Use of IPSC to define role of astrocytes in specifying risk for onset of cerebral adrenoleukodystrophy

项目概要/摘要 X-连锁肾上腺脑白质营养不良患者从良性到致命表型的疾病进展机制 物理学仍然是未知的，没有令人满意的治疗方法。60%的男性X-ALD患者 致命性脑疾病（cALD），而其余40%发展为轻度肾上腺脊髓神经病（AMN）特征。 以轴突病为特征。X-ALD的主要遗传缺陷（ABCD 1基因突变/缺失）和生物学缺陷是一个重要的遗传学问题。 化学缺陷（极长链脂肪酸的积累;血浆和组织中C>22：0）不能预测 AMN或cALD发作。长期目标是为开发新的临床有用的，机制， 基于nism的X-ALD预后指标和治疗选择。此应用程序的总体目标是 以确定差异代谢能量代谢潜在的表型变异性（AMN vs cALD）， 男性X-ALD表型的人星形胶质细胞。核心假设是改变的代谢重编程 是AMN和cALD星形胶质细胞中差异表型发展的基础。这些星形胶质细胞是神经胶质细胞- 从诱导多能干细胞（iPSC），这反过来又产生了重新编程的人类 对照、AMN和cALD患者来源的成纤维细胞。非靶向代谢组学支持这一假设 鉴定健康对照和cALD表型死后脑之间改变的代谢物的试验数据， AMN和cALD星形胶质细胞之间的联系在cALD脑白色物质中，记录到独特的代谢物变化。 在遥远的正常外观区域和斑块附近区域之间排序，表明与 疾病进展。在人cALD中发现OXPHOS和糖酵解减少（低代谢状态）， 星形胶质细胞这种低代谢状态表明了新的替代燃料来源的作用， 星形胶质细胞中cALD表型。拟议研究的基本原理是， AMN和cALD星形胶质细胞的能量代谢异常将为预测疾病进展提供基础 以及为新型治疗药物设计鉴定靶点的新机会。核心假设将 通过追求两个具体目标进行测试：1）确定代谢重编程在新“锻造”中的作用。 AMN和cALD星形胶质细胞;和2）确定线粒体功能障碍在代谢再生中的作用。 AMN和cALD星形胶质细胞中的gramming。该方法将利用对照、AMN和cALD星形胶质细胞 最近在实验室里从iPSC中产生的。这项建议是创新的，因为它脱离了 通过首次鉴定，代谢途径在人类AMN和cALD星形胶质细胞中发生了差异性改变。 拟议的研究是重要的，因为导致不太严重的AMN或致命的细胞机制 cALD表型对相同ABCD 1突变的反应仍然未知，即使在鉴定后四十年， X-ALD的基因缺陷。成功完成拟议的研究预计将提供必要的 随后制定临床有效的疾病预测策略的概念框架 进展和改善目前有限的治疗选择。

PROJECT SUMMARY/ABSTRACT The mechanism of disease progression from benign to fatal phenotypes in X-linked adrenoleukodystro- phy remains unknown and there is no satisfactory cure for the disease. 60% of male X-ALD patients develop fatal cerebral disease (cALD) while the remaining 40% develop milder adrenomyeloneuropathy (AMN) charac- terized by axonopathy. The primary genetic defect in X-ALD (mutation/deletion in ABCD1 gene) and the bio- chemical defect (accumulation of very long chain fatty acid; C>22:0 in plasma and tissues) cannot predict the onset of AMN or cALD. The long-term goal is to contribute to the development of novel clinically useful, mecha- nism-based prognostic indicators and therapeutic options for X-ALD. The overall objective for this application is to determine differential metabolic energy metabolism underlying phenotype variability (AMN vs cALD) in the human astrocytes of male X-ALD phenotypes. The central hypothesis is that altered metabolic reprogramming underlies the differential phenotype development in AMN and cALD astrocytes. These astrocytes were differen- tiated from induced pluripotent stem cells (iPSCs), which, in turn, were generated by reprogramming of human control, AMN and cALD patient-derived fibroblasts. This hypothesis is supported by untargeted metabolomics pilot data identifying metabolites altered between healthy-control and cALD phenotype postmortem brain and between AMN and cALD astrocytes. Within the cALD brain white matter, unique metabolite changes were rec- orded between distant normal looking areas and areas adjacent to the plaque suggesting an association with disease progression. OXPHOS and glycolysis were found to be decreased (low metabolic state) in human cALD astrocytes. This low metabolic state suggests a role for novel alternative source(s) of fuel driving the progression to cALD phenotype in astrocytes. The rationale for the proposed research is that a mechanistic modelling of aberrant energy metabolism in AMN and cALD astrocytes will provide a basis for predicting disease progression and new opportunities for identification of targets for novel therapeutic drug design. The central hypothesis will be tested by pursuing two specific aims: 1) Determine the role of metabolic reprogramming in newly “forged” AMN and cALD astrocytes; and 2) Determine the contribution of mitochondrial dysfunction in metabolic repro- gramming in AMN and cALD astrocytes. The approach will take advantage of control, AMN and cALD astrocytes recently generated from iPSCs in the laboratory. This proposal is innovative because it departs from the status quo by identifying for the first time, metabolic pathways differentially altered in human AMN and cALD astrocytes. The proposed research is significant because the cellular mechanism(s) that lead to less severe AMN or fatal cALD phenotype in response to same ABCD1 mutation remain unknown even four decades after the identifica- tion of gene defect in X-ALD. Successful completion of the proposed research is expected to provide a necessary conceptual framework for the subsequent development of clinically effective strategies for predicting disease progression and improving current limited treatment options.