMID: 16902422 DOI: 10.1038/sj.jid.5700493] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Earlier investigations in our laboratory have demonstrated that UVB irradiation of cultured human keratinocytes induces the conversion of 7-dehydrocholesterol (7-DHC) to hormonally active 1alpha,25-dihydroxyvitamin D3 (calcitriol). In the research presented here, we have investigated the influence of UVB-triggered calcitriol production on gene expression of the vitamin D3 hydroxylating enzymes catabolic 25-hydroxyvitamin-D3-24-hydroxylase (CYP24A1), active vitamin-D3-25-hydroxylase (CYP27A1), and 25-hydroxyvitamin-D3-1alpha-hydroxylase (CYP27B1) using real-time PCR. Our results demonstrate a marked and wavelength-dependent induction of CYP24A1-mRNA in cultured human keratinocytes supplemented with 7-DHC, which parallels the spectral optimum at about 300 nm of calcitriol production as detected by HPLC and radioimmunoassay. Owing to the high sensitivity of real-time PCR, we provide evidence of a wavelength-dependent induction of CYP24A1-mRNA even in 7-DHC-deficient keratinocytes. Interestingly, we have found a strong but transient induction of CYP24A1-mRNA in non-irradiated keratinocytes, followed by accelerated cell proliferation. In contrast, UVB and calcitriol had no effect on gene expression of CYP27A1 and CYP27B1. We conclude from these experiments a constitutive gene expression of the vitamin D3 hydroxylases, whereas the catabolic enzyme CYP24A1 is markedly regulated by UVB, calcitriol, and perhaps cell proliferation. If confirmed at protein level, these findings could have an impact on epidermal vitamin D3 metabolism and its modulation by UVB in health and disease.
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Affiliation(s)
- Michael Bär
- Department of Dermatology, Carl Gustav Carus Medical School, Dresden University of Technology, Dresden, Germany.
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Nutchey B, Kaplan J, Dwivedi P, Omdahl J, Ferrante A, May B, Hii C. Molecular action of 1,25-dihydroxyvitamin D3 and phorbol ester on the activation of the rat cytochrome P450C24 (CYP24) promoter: role of MAP kinase activities and identification of an important transcription factor binding site. Biochem J 2005; 389:753-62. [PMID: 15836435 PMCID: PMC1180726 DOI: 10.1042/bj20041947] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Although investigations of the transcriptional regulation of the rat cytochrome P450C24 [CYP24 (25-hydroxyvitamin D3 24-hydroxylase)] gene by 1,25D (1,25-dihydroxyvitamin D3) at either the genomic, or more recently at the non-genomic, level have provided insight into the mechanism of control of 1,25D levels, this regulation is still poorly characterized. Using HEK-293T cells (human embryonic kidney 293T cells), we reported that 1,25D induction of CYP24 requires JNK (c-Jun N-terminal kinase) but not the ERK1/2 (extracellular-signal-regulated kinase 1/2). The phenomenon of synergistic up-regulation of CYP24 expression by PMA and 1,25D is well known and was found to be protein kinase C-dependent. Whereas ERK1/2 was not activated by 1,25D alone, its activation by PMA was potentiated by 1,25D also. The importance of ERK1/2 for transcriptional synergy was demonstrated by transfection of a dominant-negative ERK1(K71R) mutant (where K71R stands for Lys71-->Arg), which resulted in a reduced level of synergy on a CYP24 promoter-luciferase construct. JNK was also shown to be required for synergy. We report, in the present study, the identification of a site located at -171/-163, about 30 bp upstream of the vitamin D response element-1 in the CYP24 proximal promoter. This sequence, 5'-TGTCGGTCA-3', is critical for 1,25D induction of CYP24 and is therefore termed the vitamin D stimulatory element. The vitamin D stimulatory element, a target for the JNK module, and an Ets-1 binding site were shown to be vital for synergy between PMA and 1,25D. This is the first report to identify the DNA binding sequences required for the synergy between PMA and 1,25D and a role for JNK on the CYP24 gene promoter.
