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Gunnar Ronquist - One of the best experts on this subject based on the ideXlab platform.
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Open Access Prostasome Involvement in the Development and Growth of Prostate Cancer
2016Co-Authors: Adil A Babiker, Gunnar Ronquist, Bo Nilsson, Kristina Nilsson EkdahlAbstract:Abstract: Prostasomes are extracellularly occurring submicron, membrane-surrounded organelles produced by the epithe-lial 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 eryth-rocytes). 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 dem-onstrated. 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
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Human Reproduction vol.9 no.8 pp. 1485-1489, 1994 Enhanced recruitment of motile spermatozoa by prostasome inclusion in swim-up medium
2016Co-Authors: Roberto Fabiani, Lars Johansson, Orjan Lundkvist, Gunnar RonquistAbstract:'To whom correspondence should be addressed Prostasomes, which are prostate-derived organelles, were purified from human seminal plasma for inclusion in Earle's balanced salt solution (EBSS) medium with or without human serum albumin. These media were used for swim-up experi-ments and the subsequent analyses of sperm motility parameters at different incubation times. The yield of motile spermatozoa after swim-up in EBSS medium enriched with boiled Prostasomes was increased by 32 % compared with EBSS containing albumin. Native Prostasomes were less active. Combinations of albumin and either Prostasomes or boiled Prostasomes significantly increased the recovery of motile spermatozoa and also increased the percentage of spermatozoa displaying progressive motility after 1 h of incubation. Media lacking albumin showed lower values regarding progressive motility after 22 h of incubation. A beneficial effect of Prostasomes was noted on lateral head displacement and percentage of hyperactive spermatozoa during the first 6 h of incubation. These results suggest that inclusion of Prostasomes, especially boiled Prostasomes, in swim-up media may improve the recovery of hyperactive motile spermatozoa for up to 6 h in cases of established male factor infertility, and consequently increase the opportunities for fertilization. Key words: EBSS/IVF/Prostasomes/spermatozoa/swim-u
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energy requiring uptake of Prostasomes and pc3 cell derived exosomes into non malignant and malignant cells
Journal of extracellular vesicles, 2016Co-Authors: Karl Goran Ronquist, Anders Larsson, Gunnar Ronquist, Louise Dubois, Claire Sanchez, Dimitris Chioureas, Pedro Fonseca, Anders Ullen, Jeffrey Yachnin, Theocharis PanaretakisAbstract: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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Prostasomes their characterisation implications for human reproduction
Advances in Experimental Medicine and Biology, 2015Co-Authors: Gunnar RonquistAbstract:The prostate is a principal accessory genital gland that is vital for normal fertility. Epithelial cells lining the prostate acini release in a defined fashion (exocytosis) organellar nanosized structures named Prostasomes. They are involved in the protection of sperm cells against immune response in the female reproductive tract by modulating the complement system and by inhibiting monocyte and neutrophil phagocytosis and lymphocyte proliferation. The immunomodulatory function most probably involves small non-coding RNAs present in Prostasomes. Prostasomes have also been proposed to regulate the timing of sperm cell capacitation and induction of the acrosome reaction, since they are rich in various transferable bioactive molecules (e.g. receptors and enzymes) that promote the fertilising ability of sperm cells. Antigenicity of sperm cells has been well documented and implicated in involuntary immunological infertility of human couples, and antisperm antibodies (ASA) occur in several body fluids. The propensity of sperm cells to carry attached Prostasomes suggests that they are a new category of sperm antigens. Circulating human ASA recognise Prostasomes, and among 12 identified prostasomal antigens, prolactin- inducible protein (95 %) and clusterin (85 %) were immunodominant at the expense of the other 10 that were sporadically occurring.
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biochemical characterization of stallion Prostasomes and comparison to their human counterparts
Systems Biology in Reproductive Medicine, 2013Co-Authors: Goran Ronquist, Gunnar Ronquist, Lena Carlsson, J M Morrell, Anders LarssonAbstract: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.
Anders Larsson - One of the best experts on this subject based on the ideXlab platform.
