Production of egg yolk phosphopeptides and the cellular mechanism of intestinal oxidative stress reduction
Notice bibliographique
Résumé
Oxidative stress in the gastrointestinal tract has been implicated in the initiation and propagation of inflammatory bowel diseases and other chronic intestinal pathologies. Antioxidants have limited efficacy and are sometimes pro-oxidant. An alternative, novel approach lies in the upregulation of endogenous antioxidative stress mechanisms which can combat oxidative stress and re-establish a stable cellular redox balance. Hen egg yolk-derived phosvitin phosphopeptides have been shown to exert this biological activity; however the preparation of these peptides was not suited to large-scale production. The goal of this work was to prepare bioactive peptides from delipidated egg yolk proteins with industry scale-up potential. In addition, the antioxidative stress activity of the peptides was evaluated, the bioactive fraction was identified and characterized, and the cell signaling pathways involved in influencing bioactivity was elucidated. Egg yolk peptides (EYP) were produced by Alcalase and Protease N digestion of defatted egg yolk proteins. This hydrolysate contained 1.00 ± 0.02% phosphate and significantly reduced (P<0.001) the oxidative stress biomarker, interleukin-8 (IL-8), in hydrogen peroxide-stimulated Caco-2 intestinal cells. EYP significantly (P<0.05) increased glutathione (GSH) and [gamma]-glutamylcysteine synthetase activity and mRNA expression, elevated the activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase, glutathione S-transferase), and lowered malondialdehyde and protein carbonyl concentrations in the duodenum, jejunum, ileum, and colon of piglets subjected to oxidative stress. GSH concentrations in red blood cells were also significantly (P<0.05) elevated in EYP-supplemented animals. Anion separation of EYP resulted in 4 fractions with the last fraction, EYP-F4, having 0.72 ± 0.06% phosphate. EYP-F4 significantly decreased (P<0.001) IL-8 in H202-stimulated cells and this bioactivity was maintained after pepsin and pancreatin digestion of EYP-F4 but not after dephosphorylation. Serine and phosphoserine did not reduce oxidative stress, but [Ser(PO3)]2 and [Ser(PO3)]3 significantly reduced (P<0.001) IL-8. Using mass spectrometry analysis, one of the peptides in the EYP bioactive fraction was identified as SKDSSSSSSKSNSK. This identified peptide is found in the phosvitin portion of vitellogenin-1, a yolk precursor protein. These results suggest a minimum of two contiguous phosphoserines in EYP-F4 peptides influence bioactivity. EYP-F4 and [Ser(PO3)]2 cell treatments increased the mRNA expression of antioxidant genes including glutathione reductase and glutathione peroxidase, and lowered the expression of pro-inflammatory genes such as myeloperoxidase and lactoperoxidase in an oxidative stress and antioxidant defense microarray. It is likely that EYP-F4 and [Ser(PO3)]2 increased antioxidant gene expression by activating the nuclear factor-E2-related factor 2-antioxidant response element pathway and decreased inflammatory gene expression by inhibiting the nuclear factor kappa B pathway. Egg yolk phosphopeptides influence the activation of protective antioxidative stress mechanisms which contribute to the prevention of intestinal oxidative stress.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».