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Xiong X, Wen YA, Fairchild R, Zaytseva YY, Weiss HL, Evers BM, Gao T. Upregulation of CPT1A is essential for the tumor-promoting effect of adipocytes in colon cancer. Cell Death Dis 2020; 11:736. [PMID: 32913185 PMCID: PMC7484798 DOI: 10.1038/s41419-020-02936-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 08/21/2020] [Accepted: 08/27/2020] [Indexed: 01/28/2023]
Abstract
Colon tumors grow in an adipose tissue-enriched microenvironment. Locally advanced colon cancers often invade into surrounding adipose tissue with a direct contact with adipocytes. We have previously shown that adipocytes promote tumor growth by modulating cellular metabolism. Here we demonstrate that carnitine palmitoyltransferase I (CPT1A), a key enzyme controlling fatty acid oxidation (FAO), was upregulated in colon cancer cells upon exposure to adipocytes or fatty acids. In addition, CPT1A expression was increased in invasive tumor cells within the adipose tissue compared to tumors without direct contact with adipocytes. Silencing CPT1A abolished the protective effect provided by fatty acids against nutrient deprivation and reduced tumor organoid formation in 3D culture and the expression of genes associated with cancer stem cells downstream of Wnt/β-catenin. Mechanistically, CPT1A-dependent FAO promoted the acetylation and nuclear translocation of β-catenin. Furthermore, knockdown of CPT1A blocked the tumor-promoting effect of adipocytes in vivo and inhibited xenograft tumor initiation. Taken together, our findings identify CPT1A-depedent FAO as an essential metabolic pathway that enables the interaction between adipocytes and colon cancer cells.
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Affiliation(s)
- Xiaopeng Xiong
- Markey Cancer Center, University of Kentucky, Lexington, KY, 40536-0679, USA
| | - Yang-An Wen
- Markey Cancer Center, University of Kentucky, Lexington, KY, 40536-0679, USA
| | - Rachelle Fairchild
- Markey Cancer Center, University of Kentucky, Lexington, KY, 40536-0679, USA
| | - Yekaterina Y Zaytseva
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, KY, 40536-0679, USA
| | - Heidi L Weiss
- Markey Cancer Center, University of Kentucky, Lexington, KY, 40536-0679, USA
| | - B Mark Evers
- Markey Cancer Center, University of Kentucky, Lexington, KY, 40536-0679, USA
- Department of Surgery, University of Kentucky, Lexington, KY, 40536-0679, USA
| | - Tianyan Gao
- Markey Cancer Center, University of Kentucky, Lexington, KY, 40536-0679, USA.
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, 40536-0679, USA.
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Altinoz MA, Elmaci İ, Hacimuftuoglu A, Ozpinar A, Hacker E, Ozpinar A. PPARδ and its ligand erucic acid may act anti-tumoral, neuroprotective, and myelin protective in neuroblastoma, glioblastoma, and Parkinson's disease. Mol Aspects Med 2020; 78:100871. [PMID: 32703610 DOI: 10.1016/j.mam.2020.100871] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/09/2020] [Accepted: 06/11/2020] [Indexed: 10/23/2022]
Abstract
In this review study, we focus on potential benefits of the transcription factor PPARδ and its ligand erucic acid (EA) in management of neuroectodermal tumors and Parkinson's Disease. PPARδ is a nuclear receptor and transcription factor that induces myelination, promotes oligodendroglial and neuronal differentiation, and possess anti-neuroinflammatory properties. While both pro-tumorigenic and anti-tumorigenic effects have been described for PPARδ, we propose that PPARδ may perform a predominantly anticancer role in tumors originating from the neuroectoderm. PPARδ ligand-activation via oleic acid and GW501516, or overexpression of PPARδ, elicits profound antitumor actions in neuroblastoma and melanoma. In glioblastomas, there is evidence indicating a differentiation failure of O2A (oligodendroglial-astrocytic biprogenitor) cells and it has been shown that EA reduced DNA synthesis in C6 rat glioblastoma spheroid cultures in clinically achievable concentrations. EA is a ω9 fatty acid which is being used in the treatment of adrenoleukodystrophy. EA is widely consumed in Asian countries via ingestion of cruciferous vegetables including mustard and rapeseed oil. EA also exerts antioxidant and anti-inflammatory activities. Recent studies of Parkinson's Disease (PD) have implicated demyelination, white matter pathology, oligodendroglial injury, and neural inflammation in the underlying pathophysiology. In the rotenone PD model in rats, PPARδ ligand GW501516 saves dopaminergic neurons during injury induced by chemical toxins and improves behavioral functioning in PD via alleviation of endoplasmic reticulum stress. PPARδ agonists also reduce the NLRP3 inflammasome-associated neural inflammation in the MPTP PD model in mice. Herein, we propose that PPARδ and its ligand EA highly deserve to be studied in animal models of neuroblastoma, glioblastoma, and PD.
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Affiliation(s)
- Meric A Altinoz
- Department of Biochemistry, Acibadem University, Istanbul, Turkey.
| | - İlhan Elmaci
- Department of Neurosurgery, Acibadem Hospital, Maslak, Istanbul, Turkey
| | | | - Alp Ozpinar
- Department of Neurosurgery, Pittsburgh University, United States
| | - Emily Hacker
- Department of Neurosurgery, Pittsburgh University, United States
| | - Aysel Ozpinar
- Department of Biochemistry, Acibadem University, Istanbul, Turkey
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Altinoz MA, Ozpinar A. PPAR-δ and erucic acid in multiple sclerosis and Alzheimer's Disease. Likely benefits in terms of immunity and metabolism. Int Immunopharmacol 2019; 69:245-256. [DOI: 10.1016/j.intimp.2019.01.057] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 01/09/2019] [Accepted: 01/31/2019] [Indexed: 12/17/2022]
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Cheon SY, Chung KS, Lee KJ, Choi HY, Ham IH, Jung DH, Cha YY, An HJ. HVC1 ameliorates hyperlipidemia and inflammation in LDLR -/- mice. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 17:222. [PMID: 28427397 PMCID: PMC5397752 DOI: 10.1186/s12906-017-1734-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 04/08/2017] [Indexed: 12/29/2022]
Abstract
Background HVC1 consists of Coptidis Rhizoma (dried rhizome of Coptischinensis), Scutellariae Radix (root of Scutellariabaicalensis), Rhei Rhizoma (rhizome of Rheum officinale), and Pruni Cortex (cortex of Prunusyedoensis Matsum). Although the components are known to be effective in various conditions such as inflammation, hypertension, and hypercholesterolemia, there are no reports of the molecular mechanism of its hypolipidemic effects. Methods We investigated the hypolipidemic effect of HVC1 in low-density lipoprotein receptor-deficient (LDLR−/−) mice fed a high-cholesterol diet for 13 weeks. Mice were randomized in to 6 groups: ND (normal diet) group, HCD (high-cholesterol diet) group, and treatment groups fed HCD and treated with simvastatin (10 mg/kg, p.o.) or HVC1 (10, 50, or 250 mg/kg, p.o.). Results HVC1 regulated the levels of total cholesterol, triglyceride (TG), low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol in mouse serum. In addition, it regulated the transcription level of the peroxisome proliferator-activated receptors (PPARs), sterol regulatory element-binding proteins (SREBP)-2, 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase, lipoprotein lipase (LPL), apolipoprotein B (apo B), liver X receptor (LXR), and inflammatory cytokines (IL-1β, IL-6, and TNF-α). Furthermore, HVC1 activated 5′ adenosine monophosphate-activated protein kinase (AMPK). Conclusion Our results suggest that HVC1 might be effective in preventing high-cholesterol diet-induced hyperlipidemia by regulating the genes involved in cholesterol and lipid metabolism, and inflammatory responses.
