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Pang J, Raka F, Heirali AA, Shao W, Liu D, Gu J, Feng JN, Mineo C, Shaul PW, Qian X, Coburn B, Adeli K, Ling W, Jin T. Resveratrol intervention attenuates chylomicron secretion via repressing intestinal FXR-induced expression of scavenger receptor SR-B1. Nat Commun 2023; 14:2656. [PMID: 37160898 PMCID: PMC10169763 DOI: 10.1038/s41467-023-38259-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 04/21/2023] [Indexed: 05/11/2023] Open
Abstract
Two common features of dietary polyphenols have hampered our mechanistic understanding of their beneficial effects for decades: targeting multiple organs and extremely low bioavailability. We show here that resveratrol intervention (REV-I) in high-fat diet (HFD)-challenged male mice inhibits chylomicron secretion, associated with reduced expression of jejunal but not hepatic scavenger receptor class B type 1 (SR-B1). Intestinal mucosa-specific SR-B1-/- mice on HFD-challenge exhibit improved lipid homeostasis but show virtually no further response to REV-I. SR-B1 expression in Caco-2 cells cannot be repressed by pure resveratrol compound while fecal-microbiota transplantation from mice on REV-I suppresses jejunal SR-B1 in recipient mice. REV-I reduces fecal levels of bile acids and activity of fecal bile-salt hydrolase. In Caco-2 cells, chenodeoxycholic acid treatment stimulates both FXR and SR-B1. We conclude that gut microbiome is the primary target of REV-I, and REV-I improves lipid homeostasis at least partially via attenuating FXR-stimulated gut SR-B1 elevation.
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Affiliation(s)
- Juan Pang
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, PR China
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Laboratory of Clinical Pharmacy and Adverse Drug Reaction, West China Hospital, Sichuan University, Chengdu, PR China
| | - Fitore Raka
- Department of Molecular Structure and Function Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
- Banting and Best Diabetes Centre, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Alya Abbas Heirali
- Department of Medicine, Division of Infectious Diseases, University Health Network, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Weijuan Shao
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
| | - Dinghui Liu
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China
| | - Jianqiu Gu
- Department of Endocrinology and Metabolism and The Institute of Endocrinology, The First Hospital of China Medical University, Shenyang, PR China
| | - Jia Nuo Feng
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada
- Banting and Best Diabetes Centre, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Chieko Mineo
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Philip W Shaul
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiaoxian Qian
- Department of Cardiology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China
| | - Bryan Coburn
- Department of Medicine, Division of Infectious Diseases, University Health Network, Toronto, ON, Canada
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Khosrow Adeli
- Department of Molecular Structure and Function Research Institute, The Hospital for Sick Children, Toronto, ON, Canada.
- Banting and Best Diabetes Centre, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
| | - Wenhua Ling
- Department of Nutrition, School of Public Health, Sun Yat-sen University, Guangzhou, PR China.
| | - Tianru Jin
- Division of Advanced Diagnostics, Toronto General Hospital Research Institute, University Health Network, Toronto, ON, Canada.
- Banting and Best Diabetes Centre, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
- Department of Laboratory Medicine and Pathobiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
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Gamma-Muricholic Acid Inhibits Nonalcoholic Steatohepatitis: Abolishment of Steatosis-Dependent Peroxidative Impairment by FXR/SHP/LXRα/FASN Signaling. Nutrients 2023; 15:nu15051255. [PMID: 36904254 PMCID: PMC10005659 DOI: 10.3390/nu15051255] [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: 01/26/2023] [Revised: 02/23/2023] [Accepted: 02/25/2023] [Indexed: 03/06/2023] Open
Abstract
Nonalcoholic steatohepatitis (NASH) reflects the outcome of steatosis-based peroxidative impairment. Here, the effect and mechanism of γ-muricholic acid (γ-MCA) on NASH were investigated on the basis of its actions in hepatic steatosis, lipid peroxidation, peroxidative injury, hepatocyte apoptosis, and its NAFLD activity score (NAS). The agonist action of γ-MCA on farnesoid X receptor (FXR) upregulated the small heterodimer partner (SHP) expression of hepatocytes. An increase in SHP attenuated the triglyceride-dominated hepatic steatosis which was induced in vivo by a high-fat high-cholesterol (HFHC) diet and in vitro by free fatty acids depending on the inhibition of liver X receptor α (LXRα) and fatty acid synthase (FASN). In contrast, FXR knockdown abrogated the γ-MCA-dependent lipogenic inactivation. When compared to their excessive production in HFHC diet-induced rodent NASH, products of lipid peroxidation (MDA and 4-HNE) exhibited significant reductions upon γ-MCA treatment. Moreover, the decreased levels of serum alanine aminotransferases and aspartate aminotransferases demonstrated an improvement in the peroxidative injury of hepatocytes. By TUNEL assay, injurious amelioration protected the γ-MCA-treated mice against hepatic apoptosis. The abolishment of apoptosis prevented lobular inflammation, which downregulated the incidence of NASH by lowering NAS. Collectively, γ-MCA inhibits steatosis-induced peroxidative injury to ameliorate NASH by targeting FXR/SHP/LXRα/FASN signaling.
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Cai H, Wen Z, Meng K, Yang P. Metabolomic signatures for liver tissue and cecum contents in high-fat diet-induced obese mice based on UHPLC-Q-TOF/MS. Nutr Metab (Lond) 2021; 18:69. [PMID: 34193189 PMCID: PMC8243746 DOI: 10.1186/s12986-021-00595-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/21/2021] [Indexed: 12/15/2022] Open
Abstract
Background The incidence of obesity is increasing worldwide, and it is a risk factor for diabetes, dyslipidemia, and nonalcoholic fatty liver disease. Our previous study had demonstrated that high-fat diet induced increased weight gain, fat weight, serum cholesterol, triglyceride, and ATL levels in liver, and influenced the diversity and composition of cecal microbiota in mice. Hence, this study aimed to investigate the roles of the gut microbially derived metabolites and liver metabolites between the obese and lean mice, focusing on their association with the progression of obesity induced by high-fat diet (HFD). Methods An obesity model in mice was established with HFD for 16 weeks. Cecal contents and liver tissues metabolomics based on ultraperformance liquid chromatography-quadrupole-time-of-flight mass spectrometry and orthogonal partial least squares discriminant analyses (OPLS-DA) was performed to identify the alterations in metabolites associated with obese mice. Results Obese and lean groups were clearly discriminated from each other on OPLS-DA score plot and major metabolites contributing to the discrimination were mainly involved in glycerophospholipid metabolism, primary bile acid biosynthesis, and biosynthesis of unsaturated fatty acids pathways. HFD-induced alterations of 19 metabolites in liver and 43 metabolites in cecum contents were identified as potential biomarkers related to obesity. Specifically, chenodeoxycholic acid, taurochenodeoxycholate, and tauroursodeoxycholic acid in liver were elevated 35.94, 24.36, and 18.71-fold, respectively. PI(P-16:0/18:1(9Z)), PG(19:0/16:0), PS(P-16:0/20:2(11Z,14Z)), PI(22:1(11Z)/12:0), and PE(21:0/0:0) in cecum were enhanced 884, 640.96, 226.63, 210.10, 45.13-fold in comparison with the lean mice. These metabolites were the most important biomarkers for discriminating between the obese and lean mice. In addition, cecum contents metabolites were strongly correlated with hepatic metabolites through gut-liver axis analysis. Conclusions HFD increased lipid profiles (i.e. glycerophospholipids, PC, PE, PI, PG, and PS) and total bile acid (primary and secondary bile acid) in liver and cecum, suggesting that they may play an important role in the progression of obesity. These metabolites can be used to better understand obesity and related disease induced by HFD. Furthermore, the level alterations of these metabolites can be used to assess the risk of obesity and the therapeutic effect of obesity management.
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Affiliation(s)
- Hongying Cai
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Beijing, 100081, People's Republic of China.,National Engineering Research Center of Biological Feed, Beijing, 100081, People's Republic of China
| | - Zhiguo Wen
- National Engineering Research Center of Biological Feed, Beijing, 100081, People's Republic of China
| | - Kun Meng
- National Engineering Research Center of Biological Feed, Beijing, 100081, People's Republic of China
| | - Peilong Yang
- Institute of Feed Research, Chinese Academy of Agricultural Sciences, No. 12 Zhongguancun South Street, Beijing, 100081, People's Republic of China. .,National Engineering Research Center of Biological Feed, Beijing, 100081, People's Republic of China.
