scholarly journals Tumor Necrosis Factor-α Induces Stress Fiber Formation through Ceramide Production: Role of Sphingosine Kinase

2001 ◽  
Vol 12 (11) ◽  
pp. 3618-3630 ◽  
Author(s):  
Atef N. Hanna ◽  
Luc G. Berthiaume ◽  
Yutaka Kikuchi ◽  
David Begg ◽  
Sylvain Bourgoin ◽  
...  
Keyword(s):  
Focal Adhesion ◽  
Tumor Necrosis ◽  
Sphingosine Kinase ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Stress Fiber Formation ◽  
Induced Stress ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine that activates several signaling cascades. We determined the extent to which ceramide is a second messenger for TNF-α-induced signaling leading to cytoskeletal rearrangement in Rat2 fibroblasts. TNF-α, sphingomyelinase, or C2-ceramide induced tyrosine phosphorylation of focal adhesion kinase (FAK) and paxillin, and stress fiber formation. Ly 294002, a phosphatidylinositol 3-kinase (PI 3-K) inhibitor, or expression of dominant/negative Ras (N17) completely blocked C2-ceramide- and sphingomyelinase-induced tyrosine phosphorylation of FAK and paxillin and severely decreased stress fiber formation. The TNF-α effects were only partially inhibited. Dimethylsphingosine, a sphingosine kinase (SK) inhibitor, blocked stress fiber formation by TNF-α and C2-ceramide. TNF-α, sphingomyelinase, and C2-ceramide translocated Cdc42, Rac, and RhoA to membranes, and stimulated p21-activated protein kinase downstream of Ras-GTP, PI 3-K, and SK. Transfection with inactive RhoA inhibited the TNF-α- and C2-ceramide-induced stress fiber formation. Our results demonstrate that stimulation by TNF-α, which increases sphingomyelinase activity and ceramide formation, activates sphingosine kinase, Rho family GTPases, focal adhesion kinase, and paxillin. This novel pathway of ceramide signaling can account for ∼70% of TNF-α-induced stress fiber formation and cytoskeletal reorganization.

RhoA required for acid-induced stress fiber formation and trafficking and activation of NHE3

2007 ◽  
Vol 293 (4) ◽  
pp. F1054-F1064 ◽  
Author(s):  
Xiaojing Yang ◽  
Hai-Chang Huang ◽  
Helen Yin ◽  
Robert J. Alpern ◽  
Patricia A. Preisig
Keyword(s):  
Tyrosine Phosphorylation ◽  
Focal Adhesion ◽  
Apical Membrane ◽  
Rho Kinase ◽  
Stress Fiber ◽  
Fiber Formation ◽  
Adhesion Proteins ◽  
Stress Fiber Formation ◽  
Induced Stress ◽  
Focal Adhesion Proteins

Exposure to an acid load increases apical membrane Na+/H+ antiporter (NHE3) activity, a process that involves exocytic trafficking of the transporter to the apical membrane. We have previously shown that an intact microfilament structure is required for this exocytic process (Yang X, Amemiya M, Peng Y, Moe OW, Preisig PA, Alpern RJ. Am J Physiol Cell Physiol 279: C410–C419, 2000). The present studies demonstrate that acid-induced stress fiber formation is required for stimulation of NHE3 activity. Formation of stress fibers is associated with acid-induced tyrosine phosphorylation and increases in protein abundance of two focal adhesion proteins, p125FAK and paxillin. The Rho kinase inhibitor Y27632 completely blocks acid-induced stress fiber formation and the increases in apical membrane NHE3 abundance and activity, but it has no effect on acid-induced tyrosine phosphorylation of p125FAK or paxillin. Herbimycin A completely blocks acid-induced tyrosine phosphorylation of p125FAK and paxillin but only partially blocks stress fiber formation and NHE3 activation. These studies demonstrate that Rho kinase mediates acid-induced stress fiber formation, which is required for NHE3 exocytosis, and increases in NHE3 activity. Acid-induced tyrosine phosphorylation of the focal adhesion proteins p125FAK and paxillin is not Rho kinase dependent. Thus these two acid-mediated effects are associated, yet independent processes.

