UC Riverside

The hypothalamic-pituitary-gonadal axis (HPG axis) plays an important role in sexual development and reproductive regulation. The hypothalamus releases gonadotropin releasing hormone (GnRH) to the pituitary gland through the hypophyseal portal system. The pituitary gland consists of a small population of a gonadotrope cell line, known as LbT2 cells. The gonadotrope cells produce the gonadotropins, follicle stimulating hormone (FSH) and luteinizing hormone (LH) which are composed of an alpha and beta subunit; the alpha subunit is encoded by the CGA gene and the beta subunits are encoded by the FSHb and LHb genes, respectively. There are some transcription factors (TF’s) such as, cAMP response element binding protein (CREB) and steroidogenic factor (SF-1), that have an influence on the production of gonadotropins. Additionally, a few of the GATA transcription factors, including GATA-2 and GATA-4, play a role in embryonic development and reproduction. The regulation of the HPG axis, specifically gonadotropin secretion, is an important topic as minor alterations in the endocrine loop can result in reproductive dysfunction. The goal of this study is to use the gonadotrope cell line, LbT2 cells, to determine if the secretion of GnRH has an effect on the expression of transcription factors like SF-1, CREB-1, GATA-2,GATA-3, and GATA-4, which regulate FSHb or LHb transcription.