scholarly journals Cordycepin Inhibits Lipopolysaccharide (LPS)-Induced Tumor Necrosis Factor (TNF)-α Production via Activating AMP-Activated Protein Kinase (AMPK) Signaling

2014 ◽  
Vol 15 (7) ◽  
pp. 12119-12134 ◽  
Author(s):  
Jian-Li Zhang ◽  
Ying Xu ◽  
Jie Shen
Keyword(s):  
Protein Kinase ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Ampk Signaling ◽  
Tnf Α ◽  
Amp Activated Protein Kinase ◽  
Necrosis Factor

Stimulation of protein kinase C activity by tumor necrosis factor-α in bovine bronchial epithelial cells

1997 ◽  
Vol 273 (5) ◽  
pp. L1007-L1012 ◽  
Author(s):  
Todd A. Wyatt ◽  
Harumasa Ito ◽  
Thomas J. Veys ◽  
John R. Spurzem
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tumor Necrosis Factor ◽  
Epithelial Cells ◽  
Tumor Necrosis ◽  
Bronchial Epithelial ◽  
Calphostin C ◽  
Kinase C ◽  
Tnf Α ◽  
Necrosis Factor

Bronchial epithelial cell migration, attachment, and proliferation are important processes in response to airway injury. We have shown that tumor necrosis factor (TNF)-α stimulates the migration of bovine bronchial epithelial cells (BBEC) in vitro. We hypothesized that protein kinase C (PKC) may be one of the intracellular signaling mediators of TNF-α in BBEC. In this study, we have identified multiple PKC isoforms in BBEC and measured total cellular PKC activity. Polyclonal antibodies to the PKC-α, -β2, -δ, and -ε isoforms recognized protein bands around 80–90 kDa. BBEC primary cultures treated with either 500 U/ml TNF-α for 2–4 h or 100 ng/ml 12- O-tetradecanoylphorbol 13-acetate for 15 min resulted in three- to fivefold increases in PKC activity in the particulate fractions of crude cell lysates. This activity was inhibited by 1 μM calphostin C or 10 μM H-7. Similarly, TNF-α-stimulated BBEC migration was reduced at least twofold in the presence of H-7 or calphostin C. These studies suggest that the activation of PKC is necessary for TNF-α-stimulated BBEC migration.

Tumor necrosis factor-α and ceramide induce cell death through different mechanisms in rat mesangial cells

1999 ◽  
Vol 276 (3) ◽  
pp. F390-F397 ◽  
Author(s):  
Yan-Lin Guo ◽  
Baobin Kang ◽  
Li-Jun Yang ◽  
John R. Williamson
Keyword(s):  
Cell Death ◽  
Protein Kinase ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Mesangial Cells ◽  
Tnf Α ◽  
Induced Apoptosis ◽  
Factor Α ◽  
Necrosis Factor

It has been proposed that ceramide acts as a cellular messenger to mediate tumor necrosis factor-α (TNF-α)-induced apoptosis. Based on this hypothesis, it was postulated that resistance of some cells to TNF-α cytotoxicity was due to an insufficient production of ceramide on stimulation by TNF-α. The present study was initiated to investigate whether this was the case in mesangial cells, which normally are insensitive to TNF-α-induced apoptosis. Our results indicate that although C2ceramide was toxic to mesangial cells, the cell death it induced differed both morphologically and biochemically from that induced by TNF-α in the presence of cycloheximide (CHX). The most apparent effect of C2ceramide was to cause cells to swell, followed by disruption of the cell membrane. It is evident that C2ceramide caused cell death by necrosis, whereas TNF-α in the presence of CHX killed the cells by apoptosis. C2ceramide did not mimic the effects of TNF-α on the activation of c-Jun NH2-terminal protein kinase and nuclear factor-κB transcription factor. Although mitogen-activated protein kinase [extracellular signal-related kinase (ERK)] was activated by both C2ceramide and TNF-α, such activation appeared to be mediated by different mechanisms as judged from the kinetics of ERK activation. Furthermore, the cleavage of cytosolic phospholipase A2during cell death induced by C2ceramide and by TNF-α in the presence of CHX showed distinctive patterns. The present study provides evidence that apoptosis and necrosis use distinctive signaling machinery to cause cell death.

