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Assaf Rudich - One of the best experts on this subject based on the ideXlab platform.
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oxidative stress disrupts insulin induced Cellular redistribution of insulin receptor substrate 1 and phosphatidylinositol 3 kinase in 3t3 l1 adipocytes a putative Cellular Mechanism for impaired protein kinase b activation and glut4 translocation
Journal of Biological Chemistry, 1999Co-Authors: Amir Tirosh, Ruth Potashnik, Nava Bashan, Assaf RudichAbstract:In a recent study we have demonstrated that 3T3-L1 adipocytes exposed to low micromolar H2O2 concentrations display impaired insulin stimulated GLUT4 translocation from internal membrane pools to the plasma membrane (Rudich, A., Tirosh, A., Potashnik, R., Hemi, R., Kannety, H., and Bashan, N. (1998) Diabetes 47, 1562-1569). In this study we further characterize the Cellular Mechanisms responsible for this observation. Two-hour exposure to approximately 25 microM H2O2 (generated by adding glucose oxidase to the medium) resulted in disruption of the normal insulin stimulated insulin receptor substrate (IRS)-1 and phosphatidylinositol (PI) 3-kinase Cellular redistribution between the cytosol and an internal membrane pool (low density microsomal fraction (LDM)). This was associated with reduced insulin-stimulated IRS-1 and p85-associated PI 3-kinase activities in the LDM (84 and 96% inhibition, respectively). The effect of this finding on the downstream insulin signal was demonstrated by a 90% reduction in insulin stimulated protein kinase B (PKB) serine 473 phosphorylation and impaired activation of PKBalpha and PKBgamma. Both control and oxidized cells exposed to heat shock displayed a wortmannin insensitive PKB serine phosphorylation and activity. These data suggest that activation of PKB and GLUT4 translocation are insulin signaling events dependent upon a normal insulin induced Cellular compartmentalization of PI 3-kinase and IRS-1, which is oxidative stress-sensitive. These findings represent a novel Cellular Mechanism for the induction of insulin resistance in response to changes in the extraCellular environment.
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oxidative stress disrupts insulin induced Cellular redistribution of insulin receptor substrate 1 and phosphatidylinositol 3 kinase in 3t3 l1 adipocytes a putative Cellular Mechanism for impaired protein kinase b activation and glut4 translocation
Journal of Biological Chemistry, 1999Co-Authors: Amir Tirosh, Ruth Potashnik, Nava Bashan, Assaf RudichAbstract:Abstract In a recent study we have demonstrated that 3T3-L1 adipocytes exposed to low micromolar H2O2 concentrations display impaired insulin stimulated GLUT4 translocation from internal membrane pools to the plasma membrane (Rudich, A., Tirosh, A., Potashnik, R., Hemi, R., Kannety, H., and Bashan, N. (1998) Diabetes 47, 1562–1569). In this study we further characterize the Cellular Mechanisms responsible for this observation. Two-hour exposure to ∼25 μm H2O2 (generated by adding glucose oxidase to the medium) resulted in disruption of the normal insulin stimulated insulin receptor substrate (IRS)-1 and phosphatidylinositol (PI) 3-kinase Cellular redistribution between the cytosol and an internal membrane pool (low density microsomal fraction (LDM)). This was associated with reduced insulin-stimulated IRS-1 and p85-associated PI 3-kinase activities in the LDM (84 and 96% inhibition, respectively). The effect of this finding on the downstream insulin signal was demonstrated by a 90% reduction in insulin stimulated protein kinase B (PKB) serine 473 phosphorylation and impaired activation of PKBα and PKBγ. Both control and oxidized cells exposed to heat shock displayed a wortmannin insensitive PKB serine phosphorylation and activity. These data suggest that activation of PKB and GLUT4 translocation are insulin signaling events dependent upon a normal insulin induced Cellular compartmentalization of PI 3-kinase and IRS-1, which is oxidative stress-sensitive. These findings represent a novel Cellular Mechanism for the induction of insulin resistance in response to changes in the extraCellular environment.
Nava Bashan - One of the best experts on this subject based on the ideXlab platform.
