Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran.
Med Sci Monit. 2010 Jan;16(1):BR52-60.
The lack of a brain-derived endothelial cell-based model has led researchers to exploit non-brain endothelial/epithelial cells as in vitro models for blood-brain barrier (BBB) investigations. Of these, the endothelial-like human ECV304 cell line was initially characterized as endothelial cells and has been widely used as an in vitro BBB model. It was later shown to be T24 bladder carcinoma epithelial cells. To pursue its potential as a cell-based model for drug screening and transport machineries, ECV304 cells were evaluated for their barrier and plasma membrane characteristics.
MATERIAL/METHODS: ECV304 cells treated with some tight-junction modulators (e.g. cAMP elevators, butyric acid, dexamethasone, gamma-linolenic acid, and astrocytic factors) were examined for bioelectrical resistance, transcellular/paracellular permeability, and functionality expression of some key transporters.
A significant (p<0.05) increase in trans-endothelial electrical resistance (TEER) was observed in ECV304 cells treated with astrocytic factors and cAMP elevators (i.e. to approximately 110Omegacm2 vs. approximately 60 Omegacm2 in the control). Such treatment also yielded high discrimination in the permeability coefficients of the transcellular marker propranolol (25x10-6 cm/sec) and the paracellular marker sucrose (11.3 x 10-6 cm/sec). Carrier-mediated transporters such as GLUT-1, system L, and P-glycoprotein (P-gp) as well as endocytic transport machineries (e.g. clathrin and caveolin) were found to be functionally expressed.
ECV304 cells failed to generate a discriminative tight barrier even in the presence of tight-junction modulators. Thus their implementation in drug permeability screening is not recommended. They display some important key carrier-mediated transport systems and can be considered as a useful cell-based in vitro model.
缺乏基于脑内皮细胞的模型导致研究人员利用非脑内皮/上皮细胞作为体外血脑屏障（BBB）研究的模型。在这些模型中，最初被表征为内皮细胞的人源 ECV304 细胞系已被广泛用作体外 BBB 模型。后来发现它是 T24 膀胱癌上皮细胞。为了探索其作为药物筛选和转运机制的基于细胞的模型的潜力，评估了 ECV304 细胞的屏障和质膜特性。
材料/方法：用一些紧密连接调节剂（例如 cAMP 升高剂、丁酸、地塞米松、γ-亚麻酸和星形胶质细胞因子）处理 ECV304 细胞，检测其生物电阻抗、跨细胞/旁细胞通透性以及一些关键转运体的功能表达。
用星形胶质细胞因子和 cAMP 升高剂处理的 ECV304 细胞的跨内皮电阻（TEER）显著增加（p<0.05）（约为 110Omegacm2，而对照约为 60 Omegacm2）。这种处理还导致跨细胞标记物普萘洛尔（25x10-6 cm/sec）和旁细胞标记物蔗糖（11.3 x 10-6 cm/sec）的渗透系数具有高度的区分度。发现葡萄糖转运蛋白 1（GLUT-1）、系统 L 和 P-糖蛋白（P-gp）等载体介导的转运体以及内吞转运机制（如网格蛋白和小窝蛋白）具有功能表达。
即使存在紧密连接调节剂，ECV304 细胞也未能产生具有区分性的紧密屏障。因此，不建议将其用于药物通透性筛选。它们显示出一些重要的关键载体介导的转运系统，可被视为有用的基于细胞的体外模型。
