CREB-mediated Bcl-2 protein expression after ischemic preconditioning

J Cereb Blood Flow Metab. 2005 Feb;25(2):234-46. doi: 10.1038/sj.jcbfm.9600024.

Abstract

Bcl-2 plays a pivotal role in the control of cell death and is upregulated by ischemic tolerance. Because Bcl-2 expression is regulated by the transcription factor cyclic AMP response element-binding protein (CREB), we investigated the role of CREB activation in two models of ischemic preconditioning: focal ischemic tolerance after middle cerebral artery occlusion (MCAO) and in vitro ischemic tolerance modeled by oxygen-glucose deprivation (OGD). After preconditioning ischemia (30 minutes MCAO or 30 minutes OGD), phosphorylation of CREB was increased, and there was an increased interaction between the bcl-2 cyclic AMP-responsive element (CRE) promoter and nuclear proteins after preconditioning ischemia in vivo and in vitro. Chromatin immunoprecipitation revealed an increased interaction between CREB-binding protein and the bcl-2 CRE rather than CREB, after preconditioning ischemia. Ischemic tolerance was blocked by a CRE decoy oligonucleotide, which also blocked Bcl-2 expression. The protein kinase A inhibitor H89, the calcium/calmodulin kinase inhibitor KN62, and the MEK inhibitor U0126 blocked ischemic tolerance, but not the phosphatidylinositol 3-kinase inhibitor LY294002. H89, KN62, and U0126 reduced CREB activation and Bcl-2 expression. Taken together, these data suggest that after ischemic preconditioning CREB activation regulates the expression of the prosurvival protein Bcl-2.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Blotting, Western
  • Brain Ischemia / pathology
  • Brain Ischemia / physiopathology*
  • Cells, Cultured
  • Cyclic AMP Response Element-Binding Protein / metabolism*
  • Electrophoretic Mobility Shift Assay
  • Immunohistochemistry
  • In Situ Nick-End Labeling
  • Intracellular Signaling Peptides and Proteins / drug effects
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Ischemic Preconditioning*
  • Male
  • Neurons / metabolism
  • Neurons / pathology
  • Protein Kinases / drug effects
  • Protein Kinases / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / metabolism*
  • Rats

Substances

  • Cyclic AMP Response Element-Binding Protein
  • Intracellular Signaling Peptides and Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • protein kinase modulator
  • Protein Kinases