The nature of large vessel disease in diabetes mellitus

Fibronectin-Integrin α5 Signaling in Vascular Complications of Type 1 Diabetes

Vascular complications are a major cause of illness and death in patients with type 1 diabetes (T1D). Diabetic vascular basement membranes are enriched in fibronectin (FN), an extracellular matrix protein that amplifies inflammatory signaling in endothelial cells through its main receptor, integrin α5β1. Binding of the integrin α5 cytoplasmic domain to phosphodiesterase 4D5 (PDE4D5), which increases phosphodiesterase catalytic activity and inhibits antiinflammatory cAMP signaling, was found to mediate these effects. Here, we examined mice in which the integrin α5 cytoplasmic domain is replaced by that of α2 (integrin α5/2) or the integrin α5 binding site in PDE4D is mutated (PDE4Dmut). T1D was induced via injection of streptozotocin and hyperlipidemia induced via injection of PCSK9 virus and provision of a high-fat diet. We found that in T1D and hyperlipidemia, the integrin α5/2 mutation reduced atherosclerosis plaque size by ∼50%, with reduced inflammatory cell invasion and metalloproteinase expression. Integrin α5/2 T1D mice also had improved blood-flow recovery from hindlimb ischemia and improved biomechanical properties of the carotid artery. By contrast, the PDE4Dmut had no beneficial effects in T1D. FN signaling through integrin α5 is thus a major contributor to diabetic vascular disease but not through its interaction with PDE4D.

Metabolic effects of time-released garlic powder tablets in type 2 diabetes mellitus: the results of double-blinded placebo-controlled study

Late complications in type 2 diabetic patients are commonly associated with accelerated development of atherosclerosis. In type 2 diabetes mellitus, non-enzymatic glycosylation of apo-B that is a function of hyperglycaemia is an efficient biochemical way of low-density lipoprotein atherogenic modification. So, proper metabolic control is needed to prevent late complications of diabetes. The study was performed to estimate the effects of time-released garlic powder tablet Allicor on the parameters of metabolic control and plasma lipids in type 2 diabetes mellitus. The metabolic action of Allicor was investigated in the 4-week double-blinded placebo-controlled study in 60 type 2 diabetic patients. Fasting blood glucose was measured daily, and serum fructosamine as well as cholesterol and triglyceride levels were determined at the baseline, after 1, 2, 3 and 4 weeks. It has been demonstrated that treatment with Allicor resulted in better metabolic control due to the lowering of fasting blood glucose, serum fructosamine and serum triglyceride levels. The results of this study may allow recommending garlic powder tablets Allicor for the treatment of type 2 diabetes mellitus along with dietary treatment and/or sulfonylurea derivatives to achieve better metabolic control. The benefits from garlic preparations may lead to the reduction of cardiovascular risk in diabetic patients.

Structure and composition of type IV collagen of bovine aorta

To determine the chain composition of type IV collagen of bovine thoracic aorta, we analyzed collagenase-solubilized carboxyl-terminal noncollagenous (NC1)-domains by high-pressure liquid chromatography, two-dimensional electrophoresis, immunoblotting and enzyme-linked immunoassay. In addition to the classical alpha 1- and alpha 2-chains, we found small amounts of the recently discovered alpha 3-, alpha 4- and alpha 5-chains. The alpha 3- and alpha 4-chains were, collectively, 7-13% of the total, and the alpha 5-chain was present in a low amount. Seventy-nine percent of the NC1-domains were dimerized. Immunolocalization studies on sections of aorta showed that the alpha 3- and alpha 5-chains were present, along with alpha 1- and alpha 2-chains, in the subendothelium and media. In capillaries of the media, the alpha 3-chain was found at relatively high levels and was co-localized with alpha 1- and alpha 2-chains. Digestion of aorta with Pseudomonas aeruginosa elastase yielded soluble multimolecular assemblies of type IV collagen. Electron microscopy results provided a direct demonstration of the supramolecular structure, in which the collagen molecules were tetramerized at the amino-terminal end and dimerized at the carboxyl-terminal end.

Rapid development of extensive macrovascular calcifications in a type I diabetic patient

This is a case report of a 35-year-old woman with a 15-year history of type I diabetes mellitus, who developed extensive macrovascular calcifications of the abdominal aorta and all its tributaries within 7 months of developing renal insufficiency. The patient was maintained on hemodialysis and peritoneal dialysis for a total of 3 months, then underwent combined cadaveric renal and pancreatic islet transplantation. Although some vascular calcifications are known to occur in elderly patients and in patients with long-standing uremia, it was the rapidity and extent of development of these lesions in this young woman that is astonishing.