Effects Of MiR-155 On Palmitic Acid-induced Vascular Injury And Its Mechanism

Cardiovascular disease,represented by atherosclerosis,is a chronic disease.With the aging of the population,cardiovascular disease is still recognized as the main cause of premature death in the world.Therefore,it is very important to clarify its pathogenesis and prognosis.Vascular remodeling is the basis of the pathogenesis and progress of most cardiovascular diseases,and high saturated fatty acids are also the risk factors of cardiovascular diseases.In recent years,studies have confirmed that miR-155 plays an important role in vascular homeostasis and vascular remodeling.Therefore,this study focuses on miR-155 to explore its role in regulating vascular injury induced by saturated fatty acids,such as palmitic acid.To clarify its regulatory mechanism.Part ? Differential expression of miR-155 in atherosclerosisObjective:To investigate the relationship between miR-155 and atherosclerosis,the expression of miR-155 in serum of patients with atherosclerosis was observed.Methods:After the ethical review and informed consent of patients in Xi'an,30 sera of atherosclerotic patients and 30 sera of healthy people were collected,and the content of miR-155 in sera of atherosclerotic patients was detected by RT-PCR.Results:The results showed that the miR-155 level in serum samples of atherosclerotic patients was significantly lower than that in the healthy control group,and the difference was statistically significant.Conclusions:The abnormal results suggest that miR-155 may play a role in the onset and progression of atherosclerosis.Part ? miR-155 regulates the mechanism of palmitic acid induced vascular endothelial cell injuryObjective:To study the regulatory mechanism of miR-155 on palmitic acid induced vascular endothelial cell injury.Methods:1.HUVEC was cultured and treated with palmitic acid.The total RNA of HUVEC was extracted.The expression of miR-155 in HUVEC was detected by RT-PCR.2.HUVECs were treated with 0.1m M palmitic acid and transfected with miR-155 mimic / inhibitor or Wnt pathway inhibitor xav939.HUVECs were divided into the following six groups: control group;palmitate group;MICs + palmitate group;MICs + palmitate + xav939 group;antigomir + palmitate group;antigomir + palmitate + xav939 group.3.RT-PCR was used to detect the expression of miR-155,?-Catenin and Cyclin D in HUVECs.4.MTT method was used to detect the proliferation of cells in each group.5.Transwell test was used to detect cell migration.6.Apoptosis was detected by flow cytometry.7.Western blot was used to detect the expression of Wnt protein.The localization of ?-Catenin cells was detected by immunofluorescence.Results:1.Palmitic acid down regulated the expression of miR-155 in HUVECs.2.In HUVECs induced by palmitic acid,the key protein ?-Catenin and Cyclin D in Wnt signaling pathway increased significantly,and the expression of ?-Catenin in nucleus increased.3.In HUVECs induced by palmitic acid,overexpression of miR-155 can promote cell proliferation,while inhibition of miR-155 is the opposite.4.Inhibition of Wnt signaling pathway can enhance the anti endothelial cell injury effect of miR-155 overexpression in HUVECs induced by palmitic acid,so as to promote HUVECs cell proliferation and reduce HUVECs cell apoptosis.5.On the contrary,inhibition of Wnt signaling pathway can partially reverse the inhibitory effect of miR-155 on HUVECs induced by palmitic acid.Conclusions: 1.Palmitic acid can down regulate the expression of miR-155.2.Mi R-155 can reduce the apoptosis of HUVECs cells induced by palmitic acid and promote the proliferation of HUVECs cells through the negative regulation of Wnt signaling pathway,which provides a theoretical basis for the prevention and treatment of cardiovascular diseases related to endothelial damage.Part ? To study the effect of miR-155 on palmitic acid-induced inflammation of vascular endothelial cellsObjective:After HUVECs induced by palmitic acid,the expression of miR-155 was intervened to detect the expression of ROS,inflammatory factors and adhesion factors in HUVEC cells,and to further explore the molecular mechanism of miR-155 regulating the injury of vascular endothelial cells induced by palmitic acid.Methods:1.Overexpression and inhibition of miR-155 in HUVECs induced by palmitic acid,and detection of ROS in HUVECs;2.Over expression and inhibition of miR-155,detection of IL-6,TNF-?,adhesion factor expression in HUVEC;Results:Inhibition of Wnt signaling pathway can enhance the anti endothelial cell injury effect of miR-155 overexpression in HUVECs induced by palmitic acid.Overexpression of miR-155 can down regulate inflammatory factors IL-6 and TNF-?,and reduce ROS level.Conclusion:miR-155 can reduce the production of ROS and the expression of inflammatory cytokines in HUVECs cells induced by palmitic acid by negatively regulating Wnt signaling pathway,which provides a theoretical basis for the prevention and treatment of cardiovascular diseases related to endothelial damage.Part ? To study the mechanism of miR-155 regulating the vascular remodeling induced by palmitic acidObjective:To study the expression of miR-155 in mice,extract the aortic tissue of mice,and observe the up-regulation and down-regulation of miR-155 in mice.Methods:80 FVB mice were divided into the following groups:1.Blank control group(n = 20): normal feeding,tail vein injection of normal saline;2.Palmitate group(n = 20): the rats were fed with palmitate and injected with normal saline.3.Down regulation of miR-155 + palmitate group(n = 20): feeding with palmitic acid,tail vein injection of miR-155 antagomir miR-155 up regulation + palmitate group(n = 20): feeding with palmitic acid,tail vein injection of mimics;4.After the intervention,the aorta of mice was collected,the morphological changes of the aortic wall were observed,the expression and distribution of inflammatory factors in the aorta were detected by immunohistochemistry,and Wnt signaling was detected by Western blot.Results:1.High palmitic acid feeding can induce pathological remodeling of aortic wall in mice;2.Up-regulation of miR-155 expression in high palm-fed mice significantly inhibited the activation of wnt signaling pathway and inhibited the expression of TNF-? and IL-6 in the aortic intima;Conclusion:1.High palmitic acid feeding can induce pathological remodeling of aortic wall in mice;2.miR-155 has a protective effect on the damage of aortic wall injury induced by high palmitic acid.