ABSTRACT
AIM: To investigate whether Toll-like receptor 4 ( TLR4 ) and Nod-like receptor protein 3 (NLRP3) inflammasome were involved in contrast medium (CM)-induced inflammation and injury in renal tubular epithe-lial cells.METHODS: Iopromide was used to injure NRK-52E cells in the study.The cell viability was measured by CCK-8 assay.The protein levels of TLR4, NLRP3, apoptosis-associated speckle-like protein (ASC), caspase-1 and cleaved caspase-3 were determined by Western blot .The releases of interleukin ( IL )-1βand IL-18 were detected by ELISA .The apoptotic rate was evaluated by Hoechst staining , and mitochondrial membrane potential ( MMP) was analyzed by JC-1 staining.siRNA was transfected into the NRK-52E cells to silence NLRP3 expression.RESULTS:CM decreased the viability of NRK-52E cells (P<0.05).CM also elevated the protein levels of cleaved caspase-3, TLR4, NLRP3, IL-1βand IL-18 (P<0.05).Silencing NLRP3 attenuated CM-induced releases of inflammatory cytokines .Moreover, treat-ment with TLR4 inhibitor TAK-242 or knockdown of NLRP3 by siRNA transfection both attenuated cell apoptosis and loss of MMP caused by CM .CONCLUSION:TLR4/NLRP3 inflammasome takes part in the pathogenesis of CM-induced acute kidney injury , and mediates CM-induced injury and inflammation in renal tubular epithelial cells .