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Van Welden S, Selfridge AC, Hindryckx P. Intestinal hypoxia and hypoxia-induced signalling as therapeutic targets for IBD. Nat Rev Gastroenterol Hepatol 2017; 14:596-611. [PMID: 28853446 DOI: 10.1038/nrgastro.2017.101] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Tissue hypoxia occurs when local oxygen demand exceeds oxygen supply. In chronic inflammatory conditions such as IBD, the increased oxygen demand by resident and gut-infiltrating immune cells coupled with vascular dysfunction brings about a marked reduction in mucosal oxygen concentrations. To counter the hypoxic challenge and ensure their survival, mucosal cells induce adaptive responses, including the activation of hypoxia-inducible factors (HIFs) and modulation of nuclear factor-κB (NF-κB). Both pathways are tightly regulated by oxygen-sensitive prolyl hydroxylases (PHDs), which therefore represent promising therapeutic targets for IBD. In this Review, we discuss the involvement of mucosal hypoxia and hypoxia-induced signalling in the pathogenesis of IBD and elaborate in detail on the role of HIFs, NF-κB and PHDs in different cell types during intestinal inflammation. We also provide an update on the development of PHD inhibitors and discuss their therapeutic potential in IBD.
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Affiliation(s)
- Sophie Van Welden
- Department of Gastroenterology, Ghent University, De Pintelaan 185, 1K12-E, 9000 Ghent, Belgium
| | - Andrew C Selfridge
- Robarts Clinical Trials West, 4350 Executive Drive 210, San Diego, California 92121, USA
| | - Pieter Hindryckx
- Department of Gastroenterology, Ghent University, De Pintelaan 185, 1K12-E, 9000 Ghent, Belgium
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Protective effect of decursin and decursinol angelate-rich Angelica gigas Nakai extract on dextran sulfate sodium-induced murine ulcerative colitis. ASIAN PAC J TROP MED 2017; 10:864-870. [PMID: 29080614 DOI: 10.1016/j.apjtm.2017.08.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/15/2017] [Accepted: 08/17/2017] [Indexed: 11/20/2022] Open
Abstract
OBJECTIVE To investigate the anti-inflammatory effects of decursin and decursinol angelate-rich Angelica gigas Nakai (AGNE) on dextran sulfate sodium (DSS)-induced murine ulcerative colitis (UC). METHODS The therapeutic effect of an AGNE was analyzed in a mouse model of UC induced by DSS. Disease activity index values were measured by clinical signs such as a weight loss, stool consistency, rectal bleeding and colon length. A histological analysis was performed using hematoxylin and eosin staining. Key inflammatory cytokines and mediators including IL-6, TNF-α, PGE2, COX-2 and HIF-1α were assayed by enzyme-linked immunosorbent assay or western blotting. RESULTS Treatment with the AGNE at 10, 20, and 40 mg/kg alleviated weight loss, decreased disease activity index scores, and reduced colon shortening in mice with DSS-induced UC. AGNE inhibited the production of IL-6 and TNF-α in serum and colon tissue. Moreover, AGNE suppressed the increased expression of COX-2 and HIF-1α and the increased production of PGE2 in colon tissue were observed in mice with DSS-induced UC. Additionally, histological damage was also alleviated by AGNE treatment. CONCLUSIONS The findings of this study verified that AGNE significantly improves clinical symptoms and reduces the activity of various inflammatory mediators. These results indicate the AGNE has the therapeutic potential in mice with DSS-induced UC.
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Huo X, Agoston AT, Dunbar KB, Cipher DJ, Zhang X, Yu C, Cheng E, Zhang Q, Pham TH, Tambar UK, Bruick RK, Wang DH, Odze RD, Spechler SJ, Souza RF. Hypoxia-inducible factor-2α plays a role in mediating oesophagitis in GORD. Gut 2017; 66:1542-1554. [PMID: 27694141 PMCID: PMC5464991 DOI: 10.1136/gutjnl-2016-312595] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 08/24/2016] [Accepted: 09/08/2016] [Indexed: 12/14/2022]
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 reflux-stimulated 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-1α, 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 pro-inflammatory 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 pro-inflammatory 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 pro-inflammatory 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. TRIAL REGISTRATION NUMBER NCT01733810; Results.
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Affiliation(s)
- Xiaofang Huo
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Agoston T. Agoston
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Kerry B. Dunbar
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Daisha J. Cipher
- College of Nursing and Health Innovation, University of Texas at Arlington, Arlington, TX
| | - Xi Zhang
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Chunhua Yu
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Edaire Cheng
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Pediatrics, Children's Medical Center and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Qiuyang Zhang
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Thai H. Pham
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Surgery, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX
| | - Uttam K. Tambar
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - Richard K. Bruick
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX
| | - David H. Wang
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX
| | - Robert D. Odze
- Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA
| | - Stuart J. Spechler
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX,Correspondence to: Rhonda F. Souza, M.D., Department of Gastroenterology, MC# 111B1, Dallas VA Medical Center, 4500 South Lancaster Road, Dallas, TX 75216, Phone 214-857-0301, FAX 214-857-0328, ; Stuart J. Spechler, M.D., Department of Gastroenterology, MC# 111B1, Dallas VA Medical Center, 4500 South Lancaster Road, Dallas, TX 75216, Phone 214-857-0403, FAX 214-857-1571,
| | - Rhonda F. Souza
- Esophageal Diseases Center, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Department of Medicine, VA North Texas Health Care System and the University of Texas Southwestern Medical Center, Dallas, TX,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX,Correspondence to: Rhonda F. Souza, M.D., Department of Gastroenterology, MC# 111B1, Dallas VA Medical Center, 4500 South Lancaster Road, Dallas, TX 75216, Phone 214-857-0301, FAX 214-857-0328, ; Stuart J. Spechler, M.D., Department of Gastroenterology, MC# 111B1, Dallas VA Medical Center, 4500 South Lancaster Road, Dallas, TX 75216, Phone 214-857-0403, FAX 214-857-1571,
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54
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Ma X, Zhang H, Xue X, Shah YM. Hypoxia-inducible factor 2α (HIF-2α) promotes colon cancer growth by potentiating Yes-associated protein 1 (YAP1) activity. J Biol Chem 2017; 292:17046-17056. [PMID: 28848049 DOI: 10.1074/jbc.m117.805655] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 08/25/2017] [Indexed: 01/29/2023] Open
Abstract
Colorectal cancer (CRC) is the third-leading cause of cancer mortality in the United States and other industrialized countries. A hypoxic microenvironment is a hallmark for solid tumors. The hypoxia-induced signal transduction is transcriptionally mediated by hypoxia-inducible factor (HIF). Three major HIF isoforms, HIF-1α, HIF-2α, and HIF-3α, are present in the intestine. Our previous work demonstrates that HIF-2α is essential for CRC growth and progression. However, the mechanisms mediating cell proliferation after hypoxia or HIF-2α activation in CRC are unclear. Data mining of RNA-Seq experiments with mouse models of intestinal HIF-2α or Yes-associated protein 1 (YAP1) overexpression indicates a significant overlap of genes in these conditions. YAP1 is a transcriptional co-activator in the Hippo signaling pathway, and YAP1-induced transcriptional responses are essential in cancer cell proliferation. Here, we report that HIF-2α robustly increases YAP1 expression and activity in CRC-derived cell lines and in mouse models. The potentiation of YAP1 activity by HIF-2α was not via canonical signaling mechanisms such as Src (non-receptor tyrosine kinase), PI3K, ERK, or MAPK pathways. Moreover, we detected no direct interaction of HIF-2α with YAP1. Of note, YAP1 activation was critical for cancer cell growth under hypoxia. Our findings indicate that HIF-2α increases cancer cell growth by up-regulating YAP1 activity, suggesting that this pathway might be targeted in potential anti-cancer approaches for treating CRC patients.
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Affiliation(s)
- Xiaoya Ma
- From the Departments of Molecular and Integrative Physiology and
| | - Huabing Zhang
- From the Departments of Molecular and Integrative Physiology and
| | - Xiang Xue
- From the Departments of Molecular and Integrative Physiology and
| | - Yatrik M Shah
- From the Departments of Molecular and Integrative Physiology and .,Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan 48109
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55
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Toullec A, Buard V, Rannou E, Tarlet G, Guipaud O, Robine S, Iruela-Arispe ML, François A, Milliat F. HIF-1α Deletion in the Endothelium, but Not in the Epithelium, Protects From Radiation-Induced Enteritis. Cell Mol Gastroenterol Hepatol 2017; 5:15-30. [PMID: 29276749 PMCID: PMC5738457 DOI: 10.1016/j.jcmgh.2017.08.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 08/08/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND & AIMS Radiation therapy in the pelvic area is associated with side effects that impact the quality of life of cancer survivors. Interestingly, the gastrointestinal tract is able to adapt to significant changes in oxygen availability, suggesting that mechanisms related to hypoxia sensing help preserve tissue integrity in this organ. However, hypoxia-inducible factor (HIF)-dependent responses to radiation-induced gut toxicity are unknown. Radiation-induced intestinal toxicity is a complex process involving multiple cellular compartments. Here, we investigated whether epithelial or endothelial tissue-specific HIF-1α deletion could affect acute intestinal response to radiation. METHODS Using constitutive and inducible epithelial or endothelial tissue-specific HIF-1α deletion, we evaluated the consequences of epithelial or endothelial HIF-1α deletion on radiation-induced enteritis after localized irradiation. Survival, radiation-induced tissue injury, molecular inflammatory profile, tissue hypoxia, and vascular injury were monitored. RESULTS Surprisingly, epithelium-specific HIF-1α deletion does not alter radiation-induced intestinal injury. However, irradiated VECad-Cre+/-HIF-1αFL/FL mice present with lower radiation-induced damage, showed a preserved vasculature, reduced hypoxia, and reduced proinflammatory response compared with irradiated HIF-1αFL/FL mice. CONCLUSIONS We demonstrate in vivo that HIF-1α impacts radiation-induced enteritis and that this role differs according to the targeted cell type. Our work provides a new role for HIF-1α and endothelium-dependent mechanisms driving inflammatory processes in gut mucosae. Results presented show that effects on normal tissues have to be taken into account in approaches aiming to modulate hypoxia or hypoxia-related molecular mechanisms.
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Key Words
- EndoMT, endothelial-to-mesenchymal transition
- Endothelium
- HIF, hypoxia-inducible factor
- HIF-1α
- HIF-1αFl/FL, HIF-1α floxed mice
- HIMEC, human intestinal microvascular endothelial cells
- HUVEC, human umbilical vein endothelial cells
- IL, interleukin
- PAI-1, plasminogen activator inhibitor type-1
- PCR, polymerase chain reaction
- ROSA, ROSA26R LacZ reporter mice
- Radiation
- Sham-IR, sham-irradiation
- TBI, total body irradiation
- VECad-Cre, VE-cadherin-Cre mice
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Affiliation(s)
- Aurore Toullec
- Research Laboratory of Radiobiology and Radiopathology, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
| | - Valérie Buard
- Research Laboratory of Radiobiology and Radiopathology, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
| | - Emilie Rannou
- Research Laboratory of Radiobiology and Radiopathology, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California
| | - Georges Tarlet
- Research Laboratory of Radiobiology and Radiopathology, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
| | - Olivier Guipaud
- Research Laboratory of Radiobiology and Radiopathology, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
| | | | - M. Luisa Iruela-Arispe
- Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, California
| | - Agnès François
- Research Laboratory of Radiobiology and Radiopathology, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
| | - Fabien Milliat
- Research Laboratory of Radiobiology and Radiopathology, Institute for Radiological Protection and Nuclear Safety, Fontenay-aux-Roses, France
- Correspondence Address correspondence to: Fabien Milliat, PhD, Research Laboratory of Radiobiology and Radiopathology, Institute for Radiological Protection and Nuclear Safety, 92265 Fontenay-aux-Roses, France.Research Laboratory of Radiobiology and RadiopathologyInstitute for Radiological Protection and Nuclear Safety92265 Fontenay-aux-RosesFrance
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56
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Hall CH, Campbell EL, Colgan SP. Neutrophils as Components of Mucosal Homeostasis. Cell Mol Gastroenterol Hepatol 2017; 4:329-337. [PMID: 28884136 PMCID: PMC5581871 DOI: 10.1016/j.jcmgh.2017.07.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 07/10/2017] [Indexed: 12/24/2022]
Abstract
Inflammatory responses in the intestinal mucosa inevitably result in the recruitment of neutrophils (polymorphonuclear leukocytes [PMNs]). Epithelial cells that line the mucosa play an integral role in the recruitment, maintenance, and clearance of PMNs at sites of inflammation. The consequences of such PMN-epithelial interactions often determine tissue responses and, ultimately, organ function. For this reason, there is significant interest in understanding how PMNs function in the mucosa during inflammation. Recent studies have shown that PMNs play a more significant role in molding of the immune response than previously thought. Here, we review the recent literature regarding the contribution of PMNs to the development and resolution of inflammation, with an emphasis on the role of the tissue microenvironment and pathways for promoting epithelial restitution. These studies highlight the complex nature of inflammatory pathways and provide important insight into the difficulties of treating mucosal inflammation.
