Mesenchymal Stromal Cell Growth and Glycocalyx Morphology are Regulated by Media Glucose Levels and Hypoxia
Notice bibliographique
Résumé
Physiological conditions such as hypoxia and/or chemical environments such as glucose levels in the media function as key regulators of cell behavior. Mesenchymal stromal cells (MSCs) are unique cells which have played an important role in many regenerative medicine technologies. They are characterized by a multi‐lineage potential, ability to self‐renew and immunomodulatory properties. The microenvironment of stem cells may play a crucial role in maintaining their stemness and regenerative potential, and the cellular glycocalyx may be an important cell based regulator within this microenvironment. Hyaluronan (HA), a non‐sulfonated linear glycosaminoglycan found in the glycocalyx of MSCs and other cell types has been implicated in regulation of various physiological processes including inflammation, tissue regeneration, cell proliferation and migration. Here we investigated the effect of hypoxic environments (1% O 2 or 5% O 2 ) as well as different glucose concentrations in minimal media on MSC identity, viability and potency as well as production of HA levels in the glycocalyx. MSCs were derived from bone marrow and maintained in different oxygen conditions (1% O 2 , 5% O 2 or room air (~21% O 2 )). Additionally, bone marrow derived MSCs were also grown in alpha minimal essential media (αMEM) containing either low (1 mg/mL) or high (4.5 mg/mL) levels of glucose. Cell viability was measured microscopically using Trypan blue dye exclusion as well by flow cytometry with annexin V and propidium iodide staining. MSCs were characterized for identity through flow cytometry and potency through the induction of IDO by IFN‐gamma. HA levels were detected with biotin‐conjugated HA binding protein (HABP) followed by FITC‐conjugated streptavidin. Significantly higher numbers of MSCs were derived from bone marrow in 5% O 2 (21067 ±1579 cells/cm 2 ) when compared to 1% (14000 ± 5327 cells/cm 2 ) or 21% O 2 (10721 ± 3782 cells/cm 2 ). Additionally, cells grown in 5% O 2 had significantly lower doubling times of 42.5 ± 3.8 h in passage 1 in comparison to 52.8 ± 4.9 h for cells grown in 21% O 2 . However, no significant differences in cell morphology, cell identity and cell viability were observed between cells grown in 1%, 5% or 21% O 2 . Cells grown in high glucose media resulted in significantly enhanced cell yields (39333 ± 6839 cells/cm 2 ) in comparison to those cultured in low glucose media (13111 ± 1736 cells/cm 2 ). MSCs also displayed large intricate networks of high molecular weight (HMW) HA in the glycocalyx as shown by HABP binding and fluorescence microscopy. In comparison, MSCs grown in low glucose media displayed disperse networks of HA. Additionally, there was a 3‐fold increase observed in levels of HA when MSCs were cultured in high glucose media versus cells grown in low glucose media. MSCs in high glucose also displayed enhanced levels of CD44, one of the receptors of HA. Finally, Hyaluronidase treated cells grown in high glucose media displayed a lack of network formation of high molecular HA in the glycocalyx and a 2‐fold decrease in cell yield. These results suggest that the physiological and chemical environment of MSCs can play an important role in their growth characteristics. The balance between HMW and LMW HA as observed through the presence or absence of intricate networks of HA as a part of the cellular glycocalyx could be a significant factor regulating MSC growth and potency.
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) | 0,001 | 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 ».