ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
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.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1471-4159.1995.64041800.x
