NOVEL LIPID 2ND MESSENGERS REGULATING BIOENERGETICS AND SIGNALING IN HUMAN MYOCARDIUM

摘要 线粒体是重要的亚细胞细胞器，在细胞生物学中具有多种功能，包括 能量产生、新陈代谢、脂质合成和信号传递。由于基因操作的简便性 在小鼠模型中，大多数关于心力衰竭的机制推断都是从获得 小鼠心力衰竭过程中特定酶功能或功能丧失的研究。然而，深刻的 与人类相比，小鼠线粒体在化学和生理上存在差异 线粒体。其中包括小鼠和人类线粒体磷脂的巨大差异 应激反应中产生的脂质第二信使的组成、它们的谱系以及酶 负责调节人类线粒体信号和生物能量学的介体。架起一座桥梁， 小鼠和人之间的翻译差距，我们的研究集中在脂质2的作用上 人类心脏中存在的信使及其对人心脏线粒体生物能和 信令功能。最近，我们发现了一系列由人类产生的新的脂质第二信使 线粒体在人类心力衰竭的发展过程中受到动态调节。此外，我们 已经证明这些新的脂质第二信使调节人类线粒体能量的产生， 生物能效和细胞信号。因此，拟议研究的一个主要目标是确定 线粒体功能与人类心肌细胞生理整合的化学机制 通过我们在人心肌中发现的新的脂质第二信使。通过使用集成的 我们开发/采用的一系列质谱学技术，包括带有电荷开关的LC-MS/MS 衍生化，多反应监测，产品离子组的高质量精度分析，我们有 鉴定和量化了许多新的天然产物，其中一些我们已经被证明是调节的 人类线粒体生物能量学和信号传递。第一个目标是确定分子机制， 从人心肌磷脂开始产生这些新的脂质第二信使并鉴定 产生这些天然产物的生化途径。拟议研究的第二个目标是 鉴定这些天然产物的化学多样性，并澄清它们在黄连提取物中的对映体纯度 人体心肌。人心肌组织中对映体纯天然产物的鉴定 证明它们是由特定的酶产生的，并且它们不是不定芽的产物 氧化。拟议研究的第三个目标是机械地确定它们在调节人类健康方面的作用 心脏线粒体生物能量学和信号传递。总体而言，拟议的研究是一个独特的机会 极大地加速鉴定人类心脏脂质第二信使在沉淀人类中的作用 促进人类心力衰竭进展的线粒体功能障碍。这是一个有针对性的翻译 该方法将直接确定治疗人类心力衰竭的真正药理靶点。

ABSTRACT Mitochondria are essential subcellular organelles that serve multiple functions in cellular biology including energy production, metabolism, lipid synthesis and signaling. Due to the ease of genetic manipulation in mouse models, a large majority of mechanistic inferences about heart failure have been made from gain of function or loss of function studies of specific enzymes during heart failure in mice. However, profound differences in the chemistry and physiology of murine mitochondria are present in comparison to human mitochondria. These include vast differences between murine and human mitochondrial phospholipid compositions, their repertoires of lipid 2nd messengers generated in response to stress, and the enzymic mediators responsible for modulating human mitochondrial signaling and bioenergetics. To bridge the translational gap between mouse and humans, we have focused our studies on the roles of lipid 2nd messengers present in human hearts and their impact on human heart mitochondrial bioenergetic and signaling functions. Recently, we have discovered a series of novel lipid 2nd messengers generated by human mitochondria which are dynamically regulated during the progression of heart failure in humans. Moreover, we have demonstrated that these novel lipid 2nd messengers modulate human mitochondrial energy production, bioenergetic efficiency and cellular signaling. Accordingly, a major goal of the proposed research is to identify the chemical mechanisms that integrate mitochondrial function with human cardiac myocyte physiology through novel lipid 2nd messengers we identified in human myocardium. Through utilization of an integrated series of mass spectrometric technologies we developed/employ including LC-MS/MS with charge-switch derivatization, multiple reaction monitoring, and high mass accuracy analysis of suites of product ions, we have identified and quantified many new natural products some of which we have already been shown to modulate human mitochondrial bioenergetics and signaling. The first goal is to identify the molecular mechanisms which initiate the generation of these novel lipid 2nd messengers from human myocardial phospholipids and identify the biochemical pathways which generate these natural products. The second goal of the proposed research is to identify the chemical diversity of these natural products and clarify their enantiomeric purity in extracts of human myocardium. Identification of enantiomerically pure natural products in human myocardium will demonstrate that they are produced by specific enzymes and that they are not products of adventitious oxidation. The third goal of the proposed studies is to mechanistically identify their roles in modulating human heart mitochondrial bioenergetics and signaling. Collectively, the proposed research is a unique opportunity to dramatically accelerate identification of the roles of human heart lipid 2nd messengers in precipitating human mitochondrial dysfunction that promotes the progression of human heart failure. This targeted translational approach will directly identify bona fide pharmacologic targets for treatment of human heart failure.