Abstract: In human astrocyte cultures established from second‐trimester fetal brain tissue, ∼5–10% of total astrocyte population in unstimulated cultures were GD3+/glial fibrillary acidic protein (GFAP)+. The GD3+ cells were always GFAP+ and grew as flat, highly spread cells but changed to process‐bearing cells after interleukin‐1β (IL‐1β) stimulation. It is interesting that IL‐1β, a known mitogen for rat astrocytes, suppressed human fetal astrocyte proliferation as determined by [3H]thymidine incorporation, bromodeoxyuridine (BrdU) labeling, and cell counting. The GD3+ population, however, consistently increased in absolute number after IL‐1β stimulation, in a dose‐ and time‐dependent manner. The IL‐1β‐mediated increase in number of GD3+ astrocytes was independent of initial cell density or serum concentration. By flow cytometry, IL‐1β enhanced both the mean fluorescence intensity and the percentage of GD3+ cells. To investigate whether the increase in GD3+ astrocyte cell number was due to proliferation of preexisting GD3+ astrocytes or due to conversion of GD3− to GD3+ cells, we performed BrdU/GD3 double immunocytochemistry. BrdU/GD3 double‐positive cells were extremely rare in both control and IL‐1β‐stimulated cultures. Moreover, an increase in number of GD3+ astrocytes was still observed in control and IL‐1β‐stimulated cultures where GD3+ cells had been initially eliminated by cell sorting. These results indicate that GD3+ astrocytes in human fetal culture may represent a postmitotic, differentiated, distinct phenotype.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of neurochemistry|
|State||Published - Apr 1995|
- GD3 ganglioside
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience