MAPK/AP-1-dependent regulation of PAI-1 gene expression by TGF-β in rat mesangial cells
| Autor: | Toshiro Sugimoto, Hiroyuki Mori, Takashi Sato, Masakazu Haneda, Daisuke Koya, Motohide Isono, Atsunori Kashiwagi, Ken Inoki, Baofeng Yang, Ryuichi Kikkawa, Baoliang Guo, Satoshi Akiba, Keizo Kanasaki |
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| Rok vydání: | 2005 |
| Předmět: |
MAPK/ERK pathway
TGF-β MAP Kinase Signaling System Kidney Glomerulus PAI-1 Gene Expression Antineoplastic Agents Smad Proteins SMAD Biology Rats Sprague-Dawley Transforming Growth Factor beta1 Interferon-gamma Transforming Growth Factor beta Gene expression Plasminogen Activator Inhibitor 1 SMAD binding Animals Electrophoretic mobility shift assay Northern blot RNA Messenger Enzyme Inhibitors Phosphorylation Extracellular Signal-Regulated MAP Kinases Promoter Regions Genetic Cells Cultured Activator (genetics) MEK inhibitor JNK Mitogen-Activated Protein Kinases INF-γ AP-1 Molecular biology Rats Transcription Factor AP-1 ERK Nephrology Mesangial Cells Proto-Oncogene Proteins c-fos |
| Zdroj: | Kidney International. 68(3):972-984 |
| ISSN: | 0085-2538 |
| DOI: | 10.1111/j.1523-1755.2005.00491.x |
| Popis: | MAPK/AP-1-dependent regulation of PAI-1 gene expression by TGF-β in rat mesangial cells. Background Receptor-regulated Smads and/or mitogen-activated protein kinases (MAPKs) are involved in transforming growth factor-β (TGF-β)-nduced expression of various genes, including plasminogen activator inhibitor-1 (PAI-1). Because the sequence of the promoter region in rat PAI-1 gene differs from that in the human gene, we examined the mechanisms of TGF-β-induced rat PAI-1 expression in rat mesangial cells. Methods TGF-β1-induced PAI-1 and c-fos mRNA expressions were determined by Northern blot analysis. Activation of MAPKs and Smad proteins was evaluated by an immunoblot analysis. DNA binding activities of nuclear protein were examined by using an electrophoretic mobility shift assay (EMSA). The activities of PAI-1 promoter were measured by a luciferase reporter assay. Results Extracellular-regulated kinase (ERK) and c-Jun NH-terminal kinase (JNK) phosphorylation, c-fos mRNA expression, and activator protein-1 (AP-1) DNA binding activity stimulated by TGF-β1 were completely suppressed by the ERK kinase (MEK) inhibitors. EMSA and reporter analysis revealed that an AP-1-like sequence located in the proximal region of the rat PAI-1 promoter was the target for TGF-β1, and the disruption of this AP-1-like sequence suppressed basal and TGF-β1-induced promoter activation. TGF-β1 also stimulated nuclear translocation of Smads and binding to palindromic Smad binding element (SBE) located in the rat PAI-1 promoter, without being affected by MEK inhibitor. Point mutation and deletion of palindromic SBE did not affect TGF-β1-induced rat PAI-1 promoter activity. Moreover, interferon-γ (IFN-γ) inhibited TGF-β1-induced PAI-1 expression through selectively suppressing the ERK-AP-1 pathway. Conclusion These results suggest that the essential requirement of MAPK/AP-1 activation for TGF-β1-induced PAI-1 expression is unique to rat mesangial cells. |
| Databáze: | OpenAIRE |
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