Inhibition of interleukin 1β-stimulated interleukin-6 production by cranberry components in human gingival epithelial cells

Effects on nuclear factor κB and activator protein 1 activation pathways

David Tipton, T. B. Carter, M. Kh Dabbous

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Background and Objective: In periodontitis, gingival epithelial cells can produce interleukin (IL)-6, a regulator of osteoclastic bone resorption, in response to IL-1β. IL-1β regulates cytokine expression via signaling pathways, including nuclear factor (NF)-κB and mitogen activated protein kinase (MAPK)/activator protein (AP)-1. Cranberry proanthocyanidins (PACs) inhibit IL-1β-stimulated IL-6 production, but specific mechanisms are unclear. The objectives of this study were to determine effects of cranberry PACs on NF-κB and MAPK/AP-1 activation of IL-1β-stimulated IL-6 production in gingival epithelial cells. Material and Methods: Cranberry high molecular weight non-dialyzable material (NDM), rich in PACs, was derived from cranberry juice. Human gingival epithelial cells [Smulow-Glickman (S-G)] were incubated with IL-1β in the presence or absence of NDM or inhibitors of NF-κB, [nemo-binding domain (NBD) peptide] or AP-1 (SP600125), and IL-6 levels were measured by ELISA. Effects of NDM on IL-1β-activated NF-κB and AP-1 and phosphorylated intermediates in both pathways were measured in cell extracts via binding to specific oligonucleotides and specific sandwich ELISAs, respectively. Data were analyzed using ANOVA and Scheffe's F procedure for post hoc comparisons. Results: IL-1β (≥ 0.1 nm) caused a time- and dose-dependent stimulation of S-G epithelial cell IL-6 production (p < 0.005). This was significantly decreased in a dose-dependent manner by NBD peptide or SP600125 [maximum inhibition ~30-40% (p < 0.02)], and together, the two inhibitors decreased IL-6 by ~80%, similar to the inhibition caused by NDM (p < 0.001). IL-1β stimulated NF-κB and AP-1 activation (p < 0.003), which was inhibited by NDM (p < 0.0001). NDM did not significantly affect IL-1β-stimulated levels of phosphorylated intermediates in the NF-κB pathway (IκBα) or the AP-1 pathway (c-Jun, ERK1/2). Conclusion: In S-G epithelial cells, IL-1β appeared to upregulate IL-6 production via activation of both NF-κB and MAPK/AP-1 signaling pathways because cranberry NDM decreased nuclear levels of IL-1β-activated NF-κB (p65) and AP-1 (phospho-c-Jun) and strongly inhibited IL-6 production. Lack of inhibition of phosphorylation of IκBα, c-Jun or ERK1/2 suggested that NDM might affect both pathways downstream from those points in S-G cells, such as ubiquitination and proteosomal degradation of IκBα, or inhibition of nuclear activity of c-Jun and/or ERK1/2. Defining these points of inhibition precisely may help identify molecular targets of cranberry polyphenols.

Original languageEnglish (US)
Pages (from-to)437-447
Number of pages11
JournalJournal of Periodontal Research
Volume49
Issue number4
DOIs
StatePublished - Jan 1 2014

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Vaccinium macrocarpon
Transcription Factor AP-1
Interleukin-1
Interleukin-6
Epithelial Cells
Proanthocyanidins
Mitogen-Activated Protein Kinases
Enzyme-Linked Immunosorbent Assay
Periodontitis
Ubiquitination
Polyphenols
Bone Resorption
Cell Extracts
Oligonucleotides
Analysis of Variance

