Department of Structure, Functions and Biological Technologies, University of Naples Federico II, Via Veterinaria 1, 80137 Naples, Italy.
Cell Tissue Res. 2012 Oct;350(1):45-53. doi: 10.1007/s00441-012-1450-4. Epub 2012 Jun 12.
Urocortin (UCN) is a 40-amino-acid peptide and a member of the corticotropin-releasing hormone (CRH) family, which includes CRH, urotensin I, sauvagine, UCN2 and UCN3. The biological actions of CRH family peptides are mediated via two types of G-protein-coupled receptors, namely CRH type 1 receptor (CRHR1) and CRH type 2 receptor (CRHR2). The biological effects of these peptides are mediated and modulated not only by CRH receptors but also via a highly conserved CRH-binding protein (CRHBP). Our aim was to investigate the expression of UCN, CRHR1, CRHR2 and CRHBP by immunohistochemistry, Western blot and reverse transcription with the polymerase chain reaction (RT-PCR) in the horse thyroid gland. The results showed that UCN, CRHR1 and CRHR2 were expressed in the thyroid gland, whereas CRHBP was not expressed. Specifically, UCN immunoreactivity (-IR) was found in the thyroid follicular cells, CRHR2-IR in the C-cells and CRHR1-IR in blood vessels. Western blot analysis and RT-PCR experiments confirmed the immunohistochemical data. These results suggest that a regulatory system exists in the mammalian thyroid gland based on UCN, CRHR1 and CRHR2 and that UCN plays a role in the regulation of thyroid physiological functions through a paracrine mechanism.
尿皮质素（UCN）是一种 40 个氨基酸的肽，是促肾上腺皮质激素释放激素（CRH）家族的成员，该家族还包括 CRH、尾加压素 I、沙蟾肽、UCN2 和 UCN3。CRH 家族肽的生物学作用是通过两种类型的 G 蛋白偶联受体介导的，即 CRH 受体 1（CRHR1）和 CRH 受体 2（CRHR2）。这些肽的生物学效应不仅通过 CRH 受体介导和调节，还通过高度保守的 CRH 结合蛋白（CRHBP）介导和调节。我们的目的是通过免疫组织化学、Western blot 和逆转录聚合酶链反应（RT-PCR）检测 UCN、CRHR1、CRHR2 和 CRHBP 在马甲状腺中的表达。结果表明，UCN、CRHR1 和 CRHR2 在甲状腺中表达，而 CRHBP 则不表达。具体而言，UCN 免疫反应性（-IR）存在于甲状腺滤泡细胞中，CRHR2-IR 存在于 C 细胞中，CRHR1-IR 存在于血管中。Western blot 分析和 RT-PCR 实验证实了免疫组织化学数据。这些结果表明，哺乳动物甲状腺中存在基于 UCN、CRHR1 和 CRHR2 的调节系统，UCN 通过旁分泌机制在调节甲状腺生理功能中发挥作用。
