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Yulin Deng - One of the best experts on this subject based on the ideXlab platform.
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α-Synuclein binds to Cytoplasmic Vesicles in U251 glioblastoma cells
Neuroscience letters, 2017Co-Authors: Jinyan Duan, Zhengxin Ying, Fankai Lin, Yulin DengAbstract:Abstract α-Synuclein is the major component of Lewy bodies, Lewy neurites, and glial Cytoplasmic inclusions. It plays an important role in neurodegenerative diseases such as Parkinson’s disease, multiple system atrophy, and other synucleinopathies. However, the pathogenesis and neurodegenerative effects of α-synuclein remain unknown. In this study, we established an α-synuclein and an α-synuclein-EGFP overexpressing U251 cell line. α-Synuclein overexpression increases oxidative stress and alters the cell surface and mitochondrial morphologies. We provide fluorescent-protein tagging, immunofluorescence and ultrastructural evidence showing that α-synuclein accumulations are associated with clusters of Cytoplasmic Vesicles and the diameter of these Vesicles increases by H2O2 in a time- and dose-dependent manner.
Ann M. Dvorak - One of the best experts on this subject based on the ideXlab platform.
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immunocytochemical localization of chymase to Cytoplasmic Vesicles after rat peritoneal mast cell stimulation by compound 48 80
Journal of Histochemistry and Cytochemistry, 1997Co-Authors: Gary R. Login, Mikako Aoki, Midori Yamakawa, Laurelúcia Orive Lunardi, Eleni C. Digenis, Naoko Tanda, Lawrence B. Schwartz, Ann M. DvorakAbstract:SUMMARY The subcellular events responsible for release of mediators by mast cells may help to clarify roles for mast cells in health and disease. In this study we show that the granule-associated protease chymase is also within Cytoplasmic Vesicles in appropriately stimulated rat peritoneal mast cells. Rat peritoneal mast cells were recovered before or 1‐10 sec after exposure to the secretogogue compound 48/80 (10 m g/ml) and then were examined by radioimmunoassay to quantify histamine release or were processed, using routine methods for postembedding immunoelectron microscopy, to identify the subcellular localization of chymase. In comparison to unstimulated cells, compound 48/80 stimulated cells in two independent experiments showed an increase (15%, 28%) in the surface area of the cell and a decrease (12%, 6%) in the surface area of the total granule compartment before degranulation channel formation. These global cellular changes occurred in a background of transient but significant ( p , 0.01) increases in the area and number of chymase-immunoreactive Vesicles per m m 2 cytoplasm. These changes were detectable at 5 or 7 sec after stimulation with compound 48/80 but returned to near prestimulation levels by 9 or 10 sec after addition of compound 48/80 (total cumulative histamine release was 28% by 8 sec and 47% by 14 sec). These observations suggest that Vesicles participate in the early stages of regulated secretion of chymase from rat peritoneal mast cells. (J Histochem Cytochem 45:1379‐1391, 1997)
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Immunocytochemical localization of chymase to Cytoplasmic Vesicles after rat peritoneal mast cell stimulation by compound 48/80.
