Increased TRAIL and TRAIL receptor expression in ratcorneal stroma exposed to chemical burn damage

Purpose: To study the expression levels of TRAIL and TRAIL
receptor in the rat cornea after alkali burn.
Methods: A 2mm2 filter paper embedded with a 0.5 M NaOH
solution was applied in the centre of cornea for 30 sec, then we
followed healing process up to 14 days. Immunostainings were done
for TRAIL and TRAIL receptor. For western blot analysis, corneal
epithelial cells from 5 different rats were pooled.
Results: The immunostaining showed a strong up-regulation of
TRAIL and TRAIL receptor in the nuclear and perinuclear area of
corneal stroma and limbal cells. The intensity of the staining regained
baseline levels few days later. After 14 days the central corneal stroma
appeared to be as in the control eyes.
In corneal epithelial cells, the chemical burn seems to not sensibly
affect the expression of TRAIL. The chemical burn slightly upregulated
the TRAIL receptor in corneal epithelial cells between 3 and 7 days
following the healing of the tissues.
In conjunctival cells alkali burn slightly raised up TRAIL from day 1
to 14. Instead, the expression of TRAIL receptor does not present a
significant difference between treated and control eye.
Conclusions: TRAIL may be a novel regulator and therapy target to
treat chemically damaged cornea.