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Al Jadani JM, Albadr NA, Alshammari GM, Almasri SA, Alfayez FF, Yahya MA. Esculeogenin A, a Glycan from Tomato, Alleviates Nonalcoholic Fatty Liver Disease in Rats through Hypolipidemic, Antioxidant, and Anti-Inflammatory Effects. Nutrients 2023; 15:4755. [PMID: 38004149 PMCID: PMC10675668 DOI: 10.3390/nu15224755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Revised: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023] Open
Abstract
This study examined the preventative effects of esculeogenin A (ESGA), a newly discovered glycan from tomato, on liver damage and hepatic steatosis in high-fat-diet (HFD)-fed male rats. The animals were divided into six groups (each of eight rats): a control group fed a normal diet, control + ESGA (200 mg/kg), HFD, and HFD + ESAG in 3 doses (50, 100, and 200 mg/kg). Feeding and treatments were conducted for 12 weeks. Treatment with ESGA did not affect gains in the body or fat weight nor increases in fasting glucose, insulin, and HOMA-IR or serum levels of free fatty acids (FFAs), tumor-necrosis factor-α, and interleukin-6 (IL-6). On the contrary, it significantly reduced the serum levels of gamma-glutamyl transpeptidase (GGT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), total triglycerides (TGs), cholesterol (CHOL), and low-density lipoprotein cholesterol (LDL-c) in the HFD-fed rats. In addition, it improved the liver structure, attenuating the increase in fat vacuoles; reduced levels of TGs and CHOL, and the mRNA levels of SREBP1 and acetyl CoA carboxylase (ACC); and upregulated the mRNA levels of proliferator-activated receptor α (PPARα) and carnitine palmitoyltransferase I (CPT I) in HFD-fed rats. These effects were concomitant with increases in the mRNA, cytoplasmic, and nuclear levels of nuclear factor erythroid 2-related factor 2 (Nrf2), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and heme oxygenase-1 (HO); a reduction in the nuclear activity of nuclear factor-kappa beta (NF-κB); and inhibition of the activity of nuclear factor kappa B kinase subunit beta (IKKβ). All of these effects were dose-dependent effects in which a normal liver structure and normal levels of all measured parameters were seen in HFD + ESGA (200 mg/kg)-treated rats. In conclusion, ESGA prevents NAFLD in HFD-fed rats by attenuating hyperlipidemia, hepatic steatosis, oxidative stress, and inflammation by acting locally on Nrf2, NF-κB, SREBP1, and PPARα transcription factors.
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Affiliation(s)
- Jwharah M. Al Jadani
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia; (J.M.A.J.); (G.M.A.); (S.A.A.); (M.A.Y.)
| | - Nawal A. Albadr
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia; (J.M.A.J.); (G.M.A.); (S.A.A.); (M.A.Y.)
| | - Ghedeir M. Alshammari
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia; (J.M.A.J.); (G.M.A.); (S.A.A.); (M.A.Y.)
| | - Soheir A. Almasri
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia; (J.M.A.J.); (G.M.A.); (S.A.A.); (M.A.Y.)
| | - Farah Fayez Alfayez
- Department of Medicine and Surgery, College of Medicine, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Mohammed Abdo Yahya
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia; (J.M.A.J.); (G.M.A.); (S.A.A.); (M.A.Y.)
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Wei R, Zhang W, Pu C, Shao Q, Xu Q, Li P, Zhao X, Sun T, Weng D. Assessment of lipid metabolism-disrupting effects of non-phthalate plasticizer diisobutyl adipate through in silico and in vitro approaches. ENVIRONMENTAL TOXICOLOGY 2023; 38:1395-1404. [PMID: 36896678 DOI: 10.1002/tox.23773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 02/08/2023] [Accepted: 02/20/2023] [Indexed: 05/18/2023]
Abstract
Diisobutyl adipate (DIBA), as a novel non-phthalate plasticizer, is widely used in various products. However, little effort has been made to investigate whether DIBA might have adverse effects on human health. In this study, we integrated an in silico and in vitro strategy to assess the impact of DIBA on cellular homeostasis. Since numerous plasticizers could activate peroxisome proliferator-activated receptor γ (PPARγ) pathway to interrupt metabolism systems, we first utilized molecular docking to analyze interaction between DIBA and PPARγ. Results indicated that DIBA had strong affinity with the ligand-binding domain of PPARγ (PPARγ-LBD) at Histidine 499. Afterwards, we used cellular models to investigate in vitro effects of DIBA. Results demonstrated that DIBA exposure increased intracellular lipid content in murine and human hepatocytes, and altered transcriptional expression of genes related to PPARγ signaling and lipid metabolism pathways. At last, target genes regulated by DIBA were predicted and enriched for Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Protein-protein interaction (PPI) network and transcriptional factors (TFs)-genes network were established accordingly. Target genes were enriched in Phospholipase D signaling pathway, phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) and Epidermal growth factor receptor (EGFR) signaling pathway which were related to lipid metabolism. These findings suggested that DIBA exposure might disturb intracellular lipid metabolism homeostasis via targeting PPARγ. This study also demonstrated that this integrated in silico and in vitro methodology could be utilized as a high throughput, cost-saving and effective tool to assess the potential risk of various environmental chemicals on human health.
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Affiliation(s)
- Rong Wei
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Weigao Zhang
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Chunlin Pu
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Qianchao Shao
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Qian Xu
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Peiqi Li
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Xunan Zhao
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
| | - Tingzhe Sun
- School of Life Sciences, Anqing Normal University, Anqing, Anhui, China
| | - Dan Weng
- School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing, China
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Crespo M, Nikolic I, Mora A, Rodríguez E, Leiva-Vega L, Pintor-Chocano A, Horrillo D, Hernández-Cosido L, Torres JL, Novoa E, Nogueiras R, Medina-Gómez G, Marcos M, Leiva M, Sabio G. Myeloid p38 activation maintains macrophage-liver crosstalk and BAT thermogenesis through IL-12-FGF21 axis. Hepatology 2023; 77:874-887. [PMID: 35592906 PMCID: PMC9936978 DOI: 10.1002/hep.32581] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 12/08/2022]
Abstract
Obesity features excessive fat accumulation in several body tissues and induces a state of chronic low-grade inflammation that contributes to the development of diabetes, steatosis, and insulin resistance. Recent research has shown that this chronic inflammation is crucially dependent on p38 pathway activity in macrophages, suggesting p38 inhibition as a possible treatment for obesity comorbidities. Nevertheless, we report here that lack of p38 activation in myeloid cells worsens high-fat diet-induced obesity, diabetes, and steatosis. Deficient p38 activation increases macrophage IL-12 production, leading to inhibition of hepatic FGF21 and reduction of thermogenesis in the brown fat. The implication of FGF21 in the phenotype was confirmed by its specific deletion in hepatocytes. We also found that IL-12 correlates with liver damage in human biopsies, indicating the translational potential of our results. Our findings suggest that myeloid p38 has a dual role in inflammation and that drugs targeting IL-12 might improve the homeostatic regulation of energy balance in response to metabolic stress.
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Affiliation(s)
- María Crespo
- Centro Nacional de Investigaciones Cardiovasculares , Madrid , Spain
| | - Ivana Nikolic
- Centro Nacional de Investigaciones Cardiovasculares , Madrid , Spain
| | - Alfonso Mora
- Centro Nacional de Investigaciones Cardiovasculares , Madrid , Spain
| | - Elena Rodríguez
- Centro Nacional de Investigaciones Cardiovasculares , Madrid , Spain
| | - Luis Leiva-Vega
- Centro Nacional de Investigaciones Cardiovasculares , Madrid , Spain
| | | | - Daniel Horrillo
- Departamento de Ciencias Básicas de la Salud, Área de Bioquímica y Biología Molecular, Lipobeta group , Universidad Rey Juan Carlos , Madrid , Spain.,Laboratorio LAFEMEX, Área de Bioquímica y Biología Molecular, Departamento de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud , Universidad Rey Juan Carlos , Madrid , Spain
| | - Lourdes Hernández-Cosido
- Department of General Surgery , University Hospital of Salamanca-IBSAL , Salamanca , Spain.,Department of Surgery , University of Salamanca , Salamanca , Spain
| | - Jorge L Torres
- Department of Internal Medicine , University Hospital of Salamanca-Institute of Biomedical Research of Salamanca (IBSAL) , Salamanca , Spain.,Department of Medicine , University of Salamanca , Salamanca , Spain
| | - Eva Novoa
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS) , University of Santiago de Compostela-Instituto de Investigación Sanitaria , Santiago de Compostela , Spain.,CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn) , Madrid , Spain
| | - Rubén Nogueiras
- Center for Research in Molecular Medicine and Chronic Diseases (CIMUS) , University of Santiago de Compostela-Instituto de Investigación Sanitaria , Santiago de Compostela , Spain.,CIBER Fisiopatologia de la Obesidad y Nutrición (CIBERobn) , Madrid , Spain
| | - Gema Medina-Gómez
- Departamento de Ciencias Básicas de la Salud, Área de Bioquímica y Biología Molecular, Lipobeta group , Universidad Rey Juan Carlos , Madrid , Spain.,Laboratorio LAFEMEX, Área de Bioquímica y Biología Molecular, Departamento de Ciencias Básicas de la Salud, Facultad de Ciencias de la Salud , Universidad Rey Juan Carlos , Madrid , Spain
| | - Miguel Marcos
- Department of Internal Medicine , University Hospital of Salamanca-Institute of Biomedical Research of Salamanca (IBSAL) , Salamanca , Spain.,Department of Medicine , University of Salamanca , Salamanca , Spain
| | - Magdalena Leiva
- Centro Nacional de Investigaciones Cardiovasculares , Madrid , Spain
| | - Guadalupe Sabio
- Centro Nacional de Investigaciones Cardiovasculares , Madrid , Spain
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Ramatchandirin B, Pearah A, He L. Regulation of Liver Glucose and Lipid Metabolism by Transcriptional Factors and Coactivators. Life (Basel) 2023; 13:life13020515. [PMID: 36836874 PMCID: PMC9962321 DOI: 10.3390/life13020515] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 02/08/2023] [Accepted: 02/10/2023] [Indexed: 02/16/2023] Open
Abstract
The prevalence of nonalcoholic fatty liver disease (NAFLD) worldwide is on the rise and NAFLD is becoming the most common cause of chronic liver disease. In the USA, NAFLD affects over 30% of the population, with similar occurrence rates reported from Europe and Asia. This is due to the global increase in obesity and type 2 diabetes mellitus (T2DM) because patients with obesity and T2DM commonly have NAFLD, and patients with NAFLD are often obese and have T2DM with insulin resistance and dyslipidemia as well as hypertriglyceridemia. Excessive accumulation of triglycerides is a hallmark of NAFLD and NAFLD is now recognized as the liver disease component of metabolic syndrome. Liver glucose and lipid metabolisms are intertwined and carbon flux can be used to generate glucose or lipids; therefore, in this review we discuss the important transcription factors and coactivators that regulate glucose and lipid metabolism.
