Elongated dermatan sulphate in post-inflammatory healing skin distributes among collagen fibrils separated by enlarged interfibrillar gaps

It has been reported that the disaccharide composition of dermatan sulphate shows transient changes after epicutaneous application of the hapten 2,4-d initrofluorobenzene to mouse skin, and that these changes are most conspicu ous in healing skin on day 15 after chemical insult [Kuwaba, Nomura, Irie a nd Koyama (1999) J. Dermatol. Sci. 19, 23 30]. In the present study it was found that the molecular size of dermatan sulphate was increased on day 15 after hapten application. The molecular size of decorin increased in healin g skin, whereas the size of dermatan-sulphate-depleted core protein did not increase. The length and localization of decorin dermatan sulphate were in vestigated by electron microscopy. Dermatan sulphate filaments oriented ort hogonally to collagen fibrils were longer in healing skin than in control s kin. In control skin, dermatan sulphate filaments were found among tightly packed collagen fibrils. In contrast, the interfibrillar gaps between each collagen fibril were enlarged in healing skin; elongated dermatan sulphate filaments extended from the surface of collagen fibrils across the enlarged gap. These results suggest that the increase in molecular size of decorin dermatan sulphate is important in organizing collagen fibrils separated by enlarged interfibrillar gaps in healing skin.