[Rickets/Osteomalacia. Action of FGF23.]

Area of Science:

• Endocrinology
• Nephrology
• Cardiology

Background:

• Fibroblast growth factor 23 (FGF23) is an endocrine hormone primarily secreted by osteocytes.
• FGF23 interacts with FGFR1c co-receptor, α-Klotho, to regulate phosphate and vitamin D metabolism.
• The kidney proximal tubule is a key site for FGF23 action, influencing serum phosphate levels.

Purpose of the Study:

• To review the pleiotropic actions of FGF23.
• To highlight the emerging role of FGF23 in pathological processes beyond phosphate homeostasis.
• To discuss the Klotho-independent mechanisms of FGF23 in conditions like cardiac hypertrophy.

Main Methods:

• Literature review of studies on FGF23.
• Analysis of FGF23's physiological and pathological roles.
• Examination of FGF23 signaling pathways, including Klotho-dependent and independent mechanisms.

Main Results:

• FGF23 is crucial for maintaining phosphate and vitamin D balance.
• FGF23 has been implicated in cardiac hypertrophy through mechanisms independent of α-Klotho.
• These findings suggest FGF23 has diverse biological functions.

Conclusions:

• FGF23 plays a significant role in phosphate and vitamin D regulation.
• Emerging evidence points to FGF23's involvement in cardiovascular pathology, independent of its canonical pathway.
• Further research is warranted to fully elucidate the complex roles of FGF23.