Comparison of Proliferative and Multilineage Differentiation Potential of Sheep Mesenchymal Stem Cells Derived from Bone Marrow, Liver, and Adipose Tissue

Despite major progress in our general knowledge related to the application of adult stem cells, finding alternative sources for bone marrow Mesenchymal Stem Cells (MSCs) has remained to be challenged. In this study successful isolation, multilineage differentiation, and proliferation potentials of sheep MSCs derived from bone marrow, adipose tissue, and liver were widely investigated. The primary cell cultures were prepared form tissue samples obtained from sheep 30-35 day fetus. Passage-3 cells were plated either at varying cell densities or different serum concentrations for a week. The Population Doubling Time (PDT), growth curves, and Colony Forming Unit (CFU) of MSCs was determined. The stemness and trilineage differentiation potential of MSCs were analyzed by using molecullar and cytochemical staining approaches. The data was analyzed through one way ANOVA using SigmaStat (ver.2). The highest PDT and lowest CFU were observed in adipose tissue group compared with other groups (p<0.001). Comparing different serum concentrations (5, 10, 15, and 20%), irrespective of cell sources, the highest proliferation rate was achieved in the presence of 20% serum (p<0.001). Additionally, there was an inverse relation between cell seeding density at culture initiation and proliferation rate, except for L-MSC at 300 cell seeding density. All three sources of fetal sheep MSCs had the identical trilineage differentiation potential. The proliferative capacity of liver and bone marrow derived MSCs were similar at different cell seeding densities except for the higher fold increase in B-MSCs at 2700 cells/cm2 density. Moreover, the adipose tissue derived MSCs had the lowest proliferative indices.