Bone marrow-derived cells expressing green fluorescent protein under the control of the glial fibrillary acidic protein promoter do not differentiate into astrocytes in vitro and in vivo.
Differentiation of bone marrow (BM) cells into astroglia expressing the glial fibrillary acidic protein (GFAP) has been reported in vitro and after intracerebral or systemic BM transplantation. In contrast, recent data suggest that astrocytic differentiation does not occur from BM-derived cells in vivo. Using transgenic mice that express the enhanced green fluorescent protein (GFP) under the control of the human glial fibrillary acidic protein (GFAP) promoter, we investigated the potential of adult murine BM-derived cells to differentiate into macroglia. In the brains of GFAP-GFP transgenic mice, astrocytes were brightly fluorescent from the expression of GFP. When BM from these animals was transplanted into lethally irradiated wild-type animals, the transgene was detected in the reconstituted hematopoietic system, but no GFP expression was found in the nervous system. In contrast, GFAP-GFP neuroectodermal anlage grafted into adult wild-type striatum gave rise to GFP-expressing astrocytes. Because cerebral ischemia has been suggested to promote the differentiation of BM-derived cells into astrocytes, BM chimeric mice were subjected to focal cerebral ischemia. No GFP-positive cells were found in the ischemic or contralateral hemispheres of these brains. Even after direct injection of GFAP-GFP transgenic BM cells into wild-type striatum, no GFP-expressing astroglia were detected. To test the hypothesis that the in vitro environment might be more permissible for astroglial differentiation, we cultured BM from mice that constitutively express GFP, BM cells expressing GFP from a retroviral vector, and BM from GFAP-GFP transgenic mice on astrocytes and on organotypic hippocampal slices. In all experimental paradigms, BM-derived cells were found to differentiate into ramified microglia but not into GFAP-expressing astrocytes.
Wehner
Tim
T
Department of Neurology, Charité, Humboldt-University, 10117 Berlin, Germany.
Böntert
Matthias
M
Eyüpoglu
Ilker
I
Prass
Konstantin
K
Prinz
Marco
M
Klett
Francisco Fernández
FF
Heinze
Matthias
M
Bechmann
Ingo
I
Nitsch
Robert
R
Kirchhoff
Frank
F
Kettenmann
Helmut
H
Dirnagl
Ulrich
U
Priller
Josef
J
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000378:metabolism*; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism*; D001921:Brain / Q000166:cytology / Q000196:embryology / Q000473:pathology; D016380:Brain Tissue Transplantation; D002454:Cell Differentiation / Q000235:genetics / Q000502:physiology; D002478:Cells, Cultured; D018920:Coculture Techniques; D005904:Glial Fibrillary Acidic Protein / Q000235:genetics*; D006085:Graft Survival; D049452:Green Fluorescent Proteins; D006624:Hippocampus / Q000166:cytology; D006801:Humans; D002546:Ischemic Attack, Transient / Q000473:pathology; D008164:Luminescent Proteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D017628:Microglia / Q000166:cytology; D011401:Promoter Regions, Genetic / Q000502:physiology*; D011828:Radiation Chimera; D033581:Stem Cell Transplantation
D005904:Glial Fibrillary Acidic Protein; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins