Dobariya Prakashkumar, Xie Wei, Rao Swetha Pavani, Xie Jiashu, Seelig Davis M, Vince Robert, Lee Michael K, More Swati S
Center for Drug Design, College of Pharmacy, University of Minnesota, Minneapolis, MN 55455, USA.
Comparative Pathology Shared Resource, Masonic Cancer Center, University of Minnesota, St. Paul, MN 55108, USA.
Antioxidants (Basel). 2024 May 25;13(6):648. doi: 10.3390/antiox13060648.
Acetaminophen (APAP) overdose triggers a cascade of intracellular oxidative stress events, culminating in acute liver injury. The clinically used antidote, N-acetylcysteine (NAC), has a narrow therapeutic window, and early treatment is essential for a satisfactory therapeutic outcome. For more versatile therapies that can be effective even at late presentation, the intricacies of APAP-induced hepatotoxicity must be better understood. Accumulation of advanced glycation end products (AGEs) and the consequent activation of the receptor for AGEs (RAGE) are considered one of the key mechanistic features of APAP toxicity. Glyoxalase 1 (Glo-1) regulates AGE formation by limiting the levels of methylglyoxal (MEG). In this study, we studied the relevance of Glo-1 in the APAP-mediated activation of RAGE and downstream cell death cascades. Constitutive Glo-1-knockout mice (GKO) and a cofactor of Glo-1, ψ-GSH, were used as tools. Our findings showed elevated oxidative stress resulting from the activation of RAGE and hepatocyte necrosis through steatosis in GKO mice treated with high-dose APAP compared to wild-type controls. A unique feature of the hepatic necrosis in GKO mice was the appearance of microvesicular steatosis as a result of centrilobular necrosis, rather than the inflammation seen in the wild type. The GSH surrogate and general antioxidant ψ-GSH alleviated APAP toxicity irrespective of the Glo-1 status, suggesting that oxidative stress is the primary driver of APAP toxicity. Overall, the exacerbation of APAP hepatotoxicity in GKO mice suggests the importance of this enzyme system in antioxidant defense against the initial stages of APAP overdose.
对乙酰氨基酚(APAP)过量会引发一系列细胞内氧化应激事件,最终导致急性肝损伤。临床使用的解毒剂N - 乙酰半胱氨酸(NAC)治疗窗狭窄,早期治疗对于获得满意的治疗效果至关重要。对于即使在就诊较晚时也能有效的更通用疗法,必须更好地理解APAP诱导的肝毒性的复杂性。晚期糖基化终末产物(AGEs)的积累以及由此导致的AGEs受体(RAGE)的激活被认为是APAP毒性的关键机制特征之一。乙二醛酶1(Glo - 1)通过限制甲基乙二醛(MEG)的水平来调节AGE的形成。在本研究中,我们研究了Glo - 1在APAP介导的RAGE激活和下游细胞死亡级联反应中的相关性。组成型Glo - 1基因敲除小鼠(GKO)和Glo - 1的一种辅助因子ψ - GSH被用作工具。我们的研究结果表明,与野生型对照相比,高剂量APAP处理的GKO小鼠中,RAGE激活导致氧化应激升高,肝细胞通过脂肪变性发生坏死。GKO小鼠肝坏死的一个独特特征是由于小叶中心坏死导致的微泡性脂肪变性的出现,而不是野生型中所见的炎症。GSH替代物和一般抗氧化剂ψ - GSH无论Glo - 1状态如何都能减轻APAP毒性,这表明氧化应激是APAP毒性的主要驱动因素。总体而言,GKO小鼠中APAP肝毒性的加剧表明该酶系统在对抗APAP过量初始阶段的抗氧化防御中的重要性。