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Li H, Yu XH, Ou X, Ouyang XP, Tang CK. Hepatic cholesterol transport and its role in non-alcoholic fatty liver disease and atherosclerosis. Prog Lipid Res 2021; 83:101109. [PMID: 34097928 DOI: 10.1016/j.plipres.2021.101109] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/12/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a quickly emerging global health problem representing the most common chronic liver disease in the world. Atherosclerotic cardiovascular disease represents the leading cause of mortality in NAFLD patients. Cholesterol metabolism has a crucial role in the pathogenesis of both NAFLD and atherosclerosis. The liver is the major organ for cholesterol metabolism. Abnormal hepatic cholesterol metabolism not only leads to NAFLD but also drives the development of atherosclerotic dyslipidemia. The cholesterol level in hepatocytes reflects the dynamic balance between endogenous synthesis, uptake, esterification, and export, a process in which cholesterol is converted to neutral cholesteryl esters either for storage in cytosolic lipid droplets or for secretion as a major constituent of plasma lipoproteins, including very-low-density lipoproteins, chylomicrons, high-density lipoproteins, and low-density lipoproteins. In this review, we describe decades of research aimed at identifying key molecules and cellular players involved in each main aspect of hepatic cholesterol metabolism. Furthermore, we summarize the recent advances regarding the biological processes of hepatic cholesterol transport and its role in NAFLD and atherosclerosis.
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Affiliation(s)
- Heng Li
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China
| | - Xiao-Hua Yu
- Institute of Clinical Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China
| | - Xiang Ou
- Department of Endocrinology, the First Hospital of Changsha, Changsha, Hunan 410005, China
| | - Xin-Ping Ouyang
- Department of Physiology, Institute of Neuroscience Research, Hengyang Key Laboratory of Neurodegeneration and Cognitive Impairment, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China.
| | - Chao-Ke Tang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China.
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Systematic review and meta-analysis of randomized controlled trials on the effects of obeticholic acid on the blood lipid profile: Insights into liver disorders and liver cancer. Eur J Pharmacol 2020; 889:173616. [DOI: 10.1016/j.ejphar.2020.173616] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/16/2020] [Accepted: 09/28/2020] [Indexed: 12/11/2022]
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Wang D, Huang J, Gui T, Yang Y, Feng T, Tzvetkov NT, Xu T, Gai Z, Zhou Y, Zhang J, Atanasov AG. SR-BI as a target of natural products and its significance in cancer. Semin Cancer Biol 2020; 80:18-38. [PMID: 31935456 DOI: 10.1016/j.semcancer.2019.12.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/25/2019] [Accepted: 12/30/2019] [Indexed: 02/07/2023]
Abstract
Scavenger receptor class B type I (SR-BI) protein is an integral membrane glycoprotein. SR-BI is emerging as a multifunctional protein, which regulates autophagy, efferocytosis, cell survival and inflammation. It is well known that SR-BI plays a critical role in lipoprotein metabolism by mediating cholesteryl esters selective uptake and the bi-directional flux of free cholesterol. Recently, SR-BI has also been identified as a potential marker for cancer diagnosis, prognosis, or even a treatment target. Natural products are a promising source for the discovery of new drug leads. Multiple natural products were identified to regulate SR-BI protein expression. There are still a number of challenges in modulating SR-BI expression in cancer and in using natural products for modulation of such protein expression. In this review, our purpose is to discuss the relationship between SR-BI protein and cancer, and the molecular mechanisms regulating SR-BI expression, as well as to provide an overview of natural products that regulate SR-BI expression.
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Affiliation(s)
- Dongdong Wang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Jiansheng Huang
- Department of Medicine, Vanderbilt University Medical Center, 318 Preston Research Building, 2200 Pierce Avenue, Nashville, Tennessee, 37232, USA
| | - Ting Gui
- Key Laboratory of Traditional Chinese Medicine for Classical Theory, Ministry of Education, Shandong University of Traditional Chinese Medicine, Jinan, 250355, China
| | - Yaxin Yang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Tingting Feng
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China
| | - Nikolay T Tzvetkov
- Department of Biochemical Pharmacology and Drug Design, Institute of Molecular Biology "Roumen Tsanev", Bulgarian Academy of Sciences, 21 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria
| | - Tao Xu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China
| | - Zhibo Gai
- Department of Clinical Pharmacology and Toxicology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Ying Zhou
- College of Pharmacy, Guizhou University of Traditional Chinese Medicine, Huaxi university town, 550025, Guiyang, China.
| | - Jingjie Zhang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Fei Shan Jie 32, 550003, Guiyang, China.
| | - Atanas G Atanasov
- Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, 05-552, Jastrzębiec, Poland; Department of Pharmacognosy, University of Vienna, Althanstrasse 14, 1090, Vienna, Austria; Institute of Neurobiology, Bulgarian Academy of Sciences, 23 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria; Ludwig Boltzmann Institute for Digital Health and Patient Safety, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
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Impact of obeticholic acid on the lipoprotein profile in patients with non-alcoholic steatohepatitis. J Hepatol 2020; 72:25-33. [PMID: 31634532 PMCID: PMC6920569 DOI: 10.1016/j.jhep.2019.10.006] [Citation(s) in RCA: 90] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 10/04/2019] [Accepted: 10/07/2019] [Indexed: 01/27/2023]
Abstract
BACKGROUND & AIMS Obeticholic acid (OCA), a farnesoid X receptor agonist, increases total and low-density lipoprotein cholesterol (LDL-C) in patients with non-alcoholic steatohepatitis. In the present study, we aimed to evaluate the impact of OCA therapy on lipoprotein sub-particles. METHOD This study included 196 patients (99 OCA group and 97 placebo group) who were enrolled in the FLINT trial and had samples available for lipid analysis and liver biopsies at enrollment and end-of-treatment (EOT) at 72 weeks. Very low-density lipoprotein (VLDL), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) particles were evaluated at baseline, 12 and 72 weeks after randomization, and 24 weeks following EOT. RESULTS Baseline lipoprotein profiles were similar among OCA and placebo groups. OCA did not affect total VLDL particle concentrations, but OCA vs. placebo treatment was associated with decreased large VLDL particle concentration at 12 weeks (baseline-adjusted mean: 6.8 vs. 8.9 nmol/L; p = 0.002), mirrored by an increase in less atherogenic, small VLDL particle concentration (33.9 vs. 28.0 nmol/L; p = 0.02). After 12 weeks, total LDL particle concentration was higher in the OCA group than the placebo group (1,667 vs. 1,329 nmol/L; p <0.0001), characterized by corresponding increases in both less atherogenic, large-buoyant LDL (475 vs. 308 nmol/L; p ≤0.001) and more atherogenic small-dense LDL particles (1,015 vs. 872 nmol/L; p = 0.002). The changes in LDL particle concentrations were similar between treatment groups (OCA and placebo) 24 weeks following EOT due to improvement in the OCA cohort. Compared to placebo, a reduction in total HDL particle concentration, particularly large and medium HDL particles, was noted in the OCA-treated patients, but this resolved after drug discontinuation. CONCLUSION OCA therapy is associated with increases in small VLDL particles, large and small LDL particles, and a reduction in HDL particles at 12 weeks. These lipoprotein concentrations reverted to baseline values 24 weeks after drug discontinuation. LAY SUMMARY Non-alcoholic steatohepatitis is a chronic liver disease that is associated with an increased risk of developing cirrhosis and cardiovascular disease. Recently, obeticholic acid (OCA), a farnesoid X receptor agonist, improved liver disease but led to an increase in cholesterol. However, the impact of OCA on cholesterol is not well understood. In the present study, we show that OCA therapy is associated with a detrimental increase in lipoprotein levels, which improves after drug discontinuation. ClinicalTrials.gov numbers: NCT01265498.
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Singh AB, Dong B, Kraemer FB, Xu Y, Zhang Y, Liu J. Farnesoid X Receptor Activation by Obeticholic Acid Elevates Liver Low-Density Lipoprotein Receptor Expression by mRNA Stabilization and Reduces Plasma Low-Density Lipoprotein Cholesterol in Mice. Arterioscler Thromb Vasc Biol 2019; 38:2448-2459. [PMID: 30354208 DOI: 10.1161/atvbaha.118.311122] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Objective- The objective of this study was to determine whether and how activation of farnesoid X receptor (FXR) by obeticholic acid (OCA), a clinical FXR agonist, modulates liver low-density lipoprotein receptor (LDLR) expression under normolipidemic conditions. Approach and Results- Administration of OCA to chow-fed mice increased mRNA and protein levels of LDLR in the liver without affecting the sterol-regulatory element binding protein pathway. Profiling of known LDLR mRNA-binding proteins demonstrated that OCA treatment did not affect expressions of mRNA degradation factors hnRNPD (heterogeneous nuclear ribonucleoprotein D) or ZFP36L1 but increased the expression of Hu antigen R (HuR) an mRNA-stabilizing factor. Furthermore, inducing effects of OCA on LDLR and HuR expression were ablated in Fxr-/- mice. To confirm the post-transcriptional mechanism, we used transgenic mice (albumin-luciferase-untranslated region) that express a human LDLR mRNA 3' untranslated region luciferase reporter gene in the liver. OCA treatment led to significant rises in hepatic bioluminescence signals, Luc-untranslated region chimeric mRNA levels, and endogenous LDLR protein abundance, which were accompanied by elevations of hepatic HuR mRNA and protein levels in OCA-treated transgenic mice. In vitro studies conducted in human primary hepatocytes and HepG2 cells demonstrated that FXR activation by OCA and other agonists elicited the same inducing effect on LDLR expression as in the liver of normolipidemic mice. Furthermore, depletion of HuR in HepG2 cells by short interfering RNA transfection abolished the inducing effect of OCA on LDLR expression. Conclusions- Our study is the first to demonstrate that FXR activation increases LDLR expression in liver tissue by a post-transcriptional regulatory mechanism involving LDLR mRNA-stabilizing factor HuR.