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Affiliation(s)
| | - Alexia Pearah
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Ling He
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 600 N. Wolfe St, Baltimore, MD 21287, USA
- Correspondence: ; Tel.: +1-410-502-5765; Fax: +1-410-502-5779
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Qiu Z, Zhao Y, Tao T, Guo W, Liu R, Huang J, Xu G. Activation of PPARα Ameliorates Cardiac Fibrosis in Dsg2-Deficient Arrhythmogenic Cardiomyopathy. Cells 2022; 11:3184. [PMID: 36291052 PMCID: PMC9601208 DOI: 10.3390/cells11203184] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/25/2022] [Accepted: 09/28/2022] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Arrhythmogenic cardiomyopathy (ACM) is a genetic heart muscle disease characterized by progressive fibro-fatty replacement of cardiac myocytes. Up to now, the existing therapeutic modalities for ACM are mostly palliative. About 50% of ACM is caused by mutations in genes encoding desmosomal proteins including Desmoglein-2 (Dsg2). In the current study, the cardiac fibrosis of ACM and its underlying mechanism were investigated by using a cardiac-specific knockout of Dsg2 mouse model. METHODS Cardiac-specific Dsg2 knockout (CS-Dsg2-/-) mice and wild-type (WT) mice were respectively used as the animal model of ACM and controls. The myocardial collagen volume fraction was determined by histological analysis. The expression levels of fibrotic markers such as α-SMA and Collagen I as well as signal transducers such as STAT3, SMAD3, and PPARα were measured by Western blot and quantitative real-time PCR. RESULTS Increased cardiac fibrosis was observed in CS-Dsg2-/- mice according to Masson staining. PPARα deficiency and hyperactivation of STAT3 and SMAD3 were observed in the myocardium of CS-Dsg2-/- mice. The biomarkers of fibrosis such as α-SMA and Collagen I were upregulated after gene silencing of Dsg2 in HL-1 cells. Furthermore, STAT3 gene silencing by Stat3 siRNA inhibited the expression of fibrotic markers. The activation of PPARα by fenofibrate or AAV9-Pparα improved the cardiac fibrosis and decreased the phosphorylation of STAT3, SMAD3, and AKT in CS-Dsg2-/- mice. CONCLUSIONS Activation of PPARα alleviates the cardiac fibrosis in ACM.
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Affiliation(s)
- Zirui Qiu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou 510632, China
| | - Yawen Zhao
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou 510632, China
| | - Tian Tao
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou 510632, China
| | - Wenying Guo
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou 510632, China
| | - Ruonan Liu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou 510632, China
| | - Jingmin Huang
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou 510632, China
| | - Geyang Xu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou 510632, China
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou 510317, China
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6
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Muzio G, Barrera G, Pizzimenti S. Peroxisome Proliferator-Activated Receptors (PPARs) and Oxidative Stress in Physiological Conditions and in Cancer. Antioxidants (Basel) 2021; 10:antiox10111734. [PMID: 34829605 PMCID: PMC8614822 DOI: 10.3390/antiox10111734] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 12/18/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone receptor superfamily. Originally described as “orphan nuclear receptors”, they can bind both natural and synthetic ligands acting as agonists or antagonists. In humans three subtypes, PPARα, β/δ, γ, are encoded by different genes, show tissue-specific expression patterns, and contribute to the regulation of lipid and carbohydrate metabolisms, of different cell functions, including proliferation, death, differentiation, and of processes, as inflammation, angiogenesis, immune response. The PPAR ability in increasing the expression of various antioxidant genes and decreasing the synthesis of pro-inflammatory mediators, makes them be considered among the most important regulators of the cellular response to oxidative stress conditions. Based on the multiplicity of physiological effects, PPAR involvement in cancer development and progression has attracted great scientific interest with the aim to describe changes occurring in their expression in cancer cells, and to investigate the correlation with some characteristics of cancer phenotype, including increased proliferation, decreased susceptibility to apoptosis, malignancy degree and onset of resistance to anticancer drugs. This review focuses on mechanisms underlying the antioxidant and anti-inflammatory properties of PPARs in physiological conditions, and on the reported beneficial effects of PPAR activation in cancer.
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Peroxisome Proliferator-Activated Receptors and Caloric Restriction-Common Pathways Affecting Metabolism, Health, and Longevity. Cells 2020; 9:cells9071708. [PMID: 32708786 PMCID: PMC7407644 DOI: 10.3390/cells9071708] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 07/14/2020] [Accepted: 07/14/2020] [Indexed: 02/06/2023] Open
Abstract
Caloric restriction (CR) is a traditional but scientifically verified approach to promoting health and increasing lifespan. CR exerts its effects through multiple molecular pathways that trigger major metabolic adaptations. It influences key nutrient and energy-sensing pathways including mammalian target of rapamycin, Sirtuin 1, AMP-activated protein kinase, and insulin signaling, ultimately resulting in reductions in basic metabolic rate, inflammation, and oxidative stress, as well as increased autophagy and mitochondrial efficiency. CR shares multiple overlapping pathways with peroxisome proliferator-activated receptors (PPARs), particularly in energy metabolism and inflammation. Consequently, several lines of evidence suggest that PPARs might be indispensable for beneficial outcomes related to CR. In this review, we present the available evidence for the interconnection between CR and PPARs, highlighting their shared pathways and analyzing their interaction. We also discuss the possible contributions of PPARs to the effects of CR on whole organism outcomes.
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Bougarne N, Weyers B, Desmet SJ, Deckers J, Ray DW, Staels B, De Bosscher K. Molecular Actions of PPARα in Lipid Metabolism and Inflammation. Endocr Rev 2018; 39:760-802. [PMID: 30020428 DOI: 10.1210/er.2018-00064] [Citation(s) in RCA: 432] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Accepted: 07/10/2018] [Indexed: 12/13/2022]
Abstract
Peroxisome proliferator-activated receptor α (PPARα) is a nuclear receptor of clinical interest as a drug target in various metabolic disorders. PPARα also exhibits marked anti-inflammatory capacities. The first-generation PPARα agonists, the fibrates, have however been hampered by drug-drug interaction issues, statin drop-in, and ill-designed cardiovascular intervention trials. Notwithstanding, understanding the molecular mechanisms by which PPARα works will enable control of its activities as a drug target for metabolic diseases with an underlying inflammatory component. Given its role in reshaping the immune system, the full potential of this nuclear receptor subtype as a versatile drug target with high plasticity becomes increasingly clear, and a novel generation of agonists may pave the way for novel fields of applications.
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Affiliation(s)
- Nadia Bougarne
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Receptor Research Laboratories, Nuclear Receptor Laboratory, VIB Center for Medical Biotechnology, Ghent, Belgium
| | - Basiel Weyers
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Receptor Research Laboratories, Nuclear Receptor Laboratory, VIB Center for Medical Biotechnology, Ghent, Belgium
| | - Sofie J Desmet
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Receptor Research Laboratories, Nuclear Receptor Laboratory, VIB Center for Medical Biotechnology, Ghent, Belgium
| | - Julie Deckers
- Department of Internal Medicine, Ghent University, Ghent, Belgium
- Laboratory of Immunoregulation, VIB Center for Inflammation Research, Ghent (Zwijnaarde), Belgium
| | - David W Ray
- Division of Metabolism and Endocrinology, Faculty of Biology, Medicine, and Health, University of Manchester, Manchester, United Kingdom
| | - Bart Staels
- Université de Lille, U1011-European Genomic Institute for Diabetes, Lille, France
- INSERM, U1011, Lille, France
- Centre Hospitalier Universitaire de Lille, Lille, France
- Institut Pasteur de Lille, Lille, France
| | - Karolien De Bosscher
- Department of Biomolecular Medicine, Ghent University, Ghent, Belgium
- Receptor Research Laboratories, Nuclear Receptor Laboratory, VIB Center for Medical Biotechnology, Ghent, Belgium
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Ho YK, Lee TH, Lee CI, Cheng EH, Huang CC, Huang LS, Lee MS. Effects of growth hormone plus gonadotropins on controlled ovarian stimulation in infertile women of advanced age, poor responders, and previous in vitro fertilization failure patients. Taiwan J Obstet Gynecol 2018; 56:806-810. [PMID: 29241924 DOI: 10.1016/j.tjog.2017.10.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/02/2017] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE To investigate the effects of growth hormone (GH) cotreatment in ovarian stimulation in infertile women of advanced age, poor responders, and patients with one or more previous IVF treatment failures. MATERIALS AND METHODS We conducted a retrospective observational study of 436 patients undergoing GH cotreatment in ovarian stimulation. The first arm included 134 infertile women of advanced age. The second arm included 236 patients with one or more IVF previous treatment failures, and the third arm included 66 younger poor responders. Main outcome measures were the number of oocytes and embryos, quality of embryos, and implantation and pregnancy rates. RESULTS In infertile women of advanced age, GH plus ovarian stimulation yielded no statistical differences in the numbers of oocytes and embryos, quality of embryo, and rates of implantation and pregnancy. In the second arm, the mature oocyte number (8.2 vs. 6.8), implantation rate (16.1% vs. 0%), and pregnancy rate (33.9% vs. 0%) in the GH cotreatment group differed significantly from those in the control group; the rate of good-quality embryos in the GH cotreatment group improved from 35.5% ± 31.1%-41.4% ± 30.6% in this arm. Similar results were observed in the third arm; in this arm, the clinical pregnancy rate was 30.3% in the GH cotreatment group and 6.1% in the control group. CONCLUSION No significant differences were observed in infertile women of advanced age, which may be due to the low GH dose. The GH adjuvant therapy for patients with one or more previous IVF treatment failures and for poor responders significantly improved the oocyte and embryo numbers as well as implantation and pregnancy rates.
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Affiliation(s)
- Yao-Kai Ho
- Institute of Medicine, Chung Shan Medial University, Taichung, Taiwan, ROC
| | - Tsung-Hsien Lee
- Institute of Medicine, Chung Shan Medial University, Taichung, Taiwan, ROC; Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital, Taichung, Taiwan, ROC
| | - Chun-I Lee
- Institute of Medicine, Chung Shan Medial University, Taichung, Taiwan, ROC; Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital, Taichung, Taiwan, ROC
| | - En-Hui Cheng
- Genetic Diagnosis Laboratory, Lee Women's Hospital, Taichung, Taiwan, ROC
| | - Chun-Chia Huang
- Division of Infertility Clinic, Lee Women's Hospital, Taichung, Taiwan, ROC; Department of Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan, ROC
| | - Lii-Shung Huang
- Nursing Department, Lee Women's Hospital, Taichung, Taiwan, ROC; School of Nursing, Chung Shan Medial University, Taichung, Taiwan, ROC
| | - Maw-Sheng Lee
- Institute of Medicine, Chung Shan Medial University, Taichung, Taiwan, ROC; Department of Obstetrics and Gynecology, Chung Shan Medical University Hospital, Taichung, Taiwan, ROC; Division of Infertility Clinic, Lee Women's Hospital, Taichung, Taiwan, ROC.
