RESUMO
GD2 ganglioside has been identified as a key determinant of bone marrow-derived mesenchymal stem cells (BM-MSCs). Here, we characterized GD2 ganglioside expression and its implications in umbilical cord blood-derived MSCs (UCB-MSCs). Using immune-selection analysis, we showed that both GD2-positive and GD2-negative UCB-MSCs expressed general stem cell markers and possessed mesodermal lineage differentiation potential. Although the fraction of GD2-expressing cells was lower in UCB-MSC than in BM-MSC populations, inhibition of GD2 synthesis in UCB-MSCs suppressed neuronal differentiation and down-regulated basic helix-loop-helix (bHLH) transcription factors, which are involved in early stage neuronal differentiation. In addition, the levels of bHLH factors in neuronally induced UCB-MSCs were significantly higher in GD2-positive than GD2-negative cells. Our data demonstrate that GD2 ganglioside expression is associated with regulation of bHLH factors and identify neurogenic-capable UCB-MSCs, providing new insights into the potential clinical applications of MSC-based therapy.
Assuntos
Sangue Fetal/citologia , Sangue Fetal/metabolismo , Gangliosídeos/metabolismo , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Neurônios/citologia , Neurônios/metabolismo , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Diferenciação Celular , Proliferação de Células , Separação Celular , Células Cultivadas , Ensaio de Unidades Formadoras de Colônias , Transplante de Células-Tronco de Sangue do Cordão Umbilical , Primers do DNA/genética , Humanos , Recém-Nascido , Transplante de Células-Tronco Mesenquimais , N-Acetilgalactosaminiltransferases/antagonistas & inibidores , N-Acetilgalactosaminiltransferases/genética , N-Acetilgalactosaminiltransferases/metabolismo , Neurogênese , RNA Interferente Pequeno/genéticaRESUMO
PURPOSE: The present study was aimed to assess the feasibility of using decellularized aortic allograft in a rat small animal surgical model for conducting small diameter vascular tissue engineering research. MATERIALS AND METHODS: Decellularized aortic allografts were infra-renally implanted in 12 Sprague-Dawley (SD) adult rats. The conduits were harvested at 2 (n = 6) and 8 weeks (n = 6), and assessed by hematoxylin and eosin (H&E), van Gieson, Masson Trichrome staining, and immunohistochemistry for von Willebrand factor, CD 31(+), and actin. RESULTS: Consistent, predictable, and reproducible results were produced by means of a standardized surgical procedure. All animals survived without major complications. Inflammatory immune reaction was minimal, and there was no evidence of aneurysmal degeneration or rupture of the decellularized vascular implants. However, the aortic wall appeared thinner and the elastic fibers in the medial layer showed decreased undulation compared to the normal aorta. There was also minimal cellular repopulation of the vascular media. The remodeling appeared progressive from 2 to 8 weeks with increased intimal thickening and accumulation of both collagen and cells staining for actin. Although the endothelial like cells appeared largely confluent at 8 weeks, they were not as concentrated in appearance as in the normal aorta. CONCLUSION: The results showed the present rat animal model using decellularized vascular allograft implants to be a potentially durable and effective experimental platform for conducting further research on small diameter vascular tissue engineering.