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Nenkov M, Shi Y, Ma Y, Gaßler N, Chen Y. Targeting Farnesoid X Receptor in Tumor and the Tumor Microenvironment: Implication for Therapy. Int J Mol Sci 2023; 25:6. [PMID: 38203175 PMCID: PMC10778939 DOI: 10.3390/ijms25010006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/14/2023] [Accepted: 12/15/2023] [Indexed: 01/12/2024] Open
Abstract
The farnesoid-X receptor (FXR), a member of the nuclear hormone receptor superfamily, can be activated by bile acids (BAs). BAs binding to FXR activates BA signaling which is important for maintaining BA homeostasis. FXR is differentially expressed in human organs and exists in immune cells. The dysregulation of FXR is associated with a wide range of diseases including metabolic disorders, inflammatory diseases, immune disorders, and malignant neoplasm. Recent studies have demonstrated that FXR influences tumor cell progression and development through regulating oncogenic and tumor-suppressive pathways, and, moreover, it affects the tumor microenvironment (TME) by modulating TME components. These characteristics provide a new perspective on the FXR-targeted therapeutic strategy in cancer. In this review, we have summarized the recent research data on the functions of FXR in solid tumors and its influence on the TME, and discussed the mechanisms underlying the distinct function of FXR in various types of tumors. Additionally, the impacts on the TME by other BA receptors such as takeda G protein-coupled receptor 5 (TGR5), sphingosine-1-phosphate receptor 2 (S1PR2), and muscarinic receptors (CHRM2 and CHRM3), have been depicted. Finally, the effects of FXR agonists/antagonists in a combination therapy with PD1/PD-L1 immune checkpoint inhibitors and other anti-cancer drugs have been addressed.
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Affiliation(s)
- Miljana Nenkov
- Section Pathology of the Institute of Forensic Medicine, Jena University Hospital, Friedrich Schiller University Jena, Am Klinikum 1, 07747 Jena, Germany; (M.N.); (Y.M.); (N.G.)
| | - Yihui Shi
- California Pacific Medical Center Research Institute, Sutter Bay Hospitals, San Francisco, CA 94107, USA;
| | - Yunxia Ma
- Section Pathology of the Institute of Forensic Medicine, Jena University Hospital, Friedrich Schiller University Jena, Am Klinikum 1, 07747 Jena, Germany; (M.N.); (Y.M.); (N.G.)
| | - Nikolaus Gaßler
- Section Pathology of the Institute of Forensic Medicine, Jena University Hospital, Friedrich Schiller University Jena, Am Klinikum 1, 07747 Jena, Germany; (M.N.); (Y.M.); (N.G.)
| | - Yuan Chen
- Section Pathology of the Institute of Forensic Medicine, Jena University Hospital, Friedrich Schiller University Jena, Am Klinikum 1, 07747 Jena, Germany; (M.N.); (Y.M.); (N.G.)
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Chua HH, Chen YH, Wu LL, Yang HC, Lin CR, Chen HL, Wu JF, Chang MH, Chen PJ, Ni YH. Antagonism Between Gut Ruminococcus gnavus and Akkermansia muciniphila Modulates the Progression of Chronic Hepatitis B. Cell Mol Gastroenterol Hepatol 2023; 17:361-381. [PMID: 38092311 PMCID: PMC10821531 DOI: 10.1016/j.jcmgh.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 11/14/2023] [Accepted: 12/04/2023] [Indexed: 01/01/2024]
Abstract
BACKGROUND & AIMS A long immune-tolerant (IT) phase lasting for decades and delayed HBeAg seroconversion (HBe-SC) in patients with chronic hepatitis B (CHB) increase the risk of liver diseases. Early entry into the immune-active (IA) phase and HBe-SC confers a favorable clinical outcome with an unknown mechanism. We aimed to identify factor(s) triggering IA entry and HBe-SC in the natural history of CHB. METHODS To study the relevance of gut microbiota evolution in the risk of CHB activity, fecal samples were collected from CHB patients (n = 102) in different disease phases. A hepatitis B virus (HBV)-hydrodynamic injection (HDI) mouse model was therefore established in several mouse strains and germ-free mice, and multiplatform metabolomic and bacteriologic assays were performed. RESULTS Ruminococcus gnavus was the most abundant species in CHB patients in the IT phase, whereas Akkermansia muciniphila was predominantly enriched in IA patients and associated with alanine aminotransferase flares, HBeAg loss, and early HBe-SC. HBV-HDI mouse models recapitulated this human finding. Increased cholesterol-to-bile acids (BAs) metabolism was found in IT patients because R gnavus encodes bile salt hydrolase to deconjugate primary BAs and augment BAs total pool for facilitating HBV persistence and prolonging the IT course. A muciniphila counteracted this activity through the direct removal of cholesterol. The secretome metabolites of A muciniphila, which contained small molecules structurally similar to apigenin, lovastatin, ribavirin, etc., inhibited the growth and the function of R gnavus to allow HBV elimination. CONCLUSIONS R gnavus and A muciniphila play opposite roles in HBV infection. A muciniphila metabolites, which benefit the elimination of HBV, may contribute to future anti-HBV strategies.