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Affiliation(s)
- Barbara K. Nutchey
- *School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5000, Australia
| | - Josef S. Kaplan
- *School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5000, Australia
| | - Prem P. Dwivedi
- *School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5000, Australia
| | - John L. Omdahl
- †Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, NM 87131-5221, U.S.A
| | - Antonio Ferrante
- ‡Department of Paediatrics, University of Adelaide, Adelaide, SA 5006, Australia
- §Department of Immunopathology, Women's and Children's Hospital, 72 King William Road, SA 5006, North Adelaide, Australia
- ∥School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA 5000, Australia
| | - Brian K. May
- *School of Molecular and Biomedical Science, University of Adelaide, Adelaide, SA 5000, Australia
| | - Charles S. T. Hii
- ‡Department of Paediatrics, University of Adelaide, Adelaide, SA 5006, Australia
- §Department of Immunopathology, Women's and Children's Hospital, 72 King William Road, SA 5006, North Adelaide, Australia
- To whom correspondence should be addressed (email )
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Sakaki T, Inouye K. Practical application of mammalian cytochrome P450. J Biosci Bioeng 2005; 90:583-90. [PMID: 16232916 DOI: 10.1263/jbb.90.583] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2000] [Accepted: 08/31/2000] [Indexed: 11/17/2022]
Abstract
Heterologous expression systems play an important role in the analysis of structure-function relationships of mammalian P450s. In addition, these expression systems allow practical application of mammalian P450s. Genetically engineered fused enzymes between mammalian P450 and yeast NADPH-P450 reductase have possible applications in bioconversion processes. Combined use of techniques reported thus far could produce steroid hormones in the recombinant yeast cells harboring four P450 species, CYP11A1, CYP17A1, CYP21B1 and CYP11B1. In an Escherichia coli expression system, the technology of the construction of the mitochondrial P450 electron transport chain has been established. The recombinant E. coli cells expressing CYP27B1, adrenodoxin and NADPH-adrenodoxin reductase would be applicable to a bioconversion process to produce 1alpha,25-dihydroxyvitamin D3. We also demonstrated the usefulness of heterologous expression systems for human liver microsomal P450s for the prediction of drug metabolism in the human body. Microsomal fractions prepared from recombinant yeast, insect and mammalian cells are commercially available and play an important role in preclinical drug development. Application of mammalian P450 to bioremediation with genetic engineering has also been developed. Thus, mammalian P450s appear to have great potential for a wide range of practical applications.
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Affiliation(s)
- T Sakaki
- Graduate School of Agriculture, Kyoto University, Kitashirakawa, Oiwake-cho, Sakyo-ku, Kyoto 606-8502, Japan
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Jurutka PW, Thompson PD, Whitfield GK, Eichhorst KR, Hall N, Dominguez CE, Hsieh JC, Haussler CA, Haussler MR. Molecular and functional comparison of 1,25-dihydroxyvitamin D(3) and the novel vitamin D receptor ligand, lithocholic acid, in activating transcription of cytochrome P450 3A4. J Cell Biochem 2005; 94:917-43. [PMID: 15578590 DOI: 10.1002/jcb.20359] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The vitamin D receptor (VDR) binds to and mediates the effects of the 1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3)) hormone to alter gene transcription. A newly recognized VDR ligand is the carcinogenic bile acid, lithocholic acid (LCA). We demonstrate that, in HT-29 colon cancer cells, both LCA and 1,25(OH)(2)D(3) induce expression of cytochrome P450 3A4 (CYP3A4), an enzyme involved in cellular detoxification. We also show that LCA-VDR stimulates transcription of gene reporter constructs containing DR3 and ER6 vitamin D responsive elements (VDREs) from the human CYP3A4 gene. Utilizing gel mobility shift, pulldown, and mammalian two-hybrid assays, we observe that: (i) 1,25(OH)(2)D(3) enhances retinoid X receptor (RXR) heterodimerization with VDR more effectively than LCA, (ii) the 1,25(OH)(2)D(3)-liganded VDR-RXR heterodimer recruits full-length SRC-1 coactivator, whereas this interaction is minimal with LCA unless LXXLL-containing fragments of SRC-1 are employed, and (iii) both 1,25(OH)(2)D(3) and LCA enhance the binding of VDR to DRIP205/mediator, but unlike 1,25(OH)(2)D(3)-VDR, LCA-VDR does not interact detectably with NCoA-62 or TRIP1/SUG1, suggesting a different pattern of LCA-VDR comodulator association. Finally, residues in the human VDR (hVDR) ligand binding domain (LBD) were altered to create mutants unresponsive to 1,25(OH)(2)D(3)- and/or LCA-stimulated transactivation, identifying S237 and S225/S278 as critical for 1,25(OH)(2)D(3) and LCA action, respectively. Therefore, these two VDR ligands contact distinct residues in the binding pocket, perhaps generating unique receptor conformations that determine the degree of RXR and comodulator binding. We propose that VDR is a bifunctional regulator, with the 1,25(OH)(2)D(3)-liganded conformation facilitating high affinity endocrine actions, and the LCA-liganded configuration mediating local, lower affinity cellular detoxification by upregulation of CYP3A4 in the colon.
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Affiliation(s)
- Peter W Jurutka
- Department of Biochemistry and Molecular Biophysics, University of Arizona College of Medicine, Tucson, AZ 85724, USA
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Kamao M, Hatakeyama S, Sakaki T, Sawada N, Inouye K, Kubodera N, Reddy GS, Okano T. Measurement and characterization of C-3 epimerization activity toward vitamin D3. Arch Biochem Biophys 2005; 436:196-205. [PMID: 15752725 DOI: 10.1016/j.abb.2005.01.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Revised: 01/07/2005] [Indexed: 11/15/2022]
Abstract
Recently, epimerization of the hydroxyl group at C-3 has been identified as a unique metabolic pathway of vitamin D compounds. We measured C-3 epimerization activity in subcellular fractions prepared from cultured cells and investigated the basic properties of the enzyme responsible for the epimerization. C-3 epimerization activity was detected using a NADPH-generating system containing glucose-6-phosphate, NADP, glucose-6-phosphate dehydrogenase, and Mg(2+). The highest level of activity was observed in a microsomal fraction prepared from rat osteoblastic UMR-106 cells but activity was also observed in microsomal fractions prepared from MG-63, Caco-2, Hep G2, and HUH-7 cells. In terms of maximum velocity (V(max)) and the Michaelis constant (K(m)), 25-hydroxyvitamin D(3) [25(OH)D(3)] exhibited the highest specificity for the epimerization at C-3 among 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)], 25(OH)D(3), 24,25-dihydroxyvitamin D(3) [24,25(OH)(2)D(3)], and 22-oxacalcitriol (OCT). The epimerization activity was not inhibited by various cytochrome P450 inhibitors and antiserum against NADPH cytochrome P450 reductase. Neither CYP24, CYP27A1, CYP27B1 nor 3(alpha-->beta)hydroxysteroid epimerase (HSE) catalyzed the epimerization in vitro. Based on these results, the enzyme(s) responsible for the epimerization of vitamin D(3) at C-3 are thought to be located in microsomes and different from cytochrome P450 and HSE.
