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Xiang T, Deng Z, Yang C, Tan J, Dou C, Luo F, Chen Y. Bile acid metabolism regulatory network orchestrates bone homeostasis. Pharmacol Res 2023; 196:106943. [PMID: 37777075 DOI: 10.1016/j.phrs.2023.106943] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 09/18/2023] [Accepted: 09/28/2023] [Indexed: 10/02/2023]
Abstract
Bile acids (BAs), synthesized in the liver and modified by the gut microbiota, have been widely appreciated not only as simple lipid emulsifiers, but also as complex metabolic regulators and momentous signaling molecules, which play prominent roles in the complex interaction among several metabolic systems. Recent studies have drawn us eyes on the diverse physiological functions of BAs, to enlarge the knowledge about the "gut-bone" axis due to the participation about the gut microbiota-derived BAs to modulate bone homeostasis at physiological and pathological stations. In this review, we have summarized the metabolic processes of BAs and highlighted the crucial roles of BAs targeting bile acid-activated receptors, promoting the proliferation and differentiation of osteoblasts (OBs), inhibiting the activity of osteoclasts (OCs), as well as reducing articular cartilage degradation, thus facilitating bone repair. In addition, we have also focused on the bidirectional effects of BA signaling networks in coordinating the dynamic balance of bone matrix and demonstrated the promising effects of BAs on the development or treatment for pathological bone diseases. In a word, further clinical applications targeting BA metabolism or modulating gut metabolome and related derivatives may be developed as effective therapeutic strategies for bone destruction diseases.
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Affiliation(s)
- Tingwen Xiang
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China; College of Basic Medical Science, Third Military Medical University (Army Medical University), Chongqing 400038, China
| | - Zihan Deng
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China
| | - Chuan Yang
- Department of Biomedical Materials Science, Third Military Medical University (Army Medical University), Chongqing 400038, China
| | - Jiulin Tan
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China
| | - Ce Dou
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.
| | - Fei Luo
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.
| | - Yueqi Chen
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing 400038, China.
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2
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Chiang JYL. My lifelong dedication to bile acid research. J Biol Chem 2023; 299:104672. [PMID: 37019215 PMCID: PMC10173005 DOI: 10.1016/j.jbc.2023.104672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2023] [Indexed: 04/05/2023] Open
Abstract
It is a great honor to be invited to write a reflections article on my scientific journey and lifelong bile acid research for the Journal of Biological Chemistry, in which I am proud to have published 24 manuscripts. I have also published 21 manuscripts in the Journal of Lipid Research, another journal of the American Society of Biochemistry and Molecular Biology. I begin my reflections from my early education in Taiwan, my coming to America for graduate study, and continue with my postdoctoral training in cytochrome P450 research, and my lifelong bile acid research career at Northeast Ohio Medical University. I have witnessed and helped in the transformation of this rural, not so visible medical school to a well-funded leader in liver research. Writing this reflections article on my long and rewarding journey in bile acid research brings back many good memories. I am proud of my scientific contributions and attribute my academic success to hard work, perseverance, good mentoring, and networking. I hope these reflections of my academic career would help inspire young investigators to pursue an academic career in biochemistry and metabolic diseases.
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Affiliation(s)
- John Y L Chiang
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA.
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3
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Chiang JL. My lifelong dedication to bile acid research. J Biol Chem 2023:103070. [PMID: 36842499 DOI: 10.1016/j.jbc.2023.103070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/22/2023] [Indexed: 02/28/2023] Open
Abstract
It is a great honor to be invited to write a reflection of my lifelong bile acid research for the Journal of Biological Chemistry, the premier biochemistry journal in which I am proud to have published 24 manuscripts. I published 21 manuscripts in the Journal of Lipid Research, also a journal of American Society of Biochemistry and Molecular Biology. I started my reflection from my early education in Taiwan, my coming to America for graduate study, my postdoctoral training in cytochrome P450 research, and my lifelong bile acid research career at the not so "visible" Northeast Ohio Medical University. I have witnesses and help to transform this sleepy rural medical school to a well-funded powerhouse in liver research. Writing this reflection of my long, exciting, and rewarding journey in bile acid research brought back many good memories. I am proud of my scientific contribution. I attribute my lifelong academic success to working hard, perseverance, good mentoring, and networking. I hope that this reflection of my academic career may provide guidance to younger investigators who are pursuing academic teaching and research and might inspire the next generation of researchers in biochemistry and metabolic diseases.
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Affiliation(s)
- JohnY L Chiang
- Northeast Ohio Medical University, Rootstown, OH, 44272.
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4
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Zhang L, Tang J, Wang Y, Wang X, Wang F. Association of CYP7A1 and CYP2E1 Polymorphisms with Type 2 Diabetes in the Chinese Han Populations. Pharmgenomics Pers Med 2022; 15:843-855. [PMID: 36168322 PMCID: PMC9509678 DOI: 10.2147/pgpm.s367806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 08/30/2022] [Indexed: 11/23/2022] Open
Abstract
Background Type 2 diabetes mellitus (T2DM) is caused by diverse environmental and genetic risk factors. Previous studies have reported that cytochrome P450 (CYP) is a promising gene for T2DM. Therefore, we aimed to determine the effects of CYP7A1 and CYP2E1 polymorphisms on T2DM susceptibility among the Chinese Han population. Methods A case-control study was conducted to assess the potential relationship of four polymorphisms (rs8192879, rs12542233, rs2070672 and rs2515641) with T2DM susceptibility in the Chinese population, involving 512 T2DM patients and 515 age- and gender-matched healthy individuals. We used the Agena MassARRAY platform to detect CYP7A1 and CYP2E1 polymorphisms. The relationship between genetic polymorphisms and T2DM risk was evaluated using odds ratios (ORs) and 95% confidence intervals (CIs) in various genetic models. Results After adjusting for age and gender, rs12542233 in the CYP7A1 gene was significantly associated with decreased T2DM risk (recessive: OR = 0.67, 95% CI = 0.49–0.91, p = 0.012; after FDR correction, p = 0.048). The CYP7A1 rs12542233 was associated with a reduced risk of T2DM in people over 59 years of age (p = 0.010). In the population with BMI ≤ 24 kg/m2, CYP7A1 rs12542233 was associated with an increased risk of T2DM (p < 0.05). In the population with BMI > 24 kg/m2, CYP2E1 rs2515641 can significantly reduce the risk of T2DM (p < 0.05). And rs8192879, rs2070672 and rs2515641 could significantly increase the risk of diabetes retinopathy in T2DM patients (p < 0.05). Furthermore, the Trs8192879Crs12542233 haplotype was significantly associated with T2DM (p = 0.019). Conclusion CYP7A1 and CYP2E1 polymorphisms may contribute to T2DM susceptibility in the Chinese Han population, especially in stratified analysis.
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Affiliation(s)
- Lihong Zhang
- Department of Endocrinology, Xi’an Central Hospital Affiliated to Xi’an Jiaotong University, Xi’an, 710003, People’s Republic of China
| | - Jingjing Tang
- Department of Endocrinology, Xi’an Central Hospital Affiliated to Xi’an Jiaotong University, Xi’an, 710003, People’s Republic of China
| | - Yindi Wang
- Department of Endocrinology, Xi’an Central Hospital Affiliated to Xi’an Jiaotong University, Xi’an, 710003, People’s Republic of China
| | - Xiang Wang
- Department of Endocrinology, Xi’an Central Hospital Affiliated to Xi’an Jiaotong University, Xi’an, 710003, People’s Republic of China
| | - Fang Wang
- Department of Endocrinology, Xi’an Central Hospital Affiliated to Xi’an Jiaotong University, Xi’an, 710003, People’s Republic of China
- Correspondence: Fang Wang, Department of Endocrinology, Xi’an central hospital affiliated to Xi’an Jiaotong University, No. 185, Houzaimen, Xincheng District, Xi’an, Shaanxi Province, People’s Republic of China, Tel/Fax +86 18681809668, Email
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Role of microRNA-185 in the FoxO1-CYP7A1 mediated regulation of bile acid and cholesterol metabolism: A novel target for drug discovery? Atherosclerosis 2022; 348:53-55. [DOI: 10.1016/j.atherosclerosis.2022.03.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 03/23/2022] [Indexed: 12/31/2022]
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6
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MicroRNA-185 modulates CYP7A1 mediated cholesterol-bile acid metabolism through post-transcriptional and post-translational regulation of FoxO1. Atherosclerosis 2022; 348:56-67. [DOI: 10.1016/j.atherosclerosis.2022.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/22/2022] [Accepted: 03/03/2022] [Indexed: 12/22/2022]
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7
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Zhu L, Wang J, Ding X, Bai S, Zeng Q, Xuan Y, Fraley GS, Zhang K. Serum trimethylamine-N-oxide and gut microbiome alterations are associated with cholesterol deposition in the liver of laying hens fed with rapeseed meal. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2021; 7:1258-1270. [PMID: 34786499 PMCID: PMC8566903 DOI: 10.1016/j.aninu.2021.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 01/29/2021] [Accepted: 02/23/2021] [Indexed: 02/08/2023]
Abstract
Sinapine derived from cruciferous plants could be converted into trimethylamine by intestinal microbiota. Its metabolite, trimethylamine N-oxide (TMAO), is closely linked to increased risk of cardiovascular disease and fat deposition in mammals. Hens fed with rapeseed meal (RSM) suffered from fatty liver hemorrhage syndrome (FLHS). This study was conducted to investigate whether RSM-induced fatty liver is due to TMAO via altering microbiota composition and diversity. At 33 weeks of age, 600 laying hens were randomly divided into 5 treatment groups, namely control and 14% RSM treatment groups (DY5, with 16.2% erucic acid [EA] and 74.66% glucosinolate [Gl] contents; MB1, with 3.50% EA and 43.23% Gl contents; DY6, with 6.7% EA and 22.67% Gl contents; XH3, with 44.60% EA and 132.83% Gl contents) for 8 weeks. Results revealed that 3 hens died due to liver hemorrhage after ingesting 14% RSM diet. The 14% RSM decreased serum low-density lipoprotein cholesterol (LDL-C) content (P < 0.01) while tended to increase serum TMAO content compared to the control group (P = 0.08). The 14% RSM diet increased red oil O optical density (P < 0.01), and increased total cholesterol (TC) and LDL-C content in the liver (P < 0.01, and P < 0.01, respectively). The 14% RSM decreased liver total bile acid (TBA) content compared to the control (P < 0.01). The DY6 had a higher TBA content in the liver than the XH3 (P < 0.01). The 14% RSM decreased mRNA abundance of liver X receptors alpha (LXR-α, P = 0.01), and increased mRNA abundance of sterol response element binding protein 2 (SREBP-2, P = 0.04). Results revealed that the in-feed RSM could alter richness and diversity of cecal microbiota compared to the control (P < 0.05). Liver TC content and serum TMAO showed a negative relationship with Proteobacteria and Actinobacteria (P = 0.04). In conclusion, 14% RSM increased liver TC and induced high liver score of FLHS, which was possibly associated with the altered cecal microbiota composition, increased serum TMAO levels and LXR-α and SREBP-2 expressions.