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Affiliation(s)
- Huey-Huey Chua
- Department of Pediatrics, National Taiwan University College of Medicine and Children's Hospital, Taipei, Taiwan
| | - Ya-Hui Chen
- Department of Pediatrics, National Taiwan University College of Medicine and Children's Hospital, Taipei, Taiwan
| | - Li-Ling Wu
- Department and Institute of Physiology, National Yang-Ming Chiao-Tung University College of Medicine, Taipei, Taiwan
| | - Hung-Chih Yang
- Department of Internal Medicine, Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan; Graduate Institute of Microbiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chia-Ray Lin
- Department of Pediatrics, National Taiwan University College of Medicine and Children's Hospital, Taipei, Taiwan
| | - Huey-Ling Chen
- Department of Pediatrics, National Taiwan University College of Medicine and Children's Hospital, Taipei, Taiwan; Graduate Institute of Medical Education and Bioethics, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Jia-Feng Wu
- Department of Pediatrics, National Taiwan University College of Medicine and Children's Hospital, Taipei, Taiwan
| | - Mei-Hwei Chang
- Department of Pediatrics, National Taiwan University College of Medicine and Children's Hospital, Taipei, Taiwan
| | - Pei-Jer Chen
- Department of Internal Medicine, Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, Taipei, Taiwan; Center of Genomic and Precision Medicine, National Taiwan University College of Medicine, Taipei, Taiwan; Hepatitis Research Center, National Taiwan University Hospital, Taipei, Taiwan
| | - Yen-Hsuan Ni
- Department of Pediatrics, National Taiwan University College of Medicine and Children's Hospital, Taipei, Taiwan; Center of Genomic and Precision Medicine, National Taiwan University College of Medicine, Taipei, Taiwan; Hepatitis Research Center, National Taiwan University Hospital, Taipei, Taiwan; Medical Microbiota Center, National Taiwan University College of Medicine, Taipei, Taiwan.
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Molecular Basis of Bile Acid-FXR-FGF15/19 Signaling Axis. Int J Mol Sci 2022; 23:ijms23116046. [PMID: 35682726 PMCID: PMC9181207 DOI: 10.3390/ijms23116046] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 05/24/2022] [Accepted: 05/25/2022] [Indexed: 02/04/2023] Open
Abstract
Bile acids (BAs) are a group of amphiphilic molecules consisting of a rigid steroid core attached to a hydroxyl group with a varying number, position, and orientation, and a hydrophilic side chain. While BAs act as detergents to solubilize lipophilic nutrients in the small intestine during digestion and absorption, they also act as hormones. Farnesoid X receptor (FXR) is a nuclear receptor that forms a heterodimer with retinoid X receptor α (RXRα), is activated by BAs in the enterohepatic circulation reabsorbed via transporters in the ileum and the colon, and plays a critical role in regulating gene expression involved in cholesterol, BA, and lipid metabolism in the liver. The FXR/RXRα heterodimer also exists in the distal ileum and regulates production of fibroblast growth factor (FGF) 15/FGF19, a hormone traveling via the enterohepatic circulation that activates hepatic FGF receptor 4 (FGFR4)-β-klotho receptor complex and regulates gene expression involved in cholesterol, BA, and lipid metabolism, as well as those regulating cell proliferation. Agonists for FXR and analogs for FGF15/19 are currently recognized as a promising therapeutic target for metabolic syndrome and cholestatic diseases.
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Impaired Bile Acid Synthesis in a Taurine-Deficient Cat Model. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1370:195-203. [DOI: 10.1007/978-3-030-93337-1_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Chiang JY, Ferrell JM. Up to date on cholesterol 7 alpha-hydroxylase (CYP7A1) in bile acid synthesis. LIVER RESEARCH 2020; 4:47-63. [PMID: 34290896 PMCID: PMC8291349 DOI: 10.1016/j.livres.2020.05.001] [Citation(s) in RCA: 116] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cholesterol 7 alpha-hydroxylase (CYP7A1, EC1.14) is the first and rate-limiting enzyme in the classic bile acid synthesis pathway. Much progress has been made in understanding the transcriptional regulation of CYP7A1 gene expression and the underlying molecular mechanisms of bile acid feedback regulation of CYP7A1 and bile acid synthesis in the last three decades. Discovery of bile acid-activated receptors and their roles in the regulation of lipid, glucose and energy metabolism have been translated to the development of bile acid-based drug therapies for the treatment of liver-related metabolic diseases such as alcoholic and non-alcoholic fatty liver diseases, liver cirrhosis, diabetes, obesity and hepatocellular carcinoma. This review will provide an update on the advances in our understanding of the molecular biology and mechanistic insights of the regulation of CYP7A1 in bile acid synthesis in the last 40 years.
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Impaired bile acid metabolism with defectives of mitochondrial-tRNA taurine modification and bile acid taurine conjugation in the taurine depleted cats. Sci Rep 2020; 10:4915. [PMID: 32188916 PMCID: PMC7080809 DOI: 10.1038/s41598-020-61821-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 03/03/2020] [Indexed: 11/28/2022] Open
Abstract
Taurine that conjugates with bile acid (BA) and mitochondrial-tRNA (mt-tRNA) is a conditional essential amino acid in humans, similarly to cats. To better understand the influence of acquired depletion of taurine on BA metabolism, the profiling of BAs and its intermediates, BA metabolism-enzyme expression, and taurine modified mt-tRNAs were evaluated in the taurine deficient diet-supplemented cats. In the taurine depleted cats, taurine-conjugated bile acids in bile and taurine-modified mt-tRNA in liver were significantly decreased, whereas unconjugated BA in serum was markedly increased. Impaired bile acid metabolism in the liver was induced accompanied with the decreases of mitochondrial cholesterol 27-hydroxylase expression and mitochondrial activity. Consequently, total bile acid concentration in bile was significantly decreased by the low activity of mitochondrial bile acid synthesis. These results implied that the insufficient dietary taurine intake causes impaired bile acid metabolism, and in turn, a risk for the various diseases similar to the mitochondrial diseases would be enhanced.
