| 1. |
- Crescitelli, Rossella, 1985, et al.
(författare)
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Distinct RNA profiles in subpopulations of extracellular vesicles: apoptotic bodies, microvesicles and exosomes.
- 2013
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Ingår i: Journal of extracellular vesicles. - : Wiley. - 2001-3078. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: In recent years, there has been an exponential increase in the number of studies aiming to understand the biology of exosomes, as well as other extracellular vesicles. However, classification of membrane vesicles and the appropriate protocols for their isolation are still under intense discussion and investigation. When isolating vesicles, it is crucial to use systems that are able to separate them, to avoid cross-contamination. METHOD: EVS RELEASED FROM THREE DIFFERENT KINDS OF CELL LINES: HMC-1, TF-1 and BV-2 were isolated using two centrifugation-based protocols. In protocol 1, apoptotic bodies were collected at 2,000×g, followed by filtering the supernatant through 0.8 µm pores and pelleting of microvesicles at 12,200×g. In protocol 2, apoptotic bodies and microvesicles were collected together at 16,500×g, followed by filtering of the supernatant through 0.2 µm pores and pelleting of exosomes at 120,000×g. Extracellular vesicles were analyzed by transmission electron microscopy, flow cytometry and the RNA profiles were investigated using a Bioanalyzer(®). RESULTS: RNA profiles showed that ribosomal RNA was primary detectable in apoptotic bodies and smaller RNAs without prominent ribosomal RNA peaks in exosomes. In contrast, microvesicles contained little or no RNA except for microvesicles collected from TF-1 cell cultures. The different vesicle pellets showed highly different distribution of size, shape and electron density with typical apoptotic body, microvesicle and exosome characteristics when analyzed by transmission electron microscopy. Flow cytometry revealed the presence of CD63 and CD81 in all vesicles investigated, as well as CD9 except in the TF-1-derived vesicles, as these cells do not express CD9. CONCLUSIONS: Our results demonstrate that centrifugation-based protocols are simple and fast systems to distinguish subpopulations of extracellular vesicles. Different vesicles show different RNA profiles and morphological characteristics, but they are indistinguishable using CD63-coated beads for flow cytometry analysis.
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| 2. |
- Cvjetkovic, Aleksander, et al.
(författare)
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The influence of rotor type and centrifugation time on the yield and purity of extracellular vesicles.
- 2014
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Ingår i: Journal of Extracellular Vesicles. - : Wiley. - 2001-3078. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Extracellular vesicles (EV), the collective term for vesicles released from cells, consist of vesicle species ranging in size from 30 nm to 5 µm in diameter. These vesicles are most commonly isolated by differential centrifugations, which pellets particles based on their differential movement through the liquid medium in which they are immersed. Multiple parameters, including the utilization of different rotor types, can influence the yield and purity of isolated vesicles; however, the understanding of how these factors affect is limited. MATERIALS AND METHODS: Here, we compare the influence of multiple centrifugation parameters, including the use of swinging bucket and fixed angle rotors, as well as different centrifugation times, for the isolation of the smallest EVs, "exosomes." In particular, we determine the yields of exosomal RNA and protein, as well as the nature of the isolated vesicles and possible protein contamination with methods such as electron microscopy, western blot and flow cytometry. RESULTS: Our results show that application of a specific g-force or rotation speed by itself does not predict the ability of pelleting exosomes, and that prolonged centrifugation times can achieve greater yields of exosomal RNA and protein, whereas very long centrifugation times result in excessive protein concentrations in the exosome pellet. CONCLUSION: In conclusion, rotor type, g-force and centrifugation times significantly influence exosome yield during centrifugation-based isolation procedures, and current commonly recommended isolation protocols may not be fully optimized for yield and purity of exosomes.
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| 3. |
- Ekström, Karin, 1978, et al.
