Mouse mesangial cells (MES-13) were purchased from American Type Culture Collection (ATCC, Manassas, VA, USA). The cells were cultured in low-glucose Dulbecco’s modified Eagle’s medium (DMEM, HyClone, Logan, UT, USA) supplemented with 10% fetal bovine serum (FBS, Gibco, Waltham, MA, USA) and 1% penicillin/streptomycin (Gibco). For the experiments, cells were treated with mouse TGF-β (R&D systems, Minneapolis, MN, USA) at 2 ng/mL and EW-7197 at 500 nM for 24 hours.
Conditionally immortalized mouse podocytes were kindly provided by Dr. Peter Mundel [27 (link)]. The cells were grown on type I collagen-coated 100-mm dishes (Sigma-Aldrich, Burlington, MA, USA). To enhance the expression of a thermo-sensitive T antigen, the podocytes were cultured at 33°C to proliferate in low-glucose DMEM supplemented with 10% FBS, penicillin (100 U/mL), streptomycin (100 μg/mL), and mouse recombinant interferon-γ (10 U/mL, Sigma-Aldrich). To induce differentiation, podocytes were cultured at 37°C in low-glucose DMEM supplemented with 5% FBS, penicillin (100 U/mL), streptomycin (100 μg/mL) in the absence of interferon-γ for 14 days. During the experiments, cells were treated with HG (30 mM) for 24 hours.