Posts Tagged: exosomes

Extracellular Vesicles in Angiogenesis

Extracellular Vesicles in Angiogenesis

Dilyana Todorova, Stéphanie Simoncini, Romaric Lacroix, Florence Sabatier, Françoise Dignat-George

Mechanisms involved in the modulation of Angiogenesis by platelet-derived extracellular vesicles (EVs). Platelet-derived EVs contain various growth factors and chemokines that induce proangiogenic signaling in endothelial cell (EC). Spingosine-1-phosphate (S1P1), present on the EV surface, induces PI3K activation and, together with VEGF and bFGF, promotes angiogenesis. The EVs released by platelets stimulate the proangiogenic potential of circulating angiogenic cells by increasing their expression of both membrane molecules and soluble factors. Platelet-derived EVs can inhibit angiogenesis by transferring the p22phox and gp91 subunits of NADPH oxidase and increasing the oxidative stress in EC. ? indicates that the exact content of the EVs is not reported; bFGF, basic fibroblast growth factor; EGF, epidermal growth factor; GM-CSF, granulocyte-macrophage colony-stimulating factor; HGF, hepatocyte growth factor; NADPH, nicotinamide adenine dinucleotide phosphate; PI3K, phosphoinositide 3-kinase; RANTES, regulated on activation, normal T-cell–expressed and secreted; ROS, reactive oxygen species; VEGF, vascular endothelial growth factor; and VEGFR, vascular endothelial growth factor receptor. [Powerpoint FIle]

Extracellular Vesicles in Angiogenesis

Extracellular Vesicles in Angiogenesis

Dilyana Todorova, Stéphanie Simoncini, Romaric Lacroix, Florence Sabatier, Françoise Dignat-George

Mechanisms involved in the modulation of Angiogenesis by endothelial cell (EC)–derived extracellular vesicles (EVs). EC release EVs rich in micro-RNA such as miR-214 and miR-126, that are transferred to recipient EC and induce proangiogenic signaling. EVs contain functional matrix metalloproteinases that facilitate angiogenesis through the degradation of components of the extracellular matrix. Dll4 is transferred to EC by the EVs and induces Notch receptor internalization and tip cell formation. EVs bear, at their surface, a tissue factor that interacts with β1 integrin and induces Rac1-ERK1/2-ETS1 signaling, leading to the increased secretion of CCL2. EVs transport the complex uPA/uPAR, which stimulates angiogenesis through plasmin generation. The phosphatidylserine present on the surface of the EVs interacts with CD36 and induces Fyn kinase signaling, which leads to increased oxidative stress and the inhibition of angiogenesis. ATM indicates ataxia telangiectasia mutated; CCl2, chemokine c-c motif ligand 2; Dll4, Delta-like 4; ECM, extracellular matrix; ERK1/2, extracellular signal-related kinase 1 and 2; ETS1, avian erythroblastosis virus E26 homolog-1; IL-3R, interleukin-3 receptor; MMPs, matrix metalloproteinases; NotchR, Notch receptor; PS, phosphatidylserine; Rac1, Ras-related C3 botulinum toxin substrate 1; ROS, reactive oxygen species; TF, tissue factor; TIMPS, tissue inhibitor of metalloproteinases; uPA, urokinase plasminogen activator; and uPAR, urokinase plasminogen activator receptor. [Powerpoint File]

Methodological Guidelines to Study Extracellular Vesicles

Methodological Guidelines to Study Extracellular Vesicles

Frank A.W. Coumans, Alain R. Brisson, Edit I. Buzas, Françoise Dignat-George, Esther E.E. Drees, Samir El-Andaloussi, Costanza Emanueli, Aleksandra Gasecka, An Hendrix, Andrew F. Hill, Romaric Lacroix, Yi Lee, Ton G. van Leeuwen, Nigel Mackman, Imre Mäger, John P. Nolan, Edwin van der Pol, D. Michiel Pegtel, Susmita Sahoo, Pia R.M. Siljander, Guus Sturk, Olivier de Wever, Rienk Nieuwland

