Department of Pediatrics, Section of Pediatric Gastroenterology, Hepatology and Nutrition, University of Colorado School of Medicine, Aurora, Colorado, USA.
Digestive Health Institute, Children's Hospital Colorado, Aurora, Colorado, USA.
Hepatol Commun. 2023 Jan 10;7(1):e0020. doi: 10.1097/HC9.0000000000000020. eCollection 2023 Jan 1.
Cholestatic liver diseases, including primary sclerosing cholangitis, are characterized by periportal inflammation with progression to hepatic fibrosis and ultimately cirrhosis. We recently reported that the thioredoxin antioxidant response is dysregulated during primary sclerosing cholangitis. The objective of this study was to examine the impact of genetic and pharmacological targeting of thioredoxin reductase 1 (TrxR1) on hepatic inflammation and liver injury during acute cholestatic injury.
Primary mouse hepatocytes and intrahepatic macrophages were isolated from 3-day bile duct ligated (BDL) mice and controls. Using wildtype and mice with a liver-specific deletion of TrxR1 (TrxR1LKO), we analyzed the effect of inhibition or ablation of TrxR1 signaling on liver injury and inflammation. Immunohistochemical analysis of livers from BDL mice and human cholestatic patients revealed increased TrxR1 staining in periportal macrophages and hepatocytes surrounding fibrosis. qPCR analysis of primary hepatocytes and intrahepatic macrophages revealed increased TrxR1 mRNA expression following BDL. Compared with sham controls, BDL mice exhibited increased inflammation, necrosis, and increased mRNA expression of pro-inflammatory cytokines, fibrogenesis, the NLRP3 inflammatory complex, and increased activation of NFkB, all of which were ameliorated in TrxR1LKO mice. Importantly, following BDL, TrxR1LKO induced periportal hepatocyte expression of Nrf2-dependent antioxidant proteins and increased mRNA expression of basolateral bile acid transporters with reduced expression of bile acid synthesis genes. In the acute BDL model, the TrxR1 inhibitor auranofin (10 mg/kg/1 d preincubation, 3 d BDL) ameliorated BDL-dependent increases in Nlrp3, GsdmD, Il1β, and TNFα mRNA expression despite increasing serum alanine aminotransferase, aspartate aminotransferase, bile acids, and bilirubin.
These data implicate TrxR1-signaling as an important regulator of inflammation and bile acid homeostasis in cholestatic liver injury.
胆汁淤积性肝病，包括原发性硬化性胆管炎，其特征为门脉周围炎症，进展为肝纤维化，最终发展为肝硬化。我们最近报道，在原发性硬化性胆管炎中，硫氧还蛋白抗氧化反应失调。本研究的目的是研究靶向硫氧还蛋白还原酶 1（TrxR1）的遗传和药理学方法对急性胆汁淤积性损伤过程中的肝炎症和肝损伤的影响。
从小鼠胆管结扎（BDL）3 天的小鼠和对照小鼠中分离原代小鼠肝细胞和肝内巨噬细胞。使用野生型和肝特异性 TrxR1 缺失（TrxR1LKO）的小鼠，我们分析了抑制或消融 TrxR1 信号对肝损伤和炎症的影响。BDL 小鼠和人类胆汁淤积患者肝脏的免疫组织化学分析显示，门脉周围巨噬细胞和纤维化周围的肝细胞中 TrxR1 染色增加。BDL 后原代肝细胞和肝内巨噬细胞的 qPCR 分析显示 TrxR1mRNA 表达增加。与假手术对照相比，BDL 小鼠表现出炎症、坏死增加，促炎细胞因子、纤维化、NLRP3 炎症复合物的 mRNA 表达增加，NFkB 激活增加，所有这些在 TrxR1LKO 小鼠中均得到改善。重要的是，在 BDL 后，TrxR1LKO 诱导门脉周围肝细胞表达 Nrf2 依赖性抗氧化蛋白，并增加基底外侧胆汁酸转运体的 mRNA 表达，同时减少胆汁酸合成基因的表达。在急性 BDL 模型中，尽管血清丙氨酸氨基转移酶、天冬氨酸氨基转移酶、胆汁酸和胆红素增加，TrxR1 抑制剂 auranoffin（BDL 前 1d 预处理 10mg/kg/1d，BDL 3d）仍可改善 BDL 依赖性 Nlrp3、GsdmD、Il1β 和 TNFα mRNA 表达的增加。
这些数据表明，TrxR1 信号作为胆汁淤积性肝损伤中炎症和胆汁酸动态平衡的重要调节剂。
