21 results on '"Dragovic, R."'
Search Results
2. Plasma extracellular vesicles modulate immune cell gene expression following myocardial infarction
- Author
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Akbar, N, primary, Braithwaite, A, additional, Lewe, C, additional, Lemke, S, additional, Alkhalil, M, additional, Dragovic, R, additional, Melling, G, additional, Carter, D.R.F, additional, Channon, K.M, additional, and Choudhury, R.P, additional
- Published
- 2020
- Full Text
- View/download PDF
3. Application of dynamic light scattering to the measurement of microparticles: OC-TU-056
- Author
-
Harrison, P, Dragovic, R, Albanyan, A, Lawrie, A S, Murphy, M, and Sargent, I
- Published
- 2009
- Full Text
- View/download PDF
4. Exosomes, a bio-compatible delivery platform for mammalian sperm cells: A non-invasive approach for the transfer of therapeutic compounds
- Author
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Vilanova, T, Plow, C, Jones, C, Dragovic, R, and Coward, K
- Published
- 2019
5. 2379Endothelial cell derived extracellular vesicles mediate immune cell deployment from the spleen and transcriptional programming following acute myocardial infarction
- Author
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Akbar, N, primary, Corbin, A, additional, Hogg, E, additional, Banerjee, A, additional, Lee, C, additional, Melling, G, additional, Edgar, L, additional, Dragovic, R, additional, Carter, D, additional, Riley, P, additional, Udalova, I, additional, Anthony, D, additional, and Choudhury, R, additional
- Published
- 2019
- Full Text
- View/download PDF
6. Insights into pancreatic β cell energy metabolism using rodent β cell models
- Author
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Morten, K. J. (Karl J.), Potter, M. (Michelle), Badder, L. (Luned), Sivathondan, P. (Pamela), Dragovic, R. (Rebecca), Neumann, A. (Abigale), Gavin, J. (James), Shrestha, R. (Roshan), Reilly, S. (Svetlana), Phadwal, K. (Kanchan), Lodge, T. A. (Tiffany A.), Borzychowsk, A. (Angela), Cookson, S. (Sharon), Mitchell, C. (Corey), Morova, A. (Alireza), Simon, A. K. (Anna Katharina), Uusimaa, J. (Johanna), Hynes, J. (James), Poulton, J. (Joanna), Morten, K. J. (Karl J.), Potter, M. (Michelle), Badder, L. (Luned), Sivathondan, P. (Pamela), Dragovic, R. (Rebecca), Neumann, A. (Abigale), Gavin, J. (James), Shrestha, R. (Roshan), Reilly, S. (Svetlana), Phadwal, K. (Kanchan), Lodge, T. A. (Tiffany A.), Borzychowsk, A. (Angela), Cookson, S. (Sharon), Mitchell, C. (Corey), Morova, A. (Alireza), Simon, A. K. (Anna Katharina), Uusimaa, J. (Johanna), Hynes, J. (James), and Poulton, J. (Joanna)
- Abstract
Background: Mitochondrial diabetes is primarily caused by β-cell failure, a cell type whose unique properties are important in pathogenesis. Methods: By reducing glucose, we induced energetic stress in two rodent β-cell models to assess effects on cellular function. Results: Culturing rat insulin-secreting INS-1 cells in low glucose conditions caused a rapid reduction in whole cell respiration, associated with elevated mitochondrial reactive oxygen species production, and an altered glucose-stimulated insulin secretion profile. Prolonged exposure to reduced glucose directly impaired mitochondrial function and reduced autophagy. Conclusions: Insulinoma cell lines have a very different bioenergetic profile to many other cell lines and provide a useful model of mechanisms affecting β-cell mitochondrial function.
