Significance And Changes Of Gastric Mucosal Smooth Muscle Cell Apoptosis And PI3K-AKT-mTOR And AMPK-mTOR Pathway In Diabetic Gastroparesis Rat

Objective To observe the changes of cell apoptosis,PI3K-AKT-mTOR and AMPK-mTOR pathway in gastric smooth muscle cells of diabetic rats with gastroparesis and to explore its significance in the pathogenesis of diabetic gastroparesis.Methods Diabetic rat models were established.The rats were divided into normal control group(NC),model 2W(DM2W),model 4W(DM4W)and model 6W(DM6W)groups.Diabetic gastroparesis models were established.Flow cytometry was used to detect the apoptosis rate of gastric smooth muscle cells in each model group.Western blotting was used to detect the expressions of PI3K,p-AKT,p-AMPK,p-TSC-p-mTOR,p-p70S6K,p-4E-BP1 protein expression.Results The gastric residual rate of pigment was 40.24 ± 2.15 in NC group,42.82 ± 3.19 in DM2W group,44.72 ±3.10 in DM4W group and 50.65 ± 3.31 in DM6W group,showing a trend of increasing gradually with the prolongation of duration.Compared with DM6W group(P<0.05);The apoptotic rate was 1.54 ± 0.46 in DM2W group,2.75 ± 0.54 in DM4W group and 7.48 ±0.36 in DM6W group,showing a trend of increasing with the course of disease,in which DM4W group and DM6W group(P<0.01);PI3K-AKT-mTOR pathway key The protein expression of PI3K in NC group was 0.44 ±0.03,0.65±0.03 in DM2W group,0.54±0.06 in DM4W group and 0.35±0.05 in DM6W group.The expression of PI3K in DM2W group and DM4W group was higher than that in NC group(p<0.01,The expression of p-AKT was significantly lower in DM6W group than in DM4W group(p<0.05).The relative expression of p-AKT in NC group was 0.53 ± 0.02,and in DM2W group was 0.75 ± 0.02 Compared with NC group,DM2W group and DM4W group had higher expression(p<0.01,p<0.01),DM6W group(p<0.05),DM6W group(0.73±0.03)and DM6W group(0.44± 0.02)Compared with the DM4W group,the expression of p-AMPK was down-regulated(p<0.01),the relative expression of p-AMPK in the AMPK-mTOR pathway was 0.34 ± 0.04 in the NC group,0.58 ± 0.05,0.70±0.05 in DM4W group and 0.69±0.05 in DM6W group,respectively.Compared with NC group,DM2W group,DM4W group and DM6W group had higher expression(p<0.01,p<0.01,p<0.01)The relative expression of p-TCS-2 in NC group was 0.33 ±0.02,in DM2W group was 0.60±0.03,in DM4W group was 0.72±0.02,in DM6W group was 0.73 ±0.04(P<0.05)(P<0.01,p<0.01,p<0.01).Compared with DM group,DM2W group,DM4W group and DM6W group had higher expression(p<0.01,p<0.01,p<0.01),DM group and DM4W group(p<0.01,P<0.01).Compared with NC group,the expression level of mTOR in DM2W group and DM4W group was significantly higher than that in NC group(P<0.01).The relative expression of p-p70S6K in NC group was 0.37±0.04,in DM2W group was 0.53±0.02,in DM4W group was 0.52 ±0.02,in DM6W group was 0.34 ± 0.02).Compared with NC group,DM2W group and DM4W group had higher expression(p<0.01,p<0.01),and DM6W group had lower expression(p<0.01)Quantity,NC group 0.36 ± 0.05,DM2W group 0.57 ± 0.03,DM4W group 0.54 ± 0.04,DM6W group 0.35 ± 0.02,which,compared with NC group,DM2W group and DM4W group expression increased(p<0.01,p<0.01),The expression of DM6W group decreased(p<0.01).Conclusion(1)Apoptosis is involved in the occurrence of diabetic gastroparesis and plays an important role.(2)PI3K-AKT-mTOR and AMPK-mTOR pathway are activated in the process of diabetic gastroparesis,which may be involved in the regulation of apoptosis.(3)In the process of diabetic gastroparesis,mTOR activity first increases and then inhibits,and is involved in the regulation of apoptosis,but not in the dominant position.