Increase of Mucous Glycoprotein Secretion by Tumor Necrosis Factor Alpha via a Protein Kinase C-Dependent Mechanism in Cultured Chinchilla Middle Ear Epithelial Cells

1998 ◽  
Vol 107 (3) ◽  
pp. 213-219 ◽  
Author(s):  
Jizhen Lin ◽  
Youngki Kim ◽  
Steven K. Juhn
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tumor Necrosis Factor ◽  
Epithelial Cells ◽  
Middle Ear ◽  
Tumor Necrosis ◽  
Kinase C ◽  
Tnf Α ◽  
Necrosis Factor ◽  
Dependent Mechanism

Tumor necrosis factor α (TNF-α), originally defined by its antitumoral activity, is now recognized as a polypeptide mediator of inflammatory and cellular immune response. Recent studies have demonstrated that TNF-α exists in the fluid of otitis media with effusion and, therefore, suggested its possible role in the pathogenesis of mucus hypersecretion. In this study, the effects of TNF-α on mucous glycoprotein (MGP) secretion from cultured chinchilla middle ear epithelial cells were examined, and TNF-α was found to stimulate MGP secretion in a time- and concentration-dependent manner. The action of TNF-α on MGP secretion was significantly and dose-dependently inhibited by TNF-α monoclonal antibody; this finding is suggestive of its specificity on MGP secretion. The addition of the protein kinase C inhibitor 1-(5-isoquinolinylsulfonyl)-2-methylpiperidine (H-7) to the culture significantly blocked TNF-α-induced MGP secretion, while the calmodulin inhibitor N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) did not. This suggests that TNF-α stimulates MGP secretion via a protein kinase C—dependent mechanism.

scholarly journals c-Jun N-Terminal Protein Kinase 1 (JNK1), but Not JNK2, Is Essential for Tumor Necrosis Factor Alpha-Induced c-Jun Kinase Activation and Apoptosis

2004 ◽  
Vol 24 (24) ◽  
pp. 10844-10856 ◽  
Author(s):  
Jing Liu ◽  
Yuzuru Minemoto ◽  
Anning Lin
Keyword(s):  
Protein Kinase ◽  
Tumor Necrosis Factor ◽  
Tumor Necrosis ◽  
Terminal Protein ◽  
Necrosis Factor Alpha ◽  
Kinase Activation ◽  
Jun Kinase ◽  
Tnf Α ◽  
Factor Alpha ◽  
Necrosis Factor

ABSTRACT Two ubiquitously expressed isoforms of c-Jun N-terminal protein kinase (JNK), JNK1 and JNK2, have shared functions and different functions. However, the molecular mechanism is unknown. Here we report that JNK1, but not JNK2, is essential for tumor necrosis factor alpha (TNF-α)-induced c-Jun kinase activation, c-Jun expression, and apoptosis. Using mouse fibroblasts deficient in either Jnk1 or Jnk2, we found that JNK1 was activated by TNF-α, whereas JNK2 activation was negligible. In addition, JNK2 interfered with JNK1 activation via its “futile” phosphorylation by upstream kinases. Consequently, expression and activation of c-Jun, which depends on JNK activity, were impaired in Jnk1 null cells but enhanced in Jnk2 null cells. TNF-α-induced apoptosis was also suppressed in Jnk1 null fibroblasts but increased in Jnk2 null cells. Thus, our results provide a molecular mechanism underlying the different biological functions of JNK isoforms.

Ceramide mediates inhibition of the renal epithelial sodium channel by tumor necrosis factor-α through protein kinase C

2007 ◽  
Vol 293 (4) ◽  
pp. F1178-F1186 ◽  
Author(s):  
Hui-Fang Bao ◽  
Zhi-Ren Zhang ◽  
You-You Liang ◽  
Joshua J. Ma ◽  
Douglas C. Eaton ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Tumor Necrosis Factor ◽  
Sodium Channel ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Kinase C ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

To determine whether ceramide mediates regulation of the renal epithelial sodium channel (ENaC) by tumor necrosis factor-α (TNF-α), confocal microscopy and patch-clamp experiments were performed in A6 distal nephron cells. We found that TNF-α (100 ng/ml) had no effect on ENaC activity and ceramide level when the cells were grown in the presence of aldosterone, but significantly inhibited ENaC and induced ceramide production after the cells were pretreated with LY 294002, an inhibitor of phosphatidylinositol 3-kinase, for 24 h. The inhibition of ENaC induced by TNF-α was mimicked by exogenous sphingomyelinase (0.1 U/ml) and C2-ceramide (50 μM), but neither C2-dihydroceramide, a membrane-impermeable analog of C2-ceramide, nor choline, and abolished by pretreatment with GF109203X, a protein kinase C (PKC) inhibitor. C2-ceramide failed to affect ENaC in the cells pretreated with GF109203X, but not in the cells pretreated with PD-98059, a mitogen-activated protein kinase kinase inhibitor. C2-ceramide induced the externalization of phosphatidylserine (PS) in control A6 cells, but not in the cells pretreated with GF109203X. Together with our previous finding that cytosolic PS maintains ENaC activity in A6 cells, these data suggest that ceramide mediates TNF-α inhibition of the renal ENaC via a pathway associated with PKC-dependent externalization of PS.

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