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M Schachner

Publications and source records attributed to M Schachner.

At least 451 records · Page 25Linked to original sources
PubMed1982

Changes in expression of glial antigens M1 and C1 after cerebellar injury.

In response to mechanical injury in the adult mouse cerebellum, Bergmann glia and astrocytes of the granular layer exhibit abnormally increased expression of M1 antigen, while expression of C1 antigen in Bergmann glia is reduced. these reciprocal changes in two different astrocytic antigenic determinants (each recognized by monoclonal antibodies) are easily detected in the immediate area of the wound 4 days after the lesion. Although loss of C1 antigen from Bergmann glia remains localized to the area of the wound, abnormal M1 expression becomes widespread in cerebellar astrocytes, also affecting the contralateral side of the injured cerebellum at its peak 8 to 12 days after injury. These findings suggest that previous observations of abnormal expression of the two antigens in the cerebellum of mutant mice (Sommer, I., and M. Schachner (1981) J. Supramol. Struct. 16: 53-74) might be interpreted with the view that a glial reaction to pathological state might be induced by genetically programmed neuronal cell death and/or abnormal development. We therefore postulate that expression of M1 in astrocytes that normally do not express this antigen and repression of C1 in normally positive astrocytes are indicative of a distinct functional state of astroglia, reactive gliosis.

Animals↗
PubMed1981

Neuronal and glial cells in the superficial layers of early postnatal mouse neocortex: immunofluorescence observations.

Sections of immature (postnatal day 5) mouse cerebral cortex was examined for several cell-type specific immunological markers. Glial fibrillary acidic (GFA) protein or vimentin were detected in astrocytic cell processes and--more rarely--cell bodies located in the superficial layers, but not within putative Cajal-Retzius cells (CRs). These cells did, however, react with cholera toxin, tetanus toxin and NS-4 antibodies. In agreement with previous ultrastructural observations, we conclude that CRs are neurons, or at least cells which display the basic characteristics of neurons.

Animals↗
PubMed1981

Monoclonal antibody (M2) to glial and neuronal cell surfaces.

A monoclonal antibody designated M2 arose from the fusion of mouse myeloma cells with splenocytes from a rat immunized with particulate fraction from early postnatal mouse cerebellum. Expression of M2 antigen was examined by indirect immunofluorescence on frozen sections of developing and adult mouse cerebellum and on monolayer cultures of early postnatal mouse cerebellar cells. In adult cerebellum, M2 staining outlines the cell bodies of granule and Purkinje cells. A weaker, more diffuse staining is seen in the molecular layer and white matter. In sections of newborn cerebellum, M2 antigen is weakly detectable surrounding cells of the external granular layer and Purkinje cells. The expression of M2 antigen increases during development in both cell types, reaching adult levels by postnatal day 14. At all stages of postnatal cerebellar development, granule cells that have completed migration to the internal granule layer are more heavily stained by M2 antibodies than are those before and in process of migration. In monolayer cultures, M2 antigen is detected on the cell surface of all GFA protein-positive astrocytes and on more immature oligodendrocytes that express 04 antigen but not 01 antigen. After 3 days in culture, tetanus toxin positive neurons begin to express M2 antigen. The same delayed expression of M2 antigen on neurons is observed in cultures derived from mice ranging in age from postnatal day 0 to 10.

Age Factors↗
PubMed1981

Expression of glial antigens C1 and M1 in developing and adult neurologically mutant mice.

The distribution of two glial antigens (C1 and M1) has been studied by indirect immunofluorescence during postnatal development of the cerebella of normal and neurologically mutant mice (weaver, staggerer, reeler, Purkinje cell degeneration, and wobbler). During the first postnatal week of normal development, C1 antigen is expressed in ependyma. Bergmann glial fibers (BG), and astrocytes of the internal granular layer and white matter. After day 10, C1 antigen is restricted to BG and ependymal cells. During the second and third week. BG undergo a transient loss of C1 antigen that starts in medioventral areas and spreads in a gradient dorsally and laterally. In reeler, weaver, and staggerer, C1 antigen expression is normal during the first postnatal week, and subsides in BG in a similar spatial gradient as described for the normal littermates. However, the loss of C1 antigen in BG occurs earlier (first in reeler, then in weaver, and last in staggerer) and is not reversible as it is in normal mice. In Purkinje cell degeneration, C1 antigen expression is diminished in BG after the onset of behavioral abnormalities. Wobbler is normal with respect to C1 antigen expression at adult ages. M1 antigen is detectable in white matter astrocytes from postnatal day 7 on, and persists in these cells into adulthood. Astrocytes if the internal granular layer and BG express M1 antigen only transiently in normal mice during the second and third weeks. The appearance of M1 antigen in BG occurs in a spatiotemporal gradient, matching the one in which C1 antigen disappears. M1 antigen expression is abnormally maintained in BG of reeler, staggerer, and weaver. In Purkinje cell degeneration. M1 antigen is expressed abnormally at the onset of behavioral abnormalities first in astrocytes of the internal granular layer and, with growing age, increasingly also in BG. In wobbler, BG do not express M1 antigen. However, astrocytes of the granular layer are abnormally M1 antigen-positive.

