Age and site should be considered when investigating the effect of growth factors on human bone-derived cells

摘要

We read with great interest the article by Kuhn and colleagues (1) discussing the synergistic stimulatory effect of fibroblast growth factor-2 (FGF-2) and bone morphogenetic protein-2 on elderly mouse and human bone. We noticed that the distinguishing feature of this study was the focus on age- and site-dependent effects of the two growth factors. However, a shortcoming in the design of this study may confound their work, making the concentration results less persuasive. To investigate the optimal concentrations of FGF-2 and bone morphogenetic protein-2 used in young (29-year-old) and older (59-year-old) human osteoblast cell cultures, the authors chose the calvarial progenitor cells from 5-day-old neonatal mice. We have learned that the response of os-teoblasts to growth factors such as FGF-2 is age related. According to Cowan and colleagues (2), juvenile (2-day-old) osteoblasts contain a large subpopulation of less differentiated cells.