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Goerdeler C, Engelmann B, Aldehoff AS, Schaffert A, Blüher M, Heiker JT, Wabitsch M, Schubert K, Rolle-Kampczyk U, von Bergen M. Metabolomics in human SGBS cells as new approach method for studying adipogenic effects: Analysis of the effects of DINCH and MINCH on central carbon metabolism. ENVIRONMENTAL RESEARCH 2024; 252:118847. [PMID: 38582427 DOI: 10.1016/j.envres.2024.118847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/20/2024] [Accepted: 03/31/2024] [Indexed: 04/08/2024]
Abstract
Growing evidence suggests that exposure to certain metabolism-disrupting chemicals (MDCs), such as the phthalate plasticizer DEHP, might promote obesity in humans, contributing to the spread of this global health problem. Due to the restriction on the use of phthalates, there has been a shift to safer declared substitutes, including the plasticizer diisononyl-cyclohexane-1,2-dicarboxylate (DINCH). Notwithstanding, recent studies suggest that the primary metabolite monoisononyl-cyclohexane-1,2-dicarboxylic acid ester (MINCH), induces differentiation of human adipocytes and affects enzyme levels of key metabolic pathways. Given the lack of methods for assessing metabolism-disrupting effects of chemicals on adipose tissue, we used metabolomics to analyze human SGSB cells exposed to DINCH or MINCH. Concentration analysis of DINCH and MINCH revealed that uptake of MINCH in preadipocytes was associated with increased lipid accumulation during adipogenesis. Although we also observed intracellular uptake for DINCH, the solubility of DINCH in cell culture medium was limited, hampering the analysis of possible effects in the μM concentration range. Metabolomics revealed that MINCH induces lipid accumulation similar to peroxisome proliferator-activated receptor gamma (PPARG)-agonist rosiglitazone through upregulation of the pyruvate cycle, which was recently identified as a key driver of de novo lipogenesis. Analysis of the metabolome in the presence of the PPARG-inhibitor GW9662 indicated that the effect of MINCH on metabolism was mediated at least partly by a PPARG-independent mechanism. However, all effects of MINCH were only observed at high concentrations of 10 μM, which are three orders of magnitudes higher than the current concentrations of plasticizers in human serum. Overall, the assessment of the effects of DINCH and MINCH on SGBS cells by metabolomics revealed no adipogenic potential at physiologically relevant concentrations. This finding aligns with previous in vivo studies and supports the potential of our method as a New Approach Method (NAM) for the assessment of adipogenic effects of environmental chemicals.
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Affiliation(s)
- Cornelius Goerdeler
- Department of Molecular Toxicology, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany.
| | - Beatrice Engelmann
- Department of Molecular Toxicology, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany.
| | - Alix Sarah Aldehoff
- Department of Molecular Toxicology, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany.
| | - Alexandra Schaffert
- Department of Molecular Toxicology, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany.
| | - Matthias Blüher
- Department of Endocrinology, Nephrology and Rheumatology, Faculty of Medicine, University of Leipzig, Leipzig, Germany; Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany.
| | - John T Heiker
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany.
| | - Martin Wabitsch
- Division of Pediatric Endocrinology and Diabetes, Ulm University Medical Center, Ulm, Germany.
| | - Kristin Schubert
- Department of Molecular Toxicology, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany.
| | - Ulrike Rolle-Kampczyk
- Department of Molecular Toxicology, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany.
| | - Martin von Bergen
- Department of Molecular Toxicology, Helmholtz Centre for Environmental Research (UFZ), Leipzig, Germany; Institute of Biochemistry, Leipzig University, Leipzig, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany.
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Nagano K, Nakao T, Takeda M, Hirai H, Maekita H, Nakamura M, Imakawa N, Egawa A, Fujiwara T, Gao JQ, Kinoshita K, Sakata M, Nishino M, Yamashita T, Yoshida T, Harada K, Tachibana K, Doi T, Hirata K, Tsujino H, Higashisaka K, Tsutsumi Y. Polyglycerol fatty acid ester contributes to the improvement and maintenance of water solubility of amorphous curcumin by suppressing the intermolecular interaction and the diffusion rate of curcumin. Food Chem 2024; 437:137866. [PMID: 37931447 DOI: 10.1016/j.foodchem.2023.137866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 12/15/2022] [Accepted: 10/24/2023] [Indexed: 11/08/2023]
Abstract
Curcumin (CUR), a polyphenol, is an attractive component of functional foods, owing to various physiological activities. However, CUR is highly hydrophobic, insoluble in water, and difficult to absorb in the body. Here, we report an amorphous CUR formulation containing the dispersant polyglycerol fatty acid ester (PGFE), demonstrating high and stable water solubility. Improved water solubility enhanced the absorbability of CUR in our amorphous formulation along with enhanced triglyceride inhibition, compared to that in a commercial formulation. Nuclear Overhauser effect spectroscopy (NOESY) analysis revealed that PGFE reduced CUR-CUR interaction, resulting in higher dispersion and improved solubility of CUR. Taylor dispersion analysis showed a lower diffusion coefficient of CUR in the highly water-soluble formulation (with PGFE) than that in the low water-soluble formulation (without PGFE), which prevents recontact and recrystallization of CUR, which is trapped by PGFE. Overall, the amorphous CUR with high solubility could be used as a promising functional food.
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Affiliation(s)
- Kazuya Nagano
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan; School of Pharmaceutical Sciences, Wakayama Medical University, 25-1 Shichibancho, Wakayama, Wakayama 640-8156, Japan.
| | - Tomohiro Nakao
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan; San-Ei Gen F. F. I., Inc, 1-1-11 Sanwa-cho, Toyonaka, Osaka 561-8588, Japan
| | - Mariko Takeda
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Haruna Hirai
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hikaru Maekita
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Michiko Nakamura
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Naoki Imakawa
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Ayako Egawa
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Toshimichi Fujiwara
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Jian-Qing Gao
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yuhangtang Road, Hangzhou 310058, PR China
| | - Keigo Kinoshita
- San-Ei Gen F. F. I., Inc, 1-1-11 Sanwa-cho, Toyonaka, Osaka 561-8588, Japan
| | - Makoto Sakata
- San-Ei Gen F. F. I., Inc, 1-1-11 Sanwa-cho, Toyonaka, Osaka 561-8588, Japan
| | - Masayuki Nishino
- San-Ei Gen F. F. I., Inc, 1-1-11 Sanwa-cho, Toyonaka, Osaka 561-8588, Japan
| | - Takuya Yamashita
- School of Pharmaceutical Sciences, Wakayama Medical University, 25-1 Shichibancho, Wakayama, Wakayama 640-8156, Japan
| | - Takuya Yoshida
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kazuo Harada
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan; Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Keisuke Tachibana
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takefumi Doi
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Kazumasa Hirata
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan; School of Pharmaceutical Sciences, Wakayama Medical University, 25-1 Shichibancho, Wakayama, Wakayama 640-8156, Japan
| | - Hirofumi Tsujino
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan; The Museum of Osaka University, 1-13 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Kazuma Higashisaka
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan; Institute for Advanced Co-Creation Studies, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yasuo Tsutsumi
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan; Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan; Global Center for Medical Engineering and Informatics, Osaka University, 1-6, Yamadaoka, Suita, Osaka 565-0871, Japan.
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Impact of Liver Inflammation on Bile Acid Side Chain Shortening and Amidation. Cells 2022; 11:cells11243983. [PMID: 36552746 PMCID: PMC9777420 DOI: 10.3390/cells11243983] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/03/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Abstract
Bile acid (BA) synthesis from cholesterol by hepatocytes is inhibited by inflammatory cytokines. Whether liver inflammation also affects BA side chain shortening and conjugation was investigated. In human liver cell lines (IHH, HepG2, and HepaRG), agonists of nuclear receptors including the farnesoid X receptor (FXR), liver X receptor (LXR), and peroxisome proliferator-activated receptors (PPARs) did not affect the expression of BA-related peroxisomal enzymes. In contrast, hepatocyte nuclear factor 4α (HNF4α) inhibition down-regulated acyl-CoA oxidase 2 (ACOX2). ACOX2 was repressed by fibroblast growth factor 19 (FGF19), which was prevented by extracellular signal-regulated kinase (ERK) pathway inhibition. These changes were paralleled by altered BA synthesis (HPLC-MS/MS). Cytokines able to down-regulate cholesterol-7α-hydroxylase (CYP7A1) had little effect on peroxisomal enzymes involved in BA synthesis except for ACOX2 and bile acid-CoA:amino acid N-acyltransferase (BAAT), which were down-regulated, mainly by oncostatin M (OSM). This effect was prevented by Janus kinase (JAK) inhibition, which restored BA side chain shortening and conjugation. The binding of OSM to the extracellular matrix accounted for a persistent effect after culture medium replacement. In silico analysis of four databases (n = 201) and a validation cohort (n = 90) revealed an inverse relationship between liver inflammation and ACOX2/BAAT expression which was associated with changes in HNF4α levels. In conclusion, BA side chain shortening and conjugation are inhibited by inflammatory effectors. However, other mechanisms involved in BA homeostasis counterbalance any significant impact on the serum BA profile.
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Liu HX, Liu QJ. Logistic role of carnitine shuttle system on radiation-induced L-carnitine and acylcarnitines alteration. Int J Radiat Biol 2022; 98:1-14. [PMID: 35384773 DOI: 10.1080/09553002.2022.2063430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 03/17/2022] [Accepted: 03/18/2022] [Indexed: 12/13/2022]
Abstract
PURPOSE With the development of radiation metabolomics, a large number of radiation-related metabolic biomarkers have been identified and validated. The L-carnitine and acylcarnitines have the potential to be the new promising candidate indicators of radiation exposure. This review summarizes the effect of carnitine shuttle system on the profile of acylcarnitines and correlates the radiation effects on upstream regulators of carnitine shuttle system with the change characteristics of L-carnitine and acylcarnitines after irradiation across different animal models as well as a few humans. CONCLUSIONS Studies report that acylcarnitines were ubiquitously elevated after irradiation, especially the free L-carnitine and short-chain acylcarnitines (C2-C5). However, the molecular mechanism underlying acylcarnitine alterations after irradiation is not fully investigated, and further studies are needed to explore the biological effect and its mechanism. The activity of the carnitine shuttle system plays a key role in the alteration of L-carnitine and acylcarnitines, and the upstream regulators of the system are known to be affected by irradiation. These evidences indicate that that there is a logistic role of carnitine shuttle system on radiation-induced L-carnitine and acylcarnitines alteration.
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Affiliation(s)
- Hai-Xiang Liu
- China CDC Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
| | - Qing-Jie Liu
- China CDC Key Laboratory of Radiological Protection and Nuclear Emergency, National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China
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Preventive Effects of Ilex Cornuta Aqueous Extract on High-Fat Diet-Induced Fatty Liver of Mice. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:7183471. [PMID: 35432557 PMCID: PMC9010189 DOI: 10.1155/2022/7183471] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 03/09/2022] [Indexed: 12/26/2022]
Abstract
Objective To investigate the preventive effects of Ilex cornuta aqueous extract (ICAE) on high-fat diet (HFD)-induced fatty liver of mice and its mechanisms. Materials and Methods Twenty-six male KM (Kunming) mice were divided into 3 groups, including the control group (n = 9), fed with normal diet; HFD group (n = 9), fed with HFD; ICAE + HFD group (n = 8), fed with HFD and administered with ICAE (3 g·kg-1·d-1) at the same time for 10 weeks. Body weight, liver weight, intra-abdominal and subcutaneous fat weight, serum triglyceride (TG), total cholesterol (TC), and blood glucose were determined to evaluate the preventive effects of ICAE on obesity. The average 24 h food consumption of the mice was monitored for 5 times in the 9th week of the experiment to investigate the effects of ICAE on food intake. Serum alanine transaminase (ALT) and aspartate aminotransferase (AST) were assayed to observe the influences of HFD and ICAE on liver function. HE staining was adopted to observe the influence of ICAE on the morphology of adipose tissue and liver tissue. Hepatic TG and TC content assay and oil red O staining were used to evaluate the influences of ICAE on HFD-induced fatty liver, and the protein expression of peroxisome proliferator-activated receptors γ (PPARγ) and adipose differentiation-related protein (ADRP) in liver were examined by immunoblotting. Results ICAE treatment significantly reduced the increase of body weight, intra-abdominal, and subcutaneous fat and liver weight induced by HFD (P < 0.001), but has no influence on food intake; ICAE treatment attenuated the elevation of serum TG, TC, and glucose, as well as serum ALT and AST (P < 0.01, P < 0.05, P < 0.001) and dramatically decreased the content of TG in liver (P < 0.01), but has no influence on hepatic TC content. HE staining and oil red O staining showed that ICAE significantly reduced HFD-induced white adipocyte hypertrophy and significantly inhibited lipid accumulation in liver. Immunoblotting showed that the protein levels of PPARγ and ADRP were significantly increased by HFD induction, which can be dramatically reduced by ICAE treatment (P < 0.05, P < 0.0001). Conclusion ICAE has preventive effects on HFD-induced obesity and fatty liver in mice, exerted beneficial effects upon HFD-induced hepatic injury. The preventive effects of ICAE on fatty liver are concerned with the downregulation of PPARγ and ADRP protein expression in liver.
