Triptolide improves spinal cord injury by promoting autophagy and inhibiting apoptosis

Cell Biol Int. 2020 Mar;44(3):785-794. doi: 10.1002/cbin.11273. Epub 2019 Dec 9.

Abstract

We investigated the effect of triptolide (TP) on spinal cord injury (SCI), and its underlying mechanism. Following the establishment of the SCI model using YFP H-line transgenic mice, TP was intraperitoneally injected at a dose of 0.2 mg/kg once daily for 7 days. Behavioral tests, Nissl staining, and hematoxylin-eosin staining were employed to assess motor function recovery and neuronal cell death. Western blot and immunofluorescence staining were used to assess autophagy-associated proteins (LC3B, p62, Beclin-1) and the apoptosis-associated proteins (Bcl-2, caspase-3, Bax). The TP-treated group showed improved motor functions, and reduced neuronal cell death. Also, significant upregulation of Bcl-2 and LC3B expressions, with the downregulation of p62, Bax and caspase-3 expressions were found in the TP-treated group. Additionally, phosphorylation of extracellular signal-regulated protein kinases 1 and 2 (ERK1 and ERK2) was decreased in the TP-treated group. TP mediates its protective effect in SCI by promoting the autophagic pathway while inhibiting the MAPK/ERK1/2 signaling pathway. These results demonstrate the therapeutic potential of TP in SCI.

Keywords: apoptosis; autophagy; spinal cord injury; triptolide.

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Apoptosis Regulatory Proteins / metabolism
  • Autophagy / drug effects*
  • Diterpenes* / pharmacology
  • Diterpenes* / therapeutic use
  • Epoxy Compounds / pharmacology
  • Epoxy Compounds / therapeutic use
  • Female
  • Mice
  • Mice, Transgenic
  • Neuroprotective Agents* / pharmacology
  • Neuroprotective Agents* / therapeutic use
  • Phenanthrenes* / pharmacology
  • Phenanthrenes* / therapeutic use
  • Spinal Cord / drug effects*
  • Spinal Cord / pathology
  • Spinal Cord Injuries / drug therapy*
  • Thoracic Vertebrae* / drug effects
  • Thoracic Vertebrae* / injuries

Substances

  • Apoptosis Regulatory Proteins
  • Diterpenes
  • Epoxy Compounds
  • Neuroprotective Agents
  • Phenanthrenes
  • triptolide