scholarly journals NF-κB and Activator Protein 1 Response Elements and the Role of Histone Modifications in IL-1β-Induced TGF-β1 Gene Transcription

2005 ◽  
Vol 176 (1) ◽  
pp. 603-615 ◽  
Author(s):  
Kang-Yun Lee ◽  
Kazuhiro Ito ◽  
Ryuji Hayashi ◽  
Elen P. I. Jazrawi ◽  
Peter J. Barnes ◽  
...  
2004 ◽  
Vol 18 (3) ◽  
pp. 558-573 ◽  
Author(s):  
Pulak R. Manna ◽  
Darrell W. Eubank ◽  
Douglas M. Stocco

Abstract cAMP-dependent mechanisms regulate the steroidogenic acute regulatory (StAR) protein even though its promoter lacks a consensus cAMP response-element (CRE, TGACGTCA). Transcriptional regulation of the StAR gene has been demonstrated to involve combinations of DNA sequences that provide recognition motifs for sequence-specific transcription factors. We recently identified and characterized three canonical 5′-CRE half-sites within the cAMP-responsive region (−151/−1 bp) of the mouse StAR gene. Among these CRE elements, the CRE2 half-site is analogous (TGACTGA) to an activator protein-1 (AP-1) sequence [TGA(C/G)TCA]; therefore, the role of the AP-1 transcription factor was explored in StAR gene transcription. Mutation in the AP-1 element demonstrated an approximately 50% decrease in StAR reporter activity. Using EMSA, oligonucleotide probes containing an AP-1 binding site were found to specifically bind to nuclear proteins obtained from mouse MA-10 Leydig and Y-1 adrenocortical tumor cells. The integrity of the sequence-specific AP-1 element in StAR gene transcription was assessed using the AP-1 family members, Fos (c-Fos, Fra-1, Fra-2, and Fos B) and Jun (c-Jun, Jun B, and Jun D), which demonstrated the involvement of Fos and Jun in StAR gene transcription to varying degrees. Disruption of the AP-1 binding site reversed the transcriptional responses seen with Fos and Jun. EMSA studies utilizing antibodies specific to Fos and Jun demonstrated the involvement of several AP-1 family proteins. Functional assessment of Fos and Jun was further demonstrated by transfecting antisense c-Fos, Fra-1, and dominant negative forms of Fos (A-Fos) and c-Jun (TAM-67) into MA-10 cells, which significantly (P < 0.01) repressed transcription of the StAR gene. Mutation of the AP-1 site in combination with mutations in other cis-elements resulted in a further decrease of StAR promoter activity, demonstrating a functional cooperation between these factors. Mammalian two-hybrid assays revealed high-affinity protein-protein interactions between c-Fos and c-Jun with steroidogenic factor 1, GATA-4, and CCAAT/enhancer binding protein-β. These findings demonstrate that Fos and Jun can bind to the TGACTGA element in the StAR promoter and provide novel insights into the mechanisms regulating StAR gene transcription.


2001 ◽  
Vol 268 (6) ◽  
pp. 1802-1810
Author(s):  
Danielle Naville ◽  
Estelle Bordet ◽  
Marie-Claude Berthelon ◽  
Philippe Durand ◽  
Martine Begeot

PLoS ONE ◽  
2009 ◽  
Vol 4 (3) ◽  
pp. e4864 ◽  
Author(s):  
Min-Kyoung Kim ◽  
Jung-Min Shin ◽  
Hee Chul Eun ◽  
Jin Ho Chung

2003 ◽  
Vol 278 (49) ◽  
pp. 49022-49030 ◽  
Author(s):  
Xiaoxiao Chen ◽  
Yong Li ◽  
Kaihua Wei ◽  
Li Li ◽  
Wanli Liu ◽  
...  

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e15136-e15136
Author(s):  
C. Lin ◽  
Y. Chen

e15136 Background: Silibinin, a flavonoid and the major active component of milk thistle, has been as a safe diet supplement for several decades. It has been proved with anti-hepatotoxic properties and pleiotropic anticancer capabilities. Current study aimed to investigate the role of silibinin as potential therapeutic target of colon cancer through antiangiogenesis and its related molecular mechanisms with matrix metalloproteinase- 2 (MMP-2) and activator protein-1 (AP-1). Colon cancer cell line, LoVo cells, treated with a major prognostic factor, interleukin-6 (IL-6), was studied. Methods and Results: By western blot analysis, silibinin suppressed MMP- 2 protein expression in time- and concentration-dependent manners. Furthermore, the inhibitors of JNK/AP-1 binding activity abolished the expression of MMP-2 in IL-6-stimulated LoVo cells, but not PI3K pathways. We also demonstrated that silibinin inhibited IL-6- stimulated LoVo cell migration and further tumor angiogenesis, which similar to the effects from addition with AP-1 inhibitor. By EMSA, the binding activity of AP-1 in LoVo cells was also decreased with silibinin treatment. In addition, the imaging of confocal microscopy revealed that AP-1 presentation was attenuated on IL-6-stimulated LoVo cells plus silibinin treatment. Conclusions: Taken together, these data indicated that silibinin inhibits angiogenesis through the suppression of MMP-2 expression and AP-1 binding activity in colon cancer cells. It suggests a novel anti-metastatic application of silibinin in colon cancer chemoprevention. No significant financial relationships to disclose.


2004 ◽  
Vol 64 (8) ◽  
pp. 2699-2704 ◽  
Author(s):  
Florence Brellier ◽  
Claire Marionnet ◽  
Odile Chevallier-Lagente ◽  
Rune Toftgard ◽  
Alain Mauviel ◽  
...  

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