Pharmacological GLI2 inhibition prevents myofibroblast cell-cycle progression and reduces kidney fibrosis

J Clin Invest. 2015 Aug 3;125(8):2935-51. doi: 10.1172/JCI74929. Epub 2015 Jul 20.

Abstract

Chronic kidney disease is characterized by interstitial fibrosis and proliferation of scar-secreting myofibroblasts, ultimately leading to end-stage renal disease. The hedgehog (Hh) pathway transcriptional effectors GLI1 and GLI2 are expressed in myofibroblast progenitors; however, the role of these effectors during fibrogenesis is poorly understood. Here, we demonstrated that GLI2, but not GLI1, drives myofibroblast cell-cycle progression in cultured mesenchymal stem cell-like progenitors. In animals exposed to unilateral ureteral obstruction, Hh pathway suppression by expression of the GLI3 repressor in GLI1+ myofibroblast progenitors limited kidney fibrosis. Myofibroblast-specific deletion of Gli2, but not Gli1, also limited kidney fibrosis, and induction of myofibroblast-specific cell-cycle arrest mediated this inhibition. Pharmacologic targeting of this pathway with darinaparsin, an arsenical in clinical trials, reduced fibrosis through reduction of GLI2 protein levels and subsequent cell-cycle arrest in myofibroblasts. GLI2 overexpression rescued the cell-cycle effect of darinaparsin in vitro. While darinaparsin ameliorated fibrosis in WT and Gli1-KO mice, it was not effective in conditional Gli2-KO mice, supporting GLI2 as a direct darinaparsin target. The GLI inhibitor GANT61 also reduced fibrosis in mice. Finally, GLI1 and GLI2 were upregulated in the kidneys of patients with high-grade fibrosis. Together, these data indicate that GLI inhibition has potential as a therapeutic strategy to limit myofibroblast proliferation in kidney fibrosis.

Publication types

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

MeSH terms

  • Animals
  • Arsenicals / pharmacology*
  • Cell Cycle Checkpoints / drug effects*
  • Cell Cycle Checkpoints / genetics
  • Cell Line
  • Fibrosis
  • Glutathione / analogs & derivatives*
  • Glutathione / pharmacology
  • Humans
  • Kidney / metabolism*
  • Kidney / pathology
  • Kidney Diseases / drug therapy*
  • Kidney Diseases / genetics
  • Kidney Diseases / metabolism
  • Kidney Diseases / pathology
  • Kruppel-Like Transcription Factors / antagonists & inhibitors*
  • Kruppel-Like Transcription Factors / genetics
  • Kruppel-Like Transcription Factors / metabolism
  • Mice
  • Mice, Knockout
  • Myofibroblasts / metabolism*
  • Myofibroblasts / pathology
  • Pyridines / pharmacology*
  • Pyrimidines / pharmacology*
  • Zinc Finger Protein GLI1
  • Zinc Finger Protein Gli2

Substances

  • Arsenicals
  • GANT 61
  • Gli1 protein, mouse
  • Gli2 protein, mouse
  • Kruppel-Like Transcription Factors
  • Pyridines
  • Pyrimidines
  • Zinc Finger Protein GLI1
  • Zinc Finger Protein Gli2
  • darinaparsin
  • Glutathione