Abstract
Purpose :
Age is a common risk factor among various chronic eye diseases. While age-associated ocular surface diseases and their pathophysiologic mechanisms are studied extensively, the normal molecular changes in aging eye are not fully understood. This study focuses on tear film proteomics to examine the changes in ocular surface during aging.
Methods :
Subjects of all ages undergoing either strabismus or femtosecond laser in situ keratomileusis (FS-LASIK) surgeries had open-eye tears collected with capillaries. Sampling was performed prior to any further manipulation of the eye. In addition to their refractive error or strabismus, these subjects did not have any other current, known eye diseases. Tear fluid samples were analyzed with NanoLC-TripleTOF mass spectrometer and protein quantitation analysis was performed with the SWATH-MS method. Correlations between age and relative quantification data were performed with Pearson's product-moment correlation and pathway analysis was implemented to evaluate the enriched biological functions and diseases based on correlation results.
Results :
In total 849 proteins were identified and relatively quantified from each tear sample. Age correlated significantly with several tear proteins associated previously with cell death, inflammation and immune response. For example S100A8 (R=0.4, P=0.004), serotransferrin (R=0.37, P=0.01) and albumin (R=0.35, P=0.013) correlated positively with age. According to pathway analysis, the age-protein correlation results suggested an increase in inflammation and immune response and a decrease in cell viability and survival. In addition to pathways, we identified several upstream regulators associated with aging of the ocular surface, e.g. activated NF-κB complex.
Conclusions :
Several proteins associated with immune response and inflammation were correlating significantly with age. These proteins, as well as pathways and upstream regulators presented in our work should be studied further and implemented in the research of dry eye and other ocular surface diseases associated with increased age.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.