%0 Journal Article
%T Role of pregnancy and obesity on vitamin D status, transport, and metabolism in baboons | APSselect
%A Cun Li
%A Eugenia Mata-Greenwood
%A Hillary F. Huber
%A Peter W. Nathanielsz
%A [email protected]
%J American Journal of Physiology-Renal Physiology
%D 2019
%X Human studies show that obesity is associated with vitamin D insufficiency, which contributes to obesity-related disorders. Our aim was to elucidate the regulation of vitamin D during pregnancy and obesity in a nonhuman primate species. We studied lean and obese nonpregnant and pregnant baboons. Plasma 25-hydroxy vitamin D (25-OH-D) and 1¦Á,25-(OH)2-D metabolites were analyzed using ELISA. Vitamin D-related gene expression was studied in maternal kidney, liver, subcutaneous fat, and placental tissue using real-time PCR and immunoblotting. Pregnancy was associated with an increase in plasma bioactive vitamin D levels compared with nonpregnant baboons in both lean and obese groups. Pregnant baboons had lower renal 24-hydroxylase CYP24A1 protein and chromatin-bound vitamin D receptor (VDR) than nonpregnant baboons. In contrast, pregnancy upregulated the expression of CYP24A1 and VDR in subcutaneous adipose tissue. Obesity decreased vitamin D status in pregnant baboons (162£¿¡À£¿17 vs. 235£¿¡À£¿28 nM for 25-OH-D, 671£¿¡À£¿12 vs. 710£¿¡À 10 pM for 1¦Á,25-(OH)2-D; obese vs. lean pregnant baboons, P£¿< 0.05). Lower vitamin D status correlated with decreased maternal renal expression of the vitamin D transporter cubulin and the 1¦Á-hydroxylase CYP27B1. Maternal obesity also induced placental downregulation of the transporter megalin (LRP2), CYP27B1, the 25-hydroxylase CYP2J2, and VDR. We conclude that baboons represent a novel species to evaluate vitamin D regulation. Both pregnancy and obesity altered vitamin D status. Obesity-induced downregulation of vitamin D transport and bioactivation genes are novel mechanisms of obesity-induced vitamin D regulation
%U https://journals.physiology.org/doi/full/10.1152/ajpendo.00208.2018%40apsselect.2019.6.issue-1