Abstract

Nucleotide-binding oligomerization domain 2 (NOD2) is involved in innate immune responses to peptidoglycan degradation products. Peptidoglycans are important mediators of organic dust-induced airway diseases in exposed agriculture workers; however, the role of NOD2 in response to complex organic dust is unknown. Monocytes/macrophages were exposed to swine facility organic dust extract (ODE), whereupon NOD2 expression was evaluated by real-time PCR and Western blot. ODE induced significant NOD2 mRNA and protein expression at 24 and 48 h, respectively, which was mediated via a NF-κB signaling pathway as opposed to a TNF-α autocrine/paracrine mechanism. Specifically, NF-κB translocation increased rapidly following ODE stimulation as demonstrated by EMSA, and inhibition of the NF-κB pathway significantly reduced ODE-induced NOD2 expression. However, there was no significant reduction in ODE-induced NOD2 gene expression when TNF-α was inhibited or absent. Next, it was determined whether NOD2 regulated ODE-induced inflammatory cytokine production. Knockdown of NOD2 expression by small interfering RNA resulted in increased CXCL8 and IL-6, but not TNF-α production in response to ODE. Similarly, primary lung macrophages from NOD2 knockout mice demonstrated increased IL-6, CXCL1, and CXCL1, but not TNF-α, expression. Lastly, a higher degree of airway inflammation occurred in the absence of NOD2 following acute (single) and repetitive (3 wk) ODE exposure in an established in vivo murine model. In summary, ODE-induced NOD2 expression is directly dependent on NF-κB signaling, and NOD2 is a negative regulator of complex, organic dust-induced inflammatory cytokine/chemokine production in mononuclear phagocytes.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Volume301
Issue number3
DOIs
StatePublished - Sep 1 2011

Fingerprint

Dust
Nucleotides
Peptidoglycan
Interleukin-6
Macrophages
Cytokines
Phagocytes
Agriculture
Chemokines
Innate Immunity
Knockout Mice
Small Interfering RNA
Real-Time Polymerase Chain Reaction
Monocytes
Swine
Western Blotting
Inflammation
Gene Expression
Lung
Messenger RNA

Keywords

  • Airway
  • Chemokines
  • Cytokines
  • Grampositive components
  • Inflammation
  • Monocyte/macrophage
  • Organic dust extract
  • Pathogen-associated molecular patterns
  • Pattern recognition receptor
  • Swine/hog/pig
  • siRNA

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine
  • Physiology (medical)
  • Cell Biology

Cite this

@article{17185014feb34b9d991d5eb229392fac,
title = "Organic dust augments nucleotide-binding oligomerization domain expression via an NF-κB pathway to negatively regulate inflammatory responses",
abstract = "Nucleotide-binding oligomerization domain 2 (NOD2) is involved in innate immune responses to peptidoglycan degradation products. Peptidoglycans are important mediators of organic dust-induced airway diseases in exposed agriculture workers; however, the role of NOD2 in response to complex organic dust is unknown. Monocytes/macrophages were exposed to swine facility organic dust extract (ODE), whereupon NOD2 expression was evaluated by real-time PCR and Western blot. ODE induced significant NOD2 mRNA and protein expression at 24 and 48 h, respectively, which was mediated via a NF-κB signaling pathway as opposed to a TNF-α autocrine/paracrine mechanism. Specifically, NF-κB translocation increased rapidly following ODE stimulation as demonstrated by EMSA, and inhibition of the NF-κB pathway significantly reduced ODE-induced NOD2 expression. However, there was no significant reduction in ODE-induced NOD2 gene expression when TNF-α was inhibited or absent. Next, it was determined whether NOD2 regulated ODE-induced inflammatory cytokine production. Knockdown of NOD2 expression by small interfering RNA resulted in increased CXCL8 and IL-6, but not TNF-α production in response to ODE. Similarly, primary lung macrophages from NOD2 knockout mice demonstrated increased IL-6, CXCL1, and CXCL1, but not TNF-α, expression. Lastly, a higher degree of airway inflammation occurred in the absence of NOD2 following acute (single) and repetitive (3 wk) ODE exposure in an established in vivo murine model. In summary, ODE-induced NOD2 expression is directly dependent on NF-κB signaling, and NOD2 is a negative regulator of complex, organic dust-induced inflammatory cytokine/chemokine production in mononuclear phagocytes.",
keywords = "Airway, Chemokines, Cytokines, Grampositive components, Inflammation, Monocyte/macrophage, Organic dust extract, Pathogen-associated molecular patterns, Pattern recognition receptor, Swine/hog/pig, siRNA",
author = "Poole, {Jill A} and Kielian, {Tammy L} and Wyatt, {Todd A} and Gleason, {Angela M.} and Jeremy Stone and Kelsey Palm and West, {William W.} and Debra Romberger",
year = "2011",
month = "9",
day = "1",
doi = "10.1152/ajplung.00086.2011",
language = "English (US)",
volume = "301",
journal = "American Journal of Physiology - Renal Physiology",
issn = "0363-6127",
publisher = "American Physiological Society",
number = "3",

}

TY - JOUR

T1 - Organic dust augments nucleotide-binding oligomerization domain expression via an NF-κB pathway to negatively regulate inflammatory responses

AU - Poole, Jill A

AU - Kielian, Tammy L

AU - Wyatt, Todd A

AU - Gleason, Angela M.

