251
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Ramani K, Tomasi ML. Transcriptional regulation of methionine adenosyltransferase 2A by peroxisome proliferator-activated receptors in rat hepatic stellate cells. Hepatology 2012; 55:1942-53. [PMID: 22271545 PMCID: PMC3342421 DOI: 10.1002/hep.25594] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 12/26/2011] [Indexed: 12/11/2022]
Abstract
UNLABELLED Methionine adenosyltransferases (MATs) are critical enzymes that catalyze the formation of the methyl donor S-adenosyl methionine (SAM). The MAT2A gene, which encodes the catalytic subunit α2, is induced in dedifferentiated liver. We previously demonstrated that MAT2A expression is enhanced in activated hepatic stellate cells (HSCs) and that silencing this gene reduces HSC activation. In this study, we examined the molecular mechanisms responsible for the transcriptional regulation of the MAT2A gene in HSCs. We identified peroxisome proliferator-activated receptor (PPAR) response elements (PPREs) in the rat MAT2A promoter. The PPARγ agonist rosiglitazone (RSG) promoted quiescence in the activated rat HSC cell line (BSC) or culture-activated primary rat HSCs, decreased MAT2A expression and promoter activity, and enhanced PPARγ binding to MAT2A PPREs. In vivo HSC activation in bile duct-ligated rats lowered PPARγ interaction with MAT2A PPREs. Silencing PPARγ increased MAT2A transcription, whereas overexpressing it had the opposite effect, demonstrating that PPARγ negatively controls this gene. Site-directed mutagenesis of PPREs abolished PPARγ recruitment to the MAT2A promoter and its inhibitory effect on MAT2A transcription in quiescent HSCs. PPRE mutations decreased the basal promoter activity of MAT2A in activated HSCs independent of PPARγ, indicating that other factors might be involved in PPRE interaction. We identified PPARβ binding to wild-type but not to mutated PPREs in activated cells. Furthermore, silencing PPARβ inhibited MAT2A expression and promoter activity. Forced expression of MAT2A in RSG-treated HSCs lowered PPARγ and enhanced PPARβ expression, thereby promoting an activated phenotype. CONCLUSION We identified PPARγ as a negative regulator of MAT2A in quiescent HSCs. A switch from quiescence to activation abolishes this control and allows PPARβ to up-regulate MAT2A transcription.
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Affiliation(s)
- Komal Ramani
- Division of Gastroenterology and Liver Diseases, USC Research Center for Liver Diseases, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
| | - Maria Lauda Tomasi
- Division of Gastroenterology and Liver Diseases, USC Research Center for Liver Diseases, Keck School of Medicine University of Southern California, Los Angeles, California 90033
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252
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Thal SC, Heinemann M, Luh C, Pieter D, Werner C, Engelhard K. Pioglitazone reduces secondary brain damage after experimental brain trauma by PPAR-γ-independent mechanisms. J Neurotrauma 2012; 28:983-93. [PMID: 21501066 DOI: 10.1089/neu.2010.1685] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Inflammatory and ischemic processes contribute to the development of secondary brain damage after mechanical brain injury. Recent data suggest that thiazolidinediones (TZDs), a class of drugs approved for the treatment of non-insulin-dependent diabetes mellitus, effectively reduces inflammation and brain lesion by stimulation of the peroxisome proliferator-activated receptor-γ (PPAR-γ). The present study investigates the influence of the TZD pioglitazone and rosiglitazone on inflammation and secondary brain damage after experimental traumatic brain injury (TBI). A controlled cortical impact (CCI) injury was induced in male C57BL/6 mice to investigate following endpoints: (1) mRNA expression of PPAR-γ and PPAR-γ target genes (LPL, GLT1, and IRAP/Lnpep), and inflammatory markers (TNF-α, IL-1β, IL-6, and iNOS), at 15 min, 3 h, 6 h, 12 h, and 24 h post-trauma; (2) contusion volume, neurological function, and gene expression after 24 h in mice treated with pioglitazone (0.5 and 1 mg/kg) or rosiglitazone (5 and 10 mg/kg IP at 30 min post-trauma); and (3) the role of PPAR-γ to mediate protection was determined in animals treated with pioglitazone, the PPAR-γ inhibitor T0070907, and a combination of both. Inflammatory marker genes, but not PPAR-γ gene expression, was upregulated after trauma. Pioglitazone reduced the histological damage and inflammation in a dose-dependent fashion. In contrast, rosiglitazone failed to suppress inflammation and histological damage. PPAR-γ and PPAR-γ target gene expression was not induced by pioglitazone and rosiglitazone. In line with these results, pioglitazone-mediated protection was not reversed by T0070907. The results indicate that the neuroprotective effects of pioglitazone are not solely related to PPAR-γ-dependent mechanisms.
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Affiliation(s)
- Serge C Thal
- Department of Anesthesiology, Medical Center of the Johannes Gutenberg-University, Mainz, Germany.
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253
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Ruebner M, Langbein M, Strissel PL, Henke C, Schmidt D, Goecke TW, Faschingbauer F, Schild RL, Beckmann MW, Strick R. Regulation of the human endogenous retroviral Syncytin-1 and cell-cell fusion by the nuclear hormone receptors PPARγ/RXRα in placentogenesis. J Cell Biochem 2012; 113:2383-96. [DOI: 10.1002/jcb.24110] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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254
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Liu X, Yu H, Yang L, Li C, Li L. 15-Deoxy-Δ(12,14)-prostaglandin J(2) attenuates the biological activities of monocyte/macrophage cell lines. Eur J Cell Biol 2012; 91:654-61. [PMID: 22560326 DOI: 10.1016/j.ejcb.2012.03.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 03/12/2012] [Accepted: 03/12/2012] [Indexed: 11/24/2022] Open
Abstract
Monocytes/macrophages link the innate and adaptive immune systems, and in inflammatory disorders their activation leads to tissue damage. 15-Deoxy-Δ(12,14)-prostaglandin J(2) (15d-PGJ(2)), a natural peroxisome proliferator-activated receptor gamma (PPARγ) ligand, has garnered much interest because it possesses anti-inflammatory properties in a number of experimental models. However, whether it regulates monocytes/macrophage pathophysiology is still unknown. This study was designed to examine the effects of 15d-PGJ(2) on the phagocytosis, proliferation and inflammatory cytokines generation in mouse monocyte/macrophage cell line RAW264.7 and J774A.1 cells upon lipopolysaccharide challenge. Our results showed that 15d-PGJ(2) inhibited the phagocytic activity and cell proliferation in a dose-dependent manner, and suppressed proinflammatory cytokines expression, such as tumor necrosis factor-α, transforming growth factor-β1, interleukin-6, and monocyte chemotactic protein-1. These effects were independent of PPARγ, because PPARγ agonist (troglitazone or ciglitazone) and PPARγ antagonist (GW9662) did not affect these activities mentioned above in cells. Treatment of 15d-PGJ(2) also did not modulate expression and distribution of PPARγ. However, these effects of 15d-PGJ(2) were abrogated by antioxidant N-acetylcysteine. Moreover, treatment of 15d-PGJ(2) induced a significant increase in reactive oxygen species production in RAW264.7 and J774A.1 cells. In conclusion, 15d-PGJ(2) attenuates the biological activities of mouse monocyte/macrophage cell line cells involving oxidative stress, independently of PPARγ. These data further underline the anti-inflammation potential of 15d-PGJ(2).
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Affiliation(s)
- Xin Liu
- Department of Cell Biology, Municipal Laboratory for Liver Protection and Regulation of Regeneration, Capital Medical University, Beijing 100069, China
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255
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Sgarra L, Addabbo F, Potenza MA, Montagnani M. Determinants of evolving metabolic and cardiovascular benefit/risk profiles of rosiglitazone therapy during the natural history of diabetes: molecular mechanisms in the context of integrated pathophysiology. Am J Physiol Endocrinol Metab 2012; 302:E1171-82. [PMID: 22374753 DOI: 10.1152/ajpendo.00038.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Rosiglitazone is a thiazolidinedione, a synthetic PPARγ receptor agonist with insulin-sensitizing properties that is used as an antidiabetic drug. In addition to improving glycemic control through actions in metabolic target tissues, rosiglitazone has numerous biological actions that impact on cardiovascular homeostasis. Some of these actions are helpful (e.g., improving endothelial function), whereas others are potentially harmful (e.g., promoting fluid retention). Since cardiovascular morbidity and mortality are major endpoints for diabetes, it is essential to understand how the natural history of diabetes alters the net benefits and risks of rosiglitazone therapy. This complex issue is an important determinant of optimal use of rosiglitazone and is critical for understanding cardiovascular safety issues. We give special attention to the effects of rosiglitazone in diabetic patients with stable coronary artery disease and the impact of rosiglitazone actions on atherosclerosis and plaque instability. This provides a rational conceptual framework for predicting evolving benefit/risk profiles that inform optimal use of rosiglitazone in the clinical setting and help explain the results of recent large clinical intervention trials where rosiglitazone had disappointing cardiovascular outcomes. Thus, in this perspective, we describe what is known about the molecular mechanisms of action of rosiglitazone on cardiovascular targets in the context of the evolving pathophysiology of diabetes over its natural history.
