THE CARBOHYDRATE EPITOPE 3-FUCOSYL-N-ACETYLLACTOSAMINE IS REGION-SPECIFICALLY EXPRESSED IN ASTROCYTES OF THE RAT-BRAIN - LIGHT-MICROSCOPIC AND ELECTRON-MICROSCOPIC OBSERVATIONS
A. Gocht et al., THE CARBOHYDRATE EPITOPE 3-FUCOSYL-N-ACETYLLACTOSAMINE IS REGION-SPECIFICALLY EXPRESSED IN ASTROCYTES OF THE RAT-BRAIN - LIGHT-MICROSCOPIC AND ELECTRON-MICROSCOPIC OBSERVATIONS, Acta anatomica, 150(3), 1994, pp. 205-216
The carbohydrate epitope 3-fucosyl-N-acetyllactosamine (CD15) is invol
ved in cell-to-cell recognition processes in various tissues. In the C
NS of the adult rat, immunoreactivity for CD15 reveals a region-specif
ic distribution pattern by light microscopy. In the present study we i
nvestigated the ultrastructural localization of CD15 in the rat brain
using preembedding immunocytochemical methods. In addition we studied
CD15 expression in cultured astrocytes from optic nerves of Ii-day-old
rats. In optic nerve sections, immunostaining was found on the surfac
e of astrocytes at various contact sites, i.e. astrocyte-astrocyte, as
trocyte-oligodendrocyte, astrocyte-axon myelin, and astrocyte-blood ve
ssel contacts. Oligodendrocyte-oligodendrocyte contacts, however, were
always negative. In the telencephalic cortex, CD15 immunoreactivity w
as found in glial cell processes around synapses and in the cerebellar
cortex in Bergmann glial cells. In astrocytes grown in serum-containi
ng medium, CD15 was expressed on the surface of fibroblast-like glial
fibrillary acidic protein-positive astrocytes, which were identified a
s type 1 astrocytes as well as on process-bearing A2BS-positive cells,
representing type 2 astrocytes. The present data support the assumpti
on that in the adult rodent brain, CD15 is exclusively expressed by as
trocytes. The in vivo distribution of this carbohydrate molecule on di
stinct astroglial contact sites supports the notion that CD15 could ac
t in cell-to-cell recognition processes.