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Affiliation(s)
- Maya Kamao
- Department of Hygienic Sciences, Kobe Pharmaceutical University, Kobe 658-8558, Japan
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Ren S, Nguyen L, Wu S, Encinas C, Adams JS, Hewison M. Alternative Splicing of Vitamin D-24-Hydroxylase. J Biol Chem 2005; 280:20604-11. [PMID: 15788398 DOI: 10.1074/jbc.m414522200] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Synthesis of the active form of vitamin D, 1,25-dihydroxyvitamin D (1,25-(OH)(2)D), by renal epithelial cells is tightly controlled during normal calcium homeostasis. By contrast, macrophage production of 1,25-(OH)(2)D is often dysregulated with potential hypercalcemic complications. We have postulated that this is due to abnormal catabolism of 1,25-(OH)(2)D by the feedback control enzyme, vitamin D-24-hydroxylase (CYP24). Using chick HD-11 and human THP-1 myelomonocytic cell lines, we have shown that macrophage-like cells express a splice variant of the CYP24 gene (CYP24-SV), which encodes a truncated protein. Compared with the holo-CYP24 gene product in chick and human cells (508 and 513 amino acids, respectively), the truncated CYP24-SV versions consisted of 351 and 372 amino acids. These CYP24-SV proteins retained intact substrate-binding domains but lacked mitochondrial targeting sequences and were therefore catalytically inactive. In common with CYP24, expression of the CYP24 variants was induced by 1,25-(OH)(2)D but without a concomitant rise in 24-hydroxylase activity. However, overexpression of CYP24-SV in HD-11 and THP-1 cells reduced synthesis of 1,25-(OH)(2) D (40-50%), whereas antisense CYP24-SV expression increased 1,25-(OH)(2)D production by 2-7-fold. These data suggest that alternative splicing of CYP24 leads to the generation of a dominant negative-acting protein that is catalytically dysfunctional. We theorize that expression of the CYP24-SV may contribute to the extracellular accumulation of 1,25(OH)(2)D in human health and disease.
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Affiliation(s)
- Songyang Ren
- Department of Medicine, Division of Endocrinology, Burns and Allen Research Institute, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA
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Kim S, Shevde NK, Pike JW. 1,25-Dihydroxyvitamin D3 stimulates cyclic vitamin D receptor/retinoid X receptor DNA-binding, co-activator recruitment, and histone acetylation in intact osteoblasts. J Bone Miner Res 2005; 20:305-17. [PMID: 15647825 DOI: 10.1359/jbmr.041112] [Citation(s) in RCA: 127] [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: 06/14/2004] [Revised: 08/05/2004] [Accepted: 09/14/2004] [Indexed: 11/18/2022]
Abstract
UNLABELLED 1,25(OH)2D3 induces gene expression through the VDR. We used chromatin immunoprecipitation techniques to explore this 1,25(OH)2D3-induced process on the 25-hydroxyvitamin D3-24-hydroxylase (Cyp24) and Opn gene promoters in intact osteoblasts. Our studies show that 1,25(OH)2D3-induced transactivation is a dynamic process that involves promoter-specific localization of VDR and RXR, recruitment of histone acetyltransferase complexes, and in the case of the Cyp24 gene, modification of histone 4. INTRODUCTION The vitamin D receptor (VDR) binds as a retinoid X receptor (RXR) heterodimer to target DNA sequences and facilitates the recruitment of protein complexes that are essential for transcriptional modulation. These complexes include an acetyltransferase component that contains members of the p160 family and p300/CBP as well as human mediator that contains D receptor interacting protein (DRIP205). The objective of this study was to investigate the kinetics of VDR/RXR binding to 25-hydroxyvitamin D3-24-hydroxylase (Cyp24) and osteopontin (Opn) target gene promoters and to explore the recruitment and subsequent activities of co-activator complexes on these target genes in intact cells. MATERIALS AND METHODS Mouse osteoblastic MC3T3-E1 cells and mouse primary calvarial osteoblasts (MOBs) were cultured in alphaMEM medium supplemented with 10% FBS. Confluent cells were treated with 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] or the vitamin D antagonist ZK159222, and the ability of these compounds to induce localization of VDR and RXR to specific regions of Cyp24 and Opn target genes was examined using chromatin immunoprecipitation techniques. The ability of both compounds to induce the recruitment of co-activator proteins such as p160 family members, CBP and DRIP205, and to increase the level of histone acetylation on the two gene promoters in MC3T3-E1 cells was also examined. RESULTS 1,25(OH)2D3 induces rapid association of the VDR and RXR with both the Cyp24 and the Opn gene promoters in both MC3T3-E1 osteoblasts and MOBs, interactions that are both rapid and cyclic in nature. 1,25(OH)2D3 treatment also induces rapid recruitment of co-regulators such as SRC-1, -2, and -3, CBP, and p300 to both promoters, recruitment that leads to acetylation of histone 4 on Cyp24 but not the Opn. DRIP205 is also recruited to the two promoters in response to hormonal stimulation, an appearance that correlates directly with entry of RNA pol II. Studies with the vitamin D antagonist ZK159222 suggest a complex mode of action of this compound in blocking 1,25(OH)2D3-induced transcription. Our studies indicate that 1,25(OH)2D3-induced transactivation in intact osteoblasts is a dynamic process that involves promoter-specific localization of VDR and RXR as well as the recruitment of a number of co-regulators essential to 1,25(OH)2D3-induced transcription. CONCLUSIONS We conclude that co-regulators essential for the transcriptional activity of the steroid receptor gene family are indeed critical for the actions of 1,25(OH)2D3. Selective use of co-regulators by target genes, however, may provide a mechanism for the unique and perhaps gene-selective responses observed with synthetic analogs such as ZK159222.
