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Zou J, Song Q, Shaw PC, Zuo Z. Dendrobium officinale regulate lipid metabolism in diabetic mouse liver via PPAR-RXR signaling pathway: Evidence from an integrated multi-omics analysis. Biomed Pharmacother 2024; 173:116395. [PMID: 38460364 DOI: 10.1016/j.biopha.2024.116395] [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: 12/28/2023] [Revised: 03/04/2024] [Accepted: 03/06/2024] [Indexed: 03/11/2024] Open
Abstract
Dendrobium officinale (DEN) is recognized as a kind of functional food that can effectively ameliorate endocrine and metabolic disruptions. This study delved into the pharmacological mechanism of DEN on hepatic lipotoxicity associated with Type II diabetes mellitus (T2DM). In vivo study experiments on db/db mice indicated that DEN treatment notably enhanced liver function, decreased blood lipid levels, and improved insulin sensitivity. Non-targeted metabolomics analysis revealed that DEN significantly ameliorated metabolism pathways, including lipoic acid, linoleic acid, bile secretion, and the alanine/aspartate/glutamate metabolism, as well as taurine and hypotaurine metabolism. Transcriptomics analysis demonstrated DEN treatment could modulate the expression of genes such as Cpt1b, Scd1, G6pc2, Fos, Adrb2, Atp2a1, Ppp1r1b, and Cyp7a1. Furthermore, Proteomics analysis indicated that the beneficial effect of DEN on lipid metabolism was linked to pathways like AMPK and PPAR signaling. The integrative analysis of multi-omics revealed that the PPAR-RXR signaling was critical to the therapeutic effect of DEN on T2DM-induced fatty liver. Additionally, in vitro study on AML-12 cells confirmed that DEN counteract PA-induced lipid accumulation by activating the PPAR-RXR pathway. Overall, these findings suggested that DEN exhibited the potential to mitigate T2DM-induced hepatic lipo-toxicity and manage lipid imbalances in T2DM.
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Affiliation(s)
- Junju Zou
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China; Hunan University of Chinese Medicine, The Hunan University of Chinese Medicine, PR China
| | - Qianbo Song
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Pang Chui Shaw
- Li Dak Sum Yip Yio Chin R&D Center for Chinese Medicine and School of Life Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China
| | - Zhong Zuo
- School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China; State Key Laboratory of Research on Bioactivities and Clinical Applications of Medicinal Plants, The Chinese University of Hong Kong, Hong Kong Special Administrative Region of China.
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2
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Dahal L, Graham TGW, Dailey GM, Heckert A, Tjian R, Darzacq X. Surprising Features of Nuclear Receptor Interaction Networks Revealed by Live Cell Single Molecule Imaging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.16.558083. [PMID: 37745337 PMCID: PMC10516011 DOI: 10.1101/2023.09.16.558083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Type 2 Nuclear Receptors (T2NRs) require heterodimerization with a common partner, the Retinoid X Receptor (RXR), to bind cognate DNA recognition sites in chromatin. Based on previous biochemical and over-expression studies, binding of T2NRs to chromatin is proposed to be regulated by competition for a limiting pool of the core RXR subunit. However, this mechanism has not yet been tested for endogenous proteins in live cells. Using single molecule tracking (SMT) and proximity-assisted photoactivation (PAPA), we monitored interactions between endogenously tagged retinoid X receptor (RXR) and retinoic acid receptor (RAR) in live cells. Unexpectedly, we find that higher expression of RAR, but not RXR increases heterodimerization and chromatin binding in U2OS cells. This surprising finding indicates the limiting factor is not RXR but likely its cadre of obligate dimer binding partners. SMT and PAPA thus provide a direct way to probe which components are functionally limiting within a complex TF interaction network providing new insights into mechanisms of gene regulation in vivo with implications for drug development targeting nuclear receptors.
