| 1. |
- Carlsson, Lena, et al.
(författare)
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High Concentrations of the Angiogenic Peptide VEGF-A in Seminal Fluid and its Association to Prostasomes
- 2016
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Ingår i: Clinical Laboratory. - 1433-6510. ; 62:8, s. 1515-1520
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Tidskriftsartikel (refereegranskat)abstract
- Background: Angiogenesis is the formation of new blood vessels by capillary sprouting from pre-existing vessels. This process is associated with increased expression of angiogenic factors like vascular endothelial growth factor (VEGF). The VEGF family consists of five members denoted VEGF-A, B, C, D and placenta growth factor (PlGF). Prostasomes are exosome-like extracellular vesicles existing in seminal plasma. The present study aimed at investigating the possible relationship between VEGF-A in seminal fluid and blood plasma and the prostasomal association of VEGF-A.Methods: Measurement of VEGF-A concentrations was carried out in seminal plasma from 40 males and in blood plasma from 40 male blood donors utilizing commercial ELISA kits. The prostasomal association of VEGF-A was investigated by flow cytometry.Results: We found highly elevated concentrations of VEGF-A in seminal fluid (median value 150000 pg/mL) compared with those of blood plasma. Flow cytometric analysis showed that VEGF-A is bound to the surface of prostasomes.Conclusions: Prostasomes and seminal plasma contain the angiogenic factor VEGF-A in high concentrations exceeding that of blood plasma by 1000 times.
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| 2. |
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| 3. |
- Dubois, Louise, et al.
(författare)
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Human erythrocyte-derived nanovesicles can readily be loaded with doxorubicin and act as anticancer agents
- 2018
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Ingår i: Cancer Research Frontiers. - : Cancer Research Frontiers. - 2328-5249. ; 4:1, s. 13-26
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: In future therapeutics new formulas are needed that assure lower doses, fewer side effects, targeted administration and protection of the drug from degradation. In a first step to fulfil the requirements defined above, we carried out an in vitro study by developing a new procedure to encapsulate drugs using native vesicles first from prostasomes and then from erythrocyte membranes known to be well tolerated. The new method for production of drug delivery vesicles utilized osmotic loading of detergent resistant membranes (DRMs).Materials and methods: DRMs of prostasomes and prepared human erythrocyte membranes were extracted and separated in a sucrose gradient at a density of 1.10 g/mL containing 1% Triton X-100. These DRMs were characterized by electron microscopy (transmission and scanning EM) and loaded with low and high molecular compounds. PC3 prostate cancer cells were treated with doxorubicin loaded DRMs in triplicate. DAPI (nuclear fluorescent stain) was included and fluorescence microscopic pictures were taken before the cells were trypsinized and counted after 48h.Results: The content of the well separated band was observed ultrastructurally as small spherical, double layered membrane vesicles, (DRM vesicles) which harbored hyperosmolar sucrose of the gradient. Encapsulated hyperosmolar sucrose induced a transient osmotic lysis of the DRM vesicles when suspended in isotonic buffer containing loading molecules allowing vesicular inclusion. After this proof of concept, the method was finally employed for doxorubicin loading of DRM vesicles from human erythrocytes. When incubating such vesicles with PC3 cells a complete arrest of growth was observed in sharp contrast to PC3 cells incubated with plain doxorubicin in similar conditions.Conclusion: The present results open up new possibilities for using DRM vesicles as drug delivery vesicles.
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| 4. |
- Dubois, Louise, et al.
(författare)
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Proteomic profiling of detergent resistant membranes (lipid rafts) of prostasomes
- 2015
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 14:11, s. 3015-3022
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Tidskriftsartikel (refereegranskat)abstract
- Prostasomes are exosomes derived from prostate epithelial cells through exocytosis by multivesicular bodies. Prostasomes have a bilayered membrane and readily interact with sperm. The membrane lipid composition is unusual with a high contribution of sphingomyelin at the expense of phosphatidylcholine and saturated and monounsaturated fatty acids are dominant. Lipid rafts are liquid-ordered domains that are more tightly packed than the surrounding non-raft phase of the bilayer. Lipid rafts are proposed to be highly dynamic, submicroscopic assemblies that float freely within the liquid disordered membrane bilayer and some proteins preferentially partition into the ordered raft domains. We asked the question whether lipid rafts do exist in prostasomes and, if so, which proteins might be associated with them. Prostasomes of density range 1.13-1.19g/mL were subjected to density gradient ultracentrifugation in sucrose fabricated by phosphate buffered saline (PBS) containing 1% Triton X-100 with capacity for banding at 1.10g/mL, i.e. the classical density of lipid rafts. Prepared prostasomal lipid rafts (by gradient ultracentrifugation) were analyzed by mass spectrometry and electron microscopy. The clearly visible band on top of 1.10g/mL sucrose in the Triton X-100 containing gradient was subjected to LC-MS/MS and more than 370 lipid raft associated proteins were identified. Several of them were involved in intraluminal vesicle formation, e.g. tetraspanins, ESCRTs and Ras-related proteins. This is the first comprehensive LC-MS/MS profiling of proteins in lipid rafts derived from exosomes. Data are available via ProteomeXchange with identifier PXD002163.
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| 5. |
- Inayat, S, et al.
(författare)
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High levels of cathepsins B, L and S in human seminal plasma and their association with prostasomes
- 2012
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Ingår i: Andrologia. - : Hindawi Limited. - 0303-4569 .- 1439-0272. ; 44:6, s. 423-427
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Tidskriftsartikel (refereegranskat)abstract
- Semen is a heterogenous and complex fluid with different functions, some of them well known, others still obscure. The aim of this study was to investigate the presence of cathepsins B, S and L in human seminal plasma and their possible associations with other semen variables. Cathepsin B, L and S concentrations were measured in seminal plasma from 99 men utilising commercial ELISA kits. Seminal plasma cathepsin B was approximately 70 times higher, while the cathepsin L values were approximately 500 times higher and the cathepsin S values approximately 40 times higher in seminal plasma than in a group of serum samples. The study shows that seminal plasma contains high levels of cathepsins B, L and S. All three cathepsins were also bound to the surface of prostasomes.
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| 6. |
- Larssen, Pia, et al.
(författare)
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Tracing Cellular Origin of Human Exosomes Using Multiplex Proximity Extension Assay
- 2017
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 16:3, s. 502-511
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular vesicles (EVs) are membrane-coated objects such as exosomes and microvesicles, released by many cell-types. Their presence in body fluids and the variable surface composition and content render them attractive potential biomarkers. The ability to determine their cellular origin could greatly move the field forward. We used multiplex proximity extension assays (PEA) to identify with high specificity and sensitivity the protein profiles of exosomes of different origins, including seven cell lines and two different body fluids. By comparing cells and exosomes, we successfully identified the cells originating the exosomes. Furthermore, by principal component analysis of protein patterns human milk EVs and prostasomes released from prostate acinar cells clustered with cell lines from breast and prostate tissues, respectively. Milk exosomes uniquely expressed CXCL5, MIA and KLK6, while prostasomes carried NKX31, GSTP1 and SRC, highlighting that EVs originating from different origins express distinct proteins. In conclusion, PEA provides a powerful protein screening tool in exosome research, for purposes of identifying the cell source of exosomes, or new biomarkers in diseases such as cancer and inflammation.