- Published
- 2019
7. Standardization of extracellular vesicle measurements by flow cytometry through vesicle diameter approximation
- Author
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Dep Infectieziekten Immunologie, LS Celbiologie-Algemeen, Sub General Pharmaceutics, Sub Algebra,Geometry&Mathem. Logic begr., LS Pharma, dB&C I&I, van der Pol, E., Sturk, A., van Leeuwen, T., Nieuwland, R., Coumans, F., Mobarrez, F., Arkesteijn, G., Wauben, M., Siljander, P. R.M., Sánchez-López, V., Otero-Candelera, R., Ramón, L. A., Dolz, S., Vila, V., Mackman, N., Geddings, J., Mullier, F., Bailly, N., Han, J. Y., Kwaan, H. C., Weiss, I. M., Buzás, E. I., Pállinger, E., Harrison, P., Kraan, J., Hedley, B. D., LazoLangner, A., Enjeti, A., Norris, P. J., Paris, C., Susen, S., Bonnefoy, A., Delorme, I., Chandler, W. L., Hau, C., Aass, H. C.D., Connor, D., Wu, X., Dragovic, R., Uotila, L. M., Lacroix, R., Robert, S., Dep Infectieziekten Immunologie, LS Celbiologie-Algemeen, Sub General Pharmaceutics, Sub Algebra,Geometry&Mathem. Logic begr., LS Pharma, dB&C I&I, van der Pol, E., Sturk, A., van Leeuwen, T., Nieuwland, R., Coumans, F., Mobarrez, F., Arkesteijn, G., Wauben, M., Siljander, P. R.M., Sánchez-López, V., Otero-Candelera, R., Ramón, L. A., Dolz, S., Vila, V., Mackman, N., Geddings, J., Mullier, F., Bailly, N., Han, J. Y., Kwaan, H. C., Weiss, I. M., Buzás, E. I., Pállinger, E., Harrison, P., Kraan, J., Hedley, B. D., LazoLangner, A., Enjeti, A., Norris, P. J., Paris, C., Susen, S., Bonnefoy, A., Delorme, I., Chandler, W. L., Hau, C., Aass, H. C.D., Connor, D., Wu, X., Dragovic, R., Uotila, L. M., Lacroix, R., and Robert, S.
- Published
- 2018
8. HLA-DR is aberrantly expressed at feto-maternal interface in pre-eclampsia
- Author
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Tersigni, Chiara, Redman, Cw, Dragovic, R, Tannetta, D, Scambia, Giovanni, Di Simone, Nicoletta, Sargent, I, Vatish, M, Tersigni C, Scambia G (ORCID:0000-0003-2758-1063), Di Simone N (ORCID:0000-0003-1273-3335), Tersigni, Chiara, Redman, Cw, Dragovic, R, Tannetta, D, Scambia, Giovanni, Di Simone, Nicoletta, Sargent, I, Vatish, M, Tersigni C, Scambia G (ORCID:0000-0003-2758-1063), and Di Simone N (ORCID:0000-0003-1273-3335)
- Abstract
In normal pregnancy, villous cytotrophoblast and syncytiotrophoblast do not express HLA Class I and Class II molecules, while invasive extravillous trophoblast only express class I HLA-C and the atypical class Ib antigens, HLA-G, -E and -F. Inadequate maternal tolerance of invasive trophoblast has been proposed as a possible immunologic trigger of poor trophoblast invasion and subsequent occurrence of pre-eclampsia. This study aimed to investigate possible aberrant expression of class II HLA-DR on placentae and syncytiotrophoblast-derived extracellular vesicles (STEVs), obtained by dual placental perfusion, from pre-eclampsia (n = 23) and normal pregnant (n = 14) women. Here we demonstrate that HLA-DR can be detected in syncytiotrophoblast from a significant proportion of pre-eclampsia but not control placentae. HLA-DR was also observed, by flow cytometry, on STEVs and associated with placental alkaline phosphatase to validate their placental origin. HLA-DR positive syncytiotrophoblast was detected in placental biopsies from pre-eclampsia but not normal control cases, using immunohistochemistry. The HLA may be fetal or maternal origin. In the latter case a possible mechanism of acquisition is trogocytosis.
