The role of lipid reprogramming in ferroptotic cell death in inflammatory bowel disease (IBD)

脂质重编程在炎症性肠病（IBD）铁死亡细胞死亡中的作用

• 批准号: 10559545
• 负责人: Wesley WeiQiao Huang
• 金额: $ 4.09万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10559545
• 关键词: Acute; Affect; Amino Acids; Antioxidants; Cell Death; Cell Death Induction; Cell Death Process; Cells; Chronic; Coenzyme A; Coenzyme A Ligases; Colitis; Complex; Crohn' s disease; Cysteine; Cystine; Data; Databases; Defect; Disease; Enzymes; Epithelial Cells; Epithelium; Event; Excision; Family member; Genetic; Genetically Engineered Mouse; Genotype; Glutamates; Glutathione; Histologic; Homeostasis; Immune; Immunity; Inflammation; Inflammatory; Inflammatory Bowel Diseases; Injury; Iron; Lead; Ligase; Lipid Peroxidation; Lipid Peroxides; Lipids; Mediating; Mediator; Mining; Mitochondria; Modeling; Mucous Membrane; Mus; Mutation; Nutrient; Operative Surgical Procedures; Oxidases; Oxidative Stress; Pathway interactions; Patients; Persons; Play; Polyunsaturated Fatty Acids; Pre-Clinical Model; Predisposition; Production; Proteins; Reactive Inhibition; Reactive Oxygen Species; Relapse; Resistance; Role; Sampling; Signaling Molecule; System; T-Lymphocyte; Testing; Ulcerative Colitis; Work; antimicrobial; antiporter; cell injury; data mining; dextran sulfate sodium induced colitis; dimer; druggable target; extracellular; gastrointestinal epithelium; genetic signature; global health; glutathione peroxidase; gut inflammation; immune activation; immune cell infiltrate; in vivo Model; inhibitor; intestinal epithelium; intestinal homeostasis; intestinal injury; iron metabolism; lipid metabolism; lipidomics; long chain fatty acid; mouse model; murine colitis; novel; pharmacologic; pre-clinical; response; spatiotemporal; therapeutic target; tissue injury; transcriptome sequencing; transcriptomics; wound healing

ABSTRACT Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory condition of the gut that impacts over a million people in the U.S. yearly. There are two major forms of IBD, Crohn’s disease (CD) and ulcerative colitis (UC). Chronic inflammation and unregulated mucosal immune activation lead to epithelial damage in a self- perpetuated cycle that is difficult to treat, and many patients require surgical resection of the inflamed foci. CD and UC are histologically distinct, yet the enhanced production of reactive oxygen species (ROS) is a hallmark for both CD and UC. The increase in ROS is thought to be a major mechanism of epithelial cell death in IBD. Indeed, mouse models of colitis are highly protected from tissue injury following antioxidant treatment. However, inhibiting ROS in IBD has only led to modest benefits in disease activity in patients. It is well appreciated that ROS can induce cell death via both regulated and unregulated cell death pathways and better characterization of these are needed in IBD. Mining of a large RNA-seq database of IBD, we identified an iron and lipid signature. Iron-induced lipid peroxidation is a hallmark of a relatively recent described form of cell death termed ferroptosis. The two most well studied effectors of ferroptosis are the System Xc- transporter and glutathione peroxidase (GPX)4. System Xc- is a heteromeric amino acid antiporter which mediates the import of extracellular cystine in exchange for intracellular glutamate. SLC7A11 is the subunit of the dimer with transport activity. Intracellular cystine is converted to cysteine for production of the antioxidant glutathione. GPX4 utilizes glutathione to reduce lipid peroxides. Ferroptosis can be synthetically activated via pharmacological or genetic inhibition of SLC7A11 or GPX4. More recent work has shown that ferroptosis is highly integrated to cellular lipid metabolism and the long-chain-fatty-acid-CoA ligase (ACSL)4 is a central executioner of ferroptosis. Deletion of ACSL4 leads to resistance, whereas increased expression leads to susceptibility to ferroptosis. I show that in acute models of intestinal injury, no ferroptosis is observed. Whereas, ferroptosis is a major hallmark in IBD patient samples and mouse models of chronic intestinal injury. Interestingly, deletion of GPX4 or SLC7A11 in intestinal epithelial cells did not increase ferroptosis basally or in acute models of colitis. However, these mice were highly susceptible in chronic models of intestinal injury. Consistent with these data, I have shown that ACSL4 is significantly upregulated in IBD, but not acute models of intestinal injury. Building on the preliminary data, I hypothesize that cellular lipid reprogramming via ACSL4 in chronic inflammation initiates ferroptosis in IBD. Aim 1 will assess if ferroptosis inhibitors are central protective mechanisms in models of IBD. Aim 2 will test the translational value of ACSL4 modulation in preclinical models of IBD. The importance of ROS in IBD emphasizes the need to understand how ROS can lead to cell death and injury. Upon completion of these aims I will define novel mechanisms, therapeutic targets and downstream pathways which integrate cellular nutrient reprogramming and cell death in IBD.

