The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
Kumar Sharma - One of the best experts on this subject based on the ideXlab platform.
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role of smad4 on tgf β induced extracellular Matrix Stimulation in mesangial cells
Kidney International, 2003Co-Authors: Ken-ichi Tsuchida, Yanqing Zhu, Senthuran Siva, Stephen R. Dunn, Kumar SharmaAbstract:Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells. Background The best characterized signaling pathway employed by transforming growth factor-β (TGF-β) is the Smad pathway; however, its role in Matrix production in mesangial cells is unclear. We focused on Smad4, as Smad4 is essential for the activation of Smad-dependent target genes. Methods To investigate the function of Smad4 in extracellular Matrix (ECM) production, we generated several stably transfected mesangial cell lines (MMC) that have a deletion in the linker region (Smad4ΔM4: Δ275-322) or have a deletion in MH1 of Smad4 (Smad4N4: Δ1-136). The ECM genes, α1 type I collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1) and fibronectin (FN) were assessed in wild-type mesangial cells and stably transfected Smad4-DN cell lines in the absence and presence of TGF-β. Results As compared to wild-type MMC that had a 10.8-fold Stimulation of TGF-β–induced p3TP-Lux activity, MMC stably transfected with Smad4ΔM4 and Smad4N4 had only a 2.0-fold and 1.3-fold Stimulation, respectively, indicating that they had dominant-negative effects on TGF-β signaling. Basal and TGF-β–induced COL1A1 expression in Smad4 dominant-negative cells were dramatically reduced to very low levels. The early (2 hours) TGF-β–induced PAI-1 mRNA expression was inhibited; however, the sustained (24 to 48 hours) TGF-β–induced expression was not affected in Smad4 dominant-negative cells. For FN, TGF-β–induced expression was maintained in Smad4-dominant negative cells. Conclusion These results indicate that Smad4 is essential for basal and TGF-β–induced COL1A1 expression, and contributes to the early, but not sustained TGF-β–induced PAI-1 expression in mesangial cells. However, TGF-β–induced FN expression is independent of Smad4. In conclusion, Smad4 has a discriminate effect in mediating specific ECM molecules stimulated by TGF-β in mesangial cells.
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Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells
Kidney international, 2003Co-Authors: Ken-ichi Tsuchida, Yanqing Zhu, Senthuran Siva, Stephen R. Dunn, Kumar SharmaAbstract:Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells. Background The best characterized signaling pathway employed by transforming growth factor-β (TGF-β) is the Smad pathway; however, its role in Matrix production in mesangial cells is unclear. We focused on Smad4, as Smad4 is essential for the activation of Smad-dependent target genes. Methods To investigate the function of Smad4 in extracellular Matrix (ECM) production, we generated several stably transfected mesangial cell lines (MMC) that have a deletion in the linker region (Smad4ΔM4: Δ275-322) or have a deletion in MH1 of Smad4 (Smad4N4: Δ1-136). The ECM genes, α1 type I collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1) and fibronectin (FN) were assessed in wild-type mesangial cells and stably transfected Smad4-DN cell lines in the absence and presence of TGF-β. Results As compared to wild-type MMC that had a 10.8-fold Stimulation of TGF-β–induced p3TP-Lux activity, MMC stably transfected with Smad4ΔM4 and Smad4N4 had only a 2.0-fold and 1.3-fold Stimulation, respectively, indicating that they had dominant-negative effects on TGF-β signaling. Basal and TGF-β–induced COL1A1 expression in Smad4 dominant-negative cells were dramatically reduced to very low levels. The early (2 hours) TGF-β–induced PAI-1 mRNA expression was inhibited; however, the sustained (24 to 48 hours) TGF-β–induced expression was not affected in Smad4 dominant-negative cells. For FN, TGF-β–induced expression was maintained in Smad4-dominant negative cells. Conclusion These results indicate that Smad4 is essential for basal and TGF-β–induced COL1A1 expression, and contributes to the early, but not sustained TGF-β–induced PAI-1 expression in mesangial cells. However, TGF-β–induced FN expression is independent of Smad4. In conclusion, Smad4 has a discriminate effect in mediating specific ECM molecules stimulated by TGF-β in mesangial cells.
Ken-ichi Tsuchida - One of the best experts on this subject based on the ideXlab platform.
