Physical activity improves age-related decline in the osteogenic potential of rats' bone marrow-derived mesenchymal stem cells

Aim: To examine whether physical activity increases osteogenic differentiation of bone marrow mesenchymal stem cells (BMMSCs) from adult rats compared with young rats. Methods: Eighteen female Wistar rats were divided into three groups and the following cells isolated: (1) differentiated BMMSCs from young donors, (2) differentiated BMMSCs from sedentary adult donors and (3) differentiated BMMSCs from active adult donors. We analysed MTT conversion, percentage of cells per field, mineralized nodule number and gene expression for telomerase reverse transcriptase (TERT), alkaline phosphatase, caspase 3, osteocalcin, bone sialoprotein and collagen I. Results: Telomerase reverse transcriptase expression and the percentage of cells per field in BMMSCs cultures from adult rats were smaller than those observed in young donors. However, levels of caspase 3 expression were higher in BMMSCs from adult donors (P<0.05). Despite the fact that physical activity was associated with an increase in expression of caspase 3 (P<0.05), there was no difference in the percentage of cells per field between groups of adult BMMSCs (active or sedentary). However, physical activity increased the number of mineralized nodules and osteocalcin expression after 21days, and alkaline phosphatase expression at 7, 14 and 21days in the BMMSCs of adult donors (P<0.05). However, those values were smaller when compared with young donors BMMSCs (P<0.05). Only the expression levels of alkaline phosphatase were similar to young donors BMMSCs (P=0.05). Conclusion: Physical activity increases osteogenic differentiation of BMMSCs from adult donors but does not increase the differentiation to the levels observed in BMMSCs from young donor rats.