Bouraïma-Lelong Hélène, Vanneste Marion, Delalande Christelle, Zanatta Leïla, Wolczynski Slawomir, Carreau Serge
Université de Caen Basse-Normandie, EA 2608, 14032 Caen, France.
Reprod Fertil Dev. 2010;22(3):508-15. doi: 10.1071/RD09168.
Aromatase, the enzyme responsible for the transformation of androgens into oestrogens, is encoded by the cyp19 gene expressed in the testis. The aim of the present study was to analyse the evolution of aromatase gene expression under FSH control in rat Sertoli cells between 10 and 30 days post partum, corresponding to the end of the proliferative period of Sertoli cells, establishment of the blood-testis barrier and acquisition of the mature phenotype. The maximum stimulatory effect of FSH on aromatase gene expression was obtained in 20-day-old rat Sertoli cells, compared with cells from 10- and 30-day-old rats, in parallel with the differentiation of Sertoli cells. Using two effectors of the protein kinase A pathway (i.e. forskolin and dibutyryl-cAMP) revealed differential effects between cells from rats aged 20 and 30 days, implying the involvement of another signalling pathway. Experiments using the specific phosphatidylinositol 3-kinase (PI3-K) inhibitor LY294002 revealed that PI3-K is strongly involved in FSH-induced aromatase expression in Sertoli cells from both 20- and 30-day-old rats. In vivo, this decrease could be explained by a negative effect exerted by germ cells because, in coculture, aromatase gene expression in 20-day-old Sertoli cells is greatly diminished.
芳香化酶是一种负责将雄激素转化为雌激素的酶，由睾丸中表达的cyp19基因编码。本研究的目的是分析产后10至30天大鼠支持细胞中芳香化酶基因表达在促卵泡激素（FSH）控制下的演变情况，这一时期对应支持细胞增殖期结束、血睾屏障建立以及成熟表型的获得。与10日龄和30日龄大鼠的支持细胞相比，FSH对20日龄大鼠支持细胞中芳香化酶基因表达的刺激作用最大，这与支持细胞的分化情况平行。使用蛋白激酶A途径的两种效应物（即福斯可林和二丁酰环磷腺苷）揭示了20日龄和30日龄大鼠细胞之间的差异效应，这意味着另一种信号通路的参与。使用特异性磷脂酰肌醇3激酶（PI3-K）抑制剂LY294002的实验表明，PI3-K在20日龄和30日龄大鼠支持细胞中FSH诱导的芳香化酶表达中均发挥重要作用。在体内，这种下降可能是由于生殖细胞产生的负面影响所致，因为在共培养中，20日龄支持细胞中的芳香化酶基因表达会大幅降低。
