Cyclic AMP response element modulator-1 (CREM-1) involves in neuronal apoptosis after traumatic brain injury

J Mol Neurosci. 2012 Jun;47(2):357-67. doi: 10.1007/s12031-012-9761-1. Epub 2012 May 9.

Abstract

The cyclic AMP response element-binding protein (CREB) family can regulate biological functions of various types of cells by forming homo- or heterodimers to bind the target DNA sequences; it plays an essential role in individual neuronal function and entire neuronal circuits. One attractive activity of the CREB family is regulating the transcription of apoptosis-suppressor gene bcl-2. Cyclic AMP response element modulator-1 (CREM-1) is one member of the family with limited acquaintance. To investigate whether CREM-1 is involved in central nervous system injury and repair, we performed an acute traumatic brain injury (TBI) model in adult rats. Western blot analysis and immunohistochemistry showed a significant upregulation of CREM-1 in ipsilateral peritrauma cortex. Immunofluorescent labeling indicated that CREM-1 was localized mainly in the nuclei of neurons; co-localization of CREM-1 and active-caspase-3 in the ipsilateral cortex suggested that CREM-1 might participate in neuronal apoptosis. To further investigate the function of CREM-1, a neuronal cell line PC12 was employed to establish an apoptosis model. We analyzed the association of CREM-1 with p-CREB on PC12 cells by Western blot, immunofluorescent labeling, and co-immunoprecipitation. The result implied that the association of CREM-1 with p-CREB was enhanced in apoptotic cells. Additionally, knocking CREM-1 down with siRNA demonstrated the probable pro-apoptotic role played by CREM-1 in neuronal apoptosis. Together with our data, we hypothesized that CREM-1 might play an important role in regulating neuronal death after TBI by interacting with CREB.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Apoptosis / physiology*
  • Brain Injuries / genetics
  • Brain Injuries / metabolism*
  • Brain Injuries / pathology*
  • Cyclic AMP Response Element Modulator / genetics
  • Cyclic AMP Response Element Modulator / metabolism*
  • Cyclic AMP Response Element-Binding Protein / genetics
  • Cyclic AMP Response Element-Binding Protein / metabolism*
  • Disease Models, Animal
  • Male
  • Neurons / drug effects
  • Neurons / pathology*
  • Neurons / physiology
  • PC12 Cells
  • Rats
  • Rats, Sprague-Dawley

Substances

  • Crem protein, rat
  • Cyclic AMP Response Element-Binding Protein
  • Cyclic AMP Response Element Modulator