scholarly journals Natural Epigenetic Modulators of Vitamin D Receptor

2020 ◽  
Vol 10 (12) ◽  
pp. 4096
Author(s):  
Giulia Apprato ◽  
Camilla Fiz ◽  
Isabella Fusano ◽  
Loredana Bergandi ◽  
Francesca Silvagno
Keyword(s):  
Vitamin D ◽  
Vitamin D Receptor ◽  
Histone Deacetylases ◽  
Cancer Cell Line ◽  
Dna Methyltransferases ◽  
Intestinal Epithelial ◽  
Human Liver Cancer ◽  
Enhanced Expression ◽  
Increased Sensitivity

Vitamin D plays an important role in every tissue due to its differentiating properties and the control of calcium homeostasis. The reversion of the epigenetic repression of the vitamin D receptor (VDR) could lead to an increased sensitivity of the cells to the beneficial activity of the hormone and could be exploited in many vitamin D-resistant diseases. In this study we analyzed the effects of three natural epigenetic modulators: sulforaphane, curcumin, and the products of the fermentative activity of probiotics. Sulforaphane and curcumin are inhibitors of the DNA methyltransferases (DNMT) and of the histone deacetylases (HDAC); it has been demonstrated that sulforaphane and curcumin increase VDR expression in intestinal epithelial cells and in a human liver cancer cell line, respectively. The anti-inflammatory properties associated with the probiotic administration in vivo can be linked to the increased activity of intestinal VDR. Butyrate, an inhibitor of HDAC and a known modulator of VDR expression, is the candidate byproduct of fermentation by gut microbiome that could mediate the enhanced expression of VDR triggered by probiotics in vivo. Many other natural compounds wait to be investigated and recognized as epigenetic modulators of VDR, thus opening promising therapeutic avenues for many diseases by natural means.

scholarly journals FRAP analysis of nucleocytoplasmic dynamics of the vitamin D receptor splice variant VDRB1: preferential targeting to nuclear speckles

2005 ◽  
Vol 388 (2) ◽  
pp. 509-514 ◽  
Author(s):  
Kathryn L. SUNN ◽  
John A. EISMAN ◽  
Edith M. GARDINER ◽  
David A. JANS
Keyword(s):  
Vitamin D ◽  
Vitamin D Receptor ◽  
Nuclear Import ◽  
Protein Import ◽  
Nucleocytoplasmic Transport ◽  
Nuclear Speckles ◽  
Nuclear Targeting ◽  
Nuclear Retention ◽  
First Time

Although the key components of the cellular nuclear transport machinery have largely been characterized through extensive efforts in recent years, in vivo measurements of the kinetics of nuclear protein import/export are patently few. The present study applies the approach of FRAP (fluorescence recovery after photobleaching) to examine the nucleocytoplasmic flux of a novel human VDRB1 (vitamin D receptor B1) isoform in living cells. Through an N-terminal extension containing a consensus nuclear targeting sequence, VDRB1 is capable of localizing in nuclear speckles adjacent to SC-35 (35 kDa splicing component)-containing speckles as well as in the nucleoplasm, dependent on ligand. Investigation of VDRB1 nucleocytoplasmic transport using FRAP indicates for the first time that the VDRB1 has a serum-modulated, active nuclear import mechanism. There is no evidence of an efficient, active export mechanism for VDRB1, probably as a result of nuclear retention. VDRB1 nuclear import in the absence of serum occurred more rapidly and to a greater extent to nuclear speckles compared with import to other nuclear sites. This preferential transport from the cytoplasm to and accumulation within nuclear speckles is consistent with the idea that the latter represent dynamic centres of VDRB1 interaction with other nuclear proteins. The results are consistent with the existence of specialized pathways to target proteins to nuclear subdomains.

scholarly journals 1,25-Dihydroxy-19-nor-vitamin D2, a Vitamin D Analog with Reduced Bone Resorbing Activity In Vitro

2000 ◽  
Vol 11 (10) ◽  
pp. 1857-1864
Author(s):  
L. SHANNON HOLLIDAY ◽  
STEPHEN L. GLUCK ◽  
EDUARDO SLATOPOLSKY ◽  
ALEX J. BROWN
Keyword(s):  
Vitamin D ◽  
Acid Phosphatase ◽  
Bone Resorption ◽  
Vitamin D Receptor ◽  
Intrinsic Activity ◽  
Tartrate Resistant Acid Phosphatase ◽  
Mouse Bone Marrow ◽  
Bone Resorbing Activity

