Search Results (332)

Environmental temperature-induced metabolic changes in dams can be reflected by alterations in metabolomic and fatty acid profiles in colostrum. The colostrum from 13 Black Bengal (BB) dams was collected on the day of parturition at two consecutive parities during the hot conditions (HCs) of summer or rainy seasons and the cold conditions (CCs) of winter. The metabolomic and fatty acid profiles were analyzed using nuclear magnetic resonance (NMR) and gas chromatography–mass spectrometry, respectively. The results showed significantly higher sarcosine, tyrosine, citrate, succinate, galactose, acetylglucosamine, carnitine, choline, glycerophosphocholine, and trimethylamine N-oxide during CCs than HCs; potential discriminant metabolites according to VIP scores were sarcosine, succinate, and choline. Colostrum from CCs had significantly lower levels of saturated fatty acids (SFAs), including butyric acid (C4:0), myristic acid (C14:0), and pentadecanoic acid (C15:0), but higher omega-9 monounsaturated fatty acids (MUFAs), especially oleic acid (C18:1n9c), elaidic acid (C18:1n9t), and eicosenoic acid (C20:1n9), than in HC. Linoleic acid (C18:2n6c) and the omega 6/omega 3 PUFA ratio were higher during CCs than HCs. It is concluded that a metabolic shift for nutrient utilization occurs, from glucose during HCs toward fat during CCs, which may not be due to the diet but rather neurohumoral alterations occurring during temperature adaptation. Full article

A body of evidence suggests that upregulating O-GlcNAcylation, a reversible post-translational modification of serine and threonine residues on target proteins, is beneficial in neurological diseases. However, this phenomenon is currently underexplored in the pharmacotherapy of epilepsy. Therefore, we aimed to explore the potential effects of combining N-acetylglucosamine (GlcNAc), a precursor for O-GlcNAcylation, and a centrally acting benzodiazepine (diazepam) on oxidative stress, a known driver of epilepsy, and some epileptogenesis-associated genes. Mice (n = 10) were randomly assigned to treatment groups and treated with varied oral doses (100, 200, and 400 mg/kg) of GlcNAc in combination with diazepam (1 mg/kg) for 14 days. Following this, seizure was chemically induced with 70 mg/kg pentylenetetrazol intraperitoneally. Brains of treated mice were excised for antioxidant assays and to determine the expression of genes associated with epileptogenesis: potassium chloride co-transporter (KCC4), interleukin (IL-6), tumour necrosis factor-α (TNF-α), and brain-derived neurotrophic factor (BDNF). Our findings suggest that GlcNAc, when concurrently administered with diazepam, prevents oxidative stress and reduces the gene expression of IL-6, a cytokine associated with neuroinflammation and seizures, whilst increasing the gene expression of KCC4, an ion co-transporter that promotes antiepileptogenesis. Full article

Background: Joint inflammation is significantly connected with progressive joint deterioration, potentially increasing the incidence of persistent major clinical challenges and global disability. Nutrient-based preventive strategies have been explored to investigate the interventive efficacy of the proposed prescribed formula for joint inflammation. However, the synergistic ameliorative effects of the nutritional formula should be evaluated to investigate its impact on joint inflammation. Methods: A prescribed formula including turmeric (T), N-acetylglucosamine (G), enzymatically hydrolyzed bone powder (E), and undenatured type II collagen (U) was comprehensively evaluated for its synergistic effects on joint inflammation and the underlying mechanisms. A rat model established using the Hulth method was used to evaluate the interventive effects in vivo. Moreover, in vitro analysis using the murine chondrogenic cell line ATDC5 was performed to validate the intervention and its mechanism of action. Results: The prescribed formula was shown to synergistically reduce levels of inflammation-related cytokines, reduce oxidative stress, and enhance bone metabolism to promote joint regeneration. Micro-Computed Tomography (Micro-CT) analysis revealed restoration of joint architecture and ameliorated physiological status upon formula intervention. In vitro analysis further validated the synergistic alleviation of inflammation and oxidation, as well as reductions in MMP13 and CTX-1 levels, which implies that modulating bone metabolism alleviates the deterioration and inflammation of joint architecture. Conclusions: The synergistic formula in this study achieves synchronous modulation of several core pathological pathways, yielding synergistic modulation of joint inflammation. Nutrient-based interventions or preventive strategies show promising effects against joint inflammation and progressive mechanistic deterioration. Full article

