Antagonizing Neuronal Toll-like Receptor 2 Prevents Synucleinopathy by Activating Autophagy

Cell Rep. 2015 Oct 27;13(4):771-782. doi: 10.1016/j.celrep.2015.09.044. Epub 2015 Oct 17.


Impaired autophagy has been implicated in many neurodegenerative diseases, such as Parkinson's disease (PD), and might be responsible for deposition of aggregated proteins in neurons. However, little is known about how neuronal autophagy and clearance of aggregated proteins are regulated. Here, we show a role for Toll-like receptor 2 (TLR2), a pathogen-recognizing receptor in innate immunity, in regulation of neuronal autophagy and clearance of α-synuclein, a protein aggregated in synucleinopathies, including in PD. Activation of TLR2 resulted in the accumulation of α-synuclein aggregates in neurons as a result of inhibition of autophagic activity through regulation of the AKT/mTOR pathway. In contrast, inactivation of TLR2 resulted in autophagy activation and increased clearance of neuronal α-synuclein, and hence reduced neurodegeneration, in transgenic mice and in in vitro models. These results uncover roles of TLR2 in regulating neuronal autophagy and suggest that the TLR2 pathway may be targeted for autophagy activation strategies in treating neurodegenerative disorders.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy / genetics
  • Autophagy / physiology
  • Mice
  • Mice, Knockout
  • Mice, Transgenic
  • Neurodegenerative Diseases / metabolism
  • Neurodegenerative Diseases / prevention & control
  • Oncogene Protein v-akt / genetics
  • Oncogene Protein v-akt / metabolism
  • TOR Serine-Threonine Kinases / genetics
  • TOR Serine-Threonine Kinases / metabolism
  • Toll-Like Receptor 2 / deficiency
  • Toll-Like Receptor 2 / genetics
  • Toll-Like Receptor 2 / metabolism*
  • alpha-Synuclein / metabolism


  • Toll-Like Receptor 2
  • alpha-Synuclein
  • MTOR protein, human
  • Oncogene Protein v-akt
  • TOR Serine-Threonine Kinases