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Impact of proprotein convertase subtilisin/kexin type 9 inhibition with evolocumab on the postprandial responses of triglyceride-rich lipoproteins in type II diabetic subjects. J Clin Lipidol 2019; 14:77-87. [PMID: 31917184 DOI: 10.1016/j.jacl.2019.12.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 11/21/2019] [Accepted: 12/10/2019] [Indexed: 12/15/2022]
Abstract
BACKGROUND Monoclonal antibodies to proprotein convertase subtilisin/kexin type 9 (PCSK9) significantly lower the levels of low-density lipoprotein and very-low-density lipoproteins (VLDL), but their effect on postprandial lipoprotein metabolism in dyslipidemic subjects is unclear. OBJECTIVE This study aimed to investigate the effects of evolocumab on postprandial lipid responses, ectopic fat depots, whole-body cholesterol synthesis, hepatic lipogenesis, and fat oxidation in patients with type II diabetes. METHODS The trial was a single-phase, nonrandomized study of 12-week treatment with evolocumab 140 mg subcutaneously every 2 weeks in 15 patients with type II diabetes on background statin therapy. Cardiometabolic responses to a high-fat mixed meal were assessed before and at the end of the intervention period. RESULTS Evolocumab treatment reduced significantly postprandial rises in plasma total triglyceride (by 21%; P < .0001) and VLDL1 triglyceride (by 15%; P = .018), but the increase in chylomicron triglyceride after the meal was not significantly perturbed (P = .053). There were reduced postprandial responses in plasma total apolipoprotein C-III (by 14%; P < .0001) and apolipoprotein B-48 concentration (by 17%; P = .0046) and in "remnant-like particles" cholesterol (by 29%; P < .0001) on the PCSK9 inhibitor. Treatment reduced the steady-state (ie, fasting and postprandial) concentrations of VLDL2 cholesterol by 50% (P < .0001) and VLDL2 triglyceride by 29% (P < .0001), in addition to the 78% reduction of low-density lipoprotein cholesterol (P < .001). The changes in apolipoprotein C-III associated significantly with reduction in postprandial responses of remnant-like particles cholesterol and triglyceride-rich lipoprotein cholesterol. Evolocumab therapy did not influence liver fat accumulation, hepatic de novo lipogenesis, or fasting β-hydroxybutyrate but did increase total body cholesterol synthesis (P < .01). CONCLUSION Evolocumab treatment improved postprandial responses of triglyceride-rich lipoproteins and measures of cholesterol-enriched remnant particles in type II diabetic subjects. These results indicate that postprandial phenomena need to be taken into account in assessing the full range of actions of PCSK9 inhibitors in dyslipidemic individuals.
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Pandak WM, Kakiyama G. The acidic pathway of bile acid synthesis: Not just an alternative pathway ☆. LIVER RESEARCH 2019; 3:88-98. [PMID: 32015930 PMCID: PMC6996149 DOI: 10.1016/j.livres.2019.05.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Over the last two decades, the prevalence of obesity, and metabolic syndromes (MS) such as non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM), have dramatically increased. Bile acids play a major role in the digestion, absorption of nutrients, and the body's redistribution of absorbed lipids as a function of their chemistry and signaling properties. As a result, a renewed interest has developed in the bile acid metabolic pathways with the challenge of gaining insight into novel treatment approaches for this rapidly growing healthcare problem. Of the two major pathways of bile acid synthesis in the liver, the foremost role of the acidic (alternative) pathway is to generate and control the levels of regulatory oxysterols that help control cellular cholesterol and lipid homeostasis. Cholesterol transport to mitochondrial sterol 27-hydroxylase (CYP27A1) by steroidogenic acute regulatory protein (StarD1), and the subsequent 7α-hydroxylation of oxysterols by oxysterol 7α-hydroxylase (CYP7B1) are the key regulatory steps of the pathway. Recent observations suggest CYP7B1 to be the ultimate controller of cellular oxysterol levels. This review discusses the acidic pathway and its contribution to lipid, cholesterol, carbohydrate, and energy homeostasis. Additionally, discussed is how the acidic pathway's dysregulation not only leads to a loss in its ability to control cellular cholesterol and lipid homeostasis, but leads to inflammatory conditions.
