Bufalin alleviates acute kidney injury by regulating NLRP3 inflammasome-mediated pyroptosis

Background: Recently, there has been an increasing clinical incidence of acute kidney injury (AKI), which rapidly declines renal function and leads to massive tubular cell necrosis. Pyroptosis is an inflammatory process of cell death that is more rapid than apoptosis, which is accompanied by a massive release of inflammasome activation. In the study, we aim to explore whether Bufalin regulates the AKI through the pyroptosis pathway.

Methods: We have established gentamicin (GM)-induced AKI animal and cell models to simulate the pathological conditions of kidney injury. The expression of renal injury and pyroptosis-related indicators were detected by western blot. PAS staining and IHC staining were used to analyze renal function. CCK-8 assay was performed to detect cell viability after AKI with different treatments. TUNEL staining, flow cytometry and immunofluorescence assays were performed to measure pyroptosis.

Results: After intraperitoneal injection of GM in rats, renal function was significantly decreased, along with a significant increase of damaged and necrotic cells as suggested by renal tubular epithelial tissue sections. In addition, there was an increase in the pyroptosis-related markers expression and pyroptosis-induced cell death. Consistently, studies in vitro found that GM significantly induced pyroptosis and its associated protein expression in NRK52e cells. Whereas, the administration of Bufalin reversed these effects of GM in vivo and in vitro. Further, we found that Nigericin (NLRP3 agonist) could reversed the effects of bufalin on GM-induced pyroptosis.

Conclusion: Bufalin attenuates pyroptosis generated AKI by inhibiting NLRP3 inflammasome.