Abstract
Purpose :
Keratoconus is one of the most abundant corneal degenerative disease in the developed world, affecting 1 in 2000 people and a major cause of corneal transplantation. It is characterized by a narrowing and bulging of the cornea, taking a conical shape, which makes it difficult for the patient to see. The cause of the disease is still unknown and it does not have molecular markers to make an early diagnosis. That is why, in our study, we analyzed the content of exosomes, small vesicles of around 100 nm, produced by corneal cells obtained from healthy patients and stromal cells isolated from the corneas of patients with keratoconus.
Methods :
Corneal stromal cells were obtained from cadaver donors and from penetrating keratoplasty surgeries of patients suffering keratoconus. Exosomes were isolated from cell culture medium of the two different tissues. miRNAs were analysed by NGS (Next Generation Sequencing), and proteins by LC-MS (Liquid chromatography–mass spectrometry).
Results :
A total of 466 proteins and 800 miRNAs were detected, showing 18 and 23 significant differences respectively. Among the proteins, two appeared exclusively in the exosomes produced by keratoconus stromal cells, VNN2 and VTN, while 6 proteins increased and another 10 decreased their levels significantly. Analysis of the miRNAs resulted in 2 of them not being expressed, 5 were under-expressed and 16 were overexpressed in keratoconus versus healthy tissue. These MiRNAs are related to the regulation of the synthesis of around 2,500 proteins involved in many processes such as apoptosis, cell migration, inflammation and others.
Conclusions :
This study shows the existence of differences in the composition of the exosomes produced by corneal stromal cells of patients with keratoconus compared to healthy individuals. Furthermore, these differences may be related to disease progression due to the role played by differential molecules, mainly affecting inflammatory pathways or cell migration processes, such as VNN2, VTN, SERPINE1, hsa-miR-34a-3p or hsa-miR-101-3p. These differences may be important for the development of an early diagnosis of the disease and even a possible therapeutic use of the molecules that have been described in this study.
This is a 2021 ARVO Annual Meeting abstract.