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Affiliation(s)
- Luca Sgarra
- Department of Biomedical Sciences and Human Oncology, Medical School, University of Bari, Bari, Italy
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256
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Pendse AA, Johnson LA, Kim HS, McNair M, Nipp CT, Wilhelm C, Maeda N. Pro- and antiatherogenic effects of a dominant-negative P465L mutation of peroxisome proliferator-activated receptor-γ in apolipoprotein E-Null mice. Arterioscler Thromb Vasc Biol 2012; 32:1436-44. [PMID: 22539598 DOI: 10.1161/atvbaha.112.248682] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The dominant-negative mutation, P467L, in peroxisome proliferator-activated receptor-γ (PPARγ) affects adipose tissue distribution, insulin sensitivity, and blood pressure in heterozygous humans. We hypothesized that the equivalent mutation, PPARγ-P465L, in mice will worsen atherosclerosis. METHODS AND RESULTS Apolipoprotein E-null mice with and without PPARγ-P465L mutation were bred in 129S6 inbred genetic background. Mild hypertension and lipodystrophy of PPARγ-P465L persisted in the apolipoprotein E-null background. Glucose homeostasis was normal, but plasma adiponectin was significantly lower and resistin was higher in PPARγ-P465L mice. Plasma cholesterol and lipoprotein distribution were not different, but plasma triglycerides tended to be reduced. Surprisingly, there were no overall changes in the atherosclerotic plaque size or composition. PPARγ-P465L macrophages had a small decrease in CD36 mRNA and a small yet significant reduction in very-low-density lipoprotein uptake in culture. In unloaded apolipoprotein E-null macrophages with PPARγ-P465L, cholesterol uptake was reduced whereas apolipoprotein AI-mediated efflux was increased. However, when cells were cholesterol loaded in the presence of acetylated low-density lipoprotein, no genotype difference in uptake or efflux was apparent. A reduction of vascular cell adhesion molecule-1 expression in aorta suggests a relatively antiatherogenic vascular environment in mice with PPARγ-P465L. CONCLUSIONS Small, competing pro- and antiatherogenic effects of PPARγ-P465L mutation result in unchanged plaque development in apolipoprotein E-deficient mice.
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Affiliation(s)
- Avani A Pendse
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, 710 Brinkhous-Bullitt Bldg, Chapel Hill, NC 27599-7525, USA
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257
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Oh J, Riek AE, Weng S, Petty M, Kim D, Colonna M, Cella M, Bernal-Mizrachi C. Endoplasmic reticulum stress controls M2 macrophage differentiation and foam cell formation. J Biol Chem 2012; 287:11629-41. [PMID: 22356914 PMCID: PMC3320912 DOI: 10.1074/jbc.m111.338673] [Citation(s) in RCA: 234] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2011] [Revised: 02/03/2012] [Indexed: 01/18/2023] Open
Abstract
Macrophages are essential in atherosclerosis progression, but regulation of the M1 versus M2 phenotype and their role in cholesterol deposition are unclear. We demonstrate that endoplasmic reticulum (ER) stress is a key regulator of macrophage differentiation and cholesterol deposition. Macrophages from diabetic patients were classically or alternatively stimulated and then exposed to oxidized LDL. Alternative stimulation into M2 macrophages lead to increased foam cell formation by inducing scavenger receptor CD36 and SR-A1 expression. ER stress induced by alternative stimulation was necessary to generate the M2 phenotype through JNK activation and increased PPARγ expression. The absence of CD36 or SR-A1 signaling independently of modified cholesterol uptake decreased ER stress and prevented the M2 differentiation typically induced by alternative stimulation. Moreover, suppression of ER stress shifted differentiated M2 macrophages toward an M1 phenotype and subsequently suppressed foam cell formation by increasing HDL- and apoA-1-induced cholesterol efflux indicating suppression of macrophage ER stress as a potential therapy for atherosclerosis.
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Affiliation(s)
- Jisu Oh
- From the Division of Endocrinology, Metabolism, and Lipid Research
| | - Amy E. Riek
- From the Division of Endocrinology, Metabolism, and Lipid Research
| | - Sherry Weng
- From the Division of Endocrinology, Metabolism, and Lipid Research
| | - Marvin Petty
- From the Division of Endocrinology, Metabolism, and Lipid Research
| | - David Kim
- From the Division of Endocrinology, Metabolism, and Lipid Research
| | | | | | - Carlos Bernal-Mizrachi
- From the Division of Endocrinology, Metabolism, and Lipid Research
- Division of Cell Biology and Physiology, Washington University, St. Louis, Missouri 63110
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258
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Abstract
This article reviews the current knowledge and experimental research about the mechanisms by which fatty acids and their derivatives control specific gene expression involved during carcinogenesis. Changes in dietary fatty acids, specifically the polyunsaturated fatty acids of the ω-3 and ω-6 families and some derived eicosanoids from lipoxygenases, cyclooxygenases, and cytochrome P-450, seem to control the activity of transcription factor families involved in cancer cell proliferation or cell death. Their regulation may be carried out either through direct binding to DNA as peroxisome proliferator-activated receptors or via modulation in an indirect manner of signaling pathway molecules (e.g., protein kinase C) and other transcription factors (nuclear factor kappa B and sterol regulatory element binding protein). Knowledge of the mechanisms by which fatty acids control specific gene expression may identify important risk factors for cancer and provide insight into the development of new therapeutic strategies for a better management of whole body lipid metabolism.
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259
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Abstract
Diabetes and hypertension frequently occur together. There is substantial overlap between diabetes and hypertension in etiology and disease mechanisms. Obesity, inflammation, oxidative stress, and insulin resistance are thought to be the common pathways. Recent advances in the understanding of these pathways have provided new insights and perspectives. Physical activity plays an important protective role in the two diseases. Knowing the common causes and disease mechanisms allows a more effective and proactive approach in their prevention and treatment.
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Affiliation(s)
- Bernard M. Y. Cheung
- Department of Medicine, University of Hong Kong, Pokfulam, Hong Kong
- Department of Medicine, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China
| | - Chao Li
- Department of Medicine, University of Hong Kong, Pokfulam, Hong Kong
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260
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Xu L, Shen S, Ma Y, Kim JK, Rodriguez-Agudo D, Heuman DM, Hylemon PB, Pandak WM, Ren S. 25-Hydroxycholesterol-3-sulfate attenuates inflammatory response via PPARγ signaling in human THP-1 macrophages. Am J Physiol Endocrinol Metab 2012; 302:E788-99. [PMID: 22275753 PMCID: PMC3330710 DOI: 10.1152/ajpendo.00337.2011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The nuclear receptor peroxisome proliferator-activated receptors (PPARs) are important in regulating lipid metabolism and inflammatory responses in macrophages. Activation of PPARγ represses key inflammatory response gene expressions. Recently, we identified a new cholesterol metabolite, 25-hydroxycholesterol-3-sulfate (25HC3S), as a potent regulatory molecule of lipid metabolism. In this paper, we report the effect of 25HC3S and its precursor 25-hydroxycholesterol (25HC) on PPARγ activity and on inflammatory responses. Addition of 25HC3S to human macrophages markedly increased nuclear PPARγ and cytosol IκB and decreased nuclear NF-κB protein levels. PPARγ response element reporter gene assays showed that 25HC3S significantly increased luciferase activities. PPARγ competitor assay showed that the K(i) for 25HC3S was ∼1 μM, similar to those of other known natural ligands. NF-κB-dependent promoter reporter gene assays showed that 25HC3S suppressed TNFα-induced luciferase activities only when cotransfected with pcDNAI-PPARγ plasmid. In addition, 25HC3S decreased LPS-induced expression and release of IL-1β. In the PPARγ-specific siRNA transfected macrophages or in the presence of PPARγ-specific antagonist, 25HC3S failed to increase IκB and to suppress TNFα and IL-1β expression. In contrast to 25HC3S, its precursor 25HC, a known liver X receptor ligand, decreased nuclear PPARγ and cytosol IκB and increased nuclear NF-κB protein levels. We conclude that 25HC3S acts in macrophages as a PPARγ ligand and suppresses inflammatory responses via the PPARγ/IκB/NF-κB signaling pathway.
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Affiliation(s)
- Leyuan Xu
- Department of Medicine, Virginia Commonwealth University, Richmond, VA 23249, USA
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261
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Peroxisome proliferator-activated receptor gamma (PPAR-γ) and neurodegenerative disorders. Mol Neurobiol 2012; 46:114-24. [PMID: 22434581 DOI: 10.1007/s12035-012-8259-8] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 03/06/2012] [Indexed: 10/28/2022]
Abstract
As the growth of the aging population continues to accelerate globally, increased prevalence of neurodegenerative diseases, including Alzheimer's disease (AD), Parkinson's disease (PD), and stroke, has generated substantial public concern. Unfortunately, despite of discoveries of common factors underlying these diseases, few drugs are available to effectively treat these diseases. Peroxisome proliferator-activated receptor gamma (PPAR-γ) is a ligand-activated transcriptional factor that belongs to the nuclear hormone receptor superfamily. PPAR-γ has been shown to influence the expression or activity of a large number of genes in a variety of signaling networks, including regulation of insulin sensitivity, glucose homeostasis, fatty acid oxidation, immune responses, redox balance, cardiovascular integrity, and cell fates. Recent epidemiological, preclinical animal, and clinical studies also show that PPAR-γ agonists can lower the incidence of a number of neurological disorders, despite of multiple etiological factors involved in the development of these disorders. In this manuscript, we review current knowledge on mechanisms underlying the beneficial effect of PPAR-γ in different neurodegenerative diseases, in particular, AD, PD, and stroke, and attempt to analyze common and overlapping features among these diseases. Our investigation unveiled information suggesting the ability for PPAR-γ to inhibit NF-κB-mediated inflammatory signaling at multiple sites, and conclude that PPAR-γ agonists represent a novel class of drugs for treating neuroinflammatory diseases.
