SGK1 Mediated Adipose Tissue Insulin Resistance And Mechanism Research

Patr one Studies on the treatment effect of SGK1 inhibitors on improving glucose metabolism disordersObjective:On the basis of the previous studies,and further to validate the treatment effect of SGK1 inhibitors on improving glucose metabolism disorders in the model mice of the high-fat induced obesity,and to explore whether the possible mechanism is due to the effect of improving the adipose tissue dysfunction.Methods:1?C57/BL6 male mice,after feeding high-fat food for 12 weeks,choose the model mices of obesity and diabetes.According to the fasting weight and the fasting blood glucose,the model mices were randomly divided into:high-fat group,SGK1 inhibitor group,at the same time set up the male mices with the same varietie and the same weeks of age,feeding with the ordinary fodder(named normal diet group).The intervention lasted for 12 weeks.During the intervention period,fasting blood glucose and fasting body weight were checked every two weeks.After the intervention,oral glucose tolerance test(OGTT)?intraperitoneal glucose tolerance test(IPGTT)and intraperitoneal insulin tolerance test(IPITT)were conducted.At the end of the experiment,the mice were killed.Blood serum and adipose tissues were collected and stored for further examation.2?The mRNA expression levels of the adipokines,such as adiponectin?MCP-1?PAI-1 and IL-6 were detected in the adipose tissues of the mices using quantitative real-time PCR,these adipose tissues were collected from the mices of db/m wild group?db/db control group and SGK1 inhibitor group during our previous animal experiments?3?The expression levels of the adiponectin and MCP-1 were detected in the blood serum of the mices using ELISA kit,the blood serum were collected from the mices of db/m wild group?db/db control group and SGKl inhibitor group during our previous animal experiments?Results:The carbohydrate metabolism evaluation after the treatment of SGK1 inhibitors:(1)Fasting blood glucose:Compared to high-fat group,SGK1 inhibitor group had lower blood glucose level since the second week,and a significant difference at the 6?10 and 12 week(p<0.05);(2)OGTT:Compared to high-fat group,SGK1 inhibitor group had lower blood glucose level at 30min(p<0.05);(3)IPGTT:Compared to high-fat group,SGK1 inhibitor group had lower blood glucose level at 0?120min(p<0.05);(4)IPITT:Compared to high-fat group,SGK1 inhibitor group had lower blood glucose level at 60?120min(p<0.05).2?After the treatment of SGK1 inhibitor,the mRNA expression levels of adipose tissue adipokines:Compared to the db/db control group,the mRNA expression level of adipose tissue adiponectin did not change significantly in the SGK1 inhibitor group,but the mRNA expression level of MCP-1?PAI-1 and IL-6 were significantly decreased.3?After the treatment of SGK1 inhibitor,the expression levels of blood serum cytokines:Compared with the db/db control group,the serum adiponectin expression tended to increase and the expression of MCP-1 tended to decrease in SGK1 inhibitor group.Conclusion:SGK1 inhibitors treatment can significantly improve hyperglycemia in obese mice with insulin resistance,the possible mechanisms may be partially due to its effect of improving adipose dysfunction.Patr two The increased expression and activity of SGK1 may mediate the insulin resistance in 3T3-L1 adipocytesObjective:To definite whether the increased expression and activity of SGK1 will induce the insulin resistance in 3T3-L1 adipocyte,whether SGK1 inhibitors could block this effect,and to further study the correlation of SGKI and NF-?B signaling pathway.Methods:1?3T3-L1 preadipocytes,induced differentiation and maturation,and then incubated with dexamethasone in different concentration and different time.After the intervention,the protein expression levels of SGKl?p-SGK1?IRS-1?IRS-2 and the related protein of NF-kB signaling pathway were measured by western blot.2?Constitutively active mutant S422DSGK1 overexpression lentivirus were transfected into 3T3-L1 preadipocytes,induced differentiation and maturation,with or without insulin stimulation,and then detect the protein expression levels of SGKI?AKT and P-AKT in adipocytes using Western Blot.Results:1?Compared with the control group,Dexamethasone increased the protein expression of SGK1?P-SGK1,and downergulated the protein expression of IRS-1?IRS-2 in a concentration and time dependent manner in 3T3-L2 adipocytes.Compared with the dexamethasone group,the downregulation of IRS-1 and IRS-2 protein expression is partially reversed in dexamethasone plus SGK1 inhibitor intervention group.2?After the Lentivirus transfection successfully and with insulin stimulation,the P-AKT protein levels were decreased significantly in SGK1 overexpression lentivirus group compared with the control group.3?Compared with the control group,Dexamethasone increased the I?B? phosphorylation and reduced the I?B? protein expression in a concentration and time dependent manner in 3T3-L1 adipocytes.Compared with the dexamethasone group,the downregulation of I?B?protein expression is partially reversed in dexamethasone plus SGK1 inhibitor intervention group.Conclusion:The increased expression and activity of SGK1 may mediate the insulin resistance in 3T3-L1 adipocytes,SGK1 inhibitors can block this effect partially.The increased expression and activity of SGK1 activate the NF-?B signaling pathway,Whether this effect is associated with adipocyte insulin resistance need to be further studied.