1,25-Dihydroxyvitamin D(3) (1,25D(3)) is the biologically active form of vitamin D(3) that interacts with the nuclear vitamin D(3) receptor (VDR) to modulate gene expression in a tissue-specific fashion. 1,25D(3) is a potent regulator of cell proliferation, differentiation and apoptosis in a variety of cell types, including keratinocytes. In these studies, we assessed the sensitivity of mice ho...

The vitamin D receptor (VDR) is a member of the nuclear receptor (NR) superfamily. The VDR binds to active vitamin D3 metabolites, which stimulates downstream transduction signaling involved in various physiological activities such as calcium homeostasis, bone mineralization, and cell differentiation. Quercetin is a widely distributed flavonoidin nature that is known to enhance transactivation ...

The effects of vitamin D are mediated through the vitamin D receptor (VDR), a predominantly nuclear receptor, expressed in numerous tissues including the placenta. VDR and the retinoid X receptor (RXR) form a dimer complex which binds to genomic vitamin D responsive elements located primarily in promoter regions and recruit cell-specific transcription factor complexes which regulate the express...

The active form of vitamin D3, 1,25(OH)2D3, has significant immunomodulatory properties and is an important determinant in the differentiation of CD4+ effector T cells. The biological actions of 1,25(OH)2D3 are mediated by the vitamin D receptor (VDR) and are believed to correlate with the VDR protein expression level in a given cell. The aim of this study was to determine if and how 1,25(OH)2D...

Vitamin D3 is a steroid hormone well known by its role in maintaining calcium homeostasis, however this hormone may also participate in other biological functions, including control of reproductive processes. The vitamin D3 action is mediated by the vitamin D3 receptor (VDR). VDR is widely distributed in the rodent reproductive tract, however the occurrence of VDR and the role of the vitamin D3...

Vitamin D and vitamin D receptor (VDR) deficiency results in severe symptoms of experimental inflammatory bowel disease in several different models. The intraepithelial lymphocytes of the small intestine contain large numbers of CD8αα(+) T cells that have been shown to suppress the immune response to Ags found there. In this study, we determined the role of the VDR in the development of CD8αα(+...

Dehydroepiandrosterone sulfotransferase (SULT2A1) is a cytosolic enzyme that mediates sulfo-conjugation of endogenous hydroxysteroids (dehydroepiandrosterone, testosterone, bile acids), and diverse xenobiotic compounds. Upon sulfonation, SULT2A1 substrates become polar and water-soluble and thus suitable for rapid excretion. SULT2A1 is abundantly expressed in the liver and intestine. Recent evi...

Polymorphisms of the vitamin D receptor gene (VDR) have been associated inconsistently with various diseases, across populations of diverse origin. The T(f) allele of the functional SNP FokI, in exon 2 of VDR, results in a longer vitamin D receptor protein (VDR) isoform, proposed to be less active. Genetic association of VDR with disease is likely confounded by ethnicity and environmental facto...

The vitamin D receptor (VDR) mediates the physiological and pharmacological actions of 1α,25-dihydroxyvitamin D(3) in bone and calcium metabolism, cellular growth and differentiation, and immunity. VDR also responds to secondary bile acids and belongs to the NR1I subfamily of the nuclear receptor superfamily, which regulates expression of xenobiotic metabolism genes. When compared to knockout m...

PURPOSE We previously showed that EGF receptor (EGFR) promotes tumorigenesis in the azoxymethane/dextran sulfate sodium (AOM/DSS) model, whereas vitamin D suppresses tumorigenesis. EGFR-vitamin D receptor (VDR) interactions, however, are incompletely understood. Vitamin D inhibits the renin-angiotensin system (RAS), whereas RAS can activate EGFR. We aimed to elucidate EGFR-VDR cross-talk in col...