LAMP2A regulates the loading of proteins into exosomes.

Exosomes are extracellular vesicles of endosomal origin released by virtually all cell types across metazoans. Exosomes are active vehicles of intercellular communication and can transfer lipids, RNAs and proteins between different cells, tissues or organs. However, the mechanisms that regulate the selective loading of cytosolic proteins into these vesicles are still largely unknow. Here we describe a mechanism whereby proteins containing a pentapeptide sequence, biochemically related to the KFERQ-motif, are loaded into a subpopulation of exosomes in a process that is dependent on the membrane protein LAMP2A. Moreover, this mechanism is independent of the ESCRT machinery components TSG101 and VPS4b and dependent on HSC70, CD63, Alix, Syntenin-1, Rab31 and ceramides. The transcription factor and master regulator of hypoxia HIF1A is loaded into exosomes by this mechanism to transport hypoxia signaling to normoxic cells. Additionally, by tagging fluorescent proteins with KFERQ-like sequences we were able to follow inter-organ transfer of exosomes in zebrafish larvae. Our findings identify LAMP2A as a key component in exosome biogenesis while opening new avenues for exosome engineering by allowing the loading of bioactive proteins by tagging them with KFERQ-like motifs.

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To be or not to be... secreted as exosomes, a balance finely tuned by the mechanisms of biogenesis

Essays in Biochemistry ◽

10.1042/ebc20170076 ◽

2018 ◽

Vol 62 (2) ◽

pp. 177-191 ◽

Cited By ~ 24

Author(s):

Roberta Palmulli ◽

Guillaume van Niel

Keyword(s):

Extracellular Vesicles ◽

Intercellular Communication ◽

Intracellular Trafficking ◽

Membrane Vesicles ◽

Lysosomal Degradation ◽

Trafficking Pathway ◽

Exosome Biogenesis ◽

Cargo Proteins ◽

Communication Pathway ◽

Multivesicular Endosomes

The release of extracellular vesicles such as exosomes provides an attractive intercellular communication pathway. Exosomes are 30- to 150-nm membrane vesicles that are generated in endosomal compartment and act as intercellular mediators in both physiological and pathological context. Despite the growing interest in exosome functions, the mechanisms responsible for their biogenesis and secretion are still not completely understood. Knowledge about these mechanisms is important because they control the composition, and hence the function and secretion, of exosomes. Exosomes are produced as intraluminal vesicles in extremely dynamic endosomal organelles, which undergo various maturation processes in order to form multivesicular endosomes. Notably, the function of multivesicular endosomes is balanced between exosome secretion and lysosomal degradation. In the present review, we present and discuss each intracellular trafficking pathway that has been reported or proposed as regulating exosome biogenesis, with a particular focus on the importance of endosomal dynamics in sorting out cargo proteins to exosomes and to the secretion of multivesicular endosomes. An overall picture reveals several key mechanisms, which mainly act at the crossroads of endosomal pathways as regulatory checkpoints of exosome biogenesis.

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The Emerging Role of Extracellular Vesicles in the Glioma Microenvironment: Biogenesis and Clinical Relevance

Cancers ◽

10.3390/cancers12071964 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1964

Author(s):

Anjali Balakrishnan ◽

Sabrina Roy ◽

Taylor Fleming ◽

Hon S. Leong ◽

Carol Schuurmans

Keyword(s):

Tumor Progression ◽

Extracellular Vesicles ◽

Intercellular Communication ◽

Cell Types ◽

Disease Diagnosis ◽

Neural Cells ◽

Cell Of Origin ◽

Cell Type Specificity ◽

Normal Cells ◽

Mediate Cell

Gliomas are a diverse group of brain tumors comprised of malignant cells (‘tumor’ cells) and non-malignant ‘normal’ cells, including neural (neurons, glia), inflammatory (microglia, macrophage) and vascular cells. Tumor heterogeneity arises in part because, within the glioma mass, both ‘tumor’ and ‘normal’ cells secrete factors that form a unique microenvironment to influence tumor progression. Extracellular vesicles (EVs) are critical mediators of intercellular communication between immediate cellular neighbors and distantly located cells in healthy tissues/organs and in tumors, including gliomas. EVs mediate cell–cell signaling as carriers of nucleic acid, lipid and protein cargo, and their content is unique to cell types and physiological states. EVs secreted by non-malignant neural cells have important physiological roles in the healthy brain, which can be altered or co-opted to promote tumor progression and metastasis, acting in combination with glioma-secreted EVs. The cell-type specificity of EV content means that ‘vesiculome’ data can potentially be used to trace the cell of origin. EVs may also serve as biomarkers to be exploited for disease diagnosis and to assess therapeutic progress. In this review, we discuss how EVs mediate intercellular communication in glioma, and their potential role as biomarkers and readouts of a therapeutic response.

