Identification of Therapeutic Covariant microRNA Clusters in Hypoxia Treated Cardiac Progenitor Cell Exosomes using Systems Biology
Rationale: Myocardial infarction (MI) is a leading cause of death in developed nations, and there remains a need for cardiac therapeutic systems that mitigate tissue damage and. Cardiac progenitor cells (CPCs) and other stem cell types are attractive candidates for treatment of MI; however, the benefit of these cells may be due to paracrine effects.
Objective: We tested the hypothesis that CPCs secrete pro-regenerative exosomes in response to hypoxic conditions.
Methods and Results: The angiogenic and anti-fibrotic potential of secreted exosomes on cardiac endothelial cells and cardiac fibroblasts were assessed. We found that CPC exosomes secreted in response to hypoxia enhanced tube formation of endothelial cells and decreased pro-fibrotic gene expression in TGF-β stimulated fibroblasts, indicating that these exosomes possess therapeutic potential. Microarray analysis of exosomes secreted by hypoxic CPCs identified eleven miRNAs that were upregulated compared to exosomes secreted by CPCs grown under normoxic conditions. Principle component analysis was performed to identify miRNAs that were co-regulated in response to distinct exosome generating conditions. To investigate the cue-signal-response relationships of these miRNA clusters with a physiological outcome of tube formation or fibrotic gene expression, partial least squares regression analysis was applied. The importance of each up- or downregulated miRNA on physiological outcomes was determined. Finally, to validate the model we delivered exosomes following ischemia-reperfusion injury. Exosomes from hypoxic CPCs improved cardiac function and reduced fibrosis.
Conclusions: These data provide a foundation for subsequent research of the use of exosomal miRNA and systems biology as therapeutic strategies for the damaged heart.
- Received May 10, 2014.
- Revision received October 21, 2014.
- Accepted October 24, 2014.