Integrated transcriptomic and proteomic analysis of the molecular cargo of extracellular vesicles derived from porcine adipose tissue-derived mesenchymal stem cells.

Background: Mesenchymal stromal/stem cell (MSC) transplantation is a promising therapy for tissue regeneration. Extracellular vesicles (EVs) released by MSCs act as their paracrine effectors by delivering proteins and genetic material to recipient cells. To assess how their cargo mediates biological processes that drive their therapeutic effects, we integrated miRNA, mRNA, and protein expression data of EVs from porcine adipose tissue-derived MSCs.

Methods: Simultaneous expression profiles of miRNAs, mRNAs, and proteins were obtained by high-throughput sequencing and LC-MS/MS proteomic analysis in porcine MSCs and their daughter EVs (n = 3 each). TargetScan and ComiR were used to predict miRNA target genes. Functional annotation analysis was performed using DAVID 6.7 database to rank primary gene ontology categories for the enriched mRNAs, miRNA target genes, and proteins. STRING was used to predict associations between mRNA and miRNA target genes.

Results: Differential expression analysis revealed 4 miRNAs, 255 mRNAs, and 277 proteins enriched in EVs versus MSCs (fold change >2, p<0.05). EV-enriched miRNAs target transcription factors (TFs) and EV-enriched mRNAs encode TFs, but TF proteins are not enriched in EVs. Rather, EVs are enriched for proteins that support extracellular matrix remodeling, blood coagulation, inflammation, and angiogenesis.

Conclusions: Porcine MSC-derived EVs contain a genetic cargo of miRNAs and mRNAs that collectively control TF activity in EVs and recipient cells, as well as proteins capable of modulating cellular pathways linked to tissue repair. These properties provide the fundamental basis for considering therapeutic use of EVs in tissue regeneration.