The necroptosis machinery mediates axonal degeneration in a model of Parkinson disease

Cell Death Differ. 2020 Apr;27(4):1169-1185. doi: 10.1038/s41418-019-0408-4. Epub 2019 Oct 7.

Abstract

Parkinson's disease (PD) is the second most common neurodegenerative condition, characterized by motor impairment due to the progressive degeneration of dopaminergic neurons in the substantia nigra and depletion of dopamine release in the striatum. Accumulating evidence suggest that degeneration of axons is an early event in the disease, involving destruction programs that are independent of the survival of the cell soma. Necroptosis, a programmed cell death process, is emerging as a mediator of neuronal loss in models of neurodegenerative diseases. Here, we demonstrate activation of necroptosis in postmortem brain tissue from PD patients and in a toxin-based mouse model of the disease. Inhibition of key components of the necroptotic pathway resulted in a significant delay of 6-hydroxydopamine-dependent axonal degeneration of dopaminergic and cortical neurons in vitro. Genetic ablation of necroptosis mediators MLKL and RIPK3, as well as pharmacological inhibition of RIPK1 in preclinical models of PD, decreased dopaminergic neuron degeneration, improving motor performance. Together, these findings suggest that axonal degeneration in PD is mediated by the necroptosis machinery, a process here referred to as necroaxoptosis, a druggable pathway to target dopaminergic neuronal loss.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Axons / pathology*
  • Biomarkers / metabolism
  • Disease Models, Animal
  • Dopaminergic Neurons / metabolism
  • Dopaminergic Neurons / pathology
  • Humans
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Motor Activity
  • Necroptosis*
  • Nerve Degeneration / pathology*
  • Neurites / pathology
  • Oxidopamine
  • Parkinson Disease / pathology*
  • Parkinson Disease / physiopathology
  • Phosphorylation
  • Protein Kinases / metabolism
  • Receptor-Interacting Protein Serine-Threonine Kinases / metabolism
  • Substantia Nigra / metabolism
  • Substantia Nigra / pathology

Substances

  • Biomarkers
  • Oxidopamine
  • MLKL protein, mouse
  • Protein Kinases
  • Receptor-Interacting Protein Serine-Threonine Kinases
  • Ripk3 protein, mouse