Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA.
Redox Biol. 2023 Aug;64:102792. doi: 10.1016/j.redox.2023.102792. Epub 2023 Jun 22.
In the U.S., alcohol-associated liver disease (ALD) impacts millions of people and is a major healthcare burden. While the pathology of ALD is unmistakable, the molecular mechanisms underlying ethanol hepatotoxicity are not fully understood. Hepatic ethanol metabolism is intimately linked with alterations in extracellular and intracellular metabolic processes, specifically oxidation/reduction reactions. The xenobiotic detoxification of ethanol leads to significant disruptions in glycolysis, β-oxidation, and the TCA cycle, as well as oxidative stress. Perturbation of these regulatory networks impacts the redox status of critical regulatory protein thiols throughout the cell. Integrating these key concepts, our goal was to apply a cutting-edge approach toward understanding mechanisms of ethanol metabolism in disrupting hepatic thiol redox signaling. Utilizing a chronic murine model of ALD, we applied a cysteine targeted click chemistry enrichment coupled with quantitative nano HPLC-MS/MS to assess the thiol redox proteome. Our strategy reveals that ethanol metabolism largely reduces the cysteine proteome, with 593 cysteine residues significantly reduced and 8 significantly oxidized cysteines. Ingenuity Pathway Analysis demonstrates that ethanol metabolism reduces specific cysteines throughout ethanol metabolism (Adh1, Cat, Aldh2), antioxidant pathways (Prx1, Mgst1, Gsr), as well as many other biochemical pathways. Interestingly, a sequence motif analysis of reduced cysteines showed a correlation for hydrophilic, charged amino acids lysine or glutamic acid nearby. Further research is needed to determine how a reduced cysteine proteome impacts individual protein activity across these protein targets and pathways. Additionally, understanding how a complex array of cysteine-targeted post-translational modifications (e.g., S-NO, S-GSH, S-OH) are integrated to regulate redox signaling and control throughout the cell is key to the development of redox-centric therapeutic agents targeted to ameliorate the progression of ALD.
在美国，酒精相关性肝病（ALD）影响了数百万人，是一个主要的医疗保健负担。虽然 ALD 的病理学是不可否认的，但乙醇肝毒性的分子机制尚未完全了解。肝内乙醇代谢与细胞外和细胞内代谢过程的改变密切相关，特别是氧化/还原反应。乙醇的异生物质解毒导致糖酵解、β-氧化和 TCA 循环以及氧化应激的显著破坏。这些调节网络的扰动会影响整个细胞中关键调节蛋白巯基的氧化还原状态。整合这些关键概念，我们的目标是应用一种前沿方法来理解乙醇代谢破坏肝巯基氧化还原信号的机制。利用慢性 ALD 小鼠模型，我们应用了一种半胱氨酸靶向点击化学富集技术，结合定量纳米 HPLC-MS/MS 来评估巯基氧化还原蛋白质组。我们的策略表明，乙醇代谢主要降低半胱氨酸蛋白质组，其中 593 个半胱氨酸残基显著减少，8 个半胱氨酸残基显著氧化。Ingenuity 通路分析表明，乙醇代谢减少了整个乙醇代谢（Adh1、Cat、Aldh2）、抗氧化途径（Prx1、Mgst1、Gsr）以及许多其他生化途径中的特定半胱氨酸。有趣的是，还原半胱氨酸的序列基序分析显示，附近的亲水、带电荷的氨基酸赖氨酸或谷氨酸与还原半胱氨酸有相关性。需要进一步研究以确定减少的半胱氨酸蛋白质组如何影响这些蛋白质靶标和途径中单个蛋白质的活性。此外，了解如何整合复杂的半胱氨酸靶向翻译后修饰（例如 S-NO、S-GSH、S-OH）来调节氧化还原信号并控制整个细胞，是开发针对改善 ALD 进展的氧化还原中心治疗剂的关键。
