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H Rösner

Publications and source records attributed to H Rösner.

At least 37 records · Page 2Linked to original sources
PubMed1993

Developmental changes of growth cone gangliosides of the postnatal rat cerebrum.

The ganglioside content and composition of growth cones prepared from forebrains of day 0 (p0), day 2 (p2), and day 6 (p6) postnatal rats was analysed in comparison with that of whole forebrain membranes obtained from rats of the same age. The amount of total ganglioside bound sialic acid (microgram NeuAc mg protein-1) was found to increase in both whole cerebrum membranes and growth cones from p0 to p6. The ganglioside concentrations of growth cones exceeded that of the whole cerebrum by 35-40% at all time points investigated. The major rat brain gangliosides were also found in the growth cone fractions, however, in different relative amounts. Thus, the well known developmental shift from the b- to the a-ganglioside synthesis pathway was significantly delayed in growth cones, indicating that this shift is not associated with axonal growth but more likely with the subsequent period of synaptogenesis. GQ1c, recognized by the mAb Q211, and an unidentified growth-cone specific ganglioside x were found to be expressed in growth cones of p0 rats and to decrease up to p6.

Animals↗
PubMed1992

Influence of exogenous gangliosides on the three-dimensional sprouting of goldfish retinal explants in vitro.

To investigate the 3-dimensional outgrowth of ganglion cells of normal and regenerating goldfish retina, retinal explants were cultured in a serum free 3-D fibrin matrix. Daily applications of exogenous gangliosides (GM1), injected either intraocularly (i.o.) or intraperitoneally (i.p.) had no significant effect on the sprouting activity of retinal explants prepared from lesion-activated goldfish whose corresponding optic nerve had been transected. However, in normal, unlesioned animals, a local i.o. injection of GM1 or mixed gangliosides led to a significant enhancement of the basal retinal sprouting activity as compared to controls, which were injected with a 0.9% NaCl solution. This ganglioside related stimulation was maximal after i.o. injection of low concentrations (3 micrograms/eye), didn't occur at high concentrations (30 micrograms/eye) and was similar to the response obtained after i.o. injection of NGF or insulin. I.o. injected phospholipids had no or a slightly inhibitory effect on the sprouting activity as compared to NaCl controls. Daily in vivo i.o. injections of the monoclonal antibody Q211, specifically recognizing c-pathway polysialogangliosides, led to a dose dependent inhibition of the in vitro sprouting of goldfish retina explants. In summary, these data suggest an involvement of gangliosides in the complex process of induction of neuronal sprouting.

Animals↗
PubMed1992

Gangliosides and neuronal differentiation.

Using the GD3-specific mAb R24 we demonstrate by immunohistochemistry that the first embryonic cells of chicken expressing GD3 represent heavily proliferating cells of mesodermal origin (mesenchymal stem and endothelial cells). At this developmental stage (E1-1.5) neuroectodermal cells of the forming neural tube are not stained by R24 or any other available anti-ganglioside antibodies. These cells of the neural tube start to express GD3 at around E1.5 in parallel with increasing proliferative activity. Likewise proliferating and migrating neuronal crest derivates as well as undifferentiated retinal cells, the forming lens and otic placodes increasingly express GD3 in an organ-specific pattern following the spatiotemporal increase in mitotic activity. Immunostaining of GD1b (mAb D21b) or c-pathway polysialogangliosides (mAb Q211) is not obtained before E2.5, is nervous tissue specific and restricted to "new-born" neurons, which start to migrate and form first neurites. This striking change in ganglioside synthesis and expression also occurs in primary cell cultures (after or without previous Q211-mediated complement kill of neurons) during differentiation of mitotic progenitor cells to neurons (neurogenesis). In cell culture, the fluorescence staining is evenly distributed over the whole neuronal surface including filopodia at the growth cones. Monensin (10(-8) M) prevents expression of GD1b and c-polysialogangliosides and simultaneously differentiation of neuronal morphology (neurogenesis). The presence of exogenous gangliosides from bovine brain leads to a decrease of the monensin effect or even abolishes it.

