Potential Role Of NF-κB In The Pathogenesis Of Insulin Resistance In Adipocytes In Type 2 Diabetes

PARTⅠEXPERIMENTAL STUDY ON THE ACTIVITY OF NF-κB AND INSULIN SIGNAL TRANSDUCTION MOLECULES IN ADIPOCYTES OF TYPE 2 DIABETESObjective To observe the differences between the activity of NF-κB and Insulin Signal Transduction Molecules in Type 2 Diabetes Mellitus and non- Diabetes Mellitus Adipocytes.Methods Using primary cell culture, adipocytes from abdominal subcutaneous adipose tissue of Type 2 diabetics (Type 2 diabetes group) and non-diabetics (non-diabetes control group) were cultured,IRS-1 tyrosine phosphorylation and AKT-Ser473 phosphorylation level in the adipocytes of the two groups with insulin stimulation were detected with the Immunoprecipitation and western blot. The NF-κB DNA binding activity in the adipocytes of the two groups was detected with the electrophoretic mobility shift assay (EMSA).Results The IRS-1 tyrosine phosphorylation and AKT-Ser473 phosphorylation level in the adipocytes with insulin stimulation of Type 2 diabetes group are significantly lower than that of the non-diabetes control group (P<0.01). The NF-κB DNA binding activity in the adipocytes of type 2 diabetes group is significantly higher than that of non-diabetes control group,By comparison of two groups, the differences have statistic significance (P<0.01).Conclusion The insulin resistance and excessive activation of NF-κB exist in the adipocytes of type 2 diabetes mellitus and the excessive activation of NF-κB may play an important role in the occurrence and development of adipocytes insulin resistance of type 2 diabetes mellitus.PARTY II STUDY ON THE INHIBITING EFFECT OF NF-κB DECOY ON INSULIN RESISTANCE IN ADIPOCYTESObjective To observe the effect of NF-κB decoy on the activity of NF-κB and insulin signal transduction molecules in the adipocytes of type 2 diabetes mellitus.Methods The liposome transient transfection was used to transfer the NF-κB decoy into the adipocytes of type 2 diabetes mellitus. The changes in the insulin signal transduction molecules IRS-1 tyrosine phosphorylation and AKT-Ser473 phosphorylation after transfecting the NF-κB decoy and stimulated by insulin within the adipocytes were detected with the Immunoprecipitation and western blot. The differences of NF-κB DNA binding activity in the adipocytes after transfecting the NF-κB decoy were detected with EMSA.Results The level of insulin signal transduction molecules IRS-1 tyrosine phosphorylation and AKT-Ser473 phosphorylation after transfecting NF-κB decoy and stimulated by insulin within adipocytes of type 2 diabetes mellitus is significantly upgraded over that of pre-transfection. By comparison, the differences have statistic significance (P<0.01). The NF-κB DNA binding activity in the adipocytes of type 2 diabetes mellitus after transfecting the NF-κB decoy is significantly reduced over that of pre-transfection. By comparison, the differences have statistic significance (P<0.01).Conclusion The adipocytes insulin resistance of type 2 diabetes mellitus is associated with excessive activation of NF-κB. Inhibiting the excessive activation of NF-κB by NF-κB decoy can partly reverse insulin resistance.