EFFECT OF DIETARY RESTRICTION ON GENE EXPRESSION

描述（研究者摘要）：饮食限制，即 限制总热量，是唯一有效的方法，增加 哺乳动物的最大生存，据信， 生存是由于衰老过程的改变。 因此，我们认为， 饮食限制是研究生物学的有力工具， 衰老过程的内在机制以及营养对 老化过程 几年前，申请人提出， 限制作用在基因表达水平。 在过去 三年来，申请人的实验室证明，饮食限制 改变了与年龄相关的各种mRNA水平的变化， 大鼠的几种组织，mRNA水平的变化是 通过核转录的改变来表达。 他表示， 饮食限制确实会改变基因表达， 改变主要发生在转录水平。 的目的 本提案中描述的研究旨在阐明 通过饮食限制改变转录的机制 基因. 具体而言，申请人将检验以下假设： 由饮食限制引起的转录变化是由于 特定转录因子水平/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）基因的表达进行了测试， 70，在从喂食以下物质的雄性Fisher F344大鼠中分离的肝细胞或淋巴细胞中 自由进食或限制热量饮食（60%的大鼠进食 随意）。 本文所述研究的具体目标 建议如下：（1）表征老化效应， 饮食限制对诱导hsp 70表达（合成，mRNA 水平和转录）的热休克和重金属， 通过来自年轻和老年的单个细胞表征hsp 70的表达 通过原位杂交技术检测自由采食和限制性饮食喂养的大鼠;（2） 描述衰老和饮食限制对 通过体外和体内转录启动hsp 70转录 的hsp 70启动子-报告模板;和（3）表征 衰老和饮食限制对调节热休克蛋白70转录因子的影响 表情 激活（DNA结合）和表达（即，蛋白质和 mRNA水平）的热休克转录因子以及CAAT盒 转录因子和Sp1将在年轻和老年大鼠中测定， 这两种饮食。

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.