Objective To investigate the expression of phosphatase and tension homolog(PTEN) in adipose tissue of KKAy diabetic mice, a mouse model of type 2 diabetes. Methods KKAy diabetic mice were fed with high fat diet for 4 ...Objective To investigate the expression of phosphatase and tension homolog(PTEN) in adipose tissue of KKAy diabetic mice, a mouse model of type 2 diabetes. Methods KKAy diabetic mice were fed with high fat diet for 4 weeks. After blood glucose met the criteria of diabetes(over 16.7 mmol/L), mice were randomly divided into 3 groups: a control group(without any treatment), a rosiglitazone group(treated with rosiglitazone 12.5 mg/kg·d once per day), and a metformin group(treated with metformin 3 g/kg·d twice daily). After 4 weeks, we then determined the expression of PTEN and phosphoserine 473-Akt(pS473-Akt) in the epididymal adipose tissue with Western blots. The mice in each group were further divided into the insulin(-) subgroup and insulin(+) subgroup, which were intraperitoneally injected with saline and insulin(5 mU/g body weight), respectively. Results The expression of PTEN was elevated in the epididymal adipose tissue obtained from KKAy diabetic mice compared with that from the C57BL/6J mice(P<0.001). In accordance with the enhanced expression of PTEN, the level of pS473-Akt stimulated by insulin was decreased in the adipose tissue of KKAy mice compared to the C57BL/6J mice(P<0.001). Treatment with the insulin-sensitizing agents, rosiglitazone and metformin did not inhibit the elevated expression of PTEN in adipose tissue of KKAy diabetic mice. Conclusion PTEN may play an important role in the development of insulin resistance in adipose tissue of type 2 diabetes mice model.展开更多
In addition to white adipose tissue （WAT） that stores energy, human and small mammals also have brown adipose tissue （BAT） that dissipates chemical energy for thermogenesis. BAT contains multilocular lipid droplet...In addition to white adipose tissue （WAT） that stores energy, human and small mammals also have brown adipose tissue （BAT） that dissipates chemical energy for thermogenesis. BAT contains multilocular lipid droplets and much higher numbers of mitochondria than WAT. The mitochondria in BAT uncouple large amounts of fuel oxidation from ATP for heat generation. Accumulating evidences have demonstrated that increased activity and/or amount of BAT can reverse obesity and improve insulin resistance, which highlights that BAT plays an important role in energy metabolism. In this review, we summarized recent findings that shows advantageous effects of BAT activation in metabolic diseases. In addition, we presented the function and role of brown and beige fat cells and regulatory factors for them. Finally, we discussed the potential application of brown adipocytes-based therapy and pharmacological intervention to increase BAT activity for the treatment of obesity and related diseases including insulin resistance, cardiovascular diseases and type 2 diabetes.展开更多
基金Supported by National Natural Science Foundation of China(81270878)National Key Program of Clinical Science of China(WBYZ2011-873)
文摘Objective To investigate the expression of phosphatase and tension homolog(PTEN) in adipose tissue of KKAy diabetic mice, a mouse model of type 2 diabetes. Methods KKAy diabetic mice were fed with high fat diet for 4 weeks. After blood glucose met the criteria of diabetes(over 16.7 mmol/L), mice were randomly divided into 3 groups: a control group(without any treatment), a rosiglitazone group(treated with rosiglitazone 12.5 mg/kg·d once per day), and a metformin group(treated with metformin 3 g/kg·d twice daily). After 4 weeks, we then determined the expression of PTEN and phosphoserine 473-Akt(pS473-Akt) in the epididymal adipose tissue with Western blots. The mice in each group were further divided into the insulin(-) subgroup and insulin(+) subgroup, which were intraperitoneally injected with saline and insulin(5 mU/g body weight), respectively. Results The expression of PTEN was elevated in the epididymal adipose tissue obtained from KKAy diabetic mice compared with that from the C57BL/6J mice(P<0.001). In accordance with the enhanced expression of PTEN, the level of pS473-Akt stimulated by insulin was decreased in the adipose tissue of KKAy mice compared to the C57BL/6J mice(P<0.001). Treatment with the insulin-sensitizing agents, rosiglitazone and metformin did not inhibit the elevated expression of PTEN in adipose tissue of KKAy diabetic mice. Conclusion PTEN may play an important role in the development of insulin resistance in adipose tissue of type 2 diabetes mice model.
文摘In addition to white adipose tissue （WAT） that stores energy, human and small mammals also have brown adipose tissue （BAT） that dissipates chemical energy for thermogenesis. BAT contains multilocular lipid droplets and much higher numbers of mitochondria than WAT. The mitochondria in BAT uncouple large amounts of fuel oxidation from ATP for heat generation. Accumulating evidences have demonstrated that increased activity and/or amount of BAT can reverse obesity and improve insulin resistance, which highlights that BAT plays an important role in energy metabolism. In this review, we summarized recent findings that shows advantageous effects of BAT activation in metabolic diseases. In addition, we presented the function and role of brown and beige fat cells and regulatory factors for them. Finally, we discussed the potential application of brown adipocytes-based therapy and pharmacological intervention to increase BAT activity for the treatment of obesity and related diseases including insulin resistance, cardiovascular diseases and type 2 diabetes.
