title: Dynamic changes in endothelial cell adhesion molecule nepmucin/CD300LG expression under physiological and pathological conditions.
abstract: Vascular endothelial cells often change their phenotype to adapt to their local microenvironment. Here we report that the vascular endothelial adhesion molecule nepmucin/CD300LG, which is implicated in lymphocyte binding and transmigration, shows unique expression patterns in the microvascular endothelial cells of different tissues. Under physiological conditions, nepmucin/CD300LG was constitutively and selectively expressed at the luminal surface of the small arterioles, venules, and capillaries of most tissues, but it was only weakly expressed in the microvessels of the splenic red pulp and thymic medulla. Furthermore, it was barely detectable in immunologically privileged sites such as the brain, testis, and uterus. The nepmucin/CD300LG expression rapidly decreased in lymph nodes receiving acute inflammatory signals, and this loss was mediated at least in part by TNF-α. It was also down-regulated in tumors and tumor-draining lymph nodes, indicating that nepmucin/CD300LG expression is negatively regulated by locally produced signals under these circumstances. In contrast, nepmucin/CD300LG was induced in the high endothelial venule-like blood vessels of chronically inflamed pancreatic islets in an animal model of non-obese diabetes. Interestingly, the activated CD4(+) T cells infiltrating the inflamed pancreas expressed high levels of the nepmucin/CD300LG ligand(s), supporting the idea that nepmucin/CD300LG and its ligand interactions are locally involved in pathological T cell trafficking. Taken together, these observations indicate that the nepmucin/CD300LG expression in microvascular endothelial cells is influenced by factor(s) that are locally produced in tissues, and that its expression is closely correlated with the level of leukocyte infiltration in certain tissues.
authors.affiliation: Laboratory of Immunodynamics, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan ; Laboratory of Immunodynamics, World Premier International Research Center Initiative-Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Umemoto
authors.affiliation: Laboratory of Immunodynamics, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Takeda
authors.affiliation: Laboratory of Immunodynamics, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Soojung
authors.initials: S
authors.lastname: Jin
authors.affiliation: Laboratory of Immunodynamics, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Zhijuan
authors.initials: Z
authors.lastname: Luo
authors.affiliation: Laboratory of Immunodynamics, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Nakahogi
authors.affiliation: Laboratory of Immunodynamics, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan ; Laboratory of Immunodynamics, World Premier International Research Center Initiative-Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan.
authors.forename: Haruko
authors.initials: H
authors.lastname: Hayasaka
authors.affiliation: Medical Center for Translational Research, Osaka University Hospital, Suita, Osaka, Japan.
authors.forename: Chun Man
authors.initials: CM
authors.lastname: Lee
authors.affiliation: Laboratory of Immunobiology, School of Pharmacy, Hyogo University of Health Sciences, Kobe, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Laboratory of Immunodynamics, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, Suita, Osaka, Japan ; Laboratory of Immunodynamics, World Premier International Research Center Initiative-Immunology Frontier Research Center, Osaka University, Suita, Osaka, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyasaka
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D015536:Down-Regulation; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007249:Inflammation / Q000235:genetics; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008214:Lymphocytes / Q000378:metabolism; D051379:Mice; D055806:Microvessels / Q000378:metabolism; D009928:Organ Specificity; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology; D011971:Receptors, Immunologic / Q000235:genetics*
chemical_list: C515071:Cd300lg protein, mouse; D011971:Receptors, Immunologic