Diesel Exhaust Particles selectively induce both pro-inflammatory cytokines and mucin production in Cornea and Conjunctiva Human Cell Lines

JULIA TAU; PRISCILA NOVAES; MONIQUE MATSUDA; DEBORAH TASAT; PAULO SALDIVA; ALEJANDRO BERRA

INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE

ASSOC RESEARCH VISION OPHTHALMOLOGY INC

Año: 2013

0146-0404

Purpose: To evaluate the effect of Diesel Exhaust Particles (DEP) on the viability, proliferation, apoptosis, secretion of cytokines (IL-6, IL-8 and TNF-α) and mucin gene transcription (MUC1, MUC5AC and MUC16) in human epithelial cells of cornea (HCLE) and conjunctiva (IOBA-NHC). Methods: HCLE and IOBA-NHC were incubated with DEP (10-500 μg/ml) for 24h. Cell viability was evaluated by the Trypan Blue exclusion test. Cell proliferation was evaluated by the 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay. The number of apoptotic cells was measured by annexin-V-FITC and propidium iodide (PI) kit for flow cytometry. Pro-inflammatory cytokines were determined by ELISA kit. Mucin gene transcription was quantified by real time-PCR. Results: DEP significantly decreased both the viability, proliferation and the secretion of IL-8, but increased the secretion of IL-6 on both HCLE and IOBA-NHC cell lines in a dose-dependent manner. Neither cornea nor conjunctiva cells incubated with DEP released TNF-α. DEP induced a significant increase in the percentage of apoptotic cells on IOBA-NHC, whereas no changes were observed on HCLE. Finally, DEP significantly decreased the transcription levels of MUC1, MUC5AC and MUC16 on the cultured cornea cells, but increased them on the cultured conjunctiva cells. Conclusion: These findings suggest that the human corneal and conjunctival epithelial cells incubated with DEP showed cytotoxicity and an inflammatory response mediated for IL-6, not for TNF-α or IL.8. Also, the increase in the mucin expression in the conjunctiva cells might be involved at least in the clearance of DEP to protect the ocular epithelium.