Karteris E, Papadopoulou N, Grammatopoulos D K, Hillhouse E W
Molecular Medicine, Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, UK.
J Mol Endocrinol. 2004 Feb;32(1):21-32. doi: 10.1677/jme.0.0320021.
Corticotrophin-releasing hormone (CRH) has been identified in several peripheral tissues, including the female reproductive organs. CRH is expressed in the placenta, myometrium, epithelial endometrium and the endometrial stromal cells at all phases of the menstrual cycle. Similarly, CRH receptors are present in pregnant and non-pregnant myometrium, placenta and endometrium. Putative roles of CRH in the endometrium include involvement in implantation, decidualisation and maintenance of pregnancy. In this study we sought to investigate in detail the CRH receptor repertoire expressed in the human endometrium and their signalling characteristics. Using RT-PCR we were able to demonstrate the expression of CRH receptor 1alpha (CRH-R1alpha) and CRH-R2alpha in the human endometrium. CRH-R1beta was present in 40% of endometrial cDNAs examined. No apparent expression of CRH-R2beta, CRH-R2gamma or any other CRH-R1 splice variants was detected. Chemical cross-linking studies with 125I-ovine CRH revealed that the endometrial CRH receptor has a molecular weight of 45 kDa. Using the non-hydrolysable photoreactive analogue [alpha-32P]GTP-azidoanilide and peptide antisera raised against G-protein alpha-subunits, we then studied coupling of endometrial CRH receptors to G proteins. Treatment of endometrial membranes with human CRH (100 nM) increased the labelling of Gq and Gs, but not Gi or Go. These results were supported by experiments in epithelial cells of the non-pregnant human endometrium in the secretory phase which showed that CRH induced increases in both cAMP and inositol trisphosphate levels. These results suggested that CRH may exert multiple effects in the human endometrium via distinct signalling cascades. These events are possibly mediated via different receptor subtypes.
促肾上腺皮质激素释放激素（CRH）已在包括女性生殖器官在内的多个外周组织中被鉴定出来。CRH在月经周期的各个阶段均表达于胎盘、子宫肌层、子宫内膜上皮及子宫内膜基质细胞中。同样，CRH受体存在于妊娠及非妊娠的子宫肌层、胎盘和子宫内膜中。CRH在子宫内膜中的假定作用包括参与着床、蜕膜化及维持妊娠。在本研究中，我们试图详细研究人子宫内膜中表达的CRH受体库及其信号转导特征。利用逆转录聚合酶链反应（RT-PCR），我们能够证明人子宫内膜中促肾上腺皮质激素释放激素受体1α（CRH-R1α）和CRH-R2α的表达。在所检测的40%的子宫内膜cDNA中存在CRH-R1β。未检测到CRH-R2β、CRH-R2γ或任何其他CRH-R1剪接变体的明显表达。用125I-羊CRH进行的化学交联研究表明，子宫内膜CRH受体的分子量为45 kDa。然后，我们使用不可水解的光反应类似物[α-32P]GTP-叠氮苯胺和针对G蛋白α亚基产生的肽抗血清，研究子宫内膜CRH受体与G蛋白的偶联。用人CRH（100 nM）处理子宫内膜膜增加了Gq和Gs的标记，但未增加Gi或Go的标记。这些结果得到了分泌期非妊娠人子宫内膜上皮细胞实验的支持，该实验表明CRH诱导cAMP和肌醇三磷酸水平均升高。这些结果表明，CRH可能通过不同的信号级联在人子宫内膜中发挥多种作用。这些事件可能是通过不同的受体亚型介导的。
