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Uehara K, Lee WD, Stefkovich M, Biswas D, Santoleri D, Garcia Whitlock A, Quinn W, Coopersmith T, Creasy KT, Rader DJ, Sakamoto K, Rabinowitz JD, Titchenell PM. mTORC1 controls murine postprandial hepatic glycogen synthesis via Ppp1r3b. J Clin Invest 2024; 134:e173782. [PMID: 38290087 PMCID: PMC10977990 DOI: 10.1172/jci173782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 01/26/2024] [Indexed: 02/01/2024] Open
Abstract
In response to a meal, insulin drives hepatic glycogen synthesis to help regulate systemic glucose homeostasis. The mechanistic target of rapamycin complex 1 (mTORC1) is a well-established insulin target and contributes to the postprandial control of liver lipid metabolism, autophagy, and protein synthesis. However, its role in hepatic glucose metabolism is less understood. Here, we used metabolomics, isotope tracing, and mouse genetics to define a role for liver mTORC1 signaling in the control of postprandial glycolytic intermediates and glycogen deposition. We show that mTORC1 is required for glycogen synthase activity and glycogenesis. Mechanistically, hepatic mTORC1 activity promotes the feeding-dependent induction of Ppp1r3b, a gene encoding a phosphatase important for glycogen synthase activity whose polymorphisms are linked to human diabetes. Reexpression of Ppp1r3b in livers lacking mTORC1 signaling enhances glycogen synthase activity and restores postprandial glycogen content. mTORC1-dependent transcriptional control of Ppp1r3b is facilitated by FOXO1, a well characterized transcriptional regulator involved in the hepatic response to nutrient intake. Collectively, we identify a role for mTORC1 signaling in the transcriptional regulation of Ppp1r3b and the subsequent induction of postprandial hepatic glycogen synthesis.
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Affiliation(s)
- Kahealani Uehara
- Institute for Diabetes, Obesity, and Metabolism
- Biochemistry and Molecular Biophysics Graduate Group, and
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Won Dong Lee
- Lewis Sigler Institute for Integrative Genomics
- Department of Chemistry, and
- Ludwig Institute for Cancer Research, Princeton Branch, Princeton, New Jersey, USA
| | | | - Dipsikha Biswas
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Dominic Santoleri
- Institute for Diabetes, Obesity, and Metabolism
- Biochemistry and Molecular Biophysics Graduate Group, and
| | | | | | | | - Kate Townsend Creasy
- Institute for Diabetes, Obesity, and Metabolism
- Department of Medicine, Division of Translational Medicine and Human Genetics, and
- Department of Biobehavioral Health Sciences, School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Daniel J. Rader
- Institute for Diabetes, Obesity, and Metabolism
- Department of Medicine, Division of Translational Medicine and Human Genetics, and
| | - Kei Sakamoto
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Joshua D. Rabinowitz
- Lewis Sigler Institute for Integrative Genomics
- Department of Chemistry, and
- Ludwig Institute for Cancer Research, Princeton Branch, Princeton, New Jersey, USA
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
| | - Paul M. Titchenell
- Institute for Diabetes, Obesity, and Metabolism
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Yang B, Luo Y, Wei X, Kan J. Polysaccharide from Hovenia dulcis (Guaizao) improves pancreatic injury and regulates liver glycometabolism to alleviate STZ-induced type 1 diabetes mellitus in rats. Int J Biol Macromol 2022; 214:655-663. [PMID: 35764168 DOI: 10.1016/j.ijbiomac.2022.06.147] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 06/17/2022] [Accepted: 06/21/2022] [Indexed: 11/16/2022]
Abstract
Hovenia dulcis is a traditional medicinal and edible plant and has a major geographical presence in China. In this study, a polysaccharide purified from H. dulcis (HDPs-2A) was found to ameliorate type 1 diabetes mellitus (T1DM) in streptozotocin-induced diabetic rat. HDPs-2A treatment resulted in significantly lower fasting blood glucose levels, but higher body weight, plasma insulin, and liver glycogen levels. Moreover, HDPs-2A improved dyslipidemia, pancreatic oxidative stress, and reduced serum pro-inflammatory factors. In addition, HDPs-2A up-regulated PDX-1, activated and up-regulated IRS2 expression, and regulated apoptosis and regeneration of islet β cells to recover islet β-cell function injury in TIDM rats. HDPs-2A also up-regulated the expression of pancreatic GK and GLUT2 to improve insulin secretion ability of islet β-cells, ultimately improving the glucose metabolism disorder of T1DM rats. Moreover, HDPs-2A significantly up-regulated the expression of GK and down-regulated the expression of G6Pase in liver to improve liver glycogen synthesis, inhibit liver gluconiogenesis, and improve liver glucose metabolism disorder of T1DM rats. In summary, the hypoglycemic mechanisms of HDPs-2A may include regulating the regeneration and apoptosis of islet β-cells and activating liver glycometabolism-related signaling pathways in T1DM rats.
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Affiliation(s)
- Bing Yang
- College of Food Science and Technology, Hebei Agricultural University, 289 Lingyusi Road, Baoding, Hebei 071001, PR China; College of Food Science, Southwest University, 2 Tiansheng Road, Beibei, Chongqing 400715, PR China
| | - Yuxin Luo
- College of Food Science, Southwest University, 2 Tiansheng Road, Beibei, Chongqing 400715, PR China
| | - Xunyu Wei
- College of Food Science, Southwest University, 2 Tiansheng Road, Beibei, Chongqing 400715, PR China
| | - Jianquan Kan
- College of Food Science, Southwest University, 2 Tiansheng Road, Beibei, Chongqing 400715, PR China.
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Nuclear Receptors in Energy Metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1390:61-82. [DOI: 10.1007/978-3-031-11836-4_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Kodama S, Yoshii N, Ota A, Takeshita JI, Yoshinari K, Ono A. Association between in vitro nuclear receptor-activating profiles of chemical compounds and their in vivo hepatotoxicity in rats. J Toxicol Sci 2021; 46:569-587. [PMID: 34853243 DOI: 10.2131/jts.46.569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The liver plays critical roles to maintain homeostasis of living organisms and is also a major target organ of chemical toxicity. Meanwhile, nuclear receptors (NRs) are known to regulate major liver functions and also as a critical target for hepatotoxic compounds. In this study, we established mammalian one-hybrid assay systems for five rat-derived NRs, namely PXR, PPARα, LXRα, FXR and RXRα, and evaluated a total of 326 compounds for their NR-activating profiles. Then, we assessed the association between their NR-activating profile and hepatotoxic endpoints in repeated-dose toxicity data of male rats from Hazard Evaluation Support System. In the in vitro cell-based assays, 68, 38, 20, 17 and 17 compounds were identified as positives for PXR, PPARα, LXRα, FXR and RXRα, respectively. The association analyses demonstrated that the PXR-positive compounds showed high frequency of endpoints related to liver hypertrophy, such as centrilobular hepatocellular hypertrophy, suggesting that PXR activation is involved in chemical-induced liver hypertrophy in rats. It is intriguing to note that the PXR-positive compounds also showed statistically significant associations with both prolonged activated partial thromboplastin time and prolonged prothrombin time, suggesting a possible involvement of PXR in the regulation of blood clotting factors. Collectively, our approach may be useful for discovering new functions of NRs as well as understanding the complex mechanism for hepatotoxicity caused by chemical compounds.
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Affiliation(s)
- Susumu Kodama
- Laboratory of Toxicology, Division of Pharmaceutical Sciences, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
| | - Nao Yoshii
- Laboratory of Toxicology, Division of Pharmaceutical Sciences, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
| | - Akihiro Ota
- Laboratory of Toxicology, Division of Pharmaceutical Sciences, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
| | - Jun-Ichi Takeshita
- Reserach Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology (AIST)
| | - Kouichi Yoshinari
- Laboratory of Molecular Toxicology, School of Pharmaceutical Sciences, University of Shizuoka
| | - Atsushi Ono
- Laboratory of Toxicology, Division of Pharmaceutical Sciences, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University
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5
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Lewandowski CT, Khan MW, BenAissa M, Dubrovskyi O, Ackerman-Berrier M, LaDu MJ, Layden BT, Thatcher GRJ. Metabolomic analysis of a selective ABCA1 inducer in obesogenic challenge provides a rationale for therapeutic development. EBioMedicine 2021; 66:103287. [PMID: 33752129 PMCID: PMC8010624 DOI: 10.1016/j.ebiom.2021.103287] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 03/02/2021] [Accepted: 03/02/2021] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Therapeutic agents with novel mechanisms of action are needed to combat the growing epidemic of type 2 diabetes (T2D) and related metabolic syndromes. Liver X receptor (LXR) agonists possess preclinical efficacy yet produce side effects due to excessive lipogenesis. Anticipating that many beneficial and detrimental effects of LXR agonists are mediated by ABCA1 and SREPB1c expression, respectively, we hypothesized that a phenotypic optimization strategy prioritizing selective ABCA1 induction would identify an efficacious lead compound with an improved side effect profile over existing LXRβ agonists. METHODS We synthesized and characterized a novel small molecule for selective induction of ABCA1 vs. SREBP1c in vitro. This compound was evaluated in both wild-type mice and a high-fat diet (HFD) mouse model of obesity-driven diabetes through functional, biochemical, and metabolomic analysis. FINDINGS Six weeks of oral administration of our lead compound attenuated weight gain, glucose intolerance, insulin signaling deficits, and adiposity. Global metabolomics revealed suppression of gluconeogenesis, free fatty acids, and pro-inflammatory metabolites. Target identification linked these beneficial effects to selective LXRβ agonism and PPAR/RXR antagonism. INTERPRETATION Our observations in the HFD model, combined with the absence of lipogenesis and neutropenia in WT mice, support this novel approach to therapeutic development for T2D and related conditions.
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Affiliation(s)
- Cutler T Lewandowski
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Md Wasim Khan
- Department of Medicine, University of Illinois at Chicago, 835 S. Wolcott St., Chicago, IL 60612, USA
| | - Manel BenAissa
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Oleksii Dubrovskyi
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Martha Ackerman-Berrier
- Department of Pharmacology and Toxicology, University of Arizona, 1295N. Martin, Tucson, AZ 85721, USA
| | - Mary Jo LaDu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | - Brian T Layden
- Department of Medicine, University of Illinois at Chicago, 835 S. Wolcott St., Chicago, IL 60612, USA.
| | - Gregory R J Thatcher
- Department of Pharmacology and Toxicology, University of Arizona, 1295N. Martin, Tucson, AZ 85721, USA.
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Russo-Savage L, Schulman IG. Liver X receptors and liver physiology. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166121. [PMID: 33713792 DOI: 10.1016/j.bbadis.2021.166121] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/29/2022]
Abstract
The liver x receptors LXRα (NR1H3) and LXRβ (NR1H2) are members of the nuclear hormone receptor superfamily of ligand dependent transcription factors that regulate transcription in response to the direct binding of cholesterol derivatives. Studies using genetic knockouts and synthetic ligands have defined the LXRs as important modulators of lipid homeostasis throughout the body. This review focuses on the control of cholesterol and fatty acid metabolism by LXRs in the liver and how modifying LXR activity can influence the pathology of liver diseases.
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Affiliation(s)
- Lillian Russo-Savage
- Department of Pharmacology, University of Virginia, School of Medicine, United States of America
| | - Ira G Schulman
- Department of Pharmacology, University of Virginia, School of Medicine, United States of America.
