Rosiglitazone synergizes the neuroprotective effects of valproic acid against quinolinic acid-induced neurotoxicity in rats: targeting PPARγ and HDAC pathways

Neurotox Res. 2014 Aug;26(2):130-51. doi: 10.1007/s12640-014-9458-z. Epub 2014 Feb 25.

Abstract

Huntington's disease (HD) is an autosomal dominant progressive neurodegenerative disorder which affects medium spiny GABAergic neurons mainly in the striatum. Oxidative damage, neuro-inflammation, apoptosis, protein aggregation, and signaling of neurotrophic factors are some of the common cellular pathways involved in HD. Quinolinic acid (QA) causes excitotoxicity by stimulating N-methyl-D-aspartate receptors via calcium overload leading to neurodegeneration. Neuroprotective potential of peroxisome proliferator activated receptor-γ (PPARγ) agonists and histone deacetylase (HDAC) inhibitors have been well documented in experimental models of neurodegenerative disorders; however, their exact mechanisms are not clear. Therefore, present study has been designed to explore possible neuroprotective mechanism of valproic acid (VPA) and its interaction with rosiglitazone against QA induced HD-like symptoms in rats. Single bilateral intrastriatal QA (200 nmol/2 μl saline) administration significantly caused motor incoordination, memory impairment, oxidative damage, mitochondrial dysfunction (complex I, II, II and IV), cellular alterations [tumor necrosis factor-alpha (TNF-α), caspase-3, brain derived neurotrophic factor, acetylcholinesterase], and striatal neurodegeneration as compared to sham group. Treatment with rosiglitazone (5, 10 mg/kg) and VPA (100, 200 mg/kg) for 21 days significantly attenuated these behavioral, biochemical, and cellular alterations as compared to control (QA 200 nmol) group. However, VPA (100 mg/kg) treatment in combination with rosiglitazone (5 mg/kg) for 21 days synergized their neuroprotective effect, which was significant as compared to their effects per se in QA-treated animals. The present study provides an evidence of possible interplay of PPARγ agonists and HDAC inhibitors as a novel therapeutic strategy in the management of HD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Body Weight / drug effects
  • Brain / drug effects
  • Brain / pathology
  • Brain / physiopathology
  • Disease Models, Animal
  • Drug Synergism
  • Histone Deacetylase Inhibitors / pharmacology
  • Histone Deacetylases / metabolism*
  • Huntington Disease
  • Male
  • Maze Learning / drug effects
  • Maze Learning / physiology
  • Motor Activity / drug effects
  • Motor Activity / physiology
  • Neurodegenerative Diseases / drug therapy*
  • Neurodegenerative Diseases / pathology
  • Neurodegenerative Diseases / physiopathology
  • Neuroprotective Agents / pharmacology
  • Neurotoxicity Syndromes / drug therapy*
  • Neurotoxicity Syndromes / pathology
  • Neurotoxicity Syndromes / physiopathology
  • PPAR gamma / agonists
  • PPAR gamma / metabolism*
  • Quinolinic Acid
  • Rats, Wistar
  • Rosiglitazone
  • Signal Transduction / drug effects
  • Thiazolidinediones / pharmacology*
  • Valproic Acid / pharmacology*

Substances

  • Histone Deacetylase Inhibitors
  • Neuroprotective Agents
  • PPAR gamma
  • Thiazolidinediones
  • Rosiglitazone
  • Valproic Acid
  • Histone Deacetylases
  • Quinolinic Acid