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Affiliation(s)
- Sungtae Kim
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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Dhawan P, Peng X, Sutton ALM, MacDonald PN, Croniger CM, Trautwein C, Centrella M, McCarthy TL, Christakos S. Functional cooperation between CCAAT/enhancer-binding proteins and the vitamin D receptor in regulation of 25-hydroxyvitamin D3 24-hydroxylase. Mol Cell Biol 2005; 25:472-87. [PMID: 15601867 PMCID: PMC538756 DOI: 10.1128/mcb.25.1.472-487.2005] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
1,25-Dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] induces the synthesis of 25-hydroxyvitamin D(3) 24-hydroxylase [24(OH)ase], an enzyme involved in its catabolism, thereby regulating its own metabolism. Here we demonstrate that CCAAT enhancer binding protein beta (C/EBPbeta) is induced by 1,25(OH)(2)D(3) in kidney and in osteoblastic cells and is a potent enhancer of vitamin D receptor (VDR)-mediated 24(OH)ase transcription. Transfection studies indicate that 1,25(OH)(2)D(3) induction of 24(OH)ase transcription is enhanced a maximum of 10-fold by C/EBPbeta. Suppression of 1,25(OH)(2)D(3)-induced 24(OH)ase transcription was observed with dominant negative C/EBP or osteoblastic cells from C/EBPbeta(-/-) mice. A C/EBP site was identified at positions -395 to -388 (-395/-388) in the rat 24(OH)ase promoter. Mutation of this site inhibited C/EBPbeta binding and markedly attenuated the transcriptional response to C/EBPbeta. We also report the cooperation of CBP/p300 with C/EBPbeta in regulating VDR-mediated 24(OH)ase transcription. We found that not only 1,25(OH)(2)D(3) but also parathyroid hormone (PTH) can induce C/EBPbeta expression in osteoblastic cells. PTH potentiated the induction of C/EBPbeta and 24(OH)ase expression in response to 1,25(OH)(2)D(3) in osteoblastic cells. Data with the human VDR promoter (which contains two putative C/EBP sites) indicate a role for C/EBPbeta in the protein kinase A-mediated induction of VDR transcription. From this study a fundamental role has been established for the first time for cooperative effects and cross talk between the C/EBP family of transcription factors and VDR in 1,25(OH)(2)D(3)-induced transcription. These findings also indicate a novel role for C/EBPbeta in the cross talk between PTH and 1,25(OH)(2)D(3) that involves the regulation of VDR transcription.
