Identification of new mechanistic biomarkers of adverse responses to acetaminophe

对乙酰氨基酚(APAP)是世界上最常用的治疗疼痛和发烧的药物。 今天，它也是美国急性肝功能衰竭的主要原因。APAP的初始阶段 毒性已经得到了很好的表征，涉及到母药的生物转化为化学 反应性代谢物N-乙酰-对苯醌亚胺(NAPQI)，它与细胞蛋白质共价结合。 NAPQI通过与肝脏谷胱甘肽(GSH)上的半胱氨酸硫醇结合来解毒。中毒的APAP 暴露后，GSH储备耗尽，增加了NAPQI与半胱氨酸硫醇结合的量 细胞蛋白质，产生各种APAP-蛋白质加合物。这项提案的牵头站点开创了 总APAP蛋白加合物(APAP加合物)作为APAP毒性和临床标志物的测定 在患有急性APAP过量、APAP相关急性肝功能衰竭、 最近，在接受APAP推荐剂量的患者中。接受推荐剂量的成年人 在APAP中，检测到低水平的APAP加合物，并发现较高的APAP-加合物水平与APAP-加合物有关。 这些患者的加合物水平和较高的转氨酶水平升高。根据我们最近的调查 数据，将检验以下假设；在接触过APAP的儿童和青少年中，(1) 将在接受治疗性暴露的住院儿童中检测到APAP加合物，(2) 存在独特的和特定的APAP加合物蛋白，并且随着APAP的大小而不同 和，(3)独特的蛋白质加合物将与既定的措施和共同 APAP毒性的各种变化。使用最先进的、专注于加合物的蛋白质组学方法， 该提案将识别和评估APAP毒性的特定“第二代”生物标志 接受治疗剂量的APAP的儿童/青少年和已经接受治疗的儿童/青少年 APAP过量。儿科学术中心参与儿科药理学网络 研究单位(PPRU；国家儿童健康和人类发展研究所)将协助临床 样本收集、分析和药代动力学数据分析。特异性APAP蛋白的鉴定 与新近描述的新陈代谢组学标志相关的加合物和这些特定加合物的检测 APAP毒性和已建立的肝脏毒性指数将为未来的改进奠定基础 评估儿童和青少年发生急性胰腺炎的风险和安全性。

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.