Novel Molecular Markers Governing Obesity in the Ventromedial Hypothalamus

描述(由申请人提供)： 在美国，儿童和青少年肥胖是一个严重的健康问题。在过去的20年里，它的患病率增加了10倍。几乎15%的2到18岁的儿童现在超重(BMI&GT；年龄和性别的95个百分位数)。日益增长的肥胖趋势给我们的社会带来了巨大的健康和经济负担。肥胖症的机制很复杂，而且还没有完全阐明。肥胖涉及到无数环境和遗传因素之间的复杂相互作用。大脑中的下丘脑对食物摄入量和能量平衡的调节和维持至关重要。在下丘脑中，下丘脑腹内侧核(VMH)是一个关键的饱腹感中枢。当啮齿类动物的VMH被破坏时，它们会变得过度吞噬和肥胖。了解VMH功能的分子机制对肥胖的研究至关重要；然而，由于缺乏明确的VMH标志物，VMH的研究一直受到阻碍。到目前为止，类固醇生成因子(SF-1)是VMH神经元唯一的特异性标志物，对VMH神经元的终末分化至关重要。我们的实验室利用基因图谱和微阵列分析鉴定了一系列新的富含VMH的基因。我的研究计划的总体目标是了解VMH在能量动态平衡方面的生物学。该方法是研究新的VMH富含基因的功能。其具体目的是：第一，通过评估新的转录因子前脑胚胎锌指(FEZ)的作用及其与SF-1的相互作用，研究VMH的发育；第二，通过检测囊泡谷氨酸转运体2(VGLUT2)的作用以及选择性地将其从VMH中移除时，研究VMH的兴奋功能；以及第三，通过识别孕期营养不良或营养过剩的雌性幼崽中差异表达的基因，研究VMH的适应和表观遗传功能。这些研究将使用稳定的细胞系和具有正常、转基因和条件性基因敲除背景的小鼠进行。用于完成这些项目的研究技术将包括标准的分子生物学和遗传学技术，包括细胞培养、原位杂交和免疫细胞化学、转基因技术和微阵列分析。这项研究将促进我作为一名独立内科科学家的培训，并确定在管理儿童肥胖症方面潜在的治疗和预防方法。了解VMH的功能和机制将有助于我们了解下丘脑是如何控制某些营养障碍的，如肥胖、II型糖尿病以及其他复杂的人类行为，从神经性厌食症到性别焦虑症。

DESCRIPTION (provided by applicant): Childhood and adolescent obesity is a significant health problem in the United States. Its prevalence has increased 10 fold in the last 20 years. Almost 15% of children between 2 and 18 years old are now overweight (BMI > 95th percentile for age and gender). The increasing trend of obesity places a significant health and economic burden in our society. Mechanisms governing obesity are complex and not fully elucidated. Obesity involves a complex interaction among a myriad of environmental and genetic factors. The hypothalamus in the brain is critical to the regulation and maintenance of food intake and energy balance. Within the hypothalamus, a key center for satiety is the ventromedial hypothalamic nucleus (VMH). When VMH is destroyed in rodent species, they become hyperphagic and obese. Understanding the molecular mechanisms of VMH function is critical to the study of obesity; however, research in the VMH has been impeded by a lack of definitive VMH markers. To date, steroidogenic factor (sf-1) is the only specific marker for VMH neurons and is critical for the terminal differentiation of VMH neurons. Our laboratory has identified a list of novel VMH-enriched genes with the use of gene profiling and microarray analysis. The overall goal of my research proposal is to understand the biology of the VMH in energy homeostasis. The approach is to study the function of novel VMH-enriched genes. The specific aims are first, to study the development of the VMH by evaluating the role of a novel transcription factor, forebrain embryonic zinc-finger (fez), and its interaction with sf-1; second, to study the excitatory function of the VMH by examining the role of vesicular glutamate transporter 2 (VGLUT2) and its impact on food intake and body weight when it is selectively removed from the VMH; and third, to examine the adaptive and epigenetic function of the VMH by identifying genes that are differentially expressed in pups born to females that are undernourished or overnourished during pregnancy. The studies will be performed with stable cell lines and mice of normal, transgenic, and conditional knockout background. The research techniques used to accomplish these projects will include standard molecular biology and genetics techniques, including cell culture, in situ hybridization and immunocytochemistry, transgenic technologies, and microarray analysis. This research will facilitate my training as an independent physician scientist as well as identifying potential therapeutic and preventative approaches in managing childhood obesity. Understanding the function and mechanism of the VMH will help us to understand how the hypothalamus controls certain nutritional disorders, such as obesity, and type II diabetes, as well as other complex human behaviors, ranging from anorexia nervosa to gender dysphoria.