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Fat Quality Influences the Obesogenic Effect of High Fat Diets. Nutrients 2015; 7:9475-91. [PMID: 26580650 PMCID: PMC4663608 DOI: 10.3390/nu7115480] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 11/02/2015] [Accepted: 11/06/2015] [Indexed: 12/22/2022] Open
Abstract
High fat and/or carbohydrate intake are associated with an elevated risk for obesity and chronic diseases such as diabetes and cardiovascular diseases. The harmful effects of a high fat diet could be different, depending on dietary fat quality. In fact, high fat diets rich in unsaturated fatty acids are considered less deleterious for human health than those rich in saturated fat. In our previous studies, we have shown that rats fed a high fat diet developed obesity and exhibited a decrease in oxidative capacity and an increase in oxidative stress in liver mitochondria. To investigate whether polyunsaturated fats could attenuate the above deleterious effects of high fat diets, energy balance and body composition were assessed after two weeks in rats fed isocaloric amounts of a high-fat diet (58.2% by energy) rich either in lard or safflower/linseed oil. Hepatic functionality, plasma parameters, and oxidative status were also measured. The results show that feeding on safflower/linseed oil diet attenuates the obesogenic effect of high fat diets and ameliorates the blood lipid profile. Conversely, hepatic steatosis and mitochondrial oxidative stress appear to be negatively affected by a diet rich in unsaturated fatty acids.
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Association between paraoxonases gene expression and oxidative stress in hepatotoxicity induced by CCl4. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2014; 2014:893212. [PMID: 25478064 PMCID: PMC4248367 DOI: 10.1155/2014/893212] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Revised: 08/22/2014] [Accepted: 08/22/2014] [Indexed: 12/29/2022]
Abstract
Objectives. The purpose of the study is to evaluate the hepatoprotective effect of rutin in carbon tetrachloride- (CCl4-) induced liver injuries in rat model. Methods. Forty male Wistar albino rats were divided into four groups. Group I was the control group and received dimethyl sulphoxide (DMSO) and olive oil. Group II received rutin. Groups III was treated with CCl4. Group IV was administered rutin after 48 h of CCl4 treatment. Liver enzymes level, lipid profile, lipid peroxidation, and hydrogen peroxide were measured. The genes expression levels were monitored by real time RT-PCR and western blot techniques. Results. CCl4 group showed significant increase in alanine aminotransferase (ALT), aspartate aminotransferase (AST), thiobarbituric acid reactive substances (TBAR), hydrogen peroxide (H2O2), and lipid profile and a significant decrease in glutathione peroxidase (GPx), glutathione S transferase (GST), catalase (CAT), paraoxonase-1 (PON-1), paraoxonase-3 (PON-3), peroxisome proliferator activated receptor delta (PPAR-δ), and ATP-binding cassette transporter 1 (ABAC1) genes expression levels. Interestingly, rutin supplementation completely reversed the biochemical and gene expression levels induced by CCl4 to control values. Conclusion. CCl4 administration causes aberration of genes expression levels in oxidative stress pathway resulting in DNA damage and hepatotoxicity. Rutin causes hepatoprotective effect through enhancing the antioxidant genes.
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Abstract
Oxidative stress and inflammation underpin most diseases; their mechanisms are inextricably linked. Chronic inflammation is associated with oxidation, anti-inflammatory cascades are linked to decreased oxidation, increased oxidative stress triggers inflammation, and redox balance inhibits the inflammatory cellular response. Whether or not oxidative stress and inflammation represent the cause or consequence of cellular pathology, they contribute significantly to the pathogenesis of noncommunicable diseases (NCD). The incidence of obesity and other related metabolic disturbances are increasing, as are age-related diseases due to a progressively aging population. Relationships between oxidative stress, inflammatory signaling, and metabolism are, in the broad sense of energy transformation, being increasingly recognized as part of the problem in NCD. In this chapter, we summarize the pathologic consequences of an imbalance between circulating and cellular paraoxonases, the system for scavenging excessive reactive oxygen species and circulating chemokines. They act as inducers of migration and infiltration of immune cells in target tissues as well as in the pathogenesis of disease that perturbs normal metabolic function. This disruption involves pathways controlling lipid and glucose homeostasis as well as metabolically driven chronic inflammatory states that encompass several response pathways. Dysfunction in the endoplasmic reticulum and/or mitochondria represents an important feature of chronic disease linked to oxidation and inflammation seen as self-reinforcing in NCD. Therefore, correct management requires a thorough understanding of these relationships and precise interpretation of laboratory test results.
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Feng YZ, Nikolić N, Bakke SS, Boekschoten MV, Kersten S, Kase ET, Rustan AC, Thoresen GH. PPARδ activation in human myotubes increases mitochondrial fatty acid oxidative capacity and reduces glucose utilization by a switch in substrate preference. Arch Physiol Biochem 2014; 120:12-21. [PMID: 23991827 DOI: 10.3109/13813455.2013.829105] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The role of peroxisome proliferator-activated receptor δ (PPARδ) activation on global gene expression and mitochondrial fuel utilization were investigated in human myotubes. Only 21 genes were up-regulated and 3 genes were down-regulated after activation by the PPARδ agonist GW501516. Pathway analysis showed up-regulated mitochondrial fatty acid oxidation, TCA cycle and cholesterol biosynthesis. GW501516 increased oleic acid oxidation and mitochondrial oxidative capacity by 2-fold. Glucose uptake and oxidation were reduced, but total substrate oxidation was not affected, indicating a fuel switch from glucose to fatty acid. Cholesterol biosynthesis was increased, but lipid biosynthesis and mitochondrial content were not affected. This study confirmed that the principal effect of PPARδ activation was to increase mitochondrial fatty acid oxidative capacity. Our results further suggest that PPARδ activation reduced glucose utilization through a switch in mitochondrial substrate preference by up-regulating pyruvate dehydrogenase kinase isozyme 4 and genes involved in lipid metabolism and fatty acid oxidation.
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Affiliation(s)
- Yuan Z Feng
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo , Oslo , Norway
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Cohen G, Riahi Y, Sunda V, Deplano S, Chatgilialoglu C, Ferreri C, Kaiser N, Sasson S. Signaling properties of 4-hydroxyalkenals formed by lipid peroxidation in diabetes. Free Radic Biol Med 2013; 65:978-987. [PMID: 23973638 DOI: 10.1016/j.freeradbiomed.2013.08.163] [Citation(s) in RCA: 265] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 08/11/2013] [Accepted: 08/13/2013] [Indexed: 11/29/2022]
Abstract
Peroxidation of polyunsaturated fatty acids is intensified in cells subjected to oxidative stress and results in the generation of various bioactive compounds, of which 4-hydroxyalkenals are prominent. During the progression of type 2 diabetes mellitus, the ensuing hyperglycemia promotes the generation of reactive oxygen species (ROS) that contribute to the development of diabetic complications. It has been suggested that ROS-induced lipid peroxidation and the resulting 4-hydroxyalkenals markedly contribute to the development and progression of these pathologies. Recent findings, however, also suggest that noncytotoxic levels of 4-hydroxyalkenals play important signaling functions in the early phase of diabetes and act as hormetic factors to induce adaptive and protective responses in cells, enabling them to function in the hyperglycemic milieu. Our studies and others' have proposed such regulatory functions for 4-hydroxynonenal and 4-hydroxydodecadienal in insulin secreting β-cells and vascular endothelial cells, respectively. This review presents and discusses the mechanisms regulating the generation of 4-hydroxyalkenals under high glucose conditions and the molecular interactions underlying the reciprocal transition from hormetic to cytotoxic agents.