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energy requiring uptake of Prostasomes and pc3 cell derived exosomes into non malignant and malignant cells
Journal of extracellular vesicles, 2016Co-Authors: Karl Goran Ronquist, Anders Larsson, Gunnar Ronquist, Louise Dubois, Claire Sanchez, Dimitris Chioureas, Pedro Fonseca, Anders Ullen, Jeffrey Yachnin, Theocharis PanaretakisAbstract: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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biochemical characterization of stallion Prostasomes and comparison to their human counterparts
Systems Biology in Reproductive Medicine, 2013Co-Authors: Goran Ronquist, Gunnar Ronquist, Lena Carlsson, J M Morrell, Anders LarssonAbstract: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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Prostasomes from four different species are able to produce extracellular adenosine triphosphate atp
Biochimica et Biophysica Acta, 2013Co-Authors: Goran K Ronquist, Gunnar Ronquist, J M Morrell, Anneli Stavreusevers, Bodil Strom Holst, Patrice Humblot, Anders LarssonAbstract: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 10–150 kDa. 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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human Prostasomes express glycolytic enzymes with capacity for atp production
American Journal of Physiology-endocrinology and Metabolism, 2013Co-Authors: Goran K Ronquist, Anders Larsson, Anneli Stavreusevers, Gunnar RonquistAbstract:Prostasomes are prostate-derived, exosome-like microvesicles that transmit signaling complexes between the acinar epithelial cells of the prostate and sperm cells. The vast majority of Prostasomes ...
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Prostasomes are heterogeneous regarding size and appearance but affiliated to one dna containing exosome family
The Prostate, 2012Co-Authors: Goran Ronquist, Anders Larsson, Anneli Stavreusevers, Gunnar RonquistAbstract:BACKGROUND:Prostate acinar epithelial cells release microvesicles (Prostasomes) that possess pleiotropic biological effects relevant for successful fertilization. Prostasomes are formed in a simila ...
Willem Stoorvogel - One of the best experts on this subject based on the ideXlab platform.
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Identification of Distinct Populations of Prostasomes That Differentially Express Prostate Stem Cell Antigen, Annexin A1, and GLIPR2 in Humans1
2016Co-Authors: Marca H M Wauben, Tom A. E. Stout, Willem StoorvogelAbstract:In addition to sperm cells, seminal fluid contains various small membranous vesicles. These include Prostasomes, membrane vesicles secreted by prostate epithelial cells. Prostasomes have been proposed to perform a variety of functions, including modulation of (immune) cell activity within the female reproductive tract and stimulation of sperm motility and capacitation. How Prostasomes mediate such diverse functions, however, remains unclear. In many studies, vesicles from the seminal plasma have been categorized collectively as a single population of Prostasomes; in fact, they more likely represent a heterogeneous mixture of vesicles produced by different reproductive glands and secretory mechanisms. We here characterized membranous vesicles from seminal fluid obtained from vasectomized men, thereby excluding material from the testes or epididymides. Two distinct populations of vesicles with characteristic sizes (56 6 13 nm vs. 105 6 25 nm) but similar equilibrium buoyant density (;1.15 g/ml) could be separated by using the distinct rates with which they floated into sucrose gradients. Both types of vesicle resembled exosomes in terms of their buoyant density, size, and the presence of the ubiquitous exosome marker CD9. The protein GLIPR2 was found to be specifically enriched in the lumen of the smaller vesicles, while annexin A1 was uniquely associated with the surface of the larger vesicles. Prostate stem-cell antigen (PSCA), a prostate-specific protein, was present on both populations, thereby confirming their origin. PSCA was, however, absent from membrane vesicles in the seminal fluid of some donors, indicating heterogeneity of prostasome characteristics between individuals. annexin A1, exosomes, extracellular membrane vesicles, GLIPR2, Prostasomes, PSC
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Prostasomes extracellular vesicles from the prostate
Reproduction, 2013Co-Authors: Marian Aalberts, T A E Stout, Willem StoorvogelAbstract:The term 'Prostasomes' is generally used to classify the extracellular vesicles (EVs) released into prostatic fluid by prostate epithelial cells. However, other epithelia within the male reproductive tract also release EVs that mix with 'true' Prostasomes during semen emission or ejaculation. Prostasomes have been proposed to regulate the timing of sperm cell capacitation and induction of the acrosome reaction, as well as to stimulate sperm motility where all three are prerequisite processes for spermatozoa to attain fertilising capacity. Other proposed functions of Prostasomes include interfering with the destruction of spermatozoa by immune cells within the female reproductive tract. On the other hand, it is unclear whether the distinct presumed functions are performed collectively by a single type of prostasome or by separate distinct sub-populations of EVs. Moreover, the exact molecular mechanisms through which Prostasomes exert their functions have not been fully resolved. Besides their physiological functions, Prostasomes produced by prostate tumour cells have been suggested to support prostate cancer spread development, and Prostasomes in peripheral blood plasma may prove to be valuable biomarkers for prostate cancer.
