Exosome-Mediated Targeted Delivery of miRNAs

Abstract

Many types of cells release phospholipid membrane vesicles that are thought to play key roles in cell-cell communication, antigen presentation, and the spread of infectious agents. These membrane vesicles, derived from the late endosomes, are called exosomes. Various proteins, messenger RNAs (mRNAs), and microRNAs (miRNAs) are carried by exosomes to cells in remote locations, like a message in a bottle. Because they can protect encapsulated small RNAs from ribonucleases (RNases) in body fluid, exosomes represent ideal carriers for nucleic acid drugs. In addition, because exosomes are constructed from self components, they are predicted to have low antigenicity and toxicity, extremely important properties for carriers used in drug delivery. This article describes a protocol for using exosomes as carriers for RNA drug delivery systems.

Exosomes co‐expressing AQP5‐targeting miRNAs and IL‐4 receptor‐binding peptide inhibit the migration of human breast cancer cells

“…This peptide was incorporated into a pDisplay vector, which is a 5.3 kb mammalian expression vector that can display peptides or proteins on the biomembrane. 51 The DNA sequence encoding the IL-4R-binding peptide (IL-4RPep-1: CRKRLDRNC), which was known to have a high affinity toward IL-4R, 36 was inserted into the pDisplay vector ( Figure 5A). To examine whether the transfection of the IL-4RPep-1-expressing pDisplay vector can induce IL-4RPep-1 expression in the HEK293T cells, immunoblotting using antibodies directed against Myc-tag and hemagglutinin A (HA)-tag was performed using membrane Figure 5B).…”

The roles of bone‐derived exosomes and exosomal microRNAs in regulating bone remodelling

“…Thus, the different expression level of specific contents of bone‐derived exosomes might serve as a promising diagnostic and/or prognostic tool to detect early‐stage bone disorders. Furthermore, engineered exosomes represent a promising system that can be used for the targeted delivery of RNAi molecules, while avoiding detection by the immune system . In this way, the transfer of particular ESCRT machinery or miRNAs might facilitate the treatment of bone diseases that are related to aberrant bone remodelling, such as RA, OA and osteoporosis.…”

MicroRNAs as CNS Drug Targets

“…Exogenously prepared exosomes with a carefully chosen miRNA cargo, or containing synthetic siRNAs for silencing specific miRNAs, have the potential to be developed as CNS therapeutics. Exosomes or liposomes represent ideal carriers for nucleic acid drugs [Ohno and Kuroda, ] and may readily pass the blood‐brain barrier [Wood et al, ; El Andaloussi et al, ]. For example, intranasally administered catalase‐loaded exosomes could be detected in mouse brain [Haney et al, ].…”

“…While the role of intracellularly produced miRNAs for modulation of mRNA stability and thereby of transcription has been recognized since over two decades, recent evidence suggests expands their scope as cellular regulators to include intercellular communication. We now know that exosomal‐packaged miRNAs take part in hormone‐like tissue crosstalk, where miRNA produced inside cells following transcription from DNA, packaged and released inside secreted exosomes, may affect transcription, and thereby cellular phenotypes, in another tissue [Gurwitz, ; Ohno and Kuroda, ]. This hormone‐like action suggests miRNAs as novel drug targets in oncology [Milane et al, ; Lugini et al, ].…”