Vitamins D3 and D2 have marked but different global effects on gene expression in a rat oligodendrocyte precursor cell line

Abstract

Background: Vitamin D deficiency increases the risk of developing multiple sclerosis (MS) but it is unclear whether vitamin D supplementation improves the clinical course of MS, and there is uncertainty about the dose and form of vitamin D (D2 or D3) to be used. The mechanisms underlying the effects of vitamin D in MS are not clear. Vitamin D3 increases the rate of differentiation of primary oligodendrocyte precursor cells (OPCs), suggesting that it might help remyelination in addition to modulating the immune response. Here we analyzed the transcriptome of differentiating rat CG4 OPCs treated with vitamin D2 or with vitamin D3 at 24 h and 72 h following onset of differentiation. Methods: Gene expression in differentiating CG4 cells in response to vitamin D2 or D3 was quantified using Agilent DNA microarrays (n = 4 replicates), and the transcriptome data were processed and analysed using the R software environment. Differential expression between the experimental conditions was determined using LIMMA, applying the Benjamini and Hochberg multiple testing correction to p-values, and significant genes were grouped into coexpression clusters by hierarchical clustering. The functional significance of gene groups was explored by pathway enrichment analysis using the clusterProfiler package. Results: Differentiation alone changed the expression of about 10% of the genes at 72 h compared to 24 h. Vitamin D2 and D3 exerted different effects on gene expression, with D3 influencing 1272 genes and D2 574 at 24 h. The expression of the vast majority of these genes was either not changed in differentiating cells not exposed to vitamin D or followed the same trajectory as the latter. D3-repressed genes were enriched for Gene Ontology (GO) categories including transcription factors and the Notch pathway, while D3-induced genes were enriched for the Ras pathway. Conclusions: This study shows that vitamin D3, compared with D2, changes the expression of a larger number of genes in OLs. Identification of genes affected by D3 in OLs should help to identify mechanisms mediating its action in MS.

Reply: “Vitamin D Supplementation in Influenza and COVID-19 Infections. Comment on: Evidence That Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths Nutrients 2020, 12(4), 988”

“…After publication of our review, an article was published reporting the effects of vitamin D on gene expression of rat oligodendrocyte precursor cells. The study found that vitamin D 3 influenced 1272 genes in 24 h compared to only 574 for vitamin D [ 23 ]. Most of the effects of vitamin D are through the hormonal metabolite 1,25-dihydroxyvitamin D, which activates vitamin D receptors bound to chromosomes, thereby affecting the expression of many genes.…”

Vitamins D2and D3have overlapping but different effects on human gene expression revealed through analysis of blood transcriptomes in a randomised double-blind placebo-controlled food-fortification trial

“…We examined the respective influences of the two physiologically active forms of vitamin D, 1,25(OH)D 3 and 1,25(OH)D 2 on differentiation and global gene expression in differentiating rat CG4 oligodendrocyte precursor cells and revealed considerable differences in the influence of the two types of vitamin D on gene expression at 24 h and after 72 h following onset of differentiation. We demonstrated that 1,25(OH)D 3 and 1,25(OH)D 2 respectively influenced expression of 1,272 and 574 genes at 24 h following addition of the vitamin to the culture, where many of the changes in expression were specific to one or the other form of the vitamin (Mengozzi et al, 2020). This study provides evidence of the different direct effects of the two active vitamin D metabolites on gene expression in vitro in cultured cells and provides some evidence that the changes we observed in the in vivo study may reflect the influence of the physiologically active forms of the vitamin, 1,25(OH)D 3 and 1,25(OH)D 2 .…”

“…For example, some biological processes such as histone modification and covalent chromatin modification are downregulated following vitamin D 3 supplementation only, while spliceosomal function are upregulated by vitamin D 2 only. In light of the finding that vitamins D 2 and D 3 influence expression of different genes in the human blood transcriptome, recently we undertook a parallel in vitro study with a model rat cell line (Mengozzi et al, 2020). We examined the respective influences of the two physiologically active forms of vitamin D, 1,25(OH)D 3 and 1,25(OH)D 2 on differentiation and global gene expression in differentiating rat CG4 oligodendrocyte precursor cells and revealed considerable differences in the influence of the two types of vitamin D on gene expression at 24 h and after 72 h following onset of differentiation.…”

Vitamins D2 and D3 have overlapping but different effects on human gene expression revealed through analysis of blood transcriptomes in a randomised double-blind placebo-controlled food-fortification trial

“…For example, some biological processes such as histone modification and covalent chromatin modification are downregulated following vitamin D3 supplementation only, while spliceosomal function are upregulated by vitamin D2 only. In light of the finding that vitamins D2 and D3 influence expression of different genes in the human blood transcriptome, recently we undertook a parallel in vitro study with a model rat cell line 44 . We examined the respective influences of the two physiologically active forms of vitamin D, 1,25(OH)D3 and 1,25(OH)D2 on differentiation and global gene expression in differentiating rat CG4 oligodendrocyte precursor cells and revealed considerable differences in the influence of the two types of vitamin D on gene expression at 24 h and after 72 h following onset of differentiation.…”