Inhibition of NF-κB by IκB prevents cytokine-induced NO production and promotes enterocyte apoptosis in vitro

Douglas A. Potoka, Evan P. Nadler, Xin Zhou, Xiao Ru Zhang, Jeffrey S. Upperman, Henri Ford

Research output: Contribution to journalArticle

33 Citations (Scopus)

Abstract

Nuclear factor-κB (NF-κB) plays a key role in gut inflammation. NF-κB up-regulates proinflammatory genes encoding cytokines, adhesion molecules, and inducible nitric oxide synthase (iNOS). However, NF-κB has also been shown to up-regulate protective or anti-apoptotic factors. We utilized an adenoviral vector carrying a super-repressor form of the inhibitor of NF-κB, IκB, to examine the effects of NF-κB inhibition on cytokine-induced nitric oxide production and apoptosis in rat small intestinal epithelial cells (IEC-6). Chemical inhibitors of NF-κB, including pyrrolidine dithiocarbamate (PDTC), tosyl-lysine-chloromethylketone (TLCK), genistein, and N-acetyl-leu-leu-norleucinal (n-LLnL) were also utilized. Treatment of AdkB-transfected cells with cytomix [1000 U/mL IFN-γ, 1 nM IL-1β, and 10 ng/mL tumor necrosis factor alpha (TNFα)] or TNFα-containing cytokine combinations resulted in inhibition of cytokine-induced nitrite production and a marked increase in apoptosis compared to control cells. Apoptosis occurred independently of nitric oxide (NO) production since exogenous sources of NO did not inhibit apoptosis. Inducible NOS and clAP were down-regulated in AdκB-transfected cells treated with cytomix. TLCK and LLnL treatment also induced apoptosis in cytomix-treated cells, while PDTC and genistein did not. Thus, although NF-κB up-regulates various pro-inflammatory genes, it may also have protective or anti-apoptotic effects in enterocytes. NF-κB appears necessary for upregulating cIAP in IEC-6 cells upon cytokine exposure.

Original languageEnglish (US)
Pages (from-to)366-373
Number of pages8
JournalShock
Volume14
Issue number3
DOIs
StatePublished - Jan 1 2000
Externally publishedYes

Fingerprint

Enterocytes
Nitric Oxide
Apoptosis
Cytokines
Up-Regulation
Genistein
Lysine
leucylleucine
Tumor Necrosis Factor-alpha
Nitric Oxide Synthase Type II
Nitrites
Interleukin-1
Interleukin-10
Genes
Epithelial Cells
In Vitro Techniques
Inflammation
pyrrolidine dithiocarbamic acid

Keywords

  • IEC-6
  • Inhibitor of apoptosis protein
  • iNOS
  • NF-κB
  • TNFα

ASJC Scopus subject areas

  • Emergency Medicine
  • Critical Care and Intensive Care Medicine

Cite this

Inhibition of NF-κB by IκB prevents cytokine-induced NO production and promotes enterocyte apoptosis in vitro. / Potoka, Douglas A.; Nadler, Evan P.; Zhou, Xin; Zhang, Xiao Ru; Upperman, Jeffrey S.; Ford, Henri.

In: Shock, Vol. 14, No. 3, 01.01.2000, p. 366-373.

Research output: Contribution to journalArticle

Potoka, Douglas A. ; Nadler, Evan P. ; Zhou, Xin ; Zhang, Xiao Ru ; Upperman, Jeffrey S. ; Ford, Henri. / Inhibition of NF-κB by IκB prevents cytokine-induced NO production and promotes enterocyte apoptosis in vitro. In: Shock. 2000 ; Vol. 14, No. 3. pp. 366-373.
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