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7
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Park HS, Lee K, Kim SH, Hong MJ, Jeong NJ, Kim MS. Luteolin improves hypercholesterolemia and glucose intolerance through LXRα-dependent pathway in diet-induced obese mice. J Food Biochem 2020; 44:e13358. [PMID: 32598492 DOI: 10.1111/jfbc.13358] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 06/08/2020] [Accepted: 06/08/2020] [Indexed: 01/06/2023]
Abstract
Luteolin, a naturally derived flavonoid, exerts beneficial effects such as antitumor, antioxidant, and anti-inflammatory effects. However, the molecular mechanism underlying the effect of luteolin in hypercholesterolemia remains unclear. In this study, we demonstrated that luteolin upregulated the expression of liver X receptor (LXR) α, ATP-binding cassette transporter G1 (ABCG1), and scavenger receptor class B member 1 (SRB1), which play a major role in cholesterol efflux, in HepG2 hepatocytes. Luteolin-stimulated expression of ABCG1 and SRB1 was reversed by inhibitory compound of LXRα. Luteolin administration also upregulated the expression of ABCG1, and SRB1 as well as cholesterol 7 α-hydroxylase (Cyp7α1) in the liver of diet-induced obese mice. Luteolin decreased the level of blood cholesterol and non-high-density lipoprotein cholesterol in obese mice. In addition, luteolin ameliorated glucose intolerance and reduced expression of gluconeogenesis-associated enzymes in an LXRα-dependent manner. PRACTICAL APPLICATIONS: Luteolin is known to possess various pharmacological activities. This research revealed that luteolin ameliorates hypercholesterolemia and glucose intolerance in diet-induced obesity. The results indicate that the potential properties of luteolin in cholesterol metabolism could be explained, at least in part, as being due to upregulated expression of ABCG1, and SRB1 through activation of liver X receptor, LXRα signaling pathway in HepG2 cells.
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Affiliation(s)
- Hee-Sook Park
- Research group of Healthcare, Korea Food Research Institute, Wanju-gun, Republic of Korea
| | - Kyunhee Lee
- Research group of Healthcare, Korea Food Research Institute, Wanju-gun, Republic of Korea.,Department of Food Biotechnology, Korea University of Science & Technology, Wanju-gun, Republic of Korea
| | - Soon-Hee Kim
- Research group of Healthcare, Korea Food Research Institute, Wanju-gun, Republic of Korea
| | - Moon Ju Hong
- Research group of Healthcare, Korea Food Research Institute, Wanju-gun, Republic of Korea.,Department of Food Biotechnology, Korea University of Science & Technology, Wanju-gun, Republic of Korea
| | - Nam-Joo Jeong
- Research group of Healthcare, Korea Food Research Institute, Wanju-gun, Republic of Korea
| | - Myung-Sunny Kim
- Research group of Healthcare, Korea Food Research Institute, Wanju-gun, Republic of Korea.,Department of Food Biotechnology, Korea University of Science & Technology, Wanju-gun, Republic of Korea
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8
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Zhang H, Li C, Xin Y, Cui X, Cui J, Zhou G. Suppression of NSDHL attenuates adipogenesis with a downregulation of LXR-SREBP1 pathway in 3T3-L1 cells. Biosci Biotechnol Biochem 2020; 84:980-988. [PMID: 31985358 DOI: 10.1080/09168451.2020.1719823] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Previous RNA-Seq analyses revealed that NAD(P)H steroid dehydrogenase-like (NSDHL) has a different expression during 3T3-L1 differentiation; however, its roles in adipogenesis are unknown. In the present study, using quantitative real-time PCR, we confirmed that NSDHL knockdown increased the proliferation of 3T3-L1 preadipocytes, but attenuated the differentiation of 3T3-L1 preadipocytes, as evidenced by reduced lipid accumulation and down-regulation of PPARγ gene expression. Further analyses showed that the expression peak of NSDHL was at the early stage of 3T3-L1 preadipocytes differentiation and LXR-SREBP1 signaling pathway was downregulated in NSDHL-knockdown 3T3-L1 cells. Collectively, our findings indicate that NSDHL is a novel modulator of adipogenesis. Moreover, our data provide insight into the complex relationships between sterol sensing, LXR-SREBP1 signaling pathway, and PPARγ in 3T3-L1 cells.
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Affiliation(s)
- Haiyan Zhang
- College of Life Science, Liaocheng University, Liaocheng, China
| | - Chengping Li
- College of Life Science, Liaocheng University, Liaocheng, China
| | - Youzhi Xin
- College of Life Science, Liaocheng University, Liaocheng, China.,Chinese Academy of Geological Sciences, Beijing, China
| | - Xiao Cui
- College of Life Science, Liaocheng University, Liaocheng, China
| | - Jianwei Cui
- College of Life Science, Liaocheng University, Liaocheng, China
| | - Guoli Zhou
- College of Life Science, Liaocheng University, Liaocheng, China
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9
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Chang RC, Thomas KN, Bedi YS, Golding MC. Programmed increases in LXRα induced by paternal alcohol use enhance offspring metabolic adaptation to high-fat diet induced obesity. Mol Metab 2019; 30:161-172. [PMID: 31767168 PMCID: PMC6807343 DOI: 10.1016/j.molmet.2019.09.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/25/2019] [Accepted: 09/29/2019] [Indexed: 12/12/2022] Open
Abstract
Objectives Paternally inherited alterations in epigenetic programming are emerging as relevant factors in numerous disease states, including the growth and metabolic defects observed in fetal alcohol spectrum disorders. In rodents, chronic paternal alcohol use induces fetal growth restriction, as well as sex-specific alterations in insulin signaling and lipid homeostasis in the offspring. Based on previous studies, we hypothesized that the observed metabolic irregularities are the consequence of paternally inherited alterations liver x receptor (LXR) activity. Methods Male offspring of alcohol-exposed sires were challenged with a high-fat diet and the molecular pathways controlling glucose and lipid homeostasis assayed for LXR-induced alterations. Results Similar to findings in studies employing LXR agonists we found that the male offspring of alcohol-exposed sires display resistance to diet-induced obesity and improved glucose homeostasis when challenged with a high-fat diet. This improved metabolic adaptation is mediated by LXRα trans-repression of inflammatory cytokines, releasing IKKβ inhibition of the insulin signaling pathway. Interestingly, paternally programmed increases in LXRα expression are liver-specific and do not manifest in the pancreas or visceral fat. Conclusions These studies identify LXRα as a key mediator of the long-term metabolic alterations induced by preconception paternal alcohol use. Chronic paternal alcohol use induces up-regulation of LXRα in the male offspring. Male offspring of alcohol-exposed fathers are protected from diet-induced obesity. Paternally-inherited up-regulation of LXRα only manifests in the liver. Improved metabolic adaptation is linked to LXRα suppression of cytokine production. Male offspring exhibit the same phenotypes observed in studies of LXR agonists.
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Affiliation(s)
- Richard C Chang
- Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Kara N Thomas
- Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Yudhishtar S Bedi
- Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA
| | - Michael C Golding
- Department of Veterinary Physiology & Pharmacology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA.
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Zhang T, Duan J, Zhang L, Li Z, Steer CJ, Yan G, Song G. LXRα Promotes Hepatosteatosis in Part Through Activation of MicroRNA-378 Transcription and Inhibition of Ppargc1β Expression. Hepatology 2019; 69:1488-1503. [PMID: 30281809 PMCID: PMC6519356 DOI: 10.1002/hep.30301] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 09/24/2018] [Indexed: 12/21/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a major risk factor of many end-stage liver diseases. Alterations in microRNA expression have been reported in patients with NAFLD. However, the transcriptional mechanism(s) of dysregulated microRNAs under the state of NAFLD is poorly described, and microRNAs that regulate the pathogenesis of NAFLD synergistically with their regulators remain unknown. Here we report that microRNA-378 expression is significantly increased in fatty livers of mice and patients with NAFLD. Although microRNA-378 locates within the intron of Ppargc1β (peroxisome proliferator-activated receptor γ coactivator 1-beta), there was a significant uncoupling of Ppargc1β mRNA and microRNA-378 levels in both sources of fatty livers. Further studies identified a full-length primary transcript of microRNA-378. LXRα (liver X receptor alpha) functioned as a transcription activator of microRNA-378 and a repressor of Ppargc1β transcription. It is known that miR-378 is an inhibitor of fatty acid oxidation (FAO) and the function of Ppargc1β is opposite to that of miR-378. GW3965 treatment (LXRα agonist) of murine hepatocytes and mice increased microRNA-378 and reduced Ppargc1β, which subsequently impaired FAO and aggravated hepatosteatosis. In contrast, additional treatment of miR-378 inhibitor or Ppargc1β, which knocked down increased miR-378 or recovered expression of Ppargc1β, offset the effects of GW3965. Liver-specific ablation of Lxrα led to decreased miR-378 and increased Ppargc1β, which subsequently improved FAO and reduced hepatosteatosis. Conclusion: Our findings indicated that miR-378 possesses its own transcription machinery, which challenges the well-established dogma that miR-378 transcription is controlled by the promoter of Ppargc1β. LXRα selectively activates transcription of miR-378 and inhibits expression of Ppargc1β, which synergistically impairs FAO. In addition to lipogenesis, impaired FAO by miR-378 in part contributes to LXRα-induced hepatosteatosis.
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Affiliation(s)
- Tianpeng Zhang
- Department of MedicineUniversity of Minnesota Medical SchoolMinneapolisMinnesota
| | - Jiangyan Duan
- School of Life ScienceShanxi Normal UniversityLinfen CityChina
| | - Lei Zhang
- Department of Emergency SurgeryUnion Hospital, Tongji Medical College, Huazhong University of Science and TechnologyWuhanChina
| | - Zhuoyu Li
- Institute of BiotechnologyShanxi UniversityTaiyuanChina
| | - Clifford J. Steer
- Department of MedicineUniversity of Minnesota Medical SchoolMinneapolisMinnesota
- Department of Genetics, Cell Biology and DevelopmentUniversity of MinnesotaMinneapolisMinnesota
| | - Guiqin Yan
- School of Life ScienceShanxi Normal UniversityLinfen CityChina
| | - Guisheng Song
- Department of MedicineUniversity of Minnesota Medical SchoolMinneapolisMinnesota
- School of Life ScienceShanxi Normal UniversityLinfen CityChina
- Institute of BiotechnologyShanxi UniversityTaiyuanChina
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11
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Hypoglycaemic effect of capsaicinoids via elevation of insulin level and inhibition of glucose absorption in streptozotocin-induced diabetic rats. J Funct Foods 2018. [DOI: 10.1016/j.jff.2018.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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12
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Schulman IG. Liver X receptors link lipid metabolism and inflammation. FEBS Lett 2017; 591:2978-2991. [PMID: 28555747 DOI: 10.1002/1873-3468.12702] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/23/2017] [Indexed: 12/14/2022]
Abstract
The response of immune cells to pathogens is often associated with changes in the flux through basic metabolic pathways. Indeed, in many cases changes in metabolism appear to be necessary for a robust immune response. The Liver X receptors (LXRs) are members of the nuclear hormone receptor superfamily that regulate gene networks controlling cholesterol and lipid metabolism. In immune cells, particularly in macrophages, LXRs also inhibit proinflammatory gene expression. This Review will highlight recent studies that connect LXR-dependent control of lipid metabolism to regulation of the immune response.