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262
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Bradshaw AM, Hamacher T. Nonregenerative natural resources in a sustainable system of energy supply. CHEMSUSCHEM 2012; 5:550-562. [PMID: 22351622 DOI: 10.1002/cssc.201100563] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Indexed: 05/31/2023]
Abstract
Following the lead of the European Union in introducing binding measures to promote the use of regenerative energy forms, it is not unreasonable to assume that the global demand for combustible raw materials for energy generation will be reduced considerably in the second half of this century. This will not only have a favourable effect on the CO(2) concentration in the atmosphere, but will also help preserve fossil fuels-important as raw materials in the chemical industry-for future generations. Nevertheless, associated with the concomitant massive shift to regenerative energy forms, there will be a strong demand for other exhaustible raw materials, in particular metals, some of which are already regarded as scarce. After reviewing the debate on mineral depletion between "cornucopians" and "pessimists", we discuss the meaning of mineral "scarcity", particularly in the geochemical sense, and mineral "exhaustion". The expected drastic increase in demand for mineral resources caused by demographic and societal pressures, that is, due to the increase in in-use stock, is emphasised. Whilst not discussing the issue of "strong" versus "weak" sustainability in detail, we conclude that regenerative energy systems-like nearly all resource-consuming systems in our society-do not necessarily satisfy generally accepted sustainability criteria. In this regard, we discuss some current examples, namely, lithium and cobalt for batteries, rare earth-based permanent magnets for wind turbines, cadmium and tellurium for solar cells and copper for electrical power distribution.
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Affiliation(s)
- Alex M Bradshaw
- Max-Planck-Institut für Plasmaphysik (Garching/Greifswald) and Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin, Germany.
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263
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Antonelli A, Ferrari SM, Frascerra S, Ruffilli I, Gelmini S, Minuto M, Pupilli C, Miccoli P, Sellari-Franceschini S, Ferrannini E, Fallahi P. Peroxisome proliferator-activated receptor-α agonists modulate CXCL9 and CXCL11 chemokines in Graves' ophthalmopathy fibroblasts and preadipocytes. Mol Cell Endocrinol 2012; 349:255-61. [PMID: 22101320 DOI: 10.1016/j.mce.2011.11.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 10/25/2011] [Accepted: 11/04/2011] [Indexed: 10/15/2022]
Abstract
Peroxisome proliferator-activated receptors (PPAR)α have been shown to exert immunomodulatory effects in autoimmune disorders; no study evaluated the effect of PPARα activation in Graves' ophthalmopathy (GO). We show the presence of PPARα, δ and γ in GO fibroblasts and preadipocytes. PPARα activators have a potent inhibitory action on the secretion of CXCL9 and CXCL11 chemokines (induced by IFNγ and TNFα) in fibroblasts and preadipocytes. The potency of the used PPARα agonists was maximum on the secretion of CXCL11 (67% inhibition by fenofibrate) in fibroblasts. The relative potency of the compounds in GO fibroblasts was different with each chemokine. PPARα agonists were stronger inhibitors of CXCL9 and CXCL11 (in GO fibroblasts and preadipocytes) than PPARγ activators. This study first shows that PPARα activators inhibit CXCL9 and CXCL11 chemokines in normal and GO fibroblasts and preadipocytes, suggesting that PPARα may be involved in the modulation of the immune response in GO.
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Affiliation(s)
- Alessandro Antonelli
- Department of Internal Medicine, University of Pisa - School of Medicine, Via Roma 67, I-56100 Pisa, Italy.
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264
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Hsu WH, Lee BH, Liao TH, Hsu YW, Pan TM. Monascus-fermented metabolite monascin suppresses inflammation via PPAR-γ regulation and JNK inactivation in THP-1 monocytes. Food Chem Toxicol 2012; 50:1178-86. [PMID: 22381257 DOI: 10.1016/j.fct.2012.02.029] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Revised: 12/18/2011] [Accepted: 02/15/2012] [Indexed: 12/22/2022]
Abstract
Fermentation products of the fungus Monascus offer valuable therapeutic benefits and have been used extensively for centuries in Asia. The aim of this study is to investigate the inhibitory effect of the Monascus-fermented metabolite monascin (MS) on the molecular mechanism of ovalbumin (OVA)-induced inflammation in the human THP-1 monocyte cell line. We found that 1, 5, and 25 μM of MS significantly attenuated several proinflammatory mediators, including inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression as well as nitric oxide (NO) and prostaglandin E(2) (PGE(2)) formation caused by OVA stimulation. Further, 5 and 25 μM of MS significantly reduced the generation of tumor necrosis factor-α (TNF-α) and interleukin 6 (IL-6) at both the protein and mRNA levels. MS (5 and 25 μM) decreased OVA-induced phosphorylation of mitogen-activated protein kinase (MAPK) c-Jun NH(2)-terminal kinase (JNK), but not that of extracellular signal-regulated kinase (ERK) or p38 kinase. We used the peroxisome proliferator activated receptor-γ (PPAR-γ) antagonist GW9662 to show that MS inhibit JNK phosphorylation through increased expression of PPAR-γ. Thus, the metabolites from Monascus fermentation may serve as a dietary source of anti-inflammatory agents.
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Affiliation(s)
- Wei-Hsuan Hsu
- Department of Biochemical Science and Technology, College of Life Science, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan
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265
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Lee JH, Kim H, Woo JH, Joe EH, Jou I. 5, 8, 11, 14-eicosatetraynoic acid suppresses CCL2/MCP-1 expression in IFN-γ-stimulated astrocytes by increasing MAPK phosphatase-1 mRNA stability. J Neuroinflammation 2012; 9:34. [PMID: 22339770 PMCID: PMC3308915 DOI: 10.1186/1742-2094-9-34] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Accepted: 02/18/2012] [Indexed: 01/20/2023] Open
Abstract
Background The peroxisome proliferator-activated receptor (PPAR)-α activator, 5,8,11,14-eicosatetraynoic acid (ETYA), is an arachidonic acid analog. It is reported to inhibit up-regulation of pro-inflammatory genes; however, its underlying mechanism of action is largely unknown. In the present study, we focused on the inhibitory action of ETYA on the expression of the chemokine, CCL2/MCP-1, which plays a key role in the initiation and progression of inflammation. Methods To determine the effect of ETYA, primary cultured rat astrocytes and microglia were stimulated with IFN-γ in the presence of ETYA and then, expression of CCL2/MCP-1 and MAPK phosphatase (MKP-1) were determined using RT-PCR and ELISA. MKP-1 mRNA stability was evaluated by treating actinomycin D. The effect of MKP-1 and human antigen R (HuR) was analyzed by using specific siRNA transfection system. The localization of HuR was analyzed by immunocytochemistry and subcellular fractionation experiment. Results We found that ETYA suppressed CCL2/MCP-1 transcription and secretion of CCL2/MCP-1 protein through up-regulation of MKP-1mRNA levels, resulting in suppression of c-Jun N-terminal kinase (JNK) phosphorylation and activator protein 1 (AP1) activity in IFN-γ-stimulated brain glial cells. Moreover, these effects of ETYA were independent of PPAR-α. Experiments using actinomycin D revealed that the ETYA-induced increase in MKP-1 mRNA levels reflected an increase in transcript stability. Knockdown experiments using small interfering RNA demonstrated that this increase in MKP-1 mRNA stability depended on HuR, an RNA-binding protein known to promote enhanced mRNA stability. Furthermore, ETYA-induced, HuR-mediated mRNA stabilization resulted from HuR-MKP-1 nucleocytoplasmic translocation, which served to protect MKP-1 mRNA from the mRNA degradation machinery. Conclusion ETYA induces MKP-1 through HuR at the post-transcriptional level in a receptor-independent manner. The mechanism revealed here suggests eicosanoids as potential therapeutic modulators of inflammation that act through a novel target.
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Affiliation(s)
- Jee Hoon Lee
- Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon 442-721, Korea.
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266
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The renoprotective actions of peroxisome proliferator-activated receptors agonists in diabetes. PPAR Res 2012; 2012:456529. [PMID: 22448165 PMCID: PMC3289856 DOI: 10.1155/2012/456529] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2011] [Revised: 11/21/2011] [Accepted: 11/21/2011] [Indexed: 12/17/2022] Open
Abstract
Pharmaceutical agonists of peroxisome proliferator-activated receptors (PPARs) are widely used in the management of type 2 diabetes, chiefly as lipid-lowering agents and oral hypoglycaemic agents. Although most of the focus has been placed on their cardiovascular effects, both positive and negative, these agents also have significant renoprotective actions in the diabetic kidney. Over and above action on metabolic control and effects on blood pressure, PPAR agonists also appear to have independent effects on a number of critical pathways that are implicated in the development and progression of diabetic kidney disease, including oxidative stress, inflammation, hypertrophy, and podocyte function. This review will examine these direct and indirect actions of PPAR agonists in the diabetic kidney and explore recent findings of clinical trials of PPAR agonists in patients with diabetes.
