Changes In Ganglioside Expression Research Articles

Gangliosides in T cell development and function of mice.

The molecular diversity of glycosphingolipids (GSLs) that arouse during thecourseof evolution clearly plays an essential role in maintenance of biological homeostasis. Why is such a wide variety of GSLs necessary, and what gave rise to the expression mechanisms that are selective and specific to individual cells, tissues, or organs? What is the biological significance of these mechanisms? The same questions apply to GSLs involved in T cell development and activation.Primary CD4+ T cells and CD8+ T cells preferentially express differing ganglioside series: a-series and o-series, respectively. Conversely, a-series and o-series ganglioside deficiency results respectively in CD4+ and CD8+ T cell dysfunction. Dynamic changes in ganglioside expression occur during T cell development in thymus. Ganglioside GM3 synthase deficiency, which results in lack of a-series gangliosides, ameliorated CD4+ T cell-mediated airway hypersensitivity in a mouse model of allergic asthma. In this review, we summarize findings from these and many studies to illustrate the key roles of gangliosides in T cell differentiation and function.

Aberrant ganglioside composition in glioblastoma multiforme and peritumoral tissue: A mass spectrometry characterization

Tumor cells are characterized by aberrant glycosylation of the cell surface glycoconjugates. Gangliosides are sialylated glycosphingolipids highly abundant in neural tissue and considered as tumor markers and therapeutic targets. In this study, a detailed characterization of native ganglioside mixtures from glioblastoma multiforme, corresponding peritumoral tissue and healthy human brain was performed using mass spectrometry and high performance thin layer chromatography in order to elucidate their roles as tumor-associated antigens. Distinctive changes in ganglioside expression were determined in glioblastoma compared to healthy brain tissue showing 5 times lower total ganglioside content and higher abundance of simple gangliosides. Glioblastoma gangliosides were characterized by highly diverse ceramide composition with fatty acyl chains varying from 16 to 24 carbon atoms, while in normal and peritumoral tissue mostly C18 chains were found. The most abundant ganglioside in glioblastoma was GD3 (d18:1/18:0), followed by GD3 (d18:1/24:0) that was exclusively detected in glioblastoma tissue. Peritumoral tissue expressed higher abundance of GD3- and nLM1/GM1-species while lower GT1-species vs. normal brain. O-Ac-GD1, known as neurostatin, was detected in normal and peritumoral tissue, but not in glioblastoma. O-Ac-GD3 species were found exclusively in glioblastoma; MS structural characterization of the isomeric form possessing the O-acetylation at the inner sialic acid residue confirmed our previous finding that this isomer is glioma-associated. This, to our knowledge, the most detailed characterization of ganglioside composition in glioblastoma and peritumoral tissue, especially addressing the ceramide variability and O-acetylation of tumor-associated gangliosides, could contribute to recognition of new molecular targets for glioblastoma treatment and sub-classification.

The role of glycosphingolipid metabolism in the developing brain

Glycosphingolipids (GSLs) are amphipathic lipids ubiquitously expressed in all vertebrate cells and body fluids, but they are especially abundant in the nervous system. The synthesis of GSLs generally is initiated in the endoplasmic reticulum and completed in the Golgi apparatus, followed by transportation to the plasma membrane surface as an integral component. The amount and expression patterns of GSLs change drastically in brains during the embryonic to postnatal stages. Recent studies have revealed that GSLs are highly localized in cell surface microdomains and function as important components that mediate signal transduction and cell adhesion. Also in developing brains, GSLs are suggested to play important roles in nervous system formation. Disturbance of GSL expression and metabolism affects brain function, resulting in a variety of diseases, particularly lysosomal storage diseases. In this review, we describe some aspects of the roles of GSLs, especially of gangliosides, in brain development.

