EFFECT OF DIETARY RESTRICTION ON GENE EXPRESSION

描述(调查人员摘要)：饮食限制，即 限制总热量，是增加热量的唯一有效方法 哺乳动物的最大存活率，据信 存活是由于衰老过程的改变。因此， 饮食限制是研究生物生物学的有力工具 衰老过程的机制和营养对衰老的影响 老化过程。几年前，申请人提出了饮食 限制作用于基因表达水平。在过去 三年来，申请人的实验室已经证明了饮食限制 改变与年龄相关的多种信使核糖核酸水平的变化 从大鼠的几个组织中提取，并且mRNA水平的变化是 与核转录的改变相平行。因此，他已经展示了 饮食限制确实改变了基因的表达，而且这 改变主要发生在转录水平上。目的 这项建议中描述的研究是为了阐明分子 饮食限制改变转录的机制 基因。具体地说，申请者将检验以下假设： 饮食限制引起的转录变化是由于 特定转录因子的水平/活性的变化 调节特定基因的转录。这一假设将是 通过研究热休克蛋白HSP的基因表达进行测试 70，在饲养的雄性Fisher F344大鼠肝细胞或淋巴细胞中 自由饮食或卡路里限制饮食(喂食大鼠饮食的60% 随意性)。本文件中描述的研究的具体目标 建议如下：(1)表征老龄化的影响和 饮食限制对HSP70表达的诱导(合成，mRNA 水平和转录)，通过热休克和重金属，并到 青年和老年人单个细胞热休克蛋白70的表达特征 自由采食和限食大鼠原位杂交；(2) 为了描述衰老和饮食限制对健康的影响 热休克蛋白70在体外和体内转录的启动 HSP70启动子-报告模板；以及(3)表征HSP70启动子-报告模板的作用 衰老和饮食限制对调节HSP70的转录因子的影响 表情。激活(DNA结合)和表达(即蛋白质和 热休克转录因子和CAAT-box的mRNA水平) 转录因子和Sp1在幼年和老年大鼠中的测定 这两种节食。

DESCRIPTION (Investigator's Abstract): Dietary restriction, i.e. the restriction of total calories, is the only effective method for increasing the maximum survival of mammals, and it is believed that the increase in survival is due to an alteration in the aging process(es). Therefore, dietary restriction is a powerful tool for studying the biolobical mechanism underlying the aging process and the impact of nutrition on the aging process. Several years ago, the applicant proposed that dietary restriction was acting at the level of gene expresssion. During the past three years, the applicant's laboratory has shown that dietary restriction alters the age-related change in the levels of a variety of mRNA species in several tissues from rat, and that the alteration in mRNA levels is paralelled by an alteration in nuclear transcription. Thus, he has shown that dietary restriction does indeed alter gene expression and that this alteration occurs primarily at the level of transcription. The purpose of the research described in this proposal is to elucidate the molecular mechanism through which dietary restriction alters the transcription of genes. Specifically the applicant will test the following hypothesis: the changes in transcription that arise from dietary restriction are due to changes in the levels/activities of specific transcription factors that regulate the transcription of specific genes. This hypothesis will be tested by studying the expression of the gene for a heat shock protein, hsp 70, in hepatocytes or lymphocytes isolated from male Fisher F344 rats fed ad libitum or a calorie-restricted diet (60% of diet consumed by rats fed ad libitum). The specific objectives of the research described in this proposal are as follows: (1) To characterize the effect of aging and dietary restriction on the induction of hsp70 expression (synthesis, mRNA levels, and transcription) by heat shock and a heavy metal, and to characterize the expression of hsp70 by individual cells from young and old rats fed ad libitum and the restricted-diet by in situ hybridization; (2) to characterize the effect of aging and dietary restriction on the initiation of hsp70 transcription by the in vitro and in vivo transcription of hsp70 promoter-reporter templates; and (3) to characterize the effect of aging and dietary restriction on transcription factors that regulate hsp70 expression. The activation (DNA binding) and expression (i.e., protein and mRNA levels) of heat shock transcription factor as well as CAAT-box transcription factor and Sp1 will be determined in young and old rats on the two diets.