SF-1-Key Mediator of Endocrine Development and Function

描述（由申请人提供）：孤儿核受体甾体生成因子1 （SF-1）在内分泌发育和功能中起重要作用。SF-1基因敲除（KO）小鼠表现出肾上腺和性腺发育不全，垂体促性腺功能受损，下丘脑腹内侧核（VMH）结构明显异常，下丘脑腹内侧核是与能量稳态和生殖行为相关的下丘脑区域。正在进行的研究试图扩大我们对SF-1的这些多效作用的理解，特别关注VMH。首先，我们将检查VMH特异性SF-1 KO小鼠的表型，使我们能够描述SF-1在VMH神经元中的主要作用。我们还将使用一种由SF-1调控序列引导的转基因增强绿色荧光蛋白（eGFP）报告基因，在下丘脑切片制备中体外跟踪表达SF-1的神经元，比较野生型和SF-1 KO小鼠的神经元迁移和VMH发育。SF-1/eGFP谱系标记也将用于从野生型和SF-1 KO小鼠的VMH中特异性地纯化表达SF-1的神经元（无论是全局的还是VMH特异性的），使我们能够比较在SF-1存在或不存在的情况下相同细胞的基因表达谱。我们将检测VMH中SF-1的候选靶基因，以确定它们是否在神经元转染实验中是SF-1的直接靶基因。最后，靶向eGFP表达的SF-1序列将用于靶向VMH中涉及体重调节的许多基因产物，使我们能够特异性地挽救VMH中的表达。待检测的分子包括瘦素受体、黑素皮质素3受体（MC3-R）和tubby。这些研究将为SF-1在VMH发育和功能中发挥其重要作用的方式提供新的见解。

DESCRIPTION (provided by applicant): The orphan nuclear receptor steroidogenic factor 1 (SF-1) plays essential roles in endocrine development and function. SF-1 knockout (KO) mice exhibit adrenal and gonadal agenesis, impaired pituitary gonadotrope function, and marked structural abnormalities of the ventromedial hypothalamic nucleus (VMH), a hypothalamic region linked to energy homeostasis and reproductive behavior. Ongoing studies seek to expand our understanding of these pleiotropic roles of SF-1, focusing specifically on the VMH. First, we will examine the phenotype of VMH-specific SF-1 KO mice, allowing us to delineate primary roles of SF-1 within VMH neurons. We also will use a transgenic enhanced green fluorescent protein (eGFP) reporter gene directed by SF-1 regulatory sequences to follow SF-1-expressing neurons ex vivo in hypothalamic slice preparations, comparing neuronal migration and VMH development in wild-type and SF-1 KO mice. The SF-1/eGFP lineage marker also will used to purify SF-1-expressing neurons specifically from the VMH of wild-type and SF-1 KO mice (either global or VMH-specific), allowing us to compare the gene expression profiles of the same cells in the presence or absence of SF-1. Candidate target genes of SF-1 in the VMH will be examined to determine if they are direct targets of SF-1 in neuronal transfection experiments. Finally, the SF-1 sequences that targeted eGFP expression will be used to target to the VMH a number of gene products implicated in body weight regulation, allowing us to rescue expression specifically in the VMH. Molecules to be examined include the leptin receptor, the melanocortin 3 receptor (MC3-R), and tubby. These studies will provide novel insights into the ways in which SF-1 exerts its essential actions in VMH development and function.