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Andrew H Limper - One of the best experts on this subject based on the ideXlab platform.
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pneumocystis carinii cell wall β glucan induces release of macrophage inflammatory protein 2 from alveolar epithelial cells via a Lactosylceramide mediated mechanism
Journal of Biological Chemistry, 2003Co-Authors: Peter Y Hahn, Richard E Pagano, Scott E Evans, Theodore J Kottom, Joseph E Standing, Andrew H LimperAbstract:Abstract Infiltration of the lungs with neutrophils promotes respiratory failure during severePneumocystis carinii (PC) pneumonia. Recent studies have shown that alveolar epithelial cells (AECs), in addition to promoting PC attachment, also participate in lung inflammation by the release of cytokines and chemokines. Herein, we demonstrate that a PC β-glucan rich cell wall isolate (PCBG) stimulates the release of macrophage inflammatory protein-2 (MIP-2) from isolated AECs through a Lactosylceramide-dependent mechanism. The results demonstrate that MIP-2 mRNA and protein production is significantly increased at both early and late time points after PCBG challenge. Although CD11b/CD18 (Mac-1, CR3) is the most widely studied β-glucan receptor, we demonstrate that CD11b/CD18 is not present on AECs. This study instead demonstrates that preincubation of AECs with an antibody directed against the membrane glycosphingolipid Lactosylceramide (CDw17) results in a significant decrease in MIP-2 secretion. Preincubation of the anti-CDw17 antibody with solubilized Lactosylceramide reverses this effect. Furthermore, incubation of AECs with inhibitors of glycosphingolipid biosynthesis, includingN-butyldeoxyno jirimycin andd-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol-HCl, also results in a significant decrease in AEC MIP-2 production following challenge with PCBG. These data demonstrate that PC β-glucan induces significant production of MIP-2 from AECs and that CDw17 participates in the glucan-induced inflammatory signaling in lung epithelial cells during PC infection.
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pneumocystis carinii cell wall β glucan induces release of macrophage inflammatory protein 2 from alveolar epithelial cells via a Lactosylceramide mediated mechanism
Journal of Biological Chemistry, 2003Co-Authors: Peter Y Hahn, Richard E Pagano, Scott E Evans, Theodore J Kottom, Joseph E Standing, Andrew H LimperAbstract:Infiltration of the lungs with neutrophils promotes respiratory failure during severe Pneumocystis carinii (PC) pneumonia. Recent studies have shown that alveolar epithelial cells (AECs), in addition to promoting PC attachment, also participate in lung inflammation by the release of cytokines and chemokines. Herein, we demonstrate that a PC beta-glucan rich cell wall isolate (PCBG) stimulates the release of macrophage inflammatory protein-2 (MIP-2) from isolated AECs through a Lactosylceramide-dependent mechanism. The results demonstrate that MIP-2 mRNA and protein production is significantly increased at both early and late time points after PCBG challenge. Although CD11b/CD18 (Mac-1, CR3) is the most widely studied beta-glucan receptor, we demonstrate that CD11b/CD18 is not present on AECs. This study instead demonstrates that preincubation of AECs with an antibody directed against the membrane glycosphingolipid Lactosylceramide (CDw17) results in a significant decrease in MIP-2 secretion. Preincubation of the anti-CDw17 antibody with solubilized Lactosylceramide reverses this effect. Furthermore, incubation of AECs with inhibitors of glycosphingolipid biosynthesis, including N-butyldeoxyno jirimycin and d-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol-HCl, also results in a significant decrease in AEC MIP-2 production following challenge with PCBG. These data demonstrate that PC beta-glucan induces significant production of MIP-2 from AECs and that CDw17 participates in the glucan-induced inflammatory signaling in lung epithelial cells during PC infection.
Kazuhisa Iwabuchi - One of the best experts on this subject based on the ideXlab platform.
