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Fricke HP, Krajco CJ, Perry MJ, Brettingen LJ, Wake LA, Charles JF, Hernandez LL. Fluoxetine treatment during the postpartal period may have short-term impacts on murine maternal skeletal physiology. Front Pharmacol 2023; 14:1244580. [PMID: 38074149 PMCID: PMC10701399 DOI: 10.3389/fphar.2023.1244580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 11/14/2023] [Indexed: 12/23/2023] Open
Abstract
Postpartum depression affects many individuals after parturition, and selective serotonin reuptake inhibitors (SSRIs) are often used as the first-line treatment; however, both SSRIs and lactation are independently associated with bone loss due to the role of serotonin in bone remodeling. Previously, we have established that administration of the SSRI fluoxetine during the peripartal period results in alterations in long-term skeletal characteristics. In the present study, we treated mice with either a low or high dose of fluoxetine during lactation to determine the consequences of the perturbation of serotonin signaling during this time period on the dam skeleton. We found that lactational fluoxetine exposure affected both cortical and trabecular parameters, altered gene expression and circulating markers of bone turnover, and affected mammary gland characteristics, and that these effects were more pronounced in the dams that were exposed to the low dose of fluoxetine in comparison to the high dose. Fluoxetine treatment during the postpartum period in rodents had short term effects on bone that were largely resolved 3 months post-weaning. Despite the overall lack of long-term insult to bone, the alterations in serotonin-driven lactational bone remodeling raises the question of whether fluoxetine is a safe option for the treatment of postpartum depression.
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Affiliation(s)
- Hannah P. Fricke
- Endocrinology and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, WI, United States
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, United States
| | - Chandler J. Krajco
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, United States
| | - Molly J. Perry
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, United States
| | - Lauren J. Brettingen
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, United States
| | - Lella A. Wake
- Departments of Orthopedics and Medicine, Brigham and Women’s Hospital, Boston, MA, United States
| | - Julia F. Charles
- Departments of Orthopedics and Medicine, Brigham and Women’s Hospital, Boston, MA, United States
| | - Laura L. Hernandez
- Endocrinology and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, WI, United States
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI, United States
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Bullock TA, Mack JA, Negrey J, Kaw U, Hu B, Anand S, Hasan T, Warren CB, Maytin EV. Significant Association of Poly-A and Fok1 Polymorphic Alleles of the Vitamin D Receptor with Vitamin D Serum Levels and Incidence of Squamous Cutaneous Neoplasia. J Invest Dermatol 2023; 143:1538-1547. [PMID: 36813159 PMCID: PMC10439970 DOI: 10.1016/j.jid.2023.01.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/22/2023] [Accepted: 01/30/2023] [Indexed: 02/22/2023]
Abstract
Vitamin D3, a prohormone, is converted to circulating calcidiol and then to calcitriol, the hormone that binds to the vitamin D receptor (VDR) (a nuclear transcription factor). Polymorphic genetic sequence variants of the VDR are associated with an increased risk of breast cancer and melanoma. However, the relationship between VDR allelic variants and the risk of squamous cell carcinoma and actinic keratosis remains unclear. We examined the associations between two VDR polymorphic sites, Fok1 and Poly-A, and serum calcidiol levels, actinic keratosis lesion incidence, and the history of cutaneous squamous cell carcinoma in 137 serially enrolled patients. By evaluating the Fok1 (F) and (f) alleles and the Poly-A long (L) and short (S) alleles together, a strong association between genotypes FFSS or FfSS and high calcidiol serum levels (50.0 ng/ml) was found; conversely, ffLL patients showed very low calcidiol levels (29.1 ng/ml). Interestingly, the FFSS and FfSS genotypes were also associated with reduced actinic keratosis incidence. For Poly-A, additive modeling showed that Poly-A (L) is a risk allele for squamous cell carcinoma, with an OR of 1.55 per copy of the L allele. We conclude that actinic keratosis and squamous cell carcinoma should be added to the list of squamous neoplasias that are differentially regulated by the VDR Poly-A allele.
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Affiliation(s)
- Taylor A Bullock
- Department of Dermatology, Dermatology and Plastic Surgery Institute, Cleveland Clinic, Cleveland, Ohio
| | - Judith A Mack
- Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Jeffrey Negrey
- Clinical Research Unit, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Urvashi Kaw
- Department of Dermatology, Dermatology and Plastic Surgery Institute, Cleveland Clinic, Cleveland, Ohio
| | - Bo Hu
- Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, Ohio
| | - Sanjay Anand
- Department of Dermatology, Dermatology and Plastic Surgery Institute, Cleveland Clinic, Cleveland, Ohio; Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, Ohio
| | - Tayyaba Hasan
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Christine B Warren
- Department of Dermatology, Dermatology and Plastic Surgery Institute, Cleveland Clinic, Cleveland, Ohio; Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, Ohio
| | - Edward V Maytin
- Department of Dermatology, Dermatology and Plastic Surgery Institute, Cleveland Clinic, Cleveland, Ohio; Department of Biomedical Engineering, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio; Lerner College of Medicine of Case Western Reserve University, Cleveland Clinic, Cleveland, Ohio; Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts.
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Bacchetta J, Edouard T, Laverny G, Bernardor J, Bertholet-Thomas A, Castanet M, Garnier C, Gennero I, Harambat J, Lapillonne A, Molin A, Naud C, Salles JP, Laborie S, Tounian P, Linglart A. Vitamin D and calcium intakes in general pediatric populations: A French expert consensus paper. Arch Pediatr 2022; 29:312-325. [PMID: 35305879 DOI: 10.1016/j.arcped.2022.02.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/20/2022] [Indexed: 12/18/2022]
Abstract
OBJECTIVES Nutritional vitamin D supplements are often used in general pediatrics. Here, the aim is to address vitamin D supplementation and calcium nutritional intakes in newborns, infants, children, and adolescents to prevent vitamin D deficiency and rickets in general populations. STUDY DESIGN We formulated clinical questions relating to the following categories: the Patient (or Population) to whom the recommendation will apply; the Intervention being considered; the Comparison (which may be "no action," placebo, or an alternative intervention); and the Outcomes affected by the intervention (PICO). These PICO elements were arranged into the questions to be addressed in the literature searches. Each PICO question then formed the basis for a statement. The population covered consisted of children aged between 0 and 18 years and premature babies hospitalized in neonatology. Two groups were assembled: a core working group and a voting panel from different scientific pediatric committees from the French Society of Pediatrics and national scientific societies. RESULTS We present here 35 clinical practice points (CPPs) for the use of native vitamin D therapy (ergocalciferol, vitamin D2 and cholecalciferol, vitamin D3) and calcium nutritional intakes in general pediatric populations. CONCLUSION This consensus document was developed to provide guidance to health care professionals on the use of nutritional vitamin D and dietary modalities to achieve the recommended calcium intakes in general pediatric populations. These CPPs will be revised periodically. Research recommendations to study key vitamin D outcome measures in children are also suggested.
