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

基本信息

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
项目类别：
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

项目摘要

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.

铁凋亡是一种受调节的脂肪毒性细胞死亡形式，涉及铁的依赖性产生活性氧（ROS）和氧化受损的脂质的积累（例如脂质过氧化物）。铁凋亡与退化性疾病的病因有关，例如与铁积累相关的神经变性。细胞包含一个保护途径，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断细胞死亡。通过抑制GPX4，有针对性地诱导铁铁作用已被证明是一种有效的治疗方法体外和体内癌症模型，包括耐药形式的癌症。尽管有从这些最新发现，我们对基本机制的理解中的兴奋铁凋亡仍然有限。此外，许多癌细胞对铁铁作用具有抗性癌症中氟化抗性的机制仍然是未知的。克服这一点知识的关键差距，我们进行了合成的致命，全基因组CRISPR屏幕确定保护癌细胞免受铁凋亡的因素。我们的发现确定了脂质液滴氧化还原酶AIFM2是促进癌症抗铁毒性抗性的关键因素。删除 AIFM2急剧使细胞对铁铁作用敏感，而AIFM2水平与癌症相关数百种癌细胞系的耐药性，表明AIFM2是铁凋亡的生物标志物抵抗力，并表明它广泛参与了许多类型的耐铁毒性耐药性癌症。我们提出的研究以我们的发现为基础，并采用了实现以下目标的功能基因组，细胞生物学和生物化学策略：1）阐明AIFM2防止脂质损伤和铁凋亡的机制，2）定义脂质液滴，脂肪酸代谢和铁毒之间的关系，3）确定新的保护癌细胞免受铁凋亡的涉及的因素。这些目标可能是变革性是因为它们专注于癌细胞中氟化抗性的新机制该作用与基于谷胱甘肽的规范保护系统并行起作用。