Aniridia is a rare congenital
genetic disorder caused by haploinsuffiency of the PAX6 gene, the master gene for development of the eye. The expression of
tear proteins in
aniridia is unknown. To screen for
proteins involved in the
aniridia pathophysiology, the tear fluid of patients with diagnosed
congenital aniridia was examined using two-dimensional electrophoresis (2-DE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Two-dimensional map of
tear proteins in
aniridia has been established and 7
proteins were differentially expressed with P<0.01 between
aniridia patients and control subjects. Five of them were more abundant in healthy subjects, particularly α-
enolase,
peroxiredoxin 6,
cystatin S,
gelsolin,
apolipoprotein A-1 and two other
proteins, zinc-α2-glycoprotein and
lactoferrin were more expressed in the tears of
aniridia patients. Moreover, immunoblot analysis revealed elevated levels of
vascular endothelial growth factor (
VEGF) in
aniridia tears which is in concordance with clinical finding of pathological blood and lymph vessels in the central and peripheral cornea of
aniridia patients. The
proteins with different expression in patients' tears may be new candidate molecules involved in the pathophysiology of
aniridia and thus may be helpful for development of novel treatment strategies for the symptomatic
therapy of this vision threatening condition.
BIOLOGICAL SIGNIFICANCE: