Immunohistochemical localization of different epitopes of advanced glycation end products in human atherosclerotic lesions

• Published in: Atherosclerosis Vol. 141; no. 1; pp. 61 - 75
• Main Authors: Sakata, Noriyuki, Imanaga, Yoshinobu, Meng, Jing, Tachikawa, Yutaka, Takebayashi, Shigeo, Nagai, Ryoji, Horiuchi, Seikoh, Itabe, Hiroyuki, Takano, Tatsuya
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier Ireland Ltd 01.11.1998; Elsevier
• Subjects: Adult; Advanced glycation end products; Aged; Antibodies, Monoclonal; Aorta - chemistry; Aorta - pathology; Arteriosclerosis - metabolism; Arteriosclerosis - pathology; Atherogenesis; Atherosclerosis (general aspects, experimental research); Biological and medical sciences; Blood and lymphatic vessels; Cardiology. Vascular system; ELISA; Enzyme-Linked Immunosorbent Assay; Epitopes - analysis; Extracellular Matrix - chemistry; Female; Glycation End Products, Advanced - analysis; Glycation End Products, Advanced - immunology; Humans; Immunohistochemistry; Lipoproteins, LDL - metabolism; Lysine - analogs & derivatives; Lysine - analysis; Lysine - immunology; Macrophages - chemistry; Male; Medical sciences; Middle Aged; Nε-(carboxymethyl)lysine (CML)-protein adduct; Oxidized LDL; Tunica Intima - chemistry; Immunohistochemistry; Atherogenesis; Advanced glycation end products; N ε -(carboxymethyl)lysine (CML)-protein adduct; Oxidized LDL; ELISA; Human; Antigenic determinant; Pathophysiology; Cardiovascular disease; Exploration; Product; Glycation; Vascular disease; Lipoprotein LDL; Pathology; Atherosclerotic plaque; Atherosclerosis; Oxidation
• ISSN: 0021-9150; 1879-1484
• DOI: 10.1016/S0021-9150(98)00149-X

To better understand the role of advanced glycation end products (AGEs) in atherogenesis, we developed specific antibodies against different immunological epitopes of AGE structures, including N ε -(carboxymethyl)lysine-protein adduct (CML) and a structure(s) other than CML (nonCML), and demonstrated the immunohistochemical localization of CML- and nonCML-epitopes in atherosclerotic lesions of human aorta, which were obtained at autopsy from 20 nondiabetic patients (12 males and eight females; mean age, 60.8±16.7 years). Monoclonal anti-CML antibody (6D12) recognized not only AGE-modified proteins, but also CML-modified proteins. On the other hand, polyclonal anti-nonCML antibody reacted to AGE-modified proteins, but not to CML-modified proteins. Both antibodies were unreactive to the early-stage products of glycation, including fructose-modified butyloxycarbonyl-lysine and fructose- ε-aminocaproic acid. Atherosclerotic lesions included diffuse intimal thickening (DIT), fatty streaks (FS), atherosclerotic plaques (AP) and complicated lesions. An immunohistochemical analysis showed both CML- and nonCML-epitopes to be found along the collagen fibers in DIT in subjects more than 40 years old, but not in subjects less than 40 years old. CML-epitopes accumulated mainly in the cytoplasm of macrophage/foam cells, while nonCML-epitopes accumulated exclusively in the extracellular spaces in FS. APs showed the CML-epitope stored macrophage/foam cells, and the accumulation of both CML- and nonCML-epitopes in the lipid-rich fibrous area. An immunohistochemical analysis with a monoclonal antibody against oxidized low density lipoprotein (FOH1a/DLH3) showed the presence of this antigen within the cytoplasm of the macrophage/foam cells in atherosclerotic lesions, which were also positive for the CML-epitopes. These findings thus suggest that the heterogeneous localization of AGEs in atherosclerotic lesions depends on their different epitopes, and that a close link, therefore, exists between the peroxidation of LDL and the formation of AGEs in atherosclerotic lesions.