title: Compression therapy affects collagen type balance in hypertrophic scar.
abstract: BACKGROUND
  The effects of pressure on hypertrophic scar are poorly understood. Decreased extracellular matrix deposition is hypothesized to contribute to changes observed after pressure therapy. To examine this further, collagen composition was analyzed in a model of pressure therapy in hypertrophic scar.
  
  
  METHODS
  Hypertrophic scars created on red Duroc swine (n = 8) received pressure treatment (pressure device mounting and delivery at 30 mm Hg), sham treatment (device mounting and no delivery), or no treatment for 2 wk. Scars were assessed weekly and biopsied for histology, hydroxyproline quantification, and gene expression analysis. Transcription levels of collagen precursors COL1A2 and COL3A1 were quantified using reverse transcription-polymerase chain reaction. Masson trichrome was used for general collagen quantification, whereas immunofluorescence was used for collagen types I and III specific quantification.
  
  
  RESULTS
  Total collagen quantification using hydroxyproline assay showed a 51.9% decrease after pressure initiation. Masson trichrome staining showed less collagen after 1 (P < 0.03) and 2 wk (P < 0.002) of pressure application compared with sham and untreated scars. Collagen 1A2 and 3A1 transcript decreased by 41.9- and 42.3-fold, respectively, compared with uninjured skin after pressure treatment, whereas a 2.3- and 1.3-fold increase was seen in untreated scars. This decrease was seen in immunofluorescence staining for collagen types I (P < 0.001) and III (P < 0.04) compared with pretreated levels. Pressure-treated scars also had lower levels of collagen I and III after pressure treatment (P < 0.05) compared with sham and untreated scars.
  
  
  CONCLUSIONS
  These results demonstrate the modulation of collagen after pressure therapy and further characterize its role in scar formation and therapy.
authors.affiliation: The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC; Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC.
authors.forename: Shawn
authors.initials: S
authors.lastname: Tejiram
authors.affiliation: Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC.
authors.forename: Jenny
authors.initials: J
authors.lastname: Zhang
authors.affiliation: The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC; Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC.
authors.forename: Taryn E
authors.initials: TE
authors.lastname: Travis
authors.affiliation: Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC.
authors.forename: Bonnie C
authors.initials: BC
authors.lastname: Carney
authors.affiliation: Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC.
authors.forename: Abdulnaser
authors.initials: A
authors.lastname: Alkhalil
authors.affiliation: Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC.
authors.forename: Lauren T
authors.initials: LT
authors.lastname: Moffatt
authors.affiliation: The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC; Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC.
authors.forename: Laura S
authors.initials: LS
authors.lastname: Johnson
authors.affiliation: The Burn Center, Department of Surgery, MedStar Washington Hospital Center, Washington, DC; Firefighters' Burn and Surgical Research Laboratory, MedStar Health Research Institute, Washington, DC. Electronic address: jeffrey.w.shupp@medstar.net.
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Shupp
mesh_terms: D000818:Animals; D017439:Cicatrix, Hypertrophic / Q000378:metabolism / Q000517:prevention & control*; D024042:Collagen Type I / Q000378:metabolism*; D024061:Collagen Type III / Q000378:metabolism*; D058128:Compression Bandages; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D006909:Hydroxyproline / Q000378:metabolism; D008297:Male; D011312:Pressure; D013552:Swine
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D006909:Hydroxyproline
keywords: Burn scar; Collagen; Compression therapy; Hypertrophic scar; Pressure therapy