Effect of Renin-Angiotensin System in the bone metabolism

经典的肾素血管紧张素系统（RAS）是一种维持体液平衡和血压的激素系统。除了这种经典的RAS外，最近的许多报道表明，在几种组织中存在局部RAS。在本研究中，我们检测了成骨细胞中血管紧张素II型1 （AT1）、AT2受体和血管紧张素转换酶（ACE），它们是局部RAS的必需元素。血管紧张素II （Angiotensin II， AII）刺激了ERK、AMPK、Syk等细胞信号分子，促进了成骨细胞中一些趋化因子的表达，而AII并不直接影响成骨细胞或软骨细胞的分化。这些结果表明，局部RAS在骨组织中具有功能。

The classical renin-angiotensin system (RAS) is a hormone system that maintains fluid balance and blood pressure. In addition to this classical RAS, many recent reports to suggested the existence of local RAS in several tissues. In our present study, we detected angiotensin II type 1 (AT1), AT2 receptor and angiotensin converting enzyme (ACE), which were the essential elements of local RAS, in osteoblasts. Angiotensin II (AII) stimulated some cellular signal molecules, such as ERK, AMPK and Syk, and promoted the expression of some chemokines in osteoblasts, whereas AII did not directly influence differentiation of osteoblast or chondrocyte. These results suggest that local RAS is functional in bone tissue.