Abstract
Keloid disease (KD) is a common fibroproliferative disorder of unknown etiopathogenesis. Its unique occurrence in human skin and lack of animal models pose challenges for KD research. The lack of a suitable model in KD and over-reliance on cell culture has hampered the progress in developing new treatments. Therefore, we evaluated the effect of two promising candidate antifibrotic therapies: (-)-epigallocatechin-3-gallate (EGCG) and plasminogen activator inhibitor-1 (PAI-1) silencing in a long-term human keloid organ culture (OC). Four millimeters of air-liquid interface (ALI) keloid explants on collagen gel matrix in serum-free medium (n=8 cases) were treated with different modalities (EGCG treatment; PAI-1 knockdown by short interfering RNA (siRNA) and application of dexamethasone (DEX) as control). Normal skin (n=6) was used as control (only for D0 keloid-untreated comparison). Besides routine histology and quantitative (immuno-) histomorphometry, the key phenotypic and growth parameters of KD were assessed. Results demonstrated that EGCG reduced keloid volume significantly (40% by week 4), increased apoptosis (≥40% from weeks 1 to 4), and decreased proliferation (≤17% in week 2). EGCG induced epidermal shrinkage, reduced collagen-I and -III at mRNA and protein levels, depleted 98% of keloid-associated mast cells, and reduced the percentage of both cellularity and blood vessel count by week 4. Knockdown of PAI-1 significantly reduced keloid volume by 28% in week 4, respectively, and reduced collagen-I and -III at both mRNA and protein levels. As expected, DEX increased keloid apoptosis, decreased keloid proliferation, and collagen synthesis, but induced connective tissue growth factor overexpression. In conclusion, using keloid OC model, we provide the first functional evidence for testing candidate antifibrotic compounds in KD. We show that EGCG and PAI-1 silencing effectively inhibits growth and induces shrinkage of human keloid tissue in situ. Therefore, the application of EGCG, PAI-1 silencing, and other emerging compounds tested using this model may provide effective treatment and potentially aid in the prevention of recurrence of KD following surgery.
| Original language | English |
|---|---|
| Journal | Laboratory Investigation |
| Volume | 93 |
| Issue number | 8 |
| Pages (from-to) | 946-960 |
| Number of pages | 15 |
| ISSN | 0023-6837 |
| DOIs | |
| Publication status | Published - 01.08.2013 |
Funding
1Plastic and Reconstructive Surgery Research, Manchester Institute of Biotechnology (MIB), University of Manchester, Manchester, UK; 2Institute of Inflammation and Repair, University of Manchester, Manchester, UK; 3Department of Dermatology, University of Lubeck, Lubeck, Germany; 4Department of Plastic and Reconstructive Surgery, University Hospital South Manchester NHS Foundation Trust, Wythenshawe Hospital, Manchester, UK and 5The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK Correspondence: Dr A Bayat, BSc (Hons), MB, BS, PhD, Plastic and Reconstructive Surgery Research, Manchester Institute of Biotechnology (MIB), University of Manchester, 131 Princess Street, Manchester M1 7DN, UK. E-mail: [email protected] 6The first two authors contributed equally to this work. We acknowledge study participants and nursing staff of South Manchester University Hospitals NHS Foundation Trust. We thank the GAT family foundation for their generous support of this work. AB received a personal award from the NIHR (UK).