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Affiliation(s)
- Guy Cohen
- Department of Pharmacology, Institute for Drug Research, Faculty of Medicine, The Hebrew University, Jerusalem Israel
| | - Yael Riahi
- Department of Pharmacology, Institute for Drug Research, Faculty of Medicine, The Hebrew University, Jerusalem Israel
| | - Valentina Sunda
- Lipinutragen srl, Lipidomic Laboratory, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | - Simone Deplano
- Lipinutragen srl, Lipidomic Laboratory, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | | | - Carla Ferreri
- ISOF, Consiglio Nazionale delle Ricerche, Bologna, Italy
| | - Nurit Kaiser
- Endocrinology & Metabolism Service, The Hebrew University-Hadassah Faculty of Medicine, Jerusalem, Israel
| | - Shlomo Sasson
- Department of Pharmacology, Institute for Drug Research, Faculty of Medicine, The Hebrew University, Jerusalem Israel.
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Dongiovanni P, Valenti L. Peroxisome proliferator-activated receptor genetic polymorphisms and nonalcoholic Fatty liver disease: any role in disease susceptibility? PPAR Res 2013; 2013:452061. [PMID: 23431284 PMCID: PMC3575610 DOI: 10.1155/2013/452061] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 11/13/2012] [Accepted: 11/20/2012] [Indexed: 12/21/2022] Open
Abstract
Nonalcoholic fatty liver disease (NAFLD) defines a wide spectrum of liver diseases that extend from simple steatosis, that is, increased hepatic lipid content, to nonalcoholic steatohepatitis (NASH), a condition that may progress to cirrhosis with its associated complications. Nuclear hormone receptors act as intracellular lipid sensors that coordinate genetic networks regulating lipid metabolism and energy utilization. This family of transcription factors, in particular peroxisome proliferator-activated receptors (PPARs), represents attractive drug targets for the management of NAFLD and NASH, as well as related conditions such as type 2 diabetes and the metabolic syndrome. The impact on the regulation of lipid metabolism observed for PPARs has led to the hypothesis that genetic variants within the human PPARs genes may be associated with human disease such as NAFLD, the metabolic syndrome, and/or coronary heart disease. Here we review the available evidence on the association between PPARs genetic polymorphism and the susceptibility to NAFLD and NASH, and we provide a meta-analysis of the available evidence. The impact of PPAR variants on the susceptibility to NASH in specific subgroup of patients, and in particular on the response to therapies, especially those targeting PPARs, represents promising new areas of investigation.
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Affiliation(s)
- Paola Dongiovanni
- Section of Internal Medicine, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Pad. Granelli, Via F Sforza 35, 20122 Milano, Italy
| | - Luca Valenti
- Section of Internal Medicine, Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Pad. Granelli, Via F Sforza 35, 20122 Milano, Italy
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Olson EJ, Pearce GL, Jones NP, Sprecher DL. Lipid Effects of Peroxisome Proliferator-Activated Receptor-Δ Agonist GW501516 in Subjects With Low High-Density Lipoprotein Cholesterol. Arterioscler Thromb Vasc Biol 2012; 32:2289-94. [DOI: 10.1161/atvbaha.112.247890] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Eric J. Olson
- From the GlaxoSmithKline Discovery Medicine, Philadelphia, PA (E.J.O., G.L.P., D.L.S.); and GlaxoSmithKline, Cardiovascular and Metabolic Medicine Development Center, Stockley Park, UK (N.P.J.)
| | - Gregory L. Pearce
- From the GlaxoSmithKline Discovery Medicine, Philadelphia, PA (E.J.O., G.L.P., D.L.S.); and GlaxoSmithKline, Cardiovascular and Metabolic Medicine Development Center, Stockley Park, UK (N.P.J.)
| | - Nigel P. Jones
- From the GlaxoSmithKline Discovery Medicine, Philadelphia, PA (E.J.O., G.L.P., D.L.S.); and GlaxoSmithKline, Cardiovascular and Metabolic Medicine Development Center, Stockley Park, UK (N.P.J.)
| | - Dennis L. Sprecher
- From the GlaxoSmithKline Discovery Medicine, Philadelphia, PA (E.J.O., G.L.P., D.L.S.); and GlaxoSmithKline, Cardiovascular and Metabolic Medicine Development Center, Stockley Park, UK (N.P.J.)
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Leonarduzzi G, Gamba P, Gargiulo S, Biasi F, Poli G. Inflammation-related gene expression by lipid oxidation-derived products in the progression of atherosclerosis. Free Radic Biol Med 2012; 52:19-34. [PMID: 22037514 DOI: 10.1016/j.freeradbiomed.2011.09.031] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 09/16/2011] [Accepted: 09/24/2011] [Indexed: 12/31/2022]
Abstract
Vascular areas of atherosclerotic development persist in a state of inflammation, and any further inflammatory stimulus in the subintimal area elicits a proatherogenic response; this alters the behavior of the artery wall cells and recruits further inflammatory cells. In association with the inflammatory response, oxidative events are also involved in the development of atherosclerotic plaques. It is now unanimously recognized that lipid oxidation-derived products are key players in the initiation and progression of atherosclerotic lesions. Oxidized lipids, derived from oxidatively modified low-density lipoproteins (LDLs), which accumulate in the intima, strongly modulate inflammation-related gene expression, through involvement of various signaling pathways. In addition, considerable evidence supports a proatherogenic role of a large group of potent bioactive lipids called eicosanoids, which derive from oxidation of arachidonic acid, a component of membrane phospholipids. Of note, LDL lipid oxidation products might regulate eicosanoid production, modulating the enzymatic degradation of arachidonic acid by cyclooxygenases and lipoxygenases; these enzymes might also directly contribute to LDL oxidation. This review provides a comprehensive overview of current knowledge on signal transduction pathways and inflammatory gene expression, modulated by lipid oxidation-derived products, in the progression of atherosclerosis.
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Eicosapentaenoic and docosahexaenoic acids as inflammation-modulating and lipid homeostasis influencing nutraceuticals: A review. J Funct Foods 2012. [DOI: 10.1016/j.jff.2011.10.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
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Interrelationships between paraoxonase-1 and monocyte chemoattractant protein-1 in the regulation of hepatic inflammation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 660:5-18. [PMID: 20221866 DOI: 10.1007/978-1-60761-350-3_2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Oxidative stress and inflammation play a central role in the onset and development of liver diseases irrespective of the agent causing the hepatic impairment. The monocyte chemoattractant protein-1 is intimately involved in the inflammatory reaction and is directly correlated with the degree of hepatic inflammation in patients with chronic liver disease. Recent studies showed that hepatic paraoxonase-1 may counteract the production of the monocyte chemoattractant protein-1, thus playing an anti-inflammatory role. The current review summarises experiments suggesting how paraoxonase-1 activity and expression are altered in liver diseases, and their relationships with the monocyte chemoattractant protein-1 and inflammation.