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role of smad4 on tgf β induced extracellular Matrix Stimulation in mesangial cells
Kidney International, 2003Co-Authors: Ken-ichi Tsuchida, Yanqing Zhu, Senthuran Siva, Stephen R. Dunn, Kumar SharmaAbstract:Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells. Background The best characterized signaling pathway employed by transforming growth factor-β (TGF-β) is the Smad pathway; however, its role in Matrix production in mesangial cells is unclear. We focused on Smad4, as Smad4 is essential for the activation of Smad-dependent target genes. Methods To investigate the function of Smad4 in extracellular Matrix (ECM) production, we generated several stably transfected mesangial cell lines (MMC) that have a deletion in the linker region (Smad4ΔM4: Δ275-322) or have a deletion in MH1 of Smad4 (Smad4N4: Δ1-136). The ECM genes, α1 type I collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1) and fibronectin (FN) were assessed in wild-type mesangial cells and stably transfected Smad4-DN cell lines in the absence and presence of TGF-β. Results As compared to wild-type MMC that had a 10.8-fold Stimulation of TGF-β–induced p3TP-Lux activity, MMC stably transfected with Smad4ΔM4 and Smad4N4 had only a 2.0-fold and 1.3-fold Stimulation, respectively, indicating that they had dominant-negative effects on TGF-β signaling. Basal and TGF-β–induced COL1A1 expression in Smad4 dominant-negative cells were dramatically reduced to very low levels. The early (2 hours) TGF-β–induced PAI-1 mRNA expression was inhibited; however, the sustained (24 to 48 hours) TGF-β–induced expression was not affected in Smad4 dominant-negative cells. For FN, TGF-β–induced expression was maintained in Smad4-dominant negative cells. Conclusion These results indicate that Smad4 is essential for basal and TGF-β–induced COL1A1 expression, and contributes to the early, but not sustained TGF-β–induced PAI-1 expression in mesangial cells. However, TGF-β–induced FN expression is independent of Smad4. In conclusion, Smad4 has a discriminate effect in mediating specific ECM molecules stimulated by TGF-β in mesangial cells.
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Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells
Kidney international, 2003Co-Authors: Ken-ichi Tsuchida, Yanqing Zhu, Senthuran Siva, Stephen R. Dunn, Kumar SharmaAbstract:Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells. Background The best characterized signaling pathway employed by transforming growth factor-β (TGF-β) is the Smad pathway; however, its role in Matrix production in mesangial cells is unclear. We focused on Smad4, as Smad4 is essential for the activation of Smad-dependent target genes. Methods To investigate the function of Smad4 in extracellular Matrix (ECM) production, we generated several stably transfected mesangial cell lines (MMC) that have a deletion in the linker region (Smad4ΔM4: Δ275-322) or have a deletion in MH1 of Smad4 (Smad4N4: Δ1-136). The ECM genes, α1 type I collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1) and fibronectin (FN) were assessed in wild-type mesangial cells and stably transfected Smad4-DN cell lines in the absence and presence of TGF-β. Results As compared to wild-type MMC that had a 10.8-fold Stimulation of TGF-β–induced p3TP-Lux activity, MMC stably transfected with Smad4ΔM4 and Smad4N4 had only a 2.0-fold and 1.3-fold Stimulation, respectively, indicating that they had dominant-negative effects on TGF-β signaling. Basal and TGF-β–induced COL1A1 expression in Smad4 dominant-negative cells were dramatically reduced to very low levels. The early (2 hours) TGF-β–induced PAI-1 mRNA expression was inhibited; however, the sustained (24 to 48 hours) TGF-β–induced expression was not affected in Smad4 dominant-negative cells. For FN, TGF-β–induced expression was maintained in Smad4-dominant negative cells. Conclusion These results indicate that Smad4 is essential for basal and TGF-β–induced COL1A1 expression, and contributes to the early, but not sustained TGF-β–induced PAI-1 expression in mesangial cells. However, TGF-β–induced FN expression is independent of Smad4. In conclusion, Smad4 has a discriminate effect in mediating specific ECM molecules stimulated by TGF-β in mesangial cells.
Andre Gerard - One of the best experts on this subject based on the ideXlab platform.
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chemical Stimulation techniques for geothermal wells experiments on the three well egs system at soultz sous forets france
Geothermics, 2009Co-Authors: Sandrine Portie, Francoisdavid Vuataz, Patrick Nami, Ernard Sanjua, Andre GerardAbstract:Rock Matrix Stimulation is a method of enhancing well production or injection within a broad range of challenging environments, varying from naturally fractured limestones to sandstones with complex mineralogy. A common and often successful Stimulation option, Matrix acidizing, utilizes acids that react and remove mineral phases restricting fluid flow. Reviewed is the technology of chemical treatments available for oil, gas and geothermal wells and the key elements and results of the chemical reservoir Stimulation program at the Soultz-sous-Forets, France, Enhanced Geothermal System Project.