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Original Article Properties and functions of Lactosylceramide from mouse neutrophils
2016Co-Authors: Kazuhisa Iwabuchi, Hitoshi Nakayama, Chihiro Iwahara, Toshihide Kobayashi, Naoko Kaga, Hiromi Masuda, Ryo Matsumoto, Fumiko Yoshizaki, Yuuki Tamaki, Tomohiro HayakawaAbstract:Lactosylceramide (LacCer), which is essential for many cellular processes, is highly expressed on the plasma membranes of human neutrophils and mediates innate immune functions. Less is known, however, about the properties and biological functions of LacCer in mouse neutrophils. This study therefore analyzed the properties ofmouse neutrophil LacCer. LacCer was observed on the surface of these cells, with flow cytometry indicating that mouse neutrophil LacCer could be detected by the anti-LacCer mAb T5A7, but not by the anti-LacCer antibodies Huly-m13 and MEM-74. The molecular species of LacCer were nearly identical in mouse and human neutrophils, including C24:0 and C24:1 fatty acid chain-containing species, although the LacCer content in plasmamembranes was ∼20-fold lower in mouse than in human neutrophils. Surface plasmon resonance analysis revealed that T5A7 bound to a lipid monolayer composed of LacCer, DOPC, cholesterol and sphingomyelin (molar ratio 0.1: 10: 10: 1), whereas Huly-m13 did not. T5A7 induced neutrophil migration, which was abolished by inhibitors of Src-family kinases, PI-3 kinases, and trimeric G (o/i) proteins. T5A7 also inhibited phagocytosis of non-opsonized zymosans by neutrophils. Taken together, these findings sugges
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significance of glycosphingolipid fatty acid chain length on membrane microdomain mediated signal transduction
FEBS Letters, 2010Co-Authors: Kazuhisa Iwabuchi, Hitoshi Nakayama, Chihiro Iwahara, Kenji TakamoriAbstract:Lactosylceramide (LacCer), a neutral glycosphingolipid, is abundantly expressed on human neutrophils, and specifically recognizes several pathogenic microorganisms. LacCer forms membrane microdomains coupled with the Src family kinase Lyn on the plasma membrane, and ligand binding to LacCer activates Lyn, resulting in neutrophil functions. In contrast, neutrophilic differentiated HL-60 cells do not have Lyn-associated LacCer-enriched microdomains and lack LacCer-mediated functions. In neutrophil plasma membranes, the very long fatty acid C24:0 and C24:1 chains are the main components of LacCer, whereas plasma membrane of D-HL-60 cells mainly includes C16-LacCer species. Here, we suggest that LacCer species containing very long fatty acid chains are indispensable for the association of Lyn with LacCer-enriched microdomains and LacCer-mediated functions.
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Involvement of very long fatty acid-containing Lactosylceramide in Lactosylceramide-mediated superoxide generation and migration in neutrophils
Glycoconjugate Journal, 2008Co-Authors: Kazuhisa Iwabuchi, Alessandro Prinetti, Sandro Sonnino, Laura Mauri, Toshihide Kobayashi, Kumiko Ishii, Naoko Kaga, Kimie Murayama, Hidetake Kurihara, Hitoshi NakayamaAbstract:The neutral glycosphingolipid Lactosylceramide (LacCer) forms lipid rafts (membrane microdomains) coupled with the Src family kinase Lyn on the plasma membranes of human neutrophils; ligand binding to LacCer activates Lyn, resulting in neutrophil functions, such as superoxide generation and migration (Iwabuchi and Nagaoka, Lactosylceramide-enriched glycosphingolipid signaling domain mediates superoxide generation from human neutrophils, Blood 100, 1454–1464, 2002 and Sato et al . Induction of human neutrophil chemotaxis by Candida albicans -derived beta-1,6-long glycoside side-chain-branched beta glycan, J. Leukoc. Biol. 84, 204–211, 2006). Neutrophilic differentiated HL-60 cells (D-HL-60 cells) express almost the same amount of LacCer as neutrophils. However, D-HL-60 cells do not have Lyn-associated LacCer-enriched lipid rafts and lack LacCer-mediated superoxide-generating and migrating abilities. Here, we examined the roles of LacCer molecular species of different fatty acid compositions in these processes. Liquid chromatography-mass spectrometry analyses revealed that the very long fatty acid C24:0 and C24:1 chains were the main components of LacCer (31.6% on the total fatty acid content) in the detergent-resistant membrane fraction (DRM) from neutrophil plasma membranes. In contrast, plasma membrane DRM of D-HL-60 cells included over 70% C16:0-LacCer, but only 13.6% C24-LacCer species. D-HL-60 cells loaded with C24:0 or C24:1-LacCer acquired LacCer-mediated migrating and superoxide-generating abilities, and allowed Lyn coimmunoprecipitation by anti-LacCer antibody. Lyn knockdown by siRNA completely abolished the effect of C24:1-LacCer loading on LacCer-mediated migration of D-HL-60 cells. Immunoelectron microscopy revealed that LacCer clusters were closely associated with Lyn molecules in neutrophils and C24:1-LacCer-loaded D-HL-60 cells, but not in D-HL-60 cells or C16:0-LacCer-loaded cells. Taken together, these observations suggest that LacCer species with very long fatty acids are specifically necessary for Lyn-coupled LacCer-enriched lipid raft-mediated neutrophil superoxide generation and migration.
