Secreted protease imbalance in Fuchs Corneal Endothelial Dystrophy

Abstract

Purpose : The goal of this study was to compare the secretome and the transcriptome of cultured corneal endothelial cells (CECs) isolated from healthy corneas and Fuchs endothelial corneal dystrophy (FECD) specimens.

Methods : Human CECs, isolated from surgical specimens (FECD; N=9) and healthy Eye bank corneas (N=9), were cultured 15-28 days post-confluency. Gene profiling analyses were performed using Agilent SurePrint G3 Human Gene expression microarrays. Supernatant was collected and analysed using the Proteome Profiler Human Protease/Protease Inhibitor (PI) and Cytokine array kits (R&D Systems) which analysed in total 35 proteases, 32 PIs, and 107 cytokines. Proteome signal was analysed using Image Studio Lite.

Results : Cytokine gene expression and secreted cytokine protein expression were similar between FECD and healthy CECs. For both healthy and FECD CECs, protease and PI proteome arrays revealed the presence of metalloproteinases (MMPs) and Cathepsin proteases (such as MMP-1, 2, 3 and 12, Cathepsin A, B, D and X/Z/P), as well as various serine, cysteine and metalloproteinase PI (such as Serpin E1, Cystatin B and C, TIMP-2 and 4). Of all the studied secreted proteins, a significant decrease in Cathepsin A (1.6±0.4 -fold) and MMP-12 (3.0±1.5 -fold) was observed in FECD supernatant. An increase of MMP-1 (2.4±0.4 -fold) was also observed in FECD, although the difference was not statistically significant. Gene profiling revealed a similar gene expression for Cathepsin A (1.0±0.1-fold increase) and MMP-12 (1.7 ± 1.0-fold increase) between FECD and healthy CECs. MMP-1 gene expression was significantly higher (16.4±0.1 -fold) in FECD CECs.

Conclusions : Taken together, these results show that CECs secrete proteases and PIs from which an imbalance can be observed in cultured FECD specimens. Since one of the main function of the studied proteins is to regulate the production and degradation of extracellular matrix, such an imbalance may contribute to the irregular thickening of the Descemet membrane seen in FECD.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.