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Affiliation(s)
- J Bacchetta
- Centre de Référence des Maladies Rares du Calcium et du Phosphore, Service de Néphrologie Rhumatologie Dermatologie Pédiatriques, Filières Santé Maladies Rares OSCAR, ORKID et ERKNet, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, Bron 69677 CEDEX, France; INSERM U1033, LYOS, Prévention des Maladies Osseuses, Lyon, France; Faculté de Médecine Lyon Est, Université de Lyon, Lyon, France.
| | - T Edouard
- Centre de Référence des Maladies Rares du Calcium et du Phosphore, Unité d'Endocrinologie, Génétique et Pathologies Osseuses, Filières Santé Maladies Rares OSCAR et BOND, Hôpital des Enfants, Toulouse, France
| | - G Laverny
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS UMR7104, INSERM U1258, Université de Strasbourg, Illkirch, France
| | - J Bernardor
- INSERM U1033, LYOS, Prévention des Maladies Osseuses, Lyon, France; Département de Pédiatrie, CHU de Nice, Nice, France
| | - A Bertholet-Thomas
- Centre de Référence des Maladies Rares du Calcium et du Phosphore, Service de Néphrologie Rhumatologie Dermatologie Pédiatriques, Filières Santé Maladies Rares OSCAR, ORKID et ERKNet, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, Bron 69677 CEDEX, France; INSERM U1033, LYOS, Prévention des Maladies Osseuses, Lyon, France
| | - M Castanet
- Centre de Référence des Maladies Rares du Calcium et du Phosphore, Département de Pédiatrie, Filière Santé Maladies Rares OSCAR, CHU Rouen, Rouen, France
| | - C Garnier
- Centre de Référence des Maladies Rares du Calcium et du Phosphore, Service de Néphrologie Rhumatologie Dermatologie Pédiatriques, Filières Santé Maladies Rares OSCAR, ORKID et ERKNet, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, Bron 69677 CEDEX, France
| | - I Gennero
- Centre de Référence des Maladies Rares du Calcium et du Phosphore, Unité d'Endocrinologie, Génétique et Pathologies Osseuses, Filières Santé Maladies Rares OSCAR et BOND, Hôpital des Enfants, Toulouse, France
| | - J Harambat
- Centre de Référence Maladies Rénales Rares, Unité de Néphrologie Pédiatrique, Hôpital Pellegrin-Enfants, Bordeaux, France; INSERM U1219, Bordeaux, France
| | - A Lapillonne
- Service de Pédiatrie et Réanimation Néonatales, EHU 7328 Université de Paris, Hôpital Necker- Enfants Malades, Paris, France; CNRC, Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - A Molin
- Centre de Référence des Maladies Rares du Calcium et du Phosphore, Département de Génétique, Filière Santé Maladies Rares OSCAR, CHU Caen, Caen, France
| | - C Naud
- Centre de Référence des Maladies Rares du Calcium et du Phosphore, Service de Néphrologie Rhumatologie Dermatologie Pédiatriques, Filières Santé Maladies Rares OSCAR, ORKID et ERKNet, Hôpital Femme Mère Enfant, 59 Boulevard Pinel, Bron 69677 CEDEX, France
| | - J P Salles
- Centre de Référence des Maladies Rares du Calcium et du Phosphore, Unité d'Endocrinologie, Génétique et Pathologies Osseuses, Filières Santé Maladies Rares OSCAR et BOND, Hôpital des Enfants, Toulouse, France
| | - S Laborie
- Service de Réanimation Néonatale, Hôpital Femme Mère Enfant, Bron, France
| | - P Tounian
- Service de Nutrition et Gastroentérologie Pédiatriques, Hôpital Trousseau, Faculté de Médecine Sorbonne Université, Paris, France
| | - A Linglart
- AP-HP, Centre de Référence des Maladies Rares du Calcium et du Phosphore, Service d'Endocrinologie et diabète de l'enfant, Filières Santé Maladies Rares OSCAR, ERN endoRARE et BOND, Plateforme d'expertise des maladies rares Paris Saclay, Hôpital Bicêtre Paris-Saclay, Université Paris Saclay, INSERM U1185, Le Kremlin Bicêtre, France
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Bikle DD. Ligand-Independent Actions of the Vitamin D Receptor: More Questions Than Answers. JBMR Plus 2021; 5:e10578. [PMID: 34950833 PMCID: PMC8674770 DOI: 10.1002/jbm4.10578] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 10/26/2021] [Accepted: 11/04/2021] [Indexed: 12/19/2022] Open
Abstract
Our predominant understanding of the actions of vitamin D involve binding of its ligand, 1,25(OH)D, to the vitamin D receptor (VDR), which for its genomic actions binds to discrete regions of its target genes called vitamin D response elements. However, chromatin immunoprecipitation‐sequencing (ChIP‐seq) studies have observed that the VDR can bind to many sites in the genome without its ligand. The number of such sites and how much they coincide with sites that also bind the liganded VDR vary from cell to cell, with the keratinocyte from the skin having the greatest overlap and the intestinal epithelial cell having the least. What is the purpose of the unliganded VDR? In this review, I will focus on two clear examples in which the unliganded VDR plays a role. The best example is that of hair follicle cycling. Hair follicle cycling does not need 1,25(OH)2D, and Vdr lacking the ability to bind 1,25(OH)2D can restore hair follicle cycling in mice otherwise lacking Vdr. This is not true for other functions of VDR such as intestinal calcium transport. Tumor formation in the skin after UVB radiation or the application of chemical carcinogens also appears to be at least partially independent of 1,25(OH)2D in that Vdr null mice develop such tumors after these challenges, but mice lacking Cyp27b1, the enzyme producing 1,25(OH)2D, do not. Examples in other tissues emerge when studies comparing Vdr null and Cyp27b1 null mice are compared, demonstrating a more severe phenotype with respect to bone mineral homeostasis in the Cyp27b1 null mouse, suggesting a repressor function for VDR. This review will examine potential mechanisms for these ligand‐independent actions of VDR, but as the title indicates, there are more questions than answers with respect to this role of VDR. © 2021 The Author. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
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Affiliation(s)
- Daniel D Bikle
- Departments of Medicine and Dermatology University of California San Francisco, San Francisco VA Health Center San Francisco CA USA
