The role of mTOR in mitochondrial encephalopathy

项目总结/摘要 我们的首要目标是确定的分子机制基础的发病机制， 线粒体疾病我们在这里提出的研究的总体目标，这代表了下一步， 追求这一目标，是为了表征亚急性坏死性脑病的发病机制，并确定 使用Ndufs 4（KO）模型研究mTOR在这种疾病中的作用。 遗传性线粒体疾病包括一系列症状，可能影响一个器官或表现为一种或多种疾病。 多系统疾病，并且严重程度明显不同。对于这些，几乎没有好的模型 疾病和没有有效的治疗选择的线粒体疾病的任何病因。清楚地了解 个别线粒体疾病的发病机制是严重需要的;分子机制 其多种不同的临床表现的基础目前尚不清楚。 亚急性坏死性脑脊髓病，或Leigh综合征（LS），是一种致命的儿科线粒体疾病。 LS的特征性特征包括脑的区域特异性坏死性病变。尽管这些病变 LS的主要定义特征，几乎没有什么是已知的启动事件，是什么基础的空间和 疾病的时间特异性方面，或者为什么CNS的某些区域莫名其妙地幸免于难。我们最近 研究表明，抑制营养感应信号复合物mTOR可减弱小鼠的LS 模型，但受益的机制尚不清楚。 该提案的目标是定义LS的发病机制以及mTOR在该疾病中的作用。我们 假设LS的神经病变特征是由区域和细胞类型特异性效应引起的 线粒体功能障碍，mTOR抑制作用通过一个谨慎的下游神经毒性 通路 我们的实验将利用LS的Ndufs 4（KO）小鼠模型，其是人类的主要模型。 与人类LS非常相似的遗传性线粒体疾病。使用这个模型，我们将使用 LS中神经病变的细胞和分子发病机制，通过i）鉴定最早的细胞类型， 死亡和ii）在损伤形成中首先丢失的CNS细胞类型，iii）定义区域、细胞和细胞区室 CNS损伤形成期间磷酸化蛋白质组变化的特异性，和iv）测试关键mTOR的作用 调节途径在LS中使用药理学方法。最终，这项工作将揭示 LS和线粒体疾病的一般特征。此外，职业发展和培训 这份建议书的内容将为我成功过渡到独立职业生涯提供关键要素。

Project Summary/Abstract Our overarching goal is to define the molecular mechanisms underpinning the pathogenesis of mitochondrial disease. Our overall objective in the studies proposed here, which represent the next step in pursuing this goal, is to characterize the pathogenesis of subacute necrotizing encephalopathy and define the role of mTOR in this disease using the Ndufs4(KO) model. Genetic mitochondrial diseases include an array of symptoms, may affect one organ or present as a multisystem disorder, and are remarkably heterogeneous in severity. There are few good models for these diseases and no effective treatment options for mitochondrial disease of any etiology. A clear understanding of the pathogenesis of individual mitochondrial diseases is severely needed; the molecular mechanisms underlying their multiple distinct clinical manifestations are currently unknown. Subacute necrotizing encephalomyelopathy, or Leigh syndrome (LS), is a fatal pediatric mitochondrial disease. Characteristic features of LS include region specific necrotizing lesions of the brain. Though these lesions are the major defining feature of LS, virtually nothing is known of initiating events, what underlies the spatial and temporal specific aspects of the disease, or why some regions of the CNS are inexplicably spared. Our recent work has shown that inhibition of the nutrient sensing signaling complex mTOR attenuates LS in a mouse model, but the mechanisms underlying the benefit are unknown. The goal of this proposal is to define the pathogenesis of LS and the role of mTOR in this disease. We hypothesize that the neurological lesions characteristic of LS result from region and cell-type specific effects of mitochondrial dysfunction, and that mTOR inhibition acts through a discreet downstream neurotoxic pathway. Our experiments will take advantage of the Ndufs4(KO) mouse model of LS, a premier model of human genetic mitochondrial disease which closely resembles human LS. Using this model, we will use characterize the cellular and molecular pathogenesis of neurological lesions in LS by i) identifying the earliest type of cell death and ii) the CNS cell types first lost in lesion formation, iii) defining the region, cell, and cell compartment specificity of phospho-proteome changes during CNS lesion formation, and iv) testing the role of key mTOR regulated pathways in LS using pharmacological approaches. Ultimately, this work will expose basic molecular features of LS and mitochondrial disease in general. In addition, the career development and training components of this proposal will provide key elements for my successful transition to an independent career.