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Affiliation(s)
- Ira G Schulman
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA, USA
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13
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Dong Y, Xu Z, Zhang Z, Yin X, Lin X, Li H, Zheng F. Impaired adipose expansion caused by liver X receptor activation is associated with insulin resistance in mice fed a high-fat diet. J Mol Endocrinol 2017; 58:141-154. [PMID: 28258092 DOI: 10.1530/jme-16-0196] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 01/30/2017] [Indexed: 12/23/2022]
Abstract
Liver X receptors (LXR) are deemed as potential drug targets for atherosclerosis, whereas a role in adipose tissue expansion and its relation to insulin sensitivity remains unclear. To assess the metabolic effects of LXR activation by the dual LXRα/β agonist T0901317, C57BL/6 mice fed a high-fat diet (HFD) were treated with T0901317 (30 mg/kg once daily by intraperitoneal injection) for 3 weeks. Differentiated 3T3-L1 adipocytes were used for analysing the effect of T0901317 on glucose uptake. The following results were obtained from this study. T0901317 reduced fat mass, accompanied by a massive fatty liver and lower serum adipokine levels in HFD mice. Increased adipocyte apoptosis was found in epididymal fat of T0901317-treated HFD mice. In addition, T0901317 treatment promoted basal lipolysis, but blunted the anti-lipolytic action of insulin. Furthermore, LXR activation antagonised PPARγ target genes in epididymal fat and PPARγ-PPRE-binding activity in 3T3-L1 adipocytes. Although the glucose tolerance was comparable to that in HFD mice, the insulin response during IPGTT was significantly higher and the insulin tolerance was significantly impaired in T0901317-treated HFD mice, indicating decreased insulin sensitivity by T0901317 administration, and which was further supported by impaired insulin signalling found in epididymal fat and decreased insulin-induced glucose uptake in 3T3-L1 adipocytes by T0901317 administration. In conclusion, these findings reveal that LXR activation impairs adipose expansion by increasing adipocyte apoptosis, lipolysis and antagonising PPARγ-mediated transcriptional activity, which contributes to decreased insulin sensitivity in whole body. The potential of LXR activation being a therapeutic target for atherosclerosis might be limited by the possibility of exacerbating insulin resistance.
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Affiliation(s)
- Yueting Dong
- Department of EndocrinologySir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Zhiye Xu
- Department of EndocrinologySir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Ziyi Zhang
- Department of EndocrinologySir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Xueyao Yin
- Department of EndocrinologySir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Xihua Lin
- Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang ProvinceSir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Hong Li
- Department of EndocrinologySir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Fenping Zheng
- Department of EndocrinologySir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
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Patel R, Magomedova L, Tsai R, Angers S, Orellana A, Cummins CL. Separating the Anti-Inflammatory and Diabetogenic Effects of Glucocorticoids Through LXRβ Antagonism. Endocrinology 2017; 158:1034-1047. [PMID: 28324010 DOI: 10.1210/en.2017-00094] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 01/23/2017] [Indexed: 11/19/2022]
Abstract
Synthetic glucocorticoids (GCs), including dexamethasone (DEX), are powerful anti-inflammatory drugs. Long-term use of GCs, however, can result in metabolic side effects such as hyperglycemia, hepatosteatosis, and insulin resistance. The GC receptor (GR) and liver X receptors (LXRα and LXRβ) regulate overlapping genes involved in gluconeogenesis and inflammation. We have previously shown that Lxrβ-/- mice are resistant to the diabetogenic effects of DEX but still sensitive to its immunosuppressive actions. To determine whether this finding could be exploited for therapeutic intervention, we treated mice with GSK2033, a pan-LXR antagonist, alone or combined with DEX. GSK2033 suppressed GC-induced gluconeogenic gene expression without affecting immune-responsive GR target genes. The suppressive effect of GSK2033 on DEX-induced gluconeogenic genes was specific to LXRβ, was liver cell autonomous, and occurred in a target gene-specific manner. Compared with DEX treatment alone, the coadministration of GSK2033 with DEX decreased the recruitment of GR and its accessory factors MED1 and C/EBPβ to the phosphoenolpyruvate carboxykinase promoter. However, GSK2033 had no effect on DEX-mediated suppression of inflammatory genes expressed in the liver or in mouse primary macrophages stimulated with lipopolysaccharides. In conclusion, our study provides evidence that the gluconeogenic and immunosuppressive actions of GR activation can be mechanistically dissociated by pharmacological antagonism of LXRβ. Treatment with an LXRβ antagonist could allow the safer use of existing GC drugs in patients requiring chronic dosing of anti-inflammatory agents for the treatment of diseases such as rheumatoid arthritis and inflammatory bowel disease.
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Affiliation(s)
- Rucha Patel
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Lilia Magomedova
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Ricky Tsai
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Stéphane Angers
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Arturo Orellana
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Carolyn L Cummins
- Department of Pharmaceutical Sciences, University of Toronto, Toronto, Ontario M5S 3M2, Canada
- Banting and Best Diabetes Centre, University of Toronto, Toronto, Ontario M5G 2C4, Canada
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15
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Zhang S, Ma X, Zhang L, Sun H, Liu X. Capsaicin Reduces Blood Glucose by Increasing Insulin Levels and Glycogen Content Better than Capsiate in Streptozotocin-Induced Diabetic Rats. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2017; 65:2323-2330. [PMID: 28230360 DOI: 10.1021/acs.jafc.7b00132] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Chili peppers exhibit antiobesity, anticancer, antidiabetic, and pain- and itch-relieving effects on animals and humans; these effects are due to capsaicin, which is the main pungent and biologically active component of pepper. Capsiate, a nonpungent capsaicin analogue, is similar to capsaicin in terms of structure and biological activity. In this study, we investigated whether capsaicin and capsiate exhibit the same hypoglycemic effects on rats with type 1 diabetes (T1D). Experimental rats were categorized into four groups: control, model, capsaicin, and capsiate groups. The two treatment groups were treated orally with 6 mg/kg bw capsaicin and capsiate daily for 28 days. Treatment with capsaicin and capsiate increased body weight, increased glycogen content, and inhibited intestinal absorption of sugar in T1D rats. Particularly, insulin levels were increased from 14.9 ± 0.76 mIU/L (model group) to 22.4 ± 1.39 mIU/L (capsaicin group), but the capsiate group (16.7 ± 0.79 mIU/L) was increased by only 12.2%. Analysis of the related genes suggested that the transient receptor potential vanilloid 1 (TRPV1) receptor was activated by capsaicin. Liver X receptor and pancreatic duodenum homeobox 1 controlled the glycometabolism balance by regulating the expression levels of glucose kinase, glucose transport protein 2 (GLUT2), phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase, leading to reduced blood glucose levels in T1D rats. Meanwhile, the hypoglycemic effect was enhanced by the down-regulated expression of sodium glucose cotransporter 1, GLUT2, and GLUT5 in the intestine. The results showed that the spicy characteristics of capsaicin might be the root of its ability to decrease blood glucose.
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Affiliation(s)
- Shiqi Zhang
- College of Food Science, Southwest University , Tiansheng Road 2, Chongqing 400715, People's Republic of China
| | - Xiaohan Ma
- College of Food Science, Southwest University , Tiansheng Road 2, Chongqing 400715, People's Republic of China
| | - Lei Zhang
- College of Life Science, Chongqing Normal University , Chongqing 401331, People's Republic of China
| | - Hui Sun
- College of Food Science, Southwest University , Tiansheng Road 2, Chongqing 400715, People's Republic of China
| | - Xiong Liu
- College of Food Science, Southwest University , Tiansheng Road 2, Chongqing 400715, People's Republic of China
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16
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Hyodeoxycholic acid derivatives as liver X receptor α and G-protein-coupled bile acid receptor agonists. Sci Rep 2017; 7:43290. [PMID: 28233865 PMCID: PMC5324103 DOI: 10.1038/srep43290] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/23/2017] [Indexed: 12/22/2022] Open
Abstract
Bile acids are extensively investigated for their potential in the treatment of human disorders. The liver X receptors (LXRs), activated by oxysterols and by a secondary bile acid named hyodeoxycholic acid (HDCA), have been found essential in the regulation of lipid homeostasis in mammals. Unfortunately, LXRα activates lipogenic enzymes causing accumulation of lipid in the liver. In addition to LXRs, HDCA has been also shown to function as ligand for GPBAR1, a G protein coupled receptor for secondary bile acids whose activation represents a promising approach to liver steatosis. In the present study, we report a library of HDCA derivatives endowed with modulatory activity on the two receptors. The lead optimization of HDCA moiety was rationally driven by the structural information on the binding site of the two targets and results from pharmacological characterization allowed the identification of hyodeoxycholane derivatives with selective agonistic activity toward LXRα and GPBAR1 and notably to the identification of the first example of potent dual LXRα/GPBAR1 agonists. The new chemical entities might hold utility in the treatment of dyslipidemic disorders.
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17
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Shavva VS, Bogomolova AM, Nikitin AA, Dizhe EB, Tanyanskiy DA, Efremov AM, Oleinikova GN, Perevozchikov AP, Orlov SV. Insulin-Mediated Downregulation of Apolipoprotein A-I Gene in Human Hepatoma Cell Line HepG2: The Role of Interaction Between FOXO1 and LXRβ Transcription Factors. J Cell Biochem 2016; 118:382-396. [PMID: 27404023 DOI: 10.1002/jcb.25651] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 07/11/2016] [Indexed: 12/22/2022]
Abstract
Apolipoprotein A-I (ApoA-I) is a key component of high density lipoproteins which possess anti-atherosclerotic and anti-inflammatory properties. Insulin is a crucial mediator of the glucose and lipid metabolism that has been implicated in atherosclerotic and inflammatory processes. Important mediators of insulin signaling such as Liver X Receptors (LXRs) and Forkhead Box A2 (FOXA2) are known to regulate apoA-I expression in liver. Forkhead Box O1 (FOXO1) is a well-known target of insulin signaling and a key mediator of oxidative stress response. Low doses of insulin were shown to activate apoA-I expression in human hepatoma HepG2 cells. However, the detailed mechanisms for these processes are still unknown. We studied the possible involvement of FOXO1, FOXA2, LXRα, and LXRβ transcription factors in the insulin-mediated regulation of apoA-I expression. Treatment of HepG2 cells with high doses of insulin (48 h, 100 nM) suppresses apoA-I gene expression. siRNAs against FOXO1, FOXA2, LXRβ, or LXRα abrogated this effect. FOXO1 forms a complex with LXRβ and insulin treatment impairs FOXO1/LXRβ complex binding to hepatic enhancer and triggers its nuclear export. Insulin as well as LXR ligand TO901317 enhance the interaction between FOXA2, LXRα, and hepatic enhancer. These data suggest that high doses of insulin downregulate apoA-I gene expression in HepG2 cells through redistribution of FOXO1/LXRβ complex, FOXA2, and LXRα on hepatic enhancer of apoA-I gene. J. Cell. Biochem. 118: 382-396, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Vladimir S Shavva
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Embryology, St. Petersburg State University, St. Petersburg, Russia
| | | | - Artemy A Nikitin
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Biochemistry, St. Petersburg State University, St. Petersburg, Russia
| | - Ella B Dizhe
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia
| | - Dmitry A Tanyanskiy
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Fundamental Medicine and Medical Technologies, St. Petersburg State University, St. Petersburg, Russia
| | - Alexander M Efremov
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Embryology, St. Petersburg State University, St. Petersburg, Russia
| | - Galina N Oleinikova
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia
| | - Andrej P Perevozchikov
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Embryology, St. Petersburg State University, St. Petersburg, Russia
| | - Sergey V Orlov
- Department of Biochemistry, Institute of Experimental Medicine, Russian Academy of Medical Sciences, St. Petersburg, Russia.,Department of Embryology, St. Petersburg State University, St. Petersburg, Russia
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18
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Once and for all, LXRα and LXRβ are gatekeepers of the endocrine system. Mol Aspects Med 2016; 49:31-46. [DOI: 10.1016/j.mam.2016.04.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 03/08/2016] [Accepted: 04/10/2016] [Indexed: 01/08/2023]
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19
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Cannon MV, Silljé HHW, Sijbesma JWA, Khan MAF, Steffensen KR, van Gilst WH, de Boer RA. LXRα improves myocardial glucose tolerance and reduces cardiac hypertrophy in a mouse model of obesity-induced type 2 diabetes. Diabetologia 2016; 59:634-43. [PMID: 26684450 PMCID: PMC4742491 DOI: 10.1007/s00125-015-3827-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 11/05/2015] [Indexed: 12/11/2022]
Abstract
AIMS/HYPOTHESIS Diabetic cardiomyopathy is a myocardial disease triggered by impaired insulin signalling, increased fatty acid uptake and diminished glucose utilisation. Liver X receptors (LXRs) are key transcriptional regulators of metabolic homeostasis. However, their effect in the diabetic heart is largely unknown. METHODS We cloned murine Lxrα (also known as Nr1h3) behind the α-myosin heavy chain (αMhc; also known as Myh6) promoter to create transgenic (Lxrα-Tg) mice and transgene-negative littermates (wild-type [WT]). A mouse model of type 2 diabetes was induced by a high-fat diet (HFD, 60% energy from fat) over 16 weeks and compared with a low-fat diet (10% energy from fat). A mouse model of type 1 diabetes was induced via streptozotocin injection over 12 weeks. RESULTS HFD manifested comparable increases in body weight, plasma triacylglycerol and insulin resistance per OGTT in Lxrα-Tg and WT mice. HFD significantly increased left ventricular weight by 21% in WT hearts, but only by 5% in Lxrα-Tg. To elucidate metabolic effects in the heart, microPET (positron emission tomography) imaging revealed that cardiac glucose uptake was increased by 1.4-fold in WT mice on an HFD, but further augmented by 1.7-fold in Lxrα-Tg hearts, in part through 5' adenosine monophosphate-activated protein kinase (AMPK) phosphorylation and restoration of glucose transporter 4 (GLUT4). By contrast, streptozotocin-induced ablation of insulin signalling diminished cardiac glucose uptake levels and caused cardiac dysfunction, indicating that insulin may be important in LXRα-mediated glucose uptake. Chromatin immunoprecipitation assays identified natriuretic peptides, atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP), as potential direct targets of cardiac LXRα overexpression. CONCLUSIONS/INTERPRETATION Cardiac-specific LXRα overexpression ameliorates the progression of HFD-induced left ventricular hypertrophy in association with increased glucose reliance and natriuretic peptide signalling during the early phase of diabetic cardiomyopathy. These findings implicate a potential protective role for LXR in targeting metabolic disturbances underlying diabetes.
