Figure 2.

Characterisation of microRNA in healthy and infected endothelial cells (A). Total RNA was extracted and isolated from healthy and S. aureus infected endothelial exosomes using Total Exosome RNA & Protein Isolation Kit and quantified using an AATI fragment analyser. This yielded a comprehensive miRNA expression profile for healthy and S. aureus infected endothelial exosomes. Individual miRNA expression data were calculated using the comparative cycle threshold (2-ΔΔCt) method, which indicated a significant increase in smRNA composition as a result of S. aureus infection (B) Differential expression of four upregulated and downregulated miRNA shown by fold change, with significantly high levels observed for miR-99b relative to healthy endothelial exosomes. (C) miR-99a and miR-99b levels in infected endothelial exosomes were validated using individual real-time PCR. Significant changes in both miRNAs were observed, with a 5.11-fold increase in miR-99a expression and a 38.82-fold increase in miR-99b expression. Data is representative of 4 independent experiments, as mean ± SEM. Statistics were performed using a two-tailed paired t-test, (*p<0.05, ***p<0.0001). NS, not significant.