Xie L Y, Leung A, Segre G V, Yamamoto I, Abou-Samra A B
Endocrine Unit, Massachusetts General Hospital, Boston 02114, USA.
Am J Physiol. 1996 Apr;270(4 Pt 1):E654-60. doi: 10.1152/ajpendo.1996.270.4.E654.
Effects of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] on the expression of the parathyroid hormone (PTH)/PTH-related peptide (rP) receptor protein and mRNA in ROS 17/2.8 cells were studied. Treatment of ROS 17/2.8 cells with 1,25(OH)2D3 caused time- and dose-dependent suppression of PTH/PTHrP receptor number and immunoreactivity. The effects required more than 24 h incubation with 1,25(OH)2D3 and were maximal by 72 h. The cells did not recover their PTH/PTHrP receptors even after 4 days of treatment with control medium. Treatment with low concentrations of 1,25(OH)2D3 (0.1 M) dramatically decreased the PTH/PTHrP receptor mRNA levels, which were maximal after 24 h of incubation. The half-life of the PTH/PTHrP receptor transcript, 6-8 h, was similar in control and 1,25(OH)2D3-treated cells, suggesting that 1,25(OH)2D3 acts in controlling transcription of the PTH/PTHrP receptor gene but does not change the degradation rate of the PTH/PTHrP receptor transcripts. These data indicate that 1,25(OH)2D3 has a potent inhibitory effect on the expression of the PTH/PTHrP receptor protein and mRNA in ROS 17/2.8 cells.
研究了1,25 - 二羟基维生素D3 [1,25(OH)2D3] 对ROS 17/2.8细胞中甲状旁腺激素 (PTH)/PTH相关肽 (rP) 受体蛋白表达及mRNA的影响。用1,25(OH)2D3处理ROS 17/2.8细胞导致PTH/PTHrP受体数量和免疫反应性呈时间和剂量依赖性抑制。这些效应需要与1,25(OH)2D3孵育超过24小时，72小时时达到最大。即使在用对照培养基处理4天后，细胞也未恢复其PTH/PTHrP受体。用低浓度的1,25(OH)2D3（0.1 μM）处理可显著降低PTH/PTHrP受体mRNA水平，孵育24小时后达到最大。PTH/PTHrP受体转录本的半衰期在对照细胞和1,25(OH)2D3处理的细胞中相似，为6 - 8小时，这表明1,25(OH)2D3在控制PTH/PTHrP受体基因转录中起作用，但不改变PTH/PTHrP受体转录本的降解速率。这些数据表明，1,25(OH)2D3对ROS 17/2.8细胞中PTH/PTHrP受体蛋白和mRNA的表达具有强大的抑制作用。
