Transient suppression of PPARγ directed ES cells into an osteoblastic lineage

Osteoblasts and adipocytes are believed to share a common progenitor. Peroxisome proliferator-activated receptor gamma (PPAR gamma) plays a key role in the switching of these two cell lineages. Here, we demonstrated the differentiation of ES cells into an osteoblastic lineage using siRNA against PPAR gamma without the addition of any osteogenic factors. We found that PPAR gamma-siRNA downregulated the expression of aP2 mRNA and lipid accumulation, whereas it upregulated the expression of osteocalcin and calcium deposition. These results suggested that ES cells were directed into an osteoblastic lineage. Therefore, transient suppression using PPAR gamma-siRNA may be a novel tool to induce differentiation of ES cells into osteoblasts. (c) 2006 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.