Impact of BMP2/4 on ARPE-19 Barrier

Effects of BMP2 or 4 on barrier function of ARPE-19 were evaluated by monitoring changes in Trans-Cellular Electrical Resistance (TER). Normalized TER was recorded by Electric Cell-substrate Impedance Sensing (ECIS^®Zθ (theta)) instrument (Applied Biophysics Inc, Troy, NY, USA) as previously described [27 (link),28 (link),29 (link)]. Briefly, a 96-wells arrays (catalog # 96W20idf PET, Applied Biophysics Inc) were coated with 100 µM cysteine (50 µL) for 30 min then with 0.02% gelatin (50 µL) for another 30 min. Thereafter, ARPE-19 cells were seeded in DMEM/F12 full media with 10% FBS and 1% PS. After ARPE-19 reached the confluency, indicated by a capacitance below 20F, they were serum starved then treated with BMP2 or 4. Resistance for each well was normalized by dividing the measured resistance at each time point by the baseline resistance acquired before the addition of the treatment and plotted as a function of time.