AU - Stone, Jeremy

AU - Palm, Kelsey

AU - West, William W.

AU - Romberger, Debra

PY - 2011/9/1

Y1 - 2011/9/1

N2 - Nucleotide-binding oligomerization domain 2 (NOD2) is involved in innate immune responses to peptidoglycan degradation products. Peptidoglycans are important mediators of organic dust-induced airway diseases in exposed agriculture workers; however, the role of NOD2 in response to complex organic dust is unknown. Monocytes/macrophages were exposed to swine facility organic dust extract (ODE), whereupon NOD2 expression was evaluated by real-time PCR and Western blot. ODE induced significant NOD2 mRNA and protein expression at 24 and 48 h, respectively, which was mediated via a NF-κB signaling pathway as opposed to a TNF-α autocrine/paracrine mechanism. Specifically, NF-κB translocation increased rapidly following ODE stimulation as demonstrated by EMSA, and inhibition of the NF-κB pathway significantly reduced ODE-induced NOD2 expression. However, there was no significant reduction in ODE-induced NOD2 gene expression when TNF-α was inhibited or absent. Next, it was determined whether NOD2 regulated ODE-induced inflammatory cytokine production. Knockdown of NOD2 expression by small interfering RNA resulted in increased CXCL8 and IL-6, but not TNF-α production in response to ODE. Similarly, primary lung macrophages from NOD2 knockout mice demonstrated increased IL-6, CXCL1, and CXCL1, but not TNF-α, expression. Lastly, a higher degree of airway inflammation occurred in the absence of NOD2 following acute (single) and repetitive (3 wk) ODE exposure in an established in vivo murine model. In summary, ODE-induced NOD2 expression is directly dependent on NF-κB signaling, and NOD2 is a negative regulator of complex, organic dust-induced inflammatory cytokine/chemokine production in mononuclear phagocytes.

AB - Nucleotide-binding oligomerization domain 2 (NOD2) is involved in innate immune responses to peptidoglycan degradation products. Peptidoglycans are important mediators of organic dust-induced airway diseases in exposed agriculture workers; however, the role of NOD2 in response to complex organic dust is unknown. Monocytes/macrophages were exposed to swine facility organic dust extract (ODE), whereupon NOD2 expression was evaluated by real-time PCR and Western blot. ODE induced significant NOD2 mRNA and protein expression at 24 and 48 h, respectively, which was mediated via a NF-κB signaling pathway as opposed to a TNF-α autocrine/paracrine mechanism. Specifically, NF-κB translocation increased rapidly following ODE stimulation as demonstrated by EMSA, and inhibition of the NF-κB pathway significantly reduced ODE-induced NOD2 expression. However, there was no significant reduction in ODE-induced NOD2 gene expression when TNF-α was inhibited or absent. Next, it was determined whether NOD2 regulated ODE-induced inflammatory cytokine production. Knockdown of NOD2 expression by small interfering RNA resulted in increased CXCL8 and IL-6, but not TNF-α production in response to ODE. Similarly, primary lung macrophages from NOD2 knockout mice demonstrated increased IL-6, CXCL1, and CXCL1, but not TNF-α, expression. Lastly, a higher degree of airway inflammation occurred in the absence of NOD2 following acute (single) and repetitive (3 wk) ODE exposure in an established in vivo murine model. In summary, ODE-induced NOD2 expression is directly dependent on NF-κB signaling, and NOD2 is a negative regulator of complex, organic dust-induced inflammatory cytokine/chemokine production in mononuclear phagocytes.

KW - Airway

KW - Chemokines

KW - Cytokines

KW - Grampositive components

KW - Inflammation

KW - Monocyte/macrophage

KW - Organic dust extract

KW - Pathogen-associated molecular patterns

KW - Pattern recognition receptor

KW - Swine/hog/pig

KW - siRNA

UR - http://www.scopus.com/inward/record.url?scp=80052361740&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=80052361740&partnerID=8YFLogxK

U2 - 10.1152/ajplung.00086.2011

DO - 10.1152/ajplung.00086.2011

M3 - Article

VL - 301

JO - American Journal of Physiology - Renal Physiology

JF - American Journal of Physiology - Renal Physiology

SN - 0363-6127

IS - 3

ER -