中文摘要：

目的：观察血小板源性生长因子-DD（PDGF-DD）在退行性变升主动脉瘤（degenerative ascending thoracic aortic aneurysm,DATAA）中的表达,探讨DATAA发病中PDGF-DD参与主动脉壁病理性重塑的机制。方法：升主动脉瘤术中切除标本25例为DATAA组,升主动脉直径正常的行冠状动脉搭桥患者主动脉标本25例为对照组,Masson染色分别检测主动脉壁的胶原含量。免疫组织化学方法检测主动脉壁中PDGF-DD的表达情况。蛋白印迹方法检测所有标本中PDGF-DD的蛋白表达水平。实时PCR的方法检测所有标本中PDGF-DD的mRNA表达水平。结果：病理结果与对照组标本比较显示DATAA组免疫组织化学结果表明PDGF-DD表达明显增加（P〈0.01）,主要位于中膜及内膜,对照组无明显表达;PDGF-DD的蛋白表达增加,差异有统计学意义（P〈0.01）,PDGF-DD的mRNA表达与蛋白结果一致（P〈0.01）;Masson染色及胶原半定量结果表明DATAA中胶原纤维明显增生,排列紊乱,面积百分比明显增加（P〈0.01）,相关性分析结果显示PDGF-DD蛋白表达结果与胶原纤维半定量结果及主动脉瘤径均呈正相关（r=0.68,P〈0.01;r=0.75,P〈0.01）。结论：PDGF-DD在DATAA主动脉壁中表达明显增强,并与主动脉直径大小密切相关。PDGF-DD可能参与了DATAA中主动脉壁的病理性重塑过程,导致主动脉壁胶原代偿性增加。

英文摘要：

Objective：To study the expression of Platelet-derived growth factor（PDGF-DD）in degenerative ascending thoracic aortic aneurysm（DATAA）,and to explorethe mechanisms.Method：DATAA specimens were taken from 25 patients during elective surgical intervention,while 25 control specimens of ascending aorta were obtained from patients undergoing coronary artery bypass surgery.Masson staining was used to evaluate the arrangement and aggregation of cells and collagen typesⅠ andⅢ,immunohistochemistry staining and western blot were performed to evaluate the protein expression of PDGF-DD.Real-time PCR analysis was performed to quantify the mRNA expression level of PDGF-DD.Result：Using masson staining and Real-time PCR,we observed elevated levels（P〈0.01）of collagen in the aortic media and adventitia of DATAA.When compared with controls,mRNA levels of PDGF-DD were significantly increased（P〈0.01）.Similar patterns were shown in protein levels of PDGF-DD（P〈0.01）.PDGF-DD expression had a correlation with both collagen fibers and aortic aneurysm diameter（r=0.68,P〈0.01;r=0.75,P〈0.01）.Conclusion：The expression of PDGF-DD was significantly increased in DATAA specimens and was positively correlated with the aortic diamete,which is likely to be responsible for the aortic wall pathological remodeling.