Neurotoxicity Research

, 17:189

Endoplasmic Reticulum Stress Plays Critical Role in Brain Damage After Cerebral Ischemia/Reperfusion in Rats

  • Venkata Prasuja Nakka
  • Anchal Gusain
  • Ram Raghubir
Article

DOI: 10.1007/s12640-009-9110-5

Cite this article as:
Nakka, V.P., Gusain, A. & Raghubir, R. Neurotox Res (2010) 17: 189. doi:10.1007/s12640-009-9110-5

Abstract

The endoplasmic reticulum(ER) stress plays a vital role in mediating ischemic neuronal cell death. However, very little is known about the role of ER stress in mediating pathophysiological reactions to acute brain injuries. An attempt was therefore made to assess the role of cerebral ischemia/reperfusion (I/R) induced ER stress and its modulation on outcome of ischemic insult. Focal cerebral ischemia was induced in rats by middle cerebral artery occlusion (MCAO) for 2 h followed by varying time points of reperfusion. The brain loci specific and time-dependent alterations were seen in the expression pattern of molecular markers, i.e., heat-shock protein 70 (HSP70) for cytoplasmic dysfunction, glucose-regulated protein 78 (GRP78), Caspase-12, C/EBP homologous protein/growth arrest and DNA damage-inducible gene 153 (CHOP/GADD153), activating transcription factor 4 (ATF-4), and Processed X-box protein 1 (xbp1) mRNA for ER dysfunction. Further, histological examinations indicated pronounced brain damage, massive neuronal loss, and DNA fragmentation predominantly in the striatum and cortex. The enhanced expression of GRP78, Caspase-12, CHOP/GADD153, ATF4 and processing of xbp1 mRNA in the affected brain regions clearly indicate the critical involvement of ER-mediated cell death/survival mechanisms and also collectively demonstrated the activation of unfolded protein response (UPR). Moreover, Salubrinal, a selective inhibitor of eIF2α dephosphorylation was used to counteract ER stress, which significantly increased the phosphorylation of eukaryotic translation initiation factor 2 subunit α (eIF2α), leading to reduced brain damage after I/R injury. Therefore, inhibition of ER stress following I/R injury may be used as key therapeutic target for neuroprotection.

Keywords

Cerebral ischemiaBrain damageUnfolded protein responseER stressSalubrinal

Supplementary material

12640_2009_9110_MOESM1_ESM.tif (537 kb)
Supplementary FigureCoronal brain sections of TTC staining showing the ipsilateral brain damage after 2 h ischemia followed by different time intervals of reperfusion (TIFF 536 kb)

Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Venkata Prasuja Nakka
    • 1
  • Anchal Gusain
    • 1
  • Ram Raghubir
    • 1
  1. 1.Division of PharmacologyCentral Drug Research InstituteLucknowIndia