厚朴酚对局灶性脑缺血/再灌注后血脑屏障损伤的保护效应及其机制研究

Stroke seriously harms to human health. when cerebral ischemic injury was happened, blood-brain barrier (BBB) integrity was damaged and thus brain edema and hemorrhage were exacerbated. Therefore, it is essential to reduce stroke damage by protecting BBB. Magnolol is a small molecule derived from traditional Chinese medicine Magnolia, which has a significant effect on protecting nerve damage caused by stroke. In previous studies, we have reported brain protection mechanisms of Magnolol included anti-inflammatory, antioxidant and anti-apoptotic. Can it play a protective role by stabilizing the BBB? Is there a close relationship between EphA2 receptor activation and BBB damage? Is the protective role of Magnolol related to the down regulation of EphA2 receptor? All of these are still unknown. The project is to evaluate the protective effect of Magnolol on BBB injury by observing cerebral edema, oozing dye cross BBB and BBB integrity-related protein expression changes through in vitro BBB damage model and in vivo I/R model. Furthermore, after EphA2 receptor activated or suppressed by the use of agonists or transfection of EphA2 receptor into b.End.3 cell line, the expression levels of EphA2、TJ、AJ、ZO-1 and MMP-9 related to EphA2 receptor and BBB structures in cells or tissues were determined after treated with Magnolol. After finish this project successfully, we hope to elucidate the molecular mechanisms of the interaction of Magnolol and EphA2 receptor during BBB injury. This research work will be helpful to provide a new theoretical basis for the treatment of stroke.

脑卒中严重危害健康，脑缺血损伤时，血脑屏障（BBB）完整性破坏，加剧原发损伤并引起水肿和出血等继发性损伤，因此通过保护BBB治疗来减轻脑卒中损伤至关重要。厚朴酚是源自中药厚朴的小分子，其对脑卒中引起的神经损伤具有显著疗效。目前发现厚朴酚的脑保护机制包括抗炎、抗氧化和抗凋亡，其能否通过稳定BBB而起保护作用? BBB损伤与EphA2受体的激活密切相关，厚朴酚的作用是否与EphA2受体相关？仍然未知。本课题拟建立小鼠体外、体内BBB损伤模型，通过观察脑水肿、染料跨BBB渗出，以及BBB完整性相关蛋白表达变化，评价厚朴酚对BBB损伤的保护作用。并进一步通过激动剂和将EphA2受体转染到不表达细胞系中，观察厚朴酚处理后EphA2受体下游分子以及BBB的变化，以期发现EphA2受体在厚朴酚减轻BBB损伤中的作用。本研究将进一步阐明厚朴酚保护脑卒中的机制，为脑卒中的治疗提供新的理论依据。

脑卒中是临床常见病，多发病，具有高致残率、高复发率、高死亡率的特点。脑卒中患者中80%以上为缺血性脑卒中，临床上主要以血管内溶栓、手术取栓为主要治疗手段，恢复组织血供。这一过程伴随着缺血再灌注损伤。在复杂的脑缺血损伤机制中，炎症反应及血脑屏障损伤是脑缺血再灌注损伤的主要原因之一，减轻脑缺血和再灌注过程中的炎症反应，保护血脑屏障对治疗缺血性脑血管病引起的脑组织损伤具有重要临床意义。.厚朴酚是从中药厚朴中分离出一种新木脂素类的化合物，具有肯定的治疗缺血性脑卒中的作用。本研究采用体内和体外损伤模型探讨了厚朴酚对缺血再灌注引发的神经损伤炎症和血脑屏障功能障碍的影响。研究发现厚朴酚的保护作用与它抑制胶质细胞NF-κB的激活，减少炎症因子的产生有关；与其抑制脑微血管内皮细胞的炎症反应和EphA2的磷酸化，减少紧密连接蛋白的降解进而减缓血脑屏障的破坏等机制有关。这些结果为厚朴酚的抗脑缺血再灌注损伤的提供了新的机制，提示厚朴酚是一个具有神经血管保护的化合物。目前，该课题相关研究结果已发表在《Metabolic Brain Disease》、《Journal of Chinese Pharmaceutical Sciences》上，共发表SCI学术论文1篇及国内期刊2篇（均标注基金号），培养博士生1名，硕士生3名。