Air exposure induced characteristics of dry eye in conjunctival tissue culture

PLoS One. 2014 Jan 31;9(1):e87368. doi: 10.1371/journal.pone.0087368. eCollection 2014.

Abstract

There are several animal models illustrating dry eye pathophysiology. Current study would like to establish an ex vivo tissue culture model for characterizing dry eye. Human conjunctival explants were cultured under airlift or submerged conditions for up to 2 weeks, and only airlifted conjunctival cultures underwent increased epithelial stratification. Starting on day 4, the suprabasal cells displayed decreased K19 expression whereas K10 keratin became evident in airlift group. Pax6 nuclear expression attenuated already at 2 days, while its perinuclear and cytoplasmic expression gradually increased. MUC5AC and MUC19 expression dramatically decreased whereas the full thickness MUC4 and MUC16 expression pattern disappeared soon after initiating the airlift condition. Real time PCR showed K16, K10 and MUC16 gene up-regulated while K19, MUC5AC, MUC19 and MUC4 down-regulated on day 8 and day 14. On day 2 was the appearance of apoptotic epithelial and stromal cells appeared. The Wnt signaling pathway was transiently activated from day 2 to day 10. The inflammatory mediators IL-1β, TNF-α, and MMP-9 were detected in the conditioned media after 6 to 8 days. In conclusion, airlifted conjunctival tissue cultures demonstrated Wnt signaling pathway activation, coupled with squamous metaplasia, mucin pattern alteration, apoptosis and upregulation of proinflammatory cytokine expression. These changes mimic the pathohistological alterations described in dry eye. This correspondence suggests that insight into the pathophysiology of dry eye may be aided through the use of airlifted conjunctival tissue cultures.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air*
  • Apoptosis
  • Conjunctiva / metabolism*
  • Conjunctiva / pathology
  • Dry Eye Syndromes / genetics
  • Dry Eye Syndromes / metabolism*
  • Enzyme-Linked Immunosorbent Assay
  • Epithelial Cells / metabolism
  • Eye Proteins / metabolism
  • Gene Expression
  • Homeodomain Proteins / metabolism
  • Humans
  • Immunohistochemistry
  • Interleukin-1beta / metabolism
  • Keratin-10 / genetics
  • Keratin-10 / metabolism
  • Keratin-16 / genetics
  • Keratin-16 / metabolism
  • Keratin-19 / genetics
  • Keratin-19 / metabolism
  • Matrix Metalloproteinase 9 / metabolism
  • Mucin 5AC / genetics
  • Mucin 5AC / metabolism
  • Mucin-4 / genetics
  • Mucin-4 / metabolism
  • Mucins / genetics
  • Mucins / metabolism
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors / metabolism
  • Repressor Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Time Factors
  • Tissue Culture Techniques / methods*
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • Eye Proteins
  • Homeodomain Proteins
  • Interleukin-1beta
  • Keratin-16
  • Keratin-19
  • MUC19 protein, human
  • MUC4 protein, human
  • MUC5AC protein, human
  • Mucin 5AC
  • Mucin-4
  • Mucins
  • PAX6 Transcription Factor
  • PAX6 protein, human
  • Paired Box Transcription Factors
  • Repressor Proteins
  • Tumor Necrosis Factor-alpha
  • Keratin-10
  • Matrix Metalloproteinase 9

Grants and funding

This research described was supported in part by the grants from Chinese National Key Scientific Research Project (2013CB967003 [to WL]), the National Natural Science Foundation of China (NSFC, No. 81270977 [to WL], 81000403 [to HL], U1205025 [to ZL], 81270978 [to ZL]). The funders had no role in study design, data collection and analysis.