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6
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Scorletti E, Carr RM. A new perspective on NAFLD: Focusing on lipid droplets. J Hepatol 2022; 76:934-945. [PMID: 34793866 DOI: 10.1016/j.jhep.2021.11.009] [Citation(s) in RCA: 121] [Impact Index Per Article: 60.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 10/13/2021] [Accepted: 11/06/2021] [Indexed: 02/07/2023]
Abstract
Lipid droplets (LDs) are complex and metabolically active organelles. They are composed of a neutral lipid core surrounded by a monolayer of phospholipids and proteins. LD accumulation in hepatocytes is the distinctive characteristic of non-alcoholic fatty liver disease (NAFLD), which is a chronic, heterogeneous liver condition that can progress to liver fibrosis and hepatocellular carcinoma. Though recent research has improved our understanding of the mechanisms linking LD accumulation to NAFLD progression, numerous aspects of LD biology are either poorly understood or unknown. In this review, we provide a description of several key mechanisms that contribute to LD accumulation in hepatocytes, favouring NAFLD progression. First, we highlight the importance of LD architecture and describe how the dysregulation of LD biogenesis leads to endoplasmic reticulum stress and inflammation. This is followed by an analysis of the causal nexus that exists between LD proteome composition and LD degradation. Finally, we describe how the increase in size of LDs causes activation of hepatic stellate cells, leading to liver fibrosis and hepatocellular carcinoma. We conclude that acquiring a more sophisticated understanding of LD biology will provide crucial insights into the heterogeneity of NAFLD and assist in the development of therapeutic approaches for this liver disease.
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Affiliation(s)
- Eleonora Scorletti
- Division of Translational Medicine and Human Genetics, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Rotonya M Carr
- Division of Gastroenterology, University of Washington, Seattle, WA 98195-6424, United States.
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Choi J, Bodenstein DF, Geraci J, Andreazza AC. Evaluation of postmortem microarray data in bipolar disorder using traditional data comparison and artificial intelligence reveals novel gene targets. J Psychiatr Res 2021; 142:328-336. [PMID: 34419753 DOI: 10.1016/j.jpsychires.2021.08.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 07/20/2021] [Accepted: 08/13/2021] [Indexed: 11/16/2022]
Abstract
Large-scale microarray studies on post-mortem brain tissues have been utilized to investigate the complex molecular pathology of bipolar disorder. However, a major challenge in characterizing the dysregulation of gene expression in patients with bipolar disorder includes the lack of convergence between different studies, limiting comprehensive understanding from individual results. In this study, we aimed to identify genes that are both validated in published literature and are important classification features of unsupervised machine learning analysis of Stanley Brain Bank microarray database, followed by augmented intelligence method to identify distinct patient molecular subgroups. Through combining traditional literature approaches and machine learning, we identified TBL1XR1, SMARCA2, and CHMP5 to be replicated in 3 of the 4 studies included our analysis. The expression of these genes segregated unique subgroups of patients with bipolar disorder. Our study suggests the involvement of PPARγ pathway regulation in patients with bipolar disorder.
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Affiliation(s)
- Jaehyoung Choi
- Department of Pharmacology & Toxicology, University of Toronto, Toronto, ON, Canada
| | - David F Bodenstein
- Department of Pharmacology & Toxicology, University of Toronto, Toronto, ON, Canada
| | - Joseph Geraci
- NetraMark Corp, Toronto, ON, Canada; Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, Canada; Centre for Biotechnology and Genomics Medicine, Medical College of Georgia, Augusta, GA, United States
| | - Ana C Andreazza
- Department of Pharmacology & Toxicology, University of Toronto, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada.
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Miyachi H. Structural Biology-Based Exploration of Subtype-Selective Agonists for Peroxisome Proliferator-Activated Receptors. Int J Mol Sci 2021; 22:ijms22179223. [PMID: 34502131 PMCID: PMC8430769 DOI: 10.3390/ijms22179223] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 08/22/2021] [Accepted: 08/23/2021] [Indexed: 12/17/2022] Open
Abstract
Progress in understanding peroxisome proliferator-activated receptor (PPAR) subtypes as nuclear receptors that have pleiotropic effects on biological responses has enabled the exploration of new subtype-selective PPAR ligands. Such ligands are useful chemical biology/pharmacological tools to investigate the functions of PPARs and are also candidate drugs for the treatment of PPAR-mediated diseases, such as metabolic syndrome, inflammation and cancer. This review summarizes our medicinal chemistry research of more than 20 years on the design, synthesis, and pharmacological evaluation of subtype-selective PPAR agonists, which has been based on two working hypotheses, the ligand superfamily concept and the helix 12 (H12) holding induction concept. X-ray crystallographic analyses of our agonists complexed with each PPAR subtype validate our working hypotheses.
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Affiliation(s)
- Hiroyuki Miyachi
- Lead Exploration Unit, Drug Discovery Initiative, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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Barrett E, Loverin A, Wang H, Carlson M, Larsen TD, Almeida MM, Whitman J, Baack ML, Joss-Moore LA. Uteroplacental Insufficiency with Hypoxia Upregulates Placental PPARγ-KMT5A Axis in the Rat. Reprod Sci 2021; 28:1476-1488. [PMID: 33398850 PMCID: PMC8215892 DOI: 10.1007/s43032-020-00434-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 12/13/2020] [Indexed: 12/30/2022]
Abstract
The placenta represents a critical node in fetal lipid acquisition, yet the mechanisms by which the placenta handles lipids under normal and pathologic conditions are incompletely understood. A key player in placental lipid handling is peroxisome proliferator-activated receptor gamma (PPARγ). PPARγ influences global gene expression via its regulation of the epigenetic modifier lysine methyltransferase 5A (KMT5A), which places a methyl group on histone 4 lysine 20 (H4K20me) of target genes. Here we test the hypothesis that KMT5A is present in both the human and rat placentas and is affected by uteroplacental insufficiency (UPI) in the rat in association with increased placental lipid accumulation. We assessed levels and localization of KMT5A, as well as lipid droplet accumulation, in human placental tissue collected from maternal donors after delivery by planned cesarean section. Using a rat model of UPI, we also evaluated the effects of UPI on lipid accumulation, PPARγ, KMT5A, and H4K20me in the rat placenta. In this study, we show for the first time the presence and activity of KMT5A, in human and in rat placentas. We also demonstrate that in the rat placenta, UPI increases hypoxia, KMT5a expression, and activity in association with increased lipid accumulation in placenta supporting male fetuses. Placental PPARγ-KMT5A axis may be an important mediator of placental lipid handling.
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Affiliation(s)
- Emily Barrett
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, 84109, USA
| | - Amy Loverin
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, 84109, USA
| | - Haimei Wang
- Department of Pediatrics, University of Utah, 295 Chipeta Way, UT, 84108, Salt Lake City, USA
| | | | - Tricia D Larsen
- Environmental Influences on Health and Disease, Sanford Research, Sioux Falls, SD, 57104, USA
| | - Mariana M Almeida
- Carlos Chagas Filho Biophysics Institute, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Jenna Whitman
- Department of Pediatrics, University of Utah, 295 Chipeta Way, UT, 84108, Salt Lake City, USA
| | - Michelle L Baack
- Environmental Influences on Health and Disease, Sanford Research, Sioux Falls, SD, 57104, USA
| | - Lisa A Joss-Moore
- Department of Pediatrics, University of Utah, 295 Chipeta Way, UT, 84108, Salt Lake City, USA.
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Burk O, Kronenberger T, Keminer O, Lee SML, Schiergens TS, Schwab M, Windshügel B. Nelfinavir and Its Active Metabolite M8 Are Partial Agonists and Competitive Antagonists of the Human Pregnane X Receptor. Mol Pharmacol 2021; 99:184-196. [PMID: 33483427 DOI: 10.1124/molpharm.120.000116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 12/21/2020] [Indexed: 12/12/2022] Open
Abstract
The HIV protease inhibitor nelfinavir is currently being analyzed for repurposing as an anticancer drug for many different cancers because it exerts manifold off-target protein interactions, finally resulting in cancer cell death. Xenosensing pregnane X receptor (PXR), which also participates in the control of cancer cell proliferation and apoptosis, was previously shown to be activated by nelfinavir; however, the exact molecular mechanism is still unknown. The present study addresses the effects of nelfinavir and its major and pharmacologically active metabolite nelfinavir hydroxy-tert-butylamide (M8) on PXR to elucidate the underlying molecular mechanism. Molecular docking suggested direct binding to the PXR ligand-binding domain, which was confirmed experimentally by limited proteolytic digestion and competitive ligand-binding assays. Concentration-response analyses using cellular transactivation assays identified nelfinavir and M8 as partial agonists with EC50 values of 0.9 and 7.3 µM and competitive antagonists of rifampin-dependent induction with IC50 values of 7.5 and 25.3 µM, respectively. Antagonism exclusively resulted from binding into the PXR ligand-binding pocket. Impaired coactivator recruitment by nelfinavir as compared with the full agonist rifampin proved to be the underlying mechanism of both effects on PXR. Physiologic relevance of nelfinavir-dependent modulation of PXR activity was investigated in respectively treated primary human hepatocytes, which showed differential induction of PXR target genes and antagonism of rifampin-induced ABCB1 and CYP3A4 gene expression. In conclusion, we elucidate here the molecular mechanism of nelfinavir interaction with PXR. It is hypothesized that modulation of PXR activity may impact the anticancer effects of nelfinavir. SIGNIFICANCE STATEMENT: Nelfinavir, which is being investigated for repurposing as an anticancer medication, is shown here to directly bind to human pregnane X receptor (PXR) and thereby act as a partial agonist and competitive antagonist. Its major metabolite nelfinavir hydroxy-tert-butylamide exerts the same effects, which are based on impaired coactivator recruitment. Nelfinavir anticancer activity may involve modulation of PXR, which itself is discussed as a therapeutic target in cancer therapy and for the reversal of chemoresistance.
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Affiliation(s)
- Oliver Burk
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, and University of Tübingen, Tübingen, Germany (O.B., M.S.); Fraunhofer Institute for Molecular Biology and Applied Ecology IME, ScreeningPort, Hamburg, Germany (T.K., O.K., B.W.); Biobank of the Department of General, Visceral, and Transplantion Surgery, University Hospital, Ludwig-Maximilians University, Munich, Munich, Germany (S.M.L.L., T.S.S.); Departments of Clinical Pharmacology, and Pharmacy and Biochemistry, University of Tübingen, Tübingen, Germany (M.S.); and Department of Chemistry, Institute for Biochemistry and Molecular Biology, Universität Hamburg, Hamburg, Germany (B.W.)
| | - Thales Kronenberger
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, and University of Tübingen, Tübingen, Germany (O.B., M.S.); Fraunhofer Institute for Molecular Biology and Applied Ecology IME, ScreeningPort, Hamburg, Germany (T.K., O.K., B.W.); Biobank of the Department of General, Visceral, and Transplantion Surgery, University Hospital, Ludwig-Maximilians University, Munich, Munich, Germany (S.M.L.L., T.S.S.); Departments of Clinical Pharmacology, and Pharmacy and Biochemistry, University of Tübingen, Tübingen, Germany (M.S.); and Department of Chemistry, Institute for Biochemistry and Molecular Biology, Universität Hamburg, Hamburg, Germany (B.W.)
| | - Oliver Keminer
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, and University of Tübingen, Tübingen, Germany (O.B., M.S.); Fraunhofer Institute for Molecular Biology and Applied Ecology IME, ScreeningPort, Hamburg, Germany (T.K., O.K., B.W.); Biobank of the Department of General, Visceral, and Transplantion Surgery, University Hospital, Ludwig-Maximilians University, Munich, Munich, Germany (S.M.L.L., T.S.S.); Departments of Clinical Pharmacology, and Pharmacy and Biochemistry, University of Tübingen, Tübingen, Germany (M.S.); and Department of Chemistry, Institute for Biochemistry and Molecular Biology, Universität Hamburg, Hamburg, Germany (B.W.)
| | - Serene M L Lee
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, and University of Tübingen, Tübingen, Germany (O.B., M.S.); Fraunhofer Institute for Molecular Biology and Applied Ecology IME, ScreeningPort, Hamburg, Germany (T.K., O.K., B.W.); Biobank of the Department of General, Visceral, and Transplantion Surgery, University Hospital, Ludwig-Maximilians University, Munich, Munich, Germany (S.M.L.L., T.S.S.); Departments of Clinical Pharmacology, and Pharmacy and Biochemistry, University of Tübingen, Tübingen, Germany (M.S.); and Department of Chemistry, Institute for Biochemistry and Molecular Biology, Universität Hamburg, Hamburg, Germany (B.W.)
| | - Tobias S Schiergens
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, and University of Tübingen, Tübingen, Germany (O.B., M.S.); Fraunhofer Institute for Molecular Biology and Applied Ecology IME, ScreeningPort, Hamburg, Germany (T.K., O.K., B.W.); Biobank of the Department of General, Visceral, and Transplantion Surgery, University Hospital, Ludwig-Maximilians University, Munich, Munich, Germany (S.M.L.L., T.S.S.); Departments of Clinical Pharmacology, and Pharmacy and Biochemistry, University of Tübingen, Tübingen, Germany (M.S.); and Department of Chemistry, Institute for Biochemistry and Molecular Biology, Universität Hamburg, Hamburg, Germany (B.W.)
| | - Matthias Schwab
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, and University of Tübingen, Tübingen, Germany (O.B., M.S.); Fraunhofer Institute for Molecular Biology and Applied Ecology IME, ScreeningPort, Hamburg, Germany (T.K., O.K., B.W.); Biobank of the Department of General, Visceral, and Transplantion Surgery, University Hospital, Ludwig-Maximilians University, Munich, Munich, Germany (S.M.L.L., T.S.S.); Departments of Clinical Pharmacology, and Pharmacy and Biochemistry, University of Tübingen, Tübingen, Germany (M.S.); and Department of Chemistry, Institute for Biochemistry and Molecular Biology, Universität Hamburg, Hamburg, Germany (B.W.)
| | - Björn Windshügel
- Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Stuttgart, and University of Tübingen, Tübingen, Germany (O.B., M.S.); Fraunhofer Institute for Molecular Biology and Applied Ecology IME, ScreeningPort, Hamburg, Germany (T.K., O.K., B.W.); Biobank of the Department of General, Visceral, and Transplantion Surgery, University Hospital, Ludwig-Maximilians University, Munich, Munich, Germany (S.M.L.L., T.S.S.); Departments of Clinical Pharmacology, and Pharmacy and Biochemistry, University of Tübingen, Tübingen, Germany (M.S.); and Department of Chemistry, Institute for Biochemistry and Molecular Biology, Universität Hamburg, Hamburg, Germany (B.W.)
