title: Origin and distribution of bone marrow-derived cells in the central nervous system in a mouse model of amyotrophic lateral sclerosis.
abstract: Amyotrophic lateral sclerosis (ALS) is associated with increased numbers of microglia within the central nervous system (CNS). However, it is unknown whether the microgliosis results from proliferation of CNS resident microglia, or recruitment of bone marrow (BM)-derived microglial precursors. Here we assess the distribution and number of BM-derived cells in spinal cord using transplantation of green fluorescent protein (GFP)-labeled BM cells into myelo-ablated mice over-expressing human mutant superoxide dismutase 1 (mSOD), a murine model of ALS. Transplantation of GFP+ BM did not affect the rate of disease progression in mSOD mice. Mean numbers of microglia and GFP+ cells in spinal cords of control mice were not significantly different from those in asymptomatic mSOD mice and showed no change with animal age. The number of GFP+ cells and microglia (F4/80+ and CD11b+ cells) within the spinal cord of mSOD mice increased compared to age-matched controls at a time when mSOD mice exhibited disease symptoms, continuing up to disease end-stage. Although we observed an increase in the number of GFP+ cells in spinal cords of mSOD mice with disease symptoms, mean numbers of GFP+ F4/80+ cells comprised less than 20% of all F4/80+ cells and did not increase with disease progression. Furthermore, the relative rates of proliferation in CD45+GFP- and CD45+GFP+ cells were comparable. Thus, we demonstrate that the microgliosis present in spinal cord tissue of mSOD mice is primarily due to an expansion of resident microglia and not to the recruitment of microglial precursors from the circulation.
authors.affiliation: Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: Jennifer N
authors.initials: JN
authors.lastname: Solomon
authors.forename: Coral-Ann B
authors.initials: CA
authors.lastname: Lewis
authors.forename: Bahareh
authors.initials: B
authors.lastname: Ajami
authors.forename: Stephane Y
authors.initials: SY
authors.lastname: Corbel
authors.forename: Fabio M V
authors.initials: FM
authors.lastname: Rossi
authors.forename: Charles
authors.initials: C
authors.lastname: Krieger
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology*; D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology* / Q000378:metabolism; D002452:Cell Count; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology; D049109:Cell Proliferation; D004195:Disease Models, Animal; D018450:Disease Progression; D005911:Gliosis / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D049452:Green Fluorescent Proteins; D006801:Humans; D017493:Leukocyte Common Antigens / Q000276:immunology; D051379:Mice; D008822:Mice, Transgenic; D017628:Microglia / Q000166:cytology* / Q000378:metabolism; D013116:Spinal Cord / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D013482:Superoxide Dismutase / Q000235:genetics; D000072105:Superoxide Dismutase-1
chemical_list: C000606290:SOD1 protein, human; D049452:Green Fluorescent Proteins; C000606291:Sod1 protein, mouse; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D017493:Leukocyte Common Antigens