A novel specific PERK activator reduces toxicity and extends survival in Huntington's disease models

Sci Rep. 2020 Apr 23;10(1):6875. doi: 10.1038/s41598-020-63899-4.


One of the pathways of the unfolded protein response, initiated by PKR-like endoplasmic reticulum kinase (PERK), is key to neuronal homeostasis in neurodegenerative diseases. PERK pathway activation is usually accomplished by inhibiting eIF2α-P dephosphorylation, after its phosphorylation by PERK. Less tried is an approach involving direct PERK activation without compromising long-term recovery of eIF2α function by dephosphorylation. Here we show major improvement in cellular (STHdhQ111/111) and mouse (R6/2) Huntington's disease (HD) models using a potent small molecule PERK activator that we developed, MK-28. MK-28 showed PERK selectivity in vitro on a 391-kinase panel and rescued cells (but not PERK-/- cells) from ER stress-induced apoptosis. Cells were also rescued by the commercial PERK activator CCT020312 but MK-28 was significantly more potent. Computational docking suggested MK-28 interaction with the PERK activation loop. MK-28 exhibited remarkable pharmacokinetic properties and high BBB penetration in mice. Transient subcutaneous delivery of MK-28 significantly improved motor and executive functions and delayed death onset in R6/2 mice, showing no toxicity. Therefore, PERK activation can treat a most aggressive HD model, suggesting a possible approach for HD therapy and worth exploring for other neurodegenerative disorders.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Disease Models, Animal
  • Endoplasmic Reticulum Stress / drug effects
  • Enzyme Activators / chemistry
  • Enzyme Activators / pharmacology*
  • Eukaryotic Initiation Factor-2 / metabolism
  • Huntingtin Protein / metabolism
  • Huntington Disease / enzymology*
  • Huntington Disease / pathology
  • Huntington Disease / physiopathology
  • Mice
  • Models, Biological
  • Neostriatum / pathology
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology
  • Neuroprotective Agents / pharmacology
  • Phosphorylation / drug effects
  • Signal Transduction / drug effects
  • Survival Analysis
  • eIF-2 Kinase / metabolism*


  • Enzyme Activators
  • Eukaryotic Initiation Factor-2
  • Htt protein, mouse
  • Huntingtin Protein
  • Neuroprotective Agents
  • PERK kinase
  • eIF-2 Kinase