Oxidative DNA Damage and Repair in Rat Kidney

[631166] Gallagher由于缺氧和血液恢复后的再氧化作用，细胞中发生了许多化学反应。这些细胞反应的一个副产物是形成一种高活性形式的氧，称为氧自由基。氧自由基会使遗传物质DNA发生改变，从而影响细胞正常生物功能的能力。由于DNA结构的单一变化可能是有害的，因此在细胞水平上进化出多种修复DNA的机制也就不足为奇了。本提案中概述的实验旨在检测一种修复DNA氧化损伤的酶，即氧化核酸酶。这种酶的水平将在缺氧（缺血）肾脏和再充氧再灌注的大鼠肾脏中被量化，并与未受损组织中这种蛋白质的水平进行比较。具体来说，将对组织进行检查：1)氧化DNA修复酶活性的水平；2)氧化DNA损伤的细胞修复；3)缺血或再氧化无氧事件中形成的特异性氧化DNA碱基损伤水平。这些实验的结果将为修复氧化DNA损伤的细胞机制和组织承受氧化应激条件的能力的调节提供新的见解。

9631166 Gallagher A number of chemical reactions occur in cells affected by the loss of oxygen and by reoxygenation which occurs upon resumption of blood flow. One by-product of these cellular reactions is the formation of a highly reactive form of oxygen, known as an oxygen free radical. Oxygen free radicals produce alterations in DNA, the genetic material, which may affect the ability of cells to carry out their normal biological functions. Since a single change in DNA structure may be harmful, it is not surprising that a diverse array of mechanisms for repairing DNA evolved at the cellular level. The experiments outlined in this proposal are designed to examine an enzyme, redoxyendonuclease, that repairs oxidative damage to DNA. The levels of this enzyme will be quantified in the oxygen-deprived (ischemic) kidney and the reoxygenated reperfused) rat kidney and compared to the levels of this protein in the undamaged tissue. Specifically, the tissue will be examined for 1) the level of the oxidative DNA repair enzyme activity; 2) the cellular repair of oxidized DNA damage; and 3) the levels of specific oxidized DNA base damages formed during the ischemic or reoxygenanon event. Results from these experiments will provide new insights into the regulation of the cellular mechanisms that repair oxidative DNA damage and the ability of tissues to withstand conditions of oxidant stress.