ROS induced cellular toxicity and tissue damage

描述（由申请人提供）：活性氧（ROS）似乎是决定寿命的主要因素。为了了解特定细胞类型或组织的衰老潜力，我们需要了解细胞内ROS毒性对体内特定组织的影响。在分子遗传工具出现之前，在特定组织中创造一个不影响其他组织的内在氧化应激环境并不容易。现在有可能在像果蝇这样的模型系统中提出这个问题。锰超氧化物歧化酶能催化线粒体基质中超氧化物自由基的解毒，在细胞衰老中起着核心作用，MnSOD功能的丧失严重降低了生物体的寿命，而其过表达可以延长寿命。假设：需要验证的具体假设是，特定组织中MnSOD活性的消耗会通过细胞内ROS浓度的升高引发细胞损伤；然而，对单个组织的损害程度会有所不同，它们的生物功效也会有所不同，这将反映在有机体水平上。我们将在果蝇的四种不同组织中检验我们的假设，包括脂肪体、肌肉、大脑和眼睛的视网膜细胞，除了视网膜细胞外，所有这些组织都是生物体生存所必需的。通过使用最先进的技术，MnSOD功能将在体内从这些组织中被耗尽。我们将讨论几个重要的生物学问题，包括组织特异性ROS生成，组织特异性DNA和蛋白质氧化损伤，组织特异性凋亡细胞死亡潜能。这些组织中MnSOD功能的消耗将为ROS对细胞衰老的贡献提供重要的见解。

DESCRIPTION (provided by applicant): Reactive oxygen species (ROS) is seemingly the major determinant of life-span. To understand the aging potential of specific cell types or tissue we need to understand the effect of intracellular ROS toxicity on specific tissue in vivo. The creation of an intrinsic oxidative stress environment in specific tissue without affecting others was not easy until the advent of molecular-genetic tools. It is now possible to ask this question in vivo in model systems like Drosophila. The enzyme manganese superoxide dismutase, which catalyzes the detoxification of superoxide radicals in the mitochondrial matrix, plays a central role in cellular aging, as evident from the fact that loss of MnSOD function severely reduces organismic life span, while its over-expression could extend it. Hypothesis: The specific hypothesis to be tested is that depletion of MnSOD activity from a specific tissue will trigger cellular damage through an intracellular rise in ROS concentration; however, the amount of damage to individual tissues will vary, as will their biological efficacies, which will be reflected at the organismal level. We will examine our hypothesis in four different tissues in Drosophila including fat body, muscle, brain and retinal cells of the eye, all of which are essential for the viability of the organism with the exception of retinal cells. By using a state-of-the-art technique, MnSOD function will be depleted in vivo from each of these tissues. We will address several important biological questions involving tissue specific ROS generation, tissue specific oxidative damage to DNA and protein, tissue specific apoptotic cell death potential. Depletion of MnSOD function from each of these tissues will provide important insight regarding the contribution of ROS towards cellular aging.