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Tumor-Derived Extracellular Vesicles: A Means of Co-opting Macrophage Polarization in the Tumor Microenvironment

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.746432 ◽

2021 ◽

Vol 9 ◽

Author(s):

Theodore Reed ◽

Jeffrey Schorey ◽

Crislyn D’Souza-Schorey

Keyword(s):

Tumor Microenvironment ◽

Extracellular Vesicles ◽

Immune Modulation ◽

Macrophage Polarization ◽

Cell Types ◽

Heterogeneous Population ◽

Functional Plasticity ◽

Bioactive Proteins ◽

Membrane Bound ◽

Almost All

Extracellular vesicles (EVs) are a heterogeneous population of membrane-bound parcels of bioactive proteins, nucleic acids, and lipids released from almost all cell types. The diversity of cargo packaged into EVs proffer the induction of an array of effects on recipient cells. EVs released from tumor cells have emerged as a vital means of communication and immune modulation within the tumor microenvironment (TME). Macrophages are an important contributor to the TME with seemingly paradoxical roles promoting either pro- or anti-tumoral immune function depending on their activated phenotypes. Here, we discuss the influence of tumor-derived extracellular vesicles on the functional plasticity of macrophages in tumor progression.

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Brain-Derived Extracellular Vesicles are Highly Enriched in the Prion Protein and Its C1 Fragment: Relevance for Cellular Uptake and Implications in Stroke

10.1101/850099 ◽

2019 ◽

Cited By ~ 1

Author(s):

Santra Brenna ◽

Hermann C. Altmeppen ◽

Behnam Mohammadi ◽

Björn Rissiek ◽

Florence Schlink ◽

...

Keyword(s):

Prion Protein ◽

Extracellular Vesicles ◽

Cellular Uptake ◽

Intercellular Communication ◽

Cell Types ◽

Brain Cell ◽

Surface Proteins ◽

Therapeutic Interventions ◽

Ischemic Region ◽

Brain Artery

ABSTRACTExtracellular vesicles (EVs) are important means of intercellular communication and a potent tool for regenerative therapy. In ischemic stroke, transient blockage of a brain artery leads to a lack of glucose and oxygen in the affected brain tissue, provoking neuronal death by necrosis in the core of the ischemic region. The fate of neurons in the surrounding penumbra depends on the stimuli, including EVs, received during the following hours. A detailed characterization of such stimuli is crucial not only for understanding stroke pathophysiology but also for new therapeutic interventions.In the present study, we characterize the EVs in mouse brain under physiological conditions and 24h after induction of transient ischemia in mice. We show that, in steady-state conditions, microglia are the main source of small EVs (sEVs) whereas after ischemia, the main EV population originates from astrocytes. Moreover, sEVs presented high amounts of the prion protein (PrP) which were increased after stroke. Conspicuously, sEVs were particularly enriched in a truncated PrP fragment (PrP-C1). Because of similarities between PrP-C1 and certain viral surface proteins, we studied the cellular uptake of brain-derived sEVs from mice lacking (PrP-KO) or containing PrP (WT). We show that PrP-KO-EVs are rapidly taken up by neurons and colocalize with lysosomes. Although eventually WT-EVs are also found in lysosomes, the amount taken up by neurons is significantly higher for PrP-KO-EVs. Likewise, microglia and astrocytes were also engulfing PrP-KO-sEVs more efficiently than WT-sEVs.Our results provide information on the relative contribution of brain cell types to the sEV pool in mice and indicate that increased release of sEVs by astrocytes together with elevated levels of PrP in sEVs may play a role in intercellular communication at early stages after stroke. In addition, amounts of PrP (and probably PrP-C1) in brain sEVs seem to contribute to their cellular uptake.

