Liraglutide Alleviates Palmitic Acid-induced Vascular Endothelial Cell Pyroptosis

Objective: Atherosclerosis is a chronic inflammatory disease.Increased number of cell death can be observed in vascular wall,which initiated and triggered the progression of atherosclerosis.Pyroptosis is a newly discovered type of programmed cell death and is implicated in several cardiovascular diseases,including atherosclerosis.Endothelial cell is located at the interface between blood and interstitial tissues;endothelium constitutes a protective barrier against endogenous danger signals.Previous studies have shown that EC death is a crucial and initial stage in the process of AS and pyroptosis is a main type of atherosclerosis-related endothelial cell death.Recent clinical intervention studies have shown that the GLP-1 receptor agonist liraglutide lowers cardiovascular risk,but the underlying mechanism has not been fully elucidated.Therefore,we discuss that whether liraglutide plays a role in anti-atherosclerosis via regulating pyroptosis in vascular endothelial cells.Methods: The EA.hy926 human umbilical vascular endothelial cell fused cell line were cultured and were treated with palmitic acid of different concentration including300umol/L,400umol/L and 500umol/L respectively.Scanning electron microscope was used to observe the morphological changes of endothelial cells before and after palmitic acid(400umol/L)treatment.We then observed the changes of cell morphology among the above three groups and the negative control group via converted microscope.Later the cells were divided into four groups for treatment: the negative control group(NC),palmitic acid treatment group(PA),liraglutide treatment group(LA),palmitic acid plus liraglutide treatment group(PA+LA).The cell viability was measured by CCK-8 kit.And the expression level of NLRP3,caspase-1 and GSDMD in NC,PA and PA+LA groups were detected by western-blot.Results: 1.The cells began to swell and turn into a round shape when the concentration of PA was above 300umol/L.The cells were arranged irregularly,besides there were obvious cell fragmentation and rupture observed by the converted microscope.2.Observed under the scanning electron microscope,the morphology of the cells in the NC group was relatively good,and there was no obvious swelling and scorching.In the PA group,the characteristics of cell pyrolysis were more obvious,and the overall cells were obviously edema and disintegrated.The cell membrane dissolves and disappears in a large area,the cytoskeleton is exposed,and there are many large windows on the surface.3.The cell viability in the PA group was significantly lower than that in the NC group(P(27)0.05).While when compared with PA group,the cell viability in PA+LA and LA group was much more higher(P(27)0.05,P(27)0.05).4.The protein expression level of NLRP3,caspase-1 and GSDMD were increased significantly in PA group,compared with NC group(P(27)0.05).After liraglutide treatment,the expression level of NLRP3,caspase-1 and GSDMD were decreased compared with PA group(P(27)0.05).Conclusion: Palmitic acid treatment could induce pyroptosis in human umbilical vascular endothelial cells,moreover there was distinct change in cell morphology observed by optical microscope.Liraglutide treatment could inhibit the endothelial cell pyroptosis induced by palmitic acid.