A kind of aquatic gelatin was prepared from squid skin. The technological parameters for extracting gelatin were optimized by the method of orthogonal design. The fundamental properties of the raw material and gelatin...A kind of aquatic gelatin was prepared from squid skin. The technological parameters for extracting gelatin were optimized by the method of orthogonal design. The fundamental properties of the raw material and gelatin were analyzed. The results showed that the optimal extraction conditions were as follows： pH val- ue of 8, temperature at 70 ℃, material-to-liquid ratio at 1：4, and extraction time of 1.5 h. under such conditions, the highest yield of gelatin and the purity were 5.94% and 96.73%, respectively. The physicoehemical properties of squid skin gelatin were coincided with standards of edible gelatin. In addition, the contents of amino acids were similar to many kinds of aquatic gelatin.展开更多
Increasing brown and beige fat thermogenesis have an anti-obesity effect and thus great metabolic benefits.However,the molecular mechanisms regulating brown and beige fat thermogenesis remain to be further elucidated....Increasing brown and beige fat thermogenesis have an anti-obesity effect and thus great metabolic benefits.However,the molecular mechanisms regulating brown and beige fat thermogenesis remain to be further elucidated.We recently found that fat-specific knockout of Rheb promoted beige fat thermogenesis.In the current study,we show that Rheb has distinct effects on thermogenic gene expression in brown and beige fat.Fat-specific knockout of Rheb decreased protein kinase A(PKA)activity and thermogenic gene expression in brown adipose tissue of high-fat diet-fed mice.On the other hand,overexpression of Rheb activated PKA and increased uncoupling protein 1 expression in brown adipocytes.Mechanistically,Rheb overexpression in brown adipocytes increased Notch expression,leading to disassociation of the regulatory subunit from the catalytic subunit of PKA and subsequent PKA activation.Our study demonstrates that Rheb,by selectively modulating thermogenic gene expression in brown and beige adipose tissues,plays an important role in regulating energy homeostasis.展开更多
Decreased functional β-cell mass is the hallmark of diabetes, but the cause of this metabolic defect remains elusive. Here, we show that the levels of the growth factor receptor-bound protein 10(GRB10), a negative re...Decreased functional β-cell mass is the hallmark of diabetes, but the cause of this metabolic defect remains elusive. Here, we show that the levels of the growth factor receptor-bound protein 10(GRB10), a negative regulator of insulin and m TORC1 signaling, are markedly induced in islets of diabetic mice and high glucose-treated insulinoma cell line INS-1 cells. β-cell-specific knockout of Grb10 in mice increased β-cell mass and improved β-cell function. Grb10-deficient β-cells exhibit enhanced m TORC1 signaling and reduced β-cell dedifferentiation, which could be blocked by rapamycin. On the contrary, Grb10 overexpression induced β-cell dedifferentiation in MIN6 cells. Our study identifies GRB10 as a critical regulator of β-cell dedifferentiation and β-cell mass, which exerts its effect by inhibiting m TORC1 signaling.展开更多
文摘A kind of aquatic gelatin was prepared from squid skin. The technological parameters for extracting gelatin were optimized by the method of orthogonal design. The fundamental properties of the raw material and gelatin were analyzed. The results showed that the optimal extraction conditions were as follows： pH val- ue of 8, temperature at 70 ℃, material-to-liquid ratio at 1：4, and extraction time of 1.5 h. under such conditions, the highest yield of gelatin and the purity were 5.94% and 96.73%, respectively. The physicoehemical properties of squid skin gelatin were coincided with standards of edible gelatin. In addition, the contents of amino acids were similar to many kinds of aquatic gelatin.
基金grants(81730022,81800758,and 81870601)from the National Nature Science Foundation of Chinaa grant from the National Key R&D Program of China(2018YFC2000100).
文摘Increasing brown and beige fat thermogenesis have an anti-obesity effect and thus great metabolic benefits.However,the molecular mechanisms regulating brown and beige fat thermogenesis remain to be further elucidated.We recently found that fat-specific knockout of Rheb promoted beige fat thermogenesis.In the current study,we show that Rheb has distinct effects on thermogenic gene expression in brown and beige fat.Fat-specific knockout of Rheb decreased protein kinase A(PKA)activity and thermogenic gene expression in brown adipose tissue of high-fat diet-fed mice.On the other hand,overexpression of Rheb activated PKA and increased uncoupling protein 1 expression in brown adipocytes.Mechanistically,Rheb overexpression in brown adipocytes increased Notch expression,leading to disassociation of the regulatory subunit from the catalytic subunit of PKA and subsequent PKA activation.Our study demonstrates that Rheb,by selectively modulating thermogenic gene expression in brown and beige adipose tissues,plays an important role in regulating energy homeostasis.
基金supported by grants from the National Natural Science Foundation of China (91749118, 82070807, 81770775, 81730022)Natural Science Foundation of Hunan Province, China (2021JJ30976)National Key Research and Development Program (2019YFA0801903, 2018YFC2000100)。
文摘Decreased functional β-cell mass is the hallmark of diabetes, but the cause of this metabolic defect remains elusive. Here, we show that the levels of the growth factor receptor-bound protein 10(GRB10), a negative regulator of insulin and m TORC1 signaling, are markedly induced in islets of diabetic mice and high glucose-treated insulinoma cell line INS-1 cells. β-cell-specific knockout of Grb10 in mice increased β-cell mass and improved β-cell function. Grb10-deficient β-cells exhibit enhanced m TORC1 signaling and reduced β-cell dedifferentiation, which could be blocked by rapamycin. On the contrary, Grb10 overexpression induced β-cell dedifferentiation in MIN6 cells. Our study identifies GRB10 as a critical regulator of β-cell dedifferentiation and β-cell mass, which exerts its effect by inhibiting m TORC1 signaling.
