INSEPARABLE IDURONIC ACID-CONTAINING PROTEOGLYCAN PG((IDOA)) PREPARATIONS OF HUMAN SKIN AND POSTBURN PG SCAR TISSUES - EVIDENCE FOR ELEVATED LEVELS OF ((IDOA))-I IN HYPERTROPHIC SCAR BY N-TERMINAL SEQUENCING

Hypertrophic scarring is characterized by disordered collagen fibrils. In order to determine whether this is, in part, a result of changes i n the population of proteoglycans that are thought to be involved in r egulation of collagen fibril formation, we have compared PGs from post -burn normal and hypertrophic scar tissue, as well as from human dermi s and epidermis. Efforts to separate the two major iduronic acid-conta ining proteoglycans, decorin [PG((IdoA))-II] and biglycan [PG((IdoA))- I], for quantitation were not successful. The different N-terminal seq uences of these two iduronic acid-containing proteoglycans PG((IdoA))- I and -II were utilized to estimate the relative amounts in the above PG((IdoA)) preparations. Normal scar, dermis and epidermis were all fo und to contain primarily decorin with low (<10%) levels of biglycan re lative to decorin. In contrast, iduronic acid-containing proteoglycans from hypertrophic scar were found to be approximately 30% biglycan [P G((IdoA))-I]. This may be a proximal cause of altered collagen fibrils , or may result in alterations in the sequestration of growth factors, which then results in changes in collagen that effect the appearance of the scar. (C) 1996 Elsevier Science Ltd.