Total Ganglioside Research Articles

Identification of tumor-marker gangliosides for early cancer detection: A multi-platform approach.

e17551 Background: Tumor-marker gangliosides (TMGs) have enormous potential for early-stage cancer detection as diagnostic biomarkers despite being relatively understudied in this context. AOA Dx is focused on the analytical development of three separate platforms for the quantitation of TMGs in human serum. The development of these platforms for TMG quantitation may allow for the identification of diagnostic signatures for early-stage cancer detection. Methods: First, we are developing a pipeline of antibody-based assays to target TMGs. To aid in development of multiple immunoassays, we collected specificity and affinity data on commercial and proprietary antibodies targeting TMGs using glycoarrays. We are also currently using two immune-based platforms to target TMGs. We have developed an enzyme-linked immunosorbent assay (ELISA) and we have implemented high-performance thin-layer chromatography (HPTLC) to detect individual and total gangliosides. Additionally, we are applying both targeted and untargeted mass spectrometry to human serum from confirmed cancer diagnoses. Results: The specificity and affinity data from the glycoarrays confirm that our TMG antibodies have negligible cross-reactivity and are suitable for diagnostic platform development. Additionally, our developed ELISA allows for the quantification of TMGs in diverse and complex matrices including human serum and plasma, cell lines, and exosomes. HPTLC also detects individual and total gangliosides in each of these matrices, which allows for high-throughput analysis for TMG quantitation. Finally, the application of both targeted and untargeted mass spectrometry has identified multiple TMGs characterized by unique lipid tails. Notably, MS analysis shows that the serum of melanoma and ovarian cancer patients exhibited significantly increased levels of several ganglioside species compared to age-matched healthy serum, further highlighting the potential of TMGs as a promising avenue for cancer diagnosis. Further experiments will focus on refining all platforms. We will also expand the demographic representation of our human serum sample cohort to confirm the initial findings from our mass spectrometry experiments and continue to use this platform to identify additional TMGs of interest. Conclusions: AOA Dx is advancing the development of a multi-platform approach for the detection of TMGs. Our objective is the identification of a diagnostic disease signature for early-stage cancer detection. The validation of this type of diagnostic panel would allow for expedited diagnosis and treatment of cancers currently diagnosed at late stages, ultimately reducing healthcare costs and increasing survival rates. Future research will aim to validate these biomarkers in independent prospective studies.

The Effect of Intranasal Administration of Gangliosides on the Viability of CA1 Hippocampal Neurons in Rat Two-Vessel Occlusion Model of Forebrain Ischemia/Reperfusion Injury.

Intranasal administration of total bovine brain gangliosides (6 mg/kg) to rats protected the CA1 hippocampal neurons from the death caused by two-vessel occlusion model (with hypotension) of forebrain ischemia/reperfusion injury. The immunohistochemical reaction of specific antibodies to marker proteins of activated microglia (Iba1) and astrocytes (GFAP) in hippocampal slices revealed the neuroprotective effect of exogenous gangliosides which can be mostly explained by their ability to suppress neuroinflammation and gliosis. The expression of neurotrophic factor BDNF in the CA1 region of hippocampus did not differ in sham-operated rats and animals exposed to ischemia/reperfusion. However, the administration of gangliosides increased the BDNF expression in both control and ischemic groups. The intranasal route of administration allows using lower concentrations of gangliosides preventing the death of hippocampal neurons.

Preparation of milk fat globule membrane ingredients enriched in polar lipids: Composition characterization and digestive properties

In this study, milk fat globule membrane (MFGM) ingredients enriched in polar lipids was prepared using membrane filtration, including microfiltration, diafiltration, and ultrafiltration from butter serum powder. Polar lipids (phospholipids, sterols, and gangliosides) in prepared MFGM ingredients were analyzed by 31P NMR, GC-MS, and UPLC-MS/MS, respectively. The lipolysis degree and microstructure of MFGM ingredient and soybean lecithin-emulsification during in vitro digestion were also analyzed. Microfiltration showed higher concentration efficiency than ultrafiltration which increased 2.16% and 2.73% in phospholipid, respectively. Moreover, diafiltration concentrated more polar lipids (6.39% of phospholipid) than microfiltration. MFGM ingredients had high level of sphingomyelin (1.27-1.36%) and ration of GD3 than GM3 of 9.25-9.88-fold of total gangliosides. The different lipolysis behavior between MFGM ingredient-emulsification and soybean lecithin-emulsification were correlated with their different polar lipid compositions. Phospholipids from both MFGM ingredients and soybean lecithin could help maintain the initial structure during the gastric digestion. These results could provide a scientific basic for developing high-polar lipids food, particularly infant formulas and special functional foods.