Aging↗
PubMed1981

Immuno-electron-microscopic identification of O-antigen-bearing oligodendroglial cells in vitro.

Monoclonal antibodies to cell-surface antigens of oligodendrocytes (Sommer and Schachner 1980; Schachner et al. 1980) were used to identify this cell type by immuno-electron microscopy in monolayer cultures of fetal and early postnatal mouse cerebellum. The ultrastructural features of antigen-positive cells confirm that they are immature and mature oligodendrocytes, but not neurons, astrocytes or fibroblasts or fibroblast-like cells. Type I oligodendrocytes are the immature ones with a relatively large amount of moderately electron-lucent cytoplasm, clusters of ribosomes and complex networks of rough endoplasmic reticulum. Large numbers of mitochondria and microtubules, but not intermediate-sized filaments are seen in these cells. They comprise more than 90% of all 0-antigen-positive cells. Type II cells comprise only approximately 5% of all 0-antigen-positive cells. They are characterized by a limited amount of electron-dense cytoplasm, which appears more compact and granular than in type I cells. The rough endoplasmic reticulum is distributed evenly throughout the cytoplasm. Microtubules and mitochondria are present, but more difficult to distinguish due to the compactness of the cytoplasm. Type II cells display the more mature ultrastructural features of oligodendrocytes.

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PubMed1981

Epidermal growth factor stimulates DNA-synthesis of astrocytes in primary cerebellar cultures.

The capability of epidermal growth factor (EGF) to stimulate DNA-synthesis in neural cells was investigated in primary cultures of early postnatal mouse cerebellum. At concentrations of 10(-8)M, EGF stimulates DNA synthesis in astrocytes, which were identified immunocytologically by the cell type-specific marker, glial fibrillary acidic (GFA) protein. Astrocytes express cell-surface receptors for EGF as can be shown by binding of [125 I]-labeled EGF to live monolayer cultures. In the presence of 10% horse serum, EGF stimulates DNA-synthesis by a factor of about two-fold. Stimulation by EGF over control values is approximately 4-fold in the presence of 1% serum and 6-to 10-fold in the absence of serum. Absolute numbers of astrocytes are increased after more prolonged action of EGF. DNA-synthesis in neurons or oligodendroglia is not significantly stimulated by EGF. EGF enhances cell survival of serum-deprived cerebellar cultures. Fibroblast growth factor does not increase DNA-synthesis in astrocytes under the conditions used in this study.

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PubMed1981

Demonstration of astrocytes in cultured amniotic fluid cells of three cases with neural-tube defect.

We have investigated the origin of rapidly adhering (RA) cells in three cases of neural tube defects (two anencephali, one encephalocele). We were able to demonstrate the presence of glial fibrillary acidic (GFA) protein in variable percentages (4--80%) of RA cells cultured for 4--6 days by use of indirect immunofluorescence with GFA antiserum. Cells cultured from amniotic fluids of normal pregnancies and fetal fibroblasts were completely GFA protein negative. GFA protein is well established as a highly specific marker for astrocytes. Demonstration of astrocytes may prove to be a criterion of high diagnostic value for neural tube defects. The percentage of astrocytes decreased with increasing culture time, while the percentage of fibronectin positive cells increased both in amniotic fluid cell cultures from neural tube defects and normal pregnancies.

Amniocentesis↗
PubMed1981

Expression of Thy-1, H-2, and NS-4 cell surface antigens and tetanus toxin receptors in early postnatal and adult mouse cerebellum.

The expression of several cell surface components (Thy-1, H-2 and NS-4 antigens and tetanus toxin receptors) was studied by indirect immunofluorescence in situ using histological sections and in vitro using freshly dissociated and cultured cells from mouse cerebellum. Thy-1 alloantigen is expressed in adult cerebellum predominantly in neuron-rich regions, i.e. molecular, Purkinje cell, and granular layers, however, it is not detectable at postnatal day 8. In cerebellar cultures of 6-day-old mice Thy-1 is absent from more than 99% of all cells when these are maintained as monolayers in vitro for up to 3 days. After 4 days in vitro some GFA protein-positive astrocytes and some fibronectin-positive fibroblast-like cells start to express Thy-1 antigen. After 14 days in vitro not all fibroblast-like cells and astrocytes are Thy-1 antigen-positive. Neurons with small cell bodies and oligodendrocytes never express Thy-1 at any stage examined. H-2 is not expressed sufficiently to be detectable in histological sections in early postnatal or adult cerebellum. In cerebellar cultures of 6-day-old mice H-2 becomes detectable on some fibroblast-like cells and some astrocytes after 7 days in culture. In histological sections of adult and early postnatal cerebellum NS-4 antigen and tetanus toxin receptors are expressed at higher levels on more mature granule cells. In cerebellar cultures NS-4 antigen and tetanus toxin receptors are expressed on neurons. Occasionally some astroglia can also show detectable levels of expression. NS-4 antigen is also present on some 04 antigen-positive oligodendrocytes, while tetanus toxin receptors are never detectable on these cells.