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oxidative stress disrupts insulin induced Cellular redistribution of insulin receptor substrate 1 and phosphatidylinositol 3 kinase in 3t3 l1 adipocytes a putative Cellular Mechanism for impaired protein kinase b activation and glut4 translocation
Journal of Biological Chemistry, 1999Co-Authors: Amir Tirosh, Ruth Potashnik, Nava Bashan, Assaf RudichAbstract:In a recent study we have demonstrated that 3T3-L1 adipocytes exposed to low micromolar H2O2 concentrations display impaired insulin stimulated GLUT4 translocation from internal membrane pools to the plasma membrane (Rudich, A., Tirosh, A., Potashnik, R., Hemi, R., Kannety, H., and Bashan, N. (1998) Diabetes 47, 1562-1569). In this study we further characterize the Cellular Mechanisms responsible for this observation. Two-hour exposure to approximately 25 microM H2O2 (generated by adding glucose oxidase to the medium) resulted in disruption of the normal insulin stimulated insulin receptor substrate (IRS)-1 and phosphatidylinositol (PI) 3-kinase Cellular redistribution between the cytosol and an internal membrane pool (low density microsomal fraction (LDM)). This was associated with reduced insulin-stimulated IRS-1 and p85-associated PI 3-kinase activities in the LDM (84 and 96% inhibition, respectively). The effect of this finding on the downstream insulin signal was demonstrated by a 90% reduction in insulin stimulated protein kinase B (PKB) serine 473 phosphorylation and impaired activation of PKBalpha and PKBgamma. Both control and oxidized cells exposed to heat shock displayed a wortmannin insensitive PKB serine phosphorylation and activity. These data suggest that activation of PKB and GLUT4 translocation are insulin signaling events dependent upon a normal insulin induced Cellular compartmentalization of PI 3-kinase and IRS-1, which is oxidative stress-sensitive. These findings represent a novel Cellular Mechanism for the induction of insulin resistance in response to changes in the extraCellular environment.
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oxidative stress disrupts insulin induced Cellular redistribution of insulin receptor substrate 1 and phosphatidylinositol 3 kinase in 3t3 l1 adipocytes a putative Cellular Mechanism for impaired protein kinase b activation and glut4 translocation
Journal of Biological Chemistry, 1999Co-Authors: Amir Tirosh, Ruth Potashnik, Nava Bashan, Assaf RudichAbstract:Abstract In a recent study we have demonstrated that 3T3-L1 adipocytes exposed to low micromolar H2O2 concentrations display impaired insulin stimulated GLUT4 translocation from internal membrane pools to the plasma membrane (Rudich, A., Tirosh, A., Potashnik, R., Hemi, R., Kannety, H., and Bashan, N. (1998) Diabetes 47, 1562–1569). In this study we further characterize the Cellular Mechanisms responsible for this observation. Two-hour exposure to ∼25 μm H2O2 (generated by adding glucose oxidase to the medium) resulted in disruption of the normal insulin stimulated insulin receptor substrate (IRS)-1 and phosphatidylinositol (PI) 3-kinase Cellular redistribution between the cytosol and an internal membrane pool (low density microsomal fraction (LDM)). This was associated with reduced insulin-stimulated IRS-1 and p85-associated PI 3-kinase activities in the LDM (84 and 96% inhibition, respectively). The effect of this finding on the downstream insulin signal was demonstrated by a 90% reduction in insulin stimulated protein kinase B (PKB) serine 473 phosphorylation and impaired activation of PKBα and PKBγ. Both control and oxidized cells exposed to heat shock displayed a wortmannin insensitive PKB serine phosphorylation and activity. These data suggest that activation of PKB and GLUT4 translocation are insulin signaling events dependent upon a normal insulin induced Cellular compartmentalization of PI 3-kinase and IRS-1, which is oxidative stress-sensitive. These findings represent a novel Cellular Mechanism for the induction of insulin resistance in response to changes in the extraCellular environment.
Amir Tirosh - One of the best experts on this subject based on the ideXlab platform.
