Abstract
Purpose :
Keratoconus (KC) is a multifactorial disease with misunderstood molecular pathogenesis. Sterile inflammation was recently described to be involved in such pathology; without clear identification of altered cellular pathways. The Receptor for Advanced Glycation End Products (RAGE) is actually described as one of key pathway involved in the sterile inflammation. The aim of our work is to describe RAGE, its ligands and co-actors in human normal and keratoconus corneal tissues and epithelial cells.
Methods :
All corneal samples were collected after written informed consent and in compliance with the « declaration of Helsinki ». Human keratoconus corneas were obtained from patient undergoing corneal transplantation. Corneal epithelium cells were collected from non-KC controls (n=10, patients undergoing refractive correction by photorefractive keratectomy) and KC patients (n=10, patients undergoing collagen cross-linking). First, total RNA was extracted from all samples. The characterization and differential expression of the RAGE pathway members between control and pathologic samples was done using qPCR experiments. Protein expression and localization (at tissue and cellular level) were analyzed by western blot and/or immuno-histochemistry assays. Statistical analyses for quantitative experiments were conducted using non parametric test Wilcoxon-Mann-Whitney test.
Results :
RAGE pathway is found to be expressed in corneal cells and tissues. RAGE protein is particularly present in the cornea epithelium. Expression and levels of RAGE transcripts and proteins were found as statistically different in normal versus keratoconus corneal environment.
Conclusions :
Our results demonstrate the presence of RAGE pathway in corneal environment. Alterations of RAGE pathway could be a new molecular explanation of keratoconus’ pathophysiology leading to future research in terms of altered RAGE target genes and potential therapeutic issues.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.