Myelin basic protein induces neuron-specific toxicity by directly damaging the neuronal plasma membrane

PLoS One. 2014 Sep 25;9(9):e108646. doi: 10.1371/journal.pone.0108646. eCollection 2014.

Abstract

The central nervous system (CNS) insults may cause massive demyelination and lead to the release of myelin-associated proteins including its major component myelin basic protein (MBP). MBP is reported to induce glial activation but its effect on neurons is still little known. Here we found that MBP specifically bound to the extracellular surface of the neuronal plasma membrane and induced neurotoxicity in vitro. This effect of MBP on neurons was basicity-dependent because the binding was blocked by acidic lipids and competed by other basic proteins. Further studies revealed that MBP induced damage to neuronal membrane integrity and function by depolarizing the resting membrane potential, increasing the permeability to cations and other molecules, and decreasing the membrane fluidity. At last, artificial liposome vesicle assay showed that MBP directly disturbed acidic lipid bilayer and resulted in increased membrane permeability. These results revealed that MBP induces neurotoxicity through its direct interaction with acidic components on the extracellular surface of neuronal membrane, which may suggest a possible contribution of MBP to the pathogenesis in the CNS disorders with myelin damage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cations / metabolism
  • Cell Membrane / drug effects*
  • Cell Membrane / metabolism*
  • Cell Membrane Permeability / drug effects
  • Female
  • Lipid Bilayers / chemistry
  • Lipid Bilayers / metabolism
  • Male
  • Membrane Potentials / drug effects
  • Myelin Basic Protein / metabolism
  • Myelin Basic Protein / toxicity*
  • Neurons / drug effects*
  • Neurons / physiology*
  • Protein Binding
  • Pyramidal Cells / drug effects
  • Pyramidal Cells / physiology
  • Rats

Substances

  • Cations
  • Lipid Bilayers
  • Myelin Basic Protein

Grants and funding

This work was support by the grants from National Natural Science Foundation of China (81171164) to Jianhong Luo, National Basic Research Program of China (2010CB912002 and 2014CB910300) to Jianhong Luo, and by the Fundamental Research Funds for the Central Universities of China. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.