Selection using the α1-integrin (CD49a) enhances the multipotentiality of the mesenchymal stem cell population from heterogeneous bone marrow stromal cells
Laboratory of Stem Cells and Tissue Repair, Institute of Molecular and Cell Biology, Singapore, Singapore.Journal of Molecular Histology (Impact Factor: 1.82). 11/2007; 38(5):449-58. DOI: 10.1007/s10735-007-9128-z
Bone marrow-derived mesenchymal stem cells consist of a developmentally heterogeneous population of cells obtained from colony forming progenitors. As these colonies express the alpha-1 integrin (CD49a), here we single-cell FACS sorted CD49a+ cells from bone marrow in order to create clones and then compared their colony forming efficiency and multilineage differentiation capacity to the unsorted cells. Following selection, 40% of the sorted CD49a+ cells formed colonies, whereas parental cells failed to form colonies following limited dilution plating at 1 cell/well. Following ex vivo expansion, clones shared a similar morphology to the parental cell line, and also demonstrated enhanced proliferation. Further analysis by flow cytometry using a panel of multilineage markers demonstrated that the CD49a+ clones had enhanced expression of CD90 and CD105 compared to unsorted cells. Culturing cells in adipogenic, osteogenic or chondrogenic medium for 7, 10 and 15 days respectively and then analysing them by quantitative PCR demonstrated that CD49a+ clones readily underwent multlineage differentiation into fat, bone and cartilage compared to unsorted cells. These results thus support the use of CD49a selection for the enrichment of mesenchymal stem cells, and describes a strategy for selecting the most multipotential cells from a heterogeneous pool of bone marrow mononuclear stem cells.
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- "CD105 (human endoglin) is a homodimeric integral membrane glycoprotein, belonging to the transforming growth factor-b (TGF-b) receptor system, highly expressed in mesenchymal stem cells . A higher expression of CD105 in cells has been correlated with higher growth kinetics and differentiation potential  . However, adherent cells isolated from SAT and DAT showed comparable proliferation capacity and adipogenic potential. "
ABSTRACT: Subcutaneous fat represents a valuable reservoir of adipose-derived stem cells (ASCs) in the stromal vascular fraction (SVF), widely exploited in regenerative medicine applications, being easily harvested through lipoaspiration. The lack of standardized procedures for autologous fat grafting guided research efforts aimed at identifying possible differences related to the harvesting site, which may affect cell isolation yield, cell growth properties and clinical outcomes. Subcutaneous fat features a complex architecture: the superficial fascia separates superficial adipose tissue (SAT) from deep layer tissue (DAT). We aimed to unravel the differences between SAT and DAT, considering morphological structure, SVF composition, and ASC properties. SAT and DAT were collected from female donors and comparatively analyzed to evaluate cellular yield and viability, morphology, immunophenotype and molecular profile. ASCs were isolated in primary culture and used for in vitro differentiation assays. SAT and DAT from cadaver donors were also analyzed through histology and immunohistochemistry to assess morphology and cell localization within the hypoderm. Liposuctioned SAT contained a higher stromal tissue compound, along with a higher proportion of CD105-positive cells, compared with DAT from the same harvesting site. Also, cells isolated from SAT displayed increased multipotency and stemness features. All differences were mainly evidenced in specimens harvested from the abdominal region. According to our results, SAT features overall increased stem properties. Given that subcutaneous adipose tissue is currently exploited as the gold standard source for high-yield isolation of adult stem cells, these results may provide precious hints toward the definition of standardized protocols for microharvesting. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.Cytotherapy 05/2015; 17(8). DOI:10.1016/j.jcyt.2015.04.004 · 3.29 Impact Factor
