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Journal of Visualized Experiments : JoVE Mar 2021Gangliosides are glycosphingolipids that contain one or more sialic acid residues. They are found on all vertebrate cells and tissues but are especially abundant in the...
Gangliosides are glycosphingolipids that contain one or more sialic acid residues. They are found on all vertebrate cells and tissues but are especially abundant in the brain. Expressed primarily on the outer leaflet of the plasma membranes of cells, they modulate the activities of cell surface proteins via lateral association, act as receptors in cell-cell interactions and are targets for pathogens and toxins. Genetic dysregulation of ganglioside biosynthesis in humans results in severe congenital nervous system disorders. Because of their amphipathic nature, extraction, purification, and analysis of gangliosides require techniques that have been optimized by many investigators in the 80 years since their discovery. Here, we describe bench-level methods for the extraction, purification, and preliminary qualitative and quantitative analyses of major gangliosides from tissues and cells that can be completed in a few hours. We also describe methods for larger scale isolation and purification of major ganglioside species from brain. Together, these methods provide analytical and preparative scale access to this class of bioactive molecules.
Topics: Animals; Brain; Cell Membrane; Gangliosides; Humans
PubMed: 33779615
DOI: 10.3791/62385 -
International Journal of Molecular... Apr 2020Gangliosidoses are caused by monogenic defects of a specific hydrolase or an ancillary sphingolipid activator protein essential for a specific step in the catabolism of... (Review)
Review
Gangliosidoses are caused by monogenic defects of a specific hydrolase or an ancillary sphingolipid activator protein essential for a specific step in the catabolism of gangliosides. Such defects in lysosomal function cause a primary accumulation of multiple undegradable gangliosides and glycosphingolipids. In reality, however, predominantly small gangliosides also accumulate in many lysosomal diseases as secondary storage material without any known defect in their catabolic pathway. In recent reconstitution experiments, we identified primary storage materials like sphingomyelin, cholesterol, lysosphingolipids, and chondroitin sulfate as strong inhibitors of sphingolipid activator proteins (like GM2 activator protein, saposin A and B), essential for the catabolism of many gangliosides and glycosphingolipids, as well as inhibitors of specific catabolic steps in lysosomal ganglioside catabolism and cholesterol turnover. In particular, they trigger a secondary accumulation of ganglioside GM2, glucosylceramide and cholesterol in Niemann-Pick disease type A and B, and of GM2 and glucosylceramide in Niemann-Pick disease type C. Chondroitin sulfate effectively inhibits GM2 catabolism in mucopolysaccharidoses like Hurler, Hunter, Sanfilippo, and Sly syndrome and causes a secondary neuronal ganglioside GM2 accumulation, triggering neurodegeneration. Secondary ganglioside and lipid accumulation is furthermore known in many more lysosomal storage diseases, so far without known molecular basis.
Topics: Animals; Gangliosides; Humans; Lipid Metabolism; Lysosomal Storage Diseases; Lysosomes; Sphingolipids
PubMed: 32272755
DOI: 10.3390/ijms21072566 -
Cells Mar 2020-acetylation of sialic acid residues is one of the main modifications of gangliosides, and modulates ganglioside functions. -acetylation of gangliosides is dependent on... (Review)
Review
-acetylation of sialic acid residues is one of the main modifications of gangliosides, and modulates ganglioside functions. -acetylation of gangliosides is dependent on sialyl--acetyltransferases and sialyl--acetyl-esterase activities. CAS1 Domain-Containing Protein 1 (CASD1) is the only human sialyl--acetyltransferases (SOAT) described until now. -acetylated ganglioside species are mainly expressed during embryonic development and in the central nervous system in healthy adults, but are re-expressed during cancer development and are considered as markers of cancers of neuroectodermal origin. However, the specific biological roles of -acetylated gangliosides in developing and malignant tissues have not been extensively studied, mostly because of the requirement of specific approaches and tools for sample preparation and analysis. In this review, we summarize our current knowledge of ganglioside biosynthesis and expression in normal and pathological conditions, of ganglioside -acetylation analysis and expression in cancers, and of the possible use of -acetylated gangliosides as targets for cancer immunotherapy.
Topics: Acetylation; Animals; Gangliosides; Humans; Immunotherapy; Molecular Targeted Therapy; N-Acetylneuraminic Acid; Neoplasms
PubMed: 32192217
DOI: 10.3390/cells9030741 -
Progress in Molecular Biology and... 2018An organized series of complicated biological and molecular phenomena is required for normal skin wound healing. These processes depend on normal cellular responses to... (Review)
Review
An organized series of complicated biological and molecular phenomena is required for normal skin wound healing. These processes depend on normal cellular responses to cytokines, growth factors, and other mediators, such as clotting factors, prostaglandins, free radicals, and nitric oxide. In diabetic ulcers, impaired responses to these molecules lead to abnormalities in vascularization, innervation, matrix reconstruction, and reepithelialization of wounds. keratinocyte migration and proliferation on an extracellular matrix is critical in reepithelialization, but the response to growth factors is blunted in diabetes, including the insulin/IGF-1signaling axis. Ganglioside GM3, a sialylated epidermal glycosphingolipid, has been identified as a key mediator of the inhibition of insulin/IGF-1 signaling in response to factors, such as tumor necrosis factor-alpha (TNF-α) and hyperglycemia. Decreased expression of GM3 and the enzyme required for its synthesis, GM3 synthase (GM3S), leads to increased insulin/IGF-1 receptor signaling and accelerated keratinocyte migration, even in the presence of high glucose levels. GM3 depletion in GM3S knockout diabetic mice and diet-induced diabetic mice treated topically with nanoconstruct-mediated GM3S-targeting gene regulation also accelerates wound healing. These recent observations, coupled with evidence that GM3 depletion reverses distal innervation abnormalities in diabetic mice, suggest that GM3-depleting strategies are a promising new approach for human diabetic wounds.
