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Screening Bioactive Nanoparticles in Phagocytic Immune Cells for Inhibitors of Toll-like Receptor Signaling
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Silver nanoparticles induce apoptosis through the toll-like receptor 2 pathway

An-Sook Kim1, Chang-Hoon Chae, Juliana Kim

  • 1Department of Dentistry, Hallym University, Kyounggi-do, Korea.

Oral Surgery, Oral Medicine, Oral Pathology and Oral Radiology
|June 7, 2012
PubMed
Abstract

Insights

Silver nanoparticles (AgNPs) trigger cell death through the Toll-like receptor 2 (TLR-2) pathway. Blocking TLR-2 reduces AgNP-induced apoptosis and cytotoxicity in human cells.

Area of Science:

  • Nanotechnology
  • Immunology
  • Cell Biology

Background:

  • Silver nanoparticles (AgNPs) are increasingly used in biomedical applications.
  • The interaction of AgNPs with cellular pathways, particularly immune receptors, requires further investigation.

Purpose of the Study:

  • To investigate the role of the Toll-like receptor 2 (TLR-2) pathway in silver nanoparticle (AgNP)-induced cellular responses.
  • To evaluate the impact of AgNPs on cytotoxicity and apoptosis in various human cell types.

Main Methods:

  • Cultured human chondrocytes, periodontal ligament (PDL) cells, and SCC-9 cells were exposed to AgNPs.
  • Cells were treated with TLR-2 small interfering (si) RNA or anti-TLR2 antibodies to block TLR-2 signaling.
  • Cytotoxicity assays and analysis of c-Jun phosphorylation were performed.

Main Results:

  • AgNPs induced dose-dependent cytotoxicity and altered TLR-2 expression in all tested cell types.
  • TLR-2 inhibition using siRNA or antibodies significantly reduced AgNP-mediated apoptosis and cytotoxicity.
  • AgNPs increased c-Jun phosphorylation, which was reversed by TLR-2 siRNA treatment.

Conclusions:

  • The findings strongly suggest that AgNP-induced apoptosis and cytotoxicity are mediated through the TLR-2 signaling pathway.
  • This study elucidates a key mechanism by which AgNPs interact with human cells, impacting cellular immunity.

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