Mechanism of Liraglutide in Oxidized Low-density Lipoprotein Induced Endothelial Cell Injury Based on NOD-like Receptor 3 Inflammasome Pathway postprint

Abstract: Background  Atherosclerosis is the primary cause of cardiovascular and cerebrovascular diseases worldwide，and inflammation is a current research focus，with NOD-like receptor 3（NLRP3）being the most intensively studied inflammasome. GLP-1 receptor agonists have shown anti-atherosclerotic effects，but the underlying mechanisms remain unclear. Objective  To investigates the mechanism of liraglutide in antagonizing oxidized low-density lipoprotein（ox-LDL）induced endothelial cell injury. Methods  Human umbilical vein endothelial cells（HUVECs）were cultured，and HUVEC with blank serum was served as the control group，100 μg/mL ox-LDL treated HUVECs for 48 hours was served as the model group. Liraglutide was added in concentrations of 100 nmol/L，200 nmol/L，and 400 nmol/L to the HUVECs treated with ox-LDL for 24 hours，forming low，medium，and high concentration liraglutide groups，respectively. Cell proliferation rates were calculated using the CCK-8 method. Pyroptotic cell morphology was observed by using scanning electron microscopy. Lactate dehydrogenase（LDH）activity was measured. The expression levels of interleukin （IL） 1β and IL-18 were detected using enzyme-linked immunosorbent assay（ELISA）. Western blotting was used to assess the expression levels of NLRP3，apoptosis-associated speck-like protein containing a CARD（ASC），caspase-1，gasdermin D（GSDMD），and N-terminal GSDMD（N-GSDMD）. Results  Cell proliferation rate in the model group and both low and medium concentration liraglutide groups were lower than the control group，while the rate in all liraglutide-treated groups were higher than the model group（P<0.05）. Scanning electron microscopy showed obvious pyroptosis in the model group cells，which was significantly reduced in all liraglutide-treated groups.LDH activity in the model group and the low concentration liraglutide group was higher than the control group，while it was lower in all liraglutide-treated groups compared to the model group（P<0.05）. IL-1β level in the model group and the low concentration liraglutide group was higher than the control group，whereas IL-1β levels in the medium and high concentration liraglutide groups was lower than the model group（P<0.05）. IL-18 level in the model group was higher than the model group，while level in all liraglutide-treated groups was lower than the model group（P<0.05）. The expression levels of NLRP3，ASC，caspase-1，GSDMD，and N-GSDMD in the model group were higher than the control group. In the low concentration liraglutide group，ASC and caspase-1 levels were higher than the control group，whereas in the medium concentration group，NLRP3 and ASC levels were lower than the model group. In the high concentration group，NLRP3，ASC，and caspase-1 levels were lower than the model group（P<0.05）. Conclusion  Liraglutide significantly inhibits NLRP3 inflammasome activation in endothelial cells induced by ox-LDL，and can inhibit endothelial cell pyroptosis，with anti-atherosclerotic effects.