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Affiliation(s)
- Puneet Dhawan
- Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, 185 South Orange Avenue, Newark, NJ 07103, USA
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Kamao M, Tatematsu S, Hatakeyama S, Sakaki T, Sawada N, Inouye K, Ozono K, Kubodera N, Reddy GS, Okano T. C-3 epimerization of vitamin D3 metabolites and further metabolism of C-3 epimers: 25-hydroxyvitamin D3 is metabolized to 3-epi-25-hydroxyvitamin D3 and subsequently metabolized through C-1alpha or C-24 hydroxylation. J Biol Chem 2004; 279:15897-907. [PMID: 14757768 DOI: 10.1074/jbc.m311473200] [Citation(s) in RCA: 113] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Recently, it was revealed that 1alpha,25-dihydroxyvitamin D3 (1alpha,25(OH)2D3) and 24R,25-dihydroxyvitamin D3 (24,25(OH)2D3) were metabolized to their respective epimers of the hydroxyl group at C-3 of the A-ring. We now report the isolation and structural assignment of 3-epi-25-hydroxyvitamin D3 (3-epi-25(OH)D3 as a major metabolite of 25-hydroxyvitamin D3 (25(OH)D3) and the further metabolism of C-3 epimers of vitamin D3 metabolites. When 25(OH)D3 was incubated with various cultured cells including osteosarcoma, colon adenocarcinoma, and hepatoblastoma cell lines, 3-epi-25(OH)D3 and 24,25 (OH)2D3 were commonly observed as a major and minor metabolite of 25(OH)D3, respectively. 25(OH)D3 was at least as sensitive to C-3 epimerization as 1alpha, 25(OH)2D3 which has been reported as a substrate for the C-3 epimerization reaction. Unlike these cultured cells, LLC-PK1 cells, a porcine kidney cell line, preferentially produced 24,25(OH)2D3 rather than 3-epi-25(OH)D3. We also confirmed the existence of 3-epi-25(OH)D3 in the serum of rats intravenously given pharmacological doses of 25(OH)D3. The cultured cells metabolized 3-epi-25OHD3 and 3-epi-1alpha,25(OH)2D3 to 3-epi-24,25(OH)2D3 and 3-epi-1alpha,24,25(OH)3D3, respectively. In addition, we demonstrated that 3-epi-25(OH)D3 was metabolized to 3-epi-1alpha,25(OH)2D3 by CYP27B1 and to 3-epi-24,25(OH)2D3 by CYP24 using recombinant Escherichia coli cell systems. 3-Epi-25(OH)D3, 3-epi-1alpha,25(OH)2D3, and 3-epi-24,25(OH)2D3 were biologically less active than 25(OH)D3, 1alpha,25(OH)2D3, and 24,25(OH)2D3, but 3-epi-1alpha,25(OH)2D3 showed to some extent transcriptional activity toward target genes and anti-proliferative/differentiation-inducing activity against human myeloid leukemia cells (HL-60). These results indicate that C-3 epimerization may be a common metabolic pathway for the major metabolites of vitamin D3.
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Affiliation(s)
- Maya Kamao
- Department of Hygienic Sciences, Kobe Pharmaceutical University, Kobe 658-8558, Japan
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42
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Miettinen S, Ahonen MH, Lou YR, Manninen T, Tuohimaa P, Syvälä H, Ylikomi T. Role of 24-hydroxylase in vitamin D3growth response of OVCAR-3 ovarian cancer cells. Int J Cancer 2003; 108:367-73. [PMID: 14648702 DOI: 10.1002/ijc.11520] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Vitamin D and its analogues are potent regulators of cell growth and differentiation both in vivo and in vitro. We studied the effects of 25-hydroxyvitamin D(3) [25(OH)D(3)], 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] and vitamin D analogue, EB 1089, on the growth of a human ovarian cancer cell line, OVCAR-3. We also studied the expression of vitamin D metabolising enzymes 24-hydroxylase (24OHase) and 1alpha-hydroxylase (1alphaOHase). Our results showed that high concentrations (10 and 100 nM) of 1,25(OH)(2)D(3) inhibited a cell proliferation, whereas low concentration (0.1 nM) stimulated growth of the OVCAR-3 cells. In the concentration range of 10-500 nM a prohormone, 25(OH)D(3), stimulated growth. An amount of 1 nM EB 1089 and 100 nM 1,25(OH)(2)D(3) inhibited growth with an equal magnitude. The expression of 24OHase was strongly induced by 1,25(OH)(2)D(3) and EB 1089 in OVCAR-3 cells, and analysis of vitamin D metabolites showed the functionality of 24OHase. An inhibition of 24OHase activity with a novel 24OHase inhibitor enhanced growth-inhibiting effects of 1,25(OH)(2)D(3) and suppressed the growth stimulation of 100 nM 25(OH)D(3). We also report the expression of a vitamin D activating enzyme, 1alphaOHase, in 7 ovarian cancer cell lines. The production of 1,25(OH)(2)D(3) in OVCAR-3 cells was low, possibly due to an extensive activity of 24OHase or a low 1alphaOHase activity. These results suggest that in ovarian cancer cells vitamin D metabolizing enzymes might play a key role in modulating the growth response to vitamin D. The possible mitogenic effects of vitamin D should be considered when evaluating treatment of ovarian cancer with vitamin D.
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Affiliation(s)
- Susanna Miettinen
- Department of Cell Biology, Medical School, University of Tampere, Tampere, Finland.
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Maestro B, Dávila N, Carranza MC, Calle C. Identification of a Vitamin D response element in the human insulin receptor gene promoter. J Steroid Biochem Mol Biol 2003; 84:223-30. [PMID: 12711007 DOI: 10.1016/s0960-0760(03)00032-3] [Citation(s) in RCA: 253] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The present study was designed to explore the possible presence and location of Vitamin D response elements (VDREs) in the human insulin receptor (hIR) gene promoter. To this end, the -1819 to -271 bp fragment of the hIR promoter (wild type promoter) and progressive 5' deletions of this promoter (up to -1473 and -876 bp) were linked to the luciferase pGL2-basic vector to construct the reported plasmids: phIR (-1819)-GL2, phIR(-1473)-GL2 and phIR(-876)-GL2, respectively. U-937 cells were transiently transfected with these plasmids, and then the cells were either untreated or treated for 24h with 10(-8) M 1,25-dihydroxyvitamin D(3) (1,25D(3)). Luciferase determinations revealed that, while the activity of the wild promoter was increased 1.6-fold by the hormone, the activities of progressive 5' deletions of this promoter were enhanced 1.7-, and 1.6-fold, respectively. Thus, the region extending from -876 to -271bp of the hIR promoter, appears to contain VDREs, and to be sufficient for induction by 1,25D(3). In order to identify these potential VDREs, we performed a computer search of candidate sequences by homology with a consensus VDRE sequence. This search yielded a sequence located between -761 and -732 bp (5'CGTCGGGCCTGTGGGGCGCCTCCGGGGGTC3'), which includes an overlapping AP-2 like sequence, as a good candidate. Electrophoretic mobility shift assays revealed that the Vitamin D receptor (VDR) specifically recognized this sequence, since a VDR-DNA complex was able to compete with the unlabeled probe and was cleared by the specific anti-VDR antibody 9A7. These data represent the first identification of a VDRE in the hIR gene promoter.
