Dexamethasone increases apolipoprotein A-I concentrations in medium and apolipoprotein A-I mRNA abundance from Hep G2 cells.
Dexamethasone increases apolipoprotein A-I concentrations in medium and apolipoprotein A-I mRNA abundance from Hep G2 cells.
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地塞米松可增加培养基中载脂蛋白 A-I 的浓度以及 Hep G2 细胞中载脂蛋白 A-I mRNA 的丰度。
DOI：
10.1016/0026-0495(92)90288-l
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
EttingerJr,WH
中科院分区：
文献类型：
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作者：
Varma,VK;Smith,TK;Sorci-Thomas,M;EttingerJr,WH
糖皮质激素增加体内高密度脂蛋白（HDL）水平。然而，关于糖皮质激素改变HDL代谢的机制知之甚少。将Hep G2细胞与地塞米松共同孵育，以确定糖皮质激素对载脂蛋白（apo）A-I分泌的影响。地塞米松以剂量依赖性方式增加apo A-I浓度。24小时后，5.5 × 10− 5 mol/L地塞米松使培养基中apo A-I的积累增加了54%。孵育5小时后，在培养基中观察到载脂蛋白A-I浓度可检测到增加，并持续至48小时。与地塞米松孵育24小时后，细胞apo A-I mRNA浓度增加28%。在地塞米松孵育后3小时内可检测到apo A-I mRNA浓度的增加。与此相反，地塞米松孵育降低载脂蛋白B浓度的43%，在培养基中，但它对细胞载脂蛋白B mRNA的浓度没有影响。地塞米松对培养基中胆固醇和甘油三酯的积累几乎没有影响。单独与白蛋白孵育不影响apo A-I浓度，但使培养基中apo B浓度降低30%。与白蛋白和地塞米松孵育对培养基中apo A-I浓度无影响，对apo B浓度无累加效应。这些数据表明地塞米松通过增加mRNA水平来增加Hep G2细胞的apo A-I分泌。
Glucocorticoid hormones increase high-density lipoprotein (HDL) levels in vivo. However, there is little known about the mechanism by which glucocorticoids alter HDL metabolism. Hep G2 cells were incubated with dexamethasone to determine the effect of glucocorticoids on apolipoprotein (apo) A-I secretion. Dexamethasone increased apo A-I concentration in a dose-dependent fashion. After 24 hours, 5.5 × 10−5mol/L dexamethasone increased apo A-I accumulation in culture medium by 54%. Detectable increases in apo A-I concentration were noted in medium by 5 hours of incubation and persisted up to 48 hours. Cellular apo A-I mRNA concentration increased by 28% after incubation with dexamethasone for 24 hours. The increase in apo A-I mRNA concentration was detectable within 3 hours after incubation with dexamethasone. In contrast, incubation with dexamethasone decreased apo B concentration by 43% in culture medium, but it had no effect on cellular apo B mRNA concentrations. Dexamethasone had little effect on cholesterol and triglyceride accumulation in the medium. Incubation with albumin alone did not affect apo A-I concentration, but it decreased apo B concentration by 30% in the medium. Incubation with albumin and dexamethasone had no effect on apo A-I concentration in medium and had no additive effect on apo B concentration. These data suggest dexamethasone increases secretion of apo A-I by Hep G2 cells by increasing mRNA levels.