Parkin protects dopaminergic neurons from excessive Wnt/beta-catenin signaling

Biochem Biophys Res Commun. 2009 Oct 23;388(3):473-8. doi: 10.1016/j.bbrc.2009.07.014. Epub 2009 Jul 8.

Abstract

Parkinson's disease (PD) is caused by degeneration of the dopaminergic (DA) neurons of the substantia nigra but the molecular mechanisms underlying the degenerative process remain elusive. Several reports suggest that cell cycle deregulation in post-mitotic neurons could lead to neuronal cell death. We now show that Parkin, an E3 ubiquitin ligase linked to familial PD, regulates beta-catenin protein levels in vivo. Stabilization of beta-catenin in differentiated primary ventral midbrain neurons results in increased levels of cyclin E and proliferation, followed by increased levels of cleaved PARP and loss of DA neurons. Wnt3a signaling also causes death of post-mitotic DA neurons in parkin null animals, suggesting that both increased stabilization and decreased degradation of beta-catenin results in DA cell death. These findings demonstrate a novel regulation of Wnt signaling by Parkin and suggest that Parkin protects DA neurons against excessive Wnt signaling and beta-catenin-induced cell death.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis*
  • COS Cells
  • Chlorocebus aethiops
  • Dopamine / metabolism*
  • Mice
  • Mitosis
  • Neurons / cytology
  • Neurons / metabolism
  • Neurons / physiology*
  • Ubiquitin-Protein Ligases / metabolism*
  • Wnt Proteins / metabolism*
  • beta Catenin / metabolism*

Substances

  • Wnt Proteins
  • beta Catenin
  • Ubiquitin-Protein Ligases
  • parkin protein
  • Dopamine