[Polydendrocytes--their roles in development and glial tumor formation].
Polydendrocytes or NG2 cells are the fourth major glial cell type observed in the mammalian central nervous system (CNS) that is distinct from neurons, mature oligodendrocytes, astrocytes, or microglia. They can be identified on the basis of the expression of NG2 proteoglycan and are distributed throughout the gray matter and white matter both in the developing and mature CNS. Although polydendrocytes were earlier regarded as oligodendrocyte progenitor cells, recent studies using Cre/loxP fate mapping provided the first direct evidence that endogenous polydendrocytes give rise to oligodendrocytes in vivo. In addition, the same technique showed that polydendrocytes differentiate into a subpopulation of astrocytes in a region-specific manner. On the other hand, it is highly debatable whether polydendrocytes generate neurons. Although some studies suggest the possibility that polydendrocytes produce neurons, other studies do not support this hypothesis. The possibility that polydendrocytes contribute to the formation of gliomas has been suggested in a number of clinical and basic experimental studies. In this review, we present both classical findings (and the latest reports on the basic characteristics of this cell type).
Suzuki
Ryusuke
R
Department of Physiology and Neurobiology, University of Connecticut, 75 North Eagleville Road, Storrs, CT 06269-3156, USA.
Nishiyama
Akiko
A
D000818:Animals; D000941:Antigens / Q000378:metabolism; D001253:Astrocytes / Q000166:cytology; D002454:Cell Differentiation; D019070:Cell Lineage; D002490:Central Nervous System / Q000166:cytology*; D016543:Central Nervous System Neoplasms / Q000209:etiology / Q000473:pathology; D005910:Glioma / Q000209:etiology / Q000473:pathology; D006801:Humans; D009457:Neuroglia / Q000166:cytology / Q000473:pathology; D009474:Neurons / Q000166:cytology; D009836:Oligodendroglia; D011509:Proteoglycans / Q000378:metabolism; D013234:Stem Cells; D000099216:Chondroitin Sulfate Proteoglycan 4
D000941:Antigens; D011509:Proteoglycans; D000099216:Chondroitin Sulfate Proteoglycan 4