摘要 炎症性肠病(IBD)是一种慢性复发性肠道炎症性疾病，其影响超过 美国每年有几百万人。IBD有两种主要形式，克罗恩病(CD)和溃疡性结肠炎 (UC)。慢性炎症和无调节的粘膜免疫激活导致自体上皮损伤 难以治疗的永久性循环，许多患者需要手术切除发炎的病灶。光盘 和UC在组织学上是不同的，但活性氧物种(ROS)的增加是一个标志 适用于CD和UC。ROS的增加被认为是IBD上皮细胞死亡的主要机制。 事实上，抗氧化剂治疗后，结肠炎的小鼠模型可以高度保护组织免受损伤。然而， 抑制IBD患者的ROS只对患者的疾病活动有轻微的好处。我们非常感激， ROS可以通过调节和非调节的细胞死亡途径和更好的特性来诱导细胞死亡 其中，IBD需要这些药物。挖掘IBD的一个大型RNA-seq数据库，我们鉴定出一个铁和脂的特征。 铁诱导的脂质过氧化是最近被描述的一种称为铁性下垂的细胞死亡的标志。 研究最多的两个铁下垂效应因子是XC转运蛋白系统和谷胱甘肽过氧化物酶。 (GPX)4.系统XC-是一个异构体氨基酸逆向转运体，介导胞外半胱氨酸的输入 以换取细胞内的谷氨酸。SLC7A11是具有转运活性的二聚体的亚基。 细胞内的半胱氨酸被转化为半胱氨酸，用于生产抗氧化剂谷胱甘肽。Gpx4利用 谷胱甘肽可降低过氧化脂质。铁性上睑下垂可以通过药物或 SLC7A11或Gpx4的遗传抑制。最近的研究表明，铁性下垂高度整合到 细胞脂代谢和长链脂肪酸辅酶A连接酶(ACSL)4是 铁性下垂。ACSL4缺失导致耐药性，而表达增加导致易感性 铁性下垂。我的研究表明，在急性肠道损伤模型中，没有观察到铁性下垂。然而，铁性下垂是一种 IBD患者样本和慢性肠道损伤小鼠模型的主要标志。有趣的是，删除 肠上皮细胞中的Gpx4或SLC7A11在基础或急性结肠炎模型中不增加铁性下垂。 然而，在慢性肠道损伤模型中，这些小鼠高度敏感。与这些数据一致的是，我 研究表明，ACSL4在IBD中显著上调，但在急性肠损伤模型中不明显。在基础上建设 初步数据，我假设在慢性炎症中，通过ACSL4的细胞脂质重编程启动 炎症性肠病的铁性下垂。目的1将评估铁下垂抑制剂是否是IBD模型的中枢保护机制。 目的2将验证ACSL4调节在IBD临床前模型中的翻译价值。ROS的重要性 在IBD中强调需要了解ROS如何导致细胞死亡和损伤。在完成这些任务后 目标I将定义整合细胞的新机制、治疗靶点和下游途径 IBD的营养重新编程和细胞死亡。