Necrostatin-1 suppresses autophagy and apoptosis in mice traumatic brain injury model

Neurochem Res. 2012 Sep;37(9):1849-58. doi: 10.1007/s11064-012-0791-4. Epub 2012 Jun 27.

Abstract

Traumatic brain injury (TBI) results in neuronal apoptosis, autophagic cell death and necroptosis. Necroptosis is a newly discovered caspases-independent programmed necrosis pathway which can be triggered by activation of death receptor. Previous works identified that necrostatin-1 (NEC-1), a specific necroptosis inhibitor, could reduce tissue damage and functional impairment through inhibiting of necroptosis process following TBI. However, the role of NEC-1 on apoptosis and autophagy after TBI is still not very clear. In this study, the amount of TBI-induced neural cell deaths were counted by PI labeling method as previously described. The expression of autophagic pathway associated proteins (Beclin-1, LC3-II, and P62) and apoptotic pathway associated proteins (Bcl-2 and caspase-3) were also respectively assessed by immunoblotting. The data showed that mice pretreated with NEC-1 reduced the amount of PI-positive cells from 12 to 48 h after TBI. Immunoblotting results showed that NEC-1 suppressed TBI-induced Beclin-1 and LC3-II activation which maintained p62 at high level. NEC-1 pretreatment also reversed TBI-induced Bcl-2 expression and caspase-3 activation, as well as the ratio of Beclin-1/Bcl-2. Both 3-MA and NEC-1 suppressed TBI-induced caspase-3 activation and LC3-II formation, Z-VAD only inhibited caspase-3 activation but increased LC3-II expression at 24 h post-TBI. All these results revealed that multiple cell death pathways participated in the development of TBI, and NEC-1 inhibited apoptosis and autophagy simultaneously. These coactions may further explain how can NEC-1 reduce TBI-induced tissue damage and functional deficits and reflect the interrelationship among necrosis, apoptosis and autophagy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenine / analogs & derivatives
  • Adenine / pharmacology
  • Animals
  • Apoptosis / drug effects*
  • Autophagy / drug effects*
  • Blotting, Western
  • Brain Injuries / pathology*
  • Caspase 3 / metabolism
  • Cell Death / drug effects
  • Coloring Agents
  • Enzyme Activation
  • Imidazoles / antagonists & inhibitors
  • Imidazoles / pharmacology*
  • Indoles / antagonists & inhibitors
  • Indoles / pharmacology*
  • Injections, Intraventricular
  • Male
  • Mice
  • Microtubule-Associated Proteins / biosynthesis
  • Microtubule-Associated Proteins / genetics
  • Oligopeptides / pharmacology
  • Propidium
  • Proto-Oncogene Proteins c-bcl-2 / biosynthesis

Substances

  • Coloring Agents
  • Imidazoles
  • Indoles
  • Map1lc3b protein, mouse
  • Microtubule-Associated Proteins
  • Oligopeptides
  • Proto-Oncogene Proteins c-bcl-2
  • benzyloxycarbonyl-valyl-alanyl-aspartic acid
  • necrostatin-1
  • Propidium
  • 3-methyladenine
  • Caspase 3
  • Adenine