11β-Hydroxysteroid dehydrogenase 1 activity and gene expression in human adipose stromal cells: Effect on aromatase activity
11β-Hydroxysteroid dehydrogenase 1 activity and gene expression in human adipose stromal cells: Effect on aromatase activity
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DOI：
10.1016/s0960-0760(96)00187-2
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发表时间：
1997-02
期刊：
影响因子：
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通讯作者：
Kaiping Yang;M. Khalil;B. Strutt;D. Killinger
中科院分区：
文献类型：
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作者：
Kaiping Yang;M. Khalil;B. Strutt;D. Killinger
糖皮质激素在靶组织中的生物活性可受局部产生的11β-羟基类固醇脱氢酶（11β-HSD）的影响，该酶负责皮质醇及其非活性代谢物可的松的相互转化。在人类脂肪基质细胞中，糖皮质激素是雄激素转化为雌激素（芳香化酶活性）的有效刺激物。本研究旨在确定11β-HSD活性是否存在于人脂肪基质细胞中，以及该酶活性的变化是否会影响芳香化酶活性。通过放射性转换测定法测定6例患者乳腺脂肪组织中的11β-HSD活性。结果发现，脱氢酶（皮质醇到可的松）和还原酶（可的松到皮质醇）的活动都存在于所有六个科目，还原酶的活动总是占主导地位。甘珀酸（CBX）是11β-HSD的有效抑制剂，以50和200 μM加入到培养基中，导致11β-HSD还原酶和脱氢酶活性分别抑制39 ± 4%和85 ± 1%。为了确定11β-HSD的改变是否会影响芳香化酶活性，检查了CBX（200 μM）对皮质醇和可的松诱导的雄烯二酮转化为雌酮的变化的影响。CBX阻止了可的松的刺激作用，并最低限度地增强了皮质醇对芳香酶活性的刺激作用，分别反映了对可的松的局部激活和皮质醇的局部代谢的抑制。为了确定11β-HSD 1基因的产物是否与观察到的11β-HSD活性有关，使用人11β-HSD 1 cDNA作为探针对来自这些细胞的总RNA提取物进行北方印迹分析。检测到一个单一的1.811 β-HSD 1转录本，其丰度被CBX降低。未检测到11β-HSD 2 mRNA。目前的结果表明，11β-HSD 1基因在人乳腺脂肪基质细胞中表达并发挥功能，并且11β-HSD 1活性的变化导致芳香化酶活性的改变。
The biological activity of glucocorticoids in target tissues can be influenced by locally produced 11β-hydroxysteroid dehydrogenase (11β-HSD), the enzyme responsible for the interconversion of cortisol and its inactive metabolite cortisone. In human adipose stromal cells, glucocorticoids are potent stimulators of the conversion of androgens to estrogens (aromatase activity). The present study was designed to determine whether 11β-HSD activity was present in human adipose stromal cells, and if changes in the activity of this enzyme could influence aromatase activity. 11β-HSD activity was determined by a radiometric conversion assay in breast adipose tissue from six patients. It was found that both dehydrogenase (cortisol to cortisone) and reductase (cortisone to cortisol) activities were present in all six subjects, and the reductase activity was always predominant. Carbenoxolone (CBX), a potent inhibitor of 11β-HSD, added to the culture medium at 50 and 200 μM, resulted in 39 ± 4% and 85 ± 1% inhibition, respectively, of both reductase and dehydrogenase activity of 11β-HSD. To determine whether alterations in 11β-HSD could influence aromatase activity, the effect of CBX (200 μM) on cortisol- and cortisone-induced changes in the conversion of androstenedione to estrone was examined. CBX prevented the stimulatory effect of cortisone and minimally potentiated the stimulatory effect of cortisol on aromatase activity, reflecting an inhibition of the local activation of cortisone and the local metabolism of cortisol, respectively. In order to determine whether the product of the 11β-HSD 1 gene was responsible for the observed 11β-HSD activity, total RNA extracts from these cells were subjected to Northern blot analysis using human 11β-HSD 1 cDNA as the probe. A single 1.8 11β-HSD 1 transcript was detected, and its abundance was reduced by CBX. No 11β-HSD 2 mRNA was detected. The present results demonstrate that the 11β-HSD 1 gene is expressed and functional in human breast adipose stromal cells and that changes in 11β-HSD 1 activity result in alterations in aromatase activity.