Animals↗
PubMed1992

Gangliosides and regeneration of the goldfish optic nerve in vivo and in vitro.

One to forty days after optic nerve transection, goldfish received an i.p. injection of [3H]proline (proteins), 3HNAcGluc (gangliosides) or [3H]thymidine (DNA). After 1 or 2 days of incorporation, both optic systems were analyzed by biochemical and autoradiographical procedures. In the regenerating retina an enhanced retinal mitotic activity, protein synthesis (up to 2-fold) and ganglioside synthesis (up to 1.5-fold) was found. Simultaneously, a transiently enhanced accumulation (up to 4.5-fold) of axonally transported protein- and ganglioside-bound radioactivity in the regenerating optic nerve stump occurred. These regeneration-related proliferative and metabolic changes were found to be maximal at 6-8 days post lesion, but still measurable after 40 days. Concerning the endogenous ganglioside metabolism, in the regenerating retina no obvious change in ganglioside synthesis and composition could be observed, while in the regenerating optic nerve there was an enhanced accumulation of the ganglioside GP1c. Daily i.p. application of a ganglioside mixture from bovine brain (GMix) or of the monosialoganglioside GM1, did not alter significantly the degree and time course of the above regeneration induced metabolic changes or the regain of visual acuity. Sprouting activity of goldfish retinal explants was found to strongly depend upon a conditioning lesion of the optic nerve, reaching a maximum 8 days after nerve transection. This result strictly coincided with the profile of metabolic changes observed in vivo. Again, daily i.p. or i.o. injection of exogenous gangliosides did not influence the lesion induced increase of retinal sprouting activity. However, in normal, not regenerating animals, a local i.o. injection of GMix or GM1 led to a significant enhancement of the "basal" sprouting activity, normally occurring after lesion of the retina after injection of 0.9% NaCl. This ganglioside related stimulation was maximal at low concentrations (3 micrograms/eye) and did not occur at high concentrations (> 30 micrograms/eye). Injection of the phospholipid phosphatidylcholine or phosphatidylserine had no or a slightly inhibitory effect, when compared to NaCl controls. These data suggest an involvement of gangliosides in the complex process of induction of axonal sprouting.

Acetylglucosamine↗
PubMed1992

Cell surface distribution of endogenous and effects of exogenous gangliosides on neuronal survival, cell shape and growth in vitro.

In vitro immunostaining of neurons from spinal cord or brain of embryonic chicken by means of monoclonal anti-ganglioside antibodies (Q211, D21b) revealed a fluorescence-labeling of c-polysialogangliosides and GD1b evenly distributed over the entire neuronal surface including filopodia at the growth cones. On electronmicroscopical level the gold-stained ganglioside-antigens were found more or less densely packed in small adjacent areas suggesting a concentration in local "domains". Survival in serum-free or serum-containing medium of embryonic spinal cord motoneurons, which normally died if not cultivated in muscle conditioned medium or in contact to myotubes, was remarkably improved in the presence of a ganglioside mixture (10 microM) from bovine brain. If embryonic neurons from optic lobes were cultivated at low Ca(2+)-concentration (< 20 microM) they developed flat, broad cell bodies with many filopodia and only a few flat-shaped short processes. A very weak cytoskeleton-staining by means of rhodamine-linked phalloidine indicated that polymerization of actin was impaired in these neurons. At the same low Ca(2+)-concentration of < 20 microM but in the presence of ganglioside GM1 (up to 100 microM) most of the neurons developed a "normal" cell shape with rounded perikarya and thin neurites with "normal" shaped growth cones. In this case rhodamine-linked phalloidine revealed a much more intense staining mainly concentrated within the growing tips. The morphology and growth of the ganglioside-treated neurons resembled that of neurons cultivated at a higher Ca(2+)-concentration of at least 600 microM.

Animals↗
PubMed1991

GD3 prevalence in adult rat retina correlates with the maintenance of a high GD3-/GM2-synthase activity ratio throughout development.

