scholarly journals Ciliary Rab28 and the BBSome negatively regulate extracellular vesicle shedding

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Jyothi S Akella ◽  
Stephen P Carter ◽  
Ken Nguyen ◽  
Sofia Tsiropoulou ◽  
Ailis L Moran ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
G Protein ◽  
Extracellular Vesicles ◽  
Autosomal Recessive ◽  
Extracellular Vesicle ◽  
Cell Tissue ◽  
Specific Manner ◽  
Communication Devices ◽  
Vesicle Shedding

Cilia both receive and send information, the latter in the form of extracellular vesicles (EVs). EVs are nano-communication devices that influence cell, tissue, and organism behavior. Mechanisms driving ciliary EV biogenesis are almost entirely unknown. Here, we show that the ciliary G-protein Rab28, associated with human autosomal recessive cone-rod dystrophy, negatively regulates EV levels in the sensory organs of Caenorhabditis elegans in a cilia specific manner. Sequential targeting of lipidated Rab28 to periciliary and ciliary membranes is highly dependent on the BBSome and the prenyl-binding protein phosphodiesterase 6 subunit delta (PDE6D), respectively, and BBSome loss causes excessive and ectopic EV production. We also find that EV defective mutants display abnormalities in sensory compartment morphogenesis. Together, these findings reveal that Rab28 and the BBSome are key in vivo regulators of EV production at the periciliary membrane and suggest that EVs may mediate signaling between cilia and glia to shape sensory organ compartments. Our data also suggest that defects in the biogenesis of cilia-related EVs may contribute to human ciliopathies.

scholarly journals A ciliary BBSome-ARL-6-PDE6D pathway trafficks RAB-28, a negative regulator of extracellular vesicle biogenesis

2019 ◽  
Author(s):  
Jyothi S. Akella ◽  
Stephen P. Carter ◽  
Fatima Rizvi ◽  
Ken C.Q. Nguyen ◽  
Sofia Tsiropoulou ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
G Protein ◽  
Autosomal Recessive ◽  
Extracellular Vesicle ◽  
Negative Regulator ◽  
Cell Tissue ◽  
Communication Devices ◽  
Vesicle Biogenesis ◽  
Ciliated Neurons

ABSTRACTCilia both receive and send information, the latter in the form of extracellular vesicles (EVs). EVs are nano-communication devices that cells shed to influence cell, tissue, and organism behavior. Mechanisms driving ciliary EV biogenesis and environment release are almost entirely unknown. Here, we show that the ciliary G-protein RAB28, associated with human autosomal recessive cone-rod dystrophy, negatively regulates EV levels in the sensory organs of Caenorhabditis elegans. We also find that sequential targeting of lipidated RAB28 to periciliary and ciliary membranes is highly dependent on the BBSome and PDE6D, respectively, and that BBSome loss causes excessive and ectopic EV production. Our data indicate that RAB28 and the BBSome are key in vivo regulators of EV production at the periciliary membrane. Our findings also suggest that EVs control sensory organ homeostasis by mediating communication between ciliated neurons and glia, and that defects in ciliary EV biogenesis may contribute to human ciliopathies.

scholarly journals Microvilli-derived Extracellular Vesicles Govern Morphogenesis in Drosophila wing epithelium

2020 ◽  
Author(s):  
Ilse Hurbain ◽  
Anne-Sophie Macé ◽  
Maryse Romao ◽  
Lucie Sengmanivong ◽  
Laurent Ruel ◽  
...  
Keyword(s):  
Long Range ◽  
Extracellular Vesicles ◽  
Cell Biology ◽  
Extracellular Vesicle ◽  
Wing Disc ◽  
Cellular Mechanisms ◽  
Long Distance ◽  
Drosophila Wing ◽  
And Function

ABSTRACTThe regulation and coordination of developmental processes involves the secretion of morphogens and membrane carriers, including extracellular vesicles, which facilitate their transport over long distance. The long-range activity of the Hedgehog morphogen is conveyed by extracellular vesicles. However, the site and the molecular basis of their biogenesis remains unknown. By combining fluorescence and electron microscopy combined with genetics and cell biology approaches, we investigated the origin and the cellular mechanisms underlying extracellular vesicle biogenesis, and their contribution to Drosophila wing disc development, exploiting Hedgehog as a long-range morphogen. We show that microvilli of Drosophila wing disc epithelium are the site of generation of small extracellular vesicles that transport Hedgehog across the tissue. This process requires the Prominin-like protein, whose activity, together with interacting cytoskeleton components and lipids, is critical for maintaining microvilli integrity and function in secretion. Our results provide the first evidence that microvilli-derived extracellular vesicles contribute to Hedgehog long-range signaling activity highlighting their physiological significance in tissue development in vivo.