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Lactosylceramide enriched glycosphingolipid signaling domain mediates superoxide generation from human neutrophils
Blood, 2002Co-Authors: Kazuhisa Iwabuchi, Isao NagaokaAbstract:This study is focused on the functional significance of neutrophil Lactosylceramide (LacCer)–enriched microdomains, which are involved in the initiation of a signal transduction pathway leading to superoxide generation. Treatment of neutrophils with anti-LacCer antibody, T5A7 or Huly-m13, induced superoxide generation from the cells, which was blocked by PP1, a Src kinase inhibitor; wortmannin, a phosphatidylinositol-3 kinase inhibitor; SB203580, a p38 mitogen-activated protein kinase (MAPK) inhibitor; and H7, an inhibitor for protein kinase C. When promyelocytic leukemia HL-60 cells were differentiated into neutrophilic lineage by dimethyl sulfoxide (DMSO) treatment, they acquired superoxide-generating activity but did not respond to anti-LacCer antibodies. Density gradient centrifugation revealed that LacCer and Lyn were recovered in detergent-insoluble membrane (DIM) of neutrophils and DMSO-treated HL-60 cells. However, immunoprecipitation experiments indicated that LacCer was associated with Lyn in neutrophils but not in DMSO-treated HL-60 cells. Interestingly, T5A7 induced the phosphorylation of Lyn in neutrophils but not in DMSO-treated HL-60 cells. Moreover, T5A7 induced the phosphorylation of p38 MAPK in neutrophils. T5A7-induced Lyn phosphorylation in neutrophil DIM fraction was significantly enhanced by cholesterol depletion or sequestration with methyl-β-cyclodextrin or nystatin. Collectively, these data suggest that neutrophils are characterized by the presence of cell surface LacCer-enriched glycosphingolipid signaling domain coupled with Lyn and that the ligand binding to LacCer induces the activation of Lyn, which may be suppressibly regulated by cholesterol, leading to superoxide generation through the phosphatidylinositol-3 kinase–, p38 MAPK–, and protein kinase C–dependent signal transduction pathway.
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gm3 enriched microdomain involved in cell adhesion and signal transduction through carbohydrate carbohydrate interaction in mouse melanoma b16 cells
Journal of Biological Chemistry, 1998Co-Authors: Kazuhisa Iwabuchi, Soichiro Yamamura, Alessandro Prinetti, Kazuko Handa, Senitiroh HakomoriAbstract:Mouse melanoma B16 cells are characterized by the predominant presence of ganglioside GM3 and adhere to Lactosylceramide- or Gg3-coated plates through interaction of GM3 with Lactosylceramide or Gg3, whereby not only adhesion but also spreading and enhancement of cell motility occur (Kojima, N., Hakomori, S. (1991) J. Biol. Chem. 266, 17552-17558). We now report that the adhesion process is based essentially on a glycosphingolipid-enriched microdomain (GEM) at the B16 cell surface, since >90% of GM3 present in the original cells is found in GEM, and GEM is also enriched in several signal transducer molecules, e.g. c-Src, Ras, Rho, and focal adhesion kinase (FAK). GEM was isolated as a low density membranous fraction by homogenization of B16 cells in lysis buffer under two different conditions (i.e. buffer containing 1% Triton X-100, or hypertonic sodium carbonate without detergent), followed by sucrose density gradient centrifugation. A close association of GM3 with c-Src, Rho, and FAK was indicated by co-immunoprecipitation of GM3 present in GEM by anti-GM3 monoclonal antibody DH2, followed by Western blotting with antibodies directed to these transducer molecules. The following data indicate that GEM is a structural and functional unit for initiation of GM3-dependent cell adhesion coupled with signal transduction. 1) Tyrosine phosphorylation in FAK was greatly enhanced in B16 cells adhered to Gg3-coated plates but was minimal in cells adhered to GM3-coated, GlcCer-coated, or noncoated plates. 2) GTP loading on Ras and Rho increased significantly when cells were adhered to Gg3-coated plates, compared with GM3-coated, GlcCer-coated, or noncoated plates. Since Ras and Rho are closely associated with GM3 in GEM, cell adhesion/stimulation through GM3 in GEM may induce activation of Ras and Rho through enhanced GTP binding.