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Key Words
- ATP, adenosine triphosphatase
- CGD, chronic granulomatous disease
- DMOG, dimethyloxalylglycine
- Epithelium
- GI, gastrointestinal
- HIF, hypoxia-inducible factor
- Hypoxia-Inducible Factor
- IBD, inflammatory bowel disease
- ICAM-1, intracellular adhesion molecule-1
- IL, interleukin
- Inflammation
- Metabolism
- Microbiota
- NADPH, reduced nicotinamide adenine dinucleotide phosphate
- PHD, prolyl-hydroxylase
- PMN, polymorphonuclear leukocyte
- SIRPα, signal-regulatory protein-α
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Affiliation(s)
- Caroline H.T. Hall
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado,Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado
| | - Eric L. Campbell
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado,Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado,Centre for Experimental Medicine, Queen’s University Belfast, Northern Ireland, United Kingdom
| | - Sean P. Colgan
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado,Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado,Correspondence Address correspondence to: Sean P. Colgan, PhD, University of Colorado School of Medicine, 12700 East 19th Avenue, Room 10025, Aurora, Colorado 80045. fax: (303) 724-7243.University of Colorado School of Medicine12700 East 19th AvenueRoom 10025AuroraColorado 80045
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57
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Campbell EL, Kao DJ, Colgan SP. Neutrophils and the inflammatory tissue microenvironment in the mucosa. Immunol Rev 2017; 273:112-20. [PMID: 27558331 DOI: 10.1111/imr.12456] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The interaction of neutrophils (PMNs) and epithelial cells are requisite lines of communication during mucosal inflammatory responses. Consequences of such interactions often determine endpoint organ function, and for this reason, much interest has developed around defining the constituents of the tissue microenvironment of inflammatory lesions. Physiologic in vitro and in vivo models have aided in the discovery of components that define the basic inflammatory machinery that mold the inflammatory tissue microenvironment. Here, we will review the recent literature related to the contribution of PMNs to molding of the tissue microenvironment, with an emphasis on the gastrointestinal (GI) tract. We focus on endogenous pathways for promoting tissue homeostasis and the molecular determinants of neutrophil-epithelial cell interactions during ongoing inflammation. These recent studies highlight the dynamic nature of these pathways and lend insight into the complexity of treating mucosal inflammation.
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Affiliation(s)
- Eric L Campbell
- Department of Medicine the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, CO, USA
| | - Daniel J Kao
- Department of Medicine the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, CO, USA
| | - Sean P Colgan
- Department of Medicine the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, CO, USA
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58
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Colgan SP, Campbell EL, Kominsky DJ. Hypoxia and Mucosal Inflammation. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2017; 11:77-100. [PMID: 27193451 DOI: 10.1146/annurev-pathol-012615-044231] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Sites of inflammation are defined by significant changes in metabolic activity. Recent studies have suggested that O2 metabolism and hypoxia play a prominent role in inflammation so-called "inflammatory hypoxia," which results from a combination of recruited inflammatory cells (e.g., neutrophils and monocytes), the local proliferation of multiple cell types, and the activation of multiple O2-consuming enzymes during inflammation. These shifts in energy supply and demand result in localized regions of hypoxia and have revealed the important function off the transcription factor HIF (hypoxia-inducible factor) in the regulation of key target genes that promote inflammatory resolution. Analysis of these pathways has provided multiple opportunities for understanding basic mechanisms of inflammation and has defined new targets for intervention. Here, we review recent work addressing tissue hypoxia and metabolic control of inflammation and immunity.
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Affiliation(s)
- Sean P Colgan
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado 80045; .,Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Eric L Campbell
- Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado 80045; .,Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado 80045
| | - Douglas J Kominsky
- Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, Colorado 80045.,Department of Microbiology and Immunology, Montana State University, Bozeman, Montana 59717
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Souza RF. Reflux esophagitis and its role in the pathogenesis of Barrett's metaplasia. J Gastroenterol 2017; 52:767-776. [PMID: 28451845 PMCID: PMC5488728 DOI: 10.1007/s00535-017-1342-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 04/11/2017] [Indexed: 02/04/2023]
Abstract
Reflux esophagitis damages the squamous epithelium that normally lines the esophagus, and promotes replacement of the damaged squamous lining by the intestinal metaplasia of Barrett's esophagus, the precursor of esophageal adenocarcinoma. Therefore, to prevent the development of Barrett's metaplasia and esophageal adenocarcinoma, the pathogenesis of reflux esophagitis must be understood. We have reported that reflux esophagitis, both in a rat model and in humans, develops as a cytokine-mediated inflammatory injury (i.e., cytokine sizzle), not as a caustic chemical injury (i.e., acid burn), as traditionally has been assumed. Moreover, reflux induces activation of hypoxia inducible factor (HIF)-2α, which enhances the transcriptional activity of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) causing increases in pro-inflammatory cytokines and in migration of T lymphocytes, an underlying molecular mechanism for this cytokine-mediated injury. In some individuals, reflux esophagitis heals with Barrett's metaplasia. A number of possibilities exist for the origin of the progenitor cells that give rise to this intestinal metaplasia including those of the esophagus, the proximal stomach, or the bone marrow. However, intestinal cells are not normally found in the esophagus, the stomach, or the bone marrow. Thus, the development of Barrett's intestinal metaplasia must involve some molecular reprogramming of key developmental transcription factors within the progenitor cell, a process termed transcommitment, which may be initiated by the noxious components of the gastric refluxate. This review will highlight recent studies on the pathogenesis of reflux esophagitis and on reflux-related molecular reprogramming of esophageal squamous epithelial cells in the pathogenesis of Barrett's metaplasia.
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Affiliation(s)
- Rhonda F. Souza
- Center for Esophageal Research, Baylor Scott and White Research Institute, Dallas, TX, USA
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60
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Manresa MC, Taylor CT. Hypoxia Inducible Factor (HIF) Hydroxylases as Regulators of Intestinal Epithelial Barrier Function. Cell Mol Gastroenterol Hepatol 2017; 3:303-315. [PMID: 28462372 PMCID: PMC5404106 DOI: 10.1016/j.jcmgh.2017.02.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 02/09/2017] [Indexed: 12/12/2022]
Abstract
Human health is dependent on the ability of the body to extract nutrients, fluids, and oxygen from the external environment while at the same time maintaining a state of internal sterility. Therefore, the cell layers that cover the surface areas of the body such as the lung, skin, and gastrointestinal mucosa provide vital semipermeable barriers that allow the transport of essential nutrients, fluid, and waste products, while at the same time keeping the internal compartments free of microbial organisms. These epithelial surfaces are highly specialized and differ in their anatomic structure depending on their location to provide appropriate and effective site-specific barrier function. Given this important role, it is not surprising that significant disease often is associated with alterations in epithelial barrier function. Examples of such diseases include inflammatory bowel disease, chronic obstructive pulmonary disease, and atopic dermatitis. These chronic inflammatory disorders often are characterized by diminished tissue oxygen levels (hypoxia). Hypoxia triggers an adaptive transcriptional response governed by hypoxia-inducible factors (HIFs), which are repressed by a family of oxygen-sensing HIF hydroxylases. Here, we review recent evidence suggesting that pharmacologic hydroxylase inhibition may be of therapeutic benefit in inflammatory bowel disease through the promotion of intestinal epithelial barrier function through both HIF-dependent and HIF-independent mechanisms.
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Key Words
- CD, Crohn’s disease
- DMOG, dimethyloxalylglycine
- DSS, dextran sodium sulfate
- Epithelial Barrier
- FIH, factor inhibiting hypoxia-inducible factor
- HIF, hypoxia-inducible factor
- Hypoxia
- Hypoxia-Inducible Factor (HIF) Hydroxylases
- IBD, inflammatory bowel disease
- IL, interleukin
- Inflammatory Bowel Disease
- NF-κB, nuclear factor-κB
- PHD, hypoxia-inducible factor–prolyl hydroxylases
- TFF, trefoil factor
- TJ, tight junction
- TLR, Toll-like receptor
- TNF-α, tumor necrosis factor α
- UC, ulcerative colitis
- ZO, zonula occludens
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Affiliation(s)
- Mario C. Manresa
- Conway Institute of Biomolecular and Biomedical Research, Belfield, Dublin, Ireland
- Charles Institute of Dermatology, Belfield, Dublin, Ireland
| | - Cormac T. Taylor
- Conway Institute of Biomolecular and Biomedical Research, Belfield, Dublin, Ireland
- Charles Institute of Dermatology, Belfield, Dublin, Ireland
- Systems Biology Ireland, School of Medicine and Medical Science, University College Dublin, Belfield, Dublin, Ireland
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Chun C, Zheng L, Colgan SP. Tissue metabolism and host-microbial interactions in the intestinal mucosa. Free Radic Biol Med 2017; 105:86-92. [PMID: 27687211 PMCID: PMC5797701 DOI: 10.1016/j.freeradbiomed.2016.09.027] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 09/23/2016] [Accepted: 09/26/2016] [Indexed: 01/03/2023]
Abstract
In recent years, studies in the gastrointestinal (GI) mucosa have taught us a number of important lessons related to tissue oxygenation and metabolism in health and disease. The highly vascularized mucosa lies immediately adjacent to an anaerobic lumen containing trillions of metabolically active microbes (i.e. the microbiome) that results in one of the more austere tissue microenvironments in the body. These studies have also implicated a prominent role for oxygen metabolism and hypoxia in inflammation, so called "inflammatory hypoxia", that results from the activation of multiple oxygen consuming enzymes. Inflammation-associated shifts in the composition of the microbiome and microbial-derived metabolites have revealed a prominent role for the transcription factor hypoxia-inducible factor (HIF) in the regulation of key target genes that promote inflammatory resolution. Analyses of these pathways have provided a multitude of opportunities for understanding basic mechanisms of both homeostasis and disease and have defined new targets for intervention. Here, we review recent advances in our understanding of metabolic influences on host-microbe interactions in the GI mucosa.
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Affiliation(s)
- Carlene Chun
- Department of Medicine and the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, CO, United States
| | - Leon Zheng
- Department of Medicine and the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, CO, United States
| | - Sean P Colgan
- Department of Medicine and the Mucosal Inflammation Program, University of Colorado School of Medicine, Aurora, CO, United States.
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Hypoxia and inflammatory bowel disease. Microbes Infect 2017; 19:210-221. [DOI: 10.1016/j.micinf.2016.09.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/08/2016] [Accepted: 09/13/2016] [Indexed: 12/17/2022]
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Kim H, Banerjee N, Sirven MA, Minamoto Y, Markel ME, Suchodolski JS, Talcott ST, Mertens-Talcott SU. Pomegranate polyphenolics reduce inflammation and ulceration in intestinal colitis-involvement of the miR-145/p70S6K1/HIF1α axis in vivo and in vitro. J Nutr Biochem 2017; 43:107-115. [PMID: 28282584 DOI: 10.1016/j.jnutbio.2017.02.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 01/26/2017] [Accepted: 02/13/2017] [Indexed: 12/30/2022]
Abstract
This study investigated the potential role of the p70S6K1/HIF1α axis in the anti-inflammatory activities of pomegranate (Punica granatum L.) polyphenolics in dextran sodium sulfate (DSS)-induced colitis in Sprague-Dawley rats and in lipopolysaccharide (LPS)-treated CCD-18Co colon-myofibroblastic cells. Rats were administered either control (CT) or pomegranate beverage (PG), containing ellagic acid and ellagitannins, then exposed to three cycles of 3% DSS followed by a 2-week recovery period. PG protected against DSS-induced colon inflammation and ulceration (50% and 66.7%, P=.05 and .045, respectively), and decreased the Ki-67 proliferative index in the central and basal regions compared to the control. PG also significantly reduced the expression of proinflammatory cytokines (TNF-α and IL-1β), COX-2, and iNOS at mRNA and protein levels. In addition, the expression of p70S6K1 and HIF1α was reduced, while the tumor suppressor miR-145 was induced by PG. The intestinal microbiota of rats treated with PG showed a significant increase in Ruminococcaceae that include several butyrate producing bacteria (P=.03). In vitro, PG reduced the expression of p70S6K1 and HIF1α and induced miR-145 in a dose-dependent manner. The involvement of miR-145/p70S6K1 was confirmed by treating LPS-treated CCD-18Co cells with miR-145 antagomiR, where the pomegranate polyphenolics reversed the effects of the antagomiR for p70S6K1 mRNA and protein levels. These results suggest that pomegranate polyphenols attenuated DSS-induced colitis by modulating the miR-145/p70S6K/HIF1α axis, indicating potential use in therapeutic treatment of ulcerative colitis.