All Science Journal Classification (ASJC) codes

  • Periodontics

Cite this

@article{e569b9eec8cb4c238f2a013e92bbcb41,
title = "Inhibition of interleukin 1β-stimulated interleukin-6 production by cranberry components in human gingival epithelial cells: Effects on nuclear factor κB and activator protein 1 activation pathways",
abstract = "Background and Objective: In periodontitis, gingival epithelial cells can produce interleukin (IL)-6, a regulator of osteoclastic bone resorption, in response to IL-1β. IL-1β regulates cytokine expression via signaling pathways, including nuclear factor (NF)-κB and mitogen activated protein kinase (MAPK)/activator protein (AP)-1. Cranberry proanthocyanidins (PACs) inhibit IL-1β-stimulated IL-6 production, but specific mechanisms are unclear. The objectives of this study were to determine effects of cranberry PACs on NF-κB and MAPK/AP-1 activation of IL-1β-stimulated IL-6 production in gingival epithelial cells. Material and Methods: Cranberry high molecular weight non-dialyzable material (NDM), rich in PACs, was derived from cranberry juice. Human gingival epithelial cells [Smulow-Glickman (S-G)] were incubated with IL-1β in the presence or absence of NDM or inhibitors of NF-κB, [nemo-binding domain (NBD) peptide] or AP-1 (SP600125), and IL-6 levels were measured by ELISA. Effects of NDM on IL-1β-activated NF-κB and AP-1 and phosphorylated intermediates in both pathways were measured in cell extracts via binding to specific oligonucleotides and specific sandwich ELISAs, respectively. Data were analyzed using ANOVA and Scheffe's F procedure for post hoc comparisons. Results: IL-1β (≥ 0.1 nm) caused a time- and dose-dependent stimulation of S-G epithelial cell IL-6 production (p < 0.005). This was significantly decreased in a dose-dependent manner by NBD peptide or SP600125 [maximum inhibition ~30-40{\%} (p < 0.02)], and together, the two inhibitors decreased IL-6 by ~80{\%}, similar to the inhibition caused by NDM (p < 0.001). IL-1β stimulated NF-κB and AP-1 activation (p < 0.003), which was inhibited by NDM (p < 0.0001). NDM did not significantly affect IL-1β-stimulated levels of phosphorylated intermediates in the NF-κB pathway (IκBα) or the AP-1 pathway (c-Jun, ERK1/2). Conclusion: In S-G epithelial cells, IL-1β appeared to upregulate IL-6 production via activation of both NF-κB and MAPK/AP-1 signaling pathways because cranberry NDM decreased nuclear levels of IL-1β-activated NF-κB (p65) and AP-1 (phospho-c-Jun) and strongly inhibited IL-6 production. Lack of inhibition of phosphorylation of IκBα, c-Jun or ERK1/2 suggested that NDM might affect both pathways downstream from those points in S-G cells, such as ubiquitination and proteosomal degradation of IκBα, or inhibition of nuclear activity of c-Jun and/or ERK1/2. Defining these points of inhibition precisely may help identify molecular targets of cranberry polyphenols.",
author = "David Tipton and Carter, {T. B.} and Dabbous, {M. Kh}",
year = "2014",
month = "1",
day = "1",
doi = "10.1111/jre.12122",
language = "English (US)",
volume = "49",
pages = "437--447",
journal = "Journal of Periodontal Research",
issn = "0022-3484",
publisher = "Blackwell Munksgaard",
number = "4",

}

TY - JOUR

T1 - Inhibition of interleukin 1β-stimulated interleukin-6 production by cranberry components in human gingival epithelial cells

T2 - Effects on nuclear factor κB and activator protein 1 activation pathways

AU - Tipton, David

AU - Carter, T. B.

