Molecular Mechanism And Protective Effect Of H₂S On Uranium-induced Rat Kidney Cell Pyroptosis In Vitro

Background and Object:Uranium is a potentially environmental risk factor.The molecular mechanism of uranium-induced nephrotoxicity is not fully elaborated.Scientists are looking for effective antagonists to prevent uranium nephrotoxicity.At present,pyroptosis plays an important role in renal tissue and cell injury.Our recent work has shown that H₂S,as a gasotransmitter,plays a protective role in uranium-induced rat nephrotoxicity through anti-oxidative,anti-inflammatory,and anti-apoptosis effects.The main objectives in this study are:?1?to explore whether uranium could induce kidney cell pyroptosis and its molecular mechanism;?2?to confirm that whether H₂S could alleviate pyroptosis-mdiated kidney cell cytotoxicity induced by uranium.Methods:SD rat kidney proximal cells?NRK-52^E?were intoxicated with different concentrations uranium.Pyroptosis was determined by flow cytometry.Cell viability was detected by MTT assay.Intracellular ROS level was assessed using fluorescence probe DCFH-DA.Western blots were used to determine the expression of proteins including NLRP3,cleaved Caspase 1,p-PI3K,p-AKT and p-mTOR.In uranium-intoxicated kidney cells,NaHS pretreatment was utilized to explore the protect mechanism of H₂S which attenuated pyroptosis-mediated cytotoxicity,respectively.Results:?1?Uranium exposure up-regulated the protein expression of NLRP3 and cleaved Caspase 1 and increased the rate of cell pyroptosis in kidney cells.?2?NaHS pretreatment inhibited uranium-increased NLRP3 and cleaved Caspase 1 protein expression and rate of cell pyroptosis.NaHS pretreatment also increased the protein expression of p-PI3K,p-AKT and p-mTOR down-regulated by uranium.Conclusion:?1?Uranium induces kidney cell pyroptosis through activating NLRP3 inflammasome pathway.?2?H₂S alleviates uranium-induced kidney cell pyroptosis by up-regulating PI3K/Akt/mTOR pathway.