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267
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Harmon GS, Lam MT, Glass CK. PPARs and lipid ligands in inflammation and metabolism. Chem Rev 2012; 111:6321-40. [PMID: 21988241 DOI: 10.1021/cr2001355] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Gregory S Harmon
- Department of Medicine, Division of Digestive Diseases, University of California-Los Angeles, Los Angeles, California 90095, USA
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268
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Shi SY, Martin RG, Duncan RE, Choi D, Lu SY, Schroer SA, Cai EP, Luk CT, Hopperton KE, Domenichiello AF, Tang C, Naples M, Dekker MJ, Giacca A, Adeli K, Wagner KU, Bazinet RP, Woo M. Hepatocyte-specific deletion of Janus kinase 2 (JAK2) protects against diet-induced steatohepatitis and glucose intolerance. J Biol Chem 2012; 287:10277-10288. [PMID: 22275361 DOI: 10.1074/jbc.m111.317453] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is becoming the leading cause of chronic liver disease and is now considered to be the hepatic manifestation of the metabolic syndrome. However, the role of steatosis per se and the precise factors required in the progression to steatohepatitis or insulin resistance remain elusive. The JAK-STAT pathway is critical in mediating signaling of a wide variety of cytokines and growth factors. Mice with hepatocyte-specific deletion of Janus kinase 2 (L-JAK2 KO mice) develop spontaneous steatosis as early as 2 weeks of age. In this study, we investigated the metabolic consequences of jak2 deletion in response to diet-induced metabolic stress. To our surprise, despite the profound hepatosteatosis, deletion of hepatic jak2 did not sensitize the liver to accelerated inflammatory injury on a prolonged high fat diet (HFD). This was accompanied by complete protection against HFD-induced whole-body insulin resistance and glucose intolerance. Improved glucose-stimulated insulin secretion and an increase in β-cell mass were also present in these mice. Moreover, L-JAK2 KO mice had progressively reduced adiposity in association with blunted hepatic growth hormone signaling. These mice also exhibited increased resting energy expenditure on both chow and high fat diet. In conclusion, our findings indicate a key role of hepatic JAK2 in metabolism such that its absence completely arrests steatohepatitis development and confers protection against diet-induced systemic insulin resistance and glucose intolerance.
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Affiliation(s)
- Sally Yu Shi
- Toronto General Research Institute, Toronto, Ontario M5G 2C4, Canada,; Institute of Medical Science, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | | | - Robin E Duncan
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario M5S 3E2, Canada
| | - Diana Choi
- Toronto General Research Institute, Toronto, Ontario M5G 2C4, Canada,; Institute of Medical Science, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | - Shun-Yan Lu
- Toronto General Research Institute, Toronto, Ontario M5G 2C4, Canada
| | | | - Erica P Cai
- Toronto General Research Institute, Toronto, Ontario M5G 2C4, Canada,; Institute of Medical Science, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | - Cynthia T Luk
- Toronto General Research Institute, Toronto, Ontario M5G 2C4, Canada,; Institute of Medical Science, University of Toronto, Toronto, Ontario M5G 2M9, Canada
| | - Kathryn E Hopperton
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario M5S 3E2, Canada
| | | | - Christine Tang
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Mark Naples
- Molecular Structure and Function, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Ontario M5G 1X8, Canada
| | - Mark J Dekker
- Molecular Structure and Function, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Ontario M5G 1X8, Canada
| | - Adria Giacca
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Khosrow Adeli
- Molecular Structure and Function, Research Institute, The Hospital for Sick Children, University of Toronto, Toronto, Ontario M5G 1X8, Canada
| | - Kay-Uwe Wagner
- Eppley Institute for Research in Cancer and Allied Diseases and the Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska 68198-6805, and
| | - Richard P Bazinet
- Department of Nutritional Sciences, University of Toronto, Toronto, Ontario M5S 3E2, Canada
| | - Minna Woo
- Toronto General Research Institute, Toronto, Ontario M5G 2C4, Canada,; Institute of Medical Science, University of Toronto, Toronto, Ontario M5G 2M9, Canada.,; Department of Medicine and Keenan Research Centre in the Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario M3B 1W5, Canada.
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269
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Peroxisome Proliferator-Activator Receptor γ: A Link between Macrophage CD36 and Inflammation in Malaria Infection. PPAR Res 2012; 2012:640769. [PMID: 22287954 PMCID: PMC3263638 DOI: 10.1155/2012/640769] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Accepted: 10/19/2011] [Indexed: 12/21/2022] Open
Abstract
Severe malaria infection caused by Plasmodium falciparum is a global life-threatening disease and a leading cause of death worldwide. Intensive investigations have demonstrated that macrophages play crucial roles in control of inflammatory and immune responses and clearance of Plasmodium-falciparum-parasitized erythrocytes (PE). This paper focuses on how macrophage CD36 recognizes and internalizes PE and participates the inflammatory signaling in response to Plasmodium falciparum. In addition, recent advances in our current understanding of the biological actions of PPARγ on CD36 and malaria clearance from the hosts are highlighted.
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270
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Vanden Heuvel JP. Nutrigenomics and Nutrigenetics of ω3 Polyunsaturated Fatty Acids. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 108:75-112. [DOI: 10.1016/b978-0-12-398397-8.00004-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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271
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Peroxisome proliferating activating receptor gamma-independent attenuation of interleukin 6 and interleukin 8 secretion from primary endometrial stromal cells by thiazolidinediones. Fertil Steril 2011; 97:657-64. [PMID: 22192353 DOI: 10.1016/j.fertnstert.2011.12.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 12/01/2011] [Accepted: 12/01/2011] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To assess the effect of thiazolidinediones on the regulation of inflammatory cytokines related to endometriosis in endometrial tissue and determine whether these effects occur via activation of the peroxisome proliferating activating receptor gamma (PPAR)-γ. DESIGN In vitro study using eutopic endometrial tissue. SETTING University hospital. PATIENT(S) Premenopausal women undergoing laparoscopy for infertility or abdominal pain. INTERVENTION(S) Isolation of endometrial stromal cells and the culture of these cells in the presence of thiazolidinediones, ciglitazone and pioglitazone, both with and without a pretreatment of the specific, irreversible PPAR-γ antagonist GW9662. MAIN OUTCOME MEASURE(S) Quantitation of interleukin (IL)-6 and IL-8 released into the cell culture medium by ELISA. Real-time polymerase chain reaction to quantitate PPAR-γ gene expression in the primary cell preparations and the expression of IL-6 and IL-8 after thiazolidinedione treatment. RESULT(S) Treatment of stromal cells with thiazolidinediones attenuated IL-6 and IL-8 release in a dose-dependent manner. This effect was not inhibited by GW9662 pretreatment. Ciglitazone induced IL-6 messenger RNA expression, an effect that was suppressed by GW9662 pretreatment. CONCLUSION(S) Thiazolidinediones decrease the proinflammatory cytokines IL-6 and IL-8 in endometrial stromal cells via a PPAR-γ-independent mechanism. A better understanding of the anti-inflammatory action of this class of drugs may improve their safety and efficacy for endometriosis treatment.
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272
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Lin TH, Tang CH, Wu K, Fong YC, Yang RS, Fu WM. 15-deoxy-Δ(12,14) -prostaglandin-J2 and ciglitazone inhibit TNF-α-induced matrix metalloproteinase 13 production via the antagonism of NF-κB activation in human synovial fibroblasts. J Cell Physiol 2011; 226:3242-50. [PMID: 21344384 DOI: 10.1002/jcp.22685] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Collagenase-3 (matrix metalloproteinase, MMP-13) plays an important role in the degradation of cartilage in pathologic conditions. MMP-13 is elevated in joint tissues in both rheumatoid arthritis (RA) and osteoarthritis (OA). In addition, inflammation-stimulated synovial fibroblasts are able to release MMP-13 and other cytokines in these diseases. The peroxisome proliferator-activated receptor-γ (PPARγ) ligands are recently considered as new anti-inflammatory compounds and these ligands were reported to ameliorate inflammatory arthritis. The aim of this study is to evaluate the mechanisms how PPARγ ligands inhibit the inflammatory response in synovial fibroblasts. Two PPARγ ligands, cyclopentenone prostaglandin 15-deoxy-Δ(12,14) -prostaglandin-J2 (15d-PGJ2) and synthetic thiazolidinedione compound ciglitazone were examined in this study. Here we found that 15d-PGJ2 and ciglitazone markedly inhibited TNF-α-induced MMP-13 production in human synovial fibroblasts. In addition, activation of nuclear factor κB (NF-κB) is strongly associated with MMP-13 induction by TNF-α and the activation of NF-κB was determined by Western blot, reporter assay, and immunofluorescence. It was found that 15d-PGJ2 markedly attenuated the translocation of NF-κB by direct inhibition of the activation of IKK via a PPARγ-independent manner. Ciglitazone also inhibits TNF-α-induced MMP-13 expression by suppressing NF-κB activation mainly via the modulation of p38-MAPK. Collectively, our data demonstrate that 15d-PGJ2 and ciglitazone attenuated TNF-α-induced MMP-13 expression in synovial fibroblasts primarily through the modulation of NF-κB signaling pathways. These compounds may have therapeutic application in inflammatory arthritis.
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Affiliation(s)
- Tzu-Hung Lin
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
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273
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Catalgol B, Kartal Ozer N. Lipid rafts and redox regulation of cellular signaling in cholesterol induced atherosclerosis. Curr Cardiol Rev 2011; 6:309-24. [PMID: 22043207 PMCID: PMC3083812 DOI: 10.2174/157340310793566181] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2010] [Revised: 06/13/2010] [Accepted: 06/17/2010] [Indexed: 02/06/2023] Open
Abstract
Redox mediated signaling mechanisms play crucial roles in the pathogenesis of several cardiovascular diseases. Atherosclerosis is one of the most important disorders induced mainly by hypercholesterolemia. Oxidation products and related signaling mechanisms are found within the characteristic biomarkers of atherosclerosis. Several studies have shown that redox signaling via lipid rafts play a significant role in the regulation of pathogenesis of many diseases including atherosclerosis. This review attempts to summarize redox signaling and lipid rafts in hypercholesterolemia induced atherosclerosis.
