The effect of Vdr gene ablation in the mouse placenta
Ontology highlight
ABSTRACT: Analysis of mouse placenta retrieved at day 18.5pc from vitamin D (1,25-dihydroxyvitamin D3) receptor (Vdr) knockout, heterozygous and wild-type mice. Results provide insight into the molecular mechanisms underlying the effect of vitamin D on placental function. Vdr heterozygous males and females were mated to generate Vdr knockout, heterozygous and wild-type offspring. At day 18.5pc, mouse placentae were collected and RNA was extracted and assayed on Affymetrix MoGene 2.1 ST arrays to measure the effect of Vdr on global gene expression.
Project description:The vitamin D receptor (VDR) regulates cell proliferation and differentiation including epidermal keratinocytes by modulating transcription of its target genes. We are investigating the role of VDR in epidermal stem cells and their progenies in the regeneration process of epidermis and hair in the skin. VDR null mice are utilized in which VDR is specifically deleted in keratin 14 (K14) expressing keratinocytes by Cre-lox strategy. The impact of VDR deletion was evaluated by comparison of VDR null mice with no cre littermate control mice. The VDR was abundantly expressed in potential epidermal stem cells including basal cells in interfollicular epidermis (IFE), and in CD34 expressing bulge keratinocytes in hair follicles. Gene expression profiles and subsequent pathway analysis of stem cell enriched keratinocyte populations revealed that the VDR deletion significantly suppressed β-catenin signaling as well as VDR signaling. The role of VDR in epidermal stem cells was studied during hair follicle cycling and wound healing processes. The epidermal stem cells were not appropriately stimulated by hair depilation, and did not reinitiate anagen in the hair follicles resulting in a failure of hair regrowth. In addition, the stem cells were not fully activated after full thickness wounds were generated in VDR null skin under a low calcium diet to suppress compensation pathways. Cell proliferation was not fully induced in potential stem cells located in both IFE and hair follicles near the wounding edges, and re-epithelialization rate was delayed in VDR null skin. Gene expression profiling of the wounded skin (3 days after injury) indicated that β-catenin signaling was not fully induced in VDR null skin comparable to that observed in β-catenin null mice. The β-catenin target genes including Axin2 and cell cycle regulators involved in epidermal stem cell function were not induced in the edges of the wound of VDR null skin. These results demonstrated that VDR plays an essential role in hair cycling and wound healing processes through regulation of β-catenin signaling in epidermal stem cells and their progenies. n=3 CON and KO (each sample contain RNA isolated from wounded or nonwounded skins excised from 3 mice)
Project description:To provide structural insights into the mechanism of the specific association of the coactivator MED1 with the Vitamin D nuclear (VDR)-RXR heterodimer, we used combined structural methods including X-ray crystallography, small angle X-ray scattering (SAXS), NMR, hydrogen-deuterium exchange coupled to mass spectrometry (HDX-MS), crosslinking mass spectrometry as well as biophysical methods.
Project description:Calcium and 1,25-dihydroxyvitamin D3 (1,25D3), through the actions of their respective receptors, the Ca2+-sensing receptor (CaSR) and the vitamin D receptor (VDR), potentiate keratinocyte differentiation. VDR regulates epidermal keratinocyte proliferation and differentiation by modulating gene transcription, whereas the CaSR, a member of the family C G-protein coupled receptor, calcium mobilizes intracellular calcium and induces the formation of cell-cell junctions. 