What does CYP27B1 do?
The CYP27B1 gene provides instructions for making an enzyme called 1-alpha-hydroxylase (1α-hydroxylase). This enzyme carries out the second of two reactions to convert vitamin D to its active form, 1,25-dihydroxyvitamin D3, also known as calcitriol.
What does 1 alpha hydroxylase do?
The mitochondrial enzyme 25-hydroxyvitamin D(3)-1 alpha-hydroxylase (1 alpha-hydroxylase) plays an important role in calcium homeostasis by catalyzing synthesis of the active form of vitamin D, 1,25-dihydroxyvitamin D(3), in the kidney.
What is CYP24A1?
CYP24A1 is an enzyme expressed in the mitochondrion of humans and other species. It catalyzes hydroxylation reactions which lead to the degradation of 1,25-dihydroxyvitamin D3, the physiologically active form of vitamin D.
What is calcitriol made from?
cholecalciferol
Calcitriol is, strictly, the 1-hydroxylation product of calcifediol (25-OH vitamin D3), derived from cholecalciferol (vitamin D3), rather than the product of hydroxylations of ergocalciferol (vitamin D2).
What is the function of calcitriol?
Calcitriol is used to treat and prevent low levels of calcium and bone disease in patients whose kidneys or parathyroid glands (glands in the neck that release natural substances to control the amount of calcium in the blood) are not working normally.
How does vitamin D get activated?
It is also produced endogenously when ultraviolet (UV) rays from sunlight strike the skin and trigger vitamin D synthesis. Vitamin D obtained from sun exposure, foods, and supplements is biologically inert and must undergo two hydroxylations in the body for activation.
Why is calcitriol important?
Calcitriol has several important functions in the body. It maintains serum calcium levels by increasing calcium absorption in the gastrointestinal tract. It promotes healthy bone formation by the calcification of osteoid tissue.
What is the structure of vitamin D?
Types
| Name | Chemical composition |
|---|---|
| Vitamin D1 | Mixture of molecular compounds of ergocalciferol with lumisterol, 1:1 |
| Vitamin D2 | ergocalciferol (made from ergosterol) |
| Vitamin D3 | cholecalciferol (made from 7-dehydrocholesterol in the skin). |
| Vitamin D4 | 22-dihydroergocalciferol |
Why is CYP27B1 expressed in dendritic cells?
Results show that CYP27B1 is predominantly expressed in dendritic cells (DCs). Its expression in these cells is necessary for their response to VitD, which is known to upregulate pathways involved in generating a tolerogenic DC phenotype.
Is CYP27B1 involved in the etiology of multiple sclerosis?
Results show that CYP27B1 is predominantly expressed in dendritic cells (DCs). Its expression in these cells is necessary for their response to VitD, which is known to upregulate pathways involved in generating a tolerogenic DC phenotype. The data do not support a major role for rare CYP27B1 variants in the etiology of multiple sclerosis.
What is the role of cytochrome P450 CYP27B1 in dietary calcium absorption?
Increased CYP27B1 expression and local duodenal 1,25(OH)2D3 production during puberty may be a metabolic adaptation that promotes dietary calcium absorption. Data show that cytochrome P450 CYP27B1 and CYP24A1 expression were significantly different between tumor and normal tissues in non-small cell lung cancer (NSCLC).