Phosphoinositide 3-kinase enhancer regulates neuronal dendritogenesis and survival in neocortex

J Neurosci. 2011 Jun 1;31(22):8083-92. doi: 10.1523/JNEUROSCI.1129-11.2011.

Abstract

Phosphoinositide 3-kinase enhancer (PIKE) binds and enhances phosphatidylinositol 3-kinase (PI3K)/Akt activities. However, its physiological functions in brain have never been explored. Here we show that PIKE is important in regulating the neuronal survival and development of neocortex. During development, enhanced apoptosis is observed in the ventricular zone of PIKE knock-out (PIKE(-/-)) cortex. Moreover, PIKE(-/-) neurons show reduced dendritic complexity, dendritic branch length, and soma size. These defects are due to the reduced PI3K/Akt activities in PIKE(-/-) neurons, as the impaired dendritic arborization can be rescued when PI3K/Akt cascade is augmented in vitro or in PIKE(-/-)PTEN(-/-) double-knock-out mice. Interestingly, PIKE(-/-) mice display behavioral abnormality in locomotion and spatial navigation. Because of the diminished PI3K/Akt activities, PIKE(-/-) neurons are more vulnerable to glutamate- or stroke-induced neuronal cell death. Together, our data established the critical role of PIKE in regulating neuronal survival and development by substantiating the PI3K/Akt pathway.

Publication types

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

MeSH terms

  • Animals
  • Apoptosis / genetics
  • Apoptosis / physiology
  • Brain-Derived Neurotrophic Factor / pharmacology
  • Brain-Derived Neurotrophic Factor / physiology
  • Cell Culture Techniques
  • Cell Survival / drug effects
  • Cell Survival / genetics
  • Cell Survival / physiology*
  • Dendrites / metabolism
  • Dendrites / physiology*
  • Dendrites / ultrastructure
  • GTP Phosphohydrolases / genetics
  • GTP Phosphohydrolases / physiology*
  • Glutamic Acid / pharmacology
  • Infarction, Middle Cerebral Artery / metabolism
  • Infarction, Middle Cerebral Artery / physiopathology
  • Locomotion / genetics
  • Locomotion / physiology
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neocortex / cytology
  • Neocortex / growth & development*
  • Neocortex / metabolism
  • Neocortex / physiology*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / physiology*
  • Neurogenesis / genetics
  • Neurogenesis / physiology*
  • Neurons / metabolism
  • Neurons / physiology*
  • Neurons / ultrastructure
  • Organ Size
  • PTEN Phosphohydrolase / genetics
  • PTEN Phosphohydrolase / physiology
  • Proto-Oncogene Proteins c-akt / physiology
  • Signal Transduction / genetics
  • Signal Transduction / physiology
  • Spatial Behavior / physiology

Substances

  • Brain-Derived Neurotrophic Factor
  • Nerve Tissue Proteins
  • Glutamic Acid
  • Proto-Oncogene Proteins c-akt
  • PTEN Phosphohydrolase
  • Pten protein, mouse
  • GTP Phosphohydrolases
  • PIKE protein, mouse