Enhancement of liver cell gap junction protein expression by glucocorticoids.
Enhancement of liver cell gap junction protein expression by glucocorticoids.
复制标题
糖皮质激素增强肝细胞间隙连接蛋白表达。
DOI：
10.1093/carcin/15.9.1807
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发表时间：
1994
期刊：
影响因子：
4.7
通讯作者：
Ruch,RJ
中科院分区：
文献类型：
--
作者：
Ren,P;deFeijter,AW;Paul,DL;Ruch,RJ
缝隙连接细胞间通讯(GJIC)和缝隙连接蛋白(Cxin)的表达可能参与了生长调节和肿瘤转化。连接蛋白基因在正常组织和肿瘤组织中的调控机制尚不清楚。在本研究中，糖皮质激素、地塞米松和氢化可的松增强了原代培养的大鼠肝细胞和MH1C1大鼠肝癌细胞的荧光染料偶联。其他类型的类固醇(β-雌二醇、睾酮、醛固酮和孕酮)没有作用。Northern印迹、Western印迹、核游走和免疫组织化学分析表明，糖皮质激素以剂量和时间依赖的方式增强这些细胞中连接蛋白32的表达。地塞米松对肝细胞缝隙连接蛋白26的表达也有轻微的促进作用，但对MH1C1细胞无明显影响。Cx43在这些细胞中的表达不受类固醇的影响。在WB-F344大鼠肝上皮细胞中，地塞米松对偶联蛋白或连接蛋白的表达没有影响。这些结果表明，糖皮质激素以细胞特异性的方式上调染料偶联和连接蛋白32和连接蛋白26的表达，而不是连接蛋白43的表达。这些对GJIC和缝隙连接蛋白表达的影响可能与诱导肝脏分化和抑制生长有关。
Gap junctional intercellular communication (GJIC) and the expression of gap junction proteins (connexins) may be involved in growth regulation and neoplastic transformation. The mechanisms of connexin gene regulation in normal and neoplastic tissues are poorly understood. In this study, the glucocorticoids, dexamethasone and hydrocortisone, enhanced fluorescent dye-coupling in primary cultured rat hepatocytes and MH1C1rat hepatoma cells. Other types of steroids (β-estradiol, testosterone, aldosterone and progesterone) had no effect. Northern blot, Western blot, nuclear run-on and immunohistochemical analyses showed that glucocorticoids enhanced the expression of connexin32 in these cells in a dose- and time-dependent fashion. Connexin26 expression was also enhanced slightly by dexamethasone in hepatocytes, but not MH1C1cells. Connexin43 expression in these cells was not affected by steroids. In WB-F344 rat liver epithelial cells, which were highly coupled and expressed high levels of connexin43 and no detectable connexin32 or connexin26, dexamethasone had no effect on coupling or connexin expression. These results indicate that dye-coupling and the expression of connexin32 and connexin26, but not connexin43, were upregulated by glucocorticoids in a cell-specific manner. These effects on GJIC and connexin expression may be involved in the induction of hepatic differentiation and inhibition of growth.