RESUMO
In this study, mesenchymal stem cells were isolated from rat adipose tissue (AD-MSCs) to characterize and differentiate them into endothelial-like cells. AD-MSCs were isolated by mechanical and enzymatic treatments, and their identity was verified by colony-forming units (CFU) test and by differentiation into cells of mesodermal lineages. The endothelial differentiation was induced by plating another aliquot of cells in EGM-2 medium, enriched with specific endothelial growth factors. Five subcultures were performed. The expression of stemness genes (OCT4, SOX2 and NANOG) was investigated. The presence of CD90 and the absence of the CD45 were evaluated by flow cytometry. The endothelial-like cells were characterized by the evaluation of morphological changes and gene expression analysis for endothelial markers (CD31, CD144, CD146). Characterization of AD-MSCs showed their ability to form clones, to differentiate in vitro and the OCT-4, SOX-2, NANOG genes expression. Immunophenotypic characterization showed the CD90 presence and the CD45 absence. The endothelial-like cells showed morphological changes, the expression of CD31, CD144, CD146 genes and the presence of CD31 membrane receptor. Matrigel assay showed their ability to form network and vessels-like structures. This study lays the foundations for future evaluation of the potential AD-MSCs pro-angiogenic and therapeutic role.
Assuntos
Tecido Adiposo/citologia , Diferenciação Celular/fisiologia , Células Endoteliais/citologia , Células-Tronco Mesenquimais/citologia , Ratos Wistar/anatomia & histologia , Animais , Antígenos CD/genética , Antígenos CD/metabolismo , Antígeno CD146/genética , Antígeno CD146/metabolismo , Caderinas/genética , Caderinas/metabolismo , Colágeno , Meios de Cultura , Regulação para Baixo , Combinação de Medicamentos , Citometria de Fluxo , Perfilação da Expressão Gênica , Laminina , Antígenos Comuns de Leucócito/metabolismo , Proteína Homeobox Nanog/genética , Proteína Homeobox Nanog/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Molécula-1 de Adesão Celular Endotelial a Plaquetas/genética , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Proteoglicanas , Ratos , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Antígenos Thy-1/metabolismo , Regulação para CimaRESUMO
Marginal donors represent a poorly utilized source of organs for transplantation despite their availability. The key is to reduce the ischemic damage in the effort to improve organ quality. This study investigated the histologic effects after in situ perfusion of preservation with a two-layer method compared with the classic University of Wisconsin preservation in term of tissue integrity and number of viable exocrine cells in the rat pancreas both after exsanguination and at 8 weeks of cryopreservation. Pancreata harvested from 60 rats were collected using 3 methods: two-layer method following University of Wisconsin perfusion; exsanguination; and classic University of Wisconsin perfusion/storage. In addition to histologic analysis of collected pancreata, we analyzed the number of CK19(+) cells and their viability using chi-square tests with values P < .05 considered to be significant. Rat pancreas histology showed as University of Wisconsin in situ perfusion and preservation by the two-layer method to be more effective to maintain the morphologic integrity of both exocrine and endocrine tissues. There were a larger number of CK19(+) cells with good viability. Moreover, the effects of oxygenation were visible in pancreas biopsies preserved after exsanguination. In situ University of Wisconsin perfusion and preservation for 240 minutes with the two-layer method yielded greater numbers and viability of CK19(+) cells even after 8 weeks of cryopreservation.
Assuntos
Preservação de Órgãos/métodos , Pâncreas , Animais , Criopreservação , Ratos , Ratos WistarRESUMO
The influence of a co-rotating twin screw extruder's controlling variables on its residence time distribution (RTD) patterns were measured and analyzed. Variables studied included: screw profile, throughput, screw speed, moisture content and die diameter. Throughput, screw speed and screw profile had strong influence on the mean residence time. Water content, die size and temperature did not.A combination plug flow-perfect mixing model was shown to adequately describe the dimensionless RTD data.