Regulation of cytochrome P450 aromatase gene expression in adult rat Leydig cells: comparison with estradiol production
Regulation of cytochrome P450 aromatase gene expression in adult rat Leydig cells: comparison with estradiol production
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DOI：
10.1677/joe.0.1680095
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发表时间：
2001-01-01
影响因子：
4
通讯作者：
Carreau, S
中科院分区：
文献类型：
--
作者：
Genissel, C;Levallet, J;Carreau, S
芳香化酶基因在纯化的大鼠Leydig细胞中的表达调控尚未被研究。因此，我们使用一种高度特异性的定量RT-PCR方法，测定了细胞色素P450芳香化酶（P450 arom）mRNA的量和芳香化酶活性在成熟大鼠Leydig细胞提交的各种处理24小时。在睾酮的存在下，雌二醇的产生以剂量相关的方式增强，在200 ng/ml时获得最大值（增加28%）。与P450 arom mRNA水平相关，在低浓度（50和100 ng/ml）睾酮存在下观察到降低，然后在较高浓度（200-500 ng/ml）下记录到转录物的量增加20%。在存在5 α-二氢睾酮（一种对芳香酶活性有抗性的雄激素）的情况下获得了相同的结果。向Leydig细胞培养基中加入绵羊LH（oLH; 0.1-50 ng/ml）可诱导雌二醇产量呈剂量相关性增加，最高可达10 ng/ml oLH，但与最大值相比，50 ng/ml时观察到雌二醇产量下降。在低浓度（0.1-1 ng/ml）oLH存在下，mRNA水平略有下降，添加睾酮可消除这种效应;在不存在和存在睾酮的情况下，oLH（5-10 ng/ml）分别使mRNA水平增加35%和75%（与未处理的Leydig细胞相比）。与50 ng/ml的oLH，一个大的增强（两倍）的P450 arom mRNA水平，无论是没有或有睾酮观察。二丁酰环AMP（1 mM）模拟oLH的作用。与未处理的半衰期（5.8 +/- 0.6 h）相比，在睾酮和oLH存在下，P450 arom mRNA的半衰期增加了两倍。总之，我们的数据表明，在新鲜分离的成熟大鼠睾丸间质细胞中，芳香化酶的表达和酶活性的调节是在LH（通过环AMP）和类固醇控制下，此外，曲细精管分泌因子（S）也参与其中。因此，大鼠Leydig细胞芳香化酶在转录和转录后步骤由内分泌和/或局部产生的调节剂控制。
Regulation of aromatase gene expression in purified rat Leydig cells has not yet been investigated. Therefore, using a highly specific quantitative RT-PCR method, we have measured the amount of cytochrome P450 aromatase (P450arom) mRNA and aromatase activity in mature rat Leydig cells submitted to various treatments during 24 h. Estradiol production was enhanced in a dose-related manner in the presence of testosterone, the maximum (28% increase) being obtained with 200 ng/ml. Related to the P450arom mRNA levels, a decrease was observed in the presence of low concentrations (50 and 100 ng/ml) of testosterone, then a 20% increase of the amount of transcripts was recorded for the higher concentrations (200-500 ng/ml). The same result was obtained in the presence of 5 alpha -dihydrotestosterone (an androgen resistant to aromatase activity). The addition of ovine LH (oLH; 0.1-50 ng/ml) to the Leydig cell culture medium induced a dose-related augmentation of estradiol output up to 10 ng/ml oLH, although a decrease was observed with 50 ng/ml when compared with maximal values. mRNA levels slightly decreased in the presence of low concentrations (0.1-1 ng/ml) of oLH, an effect that was abolished by the addition of testosterone; mRNA levels were increased by oLH (5-10 ng/ml) 35 and 75% respectively in the absence and presence of testosterone (when compared with Leydig cells incubated without treatment). With 50 ng/ml oLH, a large augmentation (twofold) of the P450arom mRNA level either without or with testosterone was observed. Dibutyryl cyclic AMP (1 mM) mimicked the effect of oLH. The half-life of the P450arom mRNAs was twofold increased in the presence of testosterone and oLH when compared with the half-life in the absence of treatment (5.8 +/- 0.6 h). Taken together, our data have demonstrated that, in freshly isolated Leydig cells from mature rat testes, the regulation of aromatase expression and enzymatic activity is under LH (through cyclic AMP) and steroid control; moreover seminiferous tubule-secreted factor(s) are also involved. Therefore, rat Leydig cell aromatase is controlled at both transcriptional and post-transcriptional steps by endocrine and/or locally produced modulators.