BACKGROUND & AIMS Hepatic ischaemia-reperfusion (I/R) injury is characterised by severe inflammation and extensive cell death. Multiple signalling pathways, including NF-κB and mitogen-activated protein kinase (MAPK)/c-Jun NH2-terminal kinase (JNK), have important roles in this process. Identifying the unknown critical regulators of these signalling pathways could provide potential targets for therapeutic application. Dual-specificity phosphatase 14 (DUSP14) acts as a negative regulator of NF-κB signalling. However, its function in hepatic I/R injury is unknown. METHODS Hepatocyte-specific Dusp14 knockout (HKO) and transgenic (TG) mice were subjected to hepatic I/R surgery to examine Dusp14 function in vivo. Primary hepatocytes isolated from Dusp14-HKO and Dusp14-TG mice were cultured and subjected to hypoxia/reoxygenation insult in vitro. Inflammatory cytokine production was measured using quantitative reverse transcription PCR and ELISA. Liver damage was analysed using histopathology. Co-immunoprecipitation and pull-down assays followed by Western blot were performed to detect Dusp14 and transforming growth factor (Tgf)-β-activated kinase 1 (Tak1) interactions. RESULTS Dusp14 was significantly downregulated in liver tissues from liver transplantation patients and mice subjected to hepatic I/R surgery. Dusp14-HKO and Dusp14-TG mouse models demonstrated that Dusp14 reduced cell death, ameliorated inflammation, and promoted hepatocyte proliferation and/or regeneration. Dusp14 also suppressed NF-κB and MAPK signalling via a physical interaction with Tak1, leading to its subsequent inhibition. Tak1 inhibition by 5Z-7-ox abolished Dusp14 function in vivo, indicating that TAK1 is required for Dusp14 function in hepatic I/R injury. Finally, mutant Dusp14 lost the ability to bind Tak1 and failed to protect against hepatic I/R injury. CONCLUSIONS Dusp14 is a protective factor in hepatic I/R injury, and the Dusp14-Tak1-Jnk1/2 regulatory axis is important for the pathogenesis of hepatic I/R injury. Modulation of this axis could be a novel therapeutic strategy to prevent or interfere with this pathological process. LAY SUMMARY Reductions in the level of the protein Dusp14 are closely associated with liver damage caused by inadequate blood supply followed by restoration of blood flow to the liver. Dusp14 protects against liver damage by suppressing the activity of Tak1. Targeting Dusp14 could be a strategy for prevention and treatment of this disease.

