Identification of new mechanistic biomarkers of adverse responses to acetaminophe

对乙酰氨基酚（Acetaminophen，APAP）是世界上最常用的治疗疼痛和发热的药物 在美国也是急性肝衰竭的主要原因。《亚太行动计划》的初始阶段 毒性已经得到了很好的表征，涉及母体药物的生物转化为化学上 反应性代谢物N-乙酰基-对苯醌亚胺（NAPQI），与细胞蛋白质共价结合。 NAPQI通过与肝谷胱甘肽（GSH）上的半胱氨酰巯基结合而解毒。在有毒的APAP中 暴露后，GSH储备耗尽，增加了与半胱氨酰硫醇结合的NAPQI的量， 细胞蛋白，产生各种APAP-蛋白加合物。这一提案的牵头网站开创了 总APAP-蛋白加合物（APAP-ADDUCTS）的测量作为APAP毒性的临床标志物， 在患有急性APAP过量，APAP相关急性肝衰竭， 最近，在接受推荐剂量APAP的患者中。在接受推荐剂量的成人中 在APAP中，检测到低水平的APAP-加合物，并发现较高的APAP- 这些患者的ADDUCT水平和较高的转氨酶水平升高。根据我们最近的 数据，将测试以下假设;。在APAP暴露的儿童和青少年中，（1） 在接受治疗暴露的住院儿童中将检测到APAP-加合物，（2） 存在独特和特异的APAP加合物蛋白，并且作为APAP大小的函数而不同 暴露，（3）独特的蛋白质加合物将对应于既定的措施和共同- APAP毒性的变化。使用最先进的、以内收物为重点的蛋白质组学方法， 该提案将确定和评估APAP毒性的特定“第二代”生物标志物， 接受治疗剂量APAP的儿童/青少年和接受 过量的APAP参加儿科药理学网络的儿科学术中心 研究单位（PPRU;国家儿童健康和人类发展研究所）将协助临床 样品收集和分析及药代动力学数据分析。特异性APAP蛋白的鉴定 加合物和检查这些特定的加合物相对于新描述的代谢组学标志物， APAP的毒性和肝毒性指标的建立将为今后的研究奠定基础 儿童和青少年APAP的风险和安全性评估。

Acetaminophen (APAP) is the most common drug used for the treatment of pain and fever in the world today and is also the leading cause of acute liver failure in the United States. The initial stages of APAP toxicity have been well-characterized and involve the biotransformation of the parent drug to a chemically reactive metabolite N-acetyl-p-benzoquinone imine (NAPQI), which binds covalently to cellular proteins. NAPQI is detoxified by binding to the cysteinyl thiol on hepatic glutathione (GSH). In toxic APAP exposures, GSH reserves are depleted, increasing the amount of NAPQI that binds to cysteinyl thiols on cellular proteins, producing a variety of APAP-protein adducts. The lead site for this proposal pioneered the measurement of total APAP-protein adducts (APAP-ADDUCTS) as clinical markers of APAP toxicity and tested this biomarker in children and adults with acute APAP overdose, APAP-related acute liver failure, and recently, in patients receiving recommended doses of APAP. In adults receiving recommended doses of APAP, low levels of APAP-ADDUCTS were detected and an association was found for higher APAP- ADDUCT levels and higher elevated transaminase values levels in these patients. Based on our recent data, the following hypotheseis will be tested;. In children and adolescents with APAP exposures, (1) APAP-ADDUCTS will be detected in hospitalized children receiving therapeutic exposures, (2) unique and specific APAP adduct proteins exist and differ as a function of the magnitude of APAP exposure and, (3) unique protein adducts will correspond with established measures and co- variates of APAP toxicity. Using state-of-the-art, adduct-focused proteomic approaches, the following proposal will identify and evaluateexamine specific "second generation" biomarkers of APAP toxicity in children/adolescents receiving therapeutic doses of APAP and in children/adolescents that have received overdoses of APAP. Pediatric academic centers participating in the Network of Pediatric Pharmacology Research Units (PPRU; National Institutes of Child Health and Human Development) will assist with clinical sample collection and analytical and pharmacokinetic data analysis. Identification of specific APAP protein adducts and examination of these specific adducts relative to newly described metabolomic markers of APAP toxicity and established indices of liver toxicity will lay the foundation for improved future assessments of risk and safety for APAP in children and adolescents.