Primary vitamin D receptor target genes as biomarkers for the vitamin D3 status in the hematopoietic system

Previously, we have reported that the active vitamin D metabolite, calcitriol and vitamin D3 (cholecalciferol), both remarkably inhibit hepatitis C virus production. The mechanism by which vitamin D3 exerts its effect is puzzling due to the low levels of calcitriol produced in vitamin D3-treated Huh7.5 cells. In this study, we aimed to explore the mechanism of vitamin D3 anti-hepatitis C virus effect. We show that vitamin D3 activity is not mediated by its metabolic conversion to calcitriol, but may be due to its primary metabolic product 25(OH)D3. This is inferred from the findings that 25(OH)D3 could inhibit hepatitis C virus production in our system, and that adequate concentrations needed to exert this effect are produced in Huh7.5 cells treated with vitamin D3. Using the CRISPR-Cas9 editing technology to knockout the vitamin D receptor, we found that the antiviral activity of vitamin D3 and 25(OH)D3 was not impaired in the vitamin D receptor knockout cells. This result indicates that 25(OH)D3 anti-hepatitis C virus effect is exerted by a vitamin D receptor-independent mode of action. The possibility that vitamin D3 and 25(OH)D3, being 3β-hydroxysteroids, affect hepatitis C virus production by direct inhibition of the Hedgehog pathway in a vitamin D receptor-independent manner was ruled out. Taken together, this study proposes a novel mode of action for the anti-hepatitis C virus activity of vitamin D3 that is mediated by 25(OH)D3 in a vitamin D receptor-independent mechanism.

Download Full-text

Key Vitamin D Target Genes with Functions in the Immune System

Nutrients ◽

10.3390/nu12041140 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1140 ◽

Cited By ~ 6

Author(s):

Oona Koivisto ◽

Andrea Hanel ◽

Carsten Carlberg

Keyword(s):

Vitamin D ◽

Adaptive Immunity ◽

Vitamin D3 ◽

Target Genes ◽

Mononuclear Cells ◽

Active Form ◽

Biologically Active ◽

Monocytic Cell ◽

Monocytic Cell Line ◽

Innate And Adaptive Immunity

The biologically active form of vitamin D3, 1α,25-dihydroxyvitamin D3 (1,25(OH)2D3), modulates innate and adaptive immunity via genes regulated by the transcription factor vitamin D receptor (VDR). In order to identify the key vitamin D target genes involved in these processes, transcriptome-wide datasets were compared, which were obtained from a human monocytic cell line (THP-1) and peripheral blood mononuclear cells (PBMCs) treated in vitro by 1,25(OH)2D3, filtered using different approaches, as well as from PBMCs of individuals supplemented with a vitamin D3 bolus. The led to the genes ACVRL1, CAMP, CD14, CD93, CEBPB, FN1, MAPK13, NINJ1, LILRB4, LRRC25, SEMA6B, SRGN, THBD, THEMIS2 and TREM1. Public epigenome- and transcriptome-wide data from THP-1 cells were used to characterize these genes based on the level of their VDR-driven enhancers as well as the level of the dynamics of their mRNA production. Both types of datasets allowed the categorization of the vitamin D target genes into three groups according to their role in (i) acute response to infection, (ii) infection in general and (iii) autoimmunity. In conclusion, 15 genes were identified as major mediators of the action of vitamin D in innate and adaptive immunity and their individual functions are explained based on different gene regulatory scenarios.

Download Full-text

Dynamics of 1α,25-dihydroxyvitamin D3-dependent chromatin accessibility of early vitamin D receptor target genes

Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms ◽

10.1016/j.bbagrm.2013.10.003 ◽

2013 ◽

Vol 1829 (12) ◽

pp. 1266-1275 ◽

Cited By ~ 33

Author(s):

Sabine Seuter ◽

Petri Pehkonen ◽

Sami Heikkinen ◽

Carsten Carlberg

Keyword(s):

Vitamin D ◽

Vitamin D Receptor ◽

Target Genes ◽

Chromatin Accessibility ◽

Dihydroxyvitamin D3

Download Full-text

Molecular network of chromatin immunoprecipitation followed by deep sequencing-based vitamin D receptor target genes

Multiple Sclerosis Journal ◽

10.1177/1352458512471873 ◽

2013 ◽

Vol 19 (8) ◽

pp. 1035-1045 ◽

Cited By ~ 19

Author(s):

Jun-ichi Satoh ◽

Hiroko Tabunoki

Keyword(s):

Multiple Sclerosis ◽

Vitamin D ◽

Vitamin D Receptor ◽

Deep Sequencing ◽

Immune Cells ◽

Chromatin Immunoprecipitation ◽

Target Genes ◽

Molecular Network ◽

Genome Wide

Background: Vitamin D is a liposoluble vitamin essential for calcium metabolism. The ligand-bound vitamin D receptor (VDR), heterodimerized with retinoid X receptor, interacts with vitamin D response elements (VDREs) to regulate gene expression. Vitamin D deficiency due to insufficient sunlight exposure confers an increased risk for multiple sclerosis (MS). Objective: To study a protective role of vitamin D in multiple sclerosis (MS), it is important to characterize the global molecular network of VDR target genes (VDRTGs) in immune cells. Methods: We identified genome-wide VDRTGs collectively from two distinct chromatin immunoprecipitation followed by deep sequencing (ChIP-Seq) datasets of VDR-binding sites derived from calcitriol-treated human cells of B cell and monocyte origins. We mapped short reads of next generation sequencing (NGS) data on hg19 with Bowtie, detected the peaks with Model-based Analysis of ChIP-Seq (MACS), and identified genomic locations by GenomeJack, a novel genome viewer for NGS platforms. Results: We found 2997 stringent peaks distributed on protein-coding genes, chiefly located in the promoter and the intron on VDRE DR3 sequences. However, the corresponding transcriptome data verified calcitriol-induced upregulation of only a small set of VDRTGs. The molecular network of 1541 calcitriol-responsive VDRTGs showed a significant relationship with leukocyte transendothelial migration, Fcγ receptor-mediated phagocytosis, and transcriptional regulation by VDR, suggesting a pivotal role of genome-wide VDRTGs in immune regulation. Conclusion: These results suggest the working hypothesis that persistent deficiency of vitamin D might perturb the complex network of VDRTGs in immune cells, being responsible for induction of an autoimmune response causative for MS.

Download Full-text