The bioenergetic status relates to dopamine neuron loss in familial PD with PINK1 mutations

PLoS One. 2012;7(12):e51308. doi: 10.1371/journal.pone.0051308. Epub 2012 Dec 10.

Abstract

Mutations in the PINK1 gene cause autosomal recessive familial Parkinson's disease (PD). The gene encodes a mitochondrial protein kinase that plays an important role in maintaining mitochondrial function and integrity. However, the pathophysiological link between mutation-related bioenergetic deficits and the degenerative process in dopaminergic neurons remains to be elucidated. We performed phosphorous ((31)P) and proton ((1)H) 3-T magnetic resonance spectroscopic imaging (MRSI) in 11 members of a German family with hereditary PD due to PINK1 mutations (PARK6) compared to 23 age-matched controls. All family members had prior 18-Fluorodopa (FDOPA) positron emission tomography (PET). The striatal FDOPA uptake was correlated with quantified metabolic brain mapping in MRSI. At group level, the heterozygous PINK1 mutation carriers did not show any MRSI abnormalities relative to controls. In contrast, homozygous individuals with manifest PD had putaminal GPC, PCr, HEP and β-ATP levels well above the 2SD range of controls. Across all subjects, the FDOPA K(i) values correlated positively with MI (r = 0.879, p<0.001) and inversely with β-ATP (r = -0.784, p = 0.008) and GPC concentrations (r = -0.651, p = 0.030) in the putamen. Our combined imaging data suggest that the dopaminergic deficit in this family with PD due to PINK1 mutations relates to osmolyte dysregulation, while the delivery of high energy phosphates was preserved. Our results corroborate the hypothesis that PINK1 mutations result in reduced neuronal survival, most likely due to impaired cellular stress resistance.

MeSH terms

  • Dopamine / metabolism*
  • Energy Metabolism*
  • Humans
  • Magnetic Resonance Spectroscopy
  • Mutation*
  • Neurons / cytology
  • Neurons / metabolism*
  • Parkinson Disease / metabolism*
  • Protein Kinases / genetics*

Substances

  • Protein Kinases
  • PTEN-induced putative kinase
  • Dopamine

Grants and funding

The authors have no support or funding to report.