PPARγ在不同周龄apoE-/-小鼠主动脉斑块表达及与斑块成份的相互关系  

PPARγ gene and protein expression in aortic plaque of different week-old apoE-knock out mice and the relationship with the composition of aortic plaque

作　　者：胡琴[1] 张运[1] 张宪军[1] 冯进波[1] 刘春喜[1] 姜虹[1] 蒋桂花[1] 王蓉[1] 

机构地区：[1]山东大学齐鲁医院心内科教育部和卫生部心血管重构和功能研究重点实验室

出　　处：《中国病理生理杂志》2006年第12期2289-2295,共7页Chinese Journal of Pathophysiology

摘　　要：目的:研究PPARγ基因表达与ApoE-/-小鼠主动脉斑块成份的相互关系。方法:以20和40周龄ApoE-/-小鼠(n=10/组)为研究对象,相同基因背景和周龄C57BL/6 J小鼠设为对照。采用RT-PCR和免疫印迹技术检测各组小鼠主动脉PPARγ基因和蛋白表达变化;Movat 5色套染法和油红O染色检测ApoE-/-小鼠主动脉斑块成份;免疫组织化学技术检测斑块内PPARγ、SM-actin、MOMA-2抗原表达。结合免疫荧光技术分析PPARγ基因在主动脉斑块巨噬细胞、平滑肌细胞的表达及与脂质、弹性纤维、胶原和蛋白聚糖的相互关系。结果:20和40周龄C57BL/6 J小鼠主动脉壁有少量PPARγ表达,以20周龄组明显。ApoE-/-小鼠主动脉壁和斑块内PPARγ表达增多,以斑块内表达明显(P<0.05);与20周龄组比较,40周龄组表达最显著;且斑块脂质含量丰富;弹性纤维、胶原和蛋白聚糖含量减少,血管正性重塑明显;MOMA-2表达增加,SM-actin表达降低(P<0.05)。PPARγ在斑块内巨噬细胞、血管中膜平滑肌细胞和斑块内平滑肌细胞都有表达,但以脂质含量丰富处PPARγ表达最明显。结论:PPARγ在C57BL/6 J小鼠动脉壁表达随增龄而减少;在ApoE-/-小鼠主动脉壁和斑块内PPARγ表达随AS病变进程而增加。推测ApoE-/-小鼠主动脉斑块PPARγ表达上调可能是机体一种代偿行为和自我保护机制。AIM： To investigate the relationship of PPARγ gene expression with the composition of aortic plaque in apoE - knock out mice. METHODS ： PPARγ gene and protein in aortic area of 20 - week - old and 40 - week -old apoE - knock out mice were investigated using RT - PCR and immunoblotting. The same aged wild type mice （C57BIM6J） were served as control （n = 10）. The composition of aortic plaques was analyzed by Movat method and oil red O staining. The expression of antigens such as PPARγ, SM - actin and MOMA - 2 in aortic plaque were compared using immunohistochemistry. The relationship of PPARγ with macrophage, smooth muscle cells （SMC）, lipid, elastic fiber, collagen and proteoglycan in aortic plaque were analyzed using immunofluorescence. RESULTS： PPARγ gene and protein in aortic wall and plaque of apoE - knock out mice were more significant than that in the same aged C57BIM6J mice （ P 〈 0. 05 ）. PPARγexpression at 40 - week - old apoE - knock out mice was most significant and very low in C57BIM6J mice. More PPARγ expression of gene and protein at 20 - week - old C57BIM6J mice than 40 - week - old C57BIM6J mice were observed. Compared with 20 - week - old apoE - / - mice, the lipid pool in aortic plaque at 40 - week - old apoE - / - mice were increased remarkably, while elastic fiber, collagen and proteoglycan in plaque were decreased and aortic remodeling was very significant. Even, upregulation of MOMA - 2 and downregulation of SM - actin were also detected in latter （P 〈 0. 05 ）. In addition to SMC of aortic tunica media, PPARγ also expressed in SMC and macrophages in the aortic plaque of apoE - / - mice. PPARγ was very enriched in lipid pool of the plaque. CONCLUSION ： PPARγ expression level decreases with aging in C57BL/6J mice, while increases with plaque progression in apoE - knock out mice. There is positive correlation between PPARγ expression and lipid composition in plaque. The observed upregulation of PPARγ gene expression in aortic plaque may be a compensator

关 键 词：过氧化酶体激增剂活化受体γ 动脉硬化 斑块 

分 类 号：R363[医药卫生—病理学]