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Affiliation(s)
- Betul Catalgol
- Department of Biochemistry, Faculty of Medicine, Marmara University, 34668 Haydarpasa, Istanbul, Turkey
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274
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The Monascus metabolite monascin against TNF-α-induced insulin resistance via suppressing PPAR-γ phosphorylation in C2C12 myotubes. Food Chem Toxicol 2011; 49:2609-17. [DOI: 10.1016/j.fct.2011.07.005] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 07/02/2011] [Accepted: 07/06/2011] [Indexed: 01/11/2023]
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275
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Brooks JD, Musiek ES, Koestner TR, Stankowski JN, Howard JR, Brunoldi EM, Porta A, Zanoni G, Vidari G, Morrow JD, Milne GL, McLaughlin B. The fatty acid oxidation product 15-A3t-isoprostane is a potent inhibitor of NFκB transcription and macrophage transformation. J Neurochem 2011; 119:604-16. [PMID: 21838782 DOI: 10.1111/j.1471-4159.2011.07422.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Fatty acids such as eicosapentaenoic acid (EPA) have been shown to be beneficial for neurological function and human health. It is widely thought that oxidation products of EPA are responsible for biological activity, although the specific EPA peroxidation product(s) which exert these responses have not yet been identified. In this work we provide the first evidence that the synthesized representative cyclopentenone IsoP, 15-A(3t)-IsoP, serves as a potent inhibitor of lipopolysaccharide-stimulated macrophage activation. The anti-inflammatory activities of 15-A(3t)-IsoP were observed in response not only to lipopolysaccharide, but also to tumor necrosis factor alpha and IL-1b stimulation. Subsequently, this response blocked the ability of these compounds to stimulate nuclear factor kappa b (NFκB) activation and production of proinflammatory cytokines. The bioactivity of 15-A(3t)-IsoP was shown to be dependent upon an unsaturated carbonyl residue which transiently adducts to free thiols. Site directed mutagenesis of the redox sensitive C179 site of the Ikappa kinase beta subunit, blocked the biological activity of 15-A(3t)-IsoP and NFκB activation. The vasoprotective potential of 15-A(3t)-IsoP was underscored by the ability of this compound to block oxidized lipid accumulation, a critical step in foam cell transformation and atherosclerotic plaque formation. Taken together, these are the first data identifying the biological activity of a specific product of EPA peroxidation, which is formed in abundance in vivo. The clear mechanism linking 15-A(3t)-IsoP to redox control of NFκB transcription, and the compound's ability to block foam cell transformation suggest that 15-A(3t)-IsoP provides a unique and potent tool to provide vaso- and cytoprotection under conditions of oxidative stress.
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Affiliation(s)
- Joshua D Brooks
- Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, Tennessee 37232-8548, USA
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276
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Götz AA, Vidal-Puig A, Rödel HG, de Angelis MH, Stoeger T. Carbon-nanoparticle-triggered acute lung inflammation and its resolution are not altered in PPARγ-defective (P465L) mice. Part Fibre Toxicol 2011; 8:28. [PMID: 21933390 PMCID: PMC3197489 DOI: 10.1186/1743-8977-8-28] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 09/20/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The alveolar macrophage (AM) - first line of innate immune defence against pathogens and environmental irritants - constitutively expresses peroxisome-proliferator activated receptor γ (PPARγ). PPARγ ligand-induced activation keeps the AM quiescent, and thereby contributes to combat invaders and resolve inflammation by augmenting the phagocytosis of apoptotic neutrophils and inhibiting an excessive expression of inflammatory genes. Because of these presumed anti-inflammatory functions of PPARγ we tested the hypothesis, whether reduced functional receptor availability in mutant mice resulted in increased cellular and molecular inflammatory response during acute inflammation and/or in an impairment of its resolution. METHODS To address this hypothesis we examined the effects of a carbon-nanoparticle (CNP) lung challenge, as surrogate for non-infectious environmental irritants, in a murine model carrying a dominant-negative point mutation in the ligand-binding domain of PPARγ (P465L/wt). Animals were instilled intratracheally with Printex 90 CNPs and bronchoalveolar lavage (BAL) was gained 24 h or 72 h after instillation to investigate its cellular and protein composition. RESULTS Higher BAL cell numbers - due to higher macrophage counts - were found in mutants irrespective of treatment. Neutrophil numbers in contrast were slightly lower in mutants. Intratracheal CNP instillation resulted in a profound recruitment of inflammatory neutrophils into the alveolus, but genotype related differences at acute inflammation (24 h) and resolution (72 h) were not observed. There were no signs for increased alveolar-capillary membrane damage or necrotic cell death in mutants as determined by BAL protein and lactate-dehydrogenase content. Pro-inflammatory macrophage-derived cytokine osteopontin was higher, but galectin-3 lower in female mutants. CXCL5 and lipocalin-2 markers, attributed to epithelial cell stimulation did not differ. CONCLUSIONS Despite general genotype-related differences, we had to reject our hypothesis of an increased CNP induced lung inflammation and an impairment of its resolution in PPARγ defective mice. Although earlier studies showed ligand-induced activation of nuclear receptor PPARγ to promote resolution of lung inflammation, its reduced activity did not provide signs of resolution impairment in the settings investigated here.
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Affiliation(s)
- Alexander A Götz
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg/Munich, D-85764, Germany
| | - Antonio Vidal-Puig
- Metabolic Research Laboratories, Level 4, Institute of Metabolic Science, Box 289, NIHR Cambridge Biomedical Research Centre Addenbrooke's Hospital, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Heiko G Rödel
- Laboratory of Experimental and Comparative Ethology, University of Paris 13, F-93430, Villetaneuse, France
| | - Martin Hrabé de Angelis
- Institute of Experimental Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg/Munich, D-85764, Germany
| | - Tobias Stoeger
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstaedter Landstrasse 1, Neuherberg/Munich, D-85764, Germany
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277
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Nelson SM, Lei X, Prabhu KS. Selenium levels affect the IL-4-induced expression of alternative activation markers in murine macrophages. J Nutr 2011; 141:1754-61. [PMID: 21775527 PMCID: PMC3159059 DOI: 10.3945/jn.111.141176] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Selenium (Se), in the form of selenoproteins, imparts many health benefits with antiinflammatory properties. Previous studies have shown that Se supplementation of macrophages negatively regulates the LPS-dependent production of inducible NO synthase (iNOS), a proinflammatory gene. Therefore, we hypothesized that l-arginine, a substrate for iNOS, is acted upon by arginase-I (Arg-I), contributing to the resolution of inflammation. We investigated the antiinflammatory activity of Se using LPS and IL-4-treated C57BL/6 murine bone marrow-derived macrophages (BMDM) from mice fed Se-deficient and Se-adequate diets. Supplementation with Se (100 nmol/L) of IL-4-treated macrophages significantly increased the expression of alternatively activated macrophage (M2) markers, Arg-I, Fizz1, and Mrc-1. Se treatment also increased the enzymatic activity of Arg-I and surface expression of Mrc-1. Conversely, expression of classically activated macrophage (M1) markers, TNFα, and IL-1β, was significantly decreased in LPS-treated macrophages that were cultured in Se and IL-4, suggesting a synergistic effect between Se and IL-4. Additionally, Arg-I activity was decreased in BMDM harvested from glutathione peroxidase (GPX) knockout mice compared to GPX wild-type mice, further establishing an important role for selenoproteins. Furthermore, BMDM treated with inhibitors of PPARγ and STAT6, pivotal transcription factors that mediate the activity of Se and IL-4, respectively, showed complete ablation of Se-dependent expression of M2 markers. In summary, these studies suggest that Se supplementation of macrophages produces endogenous activators to mediate the PPARγ-dependent switch from M1 to M2 phenotype in the presence of IL-4, possibly affecting pathways of wound healing and inflammation resolution.
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Affiliation(s)
- Shakira M. Nelson
- Graduate Program in Pathobiology, Center for Molecular Immunology and Infectious Disease and Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA
| | - Xingen Lei
- Department of Animal Sciences, Cornell University, Ithaca, NY
| | - K. Sandeep Prabhu
- Graduate Program in Pathobiology, Center for Molecular Immunology and Infectious Disease and Center for Molecular Toxicology and Carcinogenesis, Department of Veterinary and Biomedical Sciences, The Pennsylvania State University, University Park, PA,To whom correspondence should be addressed. E-mail:
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278
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An in vitro analysis system using a fluorescence protein reporter for evaluating anti-inflammatory effects in macrophages. Biosci Biotechnol Biochem 2011; 75:1582-7. [PMID: 21821941 DOI: 10.1271/bbb.110278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Monitoring of inflammation in adipose tissues, which causes insulin resistance, is valuable in evaluating insulin resistance. We developed an in vitro analysis system using a fluorescence protein (FP) as a reporter gene driven by pro-inflammatory cytokine promoters such as monocyte chemoattractant protein-1 (MCP-1) and tumor necrosis factor-α (TNFα). In the reporter-transfected RAW264 cells, the protein expression levels of green fluorescence protein (GFP) were increased by inflammatory stimulations such as lipopolysaccharide (LPS), conditioned medium prepared using hypertrophied 3T3-L1 adipocytes, and a co-culture system. The changes in fluorescence intensity were equivalent to those of the mRNA and protein expression levels for each cytokine. Moreover, the effects of 15-deoxy-12,14Δ-prostaglandine J(2), a natural anti-inflammatory compound, were detectable in this system. These data indicate that the FP system developed here is an analysis system of low cost with simple procedures for evaluating inflammation, suggesting usability in the large-scale screening of anti-inflammatory compounds.
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279
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Rioux CL, Tucker KL, Brugge D, Gute DM, Mwamburi M. Traffic exposure in a population with high prevalence type 2 diabetes--do medications influence concentrations of C-reactive protein? ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2011; 159:2051-60. [PMID: 21292365 PMCID: PMC3412137 DOI: 10.1016/j.envpol.2010.12.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Revised: 12/20/2010] [Accepted: 12/23/2010] [Indexed: 05/28/2023]
Abstract
Type 2 Diabetes (T2D) and particulate air pollution are associated with inflammatory dysregulation. We assessed the modifying effects of diabetes medications on the association of C-reactive protein (CRP), a marker of inflammation, and traffic exposure in adults with T2D (n = 379). CRP concentrations were significantly positively associated with residence ≤100 m of a roadway, >100 m and ≤200 m of a roadway and increased traffic density for individuals using insulin. For individuals using oral hypoglycemic medications (OHAs), CRP was significantly negatively associated with residence >100 m - ≤200 m of a roadway and multiple roadway exposure in an interaction model. Among people with diabetes, individuals on insulin appear to be most vulnerable to the effects of traffic exposure. Disease severity among insulin users may promote the pro-inflammatory response to traffic exposure, though diabetes medications may also modify the response. Possible anti-inflammatory effects of OHAs with traffic exposure merit further evaluation.
