• Journal of Animal Reproduction and Biotechnology
• /
• v.35 no.4
• /
• pp.347-356
• /
• 2020

Gangliosides are glycolipids in which oligosaccharide is combined with sialic acids. Our previous studies have suggested an interplay between ganglioside GD1a/GT1b and meiotic maturation capacity in porcine oocyte maturation. Furthermore, ganglioside GD1a and GT1b are known for its antioxidant activity, but it is still unclear whether possible antioxidant role of GD1a and GT1b is involved in porcine embryos development competence during in vitro culture (IVC). Here, the effects of ganglioside GD1a and GT1b on the embryonic developmental competence during in vitro culture of porcine were investigated. The effects of ganglioside GD1a and GT1b on the expression of ST3GAL2 were confirmed during embryos development (2-cell, 4-cell, 8-cell and blastocyst) using immunofluorescent staining (IF). As a result, the fluorescent expression of ST3GAl2 was higher in embryos at 4-8 cells stage than blastocysts. Blastocyst development rate significantly increased in only 0.1 μM GD1a and GT1b treated groups compared with control group. To investigate the cellular apoptosis, we analyzed TUNEL assay. In case of only 0.1 μM GD1a and GT1b treated groups, the total number of cells in blastocyst compared with control group, but there was no significant difference in the rate of apoptotic cells. We identified the intracellular ROS levels using DCF-DA staining. According to the result, ROS production significantly decreased in blastocysts derived from the 0.1 μM GD1a and GT1b treated groups. These results suggest that ganglioside GD1a and GT1b improve the developmental competence of porcine embryos via reduction of intracellular ROS during preimplantation stage.

• Archives of Pharmacal Research
• /
• v.29 no.8
• /
• pp.666-676
• /
• 2006

Gangliosides are widely distributed in mammalian cells and play important roles in various functions such as cell differentiation and growth control. In addition, diabetes and obesity cause abnormal development of reproductive processes in a variety of species. However, the mechanisms underlying these effects, and how they are related, are not fully understood. This study examined whether the differential expression of gangliosides is implicated in the abnormal follicular development and uterine architecture of streptozotocin (STZ)-induced and db/db diabetic mice. Based upon the mobility on high-performance thin-layer chromatography, mouse ovary consisted of at least five different ganglioside components, mainly gangliosides GM3, GM1, GD1a and GT1b, and diabetic ovary exhibited a significant reduction in ganglioside expression with apparent changes in the major gangliosides. A prominent immunofluorescence microscopy showed a dramatic loss of ganglioside GD1a expression in the primary, secondary and Graafian follicles of STZ-induced and db/db diabetic mice. A significant decrease in ganglioside GD3 expression was also observed in the ovary of db/db mice. In the uterus of STZ-induced diabetic mice, expression of gangliosides GD1a and GT1b was obviously reduced, but gangliosides GM1, GM2 and GD3 expression was increased. In contrast, the uterus of db/db mice showed a significant increase in gangliosides GM1, GD1a and GD3 expression. Taken together, a complex pattern of ganglioside expression was seen in the ovary and uterus of normoglycemic ICR and $db/^+$ mice, and the correspoding tissues in diabetic mice are characterized by appreciable changes of the major ganglioside expression. These results suggest that alterations in ganglioside expression caused by diabetes mellitus may be implicated in abnormal ovarian development and uterine structure.

• Journal of Embryo Transfer
• /
• v.32 no.1
• /
• pp.17-24
• /
• 2017

Ganglioside GD1a is specifically formed by the addition of sialic acid to ganglioside GM1a by ST3 ${\beta}$-galactoside ${\alpha}$-2,3-sialyltransferase 2 (ST3GAL2). Above all, GD1a are known to be related with the functional regulation of several growth factor receptors, including activation and dimerization of epidermal growth factor receptor (EGFR) in tumor cells. The activity of EGF and EGFR is known to be a very important factor for meiotic and cytoplasmic maturation during in vitro maturation (IVM) of mammalian oocytes. However, the role of gangliosides GD1a for EGFR-related signaling pathways in porcine oocyte is not yet clearly understood. Here, we investigated that the effect of ST3GAL2 as synthesizing enzyme GD1a for EGFR activation and phosphorylation during meiotic maturation. To investigate the expression of ST3GAL2 according to the EGF treatment (0, 10 and 50 ng/ml), we observed the patterns of ST3GAL2 genes expression by immunofluorescence staining in denuded oocyte (DO) and cumulus cell-oocyte-complex (COC) during IVM process (22 and 44 h), respectively. Expression levels of ST3GAL2 significantly decreased (p<0.01) in an EGF concentration (10 and 50 ng/ml) dependent manner. And fluorescence expression of ST3GAL2 increased (p<0.01) in the matured COCs for 44 h. Under high EGF concentration (50 ng/ml), ST3GAL2 protein levels was decreased (p<0.01), and their shown opposite expression pattern of phosphorylation-EGFR in COCs of 44 h. Phosphorylation of EGFR significantly increased (p<0.01) in matured COCs treated with GD1a for 44 h. In addition, ST3GAL2 protein levels significantly decreased (p<0.01) in GD1a ($10{\mu}M$) treated COCs without reference to EGF pre-treatment. These results suggest that treatment of exogenous ganglioside GD1a may play an important role such as EGF in EGFR-related activation and phosphorylation in porcine oocyte maturation of in vitro.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2004.10a
• /
• pp.81-90
• /
• 2004

