Abstract
Purpose: :
To identify protein changes in the vitreous humor (VH) following laser induced retinal injury in rabbits.
Methods: :
Using a continuous 532 nm laser, fifty laser spots producing minimally visible lesions (mild laser retinal injury) were applied to the retina in one eye of each animal (n=3). VH was collected from both laser treated and contralateral control eyes 24hrs after laser exposure. Samples were analyzed by Liquid Chromatography/Tandem Mass Spectrometry (LC-MS/MS) and relative protein abundances were determined by spectral counting. G test followed by post-hoc Holm Sidak for correction was used for statistical analyses to determine significance in the differential expression of proteins between treated and untreated groups.
Results: :
Analysis of VH from laser treated eyes using LC-MS/MS revealed significant differences in protein composition. Proteins from the crystallin family; Alpha crystallin A chain, Alpha crystallin B chain, Beta crystallin B1 and Beta crystallin A4 were 4-14 times more abundant in VH from treated compared to control eyes (P<0.05).
Conclusions: :
Protein changes were detectable in VH following retinal laser injury. This suggests that proteins are upregulated in the lasered retina and that these proteins may leak into the VH from the damaged tissue. These proteins that enter the vitreous can be detected using a proteomic approach and may be used as biomarkers for laser induced retinal injuries.
Keywords: retina • proteomics • crystallins