Tissue Engineering and Regenerative Medicine

Multipotent mesenchymal stromal/stem cells (MSC) can be isolated from different tissues. Their morphology, immunophenotype and differentiation potential are dependent on their tissue of origin. MSC isolated from adult human tissues are ideal candidate for tissue regeneration and tissue engineering, however, invasive methods of tissue harvesting is making this procedure uncomfortable for the tissue donors. We analyzed biological properties of MSC isolated from human bone marrow (BM), skeletal muscle and skin from post-operative tissues collected from limbs amputated due to critical limb ischemia. Long-term cultures of MSCs were performed in standard medium. Cells were observed up to 12 passages (P) and examined for phenotype and differentiation potential. Adherent cells, isolated from all examined tissues, express phenotype characteristic for naïve MSC: CD73, CD90, CD105, however their expression down-regulated during follow-up period (after P7). A fraction of MSC isolated from skeletal muscle express myogenic markers: CD56, desmin (up to P7) and dystrophin (expression increased after P7). Co-expression of CD73/CD146, CD90/CD146 and CD105/CD146 was detected on the proportion of adherent cells originated from BM, skeletal muscle and skin, and this suggest that they are proangiogenic progenitors. A fraction of cells expressing CD146 strongly co-expressed PDGFR-α. Cells isolated from examined tissues were capable to differentiate into chondrocytes, osteoblasts and adipocytes. Thus, MSC isolated from BM and skin biologically represent multipotent cells capable to differentiate into different type of tissues, whereas progenitor cells isolated from skeletal muscle have tissue-specific character. Post-operative tissues may serve as an alternative source of MSCs for potential clinical applications.