NG2⁺/Olig2⁺ Cells are the Major Cycle‐Related Cell Population of the Adult Human Normal Brain

Abstract

A persistent cycling cell population in the normal adult human brain is well established. Neural stem cells or neural progenitors have been identified in the subventricular zone and the dentate gyrus subgranular layer (SGL), two areas of persistent neurogenesis. Cycling cells in other human normal brain areas, however, remains to be established. Here, we determined the distribution and identity of these cells in the cortex, the white matter and the hippocampal formation of adult patients with and without chronic temporal lobe epilepsy using immunohistochemistry for the cell cycle markers Ki-67 (Mib-1) and minichromosome maintenance protein 2. Rare proliferative neuronal precursors expressing the neuronal antigen neuronal nuclei were restricted to the SGL. In contrast, the oligodendrocyte progenitor cell markers Olig2 and the surface antigen NG2 were expressed by the vast majority of cycling cells scattered throughout the cortex and white matter of both control and epileptic patients. Most of these cycling cells were in early G1 phase, and were significantly more numerous in epileptic than in non-epileptic patients. These results provide evidence for a persistent gliogenesis in the human cortex and white matter that is enhanced in an epileptic environment.

Abnormalities in oligodendrocyte clusters in the inferior parietal cortex in schizophrenia are associated with insight

“…It is believed that these groups are derived from the division of oligodendrocytes progenitors which replenish the oligodendrocyte population. Recently a population of residual, mitotically competent oligodendrocyte progenitor cells that express NG2-antigen have been found in the adult brain of rodent 14,17,25,26 , primate 16 and human 27,28 . These cells are able to renew the population of mature myelinating oligodendrocytes 14 .…”

Emerging insights into the molecular and cellular basis of glioblastoma

“…The finding that ''astrocytomas'' can arise from OPCs in mice could help to explain the long-standing observation that human glioblastoma and all other astrocytomas are characterized by both expression of oligodendroglial markers to an even greater degree than astrocytic markers (Ligon et al 2004;Phillips et al 2006;Verhaak et al 2010) and their dependency on the same lineage factors (e.g., OLIG2) as normal counterparts ). Distributed progenitor cells, such as OPCs, actually represent the largest pool of cycling cells in the brain and are defined by expression of OLIG2 and NG2 (Dawson et al 2003;Geha et al 2010). Targeting of these nonstem cell progenitors through transgenic or viral approaches has been shown to lead to malignant astrocytomas or oligodendrogliomas, depending on the combination of mutations and cell types targeted (Geha et al 2010;Persson et al 2010).…”

“…Distributed progenitor cells, such as OPCs, actually represent the largest pool of cycling cells in the brain and are defined by expression of OLIG2 and NG2 (Dawson et al 2003;Geha et al 2010). Targeting of these nonstem cell progenitors through transgenic or viral approaches has been shown to lead to malignant astrocytomas or oligodendrogliomas, depending on the combination of mutations and cell types targeted (Geha et al 2010;Persson et al 2010).…”

Oligodendrocyte abnormalities in layer 5 in the inferior parietal lobule are associated with lack of insight in schizophrenia: a postmortem morphometric study

“…Adult mammalian brain contains ubiquitous population of glial progenitors that develop into mature oligodendrocytes 15 . Besides, cell cycle abnormalities and incomplete differentiation of oligodendrocytes have been reported in schizophrenia [16][17][18] . The data suggest that OlC in the human IPL may represent sites of oligodendrocyte precursors proliferation and differentiation, and the reduced Nv OlC in schizophrenia may be associated with the reduced proliferation of oligodendrocyte progenitors.…”