Protective effects of oridonin against cerebral ischemia/reperfusion injury by inhibiting the NLRP3 inflammasome activation

Tissue Cell. 2021 Aug:71:101514. doi: 10.1016/j.tice.2021.101514. Epub 2021 Feb 24.

Abstract

NOD-like receptor protein 3 (NLRP3) inflammasome is tightly related to the pathogenesis of cerebral ischemia/reperfusion (I/R) injury, and oridonin (Ori) has shown the potential to alleviate ischemia/reperfusion injury with underlying mechanisms. Our study aims to figure out whether Ori protects against the cerebral ischemia/reperfusion injury by the NLRP3 inflammasome signaling. In this study, a temporary middle cerebral artery occlusion (MCAO) and reperfusion surgery was conducted on male C57BL/6 mice to mimic cerebral I/R injury in vivo. Cellular model of cerebral I/R in vitro was achieved by oxygen-glucose deprivation and reintroduction (OGD/R) in BV2 microglia cells. We found that Ori treatment significantly relieved the neurological deficits, neuronal injury and microglia activation in I/R mice according to morphological and histological analyses. Meanwhile, the inactivation of NLRP3 inflammasome was determined in Ori-treated mice with significantly down-regulated expressions of inflammasome-related genes. Western-blot analysis further demonstrated the negative effect of Ori on NF-κB signaling with diminished phosphorylation and degradation of IκBα as well as suppressed translocation of p65. Furthermore, we indicated that Ori suppressed the activation of NLRP3 inflammasome in OGD/R induced BV2 microglia cells by inhibiting NF-κB signaling. In summary, our findings make Ori a potential candidate for therapy of cerebral I/R injury in the future.

Keywords: Cerebral ischemia/reperfusion injury; NF-κB; NLRP3 inflammasome; Oridonin.

MeSH terms

  • Animals
  • Cell Line
  • Cerebrovascular Disorders* / metabolism
  • Cerebrovascular Disorders* / pathology
  • Cerebrovascular Disorders* / prevention & control
  • Diterpenes, Kaurane / pharmacology*
  • Inflammasomes / metabolism*
  • Male
  • Mice
  • NLR Family, Pyrin Domain-Containing 3 Protein* / antagonists & inhibitors
  • NLR Family, Pyrin Domain-Containing 3 Protein* / metabolism
  • Reperfusion Injury* / metabolism
  • Reperfusion Injury* / pathology
  • Reperfusion Injury* / prevention & control
  • Signal Transduction / drug effects*

Substances

  • Diterpenes, Kaurane
  • Inflammasomes
  • NLR Family, Pyrin Domain-Containing 3 Protein
  • Nlrp3 protein, mouse
  • oridonin