中文翻译：

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Dusp14 通过抑制 Tak1 防止肝缺血再灌注损伤

背景和目的 肝缺血再灌注 (I/R) 损伤的特征是严重的炎症和广泛的细胞死亡。多种信号通路，包括 NF-κB 和丝裂原活化蛋白激酶 (MAPK)/c-Jun NH2-末端激酶 (JNK)，在这一过程中发挥着重要作用。识别这些信号通路的未知关键调节剂可以为治疗应用提供潜在的目标。双特异性磷酸酶 14 (DUSP14) 充当 NF-κB 信号传导的负调节剂。然而，其在肝 I/R 损伤中的作用尚不清楚。方法 对肝细胞特异性 Dusp14 敲除 (HKO) 和转基因 (TG) 小鼠进行肝脏 I/R 手术以检查体内 Dusp14 功能。培养从 Dusp14-HKO 和 Dusp14-TG 小鼠分离的原代肝细胞并在体外进行缺氧/复氧损伤。使用定量逆转录PCR和ELISA测量炎症细胞因子的产生。使用组织病理学分析肝损伤。进行免疫共沉淀和下拉测定，然后进行蛋白质印迹以检测 Dusp14 和转化生长因子 (Tgf)-β-活化激酶 1 (Tak1) 的相互作用。结果 Dusp14 在肝移植患者和接受肝 I/R 手术的小鼠的肝组织中显着下调。Dusp14-HKO 和 Dusp14-TG 小鼠模型表明，Dusp14 可减少细胞死亡、改善炎症并促进肝细胞增殖和/或再生。Dusp14 还通过与 Tak1 的物理相互作用抑制 NF-κB 和 MAPK 信号传导，从而导致其随后的抑制。5Z-7-ox 对 Tak1 的抑制在体内消除了 Dusp14 功能，表明 TAK1 是肝脏 I/R 损伤中 Dusp14 功能所必需的。最后，突变体 Dusp14 失去了结合 Tak1 的能力，无法保护肝脏 I/R 损伤。结论 Dusp14是肝I/R损伤的保护因子，Dusp14-Tak1-Jnk1/2调控轴在肝I/R损伤的发病机制中起重要作用。该轴的调节可能是一种预防或干扰该病理过程的新治疗策略。LAY Summary 蛋白质 Dusp14 水平的降低与血液供应不足引起的肝损伤密切相关，随后恢复了流向肝脏的血流量。Dusp14 通过抑制 Tak1 的活性来防止肝损伤。靶向 Dusp14 可能是预防和治疗这种疾病的策略。突变体 Dusp14 失去了结合 Tak1 的能力，无法防止肝脏 I/R 损伤。结论 Dusp14是肝I/R损伤的保护因子，Dusp14-Tak1-Jnk1/2调控轴在肝I/R损伤的发病机制中起重要作用。该轴的调节可能是一种预防或干扰该病理过程的新治疗策略。LAY Summary 蛋白质 Dusp14 水平的降低与血液供应不足引起的肝损伤密切相关，随后恢复了流向肝脏的血流量。Dusp14 通过抑制 Tak1 的活性来防止肝损伤。靶向 Dusp14 可能是预防和治疗这种疾病的策略。突变体 Dusp14 失去了结合 Tak1 的能力，无法防止肝脏 I/R 损伤。结论 Dusp14是肝I/R损伤的保护因子，Dusp14-Tak1-Jnk1/2调控轴在肝I/R损伤的发病机制中起重要作用。该轴的调节可能是一种预防或干扰该病理过程的新治疗策略。LAY Summary 蛋白质 Dusp14 水平的降低与血液供应不足引起的肝损伤密切相关，随后恢复了流向肝脏的血流量。Dusp14 通过抑制 Tak1 的活性来防止肝损伤。靶向 Dusp14 可能是预防和治疗这种疾病的策略。结论 Dusp14是肝I/R损伤的保护因子，Dusp14-Tak1-Jnk1/2调控轴在肝I/R损伤的发病机制中起重要作用。该轴的调节可能是一种预防或干扰该病理过程的新治疗策略。LAY Summary 蛋白质 Dusp14 水平的降低与血液供应不足引起的肝损伤密切相关，随后恢复了流向肝脏的血流量。Dusp14 通过抑制 Tak1 的活性来防止肝损伤。靶向 Dusp14 可能是预防和治疗这种疾病的策略。结论 Dusp14是肝I/R损伤的保护因子，Dusp14-Tak1-Jnk1/2调控轴在肝I/R损伤的发病机制中起重要作用。该轴的调节可能是一种预防或干扰该病理过程的新治疗策略。LAY Summary 蛋白质 Dusp14 水平的降低与血液供应不足引起的肝损伤密切相关，随后恢复了流向肝脏的血流量。Dusp14 通过抑制 Tak1 的活性来防止肝损伤。靶向 Dusp14 可能是预防和治疗这种疾病的策略。LAY Summary 蛋白质 Dusp14 水平的降低与血液供应不足引起的肝损伤密切相关，随后恢复了流向肝脏的血流量。Dusp14 通过抑制 Tak1 的活性来防止肝损伤。靶向 Dusp14 可能是预防和治疗这种疾病的策略。LAY Summary 蛋白质 Dusp14 水平的降低与血液供应不足引起的肝损伤密切相关，随后恢复了流向肝脏的血流量。Dusp14 通过抑制 Tak1 的活性来防止肝损伤。靶向 Dusp14 可能是预防和治疗这种疾病的策略。