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Chemical Stimulation techniques for geothermal wells: experiments on the three-well EGS system at Soultz-sous-Forêts, France
Geothermics, 2009Co-Authors: Sandrine Portier, Francoisdavid Vuataz, Patrick Nami, Bernard Sanjuan, Andre GerardAbstract:Rock Matrix Stimulation is a method of enhancing well production or injection within a broad range of challenging environments, varying from naturally fractured limestones to sandstones with complex mineralogy. A common and often successful Stimulation option, Matrix acidizing, utilizes acids that react and remove mineral phases restricting fluid flow. Reviewed is the technology of chemical treatments available for oil, gas and geothermal wells and the key elements and results of the chemical reservoir Stimulation program at the Soultz-sous-Forêts, France, Enhanced Geothermal System Project.
Yanqing Zhu - One of the best experts on this subject based on the ideXlab platform.
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role of smad4 on tgf β induced extracellular Matrix Stimulation in mesangial cells
Kidney International, 2003Co-Authors: Ken-ichi Tsuchida, Yanqing Zhu, Senthuran Siva, Stephen R. Dunn, Kumar SharmaAbstract:Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells. Background The best characterized signaling pathway employed by transforming growth factor-β (TGF-β) is the Smad pathway; however, its role in Matrix production in mesangial cells is unclear. We focused on Smad4, as Smad4 is essential for the activation of Smad-dependent target genes. Methods To investigate the function of Smad4 in extracellular Matrix (ECM) production, we generated several stably transfected mesangial cell lines (MMC) that have a deletion in the linker region (Smad4ΔM4: Δ275-322) or have a deletion in MH1 of Smad4 (Smad4N4: Δ1-136). The ECM genes, α1 type I collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1) and fibronectin (FN) were assessed in wild-type mesangial cells and stably transfected Smad4-DN cell lines in the absence and presence of TGF-β. Results As compared to wild-type MMC that had a 10.8-fold Stimulation of TGF-β–induced p3TP-Lux activity, MMC stably transfected with Smad4ΔM4 and Smad4N4 had only a 2.0-fold and 1.3-fold Stimulation, respectively, indicating that they had dominant-negative effects on TGF-β signaling. Basal and TGF-β–induced COL1A1 expression in Smad4 dominant-negative cells were dramatically reduced to very low levels. The early (2 hours) TGF-β–induced PAI-1 mRNA expression was inhibited; however, the sustained (24 to 48 hours) TGF-β–induced expression was not affected in Smad4 dominant-negative cells. For FN, TGF-β–induced expression was maintained in Smad4-dominant negative cells. Conclusion These results indicate that Smad4 is essential for basal and TGF-β–induced COL1A1 expression, and contributes to the early, but not sustained TGF-β–induced PAI-1 expression in mesangial cells. However, TGF-β–induced FN expression is independent of Smad4. In conclusion, Smad4 has a discriminate effect in mediating specific ECM molecules stimulated by TGF-β in mesangial cells.
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Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells
Kidney international, 2003Co-Authors: Ken-ichi Tsuchida, Yanqing Zhu, Senthuran Siva, Stephen R. Dunn, Kumar SharmaAbstract:Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells. Background The best characterized signaling pathway employed by transforming growth factor-β (TGF-β) is the Smad pathway; however, its role in Matrix production in mesangial cells is unclear. We focused on Smad4, as Smad4 is essential for the activation of Smad-dependent target genes. Methods To investigate the function of Smad4 in extracellular Matrix (ECM) production, we generated several stably transfected mesangial cell lines (MMC) that have a deletion in the linker region (Smad4ΔM4: Δ275-322) or have a deletion in MH1 of Smad4 (Smad4N4: Δ1-136). The ECM genes, α1 type I collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1) and fibronectin (FN) were assessed in wild-type mesangial cells and stably transfected Smad4-DN cell lines in the absence and presence of TGF-β. Results As compared to wild-type MMC that had a 10.8-fold Stimulation of TGF-β–induced p3TP-Lux activity, MMC stably transfected with Smad4ΔM4 and Smad4N4 had only a 2.0-fold and 1.3-fold Stimulation, respectively, indicating that they had dominant-negative effects on TGF-β signaling. Basal and TGF-β–induced COL1A1 expression in Smad4 dominant-negative cells were dramatically reduced to very low levels. The early (2 hours) TGF-β–induced PAI-1 mRNA expression was inhibited; however, the sustained (24 to 48 hours) TGF-β–induced expression was not affected in Smad4 dominant-negative cells. For FN, TGF-β–induced expression was maintained in Smad4-dominant negative cells. Conclusion These results indicate that Smad4 is essential for basal and TGF-β–induced COL1A1 expression, and contributes to the early, but not sustained TGF-β–induced PAI-1 expression in mesangial cells. However, TGF-β–induced FN expression is independent of Smad4. In conclusion, Smad4 has a discriminate effect in mediating specific ECM molecules stimulated by TGF-β in mesangial cells.
