The increase in marrow adipogenesis associated with osteoporosis and age-related
osteopenia is well known clinically. However, we are only now beginning to understand the
mechanisms that control the differentiation of mesenchymal stem cells to either osteoblasts
or adipocytes. Recent work with gene silencing and overexpression has provided insight
into critical pathways that determine the fate of these multipotential cells. One of these
pathways—that of the nuclear hormone receptor peroxisome proliferator activated receptor-γ …