Bone marrow-derived myeloid cells transiently colonize the brain during postnatal development and interact with glutamatergic synapses
Micaël Carrier,
Marie-Ève Robert,
Marie-Kim St-Pierre,
Fernando González Ibáñez,
Elisa Gonçalves de Andrade,
Audrée Laroche,
Katherine Picard,
Haley A. Vecchiarelli,
Julie C. Savage,
Éric Boilard,
Michèle Desjardins,
Marie-Ève Tremblay
Affiliations
Micaël Carrier
Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC G1V 4G2, Canada; Département de psychiatrie et de neurosciences, Faculté de médecine, Université Laval, Québec, QC G1V 0A6, Canada; Division of Medical Sciences, University of Victoria, Victoria, BC V8P 3E6, Canada
Marie-Ève Robert
Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC G1V 4G2, Canada
Marie-Kim St-Pierre
Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC G1V 4G2, Canada; Division of Medical Sciences, University of Victoria, Victoria, BC V8P 3E6, Canada; Département de médecine moléculaire, Faculté de médecine, Université Laval, Québec, QC G1V 0A6, Canada
Fernando González Ibáñez
Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC G1V 4G2, Canada; Division of Medical Sciences, University of Victoria, Victoria, BC V8P 3E6, Canada; Département de médecine moléculaire, Faculté de médecine, Université Laval, Québec, QC G1V 0A6, Canada
Elisa Gonçalves de Andrade
Division of Medical Sciences, University of Victoria, Victoria, BC V8P 3E6, Canada
Audrée Laroche
Département de microbiologie et immunologie, Faculté de médecine, Université Laval, Québec, QC G1V 0A6, Canada
Katherine Picard
Division of Medical Sciences, University of Victoria, Victoria, BC V8P 3E6, Canada
Haley A. Vecchiarelli
Division of Medical Sciences, University of Victoria, Victoria, BC V8P 3E6, Canada
Julie C. Savage
Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC G1V 4G2, Canada
Éric Boilard
Département de microbiologie et immunologie, Faculté de médecine, Université Laval, Québec, QC G1V 0A6, Canada
Michèle Desjardins
Department of Physics, Physical Engineering and Optics, Université Laval, Québec City, QC G1V 0A6, Canada; Oncology Division, Centre de recherche du CHU de Québec, Université Laval, Québec City, QC G1V 4G2, Canada
Marie-Ève Tremblay
Axe neurosciences, Centre de recherche du CHU de Québec-Université Laval, Québec, QC G1V 4G2, Canada; Division of Medical Sciences, University of Victoria, Victoria, BC V8P 3E6, Canada; Département de médecine moléculaire, Faculté de médecine, Université Laval, Québec, QC G1V 0A6, Canada; Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC V6T 1Z4 Canada; Department of Neurology and Neurosurgery, McGill University, Montréal, QC H3A 0G4 Canada; Centre for Advanced Materials and Related Technology (CAMTEC), Institute on Aging and Lifelong Health (IALH), University of Victoria, Victoria, BC V8W 2Y2, Canada; Corresponding author
Summary: Although the roles of embryonic yolk sac-derived, resident microglia in neurodevelopment were extensively studied, the possible involvement of bone marrow-derived cells remains elusive. In this work, we used a fate-mapping strategy to selectively label bone marrow-derived cells and their progeny in the brain (FLT3+IBA1+). FLT3+IBA1+ cells were confirmed to be transiently present in the healthy brain during early postnatal development. FLT3+IBA1+ cells have a distinct morphology index at postnatal day(P)0, P7, and P14 compared with neighboring microglia. FLT3+IBA1+ cells also express the microglial markers P2RY12 and TMEM119 and interact with VGLUT1 synapses at P14. Scanning electron microscopy indeed showed that FLT3+ cells contact and engulf pre-synaptic elements. Our findings suggest FLT3+IBA1+ cells might assist microglia in their physiological functions in the developing brain including synaptic pruning which is performed using their purinergic sensors. Our findings stimulate further investigation on the involvement of peripheral macrophages during homeostatic and pathological development.
