CHARACTERIZATION OF GONADOTROPIN SECRETING CELL LINES

生殖内分泌学领域一直在努力研究促性腺激素β亚基基因调控的许多方面，这在很大程度上是由于缺乏分化良好的β亚基表达细胞系。LbetaT2细胞系被证明能够表达和分泌LH(1)，现在又被证明能够表达和分泌FSH(2)，第二种细胞系FSHtsT5细胞系也能分泌FSH。这两个细胞系是第一个表达所有三种促性腺激素基因的细胞系，初步研究表明它们对这些基因表现出不同的调节。然而，这两种细胞系用于研究促性腺激素基因的适用性取决于它们如何很好地再现正常的促性腺激素生理，这一点尚未确定。我们假设LbetaT2和FSHtsT5细胞系的细胞保留了分化性腺功能的元素，并提出将它们作为成熟分化性腺功能的模型进行评估。我们计划测量它们的促性腺激素特异性基因的表达，这些基因对促性腺激素亚单位的表达很重要，包括激活素、抑制素、卵泡抑素及其受体。这不仅证实了它们在LH和FSH研究中的适用性，而且也证实了激活素的细胞内信号传导和这些性腺肽之间复杂的相互作用的研究。我们还建议评估这些细胞系对已知的促性腺功能激活剂的反应，包括GnRH、激活素、抑制素和性腺类固醇。这是对lhβ、fshβ和α -亚单位的差异调节和分泌的因素进行更复杂研究的必要基础。此外，本项目还将与K08-DK 02477一起支持首席研究员的职业发展计划，为持续的科学生产力和进一步的专业研究技术培训提供技术支持。

The field of reproductive endocrinology has struggled with many aspects of the regulation of the gonadotropin beta subunit genes, in large part due to the lack of a well-differentiated beta-subunit expressing cell line. The development of the LbetaT2 cell line which was demonstrated to express and secrete LH (1) has now been shown to also express and secrete FSH(2) and a second cell line, the FSHtsT5 line, secretes FSH as well. These two cell lines are the first to express all three gonadotropin genes and preliminary studies indicate that they exhibit differential regulation of those genes. However, the applicability of these two cells lines to study of the gonadotropin genes is dependent upon how well they recapitulate normal gonadotroph physiology and that has not yet been established. We hypothesize that cells of the LbetaT2 and FSHtsT5 lines retain elements of differentiated gonadotroph function and propose to evaluate them as models of mature, differentiated gonadotrophs. We plan on measuring their expression of gonadotroph-specific genes important for the expression of the gonadotropin subunits including activin, inhibin, follistatin and their receptors. This will not only confirm their appropriateness for study of LH and FSH, but also the study of the intracellular signalling of activin and the complex interactions between these gonadal peptides. We also propose to evaluate the response of these cell lines to known activators of gonadotroph function including GnRH, activin, inhibin, and the gonadal steroids. This is essential groundwork for more complex studies of factors which contribute to the differential regulation and secretion of LHbeta, FSHbeta and alpha-subunit. In addition, this project supports the Principal Investigator's Career Development Plan in conjuction with K08-DK 02477 with technical support for continued scientific productivity and further specialized research technique training.