Cited by 863Neuroinflammation and Neurodegeneration MechanismsParkinson's Disease Mechanisms and TreatmentsNuclear Receptors and Signaling

Neuron-released oligomeric α-synuclein is an endogenous agonist of TLR2 for paracrine activation of microglia

Open access
Kim, Changyoun, Ho, Dong-Hwan, Suk, Ji-Eun, You, Sungyong, Michael, Sarah, Kang, Junghee, Joong Lee, Sung, Masliah, Eliezer +3 more·2013·Nature Communications

Abstract

Abnormal aggregation of α-synuclein and sustained microglial activation are important contributors to the pathogenic processes of Parkinson's disease. However, the relationship between disease-associated protein aggregation and microglia-mediated neuroinflammation remains unknown. Here, using a combination of in silico, in vitro and in vivo approaches, we show that extracellular α-synuclein released from neuronal cells is an endogenous agonist for Toll-like receptor 2 (TLR2), which activates inflammatory responses in microglia. The TLR2 ligand activity of α-synuclein is conformation-sensitive; only specific types of oligomer can interact with and activate TLR2. This paracrine interaction between neuron-released oligomeric α-synuclein and TLR2 in microglia suggests that both of these proteins are novel therapeutic targets for modification of neuroinflammation in Parkinson's disease and related neurological diseases.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1038/ncomms2534

Cites

57 of 57 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • In animal models of PD and in PD patients, misfolded α-synuclein is released from injured neurons into extracellular fluid.

    “In animal models of PD and in PD patients, misfolded α-synuclein was found to be released from injured neurons into the extracellular fluid.51,61,62”

    From Role of neuroinflammation in neurodegeneration development (2023) · cites this paper as [61]

    The Abstract (page unavailable) says neurons release α-synuclein and that misfolding and aggregation may facilitate its release. The Results section on cell-released α-synuclein (page unavailable) demonstrates release from cultured neuronal cells, but reports that overexpression did not affect their viability. The paper does not establish that misfolded α-synuclein was released from injured neurons in PD animal models or PD patients. (LLM, conf=0.86)

    Experimental — accuracy not yet measured
  • TLR2 plays a role in neurons in response to α-synuclein.

    “TLR2 also plays a role in neurons in response to α-synuclein in addition to microglia19,57,58.”

    From Microglia clear neuron-released α-synuclein via selective autophagy and prevent neurodegeneration (2020) · cites this paper as [19]

    The Results section on TLR2 upregulation reports TLR2 labeling in pyramidal neurons, but the α-synuclein-related increase it describes is in microglia. The in vivo Results show that α-synuclein expressed by neurons activates microglia through TLR2; they do not establish that TLR2 mediates a neuronal response to α-synuclein. Page numbers are unavailable in our copy. (LLM, conf=0.82)

    Experimental — accuracy not yet measured
  • TLR2 neutralization decreases the expression of pro-inflammatory cytokines in this mouse model of synucleinopathy.

    “We have previously demonstrated that although TLR2 neutralization decreases the expression of pro-inflammatory cytokines it may also impact neurotrophin production in this mouse model of synucleinopathy (7).”

    From LRRK2 mediates microglial neurotoxicity via NFATc2 in rodent models of synucleinopathies (2020) · cites this paper as [7]

    The Results section on α-synuclein-induced microglial activation reports that a TLR2-blocking antibody eliminated induced cytokine gene expression in isolated microglia. The in vivo Results instead report reduced microglial activation in Tlr2-deficient mice; they do not show that TLR2 neutralization decreased cytokine expression in the mouse model. (LLM, conf=0.88)

    Experimental — accuracy not yet measured
  • TLR2 neutralization may also impact neurotrophin production in this mouse model of synucleinopathy.

    “We have previously demonstrated that although TLR2 neutralization decreases the expression of pro-inflammatory cytokines it may also impact neurotrophin production in this mouse model of synucleinopathy (7).”

    From LRRK2 mediates microglial neurotoxicity via NFATc2 in rodent models of synucleinopathies (2020) · cites this paper as [7]

    The Results section on α-synuclein-induced microglial activation reports that a TLR2-blocking antibody eliminated induced cytokine gene expression in isolated microglia; the in vivo Results report reduced microglial activation in Tlr2-deficient mice. Our copy does not report an effect of TLR2 neutralization on neurotrophin production in a mouse model of synucleinopathy (pages not provided). (LLM, conf=0.84)

    Experimental — accuracy not yet measured
  • α-synuclein can activate glial cells by binding to TLR2 and enhance the spreading of α-synuclein.

    “α-synuclein can also activate glial cells by binding to TLR261,294,295 and enhance the spreading of α-synuclein.70,296”

    From Role of neuroinflammation in neurodegeneration development (2023) · cites this paper as [61]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Kim, C., Ho, D.-H., Suk, J.-E., You, S., Michael, S., Kang, J., Joong Lee, S., Masliah, E., Hwang, D., Lee, H.-J., & Lee, S.-J.
Affiliations
  • Konkuk University (KR)
  • Pohang University of Science and Technology (KR)
  • University of California San Diego (US)
  • Seoul National University (KR)
Venue
Nature Communications
Published
2013-03-05
Volume
4
Issue
1
Pages
1562-1562
ISSN
2041-1723 (ISSN-L)
OpenAlex
W2141976392
Cited by
856
References
57
Citations by year
2026: 58 · 2025: 68 · 2024: 74 · 2023: 68 · 2022: 83 · 2021: 111 · 2020: 93 · 2019: 53 · 2018: 67 · 2017: 42 · 2016: 44 · 2015: 53 · 2014: 35 · 2013: 7
FWCI
26.00
Type
journal article
Language
en
Open access
Locations
  • Nature Communications (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
  • RePEc: Research Papers in Economics (submittedVersion)
Funders
  • National Institutes of Health (AG5131, AG‐18440)
  • National Institute on Aging (R37AG018440, R01AG018440, P50AG005131, AG-5131, P01AG031097, AG 18440, P01AG022074)
  • National Institute of Neurological Disorders and Stroke (P01NS044233, P30NS076411, P30NS057096)
  • National Institute of Environmental Health Sciences (P01ES016738)
Topics
  • Life Sciences › Neuroscience › Neurology › Neuroinflammation and Neurodegeneration Mechanisms
  • Health Sciences › Medicine › Neurology › Parkinson's Disease Mechanisms and Treatments
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Nuclear Receptors and Signaling
Keywords
alpha-synuclein oligomers, TLR2, microglial activation, neuroinflammation, Parkinson's disease, paracrine signaling, microglia-neuron interaction, protein aggregation
MeSH terms
Animals, Cells, Cultured, Chromatography, Gel, Humans, Immunohistochemistry, Mice, Inbred C57BL, Mice, Transgenic, Neurons, Protein Conformation, Signal Transduction, Up-Regulation, Rats, Sprague-Dawley, Microglia, Chemokines, Paracrine Communication, Protein Structure, Quaternary, Lewy Body Disease, Toll-Like Receptor 2, Mice, Rats, alpha-Synuclein, Dopaminergic Neurons

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review