Purpose:
We previously reported that retinal specific proteins could be detected in serum and saliva of laser treated Dutch Belted (DB) rabbits by Liquid chromatography/tandem mass spectrometry (LC-MS/MS) (ARVO 2009, Abstract # 206-A306). We then hypothesized that this biomarker response could potentially vary with the severity of the injury and during the recovery period following injury.
Methods:
Using a continuous 532 nm laser, 50 spots of mild (Minimally Visible Lesion, MVL), moderate (Grade II), or severe (Grade III) laser lesions were created in retinas of DB rabbits (n=12 for each grade). Body fluids (serum and saliva) were collected from treated and control animals at 1hr, 4hrs and 24hrs following laser treatment. Samples were analyzed by LC-MS/MS to detect retinal specific proteins. One way ANOVA was used to determine the differences in the number of proteins detected in the different laser groups. P<0.05 was considered significant.
Results:
Ten, four and five retinal specific proteins were detected in the samples treated with MVL, Grade II and Grade III laser respectively (Table 1). Two, ten and seven of these proteins were detected at 1hr, 4hrs and 24 hrs following treatment respectively (Table 1). Some of these proteins were common to all laser grades (CNGB3, PDE6A, and PED6B). All proteins detected were retinal specific, membrane bound, photoreceptor outer segment proteins and none were detected in the controls. Although, more proteins were detected following treatment with MVL laser and at 4 hrs after treatment, the differences between groups were not statistically significant.
Conclusions:
Although retinal proteins were observed in both serum and saliva following all grades of laser treatment, the numbers of proteins detected did not vary with severity or time following injury. Overall, the biomarker response appears transient, peaks at 4 hours after laser treatment and may be reduced at 24hrs.Table 1. Number of proteins detected in serum and saliva at different time points following MVL, Grade II and Grade III laser treatments in rabbits.
Keywords: retina • laser • proteomics