Unlike neurons from avian retina and other regions of avian and mammalian brain, neurons from mammalian retina not only contain gangliosides of the gangliotetraosyl ceramide series but also maintain a prevalence of GD3, a ganglioside of the lactosylceramide series characteristic of proliferative neural cells, when they are fully differentiated. We show here that GD3 is prevalent at all developmental periods of the rat retina from birth [50% of total gangliosidic N-acetylneuraminic acid (NeuNAc)] to adult (30% of total gangliosidic NeuNAc). GD3-synthase specific activity increased about 1.5-fold from birth to day 7 and essentially plateaued thereafter. The GD3-/GM2-synthase specific activity ratio was compared in rat and chicken retina at early and late developmental stages. In chicken retina the ratio was about 0.7 at early (when GD3 is prevalent) and decreased to 0.07 at late (when GD1a is prevalent) developmental stages. In rat retina the ratio was about 13 and 6 at, respectively, early and late developmental stages. These findings suggest that the prevalence of GD3 and of other "b" pathway gangliosides in adult rat retina neurons could be due in part to the maintenance of a high GD3-/GM2-synthase activity ratio throughout development of the tissue.

Aging↗
PubMed1990

Migration and aggregation of embryonic chicken neurons in vitro: possible functional implication of polysialogangliosides.

The presented study reports a primary culture system of embryonic chicken optic lobe neurons, which turned out to be a suitable model for cell migration and aggregation: Freshly dissociated neurons developed short processes, contacted one another and formed fasciculated bundles, on which neurons migrated as long-shaped cells, similar to migrating neurons in vivo. We used this system to study the possible involvement of c-pathway polysialogangliosides for neuronal migration and aggregation. These highly negative charged glycosphingolipids are the predominant gangliosides of migrating and outgrowing neurons in vivo. Addition of a purified ganglioside mixture (50 microM), extracted from brains of the corresponding embryonic stage, strongly enhanced neuronal migration and aggregation, while incubation of the cells with monoclonal antibody Q211, specifically binding c-polysialogangliosides, reduced aggregate formation in a dose-dependent manner. Cultures treated with 10 micrograms/ml Q211, instead, displayed a more divergent growth, leading to the formation of a fine network of single neuronal processes. These results suggest a functional implication of c-polysialogangliosides in neuronal fasciculation, migration and aggregation.

Animals↗
PubMed1990

c-pathway polysialogangliosides in the nervous tissue of vertebrates, reacting with the monoclonal antibody Q211.

The mouse monoclonal antibody Q211, previously shown to recognize a common epitope of chicken brain GP1c and of two other polysialogangliosides containing 4 and 6 sialic acid residues respectively, is demonstrated to bind to gangliosides with identical thin-layer chromatography (TLC) migration in the brain of representatives of boney fish, rays, reptiles and mammals, including man. In the boney fish brains, the Q211 binding gangliosides were found to be alkali-labile, the Q211 epitope, however, is alkali-stable. After alkaline treatment, the cichlid fish contained at least 4 Q211-binding gangliosides, migrating as GT1c, GQ1c, GP1c and 'GH'. In the trout brain only one Q211 antigenic fraction was found, migrating as GQ1c. In the brains of ray, turtle and embryonic chicken an identical pattern of Q211-binding gangliosides (GQ1c, GP1c, 'GH') occurred. In the embryonic rat and human brain, the content of Q211-binding gangliosides was much lower as compared to the other vertebrate species. The epitope was found in two fractions, migrating like GQ1c (human and rat) and GP1c (rat). The presence of Q211 epitope in all species was confirmed by immunohistochemistry. These data confirm that the Q211-epitope contains a complete c-ganglio-tetraose structure, carrying 3 sialic residues at the inner galactose. They furthermore demonstrate that the expression of c-pathway polysialogangliosides is a general feature of the vertebrate nervous tissue, either during whole life (fish, reptiles) or more or less transient during embryonic development (birds, mammals).

Animals↗
PubMed1990

Developmental profiles of gangliosides in trisomy 19 mice.

