Presence of Arylsulfatase A and Sulfogalactosylglycerolipid in Mouse Ovaries: Localization to the Corpus Luteum.
Notice bibliographique
Résumé
The corpus luteum (CL) is a temporary endocrine gland formed in the ovary after ovulation. In contrast to the mature follicle, which consists of a cumulus oocyte complex surrounding by a substantial volume of follicular fluid, the corpus luteum is a solid structure of cells. Cell-cell communication and adhesion contribute to CL function, which is mainly to produce progesterone essential for maintaining pregnancy. However, if pregnancy ends or does not take place, the CL undergoes regression (luteolysis), induced by prostaglandinF2alpha (PGF2α). Functional regression of the luteal cells is associated with cessation of their progesterone secretory activity. Subsequently, structural luteolysis takes place with apoptosis of luteal cells and degeneration and processing of the extracellular matrices. Cytochemical studies indicate that acid hydrolases including arylsulfatase(s) are present in lysosomes of regressing luteal cells, and the increase in their activities with the progressive state of luteal regression suggests their roles in luteolysis. While it is tempting to speculate that the arylsulfatase detected in early localization studies (using an artificial substrate, p-nitrocatechol sulfate (NCS)) was arylsulfatase A (ASA) based on its pH optimum of 5, further studies to validate this postulation need to be performed, in particular by methods using an antibody monospecific to ASA. Further, the known substrates of ASA, sulfogalactosylglycerolipid (SGG) and sulfogalactosylceramide (SGC), are implicated in cell adhesion required during CL formation. Therefore, attempts to localize ASA's substrates should also be made. Our immunocytochemistry work revealed the selective presence of ASA in the CL of mouse ovaries, and immunoblotting indicated that CL ASA had a molecular mass of 66 kDa, similar to AS-A of other tissues. CL AS-A was active, capable of desulfating NCS at the optimum pH of 5. To further understand the role of ASA, its levels were determined during CL development in pseudopregnant mice and during luteolysis after cessation of pseudopregnancy (observed by a drop of serum progesterone). Immunocytochemistry, immunoblotting and NCS desulfation activity showed that ASA expression was evident at the onset of pseudopregnancy in the newly formed CL and its level rose steadily during the gland development. The increase in the expression and activity of ASA continued throughout luteolysis. SGG was also present selectively on the luteal cell surface in developed CL, as shown by immunofluorescence of mouse ovary sections as well as high performance thin layer chromatography (HPTLC) of lipids isolated from mouse and pig CL. The identity of the SGG band on the HPTLC plate was further validated by electrospray ionization mass spectrometry. Significantly, SGG disappeared in regressing CL. The SGG immunostaining in regressing CL (as denoted by their morphological properties) on the ovary sections of post-hCG Day-7 superovulated mice was minimal. HPTLC also showed SGG disappearance in lipids isolated from regressing CL of PGF2ï¡-treated estrous pigs. Therefore, lysosomal AS-A may be involved in cell surface remodeling during luteolysis by desulfating SGG, following its endocytosis and targeting to the lysosome. Funded by CIHR, Thailand Research Fund, University of Ottawa International Creative Research grant, WM Keck Foundation, MRF Fund, Development & Promotion of Science/Technology Talented Project Thailand.
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) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,000 | 0,001 |
| Bibliométrie | 0,002 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,001 |
| 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 ».