Infection of prions and treatment of PrP106-126 alter the endogenous status of protein 14-3-3 and trigger the mitochondrial apoptosis possibly via activating Bax pathway

Mol Neurobiol. 2014 Apr;49(2):840-51. doi: 10.1007/s12035-013-8560-1. Epub 2013 Oct 18.

Abstract

The 14-3-3 proteins are a family of highly homologous and ubiquitously expressed isoforms that are involved in a wide variety of physiological processes. 14-3-3 have showed actively molecular interaction with PrP and positive 14-3-3 is frequently observed in the cerebrospinal fluid (CSF) samples of the patients with sporadic Creutzfeldt-Jakob disease (CJD). However, the alterations of 14-3-3 in the brain tissues of patients with prion diseases remain little addressed. To address the possible change of brain 14-3-3 during prion infection, we firstly tested the levels of 14-3-3 in the brain tissues of scrapie agent 263 K infected hamsters. Obviously decreased 14-3-3 were observed in the samples of the infected animals, showing time-dependent reduction in the incubation period, while the amounts of S-nitrosylated 14-3-3 were increased in the brains collected at the late stage. A low level of 14-3-3 was also observed in the scrapie infectious cell line SMB-S15, accompanied with up-regulated Bax and down-regulated Bcl-2. Moreover, we found that treatment of PrP106-126 on the cultured cells decreased the cellular 14-3-3 and caused translocations of cellular Bax to the membrane fractions. Knockdown of cellular 14-3-3 sensitized the cultured cells to the challenge of PrP106-126. These data illustrate that significant down-regulation of brain 14-3-3 levels during prion infection may not only be a scenario of the terminal consequence of interacting with abnormal PrP(Sc) but may also participate in the pathogenesis of neuronal damage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 14-3-3 Proteins / metabolism*
  • Animals
  • Apoptosis / drug effects
  • Apoptosis / physiology*
  • Cricetinae
  • Cricetulus
  • HeLa Cells
  • Humans
  • Mitochondria / drug effects
  • Mitochondria / metabolism*
  • Peptide Fragments / toxicity*
  • Prion Diseases / metabolism*
  • Prion Diseases / pathology
  • Prions / toxicity*
  • bcl-2-Associated X Protein / biosynthesis*

Substances

  • 14-3-3 Proteins
  • BAX protein, human
  • Peptide Fragments
  • Prions
  • bcl-2-Associated X Protein
  • prion protein (106-126)