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Affiliation(s)
- Begoña Maestro
- Deparment of Biochemistry and Molecular Biology, School of Medicine, Complutense University, 28040-Madrid, Spain
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44
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Kamao M, Tatematsu S, Hatakeyama S, Ozono K, Kubodera N, Reddy GS, Okano T. Two novel metabolic pathways of 22-oxacalcitriol (OCT). C-25 dehydration and C-3 epimerization and biological activities of novel OCT metabolites. J Biol Chem 2003; 278:1463-71. [PMID: 12417596 DOI: 10.1074/jbc.m203773200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
22-Oxacalcitriol (OCT) is an analog of calcitriol, characterized by potent differentiation-inducing activity and low calcemic liability. The metabolism of OCT has been studied and its polar metabolites, such as 24/26-hydroxylated-OCT and hexanor-1 alpha,20-dihydroxyvitamin D(3) (1 alpha,20(OH)(2)D(3)), have been identified. In contrast, little is known about the less polar metabolites of OCT, which have been found in relatively large amounts. In this study, the in vitro metabolism of OCT was studied in UMR 106, Caco-2, and LLC-PK(1) cells to identify the less polar metabolites and to assess their biological activity. OCT was initially metabolized to three less polar metabolites, 3-epi-OCT and two dehydrates, 25-dehydroxy- 25-ene-22-oxa-1 alpha(OH)D(3) (25-ene-22-oxa-1 alpha(OH)D(3)) and 25-dehydroxy-24-ene-22-oxa-1 alpha(OH)D(3) (24-ene-22-oxa-1 alpha(OH)D(3)). We also observed further metabolites, the two C-3 epimers of the C-25 dehydrates, 25-ene-3-epi-22-oxa-1 alpha(OH)D(3) and 24-ene-3-epi-22-oxa-1 alpha(OH)D(3). The structures of these metabolites were successfully assigned by (1)H NMR and LC-MS analyses. The three cell lines differ in their ability to metabolize OCT through the C-3 epimerization or the C-25 dehydration pathway. The biological activity of the OCT metabolites assessed by a luciferase reporter gene transcriptional activation system, binding assays for the vitamin D receptor (VDR) and vitamin D-binding protein (DBP), and assays for regulatory activities of cell differentiation and proliferation was found to be lower than that of OCT. Thus, both the C-3 epimerization and C-25 dehydration may work to reduce the biological activity of OCT.
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Affiliation(s)
- Maya Kamao
- Department of Hygienic Sciences, Kobe Pharmaceutical University, Kobe 658-8558, Japan
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45
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Thompson PD, Jurutka PW, Whitfield GK, Myskowski SM, Eichhorst KR, Dominguez CE, Haussler CA, Haussler MR. Liganded VDR induces CYP3A4 in small intestinal and colon cancer cells via DR3 and ER6 vitamin D responsive elements. Biochem Biophys Res Commun 2002; 299:730-8. [PMID: 12470639 DOI: 10.1016/s0006-291x(02)02742-0] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The nuclear vitamin D receptor (VDR) mediates the effects of 1,25-dihydroxyvitamin D(3) (1,25D(3)) to alter intestinal gene transcription and promote calcium absorption. Because 1,25D(3) also exerts anti-cancer effects, we examined the efficacy of 1,25D(3) to induce cytochrome P450 (CYP) enzymes. Exposure of human colorectal adenocarcinoma cells (HT-29) to 10(-8)M 1,25D(3) resulted in >/=3-fold induction of CYP3A4 mRNA and protein as assessed by RT-PCR and Western blotting, respectively. Six vitamin D responsive element (VDRE)-like sequences in the promoter region of the CYP3A4 gene were then individually tested for their ability to enhance transcription. A canonical DR3-type element in the distal region of the promoter (-7719-GGGTCAgcaAGTTCA-7733), and a proximal, non-classical everted repeat with a spacer of 6 bp (ER6; -169-TGAACTcaaaggAGGTCA-152) were identified as functional VDREs in this CYP gene. These data suggest that 1,25D(3)-dependent, VDR-mediated induction of CYP3A4 may constitute a chemoprotective mechanism for detoxification of enteric xenobiotics and carcinogens.
