title: Fibroblasts cocultured with keloid keratinocytes: normal fibroblasts secrete collagen in a keloidlike manner.
abstract: Keloid scars represent a pathological response to cutaneous injury, reflecting a new set point between synthesis and degradation biased toward extracellular matrix (ECM) collagen accumulation. Using a serum-free two-chamber coculture model, we recently demonstrated a significant increase in normal fibroblast proliferation when cocultured with keloid-derived keratinocytes. We hypothesized that similar keratinocyte-fibroblast interactions might influence fibroblast collagen production and examined conditioned media and cell lysate from coculture for collagen I and III production by Western blot, allied with Northern analysis for procollagen I and III mRNA. Normal fibroblasts cocultured with keloid keratinocytes produced increased soluble collagen I and III with a corresponding increase in procollagen I and III mRNA transcript levels. This was associated with decreased insoluble collagen from cell lysate. When keloid fibroblasts were cocultured with keloid keratinocytes, both soluble and insoluble collagen were increased with associated procollagen III mRNA upregulation. Transmission electron microscopy of normal fibroblasts cocultured with keloid keratinocytes showed an ECM appearance similar to in vivo keloid tissue, an appearance not seen when normal fibroblasts were cocultured with normal keratinocytes.
authors.affiliation: Division of Plastic Surgery, Department of Surgery, National University of Singapore, Singapore 119074. surlimi@nus.edu.sg
authors.forename: Ivor Jiun
authors.initials: IJ
authors.lastname: Lim
authors.forename: Toan-Thang
authors.initials: TT
authors.lastname: Phan
authors.forename: Boon-Huat
authors.initials: BH
authors.lastname: Bay
authors.forename: Robert
authors.initials: R
authors.lastname: Qi
authors.forename: Hung
authors.initials: H
authors.lastname: Huynh
authors.forename: Walter Tiang-Lee
authors.initials: WT
authors.lastname: Tan
authors.forename: Seng-Teik
authors.initials: ST
authors.lastname: Lee
authors.forename: Michael Thornton
authors.initials: MT
authors.lastname: Longaker
mesh_terms: D000293:Adolescent; D000328:Adult; D015152:Blotting, Northern; D015153:Blotting, Western; D018920:Coculture Techniques; D003094:Collagen / Q000378:metabolism*; D024042:Collagen Type I / Q000235:genetics / Q000378:metabolism; D024061:Collagen Type III / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D007627:Keloid / Q000378:metabolism* / Q000473:pathology; D015603:Keratinocytes / Q000378:metabolism / Q000502:physiology; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D012333:RNA, Messenger / Q000378:metabolism; D012016:Reference Values; D012995:Solubility
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D012333:RNA, Messenger; D003094:Collagen