scholarly journals Keratin attenuates tumor necrosis factor–induced cytotoxicity through association with TRADD

2001 ◽  
Vol 155 (3) ◽  
pp. 415-426 ◽  
Author(s):  
Hiroyasu Inada ◽  
Ichiro Izawa ◽  
Miwako Nishizawa ◽  
Eriko Fujita ◽  
Tohru Kiyono ◽  
...  

Keratin 8 and 18 (K8/18) are the major components of intermediate filament (IF) proteins of simple or single-layered epithelia. Recent data show that normal and malignant epithelial cells deficient in K8/18 are nearly 100 times more sensitive to tumor necrosis factor (TNF)–induced cell death. We have now identified human TNF receptor type 1 (TNFR1)–associated death domain protein (TRADD) to be the K18-interacting protein. Among IF proteins tested in two-hybrid systems, TRADD specifically bound K18 and K14, type I (acidic) keratins. The COOH-terminal region of TRADD interacted with the coil Ia of the rod domain of K18. Endogenous TRADD coimmunoprecipitated with K18, and colocalized with K8/18 filaments in human mammary epithelial cells. Overexpression of the NH2 terminus (amino acids 1–270) of K18 containing the TRADD-binding domain as well as overexpression of K8/18 in SW13 cells, which are devoid of keratins, rendered the cells more resistant to killing by TNF. We also showed that overexpressed NH2 termini of K18 and K8/18 were associated with endogenous TRADD in SW13 cells, resulting in the inhibition of caspase-8 activation. These results indicate that K18 may sequester TRADD to attenuate interactions between TRADD and activated TNFR1 and moderate TNF-induced apoptosis in simple epithelial cells.

2010 ◽  
Vol 110 (4) ◽  
pp. 857-865 ◽  
Author(s):  
Carolina Schere Levy ◽  
Victoria Slomiansky ◽  
Albana Gattelli ◽  
Karen Nahmod ◽  
Federico Pelisch ◽  
...  

2000 ◽  
Vol 118 (4) ◽  
pp. A532
Author(s):  
Osamu Handa ◽  
Yuji Naito ◽  
Tomohisa Takagi ◽  
Takeshi Ishikawa ◽  
Naohisa Matsumoto ◽  
...  

2002 ◽  
Vol 277 (51) ◽  
pp. 50054-50061 ◽  
Author(s):  
Hideki Matsui ◽  
Yukiko Hikichi ◽  
Isamu Tsuji ◽  
Takao Yamada ◽  
Yasushi Shintani

LIGHT is a member of tumor necrosis factor (TNF) superfamily, and its receptors have been identified as lymphotoxin-β receptor (LTβR) and the herpesvirus entry mediator (HVEM)/ATAR/TR2, both of which lack the cytoplasmic sequence termed the “death domain.” The present study has demonstrated that LIGHT inhibits TNFα-mediated apoptosis of human primary hepatocytes sensitized by actinomycin D (ActD), but not Fas- or TRAIL-mediated apoptosis. Furthermore, LIGHT does not prevent some cell lines such as HepG2 or HeLa from undergoing ActD/TNFα-induced apoptosis. This protective effect requires LIGHT pretreatment at least 3 h prior to ActD sensitization. LIGHT stimulates nuclear factor-κB (NF-κB)-dependent transcriptional activity in human hepatocytes like TNFα. The time course of NF-κB activation after LIGHT administration is similar to that of the pretreatment required for the anti-apoptotic effect of LIGHT. LIGHT inhibits caspase-3 processing on the apoptotic protease cascade in TNFα-mediated apoptosis but not Fas-mediated apoptosis. In addition, increased caspase-3 and caspase-8 activities in ActD/TNFα-treated cells are effectively blocked by LIGHT pretreatment. However, LIGHT does not change the expression of TNFRp55, TNFRp75, and Fas. These results indicate that LIGHT may act as an anti-apoptotic agent against TNFα-mediated liver injury by blocking the activation of both caspase-3 and caspase-8.


