Robertson D G, Marino E M, Thulé P M, Seneviratne C K, Murphy L J
Department of Medicine, Emory University School of Medicine, Atlanta, GA 30303.
Biochem Biophys Res Commun. 1994 Apr 15;200(1):226-32. doi: 10.1006/bbrc.1994.1438.
Hepatic expression of insulin-like growth factor binding protein-1 is regulated by insulin and glucocorticoids. To study underlying mechanisms, rat hepatocytes in primary culture were transfected with deletion mutants and heterologous promoter constructs, identifying a 41 bp region of the rat insulin-like growth factor binding protein-1 promoter which is sufficient to mediate regulation by both insulin and glucocorticoids. Half maximal suppression of promoter activity by insulin occurred at a physiologic concentration, 5 x 10(-10) M, and regulation by insulin was dominant in that insulin suppressed promoter activity at all dexamethasone concentrations. Transfection of rat hepatocytes in primary culture should be a useful approach for exploring the regulation of gene expression by insulin.
胰岛素样生长因子结合蛋白-1的肝脏表达受胰岛素和糖皮质激素调节。为研究其潜在机制，将缺失突变体和异源启动子构建体转染至原代培养的大鼠肝细胞中，鉴定出大鼠胰岛素样生长因子结合蛋白-1启动子的一个41 bp区域，该区域足以介导胰岛素和糖皮质激素的调节作用。胰岛素对启动子活性的半数最大抑制作用发生在生理浓度5×10⁻¹⁰ M时，且胰岛素的调节作用占主导，因为在所有地塞米松浓度下胰岛素均能抑制启动子活性。原代培养的大鼠肝细胞转染应是探索胰岛素对基因表达调节作用的一种有用方法。
