Parathyroid hormone signaling in bone and kidney.
OBJECTIVE
Parathyroid hormone (PTH) maintains a physiological balance of calcium and phosphate concentrations by binding to its receptor on the plasma membrane of cells in bone and kidney. It signals through multiple pathways, including protein kinase A and protein kinase C, although a preference for certain pathways is apparent in each organ and function. Here, we will review the recent advancements regarding PTH signaling in bone and kidney.


RESULTS
Wnt proteins have been reported as important regulators of bone metabolism in both PTH-dependent and independent pathways. Recent studies emphasize its role as a mediator of PTH signaling, as PTH treatment increased the expression of wnt4 and sfrp4 and decreased the expression of Wnt inhibitors such as Sost and sclerostin, leading to an increase in Wnt signaling. In kidney, sodium-hydrogen exchanger regulatory factor 1, originally known for its role in the retention of NaPi-IIa at the apical membrane, was shown to have multiple roles in PTH signaling, both as a mediator and regulator.


CONCLUSIONS
PTH activates a number of different signaling pathways by binding to a single receptor in bone and kidney. Recent studies demonstrate the involvement of novel factors as well as additional roles for previously identified downstream factors of PTH.
Lee
Minnkyong
M
Department of Physiology and Biophysics, University of Medicine and Dentistry of New Jersey - Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA.
Partridge
Nicola C
NC
D000818:Animals; D001842:Bone and Bones / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D010281:Parathyroid Hormone / Q000502:physiology*; D010750:Phosphoproteins / Q000502:physiology; D011493:Protein Kinase C / Q000502:physiology; D044168:Receptor, Parathyroid Hormone, Type 1 / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology*; D017923:Sodium-Hydrogen Exchangers / Q000502:physiology
D010281:Parathyroid Hormone; D010750:Phosphoproteins; D044168:Receptor, Parathyroid Hormone, Type 1; D017923:Sodium-Hydrogen Exchangers; C093376:sodium-hydrogen exchanger regulatory factor; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D002118:Calcium