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- Fuchs, C. D., et al.
(författare)
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GLP-2 Improves Hepatic Inflammation and Fibrosis in Mdr2-/- Mice Via Activation of NR4a1/Nur77 in Hepatic Stellate Cells and Intestinal FXR Signaling
- 2023
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Ingår i: Cellular and Molecular Gastroenterology and Hepatology. - 2352-345X. ; 16:5, s. 847-856
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND & AIMS: Glucagon-like peptide (GLP)-2 may exert antifibrotic effects on hepatic stellate cells (HSCs). Thus, we aimed to test whether application of the GLP-2 analogue teduglutide has hepatoprotective and antifibrotic effects in the Mdr2/Abcb4(-/-) mouse model of sclerosing cholangitis displaying hepatic inflammation and fibrosis. METHODS: Mdr2(-/-) mice were injected daily for 4 weeks with teduglutide followed by gene expression profiling (bulk liver; isolated HSCs) and immunohistochemistry. Activated HSCs (LX2 cells) and immortalized human hepatocytes and human intestinal organoids were treated with GLP-2. mRNA profiling by reverse transcription polymerase chain reaction and elec-trophoretic mobility shift assay using cytosolic and nuclear protein extracts was performed. RESULTS: Hepatic inflammation, fibrosis, and reactive chol-angiocyte phenotype were improved in GLP-2-treated Mdr2(-/-) mice. Primary HSCs isolated from Mdr2(-/-)mice and LX2 cells exposed to GLP-2 in vitro displayed significantly increased mRNA expression levels of NR4a1/Nur77 (P < .05). Electro-phoretic mobility shift assay revealed an increased nuclear NR4a1 binding after GLP-2 treatment in LX2 cells. Moreover, GLP-2 alleviated the Tgf beta-mediated reduction of NR4a1 nuclear binding activity. In vivo, GLP-2 treatment of Mdr2(-/-) mice resulted in increased intrahepatic levels of muricholic acids (accordingly Cyp2c70 mRNA expression was significantly increased), and in reduced mRNA levels of Cyp7a1 and FXR. Serum Fgf15 levels were increased in Mdr2(-/-) mice treated with GLP-2. Accordingly, GLP-2 treatment of human intestinal organoids activated their FXR-FGF19 signaling axis. CONCLUSIONS: GLP-2 treatment increased NR4a1/Nur77 activation in HSCs, subsequently attenuating their activation. GLP-2 promoted intestinal Fxr-Fgf15/19 signaling resulting in reduced Cyp7a1 and increased Cyp2c70 expression in the liver, contributing to hepatoprotective and antifibrotic effects of GLP2 in the Mdr2(-/-) mouse model.
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| 3. |
- Fuchs, C. D., et al.
(författare)
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Absence of Bsep/Abcb11 attenuates MCD diet-induced hepatic steatosis but aggravates inflammation in mice
- 2020
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Ingår i: Liver International. - : Wiley. - 1478-3223 .- 1478-3231. ; 40:6, s. 1366-1377
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Tidskriftsartikel (refereegranskat)abstract
- Background Bile acids (BAs) regulate hepatic lipid metabolism and inflammation. Bile salt export pump (BSEP) KO mice are metabolically preconditioned with a hydrophilic BA composition protecting them from cholestasis. We hypothesize that changes in hepatic BA profile and subsequent changes in BA signalling may critically determine the susceptibility to steatohepatitis. Methods Wild-type (WT) and BSEP KO mice were challenged with methionine choline-deficient (MCD) diet to induce steatohepatitis. Serum biochemistry, lipid profiling as well as intestinal lipid absorption were assessed. Markers of inflammation, fibrosis, lipid and BA metabolism were analysed. Hepatic and faecal BA profile as well as serum levels of the BA synthesis intermediate 7-hydroxy-4-cholesten-3-one (C4) were also investigated. Results Bile salt export pump KO MCD-fed mice developed less steatosis but more inflammation than WT mice. Intestinal neutral lipid levels were reduced in BSEP KO mice at baseline and under MCD conditions. Faecal non-esterified fatty acid concentrations at baseline and under MCD diet were markedly elevated in BSEP KO compared to WT mice. Serum liver enzymes and hepatic expression of inflammatory markers were increased in MCD-fed BSEP KO animals. PPAR alpha protein levels were reduced in BSEP KO mice. Accordingly, PPAR alpha downstream targets Fabp1 and Fatp5 were repressed, while NF kappa B subunits were increased in MCD-fed BSEP KO mice. Farnesoid X receptor (FXR) protein levels were reduced in MCD-fed BSEP KO vs WT mice. Hepatic BA profile revealed elevated levels of T beta MCA, exerting FXR antagonistic action, while concentrations of TCA (FXR agonistic function) were reduced. Conclusion Presence of hydroxylated BAs result in increased faecal FA excretion and reduced hepatic lipid accumulation. This aggravates development of MCD diet-induced hepatitis potentially by decreasing FXR and PPAR alpha signalling.
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| 5. |
- Mueller, M., et al.
(författare)
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Ursodeoxycholic acid exerts farnesoid X receptor-antagonistic effects on bile acid and lipid metabolism in morbid obesity
- 2015
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Ingår i: Journal of Hepatology. - 0168-8278. ; 62:6, s. 1398-1404
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Tidskriftsartikel (refereegranskat)abstract
- Background & Aims: Bile acids (BAs) are major regulators of hepatic BA and lipid metabolism but their mechanisms of action in non-alcoholic fatty liver disease (NAFLD) are still poorly understood. Here we aimed to explore the molecular and biochemical mechanisms of ursodeoxycholic acid (UDCA) in modulating the cross-talk between liver and visceral white adipose tissue (vWAT) regarding BA and cholesterol metabolism and fatty acid/lipid partitioning in morbidly obese NAFLD patients. Methods: In this randomized controlled pharmacodynamic study, we analyzed serum, liver and vWAT samples from 40 well-matched morbidly obese patients receiving UDCA (20 mg/ kg/day) or no treatment three weeks prior to bariatric surgery. Results: Short term UDCA administration stimulated BA synthesis by reducing circulating fibroblast growth factor 19 and farnesoid X receptor (FXR) activation, resulting in cholesterol 7 alpha-hydroxylase induction mirrored by elevated C4 and 7 alpha-hydroxycholesterol. Enhanced BA formation depleted hepatic and LDL-cholesterol with subsequent activation of the key enzyme of cholesterol synthesis 3-hydroxy-3-methylglutaryl-CoA reductase. Blunted FXR anti-lipogenic effects induced lipogenic stearoyl-CoA desaturase (SCD) in the liver, thereby increasing hepatic triglyceride content. In addition, induced SCD activity in vWAT shifted vWAT lipid metabolism towards generation of less toxic and more lipogenic monounsaturated fatty acids such as oleic acid. Conclusion: These data demonstrate that by exerting FXR-antagonistic effects, UDCA treatment in NAFLD patients strongly impacts on cholesterol and BA synthesis and induces neutral lipid accumulation in both liver and vWAT. (C) 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
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