Abstract
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.
Keywords: Extracellular vesicles, exosomes, metalloproteinase 14, corneal fibroblasts, angiogenesis, biological activity.
Graphical Abstract
[http://dx.doi.org/10.1038/nrm.2017.125] [PMID: 29339798]
[http://dx.doi.org/10.15252/embr.201439363] [PMID: 25488940]
[http://dx.doi.org/10.1146/annurev-cellbio-101512-122326] [PMID: 25288114]
[PMID: 3597417]
[http://dx.doi.org/10.1126/science.1153124] [PMID: 18309083]
[PMID: 2848029]
[http://dx.doi.org/10.2174/1570159X14666160825160421] [PMID: 27568544]
[http://dx.doi.org/10.1007/s00709-015-0887-1] [PMID: 26410830]
[http://dx.doi.org/10.1038/srep40548] [PMID: 28165027]
[http://dx.doi.org/10.1083/jcb.200508014] [PMID: 16533950]
[http://dx.doi.org/10.1155/2015/657086] [PMID: 25695100]
[http://dx.doi.org/10.1084/jem.183.3.1161] [PMID: 8642258]
[http://dx.doi.org/10.1038/nm0598-594] [PMID: 9585234]
[http://dx.doi.org/10.1111/j.1600-0854.2008.00734.x] [PMID: 18331451]
[http://dx.doi.org/10.1002/pmic.200400876] [PMID: 15478216]
[http://dx.doi.org/10.1111/j.1600-0854.2010.01041.x] [PMID: 20136776]
[http://dx.doi.org/10.1083/jcb.97.2.329] [PMID: 6309857]
[http://dx.doi.org/10.4049/jimmunol.1102053] [PMID: 22262654]
[http://dx.doi.org/10.1007/s00249-007-0246-z] [PMID: 18064447]
[http://dx.doi.org/10.1016/j.jhep.2013.03.028] [PMID: 23557871]
[http://dx.doi.org/10.3390/ijms140714240] [PMID: 23839094]
[http://dx.doi.org/10.1038/s41569-018-0022-z] [PMID: 29752454]
[http://dx.doi.org/10.1126/science.1067100] [PMID: 11923519]
[http://dx.doi.org/10.1096/fasebj.12.12.1075] [PMID: 9737711]
[http://dx.doi.org/10.1002/1097-0215(20001001)88:1<21::AID-IJC4>3.0.CO;2-S] [PMID: 10962435]
[http://dx.doi.org/10.1016/S0378-1119(98)00400-4] [PMID: 9767135]
[http://dx.doi.org/10.1007/s00432-005-0030-3] [PMID: 16180025]
[http://dx.doi.org/10.1074/jbc.273.38.24360] [PMID: 9733724]
[http://dx.doi.org/10.1080/10409230701340019] [PMID: 17562450]
[http://dx.doi.org/10.1371/journal.pcbi.1003086] [PMID: 23737743]
[http://dx.doi.org/10.1074/jbc.M111.256644] [PMID: 21795678]
[http://dx.doi.org/10.1371/journal.pone.0136797] [PMID: 26331622]
[http://dx.doi.org/10.1016/j.survophthal.2015.11.006] [PMID: 26647161]
[http://dx.doi.org/10.1073/pnas.060037197] [PMID: 10737763]
[http://dx.doi.org/10.2353/ajpath.2009.080452] [PMID: 19264910]
[http://dx.doi.org/10.1074/jbc.272.4.2446] [PMID: 8999957]
[http://dx.doi.org/10.1074/jbc.M001836200] [PMID: 10930399]
[http://dx.doi.org/10.1167/iovs.16-19420] [PMID: 27327585]
[PMID: 25015352]
[http://dx.doi.org/10.1080/02713680802461106] [PMID: 19085378]
[http://dx.doi.org/10.1038/srep29511] [PMID: 27405411]
[PMID: 26074915]
[http://dx.doi.org/10.1016/j.bbapap.2004.08.001] [PMID: 15450852]
[PMID: 10967042]
[http://dx.doi.org/ 10.1167/iovs.18-26277] [PMID: 31117124]