Supplementary Material for: Sodium Citrate Inhibits Endoplasmic Reticulum Stress in Rats with Adenine-Induced Chronic Renal Failure

Background/Aims: Endoplasmic reticulum stress (ERS) is an important self-protective cellular response to harmful stimuli that contribute to various diseases, including chronic renal failure (CRF). Sodium citrate plays an important role in antioxidant and cellular immunity, but whether it improves ERS in CRF is unclear. Methods: The rats were randomly divided into five groups: the control group, the sodium citrate control group, the model group, model rats with low dose sodium citrate (216 mg/kg), and model rats with a high dose of sodium citrate (746 mg/kg). The rats were euthanized at 6, 8, 12, and 16 weeks with their blood and renal tissue in detection. Results: The increased concentrations of blood urea nitrogen and serum creatinine in the model group were significantly decreased by sodium citrate treatment. Hematoxylin-eosin and Masson staining showed that sodium citrate treatment apparently improved renal pathological changes in CRF rats. Western blot analysis showed that sodium citrate treatment decreased the protein levels of transforming growth factor-beta 1 and collagen type IV, which were increased in model rats. Moreover, immunohistochemical staining demonstrated that sodium citrate could effectively reduce the protein expression of glucose-regulated protein 78 kDa and CCAAT/enhancer-binding protein homologous protein in the model rats, which was consistent with western blot results. Additionally, the high dose of sodium citrate had a stronger protective effect in CRF rats than the low dose of sodium citrate. Conclusions: Sodium citrate has a protective effect on CRF through its effects on ERS.