2006 ◽  
Vol 74 (6) ◽  
pp. 3643-3650 ◽  
Author(s):  
Priscilla Morales ◽  
Paz Reyes ◽  
Macarena Vargas ◽  
Miguel Rios ◽  
Mónica Imarai ◽  
...  

ABSTRACT Following infection with Neisseria gonorrhoeae, bacteria may ascend into the Fallopian tubes (FT) and induce salpingitis, a major cause of infertility. In the FT, interactions between mucosal epithelial cells and gonococci are pivotal events in the pathogen's infection cycle and the inflammatory response. In the current study, primary FT epithelial cells were infected in vitro with different multiplicities of infection (MOI) of Pil+ Opa+ gonococci. Bacteria showed a dose-dependent association with cells and induced the secretion of tumor necrosis factor alpha (TNF-α). A significant finding was that gonococcal infection (MOI = 1) induced apoptosis in approximately 30% of cells, whereas increasing numbers of bacteria (MOI = 10 to 100) did not induce apoptosis. Apoptosis was observed in only 11% of cells with associated bacteria, whereas >84% of cells with no adherent bacteria were apoptotic. TNF-α was a key contributor to apoptosis, since (i) culture supernatants from cells infected with gonococci (MOI = 1) induced apoptosis in naïve cultures, suggesting that a soluble factor was responsible; (ii) gonococcal infection-induced apoptosis was inhibited with anti-TNF-α antibodies; and (iii) the addition of exogenous TNF-α induced apoptosis, which was inhibited by the presence of increasing numbers of bacteria (MOI = 10 to 100). These data suggest that TNF-α-mediated apoptosis of FT epithelial cells is likely a primary host defense mechanism to prevent pathogen colonization. However, epithelial cell-associated gonococci have evolved a mechanism to protect the cells from undergoing TNF-α-mediated apoptosis, and this modulation of the host innate response may contribute to establishment of infection. Understanding the antiapoptotic mechanisms used by Neisseria gonorrhoeae will inform the pathogenesis of salpingitis and could suggest new intervention strategies for prevention and treatment of the disease.


2010 ◽  
Vol 79 (2) ◽  
pp. 695-707 ◽  
Author(s):  
Juliane Günther ◽  
Kathrin Esch ◽  
Norbert Poschadel ◽  
Wolfram Petzl ◽  
Holm Zerbe ◽  
...  

ABSTRACTInfections of the udder byEscherichia colivery often elicit acute inflammation, whileStaphylococcus aureusinfections tend to cause mild, subclinical inflammation and persistent infections. The molecular causes underlying the different disease patterns are poorly understood. We therefore profiled the kinetics and extents of global changes in the transcriptome of primary bovine mammary epithelial cells (MEC) after challenging them with heat-inactivated preparations ofE. coliorS. aureuspathogens.E. coliswiftly and strongly induced an expression of cytokines and bactericidal factors.S. aureuselicited a retarded response and failed to quickly induce an expression of bactericidal factors. Both pathogens induced similar patterns of chemokines for cell recruitment into the udder, butE. colistimulated their synthesis much faster and stronger. The genes that are exclusively and most strongly upregulated byE. colimay be clustered into a regulatory network with tumor necrosis factor alpha (TNF-α) and interleukin-1 (IL-1) in a central position. In contrast, the expression of these master cytokines is barely regulated byS. aureus. Both pathogens quickly trigger an enhanced expression of IL-6. This is still possible after completely abrogating MyD88-dependent Toll-like receptor (TLR) signaling in MEC. TheE. coli-specific strong induction of TNF-α and IL-1 expression may be causative for the severe inflammatory symptoms of animals suffering fromE. colimastitis, while the avoidance to quickly induce the synthesis of bactericidal factors may support the persistent survival ofS. aureuswithin the udder. We suggest thatS. aureussubverts the MyD88-dependent activation of immune gene expression in MEC.


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