Wound healing
When the epithelium was fully differentiated, hydrocortisone was withdrawn from the basolateral media for three days prior to wounding. Mechanical injury was performed by scraping a P10 sterile pipette tip across the cell layer creating a wound with a diameter ranging from 600 to 1500μm. The initial wound area was expressed as 100% to remove variability from wounds of different size 6. Wounds were considered to be closed when the calculated area fell below 3%, the effective limit of detection for image processing. Wound closure was calculated as follows: Wound closure (%) = 100 - ((Area/Initial Area)*100). Wound closure (%), plotted as a function of time (hour), was used to calculate the rate of wound closure (%/hour).