Enhanced fibrillin-2 expression is a general feature of wound healing and sclerosis: potential alteration of cell attachment and storage of TGF-beta

Lab Invest. 2010 May;90(5):739-52. doi: 10.1038/labinvest.2010.49. Epub 2010 Mar 1.

Abstract

Wound healing and sclerosis are characterized by an increase of extracellular matrix proteins, which are characteristically expressed in the embryo-fetal period. We analyzed the expression of fibrillin-2, which is typically found in embryonic tissues, but only scarcely in adult skin. In wound healing and sclerotic skin diseases such as lipodermatosclerosis and scleroderma, a marked increase of fibrillin-2 expression was found by immunohistology. Double labelling of fibrillin-2 and tenascin-C, which is also expressed in wound healing and sclerosis, showed co-localization of both proteins. Solid-phase and slot blot-overlay assays showed a dose-dependent binding of the recombinant N-terminal half of fibrillin-2 (rFBN2-N) to tenascin-C. Real-time PCR showed an increase of the fibrillin-2 gene expression in cell culture triggered by typical mediators for fibroblast activation such as serum, IL-4, and TGF-beta. By contrast, prolonged hypoxia is not associated with changes in fibrillin-2 expression. Tenascin-C is an anti-adhesive substrate for fibroblasts, whereas fibrillin-2 stimulates cell attachment. Attachment assays using mixed substrates showed decreased cell attachment when tenascin-C and rFBN2-N were coated together, compared with the attachment to rFBN2-N alone. Fibrillins are involved in storage and activation of TGF-beta. Immunohistology with an antibody against the latency-associated peptide (LAP (TGF-beta1)) showed a marked increase of inactive LAP-bound TGF-beta1 in wound healing and sclerotic skin whereas normal skin showed only a weak expression. Double immunofluorescence confirmed a partial colocalization of both proteins. In conclusion, we show that a stimulation of the fibrillin-2 expression is a characteristic feature of fibroblasts present in wound healing and sclerosis, which may be involved in the alteration of cell attachment and storage of inactive TGF-beta in the matrix.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Adhesion
  • Cell Hypoxia
  • Cells, Cultured
  • Culture Media, Serum-Free / pharmacology
  • Extracellular Matrix / metabolism
  • Fibrillin-2
  • Fibrillins
  • Fibroblasts / metabolism
  • Fibroblasts / pathology
  • Fluorescent Antibody Technique
  • Gene Expression / drug effects
  • Humans
  • Immunohistochemistry
  • Interleukin-4 / pharmacology
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Scleroderma, Localized / genetics
  • Scleroderma, Localized / metabolism
  • Scleroderma, Localized / pathology
  • Sclerosis
  • Skin / metabolism*
  • Skin / pathology
  • Skin / physiopathology
  • Tenascin / genetics
  • Tenascin / metabolism
  • Transforming Growth Factor beta / genetics
  • Transforming Growth Factor beta / metabolism*
  • Transforming Growth Factor beta / pharmacology
  • Wound Healing*

Substances

  • Culture Media, Serum-Free
  • FBN2 protein, human
  • Fibrillin-2
  • Fibrillins
  • Microfilament Proteins
  • Tenascin
  • Transforming Growth Factor beta
  • Interleukin-4