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Funderburk KM, Auerbach SS, Bushel PR. Crosstalk between Receptor and Non-receptor Mediated Chemical Modes of Action in Rat Livers Converges through a Dysregulated Gene Expression Network at Tumor Suppressor Tp53. Front Genet 2017; 8:157. [PMID: 29114260 PMCID: PMC5660693 DOI: 10.3389/fgene.2017.00157] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 10/06/2017] [Indexed: 12/20/2022] Open
Abstract
Chemicals, toxicants, and environmental stressors mediate their biologic effect through specific modes of action (MOAs). These encompass key molecular events that lead to changes in the expression of genes within regulatory pathways. Elucidating shared biologic processes and overlapping gene networks will help to better understand the toxicologic effects on biological systems. In this study we used a weighted network analysis of gene expression data from the livers of male Sprague-Dawley rats exposed to chemicals that elicit their effects through receptor-mediated MOAs (aryl hydrocarbon receptor, orphan nuclear hormone receptor, or peroxisome proliferator-activated receptor-α) or non-receptor-mediated MOAs (cytotoxicity or DNA damage). Four gene networks were highly preserved and statistically significant in each of the two MOA classes. Three of the four networks contain genes that enrich for immunity and defense. However, many canonical pathways related to an immune response were activated from exposure to the non-receptor-mediated MOA chemicals and deactivated from exposure to the receptor-mediated MOA chemicals. The top gene network contains a module with 33 genes including tumor suppressor TP53 as the central hub which was slightly up-regulated in gene expression compared to control. Although, there is crosstalk between the two MOA classes of chemicals at the TP53 gene network, more than half of the genes are dysregulated in opposite directions. For example, Thromboxane A Synthase 1 (Tbxas1), a cytochrome P450 protein coding gene regulated by Tp53, is down-regulated by exposure to the receptor-mediated chemicals but up-regulated by the non-receptor-mediated chemicals. The regulation of gene expression by the chemicals within MOA classes was consistent despite varying alanine transaminase and aspartate aminotransferase liver enzyme measurements. These results suggest that overlap in toxicologic pathways by chemicals with different MOAs provides common mechanisms for discordant regulation of gene expression within molecular networks.
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Affiliation(s)
- Karen M. Funderburk
- Department of Biology and Department of Mathematics & Statistics, College of Arts & Sciences, University of North Carolina at Greensboro, Greensboro, NC, United States
- Microarray and Genome Informatics Group, Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Scott S. Auerbach
- Toxicoinformatics Group, Biomolecular Screening Branch, National Institute of Environmental Health Sciences, Durham, NC, United States
| | - Pierre R. Bushel
- Microarray and Genome Informatics Group, Biostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Durham, NC, United States
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Abushouk AI, El-Husseny MWA, Bahbah EI, Elmaraezy A, Ali AA, Ashraf A, Abdel-Daim MM. Peroxisome proliferator-activated receptors as therapeutic targets for heart failure. Biomed Pharmacother 2017; 95:692-700. [PMID: 28886529 DOI: 10.1016/j.biopha.2017.08.083] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/05/2017] [Accepted: 08/23/2017] [Indexed: 01/06/2023] Open
Abstract
Heart failure (HF) is a common clinical syndrome that affects more than 23 million individuals worldwide. Despite the marked advances in its management, the mortality rates in HF patients have remained unacceptably high. Peroxisome proliferator-activated receptors (PPARs) are nuclear transcription regulators, involved in the regulation of fatty acid and glucose metabolism. PPAR agonists are currently used for the treatment of type II diabetes mellitus and hyperlipidemia; however, their role as therapeutic agents for HF remains under investigation. Preclinical studies have shown that pharmacological modulation of PPARs can upregulate the expression of fatty acid oxidation genes in cardiomyocytes. Moreover, PPAR agonists were proven able to improve ventricular contractility and reduce cardiac remodelling in animal models through their anti-inflammatory, anti-oxidant, anti-fibrotic, and anti-apoptotic activities. Whether these effects can be replicated in humans is yet to be proven. This article reviews the interactions of PPARs with the pathophysiological mechanisms of HF and how the pharmacological modulation of these receptors can be of benefit for HF patients.
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Affiliation(s)
| | | | - Eshak I Bahbah
- Faculty of Medicine, Al-Azhar University, Damietta, Egypt
| | - Ahmed Elmaraezy
- NovaMed Medical Research Association, Cairo, Egypt; Faculty of Medicine, Al-Azhar University, Cairo, Egypt
| | - Aya Ashraf Ali
- Faculty of Medicine, Minia University, Minia, Egypt; Minia Medical Research Society, Minia University, Minia, Egypt
| | - Asmaa Ashraf
- Faculty of Medicine, Minia University, Minia, Egypt; Minia Medical Research Society, Minia University, Minia, Egypt
| | - Mohamed M Abdel-Daim
- Pharmacology Department, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522, Egypt; Department of Ophthalmology and Micro-Technology, Yokohama City University, Yokohama, Japan.
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12
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Is spaceflight-induced immune dysfunction linked to systemic changes in metabolism? PLoS One 2017; 12:e0174174. [PMID: 28542224 PMCID: PMC5443495 DOI: 10.1371/journal.pone.0174174] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 03/04/2017] [Indexed: 12/22/2022] Open
Abstract
The Space Shuttle Atlantis launched on its final mission (STS-135) on July 8, 2011. After just under 13 days, the shuttle landed safely at Kennedy Space Center (KSC) for the last time. Female C57BL/6J mice flew as part of the Commercial Biomedical Testing Module-3 (CBTM-3) payload. Ground controls were maintained at the KSC facility. Subsets of these mice were made available to investigators as part of NASA’s Bio-specimen Sharing Program (BSP). Our group characterized cell phenotype distributions and phagocytic function in the spleen, catecholamine and corticosterone levels in the adrenal glands, and transcriptomics/metabolomics in the liver. Despite decreases in most splenic leukocyte subsets, there were increases in reactive oxygen species (ROS)-related activity. Although there were increases noted in corticosterone levels in both the adrenals and liver, there were no significant changes in catecholamine levels. Furthermore, functional analysis of gene expression and metabolomic profiles suggest that the functional changes are not due to oxidative or psychological stress. Despite changes in gene expression patterns indicative of increases in phagocytic activity (e.g. endocytosis and formation of peroxisomes), there was no corresponding increase in genes related to ROS metabolism. In contrast, there were increases in expression profiles related to fatty acid oxidation with decreases in glycolysis-related profiles. Given the clear link between immune function and metabolism in many ground-based diseases, we propose a similar link may be involved in spaceflight-induced decrements in immune and metabolic function.
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Abstract
Background: Peroxisomes are small cellular organelles that were almost ignored for years because they were believed to play only a minor role in cellular functions. However, it is now known that peroxisomes play an important role in regulating cellular proliferation and differentiation as well as in the modulation of inflammatory mediators. In addition, peroxisomes have broad effects on the metabolism of lipids, hormones, and xenobiotics. Through their effects on lipid metabolism, peroxisomes also affect cellular membranes and adipocyte formation, as well as insulin sensitivity, and peroxisomes play a role in aging and tumorigenesis through their effects on oxidative stress. Objective: To review genetically determined peroxisomal disorders, especially those that particularly affect the skin, and some recent information on the specific genetic defects that lead to some of these disorders. In addition, we present some of the emerging knowledge of peroxisomal proliferator activator receptors (PPARs) and how ligands for these receptors modulate different peroxisomal functions. We also present information on how the discovery of PPARs, and the broad and diverse group of ligands that activate these members of the superfamily of nuclear binding transcription factors, has led to development of new drugs that modulate the function of peroxisomes. Conclusion: PPAR expression and ligand modulation within the skin have shown potential uses for these ligands in a number of inflammatory cutaneous disorders, including acne vulgaris, cutaneous disorders with barrier dysfunction, cutaneous effects of aging, and poor wound healing associated with altered signal transduction, as well as for side effects induced by the metabolic dysregulation of other drugs.
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14
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YU XIN, LI ZHENG. MicroRNAs regulate vascular smooth muscle cell functions in atherosclerosis (Review). Int J Mol Med 2014; 34:923-33. [DOI: 10.3892/ijmm.2014.1853] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 05/30/2014] [Indexed: 11/06/2022] Open
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15
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Chew GS, Myers S, Shu-Chien AC, Muhammad TST. Interleukin-6 inhibition of peroxisome proliferator-activated receptor alpha expression is mediated by JAK2- and PI3K-induced STAT1/3 in HepG2 hepatocyte cells. Mol Cell Biochem 2013; 388:25-37. [PMID: 24242046 DOI: 10.1007/s11010-013-1896-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 11/05/2013] [Indexed: 01/22/2023]
Abstract
Interleukin-6 (IL-6) is the major activator of the acute phase response (APR). One important regulator of IL-6-activated APR is peroxisome proliferator-activated receptor alpha (PPARα). Currently, there is a growing interest in determining the role of PPARα in regulating APR; however, studies on the molecular mechanisms and signaling pathways implicated in mediating the effects of IL-6 on the expression of PPARα are limited. We previously revealed that IL-6 inhibits PPARα gene expression through CAAT/enhancer-binding protein transcription factors in hepatocytes. In this study, we determined that STAT1/3 was the direct downstream molecules that mediated the Janus kinase 2 (JAK2) and phosphatidylinositol-3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathways in IL-6-induced repression of PPARα. Treatment of cells with pharmacological inhibitors of JAK2, PI3K, AKT, and mTOR attenuated the inhibitory effect of IL-6 on PPARα protein in a dose-dependent manner. These inhibitors also decreased the IL-6-induced repression of PPARα mRNA expression and promoter activity. Overexpression of STAT1 and STAT3 in HepG2 cells cotransfected with a reporter vector containing this PPARα promoter region revealed that both the expression plasmids inhibited the IL-6-induced repression of PPARα promoter activity. In the presence of inhibitors of JAK2 and mTOR (AG490 and rapamycin, respectively), IL-6-regulated protein expression and DNA binding of STAT1 and STAT3 were either completely or partially inhibited simultaneously, and the IL-6-induced repression of PPARα protein and mRNA was also inhibited. This study has unraveled novel pathways by which IL-6 inhibits PPARα gene transcription, involving the modulation of JAK2/STAT1-3 and PI3K/AKT/mTOR by inducing the binding of STAT1 and STAT3 to STAT-binding sites on the PPARα promoter. Together, these findings represent a new model of IL-6-induced suppression of PPARα expression by inducing STAT1 and STAT3 phosphorylation and subsequent down-regulation of PPARα mRNA expression.
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Affiliation(s)
- Guat-Siew Chew
- School of Biological Sciences, Universiti Sains Malaysia, 11800, Penang, Malaysia,
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16
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Gupta N, Mayer D. Interaction of JAK with steroid receptor function. JAKSTAT 2013; 2:e24911. [PMID: 24416641 PMCID: PMC3881601 DOI: 10.4161/jkst.24911] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/02/2013] [Accepted: 05/02/2013] [Indexed: 11/23/2022] Open
Abstract
The function of steroid receptors is not only regulated by steroid hormones, but also by multiple cellular signaling cascades activated by membrane-bound receptors which are stimulated by growth factors or cytokines. Cross-talk between JAK and steroid receptors plays a central role in the regulation of a multitude of physiological processes and aberrant signaling is involved in the development of numerous diseases including cancer. In this review we provide a brief summary of the knowledge of interactions between JAK and the function of steroid receptors in normal cells and tissues and in diseases.
