骨钙素对糖代谢的调控作用

摘要

Osteocalcin is the most abundant non-collagen protein synthesized and secreted by osteoblasts.Both carboxylated osteocalcin and undercarboxylated osteocalcin can be measured in serum.Mice studies have demonstrated undercarboxylated osteocalcin as a hormone in regulating energy metabolism, including increasing cell proliferation and promoting insulin secretion from islet cells, improving insulin sensitivity by stimulating adiponectin expression in adipo-cytes, and indirectly promoting insulin secretion through acting on glucagon-like peptide-1.Insulin exerts positive impact on the activity of osteocalcin.The negative regulation of osteocalcin by leptin through the sympathetic nervous system is important for the maintenance of whole body energy metabolism.The majority of cross-sectional clinical trials have demon-strated that the higher of serum levels of osteocalcin, the lower the blood glucose concentrations;nevertheless, evidences from cohort studies and longitudinal investigations are insufficient to support the notion that lower osteocalcin is related with higher prevalence of diabetes mellitus.The current review will summarize the endocrine function of osteocalcin from mice to human.%骨钙素是由成骨细胞合成分泌的骨基质含量丰富的非胶原蛋白，主要以羧化骨钙素及非羧化骨钙素2种形式存在于血循环中。近年动物实验结果显示，非羧化骨钙素可作为激素对能量代谢发挥重要调节作用，作用于胰腺促进胰岛β细胞增殖及胰岛素分泌，作用于脂肪细胞促进脂联素分泌并改善胰岛素敏感性，以及通过提高胰高血糖素肽－1表达间接促进胰岛素分泌等作用。骨钙素的合成及活性受胰岛素正反馈调节，而瘦素通过交感神经对骨钙素活性负性调节。对人群横断面的研究显示血糖水平随血清骨钙素浓度升高而降低，而队列研究及病例对照研究结果并不足以支持低血清骨钙素与糖尿病发生相关的结论。本文阐述了骨钙素对糖代谢的调节作用。