ALTERATIONS OF RBC MEMBRANE PROTEINS IN DIABETIC PATIENTS WITH AND WITHOUT PERIODONTITIS.

The RBC membrane is considered as a key element in their rheology. The rheological properties of RBCs significantly depend on their membranes properties - deformability. The essential contribution of integral membrane proteins in establishing/maintaining membrane stability is due to their ability to anchor the membrane skeleton to the lipid bilayer, their capacity to bind and stabilize membrane lipids, and their ability to influence and regulate local membrane curvature. The goal of the research was investigation the alterations in RBC membrane protein component in diabetic patients with or without periodontitis. We examined peripheral blood samples from type-1 diabetic patients with and without variable severity periodontitis and healthy volunteers. Freshly drawn blood samples from type 1 diabetes with and without periodontitis were obtained from the Railway Hospital (Tbilisi, Georgia). The blood samples from healthy volunteers were obtained from the the Blood Bank of the Institute of Hematology and Transfusiology (Tbilisi, Georgia). Individuals often consume alcohol addicts, pregnant women and patients with other chronic diseases were excluded from the study. The study protocol was approved by Ethical Committee of the Dabid Aghmashenebeli University of Georgia. RBCs membrane proteins have been extracted from human heparinized blood and studied by electrophoresis method. In patients with diabetes type-1 decreased of RBCs membrane low molecular weight proteins (18-22 kDa) content was detected, whereas their electrophoretic mobility (and hence their charge) does not change significantly compared to the control. In patients with diabetes type-1, suffering from periodontitis RBCs membrane low molecular weight (45-29 kDa) and high molecular weight (200, 116, 97, 55 kDa) proteins content reduced as compared with those in diabetic patients not suffering from periodontitis. In this group the electrophoretic mobility of membrane proteins reduces (especially with increasing severity of periodontitis). Reducing the negative charge (apparently caused by a decrease in the carring negative charge glycophorin C and band 3 protein content) and high molecular fraction (weight of 200, 116, 97, 55 kDa) proteins (due to a low content of Band 4.1, band 4.2, band 3 proteins, adducin and ankyrin, actively involved in the regulation of RBCs mechanical stability, deformability and shape) in RBCs membrane in patients with diabetes type-1 suffering from periodontitis, contributes to violation of RBC-RBC interactions as well disorders of their deformability and may induce adhesion of RBCs to the endothelium and disorders of blood circulation. Thus in patients with diabet-1 suffered by periodontitis alterations of the content and the mobility of RBCs membrane proteins were detected (this alterations corelated with severity of periodontitis but was not related with patients sex and age). Changes in the protein composition of the RBCs membranes promote disorder of RBCs membrane deformability and their adherence to the endothelium, pathogenetically related to the disorders of the microcirculation. So that alterations of the content and the mobility of RBCs membrane proteins may be considered as a predictor of microcirculation disturbance during periodontitis.