Background. Inflammation is a major cause of hepatic tissue damage and accelerates the progression of nonalcoholic fatty liver disease (NAFLD). Amphiregulin (AREG), an epidermal growth factor receptor ligand, is associated with human liver cirrhosis and hepatocellular carcinoma. We aimed to investigate the effects of AREG on hepatic inflammation during NAFLD progression, in vivo and in vitro. Methods. AREG gene expression was measured in the liver of mice fed a methionine choline-deficient (MCD) diet for 2 weeks. We evaluated inflammatory mediators and signaling pathways in HepG2 cells after stimulation with AREG. Nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were analyzed using an enzyme-linked immunosorbent assay and western blotting. Nuclear transcription factor kappa-B (NF-κB) and mitogen-activated protein kinases (MAPKs), including extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38 mitogen-activated protein kinase, were analyzed using western blotting. Results. Proinflammatory cytokines (interleukin (IL)-6, IL-1β, and IL-8) and immune cell recruitment (as indicated by L3T4, F4/80, and ly6G mRNA expression) increased, and expression of AREG increased in the liver of mice fed the MCD diet. AREG significantly increased the expression of IL-6 and IL-1β and the production of NO, PGE2, and IL-8 in HepG2 cells. It also activated the protein expression of iNOS and COX-2. AREG-activated NF-κB and MAPKs signaling, and together with NF-κB and MAPKs inhibitors, AREG significantly reduced the protein expression of iNOS and COX-2. Conclusion. AREG plays a role in hepatic inflammation by increasing iNOS and COX-2 expression via NF-κB and MAPKs signaling.

中文翻译：

---

双调蛋白通过 NF-κB 和 MAPK 信号传导在肝脏炎症中诱导 iNOS 和 COX-2 表达

背景。炎症是肝组织损伤的主要原因，并加速非酒精性脂肪肝（NAFLD）的进展。双调蛋白 (AREG) 是一种表皮生长因子受体配体，与人类肝硬化和肝细胞癌有关。我们的目的是在体内和体外研究 AREG 对 NAFLD 进展期间肝脏炎症的影响。方法。在喂食蛋氨酸胆碱缺乏（MCD）饮食两周的小鼠肝脏中测量 AREG 基因表达。我们评估了 AREG 刺激后 HepG2 细胞中的炎症介质和信号通路。使用酶联免疫吸附测定和蛋白质印迹分析一氧化氮 (NO)、前列腺素 E2 (PGE2)、诱导型一氧化氮合酶 (iNOS) 和环氧合酶-2 (COX-2)。使用蛋白质印迹分析核转录因子 kappa-B (NF- κ B) 和丝裂原激活蛋白激酶 (MAPK)，包括细胞外信号调节激酶、c-Jun N 末端激酶和 p38 丝裂原激活蛋白激酶。结果。促炎细胞因子（白细胞介素 (IL)-6、IL-1 β和 IL-8）和免疫细胞募集（L3T4、F4/80 和 ly6G mRNA 表达表明）增加，并且肝脏中 AREG 的表达增加小鼠喂食 MCD 饮食。AREG 显着增加HepG2 细胞中IL-6 和 IL-1 β的表达以及 NO、PGE2 和 IL-8 的产生。它还激活 iNOS 和 COX-2 的蛋白表达。AREG 激活 NF- κB和 MAPKs 信号传导，与 NF- κB和 MAPKs 抑制剂一起，AREG 显着降低 iNOS 和 COX-2 的蛋白表达。结论。AREG 通过 NF- κ B 和 MAPK 信号传导增加 iNOS 和 COX-2 的表达，从而在肝脏炎症中发挥作用。