Adiponectin and its receptors are expressed in bone-forming cells
Adiponectin and its receptors are expressed in bone-forming cells
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DOI：
10.1016/j.bone.2004.06.008
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发表时间：
2004-10-01
期刊：
影响因子：
4.1
通讯作者：
Reseland, JE
中科院分区：
文献类型：
--
作者：
Berner, HS;Lyngstadaas, SP;Reseland, JE
到目前为止，脂联素一直被认为是由脂肪组织合成和分泌的，据报道它影响能量稳态和胰岛素敏感性。此外，体重与骨密度增加和骨折风险降低呈正相关。然而，解释这种关系的机制尚不完全清楚。我们通过证明脂联素的转录、翻译和分泌，以及其受体AdipoR1和AdipoR2在骨形成细胞中的表达，报道了脂联素与骨稳态之间的联系。我们发现脂联素和受体在股骨和胫骨的原代人成骨细胞中表达。碱性磷酸酶、1型胶原、骨钙素和CD44的高表达以及矿化结节的形成证实了骨细胞的表型。单克隆抗体免疫染色也显示在人骨肉瘤细胞和正常成骨细胞中存在脂联素。培养的人成骨细胞在分化过程中mRNA的表达和脂联素向培养基的分泌均增加。饲粮中添加脂肪酸后培养3天和7 d的成骨细胞脂联素mRNA水平升高，添加重组脂联素的培养基可促进小鼠成骨细胞的增殖。脂联素在骨中的调节和详细功能尚不清楚，但我们的研究结果提示其在骨稳态中的功能作用。如果是这样，脂联素可能提供了一个重要的信号，将脂肪和体重与骨密度联系起来。(C) 2004爱思唯尔公司版权所有。
Adiponectin has until now been considered to be synthesized and secreted exclusively by the adipose tissue, and is reported to influence energy homeostasis and insulin sensitivity. It is also known that body weight is positively correlated with increased bone mineral density and decreased fracture risk. The mechanisms explaining this relation, however, are not completely understood. We report a link between adiponectin and bone homeostasis by demonstrating transcription, translation, and secretion of adiponectin, as well as expression of its receptors, AdipoR1 and AdipoR2, in bone-forming cells. We show that adiponectin and the receptors are expressed in primary human osteoblasts from femur and tibia. The phenotype of bone cells was confirmed by the high expression levels of alkaline phosphatase, collagen type 1, osteocalcin, and CD44, and the formation of mineralization nodules. Immunostaining with monoclonal antibodies also demonstrated the presence of adiponectin in human osteosarcoma cells and normal osteoblasts. Both mRNA expression and secretion of adiponectin to the medium increased during differentiation of human osteoblasts in culture. The adiponectin mRNA level increases in osteoblasts cultured 3 and 7 days in the presence of dietary fatty acids and supplementation of culture medium with recombinant adiponectin enhances the proliferation of murine osteoblasts. The regulation and detailed function of adiponectin in bone still remains obscure, but our findings suggest a functional role in bone homeostasis. If so, adiponectin may provide an important signal linking fat and body weight to bone density. (C) 2004 Elsevier Inc. All rights reserved.