Cell culture flasks and plates

HK-2 (ATCC, Manassas, VA) and tubular epithelial cell line human kidney cell (HKC) were purchased from the Chinese Academy of Medical Sciences cell bank. These 2 cell lines were both cultured in DMEM/F12 (Gibco, Carlsbad, CA) containing 10% fetal bovine serum (Gibco), penicillin (100 U/mL), and streptomycin (0.1 g/mL). And cells were incubated at 37°C in a humidified atmosphere with 5% CO₂. Cells were free of contamination with bacterial, fungal, and mycoplasma.
When the cells attached with a density of 70%–80%, they were digested with 0.25% trypsin, and then a single-cell suspension was prepared with serum culture medium. For routine cell cultures, T25 culture flasks were used, and cells were seeded in a 96-well culture plate at a density of 5000 cells per/well for CCK8 experiment. As for extracting cell protein, RNA, supernatant, and precipitation, cells were plated at a density of 20 000 cells per well in a 6-well plate. All cell culture flasks and plates were purchased from Corning Company (Corning, NY).

Unlabeled iodothyronines, silychristin, bovine serum albumin (BSA), and D-glucose were obtained from Sigma-Aldrich (Zwijndrecht, The Netherlands [NL]). [¹²⁵I]-T3 and [¹²⁵I]-T4 were prepared as previously described (23 (link)). X-tremeGENE9 transfection reagent was obtained from Roche Diagnostics (Woerden, NL). Cell culture flasks and plates were obtained from Corning (Schiphol, NL). An overview of the antibodies is provided in Supplemental Table 1 (24 ). Sulfo-NHS-biotin was obtained from Gentaur (Eersel, NL). Neutravidin agarose was obtained from Thermo Fisher Scientific (Bleiswijk, NL).