在体外bEnd.3内皮细胞模型中,银杏叶提取物761(EGb761)对β淀粉样蛋白1-42寡聚体诱导的细胞损伤和血脑屏障破坏具有保护作用。
EGb761 provides a protective effect against Aβ1-42 oligomer-induced cell damage and blood-brain barrier disruption in an in vitro bEnd.3 endothelial model.
作者信息
Wan Wen-bin, Cao Lan, Liu Lu-mei, Kalionis Bill, Chen Chuan, Tai Xian-tao, Li Ya-ming, Xia Shi-jin
机构信息
Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, China.
State Key Laboratory of Medical Neurobiology, School of Basic Medical Sciences, Fudan University, Shanghai, China.
出版信息
PLoS One. 2014 Nov 26;9(11):e113126. doi: 10.1371/journal.pone.0113126. eCollection 2014.
Alzheimer's disease (AD) is the most common form of senile dementia which is characterized by abnormal amyloid beta (Aβ) accumulation and deposition in brain parenchyma and cerebral capillaries, and leads to blood-brain barrier (BBB) disruption. Despite great progress in understanding the etiology of AD, the underlying pathogenic mechanism of BBB damage is still unclear, and no effective treatment has been devised. The standard Ginkgo biloba extract EGb761 has been widely used as a potential cognitive enhancer for the treatment of AD. However, the cellular mechanism underlying the effect remain to be clarified. In this study, we employed an immortalized endothelial cell line (bEnd.3) and incubation of Aβ(1-42) oligomer, to mimic a monolayer BBB model under conditions found in the AD brain. We investigated the effect of EGb761 on BBB and found that Aβ1-42 oligomer-induced cell injury, apoptosis, and generation of intracellular reactive oxygen species (ROS), were attenuated by treatment with EGb761. Moreover, treatment of the cells with EGb761 decreased BBB permeability and increased tight junction scaffold protein levels including ZO-1, Claudin-5 and Occludin. We also found that the Aβ(1-42) oligomer-induced upregulation of the receptor for advanced glycation end-products (RAGE), which mediates Aβ cytotoxicity and plays an essential role in AD progression, was significantly decreased by treatment with EGb761. To our knowledge, we provide the first direct in vitro evidence of an effect of EGb761 on the brain endothelium exposed to Aβ(1-42) oligomer, and on the expression of tight junction (TJ) scaffold proteins and RAGE. Our results provide a new insight into a possible mechanism of action of EGb761. This study provides a rational basis for the therapeutic application of EGb761 in the treatment of AD.
阿尔茨海默病(AD)是最常见的老年痴呆症形式,其特征是淀粉样β蛋白(Aβ)在脑实质和脑毛细血管中异常积聚和沉积,并导致血脑屏障(BBB)破坏。尽管在理解AD病因方面取得了很大进展,但血脑屏障损伤的潜在致病机制仍不清楚,并且尚未设计出有效的治疗方法。标准银杏叶提取物EGb761已被广泛用作治疗AD的潜在认知增强剂。然而,其作用的细胞机制仍有待阐明。在本研究中,我们使用永生化内皮细胞系(bEnd.3)并孵育Aβ(1-42)寡聚体,以模拟AD脑内条件下的单层血脑屏障模型。我们研究了EGb761对血脑屏障的影响,发现用EGb761处理可减轻Aβ1-42寡聚体诱导的细胞损伤、凋亡和细胞内活性氧(ROS)的产生。此外,用EGb761处理细胞可降低血脑屏障通透性,并增加紧密连接支架蛋白水平,包括闭锁小带蛋白1(ZO-1)、闭合蛋白5(Claudin-5)和闭合蛋白(Occludin)。我们还发现,用EGb761处理可显著降低Aβ(1-42)寡聚体诱导的晚期糖基化终产物受体(RAGE)上调,RAGE介导Aβ细胞毒性并在AD进展中起重要作用。据我们所知,我们首次提供了直接的体外证据,证明EGb761对暴露于Aβ(1-42)寡聚体的脑内皮细胞以及紧密连接(TJ)支架蛋白和RAGE表达的影响。我们的结果为EGb761可能的作用机制提供了新的见解。本研究为EGb761在AD治疗中的治疗应用提供了合理依据。