The Role Of PI3K/AKT Signaling Pathway In Regulation Of NLRP3 Inflammasomes In THP-1 Cells

Introduction: Phospoinositide 3-kinas/protein kinas B(PI3K/Akt)signaling pathway play critical roles in regulation of atherosclerosis.Activation of NLRP3,a member of Nod-like receptor(NLR)family of pattern recognition receptors(PRR),is a key step in the pathogenesis of atherosclerosis.NLRP3 inflammasomes activation results in the maturation of caspase-1 and the release of IL-Iβ and IL-18.However,the mechanisms of PI3K-Akt signaling pathway in regulation of NLRP3 inflammasomes are not well known.In this study,we investigated potential roles of PI3/Akt signaling on the regulation of NLRP3 inflammasomes in THP-1 cells.Methods:The THP-1 cells were used as the monocyte/macrophage cell modelin this study.Cells were divided into seven groups : Control group,Oxidized low density lipoprotein(Ox-LDL)group,PI3 K inhibitor group,PI3 K inhibitor + Ox-LDL group,Akt inhibitor group,Akt inhibitor + Ox-LDL group,and PI3 K inhibitor + Akt inhibitor + OxLDL group.Following Ox-LDL treatment(100μg/m L)for 24 hours,GDC 0941(1μg/m L,PI3 K inhibitor)and MK 2206(1μg/m L,Akt inhibitor)were added for the indicated time.Western blot analysis was used to determine the protein expression level of NLRP3,caspase-1,IL-1β and IL-18.Results: Ox-LDL activated NLRP3 inflammasomes in THP-1 cells in a dose-and timeresponse manner.The dose-response and time-response experiments showed that treatment with 100μg/m L Ox-LDL for 24-hr revealed the most effect on the activation of NLRP3 inflammasomes.Both GDC 0941 and MK 2206 efficiently inhibited the effects of NLRP3 inflammasomes activation,namely the decrease in the NLRP3 protein expression.Both GDC 0941 and MK 2206 had similar inhibitory effects on the protein expression of caspas-1,IL-Iβ and IL-18,downstream contributors to the pathogenesis of atherosclerosis of NLRP3 activation.Conclusion: Ox-LDL activates NLRP3 inflammasomes in THP-1 cells.Both PI3 K and Akt inhibitors attenuate the Ox-LDL-induced activation of NLRP3 inflammasomes.Therefore,we conclude that activation of NLRP3 inflammasomes by Ox-LDL is PI3 KAkt dependent in THP-1 cells.