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Affiliation(s)
- Liza Dahal
- Department of Molecular and Cell Biology, University of California, Berkeley, United States
- Howard Hughes Medical Institute, University of California, Berkeley, United States
| | - Thomas GW Graham
- Department of Molecular and Cell Biology, University of California, Berkeley, United States
- Howard Hughes Medical Institute, University of California, Berkeley, United States
| | - Gina M Dailey
- Department of Molecular and Cell Biology, University of California, Berkeley, United States
| | - Alec Heckert
- Eikon Therapeutics Inc., Hayward, California, United States
| | - Robert Tjian
- Department of Molecular and Cell Biology, University of California, Berkeley, United States
- Howard Hughes Medical Institute, University of California, Berkeley, United States
| | - Xavier Darzacq
- Department of Molecular and Cell Biology, University of California, Berkeley, United States
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3
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Wu J, Wang X, Zhang M, Mathews P, Kang Y. RXR Agonists Enhance Lenalidomide Anti-Myeloma Activity and T Cell Functions while Retaining Glucose-Lowering Effect. Cells 2023; 12:1993. [PMID: 37566072 PMCID: PMC10417536 DOI: 10.3390/cells12151993] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/29/2023] [Accepted: 08/01/2023] [Indexed: 08/12/2023] Open
Abstract
Retinoid X receptor (RXR) heterodimerizes with the PPAR nuclear hormone receptor and regulates its downstream events. We investigated the effects of RXR agonists (LG100754, bexarotene, AGN194204, and LG101506) on lenalidomide's anti-myeloma activity, T cell functions, and the level of glucose and lipids in vivo. Genetic overexpression and CRISPR/Cas9 knockout experiments were conducted in multiple myeloma (MM) cell lines and Jurkat T cell lines to determine the roles of CRBN in RXR-agonist mediated effects. A xenograft mouse model of MM was established to determine the combination effect of LG100754 and lenalidomide. The combination of RXR agonists and lenalidomide demonstrated synergistic activity in increasing CRBN expression and killing myeloma cells. Mechanistically, the RXR agonists reduced the binding of PPARs to the CRBN promoter, thereby relieving the repressor effect of PPARs on CRBN transcription. RXR agonists downregulated the exhaustion markers and increased the activation markers of Jurkat T cells and primary human T cells. Co-administration of LG100754 and lenalidomide showed enhanced anti-tumor activity in vivo. LG100754 retained its glucose- and lipid-lowering effects. RXR agonists demonstrate potential utility in enhancing drug sensitivity and T-cell function in the treatment of myeloma.
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Affiliation(s)
| | | | | | | | - Yubin Kang
- Division of Hematologic Malignancies and Cellular Therapy, Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA; (J.W.); (X.W.)
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4
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Qiu YY, Zhang J, Zeng FY, Zhu YZ. Roles of the peroxisome proliferator-activated receptors (PPARs) in the pathogenesis of nonalcoholic fatty liver disease (NAFLD). Pharmacol Res 2023; 192:106786. [PMID: 37146924 DOI: 10.1016/j.phrs.2023.106786] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 04/28/2023] [Accepted: 05/02/2023] [Indexed: 05/07/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) encompasses a spectrum of disease phenotypes which start with simple steatosis and lipid accumulation in the hepatocytes - a typical histological lesions characteristic. It may progress to non-alcoholic steatohepatitis (NASH) that is characterized by hepatic inflammation and/or fibrosis and subsequent onset of NAFLD-related cirrhosis and hepatocellular carcinoma (HCC). Due to the central role of the liver in metabolism, NAFLD is regarded as a result of and contribution to the metabolic abnormalities seen in the metabolic syndrome. Peroxisome proliferator-activated receptors (PPARs) has three subtypes, which govern the expression of genes responsible for energy metabolism, cellular development, inflammation, and differentiation. The agonists of PPARα, such as fenofibrate and clofibrate, have been used as lipid-lowering drugs in clinical practice. Thiazolidinediones (TZDs) - ligands of PPARγ, such as rosiglitazone and pioglitazone, are also used in the treatment of type 2 diabetes (T2D) with insulin resistance (IR). Increasing evidence suggests that PPARβ/δ agonists have potential therapeutic effects in improving insulin sensitivity and lipid metabolism disorders. In addition, PPARs ligands have been considered as potential therapeutic drugs for hypertension, atherosclerosis (AS) or diabetic nephropathy. Their crucial biological roles dictate the significance of PPARs-targeting in medical research and drug discovery. Here, it reviews the biological activities, ligand selectivity and biological functions of the PPARs family, and discusses the relationship between PPARs and the pathogenesis of NAFLD and metabolic syndrome. This will open new possibilities for PPARs application in medicine, and provide a new idea for the treatment of fatty liver and related diseases.
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Affiliation(s)
- Yuan-Ye Qiu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; Faculty of Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China.
| | - Jing Zhang
- University International College, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China.
| | - Fan-Yi Zeng
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; School of Pharmacy, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; Shanghai Institute of Medical Genetics, Shanghai Children's Hospital, Shanghai Jiao Tong University, 24/1400 West Beijing Road, Shanghai, 200040, China.
| | - Yi Zhun Zhu
- State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; Faculty of Chinese Medicine, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China; School of Pharmacy, Macau University of Science and Technology, Avenida Wai Long, Taipa, 999078, Macau, China.
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5
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Liu X, Dun M, Jian T, Sun Y, Wang M, Zhang G, Ling J. Cordyceps militaris extracts and cordycepin ameliorate type 2 diabetes mellitus by modulating the gut microbiota and metabolites. Front Pharmacol 2023; 14:1134429. [PMID: 36969858 PMCID: PMC10033974 DOI: 10.3389/fphar.2023.1134429] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 02/08/2023] [Indexed: 03/11/2023] Open
Abstract
Introduction:Cordyceps militaris, which has many potential medicinal properties, has rarely been reported to alleviate type 2 diabetes mellitus (T2DM).Methods: The effects of C. militaris extracts (CE) and cordycepin (CCS) on high-fat diet