Science and Research

Comparison of the antifibrotic effects of the pan-histone deacetylase-inhibitor panobinostat versus the IPF-drug pirfenidone in fibroblasts from patients with idiopathic pulmonary fibrosis

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease with a poor prognosis. Pirfenidone is the first antifibrotic agent to be approved for IPF-treatment as it is able to slow down disease progression. However, there is no curative treatment other than lung transplantation. Because epigenetic alterations are associated with IPF, histone deacetylase (HDAC)-inhibitors have recently been proven to attenuate fibrotic remodeling in vitro and in vivo. This study compared the effects of pirfenidone with the pan-HDAC-inhibitor panobinostat/LBH589, a FDA-approved drug for the treatment of multiple myeloma, head-to-head on survival, fibrotic activity and proliferation of primary IPF-fibroblasts in vitro. METHODS: Primary fibroblasts from six IPF-patients were incubated for 24h with vehicle (0.25% DMSO), panobinostat (LBH589, 85 nM) or pirfenidone (2.7 mM), followed by assessment of proliferation and expression analyses for profibrotic and anti-apoptosis genes, as well as for ER stress and apoptosis-markers. In addition, the expression status of all HDAC enzymes was examined. RESULTS: Treatment of IPF-fibroblasts with panobinostat or pirfenidone resulted in a downregulated expression of various extracellular matrix (ECM)-associated genes, as compared to vehicle-treated cells. In agreement, both drugs decreased protein level of phosphorylated (p)-STAT3, a transcription factor mediating profibrotic responses, in treated IPF-fibroblasts. Further, an increase in histone acetylation was observed in response to both treatments, but was much more pronounced and excessive in panobinostat-treated IPF-fibroblasts. Panobinostat, but not pirfenidone, led to a significant suppression of proliferation in IPF-fibroblasts, as indicated by WST1- and BrdU assay and markedly diminished levels of cyclin-D1 and p-histone H3. Furthermore, panobinostat-treatment enhanced alpha-tubulin-acetylation, decreased the expression of survival-related genes Bcl-XL and BIRC5/survivin, and was associated with induction of ER stress and apoptosis in IPF-fibroblasts. In contrast, pirfenidone-treatment maintained Bcl-XL expression, and was neither associated with ER stress-induction nor any apoptotic signaling. Pirfenidone also led to increased expression of HDAC6 and sirtuin-2, and enhanced alpha-tubulin-deacetylation. But in line with its ability to increase histone acetylation, pirfenidone reduced the expression of HDAC enzymes HDAC1, -2 and -9. CONCLUSIONS: We conclude that, beside other antifibrotic mechanisms, pirfenidone reduces profibrotic signaling also through STAT3 inactivation and weak epigenetic alterations in IPF-fibroblasts, and permits survival of (altered) fibroblasts. The pan-HDAC-inhibitor panobinostat reduces profibrotic phenotypes while inducing cell cycle arrest and apoptosis in IPF-fibroblasts, thus indicating more efficiency than pirfenidone in inactivating IPF-fibroblasts. We therefore believe that HDAC-inhibitors such as panobinostat can present a novel therapeutic strategy for IPF.

  • Korfei, M.
  • Stelmaszek, D.
  • MacKenzie, B.
  • Skwarna, S.
  • Chillappagari, S.
  • Bach, A. C.
  • Ruppert, C.
  • Saito, S.
  • Mahavadi, P.
  • Klepetko, W.
  • Fink, L.
  • Seeger, W.
  • Lasky, J. A.
  • Pullamsetti, S. S.
  • Kramer, O. H.
  • Guenther, A.

Keywords

  • Apoptosis/drug effects
  • Cell Proliferation/drug effects
  • Cell Survival/drug effects
  • Down-Regulation/drug effects
  • Endoplasmic Reticulum Stress/drug effects
  • Extracellular Matrix Proteins/metabolism
  • Female
  • Fibroblasts/*drug effects/pathology/physiology
  • Histone Deacetylase Inhibitors/*pharmacology
  • Histones/metabolism
  • Humans
  • Idiopathic Pulmonary Fibrosis/*drug therapy/pathology/physiopathology
  • Lung/drug effects/pathology/physiopathology
  • Male
  • Middle Aged
  • Panobinostat/*pharmacology
  • Primary Cell Culture
  • Protective Agents/*pharmacology
  • Pyridones/*pharmacology
  • STAT3 Transcription Factor/metabolism
Publication details
DOI: 10.1371/journal.pone.0207915
Journal: PloS one
Pages: e0207915 
Number: 11
Work Type: Original
Location: UGMLC
Disease Area: DPLD
Partner / Member: JLU, MPI-BN
Access-Number: 30481203
See publication on PubMed

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