Decreased expression of inhibitory SMAD6 and SMAD7 in keloid scarring

• Published in: Journal of plastic, reconstructive & aesthetic surgery reconstructive & aesthetic surgery, 2006-01, Vol.59 (3), p.221-229
• Main Authors: Yu, Haiyan, Bock, Oliver, Bayat, Ardeshir, Ferguson, Mark W.J., Mrowietz, Ulrich
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Blotting, Western; Cells, Cultured; Dermatology; Fibroblasts - metabolism; Humans; Keloid - metabolism; Keloids; Medical sciences; MEDICIN; MEDICINE; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Skin involvement in other diseases. Miscellaneous. General aspects; SMAD; Smad6 Protein - metabolism; Smad7 Protein - metabolism; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; TGFβ; TGFβ signalling; Transforming Growth Factor beta - pharmacology; Transforming Growth Factor beta1
• ISSN: 1748-6815; 1878-0539
• DOI: 10.1016/j.bjps.2005.06.010

Keloids are benign skin tumours occurring during wound healing in genetically predisposed patients. They are characterised by an abnormal deposition of extracellular matrix components, in particular collagen. There is evidence that transforming growth factor-beta (TGFβ) is involved in keloid formation. SMAD proteins play a crucial role in TGFβ signaling and in terminating the TGFβ signal by a negative feedback loop through SMAD6 and 7. It is unclear how TGFβ signalling is connected to the pathogenesis of keloids. Therefore, we investigated the expression of SMAD mRNA and proteins in keloids, in normal skin and in normal scars. Dermal fibroblasts were obtained from punch-biopsies of keloids, normal scars and normal skin. Cells were stimulated with TGFβ1 and the expression of SMAD2, 3, 4, 6 and 7 mRNA was analysed by real time RT-PCR. Protein expression was determined by Western blot analysis. Our data demonstrate a decreased mRNA expression of the inhibitory SMAD6 and 7 in keloid fibroblasts as compared to normal scar ( p