Analysis of the expression level of thermostable proteins in plasma of diabetic cardiovascular patients

Cardiovascular disease is a major complication and the leading cause of early death among people with type 2 diabetes mellitus (T2DM). People with T2DM often have abnormal cholesterol level, high blood pressure, obesity and lack of physical activity that contributes to risk for developing cardiovascular disease. Diabetic cardiovascular disease can damage the structure and function of the heart and it can lead to heart failure. Therefore, research on diabetic cardiovascular disease is very important to achieve decreased mortality for T2DM patients and prolong their life. In this study, the thermostable fractionation method was used to remove highly abundant proteins in plasma of diabetic cardiovascular patients. The thermostable proteins were then separated by using 2DE. The 2DE gel images were analyzed by using PDQuest v7.1 software. The differentially expressed protein spots between disease and control samples were identified by nanoLC-MS/MS. Among the identified proteins, thirteen were up/down-regulated in disease samples. In which, five proteins (Fibrinogen alpha chain, Fibrinogen gama chain, Haptoglobin beta chain, Haptoglobin alpha 1 chain, Zinc alpha 2 glycoprotein) were up-regulated and six proteins (Alpha 1 antitrypsin, Angiotensinogen, Antithrombin III, Apolipoprotein A-I, Apolipoprotein E, Transthyretin) were down-regulated in plasma of diabetic cardiovascular patients. Meanwhile haptoglobin alpha 2 chain and apolipoprotein A-IV showed quite different expression from case to case. Our results suggest that these proteins might be related to the generation and progression of diabetes and heart disease.