mtDNA damage and DAMPs in multiple organ dysfunction syndrome

严重损伤患者的管理具有挑战性，因为多器官功能障碍综合征可能 即使最初的侮辱得到控制，也要无情地前进。不过，一系列报道都指向了前景 线粒体（MT）相关通路发挥核心作用。具体地，已经发现， 线粒体DNA氧化损伤是细胞毒性的，并导致其断裂成促炎性线粒体DNA损伤 相关的分子模式与潜在的传播损伤到远处器官。反对这个 背景，该项目的目标是提供对起源，特征和生物学的洞察 mtDNA DAMPs在创伤相关MODS中的作用是翻译mtDNA的前奏， 指导临床应用。我们将使用一个临床相关的猪模型的MODS诱导 通过出血伴干缺血再灌注治疗，达到三个目的。因为传统的策略 对于循环mtDNA DAMP的分析，使用PCR来定量长度约为200 bp的序列， 最普遍的或生物学上最相关的mtDNA DAMP种类还没有被确定。此外，本发明还提供了一种方法， 线粒体DNA序列中存在组织特异性差异，这可能决定了 循环线粒体DNA DAMPs。因此，目标1将定义释放的mtDNA DAMP的序列特征， 在创伤相关的MODS的演变过程中，并测试这一假设， 循环中的线粒体DNA可以追溯到特定的器官，并失败。第二个目标是解决 线粒体DNA片段在创伤后循环中积累。对此，早在几十年前就已知晓 肠系膜淋巴引流的中断可预防MODS，从而支持肝脏- 肠-肠系膜轴可能是循环mtDNA DAMP的主要来源，可能刺激mtDNA DAMP 其他器官的生产。因此，目的2将检验以下假设：在创伤中，mtDNA DAMP是 存在于肠系膜淋巴引流中，并且完整的肠系膜淋巴引流系统 这是系统性mtDNA DAMP积累和MODS所必需的。最后，防止或逆转线粒体DNA 用靶向DNA修复酶的新型融合蛋白构建体损伤线粒体， 药物增强线粒体DNA DAMP降解与一个再利用的代理，DNase 1，提前IR 啮齿动物的伤害。然而，重要的是，这些策略都没有在临床相关的研究中进行过探索。 动物模型因此，关键的机械洞察力，特别是饲料的所谓操作- 线粒体DNA损伤与线粒体DNA DAMP产生之间的正向通路尚不清楚。因此，为了提供 为了提供将mtDNA导向疗法转化为临床应用所需的信息，Aim 3将使用 假设mt靶向Ogg 1和DNase 1单独或联合给药， mtDNA DAMPs和抑制MODS。

Management of severely injured patients is challenging because Multiple Organ Dysfunction Syndrome may advance relentlessly even if the initial insult is controlled. However, a series of reports point to the prospect that mitochondrial (mt)-associated pathways play a central role. Specifically, it has been discovered that oxidative mtDNA damage is both cytotoxic and leads to its fragmentation into proinflammatory mtDNA Damage Associated Molecular Patterns with the potential to disseminate injury to distant organs. Against this background, the goal of this project is to provide insight into the origin, characteristics, and biological effects of mtDNA DAMPs in the setting of trauma-related MODS as a prelude for translating mtDNA- directed therapies into clinical application. We will use a clinically-relevant porcine model of MODS induced by hemorrhage with truncal ischemia and reperfusion to address three Aims. Because conventional strategies for analysis of circulating mtDNA DAMPs use PCR to quantify sequences of about 200 bp in length, it is likely that the most prevalent or biologically relevant mtDNA DAMP species have not been identified. In addition, there are tissue-specific differences in mtDNA sequences that may dictate sequence characteristics of circulating mtDNA DAMPs. Accordingly, Aim 1 will define sequence characteristics of mtDNA DAMPs released during the evolution of trauma-related MODS and test the hypothesis that unique variant signatures of circulating mtDNA can be traced to specific organs and that fail. The second aim addresses the origin of mtDNA fragments accumulating in the circulation after trauma. In this regard, it has been known for decades that interuption of mesenteric lymphatic drainage forestalls MODS, thus supporting the concept that the liver- gut-mesenteric axis could be a major source of circulating mtDNA DAMPs, perhaps stimulating mtDNA DAMP production in other organs. Aim 2 will therefore test the hypotheses that in trauma, mtDNA DAMPs are present in the mesenteric lymphatic drainage and that an intact mesenteric lymphatic drainage system is required for systemic mtDNA DAMP accumulation and MODS. Finally, prevention or reversal of mtDNA damage with novel fusion protein constructs targeting DNA repair enzymes to mitochondria and pharmacological enhancement of mtDNA DAMP degradation with a repurposed agent, DNase1, forestalls IR injury in rodents. Importantly, however, neither of these strategies have been explored in a clinically-relevant animal model. As a consequence, critical mechanistic insight, particularly the purported operation of a feed- forward pathway linking mtDNA damage to mtDNA DAMP production, is unavailable. Accordingly, to provide information needed for translation of mtDNA-directed therapies into clinical application, Aim 3 will use test the hypothesis that mt-targeted Ogg1 and DNase1, given alone or in combination, alter disposition of circulating mtDNA DAMPs and suppress MODS.