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Affiliation(s)
- Amar Bahadur Singh
- From the Veterans Affairs Palo Alto Health Care System, CA (A.B.S., B.D., F.B.K., J.L.)
| | - Bin Dong
- From the Veterans Affairs Palo Alto Health Care System, CA (A.B.S., B.D., F.B.K., J.L.)
| | - Fredric B Kraemer
- From the Veterans Affairs Palo Alto Health Care System, CA (A.B.S., B.D., F.B.K., J.L.).,Department of Medicine, Stanford University, CA (F.B.K.)
| | - Yanyong Xu
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown (Y.X., Y.Z.)
| | - Yanqiao Zhang
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown (Y.X., Y.Z.)
| | - Jingwen Liu
- From the Veterans Affairs Palo Alto Health Care System, CA (A.B.S., B.D., F.B.K., J.L.)
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Dong B, Singh AB, Guo GL, Young M, Liu J. Activation of FXR by obeticholic acid induces hepatic gene expression of SR-BI through a novel mechanism of transcriptional synergy with the nuclear receptor LXR. Int J Mol Med 2019; 43:1927-1938. [PMID: 30896855 PMCID: PMC6443341 DOI: 10.3892/ijmm.2019.4136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2018] [Accepted: 02/13/2019] [Indexed: 11/06/2022] Open
Abstract
The farnesoid X receptor (FXR) is known to regulate the gene expression of SR‑BI, which mediates plasma high‑density lipoprotein (HDL)‑cholesterol uptake. Our previous study demonstrated that the activation of FXR by obeticholic acid (OCA) lowered plasma HDL‑cholesterol levels and increased the hepatic mRNA and protein expression levels of SR‑BI in hypercholesterolemic hamsters, but not in normolipidemic hamsters, suggesting that dietary cholesterol may be involved in the OCA‑induced transcription of SR‑BI. In the present study, a functional 90‑base‑pair regulatory region was identified in the first intron of the SR‑BI gene of hamster and mouse that contains a FXR response element (IR‑1) and an adjacent liver X receptor (LXR) response element (LXRE). By in vitro DNA binding and luciferase reporter gene assays, it was demonstrated that FXR and LXR bind to their recognition sequences within this intronic region and transactivate the SR‑BI reporter gene in a synergistic manner. It was also shown that mutations at either the IR‑1 site or the LXRE site eliminated OCA‑mediated gene transcription. Utilizing chow‑fed hamsters as an in vivo model, it was demonstrated that treating normolipidemic hamsters with OCA or GW3965 alone did not effectively induce levels of SR‑BI, whereas their combined treatment significantly increased the mRNA and protein levels of SR‑BI in the liver. The study further investigated effects of FXR and LXR coactivation on the gene expression of SR‑BI in human liver cells. The intronic FXRE and LXRE regulatory region was not conserved in the human SR‑BI genomic sequence, however, higher mRNA expression levels of SR‑BI were observed in human primary hepatocytes and HepG2 cells exposed to combined treatments of FXR and LXR agonists, compared with those in cells exposed to individual ligand treatment. Therefore, these results suggest that human SR‑BI gene transcription may also be subject to concerted activation by FXR and LXR, mediated via currently unidentified regulatory sequences.
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Affiliation(s)
- Bin Dong
- Department of Veterans Affairs, Palo Alto Health Care System, Palo Alto, CA 94304, USA
| | - Amar B Singh
- Department of Veterans Affairs, Palo Alto Health Care System, Palo Alto, CA 94304, USA
| | - Grace L Guo
- Department of Pharmacology and Toxicology, School of Pharmacy, Rutgers University, Piscataway, NJ 08854, USA
| | - Mark Young
- Mistral Therapeutics, San Diego, CA 92121, USA
| | - Jingwen Liu
- Department of Veterans Affairs, Palo Alto Health Care System, Palo Alto, CA 94304, USA
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Wu ZY, Li H, Li JR, Lv XQ, Jiang JD, Peng ZG. Farnesoid X receptor agonist GW4064 indirectly inhibits HCV entry into cells via down-regulating scavenger receptor class B type I. Eur J Pharmacol 2019; 853:111-120. [PMID: 30902657 DOI: 10.1016/j.ejphar.2019.03.033] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 03/08/2019] [Accepted: 03/18/2019] [Indexed: 02/06/2023]
Abstract
Farnesoid X receptor (FXR) agonists play important regulatory roles in bile acid, lipid and glucose metabolism in vitro and in vivo. Thus, FXR agonists exhibit potential therapeutic effects on metabolism-related diseases that are associated with extrahepatic manifestations induced by hepatitis C virus (HCV) infection. This study investigated the effect and mechanism of FXR agonist GW4064 against HCV in vitro to explore the potential application of FXR agonists. Results showed that GW4064 and other FXR agonists have potent antiviral activity against HCV in Huh7.5 cells. GW4064 down-regulated the expression of scavenger receptor class B type I protein via FXR and thereby indirectly inhibited HCV entry into cells, leading to interruption of HCV life cycle. GW4064 also exhibited synergistic anti-HCV effect with known direct-acting antiviral agents (DAAs) used in the clinic and remained sensitive to DAA-resistant HCV mutations. Therefore, FXR agonists are also a kind of antiviral agent, and might be helpful in treatment of HCV-induced hepatic and extrahepatic manifestations.
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Affiliation(s)
- Zhou-Yi Wu
- Laboratory of Antiviral Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Hu Li
- Laboratory of Antiviral Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Jian-Rui Li
- Laboratory of Antiviral Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China; Key Laboratory of Biotechnology of Antibiotics, The National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xiao-Qin Lv
- Laboratory of Antiviral Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Jian-Dong Jiang
- Laboratory of Antiviral Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China; Key Laboratory of Biotechnology of Antibiotics, The National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China; State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Zong-Gen Peng
- Laboratory of Antiviral Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China; Key Laboratory of Biotechnology of Antibiotics, The National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China; Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, China.
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Chu H, Duan Y, Yang L, Schnabl B. Small metabolites, possible big changes: a microbiota-centered view of non-alcoholic fatty liver disease. Gut 2019; 68:359-370. [PMID: 30171065 DOI: 10.1136/gutjnl-2018-316307] [Citation(s) in RCA: 195] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Revised: 08/02/2018] [Accepted: 08/06/2018] [Indexed: 12/13/2022]
Abstract
The spectrum of non-alcoholic fatty liver disease (NAFLD) ranges from simple hepatic steatosis, commonly associated with obesity, to non-alcoholic steatohepatitis, which can progress to fibrosis, cirrhosis and hepatocellular carcinoma. NAFLD pathophysiology involves environmental, genetic and metabolic factors, as well as changes in the intestinal microbiota and their products. Dysfunction of the intestinal barrier can contribute to NAFLD development and progression. Although there are technical limitations in assessing intestinal permeability in humans and the number of patients in these studies is rather small, fewer than half of the patients have increased intestinal permeability and translocation of bacterial products. Microbe-derived metabolites and the signalling pathways they affect might play more important roles in development of NAFLD. We review the microbial metabolites that contribute to the development of NAFLD, such as trimethylamine, bile acids, short-chain fatty acids and ethanol. We discuss the mechanisms by which metabolites produced by microbes might affect disease progression and/or serve as therapeutic targets or biomarkers for NAFLD.