Differences in splenic B-lymphocyte ganglioside expression and accessibility in normal and endotoxin-hyporesponsive mice

Endotoxin-responsive (C3H/HeN) and -hyporesponsive (C3H/HeJ) murine B lymphocytes purified by adherence to anti-immunoglobulin ("antibody panning") possess identical gangliosides but different ganglioside surface accessibilities. We investigated the distribution and surface accessibility of gangliosides of B lymphocytes purified by adherence to plastic ("plastic panning") or by subtraction of non-B-lymphocyte components. As with antibody panning, there were no entirely new or absent gangliosides in plastic-panned or subtraction-purified B lymphocytes of each strain. However, striking changes in relative expression of five gangliosides were detected with each purification protocol. Moreover, five gangliosides of antibody-panned and plastic-panned B lymphocytes but only two gangliosides of subtraction-purified B lymphocytes were inaccessible to surface labeling. Unlike the situation for antibody-panned B lymphocytes, no interstrain (HeN vs. HeJ) surface accessibility differences existed in gangliosides of plastic-panned or subtraction-purified cells. Exposure of subtraction-purified B lymphocytes to anti-immunoglobulin failed to elicit changes in ganglioside expression. Murine B lymphocytes have distinct protocol-dependent differences in glycolipid phenotype which likely denote individual subpopulations.

Neuroblastomas of infancy exhibit a characteristic ganglioside pattern.

Gangliosides are membrane-bound glycolipid molecules particularly prominent in neural tissue. Changes in ganglioside expression during embryologic development result from a shift in biosynthesis from the fetal b pathway to the adult a pathway. Tumor gangliosides may play a role in the clinical behavior of certain subtypes of neuroblastoma. Because neuroblastoma, which presents in infancy, has a different biologic and clinical phenotype than that which presents in older children, the authors determined whether differences in ganglioside biosynthesis exist between these two neuroblastoma subgroups. Sixty-eight tumor specimens (25 diagnosed by screening and 43 diagnosed clinically) were obtained from the Quebec Neuroblastoma Screening Project. Gangliosides were isolated and purified by solvent partitioning, separated by high performance thin-layer chromatography, and quantitated by scanning densitometry. The sum of a and b pathway gangliosides were determined for each tumor. Gangliosides of the b (fetal) pathway predominated in both screened and clinically diagnosed tumors of patients younger than 1 year of age. Twenty-three of 25 screened patients (92%) and 21 of 23 patients with clinically diagnosed tumors at younger than 1 year of age (91%) had tumor b pathway ganglioside content greater than 60%. In contrast, tumors of only 8 of 20 patients 1 year or older (40%) had b pathway ganglioside predominance. Predominance of b pathway tumor gangliosides correlated with improved outcome. Event free survival was significantly higher among patients with b pathway ganglioside tumor content greater than 60% versus those with b pathway ganglioside tumor content less than 60% (118.1 +/- 3.9 months vs. 69.2 +/- 8.6 months, P < 0.01). Fetal patterns of ganglioside biosynthesis predominate in neuroblastoma tumors from patients younger than 1 year of age and adult patterns of ganglioside biosynthesis predominate in tumors from older children, supporting the view that neuroblastoma consists of distinct but overlapping disorders, and that gangliosides may play a biologic role in the clinical differences among these patients.

Ferret pyramidal cell dendritogenesis: changes in morphology and ganglioside expression during cortical development.