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Affiliation(s)
- Nibedita Gupta
- Hematology and Oncology; University Hospital Magdeburg; Magdeburg, Germany
| | - Doris Mayer
- Hormones and Signal Transduction Group; German Cancer Research Center; Heidelberg, Germany
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17
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Hu QH, Zhang X, Pan Y, Li YC, Kong LD. Allopurinol, quercetin and rutin ameliorate renal NLRP3 inflammasome activation and lipid accumulation in fructose-fed rats. Biochem Pharmacol 2012; 84:113-25. [DOI: 10.1016/j.bcp.2012.03.005] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 03/08/2012] [Accepted: 03/08/2012] [Indexed: 12/24/2022]
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18
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Magri CJ, Gatt N, Xuereb RG, Fava S. Peroxisome proliferator-activated receptor-γ and the endothelium: implications in cardiovascular disease. Expert Rev Cardiovasc Ther 2012; 9:1279-94. [PMID: 21985541 DOI: 10.1586/erc.11.140] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Peroxisome proliferator-activated receptors-γ (PPARγs) are ligand-activated transcription factors that play a crucial regulatory role in the transcription of a large number of genes involved in lipid metabolism and inflammation. In addition to physiological ligands, synthetic ligands (the thiazoledinediones) have been developed. In spite of the much publicized adverse cardiovascular effects of one such thiazoledinedione (rosiglitazone), PPARγ activation may have beneficial cardiovascular effects. In this article we review the effects of PPARγ activation on the endothelium with special emphasis on the possible implications in cardiovascular disease. We discuss its possible role in inflammation, vasomotor function, thrombosis, angiogenesis, vascular aging and vascular rhythm. We also briefly review the clinical implications of these lines of research.
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Affiliation(s)
- Caroline Jane Magri
- Department of Cardiac Services, Mater Dei Hospital, Tal-Qroqq, Msida MSD 2090, Malta
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19
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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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20
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List EO, Sackmann-Sala L, Berryman DE, Funk K, Kelder B, Gosney ES, Okada S, Ding J, Cruz-Topete D, Kopchick JJ. Endocrine parameters and phenotypes of the growth hormone receptor gene disrupted (GHR-/-) mouse. Endocr Rev 2011; 32:356-86. [PMID: 21123740 PMCID: PMC3365798 DOI: 10.1210/er.2010-0009] [Citation(s) in RCA: 137] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Disruption of the GH receptor (GHR) gene eliminates GH-induced intracellular signaling and, thus, its biological actions. Therefore, the GHR gene disrupted mouse (GHR-/-) has been and is a valuable tool for helping to define various parameters of GH physiology. Since its creation in 1995, this mouse strain has been used by our laboratory and others for numerous studies ranging from growth to aging. Some of the most notable discoveries are their extreme insulin sensitivity in the presence of obesity. Also, the animals have an extended lifespan, which has generated a large number of investigations into the roles of GH and IGF-I in the aging process. This review summarizes the many results derived from the GHR-/- mice. We have attempted to present the findings in the context of current knowledge regarding GH action and, where applicable, to discuss how these mice compare to GH insensitivity syndrome in humans.
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Affiliation(s)
- Edward O List
- The Edison Biotechnology Institute, Ohio University, Athens, Ohio 45701, USA
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21
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van Bilsen M, van Nieuwenhoven FA. PPARs as therapeutic targets in cardiovascular disease. Expert Opin Ther Targets 2011; 14:1029-45. [PMID: 20854178 DOI: 10.1517/14728222.2010.512917] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
IMPORTANCE OF THE FIELD The role of peroxisome proliferator-activated receptors PPARα, PPARδ and PPARγ in cardiovascular disease is receiving widespread attention. As ligand-activated nuclear receptors, they play a role in regulation of lipid and glucose metabolism. This feature of the PPARs has been successfully exploited to treat systemic metabolic diseases, like hyperlipidemia and type-2 diabetes. Indirectly, their lipid lowering effect also leads to a reduction of the risk for cardiovascular diseases, primarily atherosclerosis. AREAS COVERED IN THIS REVIEW The pleiotropic effects of each of the PPAR isotypes on vascular and cardiac disease are discussed, with special emphasis on the molecular mechanism of action and on preclinical observations. The mechanism underlying the beneficial effect of PPARs is not confined to whole body metabolism, but also includes modulation of other vital processes, such as inflammation and cell fate (proliferation, differentiation, apoptosis). WHAT THE READER WILL GAIN A large body of preclinical studies indicates that, in addition to their effect on atherogenesis, PPAR ligands also impact on ischemic heart disease and the development of cardiac failure. It remains to be established to what extent these intriguing observations can be translated into clinical practice. TAKE HOME MESSAGE The versatile mechanism of action extends the potential therapeutic profile of the PPARs enormously. Conversely, this versatility makes it harder to attain a specific therapeutic effect, without increasing the risk of undesirable side effects. The future challenge will be to design PPAR-based therapeutic strategies that minimize the detrimental side effects.
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Affiliation(s)
- Marc van Bilsen
- Maastricht University, Cardiovascular Research Institute Maastricht, Department of Physiology, 6200 MD Maastricht, The Netherlands.
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22
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Majdalawieh A, Ro HS. PPARgamma1 and LXRalpha face a new regulator of macrophage cholesterol homeostasis and inflammatory responsiveness, AEBP1. NUCLEAR RECEPTOR SIGNALING 2010; 8:e004. [PMID: 20419060 PMCID: PMC2858268 DOI: 10.1621/nrs.08004] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Accepted: 03/09/2010] [Indexed: 12/26/2022]
Abstract
Peroxisome proliferator-activated receptor γ1 (PPARγ1) and liver X receptor α (LXRα) are nuclear receptors that play pivotal roles in macrophage cholesterol homeostasis and inflammation; key biological processes in atherogenesis. The activation of PPARγ1 and LXRα by natural or synthetic ligands results in the transactivation of ABCA1, ABCG1, and ApoE; integral players in cholesterol efflux and reverse cholesterol transport. In this review, we describe the structure, isoforms, expression pattern, and functional specificity of PPARs and LXRs. Control of PPARs and LXRs transcriptional activity by coactivators and corepressors is also highlighted. The specific roles that PPARγ1 and LXRα play in inducing macrophage cholesterol efflux mediators and antagonizing macrophage inflammatory responsiveness are summarized. Finally, this review focuses on the recently reported regulatory functions that adipocyte enhancer-binding protein 1 (AEBP1) exerts on PPARγ1 and LXRα transcriptional activity in the context of macrophage cholesterol homeostasis and inflammation.
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23
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Regulation of IkappaBalpha function and NF-kappaB signaling: AEBP1 is a novel proinflammatory mediator in macrophages. Mediators Inflamm 2010; 2010:823821. [PMID: 20396415 PMCID: PMC2855089 DOI: 10.1155/2010/823821] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Accepted: 01/12/2010] [Indexed: 02/08/2023] Open
Abstract
NF-κB comprises a family of transcription factors that are critically involved in various inflammatory processes. In this paper, the role of NF-κB in inflammation and atherosclerosis and the regulation of the NF-κB signaling pathway are summarized. The structure, function, and regulation of the NF-κB inhibitors, IκBα and IκBβ, are reviewed. The regulation of NF-κB activity by glucocorticoid receptor (GR) signaling and IκBα sumoylation is also discussed. This paper focuses on the recently reported regulatory function that adipocyte enhancer-binding protein 1 (AEBP1) exerts on NF-κB transcriptional activity in macrophages, in which AEBP1 manifests itself as a potent modulator of NF-κB via physical interaction with IκBα and a critical mediator of inflammation. Finally, we summarize the regulatory roles that recently identified IκBα-interacting proteins play in NF-κB signaling. Based on its proinflammatory roles in macrophages, AEBP1 is anticipated to serve as a therapeutic target towards the treatment of various inflammatory conditions and disorders.
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Abstract
Since the somatomedin hypothesis of growth hormone (GH) action was first formulated more than 50 years ago, the key roles of both GH and insulin-like growth factor-I (IGF-I) in human growth have been extended to include important effects on tissue maintenance and repair. More recent observations have revealed that this pathway has a negative side, as it has been implicated as a potential contributor to the development of several human cancers and has been linked to diminished lifespan in experimental animals. This brief review focuses on fundamental aspects of gene regulation by GH, as long-term hormonal effects all require changes in gene expression. Topics to be discussed include GH-stimulated signal transduction pathways, mechanisms of gene activation and gene repression by GH, and an analysis of control of IGF-I gene transcription by the GH-stimulated transcription factor, signal transducer and activator of transcription (Stat)5b.
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Affiliation(s)
- Peter Rotwein
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, OR 97239-3098, USA.
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25
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Carriquiry M, Weber WJ, Fahrenkrug SC, Crooker BA. Hepatic gene expression in multiparous Holstein cows treated with bovine somatotropin and fed n-3 fatty acids in early lactation. J Dairy Sci 2009; 92:4889-900. [PMID: 19762804 DOI: 10.3168/jds.2008-1676] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Multiparous cows were fed supplemental dietary fat and treated with bST to assess effects of n-3 fatty acid supply, bovine somatotropin (bST), and stage of lactation on hepatic gene expression. Cows were blocked by expected calving date and previous milk yield and assigned randomly to treatment. Supplemental dietary fat was provided from calving as either whole high-oil sunflower seeds (SS; 10% of dietary dry matter; n-6/n-3 ratio of 4.6) as a source of linoleic acid or a mixture of Alifet-High Energy and Alifet-Repro (AF; 3.5 and 1.5% of dietary dry matter, respectively; n-6/n-3 ratio of 2.6) as a source of protected n-3 fatty acids. Cows were treated with 0 (SSN, AFN) or 500 (SSY, AFY) mg of bST every 10 d from 12 to 70 d in milk (DIM) and at 14-d intervals thereafter. Liver biopsies were collected on -12, 10, 24, and 136 DIM for gene expression analysis. Growth hormone receptor (GHR), insulin-like growth factor-I (IGF-I), IGF-binding protein-3 (IGFBP3), hepatic nuclear factor 4alpha (HNF4alpha), fibroblast growth factor-21 (FGF-21), and peroxisome proliferator-activated receptor alpha (PPARalpha) were the target genes and hypoxanthine phosphoribosyltransferase (HPRT) was used as an endogenous control gene. Expression was measured by quantitative real-time reverse transcription-PCR analyses of 4 samples from each of 32 cows (8 complete blocks). Amounts of hepatic HPRT mRNA were not affected by bST or diet but were increased by approximately 3.8% in early lactation (3.42, 3.52, 3.54, and 3.41 x 10(4) message copies for -12, 10, 24, and 136 DIM, respectively). This small change had little detectable impact on the ability of HPRT to serve as an internal control gene. Amounts of hepatic GHR, IGF-I, and IGFBP3 mRNA were reduced by 1.5 to 2-fold after calving. Expression of GHR and IGF-I increased and IGFBP3 tended to increase within 12 d (by 24 DIM) of bST administration. These effects of bST persisted through 136 DIM. Hepatic HNF4alpha mRNA was not altered by DIM or any of the treatments. Abundance of PPARalpha mRNA was unchanged through 24 DIM but increased by 136 DIM. There was a trend for an interaction of bST, diet, and DIM on PPARalpha mRNA abundance from 24 to 136 DIM because the amount of PPARalpha mRNA increased in SSN, SSY, and AFN cows but was not altered in AFY cows. The amount of FGF-21 mRNA increased markedly in early lactation but, like HNF4alpha mRNA, was not affected by bST, diet, or their interactions. These results indicate 1) that bST induced increases in hepatic expression of GHR, IGF-I, and IGFBP3 when cows were in negative energy balance in early lactation, 2) there was no effect of reduced dietary n-6/n-3 content on hepatic gene expression, and 3) there was support for a potential homeorhetic role of hepatic FGF-21 via uncoupling the somatotropin-IGF-axis in early lactation.