Type 2 diabetes mellitus (T2DM) is one of the most prevalent chronic metabolic diseases, and inhibition of α-glucosidase activity represents an effective therapeutic strategy. Chitin is the most abundant renewable polysaccharide in the ocean, with its monosaccharide being N-acetylglucosamine (NAG). To evaluate the potential of NAG glycosides as novel α-glucosidase inhibitors, three common phenolic compounds were modified via NAG glycosylation. Their inhibitory activities were assessed at both the enzymatic and cellular levels. In addition, density functional theory (DFT), molecular dynamics (MD) simulations, and molecular docking analyses were employed to systematically investigate the effects of NAG glycosylation on enzyme inhibition and the underlying mechanisms. Compared with the parent phenolic compounds, NAG glycosides exhibited significantly enhanced α-glucosidase inhibitory activity, with NAG introduction markedly improving their binding affinity to α-glucosidase. Among them, glycoside 3a displayed the optimal inhibitory effect, comparable to acarbose, and at the cellular level, its activity at high concentrations was comparable to or slightly higher than that of metformin. Circular dichroism (CD) and MD analyses indicated that glycoside 3a increased the conformational flexibility of key residues and enhanced the structural looseness of the enzyme, thereby inhibiting its activity. NAG glycosides constitute a promising class of marine-derived α-glucosidase inhibitors, warranting further structural optimization and rational design to enhance their activity and selectivity. Full article

The interaction of a set of four N-acetyl-glucosamine (GlcNAc) glycomimetics with human N-acetyl-glucosaminidase (NAGLU), the genetically defective enzyme in patients suffering from mucopolysaccharidosis (MPS) IIIB, also known as Sanfilippo B syndrome, was investigated to identify potential pharmacological chaperones. Glycomimetic–NAGLU binding was initially studied by molecular docking simulations and a thermal shift assay. The effects of the glycomimetics on NAGLU activity enhancement were studied in fibroblast cells from seven MPS IIIB patients. A significant increase in NAGLU activity in four cell lines in the presence of glycomimetic MK 8719, a molecule tested in a Phase 1 study in healthy volunteers to treat Alzheimer’s disease, was demonstrated. Furthermore, MK 8719 prevented the increase in glycosaminoglycan (GAG) levels in four MPS IIIB fibroblast cells, suggesting that this molecule may be worth investigating further as a pharmacological chaperone for MPS IIIB. These results represent an important contribution towards the development of a specific therapy for MPS IIIB. Full article

Glycosylation depends on luminal nucleotide sugars delivered by solute carrier 35 (SLC35) transporters. SLC35A3 is a uridine diphosphate N-acetylglucosamine (UDP-GlcNAc) transporter. In humans, biallelic mutations in SLC35A3 cause arthrogryposis, mental retardation, and seizures (AMRS). To define how loss of SLC35A3 function reshapes the neural glycome, we profiled N-, O-, and glycosaminoglycans (GAGs) in Slc35a3 knockout mouse brains. N- and O-glycans were analyzed by MALDI-TOF MS, and GAG disaccharides were quantified by anion-exchange HPLC. Knockout mouse brains exhibited attenuation of complex-type N-glycans with a reciprocal rise in high-mannose species, as revealed by MALDI-TOF MS profiling. In contrast, ConA lectin blotting showed no significant change, consistent with its preferential detection of mannose-rich glycans. Branching analysis revealed loss of tri- and tetra-antennary structures compared with biantennary species. O-glycan profiling showed core-2-type species (Hex₂HexNAc₂ backbone) decreased. The dominant disialyl core-1 remained stable. Total GAG output (chondroitin/dermatan sulfate, heparan sulfate, and hyaluronan) was preserved. These findings support a microdomain model in which SLC35A3 acts as a locally effective supplier of UDP-GlcNAc to MGAT4 (branching N-acetylglucosaminyltransferase that installs the β1,4-GlcNAc arm) in the brain, while alternative routes buffer UDP-GlcNAc delivery for GAG and mucin-type O-glycan biosynthesis. Accordingly, AMRS may be attributed to impaired higher-order N-glycan branching in the brain. Full article

