| Background and Objective:The pathogenesis of abdominal aortic aneurysm is complicated,and there is extensive evidence that its development is closely related to vascular inflammation.Some cytokines have been found to be involved in the inflammatory response of abdominal aortic aneurysms,but it is not clear which factor induces the formation of abdominal aortic aneurysms.Some animal experiments have confirmed that interleukin-6(IL-6)and t-cell-activated secret-regulating factor(RANTES)play an important role in the pathogenesis of abdominal aortic aneurysm,but the mechanism of their influences on abdominal aortic aneurysm is still not very clear.In this study,the mechanism of inflammatory response between IL-6 and RANTES during the occurrence and development of abdominal aortic aneurysm is thoroughly studied,which has a great significance for further clarifying the pathogenesis of abdominal aortic aneurysm and for targeted intervention and clinical application.Methods:This topic mainly carries on two aspects research: one is the correlation between IL-6 and RANTES and abdominal aortic aneurysm;the other is to explore the mechanism of IL-6 and RANTES affecting the formation of abdominal aortic aneurysm.Grouping: 1.The clinical data of 40 patients with abdominal aortic aneurysm were analyzed.Forty patients in the normal control group were enrolled.The patients were divided into three groups according to the maximum diameter: normal control group,the lower diameter group of patients with abdominal aortic aneurysm(3cm < maximum diameter of AAA < 5cm),a higher diameter group of patients with abdominal aortic aneurysm(maximum diameter of AAA ≥ 5cm),and collect the blood samples.2.Normal abdominal aortic wall tissue samples and abdominal aortic aneurysm wall tissue samples were collected in 3 cases,respectively.3.RAW264.7,an abdominal aortic aneurysmarelated macrophage,was cultured and divided into 3 groups: Group A: RAW264.7 with complete medium.Group B: RAW264.7 + IL-6 group: complete medium containing 10ng/ml IL-6 was added;Group C: RAW264.7+ IL-6 +RANTES siRNA group: RANTES siRNA was transfected and cultured in complete medium containing 10ng/ml IL-6.The experiment is divided into the following parts: 1.ELISA was used to detect the level of serum IL-6 and RANTES in patients with abdominal aortic aneurysm;2.Immunohistochemical method was used to detect the expression of serum IL-6 and RANTES in the wall of abdominal aortic aneurysm;3.qRT-PCR method was used to detect the transfection efficiency of siRNA RANTE;4.cck-8 method was used to detect the effects of IL-6 and RANTES on the proliferation of abdominal macrophages associated with abdominal aortic aneurysm;5.Transwell method was used to detect the effects of IL-6 and RANTES on the migration of abdominal macrophages associated with abdominal aortic aneurysm;6.qRT-PCR was used to detect the expression of RANTES mRNA in abdominal macrophages treated with IL-6 and siRNA RANTES;7.Effects of IL-6 and RANTES on STAT3 and its phosphorylation level.Results: 1.The serum levels of IL-6 and RANTES in patients with abdominal aortic aneurysm were higher than those in healthy subjects,but there was no difference between the abdominal aortic aneurysm groups.2.The expression of IL-6 and RANTES in abdominal aortic aneurysm wall was significantly higher than that in normal abdominal aortic wall by immunohistochemical staining.3.The transfection efficiency of siRNA RANTE3 was the highest,which can effectively inhibit the expression of RANTES.siRNA RANTES was transfected into RAW264.7 cells by liposome 2000,and qRTPCR was used to detect the expression of siRNA RANTES in RAW264.7 cells.The transfection efficiency of the three siRNA RANTES plasmids synthesized by three different sequences was studied.The results showed that the three plasmids all reduced the expression of RANTES gene,and the inhibition of RANTES siRNA3 was the highest.4.IL-6 and RANTES promote the proliferation of abdominal macrophages associated with abdominal aortic aneurysm.Over time,the activity of RAW264.7 cells treated with IL-6 increased.The difference was statistically significant compared with RAW264.7 control group,which indicated that IL-6 could promote the proliferation of abdominal aortic aneurysm-related peritoneal macrophages.In the transfected RANTES siRNA cells,compared with IL-6 group,the difference was statistically significant,indicating that IL-6 could inhibit the proliferation of abdominal aortic aneurysm-related peritoneal macrophages.These results suggest that both IL-6 and RANTES can promote the proliferation of abdominal aortic aneurysmrelated peritoneal macrophages,which increases in a time-dependent manner within 72 hours.5.IL-6 and RANTES promote the migration of abdominal macrophages associated with abdominal aortic aneurysmThe results showed that RAW264.7 cells migrated to the ventricle significantly after using IL-6.However,in RAW264.7 cells transfected with siRNA RANTES,the number of migrating cells decreased.The results showed that IL-6 could induce macrophage migration,which was blocked by inhibition of RANTES.6.The expression of RANTES mRNA level was increased after the treatment of abdominal macrophages associated with abdominal aortic aneurysm via IL-6,and the expression of RANTES mRNA level was decreased after the treatment of siRNA RANTES;7.IL-6 and RANTES can activate the phosphorylation expression of STAT3.IL-6 had no effect on the expression of STAT3,but significantly promoted the expression of RANTES and the phosphorylation of STAT3.The phosphorylation of STAT3 activated by IL-6 was inhibited in RANTES siRNA RAW264.7 cells which inhibited the expression of RANTES.Conclusion:In this study,the high expression of IL-6 and RANTES in serum and vessel wall of abdominal aortic aneurysm were found,which confirmed that they were related to abdominal aortic aneurysm.IL-6 and RANTES can activate p-STAT3-induced macrophage infiltration,which is associated with increased MMP expression and oxidative stress activation.The specific mechanism needs further study. |
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