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Affiliation(s)
- Hyemee Kim
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| | - Nivedita Banerjee
- Interdisciplinary Program of Toxicology, Texas A&M University, College Station, TX, USA
| | - Maritza A Sirven
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| | - Yasushi Minamoto
- Gastrointestinal Laboratory, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Melissa E Markel
- Gastrointestinal Laboratory, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Jan S Suchodolski
- Gastrointestinal Laboratory, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA
| | - Stephen T Talcott
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA
| | - Susanne U Mertens-Talcott
- Department of Nutrition and Food Science, Texas A&M University, College Station, TX, USA; Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX, USA.
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Epithelial Hypoxia-Inducible Factor 2α Facilitates the Progression of Colon Tumors through Recruiting Neutrophils. Mol Cell Biol 2017; 37:MCB.00481-16. [PMID: 27956697 DOI: 10.1128/mcb.00481-16] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 12/02/2016] [Indexed: 12/24/2022] Open
Abstract
Inflammation is a significant risk factor for colon cancer. Recent work has demonstrated essential roles for several infiltrating immune populations in the metaplastic progression following inflammation. Hypoxia and stabilization of hypoxia-inducible factors (HIFs) are hallmark features of inflammation and solid tumors. Previously, we demonstrated an important role for tumor epithelial HIF-2α in colon tumors; however, the function of epithelial HIF-2α as a critical link in the progression of inflammation to cancer has not been elucidated. In colitis-associated colon cancer models, epithelial HIF-2α was essential in tumor growth. Concurrently, epithelial disruption of HIF-2α significantly decreased neutrophils in the colon tumor microenvironment. Intestinal epithelial HIF-2α-overexpressing mice demonstrated that neutrophil recruitment was a direct response to increased epithelial HIF-2α signaling. High-throughput RNA sequencing (RNA-seq) analysis of HIF-2α-overexpressing mice in conjunction with data mining from the Cancer Genome Atlas showed that the neutrophil chemokine CXCL1 gene was highly upregulated in colon tumor epithelium in a HIF-2α-dependent manner. Using selective peptide inhibitors of the CXCL1-CXCR2 signaling axis identified HIF-2α-dependent neutrophil recruitment as an essential mechanism to increase colon carcinogenesis. These studies demonstrate that HIF-2α is a novel regulator of neutrophil recruitment to colon tumors and that it is essential in shaping the protumorigenic inflammatory microenvironment in colon cancer.
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65
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Creatine maintains intestinal homeostasis and protects against colitis. Proc Natl Acad Sci U S A 2017; 114:E1273-E1281. [PMID: 28137860 DOI: 10.1073/pnas.1621400114] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Creatine, a nitrogenous organic acid, replenishes cytoplasmic ATP at the expense of mitochondrial ATP via the phosphocreatine shuttle. Creatine levels are maintained by diet and endogenous synthesis from arginine and glycine. Glycine amidinotransferase (GATM) catalyzes the rate-limiting step of creatine biosynthesis: the transfer of an amidino group from arginine to glycine to form ornithine and guanidinoacetate. We screened 36,530 third-generation germline mutant mice derived from N-ethyl-N-nitrosourea-mutagenized grandsires for intestinal homeostasis abnormalities after oral administration of dextran sodium sulfate (DSS). Among 27 colitis susceptibility phenotypes identified and mapped, one was strongly correlated with a missense mutation in Gatm in a recessive model of inheritance, and causation was confirmed by CRISPR/Cas9 gene targeting. Supplementation of homozygous Gatm mutants with exogenous creatine ameliorated the colitis phenotype. CRISPR/Cas9-targeted (Gatmc/c ) mice displayed a normal peripheral immune response and immune cell homeostasis. However, the intestinal epithelium of the Gatmc/c mice displayed increased cell death and decreased proliferation during DSS treatment. In addition, Gatmc/c colonocytes showed increased metabolic stress in response to DSS with higher levels of phospho-AMPK and lower levels of phosphorylation of mammalian target of rapamycin (phospho-mTOR). These findings establish an in vivo requirement for rapid replenishment of cytoplasmic ATP within colonic epithelial cells in the maintenance of the mucosal barrier after injury.
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66
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Kim H, Banerjee N, Barnes RC, Pfent CM, Talcott ST, Dashwood RH, Mertens-Talcott SU. Mango polyphenolics reduce inflammation in intestinal colitis-involvement of the miR-126/PI3K/AKT/mTOR axis in vitro and in vivo. Mol Carcinog 2017; 56:197-207. [PMID: 27061150 PMCID: PMC5053910 DOI: 10.1002/mc.22484] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2015] [Revised: 03/07/2016] [Accepted: 03/18/2016] [Indexed: 12/19/2022]
Abstract
This study sought to elucidate the mechanisms underlying the anti-inflammatory effect of mango (Mangifera Indica L.) polyphenolics containing gallic acid and gallotanins, and the role of the miR-126/PI3K/AKT/mTOR signaling axis in vitro and in vivo. Polyphenolics extracted from mango (var. Keitt) were investigated in lipopolysaccharide (LPS)-treated CCD-18Co cells. Rats received either a beverage with mango polyphenolics or a control beverage, and were exposed to three cycles of 3% dextran sodium sulfate (DSS) followed by a 2-wk recovery period. The mango extract (10 mg GAE/L) suppressed the protein expression of NF-κB, p-NF-κB, PI3K (p85β), HIF-1α, p70S6K1, and RPS6 in LPS-treated CCD-18Co cells. LPS reduced miR-126 expression, whereas, the mango extract induced miR-126 expression in a dose-dependent manner. The relationship between miR-126 and its target, PI3K (p85β), was confirmed by treating cells with miR-126 antagomiR where mango polyphenols reversed the effects of the antagomiR. In vivo, mango beverage protected against DSS-induced colonic inflammation (47%, P = 0.05) and decreased the Ki-67 labeling index in the central and basal regions compared to the control. Mango beverage significantly attenuated the expression of pro-inflammatory cytokines such as TNF-α, IL-1β, and iNOS at the mRNA and protein level. Moreover, the expression of PI3K, AKT, and mTOR was reduced, whereas, miR-126 was upregulated by the mango treatment. These results suggest that mango polyphenols attenuated inflammatory response by modulating the PI3K/AKT/mTOR pathway at least in part through upregulation of miRNA-126 expression both in vitro and in vivo; thus, mango polyphenolics might be relevant as preventive agents in ulcerative colitis. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Hyemee Kim
- Department of Nutrition and Food Science, Texas A&M University, College Station, Texas
| | - Nivedita Banerjee
- Interdisciplinary Program of Toxicology, Texas A&M University, College Station, Texas
| | - Ryan C Barnes
- Department of Nutrition and Food Science, Texas A&M University, College Station, Texas
| | - Catherine M Pfent
- Department of Veterinary Pathobiology, Texas A&M University, College Station, Texas
| | - Stephen T Talcott
- Department of Nutrition and Food Science, Texas A&M University, College Station, Texas
| | - Roderick H Dashwood
- Department of Nutrition and Food Science, Texas A&M University, College Station, Texas
- Center for Epigenetics and Disease Prevention, Texas A&M Health Science Center, Houston, Texas
- Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas
- Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Susanne U Mertens-Talcott
- Department of Nutrition and Food Science, Texas A&M University, College Station, Texas
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, Texas
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Dehn S, DeBerge M, Yeap XY, Yvan-Charvet L, Fang D, Eltzschig HK, Miller SD, Thorp EB. HIF-2α in Resting Macrophages Tempers Mitochondrial Reactive Oxygen Species To Selectively Repress MARCO-Dependent Phagocytosis. THE JOURNAL OF IMMUNOLOGY 2016; 197:3639-3649. [PMID: 27671111 DOI: 10.4049/jimmunol.1600402] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 08/24/2016] [Indexed: 12/22/2022]
Abstract
Hypoxia-inducible factor (HIF)-α isoforms regulate key macrophage (MΦ) functions during ischemic inflammation. HIF-2α drives proinflammatory cytokine production; however, the requirements for HIF-2α during other key MΦ functions, including phagocytosis, are unknown. In contrast to HIF-1α, HIF-2α was not required for hypoxic phagocytic uptake. Surprisingly, basal HIF-2α levels under nonhypoxic conditions were necessary and sufficient to suppress phagocytosis. Screening approaches revealed selective induction of the scavenger receptor MARCO, which was required for enhanced engulfment. Chromatin immunoprecipitation identified the antioxidant NRF2 as being directly responsible for inducing Marco Concordantly, Hif-2α-/- MΦs exhibited reduced antioxidant gene expression, and inhibition of mitochondrial reactive oxygen species suppressed Marco expression and phagocytic uptake. Ex vivo findings were recapitulated in vivo; the enhanced engulfment phenotype resulted in increased bacterial clearance and cytokine suppression. Importantly, natural induction of Hif-2α by IL-4 also suppressed MARCO-dependent phagocytosis. Thus, unlike most characterized prophagocytic regulators, HIF-2α can act as a phagocytic repressor. Interestingly, this occurs in resting MΦs through tempering of steady-state mitochondrial reactive oxygen species. In turn, HIF-2α promotes MΦ quiescence by blocking a MARCO bacterial-response pathway. IL-4 also drives HIF-2α suppression of MARCO, leading to compromised bacterial immunosurveillance in vivo.
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Affiliation(s)
- Shirley Dehn
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611.,Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Matthew DeBerge
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611.,Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Xin-Yi Yeap
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611.,Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Laurent Yvan-Charvet
- INSERM U1065, Centre Mediterraneen de Medecine Moleculaire, Atip-Avenir, 06204 Nice, France
| | - Deyu Fang
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Holger K Eltzschig
- Department of Anesthesiology, University of Colorado, Aurora, CO 80045; and
| | - Stephen D Miller
- Department of Microbiology-Immunology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
| | - Edward B Thorp
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611; .,Feinberg Cardiovascular Research Institute, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611
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Klebsiella pneumoniae Siderophores Induce Inflammation, Bacterial Dissemination, and HIF-1α Stabilization during Pneumonia. mBio 2016; 7:mBio.01397-16. [PMID: 27624128 PMCID: PMC5021805 DOI: 10.1128/mbio.01397-16] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Klebsiella pneumoniae is a Gram-negative pathogen responsible for a wide range of infections, including pneumonia and bacteremia, and is rapidly acquiring antibiotic resistance. K. pneumoniae requires secretion of siderophores, low-molecular-weight, high-affinity iron chelators, for bacterial replication and full virulence. The specific combination of siderophores secreted by K. pneumoniae during infection can impact tissue localization, systemic dissemination, and host survival. However, the effect of these potent iron chelators on the host during infection is unknown. In vitro, siderophores deplete epithelial cell iron, induce cytokine secretion, and activate the master transcription factor hypoxia inducible factor-1α (HIF-1α) protein that controls vascular permeability and inflammatory gene expression. Therefore, we hypothesized that siderophore secretion by K. pneumoniae directly contributes to inflammation and bacterial dissemination during pneumonia. To examine the effects of siderophore secretion independently of bacterial growth, we performed infections with tonB mutants that persist in vivo but are deficient in siderophore import. Using a murine model of pneumonia, we found that siderophore secretion by K. pneumoniae induces the secretion of interleukin-6 (IL-6), CXCL1, and CXCL2, as well as bacterial dissemination to the spleen, compared to siderophore-negative mutants at an equivalent bacterial number. Furthermore, we determined that siderophore-secreting K. pneumoniae stabilized HIF-1α in vivo and that bacterial dissemination to the spleen required alveolar epithelial HIF-1α. Our results indicate that siderophores act directly on the host to induce inflammatory cytokines and bacterial dissemination and that HIF-1α is a susceptibility factor for bacterial invasion during pneumonia. Klebsiella pneumoniae causes a wide range of bacterial diseases, including pneumonia, urinary tract infections, and sepsis. To cause infection, K. pneumoniae steals iron from its host by secreting siderophores, small iron-chelating molecules. Classically, siderophores are thought to worsen infections by promoting bacterial growth. In this study, we determined that siderophore-secreting K. pneumoniae causes lung inflammation and bacterial dissemination to the bloodstream independently of bacterial growth. Furthermore, we determined that siderophore-secreting K. pneumoniae activates a host protein, hypoxia inducible factor (HIF)-1α, and requires it for siderophore-dependent bacterial dissemination. Although HIF-1α can protect against some infections, it appears to worsen infection with K. pneumoniae. Together, these results indicate that bacterial siderophores directly alter the host response to pneumonia in addition to providing iron for bacterial growth. Therapies that disrupt production of siderophores could provide a two-pronged attack against K. pneumoniae infection by preventing bacterial growth and preventing bacterial dissemination to the blood.
