Fibroblast-Specific Protein-1 (FSP-1) Antibody Review





  • a member of the calmodulin S100 troponin C superfamily. PMID: 15618458

  • FSP1 gene encodes a filament-binding S100 protein with paired EF hands that is specifically expressed in fibroblasts. PMID: 9691022

  • a gene encoding a fibroblast-specific protein associated with mesenchymal cell morphology and motility, is expressed during epithelial-mesenchymal transformations (EMT) in vivo. PMID: 9362334

  • a specific prognostic marker for renal survival in patients with IgAN. PMID: 16105038

  • an improved marker for lung fibroblasts that could be useful for investigating the pathogenesis of pulmonary fibrosis. PMID: 15618458


  • FSP1 protein stained the cytoplasm of fibroblasts, but not epithelium. Only occasional cells stain with specific anti-FSP1 antibodies in normal parenchymal tissue. However, in kidneys fibrosing from persistent inflammation, many fibroblasts could be identified in interstitial sites of collagen deposition and also in tubular epithelium adjacent to the inflammatory process. This pattern of anti-FSP1 staining during tissue fibrosis suggests, as a hypothesis, that fibroblasts in some cases arise, as needed, from the local conversion of epithelium. Consistent with this notion that FSP1 may be involved in the transition from epithelium to fibroblasts are experiments in which the in vitro overexpression of FSP1 cDNA in tubular epithelium is accompanied by conversion to a mesenchymal phenotype, as characterized by a more stellate and elongated fibroblast-like appearance, a reduction in cytokeratin, and new expression of vimentin. PMID: 7615639

  • FSP1 identifies human fibroblasts and tubular epithelium undergoing EMT, and distinguishes them from the diaspora of alpha-SMA+ vascular smooth muscle cells. FSP1+ fibroblasts are critically related to the progression of IgAN. PMID: 16105038

  • Protein and mRNA expression of FSP1 was minimal in untreated lungs, but increased by 1 week after bleomycin administration and remained increased at 2 and 3 weeks after treatment. PMID: 15618458


  • usefulness of FSP1/S100A4 as a tool for detection of (myo)fibroblasts in inflamed kidneys and of EMT in vivo is put into question. PMID: 15856273




  • Immunolocalization of fibroblast growth factor-1 (FGF-1), its receptor (FGFR-1), and fibroblast-specific protein-1 (FSP-1) in inflammatory renal disease. PMID: 16316338

  • Cells positive for fibroblast-specific protein 1 (FSP1) were localized in renal biopsy specimens using immunohistochemistry with anti-FSP1 antibody. PMID: 16105038

  • immunolabeling for FSP1/S100A4 on thin cryostat sections of perfusion-fixed rat and mouse kidneys with peritubular inflammation. PMID: 15856273