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| 7. |
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| 8. |
- Nickel, Katrin F., et al.
(författare)
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The polyphosphate-factor XII pathway drives coagulation in prostate cancer-associated thrombosis
- 2015
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Ingår i: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 126:11, s. 1379-1389
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Tidskriftsartikel (refereegranskat)abstract
- Cancer is a leading cause of thrombosis. We identify a new procoagulant mechanism that contributes to thromboembolism in prostate cancer and allows for safe anticoagulation therapy development. Prostate cancer-mediated procoagulant activity was reduced in plasma in the absence of factor XII or its substrate of the intrinsic coagulation pathway factor XI. Prostate cancer cells and secreted prostasomes expose long chain polyphosphate on their surface that colocalized with active factor XII and initiated coagulation in a factor XII-dependent manner. Polyphosphate content correlated with the procoagulant activity of prostasomes. Inherited deficiency in factor XI or XII or high-molecular-weight kininogen, but not plasma kallikrein, protected mice from prostasome-induced lethal pulmonary embolism. Targeting polyphosphate or factor XII conferred resistance to prostate cancer-driven thrombosis in mice, without increasing bleeding. Inhibition of factor XII with recombinant 3F7 antibody reduced the increased prostasome-mediated procoagulant activity in patient plasma. The data illustrate a critical role for polyphosphate/factor XII-triggered coagulation in prostate cancer-associated thrombosis with implications for anticoagulation without therapy-associated bleeding in malignancies.
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| 9. |
- Ronquist, Göran, et al.
(författare)
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Human Prostasomes Contain Chromosomal DNA
- 2009
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Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 69:7, s. 737-743
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. The aim of this study was to perform a comprehensive evaluation of the occurrence of DNA in human prostasomes. METHODS. Prostasomes were purified from seminal fluid (seminal prostasomes) and from PC-3-cells (PC-3 cell prostasomes). DNA extracted from both sources of prostasomes was visualized on agarose gels. Further, theDNAwas cloned and sequenced (13 clones from seminal prostasomal DNAand 16 clones from PC-3 cell prostasomal DNA) and identified by alignment in the BLAST-nucleotide search database. In order to decide if the DNA was internally or externally located in/on prostasomes, prostasomes were treated with nuclease (DNase) and A260 was measured before and after treatment. Additionally, flow cytometric studies were performed with membrane permeable and membrane impermeable DNA stains. RESULTS. We identified human chromosomal DNA in purified prostasomes from both sources and treatment with DNase demonstrated that the prostasome-shielded DNA was protected from enzyme attack. Membrane-permeable DNA stain raised the fluorescence contrary to membrane-impermeable stain. Clearly discernible nucleic acid of prostasomes was separated on 1% agarose gel yieldingDNAfragments of about 13 kbp and below with a marked band at about 1 kbp. Cloning and sequencing of 13 fragments from seminal prostasomes and 16 from PC-3 cell prostasomes revealed a chromosomal origin of the DNA. In purified seminal prostasomes, 4 out of 13 DNA clones featured gene sequences (31%). The corresponding figure for PC3-derived prostasomes was 4 out of 16 clones featuring gene sequences (25%). CONCLUSION. Human prostasomes contain chromosomal DNA. Both nuclease treatment and differential DNA stainings indicated an inside location of the prostasomal DNA. Our findings suggest a DNA-delivery function of prostasomes to sperm cells.
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| 10. |
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| 11. |
- Ronquist, Göran K, et al.
(författare)
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Biochemical characterization of stallion prostasomes and comparison to their human counterparts
- 2013
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Ingår i: Systems biology in reproductive medicine. - : Informa UK Limited. - 1939-6376 .- 1939-6368. ; 59:6, s. 297-303
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Tidskriftsartikel (refereegranskat)abstract
- Release of nanometer-sized prostasomes into human and equine semen suggests essential functions in their relationships with sperm cells and the fertilization process. The two types of prostasomes displayed ultrastructural similarities, albeit the human prostasomes were somewhat larger than the stallion prostasomes. A high ratio of saturated fatty acids was characteristic for the two prostasome types. Electrophoretic separation systems revealed an equine prostasomal pattern different from that of human. The 21 distinctive low molecular weight protein spots in the 2D-gel (with no counterparts in human prostasomes) were identified via peptide mass fingerprinting, several of which may be different isoforms. Out of the three high molecular weight bands characteristic for human prostasomes (CD10, CD13, and CD26), CD10 and CD13 were retrieved in equine prostasomes. We present some new proteins of horse prostasomes not found in their human counterparts. Further studies are warranted to reveal the function of these proteins.
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| 12. |
- Ronquist, Göran K., et al.
(författare)
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Prostasomal DNA Characterization and Transfer Into Human Sperm
- 2011
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Ingår i: Molecular Reproduction and Development. - : Wiley. - 1040-452X .- 1098-2795. ; 78:7, s. 467-476
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Tidskriftsartikel (refereegranskat)abstract
- Human prostasomes, exosome-like microvesicles secreted by acinar cells of the prostate gland, contain chromosomal DNA. Agarose gel electrophoresis of DNA from seminal prostasomes displayed fragments of over 12 kb and smaller, with a distinct band around 1 kb that was excised, cloned, and sequenced. The sequences showed 8 out of 25 clones (32%) originating from genes. We elaborated the concept further by carrying out a genome-wide DNA copy number analysis of prostasomal DNA, hypothesizing that human prostasomes contain fragments of DNA randomly selected from the entire genome. Acridine orange-stained prostasomes were incubated with freshly prepared sperm for different times, and a transfer of acridine orange-stained prostasomal DNA to sperm (preferentially the head region) was observed. Fluorescence microscopy of slices in the center of 14 optical slides of the sperm head displayed an even fluorescence rather than a halo-like one, indicating DNA-uptake rather than just binding along the sperm head membrane.
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| 13. |
- Ronquist, Göran K, et al.
