Objective: 

Bone marrow-derived mesenchymal stem cells (MSCs) have long been considered as prototype of stem cells with marked proliferative potential, increased plastic ability, and presence of certain surface molecules. We isolated and cultured stem cells from different sources - bone marrow (MSC), dental pulp (DSC), skeletal muscle (MuSC) and umbilical cord (UCSC) - and comparatively analyzed their characteristics.

Methods: 

Tissue samples were processed using enzymatic digestion (Collagenase IA) or explant method, and adherent, fibroblastic-like cells were cultured in DMEM/F12 medium supplemented with 10% FCS. Starting with passage 2, using appropriate differentiation media, cells were induced towards the mesodermal lineages - adipocytes, osteoblasts and chondrocytes. Subsequently, differentiated cells were analyzed for presence of characteristic immunocytochemical markers: FABP4, osteocalcin and aggrecan. Phenotypical profile of undifferentiated cells was assessed by flowcitometry using characteristic surface markers, and we determined the ratio of positive cells between different populations: CD29, CD34, CD44, CD45, CD73, CD106, CD117, and CD90. Immunocytochemical staining used CD117, vimentin and Ki67 to certify presence of stem cells characteristics.

Results: 

Although cells of each type were obtained from 10 different subjects, we could not confirm the differentiation of DSC cells towards adipocytes, compared with stem cells from the other sources, which presented differentiation ratios ranging from 50% (MSC) to 85% (MuSC). CD29 and CD90 were significantly higher expressed in DSC compared with the other cellular types, while CD44 expression was decreased in stem cells populations. Expression of CD117 was increased in all cellular types when compared with MSC.

Conclusions: 

Stem cells from different sources are endowed with properties which make them suitable for diverse cellular therapies.