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Characterization of renal interstitial fibroblast-specific protein1/S100A4-positive cells in healthy and inflamed rodent kidneys

Le Hir, Michel ; Hegyi, Ivan ; Cueni-Loffing, Dominique ; Loffing, Johannes ; Kaissling, Brigitte

In: Histochemistry and Cell Biology, 2005, vol. 123, no. 4-5, p. 335-346

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    Titre
    • Characterization of renal interstitial fibroblast-specific protein1/S100A4-positive cells in healthy and inflamed rodent kidneys
    Auteur
    • Le Hir, Michel. Anatomical Institute, Division of Vegetative Anatomy, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
    • Hegyi, Ivan. Department of Pathology, Institut für Klinische Pathologie, University of Zürich, Zurich, Switzerland
    • Cueni-Loffing, Dominique. Anatomical Institute, Division of Vegetative Anatomy, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
    • Loffing, Johannes. Institut d‘Anatomie Université de Fribourg, Zurich, Switzerland
    • Kaissling, Brigitte. Anatomical Institute, Division of Vegetative Anatomy, University of Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Histochemistry and Cell Biology, 2005, vol. 123, no. 4-5, p. 335-346. Springer-Verlag; http://www.springer.de
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:312506
    Summary
    Fibrosis is considered as a central factor in the loss of renal function in chronic kidney diseases. The origin of fibroblasts and myofibroblasts that accumulate in the interstitium of the diseased kidney is still a matter of debate. It has been shown that accumulation of myofibroblasts in inflamed and fibrotic kidneys is associated with upregulation of fibroblast-specific protein1 (FSP1, S100A4), not only in the renal interstitium but also in the injured renal epithelia. The tubular expression of FSP1 has been taken as evidence of myofibroblast formation by epithelial-mesenchymal transition (EMT). The identity of FSP1/S100A4 cells has not been defined in detail. We originally intended to use FSP1/S100A4 as a marker of putative EMT in a model of distal tubular injury. However, since the immunoreactivity of FSP1 did not seem to fit with the distribution and shape of fibroblasts or myofibroblasts, we undertook the characterization of FSP1/S100A4-expressing cells in the interstitium of rodent kidneys. We performed immunolabeling for FSP1/S100A4 on thin cryostat sections of perfusion-fixed rat and mouse kidneys with peritubular inflammation, induced by thiazides and glomerulonephritis, respectively, in combination with ecto-5′-nucleotidase (5′NT), recognizing local cortical peritubular fibroblasts, with CD45, MHC classII, CD3, CD4 and Thy1, recognizing mononuclear cells, with alpha smooth muscle actin (αSMA), as marker for myofibroblasts, and vimentin for intracellular intermediate filaments in cells of mesenchymal origin. In the healthy interstitium of rodents the rare FSP1/S100A4+ cells consistently co-expressed CD45 or lymphocyte surface molecules. Around the injured distal tubules of rats treated for 3-4 days with thiazides, FSP1+/S100A4+, 5′NT+, αSMA+, CD45+ and MHC classII+ cells accumulated. FSP1+/S100A4+ cells consistently co-expressed CD45. In the inflamed regions, αSMA was co-expressed by 5′NT+ cells. In glomerulonephritic mice, FSP1+/S100A4+ cells co-expressed Thy1, CD4 or CD3. Thus, in the inflamed interstitium around distal tubules of rats and of glomerulonephritic mice, the majority of FSP1+ cells express markers of mononuclear cells. Consequently, the usefulness of FSP1/S100A4 as a tool for detection of (myo)fibroblasts in inflamed kidneys and of EMT in vivo is put into question. In the given rat model the consistent co-expression of αSMA and 5′NT suggests that myofibroblasts originate from resident peritubular fibroblasts