ABSTRACT
Aging is a risk factor for cardiovascular disease, the leading cause of death worldwide. Cardiac fibrosis is a harmful result of repeated myocardial infarction that increases risk of morbidity and future injury. Interestingly, rates of cardiac fibrosis are different between young and aged individuals, as well as men and women. Here, for the first time, we identify and isolate matrix-bound extracellular vesicles from the left ventricles (LVs) of young or aged men and women. These LV vesicles (LVVs) show differences in morphology and content between these four cohorts. LVVs effects on fibrosis were also investigated in vitro, and it was shown that aged male LVVs were pro-fibrotic, while other LVVs were anti-fibrotic. miRNAs identified from these LVVs could partially recapitulate these effects together, but not individually, and confer other benefits. These data suggest that synergistic effects of matrix-resident exosomal miRNAs may influence the differential clinical response to MI.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
gronan{at}nd.edu
gbahceci{at}nd.edu
jyang26{at}nd.edu
Data Availability Statement: All data required for production of the manuscript is included in this submission. Additional raw data can be provided upon request.
Funding Statement: Research reported in this publication was supported by NSF-CAREER Award # 1651385, NSF CBET Award # 1805157 and NIH Award # 1 R01 HL141909-01A1
Competing Interests Statement: The authors have no competing interest to disclose.
Ethics Statement: All animal work was performed under the approved IACUC protocol number 18-05-4687
Additional human heart tissue was acquired and utilized to bring the biological replicates in the study up to the standard n=3 for all but one cohort (YF). Supplementary figures have been added showing direct images of EVs embedded in the ECM, additional western blots showing the presence or absence of cell debris markers, individual timepoints for time point assays, and a table listing the age, sex, and any preconditions associated with each tissue donor. Manuscript language has been edited to be more concise and easily readable. Individual replicates (technical or biological) in each bar graph are now shown when appropriate to do so. Heatmaps of miRNA profile data are shown as averaged groups, with individual replicates being moved to the supplement. Included downstream pathway analysis of the identified target miRNA. This data has been added both to the main text (segments of interest) and to the supplement (whole pathways). Wound healing, a-SMA expression, and miRNA profiling data demonstrating differences between LVVs and plasma EVs has been added to the supplement.