scholarly journals Persistent fibroblast growth factor 23 signalling in the parathyroid glands for secondary hyperparathyroidism in mice with chronic kidney disease

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Kazuki Kawakami ◽  
Ai Takeshita ◽  
Kenryo Furushima ◽  
Masayasu Miyajima ◽  
Ikuji Hatamura ◽  
...  
Author(s):  
Orlando M. Gutiérrez

Fibroblast growth factor 23 (FGF23) and Klotho have emerged as major hormonal regulators of phosphorus (P) and vitamin D metabolism. FGF23 is secreted by bone cells and acts in the kidneys to increase urinary P excretion and inhibit the synthesis of 1,25 dihydroxyvitamin D (1,25(OH)2D) and in the parathyroid glands to inhibit the synthesis and secretion of parathyroid hormone. Phosphorus excess stimulates FGF23 secretion, likely as an appropriate physiological adaptation to maintain normal P homeostasis by enhancing urinary P excretion and diminishing intestinal P absorption via lower 1,25(OH)2D. The FGF23 concentrations are elevated early in the course of chronic kidney disease (CKD) and may be a primary initiating factor for the development of secondary hyperparathyroidism in this setting. Klotho exists in two forms: a transmembrane form and a secreted form, each with distinct functions. The transmembrane form acts as the key co-factor needed for FGF23 to bind to and activate its cognate receptor in the kidneys and the parathyroid glands. The secreted form of Klotho has FGF23-independent effects on renal P and calcium handling, insulin sensitivity, and endothelial function. Disturbances in the expression of Klotho may play a role in the development of altered bone and mineral metabolism in early CKD. In addition, abnormal circulating concentrations of both FGF23 and Klotho have been linked to excess cardiovascular disease, suggesting that both play an important role in maintaining cardiovascular health.


Bone Research ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Guillaume Courbon ◽  
Connor Francis ◽  
Claire Gerber ◽  
Samantha Neuburg ◽  
Xueyan Wang ◽  
...  

AbstractBone-produced fibroblast growth factor 23 (FGF23) increases in response to inflammation and iron deficiency and contributes to cardiovascular mortality in chronic kidney disease (CKD). Neutrophil gelatinase-associated lipocalin (NGAL or lipocalin 2; LCN2 the murine homolog) is a pro-inflammatory and iron-shuttling molecule that is secreted in response to kidney injury and may promote CKD progression. We investigated bone FGF23 regulation by circulating LCN2. At 23 weeks, Col4a3KO mice showed impaired kidney function, increased levels of kidney and serum LCN2, increased bone and serum FGF23, anemia, and left ventricular hypertrophy (LVH). Deletion of Lcn2 in CKD mice did not improve kidney function or anemia but prevented the development of LVH and improved survival in association with marked reductions in serum FGF23. Lcn2 deletion specifically prevented FGF23 elevations in response to inflammation, but not iron deficiency or phosphate, and administration of LCN2 increased serum FGF23 in healthy and CKD mice by stimulating Fgf23 transcription via activation of cAMP-mediated signaling in bone cells. These results show that kidney-produced LCN2 is an important mediator of increased FGF23 production by bone in response to inflammation and in CKD. LCN2 inhibition might represent a potential therapeutic approach to lower FGF23 and improve outcomes in CKD.


Sign in / Sign up

Export Citation Format

Share Document