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Wu W, Li WX, Huang CH. Phospholipase A 2, a nonnegligible enzyme superfamily in gastrointestinal diseases. Biochimie 2021; 194:79-95. [PMID: 34974145 DOI: 10.1016/j.biochi.2021.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 12/25/2021] [Accepted: 12/28/2021] [Indexed: 11/16/2022]
Abstract
Gastrointestinal tract is important for digestion, absorption, detoxification and immunity. Gastrointestinal diseases are mainly caused by the imbalance of protective and attacking factors in gastrointestinal mucosa, which can seriously harm human health. Phospholipase A2 (PLA2) is a large family closely involved in lipid metabolism and is found in almost all human cells. A growing number of studies have revealed that its metabolites are deeply implicated in various inflammatory pathways and also regulates the maintenance of numerous biological events such as dietary digestion, membrane remodeling, barrier action, and host immunity. In addition to their phospholipase activity, some members of the superfamily also have other catalytic activities. Based on the in-depth effects of phospholipase A2 on bioactive lipid metabolism and inflammatory cytokines, PLA2 and its metabolites are likely to be involved in the pathogenesis, development or prevention of gastrointestinal diseases. Therefore, this review will focus on the physiological and pathogenic roles of several important PLA2 enzymes in the gastrointestinal tract, and reveals the potential of PLA2 as a therapeutic target for gastrointestinal diseases.
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Affiliation(s)
- Wei Wu
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, China
| | - Wen-Xuan Li
- Queen Mary School, Medical Department, Nanchang University, Nanchang, Jiangxi, China
| | - Chun-Hong Huang
- School of Basic Medical Sciences, 330006, Nanchang University, Nanchang, Jiangxi, China.
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2
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Kita Y, Shindou H, Shimizu T. Cytosolic phospholipase A2 and lysophospholipid acyltransferases. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:838-845. [DOI: 10.1016/j.bbalip.2018.08.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 08/06/2018] [Accepted: 08/07/2018] [Indexed: 01/01/2023]
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Abstract
Expression of prostaglandin biosynthetic pathway enzymes in mucinous pancreatic cysts is unknown. Cyclooxygenase-2 (COX-2) inhibition is a potential cancer chemoprevention strategy for these lesions. We evaluated the expression of COX-2, cytosolic phospholipase A2 (cPLA2), and protein kinase B (AKT) in the epithelium of pancreatic cysts and correlated enzyme expression with aspirin (ASA) use and cyst fluid prostaglandin E2 (PGE2) concentration.
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Frye RE, Rose S, Slattery J, MacFabe DF. Gastrointestinal dysfunction in autism spectrum disorder: the role of the mitochondria and the enteric microbiome. MICROBIAL ECOLOGY IN HEALTH AND DISEASE 2015; 26:27458. [PMID: 25956238 PMCID: PMC4425813 DOI: 10.3402/mehd.v26.27458] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 04/09/2015] [Accepted: 04/10/2015] [Indexed: 12/26/2022]
Abstract
Autism spectrum disorder (ASD) affects a significant number of individuals worldwide with the prevalence continuing to grow. It is becoming clear that a large subgroup of individuals with ASD demonstrate abnormalities in mitochondrial function as well as gastrointestinal (GI) symptoms. Interestingly, GI disturbances are common in individuals with mitochondrial disorders and have been reported to be highly prevalent in individuals with co-occurring ASD and mitochondrial disease. The majority of individuals with ASD and mitochondrial disorders do not manifest a primary genetic mutation, raising the possibility that their mitochondrial disorder is acquired or, at least, results from a combination of genetic susceptibility interacting with a wide range of environmental triggers. Mitochondria are very sensitive to both endogenous and exogenous environmental stressors such as toxicants, iatrogenic medications, immune activation, and metabolic disturbances. Many of these same environmental stressors have been associated with ASD, suggesting that the mitochondria could be the biological link between environmental stressors and neurometabolic abnormalities associated with ASD. This paper reviews the possible links between GI abnormalities, mitochondria, and ASD. First, we review the link between GI symptoms and abnormalities in mitochondrial function. Second, we review the evidence supporting the notion that environmental stressors linked to ASD can also adversely affect both mitochondria and GI function. Third, we review the evidence that enteric bacteria that are overrepresented in children with ASD, particularly Clostridia spp., produce short-chain fatty acid metabolites that are potentially toxic to the mitochondria. We provide an example of this gut–brain connection by highlighting the propionic acid rodent model of ASD and the clinical evidence that supports this animal model. Lastly, we discuss the potential therapeutic approaches that could be helpful for GI symptoms in ASD and mitochondrial disorders. To this end, this review aims to help better understand the underlying pathophysiology associated with ASD that may be related to concurrent mitochondrial and GI dysfunction.
