Production of various cytokines by normal human osteoblast-like cells in response to interleukin-1 beta and tumor necrosis factor-alpha: lack of regulation by 17 beta-estradiol.

Endocrinology ◽  
1992 ◽  
Vol 130 (5) ◽  
pp. 2528-2534 ◽  
Author(s):  
L R Chaudhary ◽  
T C Spelsberg ◽  
B L Riggs
1994 ◽  
Vol 14 (10) ◽  
pp. 6561-6569
Author(s):  
L Klampfer ◽  
T H Lee ◽  
W Hsu ◽  
J Vilcek ◽  
S Chen-Kiang

Tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) activate transcription of the TSG-6 gene in normal human fibroblasts through a promoter region (-165 to -58) that encompasses an AP-1 and a NF-IL6 site. We show by deletion analysis and substitution mutagenesis that both sites are necessary for activation by TNF-alpha. Activation by IL-1 requires the NF-IL6 site and is enhanced by the AP-1 site. These results suggest that the NF-IL6 and AP-1 family transcription factors functionally cooperate to mediate TNF-alpha and IL-1 signals. Consistent with this possibility, IL-1 and TNF-alpha markedly increase the binding of Fos and Jun to the AP-1 site, and NF-IL6 activates the native TSG-6 promoter. Activation by NF-IL6 requires an intact NF-IL6 site and is modulated by the ratio of activator to inhibitor NF-IL6 isoforms that are translated from different in-frame AUGs. However, the inhibitor isoform can also bind to the AP-1 site and repress AP-1 site-mediated transcription. The finding that the inhibitor isoform antagonizes activation of the native TSG-6 promoter by IL-1 and TNF-alpha suggests that NF-IL6 has a physiologic role in these cytokine responses. Thus, the functionally distinct NF-IL6 isoforms cooperate with Fos and Jun to positively and negatively regulate the native TSG-6 promoter by TNF-alpha and IL-1.


1991 ◽  
Vol 261 (4) ◽  
pp. L315-L321 ◽  
Author(s):  
J. N. Allen ◽  
D. J. Herzyk ◽  
M. D. Wewers

To study the role of microtubules in cytokine production, the effect of the microtubule depolymerizing agent colchicine on lipopolysaccharide endotoxin (LPS)-induced interleukin-1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) release by blood monocytes and alveolar macrophages were examined. Immunofluorescence microscopy demonstrated that LPS resulted in the appearance of microtubule-containing cytoplasmic appendages and that colchicine, which resulted in microtubule disruption in monocytes, blocked appendage formation. Colchicine resulted in approximately 50% increase in LPS-induced IL-1 beta release and a 50% decrease in LPS-induced TNF-alpha release by human monocytes at all doses of LPS tested. Although colchicine resulted in a statistically significant increase in LPS-stimulated human alveolar macrophage IL-1 beta release, the increase was not as great as that observed with monocytes. Northern blot analysis suggested that the colchicine effect occurs pretranslationally because colchicine caused an increase in LPS-stimulated IL-1 beta mRNA levels and a decrease in TNF-alpha mRNA levels. These results suggest that microtubules contribute to the regulation of endotoxin-stimulated mononuclear phagocyte cytokine production and that this regulation differs significantly between IL-1 beta and TNF-alpha.


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