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Affiliation(s)
- Christine L Rioux
- Department of Public Health and Community Medicine, Tufts University, 136 Harrison Avenue, Boston, MA 02111, USA.
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280
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Mencarelli A, Distrutti E, Renga B, D'Amore C, Cipriani S, Palladino G, Donini A, Ricci P, Fiorucci S. Probiotics modulate intestinal expression of nuclear receptor and provide counter-regulatory signals to inflammation-driven adipose tissue activation. PLoS One 2011; 6:e22978. [PMID: 21829567 PMCID: PMC3146529 DOI: 10.1371/journal.pone.0022978] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 07/04/2011] [Indexed: 12/16/2022] Open
Abstract
Background Adipocytes from mesenteric white adipose tissue amplify the inflammatory response and participate in inflammation-driven immune dysfunction in Crohn's disease by releasing proinflammatory mediators. Peroxisome proliferator-activated receptors (PPAR)-α and -γ, pregnane x receptor (PXR), farnesoid x receptor (FXR) and liver x-receptor (LXR) are ligand-activated nuclear receptor that provide counter-regulatory signals to dysregulated immunity and modulates adipose tissue. Aims To investigate the expression and function of nuclear receptors in intestinal and adipose tissues in a rodent model of colitis and mesenteric fat from Crohn's patients and to investigate their modulation by probiotics. Methods Colitis was induced by TNBS administration. Mice were administered vehicle or VSL#3, daily for 10 days. Abdominal fat explants obtained at surgery from five Crohn's disease patients and five patients with colon cancer were cultured with VSL#3 medium. Results Probiotic administration attenuated development of signs and symptoms of colitis, reduced colonic expression of TNFα, IL-6 and IFNγ and reserved colonic downregulation of PPARγ, PXR and FXR caused by TNBS. Mesenteric fat depots isolated from TNBS-treated animals had increased expression of inflammatory mediators along with PPARγ, FXR, leptin and adiponectin. These changes were prevented by VSL#3. Creeping fat and mesenteric adipose tissue from Crohn's patients showed a differential expression of PPARγ and FXR with both tissue expressing high levels of leptin. Exposure of these tissues to VSL#3 medium abrogates leptin release. Conclusions Mesenteric adipose tissue from rodent colitis and Crohn's disease is metabolically active and shows inflammation-driven regulation of PPARγ, FXR and leptin. Probiotics correct the inflammation-driven metabolic dysfunction.
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Affiliation(s)
- Andrea Mencarelli
- Dipartimento di Medicina Clinica e Sperimentale, University of Perugia, Facoltà di Medicina e Chirurgia, Via Gerardo Dottori n° 1 S. Andrea delle Fratte, Perugia, Italy
| | - Eleonora Distrutti
- Azienda Ospedaliera di Perugia, Ospedale Santa Maria della Misericordia, S. Andrea delle Fratte, Perugia, Italy
| | - Barbara Renga
- Dipartimento di Medicina Clinica e Sperimentale, University of Perugia, Facoltà di Medicina e Chirurgia, Via Gerardo Dottori n° 1 S. Andrea delle Fratte, Perugia, Italy
| | - Claudio D'Amore
- Dipartimento di Medicina Clinica e Sperimentale, University of Perugia, Facoltà di Medicina e Chirurgia, Via Gerardo Dottori n° 1 S. Andrea delle Fratte, Perugia, Italy
| | - Sabrina Cipriani
- Dipartimento di Medicina Clinica e Sperimentale, University of Perugia, Facoltà di Medicina e Chirurgia, Via Gerardo Dottori n° 1 S. Andrea delle Fratte, Perugia, Italy
| | - Giuseppe Palladino
- Dipartimento di Medicina Clinica e Sperimentale, University of Perugia, Facoltà di Medicina e Chirurgia, Via Gerardo Dottori n° 1 S. Andrea delle Fratte, Perugia, Italy
| | - Annibale Donini
- Dipartimento di Scienze Chirurgiche, Radiologiche e Odontostomatologiche, Nuova Facoltà di Medicina e Chirurgia Sant' Andrea delle Fratte, Perugia, Italy
| | - Patrizia Ricci
- Dipartimento di Scienze Chirurgiche, Radiologiche e Odontostomatologiche, Nuova Facoltà di Medicina e Chirurgia Sant' Andrea delle Fratte, Perugia, Italy
| | - Stefano Fiorucci
- Dipartimento di Medicina Clinica e Sperimentale, University of Perugia, Facoltà di Medicina e Chirurgia, Via Gerardo Dottori n° 1 S. Andrea delle Fratte, Perugia, Italy
- * E-mail:
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281
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A Comparative Study of Mouse Hepatic and Intestinal Gene Expression Profiles under PPARα Knockout by Gene Set Enrichment Analysis. PPAR Res 2011; 2011:629728. [PMID: 21811494 PMCID: PMC3147148 DOI: 10.1155/2011/629728] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 05/05/2011] [Accepted: 06/07/2011] [Indexed: 11/18/2022] Open
Abstract
Gene expression profiling of PPARα has been used in several studies, but fewer studies went further to identify the tissue-specific pathways or genes involved in PPARα activation in genome-wide. Here, we employed and applied gene set enrichment analysis to two microarray datasets both PPARα related respectively in mouse liver and intestine. We suggested that the regulatory mechanism of PPARα activation by WY14643 in mouse small intestine is more complicated than in liver due to more involved pathways. Several pathways were cancer-related such as pancreatic cancer and small cell lung cancer, which indicated that PPARα may have an important role in prevention of cancer development. 12 PPARα dependent pathways and 4 PPARα independent pathways were identified highly common in both liver and intestine of mice. Most of them were metabolism related, such as fatty acid metabolism, tryptophan metabolism, pyruvate metabolism with regard to PPARα regulation but gluconeogenesis and propanoate metabolism independent of PPARα regulation. Keratan sulfate biosynthesis, the pathway of regulation of actin cytoskeleton, the pathways associated with prostate cancer and small cell lung cancer were not identified as hepatic PPARα independent but as WY14643 dependent ones in intestinal study. We also provided some novel hepatic tissue-specific marker genes.
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282
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Unique mode of lipogenic activation in rat preputial sebocytes. J Nutr Metab 2011; 2011:163631. [PMID: 21808727 PMCID: PMC3144693 DOI: 10.1155/2011/163631] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Accepted: 05/27/2011] [Indexed: 02/02/2023] Open
Abstract
Lipoprotein delivery of fatty acids and cholesterol is linked with peroxisome proliferator-activated receptor (PPAR) activation in adipocytes and macrophages. We postulated that similar interactions exist in sebaceous epithelial cells (sebocytes) in which PPAR activation induces differentiation. High-density lipoprotein (HDL) and very low-density lipoprotein (VLDL) markedly enhanced sebocyte differentiation above that found with PPAR agonists and were more potent than explicable by their lipid content. The PPARγ antagonist GW5393 reduced sebocyte differentiation to all PPAR isoform agonists, HDL and VLDL, suggesting that the lipoprotein effect on differentiation occurs partially through activation of PPARγ. Furthermore, we found that sebocytes expressed a unique pattern of lipogenic genes. Our results demonstrate that HDL and VLDL are the most potent inducers of sebocyte differentiation tested to date, and these actions are partially inhibited by PPAR antagonists. This suggests that substrates provided by lipoproteins are targeted to sebocytes and affect their own disposition via PPAR activation.
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283
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Wan YJY, Badr MZ. Inhibition of Carrageenan-Induced Cutaneous Inflammation by PPAR Agonists Is Dependent on Hepatocyte-Specific Retinoid X ReceptorAlpha. PPAR Res 2011; 2006:96341. [PMID: 17259670 PMCID: PMC1664714 DOI: 10.1155/ppar/2006/96341] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2006] [Revised: 04/20/2006] [Accepted: 04/21/2006] [Indexed: 01/28/2023] Open
Abstract
It has been proposed that PPAR-dependent, accelerated catabolism
of proinflammatory mediators may contribute to the fast resolution
of inflammation. Because retinoid X receptors are obligate
heterodimer partners of PPARs, we investigated the impact of
deleting hepatocyte-specific RXRα on the antiedema effect
of PPAR agonists. In wild-type mice (WT), pretreatment
with the PPARα agonist perfluorooctanoic acid diminished
carrageenan-induced paw edema by 66 ± 10%. This effect was
essentially absent (13 ± 8%) in hepatocyte-specific
RXRα-deficient mice. Similarly, pretreatment of
WT mice with the PPARδ agonist L-783483 or the
PPARγ agonist L-805645 caused 54 ± 1% and
38 ± 8% reduction in carrageenan-induced paw edema,
respectively. These effects were also significantly diminished or
absent in hepatocyte-specific RXRα-deficient mice. In
contrast, aspirin reduced carrageenan-induced paw edema equally in
WT and hepatocyte-specific RXRα-deficient mice.
The identification of RXRα as an important factor involved
in the antiedema effect produced by agonists of the three PPAR
subtypes is a significant achievement towards the goal of
designing novel, effective anti-inflammatory drugs.