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Affiliation(s)
- Megan V Cannon
- University of Groningen, University Medical Center Groningen, Department of Cardiology, Hanzeplein 1, 9713 GZ, Groningen, the Netherlands
| | - Herman H W Silljé
- University of Groningen, University Medical Center Groningen, Department of Cardiology, Hanzeplein 1, 9713 GZ, Groningen, the Netherlands
| | - Jürgen W A Sijbesma
- University of Groningen, University Medical Center Groningen, Department of Nuclear Medicine, Hanzeplein 1, 9713 GZ, Groningen, the Netherlands
| | - Mohsin A F Khan
- University of Groningen, University Medical Center Groningen, Department of Cardiology, Hanzeplein 1, 9713 GZ, Groningen, the Netherlands
| | - Knut R Steffensen
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Wiek H van Gilst
- University of Groningen, University Medical Center Groningen, Department of Cardiology, Hanzeplein 1, 9713 GZ, Groningen, the Netherlands
| | - Rudolf A de Boer
- University of Groningen, University Medical Center Groningen, Department of Cardiology, Hanzeplein 1, 9713 GZ, Groningen, the Netherlands.
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20
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Emerging role of liver X receptors in cardiac pathophysiology and heart failure. Basic Res Cardiol 2015; 111:3. [PMID: 26611207 PMCID: PMC4661180 DOI: 10.1007/s00395-015-0520-7] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/03/2015] [Indexed: 01/09/2023]
Abstract
Liver X receptors (LXRs) are master regulators of metabolism and have been studied for their pharmacological potential in vascular and metabolic disease. Besides their established role in metabolic homeostasis and disease, there is mounting evidence to suggest that LXRs may exert direct beneficial effects in the heart. Here, we aim to provide a conceptual framework to explain the broad mode of action of LXRs and how LXR signaling may be an important local and systemic target for the treatment of heart failure. We discuss the potential role of LXRs in systemic conditions associated with heart failure, such as hypertension, diabetes, and renal and vascular disease. Further, we expound on recent data that implicate a direct role for LXR activation in the heart, for its impact on cardiomyocyte damage and loss due to ischemia, and effects on cardiac hypertrophy, fibrosis, and myocardial metabolism. Taken together, the accumulating evidence supports the notion that LXRs may represent a novel therapeutic target for the treatment of heart failure.
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21
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Renga B, Festa C, De Marino S, Di Micco S, D'Auria MV, Bifulco G, Fiorucci S, Zampella A. Molecular decodification of gymnemic acids from Gymnema sylvestre. Discovery of a new class of liver X receptor antagonists. Steroids 2015; 96:121-31. [PMID: 25668616 DOI: 10.1016/j.steroids.2015.01.024] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2014] [Revised: 12/19/2014] [Accepted: 01/29/2015] [Indexed: 12/19/2022]
Abstract
The individual chemical components of commercial extract of Gymnema sylvestre, a medicinal plant used in the traditional systems of the Indian medicine for its antidiabetic and hypolipidemic properties, were isolated and evaluated for their capability to act as modulators of nuclear and membrane receptors involved in glucose and lipid homeostasis. The study disclosed for the first time that individual gymnemic acids are potent and selective antagonists for the β isoform of LXR. Indeed the above activity was shared by the most abundant aglycone gymnemagenin (10) whereas gymnestrogenin (11) was endowed with a dual LXRα/β antagonistic profile. Deep pharmacological investigation demonstrated that gymnestrogenin, reducing the expression of SREBP1c and ABCA1 in vitro, is able to decrease lipid accumulation in HepG2 cells. The results of this study substantiate the use of G. sylvestre extract in LXR mediated dislypidemic diseases.
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Affiliation(s)
- Barbara Renga
- Department of Surgery and Biomedical Sciences, Nuova Facoltà di Medicina, P.zza L. Severi, 1-06132 Perugia, Italy
| | - Carmen Festa
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano, 49, I-80131 Naples, Italy
| | - Simona De Marino
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano, 49, I-80131 Naples, Italy
| | - Simone Di Micco
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (Salerno), Italy
| | - Maria Valeria D'Auria
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano, 49, I-80131 Naples, Italy
| | - Giuseppe Bifulco
- Department of Pharmacy, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fisciano (Salerno), Italy
| | - Stefano Fiorucci
- Department of Surgery and Biomedical Sciences, Nuova Facoltà di Medicina, P.zza L. Severi, 1-06132 Perugia, Italy
| | - Angela Zampella
- Department of Pharmacy, University of Naples "Federico II", Via D. Montesano, 49, I-80131 Naples, Italy.
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22
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Lee CTC, Liese AD, Lorenzo C, Wagenknecht LE, Haffner SM, Rewers MJ, Hanley AJ. Egg consumption and insulin metabolism in the Insulin Resistance Atherosclerosis Study (IRAS). Public Health Nutr 2014; 17:1595-602. [PMID: 23777633 PMCID: PMC10282309 DOI: 10.1017/s1368980013001572] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2012] [Revised: 05/07/2013] [Accepted: 05/09/2013] [Indexed: 11/07/2022]
Abstract
OBJECTIVE To examine the association between egg consumption and measures of insulin sensitivity (SI), acute insulin response (AIR) and metabolic clearance rate of insulin (MCRI). DESIGN Cross-sectional analysis. SETTINGS Egg consumption, categorized as <1/week, 1 to <3/week, 3 to <5/week and ≥5/week, was measured using a validated FFQ. SI, AIR and MCRI were determined from frequently sampled intravenous glucose tolerance tests. SUBJECTS Non-diabetic participants (n 949) in the Insulin Resistance Atherosclerosis Study (IRAS). RESULTS Egg consumption was inversely associated with SI and MCRI, and positively associated with fasting insulin in regression models adjusted for demographic, socio-economic, lifestyle and dietary factors (β = -0·22, 95 % CI -0·38, -0·045, P = 0·05 for SI; β = -0·20, 95 % CI -0·34, -0·055, P = 0·005 for MCRI; β = 0·35, 95 % CI 0·15, 0·54, P = 0·002 for fasting insulin; all P values for linear trend). These associations remained significant after additionally adjusting for energy intake or dietary saturated fat, although dietary cholesterol and BMI attenuated these associations to non-significance. Egg consumption was not associated with AIR. CONCLUSIONS Dietary cholesterol and BMI appear to mediate the inverse association of egg consumption with insulin sensitivity and clearance. Alternatively, egg consumption may be clustered with other dietary behaviours which increase BMI, hence negatively impacting on insulin sensitivity and clearance.
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Affiliation(s)
- Chee-Tin Christine Lee
- Department of Nutritional Sciences, University of Toronto, FitzGerald Building, 150 College Street Room 341, Toronto, ON M5S 3E2, Canada
| | - Angela D Liese
- Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA
| | - Carlos Lorenzo
- Division of Clinical Epidemiology, University of Texas Health Science Centre, San Antonio, TX, USA
| | - Lynne E Wagenknecht
- Division of Public Health Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - Steven M Haffner
- Department of Medicine, Baylor College of Medicine, Houston, TX, USA
| | - Marian J Rewers
- Barbara Davis Center for Diabetes, University of Colorado School of Medicine, Aurora, CO, USA
| | - Anthony J Hanley
- Department of Nutritional Sciences, University of Toronto, FitzGerald Building, 150 College Street Room 341, Toronto, ON M5S 3E2, Canada
- Department of Medicine and Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
- Leadership Sinai Centre for Diabetes, Mount Sinai Hospital, Toronto, ON, Canada
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23
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Kruse MS, Vega MC, Rey M, Coirini H. Sex differences in LXR expression in normal offspring and in rats born to diabetic dams. J Endocrinol 2014; 222:53-60. [PMID: 24824431 DOI: 10.1530/joe-14-0054] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Gestational diabetes (GD) alters normal fetal development and is related to a diabetogenic effect in the progeny. Liver X receptors (LXRs) are considered to be potential drug targets for the regulation, treatment, or prevention of diabetes. The aim of this study was to evaluate early and late changes of LXR in the hippocampus and hypothalamus of the male and female offspring of control (CO) and diabetic (DO) mothers. We used an experimental model of streptozotocin-induced GD to assess the protein expression of LXRα (NR1H3) and LXRβ (NR1H2) by western blotting. The tissues were obtained from CO and DO animals at postnatal day 1 (1D), day 10 (10D), and day 35 (35D) and 9 months (9M). In CO, the LXR expression showed significant differences among the groups, which were tissue- and receptor-specific (P<0.05). Sex differences in CO were found only in the hypothalamus for LXRβ expression at 35D and 9M (P<0.05). When CO and DO were compared, differences between them were observed in the majority of the studied groups at 1D (male hippocampus, LXRα 31% and LXRβ 161%; female hippocampus, LXRβ 165%; male hypothalamus, LXRβ 182%; and female hypothalamus, LXRα 85%; P<0.05). However, these differences disappeared later with the exception of LXRβ expression in the male hypothalamus (P<0.05). The area under the curve during the glucose tolerance test correlated negatively with LXRβ in CO but not in DO animals. Moreover, in a male DO subpopulation this correlation was positive as it occurs in intolerant animals. These results indicate that GD affects hypothalamic LXR expression differently in male and female offspring.