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Bikle D, Christakos S. New aspects of vitamin D metabolism and action - addressing the skin as source and target. Nat Rev Endocrinol 2020; 16:234-252. [PMID: 32029884 DOI: 10.1038/s41574-019-0312-5] [Citation(s) in RCA: 163] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/12/2019] [Indexed: 12/19/2022]
Abstract
Vitamin D has a key role in stimulating calcium absorption from the gut and promoting skeletal health, as well as many other important physiological functions. Vitamin D is produced in the skin. It is subsequently metabolized to its hormonally active form, 1,25-dihydroxyvitamin D (1,25(OH)2D), by the 1-hydroxylase and catabolized by the 24-hydroxylase. In this Review, we pay special attention to the effect of mutations in these enzymes and their clinical manifestations. We then discuss the role of vitamin D binding protein in transporting vitamin D and its metabolites from their source to their targets, the free hormone hypothesis for cell entry and HSP70 for intracellular transport. This is followed by discussion of the vitamin D receptor (VDR) that mediates the cellular actions of 1,25(OH)2D. Cell-specific recruitment of co-regulatory complexes by liganded VDR leads to changes in gene expression that result in distinct physiological actions by 1,25(OH)2D, which are disrupted by mutations in the VDR. We then discuss the epidermis and hair follicle, to provide a non-skeletal example of a tissue that expresses VDR that not only makes vitamin D but also can metabolize it to its hormonally active form. This enables vitamin D to regulate epidermal differentiation and hair follicle cycling and, in so doing, to promote barrier function, wound healing and hair growth, while limiting cancer development.
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Affiliation(s)
- Daniel Bikle
- Departments of Medicine and Dermatology, University of California San Francisco, San Francisco, CA, USA.
- VA Medical Center, San Francisco, CA, USA.
| | - Sylvia Christakos
- Departments of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers, the State University of New Jersey, Newark, NJ, USA
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Udomsinprasert W, Jittikoon J. Vitamin D and liver fibrosis: Molecular mechanisms and clinical studies. Biomed Pharmacother 2018; 109:1351-1360. [PMID: 30551386 DOI: 10.1016/j.biopha.2018.10.140] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 10/22/2018] [Accepted: 10/24/2018] [Indexed: 12/21/2022] Open
Abstract
Vitamin D plays a primary role in regulation of bone metabolism and calcium homeostasis. Interestingly, emerging evidence suggests protective effects of vitamin D against liver fibrogenesis. However, the precise mechanisms of this action remain mysterious. Herein, this review aimed to summarize the role of vitamin D in liver fibrosis pathology and to update the current comprehensive knowledge regarding the clinical utility of vitamin D-based treatment in liver fibrosis. In regard to its effect on liver fibrosis, vitamin D possesses an anti-fibrotic effect on hepatic stellate cells via vitamin D receptor-mediated specific signal transduction pathways, which in turn inhibit expression of pro-fibrogenic genes. Furthermore, several studies demonstrated a significant association between low vitamin D levels and an increased risk of liver fibrosis. Additionally, high prevalence of vitamin D deficiency was noted in patients with liver fibrosis, suggesting the use of vitamin D status as a biochemical marker reflecting the progression of liver fibrosis. It is therefore reasonable to postulate that vitamin D supplementation being a cost effective and relative simple procedure may benefit to liver fibrosis. Nevertheless, further research is needed to fully elucidate its regulatory role in inhibiting liver fibrogenesis and to estimate the safety and efficiency of vitamin D supplementation as a relatively inexpensive treatment for liver fibrosis in patients with chronic liver diseases.
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Affiliation(s)
- Wanvisa Udomsinprasert
- Department of Biochemistry, Faculty of Pharmacy, Mahidol University, Bangkok 10400, Thailand.
| | - Jiraphun Jittikoon
- Department of Biochemistry, Faculty of Pharmacy, Mahidol University, Bangkok 10400, Thailand.
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Faiyaz-Ul-Haque M, AlDhalaan W, AlAshwal A, Bin-Abbas BS, AlSagheir A, Alotaiby M, Rafiq Z, Zaidi SHE. Hereditary 1,25-dihydroxyvitamin D-resistant rickets (HVDRR): clinical heterogeneity and long-term efficacious management of eight patients from four unrelated Arab families with a loss of function VDR mutation. J Pediatr Endocrinol Metab 2018; 31:861-868. [PMID: 29949513 DOI: 10.1515/jpem-2017-0312] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 06/01/2018] [Indexed: 01/27/2023]
Abstract
BACKGROUND Vitamin D regulates the concentrations of calcium and phosphate in blood and promotes the growth and remodeling of bones. The circulating active form of vitamin D, 1,25-dihydroxyvitamin D, binds to the vitamin D receptor (VDR), which heterodimerizes with the retinoid X receptor to regulate the expression of target genes. Inactivating mutations in the VDR gene cause hereditary vitamin D-resistant rickets (HVDRR), a rare disorder characterized by an early onset of rickets, growth retardation, skeletal deformities, hypocalcemia, hypophosphatemia and secondary hyperparathyroidism, and in some cases alopecia. METHODS We describe eight new HVDRR patients from four unrelated consanguineous families. The VDR gene was sequenced to identify mutations. The management of patients over a period of up to 11 years following the initial diagnosis is assessed. RESULTS Although all patients exhibit main features of HVDRR and carry the same c.885C>A (p.Y295*) loss of function mutation in the VDR gene, there was heterogeneity of the manifestations of HVDRR-associated phenotypes and developmental milestones. These eight patients were successfully treated over a period of 11 years. All clinical symptoms were improved except alopecia. CONCLUSIONS The study concludes that VDR sequencing and laboratory tests are essential to confirm HVDRR and to assess the effectiveness of the treatment.
