Engineered extracellular vesicle with RAGE-antagonist peptide for delivery of anti-miRNA155 oligonucleotides to inflammatory lung cells

Acute lung injury (ALI) is an inflammatory lung disease. In lungs afflicted with ALI, microRNA-155 (miR-155) is over-expressed, inducing pro-inflammatory cytokines by inhibition of suppressor of cytokine signalling 1 (SOCS1). In addition, receptor for advanced glycation endproducts (RAGEs) are activated, facilitating the expression of pro-inflammatory cytokines. Therefore, anti-miRNA-155 oligonucleotides (AMO155) and a RAGE-antagonist peptide (RAP) have been suggested as effective therapeutics of ALI. In this study, extracellular vesicles (EVs) were developed as a carrier of AMO155 and the RAP for a combination therapy of ALI. RAP-engineered EVs (RAP-EVs) were produced by the expression of a recombinant RAP-Lamp2b fusion protein on the surface. Then, cholesterol-modified AMO155 (AMO155c) was loaded onto the RAP-EV. <i>In vitro</i> assays showed that the RAP-EV delivered AMO155c as efficiently as unmodified EV (Unmod-EV). For <i>in vivo</i> animal experiments, AMO155c-loaded EVs (AMO155c/EVs) were administrated into the ALI models by intratracheal instillation. The results showed that the AMO155c/RAP-EV induced SOCS1 and decreased RAGE expression more efficiently than the control systems. Compared to the controls, the inflammatory responses, such as pro-inflammatory cytokines, were effectively reduced by the AMO155c/RAP-EV. The results indicated that the RAP-EV could be an efficient carrier for the combination therapy of the RAP and AMO155c.