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Mesenchymal stem cells (MSCs) are multipotent stem cells capable of differentiating into adipocytes in the presence of a hormone cocktail. These cells thus provide a promising model for studying the early events of adipogenesis. Here, we examine the involvement of the PI3K/Akt and mTOR/p70S6K signaling pathways in human MSC adipogenesis. We found that the two pathways were strongly activated with a similar temporal profile under the adipogenesis-inducing hormone cocktail and this activation could be blocked by LY294002, a specific inhibitor of PI3K. Furthermore, rapamycin, a specific inhibitor of mTOR, blocked the activation of mTOR/p70S6K but not PI3K/Akt. Both LY294002 and rapamycin severely suppressed lipid accumulation, as well as the expression of adipogenic markers, including PPAR gamma 2 and C/EBP alpha, two master adipogenic transcription factors. Together, these data indicate that the mTOR/p70S6K pathway acts downstream of the PI3K/Akt pathway in mediating the adipogenic conversion of MSCs. In conclusion, our data suggest that the PI3K/Akt and mTOR/p70S6K signaling pathways are essential for adipogenesis of human MSCs.

Objective: To observe the antiviral effect of Yu Gan capsules against DHBV in ducks., Methods: 50 Guangzhou brown spot ducks were used in this experiment. After the ducks were infected DHBV, they were divided into four groups at random (ACV 200 mg/kg group, Yu Gan capsules 6.5 g/kg group, Yu Gan capsules 3.25 g/kg group and virus control group) and Drugs were given by stomach once a day. Blood samples were taken from each duck and tested for DHBV-DNA's level. Researches left liver tissue were, sheared and used for optical analysis., Results: In Yu Gan capsules 6.5 g/kg group, DHBV-DNA's level in ducks' serum decreased on the 5th and 10th days after treatment and the 3th day after recession of treatment. There was a significant difference in the DHBV-DNA's level between the days after treatment and before treatment. there was also significant difference in the DHBV-DNA's level between Yu Gan capsules 6. 5 g/kg group and virus control group (P <0.01). Whereas, no inhibition effect was found in Yu Gan capsules 3.25 g/kg group., Conclusion: Yu Gan capsules have functions on anti-DHBV in duck.