Supplementation with milk enriched with complex lipids during pregnancy: A double-blind randomized controlled trial.

BackgroundGangliosides are a class of sphingolipids that are present in the cell membranes of vertebrates. Gangliosides influence a broad range of cellular processes through effects on signal transduction, being found abundantly in the brain, and having a role in neurodevelopment.ObjectiveWe aimed to assess the effects of maternal daily consumption of ganglioside-enriched milk vs non-enriched milk and a non-supplemented group of pregnant women on maternal ganglioside levels and pregnancy outcomes.DesignDouble-blind parallel randomized controlled trial.Methods1,500 women aged 20–40 years were recruited in Chongqing (China) between 11 and 14 weeks of a singleton pregnancy, and randomized into three groups: Control–received standard powdered milk formulation (≥4 mg gangliosides/day); Complex milk lipid-enhanced (CML-E) group–same formulation enriched with complex milk lipids (≥8 mg gangliosides/day) from milk fat globule membrane; Reference–received no milk. Serum ganglioside levels were measured in a randomly selected subsample of 250 women per group.ResultsCML-E milk was associated with marginally greater total gangliosides levels in maternal serum compared to Control (13.02 vs 12.69 μg/ml; p = 0.034) but not to Reference group. CML-E milk did not affect cord blood ganglioside levels. Among the 1500 women, CML-E milk consumption was associated with a lower rate of gestational diabetes mellitus than control milk [relative risk 0.80 (95% CI 0.64, 0.99)], but which was not different to the Reference group. CML-E milk supplementation had no other effects on maternal or newborn health.ConclusionsMaternal supplementation with milk fat globule membrane, as a source of gangliosides, was not associated with any adverse health outcomes, and did not increase serum gangliosides compared with the non-supplemented reference group.Trial registrationChinese Clinical Trial Register (ChiCTR-IOR-16007700).Clinical trial registrationChiCTR-IOR-16007700; www.chictr.org.cn/showprojen.aspx?proj=12972.

Characterization of Acidic Glycosphingolipid Changes in C6 Glioma Rats Treated With Temozolomide Using Ultra-High-Performance Liquid Chromatography Coupled With Quadrupole Time-of-Flight Mass Spectrometry

Ganglioside and sulfatide are primary components of acidic glycosphingolipids (AGSLs), which are abundant in the brain tissue. AGSLs are potential tumor markers. In this paper, we use ultra-high performance liquid chromatography–quadrupole time-of-flight mass spectrometry to generate a first-ever comprehensive profile of AGSLs in brain and plasma of C6 glioma rats treated with temozolomide (TMZ). The AGSLs detected consisted mainly of C18-/C20-sphingosine. 12, 20, 19, 14 and 12 species were identified in GM1, GD1a, GD1b, GM3 and GT1b ganglioside groups which were abundant in rat brain, respectively. These five groups accounted for 88–89% of total ganglioside content. However, no AGSLs were detected in rat plasma. Possible biomarkers for abnormal changes in the glioma model and the protective effect of TMZ were mainly found in these ganglioside groups and sulfatide. The main lipid component of central and peripheral nervous system myelin sheathes is sulfatide, which is upregulated in many tumors. Antitumor properties of TMZ are due to modulation of sulfatide levels in tumor tissues.

Dietary Intake of Gangliosides and Correlation with Serum Ganglioside Concentration: Cross-Sectional Study among Chinese Toddlers Aged 24-48 Months