1,25D3 augments the sensitivity of the prodifferentiating actions of calcium by increasing the expression of CaSR. CaSR- and VDR-deficient keratinocytes share common characteristics such as abnormal intercellular adhesion and sphigolipid metabolism. Both CaSR and VDR are abundantly expressed in epidermal stem cell populations including CD34 expressing bulge keratinocytes in hair follicles and basal cells in interfollicular epidermis. To delineate the role of CaSR- and VDR-dependent pathways in regulating epidermal development and functions in physiological state, we generated conditional CaSR-null and VDR-null mice, where Casr and VDR gene was removed from keratinocytes. Keratinocyte-specific CaSR-null and VDR-null mice manifest distinct phenotypes. CaSR-null mice display defective epidermal permeability barrier function due to aberrant keratinocyte differentiation. VDR-null mice develop alopecia after completing the first hair follicle cycling. Concurrent ablation of CaSR and VDR genes in keratinocytes delays rate of wound repair and increases incidence of skin tumor formation to a greater extent than deletion of the CaSR or VDR alone, indicative of synergistic effects of calcium and 1,25D3 signaling. Gene expression profiles and subsequent pathway analysis on the epidermis derived from 5-day-old neonates revealed that ablation of CaSR or VDR increased expression of genes associated with cancer progression and metastasis. Deletion of VDR markedly inhibited signaling pathways that regulate hair development. Furthermore, concurrent ablation of CaSR and VDR significantly suppressed calcium, VDR, Wnt/b-catenin signaling, as well as epithelial adherence junction signaling to maintain appropriate keratinocyte adhesion. These results indicated the interplay of calcium/CaSR and 1,25D3/VDR signaling in keratinocyte proliferation and differentiation, and their importance in maintaining normal epidermal adhesion and functions. n=3 CON and KO (each sample contain RNA isolated from neonatal epidermis separated from 3 mice)
Project description:The vitamin D receptor (VDR) regulates cell proliferation and differentiation including epidermal keratinocytes by modulating transcription of its target genes. We are investigating the role of VDR in epidermal stem cells and their progenies in the regeneration process of epidermis and hair in the skin. VDR null mice are utilized in which VDR is specifically deleted in keratin 14 (K14) expressing keratinocytes by Cre-lox strategy. The impact of VDR deletion was evaluated by comparison of VDR null mice with no cre littermate control mice. The VDR was abundantly expressed in potential epidermal stem cells including basal cells in interfollicular epidermis (IFE), and in CD34 expressing bulge keratinocytes in hair follicles. Gene expression profiles and subsequent pathway analysis of stem cell enriched keratinocyte populations revealed that the VDR deletion significantly suppressed β-catenin signaling as well as VDR signaling. The role of VDR in epidermal stem cells was studied during hair follicle cycling and wound healing processes. The epidermal stem cells were not appropriately stimulated by hair depilation, and did not reinitiate anagen in the hair follicles resulting in a failure of hair regrowth. In addition, the stem cells were not fully activated after full thickness wounds were generated in VDR null skin under a low calcium diet to suppress compensation pathways. Cell proliferation was not fully induced in potential stem cells located in both IFE and hair follicles near the wounding edges, and re-epithelialization rate was delayed in VDR null skin. Gene expression profiling of the wounded skin (3 days after injury) indicated that β-catenin signaling was not fully induced in VDR null skin comparable to that observed in β-catenin null mice. The β-catenin target genes including Axin2 and cell cycle regulators involved in epidermal stem cell function were not induced in the edges of the wound of VDR null skin. These results demonstrated that VDR plays an essential role in hair cycling and wound healing processes through regulation of β-catenin signaling in epidermal stem cells and their progenies. n=3 CON and KO (each sample contain RNA extracted from keratinocytes, which is isolated from VDR KO and littermate control skins excised from 3 mice)
Project description:Analysis of mouse placenta retrieved at day 18.5pc from vitamin D (1,25-dihydroxyvitamin D3) receptor (Vdr) knockout, heterozygous and wild-type mice. Results provide insight into the molecular mechanisms underlying the effect of vitamin D on placental function.
