title: Pharmacological GLI2 inhibition prevents myofibroblast cell-cycle progression and reduces kidney fibrosis.
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.
authors.forename: Rafael
authors.initials: R
authors.lastname: Kramann
authors.forename: Susanne V
authors.initials: SV
authors.lastname: Fleig
authors.forename: Rebekka K
authors.initials: RK
authors.lastname: Schneider
authors.forename: Steven L
authors.initials: SL
authors.lastname: Fabian
authors.forename: Derek P
authors.initials: DP
authors.lastname: DiRocco
authors.forename: Omar
authors.initials: O
authors.lastname: Maarouf
authors.forename: Janewit
authors.initials: J
authors.lastname: Wongboonsin
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ikeda
authors.forename: Dirk
authors.initials: D
authors.lastname: Heckl
authors.forename: Steven L
authors.initials: SL
authors.lastname: Chang
authors.forename: Helmut G
authors.initials: HG
authors.lastname: Rennke
authors.forename: Sushrut S
authors.initials: SS
authors.lastname: Waikar
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Humphreys
mesh_terms: D000818:Animals; D001152:Arsenicals / Q000494:pharmacology*; D059447:Cell Cycle Checkpoints / Q000187:drug effects* / Q000235:genetics; D002460:Cell Line; D005355:Fibrosis; D005978:Glutathione / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D007668:Kidney / Q000378:metabolism* / Q000473:pathology; D007674:Kidney Diseases / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D051741:Kruppel-Like Transcription Factors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D058628:Myofibroblasts / Q000378:metabolism* / Q000473:pathology; D011725:Pyridines / Q000494:pharmacology*; D011743:Pyrimidines / Q000494:pharmacology*; D000071676:Zinc Finger Protein GLI1; D000075746:Zinc Finger Protein Gli2
chemical_list: D001152:Arsenicals; C551027:GANT 61; C498520:Gli1 protein, mouse; C000618551:Gli2 protein, mouse; D051741:Kruppel-Like Transcription Factors; D011725:Pyridines; D011743:Pyrimidines; D000071676:Zinc Finger Protein GLI1; D000075746:Zinc Finger Protein Gli2; C515055:darinaparsin; D005978:Glutathione