AMINO ACID REGULATION OF GENE EXPRESSION IN NEURAL CELLS

充足的氨基酸（AA）营养对健康和健康至关重要- 人类和动物都一样。 由于AA没有存储池， 一个基本的AA缺乏症的发展可能会迅速发生，特别是 如果已经存在轻微的蛋白质缺乏症。 自AA以来 补充剂已经变得时尚，并且特别可能被使用， 对于节食者来说，AA失衡应该被认为是一种潜在的健康危害。 此外，患有癌症恶病质、AA代谢紊乱、 其他代谢异常也可能患有AA比例失调。 AA 已经证明缺乏会损害生长和任何身体功能 这取决于蛋白质的合成，比如伤口的愈合。 但 由于AA不平衡导致的增长减少实际上是次要的， 食物摄入减少，对AA缺乏的厌食反应。 的 这个实验室工作的长期目标是了解AA是如何 缺乏是由身体认识，以及如何表达这种缺乏 在一个现成的行为测量中，食物摄入量。 鉴于 重要的AA营养，当务之急是我们获得一个更好的 了解AA失衡影响的基本机制 摄食行为 使用AA不平衡（IMB）饮食的明确定义的营养模型是 可用于这些研究。 大脑的梨状皮质（PC） 被认为是AA缺乏症传感器的主要候选者， IMB饮食模式 摄入IMB后PC中的主要事件是 限制AA浓度的下降。 我们还确定 去甲肾上腺素，环磷酸腺苷，一氧化氮，血清素和RNA的改变 蛋白质合成可能参与了对IMB的神经反应。 然而，尽管我们已经确定这些不同的系统是 参与，我们不明白他们如何与限制AA相互作用， 对IMB的初始分子和细胞反应。 因此，主要 本研究的目的是确定分子机制 负责识别和拒绝饮食，导致 AA缺乏症 具体来说，我们将确定氨基酸如何调节 PC神经元中的基因表达。 以下三个具体目标 具体目标1：获得cDNA和基因组 克隆对应于由氨基酸缺陷调控的基因， PC，使用差异显示和消减cDNA文库。 具体目标2：进一步开发一种体外系统， PC中的氨基酸使用初级 神经元培养 具体目的3：确定tRNA氨酰化 PC神经元中的氨基酸缺乏会引起水平的变化。

Adequate amino acid (AA) nutrition is essential for the health and well- being of humans and animals alike. Because AAs have no storage pool, the development of an essential AA deficiency can occur rapidly, particularly if a mild state of protein deficiency already exists. Since AA supplements have become fashionable, and may especially be used by dieters, AA imbalance should be recognized as a potential health hazard. Moreover, individuals with cancer cachexia, disorders of AA metabolism, and other metabolic aberrancies may also suffer AA disproportion. AA deficiencies have been shown to compromise growth and any bodily function that depends on protein synthesis, such as wound healing. However, the growth reduction attributed to AA imbalance is actually secondary to the decreased food intake, an anorectic response to the AA deficiency. The long-term goal of the work in this laboratory is to understand how AA deficiency is recognized by the body, and how this deficiency is expressed in a readily available behavioral measure, food intake. Given the importance of AA nutrition, it is imperative that we gain a better understanding of the basic mechanisms by which AA imbalance affects feeding behavior. A well defined nutritional model using AA imbalanced (IMB) diets is available for these studies. The piriform cortex (PC) of the brain has been implicated as the prime candidate for the sensor of AA deficiency in the IMB-diet model. The primary event in the PC after ingestion of IMB is a drop in the concentration of the limiting AA. We have also determined that norepinephrine, cAMP, nitric oxide, serotonin and alterations in RNA and protein synthesis may be involved in the neural responses to IMB. However, although we have identified these different systems as being involved, we do not understand how they interact with the limiting AA in the initial molecular and cellular responses to IMB. Therefore, the major objective of this research is to determine the molecular mechanisms responsible for the recognition and rejection of diets that result in an AA deficiency. Specifically, we will determine how amino acids regulate gene expression in neurons of the PC. The following three Specific Aims will address these questions: SPECIFIC AIM 1: To obtain cDNA and genomic clones that correspond to genes regulated by amino acid deficiency in the PC, using both differential display and a subtracted cDNA library. SPECIFIC AIM 2: To further develop an in vitro system to dissect the complex regulation that occurs by amino acids in the PC using primary neuron cultures. SPECIFIC AIM 3: To determine if tRNA aminoacylation levels change in response to amino acid deficiency in PC neurons.