Alessandro Prinetti - One of the best experts on this subject based on the ideXlab platform.
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Involvement of very long fatty acid-containing Lactosylceramide in Lactosylceramide-mediated superoxide generation and migration in neutrophils
Glycoconjugate Journal, 2008Co-Authors: Kazuhisa Iwabuchi, Alessandro Prinetti, Sandro Sonnino, Laura Mauri, Toshihide Kobayashi, Kumiko Ishii, Naoko Kaga, Kimie Murayama, Hidetake Kurihara, Hitoshi NakayamaAbstract:The neutral glycosphingolipid Lactosylceramide (LacCer) forms lipid rafts (membrane microdomains) coupled with the Src family kinase Lyn on the plasma membranes of human neutrophils; ligand binding to LacCer activates Lyn, resulting in neutrophil functions, such as superoxide generation and migration (Iwabuchi and Nagaoka, Lactosylceramide-enriched glycosphingolipid signaling domain mediates superoxide generation from human neutrophils, Blood 100, 1454–1464, 2002 and Sato et al . Induction of human neutrophil chemotaxis by Candida albicans -derived beta-1,6-long glycoside side-chain-branched beta glycan, J. Leukoc. Biol. 84, 204–211, 2006). Neutrophilic differentiated HL-60 cells (D-HL-60 cells) express almost the same amount of LacCer as neutrophils. However, D-HL-60 cells do not have Lyn-associated LacCer-enriched lipid rafts and lack LacCer-mediated superoxide-generating and migrating abilities. Here, we examined the roles of LacCer molecular species of different fatty acid compositions in these processes. Liquid chromatography-mass spectrometry analyses revealed that the very long fatty acid C24:0 and C24:1 chains were the main components of LacCer (31.6% on the total fatty acid content) in the detergent-resistant membrane fraction (DRM) from neutrophil plasma membranes. In contrast, plasma membrane DRM of D-HL-60 cells included over 70% C16:0-LacCer, but only 13.6% C24-LacCer species. D-HL-60 cells loaded with C24:0 or C24:1-LacCer acquired LacCer-mediated migrating and superoxide-generating abilities, and allowed Lyn coimmunoprecipitation by anti-LacCer antibody. Lyn knockdown by siRNA completely abolished the effect of C24:1-LacCer loading on LacCer-mediated migration of D-HL-60 cells. Immunoelectron microscopy revealed that LacCer clusters were closely associated with Lyn molecules in neutrophils and C24:1-LacCer-loaded D-HL-60 cells, but not in D-HL-60 cells or C16:0-LacCer-loaded cells. Taken together, these observations suggest that LacCer species with very long fatty acids are specifically necessary for Lyn-coupled LacCer-enriched lipid raft-mediated neutrophil superoxide generation and migration.
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altered sphingolipid metabolism in n 4 hydroxyphenyl retinamide resistant a2780 human ovarian carcinoma cells
Journal of Biological Chemistry, 2003Co-Authors: Alessandro Prinetti, Simona Prioni, Nicoletta Loberto, Vanna Chigorno, Luisa Basso, Valentina Appierto, Maria Grazia Villani, Manuela Valsecchi, Elena Cavadini, Franca FormelliAbstract:In the present work, we studied the effects of fenretinide (N-(4-hydroxyphenyl)retinamide (HPR)), a hydroxyphenyl derivative of all-trans-retinoic acid, on sphingolipid metabolism and expression in human ovarian carcinoma A2780 cells. A2780 cells, which are sensitive to a pharmacologically achievable HPR concentration, become 10-fold more resistant after exposure to increasing HPR concentrations. Our results showed that HPR was able to induce a dose- and time-dependent increase in cellular ceramide levels in sensitive but not in resistant cells. This form of resistance in A2780 cells was not accompanied by the overexpression of multidrug resistance-specific proteins MDR1 P-glycoprotein and multidrug resistance-associated protein, whose mRNA levels did not differ in sensitive and resistant A2780 cells. HPR-resistant cells were characterized by an overall altered sphingolipid metabolism. The overall content in glycosphingolipids was similar in both cell types, but the expression of specific glycosphingolipids was different. Specifically, our findings indicated that glucosylceramide levels were similar in sensitive and resistant cells, but resistant cells were characterized by a 6-fold lower expression of Lactosylceramide levels and by a 6-fold higher expression of ganglioside levels than sensitive cells. The main gangliosides from resistant A2780 cells were identified as GM3 and GM2. The possible metabolic mechanisms leading to this difference were investigated. Interestingly, the mRNA levels of glucosylceramide and Lactosylceramide synthases were similar in sensitive and resistant cells, whereas GM3 synthase mRNA level and GM3 synthase activity were remarkably higher in resistant cells.