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Affiliation(s)
- Richard E Frye
- Autism Research Program, Arkansas Children's Hospital Research Institute, Little Rock, AR, USA.,Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA;
| | - Shannon Rose
- Autism Research Program, Arkansas Children's Hospital Research Institute, Little Rock, AR, USA.,Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - John Slattery
- Autism Research Program, Arkansas Children's Hospital Research Institute, Little Rock, AR, USA.,Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Derrick F MacFabe
- Kilee Patchell-Evans Autism Research Group, Division of Developmental Disabilities, Departments of Psychology and Psychiatry, University of Western Ontario, London, ON, Canada
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5
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Leslie CC. Cytosolic phospholipase A₂: physiological function and role in disease. J Lipid Res 2015; 56:1386-402. [PMID: 25838312 DOI: 10.1194/jlr.r057588] [Citation(s) in RCA: 266] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Indexed: 02/06/2023] Open
Abstract
The group IV phospholipase A2 (PLA2) family is comprised of six intracellular enzymes (GIVA, -B, -C, -D, -E, and -F) commonly referred to as cytosolic PLA2 (cPLA2)α, -β, -γ, -δ, -ε, and -ζ. They contain a Ser-Asp catalytic dyad and all except cPLA2γ have a C2 domain, but differences in their catalytic activities and subcellular localization suggest unique regulation and function. With the exception of cPLA2α, the focus of this review, little is known about the in vivo function of group IV enzymes. cPLA2α catalyzes the hydrolysis of phospholipids to arachidonic acid and lysophospholipids that are precursors of numerous bioactive lipids. The regulation of cPLA2α is complex, involving transcriptional and posttranslational processes, particularly increases in calcium and phosphorylation. cPLA2α is a highly conserved widely expressed enzyme that promotes lipid mediator production in human and rodent cells from a variety of tissues. The diverse bioactive lipids produced as a result of cPLA2α activation regulate normal physiological processes and disease pathogenesis in many organ systems, as shown using cPLA2α KO mice. However, humans recently identified with cPLA2α deficiency exhibit more pronounced effects on health than observed in mice lacking cPLA2α, indicating that much remains to be learned about this interesting enzyme.
