Estimation of the in vitro eye irritating and inflammatory potential of lipopolysaccharide (LPS) and dust by using reconstituted human corneal epithelium tissue cultures

Abstract

Context: Eye irritation is a common complaint in indoor environment, but the causes have still not been identified among the multiple exposures in house environments. To identify the potential environmental factors responsible for eye irritation and study the possible mechanisms, an in vitro model for eye irritation is suggested.

Materials and methods: In this study, reconstituted human corneal epithelium (HCE) tissue cultures were used to study the eye irritating and inflammatory potential of lipopolysaccharide (LPS) and dust. HCE tissue cultures were exposed to a range of concentrations of LPS for 6 h and dust for 24 h, respectively. After exposure, viability and secretion of interleukins (IL) IL-1β, IL-8, and tumor necrosis factor (TNFα) were examined. Histology was used to indicate the morphological changes after dust exposure.

Results: Both LPS and dust affected HCE viability. There was an increased level of IL-8 after LPS exposure, while the concentrations of IL-1β and TNFα remained unaffected. Dust exposure resulted in an elevation of both IL-1β and IL-8, but not TNFα. Histology study showed increased vacuolization and reduced thickness after 24 h exposure to 5 mg/mL dust.

Discussion and conclusion: LPS and dust showed in vitro eye irritating and inflammatory potential, and cytokines/chemokines like IL-1β and IL-8 may be involved in the mechanisms of eye irritation. The HCE tissue culture may be used as an in vitro model to study environmental exposure induced eye irritation and inflammation.

• Dust
• eye irritation
• human corneal epithelium tissue culture
• inflammation
• lipopolysaccharide

Acknowledgements

We sincerely acknowledge laboratory technician Inge Stage for her skillful assistance in MTT and histology studies and Zhihong Zhu for his support in SEM studies.

Declaration of interest

This work has been supported by a grant (22-03-0223) from the Danish Research Council. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this article.