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SIK2 is a key regulator for neuronal survival after ischemia via TORC1-CREB

Tsutomu Sasaki1, Hiroshi Takemori, Yoshiki Yagita

  • 1Department of Neurology, Osaka University Graduate School of Medicine, Suita, Osaka 565-0871, Japan.

Neuron
|January 12, 2011
PubMed

Insights

Salt-inducible kinase 2 (SIK2) suppresses neuronal gene expression and survival during oxygen-glucose deprivation (OGD). Inhibiting SIK2 enhances neuronal survival and reduces ischemic injury, highlighting its role in brain protection.

Area of Science:

  • Neuroscience
  • Molecular Biology
  • Cellular Biology

Background:

  • CREB (cAMP responsive element-binding protein) is crucial for biological and pathophysiological processes.
  • SIK2 (salt-inducible kinase 2) is expressed in neurons and regulates gene expression.

Purpose of the Study:

  • To investigate the role of SIK2 in neuronal survival and CREB-mediated gene expression following oxygen-glucose deprivation (OGD).
  • To elucidate the regulatory mechanisms of SIK2 degradation and its impact on CREB activation.

Main Methods:

  • Utilized oxygen-glucose deprivation (OGD) models in neuronal cultures and mouse brains.
  • Investigated protein degradation pathways and phosphorylation events.
  • Employed knockout mouse models (sik2-/-) to assess neuronal survival and ischemic injury.

Main Results:

  • OGD induced SIK2 degradation and TORC1 dephosphorylation, activating CREB and downstream targets.
  • CaMK I/IV phosphorylates SIK2 at Thr484, leading to its degradation in cortical neurons.
  • Neuronal survival increased in sik2(-/-) neurons post-OGD, and ischemic injury was reduced in sik2(-/-) mice.

Conclusions:

  • SIK2 plays a critical role in regulating neuronal survival during ischemic conditions.
  • SIK2 is modulated by CaMK I/IV and regulates CREB activity via TORC1.
  • Targeting SIK2 may offer therapeutic benefits for neuroprotection against ischemic injury.

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