Growth Kinetics and in Vitro Aging of Mesenchymal Stem Cells Isolated From Rat Adipose Versus Bone Marrow Tissues

Objective- To investigate and compare growth potential as well as aging of mesenchymal stem cells (MSCs) derived from rat bone marrow tissue and adipose tissue (AT) occurred at epicardial and epididymal regions. Design- Experimental study.   Animals- 10 Wistar Rats.   Procedures- Rat MSCs occurred at bone marrow and epicardial and epididymal AT were isolated and culture expanded through several successive passages. Differentiation potential along bone, cartilage and adipose cell lineages was used to verify MSC identity of the isolated cells, and then the cells were comparatively investigated in terms of their colonogenic ability, population doubling time and growth curve characteristics. Furthermore, the number of senescent cells at different passages was quantified using senescent- associated (SA) ß galactosidase staining method. Results- MSCs from both AT appeared to have more proliferation capacity in culture than those from bone marrow since they exhibited significantly more colony number and shorter PDT value (P<0.05). Epicardial AT-MSCs indicated even more significant proliferation capacity than their epididymal counterparts. With respect to cell aging, marrow-MSCs cultures indicated higher percentages of senescent cells than AT-MSCs (P<0.05). Although the percentages of senescent cells in epididmal AT-MSCs were higher than epicardial AT- MSCs but the difference was not statistically significant. Conclusion and Clinical Relevance- Taken together we concluded that rat epicardial AT- MSCs could be appropriate cells for experimental and preclinical settings since they possess more expansion rate and less percentages of senescent cells in culture.