Control of the expression of gonadotropine receptor

FSH是维持FSH和LH受体在升高的稳态水平后，受体诱导在颗粒细胞的diesthystillbesterol（DES）引发的未成熟大鼠。为探讨卵泡刺激素（FSH）依赖性诱导和维持大鼠颗粒细胞LH受体（LH R）表达的机制，研究了FSH和某些局部因素对颗粒细胞LH R mRNA水平的影响。为了研究LH-R的转录调控，我们分离了大鼠LH-R基因的5'侧翼区，并将核苷酸-1（相对于翻译起始密码子）至-1379亚克隆到荧光素酶报告质粒中。用8-Br-cAMP和ESH处理LH-R 5'侧翼区1379 bp的活性，并呈剂量依赖性。这些数据清楚地表明，FSH（由CAMP介导）刺激诱导的LH-R在颗粒细胞的DES引发的未成熟大鼠，至少部分，通过增加LH-R基因的转录速率。在FSH存在下，IGF-1可增强FSH受体mRNA的表达，提示IGF-1是维持颗粒细胞LH受体水平的重要因素之一。

FSH is required to maintain FSH and LH receptor at elevated steady state levels after receptor induction in the granulosa cells of diesthystillbesterol (DES)-primed immature rats. To identify the mechanisms underlying the hormone-dependent induction and maintenance of LH receptor (LH-R) in rat granulosa cells, the effect of FSH and some local factors on the LH-R mRNA levels were studied. In order to study the transcriptional regulation of the LH-R, we have isolated a 5' -flanking region of the rat LH-R gene and subcloned nucleotide -1 (relative to the translational initiation codon) to -1379 into a luciferase reporter plasmid. Treatment with 8-Br-cAMP and ESH significantly enhanced activity of 1379 bp of LH-R 5' -flanking region in a dose dependent manner. This data clearly demonstrates that FSH (mediated by CAMP) stimulates the induction of the LH-R in granulosa cells of DES-primed immature rats, at least in part, through increasing the rate of transcription of the LH-R gene. in the presence of FSH, IGF-1 augments FSH receptor mRNA.These results show that IGF-1 is one of the important factors that act in the medium to maintain LH-R levels in granulosa cells.