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Arteriosclerosis, Thrombosis, and... Jun 2024Despite being in an oxygen-rich environment, endothelial cells (ECs) use anaerobic glycolysis (Warburg effect) as the primary metabolic pathway for cellular energy...
BACKGROUND
Despite being in an oxygen-rich environment, endothelial cells (ECs) use anaerobic glycolysis (Warburg effect) as the primary metabolic pathway for cellular energy needs. PFKFB (6-phosphofructo-2-kinase/fructose-2,6-biphosphatase)-3 regulates a critical enzymatic checkpoint in glycolysis and has been shown to induce angiogenesis. This study builds on our efforts to determine the metabolic regulation of ischemic angiogenesis and perfusion recovery in the ischemic muscle.
METHODS
Hypoxia serum starvation (HSS) was used as an in vitro peripheral artery disease (PAD) model, and hind limb ischemia by femoral artery ligation and resection was used as a preclinical PAD model.
RESULTS
Despite increasing PFKFB3-dependent glycolysis, HSS significantly decreased the angiogenic capacity of ischemic ECs. Interestingly, inhibiting PFKFB3 significantly induced the angiogenic capacity of HSS-ECs. Since ischemia induced a significant in PFKFB3 levels in hind limb ischemia muscle versus nonischemic, we wanted to determine whether glucose bioavailability (rather than PFKFB3 expression) in the ischemic muscle is a limiting factor behind impaired angiogenesis. However, treating the ischemic muscle with intramuscular delivery of D-glucose or L-glucose (osmolar control) showed no significant differences in the perfusion recovery, indicating that glucose bioavailability is not a limiting factor to induce ischemic angiogenesis in experimental PAD. Unexpectedly, we found that shRNA-mediated PFKFB3 inhibition in the ischemic muscle resulted in a numerical increase in perfusion recovery and significantly higher vascular density compared with control shRNA (consistent with the increased angiogenic capacity of PFKFB3 silenced HSS-ECs). Based on these data, we hypothesized that inhibiting HSS-induced PFKFB3 in ischemic ECs activates alternative metabolic pathways that revascularize the ischemic muscle in experimental PAD. A comprehensive glucose metabolic gene qPCR arrays in PFKFB3 silenced HSS-ECs, and PFKFB3-inhibited ischemic muscle versus respective controls identified UGP2 (uridine diphosphate-glucose pyrophosphorylase 2), a regulator of protein glycosylation and glycogen synthesis, is induced upon PFKFB3 inhibition in vitro and in vivo. Antibody-mediated inhibition of UGP2 in the ischemic muscle significantly impaired perfusion recovery versus IgG control. Mechanistically, supplementing uridine diphosphate-glucose, a metabolite of UGP2 activity, significantly induced HSS-EC angiogenic capacity in vitro and enhanced perfusion recovery in vivo by increasing protein glycosylation (but not glycogen synthesis).
CONCLUSIONS
Our data present that inhibition of maladaptive PFKFB3-driven glycolysis in HSS-ECs is necessary to promote the UGP2-uridine diphosphate-glucose axis that enhances ischemic angiogenesis and perfusion recovery in experimental PAD.
PubMed: 38934117
DOI: 10.1161/ATVBAHA.124.320665 -
Frontiers in Oncology 2024MUC21, also known as Epiglycanin, is a high-molecular-weight glycoprotein with transmembrane mucin properties. It consists of a tandem repeat domain, a stem domain, a... (Review)
Review
MUC21, also known as Epiglycanin, is a high-molecular-weight glycoprotein with transmembrane mucin properties. It consists of a tandem repeat domain, a stem domain, a transmembrane domain and a cytoplasmic tail. MUC21 is expressed is observed in normal tissues in organs like the thymus, testes, lungs, and large intestine. Research has shown that MUC21 is expressed in esophageal squamous cell carcinoma, lung adenocarcinoma, glioblastoma, thyroid cancer, melanoma, and various other malignant tumors in distinctive manner. Additionally, tumor invasion, metastasis, and poor prognosis are linked to it. Some researchers believe that MUC21 has the potential to become a new target in cancer treatment. This review aims to deliver a comprehensive overview of the glycosylation, function, and research progress of MUC21 in multiple types of cancer and infectious diseases.
PubMed: 38933439
DOI: 10.3389/fonc.2024.1410761 -
Journal of Agricultural and Food... Jun 2024The human intestinal mucus layer protects against pathogenic microorganisms and harmful substances, whereas it also provides an important colonization niche for...