Age Factors↗
PubMed1981

Characterization of isolated mouse cerebellar cell populations in vitro.

Cells from early postnatal mouse cerebellar cortex were isolated by discontinuous BSA gradient centrifugation. Three cellular fractions were obtained and called A (interface at 0-10% BSA), B ( 10-15%) and C (15-25%). These fractions were characterized after maintenance in vitro for 3 days by indirect immunofluorescence labeling with several cell type-specific probes: Tetanus toxin was used as a neuronal marker.Under the described culture conditions Thy-1.2 antibodies served as additional markers for mature neurons and NS-4 antiserum for neurons and oligodendroglial cells. Glial fibrillary acidic (GFA) protein was used as a marker for differentiated astroglia, and fibronectin as a marker for fibroblasts. Monoclonal antibodies to 04 antigen and antiserum to corpus callosum served to distinguish oligodendroglia. Fraction C contains most of the cellular debris and cells with large cell bodies (about 20 micrometers in diameter) which are positive for Thy-1, NS-4, and tetanus toxin. By birthdate labeling with [3H]thymidine these cells can be identified as Purkinje cells and/or Golgi type II cells. Fraction B is relatively heterogeneous. It contains predominantly GFA protien-positive astroglial cells (about 50% of all cells) which can be classified into 3 morphologically distinct cell types, flat epithelioid cells and star-shaped cells with thick or very thin cellular processes. Fraction B is enriched also in 04 antigen-positive oligodendrocytes, fibronectin-positive fibroblasts and Thy-1 negative, but NS-4 and tetanus toxin positive cells with small cell bodies and many fine processes. These small neurons, putative stellate and basket cells, have many fine processes and are morphologically different from th bipolar putative granule cells, some of which are also present in this fraction. Fraction C contains predominantly small neurons, mostly putative granule cell (more than 0% of all cells) which are positive for NS-4 and tetanus toxin, but negative for Thy-1.

Animals↗
PubMed1981

Developmental expression of cell type-specific markers in mouse cerebellar cells in vitro.

The expression of several cell type-specific markers was studied by indirect immunofluorescence in discontinuous BSA gradient fractionated and unfractionated mouse cerebellar cells cultured for 3 days in vitro from embryonic day 13 through postnatal day 9. Cell surface antigen NS-4 and tetanus toxin receptors are present at all ages studied. Thy-1 first detected on neurons with large cell bodies (Purkinje and/or Golgi Type II.neurons) onpostnatal day 3, but absent from all neurons with small cell bodies (granule, basket, and stellate cells). At all ages Thy-1 antigen is absent from astro- and oligodendroglia, and fibroblasts or fibroblast-like cells. Fibroblast-like cells express fibronectin at all ages studied. Astroglia expressing glial fibrillary acidic (GFA) protein are first detectable in cultures from 16-day-old embryos. Their number increases at later ages. At all ages studied fluorescein conjugated Ricinus communis agglutinin 120 brightly labels the cell surfaces of fibroblastic cells and large neurons, less brightly those of astrocytes, bu not those of small neurons. Oligodendroglia become detectable in cerebellar cultures from 16- and 17-day-old embryos maintained in vitro for 3 days using antibodies to 04 antigen and bovine corpus callosum, respectively. At embryonic ages BSA step gradient procedures do not result in enrichment of particular cell types as recognized by the available markers. From birth onward, however, enrichment of cell populations was obtained corresponding to the ones characterized at postnatal day 6 as described in the companion paper (Schnitzer and Schachner 1981b).

Age Factors↗
PubMed1981

Immunocytochemical demonstration of vimentin in astrocytes and ependymal cells of developing and adult mouse nervous system.

