TLR4 signaling and the inhibition of liver hepcidin expression by alcohol

Emily Zmijewski, Sizhao Lu, Duygu Dee Harrison-Findik

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

AIM: To understand the role of toll-like receptor 4 (TLR4) signaling in the regulation of iron-regulatory hormone, hepcidin by chronic alcohol consumption. METHODS: For chronic alcohol intake studies, TLR4 mutant mice on C3H/HeJ background and wildtype counterpart on C3H/HeOuJ background were pair-fed with regular (control) and ethanol-containing Lieber De Carli liquids diets. Gene expression was determined by real-time quantitative PCR. Protein-protein interactions and protein expression were determined by co-immunoprecipitation and western blotting. The occupancy of hepcidin gene promoter was determined by chromatin immunoprecipitation assays. RESULTS: Chronic alcohol intake suppressed hepcidin mRNA expression in the livers of wildtype, but not TLR4 mutant, mice. The phosphorylation and nuclear translocation of nuclear factor (NF)-κB p65 subunit protein was observed in alcohol-fed wildtype, but not in alcohol-fed TLR4 mutant, mice. Similarly, alcohol induced the binding of NF-κB p50 subunit protein to hepcidin gene promoter in wildtype, but not in TLR4 mutant, mice. In contrast, the phosphorylation of Stat3 in the liver was stronger in alcohol-treated TLR4 mutant mice compared to alcohol-treated wildtype mice. The occupancy of hepcidin gene promoter by Stat3 was observed in alcohol-fed mutant, but not in wildtype, mice. An interaction between NF-κB p65 subunit protein and small heterodimer partner protein (SHP) was observed in the livers of both wildtype and TLR4 mutant mice fed with the control diet, as shown by co-immunoprecipitation studies. Alcohol intake elevated cytosolic SHP expression but attenuated its interaction with NF-κB in the liver, which was more prominent in the livers of wildtype compared to TLR4 mutant mice. CONCLUSION: Activation of TLR4 signaling and NF-κB are involved in the suppression of hepcidin gene transcription by alcohol in the presence of inflammation in the liver.

Original languageEnglish (US)
Pages (from-to)12161-12170
Number of pages10
JournalWorld Journal of Gastroenterology
Volume20
Issue number34
DOIs
StatePublished - Sep 14 2014

Fingerprint

Hepcidins
Toll-Like Receptor 4
Alcohols
Liver
Protein Subunits
Immunoprecipitation
Genes
Phosphorylation
Inhibition (Psychology)
Diet
Proteins
Chromatin Immunoprecipitation
Mouse Tlr4 protein
Alcohol Drinking
Real-Time Polymerase Chain Reaction
Ethanol
Iron
Western Blotting
Hormones

Keywords

  • Alcoholic liver disease
  • Inflammation
  • Iron
  • Nuclear factor-κB
  • Small heterodimer partner protein

ASJC Scopus subject areas

  • Gastroenterology

Cite this

TLR4 signaling and the inhibition of liver hepcidin expression by alcohol. / Zmijewski, Emily; Lu, Sizhao; Harrison-Findik, Duygu Dee.

In: World Journal of Gastroenterology, Vol. 20, No. 34, 14.09.2014, p. 12161-12170.

Research output: Contribution to journalArticle

Zmijewski, Emily ; Lu, Sizhao ; Harrison-Findik, Duygu Dee. / TLR4 signaling and the inhibition of liver hepcidin expression by alcohol. In: World Journal of Gastroenterology. 2014 ; Vol. 20, No. 34. pp. 12161-12170.
@article{daabd000e1794c82bb6424d6dc3cc6f8,
title = "TLR4 signaling and the inhibition of liver hepcidin expression by alcohol",
abstract = "AIM: To understand the role of toll-like receptor 4 (TLR4) signaling in the regulation of iron-regulatory hormone, hepcidin by chronic alcohol consumption. METHODS: For chronic alcohol intake studies, TLR4 mutant mice on C3H/HeJ background and wildtype counterpart on C3H/HeOuJ background were pair-fed with regular (control) and ethanol-containing Lieber De Carli liquids diets. Gene expression was determined by real-time quantitative PCR. Protein-protein interactions and protein expression were determined by co-immunoprecipitation and western blotting. The occupancy of hepcidin gene promoter was determined by chromatin immunoprecipitation assays. RESULTS: Chronic alcohol intake suppressed hepcidin mRNA expression in the livers of wildtype, but not TLR4 mutant, mice. The phosphorylation and nuclear translocation of nuclear factor (NF)-κB p65 subunit protein was observed in alcohol-fed wildtype, but not in alcohol-fed TLR4 mutant, mice. Similarly, alcohol induced the binding of NF-κB p50 subunit protein to hepcidin gene promoter in wildtype, but not in TLR4 mutant, mice. In contrast, the phosphorylation of Stat3 in the liver was stronger in alcohol-treated TLR4 mutant mice compared to alcohol-treated wildtype mice. The occupancy of hepcidin gene promoter by Stat3 was observed in alcohol-fed mutant, but not in wildtype, mice. An interaction between NF-κB p65 subunit protein and small heterodimer partner protein (SHP) was observed in the livers of both wildtype and TLR4 mutant mice fed with the control diet, as shown by co-immunoprecipitation studies. Alcohol intake elevated cytosolic SHP expression but attenuated its interaction with NF-κB in the liver, which was more prominent in the livers of wildtype compared to TLR4 mutant mice. CONCLUSION: Activation of TLR4 signaling and NF-κB are involved in the suppression of hepcidin gene transcription by alcohol in the presence of inflammation in the liver.",
keywords = "Alcoholic liver disease, Inflammation, Iron, Nuclear factor-κB, Small heterodimer partner protein",
author = "Emily Zmijewski and Sizhao Lu and Harrison-Findik, {Duygu Dee}",
year = "2014",
month = "9",
day = "14",
doi = "10.3748/wjg.v20.i34.12161",
language = "English (US)",
volume = "20",
pages = "12161--12170",
journal = "World Journal of Gastroenterology",
issn = "1007-9327",
publisher = "WJG Press",
number = "34",

