INCREASED EXPRESSION OF MATRIX METALLOPROTEINASES AND MATRIX-DEGRADING ACTIVITY IN VULNERABLE REGIONS OF HUMAN ATHEROSCLEROTIC PLAQUES
INCREASED EXPRESSION OF MATRIX METALLOPROTEINASES AND MATRIX-DEGRADING ACTIVITY IN VULNERABLE REGIONS OF HUMAN ATHEROSCLEROTIC PLAQUES
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DOI：
10.1172/jci117619
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发表时间：
1994-12-01
影响因子：
15.9
通讯作者：
LIBBY, P
中科院分区：
文献类型：
--
作者：
GALIS, ZS;SUKHOVA, GK;LIBBY, P
细胞外基质（ECM）代谢失调可能有助于人类动脉粥样硬化病变的发展和并发症的血管重塑。我们研究了基质金属蛋白酶（MMPs）的表达，MMPs是一种降解人动脉粥样硬化斑块（n=30）和未受累动脉标本（n=11）中ECM成分的酶家族。我们研究了所有三个MMP类（间质胶原酶，MMP-1，明胶酶，MMP-2和MMP-9，和基质分解素，MMP 3）和它们的内源性抑制剂（TIMPs 1和2）的免疫细胞化学，酶谱和免疫沉淀的成员。正常动脉对72-kD明胶酶和TIMPs染色均匀。相反，斑块的肩部和泡沫细胞聚集区域显示92-kD明胶酶、基质溶解素和间质胶原酶的局部表达增加。然而，仅仅MMP的存在并不能建立它们的催化能力，因为酶原缺乏活性，并且TIMP可以阻断活化的MMP。所有的斑块提取物含有明胶酶的活性形式确定的酶法和降解的H-3-胶原IV型。为了直接测试动脉粥样硬化是否真的含有活性基质降解酶原位，我们设计了一种方法，它允许直接在组织切片中检测和显微镜定位MMP酶活性。原位酶谱显示明胶分解和酪蛋白分解活性在动脉粥样硬化的冰冻切片中，但未涉及动脉组织。MMP抑制剂EDTA和1，10-菲咯啉以及重组TIMP-1降低了这些与免疫反应性MMP表达增加的区域共定位的活性，即，斑块的肩部、核心和微血管。局部过表达活化的MMP可能促进动脉粥样硬化斑块的不稳定和并发症，并为治疗干预提供新的靶点。
Dysregulated extracellular matrix (ECM) metabolism may contribute to vascular remodeling during the development and complication of human atherosclerotic lesions. We investigated the expression of matrix metalloproteinases (MMPs), a family of enzymes that degrade ECM components in human atherasclerotic plaques (n=30) and in uninvolved arterial specimens (n=11). We studied members of all three MMP classes (interstitial collagenase, MMP-1; gelatinases, MMP-2 and MMP-9; and stromelysin, MMP3) and their endogenous inhibitors (TIMPs 1 and 2) by immunocytochemistry, zymography, and immunoprecipitation. Normal arteries stained uniformly for 72-kD gelatinase and TIMPs. In contrast, plaques' shoulders and regions of foam cell accumulation displayed locally increased expression of 92-kD gelatinase, stromelysin, and interstitial collagenase. However, the mere presence of MMP does not establish their catalytic capacity, as the zymogens lack activity, and TIMPs may block activated MMPs. All plaque extracts contained activated forms of gelatinases determined zymographically and by degradation of H-3-collagen type IV. To test directly whether atheromata actually contain active matrix-degrading enzymes in situ, we devised a method which allows the detection and microscopic localization of MMP enzymatic activity directly in tissue sections. In situ zymography revealed gelatinolytic and caseinolytic activity in frozen sections of atherosclerotic but not of uninvolved arterial tissues. The MMP inhibitors, EDTA and 1,10-phenanthroline, as well as recombinant TIMP-1, reduced these activities which colocalized with regions of increased immunoreactive MMP expression, i.e., the shoulders, core, and microvasculatore of the plaques. Focal overexpression of activated MMP may promote destabilization and complication of atherosclerotic plaques and provide novel targets for therapeutic intervention.