Abstract. 1,25-Dihydroxy-19-nor-vitamin D2 (19-norD2), a new analog of 1,25(OH)2D3, suppresses parathyroid hormone in renal failure patients and in uremic rats but has less calcemic activity than 1,25(OH)2D3. Although 19-norD2 has high affinity for the vitamin D receptor and similar pharmacokinetics to those of 1,25(OH)2D3, it has much less bone resorbing activity in vivo. The intrinsic activity of 19-norD2 on osteoclastogenesis and activation of bone resorption in mouse bone marrow cultures was examined to determine the mechanism involved. 19-norD2 and 1,25(OH)2D3 (10 nM) were equivalent in stimulating the formation and maintenance of large multinucleated, tartrate-resistant acid phosphatase-positive cells. However, the amount of bone resorbed by osteoclasts stimulated by 10 nM 19-norD2, as measured by pit-forming assays, was reduced 62% compared with 10 nM 1,25(OH)2D3-stimulated osteoclasts (P < 0.05). This difference could not be attributed to enhanced catabolism or to downregulated vitamin D receptor. The rate of degradation of 19-norD2 in cultures was approximately 20% greater than 1,25(OH)2D3, not enough to account for the different effects on bone resorption. The VDR levels were identical in cultures that were treated with 19-norD2 and 1,25(OH)2D3. In summary, 19-norD2 is less effective than 1,25(OH)2D3 in stimulating mouse marrow osteoclasts to resorb bone. The reason for this difference is not clear but seems to involve the late maturation and/or activation of osteoclasts as the number of pits produced by each tartrate-resistant acid phosphatase-positive cell is reduced under stimulation by 19-norD2 compared with 1,25(OH)2D3.

scholarly journals Molecular Targets of Epigallocatechin—Gallate (EGCG): A Special Focus on Signal Transduction and Cancer

Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1936 ◽  
Author(s):  
Aide Negri ◽  
Valeria Naponelli ◽  
Federica Rizzi ◽  
Saverio Bettuzzi
Keyword(s):  
Cell Proliferation ◽  
Green Tea ◽  
Histone Deacetylases ◽  
Molecular Mechanisms ◽  
Epigallocatechin Gallate ◽  
Dna Methyltransferases ◽  
Biologically Active ◽  
Special Focus ◽  
Dependent Inhibition

Green tea is a beverage that is widely consumed worldwide and is believed to exert effects on different diseases, including cancer. The major components of green tea are catechins, a family of polyphenols. Among them, epigallocatechin-gallate (EGCG) is the most abundant and biologically active. EGCG is widely studied for its anti-cancer properties. However, the cellular and molecular mechanisms explaining its action have not been completely understood, yet. EGCG is effective in vivo at micromolar concentrations, suggesting that its action is mediated by interaction with specific targets that are involved in the regulation of crucial steps of cell proliferation, survival, and metastatic spread. Recently, several proteins have been identified as EGCG direct interactors. Among them, the trans-membrane receptor 67LR has been identified as a high affinity EGCG receptor. 67LR is a master regulator of many pathways affecting cell proliferation or apoptosis, also regulating cancer stem cells (CSCs) activity. EGCG was also found to be interacting directly with Pin1, TGFR-II, and metalloproteinases (MMPs) (mainly MMP2 and MMP9), which respectively regulate EGCG-dependent inhibition of NF-kB, epithelial-mesenchimal transaction (EMT) and cellular invasion. EGCG interacts with DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), which modulates epigenetic changes. The bulk of this novel knowledge provides information about the mechanisms of action of EGCG and may explain its onco-suppressive function. The identification of crucial signalling pathways that are related to cancer onset and progression whose master regulators interacts with EGCG may disclose intriguing pharmacological targets, and eventually lead to novel combined treatments in which EGCG acts synergistically with known drugs.

scholarly journals Intestinal epithelial vitamin D receptor signaling inhibits experimental colitis

2013 ◽  
Vol 123 (9) ◽  
pp. 3983-3996 ◽  
Author(s):  
Weicheng Liu ◽  
Yunzi Chen ◽  
Maya Aharoni Golan ◽  
Maria L. Annunziata ◽  
Jie Du ◽  
...  
Keyword(s):  
Vitamin D ◽  
Vitamin D Receptor ◽  
Experimental Colitis ◽  
Intestinal Epithelial ◽  
Receptor Signaling

The Role of Intestinal Epithelial Vitamin D Receptor in Shaping Murine Gut Microbial Homeostasis

2017 ◽  
Vol 152 (5) ◽  
pp. S631
Author(s):  
Dapeng Jin ◽  
Rong Lu ◽  
Yong-Guo Zhang ◽  
Yinglin Xia ◽  
Jun Sun
Keyword(s):  
Vitamin D ◽  
Vitamin D Receptor ◽  
Intestinal Epithelial

scholarly journals Control of Circulating IgE by the Vitamin D Receptor In Vivo Involves B Cell Intrinsic and Extrinsic Mechanisms

2016 ◽  
Vol 198 (3) ◽  
pp. 1164-1171 ◽  
Author(s):  
Jamaal James ◽  
Veronika Weaver ◽  
Margherita T. Cantorna
Keyword(s):  
Vitamin D ◽  
B Cell ◽  
Vitamin D Receptor

scholarly journals HIV compromises integrity of the podocyte actin cytoskeleton through downregulation of the vitamin D receptor

