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: 10041615
• 负责人: Karen Reue
• 金额: $ 20.59万
• 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/10041615
• 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.

摘要/摘要 降低胆固醇的他汀类药物可显着降低心血管发病率和死亡率，但一部分 他汀类药物的使用者会经历肌肉疼痛/软弱，这限制了他汀类药物在这些人中的效用。更好 对他汀类药物诱导的肌病的遗传易感性的理解将提高我们对 发病机理，还提出了预防和治疗这些症状的新策略。此应用程序建立在 我们对一个新的遗传基因座的鉴定，它影响了他汀类药物诱导的肌病的敏感性。使用 我们评估 辛伐他汀在800多只小鼠中。我们对全基因组关联（GWAS）和 表达定量位置（EQTL）数据将TPMT识别为一种高概率的休闲基因 与他汀类药物引起的肌病有关。 TPMT基因编码硫嘌呤S-甲基转移酶的酶 （tpmt），它代谢异生物，例如硫嘌呤药物；唯一已知的内源性底物是 硒代半胱氨酸，一种选择性地掺入硒蛋白的氨基酸，在硒蛋白中具有关键作用 维持细胞氧化还原状态。硒蛋白合成需要产生的等异戊烯基中间体 通过HMG COA途径进行胆固醇合成，并在他汀类药物的存在下降低。 有趣的是，某些硒蛋白的不足会导致类似他汀类药物引起的肌肉符号 肌病。我们假设TPMT表达水平与他汀类药物结合 治疗构成了他汀类药物肌病的两次打击机制：（1）汀类药物限制了供应 异戊烯基组用于硒代半胱氨酸合成，（2）遗传变异导致TPMT水平升高 减少可用于蛋白质合成的硒代半胱氨酸池。我们将使用 体内和体外研究的组合。在AIM 1中，我们将确定调节TPMT级别的影响 他汀类药物治疗的小鼠通过使用腺相关病毒（AAV）介导的功能丧失方法 基因转移到我们定义为肌病的抑制或耐药的遗传背景中。转换 在肌病的敏感性和抵抗之间将提供有力的证据，表明TPMT是他汀类药物肌病 敏感性基因。在AIM 2中，我们将研究他汀类药物的每个成分 对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 在体内和培养的肝细胞中改变硒蛋白水平。接下来，我们将确定硒蛋白是否 水平影响他汀类药物引起的肌毒性在培养的肌管中。最后，我们将评估 肌细胞线粒体功能和活性氧水平上的他汀类药物/硒蛋白。完成 我们的目标将有助于洞察他汀类药物肌病的遗传敏感性和发病机理，并建议 个性化他汀类药物疗法的策略。