-
Journal of Agricultural and Food... Apr 2024Enterotoxigenic (ETEC) K88 is the most common cause of diarrhea in neonatal and postweaning pigs. After adhering to small intestinal epithelial cells via glycoprotein...
Enterotoxigenic (ETEC) K88 is the most common cause of diarrhea in neonatal and postweaning pigs. After adhering to small intestinal epithelial cells via glycoprotein receptor recognition, the pathogen can produce enterotoxins, impair intestinal integrity, trigger watery diarrhea, and induce inflammation via nuclear factor κB (NF-κB) and mitogen-activated protein kinase phosphatase (MAPK) pathways. Inhibiting ETEC K88 adhesion to cell surfaces by interfering with the receptor-fimbriae recognition provides a promising strategy to prevent the initiation and progression of infection. Ovomucin is a highly glycosylated protein in chicken egg white with diverse bioactivities. Ovomucin hydrolysates prepared by the enzymes Protex 26L (OP) and pepsin/pancreatin (OPP) were previously revealed to prevent adhesion of ETEC K88 to IPEC-J2 cells. Herein, we investigated the protective effects of ovomucin hydrolysates on ETEC K88-induced barrier integrity damage and inflammation in IPEC-J2 and Caco-2 cells. Both hydrolysates inhibited ETEC K88 adhesion to cells and protected epithelial cell integrity by restoring transepithelial electronic resistance (TEER) values. Removing sialic acids in the hydrolysates reduced their antiadhesive capacities. Ovomucin hydrolysates suppressed ETEC-induced activation of NF-κB and MAPK signaling pathways in both cell lines. The ability of ETEC K88 in activating calcium/calmodulin-dependent protein kinase 2 (CaMK II), elevating intracellular Ca concentration, and inducing oxidative stress was attenuated by both hydrolysates. In conclusion, this study demonstrated the potential of ovomucin hydrolysates to prevent ETEC K88 adhesion and alleviate inflammation and oxidative stress in intestinal epithelial cells.
Topics: Humans; Animals; Swine; Enterotoxigenic Escherichia coli; Ovomucin; Bacterial Adhesion; Caco-2 Cells; NF-kappa B; Escherichia coli Infections; Diarrhea; Epithelial Cells; Inflammation; Intestinal Mucosa
PubMed: 38507577
DOI: 10.1021/acs.jafc.4c00185 -
JAMA Network Open Jul 2023Egg introduction in infants at age 4 to 6 months is associated with a lower risk of immunoglobulin E-mediated egg allergy (EA). However, whether their risk of EA at age... (Randomized Controlled Trial)
Randomized Controlled Trial
IMPORTANCE
Egg introduction in infants at age 4 to 6 months is associated with a lower risk of immunoglobulin E-mediated egg allergy (EA). However, whether their risk of EA at age 12 months is affected by maternal intake of eggs at birth is unknown.
OBJECTIVE
To determine the effect of maternal egg intake during the early neonatal period (0-5 days) on the development of EA in breastfed infants at age 12 months.
DESIGN, SETTING, AND PARTICIPANTS
This multicenter, single-blind (outcome data evaluators), randomized clinical trial was conducted from December 18, 2017, to May 31, 2021, at 10 medical facilities in Japan. Newborns with at least 1 of 2 parents having an allergic disease were included. Neonates whose mothers had EA or were unable to consume breast milk after the age of 2 days were excluded. Data were analyzed on an intention-to-treat basis.
INTERVENTIONS
Newborns were randomized (1:1) to a maternal egg consumption (MEC) group, wherein the mothers consumed 1 whole egg per day during the first 5 days of the neonate's life, and a maternal egg elimination (MEE) group, wherein the mothers eliminated eggs from their diet during the same period.
MAIN OUTCOMES AND MEASURES
The primary outcome was EA at age 12 months. Egg allergy was defined as sensitization to egg white or ovomucoid plus a positive test result in an oral food challenge or an episode of obvious immediate symptoms after egg ingestion.
