Neurotoxic lupus autoantibodies alter brain function through two distinct mechanisms Academic Article uri icon

Overview

MeSH Major

  • Autoantibodies
  • Brain
  • Lupus Erythematosus, Systemic
  • Lupus Vasculitis, Central Nervous System
  • Neurotoxins

abstract

  • Damaging interactions between antibodies and brain antigenic targets may be responsible for an expanding range of neurological disorders. In the case of systemic lupus erythematosus (SLE), patients generate autoantibodies (AAbs) that frequently bind dsDNA. Although some symptoms of SLE may arise from direct reactivity to dsDNA, much of the AAb-mediated damage originates from cross-reactivity with other antigens. We have studied lupus AAbs that bind dsDNA and cross-react with the NR2A and NR2B subunits of the NMDA receptor (NMDAR). In adult mouse models, when the blood-brain barrier is compromised, these NMDAR-reactive AAbs access the brain and elicit neuronal death with ensuing cognitive dysfunction and emotional disturbance. The cellular mechanisms that underlie these deleterious effects remain incompletely understood. Here, we show that, at low concentration, the NMDAR-reactive AAbs are positive modulators of receptor function that increase the size of NMDAR-mediated excitatory postsynaptic potentials, whereas at high concentration, the AAbs promote excitotoxicity through enhanced mitochondrial permeability transition. Other synaptic receptors are completely unaffected by the AAbs. NMDAR activation is required for producing both the synaptic and the mitochondrial effects. Our study thus reveals the mechanisms by which NMDAR-reactive AAbs trigger graded cellular alterations, which are likely to be responsible for the transient and permanent neuropsychiatric symptoms observed in patients with SLE. Our study also provides a model in which local AAb concentration determines the exact nature of the cellular response.

publication date

  • October 26, 2010

Research

keywords

  • Academic Article

Identity

Language

  • eng

PubMed Central ID

  • PMC2972998

Digital Object Identifier (DOI)

  • 10.1073/pnas.1006980107

PubMed ID

  • 20921396

Additional Document Info

start page

  • 18569

end page

  • 74

volume

  • 107

number

  • 43