NG2+ glial cells: a novel glial cell population in the adult brain.
We describe a major glial cell population in the central nervous system (CNS) that can be identified by the expression of 2 cell surface molecules, the NG2 proteoglycan and the alpha receptor for platelet-derived growth factor (PDGF alphaR). In vitro and in the developing brain in vivo, NG2 and PDGF alphaR are expressed on oligodendrocyte progenitor cells but are down-regulated as the progenitor cells differentiate into mature oligodendrocytes. In the mature CNS, numerous NG2+/PDGF alphaR+ cells with extensive arborization of their cell processes are found ubiquitously long after oligodendrocytes are generated. NG2+ cells in the mature CNS do not express antigens specific to mature oligodendrocytes, astrocytes, microglia, or neurons, suggesting that they are a novel population of glial cells. Recently NG2+ cells in the adult CNS have been shown to undergo proliferation and morphological changes in response to a variety of stimuli, such as demyelination and inflammation, suggesting that they are dynamic cells capable of responding to changes in the environment. Furthermore, high levels of NG2+ and PDGF alphaR are expressed on oligodendroglioma cells, raising the possibility that the NG2+/PDGF alphaR+ cells in the mature CNS contribute to glial neoplasm.
Nishiyama
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Department of Neurosciences, The Lerner Research Institute, Cleveland Clinic Foundation, Ohio, USA.
Chang
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Trapp
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D000367:Age Factors; D000818:Animals; D000941:Antigens / Q000032:analysis*; D001921:Brain / Q000166:cytology* / Q000473:pathology; D001927:Brain Diseases / Q000473:pathology; D051379:Mice; D008816:Mice, Jimpy; D009457:Neuroglia / Q000737:chemistry* / Q000166:cytology*; D011509:Proteoglycans / Q000032:analysis*; D000099216:Chondroitin Sulfate Proteoglycan 4
D000941:Antigens; D011509:Proteoglycans; D000099216:Chondroitin Sulfate Proteoglycan 4