(författare)
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Prostasomes are heterogeneous regarding size and appearance but affiliated to one DNA-containing exosome family
- 2012
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Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 72:16, s. 1736-1745
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Prostate acinar epithelial cells release microvesicles (prostasomes) that possess pleiotropic biological effects relevant for successful fertilization. Prostasomes are formed in a similar way as exosomes but are heterogeneous as regards size and appearance. Like exosomes they are thought to be mediators of intercellular communication.METHODS:We prepared seminal prostasomes in accordance with the prevailing protocol for exosome preparation including passage through a 0.2 µm filter and centrifugation in a sucrose gradient.RESULTS:We compared the "filterable prostasomes" with those trapped on the filter ("nonfilterable prostasomes") and, qualitatively, no conspicuous differences were apparent regarding ultrastructure and SDS-PAGE banding pattern. Moreover, both types of prostasomes contained DNA fragments and Western blot revealed presence of prostate specific membrane antigen (PSMA), CD38, and annexin A1.CONCLUSIONS: Reasonably, prostasomes could be included in the exosome family and be regarded as one entity containing chromosomal DNA.
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| 14. |
- Ronquist, Göran, et al.
(författare)
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Prostasome-derived proteins capable of eliciting an immune response in prostate cancer patients
- 2006
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Ingår i: International Journal of Cancer. - : Wiley. - 0020-7136 .- 1097-0215. ; 119:4, s. 847-853
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Tidskriftsartikel (refereegranskat)abstract
- Prostate cancer consistently remains a difficult clinical enigma. Therefore, the development of novel strategies for diagnosis and treatment (e.g. immunotherapy) of prostate cancer is essential. We tried to identify the prostasome-derived proteins that were immunogenic in prostate cancer patients. Prostate cancer patients’ sera (n 5 44) with high enzyme-linked immunosorbent assay (ELISA) titers against prostasomes were selected for immunoblotting against purified seminal prostasomes. The SDS-PAGE and immunoblotting experiments were performed with Bio-Rad systems. Twenty-five of the recognized proteins were isolated and analyzed by means of mass spectrometry. Out of 44 patients’ sera, 31 (70%) demonstrated in immunoblotting experiments reactivity against several prostasomal protein bands in the molecular weight range of 10– 200 kDa. Some of the bands (55, 70 and 170 kDa) were more frequently recognized by the patients’ sera. Concomitantly run control sera generated only very weak or no bands at all. The most frequently occurring prostasomal proteins were identified as heat shock proteins (HSP 70, 71) and clusterin. This study identified the most important molecular targets of autoantibodies against prostasomes generated in connection with the development of prostate cancer in man. These immunogenic prostasomal proteins could be appropriate target molecules for specific immunotherapy of prostate cancer patients.
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| 15. |
- Ronquist, Göran, et al.
(författare)
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Proteomic analysis of prostate cancer metastasis : derived prostasomes
- 2010
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Ingår i: Anticancer Research. - 0250-7005 .- 1791-7530. ; 30:2, s. 285-290
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Tidskriftsartikel (refereegranskat)abstract
- The secretory epithelial cells of the prostate gland use sophisticated vehicles in the form of prostasomes to relay important information to sperm cells in semen. This prostasome-forming and secretory ability of the epithelial cells is also preserved in poorly differentiated prostate cancer cells. We investigated prostasomes from vertebral metastases of prostate cancer, taken from the operating field at surgery, directly taken care of under protease inhibitory conditions for later 2-dimensional electrophoresis and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) protein characterization. A total of 104 spots were punched out for identification. Twenty five unique protein spots had a MALDI-TOF above 49 and another 5 proteins were determined by MS/MS. The remaining 74 spots were either identical to already determined proteins or had no reliable score. Annexins A1, A3, and A5 as well as dimethylarginine dimethylaminohydrolase 1 were among the identified proteins. The annexins and dimethylarginine dimethylaminohydrolase 1 found in cancer-derived prostasomes can act, among other things, as angiogenic factors and can increase the vascular development in the neighborhood of the tumor. Cancer-derived prostasomes may play an important role in the interaction between tumor cells and their environment.
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| 16. |
- Ronquist, Göran, et al.
(författare)
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Serum antibodies against prostasomal clusterin in prostate cancer patients
- 2008
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Ingår i: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 68:3, s. 219-227
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Clusterin is a ubiquitous secretory sulphated glycoprotein present in prostasomes. It is an antiapoptotic mediator in prostate cancer and is among the most frequently occurring prostasomal proteins immunogenic in prostate cancer patients. The aim of the present study was to investigate the occurrence of anticlusterin antibodies in the serum of patients with prostate cancer and whether there is a relationship between anticlusterin antibody titres and other clinico-pathological variables. Material and methods. Serum samples were collected from 391 consecutive patients with suspected prostate cancer (150 benign prostate and 241 prostate cancer). The patients’ serum samples were used in an ELISA where microtitre wells were coated with purified clusterin from serum of a healthy volunteer. Flow cytometric studies of clusterin and prostasomes were performed. Results. Flow cytometric analyses revealed the presence of clusterin on the surface of seminal prostasomes. Anti-clusterin ELISA titres in sera of patients did not differ significantly from those of a control group. A significant ‘‘inverse’’ correlation existed between anti-clusterin ELISA titres and lymph node metastases (p50.047), but only 11 out of 161 patients had metastases. These titres correlated significantly with total prostate (p50.021) and transitional zone (p50.015) volumes of the patients. Conclusions. The correlation between serum anti-clusterin antibody titres and other clinico-pathological variables was generally weak in prostate cancer patients, although clusterin has been assigned an important role in tumourigenesis and progression of prostate cancer. However, the anti-clusterin antibody titre appeared to be related to prostate volume, correlating to both transitional zone volume and total volume of the prostate.
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| 17. |
- Ronquist, Karl Göran, et al.
(författare)
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Energy-requiring uptake of prostasomes and PC3 cell-derived exosomes into non-malignant and malignant cells
- 2016
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Ingår i: Journal of Extracellular Vesicles. - : Wiley. - 2001-3078. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Epithelial cells lining the prostate acini release, in a regulated manner (exocytosis), nanosized vesicles called prostasomes that belong to the exosome family. Prostate cancer cells have preserved this ability to generate and export exosomes to the extracellular space. We previously demonstrated that human prostasomes have an ATP-forming capacity. In this study, we compared the capacity of extracellular vesicles (EVs) to generate ATP between normal seminal prostasomes and exosomes secreted by PC3 cells (PC3 exosomes), a prostate cancer cell line. Proteomic analyses identified enzymes of the glycolytic chain in both prostasomes and PC3 exosomes, and we found that both of them were capable of generating ATP when supplied with substrates. Notably, the net production of extracellular ATP was low for prostasomes due to a high ATPase activity contrary to an elevated net ATP level for PC3 exosomes because of their low ATPase activity. The uptake of the 2 types of EVs by normal prostate epithelial cells (CRL2221) and prostate cancer cells (PC3) was visualized and measured, demonstrating differential kinetics. Interestingly, this uptake was dependent upon an ongoing glycolytic flux involving extracellular ATP formation by EVs and/or intracellular ATP produced from the recipient cells. We conclude that the internalization of EVs into recipient cells is an energy-requiring process also demanding an active V-ATPase and the capacity of EVs to generate extracellular ATP may play a role in this process.
