“…The methods for establishing primary proximal tubule cell cultures have been described previously. 21,22,29,30 In brief, the kidney cortex was carefully sectioned, and the tissue pieces were treated with Hank's balanced salt solution containing 3 mg/mL collagenase (Sigma-Aldrich, St. Louis, MO, USA) and incubated at 37°C for 1 h. Next, the cells were rinsed with phosphate-buffered saline (PBS) through a series of sieves and then spun down at 500× g for 5 min. Following this, the cells were treated with DMEM/F12 media (Lonza) for 4-6 h, after which the tubular cells floating in the media were harvested and grown on collagen-coated plates (BD Biosciences) until colonies of epithelial cells formed.…”