| Autor: |
Yuchang Fu, Yan Huang, Sumita Bandyopadhyay, Gabriel Virella, Maria F. Lopes-Virella |
| Jazyk: |
angličtina |
| Rok vydání: |
2003 |
| Předmět: |
|
| Zdroj: |
Journal of Lipid Research, Vol 44, Iss 7, Pp 1315-1321 (2003) |
| Druh dokumentu: |
article |
| ISSN: |
0022-2275 |
| DOI: |
10.1194/jlr.M200415-JLR200 |
| Popis: |
We have previously shown that LDL-containing immune complexes (LDL-ICs) induce up-regulation of LDL receptor (LDLR) expression in human macrophages. The present study further investigated the molecular mechanisms leading to LDLR up-regulation by LDL-ICs as well as the signaling pathways involved. Results showed that treatment of U937 histiocytes with LDL-ICs did not increase the precursors and the cleaved forms of sterol-regulatory element binding proteins (SREBPs) 1a and 2, suggesting that SREBPs may not be involved in LDLR up-regulation by LDL-ICs. Promoter deletion and mutation studies showed that the AP-1 binding sites were essential for LDL-IC-stimulated LDLR expression. Electrophoretic mobility shift assays further demonstrated that LDL-ICs stimulated transcription factor AP-1 activity. Studies assessing the signaling pathways involved in LDLR up-regulation by LDL-ICs showed that the up-regulation of LDLR was extracellular signal-regulated kinase (ERK) dependent.In conclusion, the present study shows that LDL-ICs up-regulate LDLR expression via the ERK signaling pathway and the AP-1 motif-dependent transcriptional activation. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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