microRNA sequencing in rat cardiac fibroblasts and fibroblast-derived exosomes

We found that cardiac fibroblasts produce and secrete exosomes. miRNA profiling and TaqMan qRT-PCR experiments identified miR-21 expression to be higher in cardiac fibroblasts compared to those of miR-21*, whereas in exosomes miR-21* expression was higher compared to miR-21. The purpose of the study was to validate these findings by miRNA sequencing in cardiac fibroblasts and fibroblasts-derived exosomes. Overall design: Neonatal rat cardiac fibroblasts were cultured in DMEM + 1% exosome-depleted FBS for 48h. Conditioned medium was collected and exosomes were purified by several centrifugation and filtration steps, following ultracentrifugation. Afterwards total RNA from cardiac fibroblasts and exosomes was isolated for miRNA sequencing.