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Affiliation(s)
- Muhammad Faiyaz-Ul-Haque
- Department of Pathology, Molecular Genetics Pathology Unit, College of Medicine, King Khalid University Hospital, King Saud University, Riyadh, Saudi Arabia
| | - Waheeb AlDhalaan
- Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Abdullah AlAshwal
- Department of Pediatrics - MBC 58, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Bassam S Bin-Abbas
- Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Afaf AlSagheir
- Department of Pediatrics, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Maram Alotaiby
- Department of Pathology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Zulqurnain Rafiq
- Department of Orthopedic, King Saud University, Riyadh, Saudi Arabia
| | - Syed H E Zaidi
- Genome Technologies, Ontario Institute for Cancer Research, Toronto, Canada
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Lee SM, Meyer MB, Benkusky NA, O'Brien CA, Pike JW. The impact of VDR expression and regulation in vivo. J Steroid Biochem Mol Biol 2018; 177:36-45. [PMID: 28602960 PMCID: PMC5723236 DOI: 10.1016/j.jsbmb.2017.06.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 06/02/2017] [Accepted: 06/05/2017] [Indexed: 12/23/2022]
Abstract
The vitamin D receptor (VDR) mediates the pleiotropic biological actions of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). These actions include orchestration of mineral homeostasis which is coordinated by the kidney, intestine, bone and parathyroid gland wherein the VDR transcriptionally regulates expression of the genes involved in this complex process. Mutations in human VDR (hVDR) cause hereditary vitamin D resistant rickets, a genetic syndrome characterized by hypocalcemia, hyperparathyroidism and rickets resulting from dysregulation of mineral homeostasis. Expression of the VDR is regulated by external stimuli in a tissue-specific manner. However, the mechanisms of this tissue-specificity remain unclear. Studies also suggest that phosphorylation of hVDR at serine 208 impacts the receptor's transcriptional activity. These experiments were conducted in vitro, however, and therefore limited in their conclusions. In this report, we summarize (1) our most recently updated ChIP-seq data from mouse tissues to identify regulatory regions responsible for the tissues-specific regulation of the VDR and (2) our studies to understand the mechanism of hormonal regulation of Vdr expression in bone and kidney in vivo using transgenic mouse strains generated by mouse mini-genes that contain comprehensive genetic information capable of recapitulating endogenous Vdr gene regulation and expression. We also defined the functional human VDR gene locus in vivo by using a human mini-gene comparable to that in the mouse to generate a humanized VDR mouse strain in which the receptor is expressed at normal levels (normal expressor). The present report also shows that a humanized mouse model in which the VDR is expressed at levels about 10-fold lower than the normal expressor mouse rescued the VDR-null phenotype despite its reduced transcriptional activity relative to wildtype expression. We also generated an additional humanized mouse model expressing hVDR bearing a mutation converting serine 208 to alanine (hVDR-S208A). In spite of the mutation, target gene expression induced by the ligand was unchanged relative to a mouse strain expressing comparable levels of wildtype hVDR. Further characterization also showed that serum calcium and parathyroid hormone levels were normal and alopecia was not observed in this hVDR-S208A mouse strain as well. Taken together, our in vivo studies using ChIP-seq analyses and the mini-gene transgenic mice improve our understanding of the tissue-specific regulatory mechanisms of controlling VDR expression and the mechanisms of action of the VDR.
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Affiliation(s)
- Seong Min Lee
- 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
| | - Nancy A Benkusky
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
| | - Charles A O'Brien
- University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States.
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Saini V, Zhao H, Petit ET, Gori F, Demay MB. Absence of vitamin D receptor (VDR)-mediated PPARγ suppression causes alopecia in VDR-null mice. FASEB J 2017; 31:1059-1066. [PMID: 27932380 PMCID: PMC5295732 DOI: 10.1096/fj.201600863r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 11/22/2016] [Indexed: 12/19/2022]
Abstract
Vitamin D receptor (VDR) mutations in humans and mice cause alopecia. VDR-null (VDR-/-) mice exhibit lack of postmorphogenic hair cycles as a result of impaired keratinocyte stem cell (KSC) function. To identify the molecular basis for abnormal KSC function, RNA sequencing of wild-type (WT) and VDR-/- KSCs was performed. These studies demonstrated that >80% of differentially expressed genes are up-regulated in VDR-/- KSCs; thus, the VDR is a transcriptional suppressor in WT KSCs. Peroxisome proliferator-activated receptor γ (PPARγ), PPARγ coactivator 1β (PGC1β), and lipoprotein lipase (LPL) were among the up-regulated genes identified. Chromatin immunoprecipitation analyses demonstrated that these genes are direct VDR targets in WT keratinocytes. Notably, VDR occupancy of the PPARγ regulatory region precludes PPARγ occupancy of this site, based on the observation that PPARγ interacts with these sequences in VDR-/- but not WT keratinocytes. This contrasts with the VDR and PPARγ co-occupancy observed on PGC1β and LPL gene regulatory regions identified. Studies in mice with keratinocyte-specific PPARγ haploinsufficiency were performed to identify the functional consequences of enhanced PPARγ expression. PPARγ haploinsufficiency normalized PPARγ mRNA levels in VDR-/- keratinocytes and restored anagen responsiveness in vivo in VDR-/- mice, resulting in hair regrowth. Thus, absence of VDR-mediated PPARγ suppression underlies alopecia in VDR-/- mice.-Saini, V., Zhao, H., Petit, E. T., Gori, F., Demay, M. B. Absence of vitamin D receptor (VDR)-mediated PPARγ suppression causes alopecia in VDR-null mice.