Sialic acid containing glycosphingolipids (gangliosides) have been implicated in the regulation of various biological phenomena such as atherosclerosis. Recent report suggeststhat exogenously supplied disialoganglioside (GD3) serves a dual role in vascular smooth muscle cells (VSMC) proliferation and apoptosis. However, the role of the GD3 synthase gene in VSMC responses has not yet been elucidated. To determine whether a ganglioside is able to modulate VSMC growth. the effect of overexpression of the GD3 synthase gene on DNA synthesis was examined. The results show that the overexpression of this gene has a potent inhibitory effect on DNA synthesis and ERK phosphorylation in cultured VSMC in the presence of PDGF. The suppression of the GD3 synthase gene was correlated with the down-regulation of cyclinE/CDK2. the up-regulation of the CDK inhibitor p21 and blocking of the p27 inhibition,whereas up-regulation of p53 as the result of GD3 synthase gene expression was not observed. Consistently, blockade of GD3 function with anti-GD3 antibody reversed VSMC proliferation and cell cycle proteins. The expression of the CD3 synthase gene also led to the inhibition of TNF--induced matrix metalloproteinase-9 (MMP-9) expression in VSMC as determined by zymography and immunoblot. Furthermore, GD3 synthase gene expression strongly decreased MMP-9 promoteractivlty in response to TNF-. This inhibition was characterized by the down-regulation of MMP-9,which was Iranscriptionally regulated at NF-B and activation protein-1 (AP-1) sites in the MMP-9promoter Finally, the overexpression of MMP-9 in GD3 synthase transfectant cells rescued VSMC proliferation. However MMP-2 overexpression was not affected the cell proliferation. These findings suggest that the fl13 synthase gene represents a physiological modulator of VSMC responses that may contribute to plaque instability in atherosclerosis.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.4
• /
• pp.722-727
• /
• 2005

Cytosolic sialidase (Neu2), a member of the sialidase family that is responsible for hydrolysis of sialic acid from the terminal position of sialoglycoconjugates, is poorly expressed in skeletal muscle and not detected in any other adult tissues. Thus, we isolated Neu2 cDNA using splicing by overlap extension (SOEing). In order to further characterize this enzyme, a His-tagged derivative was expressed in the bacterial expression system and purified by $Ni^{2+}$-affinity chromatography. A recombinant product of approximately 42 kDa had sialidase activity toward 4-methyl-umbelliferyl-$\alpha$-D-N-acetylneuraminic acid (4MU-NeuAc). The optimal pH and temperature of the recombinant Neu2 for 4MU-NeuAc was 6.0 and $37.5^{\circ}C$, respectively. The metal ions, such as $Cu^{2+}\;and\;Cd^{2+}$, showed strong inhibitory effect on the activity of the enzyme. The enzyme efficiently hydrolyzed the gangliosides GM3 and GD3 and had relatively low activities on ganglioside GD1a and GD1b, $\alpha$2-3 sialyllactose, and sialylated glycoproteins such as fetuin, transferrin, and orsomucoid, but had hardly any activities on $\alpha$2-6 sialyllactose and ganglioside GM1 and GM2. We concluded that the recombinant Neu2 has a sialidase activity toward glycoproteins as well as gangliosides.