The occurrence of vimentin, a specific intermediate filament protein, has been studied by immunoflourescence microscopy in tissue of adult and embryonic brain as well as in cell cultures from nervous tissue. By double imminofluorescence labeling, the distribution of vimentin has been compared with that of subunit proteins of other types of intermediate filaments (glial fibrillary acidic [GFA] protein, neurofilament protein, prekeratin) and other cell-type specific markers (fibronectin, tetanus toxin receptor, 04 antigen). In adult brain tissue, vimentin is found not only in fibroblasts and cells of larger blood vessels but also in ependymal cells and astrocytes. In embryonic brain tissue, vimentin is detectable as early as embryonic day 11, the earliest stage tested, and is located in radial fibers spanning the neural tube, in ventricular cells, and in blood vessels. At all stages tested, oligodendrocytes and neurons do not express detectable amounts of vimentin. In primary cultures of early postnatal mouse cerebellum, a coincident location of vimentin and GFA protein is seen in astrocytes, and both types of filament proteins are included in the perinuclear aggregates formed upon exposure of the cells to colcemid. In cerebellar cell cultures of embryonic-day-13 mice, vimentin is seen in various cell types of epithelioid or fibroblastlike morphology but is absent from cells expressing tetanus toxin receptors. Among these embryonic, vimentin-positive cells, a certain cell type reacting neither with tetanus toxin nor with antibodies to fibronectin or GFA protein has been tentatively identified as precursor to more mature astrocytes. The results show that, in the neuroectoderm, vimentin is a specific marker for astrocytes and ependymal cells. It is expressed in the mouse in astrocytes and glial precursors well before the onset of GFA protein expression and might therefore serve as an early marker of glial differentiation. Our results show that vimentin and GFA protein coexist in one cell type not only in primary cultures in vitro but also in the intact tissue in situ.

Animals↗
PubMed1981

Recognition of Bergmann glial and ependymal cells in the mouse nervous system by monoclonal antibody.

A monoclonal antibody designated anti-Cl was obtained from a hybridoma clone isolated from a fusion of NS1 myeloma with spleen cells from BALB/c mice injected with homogenate of white matter from bovine corpus callosum. In the adult mouse neuroectoderm, C1 antigen is detectable by indirect immunohistology in the processes of Bergmann glial cells (also called Golgi epithelial cells) in the cerebellum and of Müller cells in the retina, whereas other astrocytes that express glial fibrillary acidic protein in these brain areas are negative for C1. In addition, C1 antigen is expressed in most, if not all, ependymal cells and in large blood vessels, but not capillaries. In the developing, early postnatal cerebellum, C1 antigen is not confined to Bergmann glial and ependymal cells but is additionally present in astrocytes of presumptive white matter and Purkinje cell layer. In the embryonic neuroectoderm, C1 antigen is already expressed at day 10, the earliest stage tested so far. The antigen is distinguished in radially oriented structures in telencephalon, pons, pituitary anlage, and retina. Ventricular cells are not labeled by C1 antibody at this stage. C1 antigen is not detectable in astrocytes of adult or nearly adult cerebella from the neurological mutant mice staggerer, reeler, and weaver, but is present in ependymal cells and large blood vessels. C1 antigen is expressed not only in the intact animal but also in cultured cerebellar astrocytes and fibroblastlike cells. It is localized intracellularly.

Animals↗
PubMed1980

Surface proteins of cultured mouse cerebellar cells.

Surface proteins of cultured monolayer cells from embryonic and early postnatal C57BL/6J mouse cerebella were identified by a lactoperoxidase-catalysed 131iodine labelling technique. Major iodinated polypeptides have molecular weights of approximately 200, 145, 120, 100, 85, 65, 50, and 30 x 10(3) (P200, P145,...) as estimated by sodium dodecylsulphate polyacrylamide gel electrophoresis. Membrane glycoproteins, of apparent molecular weights 200, 145, 100, 85, and 50 x 10(3), are detected by biosynthetic labelling with [3H]fucose. The two major iodinated proteins are the glycoproteins P200 and P145. P145 is released from the cells into the medium together with other surface proteins. No changes in the patterns of labelled cerebellar cell surface proteins are detectable between embryonic day 17 and postnatal day 10. A pattern similar to the one seen with cerebellum is obtained with embryonic day 12 and 17 cerebral cortex. Cultured retinal cells from 2-day-old mice, skin fibroblasts, and L-cells display a distinctly different pattern, which does not contain P145 as a major iodinated component. In granule cell-enriched fractions of cerebellar cells the two glycoproteins P200 and P145 are proportionately increased, while three proteins, P100, P85, and P50, are more abundant in the glial cell-enriched fraction. These three polypeptides are also enriched in cells obtained from staggerer mutant mice. An antiserum against 4-day-old cerebellar cells (anti-NS-4) precipitates the 145 and 200 x 10(3) molecular weight proteins, from lysates of both embryonic cerebral and postnatal cerebellar cells. From lysates of mouse retinal cells, anti-NS-4 antiserum precipitates two proteins with molecular weights of 140 and 210 x 10(3).

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