Molecular Genetics of Aging in C elegans

描述（由申请人提供）：已经确定了许多增加秀丽隐杆线虫寿命的突变。其中许多是进化上保守的。有一个令人信服的案例表明，抗压力能力的增强与寿命的延长有关；然而，这种抗逆性的具体分子机制大多是未知的。同样未知的是，哪种类型的抗逆性（抗氧化损伤、DNA突变、变性蛋白质的再折叠等）对延长寿命最为关键。目前还不清楚抗逆性的不同组织特异性在多大程度上对延长寿命很重要。线虫是探索衰老过程中组织特异性的有效系统，因为它是短暂的，但多细胞的，允许研究在单细胞生物中无法探索的后生动物对应激反应的重要方面。我们打算确定必要的效应，以及那些足以引起应激反应的效应。我们提出了一套解决这些问题的综合方法。我们的一般假设是，抵抗压力的能力是秀丽隐杆线虫延长寿命机制的必要组成部分。（我们已经知道，光有抗压能力是不够的。）我们之前已经分离出了对细胞内产生超氧化物的醌：juglone反应改变的突变体，并证明了一些抗o2胁迫的突变体增加了平均寿命和最长寿命。我们将通过选择更多抗压力突变体和使用新的高通量策略识别突变体来扩展这些研究。这些研究还将探讨这些变化是否依赖于已知的调节蛋白，如DAF-16，并将利用基于微阵列的研究来补充突变和RNAi方法，因为它们可以识别基于转录的分析可能错过的关键基因和基因产物（例如，热休克因子）。

DESCRIPTION(provided by applicant): Numerous mutations that increase the life span of the nematode Caenorhabditis elegans have been identified. Many of these are evolutionarily conserved. There is a compelling case that increased stress resistance is involved in increased longevity; however, the specific molecular mechanisms underlying this stress resistance are mostly unknown. Also unknown are what type(s) of stress resistance (resistance to oxidative damage, mutations in DNA, refolding of denatured proteins, etc.) are most crucial to increased longevity. It is also unclear to what extent differential tissue-specificity of stress resistance is important for enhanced longevity. The nematode is an efficient system for exploring tissue-specificity during aging because it is short-lived but multicellular, allowing the study of important aspects of metazoan response to stress that cannot be explored in single-celled organisms. We intend to identify necessary effectors, as well as those that are sufficient for mounting a stress response. We propose an integrated set of methods for addressing these issues. Our general hypothesis is that the ability to resist stress is a necessary part of the life-extension mechanism(s) in C. elegans. (We already know that stress-resistance is not sufficient.) We have previously isolated mutants showing altered response to the intracellular superoxide-generating quinone: juglone, and demonstrated that some O2-stress resistant mutants have increased mean and maximal life spans. We will extend these studies both by selecting more stress-resist mutants and by identifying mutants using novel high-throughput strategies. These studies will also address whether these changes are dependent on known regulatory proteins like DAF-16 and will utilize microarray-based studies to complement the mutational and RNAi approaches, as they can identify critical genes and gene products that might be missed by transcription-based analyses (e.g., heat shock factor).