Differential Localization of Glutathione‐S‐Transferase Y_p and Y_b Subunits in Oligodendrocytes and Astrocytes of Rat Brain

Abstract

Glutathione-S-transferase Yb subunits were recently identified in rat brain and localized to astrocytes, ependymal cells lining the ventricles, subventricular zone cells, and tanycytes. Another isoform, Yp (pi family), was detected in rat brain by immunoblotting, and its mRNA was detected by Northern hybridizations. Double immunofluorescence localized Yb and Yp in different glial cells. The strongly Yp-positive cells were identified as oligodendrocytes by virtue of their arrangement in rows in white-matter tracts, colocalization in strongly carbonic anhydrase-positive cells, and association with myelinated tracts in the corpus striatum. Ependymal cells in the choroid plexus and ventricular lining were also strongly Yp positive, whereas Yb was not detected in the choroid plexus. The occurrence of Yp at low levels in astrocytes was indicated after immunostaining by a sensitive peroxidase-antiperoxidase method, which revealed weak staining of those cells in the molecular layer of the cortex. The data suggest that Yb and Yp subunits are primarily localized to astrocytes and oligodendrocytes, respectively, and that both are absent from neurons. The glutathione-S-transferase in oligodendrocytes may participate in the removal of toxins from the vicinity of the myelin sheath. The finding of glutathione-S-transferases in ependymal cells and astrocytes in the brain also suggests that this enzyme could be a first line of defense against toxic substances.

Transient upregulation of Nkx2.2 expression in oligodendrocyte lineage cells during remyelination

“…The APC monoclonal antibody could not be used for double labeling with the Nkx2.2 antibody because they are both IgG2b. Therefore, we have used a rabbit antibody to the Yp subunit of glutathione S-transferase (GST-Yp), an antigen previously shown to be expressed by mature oligodendrocytes (Cammer et al, 1989;Gensert and Goldman, 1996). More than 95% of the APC ϩ cells also expressed GST-Yp, and there was no overlap between GST-Yp-and NG2-expressing cells (data not shown), indicating that GST-Yp expression can be used to identify mature oligodendrocytes.…”

Heterogeneity of cycling glial progenitors in the adult mammalian cortex and white matter

“…Astrocytes were identified with ALD10, a polyclonal antibody (1:50) that recognizes GFAP (Chiu and Goldman, 1984). The oligodendrocyte lineage specific glutathione-S-transferase subunit Yp was labeled with a polyclonal anti-Yp antibody (1:100) (BIOTRIN, Dublin, Ireland) (Cammer et al, 1989). Polyclonal NG2 (1:300), which recognizes a chondroitin sulfate proteoglycan, was kindly provided by W. Stallcup (Scripps, CA) and J.…”

Differential changes in junctional complex proteins suggest the ependymal lining as the main source of leukocyte infiltration into ventricles in murine neurocysticercosis

“…Ependyma also have transport systems and distinct enzymes able to remove endogenous and exogenous toxins from the nervous system (Abramovitz et al, 1988;Cammer et al, 1989;Carder et al, 1990). In addition, ependyma express ZO1, occludin, cadherin, α-catenin and β-catenin which are some of junctional complex proteins known to provide the anatomical basis of the CNS barriers (Lippoldt et al, 2000a;Petrov et al, 1994).…”