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Affiliation(s)
- Vaibhav Saini
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Hengguang Zhao
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Elizabeth T Petit
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Francesca Gori
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Marie B Demay
- Endocrine Unit, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
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Pike JW, Meyer MB, Lee SM, Onal M, Benkusky NA. The vitamin D receptor: contemporary genomic approaches reveal new basic and translational insights. J Clin Invest 2017; 127:1146-1154. [PMID: 28240603 DOI: 10.1172/jci88887] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The vitamin D receptor (VDR) is the single known regulatory mediator of hormonal 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] in higher vertebrates. It acts in the nucleus of vitamin D target cells to regulate the expression of genes whose products control diverse, cell type-specific biological functions that include mineral homeostasis. In this Review we describe progress that has been made in defining new cellular sites of action of this receptor, the mechanisms through which this mediator controls the expression of genes, the biology that ensues, and the translational impact of this receptor on human health and disease. We conclude with a brief discussion of what comes next in understanding vitamin D biology and the mechanisms that underlie its actions.
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Elangovan H, Chahal S, Gunton JE. Vitamin D in liver disease: Current evidence and potential directions. Biochim Biophys Acta Mol Basis Dis 2017; 1863:907-916. [PMID: 28064017 DOI: 10.1016/j.bbadis.2017.01.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 12/06/2016] [Accepted: 01/02/2017] [Indexed: 01/10/2023]
Abstract
Consistent with its multifaceted nature, growing evidence links vitamin D with hepatic disease. In this review, we summarise the roles of vitamin D in different liver pathologies and explore the clinical utility of vitamin D-based treatments in hepatology. We find that the small number of clinical trials coupled with the profound heterogeneity of study protocols limits the strength of evidence needed to ascribe definite clinical value to the hormone in liver disease. Nevertheless, the experimental data is promising and further bench and bedside studies will likely define a clearer role in hepatic therapeutics.
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Affiliation(s)
- Harendran Elangovan
- The Garvan Institute of Medical Research, The University of New South Wales (UNSW), Sydney, NSW, Australia
| | - Sarinder Chahal
- The Garvan Institute of Medical Research, The University of New South Wales (UNSW), Sydney, NSW, Australia
| | - Jenny E Gunton
- The Garvan Institute of Medical Research, The University of New South Wales (UNSW), Sydney, NSW, Australia; The Westmead Institute of Medical Research, The University of Sydney, NSW, Australia.
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12
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Lee SM, Pike JW. The vitamin D receptor functions as a transcription regulator in the absence of 1,25-dihydroxyvitamin D 3. J Steroid Biochem Mol Biol 2016; 164:265-270. [PMID: 26323657 PMCID: PMC4769962 DOI: 10.1016/j.jsbmb.2015.08.018] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 08/13/2015] [Accepted: 08/17/2015] [Indexed: 10/23/2022]
Abstract
The vitamin D receptor (VDR) is a critical mediator of the biological actions of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). As a nuclear receptor, ligand activation of the VDR leads to the protein's binding to specific sites on the genome that results in the modulation of target gene expression. The VDR is also known to play a role in the hair cycle, an action that appears to be 1,25(OH)2D3-independent. Indeed, in the absence of the VDR as in hereditary 1,25-dihydroxyvitamin D resistant rickets (HVDRR) both skin defects and alopecia emerge. Recently, we generated a mouse model of HVDRR without alopecia wherein a mutant human VDR lacking 1,25(OH)2D3-binding activity was expressed in the absence of endogenous mouse VDR. While 1,25(OH)2D3 failed to induce gene expression in these mice, resulting in an extensive skeletal phenotype, the receptor was capable of restoring normal hair cycling. We also noted a level of secondary hyperparathyroidism that was much higher than that seen in the VDR null mouse and was associated with an exaggerated bone phenotype as well. This suggested that the VDR might play a role in parathyroid hormone (PTH) regulation independent of 1,25(OH)2D3. To evaluate this hypothesis further, we contrasted PTH levels in the HVDRR mouse model with those seen in Cyp27b1 null mice where the VDR was present but the hormone was absent. The data revealed that PTH was indeed higher in Cyp27b1 null mice compared to VDR null mice. To evaluate the mechanism of action underlying such a hypothesis, we measured the expression levels of a number of VDR target genes in the duodena of wildtype mice and in transgenic mice expressing either normal or hormone-binding deficient mutant VDRs. We also compared expression levels of these genes between VDR null mice and Cyp27b1 null mice. In a subset of cases, the expression of VDR target genes was lower in mice containing the VDR as opposed to mice that did not. We suggest that the VDR may function as a selective suppressor/de-repressor of gene expression in the absence of 1,25(OH)2D3.
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Affiliation(s)
- Seong Min Lee
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States.