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11
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Poursharifi P, Attané C, Mugabo Y, Al-Mass A, Ghosh A, Schmitt C, Zhao S, Guida J, Lussier R, Erb H, Chenier I, Peyot ML, Joly E, Noll C, Carpentier AC, Madiraju SRM, Prentki M. Adipose ABHD6 regulates tolerance to cold and thermogenic programs. JCI Insight 2020; 5:140294. [PMID: 33201859 PMCID: PMC7819748 DOI: 10.1172/jci.insight.140294] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 11/11/2020] [Indexed: 12/31/2022] Open
Abstract
Enhanced energy expenditure in brown (BAT) and white adipose tissues (WAT) can be therapeutic against metabolic diseases. We examined the thermogenic role of adipose α/β-hydrolase domain 6 (ABHD6), which hydrolyzes monoacylglycerol (MAG), by employing adipose-specific ABHD6-KO mice. Control and KO mice showed similar phenotypes at room temperature and thermoneutral conditions. However, KO mice were resistant to hypothermia, which can be accounted for by the simultaneously increased lipolysis and lipogenesis of the thermogenic glycerolipid/free fatty acid (GL/FFA) cycle in visceral fat, despite unaltered uncoupling protein 1 expression. Upon cold stress, nuclear 2-MAG levels increased in visceral WAT of the KO mice. Evidence is provided that 2-MAG causes activation of PPARα in white adipocytes, leading to elevated expression and activity of GL/FFA cycle enzymes. In the ABHD6-ablated BAT, glucose and oxidative metabolism were elevated upon cold induction, without changes in GL/FFA cycle and lipid turnover. Moreover, response to in vivo β3-adrenergic stimulation was comparable between KO and control mice. Our data reveal a MAG/PPARα/GL/FFA cycling metabolic signaling network in visceral adipose tissue, which contributes to cold tolerance, and that adipose ABHD6 is a negative modulator of adaptive thermogenesis. Visceral adipose adipose α/β-hydrolase domain 6 regulates cold adaptation and acts as a brake for heat production via the regulation of thermogenic glycerolipid/free fatty acid cycling.
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Affiliation(s)
- Pegah Poursharifi
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Camille Attané
- Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, Toulouse, France
| | - Yves Mugabo
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Anfal Al-Mass
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada.,Department of Medicine, McGill University, Montréal, Québec, Canada
| | - Anindya Ghosh
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Clémence Schmitt
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Shangang Zhao
- Touchstone Diabetes Center, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Julian Guida
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Roxane Lussier
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Heidi Erb
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Isabelle Chenier
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Marie-Line Peyot
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Erik Joly
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Christophe Noll
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - André C Carpentier
- Division of Endocrinology, Department of Medicine, Centre de recherche du Centre Hospitalier Universitaire de Sherbrooke, Université de Sherbrooke, Sherbrooke, Québec, Canada
| | - S R Murthy Madiraju
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
| | - Marc Prentki
- Departments of Nutrition, Biochemistry, and Molecular Medicine, University of Montreal, and Montreal Diabetes Research Center, Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montréal, Québec, Canada
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12
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Preidis GA, Soni KG, Suh JH, Halder T, Kim KH, Choi JM, Li F, Devaraj S, Conner ME, Coarfa C, Jung SY, Moore DD. Coagulopathy in Malnourished Mice Is Sexually Dimorphic and Regulated by Nutrient-Sensing Nuclear Receptors. Hepatol Commun 2020; 4:1835-1850. [PMID: 33305154 PMCID: PMC7706303 DOI: 10.1002/hep4.1622] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/28/2020] [Accepted: 09/18/2020] [Indexed: 11/23/2022] Open
Abstract
Liver dysfunction, including coagulopathy, is a prominent feature of protein-energy malnutrition. To identify mechanisms underlying malnutrition-associated coagulopathy, we administered a low-protein low-fat diet to lactating dams and examined hepatic transcription and plasma coagulation parameters in young adult weanlings. Malnutrition impacted body composition to a greater extent in male versus female mice. Transcriptional profiles suggested opposing effects of nutrient-sensing nuclear receptors, namely induction of peroxisome proliferator-activated receptor α (PPARα) targets and repression of farnesoid-X-receptor (FXR) targets. Coagulopathy with decreased synthesis of fibrinogen-α (FGA) and factor 11 (F11) was observed in malnourished male animals but not female animals. In primary mouse hepatocytes, FXR agonist increased and PPARα agonist decreased Fga and F11 messenger RNA expression. Nuclear receptor DNA response elements were identified in the Fga and F11 gene regulatory regions, and opposing effects of FXR and PPARα were confirmed with luciferase assays. Unexpectedly, hepatic PPARα protein was markedly depleted in malnourished male liver and was not enriched on Fga or F11 response elements. Rather, there was loss of FXR binding at these response elements. Reduced PPARα protein was associated with loss of hepatocyte peroxisomes, which are necessary for bile acid biosynthesis, and with decreased concentrations of bile acids that function as FXR ligands, most notably the FXR agonist chenodeoxycholic acid. Conclusion: Malnutrition impairs growth and liver synthetic function more severely in male mice than in female mice. Malnourished male mice are coagulopathic and exhibit decreased hepatocyte peroxisomes, FXR agonist bile acids, FXR binding on Fga and F11 gene regulatory elements, and coagulation factor synthesis. These effects are absent in female mice, which have low baseline levels of PPARα, suggesting that nutrient-sensing nuclear receptors regulate coagulation factor synthesis in response to host nutritional status in a sex-specific manner.
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Affiliation(s)
- Geoffrey A. Preidis
- Section of Gastroenterology, Hepatology & NutritionDepartment of PediatricsBaylor College of Medicine and Texas Children’s HospitalHoustonTXUSA
| | - Krishnakant G. Soni
- Section of Gastroenterology, Hepatology & NutritionDepartment of PediatricsBaylor College of Medicine and Texas Children’s HospitalHoustonTXUSA
| | - Ji Ho Suh
- Section of Gastroenterology, Hepatology & NutritionDepartment of PediatricsBaylor College of Medicine and Texas Children’s HospitalHoustonTXUSA
| | - Tripti Halder
- Section of Gastroenterology, Hepatology & NutritionDepartment of PediatricsBaylor College of Medicine and Texas Children’s HospitalHoustonTXUSA
| | - Kang Ho Kim
- Department of Molecular and Cellular BiologyBaylor College of MedicineHoustonTXUSA
| | - Jong Min Choi
- Advanced Technology CoreMass Spectrometry Proteomics CoreBaylor College of MedicineHoustonTXUSA
| | - Feng Li
- Department of Molecular and Cellular BiologyBaylor College of MedicineHoustonTXUSA
- Department of Pathology and ImmunologyBaylor College of MedicineHoustonTXUSA
| | - Sridevi Devaraj
- Department of Pathology and ImmunologyBaylor College of MedicineHoustonTXUSA
| | - Margaret E. Conner
- Department of Molecular Virology and MicrobiologyBaylor College of MedicineHoustonTXUSA
| | - Cristian Coarfa
- Department of Molecular and Cellular BiologyBaylor College of MedicineHoustonTXUSA
| | - Sung Yun Jung
- Department of Molecular and Cellular BiologyBaylor College of MedicineHoustonTXUSA
- Advanced Technology CoreMass Spectrometry Proteomics CoreBaylor College of MedicineHoustonTXUSA
- Verna and Marrs McLean Department of Biochemistry and Molecular BiologyBaylor College of MedicineHoustonTXUSA
| | - David D. Moore
- Department of Molecular and Cellular BiologyBaylor College of MedicineHoustonTXUSA
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13
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Li Y, Zhang Q, Fang J, Ma N, Geng X, Xu M, Yang H, Jia X. Hepatotoxicity study of combined exposure of DEHP and ethanol: A comprehensive analysis of transcriptomics and metabolomics. Food Chem Toxicol 2020; 141:111370. [DOI: 10.1016/j.fct.2020.111370] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Revised: 04/07/2020] [Accepted: 04/16/2020] [Indexed: 12/18/2022]
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14
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Quantitative proteomics to study aging in rabbit liver. Mech Ageing Dev 2020; 187:111227. [PMID: 32126221 DOI: 10.1016/j.mad.2020.111227] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 01/24/2020] [Accepted: 02/27/2020] [Indexed: 12/23/2022]
Abstract
Aging globally effects cellular and organismal metabolism across a range of mammalian species, including humans and rabbits. Rabbits (Oryctolagus cuniculus are an attractive model system of aging due to their genetic similarity with humans and their short lifespans. This model can be used to understand metabolic changes in aging especially in major organs such as liver where we detected pronounced variations in fat metabolism, mitochondrial dysfunction, and protein degradation. Such changes in the liver are consistent across several mammalian species however in rabbits the downstream effects of these changes have not yet been explored. We have applied proteomics to study changes in the liver proteins from young, middle, and old age rabbits using a multiplexing cPILOT strategy. This resulted in the identification of 2,586 liver proteins, among which 45 proteins had significant p < 0.05) changes with aging. Seven proteins were differentially-expressed at all ages and include fatty acid binding protein, aldehyde dehydrogenase, enoyl-CoA hydratase, 3-hydroxyacyl CoA dehydrogenase, apolipoprotein C3, peroxisomal sarcosine oxidase, adhesion G-protein coupled receptor, and glutamate ionotropic receptor kinate. Insights to how alterations in metabolism affect protein expression in liver have been gained and demonstrate the utility of rabbit as a model of aging.
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15
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Liu Y, Izem L, Morton RE. Identification of a hormone response element that mediates suppression of APOF by LXR and PPARα agonists. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158583. [PMID: 31812787 DOI: 10.1016/j.bbalip.2019.158583] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 11/21/2019] [Accepted: 12/01/2019] [Indexed: 12/18/2022]
Abstract
Apolipoprotein F (ApoF) regulates cholesteryl ester transfer protein activity. We previously observed that hepatic APOF mRNA levels are decreased by high fat, cholesterol-enriched diets. Here we show in human liver C3A cells that APOF mRNA levels are reduced by agonists of LXR and PPARα nuclear receptors. This negative regulation requires co-incubation with the RXR agonist, retinoic acid. Bioinformatic analysis of the ~2 kb sequence upstream of the APOF promoter identified one potential LXR and 4 potential PPARα binding sites clustered between nucleotides -2007 and -1961. ChIP analysis confirmed agonist-dependent binding of LXRα, PPARα, and RXRα to this hormone response element complex (HREc). A luciferase reporter containing the 2 kb 5' APOF sequence was negatively regulated by LXR and PPARα ligands as seen in cells. This regulation was maintained in constructs lacking the ~1700 nucleotides between the HREc and the APOF proximal promoter. Mutations of the HREc that disrupted LXRα and PPARα binding led to the loss of reporter construct inhibition by agonists of these nuclear receptors. siRNA knockdown studies showed that APOF gene regulation by LXRα or PPARα agonists did not require an interaction between these two nuclear receptors. Thus, APOF is subject to negative regulation by agonist-activated LXR or PPARα nuclear receptors binding to a regulatory element ~1900 bases 5' to the APOF promoter. High fat, cholesterol-enriched diets likely reduce APOF gene expression via these receptors interacting at this regulatory site.
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Affiliation(s)
- Yan Liu
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, United States of America
| | - Lahoucine Izem
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, United States of America
| | - Richard E Morton
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, United States of America.
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16
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Behr AC, Plinsch C, Braeuning A, Buhrke T. Activation of human nuclear receptors by perfluoroalkylated substances (PFAS). Toxicol In Vitro 2019; 62:104700. [PMID: 31676336 DOI: 10.1016/j.tiv.2019.104700] [Citation(s) in RCA: 120] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 10/25/2022]
Abstract
Perfluoralkylated substances (PFAS) such as perfluorooctanoic acid (PFOA) or perfluorooctanesulfonic acid (PFOS) are used to produce, e.g., surface coatings with water- and dirt-repellent properties. These substances have been shown to be hepatotoxic in rodents, and the mechanism of action is mostly attributed to the PFAS-mediated activation of the peroxisome proliferator-activated receptor alpha (PPARα). In the present study, we investigated by using luciferase-based reporter gene assays whether PFOA, PFOS and six alternative PFAS can activate, in addition to PPARα, eight other human nuclear receptors. All tested PFAS except for perfluorobutanesulfonic acid (PFBS) were able to activate human PPARα. Perfluoro-2-methyl-3-oxahexanoic acid (PMOH) and 3H-perfluoro-3-[(3-methoxypropoxy) propanoic acid] (PMPP) were weak agonists of human PPARγ. The other human nuclear receptors (PPARδ, CAR, PXR, FXR, LXRα, RXRα and RARα) were not affected by any PFAS tested in this study. Although PMOH was more effective than PFOA in stimulating PPARα in the transactivation assay, it was less effective in stimulating PPARα-dependent target gene expression in human HepG2 hepatocarcinoma cells. Notably, any effect observed in this in vitro study only occurred at concentrations higher than 10 μM of the respective PFAS which is in all cases several magnitudes above the average blood concentration in the Western population. Thus, the results suggest that nuclear receptor activation may only play a minor role in potential PFAS-mediated adverse effects in humans.
