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Henkel J, Coleman CD, Schraplau A, Jöhrens K, Weiss TS, Jonas W, Schürmann A, Püschel GP. Augmented liver inflammation in a microsomal prostaglandin E synthase 1 (mPGES-1)-deficient diet-induced mouse NASH model. Sci Rep 2018; 8:16127. [PMID: 30382148 PMCID: PMC6208405 DOI: 10.1038/s41598-018-34633-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 10/22/2018] [Indexed: 12/11/2022] Open
Abstract
In a subset of patients, non-alcoholic fatty liver disease (NAFLD) is complicated by cell death and inflammation resulting in non-alcoholic steatohepatitis (NASH), which may progress to fibrosis and subsequent organ failure. Apart from cytokines, prostaglandins, in particular prostaglandin E2 (PGE2), play a pivotal role during inflammatory processes. Expression of the key enzymes of PGE2 synthesis, cyclooxygenase 2 and microsomal PGE synthase 1 (mPGES-1), was increased in human NASH livers in comparison to controls and correlated with the NASH activity score. Both enzymes were also induced in NASH-diet-fed wild-type mice, resulting in an increase in hepatic PGE2 concentration that was completely abrogated in mPGES-1-deficient mice. PGE2 is known to inhibit TNF-α synthesis in macrophages. A strong infiltration of monocyte-derived macrophages was observed in NASH-diet-fed mice, which was accompanied with an increase in hepatic TNF-α expression. Due to the impaired PGE2 production, TNF-α expression increased much more in livers of mPGES-1-deficient mice or in the peritoneal macrophages of these mice. The increased levels of TNF-α resulted in an enhanced IL-1β production, primarily in hepatocytes, and augmented hepatocyte apoptosis. In conclusion, attenuation of PGE2 production by mPGES-1 ablation enhanced the TNF-α-triggered inflammatory response and hepatocyte apoptosis in diet-induced NASH.
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Affiliation(s)
- Janin Henkel
- University of Potsdam, Institute of Nutritional Science, Department of Nutritional Biochemistry, Nuthetal, Germany.
| | - Charles Dominic Coleman
- University of Potsdam, Institute of Nutritional Science, Department of Nutritional Biochemistry, Nuthetal, Germany
| | - Anne Schraplau
- University of Potsdam, Institute of Nutritional Science, Department of Nutritional Biochemistry, Nuthetal, Germany
| | - Korinna Jöhrens
- Charité University Hospital Berlin, Institute of Pathology, Berlin, Germany
| | - Thomas Siegfried Weiss
- University Hospital Regensburg, University Children Hospital (KUNO) Regensburg, Regensburg, Germany
| | - Wenke Jonas
- German Institute of Human Nutrition, Department of Experimental Diabetology, Nuthetal, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Annette Schürmann
- German Institute of Human Nutrition, Department of Experimental Diabetology, Nuthetal, Germany.,German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Gerhard Paul Püschel
- University of Potsdam, Institute of Nutritional Science, Department of Nutritional Biochemistry, Nuthetal, Germany
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Abstract
It is widely accepted that intake of dietary fats and chronic inflammation are risk factors for developing colorectal cancer. Arachidonic acid is a major component of animal fats, and the bioactive lipids produced from this substrate play critical roles in a variety of biologic processes, including cancer. Cyclooxygenase-derived prostaglandin E2 is a known proinflammatory lipid mediator that promotes tumor progression. Metabolism of arachidonic acid by the cyclooxygenase pathway provides one mechanism for the contribution of dietary fats and chronic inflammation to carcinogenesis. In this review, we highlight recent advances in our understanding of how a proinflammatory mediator prostaglandin E2 promotes colorectal cancer immune evasion. These findings may provide a rationale for the development of new therapeutic approaches to subvert tumor-induced immunosuppression.
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Lee SO, Liu H, Cunnick JE, Murphy PA, Hendrich S. Menhaden oil inhibited gamma-glutamyltransferase-positive altered hepatic foci in female Sprague-Dawley rats. Nutr Cancer 2003; 44:71-9. [PMID: 12672644 DOI: 10.1207/s15327914nc441_10] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Feeding menhaden oil, high in n-3 fatty acids, or a mixture of lard and corn oil with a polyunsaturated-to-monounsaturated fatty acid ratio of 1:1 was hypothesized to inhibit promotion of hepatocarcinogenesis in rats by decreasing hepatic prostaglandin (PG) levels. Ten-day-old female Sprague-Dawley rats were injected with diethylnitrosamine (DEN, 15 mg/kg body wt ip). At 4 wk of age, rats were fed fumonisin B1(50 mg/kg diet) for 5 wk in diets containing 14% lard + 6% corn oil, 10% lard + 10% corn oil, 14% menhaden oil + 6% corn oil, and 7% menhaden oil + 13% corn oil. Plasma alanine aminotransferase activity was 20% lower in rats fed 10% lard than in rats fed the other diets (P < 0.05). In menhaden oil-fed rats, total plasma cholesterol concentrations decreased 26% (P < 0.05) and hepatic phospholipid C20:5n-3, C22:5n-3, and C22:6n-3 fatty acid concentrations increased compared with lard-fed rats. Hepatic n-3 fatty acids were threefold greater in rats fed 10% lard than in rats fed 14% lard. The liver-associated natural killer cell activity in rats fed menhaden oil was 58% lower than in rats fed lard (P < 0.03). Rats fed lard had threefold (P < 0.05) greater area of _-glutamyltransferase-positive altered hepatic foci (AHF) than did rats fed menhaden oil. There was no significant difference in placental glutathione S-transferase-positive AHF among the groups. Hepatic PGF2alpha production was 60-80% greater in rats fed 14% lard than in rats fed the other diets (P < 0.05). Hepatic PGE2 was 48% less in rats fed 14%; menhaden oil than in rats fed 14% lard (P < 0.05). Although gamma-glutamyltransferase-positive focal area was inhibited by menhaden oil, only 14% menhaden oil inhibited PGE2. Feeding 10% lard inhibited PGF2alpha, but not the development of AHF. Therefore, decreased hepatic PGs did not explain the inhibition of carcinogenesis.
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Affiliation(s)
- Sun-Ok Lee
- Department of Food Science and Human Nutrition, Iowa State University, Ames 50011, USA
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