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Affiliation(s)
- William M. Pandak
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA,Department of Veterans Affairs, Richmond, VA, USA
| | - Genta Kakiyama
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA,Department of Veterans Affairs, Richmond, VA, USA,Corresponding author. Department of Internal Medicine, Virginia Commonwealth University and Department of Veterans Affairs, Richmond, VA, USA. (G. Kakiyama)
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Kakiyama G, Marques D, Takei H, Nittono H, Erickson S, Fuchs M, Rodriguez-Agudo D, Gil G, Hylemon PB, Zhou H, Bajaj JS, Pandak WM. Mitochondrial oxysterol biosynthetic pathway gives evidence for CYP7B1 as controller of regulatory oxysterols. J Steroid Biochem Mol Biol 2019; 189:36-47. [PMID: 30710743 DOI: 10.1016/j.jsbmb.2019.01.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 01/17/2019] [Accepted: 01/22/2019] [Indexed: 12/13/2022]
Abstract
The aim of this paper was to more completely study the mitochondrial CYP27A1 initiated acidic pathway of cholesterol metabolism. The mitochondrial CYP27A1 initiated pathway of cholesterol metabolism (acidic pathway) is known to synthesize two well-described vital regulators of cholesterol/lipid homeostasis, (25R)-26-hydroxycholesterol (26HC) and 25-hydroxycholesterol (25HC). Both 26HC and 25HC have been shown to be subsequently 7α-hydroxylated by Cyp7b1; reducing their regulatory abilities and furthering their metabolism to chenodeoxycholic acid (CDCA). Cholesterol delivery into the inner mitochondria membrane, where CYP27A1 is located, is considered the pathway's only rate-limiting step. To further explore the pathway, we increased cholesterol transport into mitochondrial CYP27A1 by selectively increased expression of the gene encoding the steroidogenic acute transport protein (StarD1). StarD1 overexpression led to an unanticipated marked down-regulation of oxysterol 7α-hydroxylase (Cyp7b1), a marked increase in 26HC, and the formation of a third vital regulatory oxysterol, 24(S)-hydroxycholesterol (24HC), in B6/129 mice livers. To explore the further metabolism of 24HC, as well as, 25HC and 26HC, characterizations of oxysterols and bile acids using three murine models (StarD1 overexpression, Cyp7b1-/-, Cyp27a1-/-) and human Hep G2 cells were conducted. This report describes the discovery of a new mitochondrial-initiated pathway of oxysterol/bile acid biosynthesis. Just as importantly, it provides evidence for CYP7B1 as a key regulator of three vital intracellular regulatory oxysterol levels.
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Affiliation(s)
- Genta Kakiyama
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States.
| | - Dalila Marques
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - Hajime Takei
- Junshin Clinic Bile Acid Institute, Tokyo, Japan
| | | | - Sandra Erickson
- School of Medicine, University of California, San Francisco, United States
| | - Michael Fuchs
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - Daniel Rodriguez-Agudo
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - Gregorio Gil
- Department of Biochemistry & Molecular Biology, Virginia Commonwealth University, United States
| | - Phillip B Hylemon
- Department of Microbiology and Immunology, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - Huiping Zhou
- Department of Microbiology and Immunology, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - Jasmohan S Bajaj
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
| | - William M Pandak
- Department of Internal Medicine, Virginia Commonwealth University, United States; Department of Veterans Affairs, Richmond, VA, United States
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Björkhem-Bergman L, Nylén H, Eriksson M, Parini P, Diczfalusy U. Effect of Statin Treatment on Plasma 4β-Hydroxycholesterol Concentrations. Basic Clin Pharmacol Toxicol 2016; 118:499-502. [PMID: 26617265 DOI: 10.1111/bcpt.12537] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 11/10/2015] [Indexed: 11/26/2022]
Abstract
The endogenous oxysterol 4β-hydroxycholesterol may be used as a marker for the drug-metabolizing enzymes cytochrome P450 3A (CYP3A). The primary aim of this study was to investigate the effect of statin treatment on plasma 4β-hydroxycholesterol concentrations. Plasma samples from a previously performed clinical study where gallstone patients had been treated with placebo (n = 6), 20 mg fluvastatin (n = 9) or 80 mg atorvastatin (n = 9) daily for 4 weeks were analysed. Hepatic CYP3A mRNA levels had previously been shown to be unchanged in all three treatment groups. Plasma 4β-hydroxycholesterol did not change significantly (p = 0.92) in the placebo group, but treatment with low-dose fluvastatin or high-dose atorvastatin resulted in reductions in plasma concentration of 10.7% (p < 0.05) and 36.5% (p < 0.01), respectively. However, the 4β-hydroxycholesterol/cholesterol ratio did not change significantly for the patients receiving placebo or patients receiving low-dose fluvastatin. The ratio for patients receiving high-dose atorvastatin increased by 12% (p < 0.05). In conclusion, the total plasma cholesterol level is an important determinant for the plasma 4β-hydroxycholesterol level.
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Affiliation(s)
- Linda Björkhem-Bergman
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Hanna Nylén
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Mats Eriksson
- Division of Endocrinology, Department of Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Paolo Parini
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Ulf Diczfalusy
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, Stockholm, Sweden
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Ferrannini E, Camastra S, Astiarraga B, Nannipieri M, Castro-Perez J, Xie D, Wang L, Chakravarthy M, Haeusler RA. Increased Bile Acid Synthesis and Deconjugation After Biliopancreatic Diversion. Diabetes 2015; 64:3377-85. [PMID: 26015549 PMCID: PMC4587641 DOI: 10.2337/db15-0214] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 05/21/2015] [Indexed: 12/19/2022]
Abstract
Biliopancreatic diversion (BPD) improves insulin sensitivity and decreases serum cholesterol out of proportion with weight loss. Mechanisms of these effects are unknown. One set of proposed contributors to metabolic improvements after bariatric surgeries is bile acids (BAs). We investigated the early and late effects of BPD on plasma BA levels, composition, and markers of BA synthesis in 15 patients with type 2 diabetes (T2D). We compared these to the early and late effects of Roux-en-Y gastric bypass (RYGB) in 22 patients with T2D and 16 with normal glucose tolerance. Seven weeks after BPD, insulin sensitivity had doubled and serum cholesterol had halved. At this time, BA synthesis markers and total plasma BAs, particularly unconjugated BAs, had markedly risen; this effect could not be entirely explained by low FGF19. In contrast, after RYGB, insulin sensitivity improved gradually with weight loss and cholesterol levels declined marginally; BA synthesis markers were decreased at an early time point (2 weeks) after surgery and returned to the normal range 1 year later. These findings indicate that BA synthesis contributes to the decreased serum cholesterol after BPD. Moreover, they suggest a potential role for altered enterohepatic circulation of BAs in improving insulin sensitivity and cholesterol metabolism after BPD.