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spermatozoa recruit Prostasomes in response to capacitation induction
Biochimica et Biophysica Acta, 2013Co-Authors: Marian Aalberts, Marca H M Wauben, T A E Stout, Edita Sostaric, Richard Wubbolts, Esther Nolte N M T Hoen, B M Gadella, Willem StoorvogelAbstract:Abstract Seminal plasma contains various types of extracellular vesicles, including ‘Prostasomes’. Prostasomes are small vesicles secreted by prostatic epithelial cells that can be recruited by and fuse with sperm cells in response of progesterone that is released by oocyte surrounding cumulus cells. This delivers Ca 2 + signaling tools that allow the sperm cell to gain hypermotility and undergo the acrosome reaction. Conditions for binding of Prostasomes to sperm cells are however unclear. We found that classically used prostasome markers are in fact heterogeneously expressed on distinct populations of small and large vesicles in seminal plasma. To study interactions between Prostasomes and spermatozoa we used the stallion as a model organism. A homogeneous population of ~ 60 nm Prostasomes was first separated from larger vesicles and labeled with biotin. Binding of biotinylated Prostasomes to individual live spermatozoa was then monitored by flow cytometry. Contrary to assumptions in the literature, we found that such highly purified Prostasomes bound to live sperm only after capacitation had been initiated, and specifically at pH ≥ 7.5. Using fluorescence microscopy, we observed that Prostasomes bound primarily to the head of live sperm. We propose that in vivo , Prostasomes may bind to sperm cells in the uterus, to be carried in association with sperm cells into oviduct and to fuse with the sperm cell only during the final approach of the oocyte. This article is part of a Special Issue entitled: An Updated Secretome.
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distinct lipid compositions of two types of human Prostasomes
Proteomics, 2013Co-Authors: Jos F Brouwers, Marian Aalberts, Jeroen W A Jansen, Guillaume Van Niel, Marca H M Wauben, T A E Stout, Bernd J Helms, Willem StoorvogelAbstract:Prostasomes are vesicles secreted by prostate epithelial cells and found in abundance in seminal plasma. They regulate aspects of sperm cell function and are also thought to prevent immune-mediated destruction of sperm cells within the female reproductive tract. In a previous study, we isolated two distinct populations of Prostasomes, differing both in size and protein composition, from the seminal fluid of vasectomized men. In the current study, we characterized the lipid content of these two prostasome populations. Both prostasome types had an unusual lipid composition, with high levels of sphingomyelin (SM), cholesterol, and glycosphingolipids at the expense of, in particular, phosphatidylcholine. The different classes of glycerophospholipids consisted mainly of mono-unsaturated species. The sphingosine-based lipids, SM and the hexosylceramides, were characterized by a near absence of unsaturated species. The two types of prostasome differed in lipid composition, particularly with regard to the relative contributions of SM and hexosylceramides. Potential implications of the lipid compositions of Prostasomes for the mechanisms of their formation and function are discussed.
