Original investigation

Arterial heparan sulfate is negatively associated with hyperglycemia and atherosclerosis in diabetic monkeys

Iris J Edwards¹ , Janice D Wagner¹ , Catherine A Vogl-Willis¹ , Kenneth N Litwak² and William T Cefalu³

¹  Department of Pathology, Section on Comparative Medicine, Wake Forest University School of Medicine Winston-Salem, North Carolina 27157-1047 USA

²  Department of Surgery-Thoracic and Cardiovascular Cardiovascular Research Center University of Louisville School of Medicine 500 S. Floyd St Louisville, Kentucky 40292 USA

³  Pennington Biomedical Research Center Louisiana State University 6400 Perkins Road Baton Rouge, Louisiana 70808, USA

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Cardiovascular Diabetology 2004, 3:6doi:10.1186/1475-2840-3-6

Published:	29 April 2004

Abstract

Background

Arterial proteoglycans are implicated in the pathogenesis of atherosclerosis by their ability to trap plasma lipoproteins in the arterial wall and by their influence on cellular migration, adhesion and proliferation. In addition, data have suggested an anti-atherogenic role for heparan sulfate proteoglycans and a pro-atherogenic role for dermatan sulfate proteoglycans. Using a non-human primate model for human diabetes, studies examined diabetes-induced changes in arterial proteoglycans that may increase susceptibility to atherosclerosis.

Methods

Control (n = 7) and streptozotocin-induced diabetic (n = 8) cynomolgous monkeys were assessed for hyperglycemia by measurement of plasma glycated hemoglobin (GHb). Thoracic aortas obtained at necropsy, were extracted with 4 M guanidine HCL and proteoglycans were measured as hexuronic acid. Atherosclerosis was measured by enzymatic analysis of extracted tissue cholesterol. Glycosaminoglycan chains of arterial proteoglycans were released with papain, separated by agarose electrophoresis and analysed by scanning densitometry.

Results

Tissue cholesterol was positively associated with hexuronic acid content in diabetic arteries (r = .82, p < .025) but not in control arteries. Glycosaminoglycan chain analysis demonstrated that dermatan sulfate was associated with increased tissue cholesterol in both control (r = .8, p < 0.05) and diabetic (r = .8, p < .025) arteries, whereas a negative relationship was observed between heparan sulfate and tissue cholesterol in diabetic arteries only (r = -.7, p < .05). GHb, which was significantly higher in diabetic animals (8.2 ± 0.9 vs 3.8 ± 0.2%, p < .0005) was negatively associated with heparan sulfate in diabetic arteries (r = -.7, p < .05).

Conclusions

These data implicate hyperglycemia induced modifications in arterial proteoglycans that may promote atherosclerosis.