scholarly journals Bardet-Biedl syndrome proteins modulate the release of bioactive extracellular vesicles

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ann-Kathrin Volz ◽  
Alina Frei ◽  
Viola Kretschmer ◽  
António M. de Jesus Domingues ◽  
Rene F. Ketting ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Mammalian Cells ◽  
Primary Cilia ◽  
Biologically Active ◽  
Signalling Pathways ◽  
Disease Pathogenesis ◽  
Bardet Biedl Syndrome ◽  
Physiological Functions ◽  
Ciliary Membrane ◽  
Signalling Molecules

AbstractPrimary cilia are microtubule based sensory organelles important for receiving and processing cellular signals. Recent studies have shown that cilia also release extracellular vesicles (EVs). Because EVs have been shown to exert various physiological functions, these findings have the potential to alter our understanding of how primary cilia regulate specific signalling pathways. So far the focus has been on lgEVs budding directly from the ciliary membrane. An association between cilia and MVB-derived smEVs has not yet been described. We show that ciliary mutant mammalian cells demonstrate increased secretion of small EVs (smEVs) and a change in EV composition. Characterisation of smEV cargo identified signalling molecules that are differentially loaded upon ciliary dysfunction. Furthermore, we show that these smEVs are biologically active and modulate the WNT response in recipient cells. These results provide us with insights into smEV-dependent ciliary signalling mechanisms which might underly ciliopathy disease pathogenesis.

scholarly journals Current understandings of the relationship between extracellular vesicles and cilia

2020 ◽  
Author(s):  
Koji Ikegami ◽  
Faryal Ijaz
Keyword(s):  
Extracellular Vesicles ◽  
Primary Cilium ◽  
Mammalian Cells ◽  
Primary Cilia ◽  
Research Field ◽  
Historical Background ◽  
Unicellular Organism ◽  
The Relationship

Abstract Mammalian cells have a tiny hair-like protrusion on their surface called a primary cilium. Primary cilia are thought to be the antennae for the cells, receiving signals from the environment. In some studies, extracellular vesicles (EVs) were found attached to the surface of the primary cilium. An idea for the phenomenon is that the primary cilium is the receptor for receiving the EVs. Meanwhile, a unicellular organism, Chlamydomonas, which has two long cilia, usually called flagella, release EVs termed ectosomes from the surface of the flagella. Accumulating evidence suggests that the primary cilium also functions as the ‘emitter’ of EVs. Physiological and pathological impacts are also elucidated for the release of EVs from primary cilia. However, the roles of released cilia-derived EVs remain to be clarified. This review introduces the historical background of the relationship between EVs and cilia, and recent progresses in the research field.

scholarly journals Horizontal Transmission of Cytosolic Sup35 Prions by Extracellular Vesicles

mBio ◽  
2016 ◽  
Vol 7 (4) ◽  
Author(s):  
Shu Liu ◽  
André Hossinger ◽  
Julia P. Hofmann ◽  
Philip Denner ◽  
Ina M. Vorberg
Keyword(s):  
Extracellular Vesicles ◽  
Mammalian Cells ◽  
Information Transfer ◽  
Quaternary Structure ◽  
Horizontal Transmission ◽  
Biologically Active ◽  
Host Cells ◽  
Transmissible Spongiform Encephalopathies ◽  
Yeast Prion ◽  
Long Distance

ABSTRACT Prions are infectious protein particles that replicate by templating their aggregated state onto soluble protein of the same type. Originally identified as the causative agent of transmissible spongiform encephalopathies, prions in yeast ( Saccharomyces cerevisiae ) are epigenetic elements of inheritance that induce phenotypic changes of their host cells. The prototype yeast prion is the translation termination factor Sup35. Prions composed of Sup35 or its modular prion domain NM are heritable and are transmitted vertically to progeny or horizontally during mating. Interestingly, in mammalian cells, protein aggregates derived from yeast Sup35 NM behave as true infectious entities that employ dissemination strategies similar to those of mammalian prions. While transmission is most efficient when cells are in direct contact, we demonstrate here that cytosolic Sup35 NM prions are also released into the extracellular space in association with nanometer-sized membrane vesicles. Importantly, extracellular vesicles are biologically active and are taken up by recipient cells, where they induce self-sustained Sup35 NM protein aggregation. Thus, in mammalian cells, extracellular vesicles can serve as dissemination vehicles for protein-based epigenetic information transfer. IMPORTANCE Prions are proteinaceous infectious particles that propagate by templating their quaternary structure onto nascent proteins of the same kind. Prions in yeast act as heritable epigenetic elements that can alter the phenotype when transmitted to daughter cells or during mating. Prion activity is conferred by so-called prion domains often enriched in glutamine and asparagine residues. Interestingly, many mammalian proteins also contain domains with compositional similarity to yeast prion domains. We have recently provided a proof-of-principle demonstration that a yeast prion domain also retains its prion activity in mammalian cells. We demonstrate here that cytosolic prions composed of a yeast prion domain are also packaged into extracellular vesicles that transmit the prion phenotype to bystander cells. Thus, proteins with prion-like domains can behave as proteinaceous information molecules that exploit the cellular vesicle trafficking machinery for intercellular long-distance dissemination.