The ganglioside composition of the cerebrum, cerebellum, brainstem, liver, heart, and spleen was analyzed quantitatively in trisomy 19 (Ts19) mice aged 4 to 12 days postpartum. The developmental profiles of cerebral gangliosides were similar in Ts19 mice and control littermates: Total ganglioside-sialic acid as well as the proportions of the individual gangliosides GD1a and GM1 increased with age, while the percentages of GQ1b and GT1b decreased during development. Both the accretion of the total ganglioside content and the development of the individual ganglioside fractions were delayed by 2-3 days in the Ts19 telencephalon. Likewise, the shift from the b- to the a-pathway of ganglioside synthesis was retarded. Ganglioside development was equally delayed in the cerebellum and the brainstem of Ts19 mice. Since in Ts19 mice, morphogenesis of several brain regions is similarly delayed by 2 days, these results confirm the usefulness of gangliosides as biochemical markers for brain maturation. In contrast to brain gangliosides, the ganglioside composition of the Ts19 livers was clearly distinguished from that of control livers. Total ganglioside-bound sialic acid was increased by 35-50% in Ts19 livers. This elevation in ganglioside content not explicable by a simple delay in development was mainly due to an increase in GD3 and fraction 2, which is likely to contain GD1a and GD1b. In contrast, GM2 which increased considerably with age in control mice persisted on a low level in Ts19 livers. Comparable alterations of the ganglioside pattern were neither observed in the spleen nor in the heart of Ts19 mice. The data presented give additional evidence that ganglioside synthesis in the liver is under a different regulation mechanism than that in the brain, heart, and spleen.

Animals↗
PubMed1990

Density-dependent expression of ganglioside GM3 by human skin fibroblasts in an all-or-none fashion, as a possible modulator of cell growth in vitro.

The expression of GM3 in human skin fibroblasts (cell type MF II) was investigated biochemically and immunochemically by means of the monoclonal antibody M2590. A cell density-related increase in total gangliosides (about threefold) and especially in GM3 (about sixfold) was found upon attainment of confluency. Immunostaining with mAb M2590 revealed that in preconfluent cultures GM3 is expressed by only a few cells in an all-or-none fashion. The portion of GM3-expressing cells increases in parallel with cell density. In confluent cultures, which are growth-arrested by contact inhibition, all cells are intensely stained by mAb M2590, indicating a high content of GM3 in the plasma membrane. These data suggest that increased cellular M2590 binding is due to an increased GM3 content rather than to an altered conformation or arrangement in the cell membrane. GM3-expressing cells usually show a broad, flat morphology, like that of cells in the resting state (G1/G0-phase) of the cell cycle. The M2590 staining on these cells appear as clusters, orientated along straight lines and indicating an ordered distribution of GM3 in the plasma membrane. A dose-dependent inhibition of cell growth by addition of exogenous gangliosides supports the possible involvement of these glycosphingolipids in the regulation of cell growth.

Antibodies, Monoclonal↗
PubMed1990

Ultrastructural localization of gangliosides, calcium and a high-affinity Ca(2+)-ATPase in nerve terminals: a contribution to the possible functional role of gangliosides.

By means of newly developed electron microscopical techniques (electron spectroscopic imaging, ESI; electron energy loss spectroscopy, EELS; immunogold labelling) a specific accumulation of endogenous calcium within the synaptic cleft and a distinct localization of a high-affinity Ca(2+)-ATPase at the inner sides of the pre- and postsynaptic membrane of nerve cells from fish brain have been demonstrated. Additionally, a differentiation-dependent expression of polysialoganglioside epitopes on the outer surface of nerve terminals in clustered arrangements was demonstrated using their ultracytochemical detection by means of the monoclonal antibody Q211. These results which are in agreement with parallel biochemical investigations on modulatory effects of exogenous gangliosides on a high-affinity Ca(2+)-ATPase in the CNS of vertebrates support our hypothesis that Ca(2+)-ganglioside complexes act as modulators for the processes of synaptic transmission and long-term neuronal adaptations.

Animals↗
PubMed1989

Possible involvement of polysialogangliosides in nerve sprouting and cell contact formation: an ultracytochemical in vitro study.

