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Pathophysiological mechanisms of diabetic angiopathy
15th Medical Department, University Hospital Mannheim, Faculty of Clinical Medicine Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, 68167, Mannheim, Germany. hans-peter.hammes@med5.uni-heidelberg.de
Insights
Chronic hyperglycemia in diabetes leads to severe microvascular and macrovascular complications. Mitochondrial reactive oxygen species (ROS) are identified as a key factor driving these diabetes-related vascular damages.
Area of Science:
- Biochemistry
- Vascular Biology
- Diabetes Research
Background:
- Diabetes mellitus is characterized by chronic hyperglycemia, leading to microvascular (blindness, renal failure, neuropathy) and macrovascular (myocardial infarction, stroke, amputation) complications.
- Established biochemical abnormalities linking hyperglycemia to vascular damage include increased polyol pathway flux, advanced glycation end-products (AGEs), protein kinase C (PKC) activation, and hexosamine pathway flux.
Purpose of the Study:
- To identify the common underlying mechanism connecting the biochemical abnormalities in diabetes-induced vascular damage.
- To propose a novel paradigm for understanding and potentially treating diabetes complications.
Main Methods:
- The study reviews existing biochemical pathways implicated in diabetes complications.
- It focuses on the role of mitochondrial reactive oxygen species (ROS) as a central mediator.
Main Results:
- Overproduction of superoxide by the mitochondrial electron transport chain is identified as the common denominator for the four biochemical abnormalities.
- Mitochondrial ROS partially inhibit glyceraldehyde-3-phosphate dehydrogenase, redirecting glycolytic flux to glucose overutilization pathways.
Conclusions:
- Mitochondrial ROS and subsequent metabolic shifts represent a novel paradigm for diabetes-induced vascular damage.
- This understanding offers a new basis for diabetes research and the development of targeted therapeutic strategies.
Abstract:
The sequelae of chronic hyperglycemia in diabetes of all phenotypes are divided into microvascular and macrovascular complications. Microvascular disease causes blindness, renal failure, and neuropathy, and diabetes-accelerated macrovascular disease causes excessive risk for myocardial infarction, stroke, and lower limb amputation. The link between chronic hyperglycemia and vascular damage has been established by four independent biochemical abnormalities: increased polyol pathway flux, increased formation of advanced glycation end-products (AGEs), activation of protein kinase C (PKC), and increased hexosamine pathway flux. These seemingly unrelated pathways have an underlying common denominator: overproduction of superoxide by the mitochondrial electron transport chain. Mitochondrial reactive oxygen species (ROS) partially inhibit the glycolytic enzymes glyceraldehyde-3-phosphate dehydrogenase, which diverts increased substrate flux from glycolysis to pathways of glucose overutilization. Preliminary experimental evidence in vivo suggests that this new paradigm provides a novel basis for research and drug development.