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Peroxisome Proliferator-Activated Receptor Delta: A Conserved Director of Lipid Homeostasis through Regulation of the Oxidative Capacity of Muscle. PPAR Res 2011; 2008:172676. [PMID: 18815630 PMCID: PMC2547483 DOI: 10.1155/2008/172676] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 07/10/2008] [Accepted: 08/13/2008] [Indexed: 12/13/2022] Open
Abstract
The peroxisome proliferator-activated receptors (PPARs), which are ligand-inducible transcription factors expressed in a variety of tissues, have been shown to perform key roles in lipid homeostasis. In physiological situations such as fasting and physical exercise, one PPAR subtype, PPARδ, triggers a transcriptional program in skeletal muscle leading to a switch in fuel usage from glucose/fatty acids to solely fatty acids, thereby drastically increasing its oxidative capacity. The metabolic action of PPARδ has also been verified in humans. In addition, it has become clear that the action of PPARδ is not restricted to skeletal muscle. Indeed, PPARδ has been shown to play a crucial role in whole-body lipid homeostasis as well as in insulin sensitivity, and it is active not only in skeletal muscle (as an activator of fat burning) but also in the liver (where it can activate glycolysis/lipogenesis, with the produced fat being oxidized in muscle) and in the adipose tissue (by incrementing lipolysis). The main aim of this review is to highlight the central role for activated PPARδ in the reversal of any tendency toward the development of insulin resistance.
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Abstract
The peroxidation of n-3 and n-6 polyunsaturated fatty acids (PUFAs) and of their hydroperoxy metabolites is a complex process. It is initiated by free oxygen radical-induced abstraction of a hydrogen atom from the lipid molecule followed by a series of nonenzymatic reactions that ultimately generate the reactive aldehyde species 4-hydroxyalkenals. The molecule 4-hydroxy-2E-hexenal (4-HHE) is generated by peroxidation of n-3 PUFAs, such as linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid. The aldehyde product 4-hydroxy-2E-nonenal (4-HNE) is the peroxidation product of n-6 PUFAs, such as arachidonic and linoleic acids and their 15-lipoxygenase metabolites, namely 15-hydroperoxyeicosatetraenoic acid (15-HpETE) and 13-hydroperoxyoctadecadienoic acid (13-HpODE). Another reactive peroxidation product is 4-hydroxy-2E,6Z-dodecadienal (4-HDDE), which is derived from 12-hydroperoxyeicosatetraenoic acid (12-HpETE), the 12-lipoxygenase metabolite of arachidonic acid. Hydroxyalkenals, notably 4-HNE, have been implicated in various pathophysiological interactions due to their chemical reactivity and the formation of covalent adducts with macromolecules. The progressive accumulation of these adducts alters normal cell functions that can lead to cell death. The lipophilicity of these aldehydes positively correlates to their chemical reactivity. Nonetheless, at low and noncytotoxic concentrations, these molecules may function as signaling molecules in cells. This has been shown mostly for 4-HNE and to some extent for 4-HHE. The capacity of 4-HDDE to generate such "mixed signals" in cells has received less attention. This review addresses the origin and cellular functions of 4-hydroxyalkernals.
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Affiliation(s)
- Yael Riahi
- Dept. of Pharmacology, The Hebrew Univ. Jerusalem 91120, Israel
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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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Abstract
Cholesterol efflux from lipid-loaded cells is a key athero-protective event that counteracts cholesterol uptake. The imbalance between cholesterol efflux and uptake determines the prevention or development of atherosclerosis. Many proteins and factors participate in the cholesterol efflux event. However, there are currently no systematic models of reverse cholesterol transport (RCT) that include most RCT-related factors and events. On the basis of recent research findings from other and our laboratories, we propose a novel model of one center and four systems with coupling transportation and networking regulation. This model represents a common way of cholesterol efflux; however, the systems in the model consist of different proteins/factors in different cells. In this review, we evaluate the novel model in vascular smooth muscle cells (VSMCs) and macrophages, which are the most important original cells of foam cells. This novel model consists of 1) a caveolae transport center, 2) an intracellular trafficking system of the caveolin-1 complex, 3) a transmembrane transport system of the ABC-A1 complex, 4) a transmembrane transport system of the SR-B1 complex, and 5) an extracelluar trafficking system of HDL/Apo-A1. In brief, the caveolin-1 system transports cholesterol from intracellular compartments to caveolae. Subsequently, both ABC-A1 and SR-B1 complex systems transfer cholesterol from caveolae to extracellular HDL/Apo-A1. The four systems are linked by a regulatory network. This model provides a simple and concise way to understand the dynamic process of atherosclerosis.
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Lu C, Cheng SY. Thyroid hormone receptors regulate adipogenesis and carcinogenesis via crosstalk signaling with peroxisome proliferator-activated receptors. J Mol Endocrinol 2010; 44:143-54. [PMID: 19741045 PMCID: PMC3464095 DOI: 10.1677/jme-09-0107] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Peroxisome proliferator-activated receptors (PPARs) and thyroid hormone receptors (TRs) are members of the nuclear receptor superfamily. They are ligand-dependent transcription factors that interact with their cognate hormone response elements in the promoters to regulate respective target gene expression to modulate cellular functions. While the transcription activity of each is regulated by their respective ligands, recent studies indicate that via multiple mechanisms PPARs and TRs crosstalk to affect diverse biological functions. Here, we review recent advances in the understanding of the molecular mechanisms and biological impact of crosstalk between these two important nuclear receptors, focusing on their roles in adipogenesis and carcinogenesis.
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Affiliation(s)
- Changxue Lu
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 37 Convent Drive, Room 5128, Bethesda, Maryland 20892-4264, USA
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21
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Huang HJ, Schulman IG. Regulation of metabolism by nuclear hormone receptors. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2009; 87:1-51. [PMID: 20374700 DOI: 10.1016/s1877-1173(09)87001-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The worldwide epidemic of metabolic disease indicates that a better understanding of the pathways contributing to the pathogenesis of this constellation of diseases need to be determined. Nuclear hormone receptors comprise a superfamily of ligand-activated transcription factors that control development, differentiation, and metabolism. 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 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 and inflammation will be discussed and the potential of each receptor subfamily to serve as drug targets for metabolic disease will be highlighted.