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Affiliation(s)
- Ele Ferrannini
- Institute of Clinical Physiology, National Research Council, Pisa, Italy
| | - Stefania Camastra
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Brenno Astiarraga
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Monica Nannipieri
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Jose Castro-Perez
- Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ
| | - Dan Xie
- Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ
| | - Liangsu Wang
- Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ
| | - Manu Chakravarthy
- Cardiometabolic Disease, Merck Research Laboratories, Kenilworth, NJ
| | - Rebecca A Haeusler
- Department of Pathology and Cell Biology, Columbia University, New York, NY
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Increased serum oxysterol concentrations in patients with chronic hepatitis C virus infection. Biochem Biophys Res Commun 2014; 446:736-40. [PMID: 24525121 DOI: 10.1016/j.bbrc.2014.01.176] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 01/28/2014] [Indexed: 02/08/2023]
Abstract
Oxidative stress and dysregulated cholesterol metabolism are characteristic features of chronic hepatitis C virus infection (CHC). Therefore, we analyzed serum oxysterol profiles in CHC patients and examined the significance of oxysterols in CHC. The concentrations of 7α-hydroxycholesterol, 4β-hydroxycholesterol and 25-hydroxycholesterol as determined by LC-ESI-MS/MS were significantly elevated by +236%, +29% and +44%, respectively, in CHC patients compared with controls. Moreover, the elevated levels were significantly decreased by anti-viral therapy using PEGylated-interferon and ribavirin for 3 months. In contrast, 24S-hydroxycholesterol, 27-hydroxycholesterol and 7α-hydroxy-4-cholesten-3-one concentrations were not affected by CHC or anti-viral treatment. These results suggest that some oxysterols that are elevated in CHC are produced by cholesterol autoxidation due to oxidative stress or inflammation in the liver. Oxysterols may represent novel targets for the inhibition of disease progression and the prevention of hepatocarcinogenesis in CHC patients.
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Iwamoto J, Saito Y, Honda A, Miyazaki T, Ikegami T, Matsuzaki Y. Bile acid malabsorption deactivates pregnane X receptor in patients with Crohn's disease. Inflamm Bowel Dis 2013; 19:1278-84. [PMID: 23574760 DOI: 10.1097/mib.0b013e318281f423] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Recent studies have suggested that the downregulation of pregnane X receptor (PXR) may contribute to the susceptibility and exacerbation of Crohn's disease (CD). Because bile acid malabsorption is one of the features of CD and bile acids are potential activators of PXR, we explored the relationship between bile acid malabsorption and PXR activities in patients with CD. METHODS Twenty-one patients with CD (4 ileal-resected and 17 nonresected), 10 with ulcerative colitis (UC), and 26 healthy controls were studied. Serum biomarkers for the activity of CYP3A4, a target gene of PXR, and for cholesterol and bile acid metabolism were quantified by liquid chromatography-tandem mass spectrometry or enzyme-linked immunosorbent assay. RESULTS The concentrations of 4β-hydroxycholesterol (4β-HC), a known marker for CYP3A4 activity, and those of 25-hydroxycholesterol (25-HC), another metabolite by CYP3A4, were significantly reduced in all patients with CD, especially in those with the history of ileal resection. The concentration of 7α-hydroxy-4-cholesten-3-one (C4), a marker for hepatic bile acid biosynthesis, was significantly elevated, whereas the levels of fibroblast growth factor 19 (FGF19), a marker for intestinal bile acid flux, were reduced in patients with CD compared with patients with UC and controls. A significant negative correlation was observed between 4β-HC or 25-HC and C4 concentrations in all patients with CD. CONCLUSIONS The degree of bile acid malabsorption was closely associated with the deactivation of PXR in CD. Enterohepatic circulation of bile acids is a key factor for preservation of baseline activity of hepatointestinal PXR.
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Affiliation(s)
- Junichi Iwamoto
- Department of Gastroenterology, Tokyo Medical University Ibaraki Medical Center, Ibaraki, Japan.
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Honda A, Ikegami T, Nakamuta M, Miyazaki T, Iwamoto J, Hirayama T, Saito Y, Takikawa H, Imawari M, Matsuzaki Y. Anticholestatic effects of bezafibrate in patients with primary biliary cirrhosis treated with ursodeoxycholic acid. Hepatology 2013; 57:1931-41. [PMID: 22911624 DOI: 10.1002/hep.26018] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2012] [Accepted: 08/02/2012] [Indexed: 12/12/2022]
Abstract
UNLABELLED Bezafibrate is a widely used hypolipidemic agent and is known as a ligand of the peroxisome proliferator-activated receptors (PPARs). Recently this agent has come to be recognized as a potential anticholestatic medicine for the treatment of primary biliary cirrhosis (PBC) that does not respond sufficiently to ursodeoxycholic acid (UDCA) monotherapy. The aim of this study was to explore the anticholestatic mechanisms of bezafibrate by analyzing serum lipid biomarkers in PBC patients and by cell-based enzymatic and gene expression assays. Nineteen patients with early-stage PBC and an incomplete biochemical response to UDCA (600 mg/day) monotherapy were treated with the same dose of UDCA plus bezafibrate (400 mg/day) for 3 months. In addition to the significant improvement of serum biliary enzymes, immunoglobulin M (IgM), cholesterol, and triglyceride concentrations in patients treated with bezafibrate, reduction of 7α-hydroxy-4-cholesten-3-one (C4), a marker of bile acid synthesis, and increase of 4β-hydroxycholesterol, a marker of CYP3A4/5 activity, were observed. In vitro experiments using human hepatoma cell lines demonstrated that bezafibrate controlled the target genes of PPARα, as well as those of the pregnane X receptor (PXR); down-regulating CYP7A1, CYP27A1, and sinusoidal Na(+) /taurocholate cotransporting polypeptide (NTCP), and up-regulating CYP3A4, canalicular multidrug resistance protein 3 (MDR3), MDR1, and multidrug resistance-associated protein 2 (MRP2). CONCLUSION Bezafibrate is a dual PPARs/PXR agonist with potent anticholestatic efficacy in early-stage PBC patients with an incomplete biochemical response to UDCA monotherapy.
