Neddylation of Coro1a determines the fate of multivesicular bodies and biogenesis of extracellular vesicles

As neurons age, they show a decrease in their ability to degrade proteins and membranes. Because undegraded material is a source of toxic products, defects in degradation are associated with reduced cell function and survival. However, there are very few dead neurons in the aging brain, suggesting the action of compensatory mechanisms. We show in this work that ageing neurons in culture show large multivesicular bodies (MVBs) filled with intralumenal vesicles (ILVs) and secrete more small extracellular vesicles than younger neurons. We also show that the high number of ILVs is the consequence of the accumulation of cholesterol in MVBs, which in turn is due to decreased levels of the cholesterol extruding protein NPC1. NPC1 down-regulation is the consequence of a combination of upregulation of the NPC1 repressor microRNA 33, and increased degradation, due to Akt-mTOR targeting of NPC1 to the phagosome. Although releasing more exosomes can be beneficial to old neurons, other cells, neighbouring and distant, can be negatively affected by the waste material they contain.

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Tracheal tube fusion in Drosophila involves release of luminal exosomes from multivesicular bodies

10.1101/2021.08.22.457102 ◽

2021 ◽

Author(s):

Carolina Camelo ◽

Anna Koerte ◽

Thea Jacobs ◽

Peter Robin Hiesinger ◽

Stefan Luschnig

Keyword(s):

Tracheal Tube ◽

Extracellular Vesicles ◽

Multivesicular Bodies ◽

Tracheal Lumen ◽

Tracheal System ◽

Tip Cell ◽

Luminal Membrane ◽

Lysosome Related Organelles ◽

Tip Cells ◽

Development Of Organs

Fusion of endothelial or epithelial tubes is essential for the development of organs like the vertebrate vasculature or the insect tracheal system, but the mechanisms underlying the formation of tubular connections (anastomoses) are not well understood. Tracheal tube fusion in Drosophila is mediated by tip cells that transform into lumenized toroids to connect adjacent tubes. This process depends on the Munc13-4 orthologue Staccato (Stac), which localizes to tip-cell-specific lysosome-related organelles (LROs). We show that tracheal LROs display features of multivesicular bodies (MVBs) and that the tracheal lumen contains membranous extracellular vesicles (EVs), a subset of which carries Stac/Munc13-4 and is associated with tracheal anastomosis sites. The presence of LROs and luminal Stac-EVs depends on the tip-cell-specific GTPase Arl3, suggesting that Stac-EVs derive from fusion of MVBs with the luminal membrane in tip cells during anastomosis formation. The GTPases Rab27 and Rab35 cooperate downstream of Arl3 to promote Stac-MVB formation and tube fusion. We propose that Stac-MVBs act as membrane reservoirs that facilitate lumen fusion in tip cells, in a process regulated by Arl3, Rab27, Rab35, and Stac/Munc13-4.

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Tracheal tube fusion in Drosophila involves release of extracellular vesicles from multivesicular bodies

Journal of Cell Science ◽

10.1242/jcs.259590 ◽

2022 ◽

Author(s):

Carolina Camelo ◽

Anna Körte ◽

Thea Jacobs ◽

Stefan Luschnig

Keyword(s):