scholarly journals Therapeutic plasma exchange clears circulating soluble PD-L1 and PD-L1-positive extracellular vesicles

2020 ◽  
Vol 8 (2) ◽  
pp. e001113
Author(s):  
Jacob J Orme ◽  
Elizabeth Ann L Enninga ◽  
Fabrice Lucien-Matteoni ◽  
Heather Dale ◽  
Edwin Burgstaler ◽  
...  
Keyword(s):  
Plasma Exchange ◽  
Extracellular Vesicles ◽  
Poor Prognosis ◽  
Checkpoint Inhibitors ◽  
Clinical Intervention ◽  
Extracellular Vesicle ◽  
Therapeutic Plasma Exchange ◽  
Programmed Death Ligand 1 ◽  
Programmed Death

BackgroundTrans-acting programmed death-ligand 1 (PD-L1) derives from malignant cells in three known forms. High levels of secreted splice variant PD-L1 (sPD-L1), ADAM10/ADAM17-shed sPD-L1, and PD-L1-positive extracellular vesicles (evPD-L1) each predict poor prognosis and limited response to PD-(L)1 checkpoint inhibitors in cancer. To our knowledge, no clinical intervention has reduced any of these circulating forms of extracellular PD-L1. Here, we explore therapeutic plasma exchange (TPE) as a treatment to reduce circulating extracellular PD-L1.ResultsIn patients with melanoma, sPD-L1 levels above 0.277 ng/mL predicted inferior overall survival. In patients undergoing TPE for non-malignant indications, each TPE session removed a mean 70.8% sPD-L1 and 73.1% evPD-L1 detectable in plasma. TPE also reduced total and ADAM10-positive extracellular vesicles.ConclusionHere, we report the first known clinical intervention to remove either sPD-L1 or evPD-L1 from plasma in vivo. TPE reduces plasma sPD-L1 and evPD-L1 in vivo and may have a role in treatment with immunotherapy. TPE may also prove useful in patients with other extracellular vesicle-related conditions.

Extracellular vesicle secretion is tissue-dependent ex vivo and skeletal muscle myofiber extracellular vesicles reach the circulation in vivo.

2021 ◽  
Author(s):  
Andrea L. Estrada ◽  
Zackary J. Valenti ◽  
Gabriella Hehn ◽  
Adam J. Amorese ◽  
Nicholas S. Williams ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Extracellular Vesicles ◽  
Direct Evidence ◽  
Ex Vivo ◽  
Extracellular Vesicle ◽  
Fluorescent Reporter ◽  
Human Protein Atlas ◽  
Health And Disease ◽  
Vesicle Secretion

Extracellular vesicles (EVs) are biomarkers and modifiers of human disease. EVs secreted by insulin-responsive tissues like skeletal muscle (SkM) and white adipose (WAT) contribute to metabolic health and disease but the relative abundance of EVs from these tissues has not been directly examined. Human Protein Atlas data and directly measuring EV secretion in mouse SkM and WAT using an ex vivo tissue explant model confirmed that SkM tissue secretes more EVs than WAT. Differences in EV secretion between SkM and WAT were not due to SkM contraction but may be explained by differences in tissue metabolic capacity. We next examined how many EVs secreted from SkM tissue ex vivo and in vivo are myofiber-derived. To do this, a SkM myofiber-specific dual fluorescent reporter mouse was created. Spectral flow cytometry revealed that SkM myofibers are a major source of SkM tissue-derived EVs ex vivo and EV immunocapture indicate that ~5% of circulating tetraspanin-positive EVs are derived from SkM myofibers in vivo. Our findings demonstrate that 1) SkM secretes more EVs than WAT, 2) many SkM tissue EVs are derived from SkM myofibers and 3) SkM myofiber-derived EVs reach the circulation in vivo. These findings advance our understanding of EV secretion between metabolically active tissues and provide direct evidence that SkM myofibers secrete EVs that can reach the circulation in vivo.

scholarly journals Intestine epithelial cell-derived extracellular vesicles alleviate inflammation induced by Clostridioides difficile TcdB through the activity of TGF-β1

