Transcript profile of cellular senescence-related genes in Fuchs endothelial corneal dystrophy

Abstract

Fuchs endothelial corneal dystrophy (FECD) is a genetically heterogeneous disease. Hypothesizing that cellular senescence may be relevant in FECD pathogenesis, genetically undifferentiated late-onset FECD endothelial samples were analyzed to identify common changes of specific senescence-related transcripts. Total RNA was extracted from 21 FECD endothelial samples retrieved from patients undergoing lamellar keratoplasty due to clinically diagnosed end-stage FECD and from 12 endothelial samples retrieved from normal autopsy eyes. Taqman low density array (TLDA) cards were used to analyze differential expression of 89 cellular senescence-related transcripts. Result validation was performed using individual real-time PCR assays. TLDA-analysis demonstrated differential expression of 31 transcripts (fold-change >1.5; p<0.05). Thereof, 27 showed significant up-regulation and 4 significant down-regulation. Markedly elevated mRNA-levels of the constitutively active and reactive oxygen species-generating enzyme NOX4 were found in all evaluable FECD samples. In addition, increased expression of CDKN2A and its transcriptional activators ETS1 and ARHGAP18 (SENEX) along with decreased expression of CDKN2A inhibitor ID1 were detected in FECD samples. Consistent over-expression of NOX4 in FECD endothelial samples suggests a role as pathogenic factor and as a potential new treatment target in FECD. Transcriptional up-regulation of the CDKN2A-pathway provides further evidence for increased cellular senescence in FECD endothelium.

Comprehensive characterization of DNA methylation changes in Fuchs endothelial corneal dystrophy

“…Exposure of normal corneal endothelial cells to oxidative stress results in a loss of proliferative capacity and reduced cellular function [51]. Furthermore, increased expression of cellular senescence-related genes has been observed in tissue from FECD patients [52]. Intriguingly, our finding of promoter DNA hypermethylation of genes involved in cellular metabolism is consistent with a prior serial analysis of gene expression (SAGE) study that compared gene expression profiles of normal human CE with Fuchs’ CE [35].…”

Induction of Fibroblast Senescence During Mouse Corneal Wound Healing

“…In the cornea, the senescence of epithelial and endothelial cells has been reported in human samples, animal models, and cultured cells. 40,[49][50][51] To explore whether senescent cells commonly occur in the stroma after corneal injury, we further established corneal scarring, alkali burn, and PKP mouse models. The whole-mount and section staining showed that the SA-b-galþ cells accumulated in the corneal stroma, with varied numbers and locations in different models (Figs.…”

E Proteins and ID Proteins: Helix-Loop-Helix Partners in Development and Disease

“…The lack of Fuchs corneal dystrophy in PTHS patients that have heterozygous loss-of-function E2-2 mutations, suggests that Fuchs corneal dystrophy might involve E2-2 gain-of-function. Interestingly, endothelial samples from Fuchs corneal dystrophy patients exhibit reduced ID1 expression, which could be another route to elevate E2-2 activity (Matthaei et al, 2014)(Figure 1). Since corneal endothelium is normally non-proliferative, cell cycle arrest is unlikely to cause disease, but altered expression of senescence-related genes has been reported (Matthaei et al, 2014).…”

“…Interestingly, endothelial samples from Fuchs corneal dystrophy patients exhibit reduced ID1 expression, which could be another route to elevate E2-2 activity (Matthaei et al, 2014)(Figure 1). Since corneal endothelium is normally non-proliferative, cell cycle arrest is unlikely to cause disease, but altered expression of senescence-related genes has been reported (Matthaei et al, 2014). In Drosophila , elevated Da expression can be toxic and activates the Salvador-Warts-Hippo pathway of tumor suppressors (Wang and Baker, 2015), but it is not known whether this occurs in Fuchs corneal dystrophy.…”