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Affiliation(s)
- María Sol Kruse
- Laboratorio de NeurobiologíaInstituto de Biología y Medicina Experimental (IByME-CONICET), Vuelta de Obligado 2490, C1428ADN Ciudad Autónoma de Buenos Aires, ArgentinaDepartamento de Bioquímica HumanaFacultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, 5to Piso, C1121ABG Ciudad Autónoma de Buenos Aires, ArgentinaFacultad de Ciencias MedicasUniversidad Católica de Cuyo, Rivadavia, Provincia de San Juan, Argentina
| | - María Cristina Vega
- Laboratorio de NeurobiologíaInstituto de Biología y Medicina Experimental (IByME-CONICET), Vuelta de Obligado 2490, C1428ADN Ciudad Autónoma de Buenos Aires, ArgentinaDepartamento de Bioquímica HumanaFacultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, 5to Piso, C1121ABG Ciudad Autónoma de Buenos Aires, ArgentinaFacultad de Ciencias MedicasUniversidad Católica de Cuyo, Rivadavia, Provincia de San Juan, Argentina
| | - Mariana Rey
- Laboratorio de NeurobiologíaInstituto de Biología y Medicina Experimental (IByME-CONICET), Vuelta de Obligado 2490, C1428ADN Ciudad Autónoma de Buenos Aires, ArgentinaDepartamento de Bioquímica HumanaFacultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, 5to Piso, C1121ABG Ciudad Autónoma de Buenos Aires, ArgentinaFacultad de Ciencias MedicasUniversidad Católica de Cuyo, Rivadavia, Provincia de San Juan, Argentina
| | - Héctor Coirini
- Laboratorio de NeurobiologíaInstituto de Biología y Medicina Experimental (IByME-CONICET), Vuelta de Obligado 2490, C1428ADN Ciudad Autónoma de Buenos Aires, ArgentinaDepartamento de Bioquímica HumanaFacultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, 5to Piso, C1121ABG Ciudad Autónoma de Buenos Aires, ArgentinaFacultad de Ciencias MedicasUniversidad Católica de Cuyo, Rivadavia, Provincia de San Juan, ArgentinaLaboratorio de NeurobiologíaInstituto de Biología y Medicina Experimental (IByME-CONICET), Vuelta de Obligado 2490, C1428ADN Ciudad Autónoma de Buenos Aires, ArgentinaDepartamento de Bioquímica HumanaFacultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, 5to Piso, C1121ABG Ciudad Autónoma de Buenos Aires, ArgentinaFacultad de Ciencias MedicasUniversidad Católica de Cuyo, Rivadavia, Provincia de San Juan, ArgentinaLaboratorio de NeurobiologíaInstituto de Biología y Medicina Experimental (IByME-CONICET), Vuelta de Obligado 2490, C1428ADN Ciudad Autónoma de Buenos Aires, ArgentinaDepartamento de Bioquímica HumanaFacultad de Medicina, Universidad de Buenos Aires, Paraguay 2155, 5to Piso, C1121ABG Ciudad Autónoma de Buenos Aires, ArgentinaFacultad de Ciencias MedicasUniversidad Católica de Cuyo, Rivadavia, Provincia de San Juan, Argentina
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24
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Zheng F, Zhang S, Lu W, Wu F, Yin X, Yu D, Pan Q, Li H. Regulation of insulin resistance and adiponectin signaling in adipose tissue by liver X receptor activation highlights a cross-talk with PPARγ. PLoS One 2014; 9:e101269. [PMID: 24972069 PMCID: PMC4074121 DOI: 10.1371/journal.pone.0101269] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 06/05/2014] [Indexed: 01/15/2023] Open
Abstract
Liver X receptors (LXRs) have been recognized as a promising therapeutic target for atherosclerosis; however, their role in insulin sensitivity is controversial. Adiponectin plays a unique role in maintaining insulin sensitivity. Currently, no systematic experiments elucidating the role of LXR activation in insulin function based on adiponectin signaling have been reported. Here, we investigated the role of LXR activation in insulin resistance based on adiponectin signaling, and possible mechanisms. C57BL/6 mice maintained on a regular chow received the LXR agonist, T0901317 (30 mg/kg.d) for 3 weeks by intraperitoneal injection, and differentiated 3T3-L1 adipocytes were treated with T0901317 or GW3965. T0901317 treatment induced significant insulin resistance in C57BL/6 mice. It decreased adiponectin gene transcription in epididymal fat, as well as serum adiponectin levels. Activity of AMPK, a key mediator of adiponectin signaling, was also decreased, resulting in decreased Glut-4 membrane translocation in epididymal fat. In contrast, adiponectin activity was not changed in the liver of T0901317 treated mice. In vitro, both T0901317 and GW3965 decreased adiponectin expression in adipocytes in a dose-dependent manner, an effect which was diminished by LXRα silencing. ChIP-qPCR studies demonstrated that T0901317 decreased the binding of PPARγ to the PPAR-responsive element (PPRE) of the adiponectin promoter in a dose-dependent manner. Furthermore, T0901317 exerted an antagonistic effect on the expression of adiponectin in adipocytes co-treated with 3 µM Pioglitazone. In luciferase reporter gene assays, T0901317 dose-dependently inhibited PPRE-Luc activity in HEK293 cells co-transfected with LXRα and PPARγ. These results suggest that LXR activation induces insulin resistance with decreased adiponectin signaling in epididymal fat, probably due to negative regulation of PPARγ signaling. These findings indicate that the potential of LXR activation as a therapeutic target for atherosclerosis may be limited by the possibility of exacerbating insulin resistance-related disease.
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Affiliation(s)
- Fenping Zheng
- Department of Endocrinology, Sir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, P. R. China
| | - Saifei Zhang
- Department of Endocrinology, Sir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, P. R. China
| | - Weina Lu
- Department of Endocrinology, Sir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, P. R. China
| | - Fang Wu
- Department of Endocrinology, Sir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, P. R. China
| | - Xueyao Yin
- Department of Endocrinology, Sir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, P. R. China
| | - Dan Yu
- Department of Endocrinology, Sir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, P. R. China
| | - Qianqian Pan
- Biomedical Research Center and Key Laboratory of Biotherapy of Zhejiang Province, Sir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, P.R. China
| | - Hong Li
- Department of Endocrinology, Sir Run Run Shaw Hospital Affiliated with School of Zhejiang University, Hangzhou, Zhejiang, P. R. China
- * E-mail:
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Patel R, Williams-Dautovich J, Cummins CL. Minireview: new molecular mediators of glucocorticoid receptor activity in metabolic tissues. Mol Endocrinol 2014; 28:999-1011. [PMID: 24766141 DOI: 10.1210/me.2014-1062] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The glucocorticoid receptor (GR) was one of the first nuclear hormone receptors cloned and represents one of the most effective drug targets available today for the treatment of severe inflammation. The physiologic consequences of endogenous or exogenous glucocorticoid excess are well established and include hyperglycemia, insulin resistance, fatty liver, obesity, and muscle wasting. However, at the molecular and tissue-specific level, there are still many unknown protein mediators of glucocorticoid response and thus, much remains to be uncovered that will help determine whether activation of the GR can be tailored to improve therapeutic efficacy while minimizing unwanted side effects. This review summarizes recent discoveries of tissue-selective modulators of glucocorticoid signaling that are important in mediating the unwanted side effects of therapeutic glucocorticoid use, emphasizing the downstream molecular effects of GR activation in the liver, adipose tissue, muscle, and pancreas.
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Affiliation(s)
- Rucha Patel
- Department of Pharmaceutical Sciences (R.P., J.W-D., C.L.C.), University of Toronto, Toronto, Ontario, M5S 3M2, Canada; and Banting and Best Diabetes Centre (C.L.C.), Toronto, Ontario M5G 2C4 Canada
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26
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Dib L, Bugge A, Collins S. LXRα fuels fatty acid-stimulated oxygen consumption in white adipocytes. J Lipid Res 2014; 55:247-57. [PMID: 24259533 PMCID: PMC3886663 DOI: 10.1194/jlr.m043422] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2013] [Revised: 10/28/2013] [Indexed: 02/06/2023] Open
Abstract
Liver X receptors (LXRs) are transcription factors known for their role in hepatic cholesterol and lipid metabolism. Though highly expressed in fat, the role of LXR in this tissue is not well characterized. We generated adipose tissue LXRα knockout (ATaKO) mice and showed that these mice gain more weight and fat mass on a high-fat diet compared with wild-type controls. White adipose tissue (WAT) accretion in ATaKO mice results from both a decrease in WAT lipolytic and oxidative capacities. This was demonstrated by decreased expression of the β2- and β3-adrenergic receptors, reduced level of phosphorylated hormone-sensitive lipase, and lower oxygen consumption rates (OCRs) in WAT of ATaKO mice. Furthermore, LXR activation in vivo and in vitro led to decreased adipocyte size in WAT and increased glycerol release from primary adipocytes, respectively, with a concomitant increase in OCR in both models. Our findings show that absence of LXRα in adipose tissue results in elevated adiposity through a decrease in WAT oxidation, secondary to attenuated FA availability.
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Affiliation(s)
- Lea Dib
- Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, FL
| | - Anne Bugge
- Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, FL
| | - Sheila Collins
- Diabetes and Obesity Research Center, Sanford-Burnham Medical Research Institute, Orlando, FL
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27
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Parikh M, Patel K, Soni S, Gandhi T. Liver X Receptor: A Cardinal Target for Atherosclerosis and Beyond. J Atheroscler Thromb 2014. [DOI: 10.5551/jat.19778] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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28
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Ding L, Pang S, Sun Y, Tian Y, Yu L, Dang N. Coordinated Actions of FXR and LXR in Metabolism: From Pathogenesis to Pharmacological Targets for Type 2 Diabetes. Int J Endocrinol 2014; 2014:751859. [PMID: 24872814 PMCID: PMC4020365 DOI: 10.1155/2014/751859] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Accepted: 04/09/2014] [Indexed: 12/13/2022] Open
Abstract
Type 2 diabetes (T2D) is the most prevalent metabolic disease, and many people are suffering from its complications driven by hyperglycaemia and dyslipidaemia. Nuclear receptors (NRs) are ligand-inducible transcription factors that mediate changes to metabolic pathways within the body. As metabolic regulators, the farnesoid X receptor (FXR) and the liver X receptor (LXR) play key roles in the pathogenesis of T2D, which remains to be clarified in detail. Here we review the recent progress concerning the physiological and pathophysiological roles of FXRs and LXRs in the regulation of bile acid, lipid and glucose metabolism and the implications in T2D, taking into account that these two nuclear receptors are potential pharmaceutical targets for the treatment of T2D and its complications.