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| 18. |
- Ronquist, K Göran, et al.
(författare)
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Human prostasomes express glycolytic enzymes with capacity for ATP production
- 2013
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Ingår i: American Journal of Physiology. Endocrinology and Metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 304:6, s. E576-E582
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Tidskriftsartikel (refereegranskat)abstract
- Prostasomes are prostate-derived, exosome-like microvesicles that transmit signaling complexes between the acinar epithelial cells of the prostate and sperm cells. A vast majority of prostasomes has a diameter of 30 - 200 nm and they are generally surrounded by a classical membrane bilayer. Using a selected proteomic approach, it became increasingly clear that prostasomes harbor distinct subsets of proteins that may be linked to adenosine triphosphate (ATP) metabolic turnover that in turn might be of importance in the role of prostasomes as auxiliary instruments in the fertilization process. Among the 21 proteins identified most of the enzymes of anaerobic glycolysis were represented and three of the glycolytic enzymes present are among the ten top proteins found in most exosomes, once again linking prostasomes to the exosome family. Other prostasomal enzymes involved in ATP turnover were adenylate kinase, ATPase, 5'-nucleotidase and hexose transporters. The identified enzymes in their prostasomal context were operational for ATP formation when supplied with substrates. The net ATP production was low due to a high prostasomal ATPase activity that could be partially inhibited by vanadate that was utilized in order to profile the ATP forming ability of prostasomes. Glucose and fructose were equivalent as glycolytic substrates for prostasomal ATP formation and the enzymes involved were apparently surface-located on prostasomes, since an alternative substrate not being membrane-permeable (glyceraldehyde 3-phosphate) was operative, too. There is no clear cut function linked to this subset of prostasomal proteins but some possible roles are discussed.
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| 19. |
- Ronquist, K Göran, et al.
(författare)
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Prostasomes from four different species are able to produce extracellular adenosine triphosphate (ATP)
- 2013
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Ingår i: Biochimica et Biophysica Acta - General Subjects. - : Elsevier BV. - 0304-4165 .- 1872-8006. ; 1830:10, s. 4604-4610
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Prostasomes are extracellular vesicles. Intracellularly they are enclosed by another larger vesicle, a so called "storage vesicle" equivalent to a multivesicular body of late endosomal origin. Prostasomes in their extracellular context are thought to play a crucial role in fertilization.METHODS:Prostasomes were purified according to a well worked-out schedule from seminal plasmas obtained from human, canine, equine and bovine species. The various prostasomes were subjected to SDS-PAGE separation and protein banding patterns were compared. To gain knowledge of the prostasomal protein systems pertaining to prostasomes of four different species proteins were analyzed using a proteomic approach. An in vitro assay was employed to demonstrate ATP formation by prostasomes of different species.RESULTS:The SDS-PAGE banding pattern of prostasomes from the four species revealed a richly faceted picture with most protein bands within the molecular weight range of 10-150kDa. Some protein bands seemed to be concordant among species although differently expressed and the number of protein bands of dog prostasomes seemed to be distinctly fewer. Special emphasis was put on proteins involved in energy metabolic turnover. Prostasomes from all four species were able to form extracellular adenosine triphosphate (ATP). ATP formation was balanced by ATPase activity linked to the four types of prostasomes.CONCLUSION:These potencies of a possession of functional ATP-forming enzymes by different prostasome types should be regarded against the knowledge of ATP having a profound effect on cell responses and now explicitly on the success of the sperm cell to fertilize the ovum.GENERAL SIGNIFICANCE:This study unravels energy metabolic relationships of prostasomes from four different species.
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| 20. |
- Ahlström, Katarina, 1966, et al.
(författare)
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Exogenous carbon monoxide does not affect cell membrane energy availability assessed by sarcolemmal calcium fluxes during myocardial ischaemia-reperfusion in the pig
- 2011
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Ingår i: European Journal of Anaesthesiology. - 0265-0215 .- 1365-2346. ; 28:5, s. 356-362
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Tidskriftsartikel (refereegranskat)abstract
- Carbon monoxide is thought to be cytoprotective and may hold therapeutic promise for mitigating ischaemic injury. The purpose of this study was to test low-dose carbon monoxide for protective effects in a porcine model of acute myocardial ischaemia and reperfusion. In acute open-thorax experiments in anaesthetised pigs, pretreatment with low-dose carbon monoxide (5% increase in carboxyhaemoglobin) was conducted for 120 min before localised ischaemia (45 min) and reperfusion (60 min) was performed using a coronary snare. Metabolic and injury markers were collected by microdialysis sampling in the ventricular wall. Recovery of radio-marked calcium delivered locally by microperfusate was measured to assess carbon monoxide treatment effects during ischaemia/reperfusion on the intracellular calcium pool. Coronary occlusion and ischaemia/reperfusion were analysed for 16 animals (eight in each group). Changes in glucose, lactate and pyruvate from the ischaemic area were observed during ischaemia and reperfusion interventions, though there was no difference between carbon monoxide-treated and control groups during ischaemia or reperfusion. Similar results were observed for glycerol and microdialysate Ca-45(2+) recovery. These findings show that a relatively low and clinically relevant dose of carbon monoxide did not seem to provide acute protection as indicated by metabolic, energy-related and injury markers in a porcine myocardial ischaemia/reperfusion experimental model. We conclude that protective effects of carbon monoxide related to ischaemia/reperfusion either require higher doses of carbon monoxide or occur later after reperfusion than the immediate time frame studied here. More study is needed to characterise the mechanism and time frame of carbon monoxide-related cytoprotection.
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| 21. |
- Ahlström, Katarina, 1966, et al.
(författare)
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Metabolic responses in ischemic myocardium after inhalation of carbon monoxide.
- 2009
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Ingår i: Acta Anaesthesiol Scand. - : Wiley. - 1399-6576 .- 0001-5172. ; 53:8, s. 1036-42
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: To clarify the mechanisms of carbon monoxide (CO) tissue-protective effects, we studied energy metabolism in an animal model of acute coronary occlusion and pre-treatment with CO. METHODS: In anesthetized pigs, a coronary snare and microdialysis probes were placed. CO (carboxyhemoglobin 5%) was inhaled for 200 min in test animals, followed by 40 min of coronary occlusion. Microdialysate was analyzed for lactate and glucose, and myocardial tissue samples were analyzed for adenosine tri-phosphate, adenosine di-phosphate, and adenosine mono-phosphate. RESULTS: Lactate during coronary occlusion was approximately half as high in CO pre-treated animals and glucose levels decreased to a much lesser degree during ischemia. Energy charge was no different between groups. CONCLUSIONS: CO in the low-doses tested in this model results in a more favorable energy metabolic condition in that glycolysis is decreased in spite of maintained energy charge. Further work is warranted to clarify the possible mechanistic role of energy metabolism for CO protection.
