BioProject

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) plays an integral role in calcium homeostasis in higher organisms through its actions in the intestine, kidney and skeleton. More...

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) plays an integral role in calcium homeostasis in higher organisms through its actions in the intestine, kidney and skeleton. Interestingly, while several intestinal genes are known to play a contributory role in calcium homeostasis, the entire caste of key components remains to be identified. To examine the vitamin D receptor (VDR) cistrome in this issue, we conducted a ChIP-seq analysis of binding sites for the VDR across the proximal intestine in vitamin D-sufficient normal mice treated with vehicle or 1,25(OH)2D3. The residual VDR cistrome was comprised of 4617 sites which was increased almost 4-fold following hormone treatment. Interestingly, the majority of the genes regulated by 1,25(OH)2D3 in each diet group as well as those found in common in both groups contained frequent VDR sites that likely regulated their expression. This study revealed a global VDR cistrome regulating a network of genes in the intestine that both represent direct targets of vitamin D action in mice and are involved in calcium absorption. Overall design: Wildtype mice were fed a standard rodent chow diet (Harlan Teklad, #5008). At 8 weeks of age, 3 mice were treated with 1,25(OH)2D3 (10 ng/g bw) or vehicle control and the proximal half of the small intestine (duodenum and jejunum) was collected 1 h later. Less...