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Affiliation(s)
- Akira Honda
- Department of Gastroenterology, Tokyo Medical University Ibaraki Medical Center, Ami, Ibaraki, Japan
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15
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Lenicek M, Duricova D, Komarek V, Gabrysova B, Lukas M, Smerhovsky Z, Vitek L. Bile acid malabsorption in inflammatory bowel disease: assessment by serum markers. Inflamm Bowel Dis 2011; 17:1322-7. [PMID: 21058331 DOI: 10.1002/ibd.21502] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2010] [Accepted: 08/23/2010] [Indexed: 12/31/2022]
Abstract
BACKGROUND Bile acid malabsorption (BAM) is a common feature of Crohn's disease (CD). We aimed to determine whether BAM develops only in patients with a resected distal ileum or if it also occurs in patients who have not undergone surgery for CD. METHODS The study included 347 patients with CD or ulcerative colitis (UC) and 119 healthy subjects (controls). BAM was assessed by measurement of serum levels of 7α-hydroxycholest-4-en-3-one (C4) and fibroblast growth factor 19 (FGF19). We surveyed members of the European Crohn's and Colitis Organization and International Organization for the Study of Inflammatory Bowel Disease to collect current information about BAM diagnosis. RESULTS The severity of BAM was associated with resection of the distal ileum. Compared with controls, patients who received moderate or extensive ileal resection had significantly increased levels of serum C4 (12 versus 62 versus 243 μg/L, respectively; P < 0.001). However, BAM was also present in a substantial number of the patients with CD who were not treated by surgery who had ileitis or colitis (14% and 11%, respectively). There was an indirect, proportional relationship between levels of C4 and FGF19 (P < 0.001). CONCLUSIONS The most severe BAM occurs in CD patients after resection of the distal ileum, but BAM can occur in surgically untreated CD patients, regardless of disease localization. Laboratory tests for BAM should become a part of the algorithm for diagnosis of CD to identify patients who might respond to therapies such as bile acid sequestrants. FGF19 appears to be a reliable marker of BAM.
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Affiliation(s)
- Martin Lenicek
- Department of Clinical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague, Czech Republic
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16
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17
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Schreuder TCMA, Marsman HA, Lenicek M, van Werven JR, Nederveen AJ, Jansen PLM, Schaap FG. The hepatic response to FGF19 is impaired in patients with nonalcoholic fatty liver disease and insulin resistance. Am J Physiol Gastrointest Liver Physiol 2010; 298:G440-5. [PMID: 20093562 DOI: 10.1152/ajpgi.00322.2009] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Intestinal FGF19 has emerged as a novel endocrine regulator of hepatic bile salt and lipid metabolism. In patients with nonalcoholic fatty liver disease (NAFLD) hepatic lipid metabolism is deranged. A possible role of FGF19 in NAFLD has not been reported yet. In this study, we assessed intestinal FGF19 production and the hepatic response to FGF19 in NAFLD patients with and without insulin resistance [homeostasis model of assessment (HOMA) score > or =2.5 (n = 12) and HOMA score <2.5 (n = 8), respectively]. To this end, NAFLD patients received a standardized oral fat challenge. Postprandial excursions of triglycerides, bile salts, and FGF19 were monitored, and plasma levels of a marker for bile salt synthesis (7alpha-hydroxy-4-cholesten-3-one) were determined. Fasted FGF19 levels were comparable in a control group of healthy volunteers (n = 15) and in NAFLD patients (0.26 +/- 0.28 vs. 0.18 +/- 0.09 ng/ml, respectively, P = 0.94). Postprandial FGF19 levels in both controls and NAFLD patients peaked between 3-4 h and were three times higher than baseline levels. The areas under the postprandial FGF19 curve were similar in controls and in the HOMA score-based NAFLD subgroups. In NAFLD patients with HOMA score <2.5, the postprandial increase in plasma FGF19 was accompanied by a lowering of plasma levels of 7alpha-hydroxy-4-cholesten-3-one (-30%, P = 0.015). This anticipated decline was not observed in insulin-resistant NAFLD patients (+10%, P = 0.22). In conclusion, patients with NAFLD show an unimpaired intestinal FGF19 production. However, the hepatic response to FGF19 is impaired in NAFLD patients with insulin resistance (HOMA score > or =2.5). This impaired hepatic response to FGF19 may contribute to the dysregulation of lipid homeostasis in NAFLD.
