Insulin promotes the expression of the gluconeogenic rate-limiting enzymes phosphoenolpyruvate carboxykinase (Pepck) and glucose 6-phosphatase (G6pase) through PI3k/Akt/mTOR signaling pathway in goose hepatocytes

To identify what makes insulin have an activating or inhibiting role in gluconeogenesis in goose hepatocytes and whether insulin regulates PEPCK and G6Pase through the PI3k/Akt/mTOR pathway or not, goose primary hepatocytes were isolated and cultured in vitro. After 12h cultured in serum-free medium, hepatocytes were incubated for 24 h in the medium with no addition (control) or with the addition of 50, 100, and 150 nM of insulin, 1000 nM NVP-BEZ235, or co-addition of 150nM insulin and 1000nM NVP-BEZ235. Glucose concentration and PEPCK and G6Pase expression were determined. The results showed that PEPCK and G6Pase mRNA levels and activities were up regulated in the 50, 100, and 150nM insulin treatments, while glucose concentration was not significantly altered (p > 0.05). Compared with the activation role of 150nM insulin alone, the co-treatment with1000nM NVP-BEZ235 and 150nM insulin significantly down regulated PEPCK mRNA level and G6Pase protein activity (p < 0.05). However, there is a different result on mRNA level of G6Pase. In conclusion, G6Pase and PEPCK are up regulated by insulin through PI3k/Akt/mTOR pathway in goose hepatocytes. However, G6Pase mRNA and protein levels may be regulated by insulin through different signaling pathways.

Insulin promotes the expression of the gluconeogenic rate-limiting enzymes phosphoenolpyruvate carboxykinase (Pepck) and glucose 6-phosphatase (G6pase) through PI3k/Akt/mTOR signaling pathway in goose hepatocytes

To identify what makes insulin have an activating or inhibiting role in gluconeogenesis in goose hepatocytes and whether insulin regulates PEPCK and G6Pase through the PI3k/Akt/mTOR pathway or not, goose primary hepatocytes were isolated and cultured in vitro. After 12h cultured in serum-free medium, hepatocytes were incubated for 24 h in the medium with no addition (control) or with the addition of 50, 100, and 150 nM of insulin, 1000 nM NVP-BEZ235, or co-addition of 150nM insulin and 1000nM NVP-BEZ235. Glucose concentration and PEPCK and G6Pase expression were determined. The results showed that PEPCK and G6Pase mRNA levels and activities were up regulated in the 50, 100, and 150nM insulin treatments, while glucose concentration was not significantly altered (p > 0.05). Compared with the activation role of 150nM insulin alone, the co-treatment with1000nM NVP-BEZ235 and 150nM insulin significantly down regulated PEPCK mRNA level and G6Pase protein activity (p < 0.05). However, there is a different result on mRNA level of G6Pase. In conclusion, G6Pase and PEPCK are up regulated by insulin through PI3k/Akt/mTOR pathway in goose hepatocytes. However, G6Pase mRNA and protein levels may be regulated by insulin through different signaling pathways.(AU)

Change of the mtor pathway in tissues of overfed geese

This study aimed at examining the effect of overfeeding on the activity of the mTOR pathway in the liver and muscle tissues of Gang geese. Eighty healthy male Gang geese were reared under the same feeding conditions, and were divided at 14 weeks of age into a control group and an overfed group. All birds were slaughtered after three weeks of over feeding. Gene expression and protein content of several genes involved in the mTOR pathway were evaluated. The results showed that the gene expression of mTOR, raptor, and rictor, and the protein contents of mTOR and PI3K were higher in liver, breast muscle, and leg muscle of the overfed group than that of control group. However, the S6K expression level was clearly lower in the liver of the overfed group than that of control group, and there was no evident difference in both breast muscle and leg muscle between the control group and the overfed group. These results suggest that overfeeding induces the activity of raptor, rictor, and mTOR, and that mTOR signaling pathway was closely linked with PI3K pathway in the evaluated geese.(AU)

Change of the mtor pathway in tissues of overfed geese

This study aimed at examining the effect of overfeeding on the activity of the mTOR pathway in the liver and muscle tissues of Gang geese. Eighty healthy male Gang geese were reared under the same feeding conditions, and were divided at 14 weeks of age into a control group and an overfed group. All birds were slaughtered after three weeks of over feeding. Gene expression and protein content of several genes involved in the mTOR pathway were evaluated. The results showed that the gene expression of mTOR, raptor, and rictor, and the protein contents of mTOR and PI3K were higher in liver, breast muscle, and leg muscle of the overfed group than that of control group. However, the S6K expression level was clearly lower in the liver of the overfed group than that of control group, and there was no evident difference in both breast muscle and leg muscle between the control group and the overfed group. These results suggest that overfeeding induces the activity of raptor, rictor, and mTOR, and that mTOR signaling pathway was closely linked with PI3K pathway in the evaluated geese.