Gangliosides are a group of sialic-acid-containing sphingolipids, found in brain and neural tissues. The various biological roles of gangliosides have been well reported and include calcium homeostasis, regulation of neurons, neural repair, immune system functions, and cellular functions. Furthermore, dietary gangliosides have been shown to improve cognitive development in the early postnatal period and to increase brain neuroplasticity. However, the dietary intake status of gangliosides among Chinese toddlers is unknown. The aim of this study was to determine the dietary intake and food source of gangliosides among Chinese toddlers and to probe its correlation with serum ganglioside concentration. Total of 213 Chinese toddlers aged 24-48 months were enrolled in this cross-sectional study in Beijing and Xuchang City, China. A food frequency questionnaire and 24-h dietary recall methods were used to collect both long- and short-term dietary information. Food items selected from dietary records and blood serum samples collected from 197 toddlers were analyzed for ganglioside composition using high performance liquid chromatography‒mass spectrometry. The average dietary total ganglioside intake among the Chinese toddlers was 4.21 mg/day. Dairy products, meats, and growing-up milk powders were the predominant food sources of dietary gangliosides with relative proportions of 38, 31, and 29% of the daily dietary total ganglioside intake, respectively. The average serum total ganglioside concentration was 14.86 μg/mL, with GM3 making up 96%. No significant correlation was found between the dietary total ganglioside intake and the serum total ganglioside concentration. As this correlation was inconclusive, further investigation is required to understand ganglioside metabolism and the mechanisms contributing to the role of gangliosides in the growth and cognitive development of toddlers.

Dietary Ganglioside Intake and Serum Ganglioside Concentration among Indonesian Toddlers

Gangliosides are major components in the human brain. The incorporation of gangliosides into the developing human brain is rapid, increasing from the third trimester through to the first 4-5 years of life, coinciding with the neuronal and glial differentiation and maturation process. It is generally accepted that breast-fed infants consume higher levels of gangliosides than formula-fed infants. However, the dietary ganglioside intake status at the toddler age period is unclear, given that toddlers are still going through a rapid growth and learning phase. The aim of this study was to provide an understanding of the dietary ganglioside sources and intakes for a cross-section of Indonesian toddlers and to determine any correlation with their serum ganglioside concentrations. Toddlers (150) were recruited from the Pejaten, South Jakarta, region. The dietary ganglioside intake was determined from food intake data collected over 2 days using a food frequency questionnaire. The ganglioside levels in the food and the blood were determined using a high performance liquid chromatography-mass spectrometry method. The average dietary ganglioside intake and the serum ganglioside content of Indonesian toddlers were 6.13 ± 0.56 mg/day and 13.2 ± 3.3 mg/L respectively. Growing-up milk powders contributed 71.8% of the daily total ganglioside intake, and major dietary ganglioside contributor. [1] No positive correlation was observed between the dietary ganglioside intake and the serum ganglioside concentration over the 2-day study period. Long term dietary and intervention studies are required to provide a clearer picture of the impact of dietary gangliosides on serum ganglioside levels.

Ovarian Function Modulates the Effects of Long-Chain Polyunsaturated Fatty Acids on the Mouse Cerebral Cortex.

Different dietary ratios of n−6/n−3 long-chain polyunsaturated fatty acids (LC-PUFAs) may alter brain lipid profile, neural activity, and brain cognitive function. To determine whether ovarian hormones influence the effect of diet on the brain, ovariectomized and sham-operated mice continuously treated with placebo or estradiol were fed for 3 months with diets containing low or high n−6/n−3 LC-PUFA ratios. The fatty acid (FA) profile and expression of key neuronal proteins were analyzed in the cerebral cortex, with intact female mice on standard diet serving as internal controls of brain lipidome composition. Diets containing different concentrations of LC-PUFAs greatly modified total FAs, sphingolipids, and gangliosides in the cerebral cortex. Some of these changes were dependent on ovarian hormones, as they were not detected in ovariectomized animals, and in the case of complex lipids, the effect of ovariectomy was partially or totally reversed by continuous administration of estradiol. However, even though differential dietary LC-PUFA content modified the expression of neuronal proteins such as synapsin and its phosphorylation level, PSD-95, amyloid precursor protein (APP), or glial proteins such as glial fibrillary acidic protein (GFAP), an effect also dependent on the presence of the ovary, chronic estradiol treatment was unable to revert the dietary effects on brain cortex synaptic proteins. These results suggest that, in addition to stable estradiol levels, other ovarian hormones such as progesterone and/or cyclic ovarian secretory activity could play a physiological role in the modulation of dietary LC-PUFAs on the cerebral cortex, which may have clinical implications for post-menopausal women on diets enriched with different proportions of n−3 and n−6 LC-PUFAs.

Isobaric Labeling of Intact Gangliosides toward Multiplexed LC-MS/MS-Based Quantitative Analysis.