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gm3 enriched microdomain involved in cell adhesion and signal transduction through carbohydrate carbohydrate interaction in mouse melanoma b16 cells
Journal of Biological Chemistry, 1998Co-Authors: Kazuhisa Iwabuchi, Soichiro Yamamura, Alessandro Prinetti, Kazuko Handa, Senitiroh HakomoriAbstract:Mouse melanoma B16 cells are characterized by the predominant presence of ganglioside GM3 and adhere to Lactosylceramide- or Gg3-coated plates through interaction of GM3 with Lactosylceramide or Gg3, whereby not only adhesion but also spreading and enhancement of cell motility occur (Kojima, N., Hakomori, S. (1991) J. Biol. Chem. 266, 17552-17558). We now report that the adhesion process is based essentially on a glycosphingolipid-enriched microdomain (GEM) at the B16 cell surface, since >90% of GM3 present in the original cells is found in GEM, and GEM is also enriched in several signal transducer molecules, e.g. c-Src, Ras, Rho, and focal adhesion kinase (FAK). GEM was isolated as a low density membranous fraction by homogenization of B16 cells in lysis buffer under two different conditions (i.e. buffer containing 1% Triton X-100, or hypertonic sodium carbonate without detergent), followed by sucrose density gradient centrifugation. A close association of GM3 with c-Src, Rho, and FAK was indicated by co-immunoprecipitation of GM3 present in GEM by anti-GM3 monoclonal antibody DH2, followed by Western blotting with antibodies directed to these transducer molecules. The following data indicate that GEM is a structural and functional unit for initiation of GM3-dependent cell adhesion coupled with signal transduction. 1) Tyrosine phosphorylation in FAK was greatly enhanced in B16 cells adhered to Gg3-coated plates but was minimal in cells adhered to GM3-coated, GlcCer-coated, or noncoated plates. 2) GTP loading on Ras and Rho increased significantly when cells were adhered to Gg3-coated plates, compared with GM3-coated, GlcCer-coated, or noncoated plates. Since Ras and Rho are closely associated with GM3 in GEM, cell adhesion/stimulation through GM3 in GEM may induce activation of Ras and Rho through enhanced GTP binding.
Peter Y Hahn - One of the best experts on this subject based on the ideXlab platform.
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pneumocystis carinii cell wall β glucan induces release of macrophage inflammatory protein 2 from alveolar epithelial cells via a Lactosylceramide mediated mechanism
Journal of Biological Chemistry, 2003Co-Authors: Peter Y Hahn, Richard E Pagano, Scott E Evans, Theodore J Kottom, Joseph E Standing, Andrew H LimperAbstract:Abstract Infiltration of the lungs with neutrophils promotes respiratory failure during severePneumocystis carinii (PC) pneumonia. Recent studies have shown that alveolar epithelial cells (AECs), in addition to promoting PC attachment, also participate in lung inflammation by the release of cytokines and chemokines. Herein, we demonstrate that a PC β-glucan rich cell wall isolate (PCBG) stimulates the release of macrophage inflammatory protein-2 (MIP-2) from isolated AECs through a Lactosylceramide-dependent mechanism. The results demonstrate that MIP-2 mRNA and protein production is significantly increased at both early and late time points after PCBG challenge. Although CD11b/CD18 (Mac-1, CR3) is the most widely studied β-glucan receptor, we demonstrate that CD11b/CD18 is not present on AECs. This study instead demonstrates that preincubation of AECs with an antibody directed against the membrane glycosphingolipid Lactosylceramide (CDw17) results in a significant decrease in MIP-2 secretion. Preincubation of the anti-CDw17 antibody with solubilized Lactosylceramide reverses this effect. Furthermore, incubation of AECs with inhibitors of glycosphingolipid biosynthesis, includingN-butyldeoxyno jirimycin andd-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol-HCl, also results in a significant decrease in AEC MIP-2 production following challenge with PCBG. These data demonstrate that PC β-glucan induces significant production of MIP-2 from AECs and that CDw17 participates in the glucan-induced inflammatory signaling in lung epithelial cells during PC infection.
