Department of Biophysics, Warsaw University of Life Sciences-SGGW, 159 Nowoursynowska St., 02-776 Warsaw, Poland.
Process Chemistry Centre, Centre for Process Analytical Chemistry and Sensor Technology (ProSens), Biskopsgatan 8, 20500 Åbo-Turku, Finland.
Sensors (Basel). 2019 Apr 20;19(8):1881. doi: 10.3390/s19081881.
Cystic Fibrosis (CF) is the most common fatal human genetic disease, which is caused by a defect in an anion channel protein (CFTR) that affects ion and water transport across the epithelium. We devised an apparatus to enable the measurement of concentration changes of sodium, potassium, chloride, pH, and transepithelial potential difference by means of ion-selective electrodes that were placed on both sides of a 16HBE14σ human bronchial epithelial cell line that was grown on a porous support. Using flat miniaturized ISE electrodes allows for reducing the medium volume adjacent to cells to approximately 20 μL and detecting changes in ion concentrations that are caused by transport through the cell layer. In contrast to classic electrochemical measurements, in our experiments neither the calibration of electrodes nor the interpretation of results is simple. The calibration solutions might affect cell physiology, the medium composition might change the direction of actions of the membrane channels and transporters, and water flow that might trigger or cut off the transport pathways accompanies the transport of ions. We found that there is an electroneutral transport of sodium chloride in both directions of the cell monolayer in the isosmotic transepithelial concentration gradient of sodium or chloride ions. The ions and water are transported as an isosmotic solution of 145 mM of NaCl.
囊性纤维化（CF）是最常见的致命性人类遗传疾病，由阴离子通道蛋白（CFTR）缺陷引起，影响上皮细胞的离子和水转运。我们设计了一种装置，通过放置在多孔载体上生长的 16HBE14σ人支气管上皮细胞系两侧的离子选择性电极来测量钠离子、钾离子、氯离子、pH 值和跨上皮电位差的浓度变化。使用扁平微型化 ISE 电极可以将与细胞相邻的介质体积减少到约 20 μL，并检测通过细胞层转运引起的离子浓度变化。与经典电化学测量相比，在我们的实验中，电极的校准和结果的解释都不简单。校准溶液可能会影响细胞生理学，介质成分可能会改变膜通道和转运蛋白的作用方向，并且伴随着离子转运的水流动可能会触发或切断运输途径。我们发现，在钠离子或氯离子的等渗跨上皮浓度梯度中，细胞单层的两个方向都存在氯化钠的电中性转运。离子和水作为 145mM 的 NaCl 等渗溶液转运。
