Imaging Mitochondrial Redox States In Vivo by Hyperpolarized MR

通过超极化 MR 对体内线粒体氧化还原状态进行成像

• 批准号: 8598079
• 负责人: LIN Z LI
• 金额: $ 36.92万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8598079
• 关键词: 2,4-Dinitrophenol; Acetoacetates; Aging; Animal Model; Apoptosis; Biochemical; Biochemical Reaction; Biological Assay; Biological Markers; Biological Process; Biomedical Research; Biopsy Specimen; Breast Cancer Cell; Cancer Patient; Cancer cell line; Carbon; Cardiovascular Diseases; Cell model; Cells; Cessation of life; Clinical; Clinical Treatment; Coupled; Data Analyses; Development; Diabetes Mellitus; Disease; Duchenne muscular dystrophy; Electron Transport; Equilibrium; Esters; Event; Flavoproteins; Future; Glucose; Histology; Human; Human Biology; Hydroxybutyrates; Image; Indolent; Label; Link; Liver diseases; MCF7 cell; MDA MB 231; Magnetic Resonance; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Malignant Neoplasms; Mammary Neoplasms; Measurement; Measures; Mediating; Metabolic; Metabolism; Metastatic to; Methods; Mitochondria; Mus; NADH; Nicotinamide adenine dinucleotide; Oxidation-Reduction; Oxidoreductase; Parkinson Disease; Patients; Procedures; Pyruvate Carboxylase; Rare Diseases; Rotenone; Sequence Analysis; Signal Transduction; Solutions; Succinates; System; Techniques; Time; Tissues; Translations; Validation; Xenograft procedure; abstracting; cancer diagnosis; cancer therapy; cell growth; clinical Diagnosis; clinical practice; cryogenics; disease diagnosis; extracellular; fluorescence imaging; imaging modality; in vivo; magnetic resonance spectroscopic imaging; malignant breast neoplasm; melanoma; non-invasive imaging; novel; public health relevance; technique development; treatment response; tumor

DESCRIPTION (provided by applicant): Abnormalities in mitochondrial metabolism including redox state have been identified under many pathological conditions including cancer, diabetes, aging, and cardiovascular disease. Mitochondrial NAD (nicotinamide adenine dinucleotide)-coupled redox potential NAD+/NADH regulates a number of oxidation-reduction reactions in metabolism, and also mediates key signaling events important for cell growth, survival and apoptosis. There is a great need for a non-invasive method of quantifying and/or measuring mitochondrial NAD+/NADH redox potential in tissues in vivo for the purpose of developing effective approaches for disease diagnosis and treatment. In this project we will develop and validate a clinically translatable and non-invasive hyperpolarized-carbon-13 magnetic resonance spectroscopic imaging (HP-13C-MRSI) method for imaging the mitochondrial redox potential NAD+/NADH in vivo using breast cancer animal models. HP-13C-MR is over 10,000 times more sensitive than conventional MR and has been used to image tissue metabolism. The rationale is to quantify the NAD-coupled redox potential using the equilibrium constant for an enzymatic reaction in mitochondria only, i.e., -hydroxybutyrate + NAD+ ` acetoacetate + NADH + H+, provided that the ratios of acetoacetate/- hydroxybutyrate and the mitochondrial pH can be quantified by MR methods. The proposed method is specific for the NAD+/NADH couple in mitochondria. We will also propose to use 13C-labeled ester probes (e.g. ethyl- hydroxybutyrate) to differentiate between extracellular and intracellular MR signals to obtain the redox potential with higher accuracy. Since our previous studies using cryogenic NADH/flavoprotein fluorescence imaging ex vivo have linked mitochondrial redox state to the metastatic potential of human melanoma and breast cancer in mouse xenografts, this project will also establish a correlation between mitochondrial NAD+/NADH and the metastatic potential of breast cancer, which supports mitochondrial redox potential as a biomarker for cancer diagnosis and treatment response, and a target for therapy. We will investigate whether the mitochondrial redox potential NAD+/NADH measured by the HP-13C-MR method can differentiate an indolent (MCF-7) and a highly metastatic (MDA-MB-231) breast cancer cell line. We will perform redox potential measurements on perfused cell models and mouse xenografts under different mitochondrial metabolic conditions and correlate the results with biochemical assays. We will also validate the techniques on human patients with low or high grade breast tumors to demonstrate its clinical translatability.

描述（由申请人提供）：在包括癌症、糖尿病、衰老和心血管疾病在内的许多病理条件下，已经确定了线粒体代谢（包括氧化还原状态）的异常。线粒体NAD（nicotinamide adenine dinucleotide，烟酰胺腺嘌呤二核苷酸）偶联的氧化还原电位NAD+/NADH调节代谢中的许多氧化还原反应，并且还介导对细胞生长、存活和凋亡重要的关键信号事件。为了开发用于疾病诊断和治疗的有效方法的目的，非常需要在体内定量和/或测量组织中线粒体NAD+/NADH氧化还原电位的非侵入性方法。在这个项目中，我们将开发和验证一种临床上可翻译的和非侵入性的超极化碳-13磁共振光谱成像（HP-13 C-MRSI）方法，用于使用乳腺癌动物模型在体内成像线粒体氧化还原电位NAD+/NADH。HP-13 C-MR比传统MR灵敏10，000倍以上，已用于组织代谢成像。基本原理是使用仅在线粒体中的酶促反应的平衡常数来定量NAD偶联的氧化还原电位，即，- 羟基丁酸+ NAD+乙酰乙酸+ NADH + H+，条件是乙酰乙酸/-羟基丁酸的比率和线粒体pH可以通过MR方法定量。所提出的方法对线粒体中的NAD+/NADH对具有特异性。我们还将提出使用13 C标记的酯探针（例如，羟基丁酸乙酯）来区分细胞外和细胞内MR信号，以获得更高准确度的氧化还原电位。由于我们先前使用低温NADH/黄素蛋白荧光成像的离体研究已将线粒体氧化还原状态与小鼠异种移植物中人黑色素瘤和乳腺癌的转移潜力联系起来，因此本项目还将建立线粒体NAD+/NADH与乳腺癌转移潜力之间的相关性，这支持线粒体氧化还原电位作为癌症诊断和治疗反应的生物标志物以及治疗靶点。我们将研究通过HP-13 C-MR方法测量的线粒体氧化还原电位NAD+/NADH是否可以区分惰性（MCF-7）和高转移性（MDA-MB-231）乳腺癌细胞系。我们将在不同线粒体代谢条件下对灌注细胞模型和小鼠异种移植物进行氧化还原电位测量，并将结果与生化测定相关联。我们还将在患有低度或高度乳腺肿瘤的人类患者身上验证该技术，以证明其临床可移植性。