Transgenic expression of nonclassically secreted FGF suppresses kidney repair

PLoS One. 2012;7(5):e36485. doi: 10.1371/journal.pone.0036485. Epub 2012 May 14.

Abstract

FGF1 is a signal peptide-less nonclassically released growth factor that is involved in angiogenesis, tissue repair, inflammation, and carcinogenesis. The effects of nonclassical FGF export in vivo are not sufficiently studied. We produced transgenic mice expressing FGF1 in endothelial cells (EC), which allowed the detection of FGF1 export to the vasculature, and studied the efficiency of postischemic kidney repair in these animals. Although FGF1 transgenic mice had a normal phenotype with unperturbed kidney structure, they showed a severely inhibited kidney repair after unilateral ischemia/reperfusion. This was manifested by a strong decrease of postischemic kidney size and weight, whereas the undamaged contralateral kidney exhibited an enhanced compensatory size increase. In addition, the postischemic kidneys of transgenic mice were characterized by hyperplasia of interstitial cells, paucity of epithelial tubular structures, increase of the areas occupied by connective tissue, and neutrophil and macrophage infiltration. The continuous treatment of transgenic mice with the cell membrane stabilizer, taurine, inhibited nonclassical FGF1 export and significantly rescued postischemic kidney repair. It was also found that similar to EC, the transgenic expression of FGF1 in monocytes and macrophages suppresses kidney repair. We suggest that nonclassical export may be used as a target for the treatment of pathologies involving signal peptide-less FGFs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Cell Enlargement
  • DNA Primers / genetics
  • Endothelial Cells / pathology
  • Endothelial Cells / physiology
  • Fibroblast Growth Factor 1 / blood
  • Fibroblast Growth Factor 1 / genetics*
  • Fibroblast Growth Factor 1 / physiology*
  • Fibrosis
  • Kidney / blood supply
  • Kidney / injuries*
  • Kidney / pathology
  • Kidney / physiopathology*
  • Macrophages / pathology
  • Male
  • Mice
  • Mice, Transgenic
  • Mutagenesis, Site-Directed
  • Mutant Proteins / blood
  • Mutant Proteins / genetics
  • Mutant Proteins / metabolism
  • Neutrophils / pathology
  • Organ Size
  • Recombinant Proteins / blood
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Reperfusion Injury / drug therapy
  • Reperfusion Injury / genetics
  • Reperfusion Injury / pathology
  • Reperfusion Injury / physiopathology
  • Signal Transduction
  • Taurine / pharmacology
  • Wound Healing / drug effects
  • Wound Healing / genetics
  • Wound Healing / physiology

Substances

  • DNA Primers
  • Mutant Proteins
  • Recombinant Proteins
  • Fibroblast Growth Factor 1
  • Taurine