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.
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:Signaling through the vitamin D receptor (VDR) has been proposed to suppress the development of epithelial cancers, including prostate cancer. We conducted ChIP-seq to identify the VDR binding sites in the genome of the prostate epithelial cell line, RWPE1. This analysis reveals a large number of VDR binding sites in both control cells and in cells treated with 10 nM 1,25 dihydroxyvitamin D3 for 3 hours. These peaks are associated with genes controlling a wide variety of cellular functions.
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: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.
Project description:The biologically active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), is a direct regulator of gene transcription, since it is the only high affinity natural ligand of the transcription factor vitamin D receptor (VDR). Transcriptome-wide analysis of THP-1 human monocyte-like cells had indicated more than 600 genes to be significantly (p < 0.05) regulated after a 4 h stimulation with 1,25(OH)2D3. In this study, we screened of the list of primary vitamin D targets for genes encoding for transcriptional regulators and selected those of the activating transcription factor NFE2 and the transcriptional repressor BCL6. Both genes are under the control of two VDR loci and are the only 1,25(OH)2D3 targets within their respective chromosomal domain. However, NFE2 mRNA was rapidly up-regulated, while the increase of BCL6 expression showed a slower rise. After 24 h incubation of THP-1 cells with 1,25(OH)2D3 more than 1,500 genes responded significantly (p < 0.001), of which 132 where more than 2-fold induced. Public chromatin immunoprecipitation-sequencing datasets suggested that the majority of these genes could be targets of NFE2 or BCL6. In time course experiments we displayed for representative gene examples the specific delayed response of secondary 1,25(OH)2D3 targets and confirmed for the respective chromosomal domains the genomic binding of NFE2, BCL6 and VDR. In conclusion, our study indicated that the physiological response of monocytes to 1,25(OH)2D3 involves the action of NFE2 and BCL6. THP-1 cells were treated 24 h either with 0.1% ethanol (vehicle, control) or 1?,25(OH)2D3 (1,25D)