骨骼分泌的激素 z-bo 2020-11-16 451

　　A study reported that a hormone secreted by bones suppresses appetite in mice. This discovery adds the types of known bone secretion hormones and reveals a previously unknown appetite regulation mechanism.

　　Recently, bones have begun to be regarded as an organ of the endocrine system. It is known that bones secrete at least two hormones, FGF23 and osteocalcin, which help regulate kidney function and glucose homeostasis.

　　Now, Stavroula Kousteni of Columbia University and colleagues have discovered another such hormone: lipocalin-2 (LCN2) secreted by osteoblasts (cells that form bones). It can induce insulin secretion in mice, improve glucose tolerance, and improve insulin sensitivity. The authors also found that LCN2 can cross the blood-brain barrier, bind to the melanocortin receptor 4 (MC4R) in the hypothalamus, and then activate an appetite-suppressing pathway, thereby inhibiting food intake.

　　This study highlights a previously unknown role of LCN2. Previously, people thought it was an adipokine (small signal molecule secreted by adipose tissue), but its level in osteoblasts is more than 10 times higher than that in adipose tissue. At present, researchers do not know why bones inhibit food intake, but this may be a mechanism that helps maintain bone quality and skeleton growth.