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pneumocystis carinii cell wall β glucan induces release of macrophage inflammatory protein 2 from alveolar epithelial cells via a Lactosylceramide mediated mechanism
Journal of Biological Chemistry, 2003Co-Authors: Peter Y Hahn, Richard E Pagano, Scott E Evans, Theodore J Kottom, Joseph E Standing, Andrew H LimperAbstract:Infiltration of the lungs with neutrophils promotes respiratory failure during severe Pneumocystis carinii (PC) pneumonia. Recent studies have shown that alveolar epithelial cells (AECs), in addition to promoting PC attachment, also participate in lung inflammation by the release of cytokines and chemokines. Herein, we demonstrate that a PC beta-glucan rich cell wall isolate (PCBG) stimulates the release of macrophage inflammatory protein-2 (MIP-2) from isolated AECs through a Lactosylceramide-dependent mechanism. The results demonstrate that MIP-2 mRNA and protein production is significantly increased at both early and late time points after PCBG challenge. Although CD11b/CD18 (Mac-1, CR3) is the most widely studied beta-glucan receptor, we demonstrate that CD11b/CD18 is not present on AECs. This study instead demonstrates that preincubation of AECs with an antibody directed against the membrane glycosphingolipid Lactosylceramide (CDw17) results in a significant decrease in MIP-2 secretion. Preincubation of the anti-CDw17 antibody with solubilized Lactosylceramide reverses this effect. Furthermore, incubation of AECs with inhibitors of glycosphingolipid biosynthesis, including N-butyldeoxyno jirimycin and d-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol-HCl, also results in a significant decrease in AEC MIP-2 production following challenge with PCBG. These data demonstrate that PC beta-glucan induces significant production of MIP-2 from AECs and that CDw17 participates in the glucan-induced inflammatory signaling in lung epithelial cells during PC infection.
Subroto Chatterjee - One of the best experts on this subject based on the ideXlab platform.
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Use of a Glycolipid Inhibitor to Ameliorate Renal Cancer in a Mouse Model
2013Co-Authors: Subroto Chatterjee, Nezar Alsaeedi, Jennifer Hou, Veera Venkata Ratnam Bandaru, Marc K. Halushka, Roberto Pili, Georges Ndikuyeze, Norman J. HaugheyAbstract:In a xenograft model wherein, live renal cancer cells were implanted under the kidney capsule in mice, revealed a 30-fold increase in tumor volume over a period of 26 days and this was accompanied with a 32-fold increase in the level of Lactosylceramide (LacCer). Mice fed D- threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), an inhibitor of glucosylceramide synthase and Lactosylceramide synthase (LCS: β-1,4-GalT-V), showed marked reduction in tumor volume. This was accompanied by a decrease in the mass of Lactosylceramide and an increase in glucosylceramide (GlcCer) level. Mechanistic studies revealed that D-PDMP inhibited cell proliferation and angiogenesis by inhibiting p44MAPK, p-AKT-1 pathway and mammalian target for rapamycin (mTOR). By linking glycosphingolipid synthesis with tumor growth, renal cancer progression and regression can be evaluated. Thus inhibiting glycosphingolipid synthesis can be a bonafide target to prevent the progression of other types of cancer.
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D-PDMP decreased the activity of glycosyltransferases and glycohydrolase in mouse renal cancer.
