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) |
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Pages (from-to) | 1800-1807 |
Number of pages | 8 |
Journal | Journal of neurochemistry |
Volume | 64 |
Issue number | 4 |
State | Published - Apr 1995 |
Keywords
- Astrocytes
- Culture
- GD3 ganglioside
- Human
- Interleukin-1
- Proliferation
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience
- Biochemistry