Comparative study of mesenchymal stem cells from rat bone marrow and adipose tissue

Several therapeutic products based on mesenchymal stem cells (MSCs) have been translated into clinical applications. MSCs should undergo in vitro culture before a sufficient quantity can be achieved. Hence, both expansion kinetics and the biological characteristics of derived cells from primary culture are pertinent to their applications. In the present study, MSCs were isolated from rat bone marrow and adipose tissue (designated as bMSCs and aMSCs, respectively) and cells were comparatively analyzed regarding cell morphology, proliferation, colony formation, differentiation potential, and immunophenotype following the long-term subculture. No apparent differences could be noticed concerning the morphology between bMSCs and aMSCs. The long-term subculture made both types of cells smaller, weakened their colony-forming ability, and stimulated the proliferation rate. However, bMSCs demonstrated better proliferation and colony-forming ability than aMSCs. No significant difference was observed about the expression of some immunophenotypes (i.e. CD29(+)/CD90(+)/CD34(-)/CD45(-)) regardless of cell types or population doublings. Notably, bMSCs, but not aMSCs, maintained the differentiation potential well after the long-term subculture. The present study demonstrates that MSCs derived from different tissues can be well expanded for the long term, although cells display gradually declined self-renewal and differentiation potentials to different extents depending on the tissue origins.