A novel cellular defect in diabetes: membrane repair failure

OBJECTIVE—Skeletal muscle myopathy is a common diabetes complication. One possible cause of myopathy is myocyte failure to repair contraction-generated plasma membrane injuries. Here, we test the hypothesis that diabetes induces a repair defect in skeletal muscle myocytes. RESEARCH DESIGN AND METHODS—Myocytes in intact muscle from type 1 (INS2Akita+/2) and type 2 (db/db) diabetic mice were injured with a laser and dye uptake imaged confocally to test repair efficiency. Membrane repair defects were also assessed in diabetic mice after downhill running, which induces myocyte plasma membrane disruption injuries in vivo. A cell culture model was used to investigate the role of advanced gly-cation end products (AGEs) and their receptor (RAGE) in de-velopment of this repair defect. RESULTS—Diabetic myocytes displayed significantly more dy