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| 22. |
- Akerud, Helena, et al.
(författare)
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Lactate distribution in culture medium of human myometrial biopsies incubated under different conditions
- 2009
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Ingår i: American Journal of Physiology. Endocrinology and Metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 297:6, s. E1414-E1419
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Tidskriftsartikel (refereegranskat)abstract
- It is generally believed that a relationship exists between muscle fatigue and intracellular accumulation of lactate. This reasoning is relevant to obstetrical issues. Myocytes in uterus work together during labor, and the contractions need to be strong and synchronized for a child to be delivered. At labor dystocia, the progress of labor becomes slow or arrested after a normal beginning. It has been described that, during labor dystocia, when the force of the contractions is low, the uterus is under hypoxia, and anaerobic conditions with high levels of lactate in amniotic fluid dominate. The purpose of this study was to examine whether myometrial cells are involved in the production of lactate in amniotic fluid and whether there are differences in production and distribution of lactate in cells incubated under aerobic and anaerobic conditions. We also wanted to elucidate the involvement of specific membrane-bound lactate carriers. Women undergoing elective caesarean section were included. Myometrial biopsies from uteri were collected and subjected to either immunohistochemistry to identify lactate carriers or in vitro experiments to analyze production of lactate. The presence of lactate carriers named monocarboxylate transporters 1 and 4 was verified. Myometrial cells produced lactate extracellularly, and the lactate carriers operated differently under anaerobic and aerobic conditions; while being mainly unidirectional under anaerobic conditions, they became bidirectional under aerobic conditions. Human myometrial cells produced and delivered lactate to the extracellular medium under both anaerobic and aerobic conditions. The delivery was mediated by lactate carriers.
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| 23. |
- Andersson, Arne, et al.
(författare)
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A substantial increase of the impact factor
- 2012
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 117:4, s. 353-354
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Tidskriftsartikel (refereegranskat)
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| 24. |
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| 25. |
- Axelson, Hans W, et al.
(författare)
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Microdialysis and electromyography of experimental muscle fatigue in healthy volunteers and patients with mitochondrial myopathy
- 2002
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Ingår i: Muscle and Nerve. - : Wiley. - 0148-639X .- 1097-4598. ; 26:4, s. 520-526
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Tidskriftsartikel (refereegranskat)abstract
- Consecutive 60-min microdialysis samples were taken from the tibial anterior muscle in 11 healthy subjects and 4 patients with mitochondrial myopathy before (2-3 samples) and after (3-4 samples, 2 controls and 1 patient excluded) sustained isometric foot dorsiflexions. Before exercise, mean concentrations of lactate, pyruvate, hypoxanthine, urate, aspartate, and glutamate did not significantly differ between controls and patients. After exercise, the controls showed significantly increased concentrations of lactate, pyruvate, and urate, decreased hypoxanthine, and no change in aspartate and glutamate. Similar findings were observed in the patients. Plasma lactate was unchanged. Exercise-induced increase in integrated electromyogram amplitude and rated subjective fatigue were correlated to increased post-exercise lactate concentrations, with no obvious difference between the groups. Microdialysis of skeletal muscle allows the detection and monitoring of biochemical changes in the interstitial space. With the exercise protocol used, however, it was not possible to demonstrate any biochemical difference between healthy controls and patients with mitochondrial myopathy.
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| 26. |
- Babiker, Adil A., et al.
(författare)
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Mapping pro- and antiangiogenic factors on the surface of prostasomes of normal and malignant cell origin
- 2010
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Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 70:8, s. 834-847
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Angiogenesis is the formation of new blood vessels by capillary sprouting from pre-existing vessels. Tumor growth is angiogenesis-dependent and the formation of new blood vessels is associated with the increased expression of angiogenic factors. Prostasomes are secretory granules produced, stored and released by the glandular epithelial cells of the prostate. We investigated the expression of selected angiogenic and anti-angiogenic factors on the surface of prostasomes of different origins as well as the direct effect of prostasomes on angiogenesis. METHODS: VEGF, endothelin-1, endostatin, and thrombospondin-1 were determined on prostasomes from seminal fluid and human prostate cancer cell lines (DU145,PC-3,LNCaP) using different immunochemical techniques. Human dermal microvascular endothelial cells were incubated with seminal and DU145 cell-prostasomes and with radioactive thymidine. The effect of prostasomes on angiogenesis was judged by measuring the uptake of labeled thymidine. The presence of any deleterious effects of prostasomes on the endothelial cells was investigated using thymidine assay and confocal laser microscopy. RESULTS: VEGF and endothelin-1 were determined on malignant cell-prostasomes (no difference between cell lines) but not determined on seminal prostasomes. The same applies for the expression of endostatin but with much higher expression on malignant cell-prostasomes with obvious differences between them. Seminal and DU145 cell-prostasomes were found to have anti-angiogenic effect which was more expressed by DU145 cell-prostasomes. No deleterious effect of prostasomes on endothelial function was detected using either thymidine assay or microscopy. CONCLUSIONS: Prostasomes contain pro- and anti-angiogenic factors that function to counteract each other unless the impact from one side exceeds the other to bring about dysequilibrium.
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| 27. |
- Babiker, Adil A., et al.
(författare)
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Overexpression of ecto-protein kinases in prostasomes of metastatic cell origin
- 2006
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Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 66:7, s. 675-686
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Prostasomes are secretory granules produced, stored, and released by the glandular epithelial cells of the prostate. They express numerous enzymes whose physiological roles have so far not been fully evaluated. In this study, we investigated the expression and function of prostasomal protein kinases and ATPase.METHODS:The protein kinase activities of prostasomes isolated from seminal fluid and malignant prostate cell lines (PC-3, DU145, and LNCaP) were investigated using the model phosphorylation substrates histone and casein, as well as the plasma proteins C3 and fibrinogen, in combination with specific protein kinase inhibitors. The prostasomal ATPase activity was also evaluated. The expression of protein kinases and ATPase on prostasomes was verified by flow cytometry.RESULTS:Prostasomes (intact or solubilized with octylglucoside or saponin) from prostate cancer cells had higher expression of protein kinases A, C, and casein kinase II compared to prostasomes isolated from seminal plasma, resulting in higher phosphorylation of both exogenous and endogenous substrates. Using intact prostasomes, it was found that prostasomes of metastatic origin had lower ATPase activity, resulting in higher residual ATP available for the phosphorylation reaction. Finally, complement component C3 and fibrinogen (two proteins whose activities are modulated by phosphorylation) were identified as physiologically relevant phosphorylation substrates.CONCLUSIONS:These results indicate that prostasomes are capable of modifying proteins possibly involved in the innate response by extracellular phosphorylation mediated by ecto-kinases. This is a novel mechanism by which prostatic malignant cells may interact with their environment.