- Published
- 2018
9. CHARACTERISATION OF EXTRACELLULAR VESICLES BY MULTI-PARAMETER NANOPARTICLE TRACKING ANALYSIS
- Author
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Gardiner, C, Dragovic, R, Tannetta, D, Harrison, P, Redman, C, and Sargent, I
- Published
- 2016
10. Measurement of procoagulant microvesicles generated within ageing platelet concentrates
- Author
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Albanyan, A, Curry, B, Dragovic, R, Gardiner, C, Biggerstaff, J, Murphy, M, and Harrison, P
- Published
- 2011
11. Accumulation of heavy metals in different parts of Russian thistle (Salsola tragus, Chenopodiaceae), a potential hyperaccumulator plant species
- Author
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Dragović, R., Zlatković, B., Dragović, S., Petrović, J., and Janković Mandić, Lj.
- Subjects
Salsola tragus ,heavy metals ,plant parts ,accumulation ,Serbia ,Biology (General) ,QH301-705.5 - Abstract
Distribution and accumulation of 10 heavy metals was observed in plant parts of species S. tragus, a native representative of Serbian flora. According to high bioaccumulation values (BAF), more than a half of the analyzed elements were bioaccumulated in roots, as well as in the aerial part of the plant. Translocation factor (TF) value was calculated, showing the ratio between the concentration of metals in roots and aerial parts of the plant. The results indicate that S. tragus may accumulate significant amounts of Cd, Co, Cr and Pb. Concentrations of some of the individual elements are shown to be statistically different depending on the sampled plant parts. Potential capacity of S. tragus for hyperaccumulation of heavy metals and possible utilization of this plant for phytoremediation is discussed.
- Published
- 2014
12. Investigation into techniques to isolate and develop human germ cells in vitro
- Author
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Papadopoulou, E, Williams, S, and Dragovic, R
- Subjects
Fertility - Abstract
Premature ovarian insufficiency (POI) occurs in 1% of women younger than 40 years of age. The manifestation of this condition varies considerably ranging from ovaries devoid of follicles (afollicular POI) to ovaries containing follicles at various stages of development (follicular POI). No methods exist in mainstream healthcare to restore ovarian function for POI patients and ≥70% of POI cases are idiopathic. The Reaggregated Ovary (RO) method, as established for mice, enables investigation into the developmental potential of oocytes by replacing dysfunctional ovarian cells. This approach could enable us to develop a potential treatment for patients with follicular POI. Investigations carried out in this thesis led to the establishment of key processes required to adapt the RO method for human tissue. A method was developed to dissociate human ovarian tissue remnants (surplus after tissue cryopreservation) and frozen/thawed ovarian cortex obtained from pre-pubertal and post-pubertal patients. Analyses revealed that age affected the efficacy of dissociation of frozen/thawed ovarian cortical tissue. To detect germ cells in a single cell suspension of ovarian cells, a method was developed for flow cytometry using a monoclonal antibody that recognises the (cytoplasmic) N-terminus region of DDX4. To assess the use of an alternative somatic cell source to support oocyte development, human dermal fibroblasts were aggregated with mouse oocytes and follicle-like structures were formed after 7-day in culture. These findings will contribute to developing the use of the RO using human oocytes and a human somatic cell alternative. The RO method once adapted for human tissue could be used to replace the dysfunctional ovarian somatic cells in POI patients and potentially restore follicle development for pre-pubertal and post-pubertal POI patients.