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Affiliation(s)
- Christina C Leslie
- Department of Pediatrics, National Jewish Health, Denver, CO 80206; and Departments of Pathology and Pharmacology, University of Colorado Denver, Aurora, CO 80045
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Montrose DC, Nakanishi M, Murphy RC, Zarini S, McAleer JP, Vella AT, Rosenberg DW. The role of PGE2 in intestinal inflammation and tumorigenesis. Prostaglandins Other Lipid Mediat 2014; 116-117:26-36. [PMID: 25460828 DOI: 10.1016/j.prostaglandins.2014.10.002] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/30/2014] [Accepted: 10/10/2014] [Indexed: 12/24/2022]
Abstract
Release of the free fatty acid arachidonic acid (AA) by cytoplasmic phospholipase A2 (cPLA2) and its subsequent metabolism by the cyclooxygenase and lipoxygenase enzymes produces a broad panel of eicosanoids including prostaglandins (PGs). This study sought to investigate the roles of these mediators in experimental models of inflammation and inflammation-associated intestinal tumorigenesis. Using the dextran sodium sulfate (DSS) model of experimental colitis, we first investigated how a global reduction in eicosanoid production would impact intestinal injury by utilizing cPLA2 knockout mice. cPLA2 deletion enhanced colonic injury, reflected by increased mucosal ulceration and pro-inflammatory cytokine expression. Increased disease severity was associated with a significant reduction in the levels of several eicosanoid metabolites, including PGE2. We further assessed the precise role of PGE2 synthesis on mucosal injury and repair by utilizing mice with a genetic deletion of microsomal PGE synthase-1 (mPGES-1), the terminal synthase in the formation of inducible PGE2. DSS exposure caused more extensive acute injury as well as impaired recovery in knockout mice compared to wild-type littermates. Increased intestinal damage was associated with both reduced PGE2 levels as well as altered levels of other eicosanoids including PGD2. To determine whether this metabolic redirection impacted inflammation-associated intestinal tumorigenesis, Apc(Min/+) and Apc(Min/+):mPGES-1(-/-) mice were exposed to DSS. DSS administration caused a reduction in the number of intestinal polyps only in Apc(Min/+):mPGES-1(-/-) mice. These results demonstrate the importance of the balance of prostaglandins produced in the intestinal tract for maintaining intestinal homeostasis and impacting tumor development.
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Affiliation(s)
- David C Montrose
- Center for Molecular Medicine and Colon Cancer Prevention, University of Connecticut Health Center, Farmington, CT 06030, United States
| | - Masako Nakanishi
- Center for Molecular Medicine and Colon Cancer Prevention, University of Connecticut Health Center, Farmington, CT 06030, United States
| | - Robert C Murphy
- Department of Pharmacology, University of Colorado Denver, Aurora, CO 80045, United States
| | - Simona Zarini
- Department of Pharmacology, University of Colorado Denver, Aurora, CO 80045, United States
| | - Jeremy P McAleer
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030, United States
| | - Anthony T Vella
- Department of Immunology, University of Connecticut Health Center, Farmington, CT 06030, United States
| | - Daniel W Rosenberg
- Center for Molecular Medicine and Colon Cancer Prevention, University of Connecticut Health Center, Farmington, CT 06030, United States.
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Navab M, Reddy ST, Van Lenten BJ, Buga GM, Hough G, Wagner AC, Fogelman AM. High-density lipoprotein and 4F peptide reduce systemic inflammation by modulating intestinal oxidized lipid metabolism: novel hypotheses and review of literature. Arterioscler Thromb Vasc Biol 2012; 32:2553-60. [PMID: 23077141 DOI: 10.1161/atvbaha.112.300282] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Oxidized phospholipids are found in the vasculature of animal models of atherosclerosis, in human atherosclerotic lesions, and in other inflammatory diseases. Oxidized phospholipids cause vascular and nonvascular cells to initiate an inflammatory reaction. Metabolites of arachidonic acid, such as 12-hydroxyeicosatetraenoic acid, can mimic some of the inflammatory properties of oxidized phospholipids. In vitro and in vivo normal high-density lipoprotein (HDL), normal apolipoprotein A-I, and apolipoprotein A-I mimetic peptides, each likely acting in a different manner, prevent the inflammatory reaction characteristic of atherosclerosis, and this is associated with decreased levels of oxidized lipids in tissues and cells. HDL from animal models of atherosclerosis or from humans with atherosclerosis or from humans or animals with other chronic inflammatory diseases does not prevent the inflammatory reaction characteristic of atherosclerosis and may even enhance the inflammatory reaction. In mice and perhaps humans, ≈30% of the steady-state plasma HDL-cholesterol pool is derived from the small intestine. The metabolism of phospholipids by gut bacteria has been recently implicated in atherosclerosis in both mice and humans. Studies with apolipoprotein A-I mimetic peptides suggest that the small intestine is a major tissue regulating systemic inflammation in mouse models of atherosclerosis and may be important for determining the functionality of HDL.
