Novel neuroprotection by caffeine and adenosine A(2A) receptor antagonists in animal models of Parkinson's disease

J Neurol Sci. 2006 Oct 25;248(1-2):9-15. doi: 10.1016/j.jns.2006.05.003. Epub 2006 Jun 27.

Abstract

The adenosine A(2A) receptor has recently emerged as a leading non-dopaminergic therapeutic target for Parkinson's disease, largely due to the restricted distribution of the receptor in the striatum and the profound interaction between adenosine and dopamine receptors in brain. Two lines of research in particular have demonstrated the promise of the A(2A) receptor antagonists as novel anti-parkinsonian drugs. First, building on extensive preclinical animal studies, the A(2A) receptor antagonist KW6002 has demonstrated its potential to increase motor activity in PD patients of the advanced stage in a recent clinical phase IIB trial. Second, recently two prospective epidemiological studies of large cohorts have firmly established the inverse relationship between the consumption of caffeine (a non-specific adenosine antagonist) and the risk of developing PD. The potential neuroprotective effect of caffeine and A(2A) receptor antagonists in PD is further substantiated by the demonstration that pharmacological blockade (by caffeine or specific A(2A) antagonists) or genetic depletion of the A(2A) receptor attenuated dopaminergic neurotoxicity and neurodegeneration in animal models of PD. Moreover, A(2A) receptor antagonism-mediated neuroprotection goes beyond PD models and can be extended to a variety of other brain injuries induced by stroke, excitotoxicity and mitochondrial toxins. Intensive investigations are under way to dissect out common cellular mechanisms (such as A(2A) receptor modulation of neuroinflammation) which may underlie the broad spectrum of neuroprotection by A(2A) receptor inactivation in brain.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Adenosine A2 Receptor Antagonists*
  • Animals
  • Caffeine / therapeutic use*
  • Central Nervous System / drug effects
  • Central Nervous System / metabolism
  • Clinical Trials, Phase II as Topic
  • Disease Models, Animal
  • Glutamic Acid / metabolism
  • Humans
  • Inflammation / drug therapy
  • Neuroprotective Agents / therapeutic use*
  • Parkinson Disease / drug therapy*
  • Parkinson Disease / physiopathology
  • Purines / therapeutic use*

Substances

  • Adenosine A2 Receptor Antagonists
  • Neuroprotective Agents
  • Purines
  • istradefylline
  • Caffeine
  • Glutamic Acid