SF-1-Key Mediator of Endocrine Development and Function

描述(申请人提供)：孤儿核受体类固醇生成因子1(SF-1)在内分泌发育和功能中发挥重要作用。SF-1基因敲除(KO)小鼠表现为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，VMH是与能量平衡和生殖行为有关的下丘脑区域。正在进行的研究试图扩大我们对SF-1的这些多效性作用的理解，特别是集中在VMH上。首先，我们将研究VMH特异性SF-1KO小鼠的表型，使我们能够描绘出SF-1在VMH神经元中的主要作用。我们还将使用由SF-1调控序列指导的转基因增强型绿色荧光蛋白(EGFP)报告基因，在体外跟踪SF-1表达的神经元在下丘脑片制备的标本中，比较野生型和SF-1KO小鼠的神经元迁移和VMH发育。SF-1/EGFP谱系标记还将用于从野生型和SF-1 KO小鼠(无论是全局的还是VMH特异性的)VMH中提纯特异性表达SF-1的神经元，使我们能够比较在存在或不存在SF-1的情况下相同细胞的基因表达谱。在神经元转染实验中，将检测VMH中SF-1的候选靶基因，以确定它们是否是SF-1的直接靶基因。最后，靶向EGFP表达的SF-1序列将被用于靶向VMH的一些与体重调节有关的基因产物，使我们能够挽救VMH中的特异性表达。被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的发育和功能中发挥其基本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.