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Affiliation(s)
- Mohamad Navab
- Division of Cardiology, Department of Medicine, David Geffen School of Medicine at UCLA, 10833 Le Conte Ave, Room A2-237 CHS, Los Angeles, CA 90095-1679, USA.
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Maes M. Targeting cyclooxygenase-2 in depression is not a viable therapeutic approach and may even aggravate the pathophysiology underpinning depression. Metab Brain Dis 2012; 27:405-13. [PMID: 22773310 DOI: 10.1007/s11011-012-9326-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 06/26/2012] [Indexed: 01/25/2023]
Abstract
Depression is a complex progressive disorder accompanied by activation of inflammatory and Th-1 driven pathways, oxidative and nitrosative stress (O&NS), lowered antioxidant levels, mitochondrial dysfunctions, neuroprogression and increased bacterial translocation. In depression, activation of immuno-inflammatory pathways is associated with an increased risk for cardio-vascular disorder (CVD). Because of the inflammatory component, the use of cyclooxygenase 2 (COX-2) inhibitors, such as celecoxib, has been advocated to treat depression. Electronic databases, i.e. PUBMED, Scopus and Google Scholar were used as sources for this selective review on the effects of COX-2 inhibitors aggravating the abovementioned pathways. COX-2 inhibitors may induce neuroinflammation, exacerbate Th1 driven responses, increase lipid peroxidation, decrease the levels of key antioxidants, damage mitochondria and aggravate neuroprogression. COX-2 inhibitors may aggravate bacterial translocation and CVD through Th1-driven mechanisms. COX-2 inhibitors may aggravate the pathophysiology of depression. Since Th1 and O&NS pathways are risk factors for CVD, the use of COX-2 inhibitors may further aggravate the increased risk for CVD in depression. Selectively targeting COX-2 may not be a viable therapeutic approach to treat depression. Multi-targeting of the different pathways that play a role in depression is more likely to yield good treatment results.
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Affiliation(s)
- Michael Maes
- Maes Clinics @ TRIA, Piyavate Hospital 998 Rimklongsamsen Road, Bangkok, 10310, Thailand.
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Boelsterli UA, Redinbo MR, Saitta KS. Multiple NSAID-induced hits injure the small intestine: underlying mechanisms and novel strategies. Toxicol Sci 2012; 131:654-67. [PMID: 23091168 DOI: 10.1093/toxsci/kfs310] [Citation(s) in RCA: 100] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) can cause serious gastrointestinal (GI) injury including jejunal/ileal mucosal ulceration, bleeding, and even perforation in susceptible patients. The underlying mechanisms are largely unknown, but they are distinct from those related to gastric injury. Based on recent insights from experimental models, including genetics and pharmacology in rodents typically exposed to diclofenac, indomethacin, or naproxen, we propose a multiple-hit pathogenesis of NSAID enteropathy. The multiple hits start with an initial pharmacokinetic determinant caused by vectorial hepatobiliary excretion and delivery of glucuronidated NSAID or oxidative metabolite conjugates to the distal small intestinal lumen, where bacterial β-glucuronidase produces critical aglycones. The released aglycones are then taken up by enterocytes and further metabolized by intestinal cytochrome P450s to potentially reactive intermediates. The "first hit" is caused by the NSAID and/or oxidative metabolites that induce severe endoplasmic reticulum stress or mitochondrial stress and lead to cell death. The "second hit" is created by the significant subsequent inflammatory response that would follow such a first-hit injury. Based on these putative mechanisms, strategies have been developed to protect the enterocytes from being exposed to the parent NSAID and/or oxidative metabolites. Among these, a novel strategy already demonstrated in a murine model is the selective disruption of bacteria-specific β-glucuronidases with a novel small molecule inhibitor that does not harm the bacteria and that alleviates NSAID-induced enteropathy. Such mechanism-based strategies require further investigation but provide potential avenues for the alleviation of the GI toxicity caused by multiple NSAID hits.
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Affiliation(s)
- Urs A Boelsterli
- Department of Pharmaceutical Sciences, University of Connecticut School of Pharmacy, Storrs, Connecticut 06269, USA.
