Exosomes: Revisiting their role as “garbage bags”

Abstract

In recent years, the term “extracellular vesicle” (EV) has been used to define different types of vesicles released by various cells. It includes plasma membrane‐derived vesicles (ectosomes/microvesicles) and endosome‐derived vesicles (exosomes). Although it remains difficult to evaluate the compartment of origin of the two kinds of vesicles once released, it is critical to discriminate these vesicles because their mode of biogenesis is probably directly related to their physiologic function and/or to the physio‐pathologic state of the producing cell. The purpose of this review is to specifically consider exosome secretion and its consequences in terms of a material loss for producing cells, rather than on the effects of exosomes once they are taken up by recipient cells. I especially describe one putative basic function of exosomes, that is, to convey material out of cells for off‐site degradation by recipient cells. As illustrated by some examples, these components could be evacuated from cells for various reasons, for example, to promote “differentiation” or enhance homeostatic responses. This basic function might explain why so many diseases have made use of the exosomal pathway during pathogenesis.

Engineering of Exosomes to Target Cancer Metastasis

“…However, initially EVs were more widely regarded as ''garbage bags'' for disposal of undesired cellular components. 116 A subset of extracellular vesicles in the 30-150 nm range, which are released from cells upon fusion of an intermediate endocytic compartment called the multivesicular body (MVB) with the plasma membrane, were later defined as exosomes. 93 Exosomes were subsequently found to be specialized for intercellular signaling by carrying proteins, nucleic acids, lipids and metabolic cargo from source cells to neighboring recipient cells or even to distant organs.…”

“…We will only briefly introduce the biogenesis, structure, and contents of exosomes, and their roles in cancer, as several existing review articles have covered these topics. 7,11,40,64,73,75,93,104,116,132 Biogenesis Exosomes are defined as extracellular vesicles originating from the exocytosis of multivesicular endosomes (MVEs) from the plasma membrane of a cell. 35 This exosome biogenesis was discovered by two groups of researchers in the 1980s, with papers published within a week of each other.…”

EVs as Potential New Therapeutic Tool/Target in Gastrointestinal Cancer and HCC

“…Small EVs (sEVs) as exosomes are 50–100 nm in size, endosome-derived membrane vesicles. They are formed when multi-vesicular bodies (MVBs), containing the intraluminal vesicles (ILVs), fuse with the cellular plasma membrane [ 8 , 9 ]. Large EVs (lEVs) as microvesicles (MVs), also referred to as microparticles (MPs) or ectosomes, are typically larger than small EVs (100–1000 nm) and are shed directly from the cell surface [ 8 , 10 ].…”

Liposomes Embedded in Layer by Layer Constructs as Simplistic Exosome Transfer Model

“…The involvement of exosomes in different biological processes has been extensively researched and reviewed [10][11][12][13]. Once considered as "garbage bags" of cells [14], today exosomes are recognized as transport systems that carry and deliver biomolecules to modulate key signaling pathways in cell-to-cell communications [15,16] and the propagation of numerous diseases [17,18]. The exosomes capture is a largely variable event, due to the abundance of extracellular matrix (ECM) components from the donor cells presented at the surface of exosomes among other factors.…”

“…Such system provides a simplistic model for exosome-like vesicles embedded in ECM and allows to study the interactions of these vesicles with other biologics and cells. 14 ,N 14 -tetramethyl-N 1 ,N 14 -ditetradecyltetradecane-1,14-diaminium dibromide (GS14) was a generous gift from Prof. Luis García-Río's Group (USC) and synthesized as described elsewhere [34]. Gold-coated AT-cut quartz crystals were bought from AWSensors (Spain).…”