Treatment of primary hepatocytes also caused an increase in b-catenin protein

uoles containing neutral lipids. The number of differentiated adipocytes in culture increased in the presence of 10 or 100 mM nicotinamide. To test whether activation of Sirt-1 inhibits adipogenesis during osteoblastic differentiation, MSC cultures were treated with resveratrol and then co-treated with Vorapaxar various concentrations of nicotinamide in osteogenic induction medium. Pre-treatment of MSCs with resveratrol and co-treatment with nicotinamide promoted osteogenic differentiation and inhibited adipogenic differentiation. However, the inhibition of adipogenesis by resveratrol was concentration dependent. Pre-treatment of MSCs with 1 mM resveratrol and co-treatment with 100 mM nicotinamide did not result in osteogenesis, but stimulated adipogenesis. Effects of resveratrol or/and nicotinamide on osteogenic differentiation of MSC and pre-osteoblastic cells in highdensity cultures Incubation of MSCs with osteogenic induction medium resulted in osteogenesis; cells exhibited high levels of nuclear euchromatin, large numbers of morphologically normal cellular organelles, numerous cell-cell processes and large quantities of thick fibrils in a well-organized extracellular matrix. Treatment of MSC cultures with the osteogenic induction medium and resveratrol induced osteogenesis. However, no significant differences in osteogenesis were observed at the ultrastructural level between with resveratroltreated and untreated MSC cultures. In contrast, in the presence of the sirtuin inhibitor ” nicotinamide, osteogenesis was not observed, and some MSCs underwent Resveratrol Promotes Osteogenesis of MSCs apoptosis, with degeneration of the cells, membrane blebbing, nuclear damage and formation of apoptotic bodies. Remaining cells differentiated to adipocytes as demonstrated by lipid accumulation in fat vacuoles. The quantity of differentiated adipocytes in culture increased in the presence of 10 or 100 mM nicotinamide. Transmission electron microscopy clearly showed that the MSCs differentiated to adipocytes, accumulating cytoplasmic lipid droplets and exhibiting welldeveloped rough endoplasmic reticulum and mitochondria. Pre-treatment of MSCs with resveratrol and co-treatment with nicotinamide promoted osteogenic differentiation. However, the inhibition of adipogenesis by resveratrol was concentration dependent. Pre-treatment of MSCs with 1 mM resveratrol and co-treatment with 100 mM nicotinamide resulted in adipogenesis. Incubation of pre-osteoblastic MC3T3-E1 cells with the osteogenic induction medium or/and resveratrol resulted in osteogenesis. However, in contrast to MSCs, treatment of preosteoblastic MC3T3-E1 cells with nicotinamide, led to apoptosis instead of to formation of adipocytes. Pre-treatment of preosteoblastic MC3T3-E1 cells with resveratrol and co-treatment with nicotinamide promoted osteogenic differentiation. Statistical evaluation of the data clearly highlighted changes in the number of cells with fat vacuole accumulation before and after nicotinamide-treatment in MSC-osteogenesis high-density cultures. Co-treatment with resveratrol decreased the number of adipocytes with accumulated fat vacuoles. Effect of resveratrol or/and nicotinamide on extracellular matrix, Runx2 “8887974 and PPAR-c expression during MSCosteogenesis and in pre-osteoblastic cell-osteogenesis To confirm the morphological results described above and to demonstrate more precisely the identity of the osteogenesis or adipogenesis by MSCs or pre-osteoblastic cell cultures, whole c