Astrogliosis in EAE spinal cord: derivation from radial glia, and relationships to oligodendroglia.
A prominent feature of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) is the accumulation of enlarged, multipolar glial fibrillary acidic protein (GFAP) and brain lipid binding protein (BLBP) immunoreactive astroglia within and at the margins of the inflammatory demyelinative lesions. Whether this astrogliosis is due to both astroglial hyperplasia and hypertrophy or solely to astroglial hypertrophy is controversial. We now report that coincident with the first appearance of inflammation and clinical deficits in mice with myelin oligodendrocyte glycoprotein peptide (MOG peptide)-induced EAE, the radially oriented, bipolar, GFAP, and BLBP positive cells (adult radial glia) present in normal spinal cord white matter undergo mitosis and phenotypic transformation to hypertrophic astroglia. To facilitate visualization of relationships between these hypertrophic astroglia and dying and regenerating oligodendroglia, we used mice that express enhanced green fluorescent protein (EGFP) in cells of the oligodendroglial lineage. During the first week after onset of illness, markedly swollen EGFP+ cells without processes were seen within lesions, whereas EGFP+ cells that expressed immunoreactive cleaved caspase-3 were uncommon. These observations support the hypothesis that necrosis contributes to oligodendroglial loss early in the course of EAE. Later in the illness, EGFP+ cells accumulated amongst hypertrophic astroglia at the margins of the lesions, while the lesions themselves remained depleted of oligodendroglia, suggesting that migration of oligodendroglial lineage cells into the lesions was retarded by the intense perilesional gliosis.
Bannerman
Peter
P
Institute for Pediatric Regenerative Research, UC Davis School of Medicine, Shriners Hospital for Children, Northern California, Sacramento, California 95817, USA.
Hahn
Ashleigh
A
Soulika
Athena
A
Gallo
Vittorio
V
Pleasure
David
D
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001253:Astrocytes / Q000378:metabolism / Q000473:pathology*; D053148:Caspase 3 / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology*; D019070:Cell Lineage / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D004195:Disease Models, Animal; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins / Q000378:metabolism; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D005911:Gliosis / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D018836:Inflammation Mediators / Q000494:pharmacology; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009103:Multiple Sclerosis / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein / Q000494:pharmacology; D063308:Myelin-Oligodendrocyte Glycoprotein; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009836:Oligodendroglia / Q000378:metabolism / Q000473:pathology*; D013116:Spinal Cord / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*
C086936:Fabp7 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005904:Glial Fibrillary Acidic Protein; D018836:Inflammation Mediators; D019394:Ki-67 Antigen; C571327:Mog protein, mouse; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein; D063308:Myelin-Oligodendrocyte Glycoprotein; D009419:Nerve Tissue Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D053148:Caspase 3