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Affiliation(s)
- Huikuan Chu
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Department of Medicine, University of California San Diego, San Diego, California, USA
| | - Yi Duan
- Department of Medicine, University of California San Diego, San Diego, California, USA.,Department of Medicine, VA San Diego Healthcare System, San Diego, California, USA
| | - Ling Yang
- Division of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Bernd Schnabl
- Department of Medicine, University of California San Diego, San Diego, California, USA.,Department of Medicine, VA San Diego Healthcare System, San Diego, California, USA
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12
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Theiler-Schwetz V, Zaufel A, Schlager H, Obermayer-Pietsch B, Fickert P, Zollner G. Bile acids and glucocorticoid metabolism in health and disease. Biochim Biophys Acta Mol Basis Dis 2019; 1865:243-251. [DOI: 10.1016/j.bbadis.2018.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 07/18/2018] [Accepted: 08/01/2018] [Indexed: 12/12/2022]
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13
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Kowdley KV, Luketic V, Chapman R, Hirschfield GM, Poupon R, Schramm C, Vincent C, Rust C, Parés A, Mason A, Marschall H, Shapiro D, Adorini L, Sciacca C, Beecher‐Jones T, Böhm O, Pencek R, Jones D. A randomized trial of obeticholic acid monotherapy in patients with primary biliary cholangitis. Hepatology 2018; 67:1890-1902. [PMID: 29023915 PMCID: PMC5947631 DOI: 10.1002/hep.29569] [Citation(s) in RCA: 190] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 08/24/2017] [Accepted: 09/27/2017] [Indexed: 12/11/2022]
Abstract
UNLABELLED Obeticholic acid (OCA), a potent farnesoid X receptor agonist, was studied as monotherapy in an international, randomized, double-blind, placebo-controlled phase 2 study in patients with primary biliary cholangitis who were then followed for up to 6 years. The goals of the study were to assess the benefit of OCA in the absence of ursodeoxycholic acid, which is relevant for patients who are intolerant of ursodeoxycholic acid and at higher risk of disease progression. Patients were randomized and dosed with placebo (n = 23), OCA 10 mg (n = 20), or OCA 50 mg (n = 16) given as monotherapy once daily for 3 months (1 randomized patient withdrew prior to dosing). The primary endpoint was the percent change in alkaline phosphatase from baseline to the end of the double-blind phase of the study. Secondary and exploratory endpoints included change from baseline to month 3/early termination in markers of cholestasis, hepatocellular injury, and farnesoid X receptor activation. Efficacy and safety continue to be monitored through an ongoing 6-year open-label extension (N = 28). Alkaline phosphatase was reduced in both OCA groups (median% [Q1, Q3], OCA 10 mg -53.9% [-62.5, -29.3], OCA 50 mg -37.2% [-54.8, -24.6]) compared to placebo (-0.8% [-6.4, 8.7]; P < 0.0001) at the end of the study, with similar reductions observed through 6 years of open-label extension treatment. OCA improved many secondary and exploratory endpoints (including γ-glutamyl transpeptidase, alanine aminotransferase, conjugated bilirubin, and immunoglobulin M). Pruritus was the most common adverse event; 15% (OCA 10 mg) and 38% (OCA 50 mg) discontinued due to pruritus. CONCLUSION OCA monotherapy significantly improved alkaline phosphatase and other biochemical markers predictive of improved long-term clinical outcomes. Pruritus increased dose-dependently with OCA treatment. Biochemical improvements were observed through 6 years of open-label extension treatment. (Hepatology 2018;67:1890-1902).
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Affiliation(s)
| | - Velimir Luketic
- Virginia Commonwealth University and McGuire Research InstituteMcGuire DVAMCRichmondVA
| | - Roger Chapman
- Department of Gastroenterology, John Radcliffe HospitalHeadingtonOxfordUK
| | - Gideon M. Hirschfield
- Centre for Liver Research and NIHR Biomedical Research CentreUniversity of BirminghamBirminghamUK
| | | | - Christoph Schramm
- 1st Department of MedicineUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | | | - Christian Rust
- Department of Medicine 2, GrosshadernUniversity of MunichMunichGermany
| | - Albert Parés
- Liver Unit, Hospital Clinic, IDIBAPS, CIBERehdUniversity of BarcelonaBarcelonaSpain
| | - Andrew Mason
- Division of GastroenterologyUniversity of AlbertaEdmontonAlbertaCanada
| | - Hanns‐Ulrich Marschall
- Sahlgrenska AcademyDepartment of Molecular and Clinical Medicine, University of GothenburgGothenburgSweden
| | | | | | | | | | | | | | - David Jones
- Institute of Cellular MedicineNewcastle UniversityNewcastle‐upon‐TyneUK
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14
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Arab JP, Karpen SJ, Dawson PA, Arrese M, Trauner M. Bile acids and nonalcoholic fatty liver disease: Molecular insights and therapeutic perspectives. Hepatology 2017; 65:350-362. [PMID: 27358174 PMCID: PMC5191969 DOI: 10.1002/hep.28709] [Citation(s) in RCA: 397] [Impact Index Per Article: 56.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Revised: 05/09/2016] [Accepted: 06/23/2016] [Indexed: 12/11/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a burgeoning health problem worldwide and an important risk factor for both hepatic and cardiometabolic mortality. The rapidly increasing prevalence of this disease and of its aggressive form nonalcoholic steatohepatitis (NASH) will require novel therapeutic approaches to prevent disease progression to advanced fibrosis or cirrhosis and cancer. In recent years, bile acids have emerged as relevant signaling molecules that act at both hepatic and extrahepatic tissues to regulate lipid and carbohydrate metabolic pathways as well as energy homeostasis. Activation or modulation of bile acid receptors, such as the farnesoid X receptor and TGR5, and transporters, such as the ileal apical sodium-dependent bile acid transporter, appear to affect both insulin sensitivity and NAFLD/NASH pathogenesis at multiple levels, and these approaches hold promise as novel therapies. In the present review, we summarize current available data on the relationships of bile acids to NAFLD and the potential for therapeutically targeting bile-acid-related pathways to address this growing world-wide disease. (Hepatology 2017;65:350-362).
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Affiliation(s)
- Juan P. Arab
- Department of Gastroenterology, School of MedicinePontificia Universidad Católica de ChileSantiagoChile
| | - Saul J. Karpen
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of PediatricsEmory University School of MedicineAtlantaGAUSA
| | - Paul A. Dawson
- Division of Pediatric Gastroenterology, Hepatology and Nutrition, Department of PediatricsEmory University School of MedicineAtlantaGAUSA
| | - Marco Arrese
- Department of Gastroenterology, School of MedicinePontificia Universidad Católica de ChileSantiagoChile
| | - Michael Trauner
- Division of Gastroenterology and Hepatology, Department of Internal Medicine IIIMedical University of ViennaViennaAustria
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15
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Dong B, Young M, Liu X, Singh AB, Liu J. Regulation of lipid metabolism by obeticholic acid in hyperlipidemic hamsters. J Lipid Res 2016; 58:350-363. [PMID: 27940481 DOI: 10.1194/jlr.m070888] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 11/28/2016] [Indexed: 12/21/2022] Open
Abstract
The farnesoid X receptor (FXR) plays critical roles in plasma cholesterol metabolism, in particular HDL-cholesterol (HDL-C) homeostasis. Obeticholic acid (OCA) is a FXR agonist being developed for treating various chronic liver diseases. Previous studies reported inconsistent effects of OCA on regulating plasma cholesterol levels in different animal models and in different patient populations. The mechanisms underlying its divergent effects have not yet been thoroughly investigated. The scavenger receptor class B type I (SR-BI) is a FXR-modulated gene and the major receptor for HDL-C. We investigated the effects of OCA on hepatic SR-BI expression and correlated such effects with plasma HDL-C levels and hepatic cholesterol efflux in hyperlipidemic hamsters. We demonstrated that OCA induced a time-dependent reduction in serum HDL-C levels after 14 days of treatment, which was accompanied by a significant reduction of liver cholesterol content and increases in fecal cholesterol in OCA-treated hamsters. Importantly, hepatic SR-BI mRNA and protein levels in hamsters were increased to 1.9- and 1.8-fold of control by OCA treatment. Further investigations in normolipidemic hamsters did not reveal OCA-induced changes in serum HDL-C levels or hepatic SR-BI expression. We conclude that OCA reduces plasma HDL-C levels and promotes transhepatic cholesterol efflux in hyperlipidemic hamsters via a mechanism involving upregulation of hepatic SR-BI.
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Affiliation(s)
- Bin Dong
- Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304
| | - Mark Young
- Intercept Pharmaceuticals, Inc., San Diego, CA 92121
| | - Xueqing Liu
- Intercept Pharmaceuticals, Inc., San Diego, CA 92121
| | | | - Jingwen Liu
- Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304
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16
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Pencek R, Marmon T, Roth JD, Liberman A, Hooshmand-Rad R, Young MA. Effects of obeticholic acid on lipoprotein metabolism in healthy volunteers. Diabetes Obes Metab 2016; 18:936-40. [PMID: 27109453 DOI: 10.1111/dom.12681] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 04/19/2016] [Accepted: 04/20/2016] [Indexed: 12/23/2022]
Abstract
The bile acid analogue obeticholic acid (OCA) is a selective farnesoid X receptor (FXR) agonist in development for treatment of several chronic liver diseases. FXR activation regulates lipoprotein homeostasis. The effects of OCA on cholesterol and lipoprotein metabolism in healthy individuals were assessed. Two phase I studies were conducted to evaluate the effects of repeated oral doses of 5, 10 or 25 mg OCA on lipid variables after 14 or 20 days of consecutive administration in 68 healthy adults. Changes in HDL and LDL cholesterol levels were examined, in addition to nuclear magnetic resonance analysis of particle sizes and sub-fraction concentrations. OCA elicited changes in circulating cholesterol and particle size of LDL and HDL. OCA decreased HDL cholesterol and increased LDL cholesterol, independently of dose. HDL particle concentrations declined as a result of a reduction in medium and small HDL. Total LDL particle concentrations increased because of an increase in large LDL particles. Changes in lipoprotein metabolism attributable to OCA in healthy individuals were found to be consistent with previously reported changes in patients receiving OCA with non-alcoholic fatty liver disease or non-alcoholic steatohepatitis.