(författare)
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Characterization of mRNA and microRNA in human mast cell-derived exosomes and their transfer to other mast cells and blood CD34 progenitor cells
- 2012
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Ingår i: Journal of Extracellular Vesicles (JEV). - : Wiley. - 2001-3078. ; 1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Exosomes are nanosized vesicles of endocytic origin that are released into the extracellular environment by many different cells. It has been shown that exosomes from various cellular origins contain a substantial amount of RNA (mainly mRNA and microRNA). More importantly, exosomes are capable of delivering their RNA content to target cells, which is a novel way of cell-to-cell communication. The aim of 20 this study was to evaluate whether exosomal shuttle RNA could play a role in the communication between human mast cells and between human mast cells and human CD34+progenitor cells. Methods: The mRNA and microRNA content of exosomes from a human mast cell line, HMC-1, was analysed by using microarray technology. Co-culture experiments followed by flow cytometry analysis and confocal microscopy as well as radioactive labeling experiments were performed to examine the uptake of 25 these exosomes and the shuttle of the RNA to other mast cells and CD34+ progenitor cells. Results: In this study, we show that human mast cells release RNA-containing exosomes, with the capacity to shuttle RNA between cells. Interestingly, by using microRNA microarray analysis, 116 microRNAs could be identified in the exosomes and 134 microRNAs in the donor mast cells. Furthermore, DNA microarray experiments revealed the presence of approximately 1800 mRNAs in the exosomes, which represent 15% of 30 the donor cell mRNA content. In addition, transfer experiments revealed that exosomes can shuttle RNA between human mast cells and to CD34+ hematopoietic progenitor cells. Conclusion: These findings suggest that exosomal shuttle RNA (esRNA) can play a role in the communication between cells, including mast cells and CD34+ progenitor cells, implying a role in cells maturation process. 35
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| 4. |
- Gennebäck, Nina, 1982-, et al.
(författare)
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Growth factor stimulation of cardiomyocytes induces changes in the transcriptional contents of secreted exosomes
- 2013
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Ingår i: Journal of Extracellular Vesicles. - : Co-Action Publishing. - 2001-3078.
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Tidskriftsartikel (refereegranskat)abstract
- Exosomes are nano-sized extracellular vesicles, released from various cells, which can stimulate or repress responses in targets cells. We recently reported that cultured cardiomyocytes are able to release exosomes and that they, in turn, are involved in facilitating events in target cells by alteration of gene expression. We investigated whether external stimuli of the cardiomyocyte might influence the transcriptional content of the released exosomes.Exosomes were isolated from media collected from cultured cardiomyocytes (HL-1) with or without growth factor treatment (TGF-β2 and PDGF-BB), with a series of differential centrifugations, including preparative ultracentrifugation and separation with a sucrose gradient. The exosomes were characterized with dynamic light scattering (DLS), electron microscopy (EM) and Western blot and analyzed with Illumina whole genome microarray gene expression.The exosomes were rounded in shape and had an average size of 50–90 nm in diameter with no difference between treatment groups. Analysis of the mRNA content in repeated experiments conclusively revealed 505 transcripts in the control group, 562 in the TGF-β2-treated group and 300 in the PDGF-BB-treated group. Common transcripts (217) were found in all 3 groups.We show that the mode of stimulation of parental cells affects the characteristics of exosomes released. Hence, there is a difference in mRNA content between exosomes derived from cultured cardiomyocytes stimulated, or not stimulated, with growth factors. We also conclude that all exosomes contain a basic package consisting of ribosomal transcripts and mRNAs coding for proteins with functions within the energy supply system.
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| 5. |
- Kim, Dae-Kyum, et al.
(författare)
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EVpedia: an integrated database of high-throughput data for systemic analyses of extracellular vesicles.
- 2013
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Ingår i: Journal of extracellular vesicles. - : Wiley. - 2001-3078. ; 2:1
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Tidskriftsartikel (refereegranskat)abstract
- Secretion of extracellular vesicles is a general cellular activity that spans the range from simple unicellular organisms (e.g. archaea; Gram-positive and Gram-negative bacteria) to complex multicellular ones, suggesting that this extracellular vesicle-mediated communication is evolutionarily conserved. Extracellular vesicles are spherical bilayered proteolipids with a mean diameter of 20-1,000 nm, which are known to contain various bioactive molecules including proteins, lipids, and nucleic acids. Here, we present EVpedia, which is an integrated database of high-throughput datasets from prokaryotic and eukaryotic extracellular vesicles. EVpedia provides high-throughput datasets of vesicular components (proteins, mRNAs, miRNAs, and lipids) present on prokaryotic, non-mammalian eukaryotic, and mammalian extracellular vesicles. In addition, EVpedia also provides an array of tools, such as the search and browse of vesicular components, Gene Ontology enrichment analysis, network analysis of vesicular proteins and mRNAs, and a comparison of vesicular datasets by ortholog identification. Moreover, publications on extracellular vesicle studies are listed in the database. This free web-based database of EVpedia (http://evpedia.info) might serve as a fundamental repository to stimulate the advancement of extracellular vesicle studies and to elucidate the novel functions of these complex extracellular organelles.
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| 6. |
- Kucharzewska, Paulina, et al.
(författare)
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Emerging roles of extracellular vesicles in the adaptive response of tumour cells to microenvironmental stress.
