Identification of Circulating Fibrocytes and Dendritic Derivatives in Corneal Endothelium of Patients with Fuchs' Dystrophy [microarray expression analysis]

PURPOSE: Fuchs’ endothelial corneal dystrophy (FECD) is a degenerative eye disorder affecting 4% of Americans older than 40. It is the leading indication for corneal endothelial (CE) transplantation for which there is a global donor shortage. This study aimed to gain further insight into the pathophysiology of FECD and identify targets for nonsurgical therapy. METHODS: CE from patients with late-onset FECD was compared with that of normal controls using microarray expression analysis (n = 4 FECD, n = 4 normal), reverse transcriptase quantitative PCR (n = 9 FECD, n = 8 normal), and immunohistology (n = 55 FECD, n = 15 normal). RESULTS: This led to the identification of circulating fibrocytes and their dendritic derivatives in all examined CE samples with FECD (in all clinical stages of symptomatic FECD and independent of prior cataract surgery). These cells were not present in normal CE. In this study we characterize their morphology, protein expression profile, number, and localization within the CE layer of patients with FECD. CONCLUSIONS: Circulating fibrocytes and their dendritic derivatives are a new aspect of FECD that deserves further investigation. Because they are known to cause fibrosis in a variety of organs, they may play a similar role in FECD and might be a valuable target for nonsurgical therapy. This study was performed on CE monolayers with Descemet membrane from patients with late-onset FECD. Microarray expression analysis was performed on 8 samples (n = 4 FECD, n = 4 normal). RT-qPCR was done for 179 genes of interest and at least three reference genes (n = 9 FECD, n = 8 normal). Molecules of interest were validated with immunohistochemical and immunofluorescent staining on fresh corneal endothelial whole-mounts (n = 55 FECD, n = 15 normal). All stainings were optimized on external control tissues, which were included as batch controls. Dye swaps ensured specificity of double staining.