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Connexin-46 Contained in Extracellular Vesicles Enhance Malignancy Features in Breast Cancer Cells

Biomolecules ◽

10.3390/biom10050676 ◽

2020 ◽

Vol 10 (5) ◽

pp. 676 ◽

Cited By ~ 3

Author(s):

Rodrigo A. Acuña ◽

Manuel Varas-Godoy ◽

Viviana M. Berthoud ◽

Ivan E. Alfaro ◽

Mauricio A. Retamal

Keyword(s):

Breast Cancer ◽

Cancer Cells ◽

Extracellular Vesicles ◽

Intercellular Communication ◽

Breast Cancer Cells ◽

Recipient Cell ◽

Cell Types ◽

Migration And Invasion ◽

Long Distance ◽

Cancer Aggressiveness

Under normal conditions, almost all cell types communicate with their neighboring cells through gap junction channels (GJC), facilitating cellular and tissue homeostasis. A GJC is formed by the interaction of two hemichannels; each one of these hemichannels in turn is formed by six subunits of transmembrane proteins called connexins (Cx). For many years, it was believed that the loss of GJC-mediated intercellular communication was a hallmark in cancer development. However, nowadays this paradigm is changing. The connexin 46 (Cx46), which is almost exclusively expressed in the eye lens, is upregulated in human breast cancer, and is correlated with tumor growth in a Xenograft mouse model. On the other hand, extracellular vesicles (EVs) have an important role in long-distance communication under physiological conditions. In the last decade, EVs also have been recognized as key players in cancer aggressiveness. The aim of this work was to explore the involvement of Cx46 in EV-mediated intercellular communication. Here, we demonstrated for the first time, that Cx46 is contained in EVs released from breast cancer cells overexpressing Cx46 (EVs-Cx46). This EV-Cx46 facilitates the interaction between EVs and the recipient cell resulting in an increase in their migration and invasion properties. Our results suggest that EV-Cx46 could be a marker of cancer malignancy and open the possibility to consider Cx46 as a new therapeutic target in cancer treatment.

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Apoptotic Bodies: Particular Extracellular Vesicles Involved in Intercellular Communication

Biology ◽

10.3390/biology9010021 ◽

2020 ◽

Vol 9 (1) ◽

pp. 21 ◽

Cited By ~ 13

Author(s):

Michela Battistelli ◽

Elisabetta Falcieri

Keyword(s):

Extracellular Vesicles ◽

Intercellular Communication ◽

Genetic Information ◽

Cell Communication ◽

Cell Types ◽

Apoptotic Bodies ◽

Species Barrier ◽

Physiological Conditions ◽

Different Types ◽

Different Cell Types

In the last decade, a new method of cell–cell communication mediated by membranous extracellular vesicles (EVs) has emerged. EVs, including exosomes, microvesicles, and apoptotic bodies (ApoBDs), represent a new and important topic, because they are a means of communication between cells and they can also be involved in removing cellular contents. EVs are characterized by differences in size, origin, and content and different types have different functions. They appear as membranous sacs released by a variety of cells, in different physiological and patho-physiological conditions. Intringuingly, exosomes and microvesicles are a potent source of genetic information carriers between different cell types both within a species and even across a species barrier. New, and therefore still relatively poorly known vesicles are apoptotic bodies, on which numerous in-depth studies are needed in order to understand their role and possible function. In this review we would like to analyze their morpho-functional characteristics.

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Extracellular Vesicles from Healthy Cells Improves Cell Function and Stemness in Premature Senescent Stem Cells by miR-302b and HIF-1α Activation

Biomolecules ◽

10.3390/biom10060957 ◽

2020 ◽

Vol 10 (6) ◽

pp. 957

Author(s):

Cristina Mas-Bargues ◽

Jorge Sanz-Ros ◽

Aurora Román-Domínguez ◽

Lucia Gimeno-Mallench ◽

Marta Inglés ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Extracellular Vesicles ◽