The human intestinal mucus layer protects against pathogenic microorganisms and harmful substances, whereas it also provides an important colonization niche for mutualistic microbes. The main functional components of mucus are heavily glycosylated proteins, called mucins. Mucins can be cleaved and utilized by intestinal microbes. The mechanisms between intestinal microbes and the regulation of mucin glycosylation are still poorly understood. In this study, mucus was produced by HT29-MTX-E12 cells under Semi-Wet interface with Mechanical Stimulation. Cells were exposed to pasteurized nonpathogenic bacteria , , and to evaluate influence on glycosylation patterns. Following an optimized protocol, O- and N-glycans were efficiently and reproducibly released, identified, and semiquantified using MALDI-TOF-MS and PGC-LC-MS/MS. Exposure of cells to bacteria demonstrated increased diversity of sialylated O-glycans and increased abundance of high mannose N-glycans in produced mucus. Furthermore, changes in glycan ratios were observed. It is speculated that bacterial components interact with the enzymatic processes in glycan production and that pasteurized bacteria influence glycosyltransferases or genes involved. These results highlight the influence of pasteurized bacteria on glycosylation patterns, stress the intrinsic relationship between glycosylation and microbiota, and show the potential of using produced mucus to study glycosylation behavior.
PubMed: 38932522
DOI: 10.1021/acs.jafc.4c01401 -
Vaccines Jun 2024Tuberculosis (TB) is a major global health threat despite its virtual elimination in developed countries. Issues such as drug accessibility, emergence of...
Tuberculosis (TB) is a major global health threat despite its virtual elimination in developed countries. Issues such as drug accessibility, emergence of multidrug-resistant strains, and limitations of the current BCG vaccine highlight the urgent need for more effective TB control measures. This study constructed BCG strains overexpressing Rv1002c and found that the rBCG-Rv1002c strain secreted more glycosylated proteins, significantly enhancing macrophage activation and immune protection against (). These results indicate that Rv1002c overexpression promotes elevated levels of O-glycosylation in BCG bacteriophages, enhancing their phagocytic and antigenic presentation functions. Moreover, rBCG-Rv1002c significantly upregulated immune regulatory molecules on the macrophage surface, activated the NF-κB pathway, and facilitated the release of large amounts of NO and HO, thereby enhancing bacterial control. In mice, rBCG-Rv1002c immunization induced greater innate and adaptive immune responses, including increased production of multifunctional and long-term memory T cells. Furthermore, rBCG-Rv1002c-immunized mice exhibited reduced lung bacterial load and histological damage upon infection. This result shows that it has the potential to be an excellent candidate for a preventive vaccine against TB.
PubMed: 38932351
DOI: 10.3390/vaccines12060622 -
Viruses Jun 2024The HIV envelope glycoprotein (Env) is a trimeric protein that facilitates viral binding and fusion with target cells. As the sole viral protein on the HIV surface, Env...
The HIV envelope glycoprotein (Env) is a trimeric protein that facilitates viral binding and fusion with target cells. As the sole viral protein on the HIV surface, Env is important both for immune responses to HIV and in vaccine designs. Targeting Env in clinical applications is challenging due to its heavy glycosylation, high genetic variability, conformational camouflage, and its low abundance on virions. Thus, there is a critical need to better understand this protein. Flow virometry (FV) is a useful methodology for phenotyping the virion surface in a high-throughput, single virion manner. To demonstrate the utility of FV to characterize Env, we stained HIV virions with a panel of 85 monoclonal antibodies targeting different regions of Env. A broad range of antibodies yielded robust staining of Env, with V3 antibodies showing the highest quantitative staining. A subset of antibodies tested in parallel on viruses produced in CD4 T cell lines, HEK293T cells, and primary cells showed that the cellular model of virus production can impact Env detection. Finally, in addition to being able to highlight Env heterogeneity on virions, we show FV can sensitively detect differences in Env conformation when soluble CD4 is added to virions before staining.
Topics: Humans; env Gene Products, Human Immunodeficiency Virus; HIV-1; Virion; HEK293 Cells; HIV Antibodies; Antibodies, Monoclonal; CD4-Positive T-Lymphocytes; HIV Infections
PubMed: 38932227
DOI: 10.3390/v16060935 -
Nutrients Jun 2024Understanding the role of biased taste T1R2/T1R3 G protein-coupled receptors (GPCR) agonists on glycosylated receptor signaling may provide insights into the opposing...
Artificial and Natural Sweeteners Biased T1R2/T1R3 Taste Receptors Transactivate Glycosylated Receptors on Cancer Cells to Induce Epithelial-Mesenchymal Transition of Metastatic Phenotype.