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Affiliation(s)
- Anne-Cathrin Behr
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Christin Plinsch
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Albert Braeuning
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Thorsten Buhrke
- German Federal Institute for Risk Assessment, Department of Food Safety, Max-Dohrn-Str. 8-10, 10589 Berlin, Germany.
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17
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Tachibana K, Ishimoto K, Takahashi R, Kadono H, Awaji T, Yuzuriha T, Tanaka T, Hamakubo T, Sakai J, Kodama T, Aoki S, Doi T. Development of a Ligand Screening Tool Using Full-Length Human Peroxisome Proliferator-Activated Receptor-Expressing Cell Lines to Ameliorate Metabolic Syndrome. Chem Pharm Bull (Tokyo) 2019; 67:199-202. [PMID: 30827999 DOI: 10.1248/cpb.c18-00627] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) belong to the nuclear hormone receptor superfamily and include three subtypes (PPARα, PPARδ, and PPARγ). They regulate gene expression in a ligand-dependent manner. PPARα plays an important role in lipid metabolism. PPARγ is involved in glucose metabolism and is a potential therapeutic target in Type 2 diabetes. PPARδ ligands are candidates for the treatment of metabolic disorders. Thus, the detection of PPAR ligands may facilitate the treatment of various diseases. In this study, to identify PPAR ligands, we engineered reporter cell lines that can be used to quantify PPARγ and PPARδ activity. We evaluated several known ligands using these reporter cell lines and confirmed that they are useful for PPAR ligand detection. Furthermore, we evaluated extracts of approximately 200 natural resources and found various extracts that enhance reporter gene activity. Finally, we identified a main alkaloid of the Evodia fruit, evodiamine, as a PPARγ activator using this screening tool. These results suggest that the established reporter cell lines may serve as a useful cell-based screening tool for finding PPAR ligands to ameliorate metabolic syndromes.
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Affiliation(s)
| | - Kenji Ishimoto
- Graduate School of Pharmaceutical Sciences, Osaka University
| | - Rika Takahashi
- Graduate School of Pharmaceutical Sciences, Osaka University
| | - Hirokazu Kadono
- Graduate School of Pharmaceutical Sciences, Osaka University
| | - Takuya Awaji
- Graduate School of Pharmaceutical Sciences, Osaka University
| | | | - Toshiya Tanaka
- Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo
| | - Takao Hamakubo
- Department of Protein-Protein Interaction Research, Institute for Advanced Medical Sciences, Nippon Medical School
| | - Juro Sakai
- Division of Metabolic Medicine, Research Center for Advanced Science and Technology, The University of Tokyo
| | - Tatsuhiko Kodama
- Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo
| | - Shunji Aoki
- School of Pharmacy, Hyogo University of Health Sciences
| | - Takefumi Doi
- Graduate School of Pharmaceutical Sciences, Osaka University
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18
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Molecular Cloning and Transient Expression of Recombinant Human PPARγ in HEK293T Cells Under an Inducible Tet-on System. Mol Biotechnol 2019; 61:427-431. [PMID: 30941576 DOI: 10.1007/s12033-019-00173-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Peroxisome proliferator-activated receptor gamma (PPARγ) is involved in the regulation of lipid and glucose homeostasis and inflammation. PPARγ expression level has been widely studied in multiple tissues; however, there are few reports of preceding attempts to produce full-length human PPARγ (hPPARγ) in cellular models, and generally, expression level is not known or measurable. We propose an alternative strategy to express recombinant hPPARγ1, using a transient transfection with an inducible Tet-On 3G system where target and reporter gene were cloned in the same open reading frame. We transiently co-transfected human embryonic kidney 293T (HEK293T) cells with pTRE-ZsGreen1-IRES2-hPPARγ1 and pCMV-TET3G for inducible expression of hPPARγ1. Relative expression of the transcript was evaluated by RT-qPCR 48 h after transfection, obtaining a high expression level of hPPARγ (530-fold change, p < 0.002) in co-transfected HEK293T cells in the presence of doxycycline (1 μg/mL); also a significantly increased production of the reporter protein ZsGreen1 (3.6-fold change, p < 0.05) was determined by fluorescence analysis. These data indicated that HEK293T cells were successfully co-transfected and it could be an alternative model for hPPARγ expression in vitro. Additionally, this model will help to validate the quantification of inducible hPPARγ expression in vivo models for future research.
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19
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Tachibana K, Yuzuriha T, Tabata R, Fukuda S, Maegawa T, Takahashi R, Tanimoto K, Tsujino H, Nunomura K, Lin B, Matsuura Y, Tanaka T, Hamakubo T, Sakai J, Kodama T, Kobayashi T, Ishimoto K, Miyachi H, Doi T. Discovery of peroxisome proliferator-activated receptor α (PPARα) activators with a ligand-screening system using a human PPARα-expressing cell line. J Biol Chem 2018; 293:10333-10343. [PMID: 29764933 DOI: 10.1074/jbc.ra118.002077] [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] [Received: 01/24/2018] [Revised: 05/04/2018] [Indexed: 11/06/2022] Open
Abstract
Peroxisome proliferator-activated receptor α (PPARα) is a ligand-activated transcription factor that belongs to the superfamily of nuclear hormone receptors. PPARα is mainly expressed in the liver, where it activates fatty acid oxidation and lipoprotein metabolism and improves plasma lipid profiles. Therefore, PPARα activators are often used to treat patients with dyslipidemia. To discover additional PPARα activators as potential compounds for use in hypolipidemic drugs, here we established human hepatoblastoma cell lines with luciferase reporter expression from the promoters containing peroxisome proliferator-responsive elements (PPREs) and tetracycline-regulated expression of full-length human PPARα to quantify the effects of chemical ligands on PPARα activity. Using the established cell-based PPARα-activator screening system to screen a library of >12,000 chemical compounds, we identified several hit compounds with basic chemical skeletons different from those of known PPARα agonists. One of the hit compounds, a 1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid derivative we termed compound 3, selectively up-regulated PPARα transcriptional activity, leading to PPARα target gene expression both in vitro and in vivo Of note, the half-maximal effective concentrations of the hit compounds were lower than that of the known PPARα ligand fenofibrate. Finally, fenofibrate or compound 3 treatment of high fructose-fed rats having elevated plasma triglyceride levels for 14 days indicated that compound 3 reduces plasma triglyceride levels with similar efficiency as fenofibrate. These observations raise the possibility that 1H-pyrazolo[3,4-b]pyridine-4-carboxylic acid derivatives might be effective drug candidates for selective targeting of PPARα to manage dyslipidemia.
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Affiliation(s)
- Keisuke Tachibana
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871,
| | - Tomohiro Yuzuriha
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871.,the Faculty of Pharmaceutical Sciences, Setsunan University, 45-1 Nagaotoge-cho, Hirakata, Osaka 573-0101
| | - Ryotaro Tabata
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Syohei Fukuda
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Takashi Maegawa
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Rika Takahashi
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Keiichi Tanimoto
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Hirofumi Tsujino
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Kazuto Nunomura
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Bangzhong Lin
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Yoshiharu Matsuura
- the Department of Molecular Virology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871
| | | | - Takao Hamakubo
- the Department of Quantitative Biology and Medicine, and
| | - Juro Sakai
- the Division of Metabolic Medicine, Research Center for Advanced Science and Technology, Research Center for Advanced Science and Technology, University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904, and
| | | | - Tadayuki Kobayashi
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Kenji Ishimoto
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871
| | - Hiroyuki Miyachi
- the Lead Exploration Unit, Drug Discovery Initiative, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan
| | - Takefumi Doi
- From the Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871,
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20
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Al-Naemi AH, Ahmad AJ. Is the rs1801282 (G/C) Polymorphism of PPAR - Gamma Gene Associated with T2DM in Iraqi People? Open Access Maced J Med Sci 2018; 6:447-455. [PMID: 29610599 PMCID: PMC5874364 DOI: 10.3889/oamjms.2018.156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Revised: 05/12/2014] [Accepted: 05/14/2014] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Pro12Ala (rs1801282) is a common polymorphism of the human PPAR-γ gene. Studies have demonstrated conflicting results about its association with T2DM worldwide. There are no reports about such possible association among Iraqi people. OBJECTIVES This study aims at finding out whether having the mutant allele (Ala12) might be associated with T2DM among Iraqi people. METHODS One hundred and ninety-two Arabic Iraqi adult subjects (97 with T2DM and 95 controls) were genotyped using PCR- RFLP. Clinical, anthropometrical and biochemical variables were compared regarding the Pro12Ala genotypes. RESULTS About 5.67% of people with diabetes were carriers of the (Ala12) allele versus 9.47% of controls. Allelic and genotypic frequencies were not statistically different among diabetics and controls [(χ2= 1.99, p= 0.16) and (χ2= 2.17, p= 0.14)]. Age, BMI and smoking- but not Pro12Ala - were independent risk factors for T2DM in our subjects. Pro12Ala was not associated with T2DM (Odd's ratio 0.55, 95% CI 0.23- 1.32, p= 0.14). CONCLUSIONS Our study revealed a relatively high frequency of the Ala12 allele among Arabic Iraqis. These frequencies did not significantly differ between diabetics and controls indicating the absence of association of Pro12Ala with T2DM among Iraqis.
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Affiliation(s)
- Amjad Hazim Al-Naemi
- Department of Biochemistry, Mosul Medical College, University of Mosul, Mosul, Iraq
| | - Akram Jarjees Ahmad
- Department of Biochemistry, Mosul Medical College, University of Mosul, Mosul, Iraq
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21
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Ghadieh HE, Muturi HT, Russo L, Marino CC, Ghanem SS, Khuder SS, Hanna JC, Jash S, Puri V, Heinrich G, Gatto-Weis C, Lee KY, Najjar SM. Exenatide induces carcinoembryonic antigen-related cell adhesion molecule 1 expression to prevent hepatic steatosis. Hepatol Commun 2017; 2:35-47. [PMID: 29404511 PMCID: PMC5776867 DOI: 10.1002/hep4.1117] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 10/02/2017] [Accepted: 10/03/2017] [Indexed: 12/15/2022] Open
Abstract
Exenatide, a glucagon-like peptide-1 receptor agonist, induces insulin secretion. Its role in insulin clearance has not been adequately examined. Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) promotes hepatic insulin clearance to maintain insulin sensitivity. Feeding C57BL/6J mice a high-fat diet down-regulates hepatic Ceacam1 transcription to cause hyperinsulinemia, insulin resistance, and hepatic steatosis, as in Ceacam1 null mice (Cc1-/- ). Thus, we tested whether exenatide regulates Ceacam1 expression in high-fat diet-fed mice and whether this contributes to its insulin sensitizing effect. Exenatide (100 nM) induced the transcriptional activity of wild-type Ceacam1 promoter but not the constructs harboring block mutations of peroxisome proliferator-activated receptor response element and retinoid X receptor alpha, individually or collectively, in HepG2 human hepatoma cells. Chromatin immunoprecipitation analysis demonstrated binding of peroxisome proliferator-activated receptor gamma to Ceacam1 promoter in response to rosiglitazone and exenatide. Consistently, exenatide induced Ceacam1 messenger RNA expression within 12 hours in the absence but not in the presence of the glucagon-like peptide-1 receptor antagonist exendin 9-39. Exenatide (20 ng/g body weight once daily intraperitoneal injection in the last 30 days of feeding) restored hepatic Ceacam1 expression and insulin clearance to curb diet-induced metabolic abnormalities and steatohepatitis in wild-type but not Cc1-/- mice fed a high-fat diet for 2 months. Conclusion: Exenatide promotes insulin clearance in parallel with insulin secretion to prevent chronic hyperinsulinemia and the resulting hepatic steatosis, and this contributes to its insulin sensitizing effect. Our data further highlight the relevance of physiologic insulin metabolism in maintaining insulin sensitivity and normal lipid metabolism. (Hepatology Communications 2018;2:35-47).
