| [ Summary ] |
Fibroblast growth factor 23 (FGF23) which is produced by bone reduces serum phosphate and 1,25-dihydroxyvitamin D [1,25(OH)2D] levels by binding to the Klotho-FGF receptor complex in the kidneys. Klotho mice with severely reduced expression of Klotho and FGF23-null mice share common features such as hyperphosphatemia and high 1,25(OH)2D levels. In addition, these mice show similar characteristics resembling ageing including growth retardation, decreased life span and skin atrophy. Such phenotypes are improved by correcting hyperphosphatemia and the exaggerated action of 1,25(OH)2D suggesting that they are caused secondarily by abnormal mineral metabolism. Further studies are necessary regarding the relationship between mineral metabolism and ageing, especially in humans. |