Pyramidal cell ontogenesis and basilar dendritic differentiation were evaluated concomitantly with ganglioside expression and distribution in ferret cerebral cortex. Layer V neurons began basilar dendritogenesis on postnatal day 1 (P1) with a peak in dendritic arborization occurring at P21. Layer II/III neurons, in contrast, were in early stages of basilar dendritic differentiation at P14, resulting in a complex dendritic arbor at P28. High performance thin-layer chromatography showed numerous changes in ganglioside expression during cortical development, including a decline of GM2 in the mature cortex. The temporal expression and cellular distribution of GM2, GD2, GM1, GD3, and GM3 gangliosides in developing cerebral cortex were determined by immunocytochemistry. GM2 immunoreactivity (IR) was most prominent in layer V neurons between P1 and P21 and in layer II/III neurons between P14 and P28 with staining diminishing to near absent levels in the adult. GM2-IR appeared as punctate structures within the somatodendritic domain and by electron microscopy was shown to be membrane-bound vesicles often in close proximity to the plasmalemma. Expression of GM2, but not of other gangliosides studied, followed two well-documented developmental neurogenic gradients: ventrolateral to dorsomedial and radial (inside-first outside-last). Onset of significant GD2 expression in layer II/III and V pyramidal cells was delayed until P14 and persisted in adult neocortex. GD3 was localized most prominently to glial-like cells, whereas GM1 was primarily localized to white matter. The close temporal and spatial concordance of GM2-IR in cortical pyramidal neurons undergoing dendritogenesis is consistent with its proposed role as a modulator of dendritic differentiation.

N-Butyrate Mediation of Ganglioside Expression of Human and Murine Cancer Cells Demonstrates Relative Cell Specificity

1. n-Butyrate, a short chain fatty acid produced by colonic fermentation, induces differentiation in human neoplastic cell lines, and reduces expression in vitro of a sialyltransferase that glycosylates N-linked glycoproteins in hepatoblastoma cells. Gangliosides are amphipathic, sialylated glycosphingolipids that undergo profound changes in many transformed cells and may protect neoplastic cells from host immune surveillance. Colonic mucosal cells are exposed to luminal short-chain fatty acid concentrations of up to 80 mmol/l, and there is some evidence that short-chain fatty acids may alter ganglioside expression in colon cancer cells. 2. Because of the importance of gangliosides in cancer pathogenesis, we investigated the effects of n-butyrate on ganglioside expression of colonic (human and murine) and non-colonic cancer cells. 3. Three separate colon cancer cell lines (LS174T, T84 and MCA-38), when butyrate treated, demonstrated striking amplification of specific individual gangliosides. However, the total lipid-bound sialic acid content of gangliosides of butyrate-treated LS174T cells diminished. In contrast to earlier reports, n-butyrate did not mediate expression of all gangliosides and specifically did not mediate expression of GM3. This effect persisted even after removal of butyrate. 4. In contrast, exposure of extracolonic cells to butyrate, including cervical cancer (HeLa) and laryngeal cancer (HEp-2) cell lines in this study and hepatoblastoma cells (Hep G2) in our previous work, caused no detectable changes in ganglioside expression. 5. In conclusion, our results indicate a relative tissue specificity of butyrate-mediated alterations in ganglioside expression that is not universal but is limited to specific gangliosides.

The expression of a fucosyl-ganglioside in the molecular layer of the dentate gyrus following entorhinal cortical lesions

α-Galactosyl (α-fucosyl) GM1 is a ganglioside present in the outer two-thirds of the molecular layer of the dentate gyrus of the rat. This region is the terminal zone for afferents from the entorhinal cortex. In order to evaluate changes in ganglioside expression in this region following deafferentation, a monoclonal antibody (WCC4) was used to monitor the ganglioside from 3 to 30 days following a lesion to the entorhinal cortex. From 7 to 14 days postlesion, there was a relative decrease in the width of the band of immunohistochemical staining on the ipsilateral (lesioned) as compared with the contralateral (non-lesioned) side. The results of these studies indicate that α-galactosyl (α-fucosyl) GM1 is likely to be associated with dendritic shafts in the dentate molecular layer.

Induction of NILE/L1 glycoprotein during neuronal differentiation of the embryonal carcinoma cell line EC 1003