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Affiliation(s)
- Hilda E Ghadieh
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences University of Toledo Toledo OH
| | - Harrison T Muturi
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine Ohio University Athens OH
| | - Lucia Russo
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences University of Toledo Toledo OH
| | - Christopher C Marino
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences University of Toledo Toledo OH
| | - Simona S Ghanem
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences University of Toledo Toledo OH
| | - Saja S Khuder
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences University of Toledo Toledo OH
| | - Julie C Hanna
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences University of Toledo Toledo OH
| | - Sukanta Jash
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine Ohio University Athens OH
| | - Vishwajeet Puri
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine Ohio University Athens OH.,Diabetes Institute, Heritage College of Osteopathic Medicine Ohio University Athens OH
| | - Garrett Heinrich
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine Ohio University Athens OH.,Diabetes Institute, Heritage College of Osteopathic Medicine Ohio University Athens OH
| | - Cara Gatto-Weis
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences University of Toledo Toledo OH.,Department of Pathology, College of Medicine and Life Sciences University of Toledo Toledo OH
| | - Kevin Y Lee
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine Ohio University Athens OH
| | - Sonia M Najjar
- Center for Diabetes and Endocrine Research, College of Medicine and Life Sciences University of Toledo Toledo OH.,Department of Biomedical Sciences, Heritage College of Osteopathic Medicine Ohio University Athens OH.,Diabetes Institute, Heritage College of Osteopathic Medicine Ohio University Athens OH
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22
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Wang J, Shibayama Y, Kobori H, Liu Y, Kobara H, Masaki T, Wang Z, Nishiyama A. High glucose augments angiotensinogen in human renal proximal tubular cells through hepatocyte nuclear factor-5. PLoS One 2017; 12:e0185600. [PMID: 29053707 PMCID: PMC5650141 DOI: 10.1371/journal.pone.0185600] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 09/17/2017] [Indexed: 01/01/2023] Open
Abstract
High glucose has been demonstrated to induce angiotensinogen (AGT) synthesis in the renal proximal tubular cells (RPTCs) of rats, which may further activate the intrarenal renin-angiotensin system (RAS) and contribute to diabetic nephropathy. This study aimed to investigate the effects of high glucose on AGT in the RPTCs of human origin and identify the glucose-responsive transcriptional factor(s) that bind(s) to the DNA sequences of AGT promoter in human RPTCs. Human kidney (HK)-2 cells were treated with normal glucose (5.5 mM) and high glucose (15.0 mM), respectively. Levels of AGT mRNA and AGT secretion of HK-2 cells were measured by real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Consecutive 5’-end deletion mutant constructs and different site-directed mutagenesis products of human AGT promoter sequences were respectively transfected into HK-2 cells, followed by AGT promoter activity measurement through dual luciferase assay. High glucose significantly augmented the levels of AGT mRNA and AGT secretion of HK-2 cells, compared with normal glucose treatment. High glucose also significantly augmented AGT promoter activity in HK-2 cells transfected with the constructs of human AGT promoter sequences, compared with normal glucose treatment. Hepatocyte nuclear factor (HNF)-5 was found to be one of the glucose-responsive transcriptional factors of AGT in human RPTCs, since the mutation of its binding sites within AGT promoter sequences abolished the above effects of high glucose on AGT promoter activity as well as levels of AGT mRNA and its secretion. The present study has demonstrated, for the first time, that high glucose augments AGT in human RPTCs through HNF-5, which provides a potential therapeutic target for diabetic nephropathy.
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Affiliation(s)
- Juan Wang
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
- Department of Immuno-oncology, Fourth Hospital of Hebei Medical University, Shijiazhuang, P.R. China
| | - Yuki Shibayama
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Hiroyuki Kobori
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
- Departments of Pharmacology and of Nephrology, School of Medicine, International University of Health and Welfare, Tokyo, Japan
| | - Ya Liu
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Hideki Kobara
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Tsutomu Masaki
- Department of Gastroenterology and Neurology, Faculty of Medicine, Kagawa University, Kagawa, Japan
| | - Zhiyu Wang
- Department of Immuno-oncology, Fourth Hospital of Hebei Medical University, Shijiazhuang, P.R. China
| | - Akira Nishiyama
- Department of Pharmacology, Faculty of Medicine, Kagawa University, Kagawa, Japan
- * E-mail:
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23
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Williams B, Correnti J, Oranu A, Lin A, Scott V, Annoh M, Beck J, Furth E, Mitchell V, Senkal CE, Obeid L, Carr RM. A novel role for ceramide synthase 6 in mouse and human alcoholic steatosis. FASEB J 2017; 32:130-142. [PMID: 28864659 DOI: 10.1096/fj.201601142r] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 08/21/2017] [Indexed: 12/19/2022]
Abstract
Perilipin 2 (PLIN2) is a lipid-droplet protein that is up-regulated in alcoholic steatosis and associated with hepatic accumulation of ceramides, bioactive lipids implicated in alcoholic liver disease pathogenesis. The specific role of ceramide synthetic enzymes in the regulation of PLIN2 and promotion of hepatocellular lipid accumulation is not well understood. We examined the effects of pharmacologic ceramide synthesis inhibition on hepatic PLIN2 expression, steatosis, and glucose and lipid homeostasis in mice with alcoholic steatosis and in ethanol-incubated human hepatoma VL17A cells. In cells, pharmacologic inhibition of ceramide synthase reduced lipid accumulation by reducing PLIN2 RNA stability. The subtype ceramide synthase (CerS)6 was specifically up-regulated in experimental alcoholic steatosis in vivo and in vitro and was up-regulated in zone 3 hepatocytes in human alcoholic steatosis. In vivo ceramide reduction by inhibition of de novo ceramide synthesis reduced PLIN2 and hepatic steatosis in alcohol-fed mice, but only de novo synthesis inhibition, not sphingomyelin hydrolysis, improved glucose tolerance and dyslipidemia. These findings implicate CerS6 as a novel regulator of PLIN2 and suggest that ceramide synthetic enzymes may promote the earliest stage of alcoholic liver disease, alcoholic steatosis.-Williams, B., Correnti, J., Oranu, A., Lin, A., Scott, V., Annoh, M., Beck, J., Furth, E., Mitchell, V., Senkal, C. E., Obeid, L., Carr, R. M. A novel role for ceramide synthase 6 in mouse and human alcoholic steatosis.
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Affiliation(s)
- Bianca Williams
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jason Correnti
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Amanke Oranu
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Annie Lin
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Victoria Scott
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Maxine Annoh
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - James Beck
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Emma Furth
- Department of Pathology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Victoria Mitchell
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Can E Senkal
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA; and
| | - Lina Obeid
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA; and.,Northport Veterans Affairs Medical Center, Northport, New York, USA
| | - Rotonya M Carr
- Division of Gastroenterology, Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA;
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24
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Shih CT, Chang YF, Chen YT, Ma CP, Chen HW, Yang CC, Lu JC, Tsai YS, Chen HC, Tan BCM. The PPARγ-SETD8 axis constitutes an epigenetic, p53-independent checkpoint on p21-mediated cellular senescence. Aging Cell 2017; 16:797-813. [PMID: 28514051 PMCID: PMC5506440 DOI: 10.1111/acel.12607] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/02/2017] [Indexed: 01/09/2023] Open
Abstract
Cellular senescence is a permanent proliferative arrest triggered by genome instability or aberrant growth stresses, acting as a protective or even tumor‐suppressive mechanism. While several key aspects of gene regulation have been known to program this cessation of cell growth, the involvement of the epigenetic regulation has just emerged but remains largely unresolved. Using a systems approach that is based on targeted gene profiling, we uncovered known and novel chromatin modifiers with putative link to the senescent state of the cells. Among these, we identified SETD8 as a new target as well as a key regulator of the cellular senescence signaling. Knockdown of SETD8 triggered senescence induction in proliferative culture, irrespectively of the p53 status of the cells; ectopic expression of this epigenetic writer alleviated the extent doxorubicin‐induced cellular senescence. This repressive effect of SETD8 in senescence was mediated by directly maintaining the silencing mark H4K20me1 at the locus of the senescence switch gene p21. Further in support of this regulatory link, depletion of p21 reversed this SETD8‐mediated cellular senescence. Additionally, we found that PPARγ acts upstream and regulates SETD8 expression in proliferating cells. Downregulation of PPARγ coincided with the senescence induction, while its activation inhibited the progression of this process. Viewed together, our findings delineated a new epigenetic pathway through which the PPARγ‐SETD8 axis directly silences p21 expression and consequently impinges on its senescence‐inducing function. This implies that SETD8 may be part of a cell proliferation checkpoint mechanism and has important implications in antitumor therapeutics.
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Affiliation(s)
- Chieh-Tien Shih
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
| | - Yi-Feng Chang
- Molecular Medicine Research Center; Chang Gung University; Tao-Yuan Taiwan
| | - Yi-Tung Chen
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
| | - Chung-Pei Ma
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
| | - Hui-Wen Chen
- Department of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
| | - Chang-Ching Yang
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
- Department of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
| | - Juu-Chin Lu
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
- Department of Physiology and Pharmacology; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
- Division of Endocrinology and Metabolism; Department of Internal Medicine; Chang Gung Memorial Hospital; Linkou, Tao-Yuan Taiwan
| | - Yau-Sheng Tsai
- Institute of Clinical Medicine; National Cheng Kung University; Tainan Taiwan
| | - Hua-Chien Chen
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
- Molecular Medicine Research Center; Chang Gung University; Tao-Yuan Taiwan
- Department of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
| | - Bertrand Chin-Ming Tan
- Graduate Institute of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
- Molecular Medicine Research Center; Chang Gung University; Tao-Yuan Taiwan
- Department of Biomedical Sciences; College of Medicine; Chang Gung University; Kwei-San, Tao-Yuan Taiwan
- Department of Neurosurgery; Lin-Kou Medical Center; Chang Gung Memorial Hospital; Linkou, Tao-Yuan Taiwan
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25
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Lv S, Qiu X, Li J, Liang J, Li W, Zhang C, Zhang ZN, Luan B. Glucagon-induced extracellular cAMP regulates hepatic lipid metabolism. J Endocrinol 2017; 234:73-87. [PMID: 28515141 DOI: 10.1530/joe-16-0649] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 05/17/2017] [Indexed: 01/07/2023]
Abstract
Hormonal signals help to maintain glucose and lipid homeostasis in the liver during the periods of fasting. Glucagon, a pancreas-derived hormone induced by fasting, promotes gluconeogenesis through induction of intracellular cAMP production. Glucagon also stimulates hepatic fatty acid oxidation but the underlying mechanism is poorly characterized. Here we report that following the acute induction of gluconeogenic genes Glucose 6 phosphatase (G6Pase) and Phosphoenolpyruvate carboxykinase (Pepck) expression through cAMP-response element-binding protein (CREB), glucagon triggers a second delayed phase of fatty acid oxidation genes Acyl-coenzyme A oxidase (Aox) and Carnitine palmitoyltransferase 1a (Cpt1a) expression via extracellular cAMP. Increase in extracellular cAMP promotes PPARα activity through direct phosphorylation by AMP-activated protein kinase (AMPK), while inhibition of cAMP efflux greatly attenuates Aox and Cpt1a expression. Importantly, cAMP injection improves lipid homeostasis in fasted mice and obese mice, while inhibition of cAMP efflux deteriorates hepatic steatosis in fasted mice. Collectively, our results demonstrate the vital role of glucagon-stimulated extracellular cAMP in the regulation of hepatic lipid metabolism through AMPK-mediated PPARα activation. Therefore, strategies to improve cAMP efflux could serve as potential new tools to prevent obesity-associated hepatic steatosis.
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Affiliation(s)
- Sihan Lv
- Department of EndocrinologyShanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Xinchen Qiu
- Department of EndocrinologyShanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
- Translational Medical Center for Stem Cell Therapy & Institute for Regenerative MedicineShanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jian Li
- Department of EndocrinologyShanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
- Translational Medical Center for Stem Cell Therapy & Institute for Regenerative MedicineShanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Jinye Liang
- Translational Medical Center for Stem Cell Therapy & Institute for Regenerative MedicineShanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Weida Li
- Translational Medical Center for Stem Cell Therapy & Institute for Regenerative MedicineShanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Chao Zhang
- Translational Medical Center for Stem Cell Therapy & Institute for Regenerative MedicineShanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhen-Ning Zhang
- Translational Medical Center for Stem Cell Therapy & Institute for Regenerative MedicineShanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Bing Luan
- Department of EndocrinologyShanghai Tenth People's Hospital, School of Medicine, Tongji University, Shanghai, China
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26
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Cairns R, Alvarez-Guaita A, Martínez-Saludes I, Wason SJ, Hanh J, Nagarajan SR, Hosseini-Beheshti E, Monastyrskaya K, Hoy AJ, Buechler C, Enrich C, Rentero C, Grewal T. Role of hepatic Annexin A6 in fatty acid-induced lipid droplet formation. Exp Cell Res 2017; 358:397-410. [PMID: 28712927 DOI: 10.1016/j.yexcr.2017.07.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 07/07/2017] [Accepted: 07/12/2017] [Indexed: 01/17/2023]
Abstract
Annexin A6 (AnxA6) has been implicated in the regulation of endo-/exocytic pathways, cholesterol transport, and the formation of multifactorial signaling complexes in many different cell types. More recently, AnxA6 has also been linked to triglyceride storage in adipocytes. Here we investigated the potential role of AnxA6 in fatty acid (FA) - induced lipid droplet (LD) formation in hepatocytes. AnxA6 was associated with LD from rat liver and HuH7 hepatocytes. In oleic acid (OA) -loaded HuH7 cells, substantial amounts of AnxA6 bound to LD in a Ca2+-independent manner. Remarkably, stable or transient AnxA6 overexpression in HuH7 cells led to elevated LD numbers/size and neutral lipid staining under control conditions as well as after OA loading compared to controls. In contrast, overexpression of AnxA1, AnxA2 and AnxA8 did not impact on OA-induced lipid accumulation. On the other hand, incubation of AnxA6-depleted HuH7 cells or primary hepatocytes from AnxA6 KO-mice with OA led to reduced FA accumulation and LD numbers. Furthermore, morphological analysis of liver sections from A6-KO mice revealed significantly lower LD numbers compared to wildtype animals. Interestingly, pharmacological inhibition of cytoplasmic phospholipase A2α (cPLA2α)-dependent LD formation was ineffective in AnxA6-depleted HuH7 cells. We conclude that cPLA2α-dependent pathways contribute to the novel regulatory role of hepatic AnxA6 in LD formation.