}

TY - JOUR

T1 - TLR4 signaling and the inhibition of liver hepcidin expression by alcohol

AU - Zmijewski, Emily

AU - Lu, Sizhao

AU - Harrison-Findik, Duygu Dee

PY - 2014/9/14

Y1 - 2014/9/14

N2 - AIM: To understand the role of toll-like receptor 4 (TLR4) signaling in the regulation of iron-regulatory hormone, hepcidin by chronic alcohol consumption. METHODS: For chronic alcohol intake studies, TLR4 mutant mice on C3H/HeJ background and wildtype counterpart on C3H/HeOuJ background were pair-fed with regular (control) and ethanol-containing Lieber De Carli liquids diets. Gene expression was determined by real-time quantitative PCR. Protein-protein interactions and protein expression were determined by co-immunoprecipitation and western blotting. The occupancy of hepcidin gene promoter was determined by chromatin immunoprecipitation assays. RESULTS: Chronic alcohol intake suppressed hepcidin mRNA expression in the livers of wildtype, but not TLR4 mutant, mice. The phosphorylation and nuclear translocation of nuclear factor (NF)-κB p65 subunit protein was observed in alcohol-fed wildtype, but not in alcohol-fed TLR4 mutant, mice. Similarly, alcohol induced the binding of NF-κB p50 subunit protein to hepcidin gene promoter in wildtype, but not in TLR4 mutant, mice. In contrast, the phosphorylation of Stat3 in the liver was stronger in alcohol-treated TLR4 mutant mice compared to alcohol-treated wildtype mice. The occupancy of hepcidin gene promoter by Stat3 was observed in alcohol-fed mutant, but not in wildtype, mice. An interaction between NF-κB p65 subunit protein and small heterodimer partner protein (SHP) was observed in the livers of both wildtype and TLR4 mutant mice fed with the control diet, as shown by co-immunoprecipitation studies. Alcohol intake elevated cytosolic SHP expression but attenuated its interaction with NF-κB in the liver, which was more prominent in the livers of wildtype compared to TLR4 mutant mice. CONCLUSION: Activation of TLR4 signaling and NF-κB are involved in the suppression of hepcidin gene transcription by alcohol in the presence of inflammation in the liver.

AB - AIM: To understand the role of toll-like receptor 4 (TLR4) signaling in the regulation of iron-regulatory hormone, hepcidin by chronic alcohol consumption. METHODS: For chronic alcohol intake studies, TLR4 mutant mice on C3H/HeJ background and wildtype counterpart on C3H/HeOuJ background were pair-fed with regular (control) and ethanol-containing Lieber De Carli liquids diets. Gene expression was determined by real-time quantitative PCR. Protein-protein interactions and protein expression were determined by co-immunoprecipitation and western blotting. The occupancy of hepcidin gene promoter was determined by chromatin immunoprecipitation assays. RESULTS: Chronic alcohol intake suppressed hepcidin mRNA expression in the livers of wildtype, but not TLR4 mutant, mice. The phosphorylation and nuclear translocation of nuclear factor (NF)-κB p65 subunit protein was observed in alcohol-fed wildtype, but not in alcohol-fed TLR4 mutant, mice. Similarly, alcohol induced the binding of NF-κB p50 subunit protein to hepcidin gene promoter in wildtype, but not in TLR4 mutant, mice. In contrast, the phosphorylation of Stat3 in the liver was stronger in alcohol-treated TLR4 mutant mice compared to alcohol-treated wildtype mice. The occupancy of hepcidin gene promoter by Stat3 was observed in alcohol-fed mutant, but not in wildtype, mice. An interaction between NF-κB p65 subunit protein and small heterodimer partner protein (SHP) was observed in the livers of both wildtype and TLR4 mutant mice fed with the control diet, as shown by co-immunoprecipitation studies. Alcohol intake elevated cytosolic SHP expression but attenuated its interaction with NF-κB in the liver, which was more prominent in the livers of wildtype compared to TLR4 mutant mice. CONCLUSION: Activation of TLR4 signaling and NF-κB are involved in the suppression of hepcidin gene transcription by alcohol in the presence of inflammation in the liver.

KW - Alcoholic liver disease

KW - Inflammation

KW - Iron

KW - Nuclear factor-κB

KW - Small heterodimer partner protein

UR - http://www.scopus.com/inward/record.url?scp=84909609800&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84909609800&partnerID=8YFLogxK

U2 - 10.3748/wjg.v20.i34.12161

DO - 10.3748/wjg.v20.i34.12161

M3 - Article

C2 - 25232250

AN - SCOPUS:84909609800

VL - 20

SP - 12161

EP - 12170

JO - World Journal of Gastroenterology

JF - World Journal of Gastroenterology

SN - 1007-9327

IS - 34

ER -