Busto R, Carrero I, Zapata P, Colás B, Prieto J C
Department of Biochemistry and Molecular Biology, University of Alcalá, Alcalá de Henares, Spain.
Endocr Res. 2000 Aug;26(3):477-86. doi: 10.3109/07435800009066181.
A new line (FP) of human foetal lung fibroblasts was analysed for the expression of functional, G-protein coupled somatostatin receptors (SSTR). By means of RT-PCR, we identified the expression of SSTR1, SSTR2, SSTR3 and SSTR4, but not SSTR5, subtypes. The same technical approach evidenced the expression of stimulatory (alphas) and inhibitory (alphai1, alphai2 and alphai3) G-protein subunits. The functionality of SSTR was established from the observation of a dose-dependent inhibitory role of SST upon isoproterenol-stimulated adenylyl cyclase activity, an effect that involves G-protein action. Moreover, the functionality of G-proteins was assessed by means of experiments with forskolin and a nonhydrolysable GTP analogue that showed either Gi or Gs activation in the regulation of adenylyl cyclase. Present results represent a first pharmacological characterization of this new line of human foetal lung fibroblasts. The selective presence of some SSTR subtypes and G-protein subunits in addition to the regulatory network of the adenylyl cyclase pathway are features of recognized involvement in cell growth mechanisms. It is of interest for a cell class widely used to study this topic but also important in lung physiology and pathophysiology.
对人胎儿肺成纤维细胞的一个新细胞系（FP）进行了功能性G蛋白偶联生长抑素受体（SSTR）表达分析。通过逆转录聚合酶链反应（RT-PCR），我们鉴定出了SSTR1、SSTR2、SSTR3和SSTR4亚型的表达，但未发现SSTR5亚型的表达。同样的技术方法证实了刺激性（αs）和抑制性（αi1、αi2和αi3）G蛋白亚基的表达。SSTR的功能是通过观察生长抑素（SST）对异丙肾上腺素刺激的腺苷酸环化酶活性的剂量依赖性抑制作用而确定的，这一效应涉及G蛋白的作用。此外，通过使用福斯可林和一种不可水解的GTP类似物进行实验来评估G蛋白的功能，实验表明在腺苷酸环化酶的调节中，Gi或Gs被激活。目前的结果代表了对这个人胎儿肺成纤维细胞新细胞系的首次药理学特征描述。除了腺苷酸环化酶途径的调节网络外，某些SSTR亚型和G蛋白亚基的选择性存在是公认参与细胞生长机制的特征。这对于广泛用于研究该主题的细胞类型来说很有意义，而且在肺生理学和病理生理学中也很重要。