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Affiliation(s)
- R Pencek
- Intercept Pharmaceuticals, Inc., San Diego, CA, USA
| | - T Marmon
- Intercept Pharmaceuticals, Inc., San Diego, CA, USA
| | - J D Roth
- Intercept Pharmaceuticals, Inc., San Diego, CA, USA
| | - A Liberman
- Intercept Pharmaceuticals, Inc., San Diego, CA, USA
| | | | - M A Young
- Intercept Pharmaceuticals, Inc., San Diego, CA, USA
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17
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Guo F, Xu Z, Zhang Y, Jiang P, Huang G, Chen S, Lyu X, Zheng P, Zhao X, Zeng Y, Wang S, He F. FXR induces SOCS3 and suppresses hepatocellular carcinoma. Oncotarget 2016; 6:34606-16. [PMID: 26416445 PMCID: PMC4741476 DOI: 10.18632/oncotarget.5314] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 09/11/2015] [Indexed: 12/20/2022] Open
Abstract
Suppressor of cytokine signaling 3 (SOCS3) is regarded as a vital repressor in the liver carcinogenesis mainly by inhibiting signal transducer and activator of transcription 3 (STAT3) activity. Farnesoid X Receptor (FXR), highly expressed in liver, has an important role in protecting against hepatocellular carcinoma (HCC). However, it is unclear whether the tumor suppressive activity of FXR involves the regulation of SOCS3. In the present study, we found that activation of FXR by its specific agonist GW4064 in HCC cells inhibited cell growth, induced cell cycle arrest at G1 phase, elevated p21 expression and repressed STAT3 activity. The above anti-tumor effects of FXR were dramatically alleviated by knockdown of SOCS3 with siRNA. Reporter assay revealed that FXR activation enhanced the transcriptional activity of SOCS3 promoter. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assay displayed that FXR directly bound to IR9 DNA motif within SOCS3 promoter region. The in vivo study in nude mice showed that treatment with FXR ligand GW4064 could decelerate the growth of HCC xenografts, up-regulate SOCS3 and p21 expression and inhibit STAT3 phosphorylation in the xenografts. These results suggest that induction of SOCS3 may be a novel mechanism by which FXR exerts its anti-HCC effects, and the FXR-SOCS3 signaling may serve as a new potential target for the prevention/treatment of HCC.
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Affiliation(s)
- Fei Guo
- Department of Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Zhizhen Xu
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
| | - Yan Zhang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
| | - Peng Jiang
- Department of Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Gang Huang
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
| | - Shan Chen
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
| | - Xilin Lyu
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
| | - Ping Zheng
- Department of Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Xin Zhao
- Department of Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Yijun Zeng
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
| | - Shuguang Wang
- Department of Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Fengtian He
- Department of Biochemistry and Molecular Biology, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
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18
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Peeters B, Boonen E, Langouche L, Van den Berghe G. The HPA axis response to critical illness: New study results with diagnostic and therapeutic implications. Mol Cell Endocrinol 2015; 408:235-40. [PMID: 25462585 DOI: 10.1016/j.mce.2014.11.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 11/18/2014] [Accepted: 11/19/2014] [Indexed: 10/24/2022]
Abstract
For decades, elevated plasma cortisol concentrations in critically ill patients were exclusively ascribed to a stimulated hypothalamus-pituitary-adrenal axis with increased circulating adrenocorticotropic hormone (ACTH) inferred to several-fold increase adrenal cortisol synthesis. However, 'ACTH-cortisol dissociation' has been reported during critical illness, referring to low circulating ACTH coinciding with elevated circulating cortisol. It was recently shown that metabolism of cortisol is significantly reduced in critically ill patients explained by a suppression of the activity and expression of cortisol metabolizing enzymes in kidney and liver. This reduced cortisol breakdown determines hypercortisolemia, much more than increased cortisol production, in the critically ill. Although the low plasma ACTH concentrations, evoked by the elevated plasma cortisol via feedback inhibition, are part of this adaptation, they may negatively affect adrenocortical structure and function in the prolonged phase of critical illness. These new insights have implications for diagnosis and treatment of adrenal insufficiency in critically ill patients.
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Affiliation(s)
- B Peeters
- Clinical Division and Laboratory of Intensive Care Medicine, Department Cellular and Molecular Medicine, KU Leuven University, Leuven B-3000, Belgium
| | - E Boonen
- Clinical Division and Laboratory of Intensive Care Medicine, Department Cellular and Molecular Medicine, KU Leuven University, Leuven B-3000, Belgium
| | - L Langouche
- Clinical Division and Laboratory of Intensive Care Medicine, Department Cellular and Molecular Medicine, KU Leuven University, Leuven B-3000, Belgium
| | - G Van den Berghe
- Clinical Division and Laboratory of Intensive Care Medicine, Department Cellular and Molecular Medicine, KU Leuven University, Leuven B-3000, Belgium.
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19
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Abstract
Nonalcoholic fatty liver disease is a common cause of liver related morbidity and mortality. It is closely linked to underlying insulin resistance. It has recently been shown that bile acids modulate insulin signaling and can improve insulin resistance in cell based and animal studies. These effects are mediated in part by activation of farnesoid x receptors by bile acids. In human studies, FXR agonists improve insulin resistance and have recently been shown to improve NAFLD. The basis for the use of FXR agonists for the treatment of NAFLD and early human experience with such agents is reviewed in this paper.
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Affiliation(s)
- Arun J Sanyal
- Virgnia Commonwealth University School of Medicine, Richmond, Va., USA
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20
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Kardassis D, Gafencu A, Zannis VI, Davalos A. Regulation of HDL genes: transcriptional, posttranscriptional, and posttranslational. Handb Exp Pharmacol 2015; 224:113-179. [PMID: 25522987 DOI: 10.1007/978-3-319-09665-0_3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
HDL regulation is exerted at multiple levels including regulation at the level of transcription initiation by transcription factors and signal transduction cascades; regulation at the posttranscriptional level by microRNAs and other noncoding RNAs which bind to the coding or noncoding regions of HDL genes regulating mRNA stability and translation; as well as regulation at the posttranslational level by protein modifications, intracellular trafficking, and degradation. The above mechanisms have drastic effects on several HDL-mediated processes including HDL biogenesis, remodeling, cholesterol efflux and uptake, as well as atheroprotective functions on the cells of the arterial wall. The emphasis is on mechanisms that operate in physiologically relevant tissues such as the liver (which accounts for 80% of the total HDL-C levels in the plasma), the macrophages, the adrenals, and the endothelium. Transcription factors that have a significant impact on HDL regulation such as hormone nuclear receptors and hepatocyte nuclear factors are extensively discussed both in terms of gene promoter recognition and regulation but also in terms of their impact on plasma HDL levels as was revealed by knockout studies. Understanding the different modes of regulation of this complex lipoprotein may provide useful insights for the development of novel HDL-raising therapies that could be used to fight against atherosclerosis which is the underlying cause of coronary heart disease.
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Affiliation(s)
- Dimitris Kardassis
- Department of Biochemistry, University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology of Hellas, Heraklion, Crete, 71110, Greece,
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Abstract
Critical illness represents a major challenge for the human body, implicating that an adequate stress response is indispensable for survival. Therefore, for a long time, activation of the hypothalamic pituitary adrenal axis was assumed to be increased to respond to this stressful situation. Recent novel insights, however, provided evidence that the HPA-axis is regulated differently during critical illness. Cortisol metabolism was shown to be reduced which contributed to hypercortisolism in an energy efficient way without increasing cortisol production dramatically. Yet, the concomitant low ACTH levels, explained by negative feedback inhibition, could lead to an understimulation of the adrenal gland and affect adrenal structure and function, given the crucial role of ACTH for adrenal gland maintenance. This side-effect could negatively affect outcome predominantly in the prolonged phase of critical illness and could explain the increased incidence of adrenal failure in these patients. Altogether, novel findings represent a paradigm shift in our current understanding of HPA-axis regulation during critical illness and redirect future research perspectives with an urgent need to well-designed clinical trials to further explore HPA-axis functioning during critical illness.
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Bile acids reduce endocytosis of high-density lipoprotein (HDL) in HepG2 cells. PLoS One 2014; 9:e102026. [PMID: 25010412 PMCID: PMC4092120 DOI: 10.1371/journal.pone.0102026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Accepted: 06/13/2014] [Indexed: 02/06/2023] Open
Abstract
High-density lipoprotein (HDL) transports lipids to hepatic cells and the majority of HDL-associated cholesterol is destined for biliary excretion. Cholesterol is excreted into the bile directly or after conversion to bile acids, which are also present in the plasma as they are effectively reabsorbed through the enterohepatic cycle. Here, we provide evidence that bile acids affect HDL endocytosis. Using fluorescent and radiolabeled HDL, we show that HDL endocytosis was reduced in the presence of high concentrations of taurocholate, a natural non-cell-permeable bile acid, in human hepatic HepG2 and HuH7 cells. In contrast, selective cholesteryl-ester (CE) uptake was increased. Taurocholate exerted these effects extracellularly and independently of HDL modification, cell membrane perturbation or blocking of endocytic trafficking. Instead, this reduction of endocytosis and increase in selective uptake was dependent on SR-BI. In addition, cell-permeable bile acids reduced HDL endocytosis by farnesoid X receptor (FXR) activation: chenodeoxycholate and the non-steroidal FXR agonist GW4064 reduced HDL endocytosis, whereas selective CE uptake was unaltered. Reduced HDL endocytosis by FXR activation was independent of SR-BI and was likely mediated by impaired expression of the scavenger receptor cluster of differentiation 36 (CD36). Taken together we have shown that bile acids reduce HDL endocytosis by transcriptional and non-transcriptional mechanisms. Further, we suggest that HDL endocytosis and selective lipid uptake are not necessarily tightly linked to each other.
