Rosewicz S, Detjen K, Logsdon C D, Chen L M, Chao J, Riecken E O
Department of Gastroenterology, Klinikum Steglitz, FU Berlin, West Germany.
Endocrinology. 1991 May;128(5):2216-22. doi: 10.1210/endo-128-5-2216.
In this study we investigated the effects of steroid hormones on glandular kallikrein gene expression in the rat pancreatic acinar cell line AR42J. Using a cloned complementary DNA probe and a polyclonal antibody we demonstrated expression of a true glandular kallikrein gene and protein in AR42J cells by Western and Northern blot analysis. Dexamethasone resulted in a time-dependent parallel decrease of kallikrein messenger RNA and protein with a maximum at 12 and 72 h (30 +/- 10 and 8 +/- 0.5% of control, respectively, P less than 0.05, n = 6). In contrast, dexamethasone stimulated gene expression of two other serine proteases, chymotrypsin and trypsin, approximately 3 to 4-fold. The decrease of kallikrein concentration was dose dependent with half-maximal effects at 5 x 10(-8) M and maximal effects at 10(-7) M dexamethasone (23 +/- 6% of control, n = 3). The glucocorticoid antagonist RU 38486 blocked the glucocorticoid-induced decrease in cellular kallikrein content in a dose-dependent manner. Complete inhibition was observed at equimolar doses of dexamethasone and the antagonist. The inhibitory effect of dexamethasone was completely reversible after hormone withdrawal for 24 h. Neither estrogen, progesterone, testosterone, or aldosterone had significant effects on kallikrein expression. These data suggest that down-regulation of pancreatic kallikrein gene expression occurs selectively in response to glucocorticoids at a pretranslational level, mediated most likely by the glucocorticoid receptor.
在本研究中，我们调查了类固醇激素对大鼠胰腺腺泡细胞系AR42J中腺激肽释放酶基因表达的影响。使用克隆的互补DNA探针和多克隆抗体，我们通过蛋白质免疫印迹法和Northern印迹分析法在AR42J细胞中证实了真正的腺激肽释放酶基因和蛋白的表达。地塞米松导致激肽释放酶信使核糖核酸和蛋白随时间呈平行下降，在12小时和72小时时降至最低（分别为对照的30±10%和8±0.5%，P<0.05，n=6）。相反，地塞米松刺激另外两种丝氨酸蛋白酶即胰凝乳蛋白酶和胰蛋白酶的基因表达增加约3至4倍。激肽释放酶浓度的下降呈剂量依赖性，在5×10-8M地塞米松时达到半数最大效应，在10-7M地塞米松时达到最大效应（为对照的23±6%，n=3）。糖皮质激素拮抗剂RU 38486以剂量依赖性方式阻断糖皮质激素诱导的细胞激肽释放酶含量下降。在地塞米松和拮抗剂等摩尔剂量时观察到完全抑制。激素撤除24小时后，地塞米松的抑制作用完全可逆。雌激素、孕酮、睾酮或醛固酮对激肽释放酶表达均无显著影响。这些数据表明，胰腺激肽释放酶基因表达的下调是在翻译前水平上对糖皮质激素的选择性反应，最有可能由糖皮质激素受体介导。