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identification of distinct populations of Prostasomes that differentially express prostate stem cell antigen annexin a1 and glipr2 in humans
Biology of Reproduction, 2012Co-Authors: Marian Aalberts, Marca H M Wauben, T A E Stout, Federica M F Van Disselemiliani, Nick P H Van Adrichem, Merel Van Wijnen, Willem StoorvogelAbstract:In addition to sperm cells, seminal fluid contains various small membranous vesicles. These include Prostasomes, membrane vesicles secreted by prostate epithelial cells. Prostasomes have been proposed to perform a variety of functions, including modulation of (immune) cell activity within the female reproductive tract and stimulation of sperm motility and capacitation. How Prostasomes mediate such diverse functions, however, remains unclear. In many studies, vesicles from the seminal plasma have been categorized collectively as a single population of Prostasomes; in fact, they more likely represent a heterogeneous mixture of vesicles produced by different reproductive glands and secretory mechanisms. We here characterized membranous vesicles from seminal fluid obtained from vasectomized men, thereby excluding material from the testes or epididymides. Two distinct populations of vesicles with characteristic sizes (56 ± 13 nm vs. 105 ± 25 nm) but similar equilibrium buoyant density (∼1.15 g/ml) could be separated by using the distinct rates with which they floated into sucrose gradients. Both types of vesicle resembled exosomes in terms of their buoyant density, size, and the presence of the ubiquitous exosome marker CD9. The protein GLIPR2 was found to be specifically enriched in the lumen of the smaller vesicles, while annexin A1 was uniquely associated with the surface of the larger vesicles. Prostate stem-cell antigen (PSCA), a prostate-specific protein, was present on both populations, thereby confirming their origin. PSCA was, however, absent from membrane vesicles in the seminal fluid of some donors, indicating heterogeneity of prostasome characteristics between individuals.
Lena Carlsson - One of the best experts on this subject based on the ideXlab platform.
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biochemical characterization of stallion Prostasomes and comparison to their human counterparts
Systems Biology in Reproductive Medicine, 2013Co-Authors: Goran Ronquist, Gunnar Ronquist, Lena Carlsson, J M Morrell, Anders LarssonAbstract: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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multiple recognition assay reveals Prostasomes as promising plasma biomarkers for prostate cancer
Proceedings of the National Academy of Sciences of the United States of America, 2011Co-Authors: Gholamreza Tavoosidana, Anders Larsson, Gunnar Ronquist, Spyros Darmanis, Junhong Yan, Lena Carlsson, Tim Conze, Axel Semjonow, Elke Eltze, Ulf LandegrenAbstract:Prostasomes are microvesicles (mean diameter, 150 nm) that are produced and secreted by normal and malignant prostate acinar cells. It has been hypothesized that invasive growth of malignant prostate cells may cause these microvesicles, normally released into seminal fluid, to appear in interstitial space and therewith into peripheral circulation. The suitability of Prostasomes as blood biomarkers in patients with prostate cancer was tested by using an expanded variant of the proximity ligation assay (PLA). We developed an extremely sensitive and specific assay (4PLA) for detection of complex target structures such as microvesicles in which the target is first captured via an immobilized antibody and subsequently detected by using four other antibodies with attached DNA strands. The requirement for coincident binding by five antibodies to generate an amplifiable reporter results in both increased specificity and sensitivity. The assay successfully detected significantly elevated levels of Prostasomes in blood samples from patients with prostate cancer before radical prostatectomy, compared with controls and men with benign biopsy results. The medians for prostasome levels in blood plasma of patients with prostate cancer were 2.5 to sevenfold higher compared with control samples in two independent studies, and the assay also distinguished patients with high and medium prostatectomy Gleason scores (8/9 and 7, respectively) from those with low score (≤6), thus reflecting disease aggressiveness. This approach that enables detection of Prostasomes in peripheral blood may be useful for early diagnosis and assessment of prognosis in organ-confined prostate cancer.
