The transdifferentiation of vascular smooth muscle cells (VSMCs) into osteoblast-like cells has been implicated in the context of vascular calcification. We investigated the roles of vitamin D receptor (Vdr) and runt-related transcription factor 2 (Runx2) in the osteoblastic differentiation of VSMCs in response to vitamin D3 using in vitro VSMCs cultures and in vivo in Vdr knockout (Vdr(-/-)) a...

The present study assesses the effects of two isoflavones, genistein and glycitein, and equol - a product of intestinal bacterial metabolism of dietary isoflavones, on vitamin D receptor (VDR) expression in an intestinal HT29 cell line. Genistein and glycitein significantly upregulated the VDR transcription and translation in HT29 cells. The effect of equol was less pronounced. Treating HT29 ce...

The resistance of parathyroid cells to 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) in uremic hyperparathyroidism is thought to be caused, in part, by a 1,25(OH)2D3 receptor (VDR) deficiency in the parathyroids. However, results of biochemical studies addressing VDR numbers in the parathyroids are controversial. Several studies have found VDR content to be decreased in the parathyroids of uremic pati...

The human epidermis has evolved out of Africa. Increased involucrin (IVL) expression in the skin is associated with a near selective sweep Northern European populations compared to African. significance for this positive selection not clear. Our functional studies using Ivl-/- mice recently determined requirement positively regulate Vitamin D receptor and its activity epidermis. mouse treated M...

One variable that may affect the ability of vitamin D to reduce colon cancer risk is the expression of its high-affinity receptor, VDR. Here, we show that vitamin D does not reduce tumor formation in Apc(Δ14/+) mice and that VDR expression is lost in the majority of the colon tumor cells. The extent of VDR loss corresponded inversely to the level of β-catenin nuclear localization and could be o...

BACKGROUND Vitamin D3 is a secoster oid that exerts its effect by binding to its nuclear receptor called vitamin D receptor (VDR), inducing apoptosis and thereby inhibiting cell proliferation in cancer cells. The VDR receptor, located in the nucleus, is known to regulate the functions of over 200 genes. Various allelic forms of hVDR have been discovered that increase susceptibility to various c...

Emerging evidence supports a pathological link between vitamin D deficiency and the risk of inflammatory bowel disease (IBD). To explore the mechanism we used the dextran sulfate sodium (DSS)-induced colitis model to investigate the role of the vitamin D receptor (VDR) in mucosal barrier homeostasis. While VDR(+/+) mice were mostly resistant to 2.5% DSS, VDR(-/-) mice developed severe diarrhea,...

Hypercalciuria in genetic hypercalciuric stone–forming (GHS) rats is accompanied by intestinal Ca hyperabsorption with normal serum 1,25-dihydroxyvitamin D 3 [1,25(OH) 2 D 3 ] levels, elevation of intestinal, kidney, and bone vitamin D receptor (VDR) content, and greater 1,25(OH) 2 D 3 -induced bone resorption in vitro. To test the hypothesis that hyperresponsiveness of VDR gene expression to 1...

A ligand-dependent transcriptional activation domain (AF-2) exists in region E of the nuclear receptors. This highly conserved domain may contact several coactivators that are putatively involved in nuclear receptor-mediated transcription. In this study, a panel of vitamin D receptor (VDR) AF-2 mutants was created to examine the importance of several conserved residues in VDR-activated transcri...

The vitamin D receptor (VDR) gene has been involved in the modulation of susceptibility to inflammatory and autoimmune conditions, and could play a role in the pathogenesis of type 2 diabetes mellitus (T2DM). Susceptibility to T2DM was recently also suggested to associate with HLA alleles. We evaluated possible correlations between VDR polymorphisms, HLA alleles, and risk for development of T2D...