- Published
- 2021
13. The role of small extracellular vesicle-miRNAs in endometriosis.
- Author
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Nazri HM, Greaves E, Quenby S, Dragovic R, Tapmeier TT, and Becker CM
- Subjects
- Humans, Female, Animals, Mice, Biological Specimen Banks, Biomarkers, Endometriosis diagnosis, Endometriosis genetics, Endometriosis metabolism, MicroRNAs genetics, MicroRNAs metabolism, Extracellular Vesicles
- Abstract
Endometriosis is defined by the presence of extrauterine endometrial-like tissue, which can cause pain and infertility in 10% of reproductive-age women. To date, the pathogenesis is poorly understood resulting in significant diagnostic delays and poor therapeutic outcomes in many women. Small extracellular vesicles (sEVs) (<200 nm) are cell-derived vesicles containing molecules that can influence gene expression and behaviour in target cells. One such cargo are microRNAs (miRNAs), which are short, non-coding RNAs mostly 19-25 nucleotides in length that regulate post-transcriptional gene expression. This mini-review focuses on the role of sEV-miRNAs, which are conceivably better biomarkers for endometriosis than free miRNAs, which reflect the true pathophysiological state in the body, as sEV-encapsulated miRNAs are protected from degradation compared to free miRNA and provide direct cell-to-cell communication via sEV surface proteins. sEV-miRNAs have been implicated in the immunomodulation of macrophages, the proliferation, migration and invasion of endometrial cells, and angiogenesis, all hallmarks of endometriosis. The diagnostic potential of sEV-miRNA was investigated in one study that reported the sensitivity and specificity of two sEV-miRNAs (hsa-miR-22-3p and hsa-miR-320a-3p) in distinguishing endometriosis from non-endometriosis cases. Only three studies have explored the therapeutic potential of sEV-miRNAs in vivo in mice-two looked into the role of sEV-hsa-miR-214-3p in decreasing fibrosis, and one investigated sEV-hsa-miR-30c-5p in suppressing the invasive and migratory potential of endometriotic lesions. While early results are encouraging, studies need to further address the potential influence of factors such as the menstrual cycle as well as the location and extent of endometriotic lesions on miRNA expression in sEVs. Given these findings, and extrapolating from other conditions such as cancer, diabetes, and pre-eclampsia, sEV-miRNAs could present an attractive and urgently needed future diagnostic and therapeutic target for millions of women suffering from endometriosis. However, research in this area is hampered by lack of adherence to the International Society for Extracellular Vesicles 2018 guideline in separating and characterising sEVs, as well as the World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonisation Project protocols., (© The Author(s) 2023. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)
- Published
- 2023
- Full Text
- View/download PDF
14. Exosomes derived from HEK293T cells interact in an efficient and noninvasive manner with mammalian sperm in vitro .
- Author
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Vilanova-Perez T, Jones C, Balint S, Dragovic R, L Dustin M, Yeste M, and Coward K
- Subjects
- Animals, HEK293 Cells, Humans, Male, Semen, Spermatozoa, Swine, Exosomes, Sperm Motility
- Abstract
Aim: To investigate exosomes as a noninvasive delivery tool for mammalian sperm. Materials & Methods: Exosomes were isolated from HEK293T cells and co-incubated with boar sperm in vitro . Results: Internalized exosomes were detected within 10 min of co-incubation. Computer-assisted sperm analysis and flow cytometry demonstrated that even after 5-h of exposure to exosomes, there were no significant deleterious effects with regard to sperm motility, viability, membrane integrity and mitochondrial membrane potential (p > 0.05), thus indicating that exosomes did not interfere with basic sperm function. Conclusion: HEK293T-derived exosomes interacted with boar sperm without affecting sperm function. Exosomes represent a versatile and promising research tool for studying sperm biology and provide new options for the diagnosis and treatment of male infertility.
