Table 1 Some of the genes and their functions/organs regulated by vitamin D
Gene | Target Organ | Regulation | Function of genes involved |
|---|---|---|---|
PTH | Parathyroid gland | down | Induces Cyp27B1 and inhibit 24-hydroxylation, increase calcitriol synthesis |
Cyp24A1 (VD-24-hydroxylase) | kidney | up | Inactivates calcitriol to 1,24,25(OH)3D3, which can be oxidized to calcitriol acid for secretion |
Interleukin −12(IL-12) | Innate Immune Cell | down | Restrain Th1 activation by limiting IL-12 |
FGF15 (FGF19 for humans) | Ileum | up | Suppresses bile acid synthesis in hepatocytes through induction of SHP |
Cyp27B1 (VD-1alpha-hydroxylase | kidney | down | Restrains VD synthesis by feedback inhibition |
Cyp3A4 | liver | Â | Catabolizes bile acid and xenobiotics, |
SULT2A1 | liver | up | Detoxification of steroids, xenobiotics, and bile acid for secretion |
MRP3 | liver | up | Transportations of range of substrates such as anti-cancer drugs and bile acid |
Cathelicidin | intestine | up | immune defense against invasive bacterial infection |
ASBT | Ileum | up | Enhances bile acid re-adsorption from ileum, which may restrain bile acid synthesis in the liver via feedback inhibition |
Calbindin D9K | Intestine, Kidney | up | Transport of calcium across the enterocytes |
TRPV6 | intestine | up | Help in calcium absorption in the intestine |
Defensin beta 2 | Immune cells | up | Exhibits potent antimicrobial activity against Gram-negative bacteria and Candida, but not against Gram-positive S. aureus |
FasL/CD95L | Immune cells | down | Reduces apoptosis |
E-cadherin | skin | down | Restrains epithelial to mesenchymal transition |
Interferon-gamma | T cells | up | Restrains immunity |