Fig. 2.

ATRA-treated primary TBE cells alone demonstrate electrical properties of a well-differentiated respiratory tract epithelium. HBE1 cells and primary TBE cells were grown in Transwell chambers until confluent, followed by serial measurements of transepithelial electrical resistance (R_te) and transepithelial potential (V_te) over a 10-day period starting with the 1st day of ALI conditions. A: changes in R_te values for HBE1 cells or primary TBE cells treated with or without ATRA (A). B: changes in V_te values for HBE1 cells or primary TBE cells treated with or without ATRA. Displayed R_te values (Ω·cm²) were corrected for background resistance of the membrane with PBS alone (background R_te was ∼125 Ω/well). V_te values (mV) represent absolute V_te after the probe was zeroed in PBS alone. A V_te >10 mV and an R_te >300 Ω·cm² was considered significant. Means and SE of at least 3 separate experiments are displayed.