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10
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Multifaceted roles of PGE2 in inflammation and cancer. Semin Immunopathol 2012; 35:123-37. [PMID: 22996682 DOI: 10.1007/s00281-012-0342-8] [Citation(s) in RCA: 420] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Accepted: 08/31/2012] [Indexed: 12/13/2022]
Abstract
Prostaglandin E(2) (PGE(2)) is a bioactive lipid that elicits a wide range of biological effects associated with inflammation and cancer. PGE(2) exerts diverse effects on cell proliferation, apoptosis, angiogenesis, inflammation, and immune surveillance. This review concentrates primarily on gastrointestinal cancers, where the actions of PGE(2) are most prominent, most likely due to the constant exposure to dietary and environmental insults and the intrinsic role of PGE(2) in tissue homeostasis. A discussion of recent efforts to elucidate the complex and interconnected pathways that link PGE(2) signaling with inflammation and cancer is provided, supported by the abundant literature showing a protective effect of NSAIDs and the therapeutic efficacy of targeting mPGES-1 or EP receptors for cancer prevention. However, suppressing PGE(2) formation as a means of providing chemoprotection against all cancers may not ultimately be tenable, undoubtedly the situation for patients with inflammatory bowel disease. Future studies to fully understand the complex role of PGE(2) in both inflammation and cancer will be required to develop novel strategies for cancer prevention that are both effective and safe.
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Hunter AC, Elsom J, Wibroe PP, Moghimi SM. Polymeric particulate technologies for oral drug delivery and targeting: A pathophysiological perspective. Maturitas 2012; 73:5-18. [DOI: 10.1016/j.maturitas.2012.05.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 05/25/2012] [Indexed: 11/25/2022]
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Hunter AC, Elsom J, Wibroe PP, Moghimi SM. Polymeric particulate technologies for oral drug delivery and targeting: a pathophysiological perspective. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2012; 8 Suppl 1:S5-20. [PMID: 22846372 DOI: 10.1016/j.nano.2012.07.005] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 05/25/2012] [Indexed: 01/01/2023]
Abstract
The oral route for delivery of pharmaceuticals is the most widely used and accepted. Nanoparticles and microparticles are increasingly being applied within this arena to optimize drug targeting and bioavailability. Frequently the carrier systems used are either constructed from or contain polymeric materials. Examples of these nanocarriers include polymeric nanoparticles, solid lipid nanocarriers, self-nanoemulsifying drug delivery systems and nanocrystals. It is the purpose of this review to describe these cutting edge technologies and specifically focus on the interaction and fate of these polymers within the gastrointestinal system.
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Affiliation(s)
- A Christy Hunter
- University of Manchester, Department of Pharmacy and Pharmaceutical Sciences, Stopford Building, Oxford Road, Manchester, M13 9PT, United Kingdom.
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Kadaveru K, Protiva P, Greenspan EJ, Kim YI, Rosenberg DW. Dietary methyl donor depletion protects against intestinal tumorigenesis in Apc(Min/+) mice. Cancer Prev Res (Phila) 2012; 5:911-20. [PMID: 22677908 DOI: 10.1158/1940-6207.capr-11-0544] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Despite recent population data, the influence of dietary folate supplementation on colon cancer risk remains controversial. This study examines the effects of folate deficiency, in combination with choline, methionine, and vitamin B12 depletion, on intestinal tumorigenesis in Apc(Min/+) mice. Methyl donor sufficient (MDS) and deficient (MDD) diets were started at five or 10 weeks of age and tumors evaluated at 16 weeks. MDD suppressed intestinal tumor formation in Apc(Min/+) mice (~80%) when started at five weeks of age. The protective effect was lost when MDD was initiated at 10 weeks of age, indicating an important time dependency on cancer suppression. Concomitant with cancer protection, MDD restricted body weight gain. Therefore, a second study was conducted in which MDS was given ad libitum or pair-fed with MDD. Although small intestinal tumors were reduced 54% in pair-fed MDS mice, MDD caused a further reduction (96%). In colon, although MDD did not affect tumor numbers, tumor size was reduced. Gene expression profiling of normal-appearing colonic mucosa after 11 weeks on MDD identified a total of 493 significantly downregulated genes relative to the MDS group. Pathway analysis placed many of these genes within general categories of inflammatory signaling and cell-cycle regulation, consistent with recently published human data obtained during folate depletion. Further studies are warranted to investigate the complex interplay of methyl donor status and cancer protection in high-risk populations.