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| 28. |
- Babiker, Adil A., et al.
(författare)
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Prostasome Involvement in the Development and Growth of Prostate Cancer
- 2010
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Ingår i: The Open Prostate Cancer Journal. - : Bentham Science Publishers Ltd.. - 1876-8229. ; 3, s. 1-13
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Forskningsöversikt (refereegranskat)abstract
- Prostasomes are extracellularly occurring submicron, membrane-surrounded organelles produced by the epithelial cells of the prostate and present in semen after secretion. Even dedifferentiated prostate cancer cells have preserved their ability to produce and export prostasomes to the extracellular space. The precise physiological role of prostasomes is not known, although some of their properties assign them to important physiological and patho-physiological functions that could be exploited in prostate cancer growth and development. In this review, some new properties of seminal and malignant cell line (DU145, PC-3 and LNCaP) prostasomes will be discussed. There are typical differences in the expressions and activities of prostasomal CD59, ATPase, protein kinases and tissue factor (TF) as well as in the transfer of prostasomal CD59 to CD59-deficient erythrocytes (rabbit and human PNH erythrocytes). CD59, protein kinases and TF exhibit characteristic patterns of overexpression by malignant cell prostasomes. A high ATPase activity is recognized on seminal prostasomes with minimal activity on malignant cell prostasomes resulting in more residual ATP available for phosphorylation reactions. Several proteins are phosphorylated by prostasomal protein kinases, namely, complement component C3, fibrinogen, vitronectin and E-cadherin. Furthermore, TF is identified as the main endogenous phosphorylation substrate on prostasomes. In addition, prothrombotic effects of prostasomes are demonstrated. DU145 and PC-3 cell-derived prostasomes exert a higher clotting effect on whole blood and plasma compared to LNCaP cell-derived and seminal prostasomes. In conclusion, malignant cell prostasomes show an increased ability to interact with the biological system in favor of prostate cancer cell promotion and survival. The roles played by prostasomes in this context may improve the understanding of the mechanisms that help the prostate cancer cells to avoid the complement attack (CD59 transfer and phosphorylation and inactivation of C3), to promote angiogenesis (TF) and to metastasize. It may also provide a better understanding of some of the complications usually seen in some terminal prostate cancer patients like thrombotic events and tendency to develop disseminated intravascular coagulation.
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| 29. |
- Babiker, Adil A., et al.
(författare)
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Prothrombotic effect of prostasomes of metastatic cell and seminal origin
- 2007
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Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 67:4, s. 378-388
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND. Prostasomes are secretory granules produced by the glandular epithelial cells of the prostate. Seminal prostasomes contain high amounts of Tissue Factor (TF) but no studies of TF on malignant cell prostasomes have been made. Here we compare the expression, phosphorylation, and function of TF on prostasomes of different origin. METHODS. TF was detected on prostasomes isolated from seminal fluid and human prostate cancer cell lines (PC-3, DU145, and LNCaP) using FACS and enzyme immunoassay (EIA). Incubation of prostasomes with radioactive ATP under conditions favoring protein kinase A activity led to phosphorylation of TF as detected by immunoprecipitation and SDS-PAGE. The prothrombotic effect of prostasomes was investigated in whole blood and recalcified plasma. Blocking experiments were performed using anti-TF antibodies and corn trypsin inhibitor. RESULTS. TF was expressed on all tested prostasome preparations with lowest values found for seminal ones. Prostasomal TF was the main endogenous substrate for prostasomal protein kinase A. All tested prostasome preparations greatly enhanced the rate of clot formation in a dose-dependent fashion, that is, the clotting capability of prostasomes seemed to be related to the extent of their expression of TF. In addition, the density of the clot varied between different prostasome preparations. When incubated in whole blood, prostasomes were found to associate to WBC thereby inducing them to express and release TF. CONCLUSIONS. These data show that TF is overexpressed and also subjected to phosphorylation by malignant cell prostasomes. This suggests major roles for prostasomes in thrombotic events that occur in some advanced cases of prostate cancer.
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| 30. |
- Babiker, Adil A., et al.
(författare)
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Prothrombotic effects of prostasomes isolated from prostatic cancer cell lines and seminal plasma
- 2007
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Ingår i: Seminars in Thrombosis and Hemostasis. - : Georg Thieme Verlag KG. - 0094-6176 .- 1098-9064. ; 33:1, s. 80-86
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Forskningsöversikt (refereegranskat)abstract
- Thromboembolism is well recognized as a major complication of cancer. Many tumor cells overexpress tissue factor (TF), which activates blood coagulation in cancer patients. Inflammatory cells expressing TF are also contributors to this activation. In prostate cancer, we believe that prostasomes may also be involved in the initiation of blood coagulation. Prostasomes are submicron secretory granules derived from the prostate gland. They are surrounded by membrane and their extracellular appearance and membrane architecture are complex. Seminal prostasomes are believed to be necessary for successful fertilization and act as protectors of the spermatozoa in the lower and upper female genital tract. Cells from prostate cancer and its metastases are able to produce and export prostasomes to the extracellular environment. These prostasomes may differ quantitatively rather than qualitatively from their normal counterparts with regard to protein composition and function. A majority of human prostate cancers have been found to overexpress TF, and we have demonstrated by various methods that prostasomes derived from prostate cancer cells express considerably higher levels of TF compared with prostasomes of nonmalignant cell origin. The mechanism related to thromboembolic disease generated by prostasomes in prostatic cancer patients may be the early release of prostasomes from prostate cancer cells into the blood circulation, where they will evoke their blood-clotting effects.
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| 31. |
- Babiker, Adil A., et al.
(författare)
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Transfer of functional prostasomal CD59 of metastatic prostatic cancer cell origin protects cells against complement attck
- 2005
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Ingår i: The Prostate. - : Wiley. - 0270-4137 .- 1097-0045. ; 62:2, s. 105-114
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Prostasomes are secretory granules produced, stored, and released, by the glandular epithelial cells of the prostate. They express the glycosylphosphatidylinositol (GPI)-anchored complement regulatory protein CD59, which has been shown to be transferred to spermatozoa and erythrocytes.METHODS: The CD59 content of prostasomes isolated from seminal fluid and malignant prostate cells (PC-3, DU145, and LNCaP) and the transfer of prostasomal CD59 to rabbit erythrocytes (RE) and to PIPLC-treated and unmanipulated cancer cells were investigated using FACS. All prostasomes were also incubated with RE and tested in a hemolytic assay.RESULTS: Prostasomes from cancer cells had higher expression of CD59 than those of normal cells. Prostasomal CD59 of different origin could be transferred to RE, malignant cell lines stripped of CD59 by PIPLC, or unmanipulated LNCaP cells. Malignant cell prostasomes had an increased ability to inhibit complement-mediated lysis compared to those from non-malignant cells.CONCLUSIONS: These results point to a novel mechanism by which prostasomes can protect prostatic malignant cells from complement attack.
