The effect of ambient titanium dioxide microparticle exposure to the ocular surface on the expression of inflammatory cytokines in the eye and cervical lymph nodes

Youngsub Eom, Jong-Suk Song, Hyun Kyu Lee, Boram Kang, Hyeon Chang Kim, Hyung Keun Lee, Hyo Myung Kim

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10 Citations (Scopus)


PURPOSE. To investigate the ocular immune response following exposure to airborne titanium dioxide (TiO2) microparticles. METHODS. Rats in the TiO2-exposed group (n = 10) were exposed to TiO2 particles for 2 hours twice daily for 5 days, while the controls (n = 10) were not. Corneal staining score and tear lactic dehydrogenase (LDH) activity were measured to evaluate ocular surface damage, serum immunoglobulin (Ig) G and E were assayed by using enzyme-linked immunosorbent assay, and the size of cervical lymph nodes was measured. In addition, the expression of interleukin (IL)-4, IL-17, and interferon (IFN)-γ in the anterior segment of the eyeball and cervical lymph nodes was measured by immunohistochemistry, real-time reverse transcription-polymerase chain reaction (RT-PCR), and Western blot analysis. RESULTS. Median corneal staining score (3.0), tear LDH activity (0.24 optical density [OD]), and cervical lymph node size (36.9 mm2) were significantly higher in the TiO2-exposed group than in the control group (1.0, 0.13 OD, and 26.7 mm2, respectively). Serum IgG and IgE levels were found to be significantly elevated in the TiO2-exposed group (P = 0.021 and P = 0.021, respectively). Interleukin 4 expression was increased in the anterior segment of the eyeball and lymph nodes following TiO2 exposure, as measured by immunostaining, real-time RT-PCR, and Western blot. In addition, IL-17 and IFN-γ levels were also increased following TiO2 exposure compared to controls as measured by immunostaining. CONCLUSIONS. Exposure to airborne TiO2 induced ocular surface damage. The Type 2 helper Tcell pathway seems to play a dominant role in the ocular immune response following airborne TiO2 exposure.

Original languageEnglish
Pages (from-to)6580-6590
Number of pages11
JournalInvestigative Ophthalmology and Visual Science
Issue number15
Publication statusPublished - 2016 Dec 1



  • Inflammatory cytokine
  • Lymph node
  • Microparticle
  • Titanium dioxide

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

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