iduronate and Cicatrix--Hypertrophic

Hypertrophic scarring is characterized by disordered collagen fibrils. In order to determine whether this is, in part, a result of changes in the population of proteoglycans that are thought to be involved in regulation of collagen fibril formation, we have compared PGs from post-burn normal and hypertrophic scar tissue, as well as from human dermis and epidermis. Efforts to separate the two major iduronic acid-containing proteoglycans, decorin [PG(IdoA)-II] and biglycan [PG(IdoA)-I], for quantitation were not successful. The different N-terminal sequences 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 found to contain primarily decorin with low (< 10%) levels of biglycan relative to decorin. In contrast, iduronic acid-containing proteoglycans from hypertrophic scar were found to be approximately 30% biglycan [PG(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. 1966 Elsevier Science Ltd.

Topics: Amino Acid Sequence; Biglycan; Burns; Child; Cicatrix; Cicatrix, Hypertrophic; Decorin; Epidermis; Extracellular Matrix Proteins; Humans; Iduronic Acid; Male; Molecular Sequence Data; Proteoglycans; Skin

Proteoglycans (PGs) were extracted from human hypertrophic and normal scar tissues from two different stages of maturation after burn injury, under dissociative conditions (4 M guanidinium chloride containing proteinase inhibitors). The extracts were fractionated by ion-exchange chromatography, followed by ethanol precipitation, to give PG-containing iduronic acid (PGIdoA). The size of the PGIdoA decreased with the maturation of scars. Glycosaminoglycan (GAG) chains from PGIdoA were released by alkaline borohydride treatment, and their M(r) values were evaluated by polyacrylamide gel electrophoresis. The M(r) values for PGIdoA protein cores of the hypertrophic scars (5+ years and 2-5 years) and normal scar (5+ years and 2-5 years) were 22.6, 25, 19 and 21 kDa, respectively. The iduronic acid content of PGIdoA from both types of scar increased in their maturation phase. The M(r) values of PGIdoA decreased with maturation. PGIdoA carried the sulfate group mainly attached at C-4 of the 2-amino-2-deoxy-D-galactose residue. The NH2-terminal amino acid sequences of all the PGIdoA were similar to those of normal human skin or bone PG II (decorin) (i.e., Asp-Glu-Ala-B-Gly-Ile-Gly-Pro-Glu-Val-Pro-Asp-Asp-Arg).

Topics: Amino Acid Sequence; Burns; Chromatography, Gel; Cicatrix; Cicatrix, Hypertrophic; Electrophoresis, Cellulose Acetate; Electrophoresis, Polyacrylamide Gel; Humans; Iduronic Acid; Molecular Sequence Data; Molecular Weight; Proteoglycans