Understanding the role of biased taste T1R2/T1R3 G protein-coupled receptors (GPCR) agonists on glycosylated receptor signaling may provide insights into the opposing effects mediated by artificial and natural sweeteners, particularly in cancer and metastasis. Sweetener-taste GPCRs can be activated by several active states involving either biased agonism, functional selectivity, or ligand-directed signaling. However, there are increasing arrays of sweetener ligands with different degrees of allosteric biased modulation that can vary dramatically in binding- and signaling-specific manners. Here, emerging evidence proposes the involvement of taste GPCRs in a biased GPCR signaling crosstalk involving matrix metalloproteinase-9 (MMP-9) and neuraminidase-1 (Neu-1) activating glycosylated receptors by modifying sialic acids. The findings revealed that most natural and artificial sweeteners significantly activate Neu-1 sialidase in a dose-dependent fashion in RAW-Blue and PANC-1 cells. To confirm this biased GPCR signaling crosstalk, BIM-23127 (neuromedin B receptor inhibitor, MMP-9i (specific MMP-9 inhibitor), and oseltamivir phosphate (specific Neu-1 inhibitor) significantly block sweetener agonist-induced Neu-1 sialidase activity. To assess the effect of artificial and natural sweeteners on the key survival pathways critical for pancreatic cancer progression, we analyzed the expression of epithelial-mesenchymal markers, CD24, ADLH-1, E-cadherin, and N-cadherin in PANC-1 cells, and assess the cellular migration invasiveness in a scratch wound closure assay, and the tunneling nanotubes (TNTs) in staging the migratory intercellular communication. The artificial and natural sweeteners induced metastatic phenotype of PANC-1 pancreatic cancer cells to promote migratory intercellular communication and invasion. The sweeteners also induced the downstream NFκB activation using the secretory alkaline phosphatase (SEAP) assay. These findings elucidate a novel taste T1R2/T1R3 GPCR functional selectivity of a signaling platform in which sweeteners activate downstream signaling, contributing to tumorigenesis and metastasis via a proposed NFκB-induced epigenetic reprogramming modeling.
Topics: Humans; Epithelial-Mesenchymal Transition; Receptors, G-Protein-Coupled; Sweetening Agents; Cell Line, Tumor; Matrix Metalloproteinase 9; Neoplasm Metastasis; Glycosylation; Signal Transduction; Phenotype; Animals; Taste; Cell Movement; Neuraminidase
PubMed: 38931195
DOI: 10.3390/nu16121840 -
Plants (Basel, Switzerland) Jun 2024An investigation of phenolic glycosides extracted from germplasm revealed that arbusculoidin (benzyl 1--β-d-glucopyranosyl-1-hydroxy-6-oxo-2-cyclohexenyl carboxylate)...
An investigation of phenolic glycosides extracted from germplasm revealed that arbusculoidin (benzyl 1--β-d-glucopyranosyl-1-hydroxy-6-oxo-2-cyclohexenyl carboxylate) and its enolic 6-glycoside isomer, isoarbusculoidin, are widespread across the Salix family. An analysis of natural hybrid species and progeny from a willow breeding programme demonstrated that the putative biosynthetic pathway leading to the salicinoid family of phenolic glycosides runs in parallel to a "benzyl"-based pathway to arbusculoidin. The introduction of a known Diels-Alder reaction trait from , as well as an acylation trait, into progeny containing both salicyl- and benzyl- pathways caused the formation of all possible hetero-cyclodimers from mixtures of reactive dienone (acyl)glycosides that participated in cross-over reactions. In addition to providing access to new analogues of the anti-cancer dimer miyabeacin, the analysis of the breeding progeny also indicated that these dienone (acyl)glycosides are stable in planta. Although the immediate biosynthetic precursors of these compounds remain to be defined, the results suggest that the (acyl)glycosylation reactions may occur later in the pathway than previously suggested by in vitro work on cloned UGT enzymes.
PubMed: 38931042
DOI: 10.3390/plants13121609 -
Foods (Basel, Switzerland) Jun 2024Multiple emulsions can dissolve some substances with different properties, such as hydrophilicity and lipophilicity, into different phases. They play an important role...
Studies on the Properties and Stability Mechanism of Double Emulsion Gels Prepared by Heat-Induced Aggregates of Egg White Protein-Oligosaccharides Glycosylation Products.