2021 ◽  
Author(s):  
Shuangshuang Wan ◽  
Guangzhong Song ◽  
Hui Hu ◽  
Yaqing Xu ◽  
Peng Zeng ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Extracellular Vesicles ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Extracellular Vesicle ◽  
Sucrose Density Gradient Centrifugation ◽  
Clostridioides Difficile ◽  
Intestinal Immune System

Abstract Objective: Clostridioides difficile infection (CDI) has been primarily associated with the toxin B (TcdB), which can activate the intestinal immune system and lead to pathological damage. Even though the biological functions of intestine epithelial cell-derived extracellular vesicles (I-Evs) have been well documented, the role of I-Evs in the process of CDI is still unknown. Methods: I-Evs were isolated from mouse intestine tissues by ultracentrifugation protocol, identified by electron microscopy, nanoparticle tracking, sucrose density gradient centrifugation, and western blotting. Intestinal pathological damage was measured after intraperitoneal injection of TcdB into mice. Results: We isolated I-Evs ranging from 100–200 nm in mean diameter, with a density of 1.09-1.17 g/mL. These I-Evs expressed the extracellular vesicle-associated specific surface markers, CD63 and TSG101. In vitro, 50 µg I-Evs decreased the expression of IL-6, TNF-a, IL-1β, and IL-22 induced by 0.8 ng/mL C. difficile TcdB, and increased expression of TGF-b1. In vivo, I-Evs also promoted regulatory T cell induction, which improved the survival rate of mice up to 80% relative to C. difficile TcdB mice, dependent on the TGF-b1 signalling pathway. Conclusion: As an emerging immunotherapy, I-Evs can reduce the intraperitoneal infection induced by C. difficile TcdB and improve survival in mice.

scholarly journals tiRNA signaling via stress-regulated vesicle transfer in the hematopoietic niche

2021 ◽  
Author(s):  
Youmna S. Kfoury ◽  
Fei Ji ◽  
Michael Mazzola ◽  
David B. Sykes ◽  
Allison K. Scherer ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Stress Responses ◽  
Protein Translation ◽  
Extracellular Vesicle ◽  
Osteoblastic Cells ◽  
Myeloid Differentiation ◽  
Signaling Axis ◽  
Post Radiation ◽  
Hematopoietic Niche

AbstractExtracellular vesicles transfer complex biologic material between cells, whose role in in-vivo organismal physiology is poorly defined. Here, we demonstrate that osteoblastic cells in the bone marrow elaborate extracellular vesicles that are taken up by hematopoietic progenitor cells in vivo. Genotoxic or infectious stress rapidly increased stromal-derived extracellular vesicle transfer to granulocyte-monocyte progenitors. Stimulating osteoblastic cells with parathyroid hormone or activating its receptor enhanced extracellular vesicle transfer, myeloid recovery post radiation and improved animal survival from Candida sepsis. The extracellular vesicles contained tiRNAs known to modulate protein translation. 5’-ti-Pro-CGG-1 was preferentially abundant in osteoblast-derived extracellular vesicles and when transferred to granulocyte macrophage progenitors, increased protein translation, cell proliferation and myeloid differentiation. Therefore, EV-mediated tiRNA transfer provides a stress modulated signaling axis distinct from conventional cytokine-driven stress responses.One sentence summaryStress regulated tiRNA transfer alters hematopoiesis

scholarly journals Mechanism of Enhanced MerTK-Dependent Macrophage Efferocytosis by Extracellular Vesicles

2019 ◽  
Vol 39 (10) ◽  
pp. 2082-2096 ◽  
Author(s):  
Geoffrey de Couto ◽  
Ervin Jaghatspanyan ◽  
Matthew DeBerge ◽  
Weixin Liu ◽  
Kristin Luther ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Extracellular Vesicles ◽  
Apoptotic Cell ◽  
Extracellular Vesicle ◽  
Complement Factor ◽  
Irreversible Damage ◽  
Phagocytic Capacity ◽  
Cell Clearance