- Published
- 2020
- Full Text
- View/download PDF
15. Insights into pancreatic β cell energy metabolism using rodent β cell models.
- Author
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Morten KJ, Potter M, Badder L, Sivathondan P, Dragovic R, Neumann A, Gavin J, Shrestha R, Reilly S, Phadwal K, Lodge TA, Borzychowski A, Cookson S, Mitchell C, Morovat A, Simon AK, Uusimaa J, Hynes J, and Poulton J
- Abstract
Background : Mitochondrial diabetes is primarily caused by β-cell failure, a cell type whose unique properties are important in pathogenesis. Methods : By reducing glucose, we induced energetic stress in two rodent β-cell models to assess effects on cellular function. Results : Culturing rat insulin-secreting INS-1 cells in low glucose conditions caused a rapid reduction in whole cell respiration, associated with elevated mitochondrial reactive oxygen species production, and an altered glucose-stimulated insulin secretion profile. Prolonged exposure to reduced glucose directly impaired mitochondrial function and reduced autophagy. Conclusions : Insulinoma cell lines have a very different bioenergetic profile to many other cell lines and provide a useful model of mechanisms affecting β-cell mitochondrial function., Competing Interests: Competing interests: JH is an employee of Luxcel Biosciences. None of the other authors have competing interests., (Copyright: © 2019 Morten KJ et al.)
- Published
- 2019
- Full Text
- View/download PDF
16. In vitro decidualisation of human endometrial stromal cells is enhanced by seminal fluid extracellular vesicles.
- Author
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Rodriguez-Caro H, Dragovic R, Shen M, Dombi E, Mounce G, Field K, Meadows J, Turner K, Lunn D, Child T, Southcombe JH, and Granne I
- Abstract
Extracellular vesicles are highly abundant in seminal fluids and have a known role enhancing sperm function. Clinical pregnancy rates after IVF treatment are improved after female exposure to seminal fluid. Seminal fluid extracellular vesicles (SF-EVs) are candidate enhancers, however, whether SF-EVs interact with cells from the endometrium and modulate the implantation processes is unknown. Here, we investigated whether SF-EVs interact with endometrial stromal cells (ESCs) and enhance decidualisation, a requisite for implantation. SF-EVs, isolated from human seminal fluid ( n = 11) by ultracentrifugation, were characterised by nanoparticle tracking analysis and Western blotting, and purified using size exclusion chromatography. Non-decidualised and decidualised primary ESCs ( n = 5) were then treated with SF-EVs. Binding of bio-maleimide-labelled SF-EVs was detected by flow cytometry and fluorescence microscopy. Prolactin and IGFBP-1 protein levels in culture media were also analysed after single and multiple SF-EV exposure. SF-EVs size ranged from 50 to 300 nm, and they expressed exosomal markers (ALIX, SYNTENIN-1, CD9 and CD81). SF-EVs bound to non-decidualised and decidualised ESCs at similar levels. ESCs prolactin secretion was increased after single ( p = 0.0044) and multiple ( p = 0.0021) SF-EV exposure. No differences were found in IGFBP-1 protein levels. In conclusion, SF-EVs enhance in vitro ESC decidualisation and increase secretion of prolactin, an essential hormone in implantation. This elucidates a novel role of SF-EVs on endometrial receptivity. Abbreviations: ECACC: European Collection of Authenticated Cell Cultures; ESCs: endometrial stromal cells; EVs: extracellular vesicles; FCS: foetal calf serum; HRP: horse-radish peroxidase; IFNγ: interferon-gamma; IGF: insulin-like growth factor; IGFBP-1: insulin-like growth factor binding protein 1; IVF: in vitro fertilisation; MVB: multivesicular bodies; NTA: nanoparticle tracking analysis; PRLR
-/- : homozygous prolactin receptor knockout; RT: room temperature; SF-EVs: seminal fluid extracellular vesicles; STR: short tandem repeat; TGFβ: transforming growth factor β; uNK: uterine natural killer.- Published
