Hypoxia-inducible factor-2α plays a role in mediating oesophagitis in GORD

Xiaofang Huo, Agoston T. Agoston, Kerry B. Dunbar, Daisha J. Cipher, Xi Zhang, Chunhua Yu, Edaire Cheng, Qiuyang Zhang, Thai H. Pham, Uttam K. Tambar, Richard K. Bruick, David H. Wang, Robert D. Odze, Stuart J. Spechler, Rhonda F. Souza

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Objective In an earlier study wherein we induced acute reflux by interrupting proton pump inhibitor (PPI) therapy in patients with reflux oesophagitis (RO) healed by PPIs, we refuted the traditional concept that RO develops as an acid burn. The present study explored our alternative hypothesis that RO results from refluxstimulated production of pro-inflammatory molecules mediated by hypoxia-inducible factors (HIFs). Design Using oesophageal biopsies taken from patients in our earlier study at baseline and at 1 and 2 weeks off PPIs, we immunostained for HIF-1a, HIF-2α and phospho-p65, and measured pro-inflammatory molecule mRNAs. We exposed human oesophageal squamous cell lines to acidic bile salts, and evaluated effects on HIF activation, p65 function, pro-inflammatory molecule production and immune cell migration. Results In patient biopsies, increased immunostaining for HIF-2α and phospho-p65, and increased proinflammatory molecule mRNA levels were seen when RO redeveloped 1 or 2 weeks after stopping PPIs. In oesophageal cells, exposure to acidic bile salts increased intracellular reactive oxygen species, which decreased prolyl hydroxylase function and stabilised HIF-2α, causing a p65-dependent increase in proinflammatory molecules; conditioned media from these cells increased T cell migration rates. HIF-2α inhibition by small hairpin RNA or selective small molecule antagonist blocked the increases in pro-inflammatory molecule expression and T cell migration induced by acidic bile salts. Conclusions In patients developing RO, increases in oesophageal HIF-2α correlate with increased proinflammatory molecule expression. In oesophageal epithelial cells, acidic bile salts stabilise HIF-2α, which mediates expression of pro-inflammatory molecules. HIF-2α appears to have a role in RO pathogenesis.

Original languageEnglish (US)
JournalGut
DOIs
StateAccepted/In press - Sep 30 2016

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Esophagitis
Peptic Esophagitis
Bile Acids and Salts
Cell Movement
Epithelial Cells
Prolyl Hydroxylases
T-Lymphocytes
Biopsy
Messenger RNA
Proton Pump Inhibitors
Conditioned Culture Medium
endothelial PAS domain-containing protein 1
Small Interfering RNA
Reactive Oxygen Species
Cell Line
Acids
Hypoxia

ASJC Scopus subject areas

  • Gastroenterology

Cite this

Hypoxia-inducible factor-2α plays a role in mediating oesophagitis in GORD. / Huo, Xiaofang; Agoston, Agoston T.; Dunbar, Kerry B.; Cipher, Daisha J.; Zhang, Xi; Yu, Chunhua; Cheng, Edaire; Zhang, Qiuyang; Pham, Thai H.; Tambar, Uttam K.; Bruick, Richard K.; Wang, David H.; Odze, Robert D.; Spechler, Stuart J.; Souza, Rhonda F.

In: Gut, 30.09.2016.

Research output: Contribution to journalArticle

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title = "Hypoxia-inducible factor-2α plays a role in mediating oesophagitis in GORD",
abstract = "Objective In an earlier study wherein we induced acute reflux by interrupting proton pump inhibitor (PPI) therapy in patients with reflux oesophagitis (RO) healed by PPIs, we refuted the traditional concept that RO develops as an acid burn. The present study explored our alternative hypothesis that RO results from refluxstimulated production of pro-inflammatory molecules mediated by hypoxia-inducible factors (HIFs). Design Using oesophageal biopsies taken from patients in our earlier study at baseline and at 1 and 2 weeks off PPIs, we immunostained for HIF-1a, HIF-2α and phospho-p65, and measured pro-inflammatory molecule mRNAs. We exposed human oesophageal squamous cell lines to acidic bile salts, and evaluated effects on HIF activation, p65 function, pro-inflammatory molecule production and immune cell migration. Results In patient biopsies, increased immunostaining for HIF-2α and phospho-p65, and increased proinflammatory molecule mRNA levels were seen when RO redeveloped 1 or 2 weeks after stopping PPIs. In oesophageal cells, exposure to acidic bile salts increased intracellular reactive oxygen species, which decreased prolyl hydroxylase function and stabilised HIF-2α, causing a p65-dependent increase in proinflammatory molecules; conditioned media from these cells increased T cell migration rates. HIF-2α inhibition by small hairpin RNA or selective small molecule antagonist blocked the increases in pro-inflammatory molecule expression and T cell migration induced by acidic bile salts. Conclusions In patients developing RO, increases in oesophageal HIF-2α correlate with increased proinflammatory molecule expression. In oesophageal epithelial cells, acidic bile salts stabilise HIF-2α, which mediates expression of pro-inflammatory molecules. HIF-2α appears to have a role in RO pathogenesis.",
author = "Xiaofang Huo and Agoston, {Agoston T.} and Dunbar, {Kerry B.} and Cipher, {Daisha J.} and Xi Zhang and Chunhua Yu and Edaire Cheng and Qiuyang Zhang and Pham, {Thai H.} and Tambar, {Uttam K.} and Bruick, {Richard K.} and Wang, {David H.} and Odze, {Robert D.} and Spechler, {Stuart J.} and Souza, {Rhonda F.}",
year = "2016",
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T1 - Hypoxia-inducible factor-2α plays a role in mediating oesophagitis in GORD