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Affiliation(s)
- Liping Zhu
- Animal Nutrition Institute, Key Laboratory for Animal Disease-Resistance Nutrition of China, Ministry of Education, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Jianping Wang
- Animal Nutrition Institute, Key Laboratory for Animal Disease-Resistance Nutrition of China, Ministry of Education, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Xuemei Ding
- Animal Nutrition Institute, Key Laboratory for Animal Disease-Resistance Nutrition of China, Ministry of Education, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Shiping Bai
- Animal Nutrition Institute, Key Laboratory for Animal Disease-Resistance Nutrition of China, Ministry of Education, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Qiufeng Zeng
- Animal Nutrition Institute, Key Laboratory for Animal Disease-Resistance Nutrition of China, Ministry of Education, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | - Yue Xuan
- Animal Nutrition Institute, Key Laboratory for Animal Disease-Resistance Nutrition of China, Ministry of Education, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
| | | | - Keying Zhang
- Animal Nutrition Institute, Key Laboratory for Animal Disease-Resistance Nutrition of China, Ministry of Education, Sichuan Agricultural University, Chengdu, Sichuan, 611130, China
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8
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Qi L, Tian Y, Chen Y. Circulating Bile Acid Profiles: A Need for Further Examination. J Clin Endocrinol Metab 2021; 106:3093-3112. [PMID: 34279029 DOI: 10.1210/clinem/dgab531] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Indexed: 12/15/2022]
Abstract
CONTEXT Bile acids (BAs) are increasingly recognized as metabolic and chronobiologic integrators that synchronize the systemic metabolic response to nutrient availability. Alterations in the concentration and/or composition of circulating BAs are associated with a number of metabolic disorders, such as obesity, type 2 diabetes mellitus (T2DM), insulin resistance (IR), and metabolic associated fatty liver disease (MAFLD). This review summarizes recent evidence that links abnormal circulating BA profiles to multiple metabolic disorders, and discusses the possible mechanisms underlying the connections to determine the role of BA profiling as a novel biomarker for these abnormalities. EVIDENCE ACQUISITION The review is based on a collection of primary and review literature gathered from a PubMed search of BAs, T2DM, IR, and MAFLD, among other keywords. EVIDENCE SYNTHESIS Obese and IR subjects appear to have elevated fasting circulating BAs but lower postprandial increase when compared with controls. The possible underlying mechanisms are disruption in the synchronization between the feeding/fasting cycle and the properties of BA-regulated metabolic pathways. Whether BA alterations are associated per se with MAFLD remains inconclusive. However, increased fasting circulating BAs level was associated with higher risk of advanced fibrosis stage. Thus, for patients with MAFLD, dynamically monitoring the circulating BA profiles may be a promising tool for the stratification of MAFLD. CONCLUSIONS Alterations in the concentration, composition, and rhythm of circulating BAs are associated with adverse events in systemic metabolism. Subsequent investigations regarding these aspects of circulating BA kinetics may help predict future metabolic disorders and guide therapeutic interventions.
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Affiliation(s)
- Li Qi
- Department of Rheumatology and Immunology, Shengjing Hospital of China Medical University, Shenyang, 110022, Liaoning Province, China
| | - Yu Tian
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, 110004, Liaoning Province, China
| | - Yongsheng Chen
- Department of General Surgery, Shengjing Hospital of China Medical University, Shenyang, 110004, Liaoning Province, China
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9
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Matye DJ, Li Y, Chen C, Chao X, Wang H, Ni H, Ding WX, Li T. Gut-restricted apical sodium-dependent bile acid transporter inhibitor attenuates alcohol-induced liver steatosis and injury in mice. Alcohol Clin Exp Res 2021; 45:1188-1199. [PMID: 33885179 PMCID: PMC8717856 DOI: 10.1111/acer.14619] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/05/2021] [Accepted: 04/13/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND Recent studies have shown that human and experimental alcohol-related liver disease (ALD) is robustly associated with dysregulation of bile acid homeostasis, which may in turn modulate disease severity. Pharmacological agents targeting bile acid metabolism and signaling may be potential therapeutics for ALD. METHODS The potential beneficial effects of a gut-restricted apical sodium-dependent bile acid transporter (ASBT) inhibitor were studied in a chronic-plus-binge ALD mouse model. RESULTS Blocking intestinal bile acid reabsorption by the gut-restricted ASBT inhibitor GSK2330672 attenuated hepatic steatosis and liver injury in a chronic-plus-binge ALD mouse model. Alcohol feeding is associated with intestinal bile acid accumulation but paradoxically impaired ileal farnesoid × receptor (FXR) function, and repressed hepatic cholesterol 7α-hydrolase (CYP7A1) expression despite decreased hepatic small heterodimer partner (SHP) and ileal fibroblast growth factor 15 (FGF15) expression. ASBT inhibitor treatment decreased intestinal bile acid accumulation and increased hepatic CYP7A1 expression, but further decreased ileal FXR activity. Alcohol feeding induces serum bile acid concentration that strongly correlates with a liver injury marker. However, alcohol-induced serum bile acid elevation is not due to intrahepatic bile acid accumulation but is strongly and positively associated with hepatic multidrug resistance-associated protein 3 (MRP4) and MRP4 induction but poorly associated with sodium-taurocholate cotransporting peptide (NTCP) expression. ASBT inhibitor treatment decreases serum bile acid concentration without affecting hepatocyte basolateral bile acid uptake and efflux transporters. CONCLUSION ASBT inhibitor treatment corrects alcohol-induced bile acid dysregulation and attenuates liver injury in experimental ALD.
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Affiliation(s)
- David J. Matye
- Harold Hamm Diabetes Center, Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
- Department of Pharmacology, Toxicology, Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160
| | - Yuan Li
- Department of Pharmacology, Toxicology, Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160
| | - Cheng Chen
- Harold Hamm Diabetes Center, Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Xiaojuan Chao
- Department of Pharmacology, Toxicology, Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160
| | - Huaiwen Wang
- Laboratory For Molecular Biology and Cytometry Research, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Hongmin Ni
- Department of Pharmacology, Toxicology, Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160
| | - Wen-Xing Ding
- Department of Pharmacology, Toxicology, Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160
| | - Tiangang Li
- Harold Hamm Diabetes Center, Department of Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
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Mercer KE, Maurer A, Pack LM, Ono-Moore K, Spray BJ, Campbell C, Chandler CJ, Burnett D, Souza E, Casazza G, Keim N, Newman J, Hunter G, Fernadez J, Garvey WT, Harper ME, Hoppel C, Adams SH, Thyfault J. Exercise training and diet-induced weight loss increase markers of hepatic bile acid (BA) synthesis and reduce serum total BA concentrations in obese women. Am J Physiol Endocrinol Metab 2021; 320:E864-E873. [PMID: 33645254 PMCID: PMC8238126 DOI: 10.1152/ajpendo.00644.2020] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Regular exercise has profound metabolic influence on the liver, but effects on bile acid (BA) metabolism are less well known. BAs are synthesized exclusively in the liver from cholesterol via the rate-limiting enzyme cholesterol 7 alpha-hydroxylase (CYP7A1). BAs contribute to the solubilization and absorption of lipids and serve as important signaling molecules, capable of systemic endocrine function. Circulating BAs increase with obesity and insulin resistance, but effects following exercise and diet-induced weight loss are unknown. To test if improvements in fitness and weight loss as a result of exercise training enhance BA metabolism, we measured serum concentrations of total BAs (conjugated and unconjugated primary and secondary BAs) in sedentary, obese, insulin-resistant women (N = 11) before (PRE) and after (POST) a ∼14-wk exercise and diet-induced weight loss intervention. BAs were measured in serum collected after an overnight fast and during an oral glucose tolerance test (OGTT). Serum fibroblast growth factor 19 (FGF19; a regulator of BA synthesis) and 7-alpha-hydroxy-cholesten-3-one (C4, a marker of CYP7A1 enzymatic activity) also were measured. Using linear mixed-model analyses and the change in V̇O2peak (mL/min/kg) as a covariate, we observed that exercise and weight loss intervention decreased total fasting serum BA by ∼30% (P = 0.001) and increased fasting serum C4 concentrations by 55% (P = 0.004). C4 was significantly correlated with serum total BAs only in the POST condition, whereas serum FGF19 was unchanged. These data indicate that a fitness and weight loss intervention modifies BA metabolism in obese women and suggest that improved metabolic health associates with higher postabsorptive (fasting) BA synthesis. Furthermore, pre- vs. postintervention patterns of serum C4 following an OGTT support the hypothesis that responsiveness of BA synthesis to postprandial inhibition is improved after exercise and weight loss.NEW & NOTEWORTHY Exercise and weight loss in previously sedentary, insulin-resistant women facilitates a significant improvement in insulin sensitivity and fitness that may be linked to changes in bile acid metabolism. Diet-induced weight loss plus exercise-induced increases in fitness promote greater postabsorptive bile acid synthesis while also sensitizing the bile acid metabolic system to feedback inhibition during a glucose challenge when glucose and insulin are elevated.
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Affiliation(s)
- Kelly E Mercer
- Arkansas Children's Nutrition Center, Little Rock, Arkansas
- Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Adrianna Maurer
- Departments of Molecular and Integrative Physiology and Internal Medicine, Kansas Medical Center, Kansas City, Kansas
| | - Lindsay M Pack
- Arkansas Children's Nutrition Center, Little Rock, Arkansas
| | | | - Beverly J Spray
- Arkansas Children's Research Institute, Little Rock, Arkansas
| | - Caitlin Campbell
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, California
| | - Carol J Chandler
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, California
| | - Dustin Burnett
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, California
| | - Elaine Souza
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, California
| | - Gretchen Casazza
- Sports Medicine Program, University of California, Davis School of Medicine, Sacramento, California
| | - Nancy Keim
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, California
| | - John Newman
- United States Department of Agriculture-Agricultural Research Service Western Human Nutrition Research Center, Davis, California
| | - Gary Hunter
- Department of Nutrition Sciences, University of Alabama, Birmingham, Alabama
| | - Jose Fernadez
- Department of Nutrition Sciences, University of Alabama, Birmingham, Alabama
| | - W Timothy Garvey
- Department of Nutrition Sciences, University of Alabama, Birmingham, Alabama
| | - Mary-Ellen Harper
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario, Canada
| | - Charles Hoppel
- Department of Pharmacology, Case Western Reserve University, Cleveland, Ohio
| | - Sean H Adams
- Department of Surgery, University of California, Davis School of Medicine, Sacramento, California
- Center for Alimentary and Metabolic Science, University of California, Davis School of Medicine, Sacramento, California
| | - John Thyfault
- Departments of Molecular and Integrative Physiology and Internal Medicine, Kansas Medical Center, Kansas City, Kansas
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Yin C, Tang S, Liu L, Cao A, Xie J, Zhang H. Effects of Bile Acids on Growth Performance and Lipid Metabolism during Chronic Heat Stress in Broiler Chickens. Animals (Basel) 2021; 11:ani11030630. [PMID: 33673472 PMCID: PMC7997420 DOI: 10.3390/ani11030630] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/18/2021] [Accepted: 02/23/2021] [Indexed: 12/14/2022] Open
Abstract
Simple Summary The negative impacts of heat stress (HS) on growth performance and lipid metabolism have been reported, but there are still no effective nutritional strategies to alleviate heat stress. Bile acids are new for their antioxidative properties and regulatory effect on lipid metabolism. This study was carried out to evaluate the growth performance and lipid metabolism in chickens under heat stress when fed with bile acid supplements in their diet. The results showed that mild heat stress (32 °C) induced hepatic lipogenic gene (hepatic SREBP-1c) expressions and lipid deposition, without obvious tissue damage in broilers. Dietary supplementation of bile acid could decrease hepatic lipid deposition without affecting endogenous bile acid biosynthesis. Therefore, bile acid supplements can benefit broiler chickens during high ambient temperatures, serving as a new nutritional strategy against heat stress. Abstract This study aimed to investigate whether dietary bile acid (BA) supplements can improve growth performance and lipid metabolism in heat-stressed broiler chickens. A total of 288 Arbor Acres broilers were blocked by BW and then randomly allocated into 4 treatments at 21 days of age. Birds reared under 32 °C had a higher cloacal temperature (p = 0.01), faster respiratory rate (p < 0.001), and a greatly reduced average daily feed intake (ADFI, p = 0.016), average daily gain (ADG, p = 0.006), final body weight (FBW, p = 0.008), and feed conversion rate (FCR, p = 0.004). In heat stress (HS) birds, the breast muscle rate (p = 0.006) and pH 24 h postmortem (p = 0.065) were lower, and the shear force was higher (p = 0.027). Dietary BA supplements tended to increase the breast muscle rate (p = 0.075) without affecting the growth performance and serum lipids (p > 0.05). Serum total bile acid (TBA) was roughly duplicated after BA supplements (p = 0.001). In the liver, total cholesterol was lower (p = 0.046), and triglycerides were higher (p = 0.04) in the HS birds, whereas the expression of SREBP-1c showed an increasing trend (p = 0.06). In contrast, dietary BA decreased triglycerides and the expressions of hepatic SREBP-1c and FAS in the liver (p < 0.05). In summary, mild HS causes hepatic lipid accumulation without obvious tissue damages, whereas BA has positive effects on relieving abnormal lipid metabolism, indicating that BA as a nutritional strategy has a certain potential in alleviating HS.