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Kim DE, Youn YC, Kim YKI, Hong KM, Lee CS. Glycyrrhizin Prevents 7-Ketocholesterol Toxicity Against Differentiated PC12 Cells by Suppressing Mitochondrial Membrane Permeability Change. Neurochem Res 2009; 34:1433-42. [DOI: 10.1007/s11064-009-9930-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Accepted: 02/04/2009] [Indexed: 02/02/2023]
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19
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Hirayama T, Mizokami Y, Honda A, Homma Y, Ikegami T, Saito Y, Miyazaki T, Matsuzaki Y. Serum concentration of 27-hydroxycholesterol predicts the effects of high-cholesterol diet on plasma LDL cholesterol level. Hepatol Res 2009; 39:149-56. [PMID: 19208035 DOI: 10.1111/j.1872-034x.2008.00450.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
AIM The effect of dietary cholesterol on plasma cholesterol concentrations varies widely among individuals. Recent studies suggest that the synthesis of oxysterols is up-regulated when tissue cholesterol is saturated. The present study was undertaken to test the hypothesis that a serum high concentration of 27-hydroxycholesterol, one of the oxysterols, reflects positive cholesterol balance in the body and predicts intolerance to a high-cholesterol diet. METHODS In 30 subjects, 750 mg/day of cholesterol was added for 4 weeks to the ordinary diet. Blood samples were collected at the start and finish of the supplementation. Serum sterol and oxysterol concentrations were measured by high-resolution GC-MS. RESULTS A receiver operating characteristic curve was drawn and the cutoff point (80 ng/mg cholesterol) was chosen to maximize sensitivity (81.3%) and specificity (64.3%) for predicting a positive change of LDL cholesterol concentration after cholesterol loading. Subjects with higher serum 27-hydroxycholesterol concentrations (>/= 80 ng/mg cholesterol) showed significantly (P < 0.05) high values for the change of LDL cholesterol concentration (+7.4 +/- 3.4%, mean +/- SEM, n = 17) compared with those with lower 27-hydroxycholesterol levels (-5.3 +/- 2.7%, n = 13). CONCLUSIONS In subjects with high serum 27-hydroxycholesterol concentrations were unable to adapt to a high-cholesterol diet. The concentration of serum 27-hydroxycholesterol appears to reflect cholesterol saturation in the body and predicts to some extent a responsiveness to dietary cholesterol.
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Bajor A, Kilander A, Sjövall H, Rudling M, Ung KA. The bile acid turnover rate assessed with the (75)SeHCAT test is stable in chronic diarrhoea but slightly decreased in healthy subjects after a long period of time. Dig Dis Sci 2008; 53:2935-40. [PMID: 18437571 DOI: 10.1007/s10620-008-0256-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2008] [Accepted: 03/26/2008] [Indexed: 12/09/2022]
Abstract
The stability of bile acid turnover rate was evaluated retrospectively using repeat SeHCAT tests in patients with chronic diarrhoea and prospectively for 16 years in healthy subjects. The SeHCAT values were stable in 39 patients with chronic diarrhoea, as shown by a comparison of the test results [data presented as median and (25th-75th percentile)]: 18% (8-23) in the first test versus 14% (9-21) in the second test [n = 39, P = 0.37, time interval 44 months (16-68), repeatability index >95%]. In contrast, they were reduced after 16 years in healthy subjects: 38% (30-49.5) in the first test versus 31% (21-49.5) in the second test (P < 0.03). In healthy subjects, the body mass index increased by 13% from 23.2 kg/m(2) (21-24.6) to 26.2 kg/m(2) (22.5-27.8) (P < 0.01) during the 16 years. There was a negative correlation between hepatic bile acid synthesis and the SeHCAT values (r = -0.615, P = 0.02, n = 14). In conclusion, the turnover rate of bile acids is stable over a long period of time in patients with chronic diarrhoea irrespective of bile acid malabsorption, suggesting that a repeat SeHCAT test is dispensable. There is a significant negative correlation between bile acid synthesis and SeHCAT test results in healthy subjects. The SeHCAT test values are slightly reduced in healthy subjects after 16 years.
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Affiliation(s)
- Antal Bajor
- Institute of Medicine at Sahlgrenska Academy, University of Gothenburg, 41345, Gothenburg, Sweden.
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21
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Lenícek M, Komárek V, Zimolová M, Kovár J, Jirsa M, Lukás M, Vítek L. CYP7A1 promoter polymorphism -203A>C affects bile salt synthesis rate in patients after ileal resection. J Lipid Res 2008; 49:2664-7. [PMID: 18728290 DOI: 10.1194/jlr.m800364-jlr200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cholesterol 7alpha-hydroxylase (CYP7A1) plays a crucial role in cholesterol metabolism and has been implicated in genetic susceptibility to atherosclerosis. Thus, an understanding of its transcriptional regulation is of considerable importance. We evaluated the effect of a common -203A>C polymorphism in the CYP7A1 promoter region on the activity of CYP7A1, estimated as the ratios of serum 7alpha-hydroxycholest-4-en-3-one (C4) to either total or non-HDL-cholesterol. The study was performed on patients after resection of the distal ileum, leading to upregulation of CYP7A1 activity (n = 65). Healthy volunteers served as the control group (n = 66). Whereas higher CYP7A1 activity was associated with the -203A allele in the patient group (C4/cholesterol ratio, 29.0 vs. 14.8 microg/mmol, P = 0.032; C4/non-HDL-cholesterol ratio, 53.3 vs. 21.3 microg/mmol in -203AA and -203CC, P = 0.017, respectively), no differences were observed in the healthy controls. We conclude that under physiological conditions, the -203A>C polymorphism in the CYP7A1 gene promoter region does not seem to have any clinically relevant effect. However, in patients with severe bile salt malabsorption, this polymorphism markedly affects CYP7A1 activity.