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society, 1997Co-Authors: Gary R. Login, Mikako Aoki, Midori Yamakawa, Laurelúcia Orive Lunardi, Eleni C. Digenis, Naoko Tanda, Lawrence B. Schwartz, Ann M. DvorakAbstract:SUMMARY The subcellular events responsible for release of mediators by mast cells may help to clarify roles for mast cells in health and disease. In this study we show that the granule-associated protease chymase is also within Cytoplasmic Vesicles in appropriately stimulated rat peritoneal mast cells. Rat peritoneal mast cells were recovered before or 1‐10 sec after exposure to the secretogogue compound 48/80 (10 m g/ml) and then were examined by radioimmunoassay to quantify histamine release or were processed, using routine methods for postembedding immunoelectron microscopy, to identify the subcellular localization of chymase. In comparison to unstimulated cells, compound 48/80 stimulated cells in two independent experiments showed an increase (15%, 28%) in the surface area of the cell and a decrease (12%, 6%) in the surface area of the total granule compartment before degranulation channel formation. These global cellular changes occurred in a background of transient but significant ( p , 0.01) increases in the area and number of chymase-immunoreactive Vesicles per m m 2 cytoplasm. These changes were detectable at 5 or 7 sec after stimulation with compound 48/80 but returned to near prestimulation levels by 9 or 10 sec after addition of compound 48/80 (total cumulative histamine release was 28% by 8 sec and 47% by 14 sec). These observations suggest that Vesicles participate in the early stages of regulated secretion of chymase from rat peritoneal mast cells. (J Histochem Cytochem 45:1379‐1391, 1997)
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vesicular transport of charcot leyden crystal protein in tumor promoting phorbol diester stimulated human basophils
Laboratory Investigation, 1996Co-Authors: Ann M. Dvorak, Ellen S. Morgan, Steven J Ackerman, Linda Letourneau, Lawrence M Lichtenstein, Donald W. MacglashanAbstract:: Secretion from human basophils (HB) that are stimulated with a phorbol ester takes place with slower kinetics than typically regulated secretion, which is stimulated by the IgE-mediated mechanism associated with classical granule exocytosis. Phorbol ester stimulation of HB induces emptying of granule contents (with retention of granule containers) and increases the number of Cytoplasmic Vesicles, an anatomic process similar to one termed piecemeal degranulation (PMD), which is a secretory process originally described in HB that migrate from the blood in vivo into contact allergy skin lesions. Charcot-Leyden crystal (CLC) protein is a basophil granule-associated protein that is readily imaged by using a postembedding immunogold procedure. This method was used to localize this granule protein in phorbol ester-stimulated, isolated human peripheral blood basophil Cytoplasmic Vesicles in samples collected within a time frame for which histamine was secreted. The results of this study showed that the proportion of Cytoplasmic Vesicles that were gold-labeled in stimulated HB, which indicated the presence of CLC protein, increased significantly over unstimulated cells at 2, 5, and 10 minutes after stimulation. Additionally, CLC protein-labeled Vesicles in the cells that were stimulated for 10 minutes significantly exceeded the number in stimulated cells at 0, 30, and 45 minutes after exposure to phorbol ester. Thus, transport Vesicles carrying a granule-associated protein (CLC protein) were increased in phorbol ester-stimulated HB in the time frame for histamine secretion and the anatomic development of PMD. These findings support vesicular transport as a major mechanism for effecting PMD, which is morphologically the most frequent activation anatomy displayed by HB in human disease in vivo.
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Activated Human Basophils Contain Histamine in Cytoplasmic Vesicles
International archives of allergy and immunology, 1994Co-Authors: Ann M. Dvorak, Ellen S. Morgan, Donald W. MacglashanAbstract:Human basophils in contact allergy empty granules slowly – a secretory process termed piecemeal degranulation in contrast to the explosive extrusion of granules seen in anaphylactic degranulation. An
Donald W. Macglashan - One of the best experts on this subject based on the ideXlab platform.