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69
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Ramakrishnan SK, Zhang H, Takahashi S, Centofanti B, Periyasamy S, Weisz K, Chen Z, Uhler MD, Rui L, Gonzalez FJ, Shah YM. HIF2α Is an Essential Molecular Brake for Postprandial Hepatic Glucagon Response Independent of Insulin Signaling. Cell Metab 2016; 23:505-16. [PMID: 26853750 PMCID: PMC4785079 DOI: 10.1016/j.cmet.2016.01.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 11/25/2015] [Accepted: 01/02/2016] [Indexed: 01/01/2023]
Abstract
Glucagon drives hepatic gluconeogenesis and maintains blood glucose levels during fasting. The mechanism that attenuates glucagon action following refeeding is not understood. The present study demonstrates an increase in perivenous liver hypoxia immediately after feeding, which stabilizes hypoxia-inducible factor 2α (HIF2α) in liver. The transient postprandial increase in hepatic HIF2α attenuates glucagon signaling. Hepatocyte-specific disruption of HIF2α increases postprandial blood glucose and potentiates the glucagon response. Independent of insulin/AKT signaling, activation of hepatic HIF2α resulted in lower blood glucose, improved glucose tolerance, and decreased gluconeogenesis due to blunted hepatic glucagon action. Mechanistically, HIF2α abrogated glucagon-PKA signaling by activating cAMP-phosphodiesterases in a MEK/ERK-dependent manner. Repression of glucagon signaling by HIF2α ameliorated hyperglycemia in streptozotocin-induced diabetes and acute insulin-resistant animal models. This study reveals that HIF2α is essential for the acute postprandial regulation of hepatic glucagon signaling and suggests HIF2α as a potential therapeutic target in the treatment of diabetes.
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Affiliation(s)
- Sadeesh K Ramakrishnan
- Departments of Molecular & Integrative Physiology, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Huabing Zhang
- Departments of Molecular & Integrative Physiology, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Shogo Takahashi
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Brook Centofanti
- Departments of Molecular & Integrative Physiology, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Sarvesh Periyasamy
- Departments of Molecular & Integrative Physiology, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Kevin Weisz
- Departments of Molecular & Integrative Physiology, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Zheng Chen
- Departments of Molecular & Integrative Physiology, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Michael D Uhler
- Department of Biological Chemistry, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Liangyou Rui
- Departments of Molecular & Integrative Physiology, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Frank J Gonzalez
- Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yatrik M Shah
- Departments of Molecular & Integrative Physiology, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Internal Medicine, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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70
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Balamurugan K. HIF-1 at the crossroads of hypoxia, inflammation, and cancer. Int J Cancer 2016; 138:1058-66. [PMID: 25784597 PMCID: PMC4573780 DOI: 10.1002/ijc.29519] [Citation(s) in RCA: 394] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 02/24/2015] [Accepted: 03/11/2015] [Indexed: 12/14/2022]
Abstract
The complex cross-talk of intricate intercellular signaling networks between the tumor and stromal cells promotes cancer progression. Hypoxia is one of the most common conditions encountered within the tumor microenvironment that drives tumorigenesis. Most responses to hypoxia are elicited by a family of transcription factors called hypoxia-inducible factors (HIFs), which induce expression of a diverse set of genes that assist cells to adapt to hypoxic environments. Among the three HIF protein family members, the role of HIF-1 is well established in cancer progression. HIF-1 functions as a signaling hub to coordinate the activities of many transcription factors and signaling molecules that impact tumorigenesis. This mini review discusses the complex role of HIF-1 and its context-dependent partners under various cancer-promoting events including inflammation and generation of cancer stem cells, which are implicated in tumor metastasis and relapse. In addition, the review highlights the importance of therapeutic targeting of HIF-1 for cancer prevention.
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Affiliation(s)
- Kuppusamy Balamurugan
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, Frederick, MD
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71
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Abstract
In this review, I summarize some of the recent insight into pharmacological targeting of hypoxia in disease models. Studies from cultured cell systems, animal models, and translation to human patients have revealed that posttranslational modifications of individual proteins within NF-κB and hypoxia-inducible factor pathways serve as ideal targets for analysis in disease models. Studies defining differences and similarities between these responses have taught us a number of important lessons about the complexity of the inflammatory response. A clearer definition of these pathways has provided new insight into disease pathogenesis and, importantly, the potential for new therapeutic targets.
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72
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Abstract
Uncontrolled or non-resolving inflammation underpins a range of disease states including rheumatoid arthritis, inflammatory bowel disease and atherosclerosis. Hypoxia is a prominent feature of chronically inflamed tissues. This is due to elevated oxygen consumption by highly metabolically active inflamed resident cells and activated infiltrating immunocytes, as well as diminished oxygen supply due to vascular dysfunction. Tissue hypoxia can have a significant impact upon inflammatory signaling pathways in immune and non-immune cells and this can impact upon disease progression. In this review, we will discuss the relationship between tissue hypoxia and inflammation and identify how hypoxia-sensitive signaling pathways are potential therapeutic targets in chronic inflammatory disease.
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Affiliation(s)
- Eoin P Cummins
- School of Medicine and Medical Science & The Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Ciara E Keogh
- School of Medicine and Medical Science & The Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Daniel Crean
- School of Medicine and Medical Science & The Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Cormac T Taylor
- School of Medicine and Medical Science & The Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland.
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Chen Y, Zhang HS, Fong GH, Xi QL, Wu GH, Bai CG, Ling ZQ, Fan L, Xu YM, Qin YQ, Yuan TL, Sun H, Fang J. PHD3 Stabilizes the Tight Junction Protein Occludin and Protects Intestinal Epithelial Barrier Function. J Biol Chem 2015; 290:20580-9. [PMID: 26124271 PMCID: PMC4536461 DOI: 10.1074/jbc.m115.653584] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 06/25/2015] [Indexed: 12/13/2022] Open
Abstract
Prolyl hydroxylase domain proteins (PHDs) control cellular adaptation to hypoxia. PHDs are found involved in inflammatory bowel disease (IBD); however, the exact role of PHD3, a member of the PHD family, in IBD remains unknown. We show here that PHD3 plays a critical role in maintaining intestinal epithelial barrier function. We found that genetic ablation of Phd3 in intestinal epithelial cells led to spontaneous colitis in mice. Deletion of PHD3 decreases the level of tight junction protein occludin, leading to a failure of intestinal epithelial barrier function. Further studies indicate that PHD3 stabilizes occludin by preventing the interaction between the E3 ligase Itch and occludin, in a hydroxylase-independent manner. Examination of biopsy of human ulcerative colitis patients indicates that PHD3 is decreased with disease severity, indicating that PHD3 down-regulation is associated with progression of this disease. We show that PHD3 protects intestinal epithelial barrier function and reveal a hydroxylase-independent function of PHD3 in stabilizing occludin. These findings may help open avenues for developing a therapeutic strategy for IBD.
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Affiliation(s)
- Ying Chen
- From the Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Hai-Sheng Zhang
- From the Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Guo-Hua Fong
- the Center for Vascular Biology, University of Connecticut Health Center, Farmington, Connecticut 06030
| | - Qiu-Lei Xi
- the Department of Surgery, Zhongshan Hospital, Fudan University School of Medicine, Shanghai 200030, China
| | - Guo-Hao Wu
- the Department of Surgery, Zhongshan Hospital, Fudan University School of Medicine, Shanghai 200030, China
| | - Chen-Guang Bai
- the Department of Pathology, Changhai Hospital, the Second Military Medical University, Shanghai 200433, China
| | - Zhi-Qiang Ling
- the Department of Pathology, Zhejiang Cancer Research Institute, Zhejiang Cancer Hospital and Zhejiang Cancer Center, Hangzhou 310022, China, and
| | - Li Fan
- From the Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yi-Ming Xu
- From the Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yan-Qing Qin
- From the Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Tang-Long Yuan
- From the Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Heng Sun
- From the Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jing Fang
- From the Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China, the Key Laboratory of Food Safety Risk Assessment, Ministry of Health, Beijing 100021 China
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74
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Abstract
Hypoxia is a hallmark of chronically inflamed tissue. Hypoxia develops from vascular dysfunction and increased oxygen consumption by infiltrating leukocytes. With respect to inflammatory bowel disease (IBD), hypoxia is likely to be of particular importance: Impairment of the intestinal barrier during IBD allows anoxia from the lumen of the gut to spread to formerly normoxic tissue. In addition, disturbed perfusion of inflamed tissue and a higher oxygen demand of infiltrating immune cells lead to low oxygen levels in inflamed mucosal tissue. Here, cells become hypoxic and must now adapt to this condition. The hypoxia inducible factor (HIF)-1 complex is a key transcription factor for cellular adaption to low oxygen tension. HIF-1 is a heterodimer formed by two subunits: HIF-α (either HIF-1α or HIF-2α) and HIF-1β. Under normoxic conditions, hydroxylation of the HIF-α subunit by specific oxygen-dependent prolyl hydroxylases (PHDs) leads to ubiquitin proteasome-dependent degradation. Under hypoxic conditions, however, PHD activity is inhibited; thus, HIF-α can translocate into the nucleus, dimerize with HIF-1β, and bind to hypoxia-responsive elements of HIF-1 target genes. So far, most studies have addressed the function of HIF-1α in intestinal epithelial cells and the effect of HIF stabilization by PHD inhibitors in murine models of colitis. Furthermore, the role of HIF-1α in immune cells becomes more and more important as T cells or dendritic cells for which HIF-1 is of critical importance are highly involved in the pathogenesis of IBD. This review will summarize the function of HIF-1α and the therapeutic prospects for targeting the HIF pathway in intestinal mucosal inflammation.
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Affiliation(s)
- Katharina Flück
- Institut für Physiologie, Universität Duisburg-Essen, Essen, Germany
| | - Joachim Fandrey
- Institut für Physiologie, Universität Duisburg-Essen, Essen, Germany.
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Mladenova DN, Dahlstrom JE, Tran PN, Benthani F, Bean EG, Ng I, Pangon L, Currey N, Kohonen-Corish MRJ. HIF1α deficiency reduces inflammation in a mouse model of proximal colon cancer. Dis Model Mech 2015; 8:1093-103. [PMID: 26183215 PMCID: PMC4582097 DOI: 10.1242/dmm.019000] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 07/07/2015] [Indexed: 01/21/2023] Open
Abstract
Hypoxia-inducible factor 1α (HIF1α) is a transcription factor that regulates the adaptation of cells to hypoxic microenvironments, for example inside solid tumours. Stabilisation of HIF1α can also occur in normoxic conditions in inflamed tissue or as a result of inactivating mutations in negative regulators of HIF1α. Aberrant overexpression of HIF1α in many different cancers has led to intensive efforts to develop HIF1α-targeted therapies. However, the role of HIF1α is still poorly understood in chronic inflammation that predisposes the colon to carcinogenesis. We have previously reported that the transcription of HIF1α is upregulated and that the protein is stabilised in inflammatory lesions that are caused by the non-steroidal anti-inflammatory drug (NSAID) sulindac in the mouse proximal colon. Here, we exploited this side effect of long-term sulindac administration to analyse the role of HIF1α in colon inflammation using mice with a Villin-Cre-induced deletion of Hif1α exon 2 in the intestinal epithelium (Hif1αΔIEC). We also analysed the effect of sulindac sulfide on the aryl hydrocarbon receptor (AHR) pathway in vitro in colon cancer cells. Most sulindac-treated mice developed visible lesions, resembling the appearance of flat adenomas in the human colon, surrounded by macroscopically normal mucosa. Hif1αΔIEC mice still developed lesions but they were smaller than in the Hif1α-floxed siblings (Hif1αF/F). Microscopically, Hif1αΔIEC mice had significantly less severe colon inflammation than Hif1αF/F mice. Molecular analysis showed reduced MIF expression and increased E-cadherin mRNA expression in the colon of sulindac-treated Hif1αΔIEC mice. However, immunohistochemistry analysis revealed a defect of E-cadherin protein expression in sulindac-treated Hif1αΔIEC mice. Sulindac sulfide treatment in vitro upregulated Hif1α, c-JUN and IL8 expression through the AHR pathway. Taken together, HIF1α expression augments inflammation in the proximal colon of sulindac-treated mice, and AHR activation by sulindac might lead to the reduction of E-cadherin protein levels through the mitogen-activated protein kinase (MAPK) pathway. Summary: HIF1α deficiency reduces inflammation in the mouse proximal colon but is associated with defective E-cadherin expression in colon epithelial cells when mice lacking intestinal epithelium expression of Hif1α are challenged with sulindac.
