Lipopolysaccharide induces human olfactory ensheathing glial apoptosis by promoting mitochondrial dysfunction and activating the JNK-Bnip3-Bax pathway

Cell Stress Chaperones. 2019 Jan;24(1):91-104. doi: 10.1007/s12192-018-0945-7. Epub 2018 Oct 29.

Abstract

Olfactory ensheathing glia (OEG) play an important role in regulating the regeneration of an injured nervous system. However, chronic inflammation damage reduces the viability of OEG via poorly understood mechanisms. We aimed to investigate the pathological responses of OEG in response to LPS-mediated inflammation stress in vitro. The results indicated that lipopolysaccharide (LPS) treatment significantly reduced the viability of OEG in a dose-dependent fashion. Mechanistically, LPS stimuli induced mitochondrial oxidative damage, mitochondrial fragmentation, mitochondrial metabolism disruption, and mitochondrial apoptosis activation. Furthermore, we verified that LPS modulated mitochondrial apoptosis by promoting Bax upregulation, and this process was regulated by the JNK-Bnip3 pathway. Inhibition of the JNK-Bnip3 pathway prevented LPS-mediated Bax activation, thus attenuating OEG apoptosis. Altogether, our data illustrated that LPS-mediated inflammation injury evoked mitochondrial abnormalities in OEG damage via the JNK-Bnip3-Bax pathway. This finding provides a potential target to protect OEG against chronic inflammation stress.

Keywords: Bax; JNK-Bnip3 pathway; Mitochondrial dysfunction; Olfactory ensheathing glia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects*
  • Cell Survival / drug effects
  • Energy Metabolism / drug effects
  • High-Temperature Requirement A Serine Peptidase 2 / metabolism
  • Humans
  • JNK Mitogen-Activated Protein Kinases / metabolism*
  • Lipopolysaccharides / pharmacology*
  • Membrane Proteins / metabolism*
  • Mitochondria / drug effects
  • Mitochondria / metabolism
  • Mitochondria / pathology*
  • Neuroglia / drug effects
  • Neuroglia / pathology*
  • Olfactory Bulb / pathology*
  • Oxidative Stress / drug effects
  • Proto-Oncogene Proteins / metabolism*
  • Signal Transduction / drug effects
  • Up-Regulation / drug effects
  • bcl-2-Associated X Protein / metabolism*

Substances

  • BNIP3 protein, human
  • Lipopolysaccharides
  • Membrane Proteins
  • Proto-Oncogene Proteins
  • bcl-2-Associated X Protein
  • JNK Mitogen-Activated Protein Kinases
  • HTRA2 protein, human
  • High-Temperature Requirement A Serine Peptidase 2