title: Activation of Sirt1 decreases adipocyte formation during osteoblast differentiation of mesenchymal stem cells.
abstract: Mesenchymal stem cells (MSC) can differentiate into osteoblasts, adipocytes, chondrocytes and myoblasts. It has been suggested that a reciprocal relationship exists between the differentiation of MSC into osteoblasts and adipocytes. Peroxisome proliferator-activated receptor gamma2 (PPARgamma2) is a key element for the differentiation into adipocytes. Activation of the nuclear protein deacetylase Sirt1 has recently been shown to decrease adipocyte development from preadipocytes via inhibition of PPARgamma2. In vitro, MSC differentiate to osteoblasts when exposed to bone-inducing medium. However, adipocytes are also developed. In the present study we have targeted Sirt1 to control adipocyte development during differentiation of MSC into osteoblasts. The finding that resveratrol and isonicotinamide markedly inhibited adipocyte and promoted osteoblast differentiation demonstrates an interesting alternative to PPARgamma antagonists. These results are important for the evolving field of cell-based tissue engineering, but may also be relevant in the search for new treatments of osteoporosis.
authors: Department for Clinical Science, Intervention and Technology (CLINTEC), Karolinska Institutet, Karolinska University Hospital, Huddinge, Sweden. magnus@backesjo.se
authors: Carl-Magnus
authors: CM
authors: Bäckesjö
authors: Yan
authors: Y
authors: Li
authors: Urban
authors: U
authors: Lindgren
authors: Lars-Arne
authors: LA
authors: Haldosén
mesh_terms: D017667:Adipocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001854:Bone Marrow Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D002117:Calcitriol / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D005786:Gene Expression Regulation / Q000187:drug effects; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051381:Rats; D056564:Sirtuin 1; D037761:Sirtuins / Q000378:metabolism*; D017154:Stromal Cells / Q000187:drug effects / Q000378:metabolism
chemical_list: D015415:Biomarkers; C470545:Sirt1 protein, mouse; D056564:Sirtuin 1; D037761:Sirtuins; D002117:Calcitriol