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

基本信息

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
项目类别：
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

项目摘要

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/摘要降胆固醇他汀类药物可显着降低心血管发病率和死亡率，但其中一部分他汀类药物使用者会出现肌肉疼痛/无力，这限制了他汀类药物在这些人中的效用。了解他汀类药物诱发的肌病的遗传易感性将促进我们对他汀类药物引起的肌病的理解发病机制并提出了预防和治疗这些症状的新策略。我们使用一个新的基因位点来影响他汀类药物引起的肌病的易感性。 94 种不同近交系小鼠品系的独特遗传参考组，我们评估了我们对 800 多只小鼠的辛伐他汀进行了全基因组关联 (GWAS) 的综合分析和表达位点 (eQTL) 数据将 Tpmt 识别为高概率偶然基因，该基因专门针对与他汀类药物诱发的肌病相关。Tpmt 基因编码硫嘌呤 S-甲基转移酶。 (TPMT)，代谢异生物质，例如硫嘌呤药物；唯一已知的内源性底物是硒代半胱氨酸，一种选择性掺入硒蛋白的氨基酸，其在维持细胞氧化还原状态需要产生异戊烯基中间体。通过 HMG CoA 途径合成胆固醇，并且在他汀类药物存在的情况下会减少。有趣的是，某些硒蛋白不足会导致类似于他汀类药物引起的肌肉症状我们结合他汀类药物研究了 Tpmt 表达水平的遗传变异。治疗构成了诱发他汀类肌病的二次打击机制：（1）他汀类药物限制供应用于硒代半胱氨酸合成的异戊烯基团，以及（2）导致TPMT水平升高的遗传变异减少可用于蛋白质合成的硒代半胱氨酸库我们将使用以下方法来检验我们的假设。在目标 1 中，我们将结合体内和体外研究来确定调节 Tpmt 水平的效果。使用腺相关病毒（AAV）介导的功能获得和丧失方法对接受他汀类药物治疗的小鼠进行治疗基因转移到我们定义为肌病易感或抵抗的遗传背景中。肌病敏感性和耐药性之间的关系将为 Tpmt 是一种他汀类肌病提供有力的证据在目标 2 中，我们将研究他汀类药物-TPMT-硒蛋白轴的每个组成部分。我们将首先评估 Tpmt 表达水平的调节是否对他汀类肌病有潜在影响。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是否改变。最后，我们将评估他汀类药物在培养肌管中引起的肌毒性。他汀类药物/硒蛋白对心肌细胞线粒体功能和活性氧水平的影响。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，并提出建议个性化他汀类药物治疗策略。