Protective properties of spliced X box binding protein 1 in ozone‑induced spinal cord neuronal death

Mol Med Rep. 2018 Aug;18(2):2349-2355. doi: 10.3892/mmr.2018.9212. Epub 2018 Jun 22.

Abstract

Administration of ozone (O3) is often used in the treatment of low back pain. Administration of O3 can, however, cause neurotoxicity in spinal cord neurons via induction of endoplasmic reticulum (ER) calcium (Ca2+) release and activation of the Ca2+/calmodulin‑dependent protein kinase II (CaMKII)/mitogen‑activated protein kinase (MAPK) pathway. The aim of the current study was to confirm whether administration of O3 causes ER stress and if the consequential overexpression of adenovirus‑mediated spliced X box binding protein 1 (XBP1s), which is the effector of ER stress and a crucial transcriptional factor gene in charge of cell survival, has a protective effect on spinal cord neurons after O3 exposure. To address this aim, the expression of GRP78, an ER chaperone and signaling regulator, and the expression of XBP1s in rat primary spinal cord neurons that underwent O3 exposure were investigated. Primary neurons exposed to O3 exhibited increased GRP78 and XBP1s expression levels. Interestingly, the effect of decreased neuron viability was blocked when cells were pretreated with Adv‑XBP1s. Moreover, overexpression of XBP1s suppressed cell death caused by O3 exposure. These results suggest that overexpression of activated XBP1s protects against neuronal cell death following O3 exposure and that activation of the XBP1s pathway may offer a preventative way for prophylactic treatment of spinal cord neurons exposed to O3.

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Calcium Signaling / drug effects
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2 / genetics
  • Cell Death / drug effects
  • Cell Survival / drug effects
  • Endoplasmic Reticulum Chaperone BiP
  • Endoplasmic Reticulum Stress / drug effects
  • Gene Expression Regulation
  • Heat-Shock Proteins / genetics
  • Humans
  • Low Back Pain / genetics
  • Low Back Pain / physiopathology
  • Low Back Pain / therapy*
  • MAP Kinase Kinase 1 / administration & dosage
  • Neurons / drug effects
  • Ozone / administration & dosage*
  • RNA Splicing / genetics
  • Rats
  • Signal Transduction / drug effects
  • Spinal Cord / drug effects
  • Spinal Cord / physiopathology*
  • X-Box Binding Protein 1 / genetics*

Substances

  • Endoplasmic Reticulum Chaperone BiP
  • GRP78 protein, rat
  • HSPA5 protein, human
  • Heat-Shock Proteins
  • X-Box Binding Protein 1
  • Xbp1 protein, rat
  • Ozone
  • Calcium-Calmodulin-Dependent Protein Kinase Type 2
  • MAP Kinase Kinase 1