#50 Gestational exposure of tumor necrosis factor-α (TNF-α) inhibitor drugs

2019 ◽  
Vol 88 ◽  
pp. 149-150 ◽  
Author(s):  
Erkoseoglu Ilknur ◽  
Kadioglu Mine ◽  
Cavusoglu Irem ◽  
Sisman Mulkiye ◽  
Aran Turhan ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Gestational Exposure ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

Tumor Necrosis Factor-α Production-Enhancing Properties of Novel Adamantylalkylthio Derivatives of Some Heterocyclic Compounds

2005 ◽  
Vol 60 (4) ◽  
pp. 471-475 ◽  
Author(s):  
Barbara Orzeszko ◽  
Tomasz Świtaj ◽  
Anna B. Jakubowska-Mućka ◽  
Witold Lasek ◽  
Andrzej Orzeszko ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Heterocyclic Compounds ◽  
Tumor Necrosis ◽  
The Novel ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
Factor Alpha ◽  
Factor Α ◽  
Derivatives Of ◽  
Necrosis Factor

Certain adamantylated heterocycles were previously shown to enhance the secretion of tumor necrosis factor alpha (TNF-α) by murine melanoma cells that have been transduced with the gene for human TNF-α and constitutively expressed this cytokine. The stimulatory potency of those compounds depended, among other factors, on the structure of the linker between the adamantyl residue and the heterocyclic core. In the present study, a series of (1-adamantyl)alkylsulfanyl derivatives of heterocyclic compounds was prepared by alkylation of the corresponding thioheterocyles. Of the novel adamantylalkylthio compounds tested in the aforementioned cell line, 2-(2-adamantan-1-ylethylsulfanyl)- 4-methyl-pyrimidine was found to be the most active

scholarly journals Tumor necrosis factor α Inhibition for Alzheimer’s Disease

2017 ◽  
Vol 9 ◽  
pp. 117957351770927 ◽  
Author(s):  
Rudy Chang ◽  
Kei-Lwun Yee ◽  
Rachita K Sumbria
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Short Review ◽  
Tnf Α ◽  
Factor Α ◽  
Ad Therapy ◽  
Necrosis Factor

Tumor necrosis factor α (TNF-α) plays a central role in the pathophysiology of Alzheimer’s disease (AD). Food and Drug Administration–approved biologic TNF-α inhibitors are thus a potential treatment for AD, but they do not cross the blood-brain barrier. In this short review, we discuss the involvement of TNF-α in AD, challenges associated with the development of existing biologic TNF-α inhibitors for AD, and potential therapeutic strategies for targeting TNF-α for AD therapy.

Tumor necrosis factor-α-associated lysosomal permeabilization is cathepsin B dependent

2002 ◽  
Vol 283 (4) ◽  
pp. G947-G956 ◽  
Author(s):  
Nathan W. Werneburg ◽  
M. Eugenia Guicciardi ◽  
Steven F. Bronk ◽  
Gregory J. Gores
Keyword(s):  
Tumor Necrosis Factor ◽  
Cathepsin B ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Fluorescent Protein ◽  
Tnf Α ◽  
Calcein Release ◽  
Green Fluorescent ◽  
Factor Α ◽  
Necrosis Factor

Cathepsin B (Cat B) is released from lysososomes during tumor necrosis factor-α (TNF-α) cytotoxic signaling in hepatocytes and contributes to cell death. Sphingosine has recently been implicated in lysosomal permeabilization and is increased in the liver by TNF-α. Thus the aims of this study were to examine the mechanisms involved in TNF-α-associated lysosomal permeabilization, especially the role of sphingosine. Confocal microscopy demonstrated Cat B-green fluorescent protein and LysoTracker Red were both released from lysosomes after treatment of McNtcp.24 cells with TNF-α/actinomycin D, a finding compatible with lysosomal destabilization. In contrast, endosomes labeled with Texas Red dextran remained intact, suggesting lysosomes were specifically targeted for permeabilization. LysoTracker Red was released from lysosomes in hepatocytes treated with TNF-α or sphingosine in Cat B(+/+) but not Cat B(−/−) hepatocytes, as assessed by a fluorescence-based assay. With the use of a calcein release assay in isolated lysosomes, sphingosine permeabilized liver lysosomes isolated from Cat B(+/+) but not Cat B(−/−) liver. C6ceramide did not permeabilize lysosomes. In conclusion, these data implicate a sphingosine-Cat B interaction inducing lysosomal destabilization during TNF-α cytotoxic signaling.

scholarly journals Tumor necrosis factor-α exerts pro-myogenic action in C2C12 myoblasts via sphingosine kinase/S1P2signaling

