Gene-Regulatory Potential of 25-Hydroxyvitamin D3 and D2

Andrea Hanel; Cor Veldhuizen; Carsten Carlberg

doi:10.3389/fnut.2022.910601

Gene-Regulatory Potential of 25-Hydroxyvitamin D₃ and D₂

Front Nutr. 2022 Jul 13:9:910601. doi: 10.3389/fnut.2022.910601. eCollection 2022.

Authors

Andrea Hanel¹, Cor Veldhuizen², Carsten Carlberg^{1

3}

Affiliations

¹ Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland.
² Carbogen Amcis, B.V., Veenendaal, Netherlands.
³ Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland.

Abstract

Human peripheral blood mononuclear cells (PBMCs) represent a highly responsive primary tissue that is composed of innate and adaptive immune cells. In this study, we compared modulation of the transcriptome of PBMCs by the vitamin D metabolites 25-hydroxyvitamin D₃ (25(OH)D₃), 25(OH)D₂ and 1α,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃). Saturating concentrations of 1,25(OH)₂D₃, 25(OH)D₃ and 25(OH)D₂ resulted after 24 h stimulation in a comparable number and identity of target genes, but below 250 nM 25(OH)D₃ and 25(OH)D₂ were largely insufficient to affect the transcriptome. The average EC₅₀ values of 206 common target genes were 322 nM for 25(OH)D₃ and 295 nM for 25(OH)D₂ being some 600-fold higher than 0.48 nM for 1,25(OH)₂D₃. The type of target gene, such as primary/secondary, direct/indirect or up-/down-regulated, had no significant effect on vitamin D metabolite sensitivity, but individual genes could be classified into high, mid and lower responders. Since the 1α-hydroxylase CYP27B1 is very low expressed in PBMCs and early (4 and 8 h) transcriptome responses to 25(OH)D₃ and 25(OH)D₂ were as prominent as to 1,25(OH)₂D₃, both vitamin D metabolites may directly control gene expression. In conclusion, at supra-physiological concentrations 25(OH)D₃ and 25(OH)D₂ are equally potent in modulating the transcriptome of PBMCs possibly by directly activating the vitamin D receptor.

Keywords: 1α; 25-dihydroxyvitamin D3; 25-hydroxyvitamin D2; 25-hydroxyvitamin D3; PBMCs; target genes; transcriptome; vitamin D.