Background:
Exosomes secreted by corneal fibroblasts contain matrix metalloproteinase
(MMP) 14, which is known to influence pro-MMP2 accumulation on exosomes. Accordingly,
we hypothesized that the enzymatic activity of MMP14 may alter the protein content of corneal fibroblast-
secreted exosomes.
Objective:
The aim of this study was to investigate the effects of MMP14 on the composition and
biological activity of corneal fibroblast-derived exosomes.
Methods:
Knock out of the catalytic domain (ΔExon4) of MMP14 in corneal fibroblasts was used
to determine the effect of MMP14 expression on the characteristics of fibroblast-secreted exosomes.
The amount of secreted proteins and their size distribution were measured using Nano
Tracking Analysis. Proteins within exosomes from wild-type (WT) and ΔExon4-deficient fibroblasts
were identified by liquid chromatography-tandem mass spectrometry (MS/MS) proteomics
analysis. The proteolytic effects of MMP14 were evaluated in vitro via MS identification
of eliminated proteins. The biological functions of MMP14-carrying exosomes were investigated
via fusion to endothelial cells and flow cytometric assays.
Results:
Exosomes isolated from WT and ΔExon4-deficient fibroblasts exhibited similar size distributions
and morphologies, although WT fibroblasts secreted a greater amount of exosomes. The
protein content, however, was higher in ΔExon4-deficient fibroblast-derived exosomes than in WT
fibroblast-derived exosomes. Proteomics analysis revealed that WT-derived exosomes included proteins
that regulated cell migration, and ΔExon4 fibroblast-derived exosomes contained additional
proteins that were cleaved by MMP14.
Conclusion:
Our findings suggest that MMP14 expression influences the protein composition of
exosomes secreted by corneal fibroblasts, and through those biological components, MMP14 in
corneal fibroblasts derived-exosomes may regulate corneal angiogenesis.
Analysis of protein composition in Organically and Non-Organically grown Sorghum and Barnyard millet
