Analysis of protein composition and protein expression in the tear fluid of patients with congenital aniridia.
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.


CONCLUSIONS
This study is first to demonstrate protein composition and protein expression in aniridic tears and identifies proteins with different abundance in tear fluid from patients with congenital aniridia vs. healthy tears.
Integrative Regenerative Medicine Centre and Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, 581 85 Linköping, Sweden. Electronic address: robert.ihnatko@liu.se.
Robert
R
Ihnatko
Ulla
U
Edén
Neil
N
Lagali
Anette
A
Dellby
Per
P
Fagerholm
D000293:Adolescent; D000328:Adult; D015783:Aniridia / Q000235:genetics / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D005136:Eye Proteins / Q000096:biosynthesis*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D013666:Tears / Q000378:metabolism*
D005136:Eye Proteins; C042434:tear proteins
Aniridia; Keratopathy; LC–MS/MS; Tear fluid; Two-dimensional electrophoresis; α-Enolase