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Affiliation(s)
- Chang Yin
- The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (C.Y.); (S.T.); (L.L.); (H.Z.)
| | - Shanlong Tang
- The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (C.Y.); (S.T.); (L.L.); (H.Z.)
| | - Lei Liu
- The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (C.Y.); (S.T.); (L.L.); (H.Z.)
| | - Aizhi Cao
- Shandong Longchang Animal Health Care Co., Ltd., Jinan 251100, China;
| | - Jingjing Xie
- The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (C.Y.); (S.T.); (L.L.); (H.Z.)
- Correspondence:
| | - Hongfu Zhang
- The State Key Laboratory of Animal Nutrition, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (C.Y.); (S.T.); (L.L.); (H.Z.)
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12
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Takada S, Matsubara T, Fujii H, Sato-Matsubara M, Daikoku A, Odagiri N, Amano-Teranishi Y, Kawada N, Ikeda K. Stress can attenuate hepatic lipid accumulation via elevation of hepatic β-muricholic acid levels in mice with nonalcoholic steatohepatitis. J Transl Med 2021; 101:193-203. [PMID: 33303970 DOI: 10.1038/s41374-020-00509-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 10/20/2020] [Accepted: 10/20/2020] [Indexed: 02/06/2023] Open
Abstract
Stress can affect our body and is known to lead to some diseases. However, the influence on the development of nonalcohol fatty liver disease (NAFLD) remains unknown. This study demonstrated that chronic restraint stress attenuated hepatic lipid accumulation via elevation of hepatic β-muricholic acid (βMCA) levels in the development of nonalcoholic steatohepatitis (NASH) in mice. Serum cortisol and corticosterone levels, i.e., human and rodent stress markers, were correlated with serum bile acid levels in patients with NAFLD and methionine- and choline-deficient (MCD) diet-induced mice, respectively, suggesting that stress is related to bile acid (BA) homeostasis in NASH. In the mouse model, hepatic βMCA and cholic acid (CA) levels were increased after the stress challenge. Considering that a short stress enhanced hepatic CYP7A1 protein levels in normal mice and corticosterone increased CYP7A1 protein levels in primary mouse hepatocytes, the enhanced Cyp7a1 expression was postulated to be involved in the chronic stress-increased hepatic βMCA level. Interestingly, chronic stress decreased hepatic lipid levels in MCD-induced NASH mice. Furthermore, βMCA suppressed lipid accumulation in mouse primary hepatocytes exposed to palmitic acid/oleic acid, but CA did not. In addition, Cyp7a1 expression seemed to be related to lipid accumulation in hepatocytes. In conclusion, chronic stress can change hepatic lipid accumulation in NASH mice, disrupting BA homeostasis via induction of hepatic Cyp7a1 expression. This study discovered a new βMCA action in the liver, indicating the possibility that βMCA is available for NAFLD therapy.
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Affiliation(s)
- Sayuri Takada
- Department of Anatomy and Regenerative Biology, Osaka City University Graduate School of Medicine, Osaka, Japan
- Department of Hepatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Tsutomu Matsubara
- Department of Anatomy and Regenerative Biology, Osaka City University Graduate School of Medicine, Osaka, Japan.
| | - Hideki Fujii
- Department of Hepatology, Osaka City University Graduate School of Medicine, Osaka, Japan
- Endowed Department of Liver Cirrhosis Therapeutics, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Misako Sato-Matsubara
- Department of Hepatology, Osaka City University Graduate School of Medicine, Osaka, Japan
- Endowed Laboratory of Synthetic Biology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Atsuko Daikoku
- Department of Hepatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Naoshi Odagiri
- Department of Hepatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Yuga Amano-Teranishi
- Department of Hepatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Norifumi Kawada
- Department of Hepatology, Osaka City University Graduate School of Medicine, Osaka, Japan
| | - Kazuo Ikeda
- Department of Anatomy and Regenerative Biology, Osaka City University Graduate School of Medicine, Osaka, Japan
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13
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Engin A. Bile Acid Toxicity and Protein Kinases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1275:229-258. [PMID: 33539018 DOI: 10.1007/978-3-030-49844-3_9] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
If the bile acids reach to pathological concentrations due to cholestasis, accumulation of hydrophobic bile acids within the hepatocyte may result in cell death. Thus, hydrophobic bile acids induce apoptosis in hepatocytes, while hydrophilic bile acids increase intracellular adenosine 3',5'-monophosphate (cAMP) levels and activate mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) pathways to protect hepatocytes from apoptosis.Two apoptotic pathways have been described in bile acids-induced death. Both are controlled by multiple protein kinase signaling pathways. In mitochondria-controlled pathway, caspase-8 is activated with death domain-independent manner, whereas, Fas-dependent classical pathway involves ligand-independent oligomerization of Fas.Hydrophobic bile acids dose-dependently upregulate the inflammatory response by further stimulating production of inflammatory cytokines. Death receptor-mediated apoptosis is regulated at the cell surface by the receptor expression, at the death-inducing signaling complex (DISC) by expression of procaspase-8, the death receptors Fas-associated death domain (FADD), and cellular FADD-like interleukin 1-beta (IL-1β)-converting enzyme (FLICE) inhibitory protein (cFLIP). Bile acids prevent cFLIP recruitment to the DISC and thereby enhance initiator caspase activation and lead to cholestatic apoptosis. At mitochondria, the expression of B-cell leukemia/lymphoma-2 (Bcl-2) family proteins contribute to apoptosis by regulating mitochondrial cytochrome c release via Bcl-2, Bcl-2 homology 3 (BH3) interacting domain death agonist (Bid), or Bcl-2 associated protein x (Bax). Fas receptor CD95 activation by hydrophobic bile acids is initiated by reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-dependent reactive oxygen species (ROS) signaling. However, activation of necroptosis by ligands of death receptors requires the kinase activity of receptor interacting protein1 (RIP1), which mediates the activation of RIP3 and mixed lineage kinase domain-like protein (MLKL). In this chapter, mainly the effect of protein kinases signal transduction on the mechanisms of hydrophobic bile acids-induced inflammation, apoptosis, necroptosis and necrosis are discussed.
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Affiliation(s)
- Atilla Engin
- Department of General Surgery, Faculty of Medicine, Gazi University, Ankara, Turkey.
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14
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Wang XH, Xu F, Cheng M, Wang X, Zhang DM, Zhao LH, Cai HL, Huang HY, Chen T, Zhang XL, Wang XQ, Cheng XB, Su JB, Lu Y. Fasting serum total bile acid levels are associated with insulin sensitivity, islet β-cell function and glucagon levels in response to glucose challenge in patients with type 2 diabetes. Endocr J 2020; 67:1107-1117. [PMID: 32684527 DOI: 10.1507/endocrj.ej20-0201] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Type 2 diabetes (T2D) is characterized by islet β-cell dysfunction and impaired suppression of glucagon secretion of α-cells in response to oral hyperglycaemia. Bile acid (BA) metabolism plays a dominant role in maintaining glucose homeostasis. So we evaluated the association of fasting serum total bile acids (S-TBAs) with insulin sensitivity, islet β-cell function and glucagon levels in T2D. Total 2,952 T2D patients with fasting S-TBAs in the normal range were recruited and received oral glucose tolerance tests for determination of fasting and postchallenge glucose, C-peptide and glucagon. Fasting and systemic insulin sensitivity were assessed by homeostasis model assessment (HOMA) and Matsuda index using C-peptide, i.e., ISHOMA-cp and ISIM-cp, respectively. Islet β-cell function was assessed by the insulin-secretion-sensitivity-index-2 using C-peptide (ISSI2cp). The area under the glucagon curve (AUCgla) was used to assess postchallenge glucagon. The results showed ISHOMA-cp, ISIM-cp and ISSI2cp decreased, while AUCgla notably increased, across ascending quartiles of S-TBAs but not fasting glucagon. Moreover, S-TBAs were inversely correlated with ISHOMA-cp, ISIM-cp and ISSI2cp (r = -0.21, -0.15 and -0.25, respectively, p < 0.001) and positively correlated with AUCgla (r = 0.32, p < 0.001) but not with fasting glucagon (r = 0.033, p = 0.070). Furthermore, after adjusting for other clinical covariates by multiple linear regression analyses, the S-TBAs were independently associated with ISHOMA-cp (β = -0.04, t = -2.82, p = 0.005), ISIM-cp (β = -0.11, t = -7.05, p < 0.001), ISSI2cp (β = -0.15, t = -10.26, p < 0.001) and AUCgla (β = 0.29, t = 19.08, p < 0.001). Increased fasting S-TBAs are associated with blunted fasting and systemic insulin sensitivity, impaired islet β-cell function and increased glucagon levels in response to glucose challenge in T2D.
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Affiliation(s)
- Xiao-Hua Wang
- Department of Endocrinology, First Affiliated Hospital of Soochow University, Suzhou 215006, China
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Feng Xu
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Ming Cheng
- School of Rail Transportation, Soochow University, Suzhou 215006, China
| | - Xing Wang
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Dong-Mei Zhang
- Medical Research Center, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Li-Hua Zhao
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Hong-Li Cai
- Department of Geriatrics, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Hai-Yan Huang
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Tong Chen
- Department of Clinical Laboratory, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Xiu-Lin Zhang
- Department of Clinical Laboratory, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Xue-Qin Wang
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Xing-Bo Cheng
- Department of Endocrinology, First Affiliated Hospital of Soochow University, Suzhou 215006, China
| | - Jian-Bin Su
- Department of Endocrinology, Affiliated Hospital 2 of Nantong University, and First People's Hospital of Nantong City, Nantong 226001, China
| | - Yan Lu
- Department of Endocrinology, First Affiliated Hospital of Soochow University, Suzhou 215006, China
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15
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van Olst N, Meiring S, de Brauw M, Bergman JJ, Nieuwdorp M, van der Peet DL, Gerdes VE. Small intestinal physiology relevant to bariatric and metabolic endoscopic therapies: Incretins, bile acid signaling, and gut microbiome. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.tige.2020.03.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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16
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Feng X, Zhu C, Lee S, Gao J, Zhu P, Yamauchi J, Pan C, Singh S, Qu S, Miller R, Monga SP, Peng Y, Dong HH. Depletion of hepatic forkhead box O1 does not affect cholelithiasis in male and female mice. J Biol Chem 2020; 295:7003-7017. [PMID: 32273342 DOI: 10.1074/jbc.ra119.012272] [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: 12/11/2019] [Revised: 04/07/2020] [Indexed: 11/06/2022] Open
Abstract
Cholelithiasis is one of the most prevalent gastroenterological diseases and is characterized by the formation of gallstones in the gallbladder. Both clinical and preclinical data indicate that obesity, along with comorbidity insulin resistance, is a predisposing factor for cholelithiasis. Forkhead box O1 (FoxO1) is a key transcription factor that integrates insulin signaling with hepatic metabolism and becomes deregulated in the insulin-resistant liver, contributing to dyslipidemia in obesity. To gain mechanistic insights into how insulin resistance is linked to cholelithiasis, here we determined FoxO1's role in bile acid homeostasis and its contribution to cholelithiasis. We hypothesized that hepatic FoxO1 deregulation links insulin resistance to impaired bile acid metabolism and cholelithiasis. To address this hypothesis, we used the FoxO1LoxP/LoxP-Albumin-Cre system to generate liver-specific FoxO1-knockout mice. FoxO1-knockout mice and age- and sex-matched WT littermates were fed a lithogenic diet, and bile acid metabolism and gallstone formation were assessed in these animals. We showed that FoxO1 affected bile acid homeostasis by regulating hepatic expression of key enzymes in bile acid synthesis and in biliary cholesterol and phospholipid secretion. Furthermore, FoxO1 inhibited hepatic expression of the bile acid receptor farnesoid X receptor and thereby counteracted hepatic farnesoid X receptor signaling. Nonetheless, hepatic FoxO1 depletion neither affected the onset of gallstone disease nor impacted the disease progression, as FoxO1-knockout and control mice of both sexes had similar gallstone weights and incidence rates. These results argue against the notion that FoxO1 is a link between insulin resistance and cholelithiasis.