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Affiliation(s)
- M Carriquiry
- Department of Animal Science, University of Minnesota, St Paul 55108-6118, USA
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26
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Affiliation(s)
- Anna Zampetaki
- From the Cardiovascular Division, King’s College London BHF Centre, London, UK
| | - Qingbo Xu
- From the Cardiovascular Division, King’s College London BHF Centre, London, UK
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27
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O'Brien ML, Spear BT, Glauert HP. Role of Oxidative Stress in Peroxisome Proliferator-Mediated Carcinogenesis. Crit Rev Toxicol 2008; 35:61-88. [PMID: 15742903 DOI: 10.1080/10408440590905957] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
In this review, the evidence about the role of oxidative stress in the induction of hepatocellular carcinomas by peroxisome proliferators is examined. The activation of PPAR-alpha by peroxisome proliferators in rats and mice may produce oxidative stress, due to the induction of enzymes like fatty acyl coenzyme A (CoA) oxidase (AOX) and cytochrome P-450 4A1. The effect of peroxisome proliferators on the antioxidant defense system is reviewed, as is the effect on endpoints resulting from oxidative stress that may be important in carcinogenesis, such as lipid peroxidation, oxidative DNA damage, and transcription factor activation. Peroxisome proliferators clearly inhibit several enzymes in the antioxidant defense system, but studies examining effects on lipid peroxidation and oxidative DNA damage are conflicting. There is a profound species difference in the induction of hepatocellular carcinomas by peroxisome proliferators, with rats and mice being sensitive, whereas species such as nonhuman primates and guinea pigs are not susceptible to the effects of peroxisome proliferators. The possible role of oxidative stress in these species differences is also reviewed. Overall, peroxisome proliferators produce changes in oxidative stress, but whether these changes are important in the carcinogenic process is not clear at this time.
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Affiliation(s)
- Michelle L O'Brien
- Graduate Centerfor Toxicology, University of Kentucky, Lexington, Kentucky 40506-0054, USA
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Abstract
Signal transducer and activator of transcription (STAT)5A and -5B are latent transcription factors activated by cytokines and hormones of the cytokine family. In pancreatic insulin-secreting β-cells, STAT5A and -5B are activated primarily by prolactin and growth hormone stimulation and are important mediators of the potent stimulation of proliferation and insulin production caused by these hormones. STAT5A and -5B are both expressed in β-cells and control the expression of a number of mRNAs implicated in cell replication control, insulin biosynthesis and secretion. In addition to STAT5A and -5B being transcriptional activators, they may also repress gene transcription. By these means, STAT5 proteins increase the levels of anti-apoptotic transcripts in β-cells and repress expression of pro-apoptotic genes. This review focuses on the anti-apoptotic role of STAT5 signaling, providing a mechanism for β-cell resistance to pro-apoptotic cytokines, Type 1 diabetes mellitus and obesity-associated β-cell stress. It is clear from studies of STAT5 signaling in pancreatic β-cells that STAT5 is important for postnatal β-cell compensatory growth (as in pregnancy or obesity) and in the defense against β-cell stress factors.
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Affiliation(s)
- Louise T Dalgaard
- a Roskilde University, Department of Science, Universitetsvej 1, DK-4000 Roskilde, Denmark.
| | - Nils Billestrup
- b Steno Diabetes Center, Niels Steensens Vej 2, DK-2820 Gentofte, Denmark.
| | - Jens H Nielsen
- c University of Copenhagen, Department of Biomedical Research, Panum Institute, Bldg 6.5, Blegdamsvej 3C, DK-2200 Copenhagen N, Denmark.
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Sertznig P, Seifert M, Tilgen W, Reichrath J. Peroxisome proliferator-activated receptors (PPARs) and the human skin: importance of PPARs in skin physiology and dermatologic diseases. Am J Clin Dermatol 2008; 9:15-31. [PMID: 18092840 DOI: 10.2165/00128071-200809010-00002] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily that regulate lipid, glucose, and amino acid metabolism. More recently, PPARs and corresponding ligands have been shown in skin and other organs to regulate important cellular functions, including cell proliferation and differentiation, as well as inflammatory responses. These new functions identify PPARs and corresponding ligands as potential targets for the treatment of various skin diseases and other disorders. It has been shown that in inflammatory skin disorders, including hyperproliferative psoriatic epidermis and the skin of patients with atopic dermatitis, the expression of both PPARalpha and PPARgamma is decreased. This observation suggests the possibility that PPARalpha and PPARgamma activators, or compounds that positively regulate PPAR gene expression, may represent novel NSAIDs for the topical or systemic treatment of common inflammatory skin diseases such as atopic dermatitis, psoriasis, and allergic contact dermatitis. Moreover, recent findings indicate that PPAR-signaling pathways may act as a promising therapeutic target for the treatment of hyperproliferative skin diseases including skin malignancies. Studies in non-diabetic patients suggest that oral thiazolidinediones, which are synthetic ligands of PPARgamma, not only exert an antidiabetic effect but also may be beneficial for moderate chronic plaque psoriasis by suppressing proliferation and inducing differentiation of keratinocytes; furthermore, they may even induce cell growth arrest, apoptosis, and terminal differentiation in various human malignant tumors. It has been reported that PPARalpha immunoreactivity is reduced in human keratinocytes of squamous cell carcinoma (SCC) and actinic keratosis (AK), while PPARdelta appears to be upregulated. Additionally, the microvessel density is significantly higher in AK and SCC that express high levels of PPARdelta. PPARdelta has been demonstrated to have an anti-apoptotic role and to maintain survival and differentiation of epithelial cells, whereas PPARalpha and PPARgamma activators induce differentiation and inhibit proliferation and regulate apoptosis. In melanoma, the growth inhibitory effect of PPARgamma activation is independent of apoptosis and seems to occur primarily through induction of cell cycle arrest in the G1 phase of the cell cycle or induction of re-differentiation. PPARalpha activation causes inhibition of migration of melanoma cells and anchorage-independent growth, whereas primary tumor growth remains unaltered. In clinical trials of gemfibrozil, a PPARalpha ligand, significantly fewer patients treated with this lipid-lowering drug were diagnosed with melanoma as compared to those in the control group. In conclusion, an increasing body of evidence indicates that PPAR signaling pathways may represent interesting therapeutic targets for a broad variety of skin disorders, including inflammatory skin diseases such as psoriasis and atopic dermatitis, and skin malignancies.
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Affiliation(s)
- Pit Sertznig
- Department of Dermatology, The Saarland University Hospital, Homburg/Saar, Germany
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Sertznig P, Seifert M, Tilgen W, Reichrath J. Present concepts and future outlook: function of peroxisome proliferator-activated receptors (PPARs) for pathogenesis, progression, and therapy of cancer. J Cell Physiol 2007; 212:1-12. [PMID: 17443682 DOI: 10.1002/jcp.20998] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily of transcriptional regulators that regulate lipid, glucose, and amino acid metabolism. In recent studies it also has been shown that these receptors are implicated in tumor progression, cellular differentiation, and apoptosis and modulation of their function is therefore considered as a potential target for cancer prevention and treatment. PPAR ligands and other agents influencing PPAR signalling pathways have been shown to reveal chemopreventive potential by mediating tumor suppressive activities in a variety of human cancers and could represent a potential novel strategy to inhibit tumor carcinogenesis and progression. This review summarizes the currently available data on the roles of PPARs in relation to the processes of cell differentiation and carcinogenesis as well as their role as promising future therapeutic targets.
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Affiliation(s)
- P Sertznig
- Department of Dermatology, The Saarland University Hospital, Homburg/Saar, Germany
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Ono M, Chia DJ, Merino-Martinez R, Flores-Morales A, Unterman TG, Rotwein P. Signal Transducer and Activator of Transcription (Stat) 5b-Mediated Inhibition of Insulin-Like Growth Factor Binding Protein-1 Gene Transcription: A Mechanism for Repression of Gene Expression by Growth Hormone. Mol Endocrinol 2007; 21:1443-57. [PMID: 17426286 DOI: 10.1210/me.2006-0543] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Abstract
GH plays a central role in controlling somatic growth, tissue regeneration, and intermediary metabolism in most vertebrate species through mechanisms dependent on the regulation of gene expression. Recent studies using transcript profiling have identified large cohorts of genes whose expression is induced by GH. Other results have demonstrated that signal transducer and activator of transcription (Stat) 5b, a latent transcription factor activated by the GH receptor-associated protein kinase, Jak2, is a key agent in the GH-stimulated gene activation that leads to somatic growth. By contrast, little is known about the steps through which GH-initiated signaling pathways reduce gene expression. Here we show that Stat5b plays a critical role in the GH-regulated inhibition of IGF binding protein-1 gene transcription by impairing the actions of the FoxO1 transcription factor on the IGF binding protein-1 promoter. Additional observations using transcript profiling in the liver indicate that Stat5b may be a general mediator of GH-initiated gene repression. Our results provide a model for understanding how GH may simultaneously stimulate and inhibit the expression of different cohorts of genes via the same transcription factor, potentially explaining how GH action leads to integrated biological responses in the whole organism.
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Affiliation(s)
- Mitsuru Ono
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, 3181 Southwest Sam Jackson Road, Portland, Oregon 97239, USA
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Burns KA, Vanden Heuvel JP. Modulation of PPAR activity via phosphorylation. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:952-60. [PMID: 17560826 PMCID: PMC2712836 DOI: 10.1016/j.bbalip.2007.04.018] [Citation(s) in RCA: 330] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2006] [Revised: 03/06/2007] [Accepted: 04/30/2007] [Indexed: 02/08/2023]
Abstract
Peroxisome proliferator-activated receptors (PPARs) are members of the nuclear receptor superfamily of transcription factors that respond to specific ligands by altering gene expression in a cell-, developmental- and sex-specific manner. Three subtypes of this receptor have been discovered (PPARalpha, beta and gamma), each apparently evolving to fulfill different biological niches. PPARs control a variety of target genes involved in lipid homeostasis, diabetes and cancer. Similar to other nuclear receptors, the PPARs are phosphoproteins and their transcriptional activity is affected by cross-talk with kinases and phosphatases. Phosphorylation by the mitogen-activated protein kinases (ERK- and p38-MAPK), Protein Kinase A and C (PKA, PKC), AMP Kinase (AMPK) and glycogen synthase kinase-3 (GSK3) affect their activity in a ligand-dependent or -independent manner. The effects of phosphorylation depend on the cellular context, receptor subtype and residue metabolized which can be manifested at several steps in the PPAR activation sequence including ligand affinity, DNA binding, coactivator recruitment and proteasomal degradation. The review will summarize the known PPAR kinases that directly act on these receptors, the sites affected and the result of this modification on receptor activity.
