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.
"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 "
[Show abstract][Hide abstract] 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
"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. "
[Show abstract][Hide abstract] 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.
"Several attempts for purification of bone marrow-derived MSCs have been made using magnetic beads to select CD49a + [Deschaseaux et al., 2003; Rider et al., 2007], CD105 + [Aslan et al., 2006; Jarocha et al., 2008; Wong et al., 2008] and CD271 + cells [Battula et al., 2008; Jarocha et al., 2008]. To our knowledge, CD90 has not yet been used for the immunomagnetic isolation of ASCs, but is highly expressed. "
[Show abstract][Hide abstract] ABSTRACT: High hopes are put into the use of mesenchymal stem cells (MSCs) in various approaches for tissue engineering and regenerative medicine. MSCs are derived from different tissues with only small differences in their phenotype or their differentiation potential, but higher differences in the cell yield. Since fat is easily accessible and contains a high amount of MSCs to be isolated, adipose-derived stem cells (ASCs) are very promising for clinical approaches. ASCs are not a completely homogeneous cell population. Our study was initiated to explore an easy and convenient method to reduce heterogeneity. We tested different isolation methods: (1) the standard isolation method for ASCs based on plastic attachment, (2) the standard method with an initial washing step after 60 min of adherence and (3) immunomagnetic isolation by 4 typical markers (CD49a, CD90, CD105 and CD271). Cells isolated by these methods were evaluated using quantitative PCR and flow cytometry as well as by their differentiation potential. Washing led to a significantly lower expression of desmin, smA and six2, and a higher expression of the stem cell markers nestin, oct-4 and sall-1, compared to standard isolated cells, while the immunomagnetically isolated cells showed no significant changes. All cells independent of the isolation method could be induced to differentiate into adipocytes and osteoblasts. Our study demonstrates that a simple washing step reduces heterogeneity of cultured ASCs according to PCR analysis, whereas the immunomagnetic isolation only showed minor advantages compared to the standard method, but the disadvantage of significantly lower cell yields in the primary isolates.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.