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- "The absence of CD31 is a typical feature of MSCs.22 CD45 (protein tyrosine phosphatase receptor type C or leukocyte common antigen) can be found on the surface of differentiated haematopoietic cells, and it plays an important role in signal transduction to T- and B-cell receptors; therefore, it has been used as negative selective marker.23,24 CD49a, or alpha-1 integrin, has been used to isolate MSCs from bone marrow.25,26 CD49b, or alpha-2 integrin, participates in collagen I binding and might play a role in the survival of MSCs on collagen I.8 CD49d is the alpha-4 integrin subunit that is present in human MSCs under certain culture conditions.27 "
ABSTRACT: Xerostomia is a severe side effect of radiation therapy in head and neck cancer patients. To date, no satisfactory treatment option has been established. Because mesenchymal stem cells (MSCs) have been identified as a potential treatment modality, we aimed to evaluate stem cell distribution following intravenous and intraglandular injections using a surgical model of salivary gland damage and to analyse the effects of MSC injections on the recruitment of immune cells. The submandibular gland ducts of rats were surgically ligated. Syngeneic adult MSCs were isolated, immortalised by simian virus 40 (SV40) large T antigen and characterized by flow cytometry. MSCs were injected intravenously and intraglandularly. After 1, 3 and 7 days, the organs of interest were analysed for stem cell recruitment. Inflammation was analysed by immunohistochemical staining. We were able to demonstrate that, after intravenous injection, MSCs were recruited to normal and damaged submandibular glands on days 1, 3 and 7. Unexpectedly, stem cells were recruited to ligated and non-ligated glands in a comparable manner. After intraglandular injection of MSCs into ligated glands, the presence of MSCs, leucocytes and macrophages was enhanced, compared to intravenous injection of stem cells. Our data suggest that injected MSCs were retained within the inflamed glands, could become activated and subsequently recruited leucocytes to the sites of tissue damage.International Journal of Oral Science advance online publication, 9 May 2014; doi:10.1038/ijos.2014.23.International Journal of Oral Science 05/2014; 6(3). DOI:10.1038/ijos.2014.23 · 2.53 Impact Factor
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- "3G5 has not been tested as a cell surface marker for PMSCs and the expression patterns of STRO-1 and 3G5 in the placenta are not known. Another marker which has been used to enrich the CFU-F population is CD49a . Integrin alpha 1 (CD49a/VLA-1), which is the receptor for laminin and collagen, was also investigated. "
ABSTRACT: The chorionic villi of human term placentae are a rich source of mesenchymal stem cells (PMSCs). The stem cell "niche" within the chorionic villi regulates how PMSCs participate in placental tissue generation, maintenance and repair, but the anatomic location of the niche has not been defined. A number of cell surface markers for phenotypic characterisation of mesenchymal stem cells (MSCs) were employed to identify the stem cell niche within the chorionic villi of first trimester and term human placenta. This included antibodies to pericyte cell surface markers STRO-1 and 3G5, which have been used to identify mesenchymal stem cells in other tissues, but have not been studied in placental tissues. PMSCs were isolated from term human placentae and shown to have stem cell properties by their ability to grow on untreated plastic culture ware, capacity for forming clones (i.e. clonogenicity) and their capability to differentiate into adipocytes, chondrocytes and osteocytes. Western analysis confirmed that STRO-1 and 3G5 are present in placental protein extracts and in PMSCs. Immunocytochemistry revealed PMSCs were positive for MSC cell surface markers (STRO-1, 3G5, CD105, CD106, CD146, CD49a, alpha-SMA) and negative for haematopoietic stem cell markers (CD117, CD34) and endothelial markers (CD34, vWF). Immunohistochemistry with antibodies to MSC cell surface markers on first trimester and term tissues revealed a vascular niche for PMSCs. Dual-label immunofluorescence analysis was used to compare STRO-1 antibody staining with that of endothelial cell marker vWF and found no significant overlap in staining. This indicated that some PMSCs have a pericyte-like phenotype. We propose that the vascular niche harbours a pool of PMSCs that can give rise to committed progenitors for tissue maintenance and repair, and that PMSCs contribute to vessel maturation and stabilization.Placenta 03/2010; 31(3):203-12. DOI:10.1016/j.placenta.2009.12.006 · 2.71 Impact Factor