Mobilization of Endothelial Progenitor Cells in Autologous and Allogeneic Peripheral Blood Stem Cell Grafts.
Notice bibliographique
Résumé
Abstract Endothelial-like progenitor cells circulate in the peripheral blood and can be enumerated using cell culture progenitor assays. These circulating vascular progenitor cells (VPCs) are implicated in new vessel formation and regenerative potential in several animal and human models of tissue injury. A small proportion likely arise from rare marrow-derived hemangioblasts, a greater number from vessel-wall endothelial precursors, and the majority derive from circulating monocytic progenitors under angiogenic stimulation. Given the emerging role of VPCs in regenerative processes, we sought to characterize the mobilization of VPCs in peripheral blood stem cell grafts used in autologous and allogeneic hematopoietic transplantation. Mononuclear cells were separated from peripheral blood (PB) or peripheral blood stem cell (PBSC) samples using Ficoll density centrifugation and plated on fibronectin-coated plastic dishes in RPMI supplemented with 20% fetal calf serum, 50 μg/ml endothelial cell growth factor, and 10 IU/ml heparin. After 48 h, the more immature non-adherent cells were collected, washed and re-plated in fibronectin-coated dishes under similar angiogenic conditions. Media and growth factors were replaced every 2 – 3 days and putative VPC clusters were enumerated 7 days after replating. Immunohistochemistry revealed that VPC clusters from PB and PBSCs were CD45+ and acquired endothelial features (CD31 and VE-cadherin) in vitro under angiogenic stimulation and gradually lost monocytic surface markers (CD14) suggesting the important contribution of monocyte-derived VPCs. VPCs were then enumerated in transplant candidates with hematologic malignancies (multiple myeloma = 4 pts, and lymphoma = 3 pts, having received a median of 2 previous chemotherapy regimens (range: 1–4) and 7 previous treatment cycles (range: 4–14)), and compared to healthy controls (n=21). Before mobilization, VPCs were markedly reduced in patients with hematologic malignancies as compared to normal donors with 16±10 vs 99±21 VPCs per ml (mean±SD), respectively (p=0.006). In 5 patients undergoing mobilization with cyclophosphamide and G-CSF, VPCs in the PB increased from 7±2 on day 0 to 51±9 by day 7 of mobilization (p=0.05), representing a median fold-increase of 8.9 (range, 3.0 – 29.8). Levels of VPCs in PB on day 7 of mobilization correlated with the peripheral blood CD34 counts measured on the same day (r=0.94). In an effort to compare the regenerative capacity and blood-forming potential of autologously mobilized PBSCs (n=5) and PBSCs from normal donors (n=14), graft VPCs were compared with levels of CD34+ cells, total CFU and CFU-GM. None of these hematopoietic progenitors correlated with VPC numbers in a significant manner (r < 0.5 in all tests of linearity). Using standard mobilization strategies, we have observed that VPCs were higher in allogeneic (7.5±1.6 x103/kg) than autologous (2.7±1.7 x103/kg) mobilized peripheral blood grafts (p=0.05). Our analysis of PBSC grafts indicates that VPC content in patients undergoing autologous SCT is low both before and after standard mobilisation strategies. In addition, VPC mobilization may occur independently of hematopoietic mobilization. In view of the potential role of VPCs in recovery from transplant related tissue injury, it may be useful to devise angiogenic mobilization strategies that complement hematopoietic mobilization.
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 ».