Composition of proteoglycans from human atherosclerotic lesions

Proteoglycans from human atherosclerotic lesions and from uninvolved aortic intima were isolated and their composition was studied. The tissues were sequentially extracted by guanidine hydrochloride followed by hydrolysis of the tissue by elastase. Chondroitin sulfate/dermatan sulfate proteoglycans were predominant in guanidine hydrochloride extracts of the tissue. Most of the heparan sulfate proteoglycans were released from the tissue by hydrolysis with elastase. The content of proteoglycan material, measured as uronate per unit weight of wet tissue, was lower in fatty streaks and fibrous plaques than in uninvolved tissue (0.58 and 0.48 mg vs. 0.7 mg/g wet tissue). The distribution of different glycosaminoglycans in guanidine hydrochloride-extracted proteoglycans was similar among the lesions and uninvolved tissue, but varied in the elastase-hydrolyzed extracts. Gel filtration studies suggested that the major proteoglycan material, chondroitin sulfate proteoglycans, from lesions had greater molecular weight than proteoglycans from uninvolved tissue. The studies indicate that alteration in intrinsic composition and molecular size of proteoglycans occurs in atherosclerotic lesions.