Gangliosides are sialic acid-containing glycosphingolipids recognized to play essential role in biological processes. Both the glycan and lipid structures influence their biological function and thus necessitate their determination as intact molecular species. To our knowledge, no multiplexed method for intact gangliosides currently exists. In this paper, we aimed to demonstrate an approach for isobaric labeling of intact gangliosides. Specifically, we carried out the rapid, chemoselective oxidation of sialic acid side chain in common ganglioside core structures using NaIO4 followed by ligation with a carbonyl-reactive isobaric tandem mass tag (TMT) reagent and subsequent RPLC-MS/MS analysis. Attachment of the isobaric label was observed to improve the ionization efficiency of complex gangliosides using electrospray ionization. Fragmentation of the resulting [M + 2H]2+ ions of TMT-labeled gangliosides provided information-rich spectra containing fragments from the glycan, lipid, and TMT reporter ions. This facile approach enabled simultaneous quantification of up to six samples as well as identification of glycan and lipid compositions in a single injection. As a proof-of-concept, using porcine brain total ganglioside extracts pooled at known ratios, we obtained overall sample-to-sample precision of <12% RSD and mean error of <10%. This showcased the great promise and feasibility of this strategy for high-throughput analysis of intact gangliosides in biological extracts.

Sex-Related Abnormalities in Substantia Nigra Lipids in Parkinson's Disease.

Parkinson’s disease (PD) is a neurodegenerative movement disorder involving the selective loss of dopamine-producing neurons in the substantia nigra (SN). Differences in disease presentation, prevalence, and age of onset have been reported between males and females with PD. The content and composition of the major glycosphingolipids, phospholipids, and cholesterol were evaluated in the SN from 12 PD subjects and in 18 age-matched, neurologically normal controls. Total SN ganglioside sialic acid content and water content (%) were significantly lower in the male PD subjects than in the male controls. The content of all major gangliosides were reduced in the male PD subjects to some degree, but the neuronal-enriched gangliosides, GD1a and GT1b, were most significantly reduced. The distribution of phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol was also significantly lower in the male PD subjects than in the male controls. However, the distribution of myelin-enriched cerebrosides and sulfatides was significantly higher in the male PD subjects than in the male controls suggesting myelin sparing in the male PD subjects. No elevation was detected for astrocytosis-linked GD3. These neurochemical changes provide evidence of selective neuronal loss in SN of the males with PD without robust astrocytosis. In contrast to the SN lipid abnormalities found in the male PD subjects, no significant abnormalities were found in the female PD subjects for SN water content or for any major SN lipids. These data indicate sex-related differences in SN lipid abnormalities in PD.

Ouabain attenuates the oxidative stress induced by lipopolysaccharides in the cerebellum of rats.

Our study aimed to analyze the effect of ouabain administration on lipopolysaccharide (LPS)-induced changes in oxidative parameters, membrane lipid composition, and the activities of some important enzymes of the nervous system. The content of phospholipids, cholesterol, and gangliosides were analyzed in Wistar rats after intraperitoneal injection of ouabain (1.8 μg/kg), LPS (200 μg/kg), or saline. Oxidative parameters were also evaluated, including the activities of superoxide dismutase, catalase and glutathione peroxidase, the levels of glutathione and lipid peroxidation, as well as Na,K-ATPase activity and the level of glutamate transporter EAAT4. Administration of LPS resulted in increased oxidative stress, as evidenced by an increase in lipid peroxidation levels, glutathione peroxidase activity, decreased catalase activity and reduced glutathione levels. All changes recorded were attenuated by pretreatment with ouabain. Administration of ouabain plus LPS enhanced the total ganglioside content and EAAT4 levels, but failed to alter the Na,K-ATPase activity. Our data suggest a neuroprotective effect of ouabain against LPS-induced oxidative stress by promoting membrane lipid remodeling and increasing the expression of glutamate transporter EAAT4. Our results emphasize that the observed oxidative stress is not correlated with Na,K-ATPase, but with a possible ouabain-mediated effect on cellular signaling. The relevance of our results extends beyond LPS-induced changes in oxidative parameters, as nanomolar doses of ouabain might prove useful in neurodegenerative models. Further study of other cardenolides and related molecules, as well as the development of new molecules derived from ouabain, could also prove useful in the fight against the oxidative and/or general cell stress triggered by neuronal pathologies.

Muscle Sympathetic Nerve Activity Is Associated With Elements of the Plasma Lipidomic Profile in Young Asian Adults.