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| 32. |
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| 33. |
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| 34. |
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| 35. |
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| 36. |
- Branth, Stefan, et al.
(författare)
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Development of abdominal fat and incipient metabolic syndrome in young healthy men exposed to long-term stress
- 2007
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Ingår i: NMCD. Nutrition Metabolism and Cardiovascular Diseases. - : Elsevier BV. - 0939-4753 .- 1590-3729. ; 17:6, s. 427-435
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIM: The sympathetic nervous system may be involved in the pathophysiology of insulin resistance and metabolic cardiovascular syndrome in young men. The aim was to study the effects of long-term stress on different features of the metabolic syndrome (MES) in formerly non-obese healthy young males during 5 months of defined conditions. METHODS AND RESULTS: Sixteen healthy male sailors (mean age 36.5 (SD)+/-7 years) participating in a sailing race around the world were recruited for the study. Investigations were done before the start and at stop overs after finishing laps 1, 2 and 4 (1, 2(1/2) and 5 months, respectively). Anthropometric and blood pressure data as well as biochemical data associated with MES were substantiated. Food intake and exercise were chartered and largely controlled. A mean weight loss of 4.5+/-2 kg (P<0.005), comprising both fat and lean body mass, was recorded during the first lap. Subsequently after 5 months, a weight gain, mainly consisting of 1.2+/-1.1 kg body fat (P<0.05), took place, concomitantly with a protein mass drop of 0.6+/-1.1 kg (P<0.05). The body fat gain accumulated on the abdominal region. Elevated blood levels of HbA1c, insulin and the triglycerides/high-density lipoprotein ratio were also observed during the race. Likewise heart rate and systolic blood pressure increased slightly but to a statistically significant extent. CONCLUSIONS: Non-obese healthy young men exposed to long-term stress developed abdominal obesity and signs of a metabolic syndrome in embryo, also emphasized by biochemical and blood pressure alterations. It is suggested that long-term and sustained stress activation might be an additional risk factor for the development of MES, even after control of dietary and exercise habits.
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| 37. |
- Branth, Stefan, 1959-
(författare)
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Energy Metabolic Stress Syndrome : Impact of Physical Activity of Different Intensity and Duration
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- All living cell functions require an ongoing supply of energy derived from carbohydrates, lipids and proteins with their own pathways of breakdown. All of them end up in the oxidation of reduced coenzymes, yielding chemically-bound energy in the form of adenosine triphosphate (ATP). One broad definition of energy would be the capability to do work and, therefore, the more work that has to be done, the more energy is needed, which may under extreme conditions put the cell into a state of energy metabolic stress. This complex of problems has been examined in the present thesis, where individuals representing different degrees of training status, have been subjected to various types of stressful work-loads as regards intensity and duration. Meanwhile, the energy turnover has been monitored on different levels as whole body (organism)-, single organ/tissue-, cellular and molecular levels. Combined methodologies have been developed and utilized to examine carefully and in some detail energy expenditure and biochemical variables with study subjects under long-term, (outfield) physically and mentally stressful conditions.When the individuals were in a well-controlled energy balance, a diet rich in saturated fatty acids did not elicit any major metabolic stress signs concerning serum lipoproteins and/or insulin/glucose homeostasis during the test period including high volume and low intensity energy turn over. Only a slight decrease in the Apo-B / Apo-A1 ratio was observed, despite a period of totally sedentary life style among the participants. Mental stress combined with a varying energy balance during off-shore sailing races was shown to cause such an energy metabolic stress situation that development of abdominal obesity and signs of a metabolic syndrome in embryo affected the participants who were young, non-obese men and despite their fairly healthy lifestyle concerning the diet they were on and their physical activity habits. Even well-trained young individuals of both sexes, subjected to exhaustive endurance (high intensity exercise session), developed signs of insulin resistance with a deteriorated intracellular glucose availability leading to a supposed ion pump failure and a disturbed osmoregulation on a cellular level. Hence, they presented themselves as having acquired an energy metabolic stress like condition.In conclusion, an energy metabolic stress syndrome has been described, basically due to impaired fuelling of ion pumps with a cluster of signs and symptoms on single organ/tissue-, cellular and molecular levels manifested by muscular intracellular swelling, tendency towards erythrocyte shrinkage as a consequence of a relative insulin resistance concomitant with ion distribution disturbances (Gardos effect), oxidative stress and osmoregulatory taurine leakage.
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| 38. |
- Branth, Stefan, et al.
(författare)
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Metabolic stress-like condition can be induced by prolonged strenuous exercise in athletes
- 2009
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Ingår i: Upsala Journal of Medical Sciences. - : Taylor & Francis. - 0300-9734 .- 2000-1967. ; 114:1, s. 12-25
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Tidskriftsartikel (refereegranskat)abstract
- Few studies have examined energy metabolism during prolonged, strenuous exercise. We wanted therefore to investigate energy metabolic consequences of a prolonged period of continuous strenuous work with very high energy expenditure. Twelve endurance-trained athletes (6 males and 6 females) were recruited. They performed a 7-h bike race on high work-load intensity. Physiological, biochemical, endocrinological, and anthropometric muscular compartment variables were monitored before, during, and after the race. The energy expenditure was high, being 5557 kcal. Work-load intensity (% of VO2 peak) was higher in females (77.7%) than in men (69.9%). Muscular glycogen utilization was pronounced, especially in type I fibres (>90%). Additionally, muscular triglyceride lipolysis was considerably accelerated. Plasma glucose levels were increased concomitantly with an unchanged serum insulin concentration which might reflect an insulin resistance state in addition to proteolytic glyconeogenesis. Increased reactive oxygen species (malondialdehyde (MDA)) were additional signs of metabolic stress. MDA levels correlated with glycogen utilization rate. A relative deficiency of energy substrate on a cellular level was indicated by increased intracellular water of the leg muscle concomitantly with increased extracellular levels of the osmoregulatory amino acid taurine. A kindred nature of a presumed insulin-resistant state with less intracellular availability of glucose for erythrocytes was also indicated by the findings of decreased MCV together with increased MCHC (haemoconcentration) after the race. This strenuous energy-demanding work created a metabolic stress-like condition including signs of insulin resistance and deteriorated intracellular glucose availability leading to compromised fuelling of ion pumps, culminating in a disturbed cellular osmoregulation indicated by taurine efflux and cellular swelling. © 2009 Informa UK Ltd All rights reserved.
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| 39. |
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| 40. |
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| 41. |
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| 42. |
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| 43. |
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| 44. |
- Carlsson, Lena, et al.
