Molecular Regulation of Mitochondrial Permeability Transition and its Role in Regulated Necrosis

线粒体通透性转变的分子调节及其在调节性坏死中的作用

• 批准号: 10630319
• 负责人: Jason Michael Karch
• 金额: $ 40万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10630319
• 关键词: Adenine Nucleotides; Affect; Ants; Binding; Calcium; Cardiac Myocytes; Cardiomyopathies; Cause of Death; Cell Culture System; Cell Death; Cells; Cessation of life; Characteristics; Communities; Compensation; Crista ampullaris; Cyclophilin A; Cyclosporine; Data; Enterobacteria phage P1 Cre recombinase; Event; Excision; Family; Family member; Genetic; Heart; Heart failure; In Vitro; Injury; Inner mitochondrial membrane; Ischemia; Isomerism; Knockout Mice; Laboratories; Liver; Liver Mitochondria; Masks; Measures; Membrane; Membrane Potentials; Membrane Proteins; Mitochondria; Molecular; Mus; Mutate; Myocardial Infarction; Myocardial Ischemia; Necrosis; Organelles; Outer Mitochondrial Membrane; Oxygen; Peptidylprolyl Isomerase; Permeability; Probability; Production; Protein Isoforms; Proteins; Regulation; Reperfusion Injury; Resistance; Role; Rupture; SLC25A4 gene; SLC25A5 gene; Swelling; Therapeutic; Tissues; Work; candidate identification; cyclophilin D; desensitization; design; in vivo; inhibitor; insight; ischemic injury; mimetics; mitochondrial dysfunction; mitochondrial permeability transition pore; mortality; novel; novel therapeutic intervention; protective effect; therapeutic target

Project Summary/Abstract Regulated necrotic death of cardiomyocytes is the direct cause of mortality during a myocardial infarction. One crucial step that is required for regulated necrosis to occur is the opening of the mitochondrial permeability transition pore (MPTP). Opening of the MPTP, leads to loss of ATP production, mitochondrial dysfunction, and eventual necrotic cell death. Identification of the components of the MPTP has plagued the scientific community for over 30 years. The identification of the inner mitochondrial membrane pore-forming components and regulators of the MPTP is vital for the mechanistic understanding of regulated necrosis. The adenine nucleotide translocator (ANT) family was previously thought to be the pore-forming component of the MPTP within the inner mitochondrial membrane, but this was genetically disproven when mitochondria lacking ANT1 and ANT2 still underwent mitochondrial permeability transition. However, these mitochondria are significantly desensitized to MPTP opening. Recently, we generated mice lacking all three isoforms of the ANT family in liver and showed that the MPTP in mitochondria isolated from ANT null livers are even more desensitized, but the pore eventually opens in the presence of very high Ca2+. Surprisingly, when we treated the ANT null mitochondria with cyclosporine A (CsA), a cyclophilin D (CypD) inhibitor, the MPTP was inhibited. Treatment of CsA normally desensitizes the MPTP, but with enough Ca2+ CsA can be overcome and the MPTP still engages. We now have the ability to definitively determine the full therapeutic potential of complete MPTP inhibition during I/R injury by generating mice lacking the predominant isoforms of ANT and CypD in the heart. In addition to the ANT family and CypD, the MPTP is also regulated from from the outer mitochondrial membrane by Bax and Bak. The relationship between the ANTs, CypD, and Bax/Bak in regards to MPTP regulation is undefined. In this proposal, we aim to elucidate how they function in concert with one another to lead to MPTP opening. Our preliminary data suggest the existence of multiple inner membrane pore-forming components of the MPTP including the ANT family and some other unidentified pore. We will utilize ANT null mitochondria to explore this hypothesis in further detail and aim to identify the novel pore-forming component by using targeted and unbiased approaches. Together this proposal will provide crucial mechanistic insight in the composition and regulation of the MPTP that will reveal potential strategies to inhibit MPTP opening to prolong cardiomyocyte survival in the face of an ischemic event.

项目总结/摘要 心肌细胞的调节性坏死性死亡是心肌缺血期间死亡的直接原因。 梗塞发生调节性坏死所需的一个关键步骤是打开 线粒体通透性转换孔（MPTP）。MPTP的开放导致ATP的丢失 产生、线粒体功能障碍和最终的坏死细胞死亡。识别 MPTP的组成部分已经困扰了科学界30多年。的 线粒体内膜成孔成分和调节因子的鉴定 MPTP对于理解调节性坏死的机制是至关重要的。腺嚷岭核巧酸 转运子（ANT）家族以前被认为是MPTP的成孔组分 在线粒体内膜内，但当线粒体 缺乏ANT 1和ANT 2的线粒体仍发生通透性转换。但这些 线粒体对MPTP开放显著脱敏。最近，我们培育了 在肝脏中缺乏ANT家族的所有三种亚型，并表明线粒体中的MPTP 从ANT空肝中分离出来的细胞甚至更加脱敏，但是孔最终在细胞中打开。 存在非常高的Ca 2+。令人惊讶的是，当我们用 亲环素D（CypD）抑制剂环孢菌素A（CsA）可抑制MPTP。CsA治疗 通常使MPTP脱敏，但有足够的Ca 2 + CsA可以克服，MPTP仍然 订婚。我们现在有能力明确地确定 通过产生缺乏主要亚型的小鼠，在I/R损伤期间完全抑制MPTP ANT和CypD的基因除了ANT家族和CypD外，MPTP也受到调节。 Bax和巴克可从线粒体外膜上分离。的关系 关于MPTP调节的ANT、CypD和Bax/巴克是未定义的。在这份提案中，我们的目标是 以阐明它们如何相互配合以导致MPTP打开。我们 初步数据表明，存在多种内膜成孔成分， MPTP包括ANT家族和一些其它未鉴定的孔。我们将使用ANT null 线粒体进一步详细探讨这一假设，并旨在确定新的孔形成 通过使用有针对性和公正的方法。这项提案将提供 在MPTP的组成和调节方面的关键机制见解，将揭示潜在的 抑制MPTP开放以延长心肌细胞存活的策略 活动