| | - J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, United States
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13
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Vangoitsenhoven R, Wolden-Kirk H, Lemaire K, Verstuyf A, Verlinden L, Yamamoto Y, Kato S, Van Lommel L, Schuit F, Van der Schueren B, Mathieu C, Overbergh L. Effect of a transcriptional inactive or absent vitamin D receptor on beta-cell function and glucose homeostasis in mice. J Steroid Biochem Mol Biol 2016; 164:309-317. [PMID: 26877201 DOI: 10.1016/j.jsbmb.2016.02.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 12/08/2015] [Accepted: 02/09/2016] [Indexed: 12/19/2022]
Abstract
Vitamin D deficiency is associated with beta-cell dysfunction and a higher risk of diabetes, but mice and humans with an absence of the vitamin D receptor (VDR) display normal glucose tolerance. Here, we investigated the direct effects of absence of VDR or absence of ligand activation of VDR on beta-cell function. For this purpose, we generated mice, with a mutation in the AF2 domain of Vdr (VDRΔAF2), preventing ligand-driven transcriptional activation of vitamin D responsive genes. VDRΔAF2 mice were compared to Vdr full knockout (VDR-/-) and wild type (WT) mice. In order to avoid hypocalcemia, which has a direct effect on beta-cell function, mice were fed a high calcium, high lactose diet yielding comparable serum calcium in all mice. While VDR-/- mice developed extensive alopecia by the age of 24 weeks, the fur of VDRΔAF2 remained normal. All VDRΔAF2 mice weighed significantly less than WT, while male but not female VDR-/- mice had a lower body weight than WT mice. Dual-energy X-ray absorptiometry showed that both VDRΔAF2 (17.2% (females) and 16.6% (males)) and VDR-/- (15.7% and 14.8%) mice have a lower percentage of body fat (vs 19.3% and 22.2% in WT). Serum 25(OH)D3 concentrations were lower for both VDRΔAF2 (-4.55 fold, P<0.001) and VDR-/- (-3.7 fold, P<0.001) as compared to 12 week old WT mice, while serum 1,25(OH)2D3 was increased for both strains 94.5 fold (P<0.01) and 92.8 fold (P<0.001) for VDRΔAF2 and VDR-/- vs WT, respectively). In vivo glucose tolerance tests performed at 12 and 24 weeks of age, as well as ex vivo glucose stimulated insulin secretion on freshly isolated islets, revealed no major differences between the three strains. Microarray analysis on freshly isolated islets showed only 1 differentially expressed gene, phosphodiesterase 10a (Pde10a), which was 2.16 and 1.75 fold up-regulated in VDRΔAF2 and VDR-/- islets as compared to WT islets, respectively (P≤0.001). We conclude that in the presence of normocalcemia, absence of VDR or its ligand-activated transcription of genes has no direct regulatory effect on murine glucose homeostasis or gene expression in islets of Langerhans.
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Affiliation(s)
- Roman Vangoitsenhoven
- Clinical and Experimental Medicine and Endocrinology, KU Leuven, Herestraat 49, Box 902, 3000 Leuven, Belgium
| | - Heidi Wolden-Kirk
- Clinical and Experimental Medicine and Endocrinology, KU Leuven, Herestraat 49, Box 902, 3000 Leuven, Belgium
| | - Katleen Lemaire
- Gene Expression Unit, Dept. of Molecular and Cellular Medicine, KU Leuven, Herestraat 49, Box 901, 3000 Leuven, Belgium
| | - Annemieke Verstuyf
- Clinical and Experimental Medicine and Endocrinology, KU Leuven, Herestraat 49, Box 902, 3000 Leuven, Belgium
| | - Lieve Verlinden
- Clinical and Experimental Medicine and Endocrinology, KU Leuven, Herestraat 49, Box 902, 3000 Leuven, Belgium
| | - Yoko Yamamoto
- University of Tokyo Hospital, University of Tokyo, 113-8655 Tokyo, Japan
| | | | - Leentje Van Lommel
- Gene Expression Unit, Dept. of Molecular and Cellular Medicine, KU Leuven, Herestraat 49, Box 901, 3000 Leuven, Belgium
| | - Frans Schuit
- Gene Expression Unit, Dept. of Molecular and Cellular Medicine, KU Leuven, Herestraat 49, Box 901, 3000 Leuven, Belgium
| | - Bart Van der Schueren
- Clinical and Experimental Medicine and Endocrinology, KU Leuven, Herestraat 49, Box 902, 3000 Leuven, Belgium
| | - Chantal Mathieu
- Clinical and Experimental Medicine and Endocrinology, KU Leuven, Herestraat 49, Box 902, 3000 Leuven, Belgium
| | - Lut Overbergh
- Clinical and Experimental Medicine and Endocrinology, KU Leuven, Herestraat 49, Box 902, 3000 Leuven, Belgium.
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14
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Christakos S, Dhawan P, Verstuyf A, Verlinden L, Carmeliet G. Vitamin D: Metabolism, Molecular Mechanism of Action, and Pleiotropic Effects. Physiol Rev 2016; 96:365-408. [PMID: 26681795 PMCID: PMC4839493 DOI: 10.1152/physrev.00014.2015] [Citation(s) in RCA: 1071] [Impact Index Per Article: 133.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
1,25-Dihydroxvitamin D3 [1,25(OH)2D3] is the hormonally active form of vitamin D. The genomic mechanism of 1,25(OH)2D3 action involves the direct binding of the 1,25(OH)2D3 activated vitamin D receptor/retinoic X receptor (VDR/RXR) heterodimeric complex to specific DNA sequences. Numerous VDR co-regulatory proteins have been identified, and genome-wide studies have shown that the actions of 1,25(OH)2D3 involve regulation of gene activity at a range of locations many kilobases from the transcription start site. The structure of the liganded VDR/RXR complex was recently characterized using cryoelectron microscopy, X-ray scattering, and hydrogen deuterium exchange. These recent technological advances will result in a more complete understanding of VDR coactivator interactions, thus facilitating cell and gene specific clinical applications. Although the identification of mechanisms mediating VDR-regulated transcription has been one focus of recent research in the field, other topics of fundamental importance include the identification and functional significance of proteins involved in the metabolism of vitamin D. CYP2R1 has been identified as the most important 25-hydroxylase, and a critical role for CYP24A1 in humans was noted in studies showing that inactivating mutations in CYP24A1 are a probable cause of idiopathic infantile hypercalcemia. In addition, studies using knockout and transgenic mice have provided new insight on the physiological role of vitamin D in classical target tissues as well as evidence of extraskeletal effects of 1,25(OH)2D3 including inhibition of cancer progression, effects on the cardiovascular system, and immunomodulatory effects in certain autoimmune diseases. Some of the mechanistic findings in mouse models have also been observed in humans. The identification of similar pathways in humans could lead to the development of new therapies to prevent and treat disease.
