scholarly journals Suppression of Mycobacterium Tuberculosis Induced Reactive Oxygen Species andTumor Necrosis Factor-Alpha Activity in Human Monocytes of Systemic LupusErythematosus Patients by Reduced Glutathione

2012 ◽  
Vol 27 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Shah Farhan Azfar ◽  
Najmul Islam
1998 ◽  
Vol 9 (3) ◽  
pp. 433-438 ◽  
Author(s):  
E T McCarthy ◽  
R Sharma ◽  
M Sharma ◽  
J Z Li ◽  
X L Ge ◽  
...  

Tumor necrosis factor-alpha (TNF-alpha) is a cytokine that plays a central role in inflammation. Glomerular levels of TNF-alpha are elevated in human and experimental glomerulonephritis. Glomerular cells produce and respond to TNF-alpha. One of the mechanisms by which these cells respond to TNF-alpha is through generation of reactive oxygen species. In this study, the effect of TNF-alpha on albumin permeability (P(albumin)) of isolated rat glomeruli and the possible mechanism of this effect were examined. Isolated rat glomeruli were incubated with TNF-alpha (0.4 ng/ml), TNF-alpha with anti-TNF-alpha antibodies, and TNF-alpha with the reactive oxygen species scavengers superoxide dismutase, catalase, DMSO, or dimethylthiourea for 12 min at 37 degrees C, and P(albumin) was calculated. TNF-alpha increased P(albumin) of isolated glomeruli compared with control (0.70 +/- 0.02, n = 25 versus 0.00 +/- 0.05, n = 26), and this effect was abrogated by anti-TNF-alpha antibodies (-0.18 +/- 0.05, n = 23). Superoxide dismutase abolished the increase in P(albumin) (-0.04 +/- 0.11, n = 23), whereas catalase (0.73 +/- 0.08, n = 30), DMSO (0.64 +/- 0.03, n = 10), or dimethylthiourea (0.51 +/- 0.08, n = 10) did not alter the effect of TNF-alpha. These results indicate that TNF-alpha increased P(albumin+)++ of isolated glomeruli and that the mediator of the increased P(albumin) is superoxide. It is concluded that TNF-alpha derived from glomerular or extraglomerular sources can increase glomerular P(albumin) through generation of superoxide and may lead to proteinuria.


2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Xianjian Qiu ◽  
Xudong Wang ◽  
Jincheng Qiu ◽  
Yuanxin Zhu ◽  
Tongzhou Liang ◽  
...  

Accumulation of reactive oxygen species (ROS), which can be induced by inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), can significantly inhibit the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs). This process can contribute to the imbalance of bone remodeling, which ultimately leads to osteoporosis. Therefore, reducing the ROS generation during osteogenesis of BMSCs may be an effective way to reverse the impairment of osteogenesis. Melatonin (MLT) has been reported to act as an antioxidant during cell proliferation and differentiation, but its antioxidant effect and mechanism of action during osteogenesis of MSCs in the inflammatory microenvironment, especially in the presence of TNF-α, remain unknown and need further study. In our study, we demonstrate that melatonin can counteract the generation of ROS and the inhibitory osteogenesis of BMSCs induced by TNF-α, by upregulating the expression of antioxidases and downregulating the expression of oxidases. Meanwhile, MLT can inhibit the phosphorylation of p65 protein and block the degradation of IκBα protein, thus decreasing the activity of the NF-κB pathway. This study confirmed that melatonin can inhibit the generation of ROS during osteogenic differentiation of BMSCs and reverse the inhibition of osteogenic differentiation of BMSCs in vitro, suggesting that melatonin can antagonize TNF-α-induced ROS generation and promote the great effect of osteogenic differentiation of BMSCs. Accordingly, these findings provide more evidence that melatonin can be used as a candidate drug for the treatment of osteoporosis.


2001 ◽  
Vol 69 (11) ◽  
pp. 6580-6587 ◽  
Author(s):  
Jan Warwick-Davies ◽  
Amanda J. Watson ◽  
George E. Griffin ◽  
Sanjeev Krishna ◽  
Robin J. Shattock

ABSTRACT Mycobacterium tuberculosis alone induces small, donor-variable amounts of tumor necrosis factor alpha (TNF-α) from primary human monocytes in vitro. However, TNF-α release is increased 5- to 500-fold when fixed activated T cells (FAT) or their isolated, unfixed membranes are added to this system. This FAT-induced synergy was at least as potent as that induced by gamma interferon (IFN-γ) at 100 U/ml. FAT-enhanced TNF-α production is at least in part transcriptionally mediated, as reflected by quantitative changes in TNF-α mRNA between 2 and 6 h poststimulation. Unlike IFN-γ-cocultured cells, FAT-treated monocytes appeared not to have enhanced TNF-α message stability, suggesting that de novo transcription may be involved in this effect. Furthermore, M. tuberculosis alone induced only minimal DNA binding of monocyte NF-κB, but cells treated with M. tuberculosis and FAT potentiated NF-κB activity more effectively. It is therefore possible that one mechanism by which FAT synergize with M. tuberculosis to stimulate TNF-α production is via NF-κB-enhanced transcription. These data strongly suggest that in the interaction of cells involved in the immune response to M. tuberculosis, T-cell stimulation of monocyte TNF-α production involves a surface membrane interaction(s) as well as soluble mediators.


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