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Affiliation(s)
- Yu-Jui Yvonne Wan
- Department of Pharmacology, Toxicology &
Therapeutics, The University of Kansas Medical Center, Kansas
City, KS 66160, USA
| | - Mostafa Z. Badr
- Division of Pharmacology, School of Pharmacy,
University of Missouri-Kansas City, Kansas City, MO
64108, USA
- *Mostafa Z. Badr: ,
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284
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Regulation of Lymphocyte Function by PPARgamma: Relevance to Thyroid Eye Disease-Related Inflammation. PPAR Res 2011; 2008:895901. [PMID: 18354731 PMCID: PMC2266979 DOI: 10.1155/2008/895901] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2007] [Accepted: 12/12/2007] [Indexed: 01/28/2023] Open
Abstract
Thyroid eye disease (TED) is an autoimmune condition in which intense inflammation leads to orbital tissue remodeling, including the accumulation of extracellular macromolecules and fat. Disease progression depends upon interactions between lymphocytes and orbital fibroblasts. These cells engage in a cycle of reciprocal activation which produces the tissue characteristics of TED. Peroxisome proliferator-activated receptor-gamma (PPARgamma) may play divergent roles in this process, both attenuating and promoting disease progression. PPARgamma has anti-inflammatory activity, suggesting that it could interrupt intercellular communication. However, PPARgamma activation is also critical to adipogenesis, making it a potential culprit in the pathological fat accumulation associated with TED. This review explores the role of PPARgamma in TED, as it pertains to crosstalk between lymphocytes and fibroblasts and the development of therapeutics targeting cell-cell interactions mediated through this signaling pathway.
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285
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Gurnell M. 'Striking the Right Balance' in Targeting PPARgamma in the Metabolic Syndrome: Novel Insights from Human Genetic Studies. PPAR Res 2011; 2007:83593. [PMID: 17389771 PMCID: PMC1847466 DOI: 10.1155/2007/83593] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2006] [Revised: 12/13/2006] [Accepted: 12/13/2006] [Indexed: 12/03/2022] Open
Abstract
At a time when the twin epidemics of obesity and type 2 diabetes threaten to engulf even the most well-resourced Western healthcare systems, the nuclear receptor peroxisome proliferator-activated receptor γ (PPARγ) has emerged as a
bona fide therapeutic target for treating human metabolic disease. The novel insulin-sensitizing antidiabetic thiazolidinediones (TZDs, e.g., rosiglitazone, pioglitazone), which are licensed for use in the treatment of type 2 diabetes, are high-affinity PPARγ ligands, whose beneficial effects extend beyond improvement in glycaemic control to include amelioration of dyslipidaemia, lowering of blood pressure, and favourable modulation of macrophage lipid handling and inflammatory responses. However, a major drawback to the clinical use of exisiting TZDs is weight gain, reflecting both enhanced adipogenesis and fluid retention, neither of which is desirable in a population that is already overweight and prone to cardiovascular disease. Accordingly, the “search is on” to identify the next generation of PPARγ modulators that will promote maximal clinical benefit by targeting specific facets of the metabolic syndrome (glucose intolerance/diabetes, dyslipidaemia, and hypertension), while simultaneously avoiding undesirable side effects of PPARγ activation (e.g., weight gain). This paper outlines the important clinical and laboratory observations made in human subjects harboring genetic variations in PPARγ that support such a therapeutic strategy.
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Affiliation(s)
- Mark Gurnell
- Department of Medicine, University of Cambridge, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ, UK
- *Mark Gurnell:
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286
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Pathophysiological Roles of PPARgamma in Gastrointestinal Epithelial Cells. PPAR Res 2011; 2008:148687. [PMID: 18615192 PMCID: PMC2443401 DOI: 10.1155/2008/148687] [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: 03/28/2008] [Accepted: 05/19/2008] [Indexed: 12/11/2022] Open
Abstract
Although the highest levels of PPARγ expression in the body have been reported in the gastrointestinal epithelium, little is known about the physiological functions of that receptor in the gut. Moreover, there is considerable controversy concerning the effects of thiazolidinedione PPARγ agonists on the two major diseases of the gastrointestinal track: colorectal cancer and inflammatory bowel disease. We will undertake to review both historical and recently published data with a view toward summarizing what is presently known about the roles of PPARγ in both physiological and pathological processes in the gastrointestinal epithelium.
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287
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The Role of PPARgamma in the Cyclooxygenase Pathway in Lung Cancer. PPAR Res 2011; 2008:790568. [PMID: 18769553 PMCID: PMC2526169 DOI: 10.1155/2008/790568] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2008] [Revised: 06/18/2008] [Accepted: 07/08/2008] [Indexed: 02/04/2023] Open
Abstract
Decreased expression of peroxisome proliferator activated receptor-γ (PPARγ) and high levels of the proinflammatory enzyme cyclooxygenase-2 (COX-2) have been observed in many tumor types. Both reduced (PPARγ) expression and elevated COX-2 within the tumor are associated with poor prognosis in lung cancer patients, and recent work has indicated that these signaling pathways may be interrelated. Synthetic (PPARγ) agonists such as the thiazolidinedione (TZD) class of anti-diabetic drugs can decrease COX-2 levels, inhibit growth of non-small-cell lung cancer (NSCLC) cells in vitro, and block tumor progression in xenograft models. TZDs alter the expression of COX-2 and consequent production of the protumorigenic inflammatory molecule prostaglandin E2 (PGE2) through both (PPARγ) dependent and independent mechanisms. Certain TZDs also reduce expression of PGE2 receptors or upregulate the PGE2 catabolic enzyme 15-prostaglandin dehydrogenase. As several COX-2 enzymatic products have antitumor properties and specific COX-2 inhibition has been associated with increased risk of adverse cardiac events, directly reducing the effects or concentration of PGE2 may provide a more safe and effective strategy for lung cancer treatment. Understanding the mechanisms underlying these effects may be helpful for designing anticancer therapies. This article summarizes recent research on the relationship between (PPARγ), TZDs, and the COX-2/PGE2 pathways in lung cancer.
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288
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PPAR Gamma: Coordinating Metabolic and Immune Contributions to Female Fertility. PPAR Res 2011; 2008:243791. [PMID: 18309368 PMCID: PMC2246065 DOI: 10.1155/2008/243791] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2007] [Accepted: 07/02/2007] [Indexed: 01/10/2023] Open
Abstract
Peroxisome proliferator-activated receptor gamma (PPARG) regulates cellular functions such as adipogenesis and immune cell activation. However, new information has indicated additional roles of PPARG directing the cyclic changes that occur within ovarian tissue of female mammals, including those that facilitate the release of oocytes each estrous cycle. In addition to ovarian PPARG expression and function, many PPARG actions within adipocytes and macrophages have additional direct and indirect implications for ovarian function and female fertility. This encompasses the regulation of lipid uptake and transport, insulin sensitivity, glucose metabolism, and the regulation of inflammatory mediator synthesis and release. This review discusses the developing links between PPARG activity and female reproductive function, and highlights several mechanisms that may facilitate such a relationship.
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289
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Abstract
PPARs, most notably PPAR-gamma, play a crucial role in regulating the activation of alveolar macrophages, which in turn occupy a pivotal place in the immune response to pathogens and particulates drawn in with inspired air. In this review, we describe the dual role of the alveolar macrophage as both a first-line defender through its phagocytotic activity and a regulator of the immune response. Depending on its state of activation, the alveolar macrophage may either enhance or suppress different aspects of immune function in the lung. We then review the role of PPAR-gamma and its ligands in deactivating alveolar macrophages-thus limiting the inflammatory response that, if unchecked, could threaten the essential respiratory function of the alveolus-while upregulating the cell's phagocytotic activity. Finally, we examine the role that inadequate or inappropriate PPAR-gamma responses play in specific lung diseases.
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290
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Role of peroxisome proliferator-activated receptor gamma and its ligands in the treatment of hematological malignancies. PPAR Res 2011; 2008:834612. [PMID: 18528522 PMCID: PMC2408681 DOI: 10.1155/2008/834612] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Accepted: 04/21/2008] [Indexed: 02/07/2023] Open
Abstract
Peroxisome proliferator-activated receptor gamma (PPARgamma) is a multifunctional transcription factor with important regulatory roles in inflammation, cellular growth, differentiation, and apoptosis. PPARgamma is expressed in a variety of immune cells as well as in numerous leukemias and lymphomas. Here, we review recent studies that provide new insights into the mechanisms by which PPARgamma ligands influence hematological malignant cell growth, differentiation, and survival. Understanding the diverse properties of PPARgamma ligands is crucial for the development of new therapeutic approaches for hematological malignancies.
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291
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PPAR Action in Human Placental Development and Pregnancy and Its Complications. PPAR Res 2011; 2008:527048. [PMID: 18288290 PMCID: PMC2234270 DOI: 10.1155/2008/527048] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2007] [Accepted: 11/13/2007] [Indexed: 01/09/2023] Open
Abstract
During pregnancy crucial anatomic, physiologic, and metabolic changes challenge the mother and the fetus.
The placenta is a remarkable organ that allows the mother and the fetus to adapt to the new metabolic, immunologic,
and angiogenic environment imposed by gestation. One of the physiologic systems that appears to have evolved to
sustain this metabolic regulation is mediated by peroxisome proliferator-activated receptors (PPARs).
In clinical pregnancy-specific disorders, including preeclampsia, gestational diabetes, and intrauterine growth restriction, aberrant regulation of components of the PPAR system parallels dysregulation of metabolism, inflammation and angiogenesis. This review summarizes current knowledge on the role of PPARs in regulating human trophoblast invasion, early placental development, and also in the physiology of clinical pregnancy and its complications. As increasingly indicated in the literature, pregnancy disorders, such as preeclampsia and gestational diabetes, represent potential targets for treatment with PPAR ligands. With the advent of more specific PPAR agonists that exhibit efficacy in ameliorating metabolic, inflammatory, and angiogenic disturbances, further studies of their application in pregnancy-related diseases are warranted.
