Lineage-negative bone marrow cells travel bidirectionally in the olfactory migratory stream but maintain hematopoietic phenotype.
The mammalian olfactory system is a physiologically plastic region of the brain with the potential to support implanted stem cells. We performed direct injection of lineage-negative (lin-neg), green fluorescent protein-positive (GFP+) bone marrow cells into the olfactory bulb to assess cell survival and motility within the central nervous system (CNS). Before direct injection of 100,000 lin-neg cells, some of the C57/Bl mice received 1,000 cGy brain irradiation with the aim of disabling the endogenous reservoir of periventricular neural progenitor cells. Brain harvest took place up to 2 weeks after cell implantation. Brains were evaluated for presence of GFP positivity via fluorescence microscopy. Many GFP+ cells were identified within the turbinate neuroepithelium, olfactory bulb, and frontal lobe. Most of the cells that had traveled from the implantation site adopted an elongated, arborizing morphology consistent with cellular extensions arrayed in the direction of the rostral migratory stream (RMS). No difference was seen in brain-irradiated versus non-irradiated mice. Antibody staining revealed that these cells did not take on a neural, glial, or endothelial phenotype, while largely retaining their hematopoietic lineage as demonstrated by CD45 positivity.
Moore
Brian E
BE
Center for Stem Cell Biology, Roger Williams Medical Center, Providence, Rhode Island, USA. bmoore2@lifespan.org
Colvin
Gerald A
GA
Dooner
Mark S
MS
Quesenberry
Peter J
PJ
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000502:physiology*; D016026:Bone Marrow Transplantation / Q000379:methods; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D005625:Frontal Lobe / Q000166:cytology / Q000502:physiology; D006085:Graft Survival / Q000502:physiology*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology*; D016130:Immunophenotyping; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009830:Olfactory Bulb / Q000166:cytology / Q000502:physiology* / Q000601:surgery; D009831:Olfactory Mucosa / Q000166:cytology / Q000502:physiology; D013234:Stem Cells / Q000528:radiation effects
D049452:Green Fluorescent Proteins