UDP-N-acetylglucosamine pyrophosphorylase (UAP) is an essential enzyme in the insect chitin biosynthesis pathway; however, little is known regarding its molecular functions in Oedaleus asiaticus Bey-Bienko (Orthoptera: Acrididae). Here, two UAP genes, OaUAP1 and OaUAP2, were identified and characterized in O. asiaticus. The effects of exogenous treatments, including the molting hormone 20-hydroxyecdysone (20E) and the chitin biosynthesis inhibitor validamycin (VA), were assessed on chitin synthesis. Sequence analyses have shown that the cDNA and deduced amino acid sequences of O. asiaticus share over 90% identity with UAPs in Locusta migratoria. OaUAP1 and OaUAP2 are widely expressed in many tissues and developmental stages but exhibit different expression patterns: OaUAP1 shows higher expression in the epidermis and fifth-instar nymphs, while OaUAP2 is primarily expressed in the fat body and in the fifth-instar nymphs and adults. The functional analysis of two OaUAPs revealed that OaUAP2 was crucial in molting; moreover, its implication also exists in other biosynthetic processes since nymphs maintained normal growth and development. Both OaUAP expressions were upregulated by 20E and downregulated by VA in the chitin biosynthesis pathway. Our findings provide a vital molecular insight into the chitin biosynthesis pathway of O. asiaticus and lay a solid foundation for developing environmentally safe biological insecticides. Full article

GNE myopathy is a rare genetic neuromuscular disorder caused by mutations in the GNE gene. The respective gene product, UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase (GNE), is a bifunctional enzyme that initiates endogenous sialic acid biosynthesis. Sialic acids are important building blocks for the glycosylation machinery of cells and are typically found at the terminal ends of glycoprotein N- and O-glycans. The exact pathomechanism of GNE myopathy remains elusive, and a better understanding of the disease is urgently needed for the development of therapeutic strategies. The purpose of this study was to examine the effects of hyposialylation on glycan structures and subsequent downstream effects in the C2C12 Gne knockout cell model. No overall remodeling of N-glycans was observed in the absence of Gne, but differences in glycosaminoglycan expression and O-GlcNAcylation were detected. Expression analysis of myopathogenes revealed concomitant down-regulation of muscle-specific genes. Among the top candidates were the sodium channel protein type 4 subunit α (Scn4a), voltage-dependent L-type calcium channel subunit α-1s (Cacna1s), ryanodine receptor 1 (Ryr1), and glycogen phosphorylase (Pygm), which are associated with excitation-contraction coupling and energy metabolism. The results suggest that remodeling of the glycome could have detrimental effects on intracellular signaling, excitability of skeletal muscle tissue, and glucose metabolism. Full article

In recent years, sialidases (neuraminidases) derived from non-clinical sources have attracted considerable interest due to their potential applications in the food and pharmaceutical industries. A deeper understanding of the mechanisms regulating sialidase synthesis could lead to more efficient enzyme production. Induction is considered a key regulatory mechanism. However, there is a lack of data on the regulation of sialidase synthesis in filamentous fungi. This study examines how regulatory mechanisms influence the production of a sialidase enzyme exhibiting high activity at low temperatures in the Antarctic fungal strain Penicillium griseofulvum P29. The inclusion of high- and low-molecular-weight substances possessing terminal non-reducing N-acetylneuramyl groups in the tests led to a marked enhancement of sialidase activity. The strongest induction response was elicited by sialic acid, followed by glycomacropeptide, milk whey, N-acetylglucosamine, N-acetylmannosamine, and colominic acid. RT-qPCR experiments demonstrated that induction occurs at the transcriptional level of the sialidase gene. Biochemical analysis elucidates the function of inducers as triggers in the de novo synthesis of the enzyme protein. To our knowledge, this is the first study to highlight the importance of regulatory mechanism induction in the synthesis of cold-active sialidases. Full article