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Affiliation(s)
| | - John P. Vanden Heuvel
- To whom correspondence should be addressed: Jack Vanden Heuvel, PhD, Professor of Molecular Toxicology, Penn State University, 325 Life Sciences Building, University Park, PA 16802, T: (814) 863-8532, F: (814) 863-1696, , jackvh.cas.psu.edu
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Ljungberg A, Lindén D, Améen C, Bergström G, Oscarsson J. Importance of PPAR alpha for the effects of growth hormone on hepatic lipid and lipoprotein metabolism. Growth Horm IGF Res 2007; 17:154-164. [PMID: 17307376 DOI: 10.1016/j.ghir.2007.01.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Revised: 01/05/2007] [Accepted: 01/11/2007] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Growth hormone (GH) enhances lipolysis in adipose tissue, thereby increasing the flux of fatty acids to other tissues. Moreover, GH increases hepatic triglyceride synthesis and secretion in rats and decreases the action of peroxisome proliferator-activated receptor (PPAR)alpha. PPARalpha is activated by fatty acids and regulates hepatic lipid metabolism in rodents. The aim of this study was to investigate the importance of PPARalpha for the effects of GH on hepatic gene expression and lipoprotein metabolism. DESIGN Bovine GH was given as a continuous infusion (5mg/kg/day) for 7 days to PPARalpha-null and wild-type (wt) mice. Plasma and liver lipids and hepatic gene expression were measured. In separate experiments, hepatic triglyceride secretion was measured. RESULTS GH treatment decreased hepatic triglyceride content and increased hepatic triglyceride secretion rate and serum cholesterol levels. Furthermore, GH increased hepatic acylCoA:diacylglycerol acyltransferase (DGAT)2 mRNA levels, but decreased the hepatic mRNA expression of acyl-CoA oxidase, medium-chain acyl-CoA dehydrogenase and PPARgamma1. All these GH effects were independent of PPARalpha. However, the effect of GH on Cyp4a10, PPARgamma2, and DGAT1 was different between the genotypes. GH treatment decreased Cyp4a10 mRNA expression in wt mice, but increased the expression in PPARalpha-null mice. In contrast, GH decreased the expression of DGAT1 and PPARgamma2 in PPARalpha-null mice, but not in wt mice. CONCLUSIONS Most of the effects of GH on lipid and lipoprotein metabolism were independent of PPARalpha. However, GH had unique effects on Cyp4a10, DGAT1, and PPARgamma2 gene expression in PPARalpha-null mice showing cross-talk between GH and PPARalpha signalling in vivo.
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Affiliation(s)
- Anna Ljungberg
- Wallenberg Laboratory for Cardiovascular Research, The Sahlgrenska Academy at Göteborg University, Göteborg, Sweden
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Vidal OM, Merino R, Rico-Bautista E, Fernandez-Perez L, Chia DJ, Woelfle J, Ono M, Lenhard B, Norstedt G, Rotwein P, Flores-Morales A. In Vivo Transcript Profiling and Phylogenetic Analysis Identifies Suppressor of Cytokine Signaling 2 as a Direct Signal Transducer and Activator of Transcription 5b Target in Liver. Mol Endocrinol 2007; 21:293-311. [PMID: 17008382 DOI: 10.1210/me.2006-0096] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
AbstractThe GH-activated signal transducer and activator of transcription 5b (STAT5b) is an essential regulator of somatic growth. The transcriptional response to STAT5b in liver is poorly understood. We have combined microarray-based expression profiling and phylogenetic analysis of gene regulatory regions to study the interplay between STAT5b and GH in the regulation of hepatic gene expression. The acute transcriptional response to GH in vivo after a single pulse of GH was studied in the liver of hypophysectomized rats in the presence of either constitutively active or a dominant-negative STAT5b delivered by adenoviral gene transfer. Genes showing differential expression in these two situations were analyzed for the presence of STAT5b binding sites in promoter and intronic regions that are phylogenetically conserved between rats and humans. Using this approach, we showed that most rapid transcriptional effects of GH in the liver are not results of direct actions of STAT5b. In addition, we identified novel STAT5b cis regulatory elements in genes such as Frizzled-4, epithelial membrane protein-1, and the suppressor of cytokine signaling 2 (SOCS2). Detailed analysis of SOCS2 promoter demonstrated its direct transcriptional regulation by STAT5b upon GH stimulation. A novel response element was identified within the first intron of the human SOCS2 gene composed of an E-box followed by tandem STAT5b binding sites, both of which are required for full GH responsiveness. In summary, we demonstrate the power of combining transcript profiling with phylogenetic sequence analysis to define novel regulatory paradigms.
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Affiliation(s)
- Oscar M Vidal
- Department of Molecular Medicine and Surgery, Karolinska Institutet 17176 Stockholm, Sweden
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Ríos-Vázquez R, Marzoa-Rivas R, Gil-Ortega I, Kaski JC. Peroxisome proliferator-activated receptor-gamma agonists for management and prevention of vascular disease in patients with and without diabetes mellitus. Am J Cardiovasc Drugs 2006; 6:231-42. [PMID: 16913824 DOI: 10.2165/00129784-200606040-00003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Inflammation is known to have a pathogenic role in atherosclerosis and the genesis of acute coronary syndromes. The peroxisome proliferator-activated receptor (PPAR)-gamma, which is expressed in many constituent cells of atheromatous plaques, inhibits the activation of several proinflammatory genes responsible for atheromatous plaque development and maturation. Agonists of this receptor, such as rosiglitazone and pioglitazone, are currently available for the treatment of type 2 diabetes mellitus, and several lines of evidence have shown that these drugs have antiatherogenic effects. Insulin resistance is associated with inflammation and has a key role in atherogenesis. The antiatherogenic and insulin sensitizing effects of the thiazolidinediones in patients with type 2 diabetes mellitus may be associated with this action. However, in recent years there has been growing evidence that the antiatherogenic effects of PPAR-gamma agonists are not confined to patients with diabetes mellitus. PPAR-gamma agonists have been shown to downregulate the expression of endothelial activation markers, reduce circulating platelet activity, improve flow-mediated dilatation and attenuate atheromatous plaque progression in patients without diabetes mellitus. These effects of PPAR-gamma agonists appear to result from both insulin sensitization and a direct modulation of transcriptional activity in the vessel wall. This review summarizes the current understanding of the role of PPAR-gamma agonists in atherogenesis and discusses their potential role in the treatment of coronary artery disease in patients with type 2 diabetes mellitus and in nondiabetic patients.
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Affiliation(s)
- Ramón Ríos-Vázquez
- Cardiovascular Biology Research Centre, Division of Cardiac and Vascular Sciences, University of London, London, UK
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Keshava N, Caldwell JC. Key issues in the role of peroxisome proliferator-activated receptor agonism and cell signaling in trichloroethylene toxicity. ENVIRONMENTAL HEALTH PERSPECTIVES 2006; 114:1464-70. [PMID: 16966106 PMCID: PMC1570084 DOI: 10.1289/ehp.8693] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Peroxisome proliferator-activated receptor alpha (PPARalpha) is thought to be involved in several different diseases, toxic responses, and receptor pathways. The U.S. Environmental Protection Agency 2001 draft trichloroethylene (TCE) risk assessment concluded that although PPAR may play a role in liver tumor induction, the role of its activation and the sequence of subsequent events important to tumorigenesis are not well defined, particularly because of uncertainties concerning the extraperoxisomal effects. In this article, which is part of a mini-monograph on key issues in the health risk assessment of TCE, we summarize some of the scientific literature published since that time on the effects and actions of PPARalpha that help inform and illustrate the key scientific questions relevant to TCE risk assessment. Recent analyses of the role of PPARalpha in gene expression changes caused by TCE and its metabolites provide only limited data for comparison with other PPARalpha agonists, particularly given the difficulties in interpreting results involving PPARalpha knockout mice. Moreover, the increase in data over the last 5 years from the broader literature on PPARalpha agonists presents a more complex array of extraperoxisomal effects and actions, suggesting the possibility that PPARalpha may be involved in modes of action (MOAs) not only for liver tumors but also for other effects of TCE and its metabolites. In summary, recent studies support the conclusion that determinations of the human relevance and susceptibility to PPARalpha-related MOA(s) of TCE-induced effects cannot rely on inferences regarding peroxisome proliferation per se and require a better understanding of the interplay of extraperoxisomal events after PPARalpha agonism.
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Affiliation(s)
- Nagalakshmi Keshava
- National Center for Environmental Assessment, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA.
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Park SH, Wiwi C, Waxman D. Signalling cross-talk between hepatocyte nuclear factor 4alpha and growth-hormone-activated STAT5b. Biochem J 2006; 397:159-68. [PMID: 16584384 PMCID: PMC1479742 DOI: 10.1042/bj20060332] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In the present study, we have characterized signalling cross-talk between STAT5b (signal transducer and activator of transcription 5b) and HNF4alpha (hepatocyte nuclear factor 4alpha), two major regulators of sex-dependent gene expression in the liver. In a HepG2 liver cell model, HNF4alpha strongly inhibited beta-casein and ntcp (Na+/taurocholate cotransporting polypeptide) promoter activity stimulated by GH (growth hormone)-activated STAT5b, but had no effect on interferon-gamma-stimulated STAT1 transcriptional activity. By contrast, STAT5b synergistically enhanced the transcriptional activity of HNF4alpha towards the ApoCIII (apolipoprotein CIII) promoter. The inhibitory effect of HNF4alpha on STAT5b transcription was associated with the inhibition of GH-stimulated STAT5b tyrosine phosphorylation and nuclear translocation. The short-chain fatty acid, butyrate, reversed STAT5b transcriptional inhibition by HNF4alpha, but did not reverse the inhibition of STAT5b tyrosine phosphorylation. HNF4alpha inhibition of STAT5b tyrosine phosphorylation was not reversed by pervanadate or by dominant-negative phosphotyrosine phosphatase 1B, suggesting that it does not result from an increase in STAT5b dephosphorylation. Rather, HNF4alpha blocked GH-stimulated tyrosine phosphorylation of JAK2 (Janus kinase 2), a STAT5b tyrosine kinase. Thus STAT5b and HNF4alpha exhibit bi-directional cross-talk that may augment HNF4alpha-dependent gene transcription while inhibiting STAT5b transcriptional activity via the inhibitory effects of HNF4alpha on JAK2 phosphorylation, which leads to inhibition of STAT5b signalling initiated by the GH receptor at the cell surface.
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Affiliation(s)
- Soo-Hee Park
- Division of Cell and Molecular Biology, Department of Biology, Boston University, Boston, MA 02215, U.S.A
| | - Christopher A. Wiwi
- Division of Cell and Molecular Biology, Department of Biology, Boston University, Boston, MA 02215, U.S.A
| | - David J. Waxman
- Division of Cell and Molecular Biology, Department of Biology, Boston University, Boston, MA 02215, U.S.A
- To whom correspondence should be addressed (email )
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Clodfelter KH, Holloway MG, Hodor P, Park SH, Ray WJ, Waxman DJ. Sex-Dependent Liver Gene Expression Is Extensive and Largely Dependent upon Signal Transducer and Activator of Transcription 5b (STAT5b): STAT5b-Dependent Activation of Male Genes and Repression of Female Genes Revealed by Microarray Analysis. Mol Endocrinol 2006; 20:1333-51. [PMID: 16469768 DOI: 10.1210/me.2005-0489] [Citation(s) in RCA: 181] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
AbstractSexual dimorphism in mammalian liver contributes to sex differences in physiology, homeostasis, and steroid and foreign compound metabolism. Many sex-dependent liver genes are regulated by sex differences in pituitary GH secretion, with the transcription factor, signal transducer and activator of transcription (STAT5b), proposed to mediate signaling by the pulsatile, male plasma GH profile. Presently, a large-scale gene expression study was conducted using male and female mice, wild type and Stat5b inactivated, to characterize sex differences in liver gene expression and their dependence on STAT5b. The relative abundance of individual liver RNAs was determined for each sex-genotype combination by competitive hybridization to 23,574-feature oligonucleotide microarrays. Significant sex differences in hepatic expression were seen for 1603 mouse genes. Of 850 genes showing higher expression in males, 767 (90%) were down-regulated in STAT5b-deficient males. Moreover, of 753 genes showing female-predominant expression, 461 (61%) were up-regulated in STAT5b-deficient males. In contrast, approximately 90% of the sex-dependent genes were unaffected by STAT5b deficiency in females. Thus: 1) STAT5b is essential for sex-dependent liver gene expression, a characteristic of approximately 1600 mouse genes (4% of the genome); 2) male-predominant liver gene expression requires STAT5b, or STAT5b-dependent factors, which act in a positive manner; and 3) many female-predominant liver genes are repressed in males in a STAT5b-dependent manner. Several of the STAT5b-dependent male genes encode transcriptional repressors; these may include direct STAT5b targets that repress female-predominant genes in male liver. Several female-predominant repressors are elevated in STAT5b-deficient males; these may contribute to the major loss of male gene expression seen in the absence of STAT5b.
