P66Shc, a key regulator of metabolism and mitochondrial ROS production, is dysregulated by mouse embryo culture
Notice bibliographique
Résumé
STUDY QUESTION: Do high oxygen tension and high glucose concentrations dysregulate p66Shc (Src homologous-collagen homologue adaptor protein) expression during mouse preimplantation embryo culture? SUMMARY ANSWER: Compared with mouse blastocysts in vivo, P66Shc mRNA and protein levels in blastocysts maintained in vitro increased under high oxygen tension (21%), but not high glucose concentration. WHAT IS KNOWN ALREADY: Growth in culture adversely impacts preimplantation embryo development and alters the expression levels of the oxidative stress adaptor protein p66Shc, but it is not known if p66Shc expression is linked to metabolic changes observed in cultured embryos. STUDY DESIGN, SAMPLES/MATERIALS, METHODS: We used a standard wild-type CD1 mouse model of preimplantation embryo development and embryo culture with different atmospheric oxygen tension and glucose media concentrations. Changes to p66Shc expression in mouse blastocysts were measured using quantitative RT-PCR, immunoblotting and immunofluorescence followed by confocal microscopy. Changes to oxidative phosphorylation metabolism were measured by total ATP content and superoxide production. Statistical analyses were performed on a minimum of three experimental replicates using Students' t-test or one-way ANOVA. MAIN RESULTS AND THE ROLE OF CHANCE: P66Shc is basally expressed during in vivo mouse preimplantation development. Within in vivo blastocysts, p66Shc is primarily localized to the cell periphery of the trophectoderm. Blastocysts cultured under atmospheric oxygen levels have significantly increased p66Shc mRNA transcript and protein abundances compared to in vivo controls (P < 0.05). However, the ratio of phosphorylated serine 36 (S36) p66Shc to total p66Shc decreased in culture regardless of O2 atmosphere used, supporting a shift in the mitochondrial fraction of p66Shc. Total p66Shc localized to the cell periphery of the blastocyst trophectoderm and phosphorylated S36 p66Shc displayed nuclear and cytoplasmic immunoreactivity, suggesting distinct compartmentalization of phosphorylated S36 p66Shc and the remaining p66Shc fraction. Glucose concentration in the culture medium did not significantly change p66Shc mRNA or protein abundance or its localization. Blastocysts cultured under low or high oxygen conditions exhibited significantly decreased cellular ATP and increased superoxide production compared to in vivo derived embryos (P < 0.05). LIMITATIONS/REASONS FOR CAUTION: This study associates embryonic p66Shc expression levels with metabolic abnormalities but does not directly implicate p66Shc in metabolic changes. Additionally, we used one formulation of embryo culture medium that differs from that used in other mouse model studies and from clinical media used to support human blastocyst development. Our findings may, therefore, be limited to this media, or may be a species-specific phenomenon. WIDER IMPLICATIONS OF THE FINDINGS: This is the first study to show distinct immunolocalization of p66Shc to the trophectoderm of mouse blastocysts and that its levels are abnormally increased in embryos exposed to culture conditions. Changes in p66Shc expression and/or localization could possibly serve as a molecular marker of embryo viability for clinical applications. The outcomes provide insight into the potential metabolic role of p66Shc. Metabolic anomalies are induced even under the current optimal culture conditions, which could negatively impact trophectoderm and placental development. LARGE SCALE DATA: Not applicable. STUDY FUNDING AND COMPETING INTERESTS: Canadian Institutes of Health Research (CIHR) operating funds, Ontario Graduate Scholarship (OGS). There are no competing interests.
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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 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 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 ».