目的：通过建立体外血脑屏障（blood brain barrier，BBB）模型，探讨人肺腺癌PC-9 细胞在CXCR4/SDF-1 轴作用下对BBB紧密连接蛋白的影响。方法：利用永生化的小鼠脑微血管内皮细胞Bends 进行单层培养，建立体外BBB模型；通过跨内皮细胞电阻（transendothelial electrical resistance，TEER）测定及荧光素钠通透性实验判定体外BBB模型的功能状态以及观察PC-9细胞对体外BBB 模型功能的影响。Western blotting 检测PC-9 细胞在CXCR4 抑制剂AMD3100、SDF-1 单独或联合（1 μg/ml AMD3100，100 ng/ml SDF-1，AMD3100+SDF-1）作用下对BBB模型功能和内皮细胞紧密连接蛋白表达的影响，Transwell 迁移实验检测CXCR4/SDF-1 轴对PC-9 细胞跨BBB模型细胞层迁移能力的影响。结果：Bends 细胞单层培养可形成紧密连接的“屏障”并产生较高的TEER，第96 h 达到（182.13±5.19）Ω·cm2；同时行荧光色钠通透性实验结果显示，BBB具有良好屏障性能，其通透率低于空白对照组（P<0.05）。PC-9 细胞作用后，BBB模型TEER逐渐降低，第24 h 降至（46.7±4.35）Ω·cm2；同时BBB 通透率较作用前显著提高（P<0.05）。PC-9 细胞在AMD3100 作用下能够上调内皮细胞紧密连接蛋白的表达（P<0.05）；AMD3100 处理组的PC-9 细胞穿过BBB的细胞数较空白组明显减少[ （43±2）vs（81±2）个，P<0.05]。结论：AMD3100 能够减弱PC-9 细胞对Bends 细胞建立的体外BBB模型紧密连接的破坏能力。

Objective: To investigate the influences of human lung adenocarcinoma PC-9 cells on tight junction proteins of blood brain barrier (BBB) under CXCR4/SDF-1 axis by establishing a model of BBB in vitro. Methods: The immortalized mouse brain microvascular endothelial Bends cells were used to establish a model of BBB in vitro by monolayer culture; Subsequently, transendothelial electric resistance (TEER) and fluorescein sodium permeability experiment were used to detect the function of in vitro BBB model and observe the effect of PC-9 cells on the function of BBB model, respectively. Western blotting was used to detect the effect of PC-9 cells on function of BBB model and expressions of endothelial tight junction proteins under the treatment of single or combined AMD3100 and SDF-1 (1 μg/ml AMD3100,100 ng/ml SDF-1, AMD3100+SDF-1). Transwell assay was used to detect the influence of CXCR4/SDF-1 axis on the ability of PC-9 cells transmigrating the cell layer of BBB model. Results: Monolayer culture of Bends cells can form tightly connected BBB with highTEER, which reached (182.13±5.19) Ω.cm2 at the 96 h; in the meanwhile, fluorescein sodium permeability experiment showed that BBB had significantly lower permeability than that of control group ([40.31±2.43]% vs [150.10±3.17]%, P<0.05). The TEER of BBB decreased to (46.7±4.35) Ω·cm2 after coculture with PC-9 cells for 24 h, and at the same time the sodium fluorescein permeability of BBB significantly increased than that of pre-treatment ([136.32±4.93]% vs [50.24±6.21]%, P<0.05).PC-9 cells up-regulated the expressions of tight junction proteins of Bends cells under the treatment of AMD3100 (P<0.05). The number of PC-9 cells transmigrating the BBB in AMD3100 treatment group was significantly lower than that of CON group (43±2 vs 81±2,P<0.05). Conclusion: AMD3100 can reduce the ability of PC-9 cells destroying the tight junction of the BBB model established in vitro by Bends cells.

福建省卫生健康委中青年骨干人才培养项目资助（No. 2019148）；福建省立医院高水平医院建设科研联合基金资助项目（No.2018GSP008）；福建医科大学启航基金资助项目（No. 2018QH1130）