title: Arginase-1 is expressed exclusively by infiltrating myeloid cells in CNS injury and disease.
abstract: Resident microglia and infiltrating myeloid cells play important roles in the onset, propagation, and resolution of inflammation in central nervous system (CNS) injury and disease. Identifying cell type-specific mechanisms will help to appropriately target interventions for tissue repair. Arginase-1 (Arg-1) is a well characterised modulator of tissue repair and its expression correlates with recovery after CNS injury. Here we assessed the cellular localisation of Arg-1 in two models of CNS damage. Using microglia specific antibodies, P2ry12 and Fc receptor-like S (FCRLS), we show the LysM-EGFP reporter mouse is an excellent model to distinguish infiltrating myeloid cells from resident microglia. We show that Arg-1 is expressed exclusively in infiltrating myeloid cells but not microglia in models of spinal cord injury (SCI) and experimental autoimmune encephalomyelitis (EAE). Our in vitro studies suggest that factors in the CNS environment prevent expression of Arg-1 in microglia in vivo. This work suggests different functional roles for these cells in CNS injury and repair and shows that such repair pathways can be switched on in infiltrating myeloid cells in pro-inflammatory environments.
authors.affiliation: Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Greenhalgh
authors.affiliation: Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada.
authors.forename: Rosmarini
authors.initials: R
authors.lastname: Passos Dos Santos
authors.affiliation: Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada.
authors.forename: Juan Guillermo
authors.initials: JG
authors.lastname: Zarruk
authors.affiliation: Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada.
authors.forename: Christopher K
authors.initials: CK
authors.lastname: Salmon
authors.affiliation: Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada.
authors.forename: Antje
authors.initials: A
authors.lastname: Kroner
authors.affiliation: Centre for Research in Neuroscience, The Research Institute of the McGill University Health Centre, 1650 Cedar Ave., Montreal, Quebec H3G 1A4, Canada. Electronic address: sam.david@mcgill.ca.
authors.forename: Samuel
authors.initials: S
authors.lastname: David
mesh_terms: D000818:Animals; D001119:Arginase / Q000378:metabolism*; D004195:Disease Models, Animal; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000378:metabolism*; D005260:Female; D049452:Green Fluorescent Proteins; D007249:Inflammation / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D017628:Microglia / Q000378:metabolism*; D009113:Muramidase; D022423:Myeloid Cells / Q000378:metabolism*; D013119:Spinal Cord Injuries / Q000378:metabolism*
chemical_list: C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D009113:Muramidase; C472450:lysozyme M, mouse; C544448:Arg1 protein, mouse; D001119:Arginase
keywords: Arginase-1; CNS injury; Inflammation; LysM-EGFP; Macrophages; Microglia