Scope
Red meat intake is reported to be correlated with chronic diseases. A potential causal factor is N‐glycolylneuraminic acid (Neu5Gc) which metabolically incorporates into diverse glycoconjugates ...in humans. This study aims to investigate the impact of exposure to Neu5Gc‐rich red meat on healthy cytidine‐5′‐monophospho‐N‐acetylneuraminic acid hydroxylase (Cmah) knock‐out mice and the underlying mechanisms.
Methods and Results
CMAH−/− mice are fed Neu5Gc‐rich diet for short‐term (4 months) and long‐term (10 months). Health status and levels of inflammatory cytokines are assessed. Caco‐2 cells are used to investigate the intestinal absorption of Neu5Gc‐containing glycoprotein, and in vitro fermentation is used to investigate the Neu5Gc utilization by gut microbiota. Neu5Gc‐rich diets show neither measurable abnormality in physio‐biochemical and inflammatory indexes nor observable alterations of liver tissue in mice. Glycosylation of lactoferrin limits its intestinal epithelial absorption, and the absorption of Neu5Gc attach onto glycoprotein is thus limited. Neu5Gc is also simultaneously utilized by microorganisms under simulated gut conditions.
Conclusion
The results indicate that the long‐term intake of Neu5Gc‐rich red meat has no adverse effect on the health of CMAH−/− mice, which may be related to the limited absorption of Neu5Gc that is regulated by protein glycosylation, and the metabolism of Neu5Gc by gut microorganisms.
This study investigates the impact of Neu5Gc‐rich diet for short‐term (4 months, PSIM extremely rich in Neu5Gc) and long‐term (10 months, beef protein rich in Neu5Gc) on CMAH−/− mice. None of the experiments show adverse effect on mice health. The amounts of glycoprotein and attach Neu5Gc absorb by small intestine are limited. The unabsorbed Neu5Gc is primarily utilized by microorganisms.
Abstract One of the frontiers in cancer personalized-medicine aims at glycosylation. Cells are covered with a dense sugar coat of glycolipids, glycoproteins and free glycans. In cancer, the ...characteristic cell surface glycosylation is frequently transformed due to altered expression of glycan-modifying enzymes. This often leads to aberrant expression of sialic acids (Sia) that cap glycan-chains. Additionally, dietary intake of the non-human Sia N -glycolylneuraminic acid (Neu5Gc) leads to natural metabolic-glycoengineering of human carcinomas that accumulate and express Neu5Gc. This Sia provokes a polyclonal anti-Neu5Gc xeno-autoantibodies response that can exacerbate cancer. This review highlights cancer-associated changes in Sia expression and their potential for personalized-theranostics.
N-glycolylneuraminic acid (Neu5Gc) is a type of sialic acid that is not typically produced in healthy humans but detective in some visceral cancer cells. As a new carcinoma biomarker, the level ...change in the serum and urine from the patient could potentially have the relation to the disease progression. So the measurement of the Neu5Gc will help to take a better response to therapeutic schedule for the sufferers. A sensitive and rapid aptamer-nanoparticle immunochromatographic strip for the visual detection of Neu5Gc was developed. The assay is based on the competitive reaction of binding the DNA aptamer targeting the candidate molecule selected by SELEX between Neu5Gc and complementary DNA. The sensing results indicated that the aptamer-based strip was sufficiently sensitive to detect Neu5Gc. The visual limit of detection (LOD) for semi-quantitative detection was 30 ng/mL under the optimal conditions and a quantitative detection limit of 5.38 ng/mL could be obtained using a scanning strip reader. The average recovery of the spiked cancer cell samples was 88.86%, with a coefficient of variation (CV) of 5.27%. The detection could be performed in less than 15 min using a simple procedure without any complicated equipment, demonstrating that this aptamer-nanoparticle biosensor strip has great potential for use to Neu5Gc-related cancer diagnosis.
•The simple, rapid and sensitive aptamer-based immunochromatographic strip was developed to analyze the new cancer biomarker of Neu5Gc.•Both qualitative and quantitative Neu5Gc detection are achieved.•The visual limit of detection of the strip is 30 ng/mL and the quantitative limit of detection is 5.38 ng/mL.•Some relative cancer cell samples spiked different levels of Neu5Gc were studied using the developed strip.•The method displays impressive promise for point-of-care relative carcinoma diagnosis to further better response to therapeutic schedule.