Background: Gut barrier dysfunction and altered gut microbial metabolism are emerging signatures of chronic gut disorders. Considering growing interest in combining structurally and mechanistically distinct bioactives, we investigated the individual and combined effects of serum-derived bovine immunoglobulin (SBI) and N-acetylglucosamine (NAG) on the gut microbiome and barrier integrity. Methods: The validated ex vivo SIFR^® (Systemic Intestinal Fermentation Research) technology, using microbiota from healthy adults (n = 6), was combined with a co-culture of epithelial/immune (Caco-2/THP-1) cells. Results: While SBI and NAG already significantly improved gut barrier integrity (TEER, transepithelial electrical resistance, +21% and +29%, respectively), the strongest effect was observed for SBI_NAG (+36%). This potent combined effect related to the observation that SBI and NAG each induced distinct, complementary shifts in microbial composition and metabolite output. SBI most selectively increased propionate (~Bacteroidota families) and health-associated indole derivatives (e.g., indole-3-propionic acid), while NAG most specifically boosted acetate and butyrate (~Bifidobacteriaceae, Ruminococcaceae, and Lachnospiraceae). The combination of SBI_NAG displayed effects of the individual ingredients, thus, for instance, enhancing all three short-chain fatty acids (SCFA) and elevating microbial diversity (CMS, community modulation score). Conclusions: Overall, SBI and NAG exert complementary, metabolically balanced effects on the gut microbiota, supporting combined use, particularly in individuals with gut barrier impairment or dysbiosis linked to lifestyle or early-stage gastrointestinal disorders. Full article

The context of food science and biotechnology is undergoing a profound transformation, characterized by an evolutionary shift from conventional large-scale fermentation to precision biomanufacturing, positioning Lactic Acid Bacteria (LAB) as versatile cellular biofactories for next-generation functional foods. This review analyzes the evolutionary role of LAB, their utilization as probiotics, and the technological advances driving this shift. This work also recognizes the fundamental contributions of pioneering women in the field of biotechnology. The primary methodology relies on the seamless integration of synthetic biology (CRISPR-Cas editing), Multi-Omics analysis, and advanced Artificial Intelligence/Machine Learning, enabling the precise, rational design of LAB strains. This approach has yielded significant findings, including successful metabolic flux engineering to optimize the biosynthesis of high-value nutraceuticals such as Nicotinamide Mononucleotide and N-acetylglucosamine, and the development of Live Biotherapeutic Products using native CRISPR systems for the expression of human therapeutic peptides (e.g., Glucagon-like Peptide-1 for diabetes). From an industrial perspective, this convergence enhances strain robustness and supports the digitalized circular bioeconomy through the valorization of agri-food by-products. In conclusion, LAB continue to consolidate their position as central agents for the development of next-generation functional foods. Full article

In forest soils, nitrogen (N) is present in inorganic and organic forms. The organic forms include monomeric amino acids, but also polymers such as chitin. Ectomycorrhizal fungi are known to take up both inorganic and organic N forms, and to depolymerize large organic compounds; however, it is unknown if the compounds are used for growth. The aim of this investigation was to determine the growth of a range of ectomycorrhizal fungi on inorganic and organic N sources. Seven ectomycorrhizal fungi and one endophyte originating from mountain regions either in Austria, Mongolia, or Slovenia were grown in in-vitro cultures containing ammonium, nitrate, or chitin. Four ectomycorrhizal fungi were used to investigate growth on amino acids. All fungi, except Paxillus involutus, utilized nitrate as a N source. All fungi also grew on both chitin and N-acetylglucosamine, the amino sugar precursor of chitin. Paxillus involutus and Melanogaster broomeanus showed enhanced growth on chitin-containing media. Amanita muscaria, Rhizopogon roseolus, and Suillus granulatus, but not Paxillus involutus, were able to utilize the amino acids glycine and glutamate, as well as the tripeptide triglycine. The ability to utilize the different N sources was independent of the origin of the fungi. Full article

Streptococcus suis is an important zoonotic pathogen responsible for severe infections in pigs and humans. Its capacity to survive within phagocytic cells is considered a key virulence mechanism that contributes to dissemination and persistence in host tissues. This study employed comparative proteomic profiling to investigate intracellular adaptation of S. suis serotypes 2 (SS2) and 14 (SS14) during infection of human U937 macrophages. Five isolates originating from humans and pigs were analyzed using gel electrophoresis with liquid chromatography–tandem mass spectrometry (GeLC–MS/MS), revealing 118 differentially expressed proteins grouped into 11 functional categories. Translation-related proteins represented the largest group (48%), including upregulated ribosomal subunits (30S: S2, S5, S7, S8, S12, S15; 50S: L1, L5, L18, L22, L24, L33, L35) and translation factors such as GidA/TrmFO and RimP. Enrichment of carbohydrate metabolism and DNA replication proteins, including phosphoenolpyruvate carboxylase (PEP), UDP-N-acetylglucosamine pyrophosphorylase (GlmU), and ATP-dependent DNA helicase RuvB, indicated metabolic reprogramming and stress adaptation under intracellular conditions. Stress-response proteins such as molecular chaperone DnaK were also induced, supporting their multifunctional, “moonlighting” roles in virulence and host interaction. Comparative analysis showed that SS2 expressed a broader range of adaptive proteins than SS14, consistent with its higher virulence potential. These findings reveal conserved intracellular responses centered on translation, energy metabolism, and stress tolerance, which enable S. suis to survive within human macrophages. Integration of these intracellular proteomic signatures with previous exoproteomic, peptidomic, and network-based studies highlights translational and metabolic proteins—particularly DnaK, enolase, elongation factor EF-Tu, and GlmU—as multifunctional candidates linking survival and immunogenicity. This work establishes a comparative proteomic foundation for understanding S. suis intracellular adaptation and highlights potential targets for future vaccine or therapeutic development against this zoonotic pathogen. Full article