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oxidative stress disrupts insulin induced Cellular redistribution of insulin receptor substrate 1 and phosphatidylinositol 3 kinase in 3t3 l1 adipocytes a putative Cellular Mechanism for impaired protein kinase b activation and glut4 translocation
Journal of Biological Chemistry, 1999Co-Authors: Amir Tirosh, Ruth Potashnik, Nava Bashan, Assaf RudichAbstract:In a recent study we have demonstrated that 3T3-L1 adipocytes exposed to low micromolar H2O2 concentrations display impaired insulin stimulated GLUT4 translocation from internal membrane pools to the plasma membrane (Rudich, A., Tirosh, A., Potashnik, R., Hemi, R., Kannety, H., and Bashan, N. (1998) Diabetes 47, 1562-1569). In this study we further characterize the Cellular Mechanisms responsible for this observation. Two-hour exposure to approximately 25 microM H2O2 (generated by adding glucose oxidase to the medium) resulted in disruption of the normal insulin stimulated insulin receptor substrate (IRS)-1 and phosphatidylinositol (PI) 3-kinase Cellular redistribution between the cytosol and an internal membrane pool (low density microsomal fraction (LDM)). This was associated with reduced insulin-stimulated IRS-1 and p85-associated PI 3-kinase activities in the LDM (84 and 96% inhibition, respectively). The effect of this finding on the downstream insulin signal was demonstrated by a 90% reduction in insulin stimulated protein kinase B (PKB) serine 473 phosphorylation and impaired activation of PKBalpha and PKBgamma. Both control and oxidized cells exposed to heat shock displayed a wortmannin insensitive PKB serine phosphorylation and activity. These data suggest that activation of PKB and GLUT4 translocation are insulin signaling events dependent upon a normal insulin induced Cellular compartmentalization of PI 3-kinase and IRS-1, which is oxidative stress-sensitive. These findings represent a novel Cellular Mechanism for the induction of insulin resistance in response to changes in the extraCellular environment.
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oxidative stress disrupts insulin induced Cellular redistribution of insulin receptor substrate 1 and phosphatidylinositol 3 kinase in 3t3 l1 adipocytes a putative Cellular Mechanism for impaired protein kinase b activation and glut4 translocation
Journal of Biological Chemistry, 1999Co-Authors: Amir Tirosh, Ruth Potashnik, Nava Bashan, Assaf RudichAbstract:Abstract In a recent study we have demonstrated that 3T3-L1 adipocytes exposed to low micromolar H2O2 concentrations display impaired insulin stimulated GLUT4 translocation from internal membrane pools to the plasma membrane (Rudich, A., Tirosh, A., Potashnik, R., Hemi, R., Kannety, H., and Bashan, N. (1998) Diabetes 47, 1562–1569). In this study we further characterize the Cellular Mechanisms responsible for this observation. Two-hour exposure to ∼25 μm H2O2 (generated by adding glucose oxidase to the medium) resulted in disruption of the normal insulin stimulated insulin receptor substrate (IRS)-1 and phosphatidylinositol (PI) 3-kinase Cellular redistribution between the cytosol and an internal membrane pool (low density microsomal fraction (LDM)). This was associated with reduced insulin-stimulated IRS-1 and p85-associated PI 3-kinase activities in the LDM (84 and 96% inhibition, respectively). The effect of this finding on the downstream insulin signal was demonstrated by a 90% reduction in insulin stimulated protein kinase B (PKB) serine 473 phosphorylation and impaired activation of PKBα and PKBγ. Both control and oxidized cells exposed to heat shock displayed a wortmannin insensitive PKB serine phosphorylation and activity. These data suggest that activation of PKB and GLUT4 translocation are insulin signaling events dependent upon a normal insulin induced Cellular compartmentalization of PI 3-kinase and IRS-1, which is oxidative stress-sensitive. These findings represent a novel Cellular Mechanism for the induction of insulin resistance in response to changes in the extraCellular environment.
Tsutomu Tsuchida - One of the best experts on this subject based on the ideXlab platform.