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Affiliation(s)
- Huey-Jing Huang
- Department of Biology, Exelixis Inc., 4757 Nexus Centre Drive, San Diego, California 92121, USA
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22
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PPARdelta ligand L-165041 ameliorates Western diet-induced hepatic lipid accumulation and inflammation in LDLR-/- mice. Eur J Pharmacol 2009; 622:45-51. [PMID: 19766624 DOI: 10.1016/j.ejphar.2009.09.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 07/26/2009] [Accepted: 09/08/2009] [Indexed: 01/07/2023]
Abstract
Although peroxisome proliferator-activated receptor delta (PPARdelta) has been implicated in energy metabolism and lipid oxidation process, detailed roles of PPARdelta in lipid homeostasis under pathologic conditions still remain controversial. Thus, we investigated the effect of PPARdelta ligand L-165041 on Western diet-induced fatty liver using low-density lipoprotein receptor-deficient (LDLR(-/-)) mice. LDLR(-/-) mice received either L-165041 (5mg/kg/day) or vehicle (0.1N NaOH) with Western diet for 16 weeks. According to our data, L-165041 drastically reduced lipid accumulation in the liver, decreasing total hepatic cholesterol and triglyceride content compared to the vehicle group. Gene expression analysis demonstrated that L-165041 lowered hepatic expression of PPARgamma, apolipoprotein B, interleukin 1 beta (IL-1beta), and interleukin-6. In contrast, L-165041 increased hepatic expressions of PPARdelta, lipoprotein lipase (LPL), and ATP-binding cassette transporter G1 (ABCG1). Our data suggest that L-165041 might be effective in preventing Western diet-induced hepatic steatosis by regulating genes involved in lipid metabolism and the inflammatory response.
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23
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Eynon N, Meckel Y, Alves AJ, Yamin C, Sagiv M, Goldhammer E, Sagiv M. Is there an interaction between PPARD T294C and PPARGC1A Gly482Ser polymorphisms and human endurance performance? Exp Physiol 2009; 94:1147-52. [PMID: 19666693 DOI: 10.1113/expphysiol.2009.049668] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Functional Gly482Ser (rs8192678) and T294C (rs2016520) polymorphisms in the peroxisome proliferator-activated receptor gamma coactivator-1 (PPARGC1A) and peroxisome proliferator-activated receptor delta (PPARD) genes, respectively, have been associated with mRNA and/or protein activity. The aim of this study was to determine their frequency distribution among 155 Israeli athletes (endurance athletes and sprinters) and 240 healthy control subjects. There were no differences between the endurance athletes, the sprinters and the control group across the PPARD T294C genotypes (P = 0.62). Similarly, no statistical differences were found between the subgroups of elite-level endurance athletes (those who had represented Israel in a world track and field championship or in the Olympic Games) and national-level endurance athletes (P = 0.3), or between elite-level and national-level sprinters (P = 0.9). However, a combined influence of these two polymorphisms on endurance performance was found. The PPARD CC + PPARGC1A Gly/Gly genotypes were more frequently found in the elite endurance athletes than in national-level endurance athletes (P < 0.000). In the cohort of endurance athletes, the odds ratio of the 'optimal genotype' for endurance athletes (PPARD CC + PPARGC1A Gly/Gly + PPARGC1A Gly/Ser) being an elite-level athlete was 8.32 (95% confidence interval 2.2-31.4). In conclusion, the present study suggests that PPARD T294C is not associated with endurance performance. However, a higher frequency of the PPARGC1A Gly/Gly + PPARD CC genotype is associated with elite-level endurance athletes.
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Affiliation(s)
- Nir Eynon
- Department of Genetics and Molecular Biology, The Zinman College of Physical Education and Sport Sciences, Wingate Institute, Netanya 42902, Israel.
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Abstract
Dyslipidaemias, particularly those characterized by the 'atherogenic profile' of high low-density lipoprotein-cholesterol and triglycerides and low high-density lipoprotein-cholesterol, are the major modifiable risk factor for atherosclerosis. The search for drugs to favourably alter such lipid profiles, reducing the associated morbidity and mortality, remains a major research focus. Niacin (nicotinic acid) is the most effective agent available for increasing high-density lipoprotein-cholesterol, but its use is associated with side effects that negatively affect patient compliance: these appear to arise largely as a result of production of prostaglandin D(2) and its subsequent activation of the DP(1) receptor. Desire to reduce the side effects (and improve pharmacokinetic parameters) has led to the development of a number of agonists that have differing effects, both in terms of clinical potency and the severity of adverse effects. The recent discovery of the niacin G-protein-coupled receptor HM74A (GPR109A) has clarified the distinction between the mechanism whereby niacin exerts its therapeutic effects and the mechanisms responsible for the generation of side effects. This has allowed the development of new drugs that show great potential for the treatment of dyslipidaemia. However, recent advances in understanding of the contribution of prostaglandin metabolism to vascular wall health suggest that some of the beneficial effects of niacin may well result from activation of the same pathways responsible for the adverse reactions. The purpose of this review is to emphasize that the search for agonists that show higher tolerability must take into account all aspects of signalling through this receptor.
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Affiliation(s)
- Helen Vosper
- School of Pharmacy and Life Sciences, The Robert Gordon University, Aberdeen, UK.
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25
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Brass EP, Peters MA, Hinchcliff KW, He YD, Ulrich RG. Temporal pattern of skeletal muscle gene expression following endurance exercise in Alaskan sled dogs. J Appl Physiol (1985) 2009; 107:605-12. [PMID: 19498091 DOI: 10.1152/japplphysiol.91347.2008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Muscle responses to exercise are complex and include acute responses to exercise-induced injury, as well as longer term adaptive training responses. Using Alaskan sled dogs as an experimental model, changes in muscle gene expression were analyzed to test the hypotheses that important regulatory elements of the muscle's adaptation to exercise could be identified based on the temporal pattern of gene expression. Dogs were randomly assigned to undertake a 160-km run (n=9), or to remain at rest (n=4). Biceps femoris muscle was obtained from the unexercised dogs and two dogs at each of 2, 6, and 12 h after the exercise, and from three dogs 24 h after exercise. RNA was extracted and microarray analysis used to define gene transcriptional changes. The changes in gene expression after exercise occurred in a temporal pattern. Overall, 569, 469, 316, and 223 transcripts were differentially expressed at 2, 6, 12, and 24 h postexercise, respectively, compared with unexercised dogs (based on P<or=0.01 and an absolute fold change of >or=1.5). Increases in a number of known transcriptional regulators, including peroxisome proliferator-activated receptor-alpha, cAMP-responsive element modulator, and CCAAT enhancer binding protein-delta, and potential signaling molecules, including brain-derived neurotrophic factor, dermokine, and suprabasin, were observed 2 h after exercise. Biological functional analysis suggested changes in expression of genes with known functional relationships, including genes involved in muscle remodeling and growth, intermediary metabolism, and immune regulation. Sustained endurance exercise by Alaskan sled dogs induces coordinated changes in gene expression with a clear temporal pattern. RNA expression profiling has the potential to identify novel regulatory mechanisms and responses to exercise stimuli.
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Affiliation(s)
- Eric P Brass
- Department of Medicine, Harbor-University of California Los Angeles Medical Center, 1124 W. Carson St., Torrance, CA 90502, USA.