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Affiliation(s)
- Karl H Clodfelter
- Department of Biology, Boston University, 5 Cummington Street, Boston, Massachusetts 02215, USA
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Brown-Borg HM. Longevity in mice: is stress resistance a common factor? AGE (DORDRECHT, NETHERLANDS) 2006; 28:145-162. [PMID: 19943136 PMCID: PMC2464727 DOI: 10.1007/s11357-006-9003-y] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2005] [Accepted: 12/01/2005] [Indexed: 05/27/2023]
Abstract
A positive relationship between stress resistance and longevity has been reported in a multitude of studies in organisms ranging from yeast to mice. Several mouse lines have been discovered or developed that exhibit extended longevities when compared with normal, wild-type mice of the same genetic background. These long-living lines include the Ames dwarf, Snell dwarf, growth hormone receptor knockout (Laron dwarf), IGF-1 receptor heterozygote, Little, alpha-MUPA knockout, p66(shc) knockout, FIRKO, mClk-1 heterozygote, thioredoxin transgenic, and most recently the Klotho transgenic mouse. These mice are described in terms of the reported extended lifespans and studies involving resistance to stress. In addition, caloric restriction (CR) and stress resistance are briefly addressed for comparison with genetically altered mice. Although many of the long-living mice have GH/IGF-1/insulin signaling-related alterations and enhanced stress resistance, there are some that exhibit life extension without an obvious link to this hormone pathway. Resistance to oxidative stress is by far the most common system studied in long-living mice, but there is evidence of enhancement of resistance in other systems as well. The differences in stress resistance between long-living mutant and normal mice result from complex interrelationships among pathways that appear to coordinate signals of growth and metabolism, and subsequently result in differences in lifespan.
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Affiliation(s)
- H M Brown-Borg
- Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, 501 North Columbia Road, Grand Forks, ND 58203, USA.
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Abstract
The liver is a primary target for the action of GH, a pituitary protein hormone that regulates a broad range of physiological processes, including long bone growth, fatty acid oxidation, glucose uptake, and hepatic steroid and foreign compound metabolism. GH exerts sex-dependent effects on the liver in many species, with many hepatic genes, most notably genes coding for cytochrome P450 (CYP) enzymes, being transcribed in a sex-dependent manner. Sex differences in CYP expression are most striking in rats and mice (up to 500-fold male-female differences), but are also seen, albeit to a much smaller degree, in humans, where they are an important determinant of the sex dependence of hepatic drug and steroid metabolism. This article examines the mechanisms whereby GH, via its sex-dependent temporal patterns of pituitary release, activates intracellular signaling leading to the sexually dimorphic transcription of CYPs and other liver-expressed genes. Recent findings implicating the GH-regulated transcription factor STAT5b (signal transducer and activator of transcription 5b), hepatocyte nuclear factors 3beta, 4alpha and 6, and sex differences in DNA methylation and chromatin structure in the sex-dependent actions of GH are reviewed, and current mechanistic models are evaluated.
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Affiliation(s)
- David J Waxman
- Department of Biology, Boston University, 5 Cummington Street, Boston, Massachusetts 02215, USA.
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Corton JC, Brown-Borg HM. Peroxisome Proliferator-Activated Receptor Coactivator 1 in Caloric Restriction and Other Models of Longevity. J Gerontol A Biol Sci Med Sci 2005; 60:1494-509. [PMID: 16424281 DOI: 10.1093/gerona/60.12.1494] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Dietary restriction of calories (caloric restriction [CR]) increases longevity in phylogenetically diverse species. CR retards or prevents age-dependent deterioration of tissues and an array of spontaneous and chemically induced diseases associated with obesity including cardiovascular disease, diabetes, and cancer. An understanding of the molecular mechanisms that underlie the beneficial effects of CR will help identify novel dietary, pharmacological, and lifestyle strategies for slowing the rate of aging and preventing these diseases as well as identify factors which modulate chemical toxicity. Here, we review the involvement of transcriptional coactivator proteins, peroxisome proliferator-activated receptor (PPAR) gamma coactivator 1 (PGC-1) alpha and beta, and regulated nuclear receptors (NR) in mediating the phenotypic changes found in models of longevity which include rodent CR models and mouse mutants in which insulin and/or insulin-like growth factor-I signaling is attenuated. PGC-1alpha is transcriptionally or posttranslationally regulated in mammals by: 1) forkhead box "other" (FoxO) transcription factors through an insulin/insulin-like growth factor-I -dependent pathway, 2) glucagon-stimulated cellular AMP (cAMP) response element binding protein, 3) stress-activated kinase signaling through p38 mitogen-activated protein kinase, and 4) the deacetylase and longevity factor sirtuin 1 (SIRT1). PGC-1alpha and PGC-1beta regulate the ligand-dependent and -independent activation of a large number of NR including PPARalpha and constitutive activated receptor (CAR). These NR regulate genes involved in nutrient and xenobiotic transport and metabolism as well as resistance to stress. CR reverses age-dependent decreases in PGC-1alpha, PPARalpha, and regulated genes. Strategies that target one or multiple PGC-1-regulated NR could be used to mimic the beneficial health effects found in models of longevity.
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Affiliation(s)
- J Christopher Corton
- United States Environmental Protection Agency, Division of Environmental Carcinogenesis, Research Triangle Park, NC 27711, USA.
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Park SY, Cho YR, Finck BN, Kim HJ, Higashimori T, Hong EG, Lee MK, Danton C, Deshmukh S, Cline GW, Wu JJ, Bennett AM, Rothermel B, Kalinowski A, Russell KS, Kim YB, Kelly DP, Kim JK. Cardiac-specific overexpression of peroxisome proliferator-activated receptor-alpha causes insulin resistance in heart and liver. Diabetes 2005; 54:2514-24. [PMID: 16123338 DOI: 10.2337/diabetes.54.9.2514] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Diabetic heart failure may be causally associated with alterations in cardiac energy metabolism and insulin resistance. Mice with heart-specific overexpression of peroxisome proliferator-activated receptor (PPAR)alpha showed a metabolic and cardiomyopathic phenotype similar to the diabetic heart, and we determined tissue-specific glucose metabolism and insulin action in vivo during hyperinsulinemic-euglycemic clamps in awake myosin heavy chain (MHC)-PPARalpha mice (12-14 weeks of age). Basal and insulin-stimulated glucose uptake in heart was significantly reduced in the MHC-PPARalpha mice, and cardiac insulin resistance was mostly attributed to defects in insulin-stimulated activities of insulin receptor substrate (IRS)-1-associated phosphatidylinositol (PI) 3-kinase, Akt, and tyrosine phosphorylation of signal transducer and activator of transcription 3 (STAT3). Interestingly, MHC-PPARalpha mice developed hepatic insulin resistance associated with defects in insulin-mediated IRS-2-associated PI 3-kinase activity, increased hepatic triglyceride, and circulating interleukin-6 levels. To determine the underlying mechanism, insulin clamps were conducted in 8-week-old MHC-PPARalpha mice. Insulin-stimulated cardiac glucose uptake was similarly reduced in 8-week-old MHC-PPARalpha mice without changes in cardiac function and hepatic insulin action compared with the age-matched wild-type littermates. Overall, these findings indicate that increased activity of PPARalpha, as occurs in the diabetic heart, leads to cardiac insulin resistance associated with defects in insulin signaling and STAT3 activity, subsequently leading to reduced cardiac function. Additionally, age-associated hepatic insulin resistance develops in MHC-PPARalpha mice that may be due to altered cardiac metabolism, functions, and/or inflammatory cytokines.
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Affiliation(s)
- So-Young Park
- Yale University School of Medicine, Department of Internal Medicine, Section of Endocrinology and Metabolism, The Anlyan Center, S269C, P.O. Box 208020, 300 Cedar St., New Haven, CT 06520-8020, USA.
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Reiterer G, MacDonald R, Browning JD, Morrow J, Matveev SV, Daugherty A, Smart E, Toborek M, Hennig B. Zinc deficiency increases plasma lipids and atherosclerotic markers in LDL-receptor-deficient mice. J Nutr 2005; 135:2114-8. [PMID: 16140885 DOI: 10.1093/jn/135.9.2114] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Low zinc concentration can be associated with an increased risk of cardiovascular diseases. In the current study, we hypothesize that zinc deficiency can increase and zinc supplementation can decrease proatherosclerotic events in LDL receptor knock-out (LDL-R-/-) mice fed a moderate-fat diet. Mice were fed either a zinc-deficient (0 micromol Zn/g), a control (0.45 micromol Zn/g), or a zinc-supplemented (1.529 micromol Zn/g) diet for 4 wk. Mice fed the zinc-deficient diet had significantly increased concentrations of cholesterol and triacylglycerides in the VLDL and HDL fractions. Zinc supplementation decreased these lipid variables compared with control mice. We detected significantly higher concentrations of glutathione reductase mRNA in the thoracic aortae of zinc-deficient mice. Furthermore, inflammatory markers, such as nuclear factor-kappaB and vascular cell adhesion molecule-1, were significantly increased in zinc-deficient mice compared with mice of the control or supplemented groups. In addition, zinc deficiency significantly reduced the DNA binding activity of peroxisome proliferator activate receptors (PPARs) in liver extracts. Interestingly, mRNA expression levels of PPARgamma were significantly increased in thoracic aortae of zinc-deficient mice, indicating an adaptation process to decreased PPAR signaling. These data provide in vivo evidence of zinc deficiency inducing proinflammatory events in an atherogenic mouse model. These data also suggest that adequate zinc may be a critical component in protective PPAR signaling during atherosclerosis.
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Affiliation(s)
- Gudrun Reiterer
- Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, 40546, USA
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Gelman L, Michalik L, Desvergne B, Wahli W. Kinase signaling cascades that modulate peroxisome proliferator-activated receptors. Curr Opin Cell Biol 2005; 17:216-22. [PMID: 15780600 DOI: 10.1016/j.ceb.2005.02.002] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors involved in lipid and glucose homeostasis, inflammation and wound healing. In addition to ligand binding, phosphorylation can also regulate PPARs; the biological effects of phosphorylation depend on the stimulus, the kinase, the PPAR isotype, the residue modified, the cell type and the promoter investigated. The study of this dual regulation mode, which allows PPARs to integrate signals conveyed by lipophilic ligands with those coming from the plasma membrane, may ultimately offer new therapeutic strategies.