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proteomic analysis of prostate cancer metastasis derived Prostasomes
Anticancer Research, 2010Co-Authors: Goran K Ronquist, Anders Larsson, Gunnar Ronquist, Lena CarlssonAbstract:Background: The secretory epithelial cells of the prostate gland use sophisticated vehicles named 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. Aim: The aim of this thesis was to examine different characteristics of Prostasomes, especially those derived from malignant prostate cells, linked to their potential role in diagnosis and prognostication of prostate cancer. Results: Serum samples of prostate cancer patients contained autoantibodies against seminal Prostasomes in a higher concentration than did control sera. These autoantibodies were most frequently directed against 25 prostasome-associated proteins, but no one was prostate specific. Clusterin was one of the most frequently occurring prostasomal proteins. Elevated titers were however seen in both patients´ and control sera. Clusterin turned out to be a major antigen of seminal Prostasomes. No prostate specific or prostate cancer specific protein was discovered upon proteomic analysis of Prostasomes deriving from malignant cells of vertebral metastases of prostate cancer patients. Human chromosomal DNA was identified in both seminal Prostasomes and PC-3 cell Prostasomes and strong evidence existed that the DNA was localized inside the Prostasomes. Four out of 13 DNA clones of seminal Prostasomes featured gene sequences (31%). The corresponding figures for PC-3 cell Prostasomes were 4 out of 16 clones (25%). Conclusions: Prostasomes are immunogenic and give rise to serum autoantibodies. The most frequently occurring autoantibodies were directed against 25 prostasomal proteins but none of these was exclusively prostate specific. Thirty different proteins were identified in prostate cancer metastasis-derived Prostasomes but none of these proteins was prostate cancer specific. Human chromosomal DNA was identified in Prostasomes of both normal and malignant cell origin.
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human Prostasomes contain chromosomal dna
The Prostate, 2009Co-Authors: Goran K Ronquist, Lena Carlsson, Gunnar Ronquist, Anders LarssonAbstract:Background: The secretory epithelial cells of the prostate gland use sophisticated vehicles named 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. Aim: The aim of this thesis was to examine different characteristics of Prostasomes, especially those derived from malignant prostate cells, linked to their potential role in diagnosis and prognostication of prostate cancer. Results: Serum samples of prostate cancer patients contained autoantibodies against seminal Prostasomes in a higher concentration than did control sera. These autoantibodies were most frequently directed against 25 prostasome-associated proteins, but no one was prostate specific. Clusterin was one of the most frequently occurring prostasomal proteins. Elevated titers were however seen in both patients´ and control sera. Clusterin turned out to be a major antigen of seminal Prostasomes. No prostate specific or prostate cancer specific protein was discovered upon proteomic analysis of Prostasomes deriving from malignant cells of vertebral metastases of prostate cancer patients. Human chromosomal DNA was identified in both seminal Prostasomes and PC-3 cell Prostasomes and strong evidence existed that the DNA was localized inside the Prostasomes. Four out of 13 DNA clones of seminal Prostasomes featured gene sequences (31%). The corresponding figures for PC-3 cell Prostasomes were 4 out of 16 clones (25%). Conclusions: Prostasomes are immunogenic and give rise to serum autoantibodies. The most frequently occurring autoantibodies were directed against 25 prostasomal proteins but none of these was exclusively prostate specific. Thirty different proteins were identified in prostate cancer metastasis-derived Prostasomes but none of these proteins was prostate cancer specific. Human chromosomal DNA was identified in Prostasomes of both normal and malignant cell origin.
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ultrastructural and biochemical differences in tissue and secretion fron seminal vesicles and prostate gland indicating the exclusive prostatic origin of Prostasomes
2007Co-Authors: Goran Sahlen, Anders Larsson, Bo Johan Norlen, Lena Carlsson, Ove B Nilsson, Gunnar RonquistAbstract:Prostasomes are submicron-sized, membrane-bound organelles produced by the epithelial cells of the prostate and normally found in the secretion in the gland ducts. Their physiological role is in the promotion of sperm-function in human reproduction. This thesis contains four papers dealing with the production of Prostasomes and some possible applications in clinical urology of the prostasome. Paper I and II provided an ultrastructural description of the synthesis, storage and secretion of Prostasomes in benign as well as in malignant tissue. Most notable were the extracellular appearances of Prostasomes in metastatic lesions whereby the Prostasomes become exposed to the immune system of the patient. This supported findings in earlier studies in which patients with advanced prostate cancer had elevated levels of anti-prostasome antibodies. The results of paper III reinforced the view of the prostate-unique origin of the prostasome. In particular, there were no indications in SDS-PAGE patterns or flow-cytometric studies of material from seminal vesicle secretion that it contained components that could be associated with a production of Prostasomes. Some possible clinical functions of the Prostasomes were investigated in paper IV. Exposure of Prostasomes to the immune system through mechanical and thermal trauma to the prostate did not induce an evident formation of anti-prostasome autoantibodies. Furthermore, the serum levels of anti-prostasome antibodies registered by assays with preparations of Prostasomes from seminal plasma as antigen did not correlate with existing prostate cancer. Seminal Prostasomes seemed not to function as substitute markers for prostate cancer in the test kit used. A possible explanation could be underestimated differences in antigen properties between seminal or prostate gland-derived Prostasomes and Prostasomes from tumor tissue.
