CMH-Small Molecule Docks into SIRT1, Elicits Human IPF-Lung Fibroblast Cell Death, Inhibits Ku70-deacetylation, FLIP and Experimental Pulmonary Fibrosis

Biomolecules. 2020 Jul 2;10(7):997. doi: 10.3390/biom10070997.

Abstract

Regenerative capacity in vital organs is limited by fibrosis propensity. Idiopathic pulmonary fibrosis (IPF), a progressive lung disease linked with aging, is a classic example. In this study, we show that in flow cytometry, immunoblots (IB) and in lung sections, FLIP levels can be regulated, in vivo and in vitro, through SIRT1 activity inhibition by CMH (4-(4-Chloro-2-methylphenoxy)-N-hydroxybutanamide), a small molecule that, as we determined here by structural biology calculations, docked into its nonhistone substrate Ku70-binding site. Ku70 immunoprecipitations and immunoblots confirmed our theory that Ku70-deacetylation, Ku70/FLIP complex, myofibroblast resistance to apoptosis, cell survival, and lung fibrosis in bleomycin-treated mice, are reduced and regulated by CMH. Thus, small molecules associated with SIRT1-mediated regulation of Ku70 deacetylation, affecting FLIP stabilization in fibrotic-lung myofibroblasts, may be a useful strategy, enabling tissue regeneration.

Keywords: CMH; FLIP; IPF-resolution; Ku70-SIRT1; apoptosis; fibroblasts.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation / drug effects
  • Animals
  • Binding Sites
  • CASP8 and FADD-Like Apoptosis Regulating Protein / chemistry
  • CASP8 and FADD-Like Apoptosis Regulating Protein / metabolism*
  • Cell Line
  • Cell Survival / drug effects
  • Disease Models, Animal
  • Fibroblasts / cytology
  • Fibroblasts / drug effects
  • Fibroblasts / metabolism
  • Gene Expression Regulation / drug effects
  • Humans
  • Hydroxamic Acids / administration & dosage*
  • Hydroxamic Acids / chemistry
  • Hydroxamic Acids / pharmacology
  • Idiopathic Pulmonary Fibrosis / drug therapy*
  • Idiopathic Pulmonary Fibrosis / metabolism
  • Ku Autoantigen / metabolism*
  • Lung / cytology*
  • Lung / drug effects
  • Lung / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Models, Molecular
  • Molecular Docking Simulation
  • Protein Conformation
  • Protein Stability / drug effects
  • Sirtuin 1 / chemistry*
  • Sirtuin 1 / metabolism*

Substances

  • 4-(4-chloro-2-methylphenoxy)-N-hydroxybutanamide
  • CASP8 and FADD-Like Apoptosis Regulating Protein
  • CFLAR protein, human
  • Hydroxamic Acids
  • SIRT1 protein, human
  • Sirtuin 1
  • Xrcc6 protein, human
  • Ku Autoantigen