Downregulated Expression of Solute Carrier Family 26 Member 6 in NRK-52E Cells Attenuates Oxalate-Induced Intracellular Oxidative Stress

Solute carrier family 26 member 6 (Slc26a6), which is mainly expressed in the intestines and kidneys, is a multifunctional anion transporter that is crucial in the transport of oxalate anions. This study is aimed at investigating the effect of Slc26a6 expression on oxalate-induced cell oxidation and crystal formation. Lentivirus transfection was used to upregulate or downregulate Slc26a6 expression in NRK cells. Cell viability and apoptosis, reactive oxygen species (ROS) and malondialdehyde (MDA) generation, and superoxide dismutase (SOD) activity were measured. Crystal adhesion and the cell ultrastructure were observed using light and transmission electron microscopy (TEM). Three groups of rats, normal control, lentivirus-vector, and lentivirus-small interfering RNA (lv-siRNA) groups, were used, and after lentivirus transfection, they were fed 1% ethylene glycol (EG) and 0.5% ammonium chloride (NH4Cl) for 2 weeks. Dihydroethidium (DHE), terminal deoxynucleotidyl transferase (TdT) deoxyuridine dUTP nick-end labeling (TUNEL), and von Kossa staining were performed, and nuclear factor κB (NFκB) and osteopontin (OPN) expression were measured. In the vitro study, compared to the control group, downregulated Slc26a6 NRK cells showed alleviation of the cell viability decrease, cell apoptosis rate, ROS generation, and SOD activity decrease after oxalate treatment. Crystal adhesion and vesicles were significantly less after oxalate exposure than in the untreated controls. Rats infected with lentivirus-siRNA exhibited attenuated SOD generation, cell apoptosis, and crystal formation in the kidneys. Increased phosphorylation of NFκB and OPN was involved in the pathological process. In conclusion, the results of the present study indicate that reducing the expression of Slc26a6 in the kidney may be a potential strategy for preventing stone formation.