Targeting RAC1 as a novel strategy to reduce inflammation and liver damage in acute liver failure.

Background & Aims: The Rho GTPase RAC1 regulates key drivers of acute liver failure (ALF) such as oxidative stress and inflammation. The goal of this study was to determine the therapeutic potential of RAC1 pharmacological inhibition in ALF. Methods: The involvement of RAC1 in human ALF was explored by analyzing public transcriptome datasets. Murine models of ALF were induced by administration of either Concanavalin A, acetaminophen or D-Galactosamine/Lipopolysaccharide. In vitro assays were conducted on hepatocytes and macrophages primary cultures and cell lines. 1D-142 was used to explore the effect of RAC1 pharmacological inhibition. RNA-Seq analysis was performed and correlated with ALF human datasets to explore the therapeutic potential of RAC1 inhibition. Liver explants from patients with liver failure were treated in vitro with 1D-142. Results: RAC1-related pathways are upregulated in human ALF samples and correlate with immune activation and oxidative stress. Administration of 1D-142 ameliorated liver damage across all ALF murine models. 1D-142 treatment diminishes reactive oxygen species formation and reduces inflammatory cells migration and suppresses cytokine production both in vivo and in vitro. Transcriptome analysis of treated livers indicates that RAC1 pharmacological inhibition modulates dysregulated biological processes observed in ALF patients. Liver explants from ALF patients treated with 1D-142 exhibited reduced necrosis and reduced expression of pro-inflammatory genes. Conclusions: RAC1 plays a critical role in driving inflammation and oxidative stress in ALF. Targeted inhibition of RAC1 with 1D-142 protects against ALF in murine models; thus, RAC1 inhibition could be a potential therapeutic option for ALF. Transcriptomic Profiling of C57BL/6J Mouse Livers During Acute Liver Failure Induced by acetaminophen or concanavalin A and Treated with the RAC1 Inhibitor 1D-142

研究背景与目的：Rho GTP酶RAC1可调控急性肝衰竭（acute liver failure，ALF）的关键驱动因素，如氧化应激与炎症反应。本研究旨在明确RAC1药物抑制在急性肝衰竭中的治疗潜力。
研究方法：通过分析公共转录组数据集，探究RAC1在人类急性肝衰竭中的参与作用。采用刀豆蛋白A（Concanavalin A）、对乙酰氨基酚（acetaminophen）或D-半乳糖胺/脂多糖（D-Galactosamine/Lipopolysaccharide）诱导构建急性肝衰竭小鼠模型。体外实验分别在原代肝细胞、原代巨噬细胞培养体系及细胞系中开展。使用1D-142探究RAC1药物抑制的效应，开展RNA测序（RNA-Seq）分析，并与人类急性肝衰竭数据集关联分析，以探索RAC1抑制的治疗潜力。将肝衰竭患者的肝外植体进行体外培养，并用1D-142进行干预处理。
研究结果：人类急性肝衰竭样本中RAC1相关通路呈上调表达，且与免疫激活及氧化应激水平密切相关。给予1D-142治疗可改善所有急性肝衰竭小鼠模型的肝损伤程度。1D-142治疗可在体内外减少活性氧生成、抑制炎性细胞迁移并降低细胞因子产生。对给药后肝脏的转录组分析显示，RAC1药物抑制可调控急性肝衰竭患者体内观察到的失调生物学过程。经1D-142处理的急性肝衰竭患者肝外植体可见坏死程度减轻及促炎基因表达水平下调。
研究结论：RAC1在驱动急性肝衰竭的炎症反应与氧化应激过程中发挥关键作用。使用1D-142靶向抑制RAC1可在小鼠模型中对急性肝衰竭起到保护作用，因此RAC1抑制有望成为急性肝衰竭的潜在治疗方案。
经RAC1抑制剂1D-142干预的、由对乙酰氨基酚或刀豆蛋白A诱导的急性肝衰竭C57BL/6J小鼠肝脏转录组分析