Senthuran Siva - One of the best experts on this subject based on the ideXlab platform.
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role of smad4 on tgf β induced extracellular Matrix Stimulation in mesangial cells
Kidney International, 2003Co-Authors: Ken-ichi Tsuchida, Yanqing Zhu, Senthuran Siva, Stephen R. Dunn, Kumar SharmaAbstract:Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells. Background The best characterized signaling pathway employed by transforming growth factor-β (TGF-β) is the Smad pathway; however, its role in Matrix production in mesangial cells is unclear. We focused on Smad4, as Smad4 is essential for the activation of Smad-dependent target genes. Methods To investigate the function of Smad4 in extracellular Matrix (ECM) production, we generated several stably transfected mesangial cell lines (MMC) that have a deletion in the linker region (Smad4ΔM4: Δ275-322) or have a deletion in MH1 of Smad4 (Smad4N4: Δ1-136). The ECM genes, α1 type I collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1) and fibronectin (FN) were assessed in wild-type mesangial cells and stably transfected Smad4-DN cell lines in the absence and presence of TGF-β. Results As compared to wild-type MMC that had a 10.8-fold Stimulation of TGF-β–induced p3TP-Lux activity, MMC stably transfected with Smad4ΔM4 and Smad4N4 had only a 2.0-fold and 1.3-fold Stimulation, respectively, indicating that they had dominant-negative effects on TGF-β signaling. Basal and TGF-β–induced COL1A1 expression in Smad4 dominant-negative cells were dramatically reduced to very low levels. The early (2 hours) TGF-β–induced PAI-1 mRNA expression was inhibited; however, the sustained (24 to 48 hours) TGF-β–induced expression was not affected in Smad4 dominant-negative cells. For FN, TGF-β–induced expression was maintained in Smad4-dominant negative cells. Conclusion These results indicate that Smad4 is essential for basal and TGF-β–induced COL1A1 expression, and contributes to the early, but not sustained TGF-β–induced PAI-1 expression in mesangial cells. However, TGF-β–induced FN expression is independent of Smad4. In conclusion, Smad4 has a discriminate effect in mediating specific ECM molecules stimulated by TGF-β in mesangial cells.
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Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells
Kidney international, 2003Co-Authors: Ken-ichi Tsuchida, Yanqing Zhu, Senthuran Siva, Stephen R. Dunn, Kumar SharmaAbstract:Role of Smad4 on TGF-β–induced extracellular Matrix Stimulation in mesangial cells. Background The best characterized signaling pathway employed by transforming growth factor-β (TGF-β) is the Smad pathway; however, its role in Matrix production in mesangial cells is unclear. We focused on Smad4, as Smad4 is essential for the activation of Smad-dependent target genes. Methods To investigate the function of Smad4 in extracellular Matrix (ECM) production, we generated several stably transfected mesangial cell lines (MMC) that have a deletion in the linker region (Smad4ΔM4: Δ275-322) or have a deletion in MH1 of Smad4 (Smad4N4: Δ1-136). The ECM genes, α1 type I collagen (COL1A1), plasminogen activator inhibitor-1 (PAI-1) and fibronectin (FN) were assessed in wild-type mesangial cells and stably transfected Smad4-DN cell lines in the absence and presence of TGF-β. Results As compared to wild-type MMC that had a 10.8-fold Stimulation of TGF-β–induced p3TP-Lux activity, MMC stably transfected with Smad4ΔM4 and Smad4N4 had only a 2.0-fold and 1.3-fold Stimulation, respectively, indicating that they had dominant-negative effects on TGF-β signaling. Basal and TGF-β–induced COL1A1 expression in Smad4 dominant-negative cells were dramatically reduced to very low levels. The early (2 hours) TGF-β–induced PAI-1 mRNA expression was inhibited; however, the sustained (24 to 48 hours) TGF-β–induced expression was not affected in Smad4 dominant-negative cells. For FN, TGF-β–induced expression was maintained in Smad4-dominant negative cells. Conclusion These results indicate that Smad4 is essential for basal and TGF-β–induced COL1A1 expression, and contributes to the early, but not sustained TGF-β–induced PAI-1 expression in mesangial cells. However, TGF-β–induced FN expression is independent of Smad4. In conclusion, Smad4 has a discriminate effect in mediating specific ECM molecules stimulated by TGF-β in mesangial cells.