Isolation and Culture of Feline Renal Cells

Feline renal tissue was obtained with owner informed consent during post-mortem examinations, and FPTEC and CKD-FCF were isolated as previously described (Lawson et al., 2018a (link), Lawson et al., 2018b (link)). FPTEC were derived from the kidneys of cats without azotaemia, and CKD-FCF were derived from the kidneys of cats with azotaemic CKD. Experiments utilising FPTEC took place in serum-free medium (pH 7.4) supplemented with 10 ng/mL epidermal growth factor (Invitrogen), 36 ng/mL dexamethasone (Sigma-Aldrich), 2 ng/mL triiodothyronine (Sigma-Aldrich), 1% insulin-transferrin-selenium (Thermo Fisher Scientific) and 1% antimicrobial solution (Gibco Antibiotic-Antimycotic (100x); Thermo Fisher Scientific). Experiments utilising CKD-FCF were performed in reduced serum DMEM-F12 (pH 7.4) containing 3% foetal bovine serum (FBS; Thermo Fisher Scientific). All experiments were performed using cells at passages 1 or 2. Experiments were performed in quadruplicate, where each experimental repeat represented a separate isolation from an individual cat. Phosphate was supplemented, from a standard concentration of 0.95 mM, by the addition of a pH 7.4 stock solution of sodium phosphate monobasic/sodium phosphate dibasic (NaH₂PO₄/Na₂HPO₄; Sigma–Aldrich).