Topics: Animals; Diabetes Mellitus; Gangliosides; Humans; Wound Healing; Wounds and Injuries
PubMed: 29747815
DOI: 10.1016/bs.pmbts.2017.12.006 -
International Journal of Molecular... Sep 2020Gangliosides have been considered to play essential roles in the regulation of nervous systems. Novel findings about their functions based on the unique genetic and...
Gangliosides have been considered to play essential roles in the regulation of nervous systems. Novel findings about their functions based on the unique genetic and biochemical approaches have been recently accumulated, and representative results were collected here. In particular, new developments of analytical methods, regulatory mechanisms for ganglioside synthesis and degradation, and novel aspects of their functions in nervous systems and various other organs were introduced in this Special Issue, promoting further fundamental investigation and applied research.
Topics: Animals; Gangliosides; Glycosphingolipids; Humans; Nervous System
PubMed: 32911611
DOI: 10.3390/ijms21186552 -
FEBS Letters Nov 2020Gangliosides are glycosphingolipids consisting of a ceramide base and a bulky sugar chain that contains one or more sialic acids. This unique structure endows... (Review)
Review
Gangliosides are glycosphingolipids consisting of a ceramide base and a bulky sugar chain that contains one or more sialic acids. This unique structure endows gangliosides with a strong tendency to self-aggregate in solution, as well as in cellular membranes, where they can form nanoscopic assemblies called ganglioside nanodomains. As gangliosides are important biological molecules involved in a number of physiological processes, characterization of their lateral organization in membranes is essential. This review aims at providing comprehensive information about the nanoscale organization of gangliosides in various synthetic models. To this end, the impact of the hydrophobic backbone and the headgroup on the segregation of gangliosides into nanodomains are discussed in detail, as well as the way in which the properties of nanodomains are affected by ligand binding. Small size makes the characterization of ganglioside nanodomains challenging, and we thus highlight the biophysical methods that have advanced this research, such as Monte Carlo Förster resonance energy transfer, atomic force microscopy and approaches based on molecular diffusion.
Topics: Carbohydrate Sequence; Cell Membrane; Fluorescence Resonance Energy Transfer; Gangliosides; Humans; Hydrophobic and Hydrophilic Interactions; Ligands; Lipid Bilayers; Microscopy, Atomic Force
PubMed: 32592178
DOI: 10.1002/1873-3468.13871 -
The Journal of Physical Chemistry. B Apr 2017Gangliosides are glycolipids in which an oligosaccharide headgroup containing one or more sialic acids is connected to a ceramide. Gangliosides reside in the outer...
Gangliosides are glycolipids in which an oligosaccharide headgroup containing one or more sialic acids is connected to a ceramide. Gangliosides reside in the outer leaflet of the plasma membrane and play a crucial role in various physiological processes such as cell signal transduction and neuronal differentiation by modulating structures and functions of membrane proteins. Because the detailed behavior of gangliosides and protein-ganglioside interactions are poorly known, we investigated the interactions between the gangliosides GM1 and GM3 and the proteins aquaporin (AQP1) and WALP23 using equilibrium molecular dynamics simulations and potential of mean force calculations at both coarse-grained (CG) and atomistic levels. In atomistic simulations, on the basis of the GROMOS force field, ganglioside aggregation appears to be a result of the balance between hydrogen bond interactions and steric hindrance of the headgroups. GM3 clusters are slightly larger and more ordered than GM1 clusters due to the smaller headgroup of GM3. The different structures of GM1 and GM3 clusters from atomistic simulations are not observed at the CG level based on the Martini model, implying a difference in driving forces for ganglioside interactions in atomistic and CG simulations. For protein-ganglioside interactions, in the atomistic simulations, GM1 lipids bind to specific sites on the AQP1 surface, whereas they are depleted from WALP23. In the CG simulations, the ganglioside binding sites on the AQP1 surface are similar, but ganglioside aggregation and protein-ganglioside interactions are more prevalent than in the atomistic simulations. Using the polarizable Martini water model, results were closer to the atomistic simulations. Although experimental data for validation is lacking, we proposed modified Martini parameters for gangliosides to more closely mimic the sizes and structures of ganglioside clusters observed at the atomistic level.