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Affiliation(s)
- Xiaoyun Feng
- Division of Endocrinology and Diabetes, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224.,Department of Endocrinology & Metabolism, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai 200080, China
| | - Cuiling Zhu
- Division of Endocrinology and Diabetes, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224.,Department of Endocrinology & Metabolism, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Sojin Lee
- Division of Endocrinology and Diabetes, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Jingyang Gao
- Division of Endocrinology and Diabetes, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224.,Department of Endocrinology & Metabolism, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Ping Zhu
- Division of Endocrinology and Diabetes, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224.,Department of Endocrinology and Metabolism, Guangzhou Red Cross Hospital, Medical College of Jinan University, Guangzhou 510220, China
| | - Jun Yamauchi
- Division of Endocrinology and Diabetes, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Chenglin Pan
- Division of Endocrinology and Diabetes, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224.,Department of Pediatrics, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Sucha Singh
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224.,Pittsburgh Liver Research Center, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Shen Qu
- Department of Endocrinology & Metabolism, Shanghai 10th People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Rita Miller
- Division of Endocrinology and Diabetes, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Satdarshan P Monga
- Division of Experimental Pathology, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224.,Pittsburgh Liver Research Center, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Yongde Peng
- Department of Endocrinology & Metabolism, Shanghai General Hospital, Shanghai Jiaotong University, Shanghai 200080, China
| | - H Henry Dong
- Division of Endocrinology and Diabetes, Department of Pediatrics, UPMC Children's Hospital of Pittsburgh, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224 .,Pittsburgh Liver Research Center, Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
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17
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Farr S, Stankovic B, Hoffman S, Masoudpoor H, Baker C, Taher J, Dean AE, Anakk S, Adeli K. Bile acid treatment and FXR agonism lower postprandial lipemia in mice. Am J Physiol Gastrointest Liver Physiol 2020; 318:G682-G693. [PMID: 32003602 DOI: 10.1152/ajpgi.00386.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Postprandial dyslipidemia is a common feature of insulin-resistant states and contributes to increased cardiovascular disease risk. Recently, bile acids have been recognized beyond their emulsification properties as important signaling molecules that promote energy expenditure, improve insulin sensitivity, and lower fasting lipemia. Although bile acid receptors have become novel pharmaceutical targets, their effects on postprandial lipid metabolism remain unclear. Here, we investigated the potential role of bile acids in regulation of postprandial chylomicron production and triglyceride excursion. Healthy C57BL/6 mice were given an intraduodenal infusion of taurocholic acid (TA) under fat-loaded conditions, and circulating lipids were measured. Targeting of bile acid receptors was achieved with GW4064, a synthetic agonist to the farnesoid X receptor (FXR), and deoxycholic acid (DCA), an activator of the Takeda G-protein-coupled receptor 5. TA, GW4064, and DCA treatments all lowered postprandial lipemia. FXR agonism also reduced intestinal triglyceride content and activity of microsomal triglyceride transfer protein, involved in chylomicron assembly. Importantly, TA (but not DCA) effects were largely lost in FXR knockout mice. These bile acid effects are reminiscent of the antidiabetic hormone glucagon-like peptide-1 (GLP-1). Although the GLP-1 receptor agonist exendin-4 retained its ability to acutely lower postprandial lipemia during bile acid sequestration and FXR deficiency, it did raise hepatic expression of the rate-limiting enzyme for bile acid synthesis. Bile acid signaling may be an important mechanism of controlling dietary lipid absorption, and bile acid receptors may constitute novel targets for the treatment of postprandial dyslipidemia.NEW & NOTEWORTHY We present new data suggesting potentially important roles for bile acids in regulation of postprandial lipid metabolism. Specific bile acid species, particularly secondary bile acids, were found to markedly inhibit absorption of dietary lipid and reduce postprandial triglyceride excursion. These effects appear to be mediated via bile acid receptors, farnesoid X receptor (FXR) and Takeda G protein-coupled receptor 5 (TGR5). Importantly, bile acid signaling may trigger glucagon-like peptide-1 (GLP-1) secretion, which may in turn mediate the marked inhibitory effects on dietary fat absorption.
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Affiliation(s)
- Sarah Farr
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada.,Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Bogdan Stankovic
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada.,Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Simon Hoffman
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada.,Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Hassan Masoudpoor
- Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Chris Baker
- Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jennifer Taher
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada.,Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Angela E Dean
- Molecular and Cellular Biology, University of Illinois-Urbana-Champaign, Urbana, Illinois
| | | | - Khosrow Adeli
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada.,Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
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18
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Lee SG, Lee YH, Choi E, Cho Y, Kim JH. Fasting serum bile acids concentration is associated with insulin resistance independently of diabetes status. Clin Chem Lab Med 2020; 57:1218-1228. [PMID: 30964746 DOI: 10.1515/cclm-2018-0741] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 12/20/2018] [Indexed: 12/19/2022]
Abstract
Background Bile acids (BAs) have been demonstrated to exert a variety of metabolic effects and alterations in BAs have been reported in patients with obesity, insulin resistance (IR) and type 2 diabetes mellitus (T2DM). However, it is unclear which metabolic condition is the main contributor to alterations in BAs. In this study, we investigate the associations between different BA profiles with glycemia, obesity or IR status. Methods Fasting serum concentrations of 15 BA species were determined in a total of 241 individuals (71 drug-naïve patients with T2DM, 95 patients with impaired fasting glucose [IFG], and 75 healthy controls. Results A comparison of the mean values of the BAs revealed no significant differences between normoglycemic controls and patients with IFG or T2DM. However, when the entire cohort was divided according to the presence of IR as determined by a homeostasis model assessment of insulin resistance (HOMA-IR) value >2.5, the levels of total BA and most species of BAs were significantly higher in patients with IR than in patients without. In the correlation analysis, most species of BAs, as well as total BA, were significantly associated with HOMA-IR levels. Furthermore, when the subjects were divided into four groups according to IR and diabetic status, subjects with IR had significantly higher total BAs than participants without IR both in diabetic and non-diabetic groups. Ultimately, multiple linear regression analysis identified HOMA-IR as the only significant contributor to most serum BA species. Conclusions Our findings support the essential role of IR in regulating BA metabolism and that this effect is independent of diabetic status.
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Affiliation(s)
- Sang-Guk Lee
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea
| | - Yong-Ho Lee
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Eunhye Choi
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea
| | - Yonggeun Cho
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea
| | - Jeong-Ho Kim
- Department of Laboratory Medicine, Severance Hospital, Yonsei University College of Medicine, Seodaemun-gu, Seoul, Korea
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19
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Hoogerland JA, Lei Y, Wolters JC, de Boer JF, Bos T, Bleeker A, Mulder NL, van Dijk TH, Kuivenhoven JA, Rajas F, Mithieux G, Haeusler RA, Verkade HJ, Bloks VW, Kuipers F, Oosterveer MH. Glucose-6-Phosphate Regulates Hepatic Bile Acid Synthesis in Mice. Hepatology 2019; 70:2171-2184. [PMID: 31102537 PMCID: PMC6859192 DOI: 10.1002/hep.30778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 05/15/2019] [Indexed: 12/22/2022]
Abstract
It is well established that, besides facilitating lipid absorption, bile acids act as signaling molecules that modulate glucose and lipid metabolism. Bile acid metabolism, in turn, is controlled by several nutrient-sensitive transcription factors. Altered intrahepatic glucose signaling in type 2 diabetes associates with perturbed bile acid synthesis. We aimed to characterize the regulatory role of the primary intracellular metabolite of glucose, glucose-6-phosphate (G6P), on bile acid metabolism. Hepatic gene expression patterns and bile acid composition were analyzed in mice that accumulate G6P in the liver, that is, liver-specific glucose-6-phosphatase knockout (L-G6pc-/- ) mice, and mice treated with a pharmacological inhibitor of the G6P transporter. Hepatic G6P accumulation induces sterol 12α-hydroxylase (Cyp8b1) expression, which is mediated by the major glucose-sensitive transcription factor, carbohydrate response element-binding protein (ChREBP). Activation of the G6P-ChREBP-CYP8B1 axis increases the relative abundance of cholic-acid-derived bile acids and induces physiologically relevant shifts in bile composition. The G6P-ChREBP-dependent change in bile acid hydrophobicity associates with elevated plasma campesterol/cholesterol ratio and reduced fecal neutral sterol loss, compatible with enhanced intestinal cholesterol absorption. Conclusion: We report that G6P, the primary intracellular metabolite of glucose, controls hepatic bile acid synthesis. Our work identifies hepatic G6P-ChREBP-CYP8B1 signaling as a regulatory axis in control of bile acid and cholesterol metabolism.
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Affiliation(s)
- Joanne A. Hoogerland
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands
| | - Yu Lei
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands
| | - Justina C. Wolters
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands
| | - Jan Freark de Boer
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands,Laboratory MedicineUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Trijnie Bos
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands
| | - Aycha Bleeker
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands
| | - Niels L. Mulder
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands
| | - Theo H. van Dijk
- Laboratory MedicineUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Jan A. Kuivenhoven
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands
| | - Fabienne Rajas
- Institut National de la Santé et de la Recherche Médicale, U1213Université Claude Bernard LyonVilleurbanneFrance
| | - Gilles Mithieux
- Institut National de la Santé et de la Recherche Médicale, U1213Université Claude Bernard LyonVilleurbanneFrance
| | - Rebecca A. Haeusler
- Department of Pathology and Cell BiologyColumbia University College of Physicians and SurgeonsNew YorkNY
| | - Henkjan J. Verkade
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands
| | - Vincent W. Bloks
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands
| | - Folkert Kuipers
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands,Laboratory MedicineUniversity of Groningen, University Medical Center GroningenGroningenThe Netherlands
| | - Maaike H. Oosterveer
- Department of PediatricsUniversity Medical Center GroningenGroningenThe Netherlands
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20
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Polyphenol Effects on Cholesterol Metabolism via Bile Acid Biosynthesis, CYP7A1: A Review. Nutrients 2019; 11:nu11112588. [PMID: 31661763 PMCID: PMC6893479 DOI: 10.3390/nu11112588] [Citation(s) in RCA: 146] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 09/27/2019] [Accepted: 10/09/2019] [Indexed: 12/12/2022] Open
Abstract
Atherosclerosis, the main contributor to coronary heart disease, is characterised by an accumulation of lipids such as cholesterol in the arterial wall. Reverse cholesterol transport (RCT) reduces cholesterol via its conversion into bile acids (BAs). During RCT in non-hepatic peripheral tissues, cholesterol is transferred to high-density lipoprotein (HDL) particles and returned to the liver for conversion into BAs predominantly via the rate-limiting enzyme, cholesterol 7 α-hydroxylase (CYP7A1). Numerous reports have described that polyphenol induced increases in BA excretion and corresponding reductions in total and LDL cholesterol in animal and in-vitro studies, but the process whereby this occurs has not been extensively reviewed. There are three main mechanisms by which BA excretion can be augmented: (1) increased expression of CYP7A1; (2) reduced expression of intestinal BA transporters; and (3) changes in the gut microbiota. Here we summarise the BA metabolic pathways focusing on CYP7A1, how its gene is regulated via transcription factors, diurnal rhythms, and microRNAs. Importantly, we will address the following questions: (1) Can polyphenols enhance BA secretion by modulating the CYP7A1 biosynthetic pathway? (2) Can polyphenols alter the BA pool via changes in the gut microbiota? (3) Which polyphenols are the most promising candidates for future research? We conclude that while in rodents some polyphenols induce CYP7A1 expression predominantly by the LXRα pathway, in human cells, this may occur through FXR, NF-KB, and ERK signalling. Additionally, gut microbiota is important for the de-conjugation and excretion of BAs. Puerarin, resveratrol, and quercetin are promising candidates for further research in this area.
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21
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Rendic SP, Peter Guengerich F. Human cytochrome P450 enzymes 5-51 as targets of drugs and natural and environmental compounds: mechanisms, induction, and inhibition - toxic effects and benefits. Drug Metab Rev 2019; 50:256-342. [PMID: 30717606 DOI: 10.1080/03602532.2018.1483401] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cytochrome P450 (P450, CYP) enzymes have long been of interest due to their roles in the metabolism of drugs, pesticides, pro-carcinogens, and other xenobiotic chemicals. They have also been of interest due to their very critical roles in the biosynthesis and metabolism of steroids, vitamins, and certain eicosanoids. This review covers the 22 (of the total of 57) human P450s in Families 5-51 and their substrate selectivity. Furthermore, included is information and references regarding inducibility, inhibition, and (in some cases) stimulation by chemicals. We update and discuss important aspects of each of these 22 P450s and questions that remain open.
