Lankenau Institute for Medical Research, 100 Lancaster Avenue, Wynnewood, PA 19096, U.S.A.
Department of Biomedical Engineering, Drexel University, Philadelphia, PA 19104, U.S.A.
Biosci Rep. 2020 Oct 30;40(10). doi: 10.1042/BSR20201532.
The human bronchial epithelial cell line, 16HBE14o- (16HBE), is widely used as a model for respiratory epithelial diseases and barrier function. During differentiation, transepithelial electrical resistance (TER) increased to approximately 800 Ohms × cm2, while 14C-d-mannitol flux rates (Jm) simultaneously decreased. Tight junctions (TJs) were shown by diffusion potential studies to be anion-selective with PC1/PNa = 1.9. Transepithelial leakiness could be induced by the phorbol ester, protein kinase C (PKC) activator, 12-O-tetradecanoylphorbol-13-acetate (TPA), and the proinflammatory cytokine, tumor necrosis factor-α (TNF-α). Basal barrier function could not be improved by the micronutrients, zinc, or quercetin. Of methodological significance, TER was observed to be more variable and to spontaneously, significantly decrease after initial barrier formation, whereas Jm did not significantly fluctuate or increase. Unlike the strong inverse relationship between TER and Jm during differentiation, differentiated cell layers manifested no relationship between TER and Jm. There was also much greater variability for TER values compared with Jm. Investigating the dependence of 16HBE TER on transcellular ion conductance, inhibition of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) chloride channel with GlyH-101 produced a large decrease in short-circuit current (Isc) and a slight increase in TER, but no significant change in Jm. A strong temperature dependence was observed not only for Isc, but also for TER. In summary, research utilizing 16HBE as a model in airway barrier function studies needs to be aware of the complexity of TER as a parameter of barrier function given the influence of CFTR-dependent transcellular conductance on TER.
人支气管上皮细胞系 16HBE14o-（16HBE）广泛用于呼吸上皮疾病和屏障功能的模型。在分化过程中，跨上皮电阻（TER）增加到约 800 欧姆×厘米 2，而 14C-d-甘露醇通量率（Jm）同时降低。扩散电位研究表明，紧密连接（TJ）是阴离子选择性的，PC1/PNa=1.9。佛波酯、蛋白激酶 C（PKC）激活剂 12-O-十四烷酰佛波醇-13-乙酸酯（TPA）和促炎细胞因子肿瘤坏死因子-α（TNF-α）可诱导跨上皮通透性增加。基础屏障功能不能通过微量元素锌或槲皮素得到改善。具有方法学意义的是，TER 观察到更具变异性，并在初始屏障形成后自发、显著降低，而 Jm 没有显著波动或增加。与分化过程中 TER 和 Jm 之间的强反比关系不同，分化细胞层的 TER 和 Jm 之间没有关系。与 Jm 相比，TER 值的变异性也更大。研究 16HBE TER 对细胞间离子电导的依赖性时，用 GlyH-101 抑制囊性纤维化跨膜电导调节剂（CFTR）氯离子通道会导致短路电流（Isc）大幅下降，TER 略有增加，但 Jm 没有明显变化。不仅观察到 Isc，而且还观察到 TER 对温度具有很强的依赖性。综上所述，在气道屏障功能研究中，将 16HBE 用作模型时，由于 CFTR 依赖性细胞间电导对 TER 的影响，需要意识到 TER 作为屏障功能参数的复杂性。
