scholarly journals Tumour necrosis factor receptor trafficking dysfunction opens the TRAPS door to pro-inflammatory cytokine secretion

2011 ◽  
Vol 32 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Mark D. Turner ◽  
Anupama Chaudhry ◽  
Belinda Nedjai
Keyword(s):  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Nuclear Factor Κb ◽  
Cytokine Secretion ◽  
Mitogen Activated Protein Kinase ◽  
Tumour Necrosis Factor Receptor ◽  
Tnfrsf1a Gene ◽  
Mitogen Activated Protein ◽  
Necrosis Factor ◽  
Pro Inflammatory Cytokines

Cytokines are secreted from macrophages and other cells of the immune system in response to pathogens. Additionally, in autoinflammatory diseases cytokine secretion occurs in the absence of pathogenic stimuli. In the case of TRAPS [TNFR (tumour necrosis factor receptor)-associated periodic syndrome], inflammatory episodes result from mutations in the TNFRSF1A gene that encodes TNFR1. This work remains controversial, however, with at least three distinct separate mechanisms of receptor dysfunction having been proposed. Central to these hypotheses are the NF-κB (nuclear factor κB) and MAPK (mitogen-activated protein kinase) families of transcriptional activators that are able to up-regulate expression of a number of genes, including pro-inflammatory cytokines. The present review examines each proposed mechanism of TNFR1 dysfunction, and addresses how these processes might ultimately impact upon cytokine secretion and disease pathophysiology.

Role of tumour necrosis factor receptor-1 and nuclear factor-κB in production of TNF-α-induced pro-inflammatory microparticles in endothelial cells

2014 ◽  
Vol 112 (09) ◽  
pp. 580-588 ◽  
Author(s):  
Sung Kyul Lee ◽  
Seung-Hee Yang ◽  
Il Kwon ◽  
Ok-Hee Lee ◽  
Ji Hoe Heo
Keyword(s):  
Endothelial Cells ◽  
Tumour Necrosis Factor ◽  
Tumour Necrosis ◽  
Nuclear Factor Κb ◽  
Tumour Necrosis Factor Receptor ◽  
Dependent Manner ◽  
Nuclear Factor ◽  
Tnf Α ◽  
Necrosis Factor

SummaryTumour necrosis factor-α (TNF-α) is upregulated in many inflammatory diseases and is also a potent agent for microparticle (MP) generation. Here, we describe an essential role of TNF-α in the production of endothelial cell-derived microparticles (EMPs) in vivo and the function of TNF-α-induced EMPs in endothelial cells. We found that TNF-α rapidly increased blood levels of EMPs in mice. Treatment of human umbilical vein endothelial cells (HUVECs) with TNF-α also induced EMP formation in a time-dependent manner. Silencing of TNF receptor (TNFR)-1 or inhibition of the nuclear factor-κB (NF-κB) in HUVECs impaired the production of TNF-α-induced EMP. Incubation of HUVECs with PKH-67-stained EMPs showed that endothelial cells readily engulfed EMPs, and the engulfed TNF-α-induced EMPs promoted the expression of pro-apoptotic molecules and upregulated intercellular adhesion molecule-1 level on the cell surface, which led to monocyte adhesion. Collectively, our findings indicate that the generation of TNF-α-induced EMPs was mediated by TNFR1 or NF-κB and that EMPs can contribute to apoptosis and inflammation of endothelial cells.

scholarly journals Tumour necrosis factor-induced activation of c-Jun N-terminal kinase is sensitive to caspase-dependent modulation while activation of mitogen-activated protein kinase (MAPK) or p38 MAPK is not

2002 ◽  
Vol 366 (1) ◽  
pp. 145-155 ◽  
Author(s):  
Ahmed A.A. MOHAMED ◽  
Orla J. JUPP ◽  
Helen M. ANDERSON ◽  
Alison F. LITTLEJOHN ◽  
Peter VANDENABEELE ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Tumour Necrosis Factor ◽  
P38 Mapk ◽  
Hela Cells ◽  
Tumour Necrosis ◽  
Mitogen Activated Protein Kinase ◽  
Downstream Target ◽  
Mitogen Activated Protein ◽  
Induced Apoptosis ◽  
Necrosis Factor

The activation of the extracellular signal-regulated kinases (ERKs) by tumour necrosis factor-α (TNF) receptors (TNFRs) is an integral part of the cytokine's pleiotropic cellular responses. Here we report differences in the caspase sensitivity and TNFR subtype activation of members of the ERK family. Inhibition in HeLa cells of caspase function by pharmacological inhibitors or the expression of CrmA (cytokine response modifier A), a viral modifier protein, blocks TNF-induced apoptosis or caspase-dependent protein kinase Cδ and poly(ADP-ribose) polymerase protein degradation. TNFR1- or TNFR2-stimulated c-Jun N-terminal kinase (JNK) activity was attenuated in cells in which caspase activity was inhibited either by pharmacological blockers or CrmA expression. Both TNFR1- and TNFR2-stimulated JNK activity was caspase-sensitive; however, only TNFR1 was capable of stimulating p42/44 mitogen-activated protein kinase (MAPK) and p38 MAPK activities. TNFR1-stimulated p42/44 MAPK and p38 MAPK activities were insensitive to pharmacological caspase inhibition or CrmA. These findings were supported when measuring TNF-induced cytosolic phospholipase A2 activation, which is a downstream target for MAPK and p38 MAPK. Profiling caspase enzymes activated by TNF in HeLa cells showed sequential caspase-8, −3, −7, −6 and −9 activation, with their inhibition characteristics suggesting a role for caspase-3 and/or caspase-6 in modulating JNK activity. Taken together these results show delineated ERK-activation pathways employed by TNFR subtypes.

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