Topics: Aquaporins; Gangliosides; Lipids; Molecular Dynamics Simulation; Peptides; Surface Properties
PubMed: 27610460
DOI: 10.1021/acs.jpcb.6b07142 -
Progress in Molecular Biology and... 2018Since the structure of GM1 was elucidated 55years ago, researchers have been attracted by the sialylated glycans of gangliosides. Gangliosides head groups, protruding... (Review)
Review
Since the structure of GM1 was elucidated 55years ago, researchers have been attracted by the sialylated glycans of gangliosides. Gangliosides head groups, protruding toward the extracellular space, significantly contribute to the cell glycocalyx; and in certain cells, such as neurons, are major determinants of the features of the cell surface. Expression of glycosyltransferases involved in the de novo biosynthesis of gangliosides is tightly regulated along cell differentiation and activation, and is regarded as the main metabolic mechanism responsible for the acquisition of cell-specific ganglioside patterns. The resulting sialooligosaccharides are characterized by a high degree of geometrical complexity and by highly dynamic properties, which seem to be functional for complex interactions with other molecules sitting on the same cellular membrane (cis-interactions) or soluble molecules present in the extracellular environment, or molecules associated with the surface of other cells (trans-interactions). There is no doubt that the multifaceted biological functions of gangliosides are largely dependent on oligosaccharide-mediated molecular interactions. However, gangliosides are amphipathic membrane lipids, and their chemicophysical, aggregational, and, consequently, biological properties are dictated by the properties of the monomers as a whole, which are not merely dependent on the structures of their polar head groups. In this chapter, we would like to focus on the peculiar chemicophysical features of gangliosides (in particular, those of the nervous system), that represent an important driving force determining the organization and properties of cellular membranes, and to emphasize the causal connections between altered ganglioside-dependent membrane organization and relevant pathological conditions.
Topics: Animals; Cell Membrane; Gangliosides; Humans; Membrane Microdomains
PubMed: 29747825
DOI: 10.1016/bs.pmbts.2017.12.007 -
International Journal of Molecular... May 2021At the plasma membrane, gangliosides, a group of glycosphingolipids, are expressed along with glycosphingolipids, phospholipids, and cholesterol in so-called lipid rafts... (Review)
Review
At the plasma membrane, gangliosides, a group of glycosphingolipids, are expressed along with glycosphingolipids, phospholipids, and cholesterol in so-called lipid rafts that interact with signaling receptors and related molecules. Most cancers present abnormalities in the intracellular signal transduction system involved in tumor growth, invasion, and metastasis. To date, the roles of gangliosides as regulators of signal transduction have been reported in several cancer types. Gangliosides can be expressed by the exogenous ganglioside addition, with their endogenous expression regulated at the enzymatic level by targeting specific glycosyltransferases. Accordingly, the relationship between changes in the composition of cell surface gangliosides and signal transduction has been investigated by controlling ganglioside expression. In cancer cells, several types of signaling molecules are positively or negatively regulated by ganglioside expression levels, promoting malignant properties. Moreover, antibodies against gangliosides have been shown to possess cytotoxic effects on ganglioside-expressing cancer cells. In the present review, we highlight the involvement of gangliosides in the regulation of cancer cell signaling, and we explore possible therapies targeting ganglioside-expressing cancer.
Topics: Animals; Gangliosides; Glycosyltransferases; Humans; Neoplasms; Signal Transduction
PubMed: 34064863
DOI: 10.3390/ijms22105076 -
FEBS Letters Dec 2018Gangliosides (GGs) are sialic acid-containing glycosphingolipids (GSLs) and major membrane components enriched on cellular surfaces. Biosynthesis of mammalian GGs starts... (Review)
Review
Gangliosides (GGs) are sialic acid-containing glycosphingolipids (GSLs) and major membrane components enriched on cellular surfaces. Biosynthesis of mammalian GGs starts at the cytosolic leaflet of endoplasmic reticulum (ER) membranes with the formation of their hydrophobic ceramide anchors. After intracellular ceramide transfer to Golgi and trans-Golgi network (TGN) membranes, anabolism of GGs, as well as of other GSLs, is catalyzed by membrane-spanning glycosyltransferases (GTs) along the secretory pathway. Combined activity of only a few promiscuous GTs allows for the formation of cell-type-specific glycolipid patterns. Following an exocytotic vesicle flow to the cellular plasma membranes, GGs can be modified by metabolic reactions at or near the cellular surface. For degradation, GGs are endocytosed to reach late endosomes and lysosomes. Whereas membrane-spanning enzymes of the secretory pathway catalyze GSL and GG formation, a cooperation of soluble glycosidases, lipases and lipid-binding cofactors, namely the sphingolipid activator proteins (SAPs), act as the main players of GG and GSL catabolism at intralysosomal luminal vesicles (ILVs).
Topics: Animals; Carbohydrate Sequence; Ceramides; Endoplasmic Reticulum; Gangliosides; Glycosyltransferases; Humans; Lysosomes; Sphingolipid Activator Proteins; trans-Golgi Network
PubMed: 29802621
DOI: 10.1002/1873-3468.13114