Working principle of common methods to isolate extracellular vesicles (EVs). Separation is based on size, density, and immunophenotype. Straight brackets: isolated EVs; yellow: soluble components; and blue: buffer. A, In differential centrifugation, separation is based on size, and large EVs (gray) collect earlier at the bottom of the tube and at lower g forces than small EVs (green). The soluble components are not affected by centrifugation, but non-EV particles such as lipoproteins and protein aggregates may copellet with EVs. B, In density gradient centrifugation, separation is based on density, and EVs will travel to their equilibrium density. Non-EV particles such as lipoproteins may coelute with EVs because of similar density or interaction. The soluble components with a high density relative to the gradient will collect at the bottom of the tube. C, Size exclusion chromatography uses a porous matrix (dotted circles) that separates on size. Soluble components and particles smaller than the size cutoff enter the porous matrix temporarily, whereas EVs and particles larger than the size cutoff do not enter the porous matrix. As a result, EVs and particles larger than the size cutoff elute before the soluble components and particles smaller than the size cut-off. D, In ultrafiltration, soluble proteins and particles smaller than the size cutoff (≈105 kDa) are pushed through the filter, and the EVs are collected at the filter. E, In immunocapture assays, EVs are captured based on their immunophenotype. EVs are captured using an monoclonal antibody (mAb) directed against an antigen exposed on the targeted (green) EVs only. F, In precipitation, addition of a precipitating agent induces clumping of EVs, non-EV particles, and soluble proteins. The clumps will sediment, and sedimentation can be accelerated by centrifugation. [Powerpoint File]

Exosomes Generated From iPSC-Derivatives: New Direction for Stem Cell Therapy in Human Heart Diseases

Exosomes Generated From iPSC-Derivatives: New Direction for Stem Cell Therapy in Human Heart Diseases

Ji-Hye Jung, Xuebin Fu, Phillip C. Yang

Biogenesis of exosome. Exosomes are compartmentalized into the multivesicular bodies (MVBs), which fuse with the cell membrane and released to the extracellular space. This process prevents exosomes from degradation by the lysosomes. Exosomes comprise of various transmembrane and cytosolic proteins, such as integrins, CD9, CD63, and CD81. Furthermore, exosomes retain donor cells’ proteins, DNA fragments, miRNAs, and noncoding RNAs within the bilipid membrane. As such, exosomes preserve the genetic information of donor cells from enzymatic degradation while enabling targeted delivery of specific cargo. [Powerpoint File]

Exosomes Generated From iPSC-Derivatives: New Direction for Stem Cell Therapy in Human Heart Diseases

Exosomes Generated From iPSC-Derivatives: New Direction for Stem Cell Therapy in Human Heart Diseases

Ji-Hye Jung, Xuebin Fu, Phillip C. Yang

Exosomes mediated intercellular communication in heart. Exosomes facilitate communication among cardiomyocytes, endothelial cells, and vascular smooth muscle cells in the infarcted area of the heart. Exosomes transfer signaling molecules, such as miRNAs, mRNAs, and proteins to confer paracrine effects on the neighboring cells. In addition, pathological and physiological influence on the heart stimulates exosome secretion. Therefore, cardiac exosomes under pathological conditions could be used as ideal markers for diagnostic tools in the clinic. [Powerpoint FIle]

Exosomes Generated From iPSC-Derivatives: New Direction for Stem Cell Therapy in Human Heart Diseases

Exosomes Generated From iPSC-Derivatives: New Direction for Stem Cell Therapy in Human Heart Diseases

Ji-Hye Jung, Xuebin Fu, Phillip C. Yang

Personalized therapy with the exosomes generated from induced pluripotent stem cell (iPSC)–derived cardiomyocytes (iCMs). Exosomes from patient-specific iPSC derivatives provide a platform for personalized therapy by simulating endogenous repair. Exosomes can be directed to specific injured site of each individual patient to promote salvage of the existing injured cardiac cells. Exosomes isolated from the supernatant of iCM culture undergo ultracentrifugation methods, as well as advanced characterization and quantification by transmission electronical microscopy, Nanosight, and dynamic light scattering. [Powerpoint File]

More Than Tiny Sacks: Stem Cell Exosomes as Cell-Free Modality for Cardiac Repair

More Than Tiny Sacks: Stem Cell Exosomes as Cell-Free Modality for Cardiac Repair

Raj Kishore, Mohsin Khan

Stem cell–derived exosomes for cardiac repair. Exosome derived from different types of stem cells, including embryonic stem cells (ESC), induced pluripotent stem cells (iPSCs), mesenchymal stem cells (MSCs), cardiac stem cells (CSCs), and endothelial progenitor cells (EPCs) carry and deliver messanger RNAs (mRNAs), microRNAs (miRNAs), and proteins to the damaged heart tissue consequently augmenting resident cardiac stem cell activation/expansion, cardiomyocyte proliferation, neovascularization, and modulation of cardiac inflammatory response (Illustration credit: Ben Smith). [Powerpoint File]

