Cipollone Francesco, Iezzi Annalisa, Fazia Maria, Zucchelli Mirco, Pini Barbara, Cuccurullo Chiara, De Cesare Domenico, De Blasis Giovanni, Muraro Raffaella, Bei Roberto, Chiarelli Francesco, Schmidt Ann Marie, Cuccurullo Franco, Mezzetti Andrea
University of Chieti G D'Annunzio School of Medicine , Chieti, Italy.
Circulation. 2003 Sep 2;108(9):1070-7. doi: 10.1161/01.CIR.0000086014.80477.0D. Epub 2003 Aug 11.
RAGE (receptor for advanced glycation end products [AGEs]) plays a role in diabetic atherosclerosis. Recently, we have demonstrated enhanced expression of cyclooxygenase-2 and PGE synthase-1 (COX-2/mPGES-1) in human symptomatic plaques, and provided evidence that it is associated with metalloproteinase (MMP)-induced plaque rupture. However, the specific transmembrane signaling pathway(s) influencing plaque COX-2/mPGES-1 expression is unknown. The aim of this study was to characterize RAGE expression in human plaques and to correlate it with the inflammatory infiltration, COX-2/mPGES-1 and MMP expression, and with clinical evidence of diabetes.
Plaques obtained from 60 patients undergoing carotid endarterectomy were divided into diabetic and nondiabetic according to clinical evidence of type 2 diabetes. Plaques were subjected to analysis of RAGE, NF-kappaB, COX-2/mPGES-1, MMP-2 and MMP-9, lipid and oxidized LDL (oxLDL) content, and collagen content by immunohistochemistry and Western blot, whereas zymography was used to detect MMP activity. Immunohistochemistry was used to identify CD68+ macrophages, CD3+ T-lymphocytes, smooth muscle cells (SMCs), and HLA-DR+ inflammatory cells. Diabetic plaques had more (P<0.0001) macrophages, T-lymphocytes, and HLA-DR+ cells, more (P<0.0001) immunoreactivity for RAGE, activated NF-kappaB, COX-2/mPGES-1, and MMPs, increased (P<0.0001) gelatinolytic activity, reduced (P<0.0001) collagen content, and increased (P<0.0001) lipid and oxLDL content. Interestingly, RAGE, COX-2/mPGES-1, and MMP expression was linearly correlated with plasma level of HbA1c.
In conclusion, this study demonstrates in humans that RAGE overexpression is associated with enhanced inflammatory reaction and COX-2/mPGES-1 expression in diabetic plaque macrophages, and this effect may contribute to plaque destabilization by inducing culprit metalloproteinase expression.
晚期糖基化终末产物受体（RAGE）在糖尿病动脉粥样硬化中起作用。最近，我们已证实在有症状的人类斑块中环氧化酶-2和前列腺素E合酶-1（COX-2/mPGES-1）表达增强，并提供证据表明其与金属蛋白酶（MMP）诱导的斑块破裂有关。然而，影响斑块COX-2/mPGES-1表达的具体跨膜信号通路尚不清楚。本研究的目的是描述人类斑块中RAGE的表达，并将其与炎症浸润、COX-2/mPGES-1和MMP表达以及糖尿病的临床证据相关联。
根据2型糖尿病的临床证据，将60例行颈动脉内膜切除术患者的斑块分为糖尿病组和非糖尿病组。通过免疫组织化学和蛋白质印迹法对斑块进行RAGE、核因子κB（NF-κB）、COX-2/mPGES-1、MMP-2和MMP-9、脂质和氧化低密度脂蛋白（oxLDL）含量以及胶原含量的分析，而用酶谱法检测MMP活性。采用免疫组织化学法鉴定CD68+巨噬细胞、CD3+T淋巴细胞、平滑肌细胞（SMC）和HLA-DR+炎症细胞。糖尿病斑块有更多（P<0.0001）的巨噬细胞、T淋巴细胞和HLA-DR+细胞，对RAGE、活化的NF-κB、COX-2/mPGES-1和MMPs有更强的免疫反应性（P<0.0001），明胶酶活性增加（P<0.0001），胶原含量减少（P<0.0001），脂质和oxLDL含量增加（P<0.0001）。有趣的是，RAGE、COX-2/mPGES-1和MMP的表达与糖化血红蛋白（HbA1c）的血浆水平呈线性相关。
总之，本研究在人类中表明，RAGE的过度表达与糖尿病斑块巨噬细胞中炎症反应增强和COX-2/mPGES-1表达有关，并且这种作用可能通过诱导罪魁祸首金属蛋白酶的表达而导致斑块不稳定。