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Affiliation(s)
- Dessislava N Mladenova
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Jane E Dahlstrom
- ACT Pathology, The Canberra Hospital and Australian National University Medical School, Canberra, Australian Capital Territory, 2605, Australia
| | - Phuong N Tran
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Fahad Benthani
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Elaine G Bean
- ACT Pathology, The Canberra Hospital and Australian National University Medical School, Canberra, Australian Capital Territory, 2605, Australia
| | - Irvin Ng
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Laurent Pangon
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Nicola Currey
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia
| | - Maija R J Kohonen-Corish
- Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, New South Wales, 2010, Australia St Vincent's Clinical School, UNSW Medicine, UNSW Australia, Sydney, New South Wales, 2052, Australia School of Medicine, University of Western Sydney, Sydney, New South Wales, 2560, Australia
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76
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Caria CREP, Moscato CH, Tomé RBG, Pedrazzoli J, Ribeiro ML, Gambero A. Nitric oxide interferes with hypoxia signaling during colonic inflammation. ARQUIVOS DE GASTROENTEROLOGIA 2015; 51:302-8. [PMID: 25591158 DOI: 10.1590/s0004-28032014000400007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Accepted: 07/08/2014] [Indexed: 01/24/2023]
Abstract
CONTEXT Intestinal inflammation can induce a local reduction in oxygen levels that triggers an adaptive response centered on the expression of hypoxia-inducible factors (HIFs). Nitric oxide, a well-described inflammatory mediator, may interfere with hypoxia signaling. OBJECTIVES We aimed to evaluate the role of nitric oxide in hypoxia signaling during colonic inflammation. METHODS Colitis was induced by single (acute) or repeated (reactivated colitis) trinitrobenzenosulfonic acid administration in rats. In addition, one group of rats with reactivated colitis was also treated with Nw-Nitro-L-arginine methyl ester hydrochloride to block nitric oxide synthase. Colitis was assessed by macroscopic score and myeloperoxidase activity in the colon samples. Hypoxia was determined using the oxygen-dependent probe, pimonidazole. The expression of HIF-1α and HIF-induced factors (vascular endothelial growth factor - VEGF and apelin) was assessed using Western blotting. RESULTS The single or repeated administration of trinitrobenzenosulfonic acid to rats induced colitis which was characterized by a high macroscopic score and myeloperoxidase activity. Hypoxia was observed with both protocols. During acute colitis, HIF-1α expression was not increased, but VEGF and apelin were increased. HIF-1α expression was inhibited during reactivated colitis, and VEGF and apelin were not increased. Nw-Nitro-L-arginine methyl ester hydrochloride blockade during reactivated colitis restored HIF-1α, VEGF and apelin expression. CONCLUSIONS Nitric oxide could interfere with hypoxia signaling during reactivated colitis inflammation modifying the expression of proteins regulated by HIF-1α.
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Affiliation(s)
- Cintia Rabelo e Paiva Caria
- Unidade Integrada de Farmacologia e Gastroenterologia (Unifag), Faculdade de Medicina da Universidade São Francisco, São Paulo, SP, Brasil
| | - Camila Henrique Moscato
- Unidade Integrada de Farmacologia e Gastroenterologia (Unifag), Faculdade de Medicina da Universidade São Francisco, São Paulo, SP, Brasil
| | - Renata Bortolin Guerra Tomé
- Unidade Integrada de Farmacologia e Gastroenterologia (Unifag), Faculdade de Medicina da Universidade São Francisco, São Paulo, SP, Brasil
| | - José Pedrazzoli
- Unidade Integrada de Farmacologia e Gastroenterologia (Unifag), Faculdade de Medicina da Universidade São Francisco, São Paulo, SP, Brasil
| | - Marcelo Lima Ribeiro
- Unidade Integrada de Farmacologia e Gastroenterologia (Unifag), Faculdade de Medicina da Universidade São Francisco, São Paulo, SP, Brasil
| | - Alessandra Gambero
- Unidade Integrada de Farmacologia e Gastroenterologia (Unifag), Faculdade de Medicina da Universidade São Francisco, São Paulo, SP, Brasil
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77
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Sun L, Xu C, Chen G, Yu M, Yang S, Qiu Y, Peng K, Wang W, Xiao W, Yang H. A Novel Role of OS-9 in the Maintenance of Intestinal Barrier Function from Hypoxia-induced Injury via p38-dependent Pathway. Int J Biol Sci 2015; 11:664-71. [PMID: 25999789 PMCID: PMC4440256 DOI: 10.7150/ijbs.10783] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 02/18/2015] [Indexed: 12/11/2022] Open
Abstract
OS-9 is a lectin required for efficient ubquitination of glycosylated substrates of endoplasmic reticulum-associated degradation (ERAD). OS-9 has previously been implicated in ER-to-Golgi transport and transcription factor turnover. However, we know very little about other functions of OS-9 under endoplasmic reticulum stress. Here, we used gene knockdown and overexpression approaches to study the protective effect of OS-9 on intestinal barrier function of intestinal epithelial cell Caco-2 monolayer. We found that OS-9 attenuated intestinal epithelial barrier dysfunction under hypoxia through up-regulating occludin and claudin-1 protein expression. Furthermore, we showed that the up-regulation of occludin and claudin-1 induced by OS-9 was mediated by p38 and ERK1/2 phosphorylation and did not involve HIF-1α. In summary, our results demonstrate that OS-9 up-regulates occludin and claudin-1 by activating the MAP kinase (MAPK) pathway, and thus protects the epithelial barrier function of Caco-2 monolayer under hypoxia condition.
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Affiliation(s)
- Lihua Sun
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Chao Xu
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Guoqing Chen
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Min Yu
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Songwei Yang
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Yuan Qiu
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Ke Peng
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Wensheng Wang
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Weidong Xiao
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
| | - Hua Yang
- Department of General Surgery, Xinqiao Hospital, Third Military Medical University, Chongqing, China
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78
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Parra RS, Lopes AH, Carreira EU, Feitosa MR, Cunha FQ, Garcia SB, Cunha TM, da Rocha JJR, Féres O. Hyperbaric oxygen therapy ameliorates TNBS-induced acute distal colitis in rats. Med Gas Res 2015; 5:6. [PMID: 25926972 PMCID: PMC4414439 DOI: 10.1186/s13618-015-0026-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 04/06/2015] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND This study investigated the therapeutic effects of hyperbaric oxygen in experimental acute distal colitis focusing on its effect on the production of pro-inflammatory cytokines, nitric oxide and hypoxia-inducible factor 1alpha. METHODS Colitis was induced with a rectal infusion of 150 mg/kg of TNBS under anesthesia with Ketamine (50 mg/kg) and Xylazine (10 mg/kg). Control animals received only rectal saline. After colitis induction, animals were subjected to two sessions of hyperbaric oxygen and were then euthanized. The distal intestine was resected for macroscopic analysis, determination of myeloperoxidase activity, western-blotting analyses of inducible nitric oxide synthase and cyclooxygenase-2 expression and immunohistochemical analysis of hypoxia-inducible factor 1alpha and cyclooxygenase-2. Cytokines levels in the distal intestine were measured using an enzyme-linked immunosorbent assay. RESULTS Hyperbaric oxygen therapy attenuated the severity of acute distal colitis, with reduced macroscopic damage score. This effect was associated with prevention in the increase of pro-inflammatory cytokine production; myeloperoxidase activity, in the expression of inducible nitric oxide synthase and cyclooxygenase-2. Finally, hyperbaric oxygen inhibited the acute distal colitis-induced up-regulation of hypoxia-inducible factor 1alpha. CONCLUSIONS The results indicate that hyperbaric oxygen attenuates the severity of acute distal colitis through the down-regulation of pro-inflammatory events.
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Affiliation(s)
- Rogério S Parra
- />Division of Coloproctology, Department of Surgery and Anatomy. Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Alexandre H Lopes
- />Department of Pharmacology, Ribeirão Preto Medical School, University of Sao Paulo, Ribeirão Preto, SP Brazil
| | - Eleonora U Carreira
- />Department of Pharmacology, Ribeirão Preto Medical School, University of Sao Paulo, Ribeirão Preto, SP Brazil
| | - Marley R Feitosa
- />Division of Coloproctology, Department of Surgery and Anatomy. Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Fernando Q Cunha
- />Department of Pharmacology, Ribeirão Preto Medical School, University of Sao Paulo, Ribeirão Preto, SP Brazil
| | - Sérgio B Garcia
- />Department of Pathology, Ribeirão Preto Medical School, University of Sao Paulo, Ribeirão Preto, SP Brazil
| | - Thiago M Cunha
- />Department of Pharmacology, Ribeirão Preto Medical School, University of Sao Paulo, Ribeirão Preto, SP Brazil
| | - José J R da Rocha
- />Division of Coloproctology, Department of Surgery and Anatomy. Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Omar Féres
- />Division of Coloproctology, Department of Surgery and Anatomy. Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, SP Brazil
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79
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Padmanabhan H, Brookes MJ, Iqbal T. Iron and colorectal cancer: evidence from in vitro and animal studies. Nutr Rev 2015; 73:308-17. [DOI: 10.1093/nutrit/nuu015] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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80
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Colgan SP, Curtis VF, Lanis JM, Glover LE. Metabolic regulation of intestinal epithelial barrier during inflammation. Tissue Barriers 2015; 3:e970936. [PMID: 25838978 DOI: 10.4161/21688362.2014.970936] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 09/25/2014] [Indexed: 12/21/2022] Open
Abstract
The gastrointestinal mucosa has proven to be an interesting tissue for which to investigate disease-related metabolism. In this review, we outline some evidence that implicates metabolic signaling as important features of barrier in the healthy and disease. Studies from cultured cell systems, animal models and human patients have revealed that metabolites generated within the inflammatory microenvironment are central to barrier regulation. These studies have revealed a prominent role for hypoxia and hypoxia-inducible factor (HIF) at key steps in adenine nucleotide metabolism and within the creatine kinase pathway. Results from animal models of intestinal inflammation have demonstrated an almost uniformly beneficial influence of HIF stabilization on disease outcomes and barrier function. Studies underway to elucidate the contribution of immune responses will provide additional insight into how metabolic changes contribute to the complexity of the gastrointestinal tract and how such information might be harnessed for therapeutic benefit.
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Key Words
- AMP, adenosine monophosphate
- CK, creatine kinase
- ChIP, chromatin immunoprecipitation
- Colitis
- HIF, hypoxia-inducible factor
- PHD, prolyl hydroxylase
- PMN, polymorphonuclear leukcoyte, neutrophil
- TJ, tight junction
- VASP, vasodilator-stimulated
- ZO-1, zonula occludens-1
- creatine
- epithelium
- inflammation
- metabolism
- mucosa
- murine model
- neutrophil
- nucleoside
- nucleotidase
- nucleotide
- phosphocreatine
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Affiliation(s)
- Sean P Colgan
- Departments of Medicine and the Mucosal Inflammation Program; University of Colorado School of Medicine ; Aurora, CO USA
| | - Valerie F Curtis
- Departments of Medicine and the Mucosal Inflammation Program; University of Colorado School of Medicine ; Aurora, CO USA
| | - Jordi M Lanis
- Departments of Medicine and the Mucosal Inflammation Program; University of Colorado School of Medicine ; Aurora, CO USA
| | - Louise E Glover
- Departments of Medicine and the Mucosal Inflammation Program; University of Colorado School of Medicine ; Aurora, CO USA
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81
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Neutrophils and inflammatory resolution in the mucosa. Semin Immunol 2015; 27:177-83. [PMID: 25818531 DOI: 10.1016/j.smim.2015.03.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 03/10/2015] [Accepted: 03/11/2015] [Indexed: 12/13/2022]
Abstract
Inflammatory diseases in mucosal organs as diverse as the lung, liver and intestine inevitably require the intimate interactions between neutrophils and epithelia. The physiologic consequences of such interactions often determine endpoint organ function, and for this reason, much recent interest has developed in identifying mechanisms and novel targets to promote the resolution of mucosal inflammation. Physiologically-relevant in vitro and in vivo model systems have aided in discovery of novel pathways to define basic inflammatory mechanisms and approaches to defining the concepts of inflammatory resolution. Here, we will review the recent literature regarding the contribution of neutrophils to inflammatory resolution, with an emphasis on the role of the tissue microenvironment, endogenous pathways for promoting resolution and the molecular determinants of neutrophil-epithelial cell interactions during ongoing inflammation. These recent studies highlight the dynamic nature of pro-resolving pathways and lend insight into the complexity of treating mucosal inflammation.
