title: Endotoxemia-induced cytokine-mediated responses of hippocampal astrocytes transmitted by cells of the brain-immune interface.
abstract: Systemic inflammation shifts the brain microenvironment towards a proinflammatory state. However, how peripheral inflammation mediates changes in the brain remains to be clarified. We aimed to identify hippocampal cells and cytokines that respond to endotoxemia. Mice were intraperitoneally injected with lipopolysaccharide (LPS) or saline, and examined 1, 4, and 24 h after injection. Tissue cytokine concentrations in the spleens and hippocampi were determined by multiplex assays. Another group of mice were studied immunohistologically. Fourteen cytokines showed an increased concentration in the spleen, and 10 showed an increase in the hippocampus after LPS injection. Cytokines increased at 4 h (CCL2, CXCL1, CXCL2, and interleukin-6) were expressed by leptomeningeal stromal cells, choroid plexus stromal cells, choroid plexus epithelial cells, and hippocampal vascular endothelial cells, all of which were located at the brain-immune interface. Receptors for these cytokines were expressed by astrocytic endfeet. Cytokines increased at 24 h (CCL11, CXCL10, and granulocyte-colony stimulating factor) were expressed by astrocytes. Cells of the brain-immune interface therefore respond to endotoxemia with cytokine signals earlier than hippocampal parenchymal cells. In the parenchyma, astrocytes play a key role in responding to signals by using endfeet located in close apposition to the interface cells via cytokine receptors.
authors.affiliation: Japan Society for the Promotion of Science, 5-3-1 Kojimachi, Chiyoda, Tokyo 102-0083, Japan.|Department of Pathology and Laboratory Medicine, Central Hospital, Aichi Human Service Center, 713-8 Kamiya, Kasugai, Aichi 480-0392, Japan.|Graduate school of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
authors.forename: Sanae
authors.initials: S
authors.lastname: Hasegawa-Ishii
authors.affiliation: First Department of Internal Medicine, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka 573-1010, Japan.
authors.forename: Muneo
authors.initials: M
authors.lastname: Inaba
authors.affiliation: Department of Geriatrics, Graduate School of Medicine, Nagoya University, 65 Tsurumai, Showa-ku, Nagoya, Aichi 466-8550, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Umegaki
authors.affiliation: Department of Neurophysiology, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Unno
authors.affiliation: Graduate school of Integrated Pharmaceutical and Nutritional Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Wakabayashi
authors.affiliation: Department of Pathology and Laboratory Medicine, Central Hospital, Aichi Human Service Center, 713-8 Kamiya, Kasugai, Aichi 480-0392, Japan.
authors.forename: Atsuyoshi
authors.initials: A
authors.lastname: Shimada
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D001808:Blood Vessels / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D001812:Blood-Brain Barrier / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D002831:Choroid Plexus / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D016207:Cytokines / Q000145:classification / Q000235:genetics / Q000276:immunology*; D019446:Endotoxemia / Q000139:chemically induced / Q000235:genetics / Q000276:immunology* / Q000473:pathology; D005786:Gene Expression Regulation / Q000276:immunology*; D006624:Hippocampus / Q000187:drug effects / Q000276:immunology* / Q000473:pathology; D007113:Immunity, Innate; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008578:Meninges / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D022423:Myeloid Cells / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D009474:Neurons / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D018121:Receptors, Cytokine / Q000145:classification / Q000235:genetics / Q000276:immunology*; D015398:Signal Transduction; D013154:Spleen / Q000187:drug effects / Q000276:immunology / Q000473:pathology
chemical_list: D016207:Cytokines; D008070:Lipopolysaccharides; D018121:Receptors, Cytokine