Elucidating the relationship between lipid droplets, lipid metabolism, and lipotoxicity

阐明脂滴、脂质代谢和脂毒性之间的关系

• 批准号: 10293607
• 负责人: JAMES A OLZMANN
• 金额: $ 31.86万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-12-01 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10293607
• 关键词: Antioxidants; Attention; Biochemistry; Biological Markers; CRISPR screen; Cancer Model; Cell Death; Cells; Cellular biology; Coenzyme Q10; Cystine; Degenerative Disorder; Disease; Drug resistance; Etiology; Fatty Acids; Funding; Generations; Genetic Screening; Glutamates; Glutathione; Goals; Health; In Vitro; Iron; Isotopes; Knowledge; Lipid Peroxidation; Lipid Peroxides; Lipids; Malignant Neoplasms; Maps; Masks; Mediator of activation protein; Membrane; Methods; Modeling; Molecular; NADPH Oxidoreductases NADH; Nerve Degeneration; Organelles; Oxidoreductase; Pathway interactions; Peroxidases; Phospholipids; Protein Isoforms; Proteins; Raman Spectrum Analysis; Reactive Oxygen Species; Regulation; Research; Resistance; Role; Signal Transduction; System; Testing; Tumor Suppressor Proteins; base; cancer cell; cancer therapy; cancer type; cell injury; combat; efficacious treatment; fatty acid metabolism; functional genomics; improved; in vivo; in vivo Model; lipid metabolism; lipidomics; lipophilicity; novel; oxidative damage; phospholipid-hydroperoxide glutathione peroxidase; prevent; protective factors; recruit; repaired; repository; whole genome

Ferroptosis is a regulated form of lipotoxic cell death that involves iron-dependent generation of reactive oxygen species (ROS) and the accumulation of oxidatively damaged lipids (e.g. lipid peroxides). Ferroptosis has been implicated in the etiology of degenerative diseases, such as neurodegeneration associated with iron accumulation. Cells contain a protective pathway in which the glutathione-dependent peroxidase GPX4 repairs lipid peroxides and blocks cell death. Targeted induction of ferroptosis by inhibiting GPX4 has proven to be an efficacious treatment in in vitro and in vivo models of cancer, including drug-resistant forms of cancer. Despite the excitement from these recent findings, our understanding of the mechanisms underlying ferroptosis remains limited. Furthermore, many cancer cells are resistant to ferroptosis and the mechanisms of ferroptosis resistance in cancer remains mostly unknown. To overcome this critical gap in knowledge, we performed a synthetic lethal, whole-genome CRISPR screen to identify factors that protect cancer cells from ferroptosis. Our findings identify the lipid droplet oxidoreductase AIFM2 as a key factor that promotes ferroptosis resistance in cancer. Deletion of AIFM2 dramatically sensitizes cells to ferroptosis and AIFM2 levels correlate with cancer resistance across hundreds of cancer lines, indicating that AIFM2 is a biomarker of ferroptosis resistance and suggesting that it is broadly involved in ferroptosis resistance across many types of cancer. Our proposed research builds on our discovery and employs a combination of functional genomic, cell biology, and biochemistry strategies to achieve the following goals: 1) elucidate the mechanism by which AIFM2 prevents lipid damage and ferroptosis, 2) define the relationship between lipid droplets, fatty acid metabolism, and ferroptosis, and 3) identify new factors involved in protecting cancer cells from ferroptosis. These goals are potentially transformative because they focus on new mechanisms of ferroptosis resistance in cancer cells that act in parallel to the canonical glutathione-based protective system.

铁凋亡是脂毒性细胞死亡的一种调节形式，其涉及铁依赖性的铁代谢产物的产生。 活性氧（ROS）和氧化损伤的脂质（例如脂质 过氧化物）。铁下垂与退行性疾病的病因有关，例如 与铁积累相关的神经变性。细胞含有一种保护途径， 谷胱甘肽依赖性过氧化物酶GPX4修复脂质过氧化物并阻断细胞死亡。 通过抑制GPX4靶向诱导铁凋亡已被证明是一种有效的治疗， 癌症的体外和体内模型，包括耐药形式的癌症。尽管 这些最近的发现令人兴奋，我们对潜在机制的理解 铁性下垂仍然有限。此外，许多癌细胞对铁凋亡具有抗性， 癌症中抗铁凋亡的机制大多仍不清楚。为了克服这个 关键的知识差距，我们进行了合成致死，全基因组CRISPR筛选， 确定保护癌细胞免于铁凋亡的因素。我们的研究结果确定了 氧化还原酶AIFM2作为促进癌症中铁凋亡抗性的关键因子。删除 AIFM2显著地使细胞对铁凋亡敏感，并且AIFM2水平与癌症相关 AIFM2是铁凋亡的生物标志物， 这表明它广泛参与了许多类型的铁凋亡抗性 癌症。我们拟议的研究建立在我们的发现的基础上，并采用了以下方法的组合 功能基因组学、细胞生物学和生物化学策略，以实现以下目标：1） 阐明AIFM2预防脂质损伤和铁凋亡的机制，2）定义 脂滴、脂肪酸代谢和铁缺乏症之间的关系，以及3）确定新的 参与保护癌细胞免于铁凋亡的因子。这些目标有可能 因为他们专注于癌细胞中抗铁凋亡的新机制， 与经典的谷胱甘肽保护系统平行发挥作用。