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Affiliation(s)
| | - F Peter Guengerich
- b Department of Biochemistry , Vanderbilt University School of Medicine , Nashville , TN , USA
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22
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Li Y, Lu LG. Therapeutic Roles of Bile Acid Signaling in Chronic Liver Diseases. J Clin Transl Hepatol 2018; 6:425-430. [PMID: 30637221 PMCID: PMC6328738 DOI: 10.14218/jcth.2018.00025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 08/22/2018] [Accepted: 08/24/2018] [Indexed: 12/11/2022] Open
Abstract
Bile acids (BAs) are the major metabolic product of cholesterol, having detergent-like activities and being responsible for absorption of lipid and lipid-soluble vitamins. In addition, it has been increasingly recognized that BAs are important signaling molecules, regulating energy metabolism and immunity. Under physiological circumstances, synthesis and transport of BAs are precisely regulated to maintain bile acid homeostasis. Disruption of bile acid homeostasis results in pathological cholestasis and metabolic liver diseases. During the last decades, BAs have been gradually recognized as an important therapeutic target for novel treatment in chronic liver diseases. This review will provide an update on the current understanding of synthesis, transport and regulation of BAs, with a focus on the therapeutic roles of bile acid signaling in chronic liver diseases.
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Affiliation(s)
| | - Lun-Gen Lu
- *Correspondence to: Lun-Gen Lu, Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, 100 Haining Road, Shanghai 200080, China. Tel: +86-21-63240090, Fax: +86-21-63241377, E-mail:
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23
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Lee SX, Heine M, Schlein C, Ramakrishnan R, Liu J, Belnavis G, Haimi I, Fischer AW, Ginsberg HN, Heeren J, Rinninger F, Haeusler RA. FoxO transcription factors are required for hepatic HDL cholesterol clearance. J Clin Invest 2018; 128:1615-1626. [PMID: 29408809 DOI: 10.1172/jci94230] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 02/01/2018] [Indexed: 12/15/2022] Open
Abstract
Insulin resistance and type 2 diabetes are associated with low levels of high-density lipoprotein cholesterol (HDL-C). The insulin-repressible FoxO transcription factors are potential mediators of the effect of insulin on HDL-C. FoxOs mediate a substantial portion of insulin-regulated transcription, and poor FoxO repression is thought to contribute to the excessive glucose production in diabetes. In this work, we show that mice with liver-specific triple FoxO knockout (L-FoxO1,3,4), which are known to have reduced hepatic glucose production, also have increased HDL-C. This was associated with decreased expression of the HDL-C clearance factors scavenger receptor class B type I (SR-BI) and hepatic lipase and defective selective uptake of HDL cholesteryl ester by the liver. The phenotype could be rescued by re-expression of SR-BI. These findings demonstrate that hepatic FoxOs are required for cholesterol homeostasis and HDL-mediated reverse cholesterol transport to the liver.
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Affiliation(s)
- Samuel X Lee
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Markus Heine
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Christian Schlein
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Rajasekhar Ramakrishnan
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Jing Liu
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Gabriella Belnavis
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Ido Haimi
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Alexander W Fischer
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Henry N Ginsberg
- Department of Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA
| | - Joerg Heeren
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Franz Rinninger
- Department of Biochemistry and Molecular Cell Biology, University Medical Center Hamburg Eppendorf, Hamburg, Germany.,Department of Internal Medicine III, University Medical Center Hamburg Eppendorf, Hamburg, Germany
| | - Rebecca A Haeusler
- Naomi Berrie Diabetes Center, Columbia University College of Physicians and Surgeons, New York, New York, USA.,Department of Pathology and Cell Biology, Columbia University College of Physicians and Surgeons, New York, New York, USA
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Abstract
Non-alcoholic fatty liver disease (NAFLD) is a chronic progressive liver disorder that begins with simple hepatic steatosis and progresses to non-alcoholic steatohepatitis, fibrosis, cirrhosis, and even liver cancer. As the global prevalence of NAFLD rises, it is increasingly important that we understand its pathogenesis and develop effective therapies for this chronic disease. Forkhead box O (FOXO) transcription factors are key downstream regulators in the insulin/insulin-like growth factor 1 (IGF1) signaling pathway, and have been implicated in a range of cellular functions including the regulation of glucose, triglyceride, and cholesterol homeostasis. The role of FOXOs in the modulation of immune response and inflammation is complex, with reports of both pro- and anti-inflammatory effects. FOXOs are reported to protect against hepatic fibrosis by inhibiting proliferation and transdifferentiation of hepatic stellate cells. Mice that are deficient in hepatic FOXOs are more susceptible to non-alcoholic steatohepatitis than wild-type controls. In summary, FOXOs play a critical role in maintaining metabolic and cellular homeostasis in the liver, and dysregulation of FOXOs may be involved in NAFLD development.
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Affiliation(s)
- X Charlie Dong
- Department of Biochemistry and Molecular Biology, Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA
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25
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Nuñez-Garcia M, Gomez-Santos B, Buqué X, García-Rodriguez JL, Romero MR, Marin JJG, Arteta B, García-Monzón C, Castaño L, Syn WK, Fresnedo O, Aspichueta P. Osteopontin regulates the cross-talk between phosphatidylcholine and cholesterol metabolism in mouse liver. J Lipid Res 2017; 58:1903-1915. [PMID: 28754826 DOI: 10.1194/jlr.m078980] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 07/28/2017] [Indexed: 12/15/2022] Open
Abstract
Osteopontin (OPN) is involved in different liver pathologies in which metabolic dysregulation is a hallmark. Here, we investigated whether OPN could alter liver, and more specifically hepatocyte, lipid metabolism and the mechanism involved. In mice, lack of OPN enhanced cholesterol 7α-hydroxylase (CYP7A1) levels and promoted loss of phosphatidylcholine (PC) content in liver; in vivo treatment with recombinant (r)OPN caused opposite effects. rOPN directly decreased CYP7A1 levels through activation of focal adhesion kinase-AKT signaling in hepatocytes. PC content was also decreased in OPN-deficient (OPN-KO) hepatocytes in which de novo FA and PC synthesis was lower, whereas cholesterol (CHOL) synthesis was higher, than in WT hepatocytes. In vivo inhibition of cholesterogenesis normalized liver PC content in OPN-KO mice, demonstrating that OPN regulates the cross-talk between liver CHOL and PC metabolism. Matched liver and serum samples showed a positive correlation between serum OPN levels and liver PC and CHOL concentration in nonobese patients with nonalcoholic fatty liver. In conclusion, OPN regulates CYP7A1 levels and the metabolic fate of liver acetyl-CoA as a result of CHOL and PC metabolism interplay. The results suggest that CYP7A1 is a main axis and that serum OPN could disrupt liver PC and CHOL metabolism, contributing to nonalcoholic fatty liver disease progression in nonobese patients.
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Affiliation(s)
- Maitane Nuñez-Garcia
- Departments of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Beatriz Gomez-Santos
- Departments of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Xabier Buqué
- Departments of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain.,Biocruces Health Research Institute, Barakaldo, Spain
| | - Juan L García-Rodriguez
- Departments of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Marta R Romero
- Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca, Spain.,Center for the Study of Liver and Gastrointestinal Diseases (CIBERehd), Carlos III National Institute of Health, Madrid, Spain
| | - Jose J G Marin
- Experimental Hepatology and Drug Targeting (HEVEFARM), IBSAL, University of Salamanca, Salamanca, Spain.,Center for the Study of Liver and Gastrointestinal Diseases (CIBERehd), Carlos III National Institute of Health, Madrid, Spain
| | - Beatriz Arteta
- Cellular Biology and Histology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Carmelo García-Monzón
- Center for the Study of Liver and Gastrointestinal Diseases (CIBERehd), Carlos III National Institute of Health, Madrid, Spain.,Liver Research Unit, Santa Cristina University Hospital, Instituto de Investigación Sanitaria Princesa, Madrid, Spain
| | - Luis Castaño
- Biocruces Health Research Institute, Barakaldo, Spain.,Hospital Universitario Cruces, Barakaldo, Spain.,Pediatrics Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain.,CIBERDEM, CIBERER Carlos III National Institute of Health, Madrid, Spain
| | - Wing-Kin Syn
- Regeneration and Repair, Institute of Hepatology, Foundation for Liver Research, London, United Kingdom.,Division of Gastroenterology and Hepatology, Medical University of South Carolina, Charleston, SC.,Section of Gastroenterology, Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC
| | - Olatz Fresnedo
- Departments of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Patricia Aspichueta
- Departments of Physiology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain .,Biocruces Health Research Institute, Barakaldo, Spain
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26
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Mehta D, Mehta KD. PKCβ: Expanding role in hepatic adaptation of cholesterol homeostasis to dietary fat/cholesterol. Am J Physiol Gastrointest Liver Physiol 2017; 312:G266-G273. [PMID: 28104587 PMCID: PMC5401991 DOI: 10.1152/ajpgi.00373.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 01/11/2017] [Accepted: 01/17/2017] [Indexed: 01/31/2023]
Abstract
Cholesterol homeostasis relies on an intricate network of cellular processes whose deregulation in response to Western type high-fat/cholesterol diets can lead to several life-threatening pathologies. Significant advances have been made in resolving the molecular identity and regulatory function of transcription factors sensitive to fat, cholesterol, or bile acids, but whether body senses the presence of both fat and cholesterol simultaneously is not known. Assessing the impact of a high-fat/cholesterol load, rather than an individual component alone, on cholesterol homeostasis is more physiologically relevant because Western diets deliver both fat and cholesterol at the same time. Moreover, dietary fat and dietary cholesterol are reported to act synergistically to impair liver cholesterol homeostasis. A key insight into the role of protein kinase C-β (PKCβ) in hepatic adaptation to high-fat/cholesterol diets was gained recently through the use of knockout mice. The emerging evidence indicates that PKCβ is an important regulator of cholesterol homeostasis that ensures normal adaptation to high-fat/cholesterol intake. Consistent with this function, high-fat/cholesterol diets induce PKCβ expression and signaling in the intestine and liver, while systemic PKCβ deficiency promotes accumulation of cholesterol in the liver and bile. PKCβ disruption results in profound dysregulation of hepatic cholesterol and bile homeostasis and imparts sensitivity to cholesterol gallstone formation. The available results support involvement of a two-pronged mechanism by which intestine and liver PKCβ signaling converge on liver ERK1/2 to dictate diet-induced cholesterol and bile acid homeostasis. Collectively, PKCβ is an integrator of dietary fat/cholesterol signal and mediates changes to cholesterol homeostasis.
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Affiliation(s)
- Devina Mehta
- 1Department of Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio; and
| | - Kamal D. Mehta
- 2Department of Biological Chemistry and Pharmacology, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
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28
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Bozaykut P, Sahin A, Karademir B, Ozer NK. Endoplasmic reticulum stress related molecular mechanisms in nonalcoholic steatohepatitis. Mech Ageing Dev 2016; 157:17-29. [DOI: 10.1016/j.mad.2016.07.001] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Revised: 06/23/2016] [Accepted: 07/02/2016] [Indexed: 12/18/2022]
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29
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Yu DD, Andrali SS, Li H, Lin M, Huang W, Forman BM. Novel FXR (farnesoid X receptor) modulators: Potential therapies for cholesterol gallstone disease. Bioorg Med Chem 2016; 24:3986-3993. [PMID: 27372840 DOI: 10.1016/j.bmc.2016.06.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Revised: 06/16/2016] [Accepted: 06/18/2016] [Indexed: 11/24/2022]
Abstract
Metabolic disorders such as diabetes are known risk factors for developing cholesterol gallstone disease (CGD). Cholesterol gallstone disease is one of the most prevalent digestive diseases, leading to considerable financial and social burden worldwide. Ursodeoxycholic acid (UDCA) is the only bile acid drug approved by FDA for the non-surgical treatment of gallstones. However, the molecular link between UDCA and CGD is unclear. Previous data suggest that the farnesoid X receptor (FXR), a bile acid nuclear receptor, may protect against the development of CGD. In studies aimed at identifying the role of FXR, we recently identify a novel chemical tool, 6EUDCA (6-αethyl-ursodeoxycholic acid), a synthetic derivative of UDCA, for studying FXR. We found that 6EUDCA binds FXR stronger than UDCA in a TR-FRET binding assay. This result was supported by computational docking models that suggest 6EUDCA forms a more extensive hydrogen bound network with FXR. Interestingly, neither compound could activate FXR target genes in human nor mouse liver cells, suggesting UDCA and 6EUDCA activate non-genomic signals in an FXR-dependent manner. Overall these studies may lead to the identification of a novel mechanism by which bile acids regulate cell function, and 6EUDCA may be an effective targeted CGD therapeutic.
