Stimulation of the brain serotonin receptor 7 rescues mitochondrial dysfunction in female mice from two models of Rett syndrome

Neuropharmacology. 2017 Jul 15:121:79-88. doi: 10.1016/j.neuropharm.2017.04.024. Epub 2017 Apr 15.

Abstract

Rett syndrome (RTT) is a rare neurodevelopmental disorder, characterized by severe behavioral and physiological symptoms. Mutations in the methyl CpG binding protein 2 gene (MECP2) cause more than 95% of classic cases, and currently there is no cure for this devastating disorder. Recently we have demonstrated that neurobehavioral and brain molecular alterations can be rescued in a RTT mouse model, by pharmacological stimulation of the brain serotonin receptor 7 (5-HT7R). This member of the serotonin receptor family, crucially involved in the regulation of brain structural plasticity and cognitive processes, can be stimulated by systemic repeated treatment with LP-211, a brain-penetrant selective agonist. The present study extends previous findings by demonstrating that LP-211 treatment (0.25 mg/kg, once per day for 7 days) rescues mitochondrial respiratory chain impairment, oxidative phosphorylation deficiency and the reduced energy status in the brain of heterozygous female mice from two highly validated mouse models of RTT (MeCP2-308 and MeCP2-Bird mice). Moreover, LP-211 treatment completely restored the radical species overproduction by brain mitochondria in the MeCP2-308 model and partially recovered the oxidative imbalance in the more severely affected MeCP2-Bird model. These results provide the first evidence that RTT brain mitochondrial dysfunction can be rescued targeting the brain 5-HT7R and add compelling preclinical evidence of the potential therapeutic value of LP-211 as a pharmacological approach for this devastating neurodevelopmental disorder.

Keywords: Energy metabolism; Intellectual disability; LP-211(PubChem CID:25107716); Neurodevelopmental disorders; Oxidative stress; Rho GTPases; Transgenic mice.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Brain / metabolism*
  • Disease Models, Animal
  • Female
  • Glucosephosphate Dehydrogenase / metabolism
  • Glutamic Acid / metabolism
  • Histocompatibility Antigens / metabolism
  • Horseradish Peroxidase / metabolism
  • Methyl-CpG-Binding Protein 2 / genetics
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic
  • Mitochondrial Diseases / metabolism
  • Mitochondrial Diseases / therapy*
  • NADP / metabolism
  • Piperazines / therapeutic use
  • Reactive Oxygen Species / metabolism
  • Receptors, Serotonin / metabolism*
  • Rett Syndrome / complications*
  • Rett Syndrome / genetics
  • Serotonin Receptor Agonists / therapeutic use
  • Superoxide Dismutase / metabolism

Substances

  • Histocompatibility Antigens
  • Mecp2 protein, mouse
  • Methyl-CpG-Binding Protein 2
  • N-(4-cyanophenylmethyl)-4-(2-diphenyl)-1-piperazinehexanamide
  • Piperazines
  • Reactive Oxygen Species
  • Receptors, Serotonin
  • Serotonin Receptor Agonists
  • serotonin 7 receptor
  • Glutamic Acid
  • NADP
  • Adenosine Triphosphate
  • Glucosephosphate Dehydrogenase
  • Horseradish Peroxidase
  • Superoxide Dismutase