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Affiliation(s)
- Lin Ding
- Endocrinology Department, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong 250013, China
| | - Shuguang Pang
- Endocrinology Department, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong 250013, China
- *Shuguang Pang:
| | - Yongmei Sun
- Endocrinology Department, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong 250013, China
| | - Yuling Tian
- Endocrinology Department, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong 250013, China
| | - Li Yu
- Endocrinology Department, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong 250013, China
| | - Ningning Dang
- Endocrinology Department, Jinan Central Hospital Affiliated to Shandong University, No. 105 Jiefang Road, Jinan, Shandong 250013, China
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Pettersson AML, Stenson BM, Lorente-Cebrián S, Andersson DP, Mejhert N, Krätzel J, Aström G, Dahlman I, Chibalin AV, Arner P, Laurencikiene J. LXR is a negative regulator of glucose uptake in human adipocytes. Diabetologia 2013; 56:2044-54. [PMID: 23765184 DOI: 10.1007/s00125-013-2954-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 05/16/2013] [Indexed: 01/14/2023]
Abstract
AIMS/HYPOTHESIS Obesity increases the risk of developing type 2 diabetes mellitus, characterised by impaired insulin-mediated glucose uptake in peripheral tissues. Liver X receptor (LXR) is a positive regulator of adipocyte glucose transport in murine models and a possible target for diabetes treatment. However, the levels of LXRα are increased in obese adipose tissue in humans. We aimed to investigate the transcriptome of LXR and the role of LXR in the regulation of glucose uptake in primary human adipocytes. METHODS The insulin responsiveness of human adipocytes differentiated in vitro was characterised, adipocytes were treated with the LXR agonist GW3965 and global transcriptome profiling was determined by microarray, followed by quantitative RT-PCR (qRT-PCR), western blot and ELISA. Basal and insulin-stimulated glucose uptake was measured and the effect on plasma membrane translocation of glucose transporter 4 (GLUT4) was assayed. RESULTS LXR activation resulted in transcriptional suppression of several insulin signalling genes, such as AKT2, SORBS1 and CAV1, but caused only minor changes (<15%) in microRNA expression. Activation of LXR impaired the plasma membrane translocation of GLUT4, but not the expression of its gene, SLC2A4. LXR activation also diminished insulin-stimulated glucose transport and lipogenesis in adipocytes obtained from overweight individuals. Furthermore, AKT2 expression was reduced in obese adipose tissue, and AKT2 and SORBS1 expression was inversely correlated with BMI and HOMA index. CONCLUSIONS/INTERPRETATION In contrast to murine models, LXR downregulates insulin-stimulated glucose uptake in human adipocytes from overweight individuals. This could be due to suppression of Akt2, c-Cbl-associated protein and caveolin-1. These findings challenge the idea of LXR as a drug target in the treatment of diabetes.
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Affiliation(s)
- A M L Pettersson
- Department of Medicine Huddinge, Karolinska Institutet, Hälsovägen 7, Novum, 14186 Stockholm, Sweden.
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30
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Loren J, Huang Z, Laffitte BA, Molteni V. Liver X receptor modulators: a review of recently patented compounds (2009 - 2012). Expert Opin Ther Pat 2013; 23:1317-35. [PMID: 23826715 DOI: 10.1517/13543776.2013.814640] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
INTRODUCTION The development of small molecule agonists of the liver X receptors (LXRs) has been an area of interest for over a decade, given the critical role of those receptors in cholesterol metabolism, glucose homeostasis, inflammation, innate immunity and lipogenesis. Many potential indications have been characterized over time including atherosclerosis, diabetes, inflammation, Alzheimer's disease and cancer. However, concerns about the lipogenic effects of full LXRα/β agonists have required extensive efforts aimed at identifying LXRβ agonist with limited activity on the LXRα receptor to increase the safety margins. AREAS COVERED This review includes a summary of the LXR agonists that have reached the clinic and summarizes the patent applications for LXR modulators from September 2009 to December 2012 with emphasis on chemical matters, biological data associated with selected analogs and therapeutic indications. EXPERT OPINION As LXR agonists have the potential to be useful for many indications, the scientific community, despite setbacks due to on-target side effects, has maintained interest and devised strategies to overcome safety hurdles. While a clinical proof of concept still remains elusive, the recent advancement of compounds into the clinic highlights that acceptable safety margins in preclinical species have been achieved.
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Affiliation(s)
- Jon Loren
- Genomics Institute of the Novartis Research Foundation , 10675 John Jay Hopkins Drive, San Diego, CA 92121 , USA +001 858 332 4736 ;
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31
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Beaven SW, Matveyenko A, Wroblewski K, Chao L, Wilpitz D, Hsu TW, Lentz J, Drew B, Hevener AL, Tontonoz P. Reciprocal regulation of hepatic and adipose lipogenesis by liver X receptors in obesity and insulin resistance. Cell Metab 2013; 18:106-17. [PMID: 23823481 PMCID: PMC4089509 DOI: 10.1016/j.cmet.2013.04.021] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 03/28/2013] [Accepted: 04/26/2013] [Indexed: 12/25/2022]
Abstract
Liver X receptors (LXRs) regulate lipogenesis and inflammation, but their contribution to the metabolic syndrome is unclear. We show that LXRs modulate key aspects of the metabolic syndrome in mice. LXRαβ-deficient-ob/ob (LOKO) mice remain obese but show reduced hepatic steatosis and improved insulin sensitivity compared to ob/ob mice. Impaired hepatic lipogenesis in LOKO mice is accompanied by reciprocal increases in adipose lipid storage, reflecting tissue-selective effects on the SREBP, PPARγ, and ChREBP lipogenic pathways. LXRs are essential for obesity-driven SREBP-1c and ChREBP activity in liver, but not fat. Furthermore, loss of LXRs in obesity promotes adipose PPARγ and ChREBP-β activity, leading to improved insulin sensitivity. LOKO mice also exhibit defects in β cell mass and proliferation despite improved insulin sensitivity. Our data suggest that sterol sensing by LXRs in obesity is critically linked with lipid and glucose homeostasis and provide insight into the complex relationships between LXR and insulin signaling.
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Affiliation(s)
- Simon W Beaven
- Howard Hughes Medical Institute and Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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32
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Cermenati G, Brioschi E, Abbiati F, Melcangi RC, Caruso D, Mitro N. Liver X receptors, nervous system, and lipid metabolism. J Endocrinol Invest 2013; 36:435-43. [PMID: 23609963 DOI: 10.3275/8941] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lipids in the nervous system are represented by cholesterol and phospholipids as constituents of cell membranes and, in particular, of myelin. Therefore, lipids are finely regulated to guarantee physiological functions. In the central nervous system, cholesterol is locally synthesized due to the presence of the blood brain barrier. In the peripheral nervous system cholesterol is either up-taken by lipoproteins and/or produced by de novo biosynthesis. Defects in lipid homeostasis in these tissues lead to structural and functional changes that often result in different pathological conditions depending on the affected pathways (i.e. cholesterol biosynthesis, cholesterol efflux, fatty acid biosynthesis etc.). Alterations in cholesterol metabolism in the central nervous system are linked to several disorders such as Alzheimer's disease, Huntington disease, Parkinson disease, Multiple sclerosis, Smith-Lemli-Opitz syndrome, Niemann-Pick type C disease, and glioblastoma. In the peripheral nervous system changes in lipid metabolism are associated with the development of peripheral neuropathy that may be caused by metabolic disorders, injuries, therapeutics, and autoimmune diseases. Transcription factors, such as the Liver X receptors (LXR), regulate both cholesterol and fatty acid metabolism in several tissues including the nervous system. In the last few years several studies elucidated the biology of LXR in the nervous system due to the availability of knock-out mice and the development of synthetic ligands. Here, we review a survey of the literature focused on the central and peripheral nervous system and in physiological and pathological settings with particular attention to the roles played by LXR in both districts.
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Affiliation(s)
- G Cermenati
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Via Balzaretti 9, Milan, Italy
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33
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Ohsawa F, Yamada S, Yakushiji N, Shinozaki R, Nakayama M, Kawata K, Hagaya M, Kobayashi T, Kohara K, Furusawa Y, Fujiwara C, Ohta Y, Makishima M, Naitou H, Tai A, Yoshikawa Y, Yasui H, Kakuta H. Mechanism of Retinoid X Receptor Partial Agonistic Action of 1-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)-1H-benzotriazole-5-carboxylic Acid and Structural Development To Increase Potency. J Med Chem 2013; 56:1865-77. [DOI: 10.1021/jm400033f] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Fuminori Ohsawa
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Shoya Yamada
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
- Research Fellowship
Division, Japan Society for the Promotion of Science, Sumitomo-Ichibancho
FS Bldg., 8 Ichibancho, Chiyoda-ku, Tokyo 102-8472, Japan
| | - Nobumasa Yakushiji
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Ryosuke Shinozaki
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Mariko Nakayama
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Kohei Kawata
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Manabu Hagaya
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Toshiki Kobayashi
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Kazutaka Kohara
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Yuuki Furusawa
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Chisa Fujiwara
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Yui Ohta
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
| | - Makoto Makishima
- Division of Biochemistry, Department
of Biomedical Sciences, Nihon University School of Medicine, 30-1 Oyaguchi-kamicho, Itabashi-ku, Tokyo 173-8610, Japan
| | - Hirotaka Naitou
- Graduate School of Nutritional
and Environmental Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan
| | - Akihiro Tai
- Faculty of Life and Environmental
Sciences, Prefectural University of Hiroshima, 562 Nanatsuka-Cho, Shobara, Hiroshima 727-0023, Japan
| | - Yutaka Yoshikawa
- Department of Analytical and Bioinorganic Chemistry, Division of Analytical and Physical Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan
| | - Hiroyuki Yasui
- Department of Analytical and Bioinorganic Chemistry, Division of Analytical and Physical Chemistry, Kyoto Pharmaceutical University, 5 Nakauchi-cho, Misasagi, Yamashina-ku, Kyoto 607-8414, Japan
| | - Hiroki Kakuta
- Division of
Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530,
Japan
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Kruse MS, Rey M, Vega MC, Coirini H. Alterations of LXRα and LXRβ expression in the hypothalamus of glucose-intolerant rats. J Endocrinol 2012; 215:51-8. [PMID: 22836489 DOI: 10.1530/joe-12-0088] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Liver X receptor (LXR) α and β are nuclear receptors that are crucial for the regulation of carbohydrate and lipid metabolism. Activation of LXRs in the brain facilitates cholesterol clearance and improves cognitive deficits, thus they are considered as promising drug targets to treat diseases such as atherosclerosis and Alzheimer's disease. Nevertheless, little is known about the function and localization of LXRs in the brain. Here, we studied the expression of LXR in the brains of rats that received free access to 10% (w/v) fructose group (FG) in their beverages or water control drinks (control group (CG)). After 6 weeks rats in the FG presented with hypertriglyceridemia, hyperinsulinemia, and became glucose intolerant, suggesting a progression toward type 2 diabetes. We found that hypothalamic LXR expression was altered in fructose-fed rats. Rats in the FG presented with a decrease in LXRβ levels while showing an increase in LXRα expression in the hypothalamus but not in the hippocampus, cerebellum, or neocortex. Moreover, both LXRα and β expression correlated negatively with insulin and triglyceride levels. Interestingly, LXRβ showed a negative correlation with the area under the curve during the glucose tolerance test in the CG and a positive correlation in the FG. Immunocytochemistry revealed that the paraventricular and ventromedial nuclei express mainly LXRα whereas the arcuate nucleus expresses LXRβ. Both LXR immunosignals were found in the median preoptic area. This is the first study showing a relationship between glucose and lipid homeostasis and the expression of LXRs in the hypothalamus, suggesting that LXRs may trigger neurochemical and neurophysiological responses for the control of food intake and energy expenditure through these receptors.