Although the full primary structures of the alfa and beta subunits of reference r-hFSH-alfa and its biosimilars are identical, cell context-dependent differences in the expressing cell lines and ...manufacturing process can lead to variations in glycosylation profiles. In the present study, we compared the structural features of reference r-hFSH-alfa with those of five biosimilar preparations approved in different global regions outside Europe (Primapur®, Jin Sai Heng®, Follitrope®, Folisurge®, and Corneumon®) with respect to glycosylation, macro- and microheterogeneity, and other post-translational modifications and higher order structure. The mean proportion of N-glycosylation-site occupancy was highest in reference r-hFSH-alfa, decreasing sequentially in Primapur, Jin Sai Heng, Corneumon, Follisurge and Follitrope, respectively. The level of antennarity showed slightly higher complexity in Corneumon, Primapur and Follitrope versus reference r-hFSH-alfa, whereas Jin Sai Heng and Folisurge were aligned with reference r-hFSH-alfa across all N-glycosylation sites. Sialylation level was higher in Corneumon and Follitrope, but small differences were detected in other biosimilar preparations compared with reference r-hFSH-alfa. Jin Sai Heng showed higher levels of N-glyconeuramic acid than the other preparations. Minor differences in oxidation levels were seen among the different products. Therefore, in summary, we identified var ious differences in N-glycosylation occupancy, antennarity, sialylation and oxidation between reference r-hFSH-alfa and the biosimilar preparations analyzed.
Meat is a crucial nutrient for human health since it represents a giant supply of proteins, minerals, and vitamins. On the opposite hand, the intake of red and processed meat is taken into account ...dangerous due to its potential of carcinogenesis and cancer risk improvement, particularly for colorectal cancer (CRC), although it has been reported that also the contaminations of beef infected by oncogenic bovine viruses could increase colorectal cancer's risk. Regarding the mechanisms underlying the potential carcinogenicity of red and processed meat, different hypotheses have been proposed. A suggested mechanism describes the potential role of the heterocyclic amines (HACs) and polycyclic aromatic hydrocarbons (PHAs) in carcinogenesis induced by DNA mutation. Another hypothesis states that heme, through the lipid peroxidation process and therefore the formation of N-nitroso compounds (NOCs), produces cytotoxic and genotoxic aldehydes, resulting in carcinogenesis. Furthermore, a recent proposed hypothesis, is based on the combined actions between the N-Glycolylneuraminic acid (Neu5Gc) and genotoxic compounds. The purpose of this narrative review is to shed a light on the mechanisms underlying the potential carcinogenicity of red and processed meat, by summarizing the data reported in literature on this topic.
Recent reports have documented that extracellular sialyltransferases can remodel both cell-surface and secreted glycans by a process other than the canonical cell-autonomous glycosylation that occurs ...within the intracellular secretory apparatus. Despite association of the abundance of these extracellular sialyltransferases, particularly ST6Gal-1, with disease states such as cancer and a variety of inflammatory conditions, the prevalence of this extrinsic glycosylation pathway in vivo remains unknown. Here we observed no significant extrinsic sialylation in resting mice, suggesting that extrinsic sialylation is not a constitutive process. However, extrinsic sialylation in the periphery could be triggered by inflammatory challenges, such as exposure to ionizing radiation or to bacterial lipopolysaccharides. Sialic acids from circulating platelets were used in vivo to remodel target cell surfaces. Platelet activation was minimally sufficient to elicit extrinsic sialylation, as demonstrated with the FeCl3 model of mesenteric artery thrombosis. Although extracellular ST6Gal-1 supports extrinsic sialylation, other sialyltransferases are present in systemic circulation. We also observed in vivo extrinsic sialylation in animals deficient in ST6Gal-1, demonstrating that extrinsic sialylation is not mediated exclusively by ST6Gal-1. Together, these observations form an emerging picture of glycans biosynthesized by the canonical cell-autonomous glycosylation pathway, but subjected to remodeling by extracellular glycan-modifying enzymes.
Chimeric antigen receptor (CAR) T cell technology has ushered in a new era of immunotherapy, enabling the targeting of a broad range of surface antigens, surpassing the limitations of traditional T ...cell epitopes. Despite the wide range of non-protein tumor-associated antigens, the advancement in crafting CAR T cells for these targets has been limited. Owing to an evolutionary defect in the CMP-Neu5Ac hydroxylase (CMAH) that abolishes the synthesis of CMP-Neu5Gc from CMP-Neu5Ac, Neu5Gc is generally absent in human tissues. Despite this, Neu5Gc-containing antigens, including the ganglioside GM3(Neu5Gc) have consistently been observed on tumor cells across a variety of human malignancies. This restricted expression makes GM3(Neu5Gc) an appealing and highly specific target for immunotherapy. In this study, we designed and evaluated 14F7-28z CAR T cells, with a targeting unit derived from the GM3(Neu5Gc)-specific murine antibody 14F7. These cells exhibited exceptional specificity, proficiently targeting GM3(Neu5Gc)-expressing murine tumor cells in syngeneic mouse models, ranging from B cell malignancies to epithelial tumors, without compromising safety. Notably, human tumor cells enhanced with murine
were effectively targeted and eliminated by the 14F7 CAR T cells. Nonetheless, despite the detectable presence of GM3(Neu5Gc) in unmodified human tumor xenografts, the levels were insufficient to trigger a tumoricidal T-cell response with the current CAR T cell configuration. Overall, our findings highlight the potential of targeting the GM3(Neu5Gc) ganglioside using CAR T cells across a variety of cancers and set the stage for the optimization of 14F7-based therapies for future human clinical application.
