| Project/Area Number |
16590877
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Metabolomics
|
|---|
| Research Institution | Shiga University of Medical Science |
|---|
Principal Investigator |
NISHIO Yoshihiko Shiga University of Medical Science, Department of Medicine, assistant professor, 医学部, 講師 (40281084)
|
|---|
| Project Period (FY) |
2004 – 2005
|
| Project Status |
Completed (Fiscal Year 2005)
|
| Budget Amount *help |
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2005: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2004: ¥2,200,000 (Direct Cost: ¥2,200,000)
|
|---|
| Keywords | NO / CHOP / MCP-1 / C / EBP / Insulin / 血管平滑筋細胞 / 炎症 / 血管平滑筋 |
|---|
| Research Abstract |
We have reported that chronic activation of phosphatidylinositol 3-kinase (PI3K) by the overexpression of membrane-targeted p110CAAX induces proinflammatory gene expression in rat vascular smooth muscle cells (VSMCs) through the induction of CCAAT/enhancer binding protein-β (C/EBP-β) and C/EBP-δ. To examine the antiinflammatory effect of nitric oxide (NO) on the proinflammatory gene expression, we investigated the effects of sodium nitroprusside (SNP) on the monocyte chemoattractant protein-1 (MCP-1) gene expression in VSMCs under chronic activation of PI3K. At low concentration (0.05 mM) of SNP, but not at high concentration (0.5-1.0 mM), it significantly reduced MCP-1 mRNA and protein expression as well as its transcriptional activity. We found that SNP induced C/EBP homologous protein (CHOP) expression, which inhibited C/EBP binding activity and reduced the C/EBP activity induced by chronic activation of PI3K in a dose-dependent manner up to 1.0 mM. Consistently, the increase in CHOP expression significantly reduced the MCP-1 promoter activity induced by PI3K. However, the overexpression of CHOP alone up-regulated MCP-1 promoter activity in a dose-dependent manner up to high concentration. Deletion analysis of MCP-1 promoter and electrophoretic mobility shift assay identified the CHOP-response element (CHOP-RE) at the region between -190 and -179 bp of MCP-1 promoter. By CHOP-RE used as a decoy, the increase in promoter activity of MCP-1 induced by either CHOP or SNP was suppressed significantly. Thus, CHOP induced by an NO-donor has bidirectional effects on MCP-1 gene expression : it decreases the gene expression by inhibition of C/EBPs, and it increases the gene expression through the CHOP-RE.
|