FEBS Letters ◽  
2007 ◽  
Vol 581 (23) ◽  
pp. 4384-4388 ◽  
Author(s):  
Chiara Donati ◽  
Paola Nincheri ◽  
Francesca Cencetti ◽  
Elena Rapizzi ◽  
Marta Farnararo ◽  
...  
Keyword(s):  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Sphingosine Kinase ◽  
C2c12 Myoblasts ◽  
Factor Α ◽  
Necrosis Factor

Tumor Necrosis Factor-α −308 Genotypes Influence Inflammatory Activity and TNF-α Serum Concentrations in Children with Juvenile Idiopathic Arthritis

2009 ◽  
Vol 36 (4) ◽  
pp. 837-842 ◽  
Author(s):  
ANA FILIPA MOURÃO ◽  
JOANA CAETANO-LOPES ◽  
PAULA COSTA ◽  
HELENA CANHÃO ◽  
MARIA JOSÉ SANTOS ◽  
...  
Keyword(s):  
Juvenile Idiopathic Arthritis ◽  
Tumor Necrosis Factor ◽  
Disease Activity ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Inflammatory Activity ◽  
Serum Concentrations ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

Objective.Considering the relevance of tumor necrosis factor-α (TNF-α) in the pathophysiology of juvenile idiopathic arthritis (JIA), it is likely that polymorphisms in its promoter area may be relevant in disease susceptibility and activity. We investigated if clinical measures of JIA activity and TNF-α serum concentrations were associated with TNF-α −308 genotypes.Methods.Portuguese patients with JIA in 5 pediatric rheumatology centers were recruited consecutively, along with a control group of healthy subjects. Demographic and clinical data and blood samples were collected from each patient. DNA was extracted for analysis of TNF-α gene promoter polymorphisms at position −308 by restriction fragment-length polymorphism.Results.One hundred fourteen patients and 117 controls were evaluated; 57% of patients presented the oligoarticular subtype, 25% the polyarticular subtype, 8% the systemic subtype, and 9% had enthesitis-related arthritis and 5% psoriatic arthritis. Twenty-four percent of the patients presented the −308 GA/AA genotypes and 76% the −308 GG genotype, similar to findings in controls. Patients with the −308 GA/AA genotype had higher degree of functional impairment, erythrocyte sedimentation rate, 100-mm visual analog scale score for disease activity, and TNF-α levels compared to those with the −308 GG genotype.Conclusion.TNF-α −308 GA/AA genotypes were found to be related to higher inflammatory activity and worse measures of disease activity in Portuguese patients with JIA. They were not associated with susceptibility to JIA.

scholarly journals Tumor Necrosis Factor α Regulates Responses to Nerve Growth Factor, Promoting Neural Cell Survival but Suppressing Differentiation of Neuroblastoma Cells

2008 ◽  
Vol 19 (3) ◽  
pp. 855-864 ◽  
Author(s):  
Yoshinori Takei ◽  
Ronald Laskey
Keyword(s):  
Nerve Growth Factor ◽  
Growth Factor ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Neuroblastoma Cells ◽  
Erk Activation ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

Although nerve growth factor (NGF) promotes survival of neurons, tumor necrosis factor α (TNF-α) contributes to cell death triggered by NGF depletion, through TNF-α receptor (TNFR) 1. In contrast to this effect, TNF-α can promote neural cell survival via TNF-α receptor TNFR2. Although these findings demonstrate pivotal roles of TNF-α and NGF in cell fate decisions, cross-talk between these signaling pathways has not been clarified. We find that NGF can induce TNF-α synthesis through the nuclear factor-κB transcription factor. This provides a new basis for examining the cross-talk between NGF and TNF-α. Inhibition of TNFR2 shows opposite effects on two downstream kinases of NGF, extracellular signal-regulated kinase (Erk) and Akt. It increases Erk activation by NGF, and this increased activation induces differentiation of neuroblastoma cell lines. Reciprocally, inhibition of TNFR2 decreases Akt activation by NGF. Consistent with an essential role of Akt in survival signaling, inhibition of TNF-α signaling decreases NGF-dependent survival of neurons from rat dorsal root ganglia. Thus, NGF and NGF-induced TNF-α cooperate to activate Akt, promoting survival of normal neural cells. However, the NGF-induced TNF-α suppresses Erk activation by NGF, blocking NGF-induced differentiation of neuroblastoma cells. TNFR2 signaling could be a novel target to modulate cell responses to NGF.

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