Identification of the receptors for somatostatin (SST) and cortistatin (CST) in chickens and investigation of the roles of cSST28, cSST14, and cCST14 in inhibiting cGHRH1-27NH2-induced growth hormone secretion in cultured chicken pituitary cells
Identification of the receptors for somatostatin (SST) and cortistatin (CST) in chickens and investigation of the roles of cSST28, cSST14, and cCST14 in inhibiting cGHRH1-27NH2-induced growth hormone secretion in cultured chicken pituitary cells
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DOI：
10.1016/j.mce.2014.01.001
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发表时间：
2014-03-25
影响因子：
4.1
通讯作者：
Wang, Yajun
中科院分区：
文献类型：
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作者：
Meng, Fengyan;Huang, Guian;Wang, Yajun
在脊椎动物中，生长抑素受体（SSTRs）介导生长抑素（SST）及其相关肽皮质抑素（CST）的作用。然而，在包括鸟类在内的大多数非哺乳动物脊椎动物中，这些受体的身份、功能和组织表达在很大程度上仍然未知。本研究利用RT-PCR技术从鸡脑中克隆了5个SSTRs，分别为cSSTR1、cSSTR2、cSSTR3、cSSTR4、cSSTR5。利用pgl3 - cre -荧光素酶报告系统，研究人员发现，通过cSST28、cSST14和cCST14处理，激活CHO细胞中表达的每种cSSTR，可以抑制福斯可林诱导的CHO细胞荧光素酶活性，表明所有cSSTR与Gi蛋白的功能偶联。有趣的是，在CHO细胞中表达的cSSTR1-4可以被cSST28、cSST14和cCST14高效激活，这表明它们可能是这些肽的共同受体。相比之下，cSSTR5仅能被cSST28激活，表明它是cSST28特异性受体。RT-PCR检测到cSSTRs在鸡垂体等组织中广泛表达。根据它们在垂体中的表达，Western blot分析显示，cSST28、cSST14和cCST14在培养的鸡垂体细胞中抑制cGHRH（1-27NH2）诱导的基础和新型GH分泌呈剂量依赖性（0-10 nM），表明这些肽共同参与了cSSTR(s)介导它们的抑制作用。总之，我们的研究为阐明SST/CST在鸟类中的作用奠定了分子基础，并为SST/CST在脊椎动物中的作用提供了新的见解，例如它们对垂体的保守作用。2014爱思唯尔爱尔兰有限公司版权所有。
Somatostatin receptors (SSTRs) are proposed to mediate the actions of somatostatin (SST) and its related peptide, cortistatin (CST), in vertebrates. However, the identity, functionality, and tissue expression of these receptors remain largely unknown in most non-mammalian vertebrates including birds. In this study, five SSTRs (named cSSTR1, cSSTR2, cSSTR3, cSSTR4, cSSTR5) were cloned from chicken brain by RT-PCR. Using a pGL3-CRE-luciferase reporter system, we demonstrated that activation of each cSSTR expressed in CHO cells by cSST28, cSST14 and cCST14 treatment could inhibit forskolin-induced luciferase activity of CHO cells, indicating the functional coupling of all cSSTRs to Gi protein(s). Interestingly, cSSTR1-4 expressed in CHO cells could be activated by cSST28, cSST14 and cCST14 with high potencies, suggesting that they may function as the receptors common for these peptides. In contrast, cSSTR5 could be potently activated by cSST28 only, indicating that it is a cSST28-specific receptor. Using RT-PCR, wide expression of cSSTRs was detected in chicken tissues including pituitary. In accordance with their expression in pituitary, cSST28, cSST14, and cCST14 were demonstrated to inhibit basal and novel cGHRH(1-27NH2)-induced GH secretion in cultured chicken pituitary cells dose-dependently (0-10 nM) by Western blot analysis, suggesting the involvement of cSSTR(s) common for these peptides in mediating their inhibitory actions. Collectively, our study establishes a molecular basis to elucidate the roles of SST/CST in birds and provide insights into the roles of SST/CST in vertebrates, such as their conserved actions on pituitary. (C) 2014 Elsevier Ireland Ltd. All rights reserved.