Department of Orthopaedic Surgery, University of Toledo Health Sciences Campus, Toledo, OH 43614, USA.
Bone. 2012 Feb;50(2):534-9. doi: 10.1016/j.bone.2011.06.032. Epub 2011 Jul 4.
Recent advances in understanding the role of bone in the systemic regulation of energy metabolism indicate that bone marrow cells, adipocytes and osteoblasts, are involved in this process. Marrow adipocytes store significant quantities of fat and produce adipokines, leptin and adiponectin, which are known for their role in the regulation of energy metabolism, whereas osteoblasts produce osteocalcin, a bone-specific hormone that has a potential to regulate insulin production in the pancreas and adiponectin production in fat tissue. Both osteoblasts and marrow adipocytes express insulin receptor and respond to insulin-sensitizing anti-diabetic TZDs in a manner, which tightly links bone with the energy metabolism system. Metabolic profile of marrow fat resembles that of both, white and brown fat, which is reflected by its plasticity in acquiring different functions including maintenance of bone micro-environment. Marrow fat responds to physiologic and pathologic changes in energy metabolism status by changing volume and metabolic activity. This review summarizes available information on the metabolic function of marrow fat and provides hypothesis that this fat depot may acquire multiple roles depending on the local and perhaps systemic demands. These functions may include a role in bone energy maintenance and endocrine activities to serve osteogenesis during bone remodeling and bone healing.
近年来，人们对骨骼在全身能量代谢调节中的作用的认识不断深入，研究表明骨髓细胞、脂肪细胞和成骨细胞都参与了这一过程。骨髓脂肪细胞储存大量脂肪，并产生瘦素和脂联素等脂肪因子，这些因子在能量代谢调节中起着重要作用，而成骨细胞则产生骨钙素，这是一种具有调节胰腺胰岛素产生和脂肪组织脂联素产生潜力的骨特异性激素。成骨细胞和骨髓脂肪细胞都表达胰岛素受体，并以一种与能量代谢系统紧密联系的方式对胰岛素增敏型抗糖尿病 TZDs 产生反应。骨髓脂肪的代谢特征与白色脂肪和棕色脂肪相似，这反映了它在获得不同功能方面的可塑性，包括维持骨微环境。骨髓脂肪会根据能量代谢状态的生理和病理变化，通过改变体积和代谢活性来做出响应。本综述总结了骨髓脂肪代谢功能的现有信息，并提出了一个假设，即这个脂肪库可能根据局部甚至全身的需求获得多种功能。这些功能可能包括在骨骼能量维持和内分泌活动中发挥作用，以在骨重塑和骨愈合期间为成骨作用提供服务。
