Neuroprotection of Emodin by Inhibition of Microglial NLRP3 Inflammasome-Mediated Pyroptosis

J Integr Neurosci. 2023 Mar 6;22(2):48. doi: 10.31083/j.jin2202048.

Abstract

Background: Neuroinflammation triggered by chronic cerebral ischemia-induced microglial pyroptosis is a significant contributor to vascular cognitive impairment. It has been shown that emodin possesses anti-inflammatory and neuroprotective properties, however, it's potential molecular and signaling transduction pathway remains to be illuminated. This study researched the neuroprotective mechanisms of emodin focussing on emodin effects on lipopolysaccharide/adenosine triphosphate (LPS/ATP)-caused pyroptosis in BV2 cells and HT-22 hippocampal neurons.

Methods: To explore the neuroprotective effect of emodin, Emodin was applied to BV2 cells, HT-22 hippocampal neurons, and BV2/HT-22 co-cultures stimulated with LPS/ATP to evaluate the cell morphology, levels of inflammatory factors, NLRP3 inflammatory inflammasome activity and focal pyroptosis-related protein expression, as same as neuronal apoptosis.

Results: Emodin alleviated LPS/ATP-induced pyroptosis of BV2 cells by preventing the activity of the NLRP3 inflammasome and the cleavage of pyroptosis executive protein Gasdermin D (GSDMD). Furthermore, levels of interleukin (IL)-18, IL-1β and tumor necrosis factor (TNF)-α were reduced, the apoptosis of HT-22 hippocampal neurons was attenuated, and cell viability was restored.

Conclusions: Emodin can antagonize microglial neurotoxicity by inhibiting microglial pyroptosis, thereby exerting anti-inflammatory and neuroprotective effects.

Keywords: NLRP3 inflammasome; emodin; microglia; neuroinflammation; pyroptosis.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Anti-Inflammatory Agents / pharmacology
  • Cell Line
  • Emodin* / pharmacology
  • Inflammasomes / metabolism
  • Lipopolysaccharides
  • Mice
  • Microglia
  • NLR Family, Pyrin Domain-Containing 3 Protein / metabolism
  • Neuroprotection
  • Neuroprotective Agents* / pharmacology
  • Pyroptosis

Substances

  • Adenosine Triphosphate
  • Anti-Inflammatory Agents
  • Emodin
  • Inflammasomes
  • Lipopolysaccharides
  • Neuroprotective Agents
  • NLR Family, Pyrin Domain-Containing 3 Protein