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Affiliation(s)
- Rose Cairns
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Anna Alvarez-Guaita
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Inés Martínez-Saludes
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Sundeep J Wason
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Jacky Hanh
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia
| | - Shilpa R Nagarajan
- Discipline of Physiology, School of Medical Science & Bosch Institute; Sydney Medical School; Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Elham Hosseini-Beheshti
- Discipline of Physiology, School of Medical Science & Bosch Institute; Sydney Medical School; Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Katia Monastyrskaya
- Urology Research Laboratory, Department Clinical Research, University of Bern, 3010 Bern, Switzerland
| | - Andrew J Hoy
- Discipline of Physiology, School of Medical Science & Bosch Institute; Sydney Medical School; Charles Perkins Centre, University of Sydney, Sydney, NSW 2006, Australia
| | - Christa Buechler
- Department of Internal Medicine I, Regensburg University Hospital, 93042 Regensburg, Germany
| | - Carlos Enrich
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain
| | - Carles Rentero
- Departament de Biomedicina, Unitat de Biologia Cel·lular, Centre de Recerca Biomèdica CELLEX, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Facultat de Medicina i Ciències de la Salut, Universitat de Barcelona, 08036 Barcelona, Spain.
| | - Thomas Grewal
- Faculty of Pharmacy, University of Sydney, Sydney, NSW 2006, Australia.
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27
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Geisler CE, Renquist BJ. Hepatic lipid accumulation: cause and consequence of dysregulated glucoregulatory hormones. J Endocrinol 2017; 234:R1-R21. [PMID: 28428362 DOI: 10.1530/joe-16-0513] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 04/20/2017] [Indexed: 12/11/2022]
Abstract
Fatty liver can be diet, endocrine, drug, virus or genetically induced. Independent of cause, hepatic lipid accumulation promotes systemic metabolic dysfunction. By acting as peroxisome proliferator-activated receptor (PPAR) ligands, hepatic non-esterified fatty acids upregulate expression of gluconeogenic, beta-oxidative, lipogenic and ketogenic genes, promoting hyperglycemia, hyperlipidemia and ketosis. The typical hormonal environment in fatty liver disease consists of hyperinsulinemia, hyperglucagonemia, hypercortisolemia, growth hormone deficiency and elevated sympathetic tone. These endocrine and metabolic changes further encourage hepatic steatosis by regulating adipose tissue lipolysis, liver lipid uptake, de novo lipogenesis (DNL), beta-oxidation, ketogenesis and lipid export. Hepatic lipid accumulation may be induced by 4 separate mechanisms: (1) increased hepatic uptake of circulating fatty acids, (2) increased hepatic de novo fatty acid synthesis, (3) decreased hepatic beta-oxidation and (4) decreased hepatic lipid export. This review will discuss the hormonal regulation of each mechanism comparing multiple physiological models of hepatic lipid accumulation. Nonalcoholic fatty liver disease (NAFLD) is typified by increased hepatic lipid uptake, synthesis, oxidation and export. Chronic hepatic lipid signaling through PPARgamma results in gene expression changes that allow concurrent activity of DNL and beta-oxidation. The importance of hepatic steatosis in driving systemic metabolic dysfunction is highlighted by the common endocrine and metabolic disturbances across many conditions that result in fatty liver. Understanding the mechanisms underlying the metabolic dysfunction that develops as a consequence of hepatic lipid accumulation is critical to identifying points of intervention in this increasingly prevalent disease state.
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Affiliation(s)
- Caroline E Geisler
- School of Animal and Comparative Biomedical SciencesUniversity of Arizona, Tucson, Arizona, USA
| | - Benjamin J Renquist
- School of Animal and Comparative Biomedical SciencesUniversity of Arizona, Tucson, Arizona, USA
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Jiang Y, Berry DC, Jo A, Tang W, Arpke RW, Kyba M, Graff JM. A PPARγ transcriptional cascade directs adipose progenitor cell-niche interaction and niche expansion. Nat Commun 2017. [PMID: 28649987 PMCID: PMC5490270 DOI: 10.1038/ncomms15926] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Adipose progenitor cells (APCs) reside in a vascular niche, located within the perivascular compartment of adipose tissue blood vessels. Yet, the signals and mechanisms that govern adipose vascular niche formation and APC niche interaction are unknown. Here we show that the assembly and maintenance of the adipose vascular niche is controlled by PPARγ acting within APCs. PPARγ triggers a molecular hierarchy that induces vascular sprouting, APC vessel niche affinity and APC vessel occupancy. Mechanistically, PPARγ transcriptionally activates PDGFRβ and VEGF. APC expression and activation of PDGFRβ promotes the recruitment and retention of APCs to the niche. Pharmacologically, targeting PDGFRβ disrupts APC niche contact thus blocking adipose tissue expansion. Moreover, enhanced APC expression of VEGF stimulates endothelial cell proliferation and expands the adipose niche. Consequently, APC niche communication and retention are boosted by VEGF thereby impairing adipogenesis. Our data indicate that APCs direct adipose tissue niche expansion via a PPARγ-initiated PDGFRβ and VEGF transcriptional axis. Adipocyte progenitor cells (APCs) are found tethered to adipose tissue blood vessel walls and can differentiate into adipocytes. Here the authors show that PPARγ controls angiogenesis by stimulating APC–blood vessel interaction and retention via a transcriptional network that includes PDGFRβ and VEGF.
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Affiliation(s)
- Yuwei Jiang
- Division of Endocrinology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Daniel C Berry
- Division of Endocrinology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Ayoung Jo
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Wei Tang
- Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Robert W Arpke
- Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA.,Department of Medicine, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Michael Kyba
- Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA.,Department of Pediatrics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Jonathan M Graff
- Division of Endocrinology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Developmental Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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Ishimoto K, Hayase A, Kumagai F, Kawai M, Okuno H, Hino N, Okada Y, Kawamura T, Tanaka T, Hamakubo T, Sakai J, Kodama T, Tachibana K, Doi T. Degradation of human Lipin-1 by BTRC E3 ubiquitin ligase. Biochem Biophys Res Commun 2017; 488:159-164. [PMID: 28483528 DOI: 10.1016/j.bbrc.2017.04.159] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 04/18/2017] [Indexed: 10/19/2022]
Abstract
Lipin-1 has dual functions in the regulation of lipid and energy metabolism according to its subcellular localization, which is tightly controlled. However, it is unclear how Lipin-1 degradation is regulated. Here, we demonstrate that Lipin-1 is degraded through its DSGXXS motif. We show that Lipin-1 interacts with either of two E3 ubiquitin ligases, BTRC or FBXW11, and that this interaction is DSGXXS-dependent and mediates the attachment of polyubiquitin chains. Further, we demonstrate that degradation of Lipin-1 is regulated by BTRC in the cytoplasm and on membranes. These novel insights into the regulation of human Lipin-1 stability will be useful in planning further studies to elucidate its metabolic processes.
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Affiliation(s)
- Kenji Ishimoto
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Ayaka Hayase
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Fumiko Kumagai
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Megumi Kawai
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hiroko Okuno
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Nobumasa Hino
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Yoshiaki Okada
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takeshi Kawamura
- Isotope Science Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo, Tokyo 113-0032, Japan
| | - Toshiya Tanaka
- Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904, Japan
| | - Takao Hamakubo
- Department of Quantitative Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904, Japan
| | - Juro Sakai
- Division of Metabolic Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904, Japan
| | - Tatsuhiko Kodama
- Laboratory for System Biology and Medicine, Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba, Meguro, Tokyo 153-8904, Japan
| | - Keisuke Tachibana
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takefumi Doi
- Laboratory of Molecular Medicine, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Low- ω3 Fatty Acid and Soy Protein Attenuate Alcohol-Induced Fatty Liver and Injury by Regulating the Opposing Lipid Oxidation and Lipogenic Signaling Pathways. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2016; 2016:1840513. [PMID: 28074114 PMCID: PMC5203909 DOI: 10.1155/2016/1840513] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 10/14/2016] [Accepted: 11/15/2016] [Indexed: 12/20/2022]
Abstract
Chronic ethanol-induced downregulation of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α) and upregulation of peroxisome proliferator-activated receptor gamma coactivator 1-beta (PGC1β) affect hepatic lipid oxidation and lipogenesis, respectively, leading to fatty liver injury. Low-ω3 fatty acid (Low-ω3FA) that primarily regulates PGC1α and soy protein (SP) that seems to have its major regulatory effect on PGC1β were evaluated for their protective effects against ethanol-induced hepatosteatosis in rats fed with Lieber-deCarli control or ethanol liquid diets with high or low ω3FA fish oil and soy protein. Low-ω3FA and SP opposed the actions of chronic ethanol by reducing serum and liver lipids with concomitant decreased fatty liver. They also prevented the downregulation of hepatic Sirtuin 1 (SIRT1) and PGC1α and their target fatty acid oxidation pathway genes and attenuated the upregulation of hepatic PGC1β and sterol regulatory element-binding protein 1c (SREBP1c) and their target lipogenic pathway genes via the phosphorylation of 5' adenosine monophosphate-activated protein kinase (AMPK). Thus, these two novel modulators attenuate ethanol-induced hepatosteatosis and consequent liver injury potentially by regulating the two opposing lipid oxidation and lipogenic pathways.
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Ubiquitination of Lysine 867 of the Human SETDB1 Protein Upregulates Its Histone H3 Lysine 9 (H3K9) Methyltransferase Activity. PLoS One 2016; 11:e0165766. [PMID: 27798683 PMCID: PMC5087952 DOI: 10.1371/journal.pone.0165766] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 10/17/2016] [Indexed: 11/22/2022] Open
Abstract
Posttranslational modifications (PTMs) of proteins play a crucial role in regulating protein-protein interactions, enzyme activity, subcellular localization, and stability of the protein. SET domain, bifurcated 1 (SETDB1) is a histone methyltransferase that regulates the methylation of histone H3 on lysine 9 (H3K9), gene silencing, and transcriptional repression. The C-terminal region of SETDB1 is a key site for PTMs, and is essential for its enzyme activity in mammalian and insect cells. In this study, we aimed to evaluate more precisely the effect of PTMs on the H3K9 methyltransferase activity of SETDB1. Using mass spectrometry analysis, we show that the C-terminal region of human SETDB1 purified from insect cells is ubiquitinated. We also demonstrate that the ubiquitination of lysine 867 of the human SETDB1 is necessary for full H3K9 methyltransferase activity in mammalian cells. Finally, we show that SETDB1 ubiquitination regulates the expression of its target gene, serpin peptidase inhibitor, clade E, member 1 (SERPINE1) by methylating H3K9. These results suggest that the ubiquitination of SETDB1 at lysine 867 controls the expression of its target gene by activating its H3K9 methyltransferase activity.
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Identification and structural characterization of two peroxisome proliferator activated receptors and their transcriptional changes at different developmental stages and after feeding with different fatty acids. Comp Biochem Physiol B Biochem Mol Biol 2016; 193:9-16. [DOI: 10.1016/j.cbpb.2015.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/20/2015] [Accepted: 12/02/2015] [Indexed: 01/06/2023]
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Rebhun JF, Glynn KM, Missler SR. Identification of glabridin as a bioactive compound in licorice (Glycyrrhiza glabra L.) extract that activates human peroxisome proliferator-activated receptor gamma (PPARγ). Fitoterapia 2015; 106:55-61. [DOI: 10.1016/j.fitote.2015.08.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Revised: 08/11/2015] [Accepted: 08/14/2015] [Indexed: 10/23/2022]
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Gene Network Analysis of Glucose Linked Signaling Pathways and Their Role in Human Hepatocellular Carcinoma Cell Growth and Survival in HuH7 and HepG2 Cell Lines. BIOMED RESEARCH INTERNATIONAL 2015; 2015:821761. [PMID: 26380295 PMCID: PMC4561296 DOI: 10.1155/2015/821761] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 03/06/2015] [Indexed: 12/14/2022]
Abstract
Cancer progression may be affected by metabolism. In this study, we aimed to analyze the effect of glucose on the proliferation and/or survival of human hepatocellular carcinoma (HCC) cells. Human gene datasets regulated by glucose were compared to gene datasets either dysregulated in HCC or regulated by other signaling pathways. Significant numbers of common genes suggested putative involvement in transcriptional regulations by glucose. Real-time proliferation assays using high (4.5 g/L) versus low (1 g/L) glucose on two human HCC cell lines and specific inhibitors of selected pathways were used for experimental validations. High glucose promoted HuH7 cell proliferation but not that of HepG2 cell line. Gene network analyses suggest that gene transcription by glucose could be mediated at 92% through ChREBP in HepG2 cells, compared to 40% in either other human cells or rodent healthy liver, with alteration of LKB1 (serine/threonine kinase 11) and NOX (NADPH oxidases) signaling pathways and loss of transcriptional regulation of PPARGC1A (peroxisome-proliferator activated receptors gamma coactivator 1) target genes by high glucose. Both PPARA and PPARGC1A regulate transcription of genes commonly regulated by glycolysis, by the antidiabetic agent metformin and by NOX, suggesting their major interplay in the control of HCC progression.