Tracheal Tube ◽

Extracellular Vesicles ◽

Intercellular Communication ◽

Cultured Cells ◽

Multivesicular Bodies ◽

Tracheal Lumen ◽

Luminal Membrane ◽

Tip Cells ◽

Drosophila Embryos

Extracellular vesicles (EVs) comprise diverse types of cell-released membranous structures that are thought to play important roles in intercellular communication. While the formation and functions of EVs have been investigated extensively in cultured cells, studies of EVs in vivo have remained scarce. We report here that EVs are present in the developing lumen of tracheal tubes in Drosophila embryos. We defined two distinct EV subpopulations, one of which contains the Munc13-4 homologue Staccato (Stac) and is spatially and temporally associated with tracheal tube fusion (anastomosis) events. The formation of Stac-positive luminal EVs depends on the tracheal tip-cell-specific GTPase Arl3, which is also required for the formation of Stac-positive multivesicular bodies, suggesting that Stac-EVs derive from fusion of Stac-MVBs with the luminal membrane in tip cells during anastomosis formation. The GTPases Rab27 and Rab35 cooperate downstream of Arl3 to promote Stac-MVB formation and tube fusion. We propose that Stac-MVBs act as membrane reservoirs that facilitate tracheal lumen fusion in a process regulated by Arl3, Rab27, Rab35, and Stac/Munc13-4.

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Crossroads of the endosomal machinery: Multivesicular bodies, small extracellular vesicles and autophagy

Trillium Exctracellular Vesicles ◽

10.47184/tev.2020.01.06 ◽

2020 ◽

Vol 2 (1) ◽

pp. 48-53

Author(s):

Julia Christina Gross ◽

Sabnam Parbin

Keyword(s):

Plasma Membrane ◽

Extracellular Vesicles ◽

Physiological Stress ◽

Multivesicular Bodies ◽

Endosomal Trafficking ◽

Primary Role ◽

Endocytic Machinery ◽

Endosomal System ◽

Selection Of

The primary role of endosomal system is endocytic trafficking – to sort out internalized macromolecules and proteins to their destined cellular localizations. Incorporation of sorted cargos into multivesicular bodies (MVBs) confers specificities and determines their fates. This central point of the endosomal trafficking separates MVBs in two directions. The MVB populations fuse either with lysosomes to initiate autophagy or with plasma membrane to release small extracellular vesicles. Factors contributing to the selection of cargo and direction of trafficking incorporate the cells’ metabolic status and stress level. In this review, we discuss the molecular cues responsible for differential cargo sorting into MVBs and trafficking directions of MVBs in the endosomal network. Keywords: Exosomes; degradative MVB; secretory MVB; physiological stress; endocytic machinery; lysosome

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The versatile roles and clinical implications of exosomal mRNAs and microRNAs in cancer

The International Journal of Biological Markers ◽

10.1177/1724600820920293 ◽

2020 ◽

Vol 35 (2) ◽

pp. 3-19 ◽

Cited By ~ 2

Author(s):

Shuli Tang ◽

Siming Yu ◽

Jianan Cheng ◽

Yanqiao Zhang ◽

Xiaoyi Huang

Keyword(s):

Drug Resistance ◽

Cancer Therapy ◽

Clinical Application ◽

Extracellular Vesicles ◽

Intercellular Communication ◽

Bioactive Molecules ◽

Clinical Implications ◽

Multivesicular Bodies ◽

Apoptotic Bodies ◽

Application Potential

Extracellular vesicles (EVs), which include exosomes, microvesicles, and apoptotic bodies, are nanosized structures that are secreted by various cells and act as important mediators in intercellular communication. Recent studies have shown that exosomes carrying bioactive molecules are generated from multivesicular bodies and are present in various body fluids. mRNAs and microRNAs (miRNAs) are encapsulated in exosomes and have been found to be involved in multiple pathophysiological processes. Here, we provide a review of tumor-associated exosomal mRNAs and miRNAs and their roles in metastasis and drug resistance. In particular, we emphasize their clinical application potential as diagnostic and prognostic biomarkers of cancer and in cancer therapy.

