敲除miR-223促进血管炎症和动脉粥样硬化的发生

miR-223 deficiency aggravates vascular inflammation and atherosclerosis

目的研究miR-223对血管炎症和动脉粥样硬化的影响,为临床动脉硬化性疾病提供新的诊疗方向。方法miR-223敲除鼠与ApoE敲除鼠(ApoE KO)繁殖制备miR-223/ApoE双敲鼠(miR-223/ApoE DKO);检测小鼠血浆脂质水平;处死取材后检测主动脉根部及血管全长的斑块含量;通过免疫组化检测斑块的炎症细胞浸润;转录组学测序分析血管中炎症相关基因的表达;结合microRNA靶基因数据库寻找并验证其可能的靶基因。结果miR-223/ApoE双敲鼠主动脉根部及血管全长斑块量显著增加(P<0.05)。免疫组化染色显示,主动脉根部炎症细胞浸润增加;血管转录组学测序发现炎症相关基因血管细胞黏附分子1(VCAM-1)、白细胞介素1α(IL-1α)等在双敲鼠中显著上调。通过靶基因数据库筛选,发现白细胞介素6(IL-6)是miR-223的靶基因并且在双敲鼠的血管中表达显著上调;使用miR-223模拟物刺激成纤维细胞,显著抑制了IL-6的表达。结论miR-223抑制靶基因IL-6的表达降低炎症反应,敲除miR-223显著升高血管炎症水平促进动脉粥样硬化的进展。

Aim To study the effect of miR-223 on vascular inflammation and atherosclerosis,and to provide a new therapeutic target for clinical arteriosclerosis.Methods The miR-223 knockout mice and ApoE knockout mice(ApoE KO)were crossbred to prepare miR-223/ApoE double knockout mice(miR-223/ApoE DKO).The plasma lipid levels of 8-month-old mice were measured.Plaque content in the aortic root and the entire length of the blood vessel were analyzed;Immunohistochemical staining was adapted to detect inflammatory cell infiltration in the plaque;Transcriptomics sequencing was used to analyze the expression of inflammation-related genes in the blood vessel;Screening the microRNA target gene database to find and validate possible target genes.Results Atherosclerosis in aortic root of miR-223/ApoE DKO mice were significantly increased(P<0.05).Immunohistochemical staining showed that more inflammatory cells infiltrated in aortic root of DKO mice;Vascular transcriptomics sequencing revealed that expression of inflammatory genes such as vascular adhesion molecule-1(VCAM-1),interleukin-1α(IL-1α)were up-regulated in DKO mice;Through screening of target genes from database,IL-6 was found to be a potential target gene of miR-223 and its expression was significantly up-regulated in DKO mice;3 T3 cells were transfected with miR-223 mimics and the expression of interleukin-6(IL-6)was significantly down-regulated.Conclusions miR-223 inhibits the expression of target gene IL-6 and reduces the inflammatory response.Knockout miR-223 significantly increases the level of vascular inflammation and promotes the progression of atherosclerosis.