GLP-2通过在肝星状细胞中激活NR4a1/Nur77及肠道FXR信号通路，改善Mdr2-/-小鼠的肝脏炎症和纤维化。
GLP-2 improves hepatic inflammation and fibrosis in Mdr2-/-mice via activation of NR4a1/Nur77 in hepatic stellate cells and intestinal FXR signaling.
发表日期：2023 Aug 10
作者：
Claudia D Fuchs, Thierry Claudel, Veronika Mlitz, Alessandra Riva, Moritz Menz, Ksenia Brusilovskaya, Felix Haller, Maximilian Baumgartner, Philipp Königshofer, Lukas W Unger, Wilhelm Sjöland, Hubert Scharnagl, Tatjana Stojakovic, Georg Busslinger, Thomas Reiberger, Hanns-Ulrich Marschall, Michael Trauner
来源：
Cell Mol Gastroenter
摘要：
糖样胰高血糖素-2（GLP-2）可能对肝星状细胞（HSCs）产生抗纤维化作用。因此，我们旨在测试GLP-2类似物teduglutide的应用对显示肝炎和纤维化的Mdr2/Abcb4-/-小鼠胆管硬化症模型是否具有肝保护和抗纤维化作用。注射Mdr2-/-小鼠teduglutide连续4周后，进行基因表达谱（大量肝脏；分离的HSCs）和免疫组织化学分析。活化的HSCs（LX2细胞）以及永生人肝细胞（IHH）和人肠道器官样品被GLP-2处理。使用RT-PCR和电泳迁移位分析（EMSA）分析细胞质和核蛋白提取物进行mRNA表达分析。GLP-2处理的Mdr2-/-小鼠显示肝炎、纤维化以及反应性胆管细胞表型得到改善。从Mdr2-/-小鼠分离的原代HSCs和体外暴露于GLP-2的LX2细胞显示NR4a1/Nur77 mRNA表达水平显著增加（p<0.05）。EMSA在GLP-2处理后显示LX2细胞中NR4a1核结合增加。此外，GLP-2减轻了Tgfβ介导的NR4a1核结合活性下降。体内，GLP-2处理的Mdr2-/-小鼠肝脏内甲病胆酸水平增加（Cyp2c70 mRNA表达显著增加），同时Cyp7a1和FXR的mRNA水平减少。Mdr2-/-小鼠经GLP-2处理的血清Fgf15水平升高。因此，GLP-2处理的人肠道器官样品激活了其FXR-FGF19信号轴。GLP-2处理增加了HSCs中NR4a1/Nur77的激活，从而减轻了其活化。GLP-2促进肠道Fxr-Fgf15/19信号传导，导致肝脏中Cyp7a1减少和Cyp2c70增加表达，从而在Mdr2-/-小鼠模型中产生肝保护和抗纤维化作用。版权所有© 2023 The Authors. Published by Elsevier Inc. All rights reserved.
Glucagon like peptide (GLP)-2 may exert anti-fibrotic effects on hepatic stellate cells (HSCs). Thus, we aimed to test whether application of the GLP-2 analogue teduglutide has hepato-protective and anti-fibrotic effects in the Mdr2/Abcb4-/- mouse model of sclerosing cholangitis displaying hepatic inflammation and fibrosis.Mdr2-/- mice were injected daily for 4 weeks with teduglutide followed by gene expression profiling (bulk liver; isolated HSCs) and immunohistochemistry. Activated HSCs (LX2 cells) as well as immortalized human hepatocytes (IHH) and human intestinal organoids were treated with GLP-2. mRNA profiling by RT-PCR and electrophoretic mobility shift assay (EMSA) using cytosolic and nuclear protein extracts was performed.Hepatic inflammation, fibrosis as well as reactive cholangiocyte phenotype were improved in GLP-2 treated Mdr2-/- mice. Primary HSCs isolated from Mdr2-/- mice and LX2 cells exposed to GLP-2 in vitro displayed significantly increased mRNA expression levels of NR4a1/Nur77 (p<0.05). EMSA revealed an increased nuclear NR4a1 binding after GLP-2 treatment in LX2 cells. Moreover, GLP-2 alleviated the Tgfβ-mediated reduction of NR4a1 nuclear binding activity. In vivo, GLP-2 treatment of Mdr2-/- mice resulted in increased intrahepatic levels of muricholic acids (accordingly Cyp2c70 mRNA expression was significantly increased), as well as in reduced mRNA levels of Cyp7a1 and FXR. Serum Fgf15 levels were increased in Mdr2-/- mice treated with GLP-2. Accordingly, GLP-2 treatment of human intestinal organoids activated their FXR-FGF19 signaling axis.GLP-2 treatment increased NR4a1/Nur77 activation in HSCs, subsequently attenuating their activation. GLP-2 promoted intestinal Fxr-Fgf15/19 signaling resulting in reduced Cyp7a1 and increased Cyp2c70 expression in the liver, contributing to hepato-protective and anti-fibrotic effects of GLP-2 in the Mdr2-/- mouse model.Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.