Study On Differential Expression Of MafA And P16 In ? Cells Of Type 2 Diabetes Mellitus And Impaired Glucose Tolerance

Objective: To study whether the expression of Maf A and P16 in ? cells of T2 DM and IGT are differential.Methods: 1. Establishment of animal models 72 male ICR mice were randomly divided into three groups: ND group,IGT group,T2 DM group. ND Group was fed by ordinary fodder, IGT group with high fat diet. At a dose of 2g / kg glucose, there was an OGTT between ND group and IGT group, measuring blood glucose levels at 0min, 15 min, 30 min, 60 min and 120 min, then plotted glucose tolerance curve. T2 DM group was firstly fed by high fat diet for 4 weeks, then twice intraperitoneal injection of low-dose STZ, the first injection of STZ at a dose of 70 mg / kg, the second administration of 50 mg / kg. The criterion of diagnosing T2 DM mice : random blood glucose level> 16.7mmol / L and the emergence of symptom including “eat more, Polydipsia, polyuria, weight loss”. 2.Immunohistochemical double staining Pancreas of mouse amoung three groups were Separated to make specimens.Using anti-insulin+anti-Maf A and anti-insulin+anti-P16 to detect the expression of Mafa and P16 in ? cells of mouse in three groups.Under the microscope, insulin marked by the DAB reagent was brown, Mafa and P16 marked by the AP-Red reagent was red. Counting the total number of ? cells and the number of Maf A cells and P16 cells of mouse in three group. Utilizing statistical analysis software to calculate the expressed rates of Maf A and P16 of ? cells in mouse of three groups.Results: 1.Animal models OGTT: blood glucose level of IGT group was significantly higher than ND group in 30 min, 60 min and 120 min, the difference was statistically significant(P <0.05). This suggested that glucose tolerance in mouse of IGT group has been impaired.T2 DM group: blood glucose level of 21 mouse were higher than 16.7mmol/L and some symptoms including eat more, Polydipsia, Polyuria. 2. double staining Expressed rate of Maf A in ? cells of ND group, IGT group and T2 DM group was 26.51%~34.15%,25.23%~29.75%, 3.94%~6.22%; expressed rate of P16 was 3.52%~3.84%,3.61%~4.01%, 9.03%~9.71%. Expressed rate of Maf A in ? cells of T2 DM group was lower than IGT group and ND group, the difference was statistically significant(P <0.05). Between IGT group and ND group, the difference was no statistically significant(P =0.063). Expressed rate of P16 in ? cells of T2 DM group was higher than IGT group and ND group, the difference was statistically significant(P <0.05). Between IGT group and ND group, the difference was no statistically significant(P=0.294).Conclusion: Expression of Maf A and P16 in ? cells of T2 DM mice and IGT mice were differential.Expressed rate of Maf A in ? cells of T2 DM mice was lower than IGT mice, expressed rate of P16 in ? cells of T2 DM mice was higher than IGT mice.