Grants and Contributions:

Grant or Award spanning more than one fiscal year (2017-2018 to 2018-2019).

The goal of the project is to identify the distribution of an important family of enzymes, the Granzymes, in thex000D
aging eye. Granzymes are serine proteases that were shown by our partner, ViDA Therapeutics, to play anx000D
important role in the abnormal degradation of extracellular proteins and tissue matrices in many parts of thex000D
body. To date, there are no studies on the role of Granzymes in the eye, an organ that contains an importantx000D
extracellular structure called Bruch's Membrane (BM). As the eye ages, the extracellular matrix (ECM) withinx000D
BM undergoes dramatic remodelling, hypothesized to lead to a dysfunctional blood-eye barrier. Recent studiesx000D
have shown that loss of barrier function in the outer retina causes 1) retinal cell death, 2) pro-inflammatoryx000D
events and 3) abnormal angiogenesis and vascular permeability.x000D
The research proposed will provide relevant and novel information about the cellular distribution ofx000D
Granzyme B in the aging eye that will allow us to understand Granzyme B's role in ECM remodeling. Thex000D
hypothesis is that with aging, levels of Granzyme B increase in the choroidal tissues, leading to a compromisedx000D
BM and concomitant loss of tight junctional proteins, dysregulated barrier function, increased vascularx000D
permeability, angiogenesis and pro-inflammation. Eye tissues from postmortem human donors (ranging fromx000D
16yr to 80yrs of age) and wild type mice (C57Bl/6J, 3 to 18 months of age) will be assessed for longitudinalx000D
changes in protein levels of Granzyme B, cytokines (IL1b; IL1a), tight junctional proteins (ZO-1, cadherins),x000D
and angiogenic factors (VEGF, bFGF). Immunohistochemistry will identify the laminar distribution whilex000D
antibody-based multiplexes will provide quantitative values (pg/mL) of these molecules in the retina. Opticalx000D
imaging of the retina in Granzyme B knock-out mice and in aged mice treated with Granzyme B inhibitors willx000D
assess Granzyme B-induced changes in retinal structure in vivo. Key benefits include new target areas forx000D
partner's proprietary Granzyme B inhibitors. Future economic and social benefits include potential newx000D
treatments for Canadians suffering from chronic ocular inflammation.