- 2019
- Full Text
- View/download PDF
17. Insights into pancreatic β cell energy metabolism using rodent β cell models.
- Author
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Morten KJ, Potter M, Badder L, Sivathondan P, Dragovic R, Neumann A, Gavin J, Shrestha R, Reilly S, Phadwal K, Lodge TA, Borzychowski A, Cookson S, Mitchell C, Morovat A, Simon AK, Uusimaa J, Hynes J, and Poulton J
- Abstract
Background : Mitochondrial diabetes is primarily caused by β-cell failure, a cell type whose unique properties are important in pathogenesis. Methods : By reducing glucose, we induced energetic stress in two rodent β-cell models to assess effects on cellular function. Results : Culturing rat insulin-secreting INS-1 cells in low glucose conditions caused a rapid reduction in whole cell respiration, associated with elevated mitochondrial reactive oxygen species production, and an altered glucose-stimulated insulin secretion profile. Prolonged exposure to reduced glucose directly impaired mitochondrial function and reduced autophagy. Conclusions : Insulinoma cell lines have a very different bioenergetic profile to many other cell lines and provide a useful model of mechanisms affecting β-cell mitochondrial function., Competing Interests: Competing interests: JH is an employee of Luxcel Biosciences. None of the other authors have competing interests., (Copyright: © 2017 Morten KJ et al.)
- Published
- 2017
- Full Text
- View/download PDF
18. Placental Vesicles Carry Active Endothelial Nitric Oxide Synthase and Their Activity is Reduced in Preeclampsia.
- Author
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Motta-Mejia C, Kandzija N, Zhang W, Mhlomi V, Cerdeira AS, Burdujan A, Tannetta D, Dragovic R, Sargent IL, Redman CW, Kishore U, and Vatish M
- Subjects
- Adult, Blood Pressure Determination methods, Cells, Cultured, Female, Humans, Nitric Oxide metabolism, Pregnancy, Statistics as Topic, Vascular Resistance physiology, Extracellular Vesicles physiology, Hypertension diagnosis, Hypertension etiology, Nitric Oxide Synthase Type III metabolism, Pre-Eclampsia metabolism, Pre-Eclampsia pathology, Pre-Eclampsia physiopathology, Trophoblasts pathology, Trophoblasts physiology
- Abstract
Preeclampsia, a multisystem hypertensive disorder of pregnancy, is associated with increased systemic vascular resistance. Placentae from patients with preeclampsia have reduced levels of endothelial nitric oxide synthase (eNOS) and, thus, less nitric oxide (NO). Syncytiotrophoblast extracellular vesicles (STBEV), comprising microvesicles (STBMV) and exosomes, carry signals from the syncytiotrophoblast to the mother. We hypothesized that STBEV-bound eNOS (STBEV-eNOS), capable of producing NO, are released into the maternal circulation. Dual-lobe ex vivo placental perfusion and differential centrifugation was used to isolate STBEV from preeclampsia (n=8) and normal pregnancies (NP; n=11). Plasma samples of gestational age-matched preeclampsia and NP (n=6) were used to isolate circulating STBMV. STBEV expressed placental alkaline phosphatase, confirming placental origin. STBEV coexpressed eNOS, but not inducible nitric oxide synthase, confirmed using Western blot, flow cytometry, and immunodepletion. STBEV-eNOS produced NO, which was significantly inhibited by N
G -nitro-l-arginine methyl ester (eNOS inhibitor; P <0.05) but not by N -(3-(aminomethyl) bezyl) acetamidine) (inducible nitric oxide synthase inhibitor). STBEV-eNOS catalytic activity was confirmed by visualizing eNOS dimerization. STBEV-eNOS was more abundant in uterine vein compared with peripheral blood, indicating placental origin. STBEV isolated from preeclampsia-perfused placentae had lower levels of STBEV-eNOS (STBMV; P <0.05) and overall lower NO activity (STBMV, not significant; syncytiotrophoblast extracellular exosomes, P <0.05) compared with those from NP. Circulating plasma STBMV from preeclampsia women had lower STBEV-eNOS expression compared with that from NP women ( P <0.01). This is the first observation of functional eNOS expressed on STBEV from NP and preeclampsia placentae, as well as in plasma. The lower STBEV-eNOS NO production seen in preeclampsia may contribute to the decreased NO bioavailability in this disease., (© 2017 The Authors.)- Published
- 2017
- Full Text
- View/download PDF
19. UK-Russia Researcher Links Workshop: extracellular vesicles - mechanisms of biogenesis and roles in disease pathogenesis, M.V. Lomonosov Moscow State University, Moscow, Russia, 1-5 March 2015.
