Expression of alpha 2-glycoprotein by glial precursor cells: an immunocytochemical study with glial cultures.

Studies on the presence of the brain-specific alpha 2-glycoprotein in cultures of newborn rat brain cells revealed that a population of glial precursor cells expressed this antigen at an early stage of development. This cell population consisted of small, phase-dark cells that proliferated in culture and occupied the surface of a layer of flat epithelial-like astrocytes. The latter cell type did not react with the antibodies.

Synthesis of sulfated glycoproteins by glial precursor cells.

Populations of enriched glial precursor cells and astrocytes isolated from primary cultures of newborn rat brain were used to study the synthesis of sulfated glycoproteins. Both cell types incorporated [3H]glucosamine and [35S]sulfate into carbohydrate side chains of proteoglycans and glycoproteins. The rate of incorporation of [3H]glucosamine into the oligosaccharides and the pattern of distribution of the label into high mannose and complex glycopeptides recovered from the glycoproteins appeared to be similar for the two glial cell types.

Preparation of astrocyte-deficient cultures containing neurons and oligodendroglia from embryonic rat cerebral hemispheres.

Complement-dependent anti-glial fibrillary acidic protein (GFAP) antibody-mediated cytotoxicity was utilized in order to prepare astrocyte-deficient cultures from mechanically dissociated cells from 18-day-old embryonic rat cerebral hemispheres. Neurons and a lesser number of oligodendroglia were the major cell components in such cultures.

Changes in glycoprotein carbohydrate content in the aging human brain.

There is no significant change in the concentration, per gram of fresh tissue, of the total carbohydrate associated with brain glycoproteins as the human brain ages from 25 to 85 years. Nevertheless, notable shifts in the concentration of varied types of oligosaccharides do occur. The concentration and percentage of total glycopeptide-carbohydrate recovered from the whole brain represented by the N-glycosidically linked complex sialooligosaccharides of the tri- and tetraantennary type show a marked decline with age.