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Affiliation(s)
- María Sol Kruse
- Laboratorio de Neurobiología, Instituto de Biología y Medicina Experimental, Vuelta de Obligado 2490, Ciudad Autónoma de Buenos Aires, Buenos Aires, Argentina
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Zema MJ. Colesevelam hydrochloride: evidence for its use in the treatment of hypercholesterolemia and type 2 diabetes mellitus with insights into mechanism of action. CORE EVIDENCE 2012; 7:61-75. [PMID: 22936894 PMCID: PMC3426253 DOI: 10.2147/ce.s26725] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Colesevelam hydrochloride is a molecularly engineered, second-generation bile acid sequestrant demonstrating enhanced specificity for bile acids which has been approved for use as adjunctive therapy to diet and exercise as monotherapy or in combination with a β-hydroxymethylglutaryl-coenzyme A reductase inhibitor for the reduction of elevated low-density lipoprotein cholesterol in patients with primary hypercholesterolemia. It is also the only lipid-lowering agent currently available in the United States which has been approved for use as adjunctive therapy in patients with type 2 diabetes mellitus whose glycemia remains inadequately controlled on therapy with metformin, sulfonylurea, or insulin. With the recent emphasis upon drug safety by the Food and Drug Administration and various consumer agencies, it is fitting that the role of nonsystemic lipid-lowering therapies such as bile acid sequestrants – with nearly 90 years of in-class, clinically safe experience – should be reexamined. This paper presents information on the major pharmacologic effects of colesevelam, including a discussion of recent data derived from both in vitro and in vivo rodent and human studies, which shed light on the putative mechanisms involved.
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36
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Biological Roles of Liver X Receptors in Immune Cells. Arch Immunol Ther Exp (Warsz) 2012; 60:235-49. [DOI: 10.1007/s00005-012-0179-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Accepted: 03/16/2012] [Indexed: 12/17/2022]
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Moore DD. Nuclear receptors reverse McGarry's vicious cycle to insulin resistance. Cell Metab 2012; 15:615-22. [PMID: 22560214 PMCID: PMC3613429 DOI: 10.1016/j.cmet.2012.03.016] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 12/16/2011] [Accepted: 03/08/2012] [Indexed: 12/22/2022]
Abstract
Several pathways and pathologies have been suggested as connections between obesity and diabetes, including inflammation of adipose and other tissues, toxic lipids, endoplasmic reticulum stress, and fatty liver. One specific proposal is that insulin resistance induces a vicious cycle in which hyperinsulinemia increases hepatic lipogenesis and exacerbates fatty liver, in turn further increasing insulin resistance. Here I suggest that reversing this cycle via suppression of the lipogenic transcription factor SREBP-1c is a common thread that connects the antidiabetic effects of a surprising number of nuclear hormone receptors, including CAR, LRH-1, TRβ, ERα, and FXR/SHP.
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Affiliation(s)
- David D Moore
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
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38
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Transcriptional integration of metabolism by the nuclear sterol-activated receptors LXR and FXR. Nat Rev Mol Cell Biol 2012; 13:213-24. [PMID: 22414897 DOI: 10.1038/nrm3312] [Citation(s) in RCA: 554] [Impact Index Per Article: 46.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Nuclear receptors are integrators of hormonal and nutritional signals, mediating changes to metabolic pathways within the body. Given that modulation of lipid and glucose metabolism has been linked to diseases including type 2 diabetes, obesity and atherosclerosis, a greater understanding of pathways that regulate metabolism in physiology and disease is crucial. The liver X receptors (LXRs) and the farnesoid X receptors (FXRs) are activated by oxysterols and bile acids, respectively. Mounting evidence indicates that these nuclear receptors have essential roles, not only in the regulation of cholesterol and bile acid metabolism but also in the integration of sterol, fatty acid and glucose metabolism.
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Abstract
Liver X receptors (LXRs) are members of the nuclear receptor family and are present in two isoforms, α and β, encoded by two separate genes. Originally described in the liver, LXRs have in the last 15 years been implicated in central metabolic pathways, including bile acid synthesis, lipid and glucose homeostasis. Although the vast majority of studies have been performed in non-adipose cells/tissues, results in recent years suggest that LXRs may have important modulatory roles in adipose tissue and adipocytes. Although several authors have published reviews on LXR, there have been no attempts to summarize the effects reported specifically in adipose systems. This overview gives a brief introduction to LXR and describes the sometimes-contradictory results obtained in murine cell systems and in rodent adipose tissue. The so far very limited number of studies performed in human adipocytes and adipose tissue are also presented. It should be apparent that although LXR may impact on several different pathways in metabolism, the clinical role of LXR modulation in adipose tissue is still not clear.
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Méndez-González J, Julve J, Rotllan N, Llaverias G, Blanco-Vaca F, Escolà-Gil JC. ATP-binding cassette G5/G8 deficiency causes hypertriglyceridemia by affecting multiple metabolic pathways. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1811:1186-93. [DOI: 10.1016/j.bbalip.2011.07.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 07/23/2011] [Accepted: 07/27/2011] [Indexed: 10/17/2022]
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Luoma PV. Gene-activation mechanisms in the regression of atherosclerosis, elimination of diabetes type 2, and prevention of dementia. Curr Mol Med 2011; 11:391-400. [PMID: 21568932 PMCID: PMC3282906 DOI: 10.2174/156652411795976556] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Revised: 04/04/2011] [Accepted: 04/22/2011] [Indexed: 12/21/2022]
Abstract
Atherosclerotic vascular disease, diabetes mellitus (DM) and dementia are major global health problems. Both endogenous and exogenous factors activate genes functioning in biological processes. This review article focuses on gene-activation mechanisms that regress atherosclerosis, eliminate DM type 2 (DM2), and prevent cognitive decline and dementia. Gene-activating compounds upregulating functions of liver endoplasmic reticulum (ER) and affecting lipid and protein metabolism, increase ER size through membrane synthesis, and produce an antiatherogenic plasma lipoprotein profile. Numerous gene-activators regress atherosclerosis and reduce the occurrence of atherosclerotic disease. The gene-activators increase glucose disposal rate and insulin sensitivity and, by restoring normal glucose and insulin levels, remove metabolic syndrome and DM2. Patients with DM2 show an improvement of plasma lipoprotein profile and glucose tolerance together with increase in liver phospholipid (PL) and cytochrome (CYP) P450. The gene-activating compounds induce hepatic protein and PL synthesis, and upregulate enzymes including CYPs and glucokinase, nuclear receptors, apolipoproteins and ABC (ATP-binding cassette) transporters. They induce reparation of ER structures and eliminate consequences of ER stress. Healthy living habits activate mechanisms that maintain high levels of HDL and apolipoprotein AI, promote health, and prevent cognitive decline and dementia. Agonists of liver X receptor (LXR) reduce amyloid in brain plaques and improve cognitive performance in mouse models of Alzheimer's disease. The gene activation increases the capacity to withstand cellular stress and to repair cellular damage and increases life span. Life free of major health problems and in good cognitive health promotes well-being and living a long and active life.
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Affiliation(s)
- P V Luoma
- Institute of Biomedicine, Pharmacology, University of Helsinki, Finland.
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A-González N, Castrillo A. Liver X receptors as regulators of macrophage inflammatory and metabolic pathways. Biochim Biophys Acta Mol Basis Dis 2010; 1812:982-94. [PMID: 21193033 DOI: 10.1016/j.bbadis.2010.12.015] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 12/14/2010] [Accepted: 12/17/2010] [Indexed: 12/30/2022]
Abstract
The liver X receptors (LXRα and LXRβ) are members of the nuclear receptor family of transcription factors that play essential roles in the transcriptional control of lipid metabolism. LXRs are endogenously activated by modified forms of cholesterol known as oxysterols and control the expression of genes important for cholesterol uptake, efflux, transport, and excretion in multiple tissues. In addition to their role as cholesterol sensors, a number of studies have implicated LXRs in the modulation of innate and adaptive immune responses. Both through activation and repression mechanisms, LXRs regulate diverse aspects of inflammatory gene expression in macrophages. The ability of LXRs to coordinate metabolic and immune responses constitutes an attractive therapeutic target for the treatment of chronic inflammatory disorders. This article is part of a Special Issue entitled: Translating nuclear receptors from health to disease.
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Affiliation(s)
- Noelia A-González
- Department of Biochemistry and Molecular Biology, Universidad de Las Palmas de Gran Canaria, ULPGC, Las Palmas, Spain
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Ohsawa F, Morishita KI, Yamada S, Makishima M, Kakuta H. Modification at the Lipophilic Domain of RXR Agonists Differentially Influences Activation of RXR Heterodimers. ACS Med Chem Lett 2010; 1:521-5. [PMID: 24900241 DOI: 10.1021/ml100184k] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2010] [Accepted: 08/24/2010] [Indexed: 02/02/2023] Open
Abstract
RXR permissive heterodimers are reported to be activated differently depending upon the chemical structure of RXR agonists, but the relationship of agonist structure to differential heterodimer activation has not been explored in detail. In this study, we performed systematic conversion of the alkoxy side chain of 5a (6-[ethyl-(3-isopropoxy-4-isopropylphenyl)amino]nicotinic acid, NEt-3IP) and evaluated the RXR-, PPAR/RXR-, and LXR/RXR-agonist activities of the products. The cyclopropylmethoxy analogue (5c) showed similar RXR- and LXR/RXR-agonistic activities to the benzyloxy analogue (5i) and n-propoxy analogue (5k) but exhibited more potent PPAR/RXR-agonistic activity than 5i or 5k. Differential modulation of RXR heterodimer-activating ability by conversion of the alkoxy group located in the lipophilic domain of the RXR-agonist common structure is expected be a useful approach in the design of new RXR agonists for the treatment of hyperlipidemia or type 2 diabetes.
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Affiliation(s)
- Fuminori Ohsawa
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530, Japan
- Multiple Molecular Imaging Research Laboratory, RIKEN Center for Molecular Imaging Science, Minatojima-minamimachi 6-7-3, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Ken-ichi Morishita
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530, Japan
| | - Shoya Yamada
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530, Japan
| | - Makoto Makishima
- Division of Biochemistry, Nihon University School of Medicine, Itabashi-Ku, Tokyo 173-8610, Japan
| | - Hiroki Kakuta
- Division of Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 1-1-1, Tsushima-Naka, Kita-Ku, Okayama 700-8530, Japan
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Schulman IG. Nuclear receptors as drug targets for metabolic disease. Adv Drug Deliv Rev 2010; 62:1307-15. [PMID: 20655343 DOI: 10.1016/j.addr.2010.07.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2010] [Revised: 07/06/2010] [Accepted: 07/14/2010] [Indexed: 01/02/2023]
Abstract
Nuclear hormone receptors comprise a superfamily of ligand-activated transcription factors that control development, differentiation, and homeostasis. Over the last 15 years a growing number of nuclear receptors have been identified that coordinate genetic networks regulating lipid metabolism and energy utilization. Several of these receptors directly sample the levels of metabolic intermediates including fatty acids and cholesterol derivatives and use this information to regulate the synthesis, transport, and breakdown of the metabolite of interest. In contrast, other family members sense metabolic activity via the presence or absence of interacting proteins. The ability of these nuclear receptors to impact metabolism will be discussed and the challenges facing drug discovery efforts for this class of targets will be highlighted.