- Author
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Kapustin AN, Kalinina N, Lopatina T, Davidson SM, Iraci N, Tamkovich S, Smyth L, Ter-Ovanesyan D, Evtushenko EG, Savelieva O, Bertazzo S, Aushev V, Dragovic R, Gracia T, Heck M, Parfyonova YV, Shanahan CM, and Tkachuk V
- Published
- 2015
- Full Text
- View/download PDF
20. Extracellular vesicles and reproduction-promotion of successful pregnancy.
- Author
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Tannetta D, Dragovic R, Alyahyaei Z, and Southcombe J
- Subjects
- Animals, Extracellular Space, Female, Humans, Pregnancy Outcome, Obstetric Labor, Premature physiopathology, Pre-Eclampsia physiopathology, Pregnancy physiology, Reproduction physiology, Secretory Vesicles physiology
- Abstract
Extracellular vesicles (EVs) are membrane-bound complexes secreted from cells under both physiological and pathological conditions. They contain proteins, nucleic acids and lipids and act as messengers for cell-cell communication and signalling, particularly between immune cells. EV research is a rapidly evolving and expanding field, and it appears that all biological fluids contain very large numbers of EVs; they are produced from all cells that have been studied to date, and are known to have roles in several reproductive processes. This review analyses the evidence for the role of EVs throughout human reproduction, starting with the paternal and maternal gametes, followed by the establishment and continuation of successful pregnancies, with specific focus, where possible, on the interaction of EVs with the maternal immune system. Importantly, variations within the EV populations are identified in various reproductive disorders, such as pre-term labour and pre-eclampsia.
- Published
- 2014
- Full Text
- View/download PDF
21. New mechanism for Notch signaling to endothelium at a distance by Delta-like 4 incorporation into exosomes.
- Author
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Sheldon H, Heikamp E, Turley H, Dragovic R, Thomas P, Oon CE, Leek R, Edelmann M, Kessler B, Sainson RC, Sargent I, Li JL, and Harris AL
- Subjects
- Adaptor Proteins, Signal Transducing, Animals, Calcium-Binding Proteins, Cell Communication physiology, Cell Line, Tumor, Cells, Cultured, Endothelial Cells ultrastructure, Exosomes transplantation, Humans, Mice, Mice, Inbred BALB C, Mice, SCID, Neoplasm Transplantation, Neovascularization, Physiologic, Signal Transduction physiology, Transplantation, Heterologous, Endothelial Cells physiology, Exosomes physiology, Intercellular Signaling Peptides and Proteins physiology, Receptors, Notch physiology
- Abstract
Notch signaling is an evolutionary conserved pathway that is mediated by cell-cell contact. It is involved in a variety of developmental processes and has an essential role in vascular development and angiogenesis. Delta-like 4 (Dll4) is a Notch ligand that is up-regulated during angiogenesis. It is expressed in endothelial cells and regulates the differentiation between tip cells and stalk cells of neovasculature. Here, we present evidence that Dll4 is incorporated into endothelial exosomes. It can also be incorporated into the exosomes of tumor cells that overexpress Dll4. These exosomes can transfer the Dll4 protein to other endothelial cells and incorporate it into their cell membrane, which results in an inhibition of Notch signaling and a loss of Notch receptor. Transfer of Dll4 was also shown in vivo from tumor cells to host endothelium. Addition of Dll4 exosomes confers a tip cell phenotype on the endothelial cell, which results in a high Dll4/Notch-receptor ratio, low Notch signaling, and filopodia formation. This was further evidenced by increased branching in a tube-formation assay and in vivo. This reversal in phenotype appears to enhance vessel formation and is a new form of signaling for Notch ligands that expands their signaling potential beyond cell-cell contact.
- Published
- 2010
- Full Text
- View/download PDF
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