Search results for "Calcitriol"
showing 10 items of 49 documents
Diminished Vitamin D Receptor Protein Levels in Crohn´s Disease Fibroblasts: Effects of Vitamin D
2020
Vitamin D (VD) deficiency has been associated to Crohn´
Serum vitamin D levels of patients with oral squamous cell carcinoma (OSCC) and expression of vitamin D receptor in oral precancerous lesions and OSCC
2015
Background: Resistance to programmed cell death (apoptosis) is a crucial factor for the carcinogenesis of oral squamous cell carcinoma (OSCC). Vitamin D (calcitriol) may overcome apoptosis resistance in tumor cells of OSCC. Vitamin D receptor (VDR) expression in oral precancerous lesions of OSCC has not been analyzed and serum vitamin D level seems to be a predictor of cancer development. Material and Methods: Expression of VDR was analyzed in normal oral mucosa (n=5), oral precursor lesions (simple hyperplasia, n=11; squamous intraepithelial neoplasia, SIN I-III, n=35), and OSCC specimen (n=42) by immunohistochemistry (IHC). Moreover, serum vitamin D levels were measured by 25(OH)D3 (calci…
Vitamin D Receptor Activation Reduces Angiotensin-II–Induced Dissecting Abdominal Aortic Aneurysm in Apolipoprotein E–Knockout Mice
2015
Objective— Abdominal aortic aneurysm (AAA) is a vascular disorder characterized by chronic inflammation of the aortic wall. Low concentrations of vitamin D 3 are associated with AAA development; however, the potential direct effect of vitamin D 3 on AAA remains unknown. This study evaluates the effect of oral treatment with the vitamin D 3 receptor (VDR) ligand, calcitriol, on dissecting AAA induced by angiotensin-II (Ang-II) infusion in apoE −/− mice. Approach and Results— Oral treatment with calcitriol reduced Ang-II–induced dissecting AAA formation in apoE −/− mice, which was unrelated to systolic blood pressure or plasma cholesterol concentrations. Immunohistochemistry and reverse-tran…
Preliminary Findings: 25(OH)D Levels and PTH Are Indicators of Rapid Bone Accrual in Pubertal Children
2007
The objective of this study was to evaluate the role of serum levels of 25(OH)D and PTH on the accumulation of whole body bone mass in a cohort of children.This was a longitudinal study (1.98 +/- 0.07 y) of sixty-nine children (89% Caucasian, 44% male) enrolled in a calcium supplementation trial. Bone area, bone mineral content (BMC) and density (BMD) of the whole body and radius were assessed using a QDR 2000 (Hologic, Inc) dual energy x-ray absorptiometer. Serum PTH and 25(OH)D were measured using radioimmunoassays.Vitamin D stores were inversely related gain in bone area (p0.002), BMC (p0.002) BMD (p0.027), as well as to PTH levels (p0.0001). Compared to those with adequate vitamin D sto…
Impaired Vitamin D Signaling in Endothelial Cell Leads to an Enhanced Leukocyte-Endothelium Interplay: Implications for Atherosclerosis Development
2015
Endothelial cell activation leading to leukocyte recruitment and adhesion plays an essential role in the initiation and progression of atherosclerosis. Vitamin D has cardioprotective actions, while its deficiency is a risk factor for the progression of cardiovascular damage. Our aim was to assess the role of basal levels of vitamin D receptor (VDR) on the early leukocyte recruitment and related endothelial cell-adhesion-molecule expression, as essential prerequisites for the onset of atherosclerosis. Knockdown of VDR in endothelial cells (shVDR) led to endothelial cell activation, characterized by upregulation of VCAM-1, ICAM-1 and IL-6, decreased peripheral blood mononuclear cell (PBMC) ro…
Up‐regulation of the α‐secretase ADAM10 by retinoic acid receptors and acitretin
2009
Late-onset Alzheimer's disease is often connected with nutritional misbalance, such as enhanced cholesterol intake, deficiency in polyunsaturated fatty acids, or hypovitaminosis. The alpha-secretase ADAM10 has been found to be regulated by retinoic acid, the bioreactive metabolite of vitamin A. Here we show that retinoids induce gene expression of ADAM10 and alpha-secretase activity by nonpermissive retinoid acid receptor/retinoid X receptor (RAR/RXR) heterodimers, whereby alpha- and beta-isotypes of RAR play a major role. However, ligands of other RXR binding partners, such as the vitamin D receptor, do not stimulate alpha-secretase activity. On the basis of these findings, we examined the…
Immunohistochemical Expression of Vitamin D Receptor in Uterine Fibroids
2022
One of the many factors involved in the development of uterine fibroids is vitamin D deficiency. One aspect of this deficiency is decreased serum concentration of calcidiol-25(OH)D, a metabolite of D3 vitamin. The active form of vitamin D3, which arises after numerous enzymatic reactions, is calcitriol-1,25(OH)2D3; this compound is transported to various body tissues. Vitamin D possesses extra-genomic effects due to its influence on various signaling pathways, i.e., through activating tyrosine kinases and by genomic effects via binding to a specific nuclear receptor, vitamin D receptor (VDR). The vitamin D/VDR complex regulates the expression of genes and is involved in the pathogenesis of …
Vitamin D in cancer chemoprevention
2015
Context: There is increasing evidence that Vitamin D (Vit D) and its metabolites, besides their well-known calcium-related functions, may also exert antiproliferative, pro-differentiating, and immune modulatory effects on tumor cells in vitro and may also delay tumor growth in vivo. Objective: The aim of this review is to provide fresh insight into the most recent advances on the role of Vit D and its analogues as chemopreventive drugs in cancer therapy. Methods: A systematic review of experimental and clinical studies on Vit D and cancer was undertaken by using the major electronic health database including ISI Web of Science, Medline, PubMed, Scopus and Google Scholar. Results and conclus…
MTHFR and VDR Polymorphisms Improve the Prognostic Value of MYCN Status on Overall Survival in Neuroblastoma Patients
2020
Single nucleotide polymorphisms (SNPs) in Pharmacogenetics can play an important role in the outcomes of the chemotherapy treatment in Neuroblastoma, helping doctors maximize efficacy and minimize toxicity. Employing AgenaBioscience MassArray, 96 SNPs were genotyped in 95 patients looking for associations of SNP with response to induction therapy (RIT) and grade 3&ndash
Orphan nuclear receptor binding site in the human inducible nitric oxide synthase promoter mediates responsiveness to steroid and xenobiotic ligands
2002
Constitutive androstane receptor (CAR) and pregnane X receptor (PXR) are members of the nuclear receptor superfamily that regulate target gene transcription in a ligand-dependent manner. CAR and PXR have a rather broad, overlapping set of ligands that range from natural steroids to xenobiotics and also recognize similar DNA binding sites, referred to as response elements (REs), primarily in promoter regions of cytochrome P450 (CYP) genes. In this study, a CAR and PXR RE, composed of a direct repeat of two GGTTCA motifs in a distance of 4 nucleotides (DR4), was identified in the promoter of the human inducible nitric oxide (NO) synthase (iNOS) gene, which is the first nuclear receptor bindin…