Effects of Harvesting Sites and Ages on Adipose Tissue-derived Stem Cells in Rat

Adipose tissue-derived stem cells (ADSCs) are able to self-renew and to differentiate into various types of cells. For clinical application of ADSCs, the quality of ADSCs in terms of growth and differentiation should be considered. This study investigated whether the ability of ADSCs for growth and differentiation is affected by the harvesting sites of tissue or ages of animals. ADSCs were harvested from subcutaneous (Sub), inguinal (Ing), epididymal (Epi) and mesenteric (Mes) fat pads of Sprague Dawley rats. The expression levels of CD29 and CD90 were not different among harvesting sites of fat tissue. The growth of ADSCs were significantly higher in Ing and Sub during early passages (p2-p4) of cultures than in Epi and Mes. The growth of ADSCs decreased during the late passages (p6-p10) of cultures. Cell growth of ADSCs from animals of different ages was higher in 8weeks-old animals than in 4weeks-, 16 weeks- and 32 weeks-old animals. The expression levels of CD29 and CD90 were similar in all aged animals. There was no expression of CD34 and CD45 in ADSCs of all aged animals. In cell aggregation assay in ADSCs from different aged animals, ADSCs from 8 weeks- and 16 weeks-old animals formed larger cell aggregates than ADSCs from 4 weeks- and 32 weeks-old animals. The frequency of cell aggregation was higher in early passage of 8 weeks-old animals. These results showed that the harvesting sites of tissue and age of animals may influence the growth and differentiation potential of ADSCs. Therefore, the source of ADSCs should be considered for efficient clinical application.