Increased expression of the 20S proteasome in peripheral blood mononuclear cells of type 2 diabetic patients

Objective: To investigate the dynamic expression of the 20S proteasome in peripheral blood mononuclear cells (PBMCs) of type 2 diabetic patients without vascular complications. Methods: PBMCs were prepared from 30 type 2 diabetic patients and 30 nondiabetic controls. The general indexes including weight, height and blood pressure were recorded. Fasting plasma glucose, fasting plasma insulin and glycosylated hemoglobin were measured. The protein level of the 20S proteasome was measured by Western blotting. The mRNA expression levels of the 20S proteasome β1, β2 and β5 submits were detected by real-time PCR. Results: Compared with that in the nondiabetic controls, the protein level of the 20S proteasome was significantly increased in the diabetic patients and was positively associated with glycosylated hemoglobin. Conclusion: Type 2 diabetic patients without vascular complications have an increased 20S proteasome expression, the significance of which needs to be explored by further study.