Cellular and subcellular distribution of the S‐100 protein in rabbit and rat central nervous system

Abstract

The cellular and subcellular distribution of the S-100 protein in rabbit and rat central nervous system was studied both quantitatively and qualitatively. Microcomplement fixation estimations on bulk-prepared neuronal and glial cells showed at least five to six times higher amounts of water-soluble S-100 in glial cell-enriched fractions as compared to fractions enriched in neuronal perikarya. Nerve cell fractions contained a higher percent of tissue-bound S-100 protein. High levels of S-100 protein were found in mitochondria and soluble protein fractions. Immunoelectron microscope investigations demonstrated S-100 protein in neuronal structures, such as the postsynaptic membrane and part of the plasma membrane. Among glial cells the astrocytic filaments contained high levels of S-100 protein. S-100 was also found in most subcellular membranes of astrocytes and oligodendrocytes.

A Biochemical and Immunohistological Study of S100 Protein in Developing Rat Cerebellum

“…Treatment of the pellet either with a mixture of Triton X-100 and DOC (both 0.5%) or with Triton X-100 alone (1%) or with 5% n-pentanol extracted an additional 9.34 + 0.47 pg of SIOO protein per cerebellum (0.32 + 0.02 pg per mg total cerebellar protein). Thus, in agreement with the above cited studies [11,19,20,31], about 10% of S100 protein cosediments with the particulate fraction. However, since we had found [16] that the cerebellar particulate frac tion, prepared as described above, contained 10% of the activity of a cytosol marker such as LDH, we have investigated whether also the SI00 protein in the pellet was cytosolic protein trapped into membrane-limited struc tures.…”

Specific and Artefactual Cellular Localizations of S100 Protein: An Astrocyte Marker in Rat Cerebellum

“…The antiserum dilutions used in these studies [11][12][13][14][15][16]29] are not specified but it would appear that high concentrations of immune serum were used ( I/5 dilution was used by Hyden and Rônnback [16]; the other authors probably used undi luted serum): thus, these results might be due to non-immunospecific absorption of the im mune serum to these neurones in addition to the specific staining of glial cells. However, Ludwin et al [19] also used losv dilution (1/10, 1/20) of immune sera without finding any labelling of neurones, but their tissue sections were pretreated with periodate which is one way of reducing non-specific adsorption of Ig to the tissue [8,26], In addition to a high serum concentration, also exposure of HRP-treated tissue sections to light could produce a deposit of H RP reac tion products in the cytoplasm and nuclei of Purkinje and granule cells which do not correspond to the presence of SI00 protein [28],…”

“…This label may be erroneously taken as a labelling of the neuronal plasma membrane. The observation of Sviridov et al [27] and Haglid et al [13] that neurones whose membrane is damaged give a positive cytoplasmic immunoreaction with anti-SlOO protein immune serum can be explained either as due to the penetration of the antibody in the neurone through the lesion in the membrane [13,27] or as the result of a simultaneous lesion in both plasma mem branes (of the neurone and its astrocytic wrapping) with subsequent leakage of SI00 protein from the astrocytic to the neuronal cytosol.…”

Spatial and temporal expression of S100B in cells of oligodendrocyte lineage

“…Although S100B has been found primarily in astrocytes in the mammalian CNS (Langley et al, 1984), immunocytochemical data suggest that it is also expressed in subpopulations of oligodendrocytes (OLs) in several vertebrate species (Haglid et al, 1976;Ludwin et al, 1976;Dyck et al, 1993;Richter-Landsberg and Heinrich, 1995;Rickmann and Wolff, 1995a;RomeroAleman Mdel et al, 2003), including humans (Ohnishi et al, 1985). In the adult mouse, many interfascicular OLs were stained with an antibody directed against the S100 protein (Korr et al, 1994) and, more recently, colocalization of epidermal growth factor protein (EGFP) and S100B was observed in the spinal cord white matter of Cx47-EGFP mice, in which the sequence coding for the OL-specific gap junction connexin 47 protein is replaced by an EGFP reporter gene (Odermatt et al, 2003).…”