Background: Type 2 diabetes is a complex disease that still requires a great deal of work to be carried out to understand the pathophysiology. Recently, researchers have focused on studying the organs and tissues known to be involved in the development of the type 2 phenotype using a proteomic approach. Little work has been reported on plasma of type 2 diabetics in whom the clinical status has been well characterized. In this study, changes in plasma proteins of type 2 diabetics were investigated by proteomic analysis in well-characterized individuals with type 2 diabetes (early and late stage) and control groups (with or without a family history of diabetes).
Methods: Samples were analysed by two-dimensional gel electrophoresis and significantly differentiated proteins were identified by nano-LC-ESI-MS.
Results: A total of 12 protein signatures that were differentially displayed with high significance compared with controls were selected. Four of the differentially displayed proteins were identified as haptoglobin alpha2, haptoglobin Hp2(fragment) and transthyretin and Chain A (formerly prealbumin), and all were up-regulated. Thiol-specific antioxidant protein, Chain A, tertiary structures of three amyloidogenic transthretin variants and haptoglobin-related protein precursor were all down-regulated in controls with a family history of diabetes, early and late diabetic patients in comparison with the control.
Conclusion: A proteomic-based approach was used to discover and identify the differentially expressed proteins in various states of type 2 diabetes.