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Affiliation(s)
- Paul D Thompson
- Department of Biochemistry and Molecular Biophysics, College of Medicine, University of Arizona, Tucson, AZ 85724, USA
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Jurutka PW, MacDonald PN, Nakajima S, Hsieh JC, Thompson PD, Whitfield GK, Galligan MA, Haussler CA, Haussler MR. Isolation of baculovirus-expressed human vitamin D receptor: DNA responsive element interactions and phosphorylation of the purified receptor. J Cell Biochem 2002; 85:435-57. [PMID: 11948698 DOI: 10.1002/jcb.10134] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Two controversial aspects in the mechanism of human vitamin D receptor (hVDR) action are the possible significance of VDR homodimers and the functional role of receptor phosphorylation. To address these issues, milligram quantities of baculovirus-expressed hVDR were purified to 97% homogeneity, and then tested for binding to the rat osteocalcin vitamin D responsive element (VDRE) via electrophoretic mobility shift and half-site competition assays in the presence or absence of a CV-1 nuclear extract containing retinoid X receptor (RXR). Methylation interference analysis revealed that both the hVDR homodimer and the VDR-RXR heterodimer display similar patterns of VDRE G-base protection. However, in competition studies, the relative dissociation of the homodimeric hVDR complex from the VDRE was extremely rapid (t1/2 < 30 s) compared to the dissociation of the heteromeric complex (t1/2 > 5 min), thus illustrating the relative instability and low affinity of homodimeric VDR binding to DNA. These results indicate that VDR-RXR heterodimers are the preferred VDRE binding species. Further, two dimensional gel electrophoresis of hVDR demonstrated several isoelectric forms of the receptor, suggesting that it is subject to multiple phosphorylation events. In vitro kinase assays confirmed that purified hVDR is an efficient substrate for protein kinases A and Cbeta, as well as casein kinase II. In vivo studies of the expressed receptor in intact cells, namely baculovirus vector infected Sf9 insect cells and transfected mammalian COS-7 cells, demonstrated that hVDR was phosphorylated in a hormone-enhanced fashion. Functional consequences of hVDR phosphorylation were suggested by the observations that: (i) potato acid phosphatase (PAP)-treated hVDR no longer interacted with the VDRE as either a homodimer or a heteromeric complex with RXR, and (ii) treatment of transfected COS-7 cells with a phosphatase inhibitor (okadaic acid) along with 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) resulted in a synergistic enhancement of both hVDR phosphorylation and transactivation of a VDRE-linked reporter gene, compared to the effect of treatment with either agent alone. These studies point to a significant role for phosphorylation of VDR in regulating high-affinity VDR-RXR interactions with VDREs, and also in modulating 1,25(OH)2D3-elicited transcriptional activation in target cells.
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Affiliation(s)
- Peter W Jurutka
- Department of Biochemistry and Molecular Biophysics, College of Medicine, University of Arizona, Tucson, Arizona 85724, USA
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Katayama S, Matsushita O, Tamai E, Miyata S, Okabe A. Phased A-tracts bind to the alpha subunit of RNA polymerase with increased affinity at low temperature. FEBS Lett 2001; 509:235-8. [PMID: 11741595 DOI: 10.1016/s0014-5793(01)03148-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Previously we showed that the expression of a Clostridium perfringens phospholipase C gene (plc) is activated by promoter upstream phased A-tracts in a low temperature-dependent manner. In this paper we characterize the interaction between the alpha subunit of C. perfringens RNA polymerase and the phased A-tracts. Hydroxyl radical footprinting and fluorescence polarization assaying revealed that the alpha subunit binds to the minor grooves of the phased A-tracts through its C-terminal domain with increased affinity at low temperature. The result provides a molecular mechanism underlying the activation of the plc promoter by the phased A-tracts.
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Affiliation(s)
- S Katayama
- Department of Biochemistry and Chemistry, Faculty of Science, Okayama University of Science, 1-1, Ridai-cho, Okayama 700-0005, Japan
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48
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Abstract
DNA with a curved trajectory of its helix axis is called bent DNA, or curved DNA. Interestingly, biologically important DNA regions often contain this structure, irrespective of the origin of DNA. In the last decade, considerable progress has been made in clarifying one role of bent DNA in prokaryotic transcription and its mechanism of action. However, the role of bent DNA in eukaryotic transcription remains unclear. Our recent study raises the possibility that bent DNA is implicated in the "functional packaging" of transcriptional regulatory regions into chromatin. In this article, I review recent progress in bent DNA research in eukaryotic transcription, and summarize the history of bent DNA research and several subjects relevant to this theme. Finally, I propose a hypothesis that bent DNA structures that mimic a negative supercoil, or have a right-handed superhelical writhe, organize local chromatin infrastructure to help the very first interaction between cis-acting DNA elements and activators that trigger transcription.
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Affiliation(s)
- T Ohyama
- Department of Biology, Faculty of Science and High Technology Research Center, Konan University, 8-9-1 Okamoto, Higashinada-ku, Kobe 658-8501, Japan.