(författare)
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Mode of growth determines differential expression of prostasomes in cultures of prostate cancer cell lines and opens for studies of prostasome gene expression
- 2006
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Ingår i: Upsala Journal of Medical Sciences. - : Uppsala Medical Society. - 0300-9734 .- 2000-1967. ; 111:3, s. 293-301
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Tidskriftsartikel (refereegranskat)abstract
- The exocrine secretion of the acinar gland cells in the human prostate consists of, among other components, a serous secretion and prostasomes. The prostasomes are functionally associated with both reproduction and prostate cancer development and are capable to raise autoantibodies at various pathologies. Therefore, we are trying to characterize prostasome antigens by analysing prostasome- producing cell lines of prostate cancers with the cDNA microarray technique. To obtain one state with synthesis of prostasomes and another state without synthesis, we checked whether the prostasome differentiation was influenced by the mode of growing the cells, that is, whether the cells had been growing on a solid support or on a flexible one. We studied the expression of prostasomes in the cell lines PC3, DU145 and LNCaP. We grew the cells with the following methods: Monocellular layers on microbeads, multicellular spheroids, single cells in suspension cultures, and xenotransplants in nude rats. The presence of prostasomes was examined by ELISA, immunocytochemistry or electron microscopy. The results showed that growing the cells on microbeads (solid support) produced a differentiation of prostasomes, while growing the cells in multicellular spheroids (flexible support) did not. Thus it should be possible to apply cDNA microarray analyses for characterizing the genes which are active at the cellular expression of prostasomes and then deduce the prostasome antigens.
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| 45. |
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| 46. |
- Ek, Pia, et al.
(författare)
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Exogenous protein kinases A and C, but not endogenous prostasome-associated protein kinase, phosphorylate semenogelins I and II from human semen
- 2002
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Ingår i: Journal of Andrology. - 0196-3635 .- 1939-4640. ; 23:6, s. 806-814
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Tidskriftsartikel (refereegranskat)abstract
- Semenogelins I and II are the quantitatively dominating proteinsin humansemen. They comprise the major part of the sperm-entrappinggel formed atejaculation, which subsequently liquefies dueto proteolysis of thegel-forming proteins by prostate-specificantigen (PSA). The mechanism behindgel formation and its physiologicalsignificance is not known. We have studiedphosphorylation anddephosphorylation of human semenogelins. Both werephosphorylatedby protein kinases A and C (PKA and PKC, respectively) at arateabout 5 times less than that of histone. For PKA, incorporated(32P)phosphateinto semenogelin approached a maximum above 1mol/mol. Correspondingvalues for phosphorylation of the semenogelins with PKCweregreater than 10. There was no change in the sensitivity ofphosphosemenogelinsto proteolysis by PSA. Serine (PKA) and serine andthreonine(PKC) were the phosphate-accepting amino acid residues, andallincorporated (32P)phosphate could be removed from the semenogelinswithhuman acid phosphatase. Nil or very little phosphate could bedetected inpurified semenogelins isolated from seminal plasma.In vivo, about half theprotein kinase activity in seminal plasmawas bound to prostasomes. PKA butnot PKC purified from prostasomescould phosphorylate specific substrates, butthey could phosphorylateeither of the semenogelins.
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| 47. |
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| 48. |
- Falck, Bengt, et al.
(författare)
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New mechanism for amino acid influx into human epidermal Langerhans cells: L-dopa/proton counter-transport system.
- 2003
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Ingår i: Experimental Dermatology. - : Wiley. - 0906-6705. ; 12:5, s. 602-609
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Tidskriftsartikel (refereegranskat)abstract
- We have characterized a stereospecific transport mechanism for L-dopa into human epidermal Langerhans cells (LCs). It is different from any other amino acid transport system. It is highly concentrative, largely pH-independent, and independent of exogenous Na+, glucose and oxygen, and fuelled by a renewable intracellular energy source inhibited by iodoacetate but not by arsenate. We propose that the mechanism is a unidirectional L-dopa/proton counter-transport system. We have recently demonstrated anaerobic glycolysis in human epidermis, which substantiates the need of proton pumps for resident LCs. The findings prompt a re-evaluation of the profound changes LCs undergo when exposed to oxygen in aerobic culture. L-dopa is not metabolized by LCs but can rapidly be dislocated to the intercellular space by certain extracellular amino acids, i.e. LCs can profit by L-dopa in a dualistic way, altogether a remarkable biological phenomenon.
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| 49. |
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| 50. |
- Glynn, Anders, et al.
(författare)
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Immune cell counts and risks of respiratory infections among infants exposed pre- and postnatally to organochlorine compounds : a prospective study
- 2008
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Ingår i: Environmental Health. - 1476-069X. ; 7, s. 62-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Early-life chemical exposure may influence immune system development, subsequently affecting child health. We investigated immunomodulatory potentials of polychlorinated biphenyls (PCBs) and p,p'-DDE in infants. METHODS: Prenatal exposure to PCBs and p,p'-DDE was estimated from maternal serum concentrations during pregnancy. Postnatal exposure was calculated from concentrations of the compounds in mother's milk, total number of nursing days, and percentage of full nursing each week during the 3 month nursing period. Number and types of infections among infants were registered by the mothers (N = 190). White blood cell counts (N = 86) and lymphocyte subsets (N = 52) were analyzed in a subgroup of infants at 3 months of age. RESULTS: Infants with the highest prenatal exposure to PCB congeners CB-28, CB-52 and CB-101 had an increased risk of respiratory infection during the study period. In contrast, the infection odds ratios (ORs) were highest among infants with the lowest prenatal mono-ortho PCB (CB-105, CB-118, CB-156, CB-167) and di-ortho PCB (CB-138, CB-153, CB-180) exposure, and postnatal mono- and di-ortho PCB, and p,p'-DDE exposure. Similar results were found for pre- and postnatal CB-153 exposure, a good marker for total PCB exposure. Altogether, a negative relationship was indicated between infections and total organochlorine compound exposure during the whole pre- and postnatal period. Prenatal exposure to CB-28, CB-52 and CB-101 was positively associated with numbers of lymphocytes and monocytes in infants 3 months after delivery. Prenatal exposure to p,p'-DDE was negatively associated with the percentage of eosinophils. No significant associations were found between PCB and p,p'-DDE exposure and numbers/percentages of lymphocyte subsets, after adjustment for potential confounders. CONCLUSION: This hypothesis generating study suggests that background exposure to PCBs and p,p'-DDE early in life modulate immune system development. Strong correlations between mono- and di-ortho PCBs, and p,p'-DDE exposures make it difficult to identify the most important contributor to the suggested immunomodulation, and to separate effects due to pre- and postnatal exposure. The suggested PCB and p,p'-DDE modulation of infection risks may have consequences for the health development during childhood, since respiratory infections early in life may be risk factors for asthma and middle ear infections.
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