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26
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Marsillach J, Camps J, Ferré N, Beltran R, Rull A, Mackness B, Mackness M, Joven J. Paraoxonase-1 is related to inflammation, fibrosis and PPAR delta in experimental liver disease. BMC Gastroenterol 2009; 9:3. [PMID: 19144177 PMCID: PMC2632645 DOI: 10.1186/1471-230x-9-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Accepted: 01/14/2009] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Paraoxonase-1 (PON1) is an antioxidant enzyme synthesized by the liver. It protects against liver impairment and attenuates the production of the pro-inflammatory monocyte chemoattractant protein-1 (MCP-1). We investigated the relationships between hepatic PON1 and MCP-1 expression in rats with liver disease and explored the possible molecular mechanisms involved. METHODS CCl4 was administered for up to 12 weeks to induce liver damage. Serum and hepatic levels of PON1 and MCP-1, their gene and protein expression, nuclear transcription factors, and histological and biochemical markers of liver impairment were measured. RESULTS High levels of PON1 and MCP-1 expression were observed at 12th week in the hepatocytes surrounding the fibrous septa and inflammatory areas. CCl4-administered rats had an increased hepatic PON1 concentration that was related to decreased gene transcription and inhibited protein degradation. Decreased PON1 gene transcription was associated with PPARdelta expression. These changes were accompanied by increased hepatic MCP-1 concentration and gene expression. There were significant direct relationships between hepatic PON1 and MCP-1 concentrations (P = 0.005) and between PON1 and the amount of activated stellate cells (P = 0.001). CONCLUSION Our results from this experimental model suggest a hepato-protective role for PON1 against inflammation, fibrosis and liver disease mediated by MCP-1.
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Affiliation(s)
- Judit Marsillach
- Centre de Recerca Biomèdica, Hospital Universitari de Sant Joan, Institut d'Investigacions Sanitàries Pere Virgili, Universitat Rovira i Virgili, C. Sant Joan s/n, 43201 Reus, Spain
| | - Jordi Camps
- Centre de Recerca Biomèdica, Hospital Universitari de Sant Joan, Institut d'Investigacions Sanitàries Pere Virgili, Universitat Rovira i Virgili, C. Sant Joan s/n, 43201 Reus, Spain
| | - Natàlia Ferré
- Centre de Recerca Biomèdica, Hospital Universitari de Sant Joan, Institut d'Investigacions Sanitàries Pere Virgili, Universitat Rovira i Virgili, C. Sant Joan s/n, 43201 Reus, Spain
| | - Raul Beltran
- Centre de Recerca Biomèdica, Hospital Universitari de Sant Joan, Institut d'Investigacions Sanitàries Pere Virgili, Universitat Rovira i Virgili, C. Sant Joan s/n, 43201 Reus, Spain
| | - Anna Rull
- Centre de Recerca Biomèdica, Hospital Universitari de Sant Joan, Institut d'Investigacions Sanitàries Pere Virgili, Universitat Rovira i Virgili, C. Sant Joan s/n, 43201 Reus, Spain
| | - Bharti Mackness
- Centre de Recerca Biomèdica, Hospital Universitari de Sant Joan, Institut d'Investigacions Sanitàries Pere Virgili, Universitat Rovira i Virgili, C. Sant Joan s/n, 43201 Reus, Spain
| | - Michael Mackness
- Centre de Recerca Biomèdica, Hospital Universitari de Sant Joan, Institut d'Investigacions Sanitàries Pere Virgili, Universitat Rovira i Virgili, C. Sant Joan s/n, 43201 Reus, Spain
| | - Jorge Joven
- Centre de Recerca Biomèdica, Hospital Universitari de Sant Joan, Institut d'Investigacions Sanitàries Pere Virgili, Universitat Rovira i Virgili, C. Sant Joan s/n, 43201 Reus, Spain
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27
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Marsillach J, Camps J, Ferré N, Beltran R, Rull A, Mackness B, Mackness M, Joven J. Paraoxonase-1 is related to inflammation, fibrosis and PPAR delta in experimental liver disease. BMC Gastroenterol 2009. [PMID: 19144177 DOI: 10.1186/1471-230x-9-351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Paraoxonase-1 (PON1) is an antioxidant enzyme synthesized by the liver. It protects against liver impairment and attenuates the production of the pro-inflammatory monocyte chemoattractant protein-1 (MCP-1). We investigated the relationships between hepatic PON1 and MCP-1 expression in rats with liver disease and explored the possible molecular mechanisms involved. METHODS CCl4 was administered for up to 12 weeks to induce liver damage. Serum and hepatic levels of PON1 and MCP-1, their gene and protein expression, nuclear transcription factors, and histological and biochemical markers of liver impairment were measured. RESULTS High levels of PON1 and MCP-1 expression were observed at 12th week in the hepatocytes surrounding the fibrous septa and inflammatory areas. CCl4-administered rats had an increased hepatic PON1 concentration that was related to decreased gene transcription and inhibited protein degradation. Decreased PON1 gene transcription was associated with PPARdelta expression. These changes were accompanied by increased hepatic MCP-1 concentration and gene expression. There were significant direct relationships between hepatic PON1 and MCP-1 concentrations (P = 0.005) and between PON1 and the amount of activated stellate cells (P = 0.001). CONCLUSION Our results from this experimental model suggest a hepato-protective role for PON1 against inflammation, fibrosis and liver disease mediated by MCP-1.
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Affiliation(s)
- Judit Marsillach
- Centre de Recerca Biomèdica, Hospital Universitari de Sant Joan, Institut d'Investigacions Sanitàries Pere Virgili, Universitat Rovira i Virgili, C, Sant Joan s/n, 43201 Reus, Spain.
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28
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PPARdelta Agonism for the Treatment of Obesity and Associated Disorders: Challenges and Opportunities. PPAR Res 2008; 2008:125387. [PMID: 18989368 PMCID: PMC2577153 DOI: 10.1155/2008/125387] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Accepted: 09/03/2008] [Indexed: 12/13/2022] Open
Abstract
The prevalence of obesity in the USA and worldwide has reached epidemic proportions during the last two decades. Drugs currently available for the treatment of obesity provide no more than 5% placebo-adjusted weight loss and are associated with undesirable side effects. Peroxisome proliferator-activated receptor (PPAR) modulators offer potential benefits for the treatment of obesity and its associated complications but their development has been complicated by biological, technical, and regulatory challenges. Despite significant challenges, PPAR modulators are attractive targets for the treatment of obesity and could offer a viable alternative to the millions of patients who fail to lose weight following rigorous dieting and exercise protocols. In addition, PPAR modulators have the potential-added benefit of ameliorating the associated comorbidities.
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29
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Billin AN. PPAR-β/δ agonists for Type 2 diabetes and dyslipidemia: an adopted orphan still looking for a home. Expert Opin Investig Drugs 2008; 17:1465-71. [DOI: 10.1517/13543784.17.10.1465] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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30
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Mazzatti DJ, Smith MA, Oita RC, Lim FL, White AJ, Reid MB. Muscle unloading-induced metabolic remodeling is associated with acute alterations in PPARδ and UCP-3 expression. Physiol Genomics 2008; 34:149-61. [DOI: 10.1152/physiolgenomics.00281.2007] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
A number of physiological changes follow prolonged skeletal muscle unloading as occurs in spaceflight, bed rest, and hindlimb suspension (HLS) and also in aging. These include muscle atrophy, fiber type switching, and loss of the ability to switch between lipid and glucose usage, or metabolic inflexibility. The signaling and genomic events that precede these physiological manifestations have not been investigated in detail, particularly in regard to loss of metabolic flexibility. Here we used gene arrays to determine the effects of 24-h HLS on metabolic remodeling in mouse muscle. Acute unloading resulted in differential expression of a number of transcripts in soleus and gastrocnemius muscle, including many involved in lipid and glucose metabolism. These include the peroxisome proliferator-activated receptors (PPARs). In contrast to Ppar-α and Ppar-γ, which were downregulated by acute HLS, Ppar-δ was upregulated concomitant with increased expression of its downstream target, uncoupling protein-3 ( Ucp-3). However, differential expression of Ppar-δ was both acute and transient in nature, suggesting that regulation of PPARδ may represent an adaptive, compensatory response aimed at regulating fuel utilization and maintaining metabolic flexibility.
