Exosomes Released by Corneal Stromal Cells Show Molecular Alterations in Keratoconus Patients and Induce Different Cellular Behavior

Abstract

Exosomes have been related to various disorders, but their study in relation to ocular pathologies has been limited. In this article, we analyze exosomes produced by corneal stromal cells from healthy individuals and from patients with keratoconus. The proteomic study allowed for the identification of 14 new proteins with altered expression, related to molecules previously associated with the pathology. miRNA analysis detected 16 altered species, including miR-184, responsible for familial severe keratoconus. The prediction of its potential biological targets identified 1121 genes, including some related to this pathology. Exosomes produced by keratoconic cells induced a marked increase in the migration of stromal cells and corneal epithelium, while those produced by healthy cells had no effect on stromal cells. Both types of nanovesicles reduced the proliferation of stromal and corneal cells, but those produced by healthy cells had less effect. Exosomes produced by healthy cells had concentration-dependent effects on the transcription of genes encoding proteoglycans by keratoconus cells, with a relative normalization observed at concentrations of 240 µg/mL. These results show the alteration of stromal exosomes in keratoconus and suggest an influence on the development of the pathology, although the use of healthy exosomes could also have therapeutic potential.

The Binding of Pseudomonas aeruginosa to Cystic Fibrosis Bronchial Epithelial Model Cells Alters the Composition of the Exosomes They Produce Compared to Healthy Control Cells

“…The exosome suspension was applied to a standard SDS-PAGE gel and allowed to penetrate 1 cm into the resolving gel. The protein mixture was stained with Coomassie, extracted, and cut into 1 mm 2 fragments, which were deposited in 96-well plates and processed in a Proteineer DP (Bruker Daltonics, Bremen, Germany), using a digestion protocol based on Schevchenko et al [54] with minor variations as previously described [55]. The finally obtained tryptic-eluted peptides were dried by fast vacuum centrifugation.…”

Tear Film MicroRNAs as Potential Biomarkers: A Review

“…This study also found upregulated expression of corneal epithelial miR-1207 in response to bacterial antigens, suggesting miR-1207’s involvement in host defense mechanisms. miR-4466 was found to be overexpressed in human corneal stromal cell exosomes of patients with keratoconus compared to healthy controls [ 89 ]. This upregulation was also detected in the tears from VKC patients and may indicate miR-4466’s potential involvement in corneal surface integrity.…”

Animal Models for the Study of Keratoconus

“…A progressive and degradative disorder, KC presents as irregular astigmatism, myopia, and corneal scarring, which worsen over time and can result in vision loss [3]. At the tissue level, KC is marked by centralized thinning of the stroma, breaks in Bowman's layer, compaction of the collagen fibers in the stroma, and iron deposition in the epithelial basement membrane [1,[4][5][6][7]. All five layers of the cornea may be affected by KC pathogenesis, but the characteristics mentioned are well-recognized markers of KC [1].…”