Asian subjects are at increased cardio-metabolic risk at comparatively lower body mass index (BMI) compared with white subjects. Sympathetic nervous system activation and dyslipidemia, both characteristics of increased adiposity, appear to be related. We therefore analyzed the association of muscle sympathetic nerve activity (MSNA) with the plasma lipidomic profile in young adult Asian and white subjects. Blood samples were collected from 101 participants of either Asian or white background (age, 18 to 30 years; BMI, 28.1 ± 5.9 kg/m2). Lipids were extracted from plasma and analyzed using electrospray ionization-tandem mass spectrometry. MSNA was quantified using microneurography. The association of MSNA and obesity with lipid species was examined using linear regression analysis. The plasma concentrations of total dihydroceramide, ceramide, GM3 ganglioside, lysoalkylphosphatidylcholine, alkenylphosphatidylethanolamine, and lysophosphatidylinositol were elevated in the Asian subjects relative to the white subjects. After adjustment for confounders, diacylglycerols and triacylglycerols, cholesterol esters, phosphatidylinositols, phosphatidylethanolamines, and phosphatidylglycerols bore significant associations with MSNA but only in the Asian subjects. These associations remained significant after further adjustment for the participants' degree of insulin resistance and appeared not to be related to differences in diet macronutrient content between groups. The lipidomic profile differs between Asian and white subjects. There exists a strong relationship between certain lipid species and MSNA. The association is stronger in Asian subjects, despite their lower BMI. This study demonstrates an association between circulating lipids and central sympathetic outflow. Whether the stronger association between the lipid profile and sympathetic activation underpins the apparent greater risk posed by increased adiposity in Asian individuals merits further attention.

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.

Disialyl GD2 ganglioside suppresses ICAM-1-mediated invasiveness in human breast cancer MDA-MB231 cells

The disialoganglioside GD3 has been considered to be involved in tumor progression or suppression in various tumor cells. However, the significance of the biological functions of GD3 in breast cancer cells is still controversial. This prompted us to study the possible relationship(s) between GD3 expression and the metastatic potential of a breast cancer MDA-MB231 cells as an estrogen receptor negative (ER-) type. The human GD3 synthase cDNA was transfected into MDA-MB231 cells, and G-418 bulk selection was used to select cells stably overexpressing the GD3 synthase. In vitro invasion potentials of the GD3 synthase over-expressing cells (pc3-GD3s) were significantly suppressed when compared with control cells. Expression of intercellular adhesion molecule-1 (ICAM-1; CD54) was down-regulated in the pc3-GD3s cells and the decrease in ICAM-I expression is directly related to the decrease in invasiveness of the pc3-GD3s cells. Another type of ER negative SK-BR3 cells exhibited the similar level of ICAM-1 expression as MDA-MB231 cells, while the ER positive MCF-7 cells (ER+) showed the increased expression level of ICAM-1. Then, we investigated signaling pathways known to control ICAM-1 expression. No difference was observed in the phosphorylation of ERK and p38 between the pc3-GD3s and control cells (pc3), but the activation of AKT was inhibited in pc3-GD3s, and not in the control (pc3). In addition, the composition of total gangliosides was changed between control (pc3) and pc3-GD3s cells, as confirmed by HPTLC. The pc3-GD3s cells had an accumulation of the GD2 instead of the GD3. RT-PCR results showed that not only GD3 synthase, but also GM2/GD2 synthase (β4-GalNc T) expression was increased in pc3-GD3s cells. Overexpression of GD3 synthase suppresses the invasive potential of human breast cancer MDA-MB-231 cells through down-regulation of ICAM-1 and the crucial pathway to allow the apoptotic effect has been attributed to accumulation of the GD2 ganglioside. ER has been linked to the ICAM-1 expression with GD3 to GD2 conversion in human breast cancer cells. This is the first finding of the endogenous sialyltransferase functions in tumor cells.