Carlo Alberto Palmerini - One of the best experts on this subject based on the ideXlab platform.
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Identification and Partial Characterization of Two Populations of Prostasomes by a Combination of Dynamic Light Scattering and Proteomic Analysis
The Journal of Membrane Biology, 2015Co-Authors: Davide Chiasserini, Michela Mazzoni, Federico Bordi, Simona Sennato, Federica Susta, Pier Luigi Orvietani, Luciano Binaglia, Carlo Alberto PalmeriniAbstract:Prostasomes are vesicles secreted by prostate epithelial cells and are found in abundance in the semen. Here we characterized two different prostasome populations isolated from human seminal fluid. Prostasomes were isolated using differential centrifugation, while dynamic light scattering (DLS) was used to characterize their size and size distribution. Their protein content was analyzed using two-dimensional electrophoresis and mass spectrometry. DLS showed two distinct prostasome subpopulations in centrifuged seminal plasma, with an average hydrodynamic radius of 80 and 300 nm. The larger population was isolated after centrifugation at 20,000× g (P20), while the smaller one was recovered at 100,000× g (P100). The two fractions had a similar lipid composition, showing an elevated content of sphingomyelin and cholesterol. The P100 vesicles showed a significant over-expression of proteins involved in the endosomal sorting complexes required for transport (ESCRT) machinery such as Alix, TSG101, and syntenin-1. Some proteins possibly involved in prostate cancer were present only in one specific population (TMPRSS2 in P100 and VCP in P20). The different size and protein profile in the two subpopulations of Prostasomes might support differential roles of the semen vesicles toward the target cells, and/or different secretion pathways from the organ of origin.
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role of human Prostasomes in the activation of spermatozoa
Journal of Cellular and Molecular Medicine, 2004Co-Authors: Giuseppe Arienti, Carla Saccardi, E Carlini, Carlo Alberto PalmeriniAbstract:Prostasomes are small vesicles of prostatic origin contained in human semen. Their composition is peculiar under many aspects. Cholesterol is abundant and many proteins are endowed with enzymatic or other activities. The function of Prostasomes has been amply debated and several hypotheses have been put forward. The liquefaction of semen, spermatozoa motility, antibacterial activity and immunological functions have been related to Prostasomes. Under certain aspects, Prostasomes resemble synaptosomes. The fusion of Prostasomes to spermatozoa enriches spermatozoa with cholesterol and causes bursts of cytoplasmic sperm calcium. The interaction of spermatozoa and Prostasomes should be limited to vagina since Prostasomes are immobile and do not follow spermatozoa in the superior female genital tract. Calcium bursts would increase spermatozoa motility, where cholesterol would decapacitate spermatozoa, so preventing untimely activation. Since spermatozoa receive many different molecules from Prostasomes, additional effects are also possible. Prostasomes makes spermatozoa more apt to be activated by progesterone in the proximity of the ovum. Therefore, the fusion between spermatozoa and Prostasomes would influence spermatozoa behaviour under many aspects and might be relevant for fecundation. The richness of molecular species in Prostasomes is amazing and these small vesicles are expected to lead to many more discoveries in the field of human reproduction.