Objective: Extracellular vesicles secreted by cardiosphere-derived cells (CDC ev ) polarize macrophages toward a distinctive phenotype with enhanced phagocytic capacity (M CDCev ). These changes underlie cardioprotection by CDC ev and by the parent CDCs, notably attenuating the no-reflow phenomenon following myocardial infarction, but the mechanisms are unclear. Here, we tested the hypothesis that M CDCev are especially effective at scavenging debris from dying cells (ie, efferocytosis) to attenuate irreversible damage post-myocardial infarction. Approach and Results: In vitro efferocytosis assays with bone marrow-derived macrophages, and in vivo transgenic rodent models of myocardial infarction, demonstrate enhanced apoptotic cell clearance with M CDCev . CDC ev exposure induces sustained MerTK expression in M CDCev through extracellular vesicle transfer of microRNA-26a (via suppression of Adam17 ); the cardioprotective response is lost in animals deficient in MerTK. Single-cell RNA-sequencing revealed phagocytic pathway activation in M CDCev , with increased expression of complement factor C1qa , a phagocytosis facilitator. Conclusions: Together, these data demonstrate that extracellular vesicle modulation of MerTK and C1qa expression leads to enhanced macrophage efferocytosis and cardioprotection.

scholarly journals Intestine epithelial cell-Derived Extracellular Vesicles alleviate Inflammation Induced by Clostridioides Difficile TcdB through the Activity of TGF- β1

2021 ◽  
Vol 4 (1) ◽  
pp. 01-09
Author(s):  
Dazhi Jin ◽  
Shuangshuang Wan ◽  
Guangzhong Song ◽  
Hui Hu ◽  
Yaqing Xu ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Extracellular Vesicles ◽  
Extracellular Vesicle ◽  
Clostridioides Difficile ◽  
Intestinal Immune System ◽  
Cell Induction ◽  
Clostridioides Difficile Infection ◽  
Tgf Β1

Background: Clostridioides difficile infection (CDI) has been primarily associated with the toxin B (TcdB), which can activate the intestinal immune system and lead to pathological damage. Even though the biological functions of intestine epithelial cell- derived extracellular vesicles (I-Evs) have been well documented, the role of I-Evs in the process of CDI is still unknown. Results: We isolated I-Evs ranging from 100–200 nm in mean diameter, with a density of 1.09-1.17 g/mL. These I-Evs expressed the extracellular vesicle-associated specific surface markers, CD63 and TSG101. In vitro, 50 µg I-Evs decreased the expression of IL-6, TNF- β, IL-1β, and IL-22 in MC38 induced by 0.8 ng/mL C. difficile TcdB, and increased expression of TGF- β1. In vivo, I-Evs also promoted regulatory T cell induction, which improved inflammation of mice up to 80% relative to C. difficile TcdB infected mice, depending on the TGF- β1 signal pathway. Conclusion: Our study firstly demonstrated that I-Evs originated from intestine epithelial cells is potentially a novel treatment endogenous candidate to effectively reduce the local infection induced by C. difficile TcdB.

Formation and Structure of Casein Micelles in Lactating Mammary Tissue

1970 ◽  
Vol 28 ◽  
pp. 150-151
Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell
Keyword(s):  
Size Distribution ◽  
G Protein ◽  
Milk Proteins ◽  
Mammary Tissue ◽  
Colloidal System ◽  
Casein Micelles ◽  
The Stability

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

A Physiologic Regulator of Collagen-Induced Platelet Aggregation: Inhibition by Clq

1981 ◽  
Vol 45 (02) ◽  
pp. 110-115 ◽  
Author(s):  
György Csákó ◽  
Eva A Suba
Keyword(s):  
Platelet Aggregation ◽  
Human Platelet ◽  
Platelet Reactivity ◽  
High Specificity ◽  
Turbidimetric Method ◽  
Specific Manner ◽  
Aggregation Inhibition ◽  
Different Tissues

SummaryPlatelet aggregations were studied by a turbidimetric method in citrated human platelet-rich plasmas (PRP) in vitro. Human Clq inhibited the aggregations caused by collagens derived from different tissues and species. Clq was needed by weight in comparable quantities to collagen for neutralizing the aggregating effect. The dependence of the inhibitory reaction on the preincubation of platelets with Clq and the differences in the occurrence of aggregating substances in supernatants of PRP triggered with collagen in the presence or absence of Clq, confirmed that Clq exerts its effect by preventing fixation of collagen to platelets. In addition, the high specificity of the inhibitory action of Clq for collagen-induced platelet aggregation was demonstrated by results obtained for testing a variety of aggregating agents in combination with Clq and/or collagen.Since normal concentrations of Clq in the blood are in the range of inhibitory doses of Clq for collagen-induced platelet aggregations in vitro and upon activation of complement Clq is known to dissociate from Cl, it is proposed that Clq may participate in a highly specific manner in regulating platelet reactivity to collagen in vivo.

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