Chatzaki Ekaterini, Euthymiadis Christoforos, Kyriaki Sofia, Lambropoulou Maria, Tsaroucha Alexandra, Laftsidis Prodromos, Simopoulos Konstantinos
Department of Pharmacology, Democritus University of Thrace, Alexandroupolis, Greece.
Neuroendocrinology. 2005;82(3-4):177-84. doi: 10.1159/000091979. Epub 2006 Mar 13.
The corticotropin-releasing hormone (CRH) system, consisting of CRH and the homologue neuropeptide urocortin together with their receptors CRH(1) and CRH(2) and a specific binding protein (CRH-BP), holds the main role in mediating the response to stressful stimuli. Besides their expression in the brain, CRH peptides and receptors have been found in multiple peripheral sites. Here we investigate the expression of CRH, urocortin, CRH receptors, and CRH-BP in the wall of human normal and inflamed gallbladders, using RT-PCR and immunohistochemistry. Urocortin, but not CRH gene transcripts, was detected in RNA isolated from human gallbladder biopsy specimens. Urocortin immunoreactivity was localized in epithelial cells of the gallbladder mucosa. Gene expression of CRH(2) receptor was also detected, and the receptor protein had a localization similar to that of urocortin. Finally, CRH-BP gene expression and low levels of protein immunoreactivity were also shown. There were no differences in the expression profiles of all the above molecules between normal and inflamed tissues. In conclusion, the CRH system is present in the human gallbladder, urocortin being the major ligand expressed, possibly exerting an autocrine/paracrine biological role via activation of the CRH(2(alpha)) receptors found locally. Further study is required to enfold the biological role of these effectors in gallbladder physiology and pathogenesis.
促肾上腺皮质激素释放激素（CRH）系统由CRH及其同源神经肽尿皮质素、它们的受体CRH(1)和CRH(2)以及一种特异性结合蛋白（CRH-BP）组成，在介导对应激刺激的反应中起主要作用。除了在大脑中表达外，CRH肽和受体还在多个外周部位被发现。在此，我们使用逆转录聚合酶链反应（RT-PCR）和免疫组织化学方法，研究了CRH、尿皮质素、CRH受体和CRH-BP在人正常胆囊壁和发炎胆囊壁中的表达。从人胆囊活检标本中分离的RNA检测到了尿皮质素，但未检测到CRH基因转录本。尿皮质素免疫反应性定位于胆囊黏膜的上皮细胞中。还检测到了CRH(2)受体的基因表达，且该受体蛋白的定位与尿皮质素相似。最后，也显示了CRH-BP基因表达和低水平的蛋白免疫反应性。正常组织和发炎组织中上述所有分子的表达谱没有差异。总之，CRH系统存在于人胆囊中，尿皮质素是主要表达的配体，可能通过激活局部发现的CRH(2(α))受体发挥自分泌/旁分泌生物学作用。需要进一步研究来阐明这些效应分子在胆囊生理学和发病机制中的生物学作用。
