Metabolic markers for mitochondrial function

描述(申请人提供)：线粒体(MT)功能障碍是许多慢性疾病的一个因素，与环境暴露有关的毒性，但MT功能的早期缺陷很难检测到。目前线粒体功能障碍的临床标志物通常只能检测到组织损伤和疾病的晚期症状，然而，检测轻度MT功能障碍和组织内的异质性的敏感性阻碍了在早期阶段对有意义的生物标志物的稳健识别。线粒体生物学是可变的；慢性、低水平的MT功能障碍可能低于许多技术的检测灵敏度。因此，需要新的工具在早期阶段加强对环境引起的线粒体毒性的机制理解，以便能够进行预防和干预。为了解决这个问题，这组研究人员开发并应用了一种新的单细胞质谱学技术，称为纳米结构引发质谱学(NIMS)。NIMS既具有单细胞分辨率(1-10.5M)，又具有检测MT功能障碍的早期生物标志物所需的高灵敏度(大气压)，作为单个细胞中的代谢“标志”。与标准质谱学相比，NIMS具有许多优点，包括(1)超高灵敏度，(2)高选择性，(3)降低样品复杂性的单池分辨率。NIMS将被应用于确定患病动物或在“亚临床”水平上接受环境毒素治疗的动物的大脑和血液中MT早期功能障碍的代谢特征。在具体目标1中，将使用NIMS来生成MT下降的代谢特征。在具体目标2中，将使用活性测试来查看生物标记物是否反映了MT或MT在细胞环境中的功能变化。NIMS可以应用于任何组织和任何细胞类型，以定量地分类动态细胞环境中发生的复杂变化，并最大限度地减少固有的系统异质性，这种异质性阻碍了检测MT下降的有意义的标记物的努力。 公共卫生相关性：线粒体功能障碍是许多慢性病和环境暴露的一个因素，但MT功能的早期缺陷很难检测到。为了解决这个问题，我们开发并应用了一种新的单细胞质谱学技术，称为NIMS。NIMS既具有单细胞分辨率，又具有检测MT功能障碍早期生物标志物所需的高灵敏度，并将用于定义单细胞MT功能障碍的“标志”。因此，NIMS技术降低了系统的异质性，具有检测早期MT下降的有意义的代谢标志物所需的高灵敏度，以及在不同细胞类型中空间分配信号的能力。我们应用NIMS在动物模型中识别脑、血液和尿液中氧化损伤的影响。

DESCRIPTION (provided by applicant): Mitochondrial (MT) dysfunction is a factor in numerous chronic diseases and the toxicity related to environmental exposures, but early deficits in MT function are difficult to detect. Current clinical markers for mitochondrial dysfunction typically detect only advanced symptoms of tissue injury and disease, yet the sensitivity to detect mild MT dysfunction and heterogeneity within tissue has hampered robust identification of meaningful biomarkers at early stages. Mitochondrial biology is variable; and chronic, low level MT dysfunction may be below the detection sensitivity of many techniques. As a result there is the need of new tools to enhance the mechanistic understanding of environmentally-induced mitochondrial toxicity at early stages to enable prevention and intervention. To address this problem, this team of investigators has developed and applied a new technology for single cell mass spectrometry, called Nanostructure-Initiator Mass Spectrometry (NIMS). NIMS has both the single cell resolution (1-10 5m) and the high sensitivity (attomolar) needed to detect early biomarkers of MT dysfunction as metabolic "signatures" in individual cells. NIMS offers a number of advantages over standard mass spectrometry, including (1) ultra-high sensitivity, (2) high selectivity, and (3) single cell resolution to reduce sample complexity. NIMS will be applied to identify metabolic signatures for early MT dysfunction in the brain and blood of diseased animals or animals treated with environmental toxins at "subclinical" levels. In Specific Aim 1, NIMS will be employed to generate metabolic signatures for MT decline. In Specific Aim 2, an activity test will be used to see whether the biomarker reflects functional changes in MT or MT within the context of the cell. NIMS can be applied to any tissue and any cell type, to quantitatively sort out complex changes that occur in dynamic cellular environments, and minimizes the inherent system heterogeneity that has confounded efforts in detecting meaningful markers of MT decline. PUBLIC HEALTH RELEVANCE: Mitochondrial dysfunction is a factor in numerous chronic diseases and environmental exposures, but early deficits in MT function are difficult to detect. To address this problem, we have developed and applied a new technology for single cell mass spectrometry, called NIMS. NIMS has both single cell resolution and the high sensitivity needed to detect early biomarkers of MT dysfunction, and will be used to define "signatures" of early MT dysfunction in single cells. Thus, NIMS technology reduces system heterogeneity, has the high sensitivity needed for detecting meaningful metabolic markers of early MT decline, and the ability to spatially assign signatures in distinct cell types. We apply NIMS identify the effects of oxidative damage in the brain, blood and urine in animal models.