by Keyword: Progenitor cells

By year:[ 2019 | 2018 | 2017 | 2016 | 2015 | 2014 | 2013 | 2012 | 2011 | 2010 | 2009 | 2008 | 2007 | 2006 | 2005 ]

Perea-Gil, I., Uriarte, J. J., Prat-Vidal, C., Gálvez-Montón, C., Roura, S., Llucià-Valldeperas, A., Soler-Botija, C., Farré, R., Navajas, D., Bayes-Genis, A., (2015). In vitro comparative study of two decellularization protocols in search of an optimal myocardial scaffold for recellularization American Journal of Translational Research , 7, (3), 558-573

Introduction. Selection of a biomaterial-based scaffold that mimics native myocardial extracellular matrix (ECM) architecture can facilitate functional cell attachment and differentiation. Although decellularized myocardial ECM accomplishes these premises, decellularization processes may variably distort or degrade ECM structure. Materials and methods. Two decellularization protocols (DP) were tested on porcine heart samples (epicardium, mid myocardium and endocardium). One protocol, DP1, was detergent-based (SDS and Triton X-100), followed by DNase I treatment. The other protocol, DP2, was focused in trypsin and acid with Triton X-100 treatments. Decellularized myocardial scaffolds were reseeded by embedding them in RAD16-I peptidic hydrogel with adipose tissue-derived progenitor cells (ATDPCs). Results. Both protocols yielded acellular myocardial scaffolds (~82% and ~94% DNA reduction for DP1 and DP2, respectively). Ultramicroscopic assessment of scaffolds was similar for both protocols and showed filamentous ECM with preserved fiber disposition and structure. DP1 resulted in more biodegradable scaffolds (P = 0.04). Atomic force microscopy revealed no substantial ECM stiffness changes post-decellularization compared to native tissue. The Young’s modulus did not differ between heart layers (P = 0.69) or decellularization protocols (P = 0.15). After one week, recellularized DP1 scaffolds contained higher cell density (236 ± 106 and 98 ± 56 cells/mm2 for recellularized DP1 and DP2 scaffolds, respectively; P = 0.04). ATDPCs in both DP1 and DP2 scaffolds expressed the endothelial marker isolectin B4, but only in the DP1 scaffold ATDPCs expressed the cardiac markers GATA4, connexin43 and cardiac troponin T. Conclusions. In our hands, DP1 produced myocardial scaffolds with higher cell repopulation and promotes ATDPCs expression of endothelial and cardiomyogenic markers.

Keywords: Acellular myocardial scaffold, Adipose tissue-derived progenitor cells, Decellularization protocols, Extracellular matrix, Myocardial infarction, Recellularization

Almendros, Isaac, Carreras, Alba, Montserrat, Josep M., Gozal, David, Navajas, Daniel, Farre, Ramon, (2012). Potential role of adult stem cells in obstructive sleep apnea Frontiers in Neurology , 3, 1-6

Adult stem cells are undifferentiated cells that can be mobilized from the bone marrow or other organs, home into injured tissues and differentiate into different cell phenotypes to serve in a repairing capacity. Furthermore, these cells can respond to inflammation and oxidative stress by exhibiting immunomodulatory properties. The protective and reparative roles of mesenchymal stem cells (MSCs), very small embryonic-like stem cells (VSELs) and endothelial progenitor cells (EPCs) have primarily been examined and characterized in auto-immune and cardiovascular diseases. Obstructive sleep apnea (OSA) is a very prevalent disease (4-5% of adult population and 2-3% of children) characterized by an abnormal increase in upper airway collapsibility. Recurrent airway obstructions elicit arterial oxygen desaturations, increased inspiratory efforts and sleep fragmentation, which have been associated with important long-term neurocognitive, metabolic, and cardiovascular consequences. Since inflammation, oxidative stress and endothelial dysfunction are key factors in the development of the morbid consequences of OSA, bone marrow-derived stem cells could be important modulators of the morbid phenotype by affording a protective role. This mini-review is focused on the recent data available on EPCs, VSELs and MSCs in both animal models and patients with OSA.

Keywords: Mesenchymal Stem Cells, Sleep Apnea, Endothelial progenitor cells, Very Small-like Embryonic Stem Cells, Adult bone-marrow derived stem cells

Kodippili, G. C., Spector, J., Kang, G. E., Liu, H., Wickrema, A., Ritchie, K., Low, P. S., (2010). Analysis of the kinetics of band 3 diffusion in human erythroblasts during assembly of the erythrocyte membrane skeleton British Journal of Haematology , 150, (5), 592-600

Summary During definitive erythropoiesis, erythroid precursors undergo differentiation through multiple nucleated states to an enucleated reticulocyte, which loses its residual RNA/organelles to become a mature erythrocyte. Over the course of these transformations, continuous changes in membrane proteins occur, including shifts in protein abundance, rates of expression, isoform prominence, states of phosphorylation, and stability. In an effort to understand when assembly of membrane proteins into an architecture characteristic of the mature erythrocyte occurs, we quantitated the lateral diffusion of the most abundant membrane protein, band 3 (AE1), during each stage of erythropoiesis using single particle tracking. Analysis of the lateral trajectories of individual band 3 molecules revealed a gradual reduction in mobility of the anion transporter as erythroblasts differentiated. Evidence for this progressive immobilization included a gradual decline in diffusion coefficients as determined at a video acquisition rate of 120 frames/s and a decrease in the percentage of compartment sizes >100 nm. Because complete acquisition of the properties of band 3 seen in mature erythrocytes is not observed until circulating erythrocytes are formed, we suggest that membrane maturation involves a gradual and cooperative assembly process that is not triggered by the synthesis of any single protein.

Keywords: Band 3 diffusion, Erythrocyte, Progenitor cells, Single particle tracking, Streptavidin quantum dot

Rodriguez-Segui, S. A., Pla, M., Engel, E., Planell, J. A., Martinez, E., Samitier, J., (2009). Influence of fabrication parameters in cellular microarrays for stem cell studies Journal of Materials Science: Materials in Medicine , 20, (7), 1525-1533

Lately there has been an increasing interest in the development of tools that enable the high throughput analysis of combinations of surface-immobilized signaling factors and which examine their effect on stem cell biology and differentiation. These surface-immobilized factors function as artificial microenvironments that can be ordered in a microarray format. These microarrays could be useful for applications such as the study of stem cell biology to get a deeper understanding of their differentiation process. Here, the evaluation of several key process parameters affecting the cellular microarray fabrication is reported in terms of its effects on the mesenchymal stem cell culture time on these microarrays. Substrate and protein solution requirements, passivation strategies and cell culture conditions are investigated. The results described in this article serve as a basis for the future development of cellular microarrays aiming to provide a deeper understanding of the stem cell differentiation process.

Keywords: Bone-marrow, Protein microarrays, Progenitor cells, Differentiation, Surfaces, Growth, Biomaterials, Commitment, Pathways, Culture media