scholarly journals Transient accumulation and bidirectional movement of KIF13B in primary cilia

2021 ◽  
Author(s):  
Alice Dupont Juhl ◽  
Zeinab Anvarian ◽  
Julia Berges ◽  
Daniel Wustner ◽  
Lotte B Pedersen
Keyword(s):  
Mammalian Cells ◽  
Live Cell Imaging ◽  
Primary Cilia ◽  
Cell Imaging ◽  
Intraflagellar Transport ◽  
Cytoplasmic Dynein ◽  
Ciliary Membrane ◽  
Bidirectional Movement ◽  
And Function ◽  
Male Specific

Primary cilia are microtubule-based sensory organelles whose assembly and function rely on the conserved bidirectional intraflagellar transport (IFT) system, which is powered by anterograde kinesin-2 and retrograde cytoplasmic dynein 2 motors. Nematodes additionally employ a male-specific kinesin-3 motor, KLP-6, which regulates ciliary content and function by promoting release of bioactive extracellular vesicles (EVs) from cilia. Here we show by live cell imaging that a KLP-6 homolog, KIF13B, undergoes bursts of bidirectional movement within primary cilia of cultured mammalian cells at 0.64 +/- 0.07 μm/s in the anterograde direction and at 0.39 +/- 0.06 μm/s in the retrograde direction, reminiscent of conventional IFT. In addition, we found that KIF13B undergoes EV-like release from the ciliary tip whereas a ciliary membrane marker, SMO-tRFP, remains stably associated with cilia during such EV release. Our results suggest that KIF13B, similar to KLP-6, regulates ciliary membrane content by promoting ciliary EV release, possibly in coordination with conventional IFT.

scholarly journals Extracellular Vesicles: Novel Opportunities to Understand and Detect Neoplastic Diseases

2021 ◽  
pp. 030098582199932
Author(s):  
Laura Bongiovanni ◽  
Anneloes Andriessen ◽  
Marca H. M. Wauben ◽  
Esther N. M. Nolte-’t Hoen ◽  
Alain de Bruin
Keyword(s):  
Extracellular Vesicles ◽  
Biologically Active ◽  
Liquid Biopsies ◽  
Donor Cells ◽  
Recent Developments ◽  
Veterinary Pathology ◽  
Cell Components ◽  
Potential Applications ◽  
Intercellular Communications

With a size range from 30 to 1000 nm, extracellular vesicles (EVs) are one of the smallest cell components able to transport biologically active molecules. They mediate intercellular communications and play a fundamental role in the maintenance of tissue homeostasis and pathogenesis in several types of diseases. In particular, EVs actively contribute to cancer initiation and progression, and there is emerging understanding of their role in creation of the metastatic niche. This fact underlies the recent exponential growth in EV research, which has improved our understanding of their specific roles in disease and their potential applications in diagnosis and therapy. EVs and their biomolecular cargo reflect the state of the diseased donor cells, and can be detected in body fluids and exploited as biomarkers in cancer and other diseases. Relatively few studies have been published on EVs in the veterinary field. This review provides an overview of the features and biology of EVs as well as recent developments in EV research including techniques for isolation and analysis, and will address the way in which the EVs released by diseased tissues can be studied and exploited in the field of veterinary pathology. Uniquely, this review emphasizes the important contribution that pathologists can make to the field of EV research: pathologists can help EV scientists in studying and confirming the role of EVs and their molecular cargo in diseased tissues and as biomarkers in liquid biopsies.