The whitefly Bemisia tabaci is a globally invasive pest that threatens crop production through feeding and virus transmission. In this study, we identified genes encoding enzymes in the chitin metabolism pathway of B. tabaci—β-N-acetylglucosaminidase (BtNAG), N-acetylglucosamine kinase (BtNAGK), phosphoacetylglucosamine mutase (BtPAGM), UDP-N-acetylglucosamine pyrophosphorylase (BtUAP), and glucosamine-6-phosphate N-acetyltransferase (BtGNA)—using bioinformatic analysis. Quantitative reverse-transcription PCR (RT-qPCR) analyses revealed distinct stage-specific expression patterns for these genes. We used the nanomaterial star polycation (SPc) to deliver gene-specific double-stranded RNA (dsRNA) targeting these genes to fourth instar B. tabaci nymphs, which resulted in significant mortality and developmental defects upon gene silencing. Notably, the fusion dsRNA targeting three genes—BtNAG1, BtNAGK, and BtUAP—achieved approximately 80% nymph mortality, 70% inhibition of adult emergence, and an earlier onset of gene silencing. These findings provide evidence that nanomaterial-assisted delivery of dsRNA can significantly enhance RNAi effects in hemipteran pests and that dsRNA targeting chitin metabolic genes may be an effective strategy for RNAi-based control of B. tabaci. Full article

Background. Dystroglycanopathies (DGPs) constitute a set of recessive, neuromuscular congenital dystrophies that result from impaired glycosylation of dystroglycan (DG). These disorders typically course with CNS alterations, which, alongside gradual muscular dystrophy, may include brain malformations, intellectual disability and a panoply of ocular defects. In this process, the protein products of 22 genes, collectively dubbed DGP-associated genes, directly or indirectly participate sequentially along a complex, branched biosynthetic pathway. POMGNT2 and POMGNT1 are two enzymes whose catalytic activity consists of transferring the same substrate, a molecule of N-acetylglucosamine (GlcNAc) to a common substrate, the O-mannosylated α subunit of DG. Despite their presumptive role in retinal homeostasis, there are currently no reports describing their expression pattern or function in this tissue. Purpose. This work focuses on POMGNT2 and POMGNT1 expression in the mammalian retina, and on the characterization of their distribution across retinal layers, and in the 661W photoreceptor cell line. Methods. The expression of POMGNT2 protein in different mammalian species’ retinas, including those of mice, rats, cows and monkeys, was assessed by immunoblotting. Additionally, POMGNT2 and POMGNT1 distribution profiles were analyzed using immunofluorescence confocal microscopy in retinal sections of monkeys and mice, and in 661W cultured cells. Results. Expression of POMGNT2 was detected in the neural retina of all species studied, being present in both cytoplasmic and nuclear fractions of the monkey and mouse, and in 661W cells. In the cytoplasm, POMGNT2 was concentrated in the endoplasmic reticulum (ER) and/or Golgi complex, depending on the species and cell type, whereas POMGNT1 accumulated only in the Golgi complex in both monkey and mouse retinas. Additionally, both proteins were present in the nucleus of the 661W cells, concentrating in the euchromatin and heterochromatin, as well as in nuclear PML and Cajal bodies, and nuclear speckles. Conclusions. Our results are indicative that POMGNT2 and POMGNT1 participate in the synthesis of O-mannosyl glycans added to α-dystroglycan in the ER and/or Golgi complex in the cytoplasm of mammalian retinal cells. Also, they could play a role in the modulation of gene expression at the mRNA level, which remains to be established, in a number of nuclear compartments in transformed retinal neurons. Full article