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Baptissart M, Vega A, Martinot E, Baron S, Lobaccaro JMA, Volle DH. Farnesoid X receptor alpha: a molecular link between bile acids and steroid signaling? Cell Mol Life Sci 2013; 70:4511-26. [PMID: 23784309 PMCID: PMC11113643 DOI: 10.1007/s00018-013-1387-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2012] [Revised: 05/27/2013] [Accepted: 05/27/2013] [Indexed: 12/29/2022]
Abstract
Bile acids are cholesterol metabolites that have been extensively studied in recent decades. In addition to having ancestral roles in digestion and fat solubilization, bile acids have recently been described as signaling molecules involved in many physiological functions, such as glucose and energy metabolisms. These signaling pathways involve the activation of the nuclear receptor farnesoid X receptor (FXRα) or of the G protein-coupled receptor TGR5. In this review, we will focus on the emerging role of FXRα, suggesting important functions for the receptor in steroid metabolism. It has been described that FXRα is expressed in the adrenal glands and testes, where it seems to control steroid production. FXRα also participates in steroid catabolism in the liver and interferes with the steroid signaling pathways in target tissues via crosstalk with steroid receptors. In this review, we discuss the potential impacts of bile acid (BA), through its interactions with steroid metabolism, on glucose metabolism, sexual function, and prostate and breast cancers. Although several of the published reports rely on in vitro studies, they highlight the need to understand the interactions that may affect health. This effect is important because BA levels are increased in several pathophysiological conditions related to liver injuries. Additionally, BA receptors are targeted clinically using therapeutics to treat liver diseases, diabetes, and cancers.
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Affiliation(s)
- Marine Baptissart
- INSERM U1103, Génétique Reproduction et Développement (GReD), Clermont Université, 24 avenue des Landais, BP 80026, 63177 Aubière Cedex, France
- CNRS Unité Mixte de Recherche 6293, GReD, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Clermont Université, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Centre de Recherche en Nutrition Humaine d’Auvergne, 63000 Clermont-Ferrand, France
| | - Aurelie Vega
- INSERM U1103, Génétique Reproduction et Développement (GReD), Clermont Université, 24 avenue des Landais, BP 80026, 63177 Aubière Cedex, France
- CNRS Unité Mixte de Recherche 6293, GReD, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Clermont Université, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Centre de Recherche en Nutrition Humaine d’Auvergne, 63000 Clermont-Ferrand, France
| | - Emmanuelle Martinot
- INSERM U1103, Génétique Reproduction et Développement (GReD), Clermont Université, 24 avenue des Landais, BP 80026, 63177 Aubière Cedex, France
- CNRS Unité Mixte de Recherche 6293, GReD, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Clermont Université, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Centre de Recherche en Nutrition Humaine d’Auvergne, 63000 Clermont-Ferrand, France
| | - Silvère Baron
- INSERM U1103, Génétique Reproduction et Développement (GReD), Clermont Université, 24 avenue des Landais, BP 80026, 63177 Aubière Cedex, France
- CNRS Unité Mixte de Recherche 6293, GReD, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Clermont Université, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Centre de Recherche en Nutrition Humaine d’Auvergne, 63000 Clermont-Ferrand, France
| | - Jean-Marc A. Lobaccaro
- INSERM U1103, Génétique Reproduction et Développement (GReD), Clermont Université, 24 avenue des Landais, BP 80026, 63177 Aubière Cedex, France
- CNRS Unité Mixte de Recherche 6293, GReD, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Clermont Université, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Centre de Recherche en Nutrition Humaine d’Auvergne, 63000 Clermont-Ferrand, France
| | - David H. Volle
- INSERM U1103, Génétique Reproduction et Développement (GReD), Clermont Université, 24 avenue des Landais, BP 80026, 63177 Aubière Cedex, France
- CNRS Unité Mixte de Recherche 6293, GReD, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Clermont Université, Université Blaise Pascal, BP 10448, 63000 Clermont-Ferrand, France
- Centre de Recherche en Nutrition Humaine d’Auvergne, 63000 Clermont-Ferrand, France
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Peng X, Wu W, Zhu B, Sun Z, Ji L, Ruan Y, Zhou M, Zhou L, Gu J. Activation of farnesoid X receptor induces RECK expression in mouse liver. Biochem Biophys Res Commun 2013; 443:211-6. [PMID: 24291500 DOI: 10.1016/j.bbrc.2013.11.082] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 11/21/2013] [Indexed: 12/27/2022]
Abstract
Farnesoid X receptor (FXR) belongs to the ligand-activated nuclear receptor superfamily, and functions as a transcription factor regulating the transcription of numerous genes involved in bile acid homeostasis, lipoprotein and glucose metabolism. In the present study, we identified RECK, a membrane-anchored inhibitor of matrix metalloproteinases, as a novel target gene of FXR in mouse liver. We found that FXR agonist substantially augmented hepatic RECK mRNA and protein expression in vivo and in vitro. FXR regulated the transcription of RECK through directly binding to FXR response element located within intron 1 of the mouse RECK gene. Moreover, FXR agonist reversed the down-regulation of RECK in the livers from mice fed a methionine and choline deficient diet. In summary, our data suggest that RECK is a novel transcriptional target of FXR in mouse liver, and provide clues to better understanding the function of FXR in liver.
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Affiliation(s)
- Xiaomin Peng
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Weibin Wu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Bo Zhu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Zhichao Sun
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Lingling Ji
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Yuanyuan Ruan
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Meiling Zhou
- Department of Radiology, Zhongshan Hospital of Fudan University and Shanghai Institute of Medical Imaging, Shanghai 200032, China.
| | - Lei Zhou
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China.
| | - Jianxin Gu
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China; Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
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He X, Hu JL, Li J, Zhao L, Zhang Y, Zeng YJ, Dai SS, He FT. A feedback loop in PPARγ-adenosine A2A receptor signaling inhibits inflammation and attenuates lung damages in a mouse model of LPS-induced acute lung injury. Cell Signal 2013; 25:1913-23. [PMID: 23712033 DOI: 10.1016/j.cellsig.2013.05.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 05/12/2013] [Indexed: 12/13/2022]
Abstract
Although peroxisome proliferator-activated receptor-γ (PPARγ) and adenosine A2A receptor (A2AR) are reported to be anti-inflammatory factors in acute lung injury (ALI), their internal link and synergic or antagonistic effect after activation are poorly understood. Here, we found that PPARγ and A2AR could upregulate the mRNA and protein expressions of each other in lung tissues of LPS-induced mouse ALI model and murine macrophages. Further investigation demonstrated that PPARγ upregulated A2AR expression by directly binding to a DR10 response element (-218 to -197) within A2AR gene promoter region. Instead of directly interacting with PPARγ, A2AR stimulated PPARγ expression via protein kinase A (PKA)-cAMP response element binding protein (CREB) signaling by provoking the binding of CREB to a cAMP responsive element (CRE)-like site in PPARγ gene promoter region. In addition, combination of PPARγ and A2AR agonists was found to exert obviously better effect on suppressing neutrophil infiltration and inflammatory cytokine expressions, attenuating lung edema, pathological changes and improving lung function of blood gas exchange than their single application. These findings reveal a novel functional positive feedback loop between PPARγ and A2AR signaling to potentialize their effect on inhibiting inflammation and attenuating lung damages in ALI. It suggests that targeting this PPARγ-A2AR signaling rather than PPARγ or A2AR alone may be a more attractive and efficient potential therapeutic strategy for ALI.
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Affiliation(s)
- Xie He
- Department of Biochemistry and Molecular Biology, Third Military Medical University, Chongqing 400038, China
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26
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Dubé E, Ethier-Chiasson M, Lafond J. Modulation of cholesterol transport by insulin-treated gestational diabetes mellitus in human full-term placenta. Biol Reprod 2013; 88:16. [PMID: 23221398 DOI: 10.1095/biolreprod.112.105619] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Gestational diabetes mellitus (GDM) is a common complication of pregnancy that is characterized by glucose intolerance, leads to dyslipidemia, and is aggravated by obesity. Cholesterol is taken up by the placenta as part of lipoproteins through the scavenger receptor class B type I receptor (SRBI), low-density lipoprotein receptor (LDLR), and very low density lipoprotein receptor (VLDLR), and its efflux is then mediated by ABCA1 and ABCG1. PCSK9 is involved in the degradation of LDLR and VLDLR. The goal of this study was to evaluate the impact of GDM and prepregnancy body mass index (BMI) on cholesterol transport through the modulation of the expression of several key players. Human full-term placenta, maternal, and venous cord blood samples were obtained at delivery from normal-weight women without GDM (n = 10), normal-weight women with GDM (n = 6), and overweight/obese women with GDM (n = 6). Lipids (total cholesterol, high-density lipoprotein, low-density lipoprotein, triglycerides, free fatty acids, apolipoprotein A1, apolipoprotein B100) levels were evaluated in blood samples. Messenger RNA and protein expression levels (LDLR, VLDLR, SRBI, ABCA1, ABCG1, proprotein convertase subtilisin/kexin type 9, liver x receptors, peroxisome proliferator-activated receptors) were assessed in human full-term placenta, respectively, by real-time RT-PCR and Western blots. Lipoprotein lipase activity was evaluated using a commercial kit on tissue homogenates. Overall, our study demonstrates that GDM affects the maternal and neonatal lipid profiles as well as different key players of placental cholesterol transfer from the maternal to the fetal circulation, depending on the maternal BMI. These changes could affect the fetal metabolism and predispose the fetus to future metabolic diseases.
