Local extension of HMGB1 in atherosclerotic lesions of human main cerebral and carotid arteries.
High mobility group box 1 protein (HMGB1) is a non-histone chromosomal protein which is highly conserved, ubiquitous, and widely distributed. HMGB1 has multiple functions in the nucleus, including the maintenance of nucleosome structure, the regulation of gene transcription, and involvement in DNA recombination. HMBG1 is currently recognized to have a wide range of potential functions and pathological relevance. HMGB1 is released into the extracellular space from necrotic cells and from activated macrophages. HMGB1 binds to the receptor for advanced glycation end products, resulting in the induction of inflammatory cytokines, and to endothelial cell thrombomodulin. HMGB1 neutralization may also reduce the development of atherosclerosis and ameliorate brain infarction. We investigated the immunolocalization of HMGB1 in atherosclerotic lesions of human cerebral and carotid arteries using a specific antibody, and confirmed the detailed expression and cell type localization using double immunofluorolabeling. In the main cerebral arteries, this anti-HMGB1 antibody intensely immunolabeled both normal morphological vascular smooth muscle cells (VSMCs) within the tunica media and infiltrating VSMCs within the intima of thickened fibrous cap plaques. Endothelial cells were also positive for HMGB1. In carotid plaques, HMGB1-like immunoreactivity (IR) was intense in macrophages, although this IR decreased with increasing cell size. Medium-sized foam cells (50-150 μm) were the most intensely stained. This IR was also observed in the nuclei of foam cells and VSMCs. These findings may provide a basis for understanding the association of HMGB1 with atherosclerotic lesions of the cerebral and carotid arteries, and for constructing strategies to counteract atherosclerosis with anti-HMGB1 antibody.
Department of Geriatric Medicine, Tokyo Medical University, Shinjuku-ku, and Laboratory of Structural Neuropathology, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan. takahiko@tokyo-med.ac.jp.
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Umahara
Laboratory of Structural Neuropathology, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan.
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Uchihara
Department of Geriatric Medicine, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan.
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Koyama
Department of Neurosurgery, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan.
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Hashimoto
Department of Neurosurgery, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan.
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Akimoto
Department of Neurosurgery, Tokyo Medical University, Shinjuku-ku, Tokyo, Japan.
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Haraoka
Department of Geriatric Medicine, Tokyo Medical University, hinjuku-ku, Tokyo, Japan.
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Iwamoto
D000199:Actins / Q000378:metabolism; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000378:metabolism; D050197:Atherosclerosis / Q000378:metabolism* / Q000473:pathology; D002339:Carotid Arteries / Q000378:metabolism* / Q000473:pathology; D002340:Carotid Artery Diseases / Q000378:metabolism* / Q000473:pathology; D002536:Cerebral Arteries / Q000378:metabolism* / Q000473:pathology; D024243:HMGB1 Protein / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000378:metabolism / Q000473:pathology; D000097382:CD68 Molecule
D000199:Actins; D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D024243:HMGB1 Protein; C541116:ACTA2 protein, human; C067980:CD68 antigen, human; D000097382:CD68 Molecule