title: Identification of genes preferentially expressed by microglia and upregulated during cuprizone-induced inflammation.
abstract: Microglia, monocytes, and peripheral macrophages share a common origin and many characteristics, but what distinguishes them from each other at the level of gene expression remains largely unknown. In this study, we compared the transcriptional profiles of freshly purified microglia, monocytes, and spleen macrophages using Affymetrix Mouse Genome arrays to identify genes predominantly expressed by microglia. Among tens of thousands of genes assayed, 127 potential candidates were found, including nine newly discovered genes encoding plasma membrane and extracellular proteins. In the brain, the latter were selectively expressed by microglia, as revealed by in situ hybridization. Three of them were confirmed to be exclusively (MSR2) or predominantly (GPR12, GPR34) expressed in the brain compared to the other tissues examined. Furthermore, all of these genes were upregulated in activated microglia after treatment with the demyelinating toxin cuprizone, suggesting that they play roles in neuroinflammation. In conclusion, this study reports the identification of new selective markers for microglia, which should prove useful not only to identify and isolate these cells, but also to better understand their distinctive properties.
authors.affiliation: Department of Oncology and Molecular Endocrinology, Laval University Hospital Research Center, Québec City, Québec G1V 4G2, Canada.
authors.forename: Andréanne
authors.initials: A
authors.lastname: Bédard
authors.forename: Pierrot
authors.initials: P
authors.lastname: Tremblay
authors.forename: Ariel
authors.initials: A
authors.lastname: Chernomoretz
authors.forename: Luc
authors.initials: L
authors.lastname: Vallières
mesh_terms: D000818:Animals; D015415:Biomarkers; D001921:Brain / Q000166:cytology / Q000276:immunology; D002614:Chelating Agents / Q000633:toxicity; D003471:Cuprizone / Q000633:toxicity; D003711:Demyelinating Diseases / Q000139:chemically induced / Q000235:genetics / Q000276:immunology; D004195:Disease Models, Animal; D015870:Gene Expression / Q000187:drug effects / Q000276:immunology; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000187:drug effects / Q000276:immunology*; D009443:Neuritis / Q000139:chemically induced / Q000235:genetics* / Q000276:immunology*; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000032:analysis; D013154:Spleen / Q000166:cytology / Q000276:immunology; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology
chemical_list: D015415:Biomarkers; D002614:Chelating Agents; D012333:RNA, Messenger; D003471:Cuprizone