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Yamagata M, Kimoto A, Michigami T, Nakayama M, Ozono K. Hydroxylases involved in vitamin D metabolism are differentially expressed in murine embryonic kidney: application of whole mount in situ hybridization. Endocrinology 2001; 142:3223-30. [PMID: 11416045 DOI: 10.1210/endo.142.7.8122] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study we examined the expression of 25-hydroxyvitamin D-1alpha-hydroxylase (1alpha-hydroxylase) and 25-hydroxyvitamin D-24-hydroxylase (24-hydroxylase) by RT-PCR and whole mount in situ hybridization using organ culture of kidney taken from mouse embryo. First, the kidneys of mouse embryo at 11.5-17.5 days gestation were cultured in the presence or absence of forskolin and 1,25-dihydroxyvitamin D(3) [1alpha,25-(OH)(2)D(3)]. Forskolin and 1alpha,25-(OH)(2)D(3) induced the expression of 1alpha-hydroxylase and 24-hydroxylase, respectively, in a dose- and time-dependent manner. In the absence of stimulants, the expression of 1alpha-hydroxylase and 24-hydroxylase was detected from days 13.5-17.5 gestation. The expression of vitamin D receptor and megalin was detected from days 13.5 and 11.5, respectively. Next, signals for the expression of either 1alpha-hydroxylase or 24-hydroxylase were detected by whole mount in situ hybridization in kidney explants taken from embryo at 15.5 days gestation after the appropriate stimulation. However, the localization of signals differed between the two enzymes; 1alpha-hydroxylase messenger RNA was expressed in the inner area of the kidney explants, whereas 24-hydroxylase messenger RNA was expressed in the surface area. The expression of both hydroxylases was restricted to the epithelium of developing renal tubules. The pattern of megalin expression was similar to that of 1alpha-hydroxylase expression. To confirm the difference in distribution of 1alpha-hydroxylase and 24-hydroxylase transcripts, the explants were hybridized with probes for both 1alpha-hydroxylase and 24-hydroxylase using double labeling techniques after simultaneous stimulation with forskolin and 1alpha,25-(OH)(2)D(3), resulting in the detection at different locations of positive signals for the two enzymes. These results suggest that the expression of 1alpha-hydroxylase is induced in a distinct epithelium of renal tubules from that of 24-hydroxylase even at the early stage of kidney development before glomerulogenesis.
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Affiliation(s)
- M Yamagata
- Department of Environmental Medicine, Osaka Medical Center and Research Institute for Maternal and Child Health, 840 Murodo-cho, Izumi, Osaka 594-1101, Japan
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Nakagawa K, Sowa Y, Kurobe M, Ozono K, Siu-Caldera ML, Reddy GS, Uskokovic MR, Okano T. Differential activities of 1alpha,25-dihydroxy-16-ene-vitamin D(3) analogs and their 3-epimers on human promyelocytic leukemia (HL-60) cell differentiation and apoptosis. Steroids 2001; 66:327-37. [PMID: 11179741 DOI: 10.1016/s0039-128x(00)00142-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
To clarify physiological role of the carbon 3 (C-3) epimerization of 1alpha,25(OH)(2)D(3) and biologic significance of a 3-epi metabolite of 1alpha,25(OH)(2)D(3), we examined biologic activities of the 3-epimers of 1alpha,25(OH)(2)D(3) and 1alpha,25(OH)(2)-16-ene-D(3) analogs in terms of modulation of cell cycle phase distribution and cell-surface CD11b antigen expression of HL-60 cells, transactivation of vitamin D target genes in transfected cells, stimulation of VDR/RXRalpha heterodimer formation in a rabbit reticulocyte lysates transcription/translation system, stimulation of VDR/RXRalpha/VDRE complex formation, and induction of HL-60 cell apoptosis. The analogs tested here were 1) 1alpha,25(OH)(2)D(3), 2) 1alpha,25(OH)(2)-3-epi-D(3), 3) 1alpha,25(OH)(2)-16-ene-D(3), 4) 1alpha,25(OH)(2)-16-ene-3-epi-D(3), 5) 1alpha,25(OH)(2)-16-ene-23-yne-hexafluoro(F(6))-D(3), 6) 1alpha,25(OH)(2)-16-ene-23-yne-hexafluoro(F(6))-3-epi-D(3), 7) 1alpha,25-(OH)(2)-16-ene-20-epi-23-yne-D(3), and 8) 1alpha,25(OH)(2)-16-ene-20-epi-23-yne-3-epi-D(3). When compared to the 3-natural (beta) analogs, the 3-epi (alpha) analogs were biologically significantly less active. The findings support the hypothesis that the C-3 epimerization is an inactivation pathway of 1alpha,25(OH)(2)D(3) and its analogs in vitamin D target tissues. We also found that the 3-epi analogs, but not the 3-natural (beta) analogs, were the potent inducers of apoptosis of HL-60 cells. These results suggest that the analogs could be divided into two groups, in which the 3-epi analogs were the potent inducers of apoptosis of HL-60 cells, and the 3-natural analogs were the potent modulators of HL-60 cell growth and differentiation. This is the first report demonstrating that the 3-epimerization of the hydroxyl group at C-3 of the A-ring of 1alpha,25(OH)(2)D(3) plays an important role to modulate HL-60 cell differentiation and apoptosis.
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Affiliation(s)
- K Nakagawa
- Department of Hygienic Sciences, Kobe Pharmaceutical University, Motoyamakita-machi, Higashinada-ku, Kobe, Japan
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