Recombinant growth/differentiation factor-5 stimulates osteogenic differentiation of fat-derived stromal cells in vitro.

Fat-derived stromal cells can differentiate into various skeletal tissues. Currently the mechanism that determines whether stromal cells differentiate into osteoblasts is unclear and the role of growth/differentiation factor (GDF)-5 in differentiation of fat-derived stromal cells is not fully understood. It appears that the differentiation of stromal cells is greatly enhanced by GDF-5 that plays a role in a variety of musculoskeletal processes such as joint formation, tendon maintenance, and bone formation. Our study showed that GDF-5 promotes the differentiation of rat fat-derived stromal cells into osteogenic lineages in vitro. Furthermore, these findings were confirmed by histology, biochemical assay for alkaline phosphatase activity, and analysis of gene expression. The ability to preferentially stimulate fat-derived stromal cells down the osteogenic pathway holds significance in a variety of clinical scenarios.