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Affiliation(s)
- Donna D Yu
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Sreenath S Andrali
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Hongzhi Li
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Min Lin
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Wendong Huang
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Barry M Forman
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute, City of Hope National Medical Center, Duarte, CA 91010, USA
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30
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Sun W, Zhang D, Wang Z, Sun J, Xu B, Chen Y, Ding L, Huang X, Lv X, Lu J, Bi Y, Xu Q. Insulin Resistance is Associated With Total Bile Acid Level in Type 2 Diabetic and Nondiabetic Population: A Cross-Sectional Study. Medicine (Baltimore) 2016; 95:e2778. [PMID: 26962776 PMCID: PMC4998857 DOI: 10.1097/md.0000000000002778] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 12/31/2015] [Accepted: 01/19/2016] [Indexed: 02/06/2023] Open
Abstract
Bile acid metabolism was reported to be involved in glucose metabolism homeostasis. However, the exact relationship between bile acid and glucose metabolism as well as insulin sensitivity is not clarified. Therefore, we sought to investigate the association between insulin sensitivity and hyperbileacidemia in type 2 diabetic and nondiabetic population.This community-based cross-sectional study included 9603 residents from Jiading, Shanghai, China, who were 40 years and older. Standardized questionnaire, anthropometric measurements and laboratory tests were conducted. Homeostasis model assessment of insulin resistance (HOMA-IR) ≥ 2.7 was defined as insulin resistance and fasting TBA ≥ 10 mmol/L was defined as hyperbileacidemia.Multivariate stepwise regression analysis revealed that HOMA-IR, age, and male sex were positively associated with hyperbileacidemia in both nondiabetic and diabetic participants. In multivariate logistic models, participants with insulin resistance had significantly higher risk of hyperbileacidemia compared to those who have no insulin resistance, in both nondiabetic and diabetic population (nondiabetic: OR = 1.76; 95% CI 1.42-2.19; P < 0.001; diabetic: OR = 1.56; 95% CI 1.06 - 2.31; P = 0.025, respectively). Further adjustment for the HbA1c level in diabetic population did not change the significant association (OR = 1.59; 95% CI 1.06 - 2.40; P = 0.024). In nondiabetic participants, each 1-unit increment of HOMA-IR conferred an 18% higher risk of hyperbileacidemia (95% CI 1.04-1.35; P = 0.013), whereas in diabetic participants, this association was similar but not significant (95% CI 0.95-1.59; P = 0.117).Insulin resistance was positively associated with hyperbileacidemia in both nondiabetic and diabetic population. The increase in the bile acid level in insulin-resistant population regardless of status of diabetes and glucose level indicated the important role of insulin resistance in the regulation of bile acid metabolism in human.
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Affiliation(s)
- Wanwan Sun
- From the National Clinical Research Center for Metabolic Diseases, Rui Jin Hospital, Shanghai Jiao Tong University School of Medicine (WS, DZ, ZW, JS, BX, YC, LD, XH, XL, JL, YB); Institute of Health Sciences, Shanghai Institutes for Biological Sciences (JS); and Department of Research and Development, Rui-Jin Hospital, Shanghai Jiao-Tong University School of Medicine (QX), Shanghai, China
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Recent insights on the role of cholesterol in non-alcoholic fatty liver disease. Biochim Biophys Acta Mol Basis Dis 2015; 1852:1765-78. [DOI: 10.1016/j.bbadis.2015.05.015] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/25/2015] [Accepted: 05/27/2015] [Indexed: 12/18/2022]
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Zhang Y, Kim DK, Lee JM, Park SB, Jeong WI, Kim SH, Lee IK, Lee CH, Chiang JYL, Choi HS. Orphan nuclear receptor oestrogen-related receptor γ (ERRγ) plays a key role in hepatic cannabinoid receptor type 1-mediated induction of CYP7A1 gene expression. Biochem J 2015; 470:181-93. [PMID: 26348907 PMCID: PMC5333639 DOI: 10.1042/bj20141494] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Accepted: 06/29/2015] [Indexed: 12/30/2022]
Abstract
Bile acids are primarily synthesized from cholesterol in the liver and have important roles in dietary lipid absorption and cholesterol homoeostasis. Detailed roles of the orphan nuclear receptors regulating cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis, have not yet been fully elucidated. In the present study, we report that oestrogen-related receptor γ (ERRγ) is a novel transcriptional regulator of CYP7A1 expression. Activation of cannabinoid receptor type 1 (CB1 receptor) signalling induced ERRγ-mediated transcription of the CYP7A1 gene. Overexpression of ERRγ increased CYP7A1 expression in vitro and in vivo, whereas knockdown of ERRγ attenuated CYP7A1 expression. Deletion analysis of the CYP7A1 gene promoter and a ChIP assay revealed an ERRγ-binding site on the CYP7A1 gene promoter. Small heterodimer partner (SHP) inhibited the transcriptional activity of ERRγ and thus regulated CYP7A1 expression. Overexpression of ERRγ led to increased bile acid levels, whereas an inverse agonist of ERRγ, GSK5182, reduced CYP7A1 expression and bile acid synthesis. Finally, GSK5182 significantly reduced hepatic CB1 receptor-mediated induction of CYP7A1 expression and bile acid synthesis in alcohol-treated mice. These results provide the molecular mechanism linking ERRγ and bile acid metabolism.
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MESH Headings
- Animals
- Bile Acids and Salts/metabolism
- Cells, Cultured
- Cholesterol 7-alpha-Hydroxylase/biosynthesis
- Cholesterol 7-alpha-Hydroxylase/genetics
- Drug Inverse Agonism
- Ethanol/pharmacology
- Gene Expression
- Glycerides/pharmacology
- HEK293 Cells
- Hepatocytes/metabolism
- Humans
- Liver/metabolism
- Mice, Inbred C57BL
- Mice, Knockout
- Promoter Regions, Genetic
- Rats, Sprague-Dawley
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/genetics
- Receptor, Cannabinoid, CB1/metabolism
- Receptors, Cytoplasmic and Nuclear/metabolism
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Transcription, Genetic
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Affiliation(s)
- Yaochen Zhang
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Don-Kyu Kim
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Ji-Min Lee
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Seung Bum Park
- Chemical Biology Laboratory, School of Chemistry, Seoul National University, Seoul 151-742, Republic of Korea
| | - Won-Il Jeong
- Laboratory of Liver Research, Graduate School of Medical Science and Engineering, KAIST, Daejeon 305-338, Republic of Korea
| | - Seong Heon Kim
- New Drug Development Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu 701-310, Republic of Korea
| | - In-Kyu Lee
- Department of Internal Medicine, Kyungpook National University School of Medicine, Daegu 700-721, Republic of Korea
| | - Chul-Ho Lee
- Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea
| | - John Y L Chiang
- Department of Integrative Medical Sciences, Northeastern Ohio University's Colleges of Medicine and Pharmacy, Rootstown, Ohio 44272, U.S.A
| | - Hueng-Sik Choi
- National Creative Research Initiatives Center for Nuclear Receptor Signals and Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju 500-757, Republic of Korea
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Huang W, Mehta KD. Modulation of Hepatic Protein Kinase Cβ Expression in Metabolic Adaptation to a Lithogenic Diet. Cell Mol Gastroenterol Hepatol 2015; 1:395-405. [PMID: 28210689 PMCID: PMC5301293 DOI: 10.1016/j.jcmgh.2015.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 05/08/2015] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS Dietary factors are likely an important determinant of gallstone development, and difficulty in adapting to lithogenic diets may predispose individuals to gallstone formation. Identification of the critical early diet-dependent metabolic markers of adaptability is urgently needed to prevent gallstone development. We focus on the interaction between diet and genes, and the resulting potential to influence gallstone risk by dietary modification. METHODS Expression levels of hepatic protein kinase C (PKC) isoforms were determined in lithogenic diet-fed mice, and the relationship of hepatic cholesterol content and PKCβ expression and the effect of hepatic PKCβ overexpression on intracellular signaling pathways were analyzed. RESULTS Lithogenic diet feeding resulted in a striking induction of hepatic PKCβ and PKCδ mRNA and protein levels, which preceded the appearance of biliary cholesterol crystals. Unlike PKCβ deficiency, global PKCδ deficiency did not influence lithogenic diet-induced gallstone formation. Interestingly, a deficiency of apolipoprotein E abrogated the diet-induced hepatic PKCβ expression, whereas a deficiency of liver X receptor-α further potentiated the induction, suggesting a potential link between the degree of hepatic PKCβ induction and the intracellular cholesterol content. Furthermore, our results suggest that PKCβ is a physiologic repressor of ileum basal fibroblast growth factor 15 (FGF15) expression and activity of hepatic proto-oncogene serine/threonine-protein kinase Raf-1/mitogen-activated protein (MAP) kinase kinase/extracellular signal-regulated kinases 1/2 (Raf-1/MEK/ERK1/2) cascade proteins, and the complex interactions between these pathways may determine the degree of hepatic ERK1/2 activation, a potent suppressor of cholesterol 7α-hydroxylase and sterol 12α-hydroxylase expression. We found that PKCβ regulated Raf-1 activity by modulating the inhibitory Raf-1Ser259 phosphorylation. CONCLUSIONS Our results demonstrate a novel interaction between the hepatic PKCβ/Raf-1 regulatory axis and ileum PKCβ/FGF15/ERK axis, which could modulate the bile lithogenecity of dietary lipids. The data presented are consistent with a two-pronged mechanism by which intestine and liver PKCβ signaling converges on the liver ERK1/2 pathway to control the hepatic adaptive response to a lithogenic diet. Elucidating the impact and the underlying mechanism(s) of PKCβ action could help us understand how different types of dietary fat modify the risk of gallstone formation, information that could help to identify novel targets for therapeutic approaches to combat this disease.
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Key Words
- Akt, protein kinase B
- ApoE, apolipoprotein E
- Cyp7a1, cholesterol 7α-hydroxylase
- Cyp8b1, sterol 12α-hydroxylase
- ERK1/2, extracellular signal regulated kinase-1/2
- FGF15, fibroblast growth factor 15
- FXR, farnesoid X receptor
- GSK-3, glycogen synthase kinase-3
- Hepatic Cholesterol Metabolism
- JNK, c-Jun N-terminal kinase
- LDL, low-density lipoprotein
- LXR, liver X receptor
- Lithogenic Diet
- MEK, mitogen-activated protein (MAP) kinase kinase
- MMLD, modified milk fat lithogenic diet
- PKCβ, protein kinase C isoform β
- Protein Kinase Cβ
- Raf-1, Raf-1 hepatic proto-oncogene serine/threonine-protein kinase
- SREBP, sterol response element-binding protein
- Signal Transduction
- WT, wild type
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Affiliation(s)
| | - Kamal D. Mehta
- Correspondence Address correspondence to: Kamal D. Mehta, PhD, Department of Biological Chemistry and Pharmacology, Ohio State University College of Medicine, 464 Hamilton Hall, 1645 Neil Avenue, Columbus, Ohio 43210. fax: 614-292-4118.