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Affiliation(s)
- Dawn J. Mazzatti
- Unilever Corporate Research, Colworth Park, Sharnbrook, Bedfordshire, United Kingdom
| | - Melissa A. Smith
- Department of Physiology, University of Kentucky, Lexington, Kentucky
| | - Radu C. Oita
- Unilever Corporate Research, Colworth Park, Sharnbrook, Bedfordshire, United Kingdom
| | - Fei-Ling Lim
- Unilever Measurement Sciences, Colworth Park, Sharnbrook, Bedfordshire, United Kingdom
| | - Andrew J. White
- Unilever Measurement Sciences, Colworth Park, Sharnbrook, Bedfordshire, United Kingdom
| | - Michael B. Reid
- Department of Physiology, University of Kentucky, Lexington, Kentucky
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31
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Bibliography. Current world literature. Lipid metabolism. Curr Opin Lipidol 2008; 19:314-21. [PMID: 18460925 DOI: 10.1097/mol.0b013e328303e27e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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32
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Wallace KB. Mitochondrial off targets of drug therapy. Trends Pharmacol Sci 2008; 29:361-6. [PMID: 18501972 DOI: 10.1016/j.tips.2008.04.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2008] [Revised: 04/15/2008] [Accepted: 04/15/2008] [Indexed: 02/07/2023]
Abstract
The bioenergetic features of mitochondria have long been exploited in the design of pharmacological agents suited to accomplish a desired physiological effect; uncoupling of oxidative phosphorylation to induce weight loss, for example. However, more recent experience demonstrates mitochondria to be unintended off targets of other drug therapies and responsible, at least in part, for the dose-limiting adverse events associated with a large array of pharmaceuticals. Review of the fundamentals of mitochondrial molecular biology and bioenergetics reveals a multiplicity of off targets that can be invoked to explain drug-induced mitochondrial failure. It is this redundancy of mitochondrial off targets that complicates identification of discrete mechanisms of toxicity and confounds QSAR-based design of new small molecules devoid of this potential for mitochondrial toxicity. The present review article briefly reviews the molecular biology and biophysics of mitochondrial bioenergetics, which then serves as a platform for identifying the various potential off targets for drug-induced mitochondrial toxicity.
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Affiliation(s)
- Kendall B Wallace
- Department of Biochemistry and Molecular Biology, University of Minnesota Medical School, Duluth, MN 55812, USA.
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33
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Amengual J, Ribot J, Bonet ML, Palou A. Retinoic acid treatment increases lipid oxidation capacity in skeletal muscle of mice. Obesity (Silver Spring) 2008; 16:585-91. [PMID: 18239600 DOI: 10.1038/oby.2007.104] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
OBJECTIVE All-trans retinoic acid (ATRA), a carboxylic form of vitamin A, favors in mice a mobilization of body fat reserves that correlates with an increment of oxidative and thermogenic capacity in adipose tissues. The objective of this study has been to investigate the effect of ATRA treatment on skeletal muscle capacity for fatty-acid catabolism. METHODS AND PROCEDURES Tissue composition and gene expression related to lipid and oxidative metabolism were analyzed in skeletal muscle of mice acutely treated with ATRA or vehicle (olive oil). RESULTS ATRA treatment triggered a dose-dependent increase in the muscle mRNA expression levels of selected enzymes, transporters and transcription factors involved in fatty-acid oxidation, respiration, and thermogenesis namely: muscle-type carnitine palmitoyltransferase 1, acyl CoA oxidase 1, subunit II of cytochrome oxidase, uncoupling protein 3, peroxisome proliferator-activated receptor-gamma co-activator -1alpha and peroxisome proliferator-activated receptor-delta (PPARdelta). The treatment also resulted in the upregulation of the mRNA levels of acetyl-CoA carboxylase 2 (ACC2), a key regulatory enzyme for mitochondrial fatty-acid oxidation in muscle. Skeletal muscle protein levels of PPARdelta and retinoid X receptor gamma, a partner for many nuclear receptors involved in lipid metabolism, were increased after ATRA treatment. Muscle lipid content was decreased. DISCUSSION These results indicate that ATRA treatment increases the capacity of skeletal muscle for fatty-acid oxidation. Knowledge of nutrients or nutrient-derivatives capable of enhancing oxidative metabolism in muscle and other tissues can contribute to new avenues of prevention and treatment of obesity and related disorders.
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Affiliation(s)
- Jaume Amengual
- Laboratory of Molecular Biology, Nutrition and Biotechnology, Universitat de les Illes Balears, Palma de Mallorca, Spain
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34
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Nahlé Z, Hsieh M, Pietka T, Coburn CT, Grimaldi PA, Zhang MQ, Das D, Abumrad NA. CD36-dependent regulation of muscle FoxO1 and PDK4 in the PPAR delta/beta-mediated adaptation to metabolic stress. J Biol Chem 2008; 283:14317-26. [PMID: 18308721 DOI: 10.1074/jbc.m706478200] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The transcription factor FoxO1 contributes to the metabolic adaptation to fasting by suppressing muscle oxidation of glucose, sparing it for glucose-dependent tissues. Previously, we reported that FoxO1 activation in C(2)C(12) muscle cells recruits the fatty acid translocase CD36 to the plasma membrane and increases fatty acid uptake and oxidation. This, together with FoxO1 induction of lipoprotein lipase, would promote the reliance on fatty acid utilization characteristic of the fasted muscle. Here, we show that CD36-mediated fatty acid uptake, in turn, up-regulates protein levels and activity of FoxO1 as well as its target PDK4, the negative regulator of glucose oxidation. Increased fatty acid flux or enforced CD36 expression in C(2)C(12) cells is sufficient to induce FoxO1 and PDK4, whereas CD36 knockdown has opposite effects. In vivo, CD36 loss blunts fasting induction of FoxO1 and PDK4 and the associated suppression of glucose oxidation. Importantly, CD36-dependent regulation of FoxO1 is mediated by the nuclear receptor PPARdelta/beta. Loss of PPARdelta/beta phenocopies CD36 deficiency in blunting fasting induction of muscle FoxO1 and PDK4 in vivo. Expression of PPARdelta/beta in C(2)C(12) cells, like that of CD36, robustly induces FoxO1 and suppresses glucose oxidation, whereas co-expression of a dominant negative PPARdelta/beta compromises FoxO1 induction. Finally, several PPRE sites were identified in the FoxO1 promoter, which was responsive to PPARdelta/beta. Agonists of PPARdelta/beta were sufficient to confer responsiveness and transactivate the heterologous FoxO1 promoter but not in the presence of dominant negative PPARdelta/beta. Taken together, our findings suggest that CD36-dependent FA activation of PPARdelta/beta results in the transcriptional regulation of FoxO1 as well as PDK4, recently shown to be a direct PPARdelta/beta target. FoxO1 in turn can regulate CD36, lipoprotein lipase, and PDK4, reinforcing the action of PPARdelta/beta to increase muscle reliance on FA. The findings could have implications in the chronic abnormalities of fatty acid metabolism associated with obesity and diabetes.
