title: Scleroderma dermal fibroblasts overexpress vascular endothelial growth factor due to autocrine transforming growth factor β signaling.
abstract: OBJECTIVE
  Overexpression of vascular endothelial growth factor (VEGF) in scleroderma (SSc) skin may play a role in the pathogenesis of the disease. Our study was undertaken to evaluate whether dermal fibroblasts function as one of the sources of the increased VEGF in SSc, and to clarify its mechanism.
  
  
  METHODS
  Protein and mRNA levels of VEGF were analyzed using immunoblotting, enzyme-linked immunosorbent assay, and real-time PCR. The DNA-binding ability of Smad3 was evaluated by DNA affinity precipitation.
  
  
  RESULTS
  VEGF mRNA expression in vivo was increased in SSc skin compared to skin with other collagen diseases. Expression of VEGF protein and mRNA in cultured SSc dermal fibroblasts was constitutively and significantly upregulated. Ectopic TGF-β stimulation induced VEGF synthesis in normal fibroblasts, and TGF-β knockdown normalized the upregulated VEGF levels in SSc fibroblasts. Furthermore, Smad3 overexpression induced VEGF levels. We found that bp -532 to -521 on the VEGF promoter is a putative binding site for Smads, and that the binding activity of Smad3 to VEGF promoter was constitutively increased in SSc fibroblasts as well as in normal fibroblasts treated with exogenous TGF-β1.
  
  
  CONCLUSIONS
  We demonstrated that VEGF were overexpressed due to autocrine TGF-β/Smad signaling in SSc. TGF-β signaling may contribute to the pathogenesis of angiopathy as well as tissue fibrosis.
authors: Department of Dermatology and Plastic Surgery, Faculty of Life Sciences, Kumamoto University, 1-1-1 Honjo Kumamoto, Japan.
authors: Ikko
authors: I
authors: Kajihara
authors: Masatoshi
authors: M
authors: Jinnin
authors: Noritoshi
authors: N
authors: Honda
authors: Katsunari
authors: K
authors: Makino
authors: Takamitsu
authors: T
authors: Makino
authors: Shinichi
authors: S
authors: Masuguchi
authors: Keisuke
authors: K
authors: Sakai
authors: Satoshi
authors: S
authors: Fukushima
authors: Yuji
authors: Y
authors: Inoue
authors: Hironobu
authors: H
authors: Ihn
mesh_terms: D000328:Adult; D019898:Autocrine Communication / Q000502:physiology*; D005260:Female; D005347:Fibroblasts / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D011401:Promoter Regions, Genetic; D012594:Scleroderma, Localized / Q000378:metabolism* / Q000473:pathology; D012867:Skin / Q000378:metabolism* / Q000473:pathology; D051900:Smad3 Protein / Q000235:genetics / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism*
chemical_list: D051900:Smad3 Protein; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A