1,25-DIHYDROXYVITAMIN-D3 RECEPTORS AND HORMONAL RESPONSES IN CLONED HUMAN SKELETAL-MUSCLE CELLS
1,25-DIHYDROXYVITAMIN-D3 RECEPTORS AND HORMONAL RESPONSES IN CLONED HUMAN SKELETAL-MUSCLE CELLS
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DOI：
10.1210/endo-119-5-2214
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发表时间：
1986-11-01
期刊：
影响因子：
4.8
通讯作者：
FELDMAN, D
中科院分区：
文献类型：
--
作者：
COSTA, EM;BLAU, HM;FELDMAN, D
尽管骨骼肌是主要的钙调节器官，但肌肉是否是 1,25-二羟基维生素 D3 [1,25-(OH)2D3] 作用的靶器官仍存在不确定性。在这项研究中，我们检查了克隆衍生的人类肌肉细胞的纯群体中是否存在 1,25-(OH)2D3 受体以及对激素的直接反应。所有测试的克隆都表现出特异性的[3H]1,25-(OH)2D3结合，其值范围为5-70 fmol/mg蛋白质。结合数据的 Scatchard 分析揭示了与其他靶器官中的经典受体相当的解离常数（约 100 pM）。 1,25-(OH)2D3 受体在高渗蔗糖梯度上于 3.3S 处沉积。通过 1,25-(OH)2D3 比 25-羟基维生素 D3 更好地竞争 3.3S 受体结合峰，在梯度上证明了 [3H]1,25-(OH)2D3 的特异性。 1,25-(OH)2D3 受体复合物与 DNA 纤维素结合，并在 0.2 M KCl 处作为单峰洗脱。 成肌细胞和肌管在 1,25-(OH)2D3 受体的特征数量上没有显示出显着差异。除了受体的存在之外，还测试了细胞对 1,25-(OH)2D3 的功能反应。用 1,25-(OH)2D3 处理单层细胞后，两种细胞类型均表现出 25-羟基维生素 D3-24-羟化酶活性的剂量依赖性诱导。用 1,25-(OH)2D3 处理后，亮氨酸和胸苷掺入生长中的成肌细胞和融合肌管均以剂量依赖性方式受到抑制。总之，克隆的人骨骼肌细胞含有与经典 1,25-(OH)2D3 受体相容的结合蛋白，并且在激素的生理浓度下对 1,25-(OH)2D3 具有功能反应性。
Although skeletal muscle is a major calcium-regulated organ, there remains uncertainty about whether muscle is a target organ for the action of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. In this study we examine pure populations of clonally derived human muscle cells for the presence of 1,25-(OH)2D3 receptors and direct responses to the hormone. All of the clones tested exhibited specific [3H]1,25-(OH)2D3 binding, with values ranging from 5-70 fmol/mg protein. Scatchard analysis of binding data revealed a dissociation constant (.apprx. 100 pM) comparable to that of classical receptors in other target organs. The 1,25-(OH)2D3 receptors sedimented at 3.3S on hypertonic sucrose gradients. Specificity for [3H]1,25-(OH)2D3 was demonstrated on gradients by substantially better competition by 1,25-(OH)2D3 than 25-hydroxyvitamin D3 for the 3.3S receptor binding peak. The 1,25-(OH)2D3 receptor complex bound to DNA cellulose and eluted as a single peak at 0.2 M KCl. Myoblasts and myotubes did not show significant differences in either the amount of characteristics of the 1,25-(OH)2D3 receptor. In addition to the presence of receptors, cells were tested for functional responsiveness to 1,25-(OH)2D3. Both cell types exhibited a dose-dependent induction of 25-hydroxyvitamin D3-24-hydroxylase enzyme activity after treatment of monolayers with 1,25-(OH)2D3. Incorporation of both leucine and thymidine into growing myoblasts and fused myotubes was inhibited in a dose-dependent fashion after treatment with 1,25-(OH)2D3. In summary, cloned human skeletal muscle cells contain a binding protein compatible with classical 1,25-(OH)2D3 receptors as well as functional responsiveness to 1,25-(OH)2D3 at physiological concentrations of hormone.