STIMULATION OF β-ADRENERGIC RECEPTORS INHIBITS TUMOR NECROSIS FACTOR ALPHA RELEASE FROM THE ISOLATED RAT HEART

1999 ◽  
Vol 27 (Supplement) ◽  
pp. A70
Author(s):  
Walter H Newman ◽  
Manuel R Castresana ◽  
Zhongbiao Wang ◽  
Martin L Dalton ◽  
Debra J Warejcka
2000 ◽  
Vol 20 (3) ◽  
pp. 912-918 ◽  
Author(s):  
Patricia Greenwel ◽  
Shizuko Tanaka ◽  
Dmitri Penkov ◽  
Wen Zhang ◽  
Michelle Olive ◽  
...  

ABSTRACT Extracellular matrix (ECM) formation and remodeling are critical processes for proper morphogenesis, organogenesis, and tissue repair. The proinflammatory cytokine tumor necrosis factor alpha (TNF-α) inhibits ECM accumulation by stimulating the expression of matrix proteolytic enzymes and by downregulating the deposition of structural macromolecules such as type I collagen. Stimulation of ECM degradation has been linked to prolonged activation of jun gene expression by the cytokine. Here we demonstrate that TNF-α inhibits transcription of the gene coding for the α2 chain of type I collagen [α2(I) collagen] in cultured fibroblasts by stimulating the synthesis and binding of repressive CCAAT/enhancer proteins (C/EBPs) to a previously identified TNF-α-responsive element. This conclusion was based on the concomitant identification of C/EBPβ and C/EBPδ as TNF-α-induced factors by biochemical purification and expression library screening. It was further supported by the ability of the C/EBP-specific dominant-negative (DN) protein to block TNF-α inhibition of α2(I) collagen but not TNF-α stimulation of the MMP-13 protease. The DN protein also blocked TNF-α downregulation of the gene coding for the α1 chain of type I collagen. The study therefore implicates repressive C/EBPs in the TNF-α-induced signaling pathway that controls ECM formation and remodeling.


1991 ◽  
Vol 174 (1) ◽  
pp. 103-107 ◽  
Author(s):  
J R Gordon ◽  
S J Galli

Mast cell-associated mediators are generally classified into two groups: the preformed mediators, which are stored in the cells' cytoplasmic granules and are released upon exocytosis, and the newly synthesized mediators, which are not stored but are produced and secreted only after appropriate stimulation of the cell. We now report that tumor necrosis factor alpha (TNF-alpha)/cachectin represents a new type of mast cell-associated mediator, in that IgE-dependent mast cell activation results in the rapid release of preformed stores of the cytokine followed by the synthesis and sustained release of large quantities of newly formed TNF-alpha. We also demonstrate that challenge with specific antigen induces higher levels of TNF-alpha mRNA at skin sites sensitized with IgE in normal mice or mast cell-reconstituted genetically mast cell-deficient WBB6F1-W/W1' mice than at identically treated sites in WBB6F1-W/W1' mice that are devoid of mast cells. These findings identify mast cells as a biologically significant source of TNF-alpha/cachectin during IgE-dependent responses and define a mechanism whereby stimulation of mast cells via the FC epsilon RI can account for both the rapid and sustained release of this cytokine.


1990 ◽  
Vol 10 (4) ◽  
pp. 1498-1506 ◽  
Author(s):  
M A Collart ◽  
P Baeuerle ◽  
P Vassalli

This study characterizes the interaction of murine macrophage nuclear proteins with the tumor necrosis factor alpha (TNF-alpha) promoter. Gel retardation and methylation interference assays showed that stimulation of TNF-alpha gene transcription in peritoneal exudate macrophages was accompanied by induction of DNA-binding proteins that recognized with different affinities four elements related to the kappa B consensus motif and a Y-box motif. We suggest that the basal level of TNF-alpha expression in macrophages is due to the binding of a constitutive form of NF-kappa B, present at low levels in nuclei from resting thioglycolate exudate peritoneal macrophages, to some if not all of the kappa B motifs; we postulate that this constitutive form contains only the 50-kilodalton (kDa) DNA-binding protein subunits of NF-kappa B, not the 65-kDa protein subunits (P. Baeuerle and D. Baltimore, Genes Dev. 3:1689-1698, 1989). Agents such as glucocorticoids, which decrease TNF-alpha transcription, diminished the basal level of nuclear NF-kappa B. Stimulation of Stimulation of TNF-alpha transcription in macrophages by lipopolysaccharide, gamma interferon, or cycloheximide led to an increased content of nuclear NF-kappa B. This induced factor represents a different form of NF-kappa B, since it generated protein-DNA complexes of slower mobility; we propose that this induced form of NF-kappa B contains both the 50- and 65-kDa protein subunits, the latter ones being necessary to bind NF-kappa B to its cytoplasmic inhibitor in uninduced cells (Baeuerle and Baltimore, Genes Dev., 1989). In resting cells, this inducible form of NF-kappa B was indeed detectable in the cytosol after deoxycholate treatment.(ABSTRACT TRUNCATED AT 250 WORDS)


2003 ◽  
Vol 23 (2) ◽  
pp. 526-533 ◽  
Author(s):  
Robert Barthel ◽  
Alla V. Tsytsykova ◽  
Amy K. Barczak ◽  
Eunice Y. Tsai ◽  
Christopher C. Dascher ◽  
...  

ABSTRACT Tumor necrosis factor alpha (TNF-α) plays an important role in host containment of infection by Mycobacterium tuberculosis, one of the leading causes of death by an infectious agent globally. Using the pathogenic M. tuberculosis strain H37Rv, we present evidence that upon stimulation of monocytic cells by M. tuberculosis a unique TNF-α enhanceosome is formed, and it is distinct from the TNF-α enhanceosome that forms in T cells stimulated by antigen engagement or virus infection. A distinct set of activators including ATF-2, c-jun, Ets, Sp1, Egr-1 and the coactivator proteins CBP/p300 are recruited to the TNF-α promoter after stimulation with M. tuberculosis. Furthermore, the formation of this enhanceosome is dependent on inducer-specific helical phasing relationships between transcription factor binding sites. We also show that the transcriptional activity of CBP/p300 is potentiated by mycobacterial stimulation of monocytes. The identification of TNF-α regulatory elements and coactivators involved in M. tuberculosis-stimulated gene expression thus provides potential selective molecular targets in the modulation of TNF-α gene expression in the setting of mycobacterial infection.


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