Abstract A new clone of the mouse embryonal carcinoma cell line 1003 (EC 1003.16) can be maintained in an undifferentiated state in serum-containing medium. Shifting these cells to serum-free, hormonally defined medium causes them to differentiate morphologically and acquire a number of molecular properties characteristic of neurons. Whereas undifferentiated cells lack the NILE/L1 glycoprotein, expression of this neuronal cell adhesion niolecule is induced in the differentiating cells. Message for NILE/L1 becomes detectable after 5 days in serum-free medium, and cell-surface NILE/L1 can first be seen at this same time. Changes in two other cell adhesion molecules occur in parallel with the induction of NILE/L1. Fibronectin receptor is present on un- differentiated cells, but is down-regulated by the differentiating neurons. The neural cell adhesion molecule (N- CAM) undergoes a shift from the very adhesive adult form to the less adhesive, highly sialylated embryonic form. These changes would appear to emphasize the role of NILE/L1 in adhesive interactions involving differentiating neurons. Some changes in ganglioside expression also occur during EC 1003.16 differentiation. Undifferentiated cells express the D 1.1 ganglioside but lack gangliosides that are reactive with the monoclonal antibody A,B, Differentiating cells lose D 1.1 and become A,B,-positive. Since D 1.1 is characteristic of undifferentiated neuroepithelial cells and A,B, reactivity is a marker for several types of differentiated neurons, these changes in vitro appear to mimic events that occur in vivo.

Regulation of epidermal growth factor receptor signal transduction. Role of gangliosides.

The addition of gangliosides to tissue culture cells causes a decrease in the tyrosine protein kinase activity of the epidermal growth factor (EGF) receptor and an inhibition of EGF-stimulated growth. Based on these data, the hypothesis that the EGF receptor is physiologically regulated by gangliosides has been proposed by E.G. Bremer, J. Schlessinger, and S. Hakomori (J. Biol. Chem. (1986) 261, 2434-2440). To test this hypothesis, a mutant Chinese hamster ovary cell line (clone Idl D) that has a reversible defect in the biosynthesis of gangliosides (Kingsley, D.M., Kozarsky, K. F., Hobbie, L., and Krieger, M. (1986) Cell 44, 749-759) was investigated. The human EGF receptor cDNA was expressed in the mutant cells, and the properties of the EGF receptor were examined using cells grown under permissive and nonpermissive conditions. Changes in ganglioside expression were not observed to cause any significant alterations in the affinity or number of EGF receptors detected at the cell surface. However, decreased levels of ganglioside expression were associated with 1) increased EGF receptor autophosphorylation on tyrosine residues, and 2) increased EGF-stimulated cellular proliferation. The inverse correlation observed between the level of ganglioside expression and signal transduction by the EGF receptor is consistent with the hypothesis that the function of the EGF receptor is physiologically regulated by gangliosides.

Factors Mediating Lipopolysaccharide-Induced Ganglioside Expression in Murine Peritoneal Macrophages

The ganglioside composition of endotoxin-responsive C3H/HeN murine peritoneal macrophages is known to undergo dramatic changes in vivo in response to intraperitoneal lipopolysaccharides (LPS), unlike endotoxin-hyporesponsive C3H/HeJ macrophages. To better investigate the mechanism behind LPS-induced macrophage ganglioside changes, resident C3H/HeN peritoneal macrophages were treated in vitro with 0.1-1.0 micrograms/ml LPS for 6-96 hr, but showed no differences in membrane ganglioside patterns. Coincubation of macrophages with lymphocytes and treating with LPS again elicited no ganglioside changes. In contrast, interferon gamma (IFN-gamma)-primed macrophages showed a dramatic shift in intensity of one ganglioside when treated with LPS in vitro; an additional macrophage ganglioside appeared when IFN-gamma-primed, LPS-treated macrophages were coincubated with lymphocytes. Ganglioside expression induced in vitro still did not approach the complex changes seen in vivo. However, transplanting C3H/HeN macrophages intraperitoneally into C3H/HeJ mice, followed by administration of intraperitoneal LPS, did reveal striking changes in ganglioside expression that resembled the pattern seen in vivo. Thus, LPS alone does not provide the necessary direct signal to promote macrophage ganglioside change even though it alters macrophage function. IFN-gamma appears to be one important mediator; however, complex interactions involving other cytokines or migration of independent populations of mononuclear cells may be required for the full manifestation of LPS-induced ganglioside expression in macrophages.