BIGLYCAN, DECORIN, AND VERSICAN PROTEIN EXPRESSION PATTERNS IN CORONARY ARTERIOPATHY OF HUMAN CARDIAC ALLOGRAFTS - DISTINCTNESS AS COMPAREDTO NATIVE ATHEROSCLEROSIS

Background: Histochemical staining has demonstrated previously dramati c deposits of glycosaminoglycans associated with prominent lipid accum ulations in thickened vessel walls of allograft coronary arteries. In this study, we characterized the amount, distribution, and types of pr oteoglycan in the walls of coronary arteries from human cardiac allogr afts and from native atherosclerotic (NA) controls as part of a strate gy to understand the pathogenesis of transplant arteriopathy (TA). Met hod: We used polyclonal rabbit antibodies against human biglycan, deco rin, and versican to localize the proteoglycan molecules in standardiz ed transverse sections of the proximal left anterior descending and ri ght coronary arteries. Slides were scored in a blinded fashion for int ensity of proteoglycan staining (0 to 6+) and for localization in the vessel walls. Results: Unique patterns of proteoglycan distribution we re present in TA and NA. Biglycan was particularly prominent in intima and evolving atheromata in severely diseased TA coronary arteries, bu t not in NA. Decorin was present mainly in adventitia of all vessels a nd in the intima of NA. Prominent versican accumulation occurred in in tima and media of TA coronaries, associated with smooth muscle cells a nd foam cells. There was a reciprocal pattern of biglycan and decorin staining. Versican colocalized with biglycan. Intimal biglycan and ver sican deposits were positively correlated to the extent of luminal nar rowing in TA. Conclusion: The distinctive staining patterns for biglyc an, decorin and versican in both native and allograft disease indicate that the synthesis and distribution of these proteoglycans are regula ted by different local mechanisms in different atheromatous diseases.