Activation of adenosine 3',5'-monophosphate-dependent protein kinase in normal and malignant bone cells by parathyroid hormone, prostaglandin E2, and prostacyclin.
Activation of adenosine 3',5'-monophosphate-dependent protein kinase in normal and malignant bone cells by parathyroid hormone, prostaglandin E2, and prostacyclin.
复制标题
甲状旁腺激素、前列腺素 E2 和前列环素激活正常和恶性骨细胞中的腺苷 3,5-单磷酸依赖性蛋白激酶。
作者：
N. Partridge;B. Kemp;M. Veroni;T. Martin
已经在源自大鼠成骨肉瘤的培养细胞和源自新生大鼠颅骨的富含成骨细胞的细胞中研究了 cAMP 依赖性蛋白激酶的激素激活。两种细胞株均含有腺苷酸环化酶活性，可对甲状旁腺激素 (PTH) 和多种前列腺素产生反应。 PTH、前列腺素 E2 (PGE2) 和前列环素 (PGI2) 都能够在两种细胞类型的悬浮液中激活 cAMP 依赖性蛋白激酶。在所有情况下，激活都非常快，10 秒即可检测到，最长 30-60 秒。使用饱和浓度的激素，在PGE2刺激开始后长达35分钟内蛋白激酶活性比率保持升高（0.6-0.9之间），但在用PTH或PGI2刺激后5-10分钟下降至基础活性比率。每种激素都会导致两种细胞类型中 cAMP 依赖性蛋白激酶的激活呈剂量依赖性增加。对于颅骨细胞，酶的半最大激活发生在 2 X 10(-9) M 牛 PTH，对于成骨肉瘤细胞，发生在 10(-8) M bPTH，对于两种细胞类型，酶的半最大激活发生在 2-4 X 10(-8) M PGE2 和 1-3 X 10(-7) M PGI2。蛋白激酶的最大激活发生在最大 cAMP 积累之前，这意味着只有一小部分 cAMP 具有生物学意义。这两种细胞株提供了分析骨细胞激素调节中受体后事件的有用方法。
Hormonal activation of cAMP-dependent protein kinase has been studied in cultured cells derived from a rat osteogenic sarcoma and in osteoblast-rich cells grown from newborn rat calvaria. Both cell strains contain adenylate cyclase activities which respond to parathyroid hormone (PTH) and a variety of prostanoids. PTH, prostaglandin E2 (PGE2), and prostacyclin (PGI2) were all capable of activating cAMP-dependent protein kinase(s) in suspensions of the two cell types. Activation was very rapid in all cases, being detectable at 10 sec and maximal between 30-60 sec. Using saturating concentrations of hormones, the protein kinase activity ratio remained elevated (between 0.6-0.9) for up to 35 min after the start of PGE2 stimulation, but declined toward basal activity ratio 5-10 min after stimulation with PTH or PGI2. Each of the hormones caused a dose-dependent increase in activation of cAMP-dependent protein kinase in both cell types. Half-maximal activation of the enzyme occurred at 2 X 10(-9) M bovine PTH for calvarial cells, at 10(-8) M bPTH for osteogenic sarcoma cells, and at 2-4 X 10(-8) M PGE2 and 1-3 X 10(-7) M PGI2 for both cell types. Maximal activation of protein kinase occurred before maximal cAMP accumulated, implying that only a fraction of cAMP is biologically significant. These two cell strains provide a useful means of analyzing postreceptor events in the hormonal regulation of bone cells.