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vesicular transport of charcot leyden crystal protein in tumor promoting phorbol diester stimulated human basophils
Laboratory Investigation, 1996Co-Authors: Ann M. Dvorak, Ellen S. Morgan, Steven J Ackerman, Linda Letourneau, Lawrence M Lichtenstein, Donald W. MacglashanAbstract:: Secretion from human basophils (HB) that are stimulated with a phorbol ester takes place with slower kinetics than typically regulated secretion, which is stimulated by the IgE-mediated mechanism associated with classical granule exocytosis. Phorbol ester stimulation of HB induces emptying of granule contents (with retention of granule containers) and increases the number of Cytoplasmic Vesicles, an anatomic process similar to one termed piecemeal degranulation (PMD), which is a secretory process originally described in HB that migrate from the blood in vivo into contact allergy skin lesions. Charcot-Leyden crystal (CLC) protein is a basophil granule-associated protein that is readily imaged by using a postembedding immunogold procedure. This method was used to localize this granule protein in phorbol ester-stimulated, isolated human peripheral blood basophil Cytoplasmic Vesicles in samples collected within a time frame for which histamine was secreted. The results of this study showed that the proportion of Cytoplasmic Vesicles that were gold-labeled in stimulated HB, which indicated the presence of CLC protein, increased significantly over unstimulated cells at 2, 5, and 10 minutes after stimulation. Additionally, CLC protein-labeled Vesicles in the cells that were stimulated for 10 minutes significantly exceeded the number in stimulated cells at 0, 30, and 45 minutes after exposure to phorbol ester. Thus, transport Vesicles carrying a granule-associated protein (CLC protein) were increased in phorbol ester-stimulated HB in the time frame for histamine secretion and the anatomic development of PMD. These findings support vesicular transport as a major mechanism for effecting PMD, which is morphologically the most frequent activation anatomy displayed by HB in human disease in vivo.
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Activated Human Basophils Contain Histamine in Cytoplasmic Vesicles
International archives of allergy and immunology, 1994Co-Authors: Ann M. Dvorak, Ellen S. Morgan, Donald W. MacglashanAbstract:Human basophils in contact allergy empty granules slowly – a secretory process termed piecemeal degranulation in contrast to the explosive extrusion of granules seen in anaphylactic degranulation. An
Ivan A. Vorobjev - One of the best experts on this subject based on the ideXlab platform.
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centrosome dependent anisotropic random walk of Cytoplasmic Vesicles
Cell Biology International, 2002Co-Authors: Ivan V. Maly, Ivan A. VorobjevAbstract:Abstract We approach the problem of an apparently random movement of small Cytoplasmic Vesicles and its relationship to centrosome functioning. Motion of small Vesicles in the cytoplasm of BSC-1 cells was quantified using computer-assisted microscopy. The Vesicles move across the cytoplasm frequently changing their directions with negligible net displacement. The autocorrelation function for consecutive velocities of individual Vesicles becomes indistinguishable from zero in 10 s. Variance in the displacement is proportional to time. The motion of Vesicles is anisotropic: It has diffusivity along the radii drawn from the centrosome several times higher than the tangential diffusivity. This anisotropy is abolished by ultraviolet microbeam irradiation of the centrosome when the microtubule array loses radial structure. We conclude that the motion of the Vesicles in the cytoplasm can be described as diffusion-like random walk with centrosome-dependent anisotropy. The present analysis quantitatively corroborates the ‘trial and error’ model of vesicular transport.
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CENTROSOME‐DEPENDENT ANISOTROPIC RANDOM WALK OF Cytoplasmic Vesicles
Cell biology international, 2002Co-Authors: Ivan V. Maly, Ivan A. VorobjevAbstract:Abstract We approach the problem of an apparently random movement of small Cytoplasmic Vesicles and its relationship to centrosome functioning. Motion of small Vesicles in the cytoplasm of BSC-1 cells was quantified using computer-assisted microscopy. The Vesicles move across the cytoplasm frequently changing their directions with negligible net displacement. The autocorrelation function for consecutive velocities of individual Vesicles becomes indistinguishable from zero in 10 s. Variance in the displacement is proportional to time. The motion of Vesicles is anisotropic: It has diffusivity along the radii drawn from the centrosome several times higher than the tangential diffusivity. This anisotropy is abolished by ultraviolet microbeam irradiation of the centrosome when the microtubule array loses radial structure. We conclude that the motion of the Vesicles in the cytoplasm can be described as diffusion-like random walk with centrosome-dependent anisotropy. The present analysis quantitatively corroborates the ‘trial and error’ model of vesicular transport.
Yan Chen - One of the best experts on this subject based on the ideXlab platform.
