P2X7 Receptor Blockade Prevents ATP Excitotoxicity in Neurons and Reduces Brain Damage After Ischemia

Neurobiol Dis. 2012 Mar;45(3):954-61. doi: 10.1016/j.nbd.2011.12.014. Epub 2011 Dec 11.

Abstract

Overactivation of subtype P2X7 receptors can induce excitotoxic neuronal death by calcium (Ca(2+)) overload. In this study, we characterize the functional properties of P2X7 receptors using electrophysiology and Ca(2+) monitoring in primary cortical neuron cultures and in brain slices. Both electrical responses and Ca(2+) influx induced by ATP and benzoyl-ATP were reduced by Brilliant Blue G (BBG) at concentrations which specifically inhibit P2X7 receptors. In turn, oxygen-glucose deprivation (OGD) caused neuronal death that was reduced with BBG application. OGD in neuron cultures and brain slices generated an inward current, which was delayed and reduced by BBG. To assess the relevance of these in vitro findings, we used middle cerebral artery occlusion in rats as a model of transient focal cerebral ischemia to study the neuroprotective effect of BBG in vivo. Treatment with BBG (twice per day, 30 mg/kg) produced a 60% reduction in the extent of brain damage compared to treatment with vehicle alone. These results show that P2X7 purinergic receptors mediate tissue damage after OGD in neurons and following transient brain ischemia. Therefore, these receptors are a relevant molecular target for the development of new treatments to attenuate brain damage following stroke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / adverse effects*
  • Adenosine Triphosphate / analogs & derivatives
  • Adenosine Triphosphate / pharmacology
  • Analysis of Variance
  • Animals
  • Brain Injuries* / etiology
  • Brain Injuries* / pathology
  • Brain Injuries* / prevention & control
  • Calcium / metabolism
  • Cells, Cultured
  • Cerebral Cortex / cytology
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Embryo, Mammalian
  • Excitatory Amino Acid Agonists / toxicity
  • Fluoresceins
  • Glucose / deficiency
  • Hypoxia / drug therapy
  • In Vitro Techniques
  • Infarction, Middle Cerebral Artery / complications*
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • N-Methylaspartate / toxicity
  • Neurologic Examination
  • Neurons / drug effects*
  • Organic Chemicals
  • Patch-Clamp Techniques
  • Phosphopyruvate Hydratase / metabolism
  • Purinergic P2X Receptor Antagonists / therapeutic use*
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, Purinergic P2X7 / metabolism
  • Rosaniline Dyes / therapeutic use*
  • Tetrazolium Salts

Substances

  • Excitatory Amino Acid Agonists
  • Fluoresceins
  • Organic Chemicals
  • Purinergic P2X Receptor Antagonists
  • Receptors, Purinergic P2X7
  • Rosaniline Dyes
  • Tetrazolium Salts
  • fluoro jade
  • 3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate
  • N-Methylaspartate
  • triphenyltetrazolium
  • Adenosine Triphosphate
  • Phosphopyruvate Hydratase
  • Glucose
  • coomassie Brilliant Blue
  • Calcium