|
|
Blood, 15 July 2006, Vol. 108, No. 2, pp. 518-524.
Prepublished online as a Blood First Edition Paper on April 11, 2006; DOI 10.1182/blood-2005-09-3691.
Previous Article | Table of Contents | Next Article 
IMMUNOBIOLOGY
Melatonin suppresses macrophage cyclooxygenase-2 and inducible nitric oxide synthase expression by inhibiting p52 acetylation and binding
Wu-Guo Deng,
Shao-Tzu Tang,
Hui-Ping Tseng, and
Kenneth K. Wu
From the Vascular Biology Research Center, Institute of Molecular Medicine and Division of Hematology, Department of Internal Medicine, The University of Texas Health Science Center at Houston.
Melatonin has been shown to be produced by nonpineal cells and possess anti-inflammatory actions in animal models. In the present study, we tested the hypothesis that melatonin suppresses the expression of proinflammatory genes such as cyclooxygenase-2 (COX2) and inducible nitric oxide synthase (INOS) by a common transcriptional mechanism. Melatonin but not tryptophan or serotonin inhibited lipopolysaccharide (LPS)induced COX-2 and iNOS protein levels and promoter activities in RAW 264.7 cells in a time- and concentration-dependent manner. LPS or LPS plus interferon- (IFN ) increased binding of all 5 isoforms of NF- B to COX-2 and iNOS promoters. Melatonin selectively inhibited p52 binding without affecting p100 expression, p52 generation from p100, or p52 nuclear translocation. p52 acetylation was enhanced by LPS, which was abrogated by melatonin. Melatonin inhibited p300 histone acetyltransferase (HAT) activity and abrogated p300-augmented COX-2 and iNOS expression. HAT inhibitors suppressed LPS-induced p52 binding and acetylation to an extent similar to melatonin, and melatonin did not potentiate the effect of HAT inhibitors. These results suggest that melatonin inhibits COX-2 and iNOS transcriptional activation by inhibiting p300 HAT activity, thereby suppressing p52 acetylation, binding, and transactivation.

CiteULike Connotea Del.icio.us Digg Reddit Technorati What's this?
This article has been cited by other articles:

|
 |

|
 |
 
W.-G. Deng, G. Jayachandran, G. Wu, K. Xu, J. A. Roth, and L. Ji
Tumor-specific Activation of Human Telomerase Reverses Transcriptase Promoter Activity by Activating Enhancer-binding Protein-2beta in Human Lung Cancer Cells
J. Biol. Chem.,
September 7, 2007;
282(36):
26460 - 26470.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
C.-H. Tang, D.-Y. Lu, T.-W. Tan, W.-M. Fu, and R.-S. Yang
Ultrasound Induces Hypoxia-inducible Factor-1 Activation and Inducible Nitric-oxide Synthase Expression through the Integrin/Integrin-linked Kinase/Akt/Mammalian Target of Rapamycin Pathway in Osteoblasts
J. Biol. Chem.,
August 31, 2007;
282(35):
25406 - 25415.
[Abstract]
[Full Text]
[PDF]
|
 |
|

|
 |

|
 |
 
W.-G. Deng, A. J. Montero, and K. K. Wu
Interferon-{gamma} Suppresses Cyclooxygenase-2 Promoter Activity by Inhibiting C-Jun and C/EBP{beta} Binding
Arterioscler. Thromb. Vasc. Biol.,
August 1, 2007;
27(8):
1752 - 1759.
[Abstract]
[Full Text]
[PDF]
|
 |
|
|
|