Project description:Calcium and 1,25-dihydroxyvitamin D3 (1,25D3), through the actions of their respective receptors, the Ca2+-sensing receptor (CaSR) and the vitamin D receptor (VDR), potentiate keratinocyte differentiation. VDR regulates epidermal keratinocyte proliferation and differentiation by modulating gene transcription, whereas the CaSR, a member of the family C G-protein coupled receptor, calcium mobilizes intracellular calcium and induces the formation of cell-cell junctions. 1,25D3 augments the sensitivity of the prodifferentiating actions of calcium by increasing the expression of CaSR. CaSR- and VDR-deficient keratinocytes share common characteristics such as abnormal intercellular adhesion and sphigolipid metabolism. Both CaSR and VDR are abundantly expressed in epidermal stem cell populations including CD34 expressing bulge keratinocytes in hair follicles and basal cells in interfollicular epidermis. To delineate the role of CaSR- and VDR-dependent pathways in regulating epidermal development and functions in physiological state, we generated conditional CaSR-null and VDR-null mice, where Casr and VDR gene was removed from keratinocytes. Keratinocyte-specific CaSR-null and VDR-null mice manifest distinct phenotypes. CaSR-null mice display defective epidermal permeability barrier function due to aberrant keratinocyte differentiation. VDR-null mice develop alopecia after completing the first hair follicle cycling. Concurrent ablation of CaSR and VDR genes in keratinocytes delays rate of wound repair and increases incidence of skin tumor formation to a greater extent than deletion of the CaSR or VDR alone, indicative of synergistic effects of calcium and 1,25D3 signaling. Gene expression profiles and subsequent pathway analysis on the epidermis derived from 5-day-old neonates revealed that ablation of CaSR or VDR increased expression of genes associated with cancer progression and metastasis. Deletion of VDR markedly inhibited signaling pathways that regulate hair development. Furthermore, concurrent ablation of CaSR and VDR significantly suppressed calcium, VDR, Wnt/b-catenin signaling, as well as epithelial adherence junction signaling to maintain appropriate keratinocyte adhesion. These results indicated the interplay of calcium/CaSR and 1,25D3/VDR signaling in keratinocyte proliferation and differentiation, and their importance in maintaining normal epidermal adhesion and functions. n=3 CON and DKO (each sample contain RNA isolated from neonatal epidermis separated from 3 mice)
Project description:Vitamin D induces anti-proliferative and differentiating effects in prostate cancer. Thus calcitriol, the hormonally active form of Vitamin D, and its analogs have been extensively studied in prostate cancer cells. Yet despite its importance, relatively little is known about the genome-scale mechanisms by which Vitamin D, through its cognate nuclear vitamin D receptor (VDR), exerts its regulatory functions at the genomic level. In this study, we defined VDR transcriptional networks in the LNCaP prostate cancer cell line by mapping the genomic binding sites of VDR and by identifying differentially expressed genes upon calcitriol treatment. We found that VDR and androgen receptor (AR) antagonistically regulate a subset of cell cycle-related genes that are over-expressed in prostate cancer tumors. The expression balance of these genes is partially regulated through the competition dynamics between AR and VDR binding to shared cis-regulatory elements. On such shared elements, we found that FOXA1 mediates this competition by serving as a pioneering factor for both AR and VDR binding. We also found significant enrichment of AR-, VDR-, and AR/VDR overlapping binding sites in prostate cancer-associated single-nucleotide polymorphism (SNP) intervals identified from genome-wide association studies (GWAS), providing genetic evidence to link AR, VDR and their crosstalk to prostate cancer susceptibilities. In particular, we found that in a cis-regulatory element of the RFX6 gene implicated in prostate cancer progression, an allelic variant increases prostate cancer risk by switching the antagonism between AR and VDR into a synergistic interaction. Examination of AR, VDR, and FOXA1 binding in LNCaP cells, in biological replicates
Project description:Identification of primary target genes of vitamin D receptor (VDR) in an immune-related cellular model (THP-1 cells) to study, in conjunction with VDR binding data from ChIP-seq, the genome-wide mechanisms of transcriptional regulation by VDR. THP-1 cells were treated 4 h either with 0.1% ethanol (vehicle, control) or 1?,25(OH)2D3 (1,25D)
Project description:Vitamin D (VitD) deficiency is estimated to affect ~40% of the world’s population. Notably, VitD deficiency has been associated with impaired muscle maintenance and insulin resistance. VitD exerts its actions through the ubiquitous Vitamin D-receptor (VDR), the expression of which was recently confirmed in fully-differentiated muscle. To seek a possible autonomous role of the VDR in skeletal muscle, we first generated stable VDR-knockdown cells, which exhibited impaired myogenesis (i.e. cell-cycling, differentiation and myotube formation). In vivo VDR-knockdown in rat hind-limbs elicited myofibre atrophy and triggered autophagy pathways. In contrast, in vivo VDR-overexpression yielded myofibre hypertrophy; enhancing translational efficiency (e.g. mTOR-signaling), ribosomal biogenesis and satellite cell content. Neither VDR-knockdown nor overexpression impacted muscle glucose uptake. Crucially, induction of VDR mRNA correlated with muscle hypertrophy in humans following long-term resistance exercise training, but not aspects of insulin sensitivity. The VDR autonomously regulates muscle mass, acting reciprocally to limit atrophy and promote hypertrophy.
Project description:As duodenum is an important Vitamin D target organ, transcriptomic analyses were performed in this tissue. We analysed RNA extracted from duodenum of three 10 week-old wild-type and VDR-null mice using the Affymetrix Mouse Gene 2.0 ST.