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.

铁死亡是脂毒性细胞死亡的一种受调节形式，涉及铁依赖性生成 活性氧（ROS）和氧化损伤脂质（例如脂质 过氧化物）。铁死亡与退行性疾病的病因学有关，例如 与铁积累相关的神经变性。细胞包含一条保护途径，其中 谷胱甘肽依赖性过氧化物酶 GPX4 修复脂质过氧化物并阻止细胞死亡。 通过抑制 GPX4 来靶向诱导铁死亡已被证明是一种有效的治疗方法 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 铁死亡仍然有限。此外，许多癌细胞对铁死亡具有抵抗力， 癌症中铁死亡抵抗的机制仍然大多未知。为了克服这个 为了解决知识上的关键差距，我们进行了合成致命的全基因组 CRISPR 筛选 确定保护癌细胞免于铁死亡的因素。我们的研究结果确定了脂滴 氧化还原酶 AIFM2 作为促进癌症铁死亡抵抗的关键因素。删除 AIFM2 使细胞对铁死亡显着敏感，并且 AIFM2 水平与癌症相关 跨越数百个癌症系的耐药性，表明 AIFM2 是铁死亡的生物标志物 抗性并表明它广泛参与多种类型的铁死亡抗性 癌症。我们提出的研究以我们的发现为基础，并结合了 功能基因组、细胞生物学和生物化学策略以实现以下目标：1) 阐明 AIFM2 预防脂质损伤和铁死亡的机制，2) 定义 脂滴、脂肪酸代谢和铁死亡之间的关系，3) 确定新的 涉及保护癌细胞免于铁死亡的因素。这些目标有可能 变革性的，因为他们专注于癌细胞铁死亡抵抗的新机制 与典型的基于谷胱甘肽的保护系统并行作用。