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82
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Campbell EL, Colgan SP. Neutrophils and inflammatory metabolism in antimicrobial functions of the mucosa. J Leukoc Biol 2015; 98:517-22. [PMID: 25714801 DOI: 10.1189/jlb.3mr1114-556r] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 01/22/2015] [Indexed: 01/29/2023] Open
Abstract
In this mini-review, we will discuss recent findings that implicate neutrophil infiltration and function in establishing a metabolic environment to facilitate efficient pathogen clearance. For decades, neutrophils have been regarded as short lived, nonspecific granulocytes, equipped with toxic antimicrobial factors and a respiratory burst generating ROS. Recent findings demonstrate the importance of HIF signaling in leukocytes and surrounding tissues during inflammation. Here, we will review the potential mechanisms and outcomes of HIF stabilization within the intestinal mucosa.
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Affiliation(s)
- Eric L Campbell
- Mucosal Inflammation Program, Division of Gastroenterology and Hepatology and Departments of Medicine and Immunology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Sean P Colgan
- Mucosal Inflammation Program, Division of Gastroenterology and Hepatology and Departments of Medicine and Immunology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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83
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Biddlestone J, Bandarra D, Rocha S. The role of hypoxia in inflammatory disease (review). Int J Mol Med 2015; 35:859-69. [PMID: 25625467 PMCID: PMC4356629 DOI: 10.3892/ijmm.2015.2079] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 01/27/2015] [Indexed: 02/06/2023] Open
Abstract
Mammals have developed evolutionarily conserved programs of transcriptional response to hypoxia and inflammation. These stimuli commonly occur together in vivo and there is significant crosstalk between the transcription factors that are classically understood to respond to either hypoxia or inflammation. This crosstalk can be used to modulate the overall response to environmental stress. Several common disease processes are characterised by aberrant transcriptional programs in response to environmental stress. In this review, we discuss the current understanding of the role of the hypoxia-responsive (hypoxia-inducible factor) and inflammatory (nuclear factor-κB) transcription factor families and their crosstalk in rheumatoid arthritis, inflammatory bowel disease and colorectal cancer, with relevance for future therapies for the management of these conditions.
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Affiliation(s)
- John Biddlestone
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Daniel Bandarra
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Sonia Rocha
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
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84
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Eltzschig HK, Bratton DL, Colgan SP. Targeting hypoxia signalling for the treatment of ischaemic and inflammatory diseases. Nat Rev Drug Discov 2014; 13:852-69. [PMID: 25359381 PMCID: PMC4259899 DOI: 10.1038/nrd4422] [Citation(s) in RCA: 276] [Impact Index Per Article: 27.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Hypoxia-inducible factors (HIFs) are stabilized during adverse inflammatory processes associated with disorders such as inflammatory bowel disease, pathogen infection and acute lung injury, as well as during ischaemia-reperfusion injury. HIF stabilization and hypoxia-induced changes in gene expression have a profound impact on the inflamed tissue microenvironment and on disease outcomes. Although the mechanism that initiates HIF stabilization may vary, the final molecular steps that control HIF stabilization converge on a set of oxygen-sensing prolyl hydroxylases (PHDs) that mark HIFs for proteasomal degradation. PHDs are therefore promising therapeutic targets. In this Review, we discuss the emerging potential and associated challenges of targeting the PHD-HIF pathway for the treatment of inflammatory and ischaemic diseases.
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Affiliation(s)
- Holger K Eltzschig
- Organ Protection Program, Department of Anesthesiology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | - Donna L Bratton
- Department of Pediatrics, National Jewish Health, Denver, Colorado 80206, USA
| | - Sean P Colgan
- Mucosal Inflammation Program, Department of Medicine, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
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85
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Bakirtzi K, West G, Fiocchi C, Law IKM, Iliopoulos D, Pothoulakis C. The neurotensin-HIF-1α-VEGFα axis orchestrates hypoxia, colonic inflammation, and intestinal angiogenesis. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:3405-14. [PMID: 25307345 DOI: 10.1016/j.ajpath.2014.08.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 07/25/2014] [Accepted: 08/05/2014] [Indexed: 01/14/2023]
Abstract
The expression of neurotensin (NT) and its receptor (NTR1) is up-regulated in experimental colitis and inflammatory bowel disease; NT/NTR1 interactions regulate gut inflammation. During active inflammation, metabolic shifts toward hypoxia lead to the activation of hypoxia-inducible factor (HIF)-1, which enhances vascular endothelial growth factor (VEGF) expression, promoting angiogenesis. We hypothesized that NT/NTR1 signaling regulates intestinal manifestations of hypoxia and angiogenesis by promoting HIF-1 transcriptional activity and VEGFα expression in experimental colitis. We studied NTR1 signaling in colitis-associated angiogenesis using 2,4,6-trinitrobenzenesulfonic acid-treated wild-type and NTR1-knockout mice. The effects of NT on HIF-1α and VEGFα were assessed on human colonic epithelial cells overexpressing NTR1 (NCM460-NTR1) and human intestinal microvascular-endothelial cells. NTR1-knockout mice had reduced microvascular density and mucosal integrity score compared with wild-type mice after 2,4,6-trinitrobenzenesulfonic acid treatment. VEGFα mRNA levels were increased in NCM460-NTR1 cells treated with 10(-7) mol/L NT, at 1 and 6 hours post-treatment. NT exposure in NCM460-NTR1 cells caused stabilization, nuclear translocation, and transcriptional activity of HIF-1α in a diacylglycerol kinase-dependent manner. NT did not stimulate tube formation in isolated human intestinal macrovascular endothelial cells but did so in human intestinal macrovascular endothelial cells cocultured with NCM460-NTR1 cells. Our results demonstrate the importance of an NTR1-HIF-1α-VEGFα axis in intestinal angiogenic responses and in the pathophysiology of colitis and inflammatory bowel disease.
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Affiliation(s)
- Kyriaki Bakirtzi
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
| | - Gail West
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio; Department of Gastroenterology and Hepatology, Digestive Disease Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Claudio Fiocchi
- Department of Pathobiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio; Department of Gastroenterology and Hepatology, Digestive Disease Institute, Cleveland Clinic Foundation, Cleveland, Ohio
| | - Ivy Ka Man Law
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California
| | - Dimitrios Iliopoulos
- Department of Cancer Immunology & AIDS, Dana-Farber Cancer Institute, Boston, Massachusetts
| | - Charalabos Pothoulakis
- Inflammatory Bowel Disease Center, Division of Digestive Diseases, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California.
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Xue X, Ramakrishnan SK, Shah YM. Activation of HIF-1α does not increase intestinal tumorigenesis. Am J Physiol Gastrointest Liver Physiol 2014; 307:G187-95. [PMID: 24875099 PMCID: PMC4101679 DOI: 10.1152/ajpgi.00112.2014] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The hypoxic response is mediated by two transcription factors, hypoxia-inducible factor (HIF)-1α and HIF-2α. These highly homologous transcription factors are induced in hypoxic foci and regulate cell metabolism, angiogenesis, cell proliferation, and cell survival. HIF-1α and HIF-2α are activated early in cancer progression and are important in several aspects of tumor biology. HIF-1α and HIF-2α have overlapping and distinct functions. In the intestine, activation of HIF-2α increases inflammation and colon carcinogenesis in mouse models. Interestingly, in ischemic and inflammatory diseases of the intestine, activation of HIF-1α is beneficial and can reduce intestinal inflammation. HIF-1α is a critical transcription factor regulating epithelial barrier function following inflammation. The beneficial value of pharmacological agents that chronically activate HIF-1α is decreased due to the tumorigenic potential of HIFs. The present study tested the hypothesis that chronic activation of HIF-1α may enhance colon tumorigenesis. Two models of colon cancer were assessed, a sporadic and a colitis-associated colon cancer model. Activation of HIF-1α in intestinal epithelial cells does not increase carcinogenesis or progression of colon cancer. Together, the data provide proof of principle that pharmacological activation of HIF-1α could be a safe therapeutic strategy for inflammatory bowel disease.
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Affiliation(s)
- Xiang Xue
- Departments of 1Molecular and Integrative Physiology and
| | | | - Yatrik M. Shah
- Departments of 1Molecular and Integrative Physiology and ,2Internal Medicine, Division of Gastroenterology, University of Michigan Medical School, Ann Arbor, Michigan
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87
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Vujicic M, Nikolic I, Krajnovic T, Cheng KF, VanPatten S, He M, Stosic-Grujicic S, Stojanovic I, Al-Abed Y, Saksida T. Novel inhibitors of macrophage migration inhibitory factor prevent cytokine-induced beta cell death. Eur J Pharmacol 2014; 740:683-9. [PMID: 24967533 DOI: 10.1016/j.ejphar.2014.06.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 06/06/2014] [Accepted: 06/16/2014] [Indexed: 12/16/2022]
Abstract
Macrophage migration inhibitory factor is a multifunctional cytokine involved in the regulation of immune processes and also in apoptosis induction. Elevated MIF expression is detrimental for insulin-producing beta cells and MIF inhibition protected beta cells from several cytotoxic insults such as inflammatory cytokines, high fatty acids or high glucose concentrations. Therefore, the aim of this study was to investigate two newly synthesized small molecule MIF inhibitors (K664-1 and K647-1) and to compare them with previously established effects of the prototypical MIF inhibitor, ISO-1. Our results indicate that K664-1 and K647-1 are 160- and 40-fold more effective in inhibition of MIF׳s tautomerase activity than ISO-1. Also, new inhibitors confer beta cell protection from cytokine-triggered apoptosis at significantly lower concentrations than ISO-1. Although all three MIF inhibitors inhibit caspase 3 activity, K664-1 and K647-1 suppress pro-apoptotic BAX protein expression and up-regulate anti-apoptotic Bcl-2 mRNA. Finally, all three MIF inhibitors operate through blockade of nitric oxide production stimulated by cytokines. In conclusion, two novel MIF inhibitors are more potent than ISO-1 and operate through inhibition of the mitochondria-related apoptotic pathway. We propose that these compounds represent a unique class of anti-MIF antagonists that should be further tested for therapeutic use.
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Affiliation(s)
- Milica Vujicic
- Department of Immunology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Belgrade, Serbia
| | - Ivana Nikolic
- Department of Immunology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Belgrade, Serbia
| | - Tamara Krajnovic
- Department of Immunology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Belgrade, Serbia
| | - Kai-Fan Cheng
- The Feinstein Institute for Medical Research, Manhasset, New York, USA
| | - Sonya VanPatten
- The Feinstein Institute for Medical Research, Manhasset, New York, USA
| | - Mingzhu He
- The Feinstein Institute for Medical Research, Manhasset, New York, USA
| | - Stanislava Stosic-Grujicic
- Department of Immunology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Belgrade, Serbia
| | - Ivana Stojanovic
- Department of Immunology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Belgrade, Serbia
| | - Yousef Al-Abed
- The Feinstein Institute for Medical Research, Manhasset, New York, USA.
| | - Tamara Saksida
- Department of Immunology, Institute for Biological Research "Sinisa Stankovic", University of Belgrade, Belgrade, Serbia.
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88
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De Lerma Barbaro A, Perletti G, Bonapace IM, Monti E. Inflammatory cues acting on the adult intestinal stem cells and the early onset of cancer (review). Int J Oncol 2014; 45:959-68. [PMID: 24920319 PMCID: PMC4121412 DOI: 10.3892/ijo.2014.2490] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Accepted: 04/16/2014] [Indexed: 12/29/2022] Open
Abstract
The observation that cancer often arises at sites of chronic inflammation has prompted the idea that carcinogenesis and inflammation are deeply interwoven. In fact, the current literature highlights a role for chronic inflammation in virtually all the steps of carcinogenesis, including tumor initiation, promotion and progression. The aim of the present article is to review the current literature on the involvement of chronic inflammation in the initiation step and in the very early phases of tumorigenesis, in a type of cancer where adult stem cells are assumed to be the cells of origin of neoplasia. Since the gastrointestinal tract is regarded as the best-established model system to address the liaison between chronic inflammation and neoplasia, the focus of this article will be on intestinal cancer. In fact, the anatomy of the intestinal epithelial lining is uniquely suited to study adult stem cells in their niche, and the bowel crypt is an ideal developmental biology system, as proliferation, differentiation and cell migration are all distributed linearly along the long axis of the crypt. Moreover, crypt stem cells are regarded today as the most likely targets of neoplastic transformation in bowel cancer. More specifically, the present review addresses the molecular mechanisms whereby a state of chronic inflammation could trigger the neoplastic process in the intestine, focusing on the generation of inflammatory cues evoking enhanced proliferation in cells not initiated but at risk of neoplastic transformation because of their stemness. Novel experimental approaches, based on triggering an inflammatory stimulus in the neighbourhood of adult intestinal stem cells, are warranted to address some as yet unanswered questions. A possible approach, the targeted transgenesis of Paneth cells, may be aimed at 'hijacking' the crypt stem cell niche from a status characterized by the maintenance of homeostasis to local chronic inflammation, with the prospect of initiating neoplastic transformation in that site.
