Figure 6

Possible cellular origin of adipocytes induced by BRL. The number of adipocytes may be influenced by a number of recruitment pathways, including from commitment of mesenchymal stem cells or bipotential progenitors to the preadipocyte pool (pathway 1), from maturation of committed adipocyte precursors (pathway 2) and the conversion of committed osteoprogenitor cells and/or osteoblasts into adipocytes via transdifferentiation or plasticity (pathway 3). BRL directs mesenchymal stem or multipotential progenitor cells in RBM to adipocytes at the expense of osteoblast differentiation. A portion of osteoprogenitor cells in RC cells may be able to express both osteoblast and adipocyte phenotypes in response to BRL. A portion of committed adipocyte precursors in RC populations also responds to BRL with an increase in adipogenesis.