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Affiliation(s)
- Sylvia Christakos
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey; and Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Puneet Dhawan
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey; and Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Annemieke Verstuyf
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey; and Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Lieve Verlinden
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey; and Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
| | - Geert Carmeliet
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers, The State University of New Jersey, New Jersey Medical School, Newark, New Jersey; and Laboratory of Clinical and Experimental Endocrinology, KU Leuven, Leuven, Belgium
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15
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Lee SM, Meyer MB, Benkusky NA, O'Brien CA, Pike JW. Mechanisms of Enhancer-mediated Hormonal Control of Vitamin D Receptor Gene Expression in Target Cells. J Biol Chem 2015; 290:30573-86. [PMID: 26504088 PMCID: PMC4683277 DOI: 10.1074/jbc.m115.693614] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Revised: 10/14/2015] [Indexed: 12/18/2022] Open
Abstract
The biological actions of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) are mediated by the vitamin D receptor (VDR), whose expression in bone cells is regulated positively by 1,25(OH)2D3, retinoic acid, and parathyroid hormone through both intergenic and intronic enhancers. In this report, we used ChIP-sequencing analysis to confirm the presence of these Vdr gene enhancers in mesenchyme-derived bone cells and to describe the epigenetic histone landscape that spans the Vdr locus. Using bacterial artificial chromosome-minigene stable cell lines, CRISPR/Cas9 enhancer-deleted daughter cell lines, transient transfection/mutagenesis analyses, and transgenic mice, we confirmed the functionality of these bone cell enhancers in vivo as well as in vitro. We also identified VDR-binding sites across the Vdr gene locus in kidney and intestine using ChIP-sequencing analysis, revealing that only one of the bone cell-type enhancers bound VDR in kidney tissue, and none were occupied by the VDR in the intestine, consistent with weak or absent regulation by the 1,25(OH)2D3 hormone in these tissues, respectively. However, a number of additional sites of VDR binding unique to either kidney or intestine were present further upstream of the Vdr gene, suggesting the potential for alternative regulatory loci. Importantly, virtually all of these regions retained histone signatures consistent with those of enhancers and exhibited unique DNase I hypersensitivity profiles that reflected the potential for chromatin access. These studies define mechanisms associated with hormonal regulation of the Vdr and hint at the differential nature of VDR binding activity at the Vdr gene in different primary target tissues in vivo.
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Affiliation(s)
- Seong Min Lee
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
| | - Mark B Meyer
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
| | - Nancy A Benkusky
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
| | - Charles A O'Brien
- the Department of Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - J Wesley Pike
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 and
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16
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Kaufmann M, Lee SM, Pike JW, Jones G. A High-Calcium and Phosphate Rescue Diet and VDR-Expressing Transgenes Normalize Serum Vitamin D Metabolite Profiles and Renal Cyp27b1 and Cyp24a1 Expression in VDR Null Mice. Endocrinology 2015; 156:4388-97. [PMID: 26441239 PMCID: PMC4655220 DOI: 10.1210/en.2015-1664] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Vitamin D receptor (VDR)-mediated 1,25-dihydroxyvitamin D3 (1,25(OH)2D3)-dependent gene expression is compromised in the VDR null mouse. The biological consequences include: hypocalcemia, hypophosphatemia, elevated parathyroid hormone (PTH) and 1,25(OH)2D3, and consequential skeletal abnormalities. CYP24A1 is a cytochrome P450 enzyme that is involved in the side chain oxidation and destruction of both 1,25(OH)2D3 and 25-hydroxyvitamin D3 (25-OH-D3). In the current studies, we used liquid chromatography-tandem mass spectrometry technology to compare the metabolic profiles of VDR null mice fed either a normal or a calcium and phosphate-enriched rescue diet and to assess the consequence of transgenic expression of either mouse or human VDR genes in the same background. Serum 1,25(OH)2D3 levels in VDR null mice on normal chow were highly elevated (>3000 pg/mL) coincident with undetectable levels of catabolites such as 24,25-(OH)2D3 and 25-OH-D3-26,23-lactone normally observed in wild-type mice. The rescue diet corrected serum Ca(++), PTH, and 1,25(OH)2D3 values and restored basal expression of Cyp24a1 as evidenced by both renal expression of Cyp24a1 and detection of 24,25-(OH)2D3 and the 25-OH-D3-26,23-lactone. Unexpectedly, this diet also resulted in supranormal levels of 3-epi-24,25-(OH)2D3 and 3-epi-25-OH-D3-26,23-lactone. The reappearance of serum 24,25-(OH)2D3 and renal Cyp24a1 expression after rescue suggests that basal levels of Cyp24a1 may be repressed by high PTH. Introduction of transgenes for either mouse or human VDR also normalized vitamin D metabolism in VDR null mice, whereas this metabolic pattern was unaffected by a transgene encoding a ligand binding-deficient mutant (L233S) human VDR. We conclude that liquid chromatography-tandem mass spectrometry-based metabolic profiling is an ideal analytical method to study mouse models with alterations in calcium/phosphate homeostasis.
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Affiliation(s)
- Martin Kaufmann
- Department of Biomedical and Molecular Sciences (M.K., G.J.), Queen's University, Kingston, Ontario, Canada K7L3N6; and Department of Biochemistry (S.M.L., J.W.P.), University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Seong Min Lee
- Department of Biomedical and Molecular Sciences (M.K., G.J.), Queen's University, Kingston, Ontario, Canada K7L3N6; and Department of Biochemistry (S.M.L., J.W.P.), University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - J Wesley Pike
- Department of Biomedical and Molecular Sciences (M.K., G.J.), Queen's University, Kingston, Ontario, Canada K7L3N6; and Department of Biochemistry (S.M.L., J.W.P.), University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Glenville Jones
- Department of Biomedical and Molecular Sciences (M.K., G.J.), Queen's University, Kingston, Ontario, Canada K7L3N6; and Department of Biochemistry (S.M.L., J.W.P.), University of Wisconsin-Madison, Madison, Wisconsin 53706
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17
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Pike JW, Meyer MB, Benkusky NA, Lee SM, St John H, Carlson A, Onal M, Shamsuzzaman S. Genomic Determinants of Vitamin D-Regulated Gene Expression. VITAMINS AND HORMONES 2015; 100:21-44. [PMID: 26827947 DOI: 10.1016/bs.vh.2015.10.011] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Insight into mechanisms that link the actions of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) to the regulation of gene expression has evolved extensively since the initial discovery of a nuclear protein known as the vitamin D receptor (VDR). Perhaps most important was the molecular cloning of this receptor which enabled its inclusion within the nuclear receptor gene family and further studies of both its structure and regulatory function. Current studies are now refocused on the vitamin D hormone's action at the genome, where VDR together with other transcription factors coordinates the recruitment of chromatin active coregulatory complexes that participate directly in the modification of gene output. These studies highlight the role of chromatin in the expression of genes and the dynamic impact of the epigenetic landscape that contextualizes individual gene loci thus influencing the VDR's transcriptional actions. In this chapter, we summarize advances made over the past few years in understanding vitamin D action on a genome-wide scale, focusing on overarching principles that have emerged at this level. Of particular significance is the finding that dynamic changes that occur to the genome during cellular differentiation at both genetic and epigenetic levels profoundly alter the ability of 1,25(OH)2D3 and its receptor to regulate gene expression. We address the broad impact of differentiation on specific epigenetic histone modifications that occur across the genome and the ability of the VDR to influence this activity at selected gene loci as well. These studies advance our understanding of not only vitamin D action but also of the complex and dynamic role played by the genome itself as a major determinant of VDR activity.
