title: Diurnal dynamic behavior of microglia in response to infected bacteria through the UDP-P2Y6 receptor system.
abstract: It has long been believed that microglia morphologically transform into the activated state by retracting their long processes and consuming pathogens when bacteria infect into the brain parenchyma. In the present study, however, we showed for the first time that murine cortical microglia extend their processes towards focally injected Porphyromonas gingivalis. This P. gingivalis-induced microglial process extension was significantly increased during the light (sleeping) phase than the dark (waking) phase. In contrast, focally injected ATP-induced microglial process extension was significantly increased during the dark phase than the light phase. Furthermore, in contrast to the P2Y12 receptor-mediated mechanism of ATP-induced microglial process extension, the P. gingivalis-mediated microglial process extension was mediated by P2Y6 receptors. The infection of bacteria such as P. gingivalis to the brain parenchyma may induce the secretion of UDP from microglia at the site of infection, which in turn induces the process extension of the neighboring microglia.
authors.affiliation: Department of Aging Science and Pharmacology, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan.|JSPS Research Fellow, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083, Japan.
authors.forename: Fumiko
authors.initials: F
authors.lastname: Takayama
authors.affiliation: Department of Aging Science and Pharmacology, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Aging Science and Pharmacology, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan.|OBT Research Center, Faculty of Dental Science, Kyushu University, Fukuoka, 812-8582, Japan.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Department of Aging Science and Pharmacology, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Yicong
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Aging Science and Pharmacology, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakanishi
mesh_terms: D000818:Animals; D001921:Brain / Q000276:immunology / Q000382:microbiology; D022081:Cell Surface Extensions / Q000378:metabolism; D002940:Circadian Rhythm; D004195:Disease Models, Animal; D008590:Meningoencephalitis / Q000276:immunology / Q000382:microbiology; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000166:cytology / Q000276:immunology* / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000276:immunology*; D018048:Receptors, Purinergic P2 / Q000378:metabolism*; D014530:Uridine Diphosphate / Q000378:metabolism*
chemical_list: D018048:Receptors, Purinergic P2; C099845:purinoceptor P2Y6; D014530:Uridine Diphosphate