title: Small leucine-rich proteoglycans, decorin and fibromodulin, are reduced in postburn hypertrophic scar.
abstract: Small leucine-rich proteoglycans (SLRPs) are extracellular matrix molecules that regulate collagen fibrillogenesis and inhibit transforming growth factor-β activity; thus, they may play a critical role in wound healing and scar formation. Hypertrophic scarring is a dermal form of fibroproliferative disorders, which occurs in over 70% of burn patients and leads to disfigurement and limitations in function. By understanding the cellular and molecular mechanisms that lead to scarring after injury, new clinical therapeutic approaches can by developed to minimize abnormal scar formation in hypertrophic scarring and other fibroproliferative disorders. To study the expression and localization of SLRPs with connective tissue cells in tissue immunohistochemistry, immunofluorescence staining, immunoblotting, and reverse-transcription polymerase chain reaction were used in normal skin and hypertrophic scar (HTS). In normal skin, there was more decorin and fibromodulin accumulation in the superficial layers than in the deeper dermal layers. The levels of decorin and fibromodulin were significantly lower in HTS, whereas biglycan was increased when compared with normal skin. There was an increased expression of biglycan, fibromodulin, and lumican in the basement membrane and around basal epithelial cells. In contrast, these proteoglycans were absent or weakly expressed in HTS. The findings suggest that down-regulation of SLRPs after wound healing in deep injuries to the skin plays an important role in the development of fibrosis and HTS.
authors.affiliation: Wound Healing Research Group, Department of Surgery, Division of Plastic and Reconstructive Surgery, University of Alberta, Edmonton, Alberta, Canada.
authors.forename: Dariush
authors.initials: D
authors.lastname: Honardoust
authors.forename: Mathew
authors.initials: M
authors.lastname: Varkey
authors.forename: Keijiro
authors.initials: K
authors.lastname: Hori
authors.forename: Jie
authors.initials: J
authors.lastname: Ding
authors.forename: Heather A
authors.initials: HA
authors.lastname: Shankowsky
authors.forename: Edward E
authors.initials: EE
authors.lastname: Tredget
mesh_terms: D000328:Adult; D058578:Biglycan / Q000378:metabolism; D015153:Blotting, Western; D002056:Burns / Q000150:complications / Q000378:metabolism; D002648:Child; D017439:Cicatrix, Hypertrophic / Q000209:etiology / Q000378:metabolism*; D058575:Decorin / Q000378:metabolism*; D015536:Down-Regulation / Q000502:physiology; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005260:Female; D005347:Fibroblasts / Q000502:physiology; D000071235:Fibromodulin; D005455:Fluorescent Antibody Technique; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D011509:Proteoglycans / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014945:Wound Healing / Q000502:physiology*
chemical_list: D058578:Biglycan; D058575:Decorin; D016326:Extracellular Matrix Proteins; C000604330:FMOD protein, human; D011509:Proteoglycans; D000071235:Fibromodulin