The rapid growth of infant brains places an exceptionally high demand on the supply of nutrients from the diet, particularly for preterm infants. Sialic acid (Sia) is an essential component of brain ...gangliosides and the polysialic acid (polySia) chains that modify neural cell adhesion molecules (NCAM). Sia levels are high in human breast milk, predominately as N-acetylneuraminic acid (Neu5Ac). In contrast, infant formulas contain a low level of Sia consisting of both Neu5Ac and N-glycolylneuraminic acid (Neu5Gc). Neu5Gc is implicated in some human inflammatory diseases. Brain gangliosides and polysialylated NCAM play crucial roles in cell-to-cell interactions, neuronal outgrowth, modifying synaptic connectivity, and memory formation. In piglets, a diet rich in Sia increases the level of brain Sia and the expression of two learning-related genes and enhances learning and memory. The purpose of this review is to summarize the evidence showing the importance of dietary Sia as an essential nutrient for brain development and cognition.
Sialic acid Neu5Gc, a non-human glycan, is recognized as a new harmful substance that can cause vascular disease and cancer. Humans are unable to synthesize Neu5Gc due to a genetic defect that ...converts Neu5Ac to Neu5Gc, but Neu5Gc is often observed in human biological samples. Therefore, the demand for accurately measuring the amount of Neu5Gc present in human blood or tissues is rapidly increasing, but there is still no method to reliably quantify trace amounts of a non-human sugar. In particular, selective isolation and detection of Neu5Gc from human serum is analytically challenging due to the presence of excess sialic acid Neu5Ac, which has physicochemical properties very similar to Neu5Gc. Herein, we developed the label-free approach based on ZIC-HILIC/MRM-MS that can enrich sialic acids released from human serum and simultaneously monitor Neu5Ac and Neu5Gc. The combination of complete separation of Neu5Gc from abundant Neu5Ac by hydrophilic and electrostatic interactions with selective monitoring of structure-specific cross-ring cleavage ions generated by negative CID-MS/MS was remarkably effective for quantification of Neu5Ac and Neu5Gc at the femtomole level. Indeed, we were able to successfully determine the absolute quantitation of Neu5Gc from 30 healthy donors in the range of 3.336 ± 1.252 pg/μL (mean ± SD), 10,000 times lower than Neu5Ac. In particular, analysis of sialic acids in protein-free serum revealed that both Neu5Ac and Neu5G are mostly bound to proteins and/or lipids, but not in free form. In addition, the correlation between expression level of Neu5Gc and biological factors such as BMI, age, and sex was investigated. This method can be widely used in studies requiring sialic acid–related measurements such as disease diagnosis or prediction of immunogenicity in biopharmaceuticals as it is both fast and highly sensitive.
Graphical abstract
The B subunit of the subtilase cytotoxin (SubB) recognises N-glycolylneuraminic acid (Neu5Gc) containing glycans, the most prominent form of aberrant glycosylation in human cancers. We have ...previously engineered SubB by construction of a SubBΔS106/ΔT107 mutant (SubB2M) for greater specificity and enhanced recognition of Neu5Gc containing glycans. In this study, we further explore the utility of SubB2M as a Neu5Gc lectin by showing its improved specificity and recognition for Neu5Gc containing glycans over the wild-type SubB protein and an anti-Neu5Gc IgY antibody in a N-acetylneuraminic acid (Neu5Ac)/Neu5Gc glycan array and by surface plasmon resonance. Far-western blot analysis showed that SubB2M preferentially binds to bovine serum glycoproteins over human serum glycoproteins. SubB2M was also able to detect Neu5Gc containing bovine glycoproteins spiked into normal human serum with greater sensitivity than the wild-type SubB and the anti-Neu5Gc IgY antibody. These results suggest that SubB2M will be a useful tool for the testing of serum and other bodily fluids for cancer diagnosis and prognosis.
•SubB2M showed improved specificity and recognition for Neu5Gc containing glycans in a Neu5Ac/Neu5Gc glycan array and by surface plasmon resonance.•Far-western blot analysis showed that SubB2M preferentially binds to serum glycoproteins from bovine over human.•SubB2M detected Neu5Gc-glycoproteins spiked into normal human serum with greater sensitivity than SubB and anti-Neu5Gc IgY.•SubB2M will be a useful tool for the testing of serum and other bodily fluids for cancer diagnosis and prognosis.
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