MiR-124 Targeting IQGAP1 Regulates Vascular Endothelial Cell Activation In Atherosclerosis

The main pathological basis of atherosclerosis(AS)is ischemic cardiovascular and cerebrovascular diseases,such as coronary heart disease,cerebral infarction,peripheral vascular disease,etc.,which are more common and seriously endanger people’s health.So far,the pathogenesis of atherosclerosis is still unclear.Therefore,the pathological mechanism of atherosclerosis and the potential therapeutic targets of myocardial ischemic diseases such as coronary heart disease and angina pectoris have become one of the focuses of attention.It is generally believed that the development of atherosclerosis has experienced the formation of lipid plaques,fibrous plaques and atherosclerotic plaques,which are secondary to changes such as plaque hemorrhage,plaque rupture,thrombosis,and calcification.Atherosclerosis is an abnormal response of the blood vessel wall to external damage and is characteristic of chronic inflammatory diseases.At present,there are many pathogenic factors of atherosclerosis,involving multiple pathogenic mechanisms.Inflammation may be the hub of the pathogenesis of atherosclerosis.IQ motif containing GTPase activating proteins 1(IQ motif containing GTPase activating proteins 1,IQGAP1)is a scaffold protein,which is highly expressed in many diseases,including atherosclerosis.Other studies have shown that miR-124(micro RNA124)has low expression in patients with atherosclerosis.Bioinformatics suggests that IQGAP1 is a potential target of miR-124.Therefore,this subject focuses on the atherosclerotic vascular endothelial cells and the inflammatory factors secreted by them,and in-depth study of the molecular mechanism of the occurrence and development of atherosclerosis.Objective: To study the regulatory effects of IQGAP1 and miR-124 on the activation of vascular endothelial cells in atherosclerosis.Research method: 1.Search the regulatory target of micro RNA 124 through the Target Scan Human database;then verify whether miR-124 can directly bind to its target through the Dual Luciferase reporter assay(DR);2.Culture human coronary artery endothelial cells(Human Coronary Artery Endothelial Cells,HCAEC)in vitro,and use Oxidized Low Density Lipoprotein(ox-LDL)to stimulate normal HCAEC for 24 hours to establish ox-LDL-induced endothelial cell damage The model is divided into a control group and a model group.Observe the changes in cell morphology under a microscope to confirm that the model is successful;3.Culture human coronary artery endothelial cells in vitro,transfect miR-124 mimics and inhibitors with liposomes,continue to culture the cells,and build miR-124 overexpression and silence models.The total RNA and total protein of endothelial cells were extracted,and quantitative realtime PCR(q RT-PCR)and Western blot were used to detect downstream IQGAP1 and inflammation-related proteins TNF-α,IL-6 and the expression level of IL-1β;4.Flow cytometry to detect the apoptosis and cell cycle progression of endothelial cells in the miR-124 overexpression group and the silent group;5.Culture human coronary artery endothelial cells in vitro,transfect IQGAP1 mimics and inhibitors with liposomes,continue to culture the cells,and construct IQGAP1 silencing and overexpression models;6.Flow cytometry was used to detect the apoptosis and cell cycle progression of endothelial cells in IQGAP1 overexpression group and silence group,and Western blot was performed to detect the protein expression changes of downstream inflammatory factors TNF-α,IL-6 and IL-1β.Result:1.It was retrieved from Target Scan Human database that miR-124 can act on the 3’noncoding region of IQGAP1 m RNA,and the luciferase report result confirmed that IQGAP1 m RNA is the direct target of miR-124;2.Compared with the control group without ox-LDL stimulation,the endothelial cell activity of the model group with oxLDL stimulation was significantly reduced under the microscope;Western blot detection showed that the expression of IQGAP1 in the model group was significantly increased(P <0.01),statistically significant;3.Compared with the miR-124 overexpression group and the silence group,the m RNA level of IQGAP1 in the overexpression group was significantly lower than that in the silence group(P<0.05),which was statistically significant.The expression levels of inflammationrelated proteins TNF-α,IL-6 and IL-1β were significantly increased,and there were significant differences between the two groups(P<0.01);the results of flow cytometry showed that the overexpression group significantly promoted the apoptosis of HCAEC,Block the cell cycle;4.Compared with the IQGAP1 silent group,the expression of downstream inflammatory factors in the overexpression group was significantly increased(P<0.01),which was statistically significant;the results of flow cytometry showed that the silent group significantly promoted HCAEC apoptosis and blocked The cell cycle.Conclusion: 1.IQGAP1 can promote the secretion of inflammatory factors in human coronary artery endothelial cells,block the cell cycle process,and promote apoptosis;2.miR-124 can inhibit the secretion of inflammatory factors in human coronary artery endothelial cells,promote cell cycle progress,and reduce apoptosis;3.miR-124 inhibits the activation of coronary artery endothelial cells by targeting IQGAP1 and plays an anti-inflammatory effect.