In Cichlid fish (Oreochromis mossambicus) primary cell cultures from whole brain and optic tectum, the differentiation-dependent distribution of polysialogangliosides on the outer cell surface has been followed on an ultrastructural level. For this, a two-step labeling technique with the monoclonal mouse antibody Q211, recognizing a polysialoganglioside-associated epitope, followed by a secondary IgM antibody, coupled to colloidal gold sols as an electron-dense marker, has been used. The gold grains are not uniformly distributed over the whole cell surface, but rather are clearly arranged clusters. In cells from freshly hatched larvae, both cell bodies and nerve fibers strongly exhibit the polysialoganglioside epitope on their surface. With progressing development, neuronal cell labeling is more and more restricted to nerve fibers and especially to cellular adhesion zones, including synaptic terminals, thus suggesting a functional involvement of polysialogangliosides in nerve sprouting and initiation of both cell-to-extracellular matrix and cell-to-cell contacts.

Animals↗
PubMed1988

Developmental expression in embryonic rat and chicken brain of a polysialoganglioside-antigen reacting with the monoclonal antibody Q 211.

The monoclonal mouse antibody Q 211 binds to an antigen, which is expressed by postmitotic growing neurons of embryonic chicken and rat brain. In chicken, thin layer chromatography (TLC) immunostaining confirms the presence of the Q 211 antigen in at least 3 different polysialoganglioside fractions. One comigrates on TLC plates with GP1c and the others with gangliosides, which have been previously preliminary characterized as GQ1c, and as a hexasialoganglioside. Thus, 3 sialic acid residues linked to the inner galactose of a complete tetraose moiety is suggested as the common epitope of the different Q 211-antigen-active gangliosides. Also in the embryonic rat brain, immunohistochemistry reveals a transient expression of the Q 211 antigen in areas containing growing nerve fibres. Unlike chicken, however, in the rat the staining is restricted to early thalamocortical innervations and to a fibre system (probably long distance projections) connecting the mamillary body with the hippocampus formation. In ganglioside extracts from rat forebrain 2 polysialogangliosides are shown by immuno-TLC to bind Q 211. One of these fractions, occurring transiently and in parallel with histochemical staining, comigrates on TLC plates with chicken GP1c. The other comigrates with the second main Q 211 antigen-containing band of chicken, which was preliminary identified as GQ1c.

Animals↗
PubMed1988

Axonal transport of intraocularly injected [3H-Sph]-GD1a in the chicken optic system and the fate of the exogenous ganglioside distributed by blood.

Twelve-day-old chicks (White Leghorn) received an injection of 481 kBq (8.1 nmol) of [3H-Sph]-GD1a, which was labeled in its sphingoid, into the right eye. Structures of the injected and the non-injected (control) optic system (retinae, optic nerves, chiasm, optic lobes), the cerebrum, blood liver, kidney, and fly-muscle were analyzed 1, 4, 8 and 14 days later, with respect to total non-volatile radioactivity and to that bound to lower-phase lipids and gangliosides. It was demonstrated that exogenous [3H-Sph]-GD1a was taken up by the retina and mainly catabolized. 3H-label, reincorporated into the lower-phase lipids and gangliosides as well as authentic exogenous [3H-Sph]-GD1a were transported rapidly anterogradely in the entire optic system. [3H-Sph]-GD1a, distributed via the blood stream, was taken up by liver, kidney and muscle and was metabolized faster in these organs than in the retina. The cerebrum and the brain structures of the control optic system incorporated 3H-radioactivity to a much lower extent than the non-neural organs.

Animals↗
PubMed1986

Early cytoarchitectonic development of the anlage of the basal nucleus of Meynert in the human fetus.

The present study describes a short period of cytoarchitectonic development of the anlage of the basal nucleus of Meynert between 9 and 15 weeks of gestation (crown-rump length 42-120 mm). On the basis of temporo-spatial reconstruction of the cytoarchitectonic pattern within the basal telencephalon it was evident that magnocellular aggregations of the basal telencephalon contain the most differentiated cells in the whole prosencephalon of the 15-week-old human fetus. At this stage development many magnocellular islands can be observed in the sublenticular region. However, it seems that they are in antero-posterioral continuation and the real number of magnocellular islands is much smaller than observed in a single section. The most voluminous magnocellular aggregations are situated around the temporal limb of the anterior commissure and below the ventral pallidal surface in the 15th week of gestation. Between 12 and 15 weeks of gestation, at the most rostral levels, the distinct cell group appeared with unique cytoarchitectonic properties ('albino cell group'). This cell group is situated close to the ventral putaminal surface within the capsula externa fibres and it corresponds to the subputaminal nucleus of Ayala.