Correlation between dietary intake and serum ganglioside concentrations: a cross-sectional study among Malaysian toddlers

Gangliosides are a group of sialylglycosphingolipids, widely distributed in body tissues, mainly as components of plasma membranes. They play crucial roles in neurodevelopment, gut maturation, and immune system. Dietary gangliosides have been shown to bring about benefits including cognition and immune support for breastfed infants. There is dearth of studies on dietary gangliosides intake or plasma ganglioside levels for toddlers. Given toddlers are still growing rapidly, a good understanding of ganglioside intake during this early childhood period is important for future dietary recommendations. The aim of this study was to provide information on dietary ganglioside intake in Malaysian toddlers and correlations with serum ganglioside levels. Toddlers who fulfilled the inclusion criteria were recruited from the Federal Territory of Putrajaya and neighboring urban suburbs. Background characteristics and food intake using food frequency questionnaire were collected for the entire sample (n = 153). As for ganglioside correlation determination, a 2 day weighed food record was conducted on a sub-group who provided blood (n = 74). Ganglioside levels in the food and blood were determined using modern high performance liquid chromatography mass spectrometry method. The average dietary intake of total gangliosides for the Malaysian toddlers (aged 12–24.5 months) was 5.86 ± 0.56 mg/day. Growing up milks had a wide ganglioside concentration range (0.03 11.4 mg/100 g), and were the major contributor to dietary ganglioside intake (85%). The remaining dietary gangliosides were provided by other dairy products, meat, fish, bakery and biscuits. Serum levels varied from 5.05 μg/mL to 16.15 μg/mL. While no significant correlation was observed between dietary ganglioside intake from growing up milks and serum ganglioside levels in the toddlers, there was a significant but weak correlation between dietary ganglioside intake from dairy products (r = 0.241; p = 0.038) and meat (r = 0.294; p = 0.010) with serum ganglioside levels Gangliosides are a component of the Malaysian toddlers’ diet (5.68 ± 0.56 mg/day), and were measured in their plasma at levels ranging from 5.05 to 16.15 μg/mL. Growing up milk contributed to 85% of the total dietary gangliosides intake, with remaining contributions from chicken meat and fish. More studies should be undertaken on the contributions of dietary gangliosides, including breast milk, in bringing about health benefits to young children.

Gangliosides in dairy products: Milk sphingolipids

Milk gangliosides have gained considerable attention because they participate in diverse biological processes, including neural development, pathogen binding, and activation of the immune system. The aim of this study was to determine the concentrations of total gangliosides in dairy products and to determine whether there is a significant difference in comparison to concentration of gangliosides in cow’s milk. The concentration of total gangliosides in dairy products was significantly higher than concentration in cow’s milk. The highest concentration of gangliosides was determined in yogurt with 3.2% of milk fat.

Temporal Changes of Human Breast Milk Lipids of Chinese Mothers.

Fatty acids (FA), phospholipids (PL), and gangliosides (GD) play a central role in infant growth, immune and inflammatory responses. The aim of this study was to determine FA, PL, and GD compositional changes in human milk (HM) during lactation in a large group of Chinese lactating mothers (540 volunteers) residing in Beijing, Guangzhou, and Suzhou. HM samples were collected after full expression from one breast and while the baby was fed on the other breast. FA were assessed by direct methylation followed by gas chromatography (GC) analysis. PL and GD were extracted using chloroform and methanol. A methodology employing liquid chromatography coupled with an evaporative light scattering detector (ELSD) and with time of flight (TOF) mass spectrometry was used to quantify PL and GD classes in HM, respectively. Saturated FA (SFA), mono-unsaturated FA (MUFA), and PL content decreased during lactation, while polyunsaturated FA (PUFA) and GD content increased. Among different cities, over the lactation time, HM from Beijing showed the highest SFA content, HM from Guangzhou the highest MUFA content and HM from Suzhou the highest n-3PUFA content. The highest total PL and GD contents were observed in HM from Suzhou. In order to investigate the influence of the diet on maternal milk composition, a careful analyses of dietary habits of these population needs to be performed in the future.

Isotopic labeling of milk disialogangliosides (GD3)

