Abstract：
We aim to investigate the effect of RVG-Lamp2b-modified exosomes (exos) loaded with neurotrophin-3 (NT-3) on facial nerve injury. Exos were collected from control cells (Ctrl Exo) or bone marrow mesenchymal stem cells co-transfected with RVG-Lamp2b and NT-3 plasmids (RVG-NT-3 Exo) by gradient centrifugation and identified by western blotting, transmission electron microscopy, and nanoparticle tracking analysis. Effect of RVG-NT-3 Exo on oxidative stress damage was determined by analysis of the morphology, viability, and ROS production of neurons. Effect of RVG-NT-3 Exo on facial nerve axotomy (FNA) was determined by detecting ROS production, neuroinflammatory reaction, microglia activation, facial motor neuron (FMN) death, and myelin sheath repair. Loading NT-3 and modifying with RVG-Lamp2b did not alter the properties of the exos. Moreover, RVG-NT-3 Exo could effectively target neurons to deliver NT-3. Treatment with RVG-NT-3 Exo lowered H2O2-induced oxidative stress damage in primary neurons and Nsc-34 cells. RVG-NT-3 Exo treatment significantly decreased ROS production, neuroinflammatory response, FMN death, and elevated microglia activation and myelin sheath repair in FNA rat models. Our findings suggested that RVG-NT-3 Exo-mediated delivery of NT-3 is effective for the treatment of facial nerve injury.
摘要：
我们旨在研究加载神经营养蛋白3（NT-3）的RVG-Lamp2b修饰的外泌体（exos）对面神经损伤的影响。通过梯度离心从对照细胞（CtrlExo）或与RVG-Lamp2b和NT-3质粒（RVG-NT-3Exo）共转染的骨髓间充质干细胞中收集Exos，并通过蛋白质印迹进行鉴定，透射电子显微镜,和纳米粒子跟踪分析。通过形态学分析确定RVG-NT-3Exo对氧化应激损伤的影响，生存能力，和神经元的ROS产生。通过检测ROS的产生来确定RVG-NT-3Exo对面神经轴突切开术（FNA）的影响，神经炎症反应，小胶质细胞激活，面部运动神经元（FMN）死亡，和髓鞘修复。加载NT-3并用RVG-Lamp2b修饰不会改变exos的性质。此外，RVG-NT-3Exo可有效靶向神经元递送NT-3。用RVG-NT-3Exo处理降低了H2O2诱导的原代神经元和Nsc-34细胞的氧化应激损伤。RVG-NT-3Exo处理显著降低了ROS的产生，神经炎症反应，FMN死亡，在FNA大鼠模型中，小胶质细胞活化和髓鞘修复升高。我们的发现表明，RVG-NT-3Exo介导的NT-3递送可有效治疗面神经损伤。