Macrophages produce somnogenic and pyrogenic muramyl peptides during digestion of staphylococci

1991 ◽  
Vol 260 (1) ◽  
pp. R126-R133 ◽  
Author(s):  
L. Johannsen ◽  
J. Wecke ◽  
F. Obal ◽  
J. M. Krueger
Keyword(s):  
Immune Response ◽  
Body Temperature ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Mammalian Cells ◽  
Slow Wave Sleep ◽  
Biological Effects ◽  
Biologically Active ◽  
Chromatographic Behavior ◽  
Bacterial Cell Walls

Muramyl peptides have a variety of biological effects in mammals, including enhancement of the immune response, sleep, and body temperature. Although mammals lack biosynthetic pathways for muramyl peptides, they are found in mammals and are well known as components of bacterial cell walls. This suggests that phagocytic mammalian cells digest bacterial cell walls and produce biologically active muramyl peptides. Staphylococcal cell walls were radioactively labeled during growth of the bacteria. During the digestion of these radiolabeled bacteria, murine bone marrow macrophages produced low-molecular-weight substances that coeluted chromatographically with the radioactive cell wall marker. Further separation of these substances using reversed-phase high-performance liquid chromatography resulted in the isolation of substances with high specific biological activity. Intracerebroventricular injection of rabbits with these substances induced an increase in slow-wave sleep and body temperature and a suppression of rapid-eye-movement sleep. The characteristics of the biological responses and the chromatographic behavior of the active components are consistent with those of muramyl peptides. The ability of macrophages to tailor muramyl peptides from peptidoglycan may provide an amplification step for the immune response. Muramyl peptides released by macrophages may also act as mediators for various facets of the acute phase response elicited by bacterial infections such as fever and sleep.

scholarly journals Trafficking to the primary cilium membrane

2017 ◽  
Vol 28 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Saikat Mukhopadhyay ◽  
Hemant B. Badgandi ◽  
Sun-hee Hwang ◽  
Bandarigoda Somatilaka ◽  
Issei S. Shimada ◽  
...  
Keyword(s):  
Membrane Proteins ◽  
Signaling Pathways ◽  
Primary Cilium ◽  
Hedgehog Signaling ◽  
Diffusion Barriers ◽  
Disease Pathogenesis ◽  
Ciliary Membrane ◽  
Multiple Organs ◽  
Sensory Reception

The primary cilium has been found to be associated with a number of cellular signaling pathways, such as vertebrate hedgehog signaling, and implicated in the pathogenesis of diseases affecting multiple organs, including the neural tube, kidney, and brain. The primary cilium is the site where a subset of the cell's membrane proteins is enriched. However, pathways that target and concentrate membrane proteins in cilia are not well understood. Processes determining the level of proteins in the ciliary membrane include entry into the compartment, removal, and retention by diffusion barriers such as the transition zone. Proteins that are concentrated in the ciliary membrane are also localized to other cellular sites. Thus it is critical to determine the particular role for ciliary compartmentalization in sensory reception and signaling pathways. Here we provide a brief overview of our current understanding of compartmentalization of proteins in the ciliary membrane and the dynamics of trafficking into and out of the cilium. We also discuss major unanswered questions regarding the role that defects in ciliary compartmentalization might play in disease pathogenesis. Understanding the trafficking mechanisms that underlie the role of ciliary compartmentalization in signaling might provide unique approaches for intervention in progressive ciliopathies.

Cell surface interactions in conjugation: Tetrahymena ciliary membrane vesicles

1984 ◽  
Vol 4 (4) ◽  
pp. 681-687
Author(s):  
B Love ◽  
M B Rotheim
Keyword(s):  
Cell Surface ◽  
Mating Type ◽  
Mammalian Cells ◽  
Membrane Vesicles ◽  
Surface Interactions ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Ciliary Membrane ◽  
Adhesion Sites ◽  
Cell Surface Interactions

Tetrahymena ciliary membrane vesicles are shown to interact with preconjugant cells in a mating type-specific way. When cells are treated with vesicles of a different mating type before mixing for conjugation, cell pairing is enhanced, and the normal prepairing period is partially eliminated. This enhancement is mating type specific since it is not observed after pretreatment of cells with vesicles of their own mating type. In contrast, when vesicles are added at the time of mixing of two starved cultures, cell pairing is delayed in a concentration-dependent manner. By varying the conditions, we demonstrated enhancement or inhibition, or both. These results are interpreted in terms of two independent interactions of cells with vesicles. We suggest that first, vesicles substitute for another cell in cell-cell prepairing interaction and second, vesicles compete for adhesion sites produced during the prepairing period. Finally, the data presented are summarized within a speculative framework that calls attention to potential analogies with hormone-receptor signaling in mammalian cells.

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