Regulatory Mechanism of Rat Preantral Follicular Development: Involvement of FSH, Thyroid Hormone and Growth Differentiation Factor-9.
Notice bibliographique
Résumé
Hypothyroidism is associated with suppressed ovarian follicular growth and infertility, although the cellular and molecular mechanism(s) involved is not known. While FSH promotes growth of cultured follicles, this response is markedly enhanced by the presence of growth differentiation factor-9 (GDF-9) or Triiodothyronine (T3). In vivo studies have shown that the effect of thyroid hormone on FSH-induced follicular growth is specific to the preantral stage. While GDF-9 is required for FSH receptor (FSHR) expression in preantral follicles, whether this response is required for the FSH-T3 interaction during preantral growth is unclear. The objective in the present study is to assess the role of T3 in the regulation of preantral follicular growth and the cellular mechanism involved. Preantral follicles (diameter: 150-180 µm) isolated from ovaries of 14-day old rats were cultured in serum-free medium for various durations (0 - 60h) and concentrations of FSH (0 - 100 ng/ml) or T3 (0 - 10-8 M). FSHR mRNA abundance and 18S rRNA levels were determined by quantitative real-time PCR. GDF-9 Morpholino antisense oligos (GDF-9 MO, 10 µM) or its control (CTL MO, 10 µM) were injected into the oocyte and the follicles were cultured for 4 6 days ± FSH and/or T3. Apoptosis (TUNEL) and GDF-9 expression (IHC) were performed at the end of the culture period. T3 markedly enhanced FSH-induced preantral follicular growth during 4-days of culture. GDF-9 in the cultured follicles was predominantly immunolocalized in the oocyte and significant oocyte GDF-9 expression is associated with follicles with minimal or absence of apoptosis. Addition of T3 or FSH markedly increased GDF-9 mRNA abundance in 12-18h (P<0.05). Intra-oocyte injection of GDF-9 MO decreased oocyte GDF-9 expression and induced follicular apoptosis, as well as suppressed growth of preantral follicles cultured with FSH and T3 (P<0.001). Addition of GDF-9 (100 ng/ml) to the MO-treated follicles significantly prevented the decrease in preantral follicular growth (P<0.01). In addition, T3 significantly increased FSHR mRNA abundance in the presence but not absence of FSH at 36h of culture period (P<0.001). Maximal responses were observed at 10 ng/ml FSH and 10-9 M T3. The level of FSHR mRNA was significantly decreased in GDF-9 MO-injected follicles cultured for 36h with both FSH and T3 (P<0.001). Our findings suggest that T3 plays an important role in the regulation of ovarian follicular growth. It interacts with FSH in promoting preantral follicular growth and this action is mediated through increased FSHR expression which in turn is dependent on adequate oocyte GDF-9 expression and action. This study offers new insight into the molecular and cellular mechanism of impaired follicular growth during hypothyroid state. (Supported by CIHR-IHDCYH Program on Oocyte Health and STIRRHS).
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 distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| 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 tête enseignante, 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 ».