Microvesicles as Cell–Cell Messengers in Cardiovascular Diseases

Microvesicles as Cell–Cell Messengers in Cardiovascular Diseases

Xavier Loyer, Anne-Clémence Vion, Alain Tedgui, Chantal M. Boulanger

Mechanisms involving extracellular vesicles in cell-to-cell communication. Once released, exosomes, microparticles, and apoptotic bodies target recipient cells and are able to transfer information (microRNAs, proteins, etc) by membrane fusion (1), endocytosis (2), or receptor-mediated binding (3). (Illustration credit: Ben Smith). [Powerpoint File]

Exosomes and Cardiac Repair After Myocardial Infarction

Exosomes and Cardiac Repair After Myocardial Infarction

Susmita Sahoo, Douglas W. Losordo

Biogenesis of and release of exosomes from multivesicular bodies (MVBs). Endosomes originate by inward invagination of plasma membrane and have inverted plasma membrane. At the time of exosome formation, endosome membrane invaginates again toward its lumen, forming exosomes with the same membrane orientation as the plasma membrane. Outer and inner plasma membranes are shown in red and green color, respectively. [Powerpoint File]

Exosomes and Cardiac Repair After Myocardial Infarction

Exosomes and Cardiac Repair After Myocardial Infarction

Susmita Sahoo, Douglas W. Losordo

A suggested hypothesis on the role of exosomes released from a damaged heart as a potential intercellular communicator. Exosomes can carry signaling molecules to activate local tissues (C indicates cardiomyocytes; E, endothelial cells; F, fibroblasts; and S, stem cells) and distant organs such as bone marrow (BM). Furthermore, the exosomes released from progenitor cells and the reprogrammed BM can reprogram the ischemic tissues of the heart, inducing protection and regeneration (illustration credit: Ben Smith). [Powerpoint File]

Exosomes: Nanoparticles Involved in Cardioprotection?

Exosomes: Nanoparticles Involved in Cardioprotection?

Derek M. Yellon, Sean M. Davidson

Some of the various ways in which exosomes may affect recipient cells. A, Protein ligands in the membrane of the exosome may activate receptors and downstream signaling pathways in recipient cells. B, Exosomes may contain activated receptors, which are transferred. Exosomes contain protein (C), or miRNA or mRNA (D), which may be transferred to recipient cells. GPCR indicates G-protein–coupled receptor. [Powerpoint File]

Exosomes: Nanoparticles Involved in Cardioprotection?

Exosomes: Nanoparticles Involved in Cardioprotection?

Derek M. Yellon, Sean M. Davidson

Microvesicles are released via plasma membrane shedding in contrast to the directed release of exosomes from multivesicular bodies (MVBs) that fuse with the plasma membrane. Exosomes form by invagination of the MVB membrane. Like microvesicles, they engulf cytosolic contents and, therefore, might be thought of as status updates released from the cell. [Powerpoint File]

Circulating MicroRNAs: Novel Biomarkers and Extracellular Communicators in Cardiovascular Disease?

Circulating MicroRNAs: Novel Biomarkers and Extracellular Communicators in Cardiovascular Disease?

Esther E. Creemers, Anke J. Tijsen, Yigal M. Pinto

Cellular release mechanisms and extracellular transportation systems of miRNAs. In the nucleus, miRNAs are transcribed from DNA. A precursor hairpin miRNA (pre-miRNA) is formed after cleavage by the RNase III enzyme Drosha. After being transported into the cytoplasm, the pre-miRNA can be further cleaved into 19- to 23-nucleotide mature miRNA duplexes. One strand of the miRNA duplex can be loaded into the RNA-induced silencing complex (RISC), where it can guide the RISC to specific mRNA targets to prevent translation of the mRNA into protein (1). The other strand may be degraded or released from the cell through export mechanisms described below. In the cytoplasm, pre-miRNAs can also be incorporated into small vesicles called exosomes, which originate from the endosome and are released from cells when multivesicular bodies (MVB) fuse with the plasma membrane (2). Cytoplasmic miRNAs (pre-miRNA or mature miRNA) can also be released by microvesicles, which are released from the cell through blebbing of the plasma membrane (3). miRNAs are also found in circulation in microparticle-free form. These miRNAs can be associated with high-density lipoproteins or bound to RNA-binding proteins such as Ago2. It is not known how these miRNA-protein complexes are released from the cell. These miRNAs may be released passively, as by-products of dead cells, or actively, in an miRNA-specific manner, through interaction with specific membrane channels or proteins (4). Although pre-miRNAs have been detected in exosomes and microvesicles,20 and mature miRNAs have been found in complex with Ago28 and HDL,9 the exact proportion of mature and pre-miRNAs in the different extracellular compartments is not known. Illustration credit: Cosmocyte/Ben Smith. [Powerpoint File]