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Affiliation(s)
- Martin Lenícek
- Department of Clinical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University in Prague.
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Yoshida T, Honda A, Miyazaki H, Matsuzaki Y. Determination of key intermediates in cholesterol and bile acid biosynthesis by stable isotope dilution mass spectrometry. ANALYTICAL CHEMISTRY INSIGHTS 2008; 3:45-60. [PMID: 19609389 PMCID: PMC2701176 DOI: 10.4137/aci.s611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
For more than a decade, we have developed stable isotope dilution mass spectrometry methods to quantify key intermediates in cholesterol and bile acid biosynthesis, mevalonate and oxysterols, respectively. The methods are more sensitive and reproducible than conventional radioisotope (RI), gas-chromatography (GC) or high-performance liquid chromatography (HPLC) methods, so that they are applicable not only to samples from experimental animals but also to small amounts of human specimens. In this paper, we review the development of stable isotope dilution mass spectrometry for quantifying mevalonate and oxysterols in biological materials, and demonstrate the usefulness of this technique.
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23
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Johansson L, Rudling M, Scanlan TS, Lundåsen T, Webb P, Baxter J, Angelin B, Parini P. Selective thyroid receptor modulation by GC-1 reduces serum lipids and stimulates steps of reverse cholesterol transport in euthyroid mice. Proc Natl Acad Sci U S A 2005; 102:10297-302. [PMID: 16006512 PMCID: PMC1177400 DOI: 10.1073/pnas.0504379102] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Thyroid hormones [predominantly 3,5,3'-triiodo-L-thyronine (T3)] regulate cholesterol and lipoprotein metabolism, but cardiac effects restrict their use as hypolipidemic drugs. T3 binds to thyroid hormone receptors (TRs) alpha and beta. TRbeta is the predominant isoform in liver, whereas T3 effects on heart rate are mediated mostly by TRalpha. Drugs that target TRbeta or exhibit tissue-selective uptake may improve plasma lipid levels while sparing the heart. Here, we asked how the TRbeta- and liver uptake-selective agonist GC-1 influences cholesterol and triglyceride metabolism in euthyroid mice. GC-1 treatment reduced serum cholesterol levels by 25% and serum triglycerides by 75% in chow-fed mice and also attenuated diet-induced hypercholesterolemia. GC-1 reduced plasma high-density lipoprotein cholesterol levels; increased expression of the hepatic high-density lipoprotein receptor, SR-BI; stimulated activity of cholesterol 7alpha-hydroxylase; and increased fecal excretion of bile acids. Collectively, these results suggest that GC-1 stimulates important steps in reverse cholesterol transport. Use of TRbeta and uptake selective agonists such as GC-1 should be further explored as a strategy to improve lipid metabolism in dyslipoproteinemia.
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Affiliation(s)
- Lisen Johansson
- Metabolism Unit, Center for Metabolism and Endocrinology, Department of Medicine, and Molecular Nutrition Unit, Center for Nutrition and Toxicology, NOVUM, Karolinska Institute at Karolinska University Hospital-Huddinge, SE-141 86 Stockholm, Sweden
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Boekschoten MV, Hofman MK, Buytenhek R, Schouten EG, Princen HMG, Katan MB. Coffee oil consumption increases plasma levels of 7alpha-hydroxy-4-cholesten-3-one in humans. J Nutr 2005; 135:785-9. [PMID: 15795435 DOI: 10.1093/jn/135.4.785] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Unfiltered coffee brews such as French press and espresso contain a lipid from coffee beans named cafestol that raises serum cholesterol in humans. Cafestol decreases the expression and activity of cholesterol 7alpha-hydroxylase, the rate-limiting enzyme in the classical pathway of bile acid synthesis, in cultured rat hepatocytes and livers of APOE3Leiden mice. Inhibition of bile acid synthesis has been suggested to be responsible for the cholesterol-raising effect of cafestol. Therefore, we assessed whether cafestol decreases the activity of cholesterol 7alpha-hydroxylase in humans. Because liver biopsies were not feasible, we measured plasma levels of 7alpha-hydroxy-4-cholesten-3-one, a marker for the activity of cholesterol 7alpha-hydroxylase in the liver. Plasma 7alpha-hydroxy-4-cholesten-3-one was measured in 2 separate periods in which healthy volunteers consumed coffee oil containing cafestol (69 mg/d) for 5 wk. Plasma levels of 7alpha-hydroxy-4-cholesten-3-one increased by 47 +/- 13% (mean +/- SEM, n = 38, P = 0.001) in the first period and by 23 +/- 10% (n = 31, P = 0.03) in the second treatment period. Serum cholesterol was raised by 23 +/- 2% (P < 0.001) in the first period and by 18 +/- 2% (P < 0.001) in the second period. We corrected individual 7alpha-hydroxy-4-cholesten-3-one levels for serum cholesterol levels, because coffee oil increases serum cholesterol and 7alpha-hydroxy-4-cholesten-3-one is probably present in the lipoprotein fraction of serum. After correction, the increase in 7alpha-hydroxy-4-cholesten-3-one was 24 +/- 11% (P = 0.04) in the first period and there was no effect in period 2. Our study showed that coffee oil did not decrease, and actually increased, plasma levels of 7alpha-hydroxy-4-cholesten-3-one in humans in 2 separate treatment periods. Therefore, this study does not support the hypothesis that cafestol decreases bile acid synthesis in humans.
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Affiliation(s)
- Mark V Boekschoten
- Division of Human Nutrition, Wageningen University, Wageningen, The Netherlands.
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