A novel gene and mechanisms for statin-induced myopathy in the mouse

他汀类药物诱导的小鼠肌病的新基因和机制

• 批准号: 10265483
• 负责人: Karen Reue
• 金额: $ 16.65万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-09-17 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10265483
• 关键词: 3-hydroxy-3-methylglutaryl-coenzyme A; Adverse effects; Amino Acids; Candidate Disease Gene; Cardiovascular system; Cells; Cholesterol; Data; Dependovirus; Enzymes; Gene Transfer; Genes; Genetic; Genetic Predisposition to Disease; Genetic Variation; Hepatocyte; Impairment; In Vitro; Inbred Strains Mice; Individual; Mediating; Metabolism; Mitochondria; Morbidity - disease rate; Mus; Muscle; Muscle Cells; Muscle Fibers; Muscle Weakness; Muscle function; Myalgia; Myopathy; Oxidation-Reduction; Pathogenesis; Pathway interactions; Pharmaceutical Preparations; Predisposition; Probability; Protein Biosynthesis; Proteins; Reactive Oxygen Species; Resistance; Role; Selenocysteine; Simvastatin; Susceptibility Gene; Symptoms; TPMT gene; Testing; Transfer RNA; Work; Xenobiotics; base; cardiovascular disorder risk; cell growth regulation; experience; genetic variant; genome wide association study; genome-wide analysis; genomic locus; in vivo; insight; loss of function; mortality; muscle metabolism; novel; personalized strategies; prevent; selenoprotein; side effect; symptom treatment; thiopurine; thiopurine methyltransferase

SUMMARY/ABSTRACT Cholesterol-lowering statin drugs significantly reduce cardiovascular morbidity and mortality, but a subset of statin users experience muscle pain/weakness, which limits the utility of statins in these individuals. A better understanding of the genetic predisposition to statin-induced myopathy will advance our understanding of the pathogenesis and also suggest new strategies to prevent and treat these symptoms. This application builds on our identification of a novel genetic locus that influences susceptibility to statin-induced myopathy. Using a unique genetic reference panel of 94 diverse inbred mouse strains, we assessed the adverse effects of simvastatin in more than 800 individual mice. Our integrated analysis of genome-wide association (GWAS) and expression quantitative loci (eQTL) data identified Tpmt as a high-probability casual gene that is specifically associated with statin-induced myopathy. The Tpmt gene encodes the enzyme thiopurine S-methyltransferase (TPMT), which metabolizes xenobiotics such as thiopurine drugs; the only known endogenous substrate is selenocysteine, an amino acid that is selectively incorporated into selenoproteins, which have critical roles in maintaining cellular redox state. Selenoprotein synthesis requires isopentenyl intermediates that are produced by the HMG CoA pathway for cholesterol synthesis, and which are reduced in the presence of statins. Interestingly, insufficiency of some selenoproteins causes muscle symptoms that resemble statin-induced myopathy. We hypothesize that genetic variation in Tpmt expression levels in combination with statin treatment constitutes a two-hit mechanism for the induction of statin myopathy: (1) statin limits the supply of isopentenyl groups for selenocysteine synthesis, and (2) genetic variation causing elevated TPMT levels reduces the pool of selenocysteine available for protein synthesis. We will test our hypothesis using a combination of in vivo and in vitro studies. In Aim 1, we will determine the effect of modulating Tpmt levels in statin-treated mice through gain- and loss-of-function approaches using adeno-associated virus (AAV)-mediated gene transfer into genetic backgrounds that we have defined as myopathy-susceptible or -resistant. Conversion between myopathy sensitivity and resistance will provide strong evidence that Tpmt is a statin myopathy susceptibility gene. In Aim 2, we will investigate each component of the statin–TPMT–selenoprotein axis for potential contributions to statin myopathy. We will first assess whether modulation of Tpmt expression levels alters selenoprotein levels in vivo and in cultured hepatocytes. We will next determine whether selenoprotein levels influence statin-induced myotoxicity in cultured myotubes. Finally, we will assess the effects of statin/selenoproteins on myocyte mitochondrial function and reactive oxygen species levels. The completion of our aims will contribute insights into the genetic susceptibility and pathogenesis of statin myopathy, and suggest strategies for personalized statin therapy.

总结/摘要 降胆固醇他汀类药物可显着降低心血管发病率和死亡率，但也有一部分 他汀类药物使用者经历肌肉疼痛/无力，这限制了他汀类药物在这些个体中的效用。更好的 了解他汀类药物诱导的肌病的遗传易感性将促进我们对 发病机制，并提出新的策略，以预防和治疗这些症状。此应用程序基于 我们发现了一个新的影响他汀类药物诱导的肌病易感性的遗传位点。使用 独特的遗传参考面板的94个不同的近交系小鼠品系，我们评估了不利影响， 辛伐他汀在800多只小鼠中的作用。我们对全基因组关联（GWAS）和 表达数量基因座（eQTL）数据确定Tpmt作为一个高概率的因果基因， 与他汀类药物引起的肌病有关Tpmt基因编码硫嘌呤S-甲基转移酶 （TPMT），其代谢异生物质如硫嘌呤药物;唯一已知的内源性底物是 硒代半胱氨酸是一种选择性地结合到硒蛋白中的氨基酸，其在 维持细胞的氧化还原状态。硒蛋白的合成需要异戊烯基中间体， 通过HMG CoA途径合成胆固醇，并且在他汀类药物存在下减少。 有趣的是，某些硒蛋白不足会导致类似他汀类药物诱导的肌肉症状。 肌病我们假设Tpmt表达水平的遗传变异与他汀类药物联合使用 治疗构成了诱导他汀类肌病的双重机制：（1）他汀类限制了供应， 硒代半胱氨酸合成的异戊烯基，以及（2）导致TPMT水平升高的遗传变异 减少了可用于蛋白质合成的硒代半胱氨酸库。我们将使用一个 结合体内和体外研究。在目标1中，我们将确定调节Tpmt水平的影响 通过使用腺相关病毒（AAV）介导的功能获得和丧失方法， 基因转移到我们定义为肌病易感或抵抗的遗传背景中。转换 肌病敏感性和抵抗性之间的关系将为Tpmt是他汀类肌病提供强有力的证据 易感基因在目标2中，我们将研究他汀类药物-TPMT-硒蛋白轴的每个组成部分， 他汀类肌病的潜在贡献。我们将首先评估Tpmt表达水平的调节是否 改变体内和培养的肝细胞中的硒蛋白水平。接下来我们将确定硒蛋白 水平影响培养的肌管中他汀类药物诱导的肌毒性。最后，我们将评估 他汀类/硒蛋白对肌细胞线粒体功能和活性氧水平的影响。完成 我们的目标将有助于深入了解他汀类肌病的遗传易感性和发病机制，并建议 个性化他汀类药物治疗的策略。