West A P, Sharpe R M, Saunders P T
MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, United Kingdom.
Biol Reprod. 1994 Apr;50(4):869-81. doi: 10.1095/biolreprod50.4.869.
Hormonal regulation of the expression of mRNA transcripts for cAMP response element-binding protein (CREB) and cAMP response element modulator (CREM) during spermatogenesis was studied in the adult rat testis. Northern analysis of CREB and CREM identified two mRNA transcripts for CREM (2.4 and 1.6 kb) and one transcript for CREB (2.0 kb). Analysis of mRNAs from isolated testicular cells by reverse transcriptase polymerase chain reaction (RT/PCR) showed that CREM mRNAs were expressed by the germ cells but not the Sertoli or interstitial cells, whereas CREB mRNA was located in germ cells, Sertoli cells, and interstitial cells. RNA was isolated and analyzed from the testes of 1) rats treated for 24 h with FSH, 2) rats in which androgen withdrawal had been induced by ethane dimethane sulphonate (EDS) treatment 6 days earlier (EDS-treated), 3) EDS-treated rats supplemented with testosterone (EDS + T), or 4) intratesticular administration or dibutyryl cAMP (dbcAMP) in the preceding 24 h. CREM mRNA transcript expression was found to be decreased after all of these treatments in samples from intact testis and from isolated cells. Expression of the CREB transcript was also decreased by EDS-induced androgen withdrawal, but not by FSH or EDS + T. In situ hybridization of paraffin-embedded testis sections probed with digoxigenin-labeled riboprobes confirmed the localization of CREB and CREM mRNA to the same cell types as found with RT/PCR. No stage-dependent expression of CREM mRNA transcripts could be observed. Hybridization of the CREB probe was highest around the base of stage VII-VIII tubules, and this was shown to be androgen-dependent. The data presented suggest that regulation of the expression of CRE-binding protein mRNAs in Sertoli and germ cells during spermatogenesis is dependent on both androgen and FSH. However, the effects of androgen or FSH on the regulation of CRE-binding protein mRNAs are different.
在成年大鼠睾丸中研究了精子发生过程中促性腺激素释放激素（GnRH）、促卵泡激素（FSH）、促黄体生成素（LH）对环磷酸腺苷反应元件结合蛋白（CREB）和环磷酸腺苷反应元件调节剂（CREM）mRNA转录物表达的激素调节。对CREB和CREM的Northern分析鉴定出两种CREM的mRNA转录物（2.4和1.6 kb）和一种CREB的转录物（2.0 kb）。通过逆转录聚合酶链反应（RT/PCR）对分离的睾丸细胞的mRNA分析表明，CREM mRNA由生殖细胞表达，而不是支持细胞或间质细胞，而CREB mRNA位于生殖细胞、支持细胞和间质细胞中。从以下大鼠的睾丸中分离并分析RNA：1）用FSH处理24小时的大鼠；2）6天前用乙烷二甲磺酸盐（EDS）处理诱导雄激素撤退的大鼠（EDS处理组）；3）补充睾酮的EDS处理大鼠（EDS + T）；或4）在之前24小时内进行睾丸内注射二丁酰环磷酸腺苷（dbcAMP）的大鼠。发现在完整睾丸和分离细胞的样品中，所有这些处理后CREM mRNA转录物表达均降低。CREB转录物的表达也因EDS诱导的雄激素撤退而降低，但不受FSH或EDS + T的影响。用洋地黄毒苷标记的核糖探针探测石蜡包埋的睾丸切片的原位杂交证实，CREB和CREM mRNA定位于与RT/PCR相同的细胞类型。未观察到CREM mRNA转录物的阶段依赖性表达。CREB探针的杂交在VII-VIII期小管基部周围最高，并且显示这是雄激素依赖性的。所呈现的数据表明，精子发生过程中支持细胞和生殖细胞中CRE结合蛋白mRNA表达的调节取决于雄激素和FSH。然而，雄激素或FSH对CRE结合蛋白mRNA调节的作用是不同的。