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Affiliation(s)
- Zaher Nahlé
- Department of Medicine, Washington University School of Medicine, St Louis, MO 63110, USA.
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35
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Muscle-Specific PPARbeta/delta Agonism May Provide Synergistic Benefits with Life Style Modifications. PPAR Res 2008; 2007:30578. [PMID: 18274626 PMCID: PMC2220041 DOI: 10.1155/2007/30578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Revised: 08/08/2007] [Accepted: 11/13/2007] [Indexed: 11/26/2022] Open
Abstract
Peroxisome proliferator-activated receptor β/δ
(PPARβ/δ)
has emerged as a powerful metabolic regulator in diverse tissues
including fat, skeletal muscle, and the heart. It is now
established that activation of
PPARβ/δ
promotes fatty acid oxidation in several tissues, such as skeletal
muscle and adipose tissue. In muscle,
PPARβ/δ
appears to act as a central regulator of fatty acid catabolism.
PPARβ/δ contents are increased in muscle during physiological situations
such as physical exercise or long-term fasting, characterized by
increased fatty acid oxidation. Targeted expression of an
activated form of PPARβ/δ
in skeletal muscle induces a switch to form increased numbers of
type I muscle fibers resembling the fiber type transition by
endurance training. Activation of
PPARβ/δ
also enhances mitochondrial capacity and fat oxidation in the
skeletal muscle that resembles the effect of regular exercise.
Therefore, it is hypothesized that muscle-specific
PPARβ/δ
agonists could be a key strategy to support the poor
cardiorespiratory fitness associated with metabolic disorders.
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36
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Abstract
Hormesis is defined operationally as responses of cells or organisms to an exogenous or intrinsic factor (chemical, temperature, psychological challenge, etc.) in which the factor induces stimulatory or beneficial effects at low doses and inhibitory or adverse effects at high doses. The compendium of articles by Calabrese entitled "Neuroscience and Hormesis" provides a broad range of examples of neurobiological processes and responses to environmental factors that exhibit biphasic dose responses, the signature of hormesis. Nerve cell networks are the "first responders" to environmental challenges--they perceive the challenge and orchestrate coordinated adaptive responses that typically involve autonomic, neuroendocrine, and behavioral changes. In addition to direct adaptive responses of neurons to environmental stressors, cells subjected to a stressor produce and release molecules such as growth factors, cytokines, and hormones that alert adjacent and even distant cells to impending danger. The discoveries that some molecules (e.g., carbon monoxide and nitric oxide) and elements (e.g., selenium and iron) that are toxic at high doses play fundamental roles in cellular signaling or metabolism suggest that during evolution, organisms (and their nervous systems) co-opted environmental toxins and used them to their advantage. Neurons also respond adaptively to everyday stressors, including physical exercise, cognitive challenges, and dietary energy restriction, each of which activates pathways linked to the production of neurotrophic factors and cellular stress resistance proteins. The development of interventions that activate hormetic signaling pathways in neurons is a promising new approach for the preventation and treatment of a range of neurological disorders.
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Affiliation(s)
- Mark P Mattson
- Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, Maryland 21224, USA.
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37
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Abstract
Understanding the molecular regulation of metabolism will lead to a better understanding of the pathogenesis and treatment of common metabolic conditions, including obesity and diabetes. Nuclear receptors are a family of transcription factors, many of which play major roles in regulating metabolic genes in key tissues. They function by recruiting coregulators to the promoters of metabolic genes that can either activate or repress transcription. This review examines the roles of these coregulators in the control of metabolism in adipose tissue and skeletal muscle, and discusses how they result in coordinated and regulated control of metabolic pathways. In particular, the ligand-dependent recruitment of both coactivators and corepressors has potential implications for the treatment of obesity and diabetes.
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Affiliation(s)
- Daniel L Morganstein
- a Imperial College, Molecular Endocrinology, Institute of Reproductive and Developmental Biology, Imperial College, London, UK.
| | - Malcolm G Parker
- b Imperial College, Molecular Endocrinology, Institute of Reproductive and Developmental Biology, Imperial College, London, UK.
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Ahmetov II, Astratenkova IV, Rogozkin VA. Association of a PPARD polymorphism with human physical performance. Mol Biol 2007. [DOI: 10.1134/s002689330705010x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
Overweight, obesity and the metabolic syndrome occur in genetically susceptible individuals with environmental influences, and may be further compounded by other disorders of metabolism or pharmacological therapy that increase insulin resistance or promotes weight gain. Treatment of the metabolic syndrome should focus on treatment on [corrected] each individual component, but first, lifestyle modification, including diet and exercise with weight reduction, should be [corrected] the foundation of any successful treatment regimen for the metabolic syndrome. Pharmacological therapy should be individualized and targeted to normalize blood pressure, HDL cholesterol, triglycerides and glucose values. If successful, comprehensive management of the metabolic syndrome promises to delay or prevent the development of coronary heart disease and Type 2 diabetes mellitus.
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Affiliation(s)
- Neil J Stone
- Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA.
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Remels AH, Gosker HR, van der Velden J, Langen RC, Schols AM. Systemic Inflammation and Skeletal Muscle Dysfunction in Chronic Obstructive Pulmonary Disease: State of the Art and Novel Insights in Regulation of Muscle Plasticity. Clin Chest Med 2007; 28:537-52, vi. [PMID: 17720042 DOI: 10.1016/j.ccm.2007.06.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Systemic inflammation is a recognized hallmark of chronic obstructive pulmonary disease pathogenesis. Although the origin and mechanisms responsible for the persistent chronic inflammatory process remain to be elucidated, it is recognized that it plays an important role in skeletal muscle pathology as observed in chronic obstructive pulmonary disease and several other chronic inflammatory disorders. This article describes state-of-the-art knowledge and novel insights in the role of inflammatory processes on several aspects of inflammation-related skeletal muscle pathology and offers new insights in therapeutic perspectives.
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Affiliation(s)
- Alexander H Remels
- Department of Respiratory Medicine, Nutrition and Toxicology Research Institute, University of Maastricht, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
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Suckling K. Drug discovery in the metabolic syndrome: context and some recent developments. Expert Opin Ther Targets 2007; 11:801-8. [PMID: 17504017 DOI: 10.1517/14728222.11.6.801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The metabolic syndrome, encompassing the clinically distinct but related areas of dyslipidaemia, insulin resistance, obesity and vascular disease, offers a wide arena for drug discovery. There is substantial and growing unmet medical need, particularly as the worldwide epidemic of obesity continues to develop. There are also many targets and biological mechanisms that can be exploited. However, the context for clinical development is challenging because of the many ways in which the syndrome can be approached. As with most therapeutic areas, preclinical data provide only limited confidence in the potential of a novel target in humans. In this review, the author outlines the context for drug discovery in the metabolic syndrome, the clinical and biological scope and recent developments in preclinical models. Finally, existing examples of drug targets for a range of biological mechanisms are considered, outlining their biology and points relevant to lead identification and optimisation and clinical development.
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