Mass Spectrometric Characterization of Circulating Covalent Protein Adducts Derived from Epoxide Metabolites of Carbamazepine in Patients
Mass Spectrometric Characterization of Circulating Covalent Protein Adducts Derived from Epoxide Metabolites of Carbamazepine in Patients
复制标题
DOI：
10.1021/acs.chemrestox.7b00063
复制
发表时间：
2017-07-01
影响因子：
4.1
通讯作者：
Pirmohamed, Munir
中科院分区：
文献类型：
--
作者：
Yip, Vincent L. M.;Meng, Xiaoli;Pirmohamed, Munir
卡马西平（CBZ）是一种有效的抗癫痫药物，但与过敏反应有关。这些反应的发病机制尚不完全清楚，但假设涉及药物代谢、人类白细胞抗原的遗传变异和免疫系统的不良激活之间的复杂相互作用。已经假设了多种T细胞活化机制，包括通过衍生自由反应性代谢物半抗原化的蛋白质的药物肽缀合物的活化。然而，缺乏患者体内药物蛋白加合物的确切证据。在这项研究中，质谱法被用来表征蛋白质修饰的微粒体产生的代谢产物的CBZ和服用CBZ治疗的患者。CBZ 10，11-环氧化物（CBZE）是CBZ的主要亲电血浆代谢产物，在体外通过显著不同的侧链选择性与谷胱甘肽-S-转移酶pi（GSTP; Cys 47）和人血清白蛋白（HSA; His 146和His 338，但不与Cys 34）形成加合物。当与人肝微粒体、NADPH和CBZ孵育时，两种蛋白质在相同残基处被未定义的单氧代谢产物（[0]CBZ）加合。还有证据表明，通过中间体芳烃氧化物加合物的脱水，在HSA的His 146和His 338处形成了CBZ加合物。反应性代谢产物的Glucoprotein捕获证实了CBZE的微粒体生产，并指示芳烃氧化物的同时生产。在15例接受CBZ治疗的患者中，[0]在所有受试者中均检测到CBZ修饰的HSA（His 146）。加合物的相对量与CBZ的血浆浓度呈中度正相关（r（2）= 0.44，p = 0.002）和CBZE = 0.35，p = 0.006）。我们的研究结果提供了第一个化学证据，微粒体生产的[0]CBZ种类，能够逃脱微粒体域共价反应与可溶性蛋白。本研究还证明了接受标准CBZ治疗的无超敏反应患者中存在循环[0] CBZ修饰的HSA。这些循环加合物对CBZ超敏反应敏感性的影响值得在超敏患者中进行进一步的免疫学研究。
Carbamazepine (CBZ) is an effective anti epileptic drug that has been associated with hypersensitivity reactions. The pathogenesis of those reactions is incompletely understood but is postulated to involve a complex interplay between the drug's metabolism, genetic variation in human leukocyte antigens, and adverse activation of the immune system. Multiple T-cell activation mechanisms have been hypothesized including activation by drug peptide conjugates derived from proteins haptenated by reactive metabolites. However, definitive evidence of the drug protein adducts in patients has been lacking. In this study, mass spectrometry was used to characterize protein modifications by microsomally-generated metabolites of CBZ and in patients taking CBZ therapy. CBZ 10,11-epoxide (CBZE), a major electrophilic plasma metabolite of CBZ, formed adducts with glutathione-S-transferase pi (GSTP; Cys47) and human serum albumin (HSA; His146 and His338, but not Cys34) in vitro via notably divergent side-chain selectivity. Both proteins were adducted at the same residues by undefined monoxygenated metabolites ([0]CBZ) when they were incubated with human liver microsomes, NADPH and CBZ. There was also evidence for formation of a CBZ adduct at His146 and His338 of HSA derived via dehydration from an intermediate arene oxide adduct. Glutathione trapping of reactive metabolites confirmed microsomal production of CBZE and indicated simultaneous production of arene oxides. In 15 patients prescribed CBZ therapy, [0]CBZ-modified HSA (His146) was detected in all subjects. The relative amount of adduct was moderately positively correlated with plasma concentrations of CBZ (r(2) = 0.44, p = 0.002) and CBZE = 0.35, p = 0.006). Our results have provided the first chemical evidence for microsomal production of [0]CBZ species that are able to escape the microsomal domain to react covalently with soluble proteins. This study has also demonstrated the presence of circulating [0] CBZ-modified HSA in patients without hypersensitivity reactions who were receiving standard CBZ therapy. The implications of those circulating adducts for susceptibility to CBZ hypersensitivity merit further immunological investigation in hypersensitive patients.