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292
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Abstract
Mononuclear phagocytes often function as control switches of the immune system, securing the balance between pro- and anti-inflammatory reactions. For this purpose and depending on the activating stimuli, these cells can develop into different subsets: proinflammatory classically activated (M1) or anti-inflammatory alternatively activated (M2) macrophages. The expression of the nuclear peroxisome proliferator-activated receptors (PPARs) is regulated by M1- or M2-inducing stimuli, and these receptors are generally considered to counteract inflammatory M1 macrophages, while actively promoting M2 activation. This is of importance in a tumor context, where M1 are important initiators of inflammation-driven cancers. As a consequence, PPAR agonists are potentially usefull for inhibiting the early phases of tumorigenesis through their antagonistic effect on M1. In more established tumors, the macrophage phenotype is more diverse, making it more difficult to predict the outcome of PPAR agonism. Overall, in our view current knowledge provides a sound basis for the clinical evaluation of PPAR ligands as chemopreventive agents in chronic inflammation-associated cancer development, while cautioning against the unthoughtful application of these agents as cancer therapeutics.
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293
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Abstract
Peroxisome proliferator-activated receptor-γ (PPAR-γ), an essential transcriptional mediator of adipogenesis, lipid metabolism, insulin sensitivity, and glucose homeostasis, is increasingly recognized as a key player in inflammatory cells and in cardiovascular diseases (CVD) such as hypertension, cardiac hypertrophy, congestive heart failure, and atherosclerosis. PPAR-γ agonists, the thiazolidinediones (TZDs), increase insulin sensitivity, lower blood glucose, decrease circulating free fatty acids and triglycerides, lower blood pressure, reduce inflammatory markers, and reduce atherosclerosis in insulin-resistant patients and animal models. Human genetic studies on PPAR-γ have revealed that functional changes in this nuclear receptor are associated with CVD. Recent controversial clinical studies raise the question of deleterious action of PPAR-γ agonists on the cardiovascular system. These complex interactions of metabolic responsive factors and cardiovascular disease promise to be important areas of focus for the future.
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294
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Barak Y, Kim S. Genetic manipulations of PPARs: effects on obesity and metabolic disease. PPAR Res 2011; 2007:12781. [PMID: 17389768 PMCID: PMC1791068 DOI: 10.1155/2007/12781] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 11/10/2006] [Accepted: 11/16/2006] [Indexed: 12/18/2022] Open
Abstract
The interest in genetic manipulations of PPARs is as old as their discovery as receptors of ligands with beneficial clinical activities. Considering the effects of PPAR ligands on critical aspects of systemic physiology, including obesity, lipid metabolism, insulin resistance, and diabetes, gene knockout (KO) in mice is the ideal platform for both hypothesis testing and discovery of new PPAR functions in vivo. With the fervent pursuit of the magic bullet to eradicate the obesity epidemic, special emphasis has been placed on the impacts of PPARs on obesity and its associated diseases. As detailed in this review, understanding how PPARs regulate gene expression and basic metabolic pathways is a necessary intermediate en route to deciphering their effects on obesity. Over a decade and dozens of genetic modifications of PPARs into this effort, valuable lessons have been learned, but we are left with more questions to be answered. These lessons and future prospects are the subject of this review.
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Affiliation(s)
- Yaacov Barak
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
- *Yaacov Barak:
| | - Suyeon Kim
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME 04609, USA
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295
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Celinski K, Dworzanski T, Korolczuk A, Slomka M, Radej S, Cichoz-Lach H, Madro A. Activated and inactivated PPARs-γ modulate experimentally induced colitis in rats. Med Sci Monit 2011; 17:BR116-24. [PMID: 21455100 PMCID: PMC3539512 DOI: 10.12659/msm.881712] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Background This study sought to define the mechanism by which PPAR-γ ligands affect the course of experimentally induced colitis in rats. Material/Methods Inflammation was induced in Wistar rats by a single rectal administration of 2,4,6,-trinitrobenzene sulfonic acid (TNBS). The antagonist of PPARγ antagonist, bisphenol A diglycidyl ether (BADGE), was administrated intraperitoneally 120 mg/kg 4 times every other day. Rosiglitazone 8 mg/kg was administrated by gastric tube 4 times. Body weight was measured daily. After killing, the large intestinal tissue was weighed and collected for histopathologic and immunoenzymatic tests. Levels of IL-6, IL-10, and myeloperoxidase (MPO) were determined in serum and in intestinal homogenates. Results Rats receiving rosiglitazone had higher body weight, whereas large intestine weight/length ratio was lower; histology showed fewer inflammatory markers. Rats receiving TNBS and TNBS along with BADGE had more intensive inflammatory changes. Rosiglitazone alone decreased expression of IL-6; used with TNBS it decreased expression of MPO in intestinal tissue, yet did not increase the expression of IL-10. Decreased levels of MPO indicate reduced neutrophil-dependent immune response. The antagonist of PPAR-γ increased IL-6 in serum and decreased IL-10 in intestinal homogenates. Bisphenol A diglycidyl ether administrated to healthy animals increases serum IL-6 levels. Conclusions Rosiglitazone inhibits experimental inflammation; administration of its selective antagonist abolishes this protective influence. Rosiglitazone inhibits expression of proinflammatory IL-6 and does not affect IL-10. Agonists of PPARs-γ are possibilities for inflammatory bowel disease prevention. Exogenous substances blocking PPARs-γ may contribute to development or relapse of nonspecific inflammatory bowel diseases.
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Affiliation(s)
- Krzysztof Celinski
- Department of Gastroenterology, Medical University of Lublin, Lublin, Poland.
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296
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Thomas MC, Groop PH. New approaches to the treatment of nephropathy in diabetes. Expert Opin Investig Drugs 2011; 20:1057-71. [DOI: 10.1517/13543784.2011.591785] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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297
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Esposito E, Cuzzocrea S. Targeting the peroxisome proliferator-activated receptors (PPARs) in spinal cord injury. Expert Opin Ther Targets 2011; 15:943-59. [DOI: 10.1517/14728222.2011.581231] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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298
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Abstract
Vascular inflammation is associated with and in large part driven by changes in the leukocyte compartment of the vessel wall. Here, we focus on monocyte influx during atherosclerosis, the most common form of vascular inflammation. Although the arterial wall contains a large number of resident macrophages and some resident dendritic cells, atherosclerosis drives a rapid influx of inflammatory monocytes (Ly-6C(+) in mice) and other monocytes (Ly-6C(-) in mice, also known as patrolling monocytes). Once in the vessel wall, Ly-6C(+) monocytes differentiate to a phenotype consistent with inflammatory macrophages and inflammatory dendritic cells. The phenotype of these cells is modulated by lipid uptake, Toll-like receptor ligands, hematopoietic growth factors, cytokines, and chemokines. In addition to newly recruited macrophages, it is likely that resident macrophages also change their phenotype. Monocyte-derived inflammatory macrophages have a short half-life. After undergoing apoptosis, they may be taken up by surrounding macrophages or, if the phagocytic capacity is overwhelmed, can undergo secondary necrosis, a key event in forming the necrotic core of atherosclerotic lesions. In this review, we discuss these and other processes associated with monocytic cell dynamics in the vascular wall and their role in the initiation and progression of atherosclerosis.
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Affiliation(s)
- Klaus Ley
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA.
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299
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Peroxisome proliferator-activated receptor α agonists modulate Th1 and Th2 chemokine secretion in normal thyrocytes and Graves' disease. Exp Cell Res 2011; 317:1527-33. [DOI: 10.1016/j.yexcr.2011.04.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2010] [Revised: 03/29/2011] [Accepted: 04/14/2011] [Indexed: 11/20/2022]
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300
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Peroxisome proliferator-activated receptor γ: innate protection from excessive fibrogenesis and potential therapeutic target in systemic sclerosis. Curr Opin Rheumatol 2011; 22:671-6. [PMID: 20693905 DOI: 10.1097/bor.0b013e32833de1a7] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
PURPOSE OF REVIEW Progressive organ fibrosis and pulmonary arterial hypertension (PAH) are the leading causes of death in patients with systemic sclerosis (SSc). However, the pathogenesis and the link between these two processes remain obscure. A better understanding of these events is needed in order to facilitate the discovery and development of effective therapies for SSc. RECENT FINDINGS Recent reports provide evidence that the orphan receptor peroxisome proliferator-activated receptor γ (PPARγ), better known for its pivotal role in metabolism, has potent effects on inflammation, fibrogenesis and vascular remodeling and is important in the pathogenesis of fibrosis and PAH, and as a potential therapeutic target in SSc. The studies discussed in this review indicate that ligands of PPARγ potently modulate connective tissue turnover and suggest that aberrant expression or function of PPARγ is associated with, and very likely contributes to, the progression of pathological fibrosis and vascular remodeling. These observations are of particularly relevance because FDA-approved drugs of the thiazolidinedione class currently used for the treatment of obesity-associated type 2 diabetes activate PPARγ signaling. Moreover, novel PPARγ ligands with selective activity are under development or in clinical trials for inflammatory diseases, asthma, Alzheimer disease and cancer. SUMMARY Drugs targeting the PPARγ pathway might be effective for the control of fibrosis as well as pathological vascular remodeling underlying PAH and, therefore, might have a therapeutic potential in SSc. A greater understanding of the mechanisms underlying the antifibrogenic and vascular remodeling activities of PPARγ ligands will be necessary in order to advance these drugs into clinical use.
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