Bone Abstracts

Fibroblast growth factor-23 (FGF23) is a hormone originating from osteocytes with suppressive actions on renal phosphate reabsorption and vitamin D synthesis. We recently identified FGF23 as a calcium-conserving hormone, regulating the membrane transport of the epithelial calcium channel TRPV5 in distal renal tubules. Here, we analyzed the long term sequelae of Fgf23 deficiency and renal calcium wasting on bone and mineral metabolism in 9-month-old mice lacking both Fgf23<...

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Pseudohypoaldosteronism type II (PHAII) is a hereditary disease characterized by hypertension, hypercalciuria and osteopenia. PHAII is caused by mutations in with-no-lysine kinase 1 (WNK1), WNK4, or the cullin RING ligase family members kelch-like 3 (KLHL3) or cullin 3 (CUL3). All mutations result in up-regulation of the WNK signalling pathway which activates thiazide-sensitive Na-Cl cotransporters (NCC) in renal distal tubules, leading to salt retention and hypertension in PH...

Lack of Klotho, the co-receptor for the bone-derived hormone fibroblast growth factor-23 (FGF23), leads to a severe impairment in bone mineralization in mice. However, the mechanisms underlying the Klotho deficiency-associated defects in bone mineralization are still poorly understood. Here, we sought to elucidate the vitamin D independent role of Klotho in bone mineralization. To ablate increased vitamin D signaling in Klotho knockout mice (Kl−/−), we c...