Human parathyroid hormone carboxyterminal peptide (53-84) stimulates alkaline phosphatase activity in dexamethasone-treated rat osteosarcoma cells in vitro.
Human parathyroid hormone carboxyterminal peptide (53-84) stimulates alkaline phosphatase activity in dexamethasone-treated rat osteosarcoma cells in vitro.
复制标题
人甲状旁腺激素羧基末端肽 (53-84) 在体外刺激地塞米松处理的大鼠骨肉瘤细胞中的碱性磷酸酶活性。
DOI：
10.1210/endo-124-2-1097
复制
发表时间：
1989
期刊：
影响因子：
4.8
通讯作者：
H. Ly
中科院分区：
文献类型：
--
作者：
T. Murray;L. Rao;S. Muzaffar;H. Ly
我们实验室以前的研究已经证明，在克隆的成骨细胞系ROS17/2.8大鼠骨肉瘤细胞上，PTH的羧基末端(53-84)区域有较多的细胞表面结合位点。为了深入了解这些羧基末端结合位点的意义，我们研究了完整的牛PTH(1-84)及其氨基末端片段牛PTH(1-34)和人PTH羧基末端片段(53-84)对地塞米松处理的大鼠骨肉瘤(ROS)17/2.8细胞碱性磷酸酶活性的影响。当牛PTH(1-84)及其氨基末端1-34片段抑制碱性磷酸酶活性时，我们发现人PTH(53-84)对碱性磷酸酶有剂量依赖性的刺激作用，最大刺激发生在浓度为10(-8)M的120小时后，而在未加地塞米松处理的细胞中未见此作用。据我们所知，这是首次发表的关于这种羧基末端PTH多肽的生物活性的演示，以前人们认为它是没有活性的。地塞米松可能导致细胞分化为对人甲状旁腺激素更敏感的类型(53-84)。需要进一步的研究来阐明这些发现的生理学意义。
Previous studies in our laboratory have demonstrated relatively large numbers of cell surface binding sites for the carboxylterminal (53-84) region of PTH on ROS 17/2.8 rat osteosarcoma cells, a clonal osteoblast-like cell line. In order to gain insight into the significance of these carboxylterminal binding sites, we studied the effect of intact bovine PTH (1-84), its aminoterminal fragment bovine PTH (1-34), and the human PTH carboxylterminal fragment (53-84) on alkaline phosphatase activity in dexamethasone-treated rat osteosarcoma (ROS) 17/2.8 cells. While bovine PTH (1-84) and its aminoterminal 1-34 fragment inhibited alkaline phosphatase activity, we saw a dose-related stimulation of activity by human PTH (53-84), with maximal stimulation occurring after 120 hours, at a concentration of 10(-8) M. The effect was not seen in dexamethasone-untreated cells. To our knowledge, this is the first published demonstration of biological activity of this carboxylterminal PTH peptide, previously thought to be inactive. It is likely that dexamethasone caused differentiation of cells to a type more sensitive to human PTH (53-84). Further studies are necessary to elucidate the physiological significance of these findings.