改性SFN-mPEG-PLGA纳米粒经Nrf2/ARE通路靶向治疗一氧化碳中毒脑损伤的机制研究

氧化应激损伤和细胞凋亡在急性一氧化碳中毒（ACOP）脑损伤的发病中起重要作用。核转录因子红细胞2相关因子-2（Nrf2）是抗氧化应激Nrf2/ARE通路中的关键分子，其活性直接调控机体的抗氧化能力。申请者前期研究表明，ACOP大鼠脑组织中Nrf2蛋白低水平表达，细胞凋亡增加。应用莱菔硫烷（SFN）或脑内注射负载Nrf2基因的慢病毒均能增加Nrf2蛋白表达、减少细胞凋亡，减轻ACOP脑损伤。但其缺陷为：脑内药物蓄积浓度不足，药物半衰期短（仅2.2h），脑内注射创伤大、易并发感染等。因此，制备高通透性、长循环脑靶向药物是关键。本研究拟用改进的双乳化法制备长循环SFN-mPEG-PLGA纳米粒，用转铁蛋白受体单克隆抗体OX26对其功能化修饰后，通过体内外实验探讨Nrf2/ARE通路相关分子在ACOP脑损伤中的作用，明确该纳米粒治疗ACOP脑损伤的分子机制及可行性，为脑内靶向治疗提供理论依据。

Oxidative stress injury and apoptosis play an important role in the pathogenesis of brain damage induced by acute carbon monoxide poisoning (ACOP). As a key signal molecule in the nuclear factor erythrocyte two related factors-2 (Nrf2)/ARE pathway of antioxidant stress, the active status of Nrf2 directly regulates the antioxidant capacity of the body. The results in our previous studies indicated that the expression level of Nrf2 protein decreased, and apoptosis of neurons increased in brain tissue in ACOP rats. The administration of either Sulforaphane (SFN) or the intracerebral injection of lentivirus loaded with Nrf2 gene could increase the expression of Nrf2 protein and reduce neuronal apoptosis, and obviously alleviate brain damage after ACOP. Nevertheless, the methods mentioned above have the disadvantages including insufficient concentration of drug accumulation in brain tissue, too short half-life period of drug action (only 2.2 h), large trauma and high risk of intracerebral infection caused by local injection. Therefore, a key issue is to develop the brain targeted drugs with high permeability and long circulation. In the present project, the long-circulating SFN-mPEG-PLGA nanoparticles will be prepared by an improved double emulsification method, and its relevant parameters were characterized after functional modification with the transferrin receptor monoclonal antibodies OX26. We aim to explore the function of Nrf2/ARE pathway- related molecules, clarify the molecular mechanism and feasibility of the nanoparticles modified with OX26 in the treatment of brain injury caused by ACOP in vitro and in vivo, and thus providing a theoretical basis for brain targeted treatment in ACOP.