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Affiliation(s)
- J Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA.
| | - Mark B Meyer
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Nancy A Benkusky
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Seong Min Lee
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Hillary St John
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Alex Carlson
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Melda Onal
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Sohel Shamsuzzaman
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, USA
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18
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Onal M, Bishop KA, St John HC, Danielson AL, Riley EM, Piemontese M, Xiong J, Goellner JJ, O'Brien CA, Pike JW. A DNA segment spanning the mouse Tnfsf11 transcription unit and its upstream regulatory domain rescues the pleiotropic biologic phenotype of the RANKL null mouse. J Bone Miner Res 2015; 30:855-68. [PMID: 25431114 PMCID: PMC5240630 DOI: 10.1002/jbmr.2417] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 11/15/2014] [Accepted: 11/24/2014] [Indexed: 12/26/2022]
Abstract
Receptor activator of NF-κB ligand (RANKL) is a TNFα-like cytokine that is produced by a diverse set of lineage-specific cells and is involved in a wide variety of physiological processes that include skeletal remodeling, lymph node organogenesis, mammary gland development, and thermal regulation. Consistent with these diverse functions, control of RANKL expression is accomplished in a cell-specific fashion via a set of at least 10 regulatory enhancers that are located up to 170 kb upstream of the gene's transcriptional start site. Here we examined the in vivo consequence of introducing a contiguous DNA segment containing these components into a genetically deleted RANKL null mouse strain. In contrast to RANKL null littermates, null mice containing the transgene exhibited normalized body size, skeletal development, and bone mass as well as normal bone marrow cavities, normalized spleen weights, and the presence of developed lymph nodes. These mice also manifested normalized reproductive capacity, including the ability to lactate and to produce normal healthy litters. Consistent with this, the transgene restored endogenous-like RANKL transcript levels in several RANKL-expressing tissues. Most importantly, restoration of RANKL expression from this segment of DNA was fully capable of rescuing the complex aberrant skeletal and immune phenotype of the RANKL null mouse. RANKL also restored appropriate levels of B220+ IgM+ and B220+ IgD+ B cells in spleen. Finally, we found that RANKL expression from this transgene was regulated by exogenously administered 1,25(OH)2 D3 , parathyroid hormone (PTH), and lipopolysaccharide (LPS), thus recapitulating the ability of these same factors to regulate the endogenous gene. These findings fully highlight the properties of the Tnfsf11 gene locus predicted through previous in vitro dissection. We conclude that the mouse Tnfsf11 gene locus identified originally through unbiased chromatin immunoprecipitation with DNA microarray (ChIP-chip) analysis contains the necessary genetic information to direct appropriate tissue-specific and factor-regulated RANKL expression in vivo.
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Affiliation(s)
- Melda Onal
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, USA
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19
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Huet T, Laverny G, Ciesielski F, Molnár F, Ramamoorthy TG, Belorusova AY, Antony P, Potier N, Metzger D, Moras D, Rochel N. A vitamin D receptor selectively activated by gemini analogs reveals ligand dependent and independent effects. Cell Rep 2015; 10:516-26. [PMID: 25620699 DOI: 10.1016/j.celrep.2014.12.045] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 11/08/2014] [Accepted: 12/02/2014] [Indexed: 01/01/2023] Open
Abstract
The bioactive form of vitamin D [1,25(OH)2D3] regulates mineral and bone homeostasis and exerts potent anti-inflammatory and antiproliferative properties through binding to the vitamin D receptor (VDR). The 3D structures of the VDR ligand-binding domain with 1,25(OH)2D3 or gemini analogs unveiled the molecular mechanism underlying ligand recognition. On the basis of structure-function correlations, we generated a point-mutated VDR (VDR(gem)) that is unresponsive to 1,25(OH)2D3, but the activity of which is efficiently induced by the gemini ligands. Moreover, we show that many VDR target genes are repressed by unliganded VDR(gem) and that mineral ion and bone homeostasis are more impaired in VDR(gem) mice than in VDR null mice, demonstrating that mutations abolishing VDR ligand binding result in more severe skeletal defects than VDR null mutations. As gemini ligands induce VDR(gem) transcriptional activity in mice and normalize their serum calcium levels, VDR(gem) is a powerful tool to further unravel both liganded and unliganded VDR signaling.
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Affiliation(s)
- Tiphaine Huet
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Centre National de la Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Gilles Laverny
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Centre National de la Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Fabrice Ciesielski
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Centre National de la Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Ferdinand Molnár
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Centre National de la Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Thanuja Gali Ramamoorthy
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Centre National de la Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Anna Y Belorusova
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Centre National de la Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Pierre Antony
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Centre National de la Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Noelle Potier
- Institut de Chimie LC3-CNRS-UMR 7177, 67008 Strasbourg, France
| | - Daniel Metzger
- Department of Functional Genomics and Cancer, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Centre National de la Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France.
| | - Dino Moras
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Centre National de la Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France
| | - Natacha Rochel
- Department of Integrative Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Institut National de la Santé et de la Recherche Médicale (INSERM) U964, Centre National de la Recherche Scientifique (CNRS) UMR 7104, Université de Strasbourg, 67404 Illkirch, France.
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