载IR1048及mNOX-E36的巨噬细胞来源细胞外囊泡用于非酒精性脂肪性肝炎诊疗一体化的实验研究

非酒精性脂肪肝性肝炎（NASH）是非酒精性脂肪性肝病（NAFLD）的进展阶段，早期诊断及治疗NASH可改善其预后。但目前尚无NASH的无创诊断方法和临床治疗方案。研究表明，肝内趋化因子配体2（CCL2）增加继而募集单核细胞是NASH进展的关键环节，提供了重要的治疗分子靶点。巨噬细胞来源的细胞外囊泡（Mø-EVs）具有炎症靶向性，有望作为NASH评估的靶向造影剂及药物载体。本项目拟对Mø-EVs进行修饰，使其负载近红外二区染料IR1048及CCL2的镜像异构核酸适配体mNOX-E36，利用IR1048进行光声/荧光成像示踪，观察NASH局部Mø-EVs的聚集及其与NASH活动度的关系，探索其无创诊断NASH的价值；同时将mNOX-E36递送至NASH病灶部位，消耗局部CCL2以阻碍单核细胞的募集，对NASH进行治疗。本项目的顺利开展将为NASH的诊疗一体化提供一种新思路。

Nonalcoholic steatohepatitis (NASH) is a progressive stage of nonalcoholic fatty liver disease (NAFLD) with active inflammation. Early diagnosis and treatment of NASH can improve outcomes of NAFLD and reduce the risk of progression to cirrhosis and even liver cancer. However, there is still no noninvasive diagnostic method and reliable medical treatment strategy for NASH. Previous studies have shown that the chemokine ligand 2 (CCL2), which has a chemotactic function on chemokine receptor 2 (CCR2) expressed monocytes, is upgraded in the NASH. Then the monocytes are recruited and adhered to NASH sites, pass through vascular endothelium, and then infiltrate into the interstitial space. This chemotaxis is a key link in the progression of NASH. The number of infiltrated CCR2+ macrophages in the liver is positively correlated with disease activity of NASH. Blocking the adhesion and infiltration of monocytes become an important therapeutic target for NASH. .Macrophage-derived extracellular vesicles (Mø-EVs) showed a inflammation-targeting property and are expected to be used as a new theranostic platform. This study designed to prepare engineering Mø-EVs, by loading IR1048 (a dye of the second near infrared window (NIR-II)) and mNOX-E36 (an antagonist of CCl2) on it. By using IR1048, the Mø-EVs can be traced by photoacoustic/fluorescence imaging to observe the local accumulation of EVs in NASH sites, and the relationship between EVs accumulation and NASH severity can be analyzed to explore its value on non-invasive diagnosis and evaluation of NASH. By using the inflammatory targeting ability of Mø-EVs, mNOX-E36 could be delivered into NASH lesions to neutralize local CCl2, and then block the recruitment, adhesion, and infiltration of monocytes in the liver, thereby treating NASH. The project will provide a new idea for the integration of diagnosis and treatment for NASH.