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Affiliation(s)
- A De Lerma Barbaro
- Biomedical Research Division, Department of Theoretical and Applied Sciences, University of Insubria, Busto Arsizio, Varese, Italy
| | - G Perletti
- Biomedical Research Division, Department of Theoretical and Applied Sciences, University of Insubria, Busto Arsizio, Varese, Italy
| | - I M Bonapace
- Biomedical Research Division, Department of Theoretical and Applied Sciences, University of Insubria, Busto Arsizio, Varese, Italy
| | - E Monti
- Biomedical Research Division, Department of Theoretical and Applied Sciences, University of Insubria, Busto Arsizio, Varese, Italy
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89
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Hypoxia-inducible factor/MAZ-dependent induction of caveolin-1 regulates colon permeability through suppression of occludin, leading to hypoxia-induced inflammation. Mol Cell Biol 2014; 34:3013-23. [PMID: 24891620 DOI: 10.1128/mcb.00324-14] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Caveolae are specialized microdomains on membranes that are critical for signal transduction, cholesterol transport, and endocytosis. Caveolin-1 (CAV1) is a multifunctional protein and a major component of caveolae. Cav1 is directly activated by hypoxia-inducible factor (HIF). HIFs are heterodimers of an oxygen-sensitive α subunit, HIF1α or HIF2α, and a constitutively expressed β subunit, aryl hydrocarbon receptor nuclear translocator (ARNT). Whole-genome expression analysis demonstrated that Cav1 is highly induced in mouse models of constitutively activated HIF signaling in the intestine. Interestingly, Cav1 was increased only in the colon and not in the small intestine. Currently, the mechanism and role of HIF induction of CAV1 in the colon are unclear. In mouse models, mice that overexpressed HIF1α or HIF2α specifically in intestinal epithelial cells demonstrated an increase in Cav1 gene expression in the colon but not in the duodenum, jejunum, or ileum. HIF2α activated the Cav1 promoter in a HIF response element-independent manner. myc-associated zinc finger (MAZ) protein was essential for HIF2α activation of the Cav1 promoter. Hypoxic induction of CAV1 in the colon was essential for intestinal barrier integrity by regulating occludin expression. This may provide an additional mechanism by which chronic hypoxia can activate intestinal inflammation.
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90
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Vavricka SR, Rogler G, Maetzler S, Misselwitz B, Safroneeva E, Frei P, Manser CN, Biedermann L, Fried M, Higgins P, Wojtal KA, Schoepfer AM. High altitude journeys and flights are associated with an increased risk of flares in inflammatory bowel disease patients. J Crohns Colitis 2014; 8:191-9. [PMID: 23953239 DOI: 10.1016/j.crohns.2013.07.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Revised: 07/07/2013] [Accepted: 07/20/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND AIMS Hypoxia can induce inflammation in the gastrointestinal tract. However, the impact of hypoxia on the course of inflammatory bowel disease (IBD) is poorly understood. We aimed to evaluate whether flights and/or journeys to regions lying at an altitude of >2000 m above the sea level are associated with flare-ups within 4 weeks of the trip. METHODS IBD patients with at least one flare-up during a 12-month observation period were compared to a group of patients in remission. Both groups completed a questionnaire. RESULTS A total of 103 IBD patients were included (43 with Crohn's disease (CD): mean age 39.3 ± 14.6 years; 60 with ulcerative colitis (UC): mean age 40.4 ± 15.1 years). Fifty-two patients with flare-ups were matched to 51 patients in remission. IBD patients experiencing flare-ups had more frequently undertaken flights and/or journeys to regions >2000 m above sea level within four weeks of the flare-up when compared to patients in remission (21/52 [40.4%] vs. 8/51 [15.7%], p=0.005). CONCLUSIONS Journeys to high altitude regions and/or flights are a risk factor for IBD flare-ups occurring within 4 weeks of travel.
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Affiliation(s)
- Stephan R Vavricka
- Division of Gastroenterology and Hepatology, Stadtspital Triemli, Zurich, Switzerland; Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland.
| | - Gerhard Rogler
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Sandra Maetzler
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Benjamin Misselwitz
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Ekaterina Safroneeva
- Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland
| | - Pascal Frei
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Christine N Manser
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Luc Biedermann
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Michael Fried
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Peter Higgins
- Division of Gastroenterology, University of Michigan, Ann Arbor, MI, USA
| | - Kacper A Wojtal
- Division of Gastroenterology and Hepatology, University Hospital Zurich, Zurich, Switzerland
| | - Alain M Schoepfer
- Division of Gastroenterology and Hepatology, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
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91
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Loss of von Hippel-Lindau protein (VHL) increases systemic cholesterol levels through targeting hypoxia-inducible factor 2α and regulation of bile acid homeostasis. Mol Cell Biol 2014; 34:1208-20. [PMID: 24421394 DOI: 10.1128/mcb.01441-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cholesterol synthesis is a highly oxygen-dependent process. Paradoxically, hypoxia is correlated with an increase in cellular and systemic cholesterol levels and risk of cardiovascular diseases. The mechanism for the increase in cholesterol during hypoxia is unclear. Hypoxia signaling is mediated through hypoxia-inducible factor 1α (HIF-1α) and HIF-2α. The present study demonstrates that activation of HIF signaling in the liver increases hepatic and systemic cholesterol levels due to a decrease in the expression of cholesterol hydroxylase CYP7A1 and other enzymes involved in bile acid synthesis. Specifically, activation of hepatic HIF-2α (but not HIF-1α) led to hypercholesterolemia. HIF-2α repressed the circadian expression of Rev-erbα, resulting in increased expression of E4BP4, a negative regulator of Cyp7a1. To understand if HIF-mediated decrease in bile acid synthesis is a physiologically relevant pathway by which hypoxia maintains or increases systemic cholesterol levels, two hypoxic mouse models were assessed, an acute lung injury model and mice exposed to 10% O2 for 3 weeks. In both models, cholesterol levels increased with a concomitant decrease in expression of genes involved in bile acid synthesis. The present study demonstrates that hypoxic activation of hepatic HIF-2α leads to an adaptive increase in cholesterol levels through inhibition of bile acid synthesis.
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92
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Control of creatine metabolism by HIF is an endogenous mechanism of barrier regulation in colitis. Proc Natl Acad Sci U S A 2013; 110:19820-5. [PMID: 24248342 DOI: 10.1073/pnas.1302840110] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Mucosal surfaces of the lower gastrointestinal tract are subject to frequent, pronounced fluctuations in oxygen tension, particularly during inflammation. Adaptive responses to hypoxia are orchestrated largely by the hypoxia-inducible transcription factors (HIFs). As HIF-1α and HIF-2α are coexpressed in mucosal epithelia that constitute the barrier between the lumen and the underlying immune milieu, we sought to define the discrete contribution of HIF-1 and HIF-2 transactivation pathways to intestinal epithelial cell homeostasis. The present study identifies creatine kinases (CKs), key metabolic enzymes for rapid ATP generation via the phosphocreatine-creatine kinase (PCr/CK) system, as a unique gene family that is coordinately regulated by HIF. Cytosolic CKs are expressed in a HIF-2-dependent manner in vitro and localize to apical intestinal epithelial cell adherens junctions, where they are critical for junction assembly and epithelial integrity. Supplementation with dietary creatine markedly ameliorated both disease severity and inflammatory responses in colitis models. Further, enzymes of the PCr/CK metabolic shuttle demonstrate dysregulated mucosal expression in a subset of ulcerative colitis and Crohn disease patients. These findings establish a role for HIF-regulated CK in epithelial homeostasis and reveal a fundamental link between cellular bioenergetics and mucosal barrier.
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93
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Sulindac activates NF-κB signaling in colon cancer cells. Cell Commun Signal 2013; 11:73. [PMID: 24083678 PMCID: PMC3896984 DOI: 10.1186/1478-811x-11-73] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 09/25/2013] [Indexed: 01/02/2023] Open
Abstract
BACKGROUND The non-steroidal anti-inflammatory drug (NSAID) sulindac has shown efficacy in preventing colorectal cancer. This potent anti-tumorigenic effect is mediated through multiple cellular pathways but is also accompanied by gastrointestinal side effects, such as colon inflammation. We have recently shown that sulindac can cause up-regulation of pro-inflammatory factors in the mouse colon mucosa. The aim of this study was to determine the signaling pathways that mediate the transcriptional activation of pro-inflammatory cytokines in colon cancer epithelial cells treated with sulindac sulfide. RESULTS We found that sulindac sulfide increased NF-κB signaling in HCT-15, HCT116, SW480 and SW620 cells, although the level of induction varied between cell lines. The drug caused a decrease in IκBα levels and an increase of p65(RelA) binding to the NF-κB DNA response element. It induced expression of IL-8, ICAM1 and A20, which was inhibited by the NF-κB inhibitor PDTC. Sulindac sulfide also induced activation of the AP-1 transcription factor, which co-operated with NF-κB in up-regulating IL-8. Up-regulation of NF-κB genes was most prominent in conditions where only a subset of cells was undergoing apoptosis. In TNFα stimulated conditions the drug treatment inhibited phosphorylation on IκBα (Ser 32) which is consistent with previous studies and indicates that sulindac sulfide can inhibit TNFα-induced NF-κB activation. Sulindac-induced upregulation of NF-κB target genes occurred early in the proximal colon of mice given a diet containing sulindac for one week. CONCLUSIONS This study shows for the first time that sulindac sulfide can induce pro-inflammatory NF-κB and AP-1 signaling as well as apoptosis in the same experimental conditions. Therefore, these results provide insights into the effect of sulindac on pro-inflammatory signaling pathways, as well as contribute to a better understanding of the mechanism of sulindac-induced gastrointestinal side effects.
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94
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Xue X, Ramakrishnan S, Anderson E, Taylor M, Zimmermann EM, Spence JR, Huang S, Greenson JK, Shah YM. Endothelial PAS domain protein 1 activates the inflammatory response in the intestinal epithelium to promote colitis in mice. Gastroenterology 2013; 145:831-41. [PMID: 23860500 PMCID: PMC3799890 DOI: 10.1053/j.gastro.2013.07.010] [Citation(s) in RCA: 135] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 06/26/2013] [Accepted: 07/01/2013] [Indexed: 12/29/2022]
Abstract
BACKGROUND & AIMS Hypoxic inflammation (decreased oxygen tension at sites of inflammation) is a feature of inflammatory bowel disease (IBD). The hypoxia response is mediated by the transcription factors hypoxia-inducible factor (HIF) 1α and endothelial PAS domain protein 1 (EPAS1 or HIF2α), which are induced in intestinal tissues of patients with IBD. HIF1α limits intestinal barrier dysfunction, but the role of EPAS1 has not been assessed under conditions of hypoxic inflammation or in models of IBD. METHODS Acute colitis was induced by administration of Citrobacter rodentium or dextran sulfate sodium (DSS) to transgenic hypoxia reporter mice (oxygen-dependent degradation-luciferase), mice with conditional overexpression of Epas1 (Epas1(LSL/LSL)), mice with intestinal epithelium-specific deletion of Epas1 (Epas1(ΔIE) ), or wild-type littermates (controls). Colon tissues from these mice and from patients with ulcerative colitis or Crohn's disease were assessed by histologic and immunoblot analyses, immunohistochemistry, and quantitative polymerase chain reaction. RESULTS Levels of hypoxia and EPAS1 were increased in colon tissues of mice after induction of colitis and patients with ulcerative colitis or Crohn's disease compared with controls. Epas1(ΔIE) mice had attenuated colonic inflammation and were protected from DSS-induced colitis. Intestine-specific overexpression of EPAS1, but not HIF-1α, led to spontaneous colitis, increased susceptibility to induction of colitis by C rodentium or DSS, and reduced survival times compared with controls. Disruption of intestinal epithelial EPAS1 attenuated the inflammatory response after administration of DSS or C rodentium, and intestine-specific overexpression of EPAS1 increased this response. We found EPAS1 to be a positive regulator of tumor necrosis factor-α production by the intestinal epithelium. Blocking tumor necrosis factor-α completely reduced hypoxia-induced intestinal inflammation. CONCLUSIONS EPAS1 is a transcription factor that activates mediators of inflammation, such as tumor necrosis factor-α, in the intestinal epithelium and promotes development of colitis in mice.
