Comparative study of the osteogenic differentiation of mesenchymal stem cells from bone marrow and adipose tissue of adult dogs

摘要

The aim of this study was to compare the osteogenic potential of mesenchymal stem cells obtained from bone marrow (BM-MSC) with those extracted from adipose tissue (AT-MSC) of adult dogs. The cells were phenotypically categorized according to the expression of CD29, CD90, CD34 and CD45, and submitted to adipogenic and chondrogenic differentiation for 21 days and osteogenic differentiation for 7, 14 and 21 days. Four groups were formed: BM-MSC in osteogenic medium (1), BM-MSC in basal medium (2), AT-MSC in osteogenic medium (3) and ATMSC in basal medium (4). On days 7, 14 and 21 of osteogenic differentiation, the cultures were submitted to evaluations of MTT conversion in formazan, of alkaline phosphatase activity (AP), of collagen and mineralized matrix synthesis, evaluation of the number of cells per field and there was quantification of the gene transcripts for osterix, bone sialoprotein (BSP), osteonectin (ON) and osteocalcin (OC). Both the cells obtained from bone marrow and those from adipose tissue showed high expression of stem cells markers and low expression of hematopoietic cells markers (lower than 2%). Besides, they were able to differentiate into osteoblasts, chondrocytes and adipocytes. AT-MSC submitted to osteogenic differentiation showed higher MTT conversion in formazan than BM-MSC, under the same conditions on days 7 and 21. The number of cells per field, the AP activity, the collagen and mineralized matrix synthesis were higher in AT-MSC en differentiation, in relation to BM-MSC under the same conditions in all evaluated times. Expressions of osterix, BSP and OC were predominantly higher in differentiated BMMSC, however the expression of ON was higher AT-MSC differentiated on days 7, 14 and 21. In conclusion, AT-MSC present higher osteogenic potential than BM-MSC when extracted from adult dogs.