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Characterization of RNA in Extracellular Vesicles

Applied Sciences ◽

10.3390/app11167520 ◽

2021 ◽

Vol 11 (16) ◽

pp. 7520

Author(s):

Silvia Fischer ◽

Elisabeth Deindl

Keyword(s):

Extracellular Vesicles ◽

Noncoding Rnas ◽

Circular Rnas ◽

Target Cells ◽

Multivesicular Bodies ◽

Bioactive Lipids ◽

Rna Molecules ◽

Different Types ◽

Endosomal Pathway

Extracellular vesicles (EVs) are important players in the communication between different kinds of cells by delivering their content, consisting of different types of RNA, proteins, bioactive lipids, or signaling nucleotides, into their target cells. Several types of EVs are distinguished: (1) exosomes with sizes from 30 to 150 nm originate from the endosomal pathway and form intracellular multivesicular bodies (MVBs), which fuse to the plasma membrane before their secretion. (2) EVs with sizes ranging from 100 to 1000 nm in diameter are formed during cell surface budding. (3) Apoptotic bodies with diameters from 500 to 2000 nm are released from blebbing of the cell membrane of apoptotic cells. It is well established that various RNA molecules such as coding RNAs and noncoding RNAs (long noncoding RNAs, microRNAs, circular RNAs, and rRNAs) are present in different amounts in EVs depending on the type and origin of EV. Here we will give an overview of methods to isolate different types of EVs and to quantify and characterize different RNA species.

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Extracellular vesicles direct migration by synthesizing and releasing chemotactic signals

The Journal of Cell Biology ◽

10.1083/jcb.201710170 ◽

2018 ◽

Vol 217 (8) ◽

pp. 2891-2910 ◽

Cited By ~ 18

Author(s):

Paul W. Kriebel ◽

Ritankar Majumdar ◽

Lisa M. Jenkins ◽

Hiroshi Senoo ◽

Weiye Wang ◽

...

Keyword(s):

Adenylyl Cyclase ◽

Dictyostelium Discoideum ◽

Extracellular Vesicles ◽

Cyclic Adenosine Monophosphate ◽

Adenosine Monophosphate ◽

Multivesicular Bodies ◽

Signal Relay

Chemotactic signals are relayed to neighboring cells through the secretion of additional chemoattractants. We previously showed in Dictyostelium discoideum that the adenylyl cyclase A, which synthesizes the chemoattractant cyclic adenosine monophosphate (cAMP), is present in the intraluminal vesicles of multivesicular bodies (MVBs) that coalesce at the back of cells. Using ultrastructural reconstructions, we now show that ACA-containing MVBs release their contents to attract neighboring cells. We show that the released vesicles are capable of directing migration and streaming and are central to chemotactic signal relay. We demonstrate that the released vesicles not only contain cAMP but also can actively synthesize and release cAMP to promote chemotaxis. Through proteomic, pharmacological, and genetic approaches, we determined that the vesicular cAMP is released via the ABCC8 transporter. Together, our findings show that extracellular vesicles released by D. discoideum cells are functional entities that mediate signal relay during chemotaxis and streaming.

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Extracellular Vesicles and Their Convergence with Viral Pathways

Advances in Virology ◽

10.1155/2012/767694 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 79

Author(s):

Thomas Wurdinger ◽

NaTosha N. Gatson ◽

Leonora Balaj ◽

Balveen Kaur ◽

Xandra O. Breakefield ◽

...

Keyword(s):

Viral Infection ◽

Extracellular Vesicles ◽

Complex Function ◽

Viral Assembly ◽

Endogenous Retrovirus ◽

Intervention Strategies ◽

Multivesicular Bodies ◽

Virus Release ◽

Viral Origin ◽

Cellular Components

Extracellular vesicles (microvesicles), such as exosomes and shed microvesicles, contain a variety of molecules including proteins, lipids, and nucleic acids. Microvesicles appear mostly to originate from multivesicular bodies or to bud from the plasma membrane. Here, we review the convergence of microvesicle biogenesis and aspects of viral assembly and release pathways. Herpesviruses and retroviruses, amongst others, recruit several elements from the microvesicle biogenesis pathways for functional virus release. In addition, noninfectious pleiotropic virus-like vesicles can be released, containing viral and cellular components. We highlight the heterogeneity of microvesicle function during viral infection, addressing microvesicles that can either block or enhance infection, or cause immune dysregulation through bystander action in the immune system. Finally, endogenous retrovirus and retrotransposon elements deposited in our genomes millions of years ago can be released from cells within microvesicles, suggestive of a viral origin of the microvesicle system or perhaps of an evolutionary conserved system of virus-vesicle codependence. More research is needed to further elucidate the complex function of the various microvesicles produced during viral infection, possibly revealing new therapeutic intervention strategies.