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Affiliation(s)
- Xiang Xue
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Sadeesh Ramakrishnan
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Erik Anderson
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Matthew Taylor
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan
| | - Ellen M. Zimmermann
- Department of Internal Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, Michigan
| | - Jason R. Spence
- Department of Internal Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, Michigan,Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan,Center for Organogenesis, University of Michigan, Ann Arbor, Michigan
| | - Sha Huang
- Department of Internal Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, Michigan
| | - Joel K. Greenson
- Department of Pathology, University of Michigan, Ann Arbor, Michigan
| | - Yatrik M. Shah
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan,Department of Internal Medicine, Division of Gastroenterology, University of Michigan, Ann Arbor, Michigan, To whom correspondence should be addressed. Tel: +1 734 6150567; Fax: +1 734 9368813;
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95
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Wang WS, Liang HY, Cai YJ, Yang H. DMOG ameliorates IFN-γ-induced intestinal barrier dysfunction by suppressing PHD2-dependent HIF-1α degradation. J Interferon Cytokine Res 2013; 34:60-9. [PMID: 24010824 DOI: 10.1089/jir.2013.0040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Hypoxia-inducible factor 1α (HIF-1α) has been well established as a protective factor for intestinal barrier function in intestinal epithelial cells. Recently, a study found that increased HIF-1α-induced intestinal barrier dysfunction. We proposed that lymphocyte-derived interferon-gamma (IFN-γ) might be responsible for the intestinal barrier dysfunction caused by increased HIF-1α. HT-29 cell monolayers were grown in the presence or absence of IFN-γ under hypoxia. Then, the transepithelial electrical resistance was measured, and HIF-1α-modulated intestinal barrier protective factors were quantified by polymerase chain reaction (PCR). PCR, western blotting, and chromatin immunoprecipitation of HIF-1α were performed. Dimethyloxalyglycine (DMOG), an inhibitor of prolyl-hydroxylases (PHDs) that stabilizes HIF-1α during normoxia, and RNA interference of PHDs were also used to identify the signal pathway between IFN-γ and HIF-1α. We demonstrated that IFN-γ caused barrier dysfunction in hypoxic HT-29 cell monolayers via suppressing HIF-1α and HIF-1α-modulated intestinal barrier protective factors. We found that IFN-γ decreased HIF-1α protein expression instead of affecting HIF-1α transcription or transcriptional activity. Study also showed that DMOG reversed the IFN-γ-induced decrease in HIF-1α protein expression. Further, we found that PHD2 is the major regulator of IFN-γ-induced HIF-1α degradation by PHD inhibition and RNA interference. We conclude that IFN-γ caused barrier dysfunction by promoting PHD-, especially PHD2-, dependent HIF-1α degradation, and DMOG or PHD2 inhibition reversed this HIF-1α suppression and ameliorated barrier dysfunction. Combined with other studies demonstrating HIF-1α activation in lymphocytes promotes IFN-γ secretion, these findings suggest a mechanism by which increased HIF-1α-induced intestinal barrier dysfunction.
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Affiliation(s)
- Wen-Sheng Wang
- 1 Department of General Surgery, Xinqiao Hospital, Third Military Medical University , Chongqing, China
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96
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Abstract
A current view of the inflammatory bowel diseases (IBDs) includes the luminal triggering of innate immune disease in a genetically susceptible host. Given the unique anatomy and complex environment of the intestine, local microenvironmental cues likely contribute significantly to both disease progression and resolution in IBD. Compartmentalized tissue and microbe populations within the intestine result in significant metabolic shifts within these tissue microenvironments. During active inflammatory disease, metabolic demands often exceed supply, resulting in localized areas of metabolic stress and diminished oxygen delivery (hypoxia). There is much recent interest in harnessing these microenvironmental changes to the benefit of the tissue, including targeting these pathways for therapy of IBD. Here, we review the current understanding of metabolic microenvironments within the intestine in IBD, with discussion of the advantages and disadvantages of targeting these pathways to treat patients with IBD.
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97
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Elimination of von Hippel-Lindau function perturbs pancreas endocrine homeostasis in mice. PLoS One 2013; 8:e72213. [PMID: 23977255 PMCID: PMC3748057 DOI: 10.1371/journal.pone.0072213] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Accepted: 07/08/2013] [Indexed: 12/23/2022] Open
Abstract
Mutations in the human homolog of the Vhlh gene [encoding the von-Hippel Lindau (VHL) protein] lead to tumor development. In mice, depletion of Vhlh in pancreatic ß-cells causes perturbed glucose homeostasis, but the role of this gene in other pancreatic cells is poorly understood. To investigate the function of VHL/HIF pathway in pancreatic cells, we inactivated Vhlh in the pancreatic epithelium as well as in the endocrine and exocrine lineages. Our results show that embryonic depletion of Vhlh within the pancreatic epithelium causes postnatal lethality due to severe hypoglycemia. The hypoglycemia is recapitulated in mice with endocrine-specific removal of Vhlh, while animals with loss of Vhlh predominantly in the exocrine compartment survive to adulthood with no overt defects in glucose metabolism. Mice with hypoglycemia display diminished insulin release in response to elevated glucose. Significantly, the glucagon response is impaired both in vivo (circulating glucagon levels) as well as in an in vitro secretion assay in isolated islets. Hypoxia also impairs glucagon secretion in a glucagon-expressing cell line in culture. Our results reveal a novel role for the hypoxia/HIF pathway in islet hormone secretion and maintenance of the fine balance that allows for the establishment of normoglycemia.
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98
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Brüne B, Dehne N, Grossmann N, Jung M, Namgaladze D, Schmid T, von Knethen A, Weigert A. Redox control of inflammation in macrophages. Antioxid Redox Signal 2013; 19:595-637. [PMID: 23311665 PMCID: PMC3718318 DOI: 10.1089/ars.2012.4785] [Citation(s) in RCA: 275] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 12/14/2012] [Accepted: 01/11/2013] [Indexed: 12/13/2022]
Abstract
Macrophages are present throughout the human body, constitute important immune effector cells, and have variable roles in a great number of pathological, but also physiological, settings. It is apparent that macrophages need to adjust their activation profile toward a steadily changing environment that requires altering their phenotype, a process known as macrophage polarization. Formation of reactive oxygen species (ROS), derived from NADPH-oxidases, mitochondria, or NO-producing enzymes, are not necessarily toxic, but rather compose a network signaling system, known as redox regulation. Formation of redox signals in classically versus alternatively activated macrophages, their action and interaction at the level of key targets, and the resulting physiology still are insufficiently understood. We review the identity, source, and biological activities of ROS produced during macrophage activation, and discuss how they shape the key transcriptional responses evoked by hypoxia-inducible transcription factors, nuclear-erythroid 2-p45-related factor 2 (Nrf2), and peroxisome proliferator-activated receptor-γ. We summarize the mechanisms how redox signals add to the process of macrophage polarization and reprogramming, how this is controlled by the interaction of macrophages with their environment, and addresses the outcome of the polarization process in health and disease. Future studies need to tackle the option whether we can use the knowledge of redox biology in macrophages to shape their mediator profile in pathophysiology, to accelerate healing in injured tissue, to fight the invading pathogens, or to eliminate settings of altered self in tumors.
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Affiliation(s)
- Bernhard Brüne
- Faculty of Medicine, Institute of Biochemistry I-Pathobiochemistry, Goethe-University Frankfurt, Frankfurt, Germany.
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99
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Dashdorj A, Jyothi KR, Lim S, Jo A, Nguyen MN, Ha J, Yoon KS, Kim HJ, Park JH, Murphy MP, Kim SS. Mitochondria-targeted antioxidant MitoQ ameliorates experimental mouse colitis by suppressing NLRP3 inflammasome-mediated inflammatory cytokines. BMC Med 2013. [PMID: 23915129 DOI: 10.1186/17] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
BACKGROUND MitoQ is a mitochondria-targeted derivative of the antioxidant ubiquinone, with antioxidant and anti-apoptotic functions. Reactive oxygen species are involved in many inflammatory diseases including inflammatory bowel disease. In this study, we assessed the therapeutic effects of MitoQ in a mouse model of experimental colitis and investigated the possible mechanisms underlying its effects on intestinal inflammation. METHODS Reactive oxygen species levels and mitochondrial function were measured in blood mononuclear cells of patients with inflammatory bowel disease. The effects of MitoQ were evaluated in a dextran sulfate sodium-induced colitis mouse model. Clinical and pathological markers of disease severity and oxidative injury, and levels of inflammatory cytokines in mouse colonic tissue were measured. The effect of MitoQ on inflammatory cytokines released in the human macrophage-like cell line THP-1 was also analyzed. RESULTS Cellular and mitochondrial reactive oxygen species levels in mononuclear cells were significantly higher in patients with inflammatory bowel disease (P <0.003, cellular reactive oxygen species; P <0.001, mitochondrial reactive oxygen species). MitoQ significantly ameliorated colitis in the dextran sulfate sodium-induced mouse model in vivo, reduced the increased oxidative stress response (malondialdehyde and 3-nitrotyrosine formation), and suppressed mitochondrial and histopathological injury by decreasing levels of inflammatory cytokines IL-1 beta and IL-18 (P <0.001 and P <0.01 respectively). By decreasing mitochondrial reactive oxygen species, MitoQ also suppressed activation of the NLRP3 inflammasome that was responsible for maturation of IL-1 beta and IL-18. In vitro studies demonstrated that MitoQ decreases IL-1 beta and IL-18 production in human THP-1 cells. CONCLUSION Taken together, our results suggest that MitoQ may have potential as a novel therapeutic agent for the treatment of acute phases of inflammatory bowel disease.
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Affiliation(s)
- Amarjargal Dashdorj
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea
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100
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Dashdorj A, Jyothi KR, Lim S, Jo A, Nguyen MN, Ha J, Yoon KS, Kim HJ, Park JH, Murphy MP, Kim SS. Mitochondria-targeted antioxidant MitoQ ameliorates experimental mouse colitis by suppressing NLRP3 inflammasome-mediated inflammatory cytokines. BMC Med 2013; 11:178. [PMID: 23915129 PMCID: PMC3750576 DOI: 10.1186/1741-7015-11-178] [Citation(s) in RCA: 147] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/08/2013] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND MitoQ is a mitochondria-targeted derivative of the antioxidant ubiquinone, with antioxidant and anti-apoptotic functions. Reactive oxygen species are involved in many inflammatory diseases including inflammatory bowel disease. In this study, we assessed the therapeutic effects of MitoQ in a mouse model of experimental colitis and investigated the possible mechanisms underlying its effects on intestinal inflammation. METHODS Reactive oxygen species levels and mitochondrial function were measured in blood mononuclear cells of patients with inflammatory bowel disease. The effects of MitoQ were evaluated in a dextran sulfate sodium-induced colitis mouse model. Clinical and pathological markers of disease severity and oxidative injury, and levels of inflammatory cytokines in mouse colonic tissue were measured. The effect of MitoQ on inflammatory cytokines released in the human macrophage-like cell line THP-1 was also analyzed. RESULTS Cellular and mitochondrial reactive oxygen species levels in mononuclear cells were significantly higher in patients with inflammatory bowel disease (P <0.003, cellular reactive oxygen species; P <0.001, mitochondrial reactive oxygen species). MitoQ significantly ameliorated colitis in the dextran sulfate sodium-induced mouse model in vivo, reduced the increased oxidative stress response (malondialdehyde and 3-nitrotyrosine formation), and suppressed mitochondrial and histopathological injury by decreasing levels of inflammatory cytokines IL-1 beta and IL-18 (P <0.001 and P <0.01 respectively). By decreasing mitochondrial reactive oxygen species, MitoQ also suppressed activation of the NLRP3 inflammasome that was responsible for maturation of IL-1 beta and IL-18. In vitro studies demonstrated that MitoQ decreases IL-1 beta and IL-18 production in human THP-1 cells. CONCLUSION Taken together, our results suggest that MitoQ may have potential as a novel therapeutic agent for the treatment of acute phases of inflammatory bowel disease.
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Affiliation(s)
- Amarjargal Dashdorj
- Department of Biochemistry and Molecular Biology, School of Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea
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