A comparative analysis of mesenchymal stem-cell lines derived from bone marrow and limb muscle of early human embryos

Abstract

The properties of mesenchymal stem-cell (MSC) lines derived from bone marrow (FetMSC) and limb muscle (M-FetMSC) of 5- to 6-week human embryos were assayed. The main cell-line characteristics were obtained at the sixth passage. The average cell-population doubling time was 33.0 ± 1.4 h for FetMSC and 25.0 ± 0.1 h for M-FetMSC. Growth curves indicated active cell proliferation. Numerical and structural karyotypic analysis showed that these lines have normal karyotype, 46, XY. Cell surface markers were analyzed by flow cytometry. It was found that the cells express CD44, CD73, CD90, CD105, and HLA-ABC surface antigens and vimentin, which are common for human MSC beings, and lack CD34 and HLA-DR. The cells were capable of osteogenic, chondrogenic, and adipogenic differentiation. Immunofluorescence and flow-cytometry assays reveled a lack of surface antigen TRA-1-60, high expression of surface antigen SSEA-4, and low expression of transcription factor Oct-4 attributed to human embryonic stem cells. Immunofluorescence analysis showed the presence of early differentiation markers, three germ-layer derivatives for human embryonic stem cells. This makes MSCs useful for repair of damaged tissue in the corresponding microenvironment. Despite their shared MSC status, the FetMSC and M-FetMSC lines displayed some interlinear differences related to growth characteristics and differentiation potential. The MFetMSC line exhibited reduced potential for adipogenic differentiation compared to the FetMSC line. Immunofluorescence analysis revealed Z-disks in M-FetMSC, but not in FetMSC, during skeletal-muscle differentiation. These findings suggest that the different microenvironment has an influence when cells are in an organism before their transplantation in vitro.