• Development and Reproduction
• /
• v.2 no.2
• /
• pp.149-155
• /
• 1998

The polysialic acid (polySia) glycotope covalently modifies cell surface glycoconjugates on cells as evolutionarily diverse as microbes and human. The recent chemical identification of polysialylated glycoproteins in the jelly coat and on the cell surface of the sea urchin egg raises important questions about their biosynthesis and possible function. Using CMP-[$^{14}$ C]Neu5Ac as substrate and cell free preparations from eggs and embryos of the sea urchin Stronglylcentrotus nudus, we have identified a membrane associated CMP-Neu5Ac:poly-$\alpha$2, 8 sialosyl sialyltransferase (polyST) that transfers Neu5Ac to an endogenous acceptor. Optimal conditions for the polyST activity were found to be 2$0^{\circ}C$ in 20 mM MOPS buffer (pH 7.0). The polyST activity was increased 2.7 times by the addition of 10 mM $Mg^2$$^{+}$. The membrane-associated polyST also catalyzed the polysialylation of mammalian ganglioside GD3. Given that no structurally similar natural polysialylated gangliosides have been described, nor were observed in the present study, we conclude that a single polyST activity catalyzes sialylation of the endogenous acceptor and the gangliosides. Using an excess of GD3 as an exogenous acceptor, it was established that the expression of the polyST in S. nudus embryos increased rapidly at the mesenchyme blastula stage and reached at maximum at the gastrula stage. The finding that this polyST in the sea urchin embryo is developmentally regulated raises the possibility that it may play a role in the changing cell and tissue interactions that occur during gastrulation and the early stages of spicule formation.n.

• Clinical and Experimental Pediatrics
• /
• v.53 no.4
• /
• pp.607-611
• /
• 2010

Bickerstaff's brainstem encephalitis (BBE) is a rare disease diagnosed by specific clinical features such as 'progressive, relatively symmetric external ophthalmoplegia and ataxia by 4 weeks' and 'disturbance of consciousness or hyperreflexia' after the exclusion of other diseases involving the brain stem. Anti-ganglioside antibodies (GM, GD and GQ) in the serum or cerebrospinal fluid (CSF) are sometimes informative for the diagnosis of BBE because of the rarity of positive findings in other diagnositic methods: brain magnetic resonance imaging (MRI), routine CSF examination, motor nerve conduction study, and needle electromyography. We report a rare case of childhood BBE with elevated anti-GM1 antibodies in the serum, who had specific clinical symptoms such as a cranial polyneuropathy presenting as ophthalmoplegia, dysarthria, dysphagia, and facial weakness; progressive motor weakness; altered mental status; and ataxia. However, the brain MRI, routine CSF examination, nerve conduction studies, electromyography, somatosensory evoked potentials, and brainstem auditory evoked potentials were normal. BBE was suspected and the patient was successfully treated with intravenous immunoglobulins.

• Journal of Life Science
• /
• v.20 no.4
• /
• pp.467-473
• /
• 2010

Gangliosides are a major component of the plasma membrane of mammalian cells, which are directly involved in a variety of immunological events, including cell-to cell or cell-to-protein interactions. In this study, we investigated whether gangliosides, sialic acid-containing glycosphingolipids, are related to rejection during the xenotransplantation of NIH-miniature pig livers and hearts to humans. Both high performance thin-layer chromatography and immunohistochemistry analyses revealed that the expression of gangliosides in the liver tissue of NIH-miniature pigs was higher than that in the heart. Gangliosides GD3, GD1a, GD1b, GT1b and GQ1b were observed in both the liver and heart, whereas GQ1b was detected only in the liver, indicating that the ganglioside expression profiles are tissue specific. Moreover, other ganglio-series gangliosides, including GM3, were not detected in the livers and hearts of NIH-miniature pigs. Taken together, these results suggest that gangliosides may play important roles in immune responses in clinical xenotransplants of pig livers and hearts.

• Food Science of Animal Resources
• /
• v.40 no.2
• /
• pp.209-220
• /
• 2020

Milk fat globule membrane (MFGM) is a lipid carrier in mammals including humans that consists mainly of polar lipids, like phospholipids and glycolipids. In this study, a process to enrich polar lipids in commercial butter and whey powder, including polar lipids of MFGM, was developed. WPC (whey protein concentrate) 60 was selected as the most suitable raw material based on the yield, phospholipid, protein, and lactose content of the polar lipid fraction obtained by ethanol extraction of two WPC (WPC60 and WPC70) and two buttermilk (A and B). After fractionation under optimum conditions, the polar-lipid enriched fraction from WPC60 contained 38.56% phospholipids. The content of glycolipids, cerebroside, lactosylceramide, ganglioside GM3, ganglioside GD3, was 0.97%, 0.55%, 0.09%, and 0.14%, respectively. Rancimat results showed that the oxidation stability of fish oil increased with an increase in the polar-lipid fraction by more than 30 times. In addition, the secretion of IL-6 and TNF-α decreased in a concentration-dependent manner after treatment of RAW 264.7 cells with 0.1 to 100 ppm of the polar lipid fraction. In this study, polar lipid concentrates with antioxidant and anti-inflammatory activity, were prepared from milk processing by-products. The MFGM polar lipid concentrates made from by-products are not only additives for infants, but are also likely to be used as antioxidants in cooking oils and as active ingredients for functional foods.