RESULTS
Of the 380 newborns included (198 [52.1%] female), 367 (MEC: n = 183; MEE: n = 184) were followed up for 12 months. On days 3 and 4 after delivery, the proportions of neonates with ovalbumin and ovomucoid detection in breast milk were higher in the MEC group than in the MEE group (ovalbumin: 10.7% vs 2.0%; risk ratio [RR], 5.23; 95% CI, 1.56-17.56; ovomucoid: 11.3% vs 2.0%; RR, 5.55; 95% CI, 1.66-18.55). At age 12 months, the MEC and MEE groups did not differ significantly in EA (9.3% vs 7.6%; RR, 1.22; 95% CI, 0.62-2.40) or sensitization to egg white (62.8% vs 58.7%; RR, 1.07; 95% CI, 0.91-1.26). No adverse effects were reported.
CONCLUSIONS AND RELEVANCE
In this randomized clinical trial, EA development and sensitization to eggs were unaffected by MEC during the early neonatal period.
TRIAL REGISTRATION
UMIN Clinical Trials Registry: UMIN000027593.
Topics: Infant; Infant, Newborn; Humans; Female; Male; Egg Hypersensitivity; Breast Feeding; Ovalbumin; Mothers; Ovomucin; Single-Blind Method; Milk, Human
PubMed: 37428506
DOI: 10.1001/jamanetworkopen.2023.22318 -
Poultry Science May 2024Chicken egg chalaza (CLZ) is a natural colloidal structure in eggs that exists as an egg yolk stabilizer and is similar in composition to egg white. In this study, the...
Chicken egg chalaza (CLZ) is a natural colloidal structure in eggs that exists as an egg yolk stabilizer and is similar in composition to egg white. In this study, the proteome, phosphoproteome, and N-glycoproteome of CLZ were characterized in depth. We hydrolyzed the CLZ proteins and enriched the phosphopeptides and glycopeptides. We identified 45 phosphoproteins and 80 N-glycoproteins, containing 59 phosphosites and 203 N-glycosylation sites, respectively. Typically, the ovalbumin in CLZ was both phosphorylated and N-glycosylated, with 4 phosphosites and 4 N-glycosylation sites. Moreover, we identified 2 N-glycosylated subunits of ovomucin, mucin-5B and mucin-6, with 32 and nine N- glycosylation sites, respectively. Analysis of the phosphorylation and N-glycosylation status of CLZ proteins could provide novel insights into the structural and functional characteristics of CLZ.
Topics: Animals; Chickens; Egg Proteins; Proteomics; Proteome; Avian Proteins; Glycoproteins; Glycosylation; Ovum; Phosphoproteins
PubMed: 38518664
DOI: 10.1016/j.psj.2024.103629 -
Food Research International (Ottawa,... Aug 2023The protein profiles and properties of chicken egg white and its three components (thick egg white, TKEW; thin egg white, TNEW; and chalaza, CLZ) were comprehensively...
The protein profiles and properties of chicken egg white and its three components (thick egg white, TKEW; thin egg white, TNEW; and chalaza, CLZ) were comprehensively compared. The proteomes of TNEW and TKEW are relatively similar, but the abundance of mucin-5B and mucin-6 (the two subunits of ovomucin) is significantly higher in TKEW than in TNEW (42.97% and 870.04%, respectively), while the lysozymes in TKEW are 32.57% higher (p < 0.05) than those in TNEW. Meanwhile, the properties (including the spectroscopy, viscosity, and turbidity) of TKEW and TNEW are significantly different. Comprehensively, it is speculated that the electrostatic interactions between lysozyme and ovomucin are the main reason for the high viscosity and turbidity of TKEW. Compared with egg white sample (EW), CLZ has a higher abundance of insoluble proteins (mucin-5B, 4.23-fold; mucin-6, 6.89-fold) and a lower abundance of soluble proteins (ovalbumin-related protein X, 89.35% lower than EW; ovalbumin-related protein Y, 78.51% lower; ovoinhibitor, 62.08% lower; riboflavin-binding protein, 93.67% lower). These compositional differences should explain the insolubility of CLZ. These findings are important references for deepening the research and development of egg white in the future, such as the thinning of egg white, the molecular basis of changes in egg white properties, and the differential application of TKEW and TNEW.
