Compositional alterations in erythrocyte membranes in Type II diabetes

Abstract

Loss of erythrocyte membrane deformability is one of the most crucial factors in developing complications associated with Type II diabetes. The observed loss of erythrocyte membrane deformability could be related to structural changes in the membrane. In this context, here, we have made an attempt at gaining a better insight (quantitative as well as qualitative) into the protein and lipid contents in erythrocyte membranes and their interrelationships in Type II diabetes. Age matched control (n=12) and Type II diabetic subjects (n=22) were selected for this study. Morphological characteristics were studied by atomic force microscopy (AFM). AFM study confirmed remarkable alterations in morphology of the diabetic erythrocytes. In diabetic erythrocytes following changes were noted: (i) Significant increase in membrane as well as cytosolic proteins with a marginal increase in phospholipids content; (ii) The membrane total lipids:protein, phospholipids:protein, cholesterol:protein and phospholipids:cholesterol (mole:mole) ratios decreased significantly; (iii). A reproducible decrease in docosahexaenoic acid (DHA) and Omega-3 index with increase in Omega-6:Omega-3 ratio in membrane fatty acids; and (iv) The SDS-PAGE analysis indicated that all membrane proteins increased in almost equal proportion leading to increased membrane protein content. The observed compositional and stochiometric changes in lipids, proteins and their ratios may underlie morphological alterations and loss of deformability.