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Apro J, Beckman L, Angelin B, Rudling M. Influence of dietary sugar on cholesterol and bile acid metabolism in the rat: Marked reduction of hepatic Abcg5/8 expression following sucrose ingestion. Biochem Biophys Res Commun 2015; 461:592-7. [PMID: 25912874 DOI: 10.1016/j.bbrc.2015.04.070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 04/13/2015] [Indexed: 12/21/2022]
Abstract
Previous studies have indicated that dietary intake of sugar may lower bile acid production, and may promote cholesterol gallstone formation in humans. We studied the influence of dietary sucrose on cholesterol and bile acid metabolism in the rat. In two different experiments, rats received high-sucrose diets. In the first, 60% of the weight of standard rat chow was replaced with sucrose (high-sucrose diet). In the second, rats received a diet either containing 65% sucrose (controlled high-sucrose diet) or 65% complex carbohydrates, in order to keep other dietary components constant. Bile acid synthesis, evaluated by measurements of the serum marker 7-alpha-hydroxy-4-cholesten-3-one (C4) and of the hepatic mRNA expression of Cyp7a1, was markedly reduced by the high-sucrose diet, but not by the controlled high-sucrose diet. Both diets strongly reduced the hepatic - but not the intestinal - mRNA levels of Abcg5 and Abcg8. The differential patterns of regulation of bile acid synthesis induced by the two sucrose-enriched diets indicate that it is not sugar per se in the high-sucrose diet that reduces bile acid synthesis, but rather the reduced content of fiber or fat. In contrast, the marked reduction of hepatic Abcg5/8 observed is an effect of the high sugar content of the diets.
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Affiliation(s)
- Johanna Apro
- Metabolism Unit, Department of Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, C2-84, S-141 86 Stockholm, Sweden; KI/AZ Integrated CardioMetabolic Center, Department of Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, C2-84, S-141 86 Stockholm, Sweden; Molecular Nutrition Unit, Center for Innovative Medicine, Department of Biosciences and Nutrition, Karolinska Institutet at Karolinska University Hospital Huddinge, S-141 86 Stockholm, Sweden.
| | - Lena Beckman
- Metabolism Unit, Department of Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, C2-84, S-141 86 Stockholm, Sweden; Molecular Nutrition Unit, Center for Innovative Medicine, Department of Biosciences and Nutrition, Karolinska Institutet at Karolinska University Hospital Huddinge, S-141 86 Stockholm, Sweden
| | - Bo Angelin
- Metabolism Unit, Department of Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, C2-84, S-141 86 Stockholm, Sweden; KI/AZ Integrated CardioMetabolic Center, Department of Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, C2-84, S-141 86 Stockholm, Sweden; Molecular Nutrition Unit, Center for Innovative Medicine, Department of Biosciences and Nutrition, Karolinska Institutet at Karolinska University Hospital Huddinge, S-141 86 Stockholm, Sweden
| | - Mats Rudling
- Metabolism Unit, Department of Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, C2-84, S-141 86 Stockholm, Sweden; KI/AZ Integrated CardioMetabolic Center, Department of Medicine, Karolinska Institutet at Karolinska University Hospital Huddinge, C2-84, S-141 86 Stockholm, Sweden; Molecular Nutrition Unit, Center for Innovative Medicine, Department of Biosciences and Nutrition, Karolinska Institutet at Karolinska University Hospital Huddinge, S-141 86 Stockholm, Sweden
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Abstract
Bile acids are important physiological agents for intestinal nutrient absorption and biliary secretion of lipids, toxic metabolites, and xenobiotics. Bile acids also are signaling molecules and metabolic regulators that activate nuclear receptors and G protein-coupled receptor (GPCR) signaling to regulate hepatic lipid, glucose, and energy homeostasis and maintain metabolic homeostasis. Conversion of cholesterol to bile acids is critical for maintaining cholesterol homeostasis and preventing accumulation of cholesterol, triglycerides, and toxic metabolites, and injury in the liver and other organs. Enterohepatic circulation of bile acids from the liver to intestine and back to the liver plays a central role in nutrient absorption and distribution, and metabolic regulation and homeostasis. This physiological process is regulated by a complex membrane transport system in the liver and intestine regulated by nuclear receptors. Toxic bile acids may cause inflammation, apoptosis, and cell death. On the other hand, bile acid-activated nuclear and GPCR signaling protects against inflammation in liver, intestine, and macrophages. Disorders in bile acid metabolism cause cholestatic liver diseases, dyslipidemia, fatty liver diseases, cardiovascular diseases, and diabetes. Bile acids, bile acid derivatives, and bile acid sequestrants are therapeutic agents for treating chronic liver diseases, obesity, and diabetes in humans.
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Reshetnyak VI. Physiological and molecular biochemical mechanisms of bile formation. World J Gastroenterol 2013; 19:7341-7360. [PMID: 24259965 PMCID: PMC3831216 DOI: 10.3748/wjg.v19.i42.7341] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 07/17/2013] [Accepted: 09/29/2013] [Indexed: 02/06/2023] Open
Abstract
This review considers the physiological and molecular biochemical mechanisms of bile formation. The composition of bile and structure of a bile canaliculus, biosynthesis and conjugation of bile acids, bile phospholipids, formation of bile micellar structures, and enterohepatic circulation of bile acids are described. In general, the review focuses on the molecular physiology of the transporting systems of the hepatocyte sinusoidal and apical membranes. Knowledge of physiological and biochemical basis of bile formation has implications for understanding the mechanisms of development of pathological processes, associated with diseases of the liver and biliary tract.
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Pathak P, Li T, Chiang JYL. Retinoic acid-related orphan receptor α regulates diurnal rhythm and fasting induction of sterol 12α-hydroxylase in bile acid synthesis. J Biol Chem 2013; 288:37154-65. [PMID: 24226095 DOI: 10.1074/jbc.m113.485987] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Sterol 12α-hydroxylase (CYP8B1) is required for cholic acid synthesis and plays a critical role in intestinal cholesterol absorption and pathogenesis of cholesterol gallstone, dyslipidemia, and diabetes. In this study we investigated the underlying mechanism of fasting induction and circadian rhythm of CYP8B1 by a cholesterol-activated nuclear receptor and core clock gene retinoic acid-related orphan receptor α (RORα). Fasting stimulated, whereas restricted-feeding reduced expression of CYP8B1 mRNA and protein. However, fasting and feeding had little effect on the diurnal rhythm of RORα mRNA expression, but fasting increased RORα protein levels by cAMP-activated protein kinase A-mediated phosphorylation and stabilization of the protein. Adenovirus-mediated gene transduction of RORα to mice strongly induced CYP8B1 expression, and increased liver cholesterol and 12α-hydroxylated bile acids in the bile acid pool and serum. A reporter assay identified a functional RORα response element in the CYP8B1 promoter. RORα recruited cAMP response element-binding protein-binding protein (CBP) to stimulate histone acetylation on the CYP8B1 gene promoter. In conclusion, RORα is a key regulator of diurnal rhythm and fasting induction of CYP8B1, which regulates bile acid composition and serum and liver cholesterol levels. Antagonizing RORα activity may be a therapeutic strategy for treating inflammatory diseases such as non-alcoholic fatty liver disease and type 2 diabetes.
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Affiliation(s)
- Preeti Pathak
- From the Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272 and
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Inamine T, Higa S, Noguchi F, Kondo S, Omagari K, Yatsuhashi H, Tsukamoto K, Nakamura M. Association of genes involved in bile acid synthesis with the progression of primary biliary cirrhosis in Japanese patients. J Gastroenterol 2013; 48:1160-70. [PMID: 23354620 DOI: 10.1007/s00535-012-0730-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 11/26/2012] [Indexed: 02/04/2023]
Abstract
BACKGROUND Patients with primary biliary cirrhosis (PBC) exhibit a variety of clinical manifestations and patterns of disease progression. The aim of this study was to identify genetic determinants of PBC progression. METHODS A total of 52 tag single nucleotide polymorphisms (SNPs) of 11 candidate genes involved in regulating bile acid synthesis were analyzed by polymerase chain reaction (PCR)-restriction fragment length polymorphism, -high resolution melting curve analysis, or -direct DNA sequencing in 315 Japanese patients with PBC. RESULTS In this study, four tag SNPs of CYP7A1 (rs1457043, rs8192870, rs3808607, and rs3824260), two tag SNPs of HNF4A (rs6017340 and 6031587), and one SNP of PPARGC1A (rs8192678) showed a significant association with PBC progression. In addition, a dual luciferase assay revealed that the polymorphism of rs3808607 in CYP7A1 altered the expression of CYP7A1 in HepG2. Specifically, the CYP7A1 promoter carrying the risk G allele for PBC progression induced higher expression of CYP7A1 under both the normal and cholestatic conditions in vitro as compared to another promoter carrying the non-risk T allele. CONCLUSION These results suggested that the genetic variants of CYP7A1 and its transcriptional activators (HNF4A and PPARGC1A) may activate bile acid synthesis, resulting in the accumulation of bile acids in hepatocytes and eventually leading to the predisposition to PBC progression. Thus, the regulation of CYP7A1 expression may represent an attractive therapeutic target for cholestatic liver diseases including PBC.
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Affiliation(s)
- Tatsuo Inamine
- Department of Pharmacotherapeutics, Nagasaki University Graduate School of Biomedical Sciences, 1-14 Bunkyo-machi, Nagasaki, 852-8521, Japan
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Dipeptidyl peptidase 4-deficient rats have improved bile secretory function in high fat diet-induced steatosis. Dig Dis Sci 2013; 58:172-8. [PMID: 22918684 DOI: 10.1007/s10620-012-2353-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2012] [Accepted: 08/01/2012] [Indexed: 12/21/2022]
Abstract
BACKGROUND/AIMS Rodent obesity models have been shown to display impaired bile secretory functions. We have shown that glucagon-like peptide 1 (GLP-1) attenuates hepatic lipogenesis, and in the present study we investigated whether GLP-1 also improves high fat diet-associated cholestatic injury. METHODS Wild type (WT) and dipeptidyl peptidase 4-deficient rats (DPP4-) with chronic elevated serum levels of active GLP-1 were fed regular chow and a Western diet for 2 months. Primary hepatocytes were used to assess GLP-1 effects on mRNA expression and transcription of genes encoding bile acid synthesis enzymes and transporters. RESULTS DPP4- exhibited attenuated liver injury as expressed by lower serum AST and ALT after 2 months of a Western diet. In addition, DPP4- had better insulin sensitivity, lower serum triglycerides, cholesterol and bile acids. Hepatic expression of cyp7A1, the rate limiting enzyme in conversion of cholesterol into bile acids, was strongly attenuated in DPP4- fed with a Western diet. Moreover, hepatic expression of bile transporter, ABCB11, was increased, facilitating a higher rate of bile secretion. Mechanistically, we showed that GLP-1 directly reduced basal and LXR-induced cyp7A1 mRNA expression and suppressed cyp7A1 transcription in transient transfection assays in primary hepatocytes. However, GLP-1 and its analog exendin 4 also induced mRNA expression of bile acid transporter ABCC3 in primary rat hepatocyte cultures. CONCLUSIONS Our data suggest that GLP-1 analogs may serve as a novel therapeutic drug to alleviate obesity-induced liver injury by reducing bile acid synthesis and improving liver bile secretory function.
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Cong R, Jia Y, Li R, Ni Y, Yang X, Sun Q, Parvizi N, Zhao R. Maternal low-protein diet causes epigenetic deregulation of HMGCR and CYP7α1 in the liver of weaning piglets. J Nutr Biochem 2012; 23:1647-54. [DOI: 10.1016/j.jnutbio.2011.11.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 11/18/2011] [Accepted: 11/22/2011] [Indexed: 12/30/2022]
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Raymond F, Wang L, Moser M, Metairon S, Mansourian R, Zwahlen MC, Kussmann M, Fuerholz A, Macé K, Chou CJ. Consequences of exchanging carbohydrates for proteins in the cholesterol metabolism of mice fed a high-fat diet. PLoS One 2012; 7:e49058. [PMID: 23139832 PMCID: PMC3490911 DOI: 10.1371/journal.pone.0049058] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 10/09/2012] [Indexed: 01/25/2023] Open
Abstract
Consumption of low-carbohydrate, high-protein, high-fat diets lead to rapid weight loss but the cardioprotective effects of these diets have been questioned. We examined the impact of high-protein and high-fat diets on cholesterol metabolism by comparing the plasma cholesterol and the expression of cholesterol biosynthesis genes in the liver of mice fed a high-fat (HF) diet that has a high (H) or a low (L) protein-to-carbohydrate (P/C) ratio. H-P/C-HF feeding, compared with L-P/C-HF feeding, decreased plasma total cholesterol and increased HDL cholesterol concentrations at 4-wk. Interestingly, the expression of genes involved in hepatic steroid biosynthesis responded to an increased dietary P/C ratio by first down-regulation (2-d) followed by later up-regulation at 4-wk, and the temporal gene expression patterns were connected to the putative activity of SREBF1 and 2. In contrast, Cyp7a1, the gene responsible for the conversion of cholesterol to bile acids, was consistently up-regulated in the H-P/C-HF liver regardless of feeding duration. Over expression of Cyp7a1 after 2-d and 4-wk H-P/C-HF feeding was connected to two unique sets of transcription regulators. At both time points, up-regulation of the Cyp7a1 gene could be explained by enhanced activations and reduced suppressions of multiple transcription regulators. In conclusion, we demonstrated that the hypocholesterolemic effect of H-P/C-HF feeding coincided with orchestrated changes of gene expressions in lipid metabolic pathways in the liver of mice. Based on these results, we hypothesize that the cholesterol lowering effect of high-protein feeding is associated with enhanced bile acid production but clinical validation is warranted. (246 words).
