Tumor Necrosis Factor-α Inhibits Na+-Methionine Cotransport in Intestinal Epithelial Cells

2011 ◽  
Vol 140 (5) ◽  
pp. S-662-S-663
Author(s):  
Jamilur R. Talukder ◽  
Brittney Boyd
FEBS Letters ◽  
2015 ◽  
Vol 589 (23) ◽  
pp. 3640-3647 ◽  
Author(s):  
Md Rafiqul Islam Khan ◽  
Junsuke Uwada ◽  
Takashi Yazawa ◽  
Md Tariqul Islam ◽  
Susanne M. Krug ◽  
...  

2007 ◽  
Vol 292 (5) ◽  
pp. G1411-G1419 ◽  
Author(s):  
Erika C. Claud ◽  
Xiaoqiong Zhang ◽  
Elaine O. Petrof ◽  
Jun Sun

Premature infants are susceptible to many conditions that are inflammatory in nature. For this patient population, which is expecting the intrauterine environment, pathways necessary for fetal life and development may not have completed the transitions necessary for extrauterine life. In this study, responses to tumor necrosis factor-α were compared in human fetal and adult intestinal epithelial cell lines along with preweaned and postweaned mouse intestinal sections to identify a potential developmental difference that may explain the heightened inflammatory response of preterm infants. The nuclear factor-κB (NF-κB) pathway regulates a wide variety of genes involved in immune and inflammatory processes. We report that, compared with adult intestinal epithelial cells, immature intestinal epithelial cells have increased NF-κB activity associated with increased NF-κB-DNA binding and transcriptional activity. This increased activity appears due to inadequate inhibition of signaling leading to NF-κB activation since there is also increased phosphorylation, ubiquitination, and degradation of the inhibitor of NF-κB in conjunction with decreased baseline expression and delayed resynthesis of this inhibitor. Thus we demonstrate a potential mechanism for the heightened inflammatory response of immature intestinal epithelial cells.


2017 ◽  
Vol 5 (19) ◽  
pp. e13451 ◽  
Author(s):  
Michael A. Peplowski ◽  
Andrew J. Vegso ◽  
Vadim Iablokov ◽  
Michael Dicay ◽  
Raza S. Zaheer ◽  
...  

2010 ◽  
Vol 299 (1) ◽  
pp. G96-G105 ◽  
Author(s):  
Angela O'Gorman ◽  
Amy Colleran ◽  
Aideen Ryan ◽  
Jelena Mann ◽  
Laurence John Egan

Intestinal epithelial cells play critical roles in regulating mucosal immunity. Since epigenetic factors such as DNA methylation and histone modifications are implicated in aging, carcinogenesis, and immunity, we set out to assess any role for epigenetic factors in the regulation of intestinal epithelial cell immune responses. Experiments were conducted using the HCT116 cell line, and a subclone was genetically engineered to lack DNA methyltransferases (DNMT). The induction of the chemokine interleukin-8 and the antiapoptotic protein cFLIP by tumor necrosis factor-α were markedly less in HCT116 cells lacking DNMT than in parental cells. These effects were accompanied by lower monocyte chemotaxis and higher caspase signaling in HCT116 cells lacking DNMT than parental cells. Tumor necrosis factor-α-induced NF-κB activation was blocked and IκBα expression was higher in HCT116 cells lacking DNMT than in parental cells. A CpG island in the IκBα gene promoter region was found to contain variable levels of methylation in parental HCT116 cells. Chromatin immunoprecipitation analysis of histone proteins bound to the IκBα gene promoter revealed that higher levels of IκBα expression in HCT116 cells lacking DNMT compared with parental cells were accompanied by more chromatin marks permissive to gene transcription. These findings show that epigenetic factors influence the NF-κB system in intestinal epithelial cells, resulting in a previously unrecognized mechanism of innate immune regulation.


2005 ◽  
Vol 289 (5) ◽  
pp. C1085-C1093 ◽  
Author(s):  
Ya-Qin Zhu ◽  
Xiao-Di Tan

Trefoil factor 3 (intestinal trefoil factor) is a cytoprotective factor in the gut. Herein we compared the effect of trefoil factor 3 with tumor necrosis factor-α on 1) activation of NF-κB in intestinal epithelial cells; 2) expression of Twist protein (a molecule essential for downregulation of nuclear factor-κB activity in vivo); and 3) production of interleukin-8. We showed that Twist protein is constitutively expressed in intestinal epithelial cells. Tumor necrosis factor-α induced persistent degradation of Twist protein in intestinal epithelial cells via a signaling pathway linked to proteasome, which was associated with prolonged activation of NF-κB. In contrast to tumor necrosis factor, trefoil factor 3 triggered transient activation of NF-κB and prolonged upregulation of Twist protein in intestinal epithelial cells via an ERK kinase-mediated pathway. Unlike tumor necrosis factor-α, transient activation of NF-κB by trefoil factor 3 is not associated with induction of IL-8 in cells. To examine the role of Twist protein in intestinal epithelial cells, we silenced the Twist expression by siRNA. Our data showed that trefoil factor 3 induced interleukin-8 production after silencing Twist in intestinal epithelial cells. Together, these observations indicated that 1) trefoil factor 3 triggers a diverse signal from tumor necrosis factor-α on the activation of NF-κB and its associated molecules in intestinal epithelial cells; and 2) trefoil factor 3-induced Twist protein plays an important role in the modulation of inflammatory cytokine production in intestinal epithelial cells.


Sign in / Sign up

Export Citation Format

Share Document