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Stenson BM, Rydén M, Venteclef N, Dahlman I, Pettersson AML, Mairal A, Aström G, Blomqvist L, Wang V, Jocken JWE, Clément K, Langin D, Arner P, Laurencikiene J. Liver X receptor (LXR) regulates human adipocyte lipolysis. J Biol Chem 2010; 286:370-9. [PMID: 21030586 DOI: 10.1074/jbc.m110.179499] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The Liver X receptor (LXR) is an important regulator of carbohydrate and lipid metabolism in humans and mice. We have recently shown that activation of LXR regulates cellular fuel utilization in adipocytes. In contrast, the role of LXR in human adipocyte lipolysis, the major function of human white fat cells, is not clear. In the present study, we stimulated in vitro differentiated human and murine adipocytes with the LXR agonist GW3965 and observed an increase in basal lipolysis. Microarray analysis of human adipocyte mRNA following LXR activation revealed an altered gene expression of several lipolysis-regulating proteins, which was also confirmed by quantitative real-time PCR. We show that expression and intracellular localization of perilipin1 (PLIN1) and hormone-sensitive lipase (HSL) are affected by GW3965. Although LXR activation does not influence phosphorylation status of HSL, HSL activity is required for the lipolytic effect of GW3965. This effect is abolished by PLIN1 knockdown. In addition, we demonstrate that upon activation, LXR binds to the proximal regions of the PLIN1 and HSL promoters. By selective knock-down of either LXR isoform, we show that LXRα is the major isoform mediating the lipolysis-related effects of LXR. In conclusion, the present study demonstrates that activation of LXRα up-regulates basal human adipocyte lipolysis. This is at least partially mediated through LXR binding to the PLIN1 promoter and down-regulation of PLIN1 expression.
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Affiliation(s)
- Britta M Stenson
- Department of Medicine, Karolinska Institutet, Huddinge, S-14186, Sweden
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Dave VP, Kaul D. Coronary heart disease: Significance of liver X receptor α genomics. World J Cardiol 2010; 2:140-9. [PMID: 21160732 PMCID: PMC2999051 DOI: 10.4330/wjc.v2.i6.140] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 06/11/2010] [Accepted: 06/18/2010] [Indexed: 02/06/2023] Open
Abstract
Crosstalk between lipid peroxidation and inflammation is known to be a pathognomonic feature for the development of coronary heart disease (CHD). In this regard ligand activated liver X receptor (LXR)-α has emerged as a key molecular switch by its inherent ability to modulate an array of genes involved in these two fundamental cellular processes. In addition, LXR-α has also been found to play a role in hepatic lipogenesis and innate immunity. Although several lines of evidence in experimental model systems have established the atheroprotective nature of LXR-α, human subjects have been reported to possess a paradoxical situation in which increased blood cellular LXR-α gene expression is always accompanied by increased coronary occlusion. This apparent paradox was resolved recently by the finding that CHD patients possess a deregulated LXR-α transcriptome due to impaired ligand-receptor interaction. This blood cellular mutated LXR-α gene expression correlated specifically with the extent of coronary occlusion and hence need is felt to devise new synthetic ligands that could restore the function of this mutated LXR-α protein in order to modulate genes involved in reverse cholesterol transport and suppression of the inflammatory response leading to the effective treatment of CHD.
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Affiliation(s)
- Vivek Priy Dave
- Vivek Priy Dave, Deepak Kaul, Department of Experimental Medicine and Biotechnology, Post Graduate Institute of Medical Education and Research, Chandigarh 160012, India
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Oosterveer MH, Grefhorst A, Groen AK, Kuipers F. The liver X receptor: control of cellular lipid homeostasis and beyond Implications for drug design. Prog Lipid Res 2010; 49:343-52. [PMID: 20363253 DOI: 10.1016/j.plipres.2010.03.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2010] [Revised: 02/22/2010] [Accepted: 03/19/2010] [Indexed: 11/30/2022]
Abstract
Liver X receptor (LXR) α and β are nuclear receptors that control cellular metabolism. LXRs modulate the expression of genes involved in cholesterol and lipid metabolism in response to changes in cellular cholesterol status. Because of their involvement in cholesterol homeostasis, LXRs have emerged as promising drug targets for anti-atherosclerotic therapies. In rodents, synthetic LXR agonists promote cellular cholesterol efflux, transport and excretion. As a result, the progression of atherosclerosis is halted. However, pharmacological LXR activation also induces hepatic steatosis and promotes the secretion of atherogenic triacylglycerol-rich VLDL particles by the liver, complicating the clinical application of LXR agonists. The more recently emerged roles of LXRs in fat tissue, pituitary and brain may have implications for treatment of obesity and Alzheimer disease. In addition to the improvements in atherosclerosis, LXR activation exerts beneficial effects on glucose control in mouse models of type 2 diabetes. Future therapeutic strategies aiming to exert beneficial effects on cholesterol and glucose homeostasis, while circumventing the undesired effects on hepatic lipid metabolism, should target specific LXR-mediated processes. Therefore, tissue and/or isotype-specific effects of LXR action need to be established. The consequences of combinatorial drug approaches and the identification of the co-regulatory networks involved in the LXR-mediated control of particular genes may contribute to development of novel LXR agonists. Finally, pathway analyses of LXR actions provide tools to evaluate and optimize the effectiveness of novel therapeutic strategies to prevent and/or treat metabolic diseases.
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Affiliation(s)
- Maaike H Oosterveer
- Department of Pediatrics, Center for Liver Digestive and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
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Ogihara T, Chuang JC, Vestermark GL, Garmey JC, Ketchum RJ, Huang X, Brayman KL, Thorner MO, Repa JJ, Mirmira RG, Evans-Molina C. Liver X receptor agonists augment human islet function through activation of anaplerotic pathways and glycerolipid/free fatty acid cycling. J Biol Chem 2010; 285:5392-404. [PMID: 20007976 PMCID: PMC2820768 DOI: 10.1074/jbc.m109.064659] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Recent studies in rodent models suggest that liver X receptors (LXRs) may play an important role in the maintenance of glucose homeostasis and islet function. To date, however, no studies have comprehensively examined the role of LXRs in human islet biology. Human islets were isolated from non-diabetic donors and incubated in the presence or absence of two synthetic LXR agonists, TO-901317 and GW3965, under conditions of low and high glucose. LXR agonist treatment enhanced both basal and stimulated insulin secretion, which corresponded to an increase in the expression of genes involved in anaplerosis and reverse cholesterol transport. Furthermore, enzyme activity of pyruvate carboxylase, a key regulator of pyruvate cycling and anaplerotic flux, was also increased. Whereas LXR agonist treatment up-regulated known downstream targets involved in lipogenesis, we observed no increase in the accumulation of intra-islet triglyceride at the dose of agonist used in our study. Moreover, LXR activation increased expression of the genes encoding hormone-sensitive lipase and adipose triglyceride lipase, two enzymes involved in lipolysis and glycerolipid/free fatty acid cycling. Chronically, insulin gene expression was increased after treatment with TO-901317, and this was accompanied by increased Pdx-1 nuclear protein levels and enhanced Pdx-1 binding to the insulin promoter. In conclusion, our data suggest that LXR agonists have a direct effect on the islet to augment insulin secretion and expression, actions that should be considered either as therapeutic or unintended side effects, as these agents are developed for clinical use.
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Affiliation(s)
- Takeshi Ogihara
- From the Herman B Wells Center for Pediatric Research and
- the Departments of Pediatrics and
| | | | | | | | - Robert J. Ketchum
- the Department of Structural Medicine, Rocky Vista University, Parker, Colorado 80134
| | - Xiaolun Huang
- Surgery, University of Virginia, Charlottesville, Virginia 22904, and
| | | | | | - Joyce J. Repa
- the Departments of Physiology and
- Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Raghavendra G. Mirmira
- From the Herman B Wells Center for Pediatric Research and
- the Departments of Pediatrics and
- Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202
| | - Carmella Evans-Molina
- From the Herman B Wells Center for Pediatric Research and
- Medicine, Indiana University School of Medicine, Indianapolis, Indiana 46202
- To whom correspondence should be addressed: Indiana University School of Medicine, 635 Barnhill Dr., MS 2031A, Indianapolis, IN 46202. Tel.: 317-274-4145; Fax: 317-274-4107; E-mail:
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LXRbeta deficient mice have reduced hepatic insulin clearance during hyperinsulinemic euglucemic clamp. Biochem Biophys Res Commun 2010; 392:436-41. [PMID: 20079709 DOI: 10.1016/j.bbrc.2010.01.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Accepted: 01/12/2010] [Indexed: 11/21/2022]
Abstract
The present study addresses the insulin sensitivity in mice deficient in LXRbeta (LXRbeta(-/-)) as well as in wild type (wt) mice assessed by hyperinsulinemic euglycemic clamp. Wt and LXRbeta(-/-) mice were fed either a normal chow diet or a high fat and high cholesterol diet (HFCD), and insulin sensitivity was assessed by hyperinsulinemic euglycemic clamps. We show that LXRbeta(-/-) mice have reduced insulin clearance during hyperinsulinemic clamps upon feeding both HFCD and a regular chow diet. Moreover we also observed reduced hepatic inflammation in LXRbeta(-/-) mice compared to wt mice upon feeding an HFCD, despite equal levels of hepatic steatosis. In summary, our results indicate that LXRbeta(-/-) mice have reduced insulin clearance during hyperinsulinemic euglycemic clamps and also reduced hepatic inflammation upon feeding an HFCD for 26weeks.
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Korach-André M, Parini P, Larsson L, Arner A, Steffensen KR, Gustafsson JA. Separate and overlapping metabolic functions of LXRalpha and LXRbeta in C57Bl/6 female mice. Am J Physiol Endocrinol Metab 2010; 298:E167-78. [PMID: 19690071 DOI: 10.1152/ajpendo.00184.2009] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The two liver X receptors (LXRs), LXRalpha and LXRbeta, are transcriptional regulators of cholesterol, lipid, and glucose metabolism and are both activated by oxysterols. Impaired metabolism is linked with obesity, insulin resistance, and type 2-diabetes (T2D). In the present study, we aimed to delineate the specific roles of LXRalpha and -beta in metabolic processes. C57Bl/6 female mice were fed a normal or a high-fat diet (HFD) and metabolic responses in wild-type, LXRalpha(-/-), LXRbeta(-/-), and LXRalphabeta(-/-) mice were analyzed. Whole body fat and intramyocellular lipid contents were measured by nuclear magnetic resonance. Energy expenditure was measured in individual metabolic cages. Glucose, insulin, and pyruvate tolerance tests were performed and gene expression profiles analyzed by qPCR. We found that both LXRbeta(-/-) and LXRalphabeta(-/-) mice are resistant to HFD-induced obesity independently of the presence of high cholesterol. Using tolerance tests, we found that, on an HFD, LXRbeta(-/-) mice enhanced their endogenous glucose production and became highly insulin resistant, whereas LXRalpha(-/-) and LXRalphabeta(-/-) mice remained glucose tolerant and insulin sensitive. Gene expression profiling confirmed that LXRbeta is the regulator of lipogenic genes in visceral white adipose tissue (WAT) and muscle tissue and, surprisingly, that Ucp1 and Dio2 are not responsible for the protection against diet-induced obesity observed in LXRbeta(-/-) and LXRalphabeta(-/-) mice. LXRalpha is required for the control of cholesterol metabolism in the liver, while LXRbeta appears to be a major regulator of glucose homeostasis and energy utilization and of fat storage in muscle and WAT. We conclude that selective LXRbeta agonists would be novel pharmaceuticals in the treatment of T2D.
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Affiliation(s)
- Marion Korach-André
- Dept. of Biosciences and Nutrition, Karolinska Institutet, S-141 57 Huddinge, Sweden.
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