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Affiliation(s)
- Frédéric Raymond
- Bioanalytical Science Department, Nestlé Research Center, Lausanne, Switzerland
| | - Long Wang
- Department of Nutrition Science and Dietetics, Syracuse University, Syracuse, New York, United States of America
| | - Mireille Moser
- Bioanalytical Science Department, Nestlé Research Center, Lausanne, Switzerland
| | - Sylviane Metairon
- Bioanalytical Science Department, Nestlé Research Center, Lausanne, Switzerland
| | - Robert Mansourian
- Bioanalytical Science Department, Nestlé Research Center, Lausanne, Switzerland
| | | | - Martin Kussmann
- Proteomics and Metabonomics Core, Nestlé Institute of Health Sciences, Lausanne, Switzerland
- Faculty of Science, Aarhus University, Aarhus, Denmark
- Faculty of Life Sciences, Federal Institute of Technology, Lausanne, Switzerland
| | - Andreas Fuerholz
- Bioanalytical Science Department, Nestlé Research Center, Lausanne, Switzerland
| | - Katherine Macé
- Nutrition and Health Department, Nestlé Research Center, Lausanne, Switzerland
| | - Chieh Jason Chou
- Nutrition and Health Department, Nestlé Research Center, Lausanne, Switzerland
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Abstract
Diabetes represents one of the most important global health problems because it is associated with a large economic burden on the health systems of many countries. Whereas the diagnosis and treatment of manifest diabetes have been well investigated, the identification of novel pathways or early biomarkers indicative of metabolic alterations or insulin resistance related to the development of diabetes is still in progress. Over half of the type 2 diabetes patients show manifestations of diabetes-related diseases, which highlight the need for early screening markers of diabetes. During the last decade, the rapidly growing research field of metabolomics has introduced new insights into the pathology of diabetes as well as methods to predict disease onset and has revealed new biomarkers. Recent epidemiological studies first used metabolism to predict incident diabetes and revealed branched-chain and aromatic amino acids including isoleucine, leucine, valine, tyrosine and phenylalanine as highly significant predictors of future diabetes. This review summarises the current findings of metabolic research regarding diabetes in animal models and human investigations.
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Affiliation(s)
- Nele Friedrich
- Institute for Clinical Chemistry and Laboratory Medicine, University of Greifswald, Ferdinand-Sauerbruch-Strasse, D-17475 Greifswald, Germany.
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Xing WJ, Gao L, Zhao JJ. Expression and regulation of cholesterol 7 alpha-hydroxylase: An update. Shijie Huaren Xiaohua Zazhi 2012; 20:1439-1446. [DOI: 10.11569/wcjd.v20.i16.1439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cholesterol 7-alpha hydroxylase (CYP7A1) is the first and rate-limiting enzyme in the neutral pathway of bile acids synthesis. The expression of CYP7A1 can be regulated not only by diurnal rhythm, but also by gene polymorphism, diet, hormones, cytokines and drugs. CYP7A1 gene polymorphism is associated not only with some diseases but also with response to drug therapy. A cascade network consisting of multiple nuclear receptors is involved in the regulation of CYP7A1 expression to control bile acid synthesis and lipid metabolism.
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Park WH, Pak YK. Insulin-dependent suppression of cholesterol 7α-hydroxylase is a possible link between glucose and cholesterol metabolisms. Exp Mol Med 2012; 43:571-9. [PMID: 21817852 DOI: 10.3858/emm.2011.43.10.064] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Cholesterol 7α-hydroxylase (CYP7A1) regulates the balance between cholesterol supply and metabolism by catalyzing the rate-limiting step of bile acid biosynthesis. The transcriptional activity of CYP7A1 is tightly controlled by various nuclear receptors. A forkhead transcription factor O1 (FOXO1) plays a critical role in metabolism, and insulin inactivates FOXO1 through Akt-dependent phosphorylation and nuclear exclusion. We investigated the role of insulin- Akt-FOXO1 signaling pathway in CYP7A1 transcriptional regulation since we found putative insulin-response elements, FOXO1 binding sequences, in both rat and human CYP7A1 promoters. However, ectopic expression of FOXO1 increased the rat CYP7A1-, but mildly reduced human CYP7A1-promoter activities in a dose-dependent manner. Similarly to bile acids, insulin treatment increased small heterodimer partner (SHP) mRNA rapidly and transiently, leading to the suppression of CYP7A1 transcription in both human and rodents. Chromatin immunoprecipitation showed that FOXO1 directly bound to rat CYP1A1 promoter in the absence of insulin. FOXO1 binding to the rat promoter was diminished by insulin treatment as well as by expression of SHP. Our results suggest that the stimulation of insulin- signaling pathway of Akt-FOXO1 and SHP expression may regulate cholesterol/bile acid metabolisms in liver, linking carbohydrate and cholesterol metabolic pathways. A prolonged exposure of insulin in hyperinsulinemic insulin resistance or diabetic status represses CYP7A1 transcription and bile acid biosynthesis through SHP induction and FOXO1 inactivation, leading to impairment of the hepatic cholesterol/bile acid metabolisms.
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Affiliation(s)
- Wook Ha Park
- Department of Physiology, Department of Neuroscience College of Medicine, Kyung Hee University, Seoul, Korea
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Haeusler RA, Pratt-Hyatt M, Welch CL, Klaassen CD, Accili D. Impaired generation of 12-hydroxylated bile acids links hepatic insulin signaling with dyslipidemia. Cell Metab 2012; 15:65-74. [PMID: 22197325 PMCID: PMC3253887 DOI: 10.1016/j.cmet.2011.11.010] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Revised: 10/06/2011] [Accepted: 11/28/2011] [Indexed: 12/27/2022]
Abstract
The association of type 2 diabetes with elevated plasma triglyceride (TG) and very low-density lipoproteins (VLDL), and intrahepatic lipid accumulation represents a pathophysiological enigma and an unmet therapeutic challenge. Here, we uncover a link between insulin action through FoxO1, bile acid (BA) composition, and altered lipid homeostasis that brings new insight to this longstanding conundrum. FoxO1 ablation brings about two signature lipid abnormalities of diabetes and the metabolic syndrome, elevated liver and plasma TG. These changes are associated with deficiency of 12α-hydroxylated BAs and their synthetic enzyme, Cyp8b1, that hinders the TG-lowering effects of the BA receptor, Fxr. Accordingly, pharmacological activation of Fxr with GW4064 overcomes the BA imbalance, restoring hepatic and plasma TG levels of FoxO1-deficient mice to normal levels. We propose that generation of 12α-hydroxylated products of BA metabolism represents a signaling mechanism linking hepatic lipid abnormalities with type 2 diabetes, and a treatment target for this condition.
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47
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Abstract
This chapter will review the various biological actions of the mouse fibroblast growth factor 15 (Fgf15) and human fibroblast growth factor 19 (FGF19). Unlike other members of the fibroblast growth factor (FGF) family, the Fgf15 and FGF19 orthologs do not share a high degree of sequence identity. Fgf15 and FGF19 are members of an atypical subfamily of FGFs that function as hormones. Due to subtle changes in tertiary structure, these FGFs have low heparin binding affinity enabling them to diffuse away from their site of secretion and signal to distant cells. FGF signaling through the FGF receptors is also different for this sub-family, requiring klotho protein cofactors rather than heparin sulfate proteoglycan. Mouse Fgf15 and human FGF19 play key roles in enterohepatic signaling, regulation of liver bile acid biosynthesis, gallbladder motility and metabolic homeostasis.
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Tominaga M, Nakano A. Plant-Specific Myosin XI, a Molecular Perspective. FRONTIERS IN PLANT SCIENCE 2012; 3:211. [PMID: 22973289 PMCID: PMC3437519 DOI: 10.3389/fpls.2012.00211] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 08/21/2012] [Indexed: 05/04/2023]
Abstract
In eukaryotic cells, organelle movement, positioning, and communications are critical for maintaining cellular functions and are highly regulated by intracellular trafficking. Directional movement of motor proteins along the cytoskeleton is one of the key regulators of such trafficking. Most plants have developed a unique actin-myosin system for intracellular trafficking. Although the composition of myosin motors in angiosperms is limited to plant-specific myosin classes VIII and XI, there are large families of myosins, especially in class XI, suggesting functional diversification among class XI members. However, the molecular properties and regulation of each myosin XI member remains unclear. To achieve a better understanding of the plant-specific actin-myosin system, the characterization of myosin XI members at the molecular level is essential. In the first half of this review, we summarize the molecular properties of tobacco 175-kDa myosin XI, and in the later half, we focus on myosin XI members in Arabidopsis thaliana. Through detailed comparison of the functional domains of these myosins with the functional domain of myosin V, we look for possible diversification in enzymatic and mechanical properties among myosin XI members concomitant with their regulation.
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Affiliation(s)
- Motoki Tominaga
- Molecular Membrane Biology Laboratory, RIKEN Advanced Science InstituteWako, Saitama, Japan
- Japan Science and Technology Agency, PRESTOKawaguchi, Saitama, Japan
- *Correspondence: Motoki Tominaga, Molecular Membrane Biology Laboratory, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan. e-mail:
| | - Akihiko Nakano
- Molecular Membrane Biology Laboratory, RIKEN Advanced Science InstituteWako, Saitama, Japan
- Department of Biological Sciences, Graduate School of Science, University of TokyoBunkyo-ku, Tokyo, Japan
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Li T, Francl JM, Boehme S, Ochoa A, Zhang Y, Klaassen CD, Erickson SK, Chiang JYL. Glucose and insulin induction of bile acid synthesis: mechanisms and implication in diabetes and obesity. J Biol Chem 2011; 287:1861-73. [PMID: 22144677 DOI: 10.1074/jbc.m111.305789] [Citation(s) in RCA: 159] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Bile acids facilitate postprandial absorption of nutrients. Bile acids also activate the farnesoid X receptor (FXR) and the G protein-coupled receptor TGR5 and play a major role in regulating lipid, glucose, and energy metabolism. Transgenic expression of cholesterol 7α-hydroxylase (CYP7A1) prevented high fat diet-induced diabetes and obesity in mice. In this study, we investigated the nutrient effects on bile acid synthesis. Refeeding of a chow diet to fasted mice increased CYP7A1 expression, bile acid pool size, and serum bile acids in wild type and humanized CYP7A1-transgenic mice. Chromatin immunoprecipitation assays showed that glucose increased histone acetylation and decreased histone methylation on the CYP7A1 gene promoter. Refeeding also induced CYP7A1 in fxr-deficient mice, indicating that FXR signaling did not play a role in postprandial regulation of bile acid synthesis. In streptozocin-induced type I diabetic mice and genetically obese type II diabetic ob/ob mice, hyperglycemia increased histone acetylation status on the CYP7A1 gene promoter, leading to elevated basal Cyp7a1 expression and an enlarged bile acid pool with altered bile acid composition. However, refeeding did not further increase CYP7A1 expression in diabetic mice. In summary, this study demonstrates that glucose and insulin are major postprandial factors that induce CYP7A1 gene expression and bile acid synthesis. Glucose induces CYP7A1 gene expression mainly by epigenetic mechanisms. In diabetic mice, CYP7A1 chromatin is hyperacetylated, and fasting to refeeding response is impaired and may exacerbate metabolic disorders in diabetes.
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Affiliation(s)
- Tiangang Li
- Department of Integrative Medical Sciences, Northeast Ohio Medical University, Rootstown, Ohio 44272, USA
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50
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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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