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Affiliation(s)
- Evemie Dubé
- Laboratoire de Physiologie Materno-Fœtale, Département des Sciences Biologiques, Université du Québec à Montréal, Montréal, Québec, Canada
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Hambruch E, Miyazaki-Anzai S, Hahn U, Matysik S, Boettcher A, Perović-Ottstadt S, Schlüter T, Kinzel O, Krol HD, Deuschle U, Burnet M, Levi M, Schmitz G, Miyazaki M, Kremoser C. Synthetic farnesoid X receptor agonists induce high-density lipoprotein-mediated transhepatic cholesterol efflux in mice and monkeys and prevent atherosclerosis in cholesteryl ester transfer protein transgenic low-density lipoprotein receptor (-/-) mice. J Pharmacol Exp Ther 2012; 343:556-67. [PMID: 22918042 PMCID: PMC11047796 DOI: 10.1124/jpet.112.196519] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Accepted: 08/22/2012] [Indexed: 01/03/2023] Open
Abstract
Farnesoid X receptor (FXR), a bile acid-activated nuclear hormone receptor, plays an important role in the regulation of cholesterol and more specifically high-density lipoprotein (HDL) homeostasis. Activation of FXR is reported to lead to both pro- and anti-atherosclerotic effects. In the present study we analyzed the impact of different FXR agonists on cholesterol homeostasis, plasma lipoprotein profiles, and transhepatic cholesterol efflux in C57BL/6J mice and cynomolgus monkeys and atherosclerosis development in cholesteryl ester transfer protein transgenic (CETPtg) low-density lipoprotein receptor (LDLR) (-/-) mice. In C57BL/6J mice on a high-fat diet the synthetic FXR agonists isopropyl 3-(3,4-difluorobenzoyl)-1,1-dimethyl-1,2,3,6-tetrahydroazepino[4,5-b]indole-5-carboxylate (FXR-450) and 4-[2-[2-chloro-4-[[5-cyclopropyl-3-(2,6-dichlorophenyl)-4-isoxazolyl]methoxy]phenyl]cyclopropyl]benzoic acid (PX20606) demonstrated potent plasma cholesterol-lowering activity that affected all lipoprotein species, whereas 3-[2-[2-chloro-4-[[3-(2,6-dichlorophenyl)-5-(1-methylethyl)-4-isoxazolyl]methoxy]phenyl]ethenyl]benzoic acid (GW4064) and 6-ethyl chenodeoxycholic acid (6-ECDCA) showed only limited effects. In FXR wild-type mice, but not FXR(-/-) mice, the more efficacious FXR agonists increased fecal cholesterol excretion and reduced intestinal cholesterol (re)uptake. In CETPtg-LDLR(-/-) mice PX20606 potently lowered total cholesterol and, despite the observed HDL cholesterol (HDLc) reduction, caused a highly significant decrease in atherosclerotic plaque size. In normolipidemic cynomolgus monkeys PX20606 and 6-ECDCA both reduced total cholesterol, and PX20606 specifically lowered HDL(2c) but not HDL(3c) or apolipoprotein A1. That pharmacological FXR activation specifically affects this cholesterol-rich HDL(2) subclass is a new and highly interesting finding and sheds new light on FXR-dependent HDLc lowering, which has been perceived as a major limitation for the clinical development of FXR agonists.
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Huang G, Xu Z, Huang Y, Duan X, Gong W, Zhang Y, Fan J, He F. Curcumin Protects Against Collagen-Induced Arthritis via Suppression of BAFF Production. J Clin Immunol 2012. [DOI: 10.1007/s10875-012-9839-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Xin P, Han H, Gao D, Cui W, Yang X, Ying C, Sun X, Hao L. Alleviative effects of resveratrol on nonalcoholic fatty liver disease are associated with up regulation of hepatic low density lipoprotein receptor and scavenger receptor class B type I gene expressions in rats. Food Chem Toxicol 2012; 52:12-8. [PMID: 23127599 DOI: 10.1016/j.fct.2012.10.026] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 10/10/2012] [Accepted: 10/23/2012] [Indexed: 10/27/2022]
Abstract
Lipid metabolic disorders are widely considered to be one of the most critical and basic link in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). The aim of this study was to illustrate the alleviation function of resveratrol (Res) on NAFLD and the roles of hepatic fatty acid synthase (FAS), low density lipoprotein receptor (LDLr), scavenger receptor class B type I (SR-BI), and thyroid hormone receptor β1 (TRβ1), which are the key molecules involved in lipid metabolism. Adult male Wistar rats were fed a normal diet or high fat/sucrose diet (HFS) with or without resveratrol for 13 weeks. HFS induced NAFLD formation and increased the lipids concentrations in serum and livers of rats, while noticeable improvement has been reached by Res intervention. Moreover, Res protected against HFS-induced decrease in hepatic LDLr and SR-BI mRNA and protein expressions, whereas TRβ1 expressions were impervious with/without Res. Unexpectedly, hepatic FAS gene expressions were markedly diminished in NAFLD rats and were gradually increased by treatment with Res. These data indicate that the alleviative effects of Res on NAFLD are associated with up regulation of hepatic LDLr and SR-BI gene expressions, which provide new insights into the pharmacological targets of Res in the prevention of NAFLD.
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Affiliation(s)
- Peng Xin
- Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science & Technology, Wuhan 430030, PR China
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30
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Hoekstra M, van der Sluis RJ, Li Z, Oosterveer MH, Groen AK, Van Berkel TJC. FXR agonist GW4064 increases plasma glucocorticoid levels in C57BL/6 mice. Mol Cell Endocrinol 2012; 362:69-75. [PMID: 22643070 DOI: 10.1016/j.mce.2012.05.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 05/21/2012] [Accepted: 05/21/2012] [Indexed: 01/09/2023]
Abstract
Since high expression of farnesoid X receptor (FXR) has been detected in glucocorticoid-producing adrenocortical cells, we evaluated the potential role of FXR in adrenal glucocorticoid production. FXR agonist GW4064 increased fasting plasma corticosterone levels (+45%; P<0.01) in C57BL/6 mice, indicative of enhanced adrenal steroidogenesis. GW4064 treatment did not affect plasma ACTH levels, adrenal weight, or adrenal expression of steroidogenic genes. Scavenger receptor BI (SR-BI) mRNA and protein expression, respectively, increased 1.9-fold (P<0.01) and 1.5-fold, which suggests a stimulated lipoprotein-associated cholesterol uptake into the adrenals upon GW4064 treatment. In line with an enhanced flux of cellular cholesterol into the steroidogenic pathway, adrenal unesterified and esterified cholesterol stores were 21-41% decreased (P<0.01) upon GW4064 treatment. In conclusion, we have shown that the FXR agonist GW4064 stimulates plasma corticosterone levels in C57BL/6 mice. Our findings suggest a novel role for FXR in the modulation of adrenal cholesterol metabolism and glucocorticoid synthesis in mice.
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MESH Headings
- Adrenal Glands/anatomy & histology
- Adrenal Glands/drug effects
- Adrenal Glands/metabolism
- Adrenocorticotropic Hormone/blood
- Animals
- Apolipoproteins A/genetics
- Apolipoproteins A/metabolism
- Cholesterol Side-Chain Cleavage Enzyme/genetics
- Cholesterol Side-Chain Cleavage Enzyme/metabolism
- Corticosterone/blood
- Female
- Glucocorticoids/blood
- Isoxazoles/pharmacology
- Lipid Metabolism
- Lipids/blood
- Liver/metabolism
- Membrane Transport Proteins/genetics
- Membrane Transport Proteins/metabolism
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Organ Size/drug effects
- Phosphoenolpyruvate Carboxykinase (ATP)/genetics
- Phosphoenolpyruvate Carboxykinase (ATP)/metabolism
- Progesterone Reductase/genetics
- Progesterone Reductase/metabolism
- Receptor, Melanocortin, Type 2/genetics
- Receptor, Melanocortin, Type 2/metabolism
- Receptors, Cytoplasmic and Nuclear/agonists
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Scavenger Receptors, Class B/genetics
- Scavenger Receptors, Class B/metabolism
- Steroid 11-beta-Hydroxylase/genetics
- Steroid 11-beta-Hydroxylase/metabolism
- Steroid 21-Hydroxylase/genetics
- Steroid 21-Hydroxylase/metabolism
- Tryptophan Oxygenase/genetics
- Tryptophan Oxygenase/metabolism
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Affiliation(s)
- Menno Hoekstra
- Division of Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, Gorlaeus Laboratories, 2300 RA Leiden, The Netherlands.
