Proteomic profiling of exosomes: Current perspectives

Abstract

Exosomes are 40-100 nm membrane vesicles of endocytic origin secreted by most cell types in vitro. Recent studies have shown that exosomes are also found in vivo in body fluids such as blood, urine, amniotic fluid, malignant ascites, bronchoalveolar lavage fluid, synovial fluid, and breast milk. While the biological function of exosomes is still unclear, they can mediate communication between cells, facilitating processes such as antigen presentation and in trans signaling to neighboring cells. Exosome-like vesicles identified in Drosophila (referred to as argosomes) may be potential vehicles for the spread of morphogens in epithelia. The advent of current MS-based proteomic technologies has contributed significantly to our understanding of the molecular composition of exosomes. In addition to a common set of membrane and cytosolic proteins, it is becoming increasingly apparent that exosomes harbor distinct subsets of proteins that may be linked to cell-type associated functions. The secretion of exosomes by tumor cells and their implication in the transport and propagation of infectious cargo such as prions and retroviruses such as HIV suggest their participation in pathological situations. Interestingly, the recent observation that exosomes contain both mRNA and microRNA, which can be transferred to another cell, and be functional in that new environment, is an exciting new development in the unraveling exosome saga. The present review aims to summarize the physical properties that define exosomes as specific cell-type secreted membrane vesicles.

Different Modalities of Intercellular Membrane Exchanges Mediate Cell-to-cell P-glycoprotein Transfers in MCF-7 Breast Cancer Cells

“…38); even so, a release of exosomes by MCF-7 has been shown (39). Excepting our study and the article of Bebawy et al (25), P-gp was not previously identified in the proteome analysis of exosomes (40). However, another ABC transporter, the MRP2 protein, has been found in exosomes isolated from ovarian carcinoma cells (41).…”

Synapsin I Is an Oligomannose-Carrying Glycoprotein, Acts As an Oligomannose-Binding Lectin, and Promotes Neurite Outgrowth and Neuronal Survival When Released via Glia-Derived Exosomes

“…Mean values Ϯ SEM of three independent experiments are indicated. actin, and GAPDH, which all have been found in exosomes (Simpson et al, 2008), and proteins of the endoplasmic reticulum, such as PDI, were also detected in cell lysates and in exosomes from cultures enriched in cortical astrocytes (Fig. 5C).…”

Reduced body weight in male Tspan8-deficient mice

“…[31][32][33] Recently, TSPAN8 was identified as an exosome component in the human colon cancer cell line HT29 by use of a mass spectrometry-based approach. 34,35 Exosomes have been shown to have a role in communication processes between cells by transporting proteins and mRNA molecules that regulate gene expression in target cells. 36 Indeed, TSPAN8 was recently shown to contribute to the recruitment of proteins and mRNA into exosomes and induce angiogenesis in target tissues.…”