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comobility of gabarap and phosphatidylinositol 4 kinase 2a on Cytoplasmic Vesicles
Biochemistry, 2018Co-Authors: Yan Chen, Hui Qiao Sun, John P. Eichorst, Joseph P. Albanesi, Helen L. Yin, Joachim D. MuellerAbstract:We previously reported that recruitment of the type IIA phosphatidylinositol 4-kinase (PI4K2A) to autophagosomes by GABARAP, a member of the Atg8 family of autophagy-related proteins, is important for autophagosome-lysosome fusion. Because both PI4K2A and GABARAP have also been implicated in the intracellular trafficking of plasma membrane receptors in the secretory/endocytic pathway, we characterized their interaction in cells under nonautophagic conditions. Fluorescence fluctuation spectroscopy measurements revealed that GABARAP exists predominantly as a cytosolic monomer in live cells, but is recruited to small Cytoplasmic Vesicles upon overexpression of PI4K2A. C-Terminal lipidation of GABARAP, which is essential for its autophagic activities, is not necessary for its recruitment to these PI4K2A-containing transport Vesicles. However, a GABARAP truncation mutant lacking C-terminal residues 103-117 fails to bind to PI4K2A, is not recruited to Cytoplasmic Vesicles, and does not codistribute with PI4K2A on subcellular organelles. These observations suggest that the PI4K2A-GABARAP interaction plays a role in membrane trafficking both under autophagic and nonautophagic conditions.
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Comobility of GABARAP and Phosphatidylinositol 4-Kinase 2A on Cytoplasmic Vesicles.
Biochemistry, 2018Co-Authors: Yan Chen, Hui Qiao Sun, John P. Eichorst, Joseph P. Albanesi, Helen L. Yin, Joachim D. MuellerAbstract:We previously reported that recruitment of the type IIA phosphatidylinositol 4-kinase (PI4K2A) to autophagosomes by GABARAP, a member of the Atg8 family of autophagy-related proteins, is important for autophagosome–lysosome fusion. Because both PI4K2A and GABARAP have also been implicated in the intracellular trafficking of plasma membrane receptors in the secretory/endocytic pathway, we characterized their interaction in cells under nonautophagic conditions. Fluorescence fluctuation spectroscopy measurements revealed that GABARAP exists predominantly as a cytosolic monomer in live cells, but is recruited to small Cytoplasmic Vesicles upon overexpression of PI4K2A. C-Terminal lipidation of GABARAP, which is essential for its autophagic activities, is not necessary for its recruitment to these PI4K2A-containing transport Vesicles. However, a GABARAP truncation mutant lacking C-terminal residues 103–117 fails to bind to PI4K2A, is not recruited to Cytoplasmic Vesicles, and does not codistribute with PI4K2A ...
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Association of Endophilin B1 with Cytoplasmic Vesicles.
Biophysical journal, 2016Co-Authors: Barbara Barylko, Joseph P. Albanesi, John P. Eichorst, Joachim D. Mueller, Yan ChenAbstract:Endophilins are SH3- and BAR domain-containing proteins implicated in membrane remodeling and vesicle formation. Endophilins A1 and A2 promote the budding of endocytic Vesicles from the plasma membrane, whereas endophilin B1 has been implicated in vesicle budding from intracellular organelles, including the trans-Golgi network and late endosomes. We previously reported that endophilins A1 and A2 exist almost exclusively as soluble dimers in the cytosol. Here, we present results of fluorescence fluctuation spectroscopy analyses indicating that, in contrast, the majority of endophilin B1 is present in multiple copies on small, highly mobile Cytoplasmic Vesicles. Formation of these Vesicles was enhanced by overexpression of wild-type dynamin 2, but suppressed by expression of a catalytically inactive dynamin 2 mutant. Using dual-color heterospecies partition analysis, we identified the epidermal growth factor receptor on endophilin B1 Vesicles. Moreover, a proportion of endophilin B1 Vesicles also contained caveolin, whereas clathrin was almost undetectable on those Vesicles. These results raise the possibility that endophilin B1 participates in dynamin 2-dependent formation of a population of transport Vesicles distinct from those generated by A-type endophilins.