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31
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Li J, Li P, Zhang Y, Li GB, He FT, Zhou YG, Yang K, Dai SS. Upregulation of ski in fibroblast is implicated in the peroxisome proliferator--activated receptor δ-mediated wound healing. Cell Physiol Biochem 2012; 30:1059-71. [PMID: 23052247 DOI: 10.1159/000341482] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/24/2012] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND/AIM Both peroxisome proliferator-activated receptor (PPAR) δ and Ski are investigate the interaction of PPARδ and Ski and this interaction-associated effect in wound healing. METHODS Effect of PPARδ activation on Ski expression was detected in rat skin fibroblasts by real-time PCR and western blot. Luciferase assay, electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assay were performed to identify the binding site of PPARδ in the promoter region of rat Ski gene. And the functional activity of PPARδ regulation to Ski was detected in fibroblast proliferation and rat skin wound healing model. RESULTS PPARδ agonist GW501516 upregulated Ski expression in a dose-dependent manner. Direct repeat-1 (DR1) response element locating at -865∼-853 in Ski promoter region was identified to mediate PPARδ binding to Ski and associated induction of Ski. Furthermore, PPARδ upregulated Ski to promote fibroblasts proliferation and rat skin wound repair, which could be largely blocked by pre-treated with Ski RNA interference. CONCLUSION This study demonstrates that Ski is a novel target gene for PPARδ and upregulation of Ski to promote fibroblast proliferation is implicated in the PPARδ-mediated wound healing.
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Affiliation(s)
- Jun Li
- Department of Cardiothoracic Surgery, Southwest Hospital, Third Military Medical University, Chongqing, China
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32
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Li G, Thomas AM, Williams JA, Kong B, Liu J, Inaba Y, Xie W, Guo GL. Farnesoid X receptor induces murine scavenger receptor Class B type I via intron binding. PLoS One 2012; 7:e35895. [PMID: 22540009 PMCID: PMC3335076 DOI: 10.1371/journal.pone.0035895] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Accepted: 03/23/2012] [Indexed: 12/22/2022] Open
Abstract
Farnesoid X receptor (FXR) is a nuclear receptor and a key regulator of liver cholesterol and triglyceride homeostasis. Scavenger receptor class B type I (SR-BI) is critical for reverse cholesterol transport (RCT) by transporting high-density lipoprotein (HDL) into liver. FXR induces SR-BI, however, the underlying molecular mechanism of this induction is not known. The current study confirmed induction of SR-BI mRNA by activated FXR in mouse livers, a human hepatoma cell line, and primary human hepatocytes. Genome-wide FXR binding analysis in mouse livers identified 4 putative FXR response elements in the form of inverse repeat separated by one nucleotide (IR1) at the first intron and 1 IR1 at the downstream of the mouse Sr-bi gene. ChIP-qPCR analysis revealed FXR binding to only the intronic IR1s, but not the downstream one. Luciferase assays and site-directed mutagenesis further showed that 3 out of 4 IR1s were able to activate gene transcription. A 16-week high-fat diet (HFD) feeding in mice increased hepatic Sr-bi gene expression in a FXR-dependent manner. In addition, FXR bound to the 3 bona fide IR1s in vivo, which was increased following HFD feeding. Serum total and HDL cholesterol levels were increased in FXR knockout mice fed the HFD, compared to wild-type mice. In conclusion, the Sr-bi/SR-BI gene is confirmed as a FXR target gene in both mice and humans, and at least in mice, induction of Sr-bi by FXR is via binding to intronic IR1s. This study suggests that FXR may serve as a promising molecular target for increasing reverse cholesterol transport.
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MESH Headings
- Animals
- Base Sequence
- Cells, Cultured
- Cholesterol/metabolism
- Diet, High-Fat
- Female
- Hep G2 Cells
- Hepatocytes/drug effects
- Hepatocytes/metabolism
- Humans
- Introns
- Isoxazoles/pharmacology
- Lipoproteins, HDL/metabolism
- Liver/drug effects
- Liver/metabolism
- Mice
- Mice, Inbred C57BL
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- RNA, Messenger/metabolism
- Receptors, Cytoplasmic and Nuclear/deficiency
- Receptors, Cytoplasmic and Nuclear/genetics
- Receptors, Cytoplasmic and Nuclear/metabolism
- Scavenger Receptors, Class B/genetics
- Scavenger Receptors, Class B/metabolism
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Affiliation(s)
- Guodong Li
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- Department of Abdominal Surgery, Cancer Treatment Center, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, People's Republic of China
| | - Ann M. Thomas
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Jessica A. Williams
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Bo Kong
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Jie Liu
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
| | - Yuka Inaba
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Wen Xie
- Center for Pharmacogenetics and Department of Pharmaceutical Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Grace L. Guo
- Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, Kansas, United States of America
- * E-mail:
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33
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Bile Acid signaling in liver metabolism and diseases. J Lipids 2011; 2012:754067. [PMID: 21991404 PMCID: PMC3185234 DOI: 10.1155/2012/754067] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Accepted: 08/04/2011] [Indexed: 12/12/2022] Open
Abstract
Obesity, diabetes, and metabolic syndromes are increasingly recognized as health concerns worldwide. Overnutrition and insulin resistance are the major causes of diabetic hyperglycemia and hyperlipidemia in humans. Studies in the past decade provide evidence that bile acids are not just biological detergents facilitating gut nutrient absorption, but also important metabolic regulators of glucose and lipid homeostasis. Pharmacological alteration of bile acid metabolism or bile acid signaling pathways such as using bile acid receptor agonists or bile acid binding resins may be a promising therapeutic strategy for the treatment of obesity and diabetes. On the other hand, bile acid signaling is complex, and the molecular mechanisms mediating the bile acid effects are still not completely understood. This paper will summarize recent advances in our understanding of bile acid signaling in regulation of glucose and lipid metabolism, and the potentials of developing novel therapeutic strategies that target bile acid metabolism for the treatment of metabolic disorders.
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Abstract
Cholesterol is an essential molecule for the life cycle of the hepatitis C virus (HCV). This review focuses on the roles of cholesterol in HCV infection and introduces HCV events related to cholesterol metabolism and applications for cholesterol metabolism as a therapeutic target. HCV appears to alter host lipid metabolism into its preferable state, which is clinically recognized as steatosis and hypocholesterolemia. While hepatic fatty acid and triglyceride syntheses are upregulated in chronic hepatitis C patients, no direct evidence of increased hepatic de novo cholesterol biosynthesis has been obtained. Impaired VLDL secretion from hepatocytes is suggested to increase intracellular cholesterol concentrations, which may lead to hypocholesterolemia. Clinically, lower serum cholesterol levels are associated with lower rates of sustained virological responses (SVR) to pegylated-interferon plus ribavirin therapy, but the reason remains unclear. Clinical trials targeting HMG-CoA reductase, the rate-limiting enzyme in the cholesterol biosynthetic pathway, are being conducted using statins. Anti-HCV actions by statins appear to be caused by the inhibition of geranylgeranyl pyrophosphate synthesis rather than their cholesterol lowering effects. Other compounds that block various steps of cholesterol metabolic pathways have also been studied to develop new strategies for the complete eradication of this virus.
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Affiliation(s)
- Akira Honda
- Department of Gastroenterology, Tokyo Medical University Ibaraki Medical Center, Ibaraki, Japan
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35
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Kent AP, Stylianou IM. Scavenger receptor class B member 1 protein: hepatic regulation and its effects on lipids, reverse cholesterol transport, and atherosclerosis. Hepat Med 2011; 3:29-44. [PMID: 24367219 PMCID: PMC3846864 DOI: 10.2147/hmer.s7860] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Scavenger receptor class B member 1 (SR-BI, also known as SCARB1) is the primary receptor for the selective uptake of cholesterol from high-density lipoprotein (HDL). SR-BI is present in several key tissues; however, its presence and function in the liver is deemed the most relevant for protection against atherosclerosis. Cholesterol is transferred from HDL via SR-BI to the liver, which ultimately results in the excretion of cholesterol via bile and feces in what is known as the reverse cholesterol transport pathway. Much of our knowledge of SR-BI hepatic function and regulation is derived from mouse models and in vitro characterization. Multiple independent regulatory mechanisms of SR-BI have been discovered that operate at the transcriptional and post-transcriptional levels. In this review we summarize the critical discoveries relating to hepatic SR-BI cholesterol metabolism, atherosclerosis, and regulation of SR-BI, as well as alternative functions that may indirectly affect atherosclerosis.
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Affiliation(s)
- Anthony P Kent
- Department of Medicine and Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - Ioannis M Stylianou
- Department of Medicine and Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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