Ceftriaxone Calcium Crystals Induce Acute Kidney Injury by NLRP3-Mediated Inflammation and Oxidative Stress Injury

OBJECTIVE: To investigate the role of inflammatory reactions and oxidative stress injury in the mechanisms of ceftriaxone calcium crystal-induced acute kidney injury (AKI) both in vivo and in vitro. METHODS: Male Sprague Dawley rats were randomly divided into five groups of ten each according to different concentrations of ceftriaxone and calcium. Based on the levels of serum creatinine (Scr) and blood urea nitrogen (BUN), the AKI group was chosen for the subsequent experiments. Kidney histological examination and immunohistochemistry were performed. The expression of NLRP3 and IL-1β protein and the concentrations of oxidative stress markers such as ROS, MDA, and H(2)O(2) in kidney tissues were estimated. In parallel, HK-2 human renal proximal tubule cells were exposed to ceftriaxone calcium crystals. The mRNA expression levels of NLRP3 and IL-1β and the concentrations of oxidative stress markers were evaluated. Finally, cell viability and rat survival were also assessed. RESULTS: The results showed that significantly increased Scr and BUN levels, consistent with morphological changes and kidney stones, were found in the rats that received the highest concentration of ceftriaxone (1000 mg/kg) combined with calcium (800 mg/kg). The activation of the NLRP3 inflammasome axis and the marked elevation of MDA, H(2)O(2), and ROS levels were observed both in vivo and in vitro. High expression of Nrf2, HO-1, and NQO1 was also documented. In addition, cell apoptosis and rat mortality were promoted by ceftriaxone calcium crystals. CONCLUSIONS: Notably, we found that ceftriaxone-induced urolithiasis was associated with a high risk of AKI and NLRP3-mediated inflammasome and oxidative stress injury were of major importance in the pathogenesis.