The most abundant ganglioside group in both human milk and bovine milk during the first postnatal week is ganglioside GD3. This group of disialogangliosides forms up to 80% of the total ganglioside content of colostrum. Although dietary gangliosides have shown biological activity such as improvement of cognitive development, gastrointestinal health, and immune function, there is still a gap in our understanding of the molecular mechanisms governing its uptake and the metabolic processes affecting its bioavailability. The use of isotopically labeled ganglioside to track the bioavailability, absorption, distribution, and metabolism of gangliosides may provide key information to bridge this gap. However, isotope labeledGD3 is not commercially available and its preparation has not been described. We report for the first time the preparation of labeled GD3 with stable isotopes. Using alkaline hydrolysis, we were able to selectively remove both acetyl groups from the tetrasaccharide portion of GD3 without promoting significant hydrolysis of the ceramide portion of the molecule to generate N-deacetyl-GD3 (Neu5α2-8Neu5-GD3). The N-deacetyl-GD3 was then chemoselectively re-acetylated in aqueous medium using deuterated acetic anhydride in the presence of Triton X 100 to produce 2H6-GD3 {GD3[(Neu5Ac-11-2H3)-(Neu5Ac-11-2H3)]}. This method provided 2H6-GD3 with approximately 60% yield. This compound was characterized by proton nuclear magnetic resonance (1H NMR) and liquid chromatography mass spectrometry (LC–MS). The oral absorption of the 2H6-GD3 was demonstrated using a Sprague-Dawley weaning rats. Our results indicate that some ingested labeled milk gangliosides are absorbed and transported into the bloodstream without modification.

Enhanced expression of unique gangliosides with GM2-determinant in human uterine cervical carcinoma-derived cell lines

Monoclonal antibody YHD-06 generated by immunization with GM2 reacted with gangliosides with GM2-determinant, i.e., GM2, GalNAc-GM1b and GalNAc-GD1a, among which GalNAc-GD1a was characterized as an antigen of autoimmune peripheral neuropathies including Guillain-Barré syndrome. When glycolipids were examined by TLC-immunostaining with YHD-06 in seven human cervical carcinoma-derived cell lines, GM2 was found in all cell lines, amounting to 15.5% to 57.5% of total gangliosides. Whereas GalNAc-GD1a was present in three cell lines, amounting to 5.4-17.5% of total gangliosides, and GalNAc-GM1b in four cell lines in amounts of less than 2%. The elevated amounts of gangliosides with GM2 determinant were closely correlated with the relative intensities of gene expression of GalNAc transferase, this being characteristic of cervical carcinoma-derived cells. However, in tissues from patients with several histological types of cervical carcinomas, GM3 was ubiquitously expressed in amounts of more than 66% of total gangliosides, GM2 was expressed in only five of 15 tissues, and both GalNAc-GM1b and GalNAc-GD1a were not even detected in trace amounts. Since GM1 was detected in all tissues in amounts of less than 0.06μg/mg dried tissue, all cervical carcinoma tissues were revealed to exhibit GM2 synthesis, indicating that enhanced synthesis of gangliosides with GM2 determinant is a characteristic of cultivated cells in vitro. Similarly, although I(3)SO3-GalCer was not present in the squamous cell carcinoma (SCC) tissues, SCC-derived cells selectively expressed II(3)SO3-LacCer. Since enhanced synthesis of GM2 has been reported in SV-40 virus-transfected fibroblasts, papilloma virus might be involved in the expression of GM2 in cervical carcinoma-derived cells.

Defensive role of silibinin against arsenic induced oxidative stress mediated dyslipidemia and neurotoxicity in rats

Arsenic (As) is an environmental toxic metalloid that is present in everywhere such as air, water and soil. Generally, inorganic arsenic has a tendency to be more toxic than organic arsenic. The present study was designed to determine whether oral administration of silibinin (SB), which has been shown to have substantial antioxidant properties, when pre-administered (75 mg/kg body weight) once daily for 4 weeks along with arsenic (5 mg/kg) would prevent arsenic-induced changes in antioxidant defense system, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX),glutathione-S-transferase (GST),glutathione reductase (GR), glucose-6-phosphate dehydrogenase (G6PD), reduced glutathione (GSH), total sulfhydryl groups (TSH) and vitamin C in rat brain regions such as cortex, striatum, cerebellum, hippocampus and brain stem. Our study also examined the effect of SB over arsenic-induced reactive oxygen species (ROS) production and lipid peroxidation level (LPO) and protein carbonyl content (PC) in distinct brain regions of rats. Moreover, As also alters the lipid profiles such as total lipids, phospholipids, cholesterol, cerebrosides and gangliosides in various regions of the brain. Pre-administration of SB restores the altered enzymatic and non-enzymatic antioxidants, lipid profiles and also markedly reduced the ROS, LPO, PC and accumulation of As in various regions of the brain. These results suggested that arsenic-induced deficits in antioxidant enzyme activities and increase in ROS production and lipid peroxidation levels in brain regions can be remarkably prevented by pre-administration of SB.Â