富含整合素 β1 的细胞外囊泡介导单核细胞粘附并促进小鼠 NASH 中的肝脏炎症,Journal of Hepatology

当前位置： X-MOL 学术 › J. Hepatol. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

富含整合素 β1 的细胞外囊泡介导单核细胞粘附并促进小鼠 NASH 中的肝脏炎症
Journal of Hepatology ( IF 26.8 ) Pub Date : 2019-12-01 , DOI: 10.1016/j.jhep.2019.07.019
Qianqian Guo ₁ , Kunimaro Furuta ₁ , Fabrice Lucien ₂ , Luz Helena Gutierrez Sanchez ₃ , Petra Hirsova ₁ , Anuradha Krishnan ₁ , Ayano Kabashima ₁ , Kevin D Pavelko ₄ , Benjamin Madden ₅ , Husam Alhuwaish ₆ , Yandong Gao ₇ , Alexander Revzin ₇ , Samar H Ibrahim ₈

Affiliation

背景和目的单核细胞衍生巨噬细胞 (MoMF) 的肝脏募集有助于非酒精性脂肪性肝炎 (NASH) 的炎症反应。然而，肝细胞脂毒性如何促进 MoMF 炎症尚不清楚。在这里，我们证明脂毒性肝细胞衍生的细胞外囊泡 (EV) 富含活性整合素 β1 (ITGβ1)，可促进小鼠 NASH 中的单核细胞粘附和肝脏炎症。方法用载体或毒性脂质介质溶血磷脂酰胆碱 (LPC) 处理肝细胞；EVs 从条件培养基中分离出来并进行蛋白质组学分析。C57BL/6J 小鼠被喂食富含脂肪、果糖和胆固醇 (FFC) 的饮食以诱导 NASH。用抗 ITGβ1 中和抗体 (ITGβ1Ab) 或对照 IgG 同种型处理小鼠。结果脂毒性肝细胞衍生的 EV (LPC-EVs) 蛋白质组的独创性通路分析表明，整合素信号是一种过度表达的典型通路。免疫金电子显微镜和纳米级流式细胞术证实了具有活性 ITGβ1 的 LPC-EVs 的富集。此外，我们发现肝细胞中的 LPC 治疗激活 ITGβ1 并介导其内吞运输和分类为 EV。通过剪切应力粘附试验观察到 LPC-EVs 增强的单核细胞与肝窦内皮细胞 (LSECs) 的粘附，并在 ITGβ1Ab 存在下减弱。通过免疫组织化学、mRNA 表达和流式细胞术评估，FFC 喂养、ITGβ1Ab 治疗的小鼠表现出炎症减轻，其定义为促炎性 MoMF 肝脏浸润和激活减少。同样地，通过飞行时间 (CyTOF) 对肝内白细胞 (IHL) 进行的质谱流式细胞术显示浸润性促炎单核细胞减少。此外，ITGβ1Ab 治疗显着改善肝损伤和纤维化。结论脂毒性 EVs 主要通过 ITGβ1 依赖性机制介导单核细胞与 LSECs 的粘附。ITGβ1Ab 通过减少 MoMF 驱动的炎症来改善小鼠饮食诱导的 NASH，表明阻断 ITGβ1 是人类 NASH 的潜在抗炎治疗策略。概述在此，我们报告称一种称为整合素 β1 (ITGβ1) 的细胞粘附分子在非酒精性脂肪性肝炎 (NASH) 的进展中起关键作用。ITGβ1 在脂毒性应激下作为细胞外囊泡的货物从肝细胞中释放出来，并介导单核细胞与肝窦内皮细胞的粘附，这是肝脏炎症的重要步骤。在 NASH 小鼠模型中，阻断 ITGβ1 可减少肝脏炎症、损伤和纤维化。因此，抑制 ITGβ1 可能成为 NASH 的新治疗策略。

"点击查看英文标题和摘要"

Integrin β1-enriched Extracellular Vesicles Mediate Monocyte Adhesion and Promote Liver Inflammation in Murine NASH

BACKGROUND AND AIMS Hepatic recruitment of monocyte-derived macrophages (MoMF) contributes to the inflammatory response in nonalcoholic steatohepatitis (NASH). However, how hepatocyte lipotoxicity promotes MoMF inflammation is unclear. Here we demonstrate that lipotoxic hepatocyte-derived extracellular vesicles (EVs) are enriched with active integrin β1 (ITGβ1), which promotes monocyte adhesion and liver inflammation in murine NASH. METHODS Hepatocytes were treated with either vehicle or the toxic lipid mediator lysophosphatidylcholine (LPC); EVs were isolated from the conditioned media and subjected to proteomic analysis. C57BL/6J mice were fed a diet rich in fat, fructose, and cholesterol (FFC) to induce NASH. Mice were treated with anti-ITGβ1 neutralizing antibody (ITGβ1Ab) or control IgG isotype. RESULTS Ingenuity Pathway Analysis of the lipotoxic hepatocyte-derived EV (LPC-EVs) proteome indicated that integrin signaling is an overrepresented canonical pathway. Immunogold electron microscopy and nanoscale flow cytometry confirmed enrichment of LPC-EVs with active ITGβ1. Furthermore, we showed that LPC treatment in hepatocytes activates ITGβ1 and mediates its endocytic trafficking and sorting into EVs. LPC-EVs-enhanced monocytes adhesion to liver sinusoidal endothelial cells (LSECs) was observed by shear stress adhesion assay, and was attenuated in the presence of ITGβ1Ab. FFC-fed, ITGβ1Ab-treated mice displayed reduced inflammation defined by decreased proinflammatory MoMF hepatic infiltration and activation as assessed by immunohistochemistry, mRNA expression, and flow cytometry. Likewise, mass cytometry by time-of-flight (CyTOF) on intrahepatic leukocytes (IHL) displayed reduced infiltrating proinflammatory monocytes. Furthermore, ITGβ1Ab treatment significantly ameliorated liver injury and fibrosis. CONCLUSIONS Lipotoxic EVs mediate monocyte adhesion to LSECs mainly by an ITGβ1-dependent mechanism. ITGβ1Ab ameliorates diet-induced NASH in mice by reducing MoMF-driven inflammation, suggesting that blocking ITGβ1 is a potential anti-inflammatory therapeutic strategy in human NASH. LAY SUMMARY Herein, we report that a cell adhesion molecule termed integrin β1 (ITGβ1) plays a key role in the progression of nonalcoholic steatohepatitis (NASH). ITGβ1 is released from hepatocytes under lipotoxic stress as a cargo of extracellular vesicles, and mediates monocyte adhesion to liver sinusoidal endothelial cells, which is an essential step in hepatic inflammation. In a mouse model of NASH, blocking ITGβ1 reduces liver inflammation, injury and fibrosis. Hence, ITGβ1 inhibition may serve as a new therapeutic strategy for NASH.

更新日期：2019-12-01

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南