| 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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