AU - Dabbous, M. Kh

PY - 2014/1/1

Y1 - 2014/1/1

N2 - Background and Objective: In periodontitis, gingival epithelial cells can produce interleukin (IL)-6, a regulator of osteoclastic bone resorption, in response to IL-1β. IL-1β regulates cytokine expression via signaling pathways, including nuclear factor (NF)-κB and mitogen activated protein kinase (MAPK)/activator protein (AP)-1. Cranberry proanthocyanidins (PACs) inhibit IL-1β-stimulated IL-6 production, but specific mechanisms are unclear. The objectives of this study were to determine effects of cranberry PACs on NF-κB and MAPK/AP-1 activation of IL-1β-stimulated IL-6 production in gingival epithelial cells. Material and Methods: Cranberry high molecular weight non-dialyzable material (NDM), rich in PACs, was derived from cranberry juice. Human gingival epithelial cells [Smulow-Glickman (S-G)] were incubated with IL-1β in the presence or absence of NDM or inhibitors of NF-κB, [nemo-binding domain (NBD) peptide] or AP-1 (SP600125), and IL-6 levels were measured by ELISA. Effects of NDM on IL-1β-activated NF-κB and AP-1 and phosphorylated intermediates in both pathways were measured in cell extracts via binding to specific oligonucleotides and specific sandwich ELISAs, respectively. Data were analyzed using ANOVA and Scheffe's F procedure for post hoc comparisons. Results: IL-1β (≥ 0.1 nm) caused a time- and dose-dependent stimulation of S-G epithelial cell IL-6 production (p < 0.005). This was significantly decreased in a dose-dependent manner by NBD peptide or SP600125 [maximum inhibition ~30-40% (p < 0.02)], and together, the two inhibitors decreased IL-6 by ~80%, similar to the inhibition caused by NDM (p < 0.001). IL-1β stimulated NF-κB and AP-1 activation (p < 0.003), which was inhibited by NDM (p < 0.0001). NDM did not significantly affect IL-1β-stimulated levels of phosphorylated intermediates in the NF-κB pathway (IκBα) or the AP-1 pathway (c-Jun, ERK1/2). Conclusion: In S-G epithelial cells, IL-1β appeared to upregulate IL-6 production via activation of both NF-κB and MAPK/AP-1 signaling pathways because cranberry NDM decreased nuclear levels of IL-1β-activated NF-κB (p65) and AP-1 (phospho-c-Jun) and strongly inhibited IL-6 production. Lack of inhibition of phosphorylation of IκBα, c-Jun or ERK1/2 suggested that NDM might affect both pathways downstream from those points in S-G cells, such as ubiquitination and proteosomal degradation of IκBα, or inhibition of nuclear activity of c-Jun and/or ERK1/2. Defining these points of inhibition precisely may help identify molecular targets of cranberry polyphenols.

AB - Background and Objective: In periodontitis, gingival epithelial cells can produce interleukin (IL)-6, a regulator of osteoclastic bone resorption, in response to IL-1β. IL-1β regulates cytokine expression via signaling pathways, including nuclear factor (NF)-κB and mitogen activated protein kinase (MAPK)/activator protein (AP)-1. Cranberry proanthocyanidins (PACs) inhibit IL-1β-stimulated IL-6 production, but specific mechanisms are unclear. The objectives of this study were to determine effects of cranberry PACs on NF-κB and MAPK/AP-1 activation of IL-1β-stimulated IL-6 production in gingival epithelial cells. Material and Methods: Cranberry high molecular weight non-dialyzable material (NDM), rich in PACs, was derived from cranberry juice. Human gingival epithelial cells [Smulow-Glickman (S-G)] were incubated with IL-1β in the presence or absence of NDM or inhibitors of NF-κB, [nemo-binding domain (NBD) peptide] or AP-1 (SP600125), and IL-6 levels were measured by ELISA. Effects of NDM on IL-1β-activated NF-κB and AP-1 and phosphorylated intermediates in both pathways were measured in cell extracts via binding to specific oligonucleotides and specific sandwich ELISAs, respectively. Data were analyzed using ANOVA and Scheffe's F procedure for post hoc comparisons. Results: IL-1β (≥ 0.1 nm) caused a time- and dose-dependent stimulation of S-G epithelial cell IL-6 production (p < 0.005). This was significantly decreased in a dose-dependent manner by NBD peptide or SP600125 [maximum inhibition ~30-40% (p < 0.02)], and together, the two inhibitors decreased IL-6 by ~80%, similar to the inhibition caused by NDM (p < 0.001). IL-1β stimulated NF-κB and AP-1 activation (p < 0.003), which was inhibited by NDM (p < 0.0001). NDM did not significantly affect IL-1β-stimulated levels of phosphorylated intermediates in the NF-κB pathway (IκBα) or the AP-1 pathway (c-Jun, ERK1/2). Conclusion: In S-G epithelial cells, IL-1β appeared to upregulate IL-6 production via activation of both NF-κB and MAPK/AP-1 signaling pathways because cranberry NDM decreased nuclear levels of IL-1β-activated NF-κB (p65) and AP-1 (phospho-c-Jun) and strongly inhibited IL-6 production. Lack of inhibition of phosphorylation of IκBα, c-Jun or ERK1/2 suggested that NDM might affect both pathways downstream from those points in S-G cells, such as ubiquitination and proteosomal degradation of IκBα, or inhibition of nuclear activity of c-Jun and/or ERK1/2. Defining these points of inhibition precisely may help identify molecular targets of cranberry polyphenols.

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U2 - 10.1111/jre.12122

DO - 10.1111/jre.12122

M3 - Article

VL - 49

SP - 437

EP - 447

JO - Journal of Periodontal Research

JF - Journal of Periodontal Research

SN - 0022-3484

IS - 4

ER -