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Sullivan CJ, Pendleton ED, Abrams RE, Valente DL, Alvarez ML, Griffey RH, Dresios J. Chromatin structure analysis enables detection of DNA insertions into the mammalian nuclear genome. Biochem Biophys Rep 2015; 2:143-152. [PMID: 29124156 PMCID: PMC5668663 DOI: 10.1016/j.bbrep.2015.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 05/28/2015] [Accepted: 06/08/2015] [Indexed: 01/03/2023] Open
Abstract
Background Genetically modified organisms (GMOs) have numerous biomedical, agricultural and environmental applications. Development of accurate methods for the detection of GMOs is a prerequisite for the identification and control of authorized and unauthorized release of these engineered organisms into the environment and into the food chain. Current detection methods are unable to detect uncharacterized GMOs, since either the DNA sequence of the transgene or the amino acid sequence of the protein must be known for DNA-based or immunological-based detection, respectively. Methods Here we describe the application of an epigenetics-based approach for the detection of mammalian GMOs via analysis of chromatin structural changes occurring in the host nucleus upon the insertion of foreign or endogenous DNA. Results Immunological methods combined with DNA next generation sequencing enabled direct interrogation of chromatin structure and identification of insertions of various size foreign (human or viral) DNA sequences, DNA sequences often used as genome modification tools (e.g. viral sequences, transposon elements), or endogenous DNA sequences into the nuclear genome of a model animal organism. Conclusions The results provide a proof-of-concept that epigenetic approaches can be used to detect the insertion of endogenous and exogenous sequences into the genome of higher organisms where the method of genetic modification, the sequence of inserted DNA, and the exact genomic insertion site(s) are unknown. General significance Measurement of chromatin dynamics as a sensor for detection of genomic manipulation and, more broadly, organism exposure to environmental or other factors affecting the epigenomic landscape are discussed. Insertion of DNA sequences into a host genome causes chromatin structure remodeling. ChIP-seq identifies molecular signatures of DNA insertion into the mammalian genome. Focus on epigenetic marks limits sequencing data amount required for GMO detection. Proof-of-concept for use of chromatin dynamics as a sensor of genomic manipulation.
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Giordano Attianese GMP, Desvergne B. Integrative and systemic approaches for evaluating PPARβ/δ (PPARD) function. NUCLEAR RECEPTOR SIGNALING 2015; 13:e001. [PMID: 25945080 PMCID: PMC4419664 DOI: 10.1621/nrs.13001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 03/09/2015] [Indexed: 12/13/2022]
Abstract
The peroxisome proliferator-activated receptors (PPARs) are a group of nuclear receptors that function as transcription factors regulating the expression of genes involved in cellular differentiation, development, metabolism and also tumorigenesis. Three PPAR isotypes (α, β/δ and γ) have been identified, among which PPARβ/δ is the most difficult to functionally examine due to its tissue-specific diversity in cell fate determination, energy metabolism and housekeeping activities. PPARβ/δ acts both in a ligand-dependent and -independent manner. The specific type of regulation, activation or repression, is determined by many factors, among which the type of ligand, the presence/absence of PPARβ/δ-interacting corepressor or coactivator complexes and PPARβ/δ protein post-translational modifications play major roles. Recently, new global approaches to the study of nuclear receptors have made it possible to evaluate their molecular activity in a more systemic fashion, rather than deeply digging into a single pathway/function. This systemic approach is ideally suited for studying PPARβ/δ, due to its ubiquitous expression in various organs and its overlapping and tissue-specific transcriptomic signatures. The aim of the present review is to present in detail the diversity of PPARβ/δ function, focusing on the different information gained at the systemic level, and describing the global and unbiased approaches that combine a systems view with molecular understanding.
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Rebhun JF, Roloff SJ, Velliquette RA, Missler SR. Identification of evodiamine as the bioactive compound in evodia (Evodia rutaecarpa Benth.) fruit extract that activates human peroxisome proliferator-activated receptor gamma (PPARγ). Fitoterapia 2014; 101:57-63. [PMID: 25542684 DOI: 10.1016/j.fitote.2014.12.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 12/10/2014] [Accepted: 12/16/2014] [Indexed: 11/25/2022]
Abstract
The dried unripe fruit from Evodia rutaecarpa Benth., known as Wu zhu yu in China, has long been used in traditional Chinese medicine. In this research, we provide evidence that evodia fruit extract activates peroxisome proliferator-activated receptor gamma (PPARγ) and, as identified through HPLC fractionation and mass spectroscopy, the activating phytochemical is evodiamine. Evodiamine was shown to bind to and activate PPARγ. It was also shown to activate PPARγ-regulated gene expression in human hepatoma cells similar to known PPARγ ligands and that the expression was blocked by a PPARγ specific antagonist.
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Affiliation(s)
- John F Rebhun
- Analytical Sciences, Amway Corporation, 7575 East Fulton Avenue, Ada, MI 49355, United States.
| | - Samantha J Roloff
- Analytical Sciences, Amway Corporation, 7575 East Fulton Avenue, Ada, MI 49355, United States
| | - Rodney A Velliquette
- Analytical Sciences, Amway Corporation, 7575 East Fulton Avenue, Ada, MI 49355, United States
| | - Stephen R Missler
- Analytical Sciences, Amway Corporation, 7575 East Fulton Avenue, Ada, MI 49355, United States
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Carboxymefloquine, the major metabolite of the antimalarial drug mefloquine, induces drug-metabolizing enzyme and transporter expression by activation of pregnane X receptor. Antimicrob Agents Chemother 2014; 59:96-104. [PMID: 25313206 DOI: 10.1128/aac.04140-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Malaria patients are frequently coinfected with HIV and mycobacteria causing tuberculosis, which increases the use of coadministered drugs and thereby enhances the risk of pharmacokinetic drug-drug interactions. Activation of the pregnane X receptor (PXR) by xenobiotics, which include many drugs, induces drug metabolism and transport, thereby resulting in possible attenuation or loss of the therapeutic responses to the drugs being coadministered. While several artemisinin-type antimalarial drugs have been shown to activate PXR, data on nonartemisinin-type antimalarials are still missing. Therefore, this study aimed to elucidate the potential of nonartemisinin antimalarial drugs and drug metabolites to activate PXR. We screened 16 clinically used antimalarial drugs and six major drug metabolites for binding to PXR using the two-hybrid PXR ligand binding domain assembly assay; this identified carboxymefloquine, the major and pharmacologically inactive metabolite of the antimalarial drug mefloquine, as a potential PXR ligand. Two-hybrid PXR-coactivator and -corepressor interaction assays and PXR-dependent promoter reporter gene assays confirmed carboxymefloquine to be a novel PXR agonist which specifically activated the human receptor. In the PXR-expressing intestinal LS174T cells and in primary human hepatocytes, carboxymefloquine induced the expression of drug-metabolizing enzymes and transporters on the mRNA and protein levels. The crucial role of PXR for the carboxymefloquine-dependent induction of gene expression was confirmed by small interfering RNA (siRNA)-mediated knockdown of the receptor. Thus, the clinical use of mefloquine may result in pharmacokinetic drug-drug interactions by means of its metabolite carboxymefloquine. Whether these in vitro findings are of in vivo relevance has to be addressed in future clinical drug-drug interaction studies.
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Arya N, Kharjul MD, Shishoo CJ, Thakare VN, Jain KS. Some molecular targets for antihyperlipidemic drug research. Eur J Med Chem 2014; 85:535-68. [DOI: 10.1016/j.ejmech.2014.08.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 08/01/2014] [Accepted: 08/05/2014] [Indexed: 12/17/2022]
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Sahasrabuddhe NA, Huang TC, Ahmad S, Kim MS, Yang Y, Ghosh B, Leach SD, Gowda H, Somani BL, Chaerkady R, Pandey A. Regulation of PPAR-alpha pathway by Dicer revealed through proteomic analysis. J Proteomics 2014; 108:306-15. [DOI: 10.1016/j.jprot.2014.04.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 03/31/2014] [Accepted: 04/13/2014] [Indexed: 12/22/2022]
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Kienesberger K, Pordes AG, Völk TG, Hofbauer R. L-carnitine and PPARα-agonist fenofibrate are involved in the regulation of Carnitine Acetyltransferase (CrAT) mRNA levels in murine liver cells. BMC Genomics 2014; 15:514. [PMID: 24962334 PMCID: PMC4089027 DOI: 10.1186/1471-2164-15-514] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 06/19/2014] [Indexed: 12/25/2022] Open
Abstract
Background The carnitine acetyltransferase (CrAT) is a mitochondrial matrix protein that directly influences intramitochondrial acetyl-CoA pools. Murine CrAT is encoded by a single gene located in the opposite orientation head to head to the PPP2R4 gene, sharing a very condensed bi-directional promoter. Since decreased CrAT expression is correlated with metabolic inflexibility and subsequent pathological consequences, our aim was to reveal and define possible activators of CrAT transcription in the normal embryonic murine liver cell line BNL CL. 2 and via which nuclear factors based on key metabolites mainly regulate hepatic expression of CrAT. Here we describe a functional characterization of the CrAT promoter region under conditions of L-carnitine deficiency and supplementation as well as fenofibrate induction in cell culture cells. Results The murine CrAT promoter displays some characteristics of a housekeeping gene: it lacks a TATA-box, is very GC-rich and harbors two Sp1 binding sites. Analysis of the promoter activity of CrAT by luciferase assays uncovered a L-carnitine sensitive region within −342 bp of the transcription start. Electrophoretic mobility shift and supershift assays proved the sequence element (−228/-222) to be an L-carnitine sensitive RXRα binding site, which also showed sensitivity to application of anti-PPARα and anti-PPARbp antibodies. In addition we analysed this specific RXRα/PPARα site by Southwestern Blotting technique and could pin down three protein factors binding to this promoter element. By qPCR we could quantify the nutrigenomic effect of L-carnitine itself and fenofibrate. Conclusions Our results indicate a cooperative interplay of L-carnitine and PPARα in transcriptional regulation of murine CrAT, which is of nutrigenomical relevance. We created experimental proof that the muCrAT gene clearly is a PPARα target. Both L-carnitine and fenofibrate are inducers of CrAT transcripts, but the important hyperlipidemic drug fenofibrate being a more potent one, as a consequence of its pharmacological interaction. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-514) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | - Reinhold Hofbauer
- Centre for Molecular Biology, Department of Biochemistry and Cell Biology, Max F, Perutz Laboratories, University of Vienna, Dr, Bohrg, 9, Vienna A-1030, Austria.
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He S, Minton AZ, Ma HY, Stankowska DL, Sun X, Krishnamoorthy RR. Involvement of AP-1 and C/EBPβ in upregulation of endothelin B (ETB) receptor expression in a rodent model of glaucoma. PLoS One 2013; 8:e79183. [PMID: 24265756 PMCID: PMC3827153 DOI: 10.1371/journal.pone.0079183] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 09/23/2013] [Indexed: 12/31/2022] Open
Abstract
Previous studies showed that the endothelin B receptor (ETB) expression was upregulated and played a key role in neurodegeneration in rodent models of glaucoma. However, the mechanisms underlying upregulation of ETB receptor expression remain largely unknown. Using promoter-reporter assays, the 1258 bp upstream the human ETB promoter region was found to be essential for constitutive expression of ETB receptor gene in human non-pigmented ciliary epithelial cells (HNPE). The −300 to −1 bp and −1258 to −600 bp upstream promoter regions of the ETB receptor appeared to be the key binding regions for transcription factors. In addition, the crucial AP-1 binding site located at −615 to −624 bp upstream promoter was confirmed by luciferase assays and CHIP assays which were performed following overexpression of c-Jun in HNPE cells. Overexpression of either c-Jun or C/EBPβ enhanced the ETB receptor promoter activity, which was reflected in increased mRNA and protein levels of ETB receptor. Furthermore, knock-down of either c-Jun or C/EBPβ in HNPE cells was significantly correlated to decreased mRNA levels of both ETB and ETA receptor. These observations suggest that c-Jun and C/EBPβ are important for regulated expression of the ETB receptor in HNPE cells. In separate experiments, intraocular pressure (IOP) was elevated in one eye of Brown Norway rats while the corresponding contralateral eye served as control. Two weeks of IOP elevation produced increased expression of c-Jun and C/EBPβ in the retinal ganglion cell (RGC) layer from IOP-elevated eyes. The mRNA levels of c-Jun, ETA and ETB receptor were upregulated by 2.2-, 3.1- and 4.4-fold in RGC layers obtained by laser capture microdissection from retinas of eyes with elevated IOP, compared to those from contralateral eyes. Taken together, these data suggest that transcription factor AP-1 plays a key role in elevation of ETB receptor in a rodent model of ocular hypertension.
