*4.2. Cell Culture and Treatment*

Mouse J774A.1 macrophages (Bioresource Collection and Research Center, Hsin-Chu, Taiwan) were cultured in Dulbecco's modified Eagle's medium (10-013-CM, Corning Inc., Corning, NY, USA) supplemented with 10% fetal bovine serum (Gibco, Grand Island, NY, USA) in a 5% CO2, 37 ◦C humidified incubator. To examine the effect of TSA on the macrophage subpopulation, J774A.1 macrophages were first seeded in 6-well dishes (5 <sup>×</sup> 106 cells/well). Afterwards, J774A.1 macrophages were polarized into the M2a phenotype by stimulation with IL-4 (20 ng/mL, PeproTech, Rocky Hill, NJ, USA) and IL-13 (20 ng/mL, PeproTech) or into the M2c phenotype by stimulation with IL-10 (20 ng/mL, PeproTech) and TGF-b1 (20 ng/mL, PeproTech) for 24 h in the presence or absence of TSA (200 nM and 500 nM, T8552, Sigma-Aldrich, St. Louis, MO, USA) at different concentrations.

Normal rat renal tubular NRK-52E cells (Bioresource Collection and Research Center) were cultured in the low-glucose Dulbecco's modified Eagle's medium (10-014-CV, Corning Inc.) supplemented with 5% fetal bovine serum (Gibco). To determine the effect of TSA on renal myofibroblasts, NRK-52E were stimulated with TGF-β1 (20 ng/mL, PeproTech) for 1, 2 and 4 days in the presence or absence of TSA (500 nM, Sigma-Aldrich).