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Affiliation(s)
- Laurent Gelman
- Center for Integrative Genomics, NCCR Frontiers in Genetics, University of Lausanne, Switzerland
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Li S, Gokden N, Okusa MD, Bhatt R, Portilla D. Anti-inflammatory effect of fibrate protects from cisplatin-induced ARF. Am J Physiol Renal Physiol 2005; 289:F469-80. [PMID: 15814532 DOI: 10.1152/ajprenal.00038.2005] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recently, we demonstrated that peroxisome proliferator-activated receptor-α (PPARα) ligand ameliorates cisplatin-induced acute renal failure (ARF) by preventing inhibition of substrate oxidation, and also by preventing apoptosis and necrosis of the proximal tubule (Li S, Bhatt R, Megyesi J, Gokden N, Shah SV, and Portilla D. Am J Physiol Renal Physiol 287: F990–F998, 2004). In the following studies, we examined the protective effect of PPARα ligand on cisplatin-induced inflammatory responses during ARF. Mice subjected to a single intraperitoneal injection of cisplatin developed ARF at day 3. Cisplatin increased mRNA and protein expression of TNF-α, RANTES, and also upregulated endothelial adhesion molecules ICAM-1/VCAM-1 and chemokine receptors CCR1/CCR5. Cisplatin also led to neutrophil infiltration in the corticomedullary region. Pretreatment of wild-type mice with WY-14,643, a fibrate class of PPARα ligands, before cisplatin significantly suppressed cisplatin-induced upregulation of cytokine/chemokine expression, prevented neutrophil accumulation, and ameliorated renal dysfunction. In contrast, treatment with PPARα ligand before cisplatin did not prevent cytokine/chemokine production, neutrophil accumulation, and did not protect kidney function in PPARα null mice. In addition, we observed that cisplatin-induced NF-κB binding activity in nuclear extracts from wild-type mice was markedly reduced by treatment with PPARα ligand. These results demonstrate that PPARα exerts an anti-inflammatory effect in kidney tissue by a mechanism that includes inhibition of NF-κB DNA binding activity, and this effect results in inhibition of neutrophil infiltration, cytokine/chemokine release, and amelioration of cisplatin-induced ARF.
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Affiliation(s)
- Shenyang Li
- Division of Nephrology, Department of Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, 72205, USA
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Su GM, Fiala-Beer E, Weber J, Jahn D, Robertson GR, Murray M. Pretranslational upregulation of microsomal CYP4A in rat liver by intake of a high-sucrose, lipid-devoid diet containing orotic acid. Biochem Pharmacol 2005; 69:709-17. [PMID: 15670589 DOI: 10.1016/j.bcp.2004.11.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2004] [Accepted: 11/08/2004] [Indexed: 02/07/2023]
Abstract
In rodents, high-fat diets promote hepatic lipid accumulation in rodents, activation of peroxisome proliferator activated receptor-alpha (PPARalpha) and upregulation of cytochrome P450 (CYP) 4A gene expression. Lipid-devoid diets containing sucrose and orotic acid (S/OA-diet) also cause lipid infiltration by stimulating intrahepatic lipid synthesis and preventing lipoprotein transport through the Golgi apparatus. This study evaluated the impact of the lipid-deficient S/OA-diet on CYP4A expression and PPARalpha activation in rodent liver. CYP4A protein and laurate omega-hydroxylation activity were increased in rat liver after S/OA-feeding for 21 days. CYP4A1 and CYP4A2 mRNAs were induced to 2.1- and 2.6-fold of control, but mRNAs corresponding to CYP4A3 and the peroxisomal acyl-CoA oxidase (AOX) were unchanged. Coadministration of clofibric acid and the S/OA-diet prevented hepatic lipid accumulation and upregulated CYP4A protein to levels comparable with clofibric acid alone (five-fold of control). Clofibric acid, alone and in combination with the S/OA-diet, upregulated CYP4A1-3 and AOX mRNAs. Hepatic PPARalpha protein was decreased by the S/OA-diet but was increased to 5.7-fold of control by clofibric acid; retinoid X-receptor-alpha (RXRalpha) protein was decreased to 26-41% of control by all treatments. In further studies, administration of the S/OA-diet to control and PPARalpha-null mice promoted hepatic lipid deposition; microsomal CYP4A protein was induced in wild-type but not PPARalpha-null mice. These findings implicate PPARalpha in the induction of CYP4A in rodent liver by the lipid-devoid S/OA-diet. Decreased availability of hepatic PPARalpha and RXRalpha after intake of the diet may contribute to the selective upregulation of hepatic CYP4A1 and CYP4A2 in this model.
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Affiliation(s)
- Gloria M Su
- Pharmacogenomics and Drug Development Group, Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
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Litterst CM, Kliem S, Lodrini M, Pfitzner E. Coactivators in Gene Regulation by STAT5. VITAMINS & HORMONES 2005; 70:359-86. [PMID: 15727811 DOI: 10.1016/s0083-6729(05)70012-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Signal transducer and activator of transcription 5 (STAT5) is a member of the STAT family of transcription factors that relay the effect of diverse cytokines, hormones, and growth factors by regulating the transcription of distinct target genes. This function is emphasized by its crucial role in the development of the mammary gland and the hematopoietic system. Cytokine receptor-associated Janus kinases (JAKs) induce dimerization, nuclear translocation, and DNA binding through tyrosine phosphorylation of STAT5. STAT5 regulates the expression of cytokine target genes by binding to gamma interferon-activated sequence (GAS) motifs. Transcriptional activation requires the contact of STAT5 to coactivators and components of the transcription machinery. Another important point in transcriptional activation is the cooperation with other transcription factors that bind in close vicinity to the target gene promoters and enhancers. Their concerted action can result in an enhanced binding to the promoters or in cooperative recruitment of coactivators. In addition, cross-talk with other signaling pathways as well as secondary modifications of STAT5 have been described to affect transactivation function.
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Affiliation(s)
- Claudia M Litterst
- Georg-Speyer-Haus, Institute for Biomedical Research, D-60596 Frankfurt, Germany
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Stauber AJ, Brown-Borg H, Liu J, Waalkes MP, Laughter A, Staben RA, Coley JC, Swanson C, Voss KA, Kopchick JJ, Corton JC. Constitutive expression of peroxisome proliferator-activated receptor alpha-regulated genes in dwarf mice. Mol Pharmacol 2004; 67:681-94. [PMID: 15576629 DOI: 10.1124/mol.104.007278] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Defects in growth hormone secretion or signaling in mice are associated with decreased body weights (dwarfism), increased longevity, increased resistance to stress, and decreases in factors that contribute to cardiovascular disease and cancer. Peroxisome proliferators (PP) alter a subset of these changes in wild-type mice through activation of the nuclear receptor family member PP-activated receptor alpha (PPARalpha). We tested the hypothesis that an overlap in the transcriptional programs between untreated dwarf mice and PP-treated wild-type mice underlies these similarities. Using transcript profiling, we observed a statistically significant overlap in the expression of genes differentially regulated in control Snell dwarf mice (Pit-1dw) compared with phenotypically normal heterozygote (+/dw) control mice and those altered by the PP 4-chloro-6-(2,3-xylidino)-2-pyrimidinyl)thioacetic acid (WY-14,643) in +/dw mice. The genes included those involved in beta- and omega-oxidation of fatty acids (Acox1, Cyp4a10, Cyp4a14) and those involved in stress responses (the chaperonin, T-complex protein1epsilon) and cardiovascular disease (fibrinogen). The levels of some of these gene products were also altered in other dwarf mouse models, including Ames, Little, and growth hormone receptor-null mice. The constitutive increases in PPARalpha-regulated genes may be partly caused by increased expression of PPARalpha mRNA and protein as observed in the livers of control Snell dwarf mice. These results indicate that some of the beneficial effects associated with the dwarf phenotype may be caused by constitutive activation of PPARalpha and regulated genes.
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Affiliation(s)
- Anja J Stauber
- CIIT Centers for Health Research, Research Triangle Park, North Carolina, USA
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Chen K, Li D, Zhang X, Hermonat PL, Mehta JL. Anoxia-Reoxygenation Stimulates Collagen Type-I and MMP-1 Expression in Cardiac Fibroblasts. J Cardiovasc Pharmacol 2004; 44:682-7. [PMID: 15550788 DOI: 10.1097/00005344-200412000-00010] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Cardiac remodeling after ischemic injury is a major cause of heart failure. In this process, fibroblast growth and collagen synthesis and degradation play a critical role. Recent studies indicate that ligands of the peroxisome proliferator-activated receptors-gamma (PPAR-gamma) alter cardiac remodeling during chronic ischemia. This study was designed to investigate if the PPAR-gamma ligand pioglitazone would modulate fibroblast growth and collagen type-I synthesis (and expression) in cardiac fibroblasts exposed to anoxia-reoxygenation (A-R). METHODS AND RESULTS Cardiac fibroblasts were exposed to anoxia (95% N2/5% CO2) and then reoxygenation (95% air/5% CO2). A-R increased fibroblast growth (MTT assay) as well as collagen type-I synthesis (H-proline incorporation) and protein expression (Western analysis). Concurrently, there was a parallel increase in the expression of matrix metalloproteinase-1 (MMP-1) in fibroblasts. Pretreatment of cardiac fibroblasts with pioglitazone (10 M) reduced all these effects of A-R. Further, A-R stimulated intracellular reactive oxygen species (ROS) generation and activated the redox-sensitive transcription factor NF-kappaB (both P < 0.05). Both these phenomena were inhibited by pretreatment of cells with pioglitazone. CONCLUSION Thus, it appears that A-R stimulates fibroblast cell growth, collagen type-I synthesis, and MMP-1 expression in cardiac fibroblasts, most likely a result of ROS generation. Inhibition of ROS generation and induction of NF-kappaB in cardiac fibroblasts during A-R may be a mechanism of action of pioglitazone.
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Affiliation(s)
- Kui Chen
- Department of Internal Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas 72205, USA
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Sanguino E, Roglans N, Alegret M, Sánchez RM, Vázquez-Carrera M, Laguna JC. Prevention of age-related changes in rat cortex transcription factor activator protein-1 by hypolipidemic drugs. Biochem Pharmacol 2004; 68:1411-21. [PMID: 15345331 DOI: 10.1016/j.bcp.2004.06.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2004] [Accepted: 06/14/2004] [Indexed: 11/24/2022]
Abstract
We sought to investigate if, similar to what has been described in other rodent tissues, ageing changes the activity of several transcription factors, namely signal transducer and activator of transcription, nuclear factor-kappa B (NFkappaB), activated protein-1 (AP-1) and peroxisome proliferator-activated receptor (PPAR), in cortex of Sprague-Dawley rats. We also investigated if the administration of two hypolipidemic drugs, gemfibrozil (GFB) and atorvastatin (ATV), could prevent those changes. To this purpose, we determined the expression and binding activity of these transcription factors in cortex samples from 3-month and 18-month old male and female rats, and in 18-month old rats of both sexes treated for 21 days with a daily dose of 3mg GFB/kg or 10mg ATV/kg. Ageing increased rat cortex NFkappaB binding activity by 35-40%, and decreased by 22-26% the amount of PPARalpha in rats of both sexes, while cortex AP-1 binding activity and c-Jun content were reduced only in old females (-26 and -50%, respectively). Cortex cyclooxigenase-2 (COX-2) and receptor for activated C-kinase 1 (RACK1) expression was also reduced by old age. Hypolipidemic drugs prevented the age-related decrease of cortex AP-1 in old females and increased AP-1 binding activity and c-Jun protein in cortex from both old male and female rats. GFB increased also by 80% the cortex PPARalpha content in old males. Our data indicate that 18-month old rats show signs of cortex biochemical deterioration related to the ageing process, and that hypolipidemic drug administration partially prevents the appearance of some of the age-related changes in cortex biochemistry.
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Affiliation(s)
- Elena Sanguino
- Unidad de Farmacología y Farmacognosia, Facultad de Farmacia, Universidad de Barcelona Avda Diagonal 643, 08028 Barcelona, Spain
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