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Affiliation(s)
- Shaoqing He
- Department of Cell Biology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
- * E-mail:
| | - Alena Z. Minton
- Department of Cell Biology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
| | - Hai-Ying Ma
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
| | - Dorota L. Stankowska
- Department of Cell Biology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
| | - Xiangle Sun
- Department of Molecular Biology and Immunology, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
| | - Raghu R. Krishnamoorthy
- Department of Cell Biology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
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Corton JC, Cunningham ML, Hummer BT, Lau C, Meek B, Peters JM, Popp JA, Rhomberg L, Seed J, Klaunig JE. Mode of action framework analysis for receptor-mediated toxicity: The peroxisome proliferator-activated receptor alpha (PPARα) as a case study. Crit Rev Toxicol 2013; 44:1-49. [PMID: 24180432 DOI: 10.3109/10408444.2013.835784] [Citation(s) in RCA: 161] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Several therapeutic agents and industrial chemicals induce liver tumors in rodents through the activation of the peroxisome proliferator-activated receptor alpha (PPARα). The cellular and molecular events by which PPARα activators induce rodent hepatocarcinogenesis has been extensively studied and elucidated. This review summarizes the weight of evidence relevant to the hypothesized mode of action (MOA) for PPARα activator-induced rodent hepatocarcinogenesis and identifies gaps in our knowledge of this MOA. Chemical-specific and mechanistic data support concordance of temporal and dose-response relationships for the key events associated with many PPARα activators including a phthalate ester plasticizer di(2-ethylhexyl) phthalate (DEHP) and the drug gemfibrozil. While biologically plausible in humans, the hypothesized key events in the rodent MOA, for PPARα activators, are unlikely to induce liver tumors in humans because of toxicodynamic and biological differences in responses. This conclusion is based on minimal or no effects observed on growth pathways, hepatocellular proliferation and liver tumors in humans and/or species (including hamsters, guinea pigs and cynomolgous monkeys) that are more appropriate human surrogates than mice and rats at overlapping dose levels. Overall, the panel concluded that significant quantitative differences in PPARα activator-induced effects related to liver cancer formation exist between rodents and humans. On the basis of these quantitative differences, most of the workgroup felt that the rodent MOA is "not relevant to humans" with the remaining members concluding that the MOA is "unlikely to be relevant to humans". The two groups differed in their level of confidence based on perceived limitations of the quantitative and mechanistic knowledge of the species differences, which for some panel members strongly supports but cannot preclude the absence of effects under unlikely exposure scenarios.
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Tachibana K, Takeuchi K, Inada H, Sugimoto K, Ishimoto K, Yamashita M, Maegawa T, Yamasaki D, Osada S, Tanaka T, Rakugi H, Hamakubo T, Sakai J, Kodama T, Doi T. Human mannose-binding lectin 2 is directly regulated by peroxisome proliferator-activated receptors via a peroxisome proliferator responsive element. J Biochem 2013; 154:265-73. [PMID: 23711995 DOI: 10.1093/jb/mvt050] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Human mannose-binding lectin (MBL) is encoded by the MBL2 gene and is a key player in innate immunity. However, the mechanism of the transcriptional regulation of MBL2 is largely unknown. The peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that play an important role in a number of biological responses, including lipid homeostasis, immune function and adipogenesis. In this study, we showed that PPARα and PPARγ up-regulate the expression of human MBL2. Using a luciferase assay, electrophoretic mobility-shift assay and chromatin immunoprecipitation assay, we demonstrated that PPARs regulate the expression of human MBL2 via the peroxisome proliferator responsive element (PPRE). On the other hand, MBL2 mRNA expression was not affected by the PPARα ligand both in vivo in rat liver and in vitro in rat H4IIE hepatoma cells. Thus, there is a species difference in regulation of MBL2 gene expression by PPARs between humans and rodents. We also show that the species differences in response to PPAR could be due in part to sequence-specific differences in the PPRE in the promoter region of MBL2. These results indicate that human, but not rat, MBL2 expression is regulated by PPARs via a PPRE.
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Affiliation(s)
- Keisuke Tachibana
- Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan
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45
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Tani H, Torimura M, Akimitsu N. The RNA degradation pathway regulates the function of GAS5 a non-coding RNA in mammalian cells. PLoS One 2013; 8:e55684. [PMID: 23383264 PMCID: PMC3559549 DOI: 10.1371/journal.pone.0055684] [Citation(s) in RCA: 136] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2012] [Accepted: 12/28/2012] [Indexed: 01/02/2023] Open
Abstract
Studies of various mRNAs have revealed that changes in the abundance of transcripts, through mRNA degradation, act as a critical step in the control of various biological pathways. Similarly, the regulation of non-coding RNA (ncRNA) levels is also considered to be important for their biological functions; however, far less is known about the mechanisms and biological importance of ncRNA turnover for the regulation of ncRNA functions. The growth arrest-specific 5 (GAS5) ncRNA accumulates during growth arrest induced by serum starvation and its transcript is degraded by the well characterized nonsense-mediated RNA decay (NMD) pathway. Historically, NMD was discovered as a RNA quality control system to eliminate aberrant transcripts; however, accumulating evidence shows that NMD also regulates the abundance of physiological transcripts. Interestingly, the GAS5 transcript has the ability to bind the glucocorticoid receptor (GR), resulting in the inhibition of its ligand-dependent association with DNA. The GR binds the promoters of various glucocorticoid-responsive genes, including apoptosis-related genes. In this study, we examined whether the RNA degradation pathway can regulate this function of GAS5. We measured the steady-state abundance and the decay rate of GAS5 in UPF1-depleted human cells using the 5′-bromo-uridine immunoprecipitation chase (BRIC) method, an inhibitor-free method for directly measuring RNA stability. We found that levels of the GAS5 transcript were elevated owing to prolonged decay rates in response to UPF1 depletion, and consequently the apoptosis-related genes, cIAP2 and SGK1, were down-regulated. In addition, serum starvation also increased the transcript levels of GAS5 because of prolonged decay rates, and conversely decreased levels of cIAP2 and SGK1 mRNA. Taken together, we found that the RNA degradation pathway can regulate the function of the GAS5 ncRNA in mammalian cells.
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Affiliation(s)
- Hidenori Tani
- Research Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
- * E-mail: (HT); (NA)
| | - Masaki Torimura
- Research Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki, Japan
| | - Nobuyoshi Akimitsu
- Radioisotope Center, The University of Tokyo, Bunkyo, Tokyo, Japan
- * E-mail: (HT); (NA)
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Ramani K, Tomasi ML. Transcriptional regulation of methionine adenosyltransferase 2A by peroxisome proliferator-activated receptors in rat hepatic stellate cells. Hepatology 2012; 55:1942-53. [PMID: 22271545 PMCID: PMC3342421 DOI: 10.1002/hep.25594] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Accepted: 12/26/2011] [Indexed: 12/11/2022]
Abstract
UNLABELLED Methionine adenosyltransferases (MATs) are critical enzymes that catalyze the formation of the methyl donor S-adenosyl methionine (SAM). The MAT2A gene, which encodes the catalytic subunit α2, is induced in dedifferentiated liver. We previously demonstrated that MAT2A expression is enhanced in activated hepatic stellate cells (HSCs) and that silencing this gene reduces HSC activation. In this study, we examined the molecular mechanisms responsible for the transcriptional regulation of the MAT2A gene in HSCs. We identified peroxisome proliferator-activated receptor (PPAR) response elements (PPREs) in the rat MAT2A promoter. The PPARγ agonist rosiglitazone (RSG) promoted quiescence in the activated rat HSC cell line (BSC) or culture-activated primary rat HSCs, decreased MAT2A expression and promoter activity, and enhanced PPARγ binding to MAT2A PPREs. In vivo HSC activation in bile duct-ligated rats lowered PPARγ interaction with MAT2A PPREs. Silencing PPARγ increased MAT2A transcription, whereas overexpressing it had the opposite effect, demonstrating that PPARγ negatively controls this gene. Site-directed mutagenesis of PPREs abolished PPARγ recruitment to the MAT2A promoter and its inhibitory effect on MAT2A transcription in quiescent HSCs. PPRE mutations decreased the basal promoter activity of MAT2A in activated HSCs independent of PPARγ, indicating that other factors might be involved in PPRE interaction. We identified PPARβ binding to wild-type but not to mutated PPREs in activated cells. Furthermore, silencing PPARβ inhibited MAT2A expression and promoter activity. Forced expression of MAT2A in RSG-treated HSCs lowered PPARγ and enhanced PPARβ expression, thereby promoting an activated phenotype. CONCLUSION We identified PPARγ as a negative regulator of MAT2A in quiescent HSCs. A switch from quiescence to activation abolishes this control and allows PPARβ to up-regulate MAT2A transcription.
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Affiliation(s)
- Komal Ramani
- Division of Gastroenterology and Liver Diseases, USC Research Center for Liver Diseases, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
| | - Maria Lauda Tomasi
- Division of Gastroenterology and Liver Diseases, USC Research Center for Liver Diseases, Keck School of Medicine University of Southern California, Los Angeles, California 90033
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Xu M, Lu N, Sun Z, Zhang H, Dai Q, Wei L, Li Z, You Q, Guo Q. Activation of the unfolded protein response contributed to the selective cytotoxicity of oroxylin A in human hepatocellular carcinoma HepG2 cells. Toxicol Lett 2012; 212:113-25. [PMID: 22609744 DOI: 10.1016/j.toxlet.2012.05.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 05/05/2012] [Accepted: 05/08/2012] [Indexed: 12/24/2022]
Abstract
Hepatocellular carcinoma (HCC) is a refractory malignancy with a high incidence and large mortality. Current strategy for the chemotherapy of HCC focuses on developing agents with better efficacy and lower toxicity. In this study, we demonstrated that the natural flavonoid oroxylin A preferentially inhibited the viability of HCC cell line HepG2 but not the normal hepatic cell line L02. In HepG2 but not L02 cells, oroxylin A induced substantial production of intracellular H₂O₂ and inordinate activation of the PERK-eIF2α-ATF4-CHOP branch of the unfolded protein response (UPR) pathway, which resulted in the induction of TRB3 and causal reduction of p-AKT1/2/3 (Ser473). Moreover, these effects were eliminated by either the stable knockdown of CHOP or the pretreatment and then co-incubation with the specific H₂O₂ scavenger catalase. These results indicated that the H₂O₂-triggered overactivation of the UPR pathway and causal inactivation of AKT signaling contributed to the preferential cytotoxicity of oroxylin A in malignant HepG2 cells. Therefore, present study proposed an underlying molecular mechanism that implicated the selective antitumor effect of oroxylin A and recommended oroxylin A as a prospect for improving the current chemotherapeutic strategy for the treatment of HCC.
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Affiliation(s)
- Min Xu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Carcinogenesis and Intervention, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, PR China
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Novel repressor regulates insulin sensitivity through interaction with Foxo1. EMBO J 2012; 31:2275-95. [PMID: 22510882 PMCID: PMC3364737 DOI: 10.1038/emboj.2012.97] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 03/20/2012] [Indexed: 12/19/2022] Open
Abstract
Forkhead box-containing protein o (Foxo) 1 is a key transcription factor in insulin and glucose metabolism. We identified a Foxo1-CoRepressor (FCoR) protein in mouse adipose tissue that inhibits Foxo1's activity by enhancing acetylation via impairment of the interaction between Foxo1 and the deacetylase Sirt1 and via direct acetylation. FCoR is phosphorylated at Threonine 93 by catalytic subunit of protein kinase A and is translocated into nucleus, making it possible to bind to Foxo1 in both cytosol and nucleus. Knockdown of FCoR in 3T3-F442A cells enhanced expression of Foxo target and inhibited adipocyte differentiation. Overexpression of FCoR in white adipose tissue decreased expression of Foxo-target genes and adipocyte size and increased insulin sensitivity in Lepr(db/db) mice and in mice fed a high-fat diet. In contrast, Fcor knockout mice were lean, glucose intolerant, and had decreased insulin sensitivity that was accompanied by increased expression levels of Foxo-target genes and enlarged adipocytes. Taken together, these data suggest that FCoR is a novel repressor that regulates insulin sensitivity and energy metabolism in adipose tissue by acting to fine-tune Foxo1 activity.
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Peters JM, Foreman JE, Gonzalez FJ. Dissecting the role of peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) in colon, breast, and lung carcinogenesis. Cancer Metastasis Rev 2012; 30:619-40. [PMID: 22037942 DOI: 10.1007/s10555-011-9320-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) is a promising drug target since its agonists increase serum high-density lipoprotein; decrease low-density lipoprotein, triglycerides, and insulin associated with metabolic syndrome; improve insulin sensitivity; and decrease high fat diet-induced obesity. PPARβ/δ agonists also promote terminal differentiation and elicit anti-inflammatory activities in many cell types. However, it remains to be determined whether PPARβ/δ agonists can be developed as therapeutics because there are reports showing either pro- or anti-carcinogenic effects of PPARβ/δ in cancer models. This review examines studies reporting the role of PPARβ/δ in colon, breast, and lung cancers. The prevailing evidence would suggest that targeting PPARβ/δ is not only safe but could have anti-carcinogenic protective effects.
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Affiliation(s)
- Jeffrey M Peters
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, PA 16802, USA.
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Peters JM, Shah YM, Gonzalez FJ. The role of peroxisome proliferator-activated receptors in carcinogenesis and chemoprevention. Nat Rev Cancer 2012; 12:181-95. [PMID: 22318237 PMCID: PMC3322353 DOI: 10.1038/nrc3214] [Citation(s) in RCA: 343] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors that are involved in regulating glucose and lipid homeostasis, inflammation, proliferation and differentiation. Although all of these functions might contribute to the influence of PPARs in carcinogenesis, there is a distinct need for a review of the literature and additional experimentation to determine the potential for targeting PPARs for cancer therapy and cancer chemoprevention. As PPAR agonists include drugs that are used for the treatment of metabolic diseases, a more complete understanding of the roles of PPARs in cancer will aid in determining any increased cancer risk for patients undergoing therapy with PPAR agonists.
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Affiliation(s)
- Jeffrey M Peters
- Department of Veterinary and Biomedical Sciences and The Center for Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
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