Stem Cell Antigen-1 Expression Marks a Population of Mouse Ovarian Surface Epithelial Cells with Enhanced Stem/Progenitor Cell Characteristics.
Notice bibliographique
Résumé
Stem cell antigen-1 (Sca-1) is the most common marker used to enrich for murine hematopoietic stem cells and with the realization that many stem cell types share conserved biochemical pathways, Sca-1 has become an attractive stem cell marker candidate for identifying a variety of tissue specific stem/progenitor cells (referred to as stem cells). The mouse ovarian surface epithelium (OSE) is a single layer of poorly differentiated cells that covers the surface of the ovary and is ruptured during ovulation. The remaining OSE cells surrounding the ovulatory wound then proliferate rapidly to regenerate the surface layer of cells. Since rapid healing also occurs in other epithelial tissues where stem cells are the source of proliferating cells, we propose that the OSE contains a Sca-1+ stem cell population which gives rise to the rapidly proliferating cells that close ovulatory wounds. Using flow cytometry we have shown that the OSE contains a side population of cells (SP, 3% of all OSE) that rapidly effluxes Hoechst 33342, a characteristic that is frequently found in stem cells in other tissues. Since SP analysis typically identifies a heterogeneous population of cells we used quantitative RT-PCR to compare expression levels of specific stem cell markers in SP versus non-SP cells. We have determined that OSE SP cells express 5-fold higher levels of Sca-1 mRNA and 3-fold higher levels of the stem cell marker CD117 (KIT) mRNA when compared to non-SP cells. These results indicate that both Sca-1 and CD117 are potential candidate stem cell markers in the OSE. To compare growth potential and the ability of the Sca-1+/- and CD117+/- OSE cells to self-renew in vitro, spheroid generating efficiency was assessed. Using magnet assisted cell sorting, we divided OSE cells into Sca-1+ and Sca-1- fractions (0.89% and 99.1% respectively) and CD117+ and CD117- fractions (2.3% and 97.7% respectively) and compared sphere generating efficiency in methylcellulose. The Sca-1+ fraction yielded significantly more spheres (p<0.001) compared to all other fractions (% sphere generating efficiency after 28 days: Sca-1+ 0.37; Sca-1- 0.020; CD117+ 0.028; CD117- 0.013) suggesting that it is a good marker for OSE stem cell enrichment. The sphere generating efficiencies of the CD117+ and CD117- OSE fractions (0.028% vs. 0.013%) was not statistically different indicating that CD117 may not be a useful marker for isolating a population of OSE cells with enhanced stem cell characteristics. The incidence of sphere formation can be increased by at least two factors highly expressed at ovulation (TGF-beta and LIF) indicating that ovulation may influence the OSE stem cell population. Currently, we are performing in vivo experiments to determine if Sca-1+ OSE have the ability to repopulate the surface of the ovary. Preliminary results show that only the Sca-1+ OSE are able to attach to the surface of the ovary and survive for at least 5 weeks which indicates that this fraction may be enriched for OSE stem cells. These results indicate that the OSE contains a population of Sca-1+ cells with enhanced stem cell properties (inclusion in SP, enhanced sphere generating efficiency, ability to attach and survive on the surface of the ovary). Interestingly, we have also found that factors highly expressed in follicular fluid at the time of ovulation may influence OSE stem cell activity thereby driving ovulatory wound healing. (platform)
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 | 0,001 | 0,001 |
| 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 | 0,001 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,002 | 0,001 |
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 ».