Topics: Animals; Egg White; Ovalbumin; Ovomucin; Chickens; Mucin-5B; Mucin-6; Proteomics
PubMed: 37316084
DOI: 10.1016/j.foodres.2023.113019 -
International Journal of Biological... Jun 2024Ovomucin-Complex extracted from egg white is expected to have a barrier function similar to gastric mucin. In this study, the dynamic changes in structure, rheological...
Ovomucin-Complex extracted from egg white is expected to have a barrier function similar to gastric mucin. In this study, the dynamic changes in structure, rheological properties and binding ability of Ovomucin-Complex during in vitro simulated gastric digestion were investigated. The results from HPLC and CLSM showed that extremely acidic pH (pH = 2.0) promoted Ovomucin-Complex to form aggregation. Acid-induced aggregation may hinder its binding to pepsin, thus rendering Ovomucin-Complex resistant to pepsin. Consequently, most of the polymer structure and weak gel properties of Ovomucin-Complex retained after simulated gastric digestion as verified by HPLC, CLSM and rheological measurement, although there was a small breakdown of the glycosidic bond as confirmed by the increased content of reducing sugar. The significantly reduced hydrophobic interactions of Ovomucin-Complex were observed under extremely acidic conditions and simulated gastric digestion compared with the native. Noticeably, the undigested Ovomucin-Complex after simulated gastric digestion showed a higher affinity (K = 5.0 ± 3.2 nm) for urease - the key surface antigen of Helicobacter pylori. The interaction mechanism between Ovomucin-Complex and urease during gastric digestion deserves further studies. This finding provides a new insight to develop an artificial physical mucus barrier to reduce Helicobacter pylori infection.
Topics: Urease; Ovomucin; Hydrogen-Ion Concentration; Digestion; Protein Binding; Pepsin A; Polymerization; Helicobacter pylori; Rheology; Humans
PubMed: 38735615
DOI: 10.1016/j.ijbiomac.2024.132295 -
International Journal of Biological... Aug 2023Ovomucin (OVM) is an ideal natural macromolecular glycoprotein extracted from eggs with good adhesion. Based on the defect that glycyrrhizin (GL) has good antiviral...
Ovomucin (OVM) is an ideal natural macromolecular glycoprotein extracted from eggs with good adhesion. Based on the defect that glycyrrhizin (GL) has good antiviral activity but fast metabolism, this study aimed to explore the binding effect and mechanism of GL to OVM, using multi-spectroscopic techniques, isothermal titration calorimetry (ITC), and molecular docking. The adhesion ability of OVM to the hydrophilic interface and GL was first demonstrated by dual polarization interferometry (DPI) analysis and binding capacity assay, and the OVM-GL complex exhibited a similar affinity for the spike protein of COVID-19. The spectroscopic results show that GL can quench the inherent fluorescence and change the glycosidic bond and secondary structure of OVM. The ITC measurements suggested that the binding was exothermic, the hydrogen bond was the dominant binding force for forming OVM-GL. Finally, molecular docking results indicated that GL has hydrogen bond interaction with several amino acid residues located in α-OVM and β-OVM while embedding into the hydrophobic pocket of OVM via hydrophobic interactions. In conclusion, OVM can adhere to the hydrophilic interface and bind to GL through hydrogen bonding and hydrophobic interactions to form a stable complex, that is expected to be helpful in virus prophylaxis.
