Does FGF23 increase calcium?
Moreover, FGF23 has several additional physiological functions, which include inhibition of renal phosphate reabsorption, increased conservation of calcium and sodium in the kidney, support of a normal responsiveness of the kidney to PTH, and regulation of bone mineralization.
Does FGF23 inhibit vitamin D?
FGF23 plays a central role in vitamin D metabolism: It inhibits calcitriol synthesis in the kidney and stimulates the catabolism of active vitamin D sterols.
What is the role of FGF23 hormone?
FGF23 is a bone-derived hormone that regulates systemic phosphate homeostasis, vitamin D metabolism and α-Klotho expression through a novel bone-kidney axis.
Where is FGF23 produced?
Fibroblast growth factor 23 (FGF23), a known regulator of phosphate homeostasis, is produced by cells residing in bone, namely, osteocytes, to target a distant organ, the kidney. Elevated FGF23 levels have recently been found systemically and in osteocytes in patients and animal models of chronic kidney disease.
Why does FGF23 increase in CKD?
In patients with chronic kidney disease (CKD), circulating FGF23 levels are progressively increased to compensate for persistent phosphate retention, but this results in reduced renal production of 1,25-dihydroxyvitamin D and leads to hypersecretion of parathyroid hormone.
What stimulates FGF23?
Recently, it has been shown that leptin, a hormone secreted by white adipose tissue that acts centrally on hypothalamus and peripherally on other organs to control energy intake, expenditure, and bone homeostasis, stimulates FGF23 production in bone (205).
What does FGF23 do to bone?
The FGF23 gene provides instructions for making a protein called fibroblast growth factor 23, which is produced in bone cells. This protein is necessary in regulating the phosphate levels within the body (phosphate homeostasis).
What organ is the target of action for FGF23?
Abstract. Relatively recently, FGF23 has been established as the main hormone regulating phosphate metabolism. FGF23, produced in skeletal osteocytes, regulates Pi metabolism through actions in the kidneys.
What triggers FGF23?
The expression of FGF23 is regulated by both VDR-dependent and VDR-independent signaling. Stimulation of the 1,25(OH)2D-VDR pathway induces the expression of FGF23, as evidenced by increased FGF23 levels after 1,25(OH)2D administration.
How does FGF23 affect phosphate?
FGF23 inhibits renal tubular reabsorption of phosphate through mechanisms independent of PTH as well as reduces circulating 1, 25(OH)2D through its dual effects to suppress Cyp27b1 production and to stimulate Cyp24 catabolism of 1,25(OH)2D.
How is FGF23 measured?
FGF23 can be measured by ELISA, detecting either the intact peptide only or both the intact peptide and a c-terminal fragment. These two test result reflect very different metabolic processes.
What is FGF23 blood test?
Fibroblast growth factor 23 (FGF23) is a major regulator of phosphate homeostasis. FGF23 measurements are useful in the differential diagnosis of hypophosphatemic diseases. Intact FGF23 is elevated in patients with tumor induced osteomalacia (TIO) or X-linked hypophosphatemia (XLH).