Corneal epithelial proliferation and thickness in a mouse model of dry eye

Claudia Fabiani, Stefano Barabino, Saadia Rashid, M. Reza Dana

Research output: Contribution to journalArticle

49 Citations (Scopus)

Abstract

Although several studies have previously focused on the conjunctival epithelial response to surface dryness, little is known about the effect of a dry environment on corneal epithelium, which is the most clinically significant tissue affected in dry eye. The aim of this study was to quantitatively evaluate the effect of desiccating stress on the number of proliferating corneal epithelial cells and corneal epithelial thickness in mice placed in a controlled-environment chamber (CEC) that induces dry eye. Corneal epithelial cell proliferation and thickness were studied in 8- to 12-week-old female BALB/c mice placed in the CEC (temperature: 22.3 ± 0.7 °C; relative humidity: 22.5 ± 4.5%; airflow: 15 L/min) for 7 days and compared to a control group of mice with no dry eye. Actively proliferating cells were identified by immunofluorescence using a FITC-conjugated antibody against the Ki-67 protein, a cell proliferation marker expressed during active phases of the cell cycle. To detect the spatial distribution of proliferative cells, Ki-67+ cells were counted in three areas of the epithelium: center, periphery, and limbus. Corneal epithelial thickness was evaluated in the central cornea after staining with hematoxylin-eosin. Results from each experimental group were compared using the Mann-Whitney test. The number of Ki-67+ cells observed in the corneal epithelium of mice exposed to the CEC was significantly higher in each area (center: 32.1 ± 1.1; periphery: 94.2 ± 5.3; limbus: 4.0 ± 1.5) than in the control group (center: 13.2 ± 1.0, p = 0.02; periphery: 42.9 ± 2.3, p = 0.02; limbus: 0.0, p = 0.01). In mice subjected to desiccating stress, a significant number of Ki-67+ positive cells were detected in the basal and suprabasal cell layers (central area 46%; periphery 30.8%: limbus 0%), whereas in the control group the cells were exclusively distributed through the basal cell layer. Ki-67+ cells were not found in the corneal stroma or endothelium in any group. The corneal epithelium was found to be significantly thicker in dry eye mice (54.94 ± 6.09 μm) as compared to the controls (43.9 ± 6.23 μm, p < 0.0001) by a mean of 25%. These results demonstrate that desiccating stress increases corneal epithelial turnover and thickness, similar to what is observed in other chronic inflammatory states of other epithelialized surfaces. The CEC can facilitate the study of the regulation of epithelial cell function and turnover at the molecular and cellular levels under desiccating stress conditions.

Original languageEnglish (US)
Pages (from-to)166-171
Number of pages6
JournalExperimental Eye Research
Volume89
Issue number2
DOIs
StatePublished - Aug 2009
Externally publishedYes

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Controlled Environment
Corneal Epithelium
Epithelial Cells
Control Groups
Cell Proliferation
Corneal Stroma
Corneal Endothelium
Fluorescein-5-isothiocyanate
Hematoxylin
Eosine Yellowish-(YS)
Humidity
Cornea
Fluorescent Antibody Technique
Cell Cycle
Epithelium
Staining and Labeling
Temperature
Antibodies
Proteins

Keywords

  • animal model
  • cell proliferation
  • corneal epithelium
  • dry eye

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

Cite this

Corneal epithelial proliferation and thickness in a mouse model of dry eye. / Fabiani, Claudia; Barabino, Stefano; Rashid, Saadia; Dana, M. Reza.

In: Experimental Eye Research, Vol. 89, No. 2, 08.2009, p. 166-171.

Research output: Contribution to journalArticle

Fabiani, Claudia ; Barabino, Stefano ; Rashid, Saadia ; Dana, M. Reza. / Corneal epithelial proliferation and thickness in a mouse model of dry eye. In: Experimental Eye Research. 2009 ; Vol. 89, No. 2. pp. 166-171.
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