Topics: Ovomucin; Glycyrrhizic Acid; Molecular Docking Simulation; Spectrum Analysis; Eggs; Binding Sites; Protein Binding
PubMed: 37356685
DOI: 10.1016/j.ijbiomac.2023.125535 -
Jornal de Pediatria 2024Evaluate biomarkers capable of safely guiding Yellow fever vaccine (YFV) vaccination among individuals suspicious of hen's egg allergy, and identify factors associated...
OBJECTIVE
Evaluate biomarkers capable of safely guiding Yellow fever vaccine (YFV) vaccination among individuals suspicious of hen's egg allergy, and identify factors associated with a higher risk for adverse events after immunization (AEAI).
METHODS
Patients underwent skin prick test (SPT) for standardized allergens: whole egg, egg white, egg yolk; YFV (1:10 dilution; Biomanguinhos-Fiocruz), and intradermal test (IDT; YFV 0.02 mL, 1:100 dilution) and positive and negative controls. Serum levels of specific IgE (sIgE) for a whole egg, egg white, egg yolk, egg albumin, ovomucoid, lysozyme, and conalbumin (ImmunoCap®; ThermoFisher®) were obtained. Patients sensitized to YFV were submitted to YFV desensitization, and those negatives received YFV (0.5mL) and remained under surveillance for at least one hour.
RESULTS
103 patients were enrolled, 95% under 12 years old. 71% (81/103) of patients had reactions: 80% immediate, 11% mixed, and 9% delayed. There was an association between positive skin test results with YFV and the severity of the reaction (OR:7.64; 95%CI:1.61-36.32; p = 0,011). Only the presence of sIgE to ovomucoid was associated with clinical symptoms (p = 0,025). Thirty patients underwent the YFV desensitization protocol.
CONCLUSION
There is a relationship between the positivity of the egg's components and the severity of the clinical reaction. Furthermore, the relationship between the positivity of the tests with the YFV and egg's components may show a tendency to look at ovomucoid and conalbumin, but it is not a certainty. Therefore, further studies are needed to confirm these associations, and for now, the authors still recommend using the vaccine for testing when necessary.
Topics: Humans; Animals; Female; Child; Egg Hypersensitivity; Ovomucin; Yellow Fever; Conalbumin; Chickens; Immunoglobulin E; Vaccination; Allergens
PubMed: 37597532
DOI: 10.1016/j.jped.2023.07.004 -
Critical Reviews in Food Science and... 2024Some bioactive substances in food have problems such as poor solubility, unstable chemical properties and low bioavailability, which limits their application in... (Review)
Review
Some bioactive substances in food have problems such as poor solubility, unstable chemical properties and low bioavailability, which limits their application in functional food. Recently, many egg white protein-based delivery carriers have been developed to improve the chemical stability, biological activity and bioavailability of bioactive substances. This article reviewed the structure and properties of several major egg white proteins commonly used to construct bioactive substance delivery systems. Several common carrier types based on egg white proteins, including hydrogels, emulsions, micro/nanoparticles, aerogels and electrospinning were then introduced. The biological functions of common bioactive substances, the limitations, and the role of egg white protein-based delivery systems were also discussed. At present, whole egg white protein, ovalbumin and lysozyme are most widely used in delivery systems, while ovotransferrin, ovomucoid and ovomucin are less developed and applied. Egg white protein-based nanoparticles are currently the most commonly used delivery carriers. Egg white protein-based hydrogels, emulsions, and microparticles are also widely used. Future research on the application of various egg white proteins in developed new delivery systems will provide more choices for the delivery of various bioactive substances.
Topics: Animals; Chickens; Egg Proteins; Ovomucin; Functional Food; Emulsions; Hydrogels
PubMed: 35930299
DOI: 10.1080/10408398.2022.2107612 -
Foods (Basel, Switzerland) Dec 2023To compare the physical and chemical changes in egg whites during storage, assisting in the evaluation of differences in egg freshness between various chicken breeds, we...