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Nano-Vesicle (Mis)Communication in Senescence-Related Pathologies

Cells ◽

10.3390/cells9091974 ◽

2020 ◽

Vol 9 (9) ◽

pp. 1974

Author(s):

Sherin Saheera ◽

Ajay Godwin Potnuri ◽

Prasanna Krishnamurthy

Keyword(s):

Extracellular Vesicles ◽

Biological Fluids ◽

Critical Role ◽

Biological Information ◽

Multivesicular Bodies ◽

Apoptotic Bodies ◽

Signaling Crosstalk ◽

Progressive Decline ◽

Exosome Biogenesis ◽

And Function

Extracellular vesicles are a heterogeneous group of cell-derived membranous structures comprising of exosomes, apoptotic bodies, and microvesicles. Of the extracellular vesicles, exosomes are the most widely sorted and extensively explored for their contents and function. The size of the nanovesicular structures (exosomes) range from 30 to 140 nm and are present in various biological fluids such as saliva, plasma, urine etc. These cargo-laden extracellular vesicles arise from endosome-derived multivesicular bodies and are known to carry proteins and nucleic acids. Exosomes are involved in multiple physiological and pathological processes, including cellular senescence. Exosomes mediate signaling crosstalk and play a critical role in cell–cell communications. Exosomes have evolved as potential biomarkers for aging-related diseases. Aging, a physiological process, involves a progressive decline of function of organs with a loss of homeostasis and increasing probability of illness and death. The review focuses on the classic view of exosome biogenesis, biology, and age-associated changes. Owing to their ability to transport biological information among cells, the review also discusses the interplay of senescent cell-derived exosomes with the aging process, including the susceptibility of the aging population to COVID-19 infections.

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Distinct role of Sirtuin 1 (SIRT1) and Sirtuin 2 (SIRT2) in inhibiting cargo-loading and release of extracellular vesicles

Scientific Reports ◽

10.1038/s41598-019-56635-0 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Byung Rho Lee ◽

Bethany J. Sanstrum ◽

Yutao Liu ◽

Sang-Ho Kwon

Keyword(s):

Extracellular Vesicles ◽

Sirtuin 1 ◽

Multivesicular Bodies ◽

Vesicle Traffic ◽

Cargo Protein ◽

Extracellular Release ◽

Golgi Network ◽

Protein Deacetylase ◽

Distinct Role

AbstractExosomes, vehicles for intercellular communication, are formed intracellularly within multivesicular bodies (MVBs) and are released upon fusion with the plasma membrane. For their biogenesis, proper cargo loading to exosomes and vesicle traffic for extracellular release are required. Previously we showed that the L-type lectin, LMAN2, limits trans-Golgi Network (TGN)-to-endosomes traffic of GPRC5B, an exosome cargo protein, for exosome release. Here, we identified that the protein deacetylase sirtuin 2 (SIRT2) as a novel interactor of LMAN2. Loss of SIRT2 expression resulted in exosomal release of LMAN2, a Golgi resident protein, along with increased exosomal release of GPRC5B. Furthermore, knockout of SIRT2 increased total number of extracellular vesicles (EVs), indicating increased MVB-to-EV flux. While knockout of SIRT1 increased EV release with enlarged late endolysosome, knockout of SIRT2 did not exhibit endolysosome enlargement for increased EV release. Taken together, our study suggests that SIRT2 regulates cargo loading to MVBs and MVB-to-EV flux through a mechanism distinct from that of SIRT1.

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