2013 ◽  
Vol 304 (11) ◽  
pp. F1347-F1357 ◽  
Author(s):  
Nirupama Chandel ◽  
Bipin Sharma ◽  
Mohammad Husain ◽  
Divya Salhan ◽  
Tejinder Singh ◽  
...  
Keyword(s):  
Vitamin D ◽  
Actin Cytoskeleton ◽  
Vitamin D Receptor ◽  
Kidney Diseases ◽  
Cathepsin L ◽  
Free Radical Scavengers ◽  
Ros Generation ◽  
Type I ◽  
Ang Ii ◽  
Enhanced Expression

Alterations in the podocyte actin cytoskeleton have been implicated in the development of proteinuric kidney diseases. In the present study, we evaluated the effect of HIV on the podocyte actin cytoskeleton and the mechanism involved. We hypothesized that HIV may be compromising the actin cytoskeleton via downregulation of the vitamin D receptor (VDR) of conditionally immortalized differentiated human podocytes (CIDHPs). HIV-transduced podocytes (HIV/CIDHPs) not only displayed downregulation of VDR but also showed activation of the renin-angiotensin system (RAS) in the form of enhanced expression of renin and increased production of ANG II. Moreover, CIDHPs lacking VDR displayed enhanced ANG II production, and treatment of HIV/CIDHPs with EB1089 (vitamin D3; VD) attenuated ANG II production. HIV/CIDHPs as well as ANG II-treated CIDHPs exhibited enhanced expression of cathepsin (CTS) L. Additionally, losartan (an ANG II type I receptor blocker) inhibited both HIV- and ANG II-induced podocyte cathepsin L expression. Furthermore, VD downregulated HIV-induced podocyte CTSL expression. Both losartan and free radical scavengers attenuated HIV- and ANG II-induced podocyte reactive oxygen species (ROS) generation. HIV also led to cytosolic CTSL accumulation through enhancement of podocyte lysosomal membrane permeabilization; on the other hand, VD, losartan, and superoxide dismutase (SOD) attenuated HIV-induced enhanced podocyte cytosolic CTSL accumulation. Morphological evaluation of HIV/CIDHPs revealed sparse actin filaments and attenuated expression of dynamin. Interestingly, podocytes lacking CTSL displayed enhanced dynamin expression, and HIV/CIDHPs expressing CTSL exhibited downregulation of dynamin. These findings indicate that HIV-induced downregulation of podocyte VDR and associated RAS activation and cytosolic CTSL accumulation compromised the actin cytoskeleton.

scholarly journals The Vitamin D Receptor Is Present in Caveolae-Enriched Plasma Membranes and Binds 1α,25(OH)2-Vitamin D3in Vivo and in Vitro

2004 ◽  
Vol 18 (11) ◽  
pp. 2660-2671 ◽  
Author(s):  
Johanna A. Huhtakangas ◽  
Christopher J. Olivera ◽  
June E. Bishop ◽  
Laura P. Zanello ◽  
Anthony W. Norman
Keyword(s):  
Vitamin D ◽  
Plasma Membrane ◽  
Vitamin D Receptor ◽  
Plasma Membranes ◽  
Binding Protein ◽  
Kidney Tissue ◽  
Mouse Lung ◽  
Nuclear Fraction

Abstract The steroid hormone 1α,25(OH)2-vitamin D3 (1,25D) regulates gene transcription through a nuclear receptor [vitamin D receptor (VDR)] and initiation of rapid cellular responses through a putative plasma membrane-associated receptor (VDRmem). This study characterized the VDRmem present in a caveolae-enriched membrane fraction (CMF), a site of accumulation of signal transduction agents. Saturable and specific [3H]-1,25D binding in vitro was found in CMF of chick, rat, and mouse intestine; mouse lung and kidney; and human NB4 leukemia and rat ROS 17/2.8 osteoblast-like cells; in all cases the 1,25D KD binding dissociation constant = 1–3 nm. Our data collectively support the classical VDR being the VDRmem in caveolae: 1) VDR antibody immunoreactivity was detected in CMF of all tissues tested; 2) competitive binding of [3H]-1,25D by eight analogs of 1,25D was significantly correlated between nuclei and CMF (r2 = 0.95) but not between vitamin D binding protein (has a different ligand binding specificity) and CMF; 3) confocal immunofluorescence microscopy of ROS 17/2.8 cells showed VDR in close association with the caveolae marker protein, caveolin-1, in the plasma membrane region; 4) in vivo 1,25D pretreatment reduced in vitro [3H]-1,25D binding by 30% in chick and rat intestinal CMF demonstrating in vivo occupancy of the CMF receptor by 1,25D; and 5) comparison of [3H]-1,25D binding in VDR KO and WT mouse kidney tissue showed 85% reduction in VDR KO CMF and 95% reduction in VDR KO nuclear fraction. This study supports the presence of VDR as the 1,25D-binding protein associated with plasma membrane caveolae.

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