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fusion of Prostasomes to human spermatozoa stimulates the acrosome reaction
Fertility and Sterility, 2003Co-Authors: Carlo Alberto Palmerini, Enrico Carlini, Carla Saccardi, Roberto Fabiani, Giuseppe ArientiAbstract:Abstract Objective To determine the effect of the fusion of Prostasomes to spermatozoa on the acrosome reaction. Design In vitro study of human spermatozoa. Setting Healthy volunteers in an academic research environment. Patient(s) Healthy volunteer men, 25 to 35 years old. Intervention(s) Human semen was fractionated into spermatozoa and Prostasomes. Fusion of prostasome to spermatozoa was performed at pH 5.5. Progesterone (1 μM) was added when required. Main outcome measure(s) Evaluation of the acrosome reaction by fluorescence microscopy. Result(s) The percentage of spontaneously acrosome-reacted cells was very low unless the Ca 2+ -ionophore A 23187 was added. The treatment of spermatozoa with 1 μM of progesterone scarcely affected the acrosome reaction; a pretreatment in conditions permitting fusion increased it. The addition of progesterone to prostasome-fused spermatozoa further increased the extent of the acrosome reaction. Conclusion(s) The H + -dependent fusion with Prostasomes makes spermatozoa more sensitive to the effect of progesterone on acrosome-reaction induction.
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nitric oxide and fusion with Prostasomes increase cytosolic calcium in progesterone stimulated sperm
Archives of Biochemistry and Biophysics, 2002Co-Authors: Giuseppe Arienti, Enrico Carlini, Carla Saccardi, Carlo Alberto PalmeriniAbstract:Spermatozoa must undergo a number of reactions before they are able to fertilize the oocyte. Among these is the acrosome reaction, which is related to an increase in cytosolic Ca2+ concentration ([Ca2+]i). It has been reported in the literature that progesterone may achieve this effect through the intervention of extragenomic receptors. Nitric oxide (NO) has been reported to affect spermatozoa; the nature of the effect depends on the concentration of the radical. In a previous paper, we reported that the fusion of spermatozoa with Prostasomes may also produce a transient increase in spermatozoa [Ca2+]i; in addition, this phenomenon causes a long-lasting effect that influences the action of progesterone. In this paper, we test the effects of a NO donor (CysNO) and of fusion of the prostasome to spermatozoa on progesterone-induced [Ca2+]i increase. No effect at all was noticed in the absence of progesterone stimulation. In the presence of the hormone, both CysNO and fusion increased the progesterone effect. This phenomenon was much more evident if the two treatments were used together. We conclude that both NO and fusion with Prostasomes act on the progesterone-dependent pathway additively. Probably the effects are independent.
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increase of human spermatozoa intracellular ca2 concentration after fusion with Prostasomes
Cell Calcium, 1999Co-Authors: Carlo Alberto Palmerini, Enrico Carlini, A Nicolucci, Giuseppe ArientiAbstract:Abstract Prostasomes are membranous vesicles (150–200 nm diameter) present in human semen. They are secreted by the prostate gland and contain large amounts of cholesterol, sphingomyelin and calcium, and some of their proteins are enzymes. Prostasomes are involved in a number of biological functions. In previous work, we discovered that Prostasomes may fuse to sperm at neutral or at slightly acidic pH values. This mechanism may deliver calcium to sperm, thereby influencing sperm functions. We measured sperm [Ca2+]iwith the fura-2 AM method and found that it increased after mixing Prostasomes and sperm at pH values allowing fusion (pH 5–7). The increase of [Ca2+]iwas proportional to the extent of fusion as measured through the relief of R18self-quenching. We also examined the increase of sperm [Ca2+]iand the extent of fusion as a function of sperm to prostasome ratio and, also in this case, there was proportionality between the extent of fusion and the increase of [Ca2+]ithat reached its maximal values in about 10–20 min. However, a detectable increase of [Ca2+]iwas attained after 2 min of fusion. This would represent a new mechanism to influence sperm [Ca2+]ibesides ion-exchange systems and ATP-dependent pumps. The value of [Ca2+]iremained elevated, unless Na+was also present in the external medium. Therefore, the mechanism of fusion might influence deeply the physiology of sperm by producing a transient increase of [Ca2+]i.
