IKKε增加血管平滑肌细胞自噬促进小鼠腹主动脉瘤形成作用研究

IKKεaccelerates abdominal aortic aneurysm formation in mice by increasing VSMCs autophagy

目的探讨IKKε对小鼠腹主动脉瘤形成过程中血管平滑肌细胞自噬的影响。方法将载脂蛋白E敲除(ApoE^(-/-))的小鼠与载脂蛋白E和IKKε双敲(ApoE^(-/-)IKKε^(-/-))的小鼠用生理盐水(saline)和血管紧张素Ⅱ(AngⅡ)分别刺激28天,检测小鼠的代谢水平以及用超声心动图检测小鼠的动脉直径,应用HE染色检测动脉瘤的病理性变化,马松染色检测小鼠动脉的纤维化水平,荧光法检测活性氧的产生和释放水平,免疫组化和Western blot检测自噬相关因子的表达变化情况。结果ApoE^(-/-)IKKε^(-/-)双敲小鼠与ApoE^(-/-)单敲小鼠代谢水平差异无统计学意义,ApoE^(-/-)IKKε^(-/-)双敲小鼠动脉直径显著小于ApoE^(-/-)单敲小鼠。ApoE^(-/-)IKKε^(-/-)双敲小鼠纤维胶原化水平显著低于ApoE^(-/-)单敲小鼠,且ApoE^(-/-)IKKε^(-/-)双敲小鼠中活性氧的产生水平明显低于ApoE^(-/-)单敲小鼠。免疫组化与Western blot结果均发现,ApoE^(-/-)IKKε^(-/-)双敲小鼠中LC3B与Beclin-1的表达水平均较ApoE^(-/-)单敲小鼠有明显的降低。结论小鼠IKKε基因的敲除能够明显抑制血管平滑肌细胞自噬,从而减少小鼠腹主动脉瘤的形成。

Objective To investigate the effect of IKKεon autophagy during abdominal aortic aneurysm formation in mice.Methods We stimulated ApoE^(-/-)mice and ApoE^(-/-)IKKε^(-/-)mice with AngⅡand saline for 28 days.Metaboilic levels and aortic diameter of ApoE^(-/-)mice and ApoE^(-/-)IKKε^(-/-)mice were measured.The arterial fibrosis of mice was detected by Masson staining and HE staining,mitochondrial reactive oxides were detected by fluorescence assay,the expression levels of autophagy factors LC3B and Beclin-1 were detected by immunohistochemistry,and the protein level of LC3B was detected by Western blot.Results There was no significant difference in metaboilic levels between ApoE^(-/-)mice and ApoE^(-/-)IKKε^(-/-)mice.However,the aortic diameterf ApoE^(-/-)IKKε^(-/-)mice was significantly less than that of ApoE^(-/-)mice.The fibrosis level of ApoE^(-/-)IKKε^(-/-)mice was significantly lower than that of ApoE^(-/-)mice.Furthermore,ROS in ApoE^(-/-)IKKε^(-/-)mice was lower than that in ApoE^(-/-)mice.In addition,immunohistochemical and western blot showed that the expression levels of LC3B and Beclin-1 in ApoE^(-/-)IKKε^(-/-)mice were significantly lower than in ApoE^(-/-)mice.Conclusion IKKε^(-/-)deficiency can significantly inhibit autophagy,thus reducing the development of abdominal aortic aneurysm in mice.