IL-17A contributes to brain ischemia reperfusion injury through calpain-TRPC6 pathway in mice

Neuroscience. 2014 Aug 22;274:419-28. doi: 10.1016/j.neuroscience.2014.06.001. Epub 2014 Jun 10.

Abstract

Interleukin (IL)-17A plays an important role in the cerebral ischemia/reperfusion (I/R) injury. However, the mechanisms are still largely unknown. Calpain-transient receptor potential canonical (subtype) 6 (TRPC6) signaling pathway has been recently found to be implicated in brain I/R injury. However, their relationships with IL-17A remain unknown. This study aims to test whether this important signaling has correlation with IL-17A and how they led to the neuronal damage in I/R injury. In the present study, mice were subjected to middle cerebral artery occlusion (60 min) followed by reperfusion for different times. Infarct volumes and neurological deficits were examined. Real-time PCR (RT-PCR) and Western blotting were conducted to detect IL-17A expression in the penumbral brain tissue. Activation of calpain and expression of TRPC6 were also studied. We found that cerebral I/R significantly increased the levels of IL-17A at 1, 3 and 6 days after reperfusion in the penumbral area. IL-17A knockout or anti-IL-17A monoclonal antibody (mAb) significantly reduced whereas recombinant mouse-IL-17A (rIL-17A) increased the activation of calpain at 3 days after reperfusion. The calpain specific inhibitor calpeptin significantly increased TRPC6 expression. Brain injury and neurological deficits were largely abrogated by IL-17A knockout, anti-IL-17A mAb or calpeptin. Recombinant IL-17A treatment markedly increased I/R injury. In conclusion, IL-17A may promote brain I/R injury through the increase of calpain-mediated TRPC6 proteolysis. These results further outline a novel neuroprotective strategy with increased effectiveness for the inhibition of excess brain IL-17A in cerebral I/R injury.

Keywords: IL-17A; TRPC6; calpain; ischemic stroke; middle cerebral artery occlusion.

MeSH terms

  • Animals
  • Brain / drug effects
  • Brain / pathology
  • Brain / physiopathology*
  • Brain Ischemia / pathology
  • Brain Ischemia / physiopathology*
  • Calpain / antagonists & inhibitors
  • Calpain / metabolism*
  • Cysteine Proteinase Inhibitors / pharmacology
  • Dipeptides / pharmacology
  • Disease Models, Animal
  • Infarction, Middle Cerebral Artery
  • Interleukin-17 / genetics
  • Interleukin-17 / metabolism*
  • Male
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Proteolysis
  • Recombinant Proteins / metabolism
  • Reperfusion Injury / pathology
  • Reperfusion Injury / physiopathology*
  • TRPC Cation Channels / metabolism*
  • Time Factors

Substances

  • Cysteine Proteinase Inhibitors
  • Dipeptides
  • Il17a protein, mouse
  • Interleukin-17
  • Recombinant Proteins
  • TRPC Cation Channels
  • Trpc6 protein, mouse
  • calpeptin
  • Calpain