Department of Health and Scienses - Pontifícia Universidade Católica do Paraná, Rua Imaculada Conceição 1155, Curitiba - Paraná - CEP:80215901 - Brazil.
Thromb J. 2011 Apr 3;9(1):6. doi: 10.1186/1477-9560-9-6.
Mature carotid plaques are complex structures, and their histological classification is challenging. The carotid plaques of asymptomatic and symptomatic patients could exhibit identical histological components.
To investigate whether matrix metalloproteinase 9 (MMP-9), tissue inhibitor of MMP (TIMP), and cyclooxygenase-2 (COX-2) have different expression levels in advanced symptomatic carotid plaques, asymptomatic carotid plaques, and normal tissue.
Thirty patients admitted for carotid endarterectomy were selected. Each patient was assigned preoperatively to one of two groups: group I consisted of symptomatic patients (n = 16, 12 males, mean age 66.7 ± 6.8 years), and group II consisted of asymptomatic patients (n = 14, 8 males, mean age 67.6 ± 6.81 years). Nine normal carotid arteries were used as control. Tissue specimens were analyzed for fibromuscular, lipid and calcium contents. The expressions of MMP-9, TIMP-1 and COX-2 in each plaque were quantified.
Fifty-eight percent of all carotid plaques were classified as Type VI according to the American Heart Association Committee on Vascular Lesions. The control carotid arteries all were classified as Type III. The median percentage of fibromuscular tissue was significantly greater in group II compared to group I (p < 0.05). The median percentage of lipid tissue had a tendency to be greater in group I than in group II (p = 0.057). The percentages of calcification were similar among the two groups. MMP-9 protein expression levels were significantly higher in group II and in the control group when compared with group I (p < 0.001). TIMP-1 expression levels were significantly higher in the control group and in group II when compared to group I, with statistical difference between control group and group I (p = 0.010). COX-2 expression levels did not differ among groups. There was no statistical correlation between MMP-9, COX-2, and TIMP-1 levels and fibrous tissue.
MMP-9 and TIMP-1 are present in all stages of atherosclerotic plaque progression, from normal tissue to advanced lesions. When sections of a plaque are analyzed without preselection, MMP-9 concentration is higher in normal tissues and asymptomatic surgical specimens than in symptomatic specimens, and TIMP-1 concentration is higher in normal tissue than in symptomatic specimens.
成熟的颈动脉斑块是复杂的结构，其组织学分类具有挑战性。无症状和有症状患者的颈动脉斑块可能具有相同的组织学成分。
研究基质金属蛋白酶 9（MMP-9）、基质金属蛋白酶组织抑制剂（TIMP）和环氧化酶-2（COX-2）在晚期有症状颈动脉斑块、无症状颈动脉斑块和正常组织中的表达水平是否不同。
选择 30 例因颈动脉内膜切除术而入院的患者。每位患者术前被分为两组之一：I 组为有症状患者（n=16，男 12 例，平均年龄 66.7±6.8 岁），II 组为无症状患者（n=14，男 8 例，平均年龄 67.6±6.81 岁）。9 例正常颈动脉用作对照。分析每个斑块中的纤维肌、脂质和钙含量。定量分析 MMP-9、TIMP-1 和 COX-2 在每个斑块中的表达。
根据美国心脏协会血管病变委员会，所有颈动脉斑块中有 58%被归类为 VI 型。对照颈动脉均被归类为 III 型。与 I 组相比，II 组的纤维组织百分比中位数明显更高（p<0.05）。I 组的脂质组织百分比中位数有高于 II 组的趋势（p=0.057）。两组的钙化百分比相似。与 I 组相比，II 组和对照组的 MMP-9 蛋白表达水平显著升高（p<0.001）。与 I 组相比，对照组和 II 组的 TIMP-1 表达水平显著升高，且对照组与 I 组之间存在统计学差异（p=0.010）。COX-2 表达水平在各组之间无差异。MMP-9、COX-2 和 TIMP-1 水平与纤维组织之间无统计学相关性。
MMP-9 和 TIMP-1 存在于动脉粥样硬化斑块进展的所有阶段，从正常组织到晚期病变。当对斑块切片进行无预选分析时，MMP-9 浓度在正常组织和无症状手术标本中高于有症状标本，而 TIMP-1 浓度在正常组织中高于有症状标本。