AU - Huo, Xiaofang

AU - Agoston, Agoston T.

AU - Dunbar, Kerry B.

AU - Cipher, Daisha J.

AU - Zhang, Xi

AU - Yu, Chunhua

AU - Cheng, Edaire

AU - Zhang, Qiuyang

AU - Pham, Thai H.

AU - Tambar, Uttam K.

AU - Bruick, Richard K.

AU - Wang, David H.

AU - Odze, Robert D.

AU - Spechler, Stuart J.

AU - Souza, Rhonda F.

PY - 2016/9/30

Y1 - 2016/9/30

N2 - Objective In an earlier study wherein we induced acute reflux by interrupting proton pump inhibitor (PPI) therapy in patients with reflux oesophagitis (RO) healed by PPIs, we refuted the traditional concept that RO develops as an acid burn. The present study explored our alternative hypothesis that RO results from refluxstimulated production of pro-inflammatory molecules mediated by hypoxia-inducible factors (HIFs). Design Using oesophageal biopsies taken from patients in our earlier study at baseline and at 1 and 2 weeks off PPIs, we immunostained for HIF-1a, HIF-2α and phospho-p65, and measured pro-inflammatory molecule mRNAs. We exposed human oesophageal squamous cell lines to acidic bile salts, and evaluated effects on HIF activation, p65 function, pro-inflammatory molecule production and immune cell migration. Results In patient biopsies, increased immunostaining for HIF-2α and phospho-p65, and increased proinflammatory molecule mRNA levels were seen when RO redeveloped 1 or 2 weeks after stopping PPIs. In oesophageal cells, exposure to acidic bile salts increased intracellular reactive oxygen species, which decreased prolyl hydroxylase function and stabilised HIF-2α, causing a p65-dependent increase in proinflammatory molecules; conditioned media from these cells increased T cell migration rates. HIF-2α inhibition by small hairpin RNA or selective small molecule antagonist blocked the increases in pro-inflammatory molecule expression and T cell migration induced by acidic bile salts. Conclusions In patients developing RO, increases in oesophageal HIF-2α correlate with increased proinflammatory molecule expression. In oesophageal epithelial cells, acidic bile salts stabilise HIF-2α, which mediates expression of pro-inflammatory molecules. HIF-2α appears to have a role in RO pathogenesis.

AB - Objective In an earlier study wherein we induced acute reflux by interrupting proton pump inhibitor (PPI) therapy in patients with reflux oesophagitis (RO) healed by PPIs, we refuted the traditional concept that RO develops as an acid burn. The present study explored our alternative hypothesis that RO results from refluxstimulated production of pro-inflammatory molecules mediated by hypoxia-inducible factors (HIFs). Design Using oesophageal biopsies taken from patients in our earlier study at baseline and at 1 and 2 weeks off PPIs, we immunostained for HIF-1a, HIF-2α and phospho-p65, and measured pro-inflammatory molecule mRNAs. We exposed human oesophageal squamous cell lines to acidic bile salts, and evaluated effects on HIF activation, p65 function, pro-inflammatory molecule production and immune cell migration. Results In patient biopsies, increased immunostaining for HIF-2α and phospho-p65, and increased proinflammatory molecule mRNA levels were seen when RO redeveloped 1 or 2 weeks after stopping PPIs. In oesophageal cells, exposure to acidic bile salts increased intracellular reactive oxygen species, which decreased prolyl hydroxylase function and stabilised HIF-2α, causing a p65-dependent increase in proinflammatory molecules; conditioned media from these cells increased T cell migration rates. HIF-2α inhibition by small hairpin RNA or selective small molecule antagonist blocked the increases in pro-inflammatory molecule expression and T cell migration induced by acidic bile salts. Conclusions In patients developing RO, increases in oesophageal HIF-2α correlate with increased proinflammatory molecule expression. In oesophageal epithelial cells, acidic bile salts stabilise HIF-2α, which mediates expression of pro-inflammatory molecules. HIF-2α appears to have a role in RO pathogenesis.

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U2 - 10.1136/gutjnl-2016-312595

DO - 10.1136/gutjnl-2016-312595

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