Multiple emulsions can dissolve some substances with different properties, such as hydrophilicity and lipophilicity, into different phases. They play an important role in protection, controlled release and targeted release of the encapsulated substances. However, it's poor stability has always been one of the main problems restricting its application in the food industry. For this reason, a heat-induced aggregate (HIA) of Maillard graft product of isomalto-oligosaccharides (IMO), as well as egg white protein (EWP), was used as hydrophilic emulsifier to improve the stability of W/O/W emulsions. Moreover, gelatin was added into the internal aqueous phase (W) to construct W/O/W emulsion-gels system. The encapsulation efficiency of HIA-stabilized W/O/W emulsions remained nearly unaltered, dropping by only 0.86%, significantly outperforming the conjugates and physical mixture of IMO and EWP in terms of encapsulation stability. The emulsion-gels system was constructed by adding 5% gelatin in the W, and had the highest EE% and good salt and heat stability after 30 days of storage. This experiment provides guidance for improving the stability of W/O/W emulsions system and its application in the package delivery of functional substances in the food field.
PubMed: 38928764
DOI: 10.3390/foods13121822 -
International Journal of Molecular... Jun 2024Exoglycosidase enzymes hydrolyze the N-glycosylations of cell wall enzymes, releasing N-glycans that act as signal molecules and promote fruit ripening. Vesicular...
Exoglycosidase enzymes hydrolyze the N-glycosylations of cell wall enzymes, releasing N-glycans that act as signal molecules and promote fruit ripening. Vesicular exoglycosidase α-mannosidase enzymes of the GH38 family (EC 3.2.1.24; α-man) hydrolyze N-glycans in non-reduced termini. Strawberry fruit ( × ) is characterized by rapid softening as a result of cell wall modifications during the fruit ripening process. Enzymes acting on cell wall polysaccharides explain the changes in fruit firmness, but α-man has not yet been described in × , meaning that the indirect effects of N-glycan removal on its fruit ripening process are unknown. The present study identified 10 GH38 α-man sequences in the × genome with characteristic conserved domains and key residues. A phylogenetic tree built with the neighbor-joining method and three groups of α-man established, of which group I was classified into three subgroups and group III contained only spp. sequences. The real-time qPCR results demonstrated that genes decreased during fruit ripening, a trend mirrored by the total enzyme activity from the white to ripe stages. The analysis of the promoter regions of these genes was enriched with ripening and phytohormone response elements, and contained -regulatory elements related to stress responses to low temperature, drought, defense, and salt stress. This study discusses the relevance of α-man in fruit ripening and how it can be a useful target to prolong fruit shelf life.
Topics: Fragaria; Fruit; Gene Expression Regulation, Plant; Phylogeny; alpha-Mannosidase; Plant Proteins; Cell Wall
PubMed: 38928287
DOI: 10.3390/ijms25126581 -
International Journal of Molecular... Jun 2024Sepsis is a life-threatening condition with a rising disease burden worldwide. It is a multifactorial disease and is defined as a dysregulated host response to...
Sepsis is a life-threatening condition with a rising disease burden worldwide. It is a multifactorial disease and is defined as a dysregulated host response to infection. Neutrophils have been shown to be involved in the pathogenesis of sepsis by exacerbating inflammation. However, the exact effector mechanism of action still remains a mystery. Changes in the glycosylation pattern of the immunoglobulin G (IgG) Fc region are described for several diseases including meningococcal sepsis. In this study, we investigated the possible contribution of neutrophils and neutrophil implication, potentially related to degranulation or neutrophil extracellular trap (NET) formation in changing the IgG Fc N-glycosylation pattern in a murine sepsis model. We have measured the serum level of cytokines/chemokines and immunoglobulins, the serum activity of neutrophil elastase (NE), and analyzed the IgG Fc glycosylation pattern by Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (LC-ESI-MS) and Lectin enzyme-linked immunosorbent assay (ELISA). We observed an increased activity of NE- and neutrophil-associated cytokines such as keratinocyte chemoattractant (KC) with the development of sepsis. Regarding the IgG Fc N-glycosylation, we observed an increase in fucosylation and α1,3-galactosylation and a decrease for sialyation. Interestingly, these changes were not uniform for all IgG subclasses. After depletion of neutrophils, we saw a change in the exposure of fucose and α2,6-linked sialic acid during the time course of our experimental sepsis model. In conclusion, neutrophils can influence changes in the IgG glycosylation pattern in experimental sepsis.
Topics: Animals; Sepsis; Neutrophils; Glycosylation; Immunoglobulin G; Mice; Disease Models, Animal; Cytokines; Immunoglobulin Fc Fragments; Mice, Inbred C57BL; Leukocyte Elastase; Male; Extracellular Traps; Glycoproteins
PubMed: 38928183
DOI: 10.3390/ijms25126478