Intercellular Communication ◽

Cell Function ◽

Cell Types ◽

Culture Conditions ◽

Target Cells ◽

Activity Levels ◽

Functional Changes

Aging is accompanied by the accumulation of senescent cells that alter intercellular communication, thereby impairing tissue homeostasis and reducing organ regenerative potential. Recently, the administration of mesenchymal stem cells (MSC)-derived extracellular vesicles has proven to be more effective and less challenging than current stem cell-based therapies. Extracellular vesicles (EVs) contain a cell-specific cargo of proteins, lipids and nucleic acids that are released and taken up by probably all cell types, thereby inducing functional changes via the horizontal transfer of their cargo. Here, we describe the beneficial properties of extracellular vesicles derived from non-senescent MSC, cultured in a low physiological oxygen tension (3%) microenvironment into prematurely senescent MSC, cultured in a hyperoxic ambient (usual oxygen culture conditions, i.e., 21%). We observed that senescent MCS, treated with EVs from non-senescent MCS, showed reduced SA-β-galactosidase activity levels and pluripotency factor (OCT4, SOX2, KLF4 and cMYC, or OSKM) overexpression and increased glycolysis, as well as reduced oxidative phosphorylation (OXPHOS). Moreover, these EVs’ cargo induced the upregulation of miR-302b and HIF-1α levels in the target cells. We propose that miR-302b triggered HIF-1α upregulation, which in turn activated different pathways to delay premature senescence, improve stemness and switch energetic metabolism towards glycolysis. Taken together, we suggest that EVs could be a powerful tool to restore altered intercellular communication and improve stem cell function and stemness, thus delaying stem cell exhaustion in aging.

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Extracellular Vesicles in Blood: Sources, Effects and Applications

International Journal of Molecular Sciences ◽

10.3390/ijms22158163 ◽

2021 ◽

Vol 22 (15) ◽

pp. 8163

Author(s):

Ainhoa Alberro ◽

Leire Iparraguirre ◽

Adelaide Fernandes ◽

David Otaegui

Keyword(s):

Extracellular Vesicles ◽

Intercellular Communication ◽

Blood Cells ◽

Circulatory System ◽

Cell Types ◽

Treatment Monitoring ◽

Body Fluids ◽

Comprehensive Overview ◽

Isolation And Characterization ◽

Almost All

Extracellular vesicles (EVs) are important players for intercellular communication. EVs are secreted by almost all cell types; they can transfer information between nearby or distant cells, and they are highly abundant in body fluids. In this review, we describe the general characteristics of EVs, as well as isolation and characterization approaches. Then, we focus on one of the most relevant sources of EVs: the blood. Indeed, apart from EVs secreted by blood cells, EVs of diverse origins travel in the bloodstream. We present the numerous types of EVs that have been found in circulation. Besides, the implications of blood-derived EVs in both physiological and pathological processes are summarized, highlighting their potential as biomarkers for the diagnosis, treatment monitoring, and prognosis of several diseases, and also as indicators of physiological modifications. Finally, the applications of EVs introduced in the circulatory system are discussed. We describe the use of EVs from distinct origins, naturally produced or engineered, autologous, allogeneic, or even from different species and the effects they have when introduced in circulation. Therefore, the present work provides a comprehensive overview of the components, effects, and applications of EVs in blood.

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Fostering “Education”: Do Extracellular Vesicles Exploit Their Own Delivery Code?

Cells ◽

10.3390/cells10071741 ◽

2021 ◽

Vol 10 (7) ◽

pp. 1741

Author(s):

Mayra Paolillo ◽

Sergio Comincini ◽

Sergio Schinelli

Keyword(s):

Extracellular Vesicles ◽

Intercellular Communication ◽

Surface Membrane ◽

Cell Types ◽

Future Research ◽

Target Cells ◽

Bioinformatic Tools ◽

Experimental Approaches ◽

Different Cell Types

Extracellular vesicles (EVs), comprising large microvesicles (MVs) and exosomes (EXs), play a key role in intercellular communication, both in physiological and in a wide variety of pathological conditions. However, the education of EV target cells has so far mainly been investigated as a function of EX cargo, while few studies have focused on the characterization of EV surface membrane molecules and the mechanisms that mediate the addressability of specific EVs to different cell types and tissues. Identifying these mechanisms will help fulfill the diagnostic, prognostic, and therapeutic promises fueled by our growing knowledge of EVs. In this review, we first discuss published studies on the presumed EV “delivery code” and on the combinations of the hypothesized EV surface membrane “sender” and “recipient” molecules that may mediate EV targeting in intercellular communication. Then we briefly review the main experimental approaches and techniques, and the bioinformatic tools that can be used to identify and characterize the structure and functional role of EV surface membrane molecules. In the final part, we present innovative techniques and directions for future research that would improve and deepen our understandings of EV-cell targeting.

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