Bradykinin, Nitric Oxide and Mitochondrial DNA Damage in Diabetic Complications

描述(由申请人提供)： 在我们以前的工作中，我们已经证明了控制缓激肽(BK)和一氧化氮(NO)的产生的遗传因素对链脲佐菌素(STZ)诱导的糖尿病小鼠肾脏并发症的发生或由INS-2的秋田非糖尿病基因C86Y突变造成的肾脏并发症的发生有很大的影响。我们还发现糖尿病肾病和一些衰老指标按野生型和lt；缓激素受体B2零和lt；秋田糖尿病和B2受体零的秋田糖尿病的顺序递增。线粒体(Mt)DNA的8-OHdG含量、点突变和缺失在同一进程中增加，氧化应激指标也是如此。我们现在提出了三个特定的目标和两个新的小鼠模型来确定影响BK作用的遗传因素、NO的产生和糖尿病相关的mtDNA突变增加之间的相互作用。具体目标1将确定在体内消除两种BK受体或以组织或细胞特有的方式消除两种BK受体对糖尿病并发症的影响；还将确定这些小鼠减少氧化应激的效果。特定目的2将研究eNOS-/-糖尿病小鼠肾小球损伤与mtDNA突变之间的关系，我们发现在eNOS+/+糖尿病小鼠中，氧化应激反而更少。具体目标3将测试这样一种假设，即通过在线粒体DNA聚合酶伽马中引入校对缺陷来增加mtDNA突变的频率将加剧秋田糖尿病小鼠的并发症，即使氧化应激不会比单纯由于糖尿病而进一步增加。

DESCRIPTION (provided by applicant): In our previous work we have demonstrated that genetic factors controlling the production of bradykinin (BK) and nitric oxide (NO) influence greatly the development of renal complications in mice made diabetic with streptozotocin (STZ) or by the Akita diabetogenic C86Y mutation in Ins 2. We also showed that diabetic nephropathy and several indicators of senescence increase progressively in the order wildtype < bradykinin receptor B2 null < Akita diabetic < B2 receptor null Akita diabetic. 8-OHdG content, point mutations and deletions in mitochondrial (mt) DNA increased in the same progression, as did indicators of oxidative stress. We now propose three specific aims and the generation of two new mouse models to determine the interplay between genetic factors that influence BK action, the production of NO, and diabetes-related increases in mutations in mtDNA. Specific aim 1 will determine the effect on diabetic complications of eliminating both BK receptors throughout the body, or in a tissue or cell specific manner; the effects of reducing oxidative stress in these mice will also be determined. Specific aim 2 will investigate the relationship between glomerular damage and mtDNA mutations in eNOS -/- diabetic mice in which we have found that oxidative stress is paradoxically less than in eNOS +/+ diabetic mice. Specific aim 3 will test the hypothesis that increasing the frequency of mtDNA mutations by introducing a proof reading defect into mitochondrial DNA polymerase gamma will exacerbate the complications in Akita diabetic mice even though oxidative stress is not further increased over that due to the diabetes alone.