Basal Ganglia↗
PubMed1985

Developmental expression of GD3 and polysialogangliosides in embryonic chicken nervous tissue reacting with monoclonal antiganglioside antibodies.

The appearance and developmental distribution of GD3 and polysialogangliosides was studied immunohistochemically by means of the monoclonal mouse antibodies AbR24 and Q211. Cryostat sections of chicken embryos from 1 to 5 days (E1-E5) of incubation (Hamburger and Hamilton, stages 9-26) were prepared. GD3, detected by AbR24, is expressed on E2 by proliferating neuroepithelial cells of all regions of the developing brain and spinal cord and by migrating neural crest cells. As development continues, GD3 drops to a much lower level in postmitotic neurons, but is still strongly expressed by cells of the mitotically active germinal zones. In non-neural tissues the antigen was found in much lower concentrations than in the neuroectoderm, with the exception of very early, heavily proliferating endodermal and mesodermal epithelia. In contrast, the antigen(s) of the monoclonal mouse antibody Q211, identified on TLC-plates in polysialoganglioside fractions, was found to be specific for central and peripheral derivatives of the neural ectoderm. In the CNS, these polysialogangliosides are absent in the proliferating neural epithelium and appear for the first time on cells of the developing peripheral mantle layers at E2.5 (stage 17). Sections from all brain areas, retina, optic stalk, spinal cord, and peripheral nerves and ganglia of later stages (E4-5) showed that the antigen(s) of Q211 is expressed by neuronal perikarya and cell processes. The data strongly suggest that the developmental appearance of these polysialogangliosides is synchronized with the withdrawal of proliferating precursor cells from the mitotic cycle and differentiation to neurons.

Animals↗
PubMed1984

Topographical atlas of the gangliosides of the adult human brain.

Forty different brain samples, consisting of neocortical, archicortical, and paleocortical areas; telencephalic, diencephalic, and mesencephalic subcortical nuclei; and the cerebellum as well as some of the corresponding white matter bundles were analyzed with respect to total content of ganglioside-sialic acid and the ganglioside pattern. The total content of gangliosides seems to depend mainly on the proportions of gray and white matter. Thus, neocortical areas, which are rich in gray matter, have a four- to fivefold higher ganglioside content (per milligram of protein) than white matter-rich samples such as optic chiasm, capsula interna, or corpus callosum. White matter-rich regions, although very heterogeneous in ganglioside composition, are further characterized by appreciable amounts of the myelin-enriched GM4. In the neocortex a remarkable degree of regional pattern differences was revealed. In the frontal and parietal areas there is a moderate, and in the temporal region a strong preponderance of sialic acid bound to gangliosides of the a-pathway (GD1a, GM1). In contrast, the occipital cortex favors the b-pathway of ganglioside synthesis (GQ1b, GT1b, GD1b). A predominance of "b-gangliosides" was found in all structures that are related to the visual system (optic chiasm, pulvinar-thalamus, superior colliculi, visual cortex) as well as in the cerebellum and the nucleus ruber. All diencephalic nuclei tend to favor slightly "b-gangliosides," while the mesencephalic nuclei are very heterogeneous in their ganglioside composition. A preponderance of "a-gangliosides" was found in the periamygdalar cortex, putamen, inferior colliculi, substantia nigra, frontal white matter, internal capsule, globus pallidus, basal nucleus of Meynert, and corpus callosum as well as in the frontal, parietal, and temporal cortices. An exceptional predominance of GM1 and GD1a was revealed for the hippocampal archicortex and the amygdala, suggesting a possible functional correlation to glutaminergic synaptic transmission.

Brain Chemistry↗