Inhibition of NAE-dependent protein hyper-NEDDylation in cystic cholangiocytes halts cystogenesis in experimental models of polycystic liver disease

United European Gastroenterol J. 2021 Sep;9(7):848-859. doi: 10.1002/ueg2.12126. Epub 2021 Jul 26.

Abstract

Background: Polycystic liver diseases (PLDs) are genetic inherited disorders characterized by the progressive growth of numerous intrahepatic biliary cysts, which are the main cause of morbidity. Previous studies revealed that cystic cholangiocytes are characterized by endoplasmic reticulum stress and aberrant posttranslational modification (PTM) of proteins, in particular hyper-SUMOylation, that promote PLD pathobiology. Protein NEDDylation is a newly characterized PTM that modulates a plethora of biological processes and its dysregulation is associated with the development and progression of several human diseases. However, the role of NEDDylation in PLD remains elusive.

Objective: To explore the role of protein NEDDylation in PLD and its potential therapeutic regulatory value.

Methods: Levels and functional effects of NEDDylation, including response to Pevonedistat (first-in-class selective inhibitor of the NEDDylation E1 enzyme NAE), were assessed in vitro, in vivo, and/or in patients with PLD. NEDDylated protein levels in normal and cystic human cholangiocytes were assessed by immunoprecipitation, and the proteomic profile was further analyzed by mass spectrometry.

Results and conclusion: The genes involved in the NEDDylation pathway were found overexpressed (mRNA) in polycystic human and rat liver tissue, as well as in cystic cholangiocytes in culture, compared to controls. Elevated levels of NEDDylated proteins were further confirmed in cystic cholangiocytes in vitro, which diminished under Pevonedistat incubation. Pevonedistat promoted apoptotic cell death and reduced proliferation in cystic cholangiocytes in vitro. Comparative proteomic profiling of NEDD8-immunoprecipitated proteins between normal and cystic cholangiocytes in culture reported candidate proteins involved in cystogenesis, mostly associated with protein biogenesis and quality control. All these data indicate that cystic cholangiocytes display increased protein NEDDylation, contributing to cell survival and proliferation, ultimately supporting hepatic cystogenesis. Targeting of protein hyper-NEDDylation in cystic cholangiocytes inhibits cystogenesis in experimental models, representing a novel therapeutic opportunity in PLD.

Keywords: NAE; NEDDylation; hepatic cystogenesis; posttranslational modifications; therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Bile Ducts / pathology
  • Cell Proliferation / drug effects
  • Cell Survival / drug effects
  • Cyclopentanes / therapeutic use*
  • Cysts / drug therapy*
  • Cysts / genetics
  • Cysts / metabolism*
  • Cysts / pathology
  • Enzyme Inhibitors / therapeutic use*
  • Humans
  • Liver Diseases / drug therapy*
  • Liver Diseases / genetics
  • Liver Diseases / metabolism*
  • Liver Diseases / pathology
  • NEDD8 Protein / metabolism
  • Protein Processing, Post-Translational / drug effects*
  • Protein Processing, Post-Translational / genetics
  • Pyrimidines / therapeutic use*
  • Rats
  • Sumoylation
  • Ubiquitin-Activating Enzymes / metabolism
  • Ubiquitin-Conjugating Enzymes / metabolism
  • Up-Regulation

Substances

  • Cyclopentanes
  • Enzyme Inhibitors
  • NEDD8 Protein
  • Pyrimidines
  • Ubiquitin-Conjugating Enzymes
  • Ubiquitin-Activating Enzymes
  • NAE protein, human
  • UBE2F protein, human
  • UBE2M protein, human
  • pevonedistat

Supplementary concepts

  • Polycystic liver disease