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Cellular Mechanism for selective vertical transmission of an obligate insect symbiont at the bacteriocyte embryo interface
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Ryuichi Koga, Tsutomu Tsuchida, Xianying Meng, Takema FukatsuAbstract:Many insects are associated with obligate symbiotic bacteria, which are localized in specialized cells called bacteriocytes, vertically transmitted through host generations via ovarial passage, and essential for growth and reproduction of their hosts. Although vertical transmission is pivotal for maintenance of such intimate host–symbiont associations, molecular and Cellular Mechanisms underlying the process are largely unknown. Here we report a Cellular Mechanism for vertical transmission of the obligate symbiont Buchnera in the pea aphid Acyrthosiphon pisum. In the aphid body, Buchnera cells are transmitted from maternal bacteriocytes to adjacent blastulae at the ovariole tips in a highly coordinated manner. By making use of symbiont-manipulated strains of A. pisum, we demonstrated that the facultative symbiont Serratia is, unlike Buchnera, not transmitted from maternal bacteriocytes to blastulae, suggesting a specific Mechanism for Buchnera transmission. EM observations revealed a series of exo-/endocytotic processes operating at the bacteriocyte–blastula interface: Buchnera cells are exocytosed from the maternal bacteriocyte, temporarily released to the extraCellular space, and endocytosed by the posterior syncytial cytoplasm of the blastula. These results suggest that the selective Buchnera transmission is likely attributable to Buchnera-specific exocytosis by the maternal bacteriocyte, whereas both Buchnera and Serratia are nonselectively incorporated by the endocytotic activity of the posterior region of the blastula. The sophisticated Cellular Mechanism for vertical transmission of Buchnera must have evolved to ensure the obligate host–symbiont association, whereas facultative symbionts like Serratia may coopt the endocytotic component of the Mechanism for their entry into the host embryos.
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Cellular Mechanism for selective vertical transmission of an obligate insect symbiont at the bacteriocyte-embryo interface.
Proceedings of the National Academy of Sciences of the United States of America, 2012Co-Authors: Tsutomu TsuchidaAbstract:Many insects are associated with obligate symbiotic bacteria, which are localized in specialized cells called bacteriocytes, vertically transmitted through host generations via ovarial passage, and essential for growth and reproduction of their hosts. Although vertical transmission is pivotal for maintenance of such intimate host-symbiont associations, molecular and Cellular Mechanisms underlying the process are largely unknown. Here we report a Cellular Mechanism for vertical transmission of the obligate symbiont Buchnera in the pea aphid Acyrthosiphon pisum. In the aphid body, Buchnera cells are transmitted from maternal bacteriocytes to adjacent blastulae at the ovariole tips in a highly coordinated manner. By making use of symbiont-manipulated strains of A. pisum, we demonstrated that the facultative symbiont Serratia is, unlike Buchnera, not transmitted from maternal bacteriocytes to blastulae, suggesting a specific Mechanism for Buchnera transmission. EM observations revealed a series of exo-/endocytotic processes operating at the bacteriocyte-blastula interface: Buchnera cells are exocytosed from the maternal bacteriocyte, temporarily released to the extraCellular space, and endocytosed by the posterior syncytial cytoplasm of the blastula. These results suggest that the selective Buchnera transmission is likely attributable to Buchnera-specific exocytosis by the maternal bacteriocyte, whereas both Buchnera and Serratia are nonselectively incorporated by the endocytotic activity of the posterior region of the blastula. The sophisticated Cellular Mechanism for vertical transmission of Buchnera must have evolved to ensure the obligate host-symbiont association, whereas facultative symbionts like Serratia may coopt the endocytotic component of the Mechanism for their entry into the host embryos.
Dan R Halm - One of the best experts on this subject based on the ideXlab platform.
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distinct k conductive pathways are required for cl and k secretion across distal colonic epithelium
American Journal of Physiology-cell Physiology, 2006Co-Authors: Susan T Halm, Tianjiang Liao, Dan R HalmAbstract:Secretion of Cl− and K+ in the colonic epithelium operates through a Cellular Mechanism requiring K+ channels in the basolateral and apical membranes. Transepithelial current [short-circuit current...
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k channel kvlqt1 located in the basolateral membrane of distal colonic epithelium is not essential for activating cl secretion
American Journal of Physiology-cell Physiology, 2005Co-Authors: Tianjiang Liao, Susan T Halm, Ling Wang, Robert E W Fyffe, Dan R HalmAbstract:The Cellular Mechanism for Cl− and K+ secretion in the colonic epithelium requires K+ channels in the basolateral and apical membranes. Colonic mucosa from guinea pig and rat were fixed, sectioned,...