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Affiliation(s)
- Krishna Kadaveru
- Molecular Medicine, University of Connecticut Health Center, Farmington, CT 06030, USA
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Schoultz I, Söderholm JD, McKay DM. Is metabolic stress a common denominator in inflammatory bowel disease? Inflamm Bowel Dis 2011; 17:2008-18. [PMID: 21830276 DOI: 10.1002/ibd.21556] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Accepted: 10/04/2010] [Indexed: 01/06/2023]
Abstract
The enteric epithelium represents the major boundary between the outside world and the body, and in the colon it is the interface between the host and a vast and diverse microbiota. A common feature of inflammatory bowel disease (IBD) is decreased epithelial barrier function, and while a cause-and-effect relationship can be debated, prolonged loss of epithelial barrier function (whether this means the ability to sense bacteria or exclude them) would contribute to inflammation. While there are undoubtedly individual nuances in IBD, we review data in support of metabolic stress--that is, perturbed mitochondrial function--in the enterocyte as a contributing factor to the initiation of inflammation and relapses in IBD. The postulate is presented that metabolic stress, which can arise as a consequence of a variety of stimuli (e.g., infection, bacterial dysbiosis, and inflammation also), will reduce epithelial barrier function and perturb the enterocyte-commensal flora relationship and suggest that means to negate enterocytic metabolic stress should be considered as a prophylactic or adjuvant therapy in IBD.
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Affiliation(s)
- Ida Schoultz
- Gastrointestinal Research Group, Department of Physiology & Pharmacology, The Calvin, Phoebe and Joan Snyder Institute of Infection Immunity and Inflammation, University of Calgary, Calgary, Alberta, Canada
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Nakanishi M, Menoret A, Tanaka T, Miyamoto S, Montrose DC, Vella AT, Rosenberg DW. Selective PGE(2) suppression inhibits colon carcinogenesis and modifies local mucosal immunity. Cancer Prev Res (Phila) 2011; 4:1198-208. [PMID: 21576350 DOI: 10.1158/1940-6207.capr-11-0188] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Prostaglandin E(2) (PGE(2)) is a bioactive lipid that mediates a wide range of physiologic effects and plays a central role in inflammation and cancer. PGE(2) is generated from arachidonic acid by the sequential actions of the COX and terminal synthases (PGES). Increased levels of COX-2, with a concomitant elevation of PGE(2), are often found in colorectal cancers (CRC), providing the rationale for the use of COX-2 inhibitors for chemoprevention. Despite their proven efficacy in cancer prevention, however, COX-2 inhibitors exhibit dose-dependent toxicities that are mediated in part by their nonspecific reduction of essential prostanoids, thus limiting their chemopreventive benefit. To achieve enhanced specificity, recent efforts have been directed toward targeting the inducible terminal synthase in the production of PGE(2), microsomal PGES (mPGES-1). In the present study, we show that genetic deletion of mPGES-1 affords significant protection against carcinogen-induced colon cancer. mPGES-1 gene deletion results in an about 80% decrease in tumor multiplicity and up to a 90% reduction in tumor load in the distal colon of azoxymethane (AOM)-treated mice. Associated with the striking cancer suppression, we have identified a critical role for PGE(2) in the control of immunoregulatory cell expansion (FoxP3-positive regulatory T cells) within the colon-draining mesenteric lymph nodes, providing a potential mechanism by which suppression of PGE(2) may protect against CRC. These results provide new insights into how PGE(2) controls antitumor immunity.
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Affiliation(s)
- Masako Nakanishi
- Center for Molecular Medicine, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030, USA
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