2013Co-Authors: Subroto Chatterjee, Nezar Alsaeedi, Jennifer Hou, Veera Venkata Ratnam Bandaru, Marc K. Halushka, Roberto Pili, Georges Ndikuyeze, Norman J. HaugheyAbstract:Measurement of Lactosylceramide synthase activity in mouse kidney was conducted using UDP[14C] galactose as galactose donor and GlcCer as the acceptor, as detailed [11]. We observed that feeding D-PDMP dose-dependently decreased the activity of this enzyme A: glucosylceramide synthase activity was decreased to the same extent irrespective of whether 3 MPK or 10 MPK of D-PDMP was fed to mice with renal cancer, B: glucosylceramidehydrolase activity was decreased by D-PDMP treatment and C: Lactosylceramide synthase activity was dose-dependently decreased in D-PDMP fed mice with renal cancer (N = 4; *p
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Lactosylceramide promotes hypertrophy through ROS generation and activation of ERK1/2 in cardiomyocytes
2013Co-Authors: Sumita Mishra, Subroto ChatterjeeAbstract:Hypertrophy is central to several heart diseases; however, not much is known about the role of glycosphingolipids (GSLs) in this phenotype. Since GSLs have been accorded several physiological functions, we sought to determine whether these compounds affect cardiac hypertrophy. By using a rat cardiomyoblast cell line, H9c2 cells and cultured primary neonatal rat cardiomyocytes, we have determined the effects of GSLs on hypertrophy. Our study comprises (a) measure-ment of [3H]-leucine incorporation into protein, (b) measure-ment of cell size and morphology by immunofluorescence microscopy and (c) real-time quantitative mRNA expression assay for atrial natriuretic peptide and brain natriuretic peptide. Phenylephrine (PE), a well-established agonist of cardiac hypertrophy, served as a positive control in these studies. Subsequently, mechanistic studies were performed to explore the involvement of various signaling transduction path-ways that may contribute to hypertrophy in these cardiomyo-cytes. We observed that Lactosylceramide specifically exerted a concentration- (50–100 µM) and time (48 h)-dependent in-crease in hypertrophy in cardiomyocytes but not a library of other structurally related GSLs. Further, in cardiomyocytes, LacCer generated reactive oxygen species, stimulated the phos-phorylation of p44 mitogen activated protein kinase and protein kinase-C, and enhanced c-jun and c-fos expression, ultimately leading to hypertrophy. In summary, we report here that LacCer specifically induces hypertrophy in cardiomyo-cytes via an “oxygen-sensitive signal transduction pathway.
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Lactosylceramide promotes hypertrophy through ROS generation and activation of ERK1/2 in cardiomyocytes
2013Co-Authors: Sumita Mishra, Subroto ChatterjeeAbstract:Hypertrophy is central to several heart diseases, however, not much is known about the role of glycosphingolipids (GSLs) in this phenotype. Since GSLs have been accorded several physiological functions, we sought to determine whether these compounds affect cardiac hypertrophy. By using a rat cardiomyoblast cell line; H9c2 cells and cultured primary neonatal rat cardiomyocytes, we have determined the effects of GSLs on hypertrophy. Our study comprises (a) measure-ment of [3H]-leucine incorporation into protein, (b) measure-ment of cell size and morphology by immunofluorescence microscopy and (c) real-time quantitative mRNA expression assay for atrial natriuretic peptide and brain natriuretic peptide. Phenylephrine (PE), a well-established agonist of cardiac hypertrophy, served as a positive control in these studies. Subsequently, mechanistic studies were performed to explore the involvement of various signaling transduction pathways that may contribute to hypertrophy in these cardio-myocytes. We observed that Lactosylceramide specifically exerted a concentration- (50–100 µM) and time (48 h)-depend-ent increase in hypertrophy in cardiomyocytes but not a library of other structurally related GSLs. Further, in cardio-myocytes, LacCer generated reactive oxygen species and sti-mulated the phosphorylation of p44 mitogen activated protein kinase and protein kinase-C and c-jun and c-fos expressions, ultimately leading to hypertrophy. In summary, we report here that LacCer specifically induces hypertrophy in cardiomyo-cytes via an “oxygen-sensitive signal transduction pathway.
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sphingolipid metabolism and signaling in atherosclerosis
Advances in Cell Aging and Gerontology, 2003Co-Authors: Subroto Chatterjee, Sergio F MartinAbstract:Publisher Summary This chapter focuses on the enzymes that are involved in the metabolism of the sphingolipids and on some representative bioactive sphingolipids that have been implicated in mediating signaling events that contribute to phenotypic changes in cells. In particular, the chapter focuses on ceramide (Cer), sphingosine-l-phosphate (S-l-P), Lactosylceramide (LacCer), and a disialoganglioside (GDs). The chapter focuses on sphingolipids in view of their involvement in atherosclerosis and vascular biology. Oxidative stress, an excess production of reactive oxygen species, plays a critical role in different pathological conditions, such as atherosclerosis, cancer, and arthritis. By virtue of being rapidly diffusible through cell membranes, the reactive oxygen species can impact upon many critical phenotypic changes, including induction of growth, regulation of kinase activity, and the activation of endothelial-derived relaxation factor NO.
