Reactive Metabolite-induced Protein Glutathionylation: A Potentially Novel Mechanism Underlying Acetaminophen Hepatotoxicity
Reactive Metabolite-induced Protein Glutathionylation: A Potentially Novel Mechanism Underlying Acetaminophen Hepatotoxicity
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DOI：
10.1074/mcp.ra118.000875
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发表时间：
2018-10-01
影响因子：
7
通讯作者：
Chan, Eric Chun Yong
中科院分区：
文献类型：
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作者：
Chan, James Chun Yip;Soh, Alex Cheow Khoon;Chan, Eric Chun Yong
虽然共价蛋白结合被认为是对乙酰氨基酚(APAP)毒性的关键事件，但其机制细节仍不清楚。在这项研究中，我们证明了APAP以时间、剂量和生物激活依赖的方式在HepaRG细胞中诱导广泛的蛋白质谷胱甘肽基化。蛋白质代谢组学图谱提供的证据表明，APAP诱导的谷胱甘肽基化导致能量代谢功能障碍、氧化应激和胞浆钙升高，以及线粒体功能障碍，这与APAP公认的毒性特征密切相关。我们还提供了新的证据，APAP诱导的肉碱O-棕榈酰基转移酶1(CPT1)的谷胱甘肽基化和电压依赖的阴离子选择通道蛋白1分别参与了抑制脂肪酸β氧化和开放线粒体通透性转换孔。重要的是，我们发现CPT1谷胱甘肽的抑制作用可以被PPARα诱导缓解，这为PPARα配体贝特对APAP毒性的预防作用提供了机制解释。最后，我们认为APAP诱导的蛋白质谷胱甘肽基化可能发生在共价结合之后，这是以前未知的谷胱甘肽修饰机制，提示这种翻译后修饰可能在药物诱导的毒性中起作用。
Although covalent protein binding is established as the pivotal event underpinning acetaminophen (APAP) toxicity, its mechanistic details remain unclear. In this study, we demonstrated that APAP induces widespread protein glutathionylation in a time-, dose- and bioactivation-dependent manner in HepaRG cells. Proteo-metabonomic mapping provided evidence that APAP-induced glutathionylation resulted in functional deficits in energy metabolism, elevations in oxidative stress and cytosolic calcium, as well as mitochondrial dysfunction that correlate strongly with the well-established toxicity features of APAP. We also provide novel evidence that APAP-induced glutathionylation of carnitine O-palmitoyltransferase 1 (CPT1) and voltage-dependent anion-selective channel protein 1 are respectively involved in inhibition of fatty acid beta-oxidation and opening of the mitochondrial permeability transition pore. Importantly, we show that the inhibitory effect of CPT1 glutathionylation can be mitigated by PPAR alpha induction, which provides a mechanistic explanation for the prophylactic effect of fibrates, which are PPAR alpha ligands, against APAP toxicity. Finally, we propose that APAP-induced protein glutathionylation likely occurs secondary to covalent binding, which is a previously unknown mechanism of glutathionylation, suggesting that this post-translational modification could be functionally implicated in drug-induced toxicity.