- 2013
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Ingår i: Journal of Extracellular Vesicles. - : Wiley. - 2001-3078. ; 2
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Forskningsöversikt (refereegranskat)abstract
- Cells are constantly subjected to various types of endogenous and exogenous stressful stimuli, which can cause serious and even permanent damage. The ability of a cell to sense and adapt to environmental alterations is thus vital to maintain tissue homeostasis during development and adult life. Here, we review some of the major phenotypic characteristics of the hostile tumour microenvironment and the emerging roles of extracellular vesicles in these events.
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| 7. |
- Lötvall, Jan, 1956, et al.
(författare)
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Minimal experimental requirements for definition of extracellular vesicles and their functions: a position statement from the International Society for Extracellular Vesicles.
- 2014
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Ingår i: Journal of extracellular vesicles. - : Wiley. - 2001-3078. ; 3
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Secreted membrane-enclosed vesicles, collectively called extracellular vesicles (EVs), which include exosomes, ectosomes, microvesicles, microparticles, apoptotic bodies and other EV subsets, encompass a very rapidly growing scientific field in biology and medicine. Importantly, it is currently technically challenging to obtain a totally pure EV fraction free from non-vesicular components for functional studies, and therefore there is a need to establish guidelines for analyses of these vesicles and reporting of scientific studies on EV biology. Here, the International Society for Extracellular Vesicles (ISEV) provides researchers with a minimal set of biochemical, biophysical and functional standards that should be used to attribute any specific biological cargo or functions to EVs.
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| 8. |
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| 9. |
- Pope, Samuel M, et al.
(författare)
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Toxoplasma gondii infection of fibroblasts causes the production of exosome-like vesicles containing a unique array of mRNA and miRNA transcripts compared to serum starvation
- 2013
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Ingår i: Journal of Extracellular Vesicles. - 2001-3078. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- Background: Until recently thought to be of little significance unless occurring during pregnancy, Toxoplasma gondii infection of human hosts is now known to play a larger role in mental health and is a growing concern in the health care community. We sought to elucidate a possible mechanism by which Toxoplasma infection may cause some of the behavioural pathology now associated with infection. We hypothesized that exosomes may be playing a role. Methods: We utilized electron microscopy to detect the presence and size of extracellular vesicles in the supernatants of Toxoplasma-infected human foreskin fibroblasts (HFF). We then utilized microarray analysis to discern mRNA and miRNA content of the vesicles isolated from supernatants of Toxoplasma-infected (Toxo) and serum-starved (SS) HFF. Results: We recovered extracellular vesicles with a size consistent with exosomes that we called exosome-like vesicles (ELVs) from the supernatants of SS and Toxo cultures. The mRNA and miRNA content of these ELVs was highly regulated creating specific and unique expression profiles comparing Toxo ELVs, SS ELVs and RNA isolated from whole cell homogenates. Interestingly, among the most enriched mRNA isolated from ELVs of Toxo cells are 4 specific mRNA species that have been described in the literature as having neurologic activity: Rab-13, eukaryotic translation elongation factor 1 alpha 1, thymosin beta 4 and LLP homolog. In addition, miRNA species uniquely expressed in Toxo ELVs include miR-23b, a well-known regulator of IL-17. Conclusion: While the production of ELVs containing mRNAs that modify behaviour are consistent with reported Toxoplasma pathology, the mechanism of enrichment and ultimate in vivo effect of these mRNA and miRNA containing ELVs remains to be investigated.
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| 10. |
- Shelke, Ganesh V, 1986, et al.
(författare)
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Importance of exosome depletion protocols to eliminate functional and RNA-containing extracellular vesicles from fetal bovine serum
- 2014
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Ingår i: Journal of Extracellular Vesicles. - : Wiley. - 2001-3078. ; 3
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular vesicles (EVs), including the nano-sized exosomes, have the capacity to transfer multiple functional molecules between cells. In cell culture experiments, fetal bovine serum (FBS) is often used to supplement cell culture medium as a nutrient, but it is important to know that the FBS also contain significant quantities of EVs. The aim of the current study was to determine whether the FBS EVs can influence cultured cell phenotype, and secondly to determine the efficiency of FBS-EV elimination protocols. Firstly, FBS that had not been depleted of EVs induced a migratory phenotype in a lung cancer epithelial cell line (A549 cells), an effect that could be mimicked by isolated FBS EVs alone. FBS-derived EVs also contained RNA, which was protected from consecutive proteinase K and RNase A treatment. Comparison of common isolation protocols suggested that an 18-hour centrifugation period eliminates approximately 95% of RNA-containing FBS EVs, whereas a 1.5-hour protocol is insufficient. In conclusion, this study shows that FBS EVs substantially influence cultured cell behaviour, but also that they can be virtually removed by an 18-hour ultracentrifugation protocol.
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| 11. |
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