To compare the physical and chemical changes in egg whites during storage, assisting in the evaluation of differences in egg freshness between various chicken breeds, we chose 240 blue-shelled eggs (Blue group) and 240 commercial brown-shelled eggs (Brown group) that 28-week-old hens had laid. In this study, all eggs were stored at 25 °C. The egg weight, egg components' weight and proportion, Haugh Unit value and the contents of S-ovalbumin, ovomucin and lysozyme in the thick albumen (KA) and thin albumen (NA) were measured at eight time points every 3 days until the 21st day of storage. The eggshell, yolk and KA proportions in the Brown group were significantly lower, whereas the NA proportion was significantly higher than that in the Blue group ( < 0.001). The Haugh Unit value and S-ovalbumin in the Brown group were significantly higher, whereas KA ovomucin and NA lysozyme were significantly lower than those in the Blue group ( < 0.001). There existed significant negative correlations between the KA and NA, irrespective of weight or proportion. The Haugh Unit value was significantly positively correlated with lysozyme and ovomucin, but significantly negatively correlated with S-ovalbumin. During storage, the KA weight (proportion), Haugh Unit value, lysozyme and ovomucin decreased, whereas the NA weight (proportion) and S-ovalbumin increased. At each time point, the NA lysozyme in the Brown group was lower than that in the Blue group ( < 0.05). After storage for 6 days, the KA ovomucin in the Brown group began to be lower than that in the Blue group ( < 0.05). The study showed that the weight (proportion) differences in egg components between blue-shelled eggs and commercial brown-shelled eggs are mainly due to the NA. The Haugh Unit value and albumin protein indexes of blue-shelled eggs were better than those of brown-shelled eggs, and showed mild changes during storage, indicating the better storage performance of blue-shelled eggs.
PubMed: 38137245
DOI: 10.3390/foods12244441 -
Allergy Feb 2024Identifying patients at risk of severe allergic reactions and/or low threshold of reactivity is very important, particularly for staple foods like egg.
BACKGROUND
Identifying patients at risk of severe allergic reactions and/or low threshold of reactivity is very important, particularly for staple foods like egg.
METHODS
One hundred and fifty children underwent double-blind placebo-controlled food challenge (DBPCFC) to baked egg (BE), skin prick testing and blood collection for serology and basophil activation test (BAT). Patients who passed BE DBPCFC underwent loosely cooked egg (LCE) DBPCFC. Severity of allergic reactions was classified following Practall guidelines and threshold dose was determined during DBPCFC.
RESULTS
Sixty out of 150 (40%) children reacted to BE and 16 out of 77 (21%) to LCE on DBPCFC. Considering DBPCFC to BE, 23 children (38%) had severe reactions and 33 (55%) reacted to 0.13 g or less of egg protein (low threshold group). Two children (2 out of 16 = 12%) had severe reactions to LCE. Demographic, clinical and most immunological features were not significantly different between severe/non-severe BE reactors or low/high threshold groups. Severe BE reactors had higher ovomucoid-sIgE (p = .009) and higher BAT to BE (p = .001). Patients with lower threshold to BE had higher IgE-specific activity (p = .027) and BAT to egg (p = .007) but lower severity score (p = .008). Optimal cut-offs for ovomucoid-sIgE had 100% sensitivity, 35% specificity and 60% accuracy and for BAT 76% sensitivity, 74% specificity and 75% accuracy to identify BE severe reactors. Optimal cut-offs for specific activity had 70% sensitivity, 68% specificity and 69% accuracy and for BAT 70% sensitivity, 72% specificity and 71% accuracy to identify low threshold patients.
CONCLUSIONS
BAT was the best biomarker to predict severity and threshold of allergic reactions to BE and can be useful when making decisions about management of egg allergy.
Topics: Child; Humans; Allergens; Basophil Degranulation Test; Egg Hypersensitivity; Immunoglobulin E; Ovomucin; Skin Tests; Double-Blind Method
PubMed: 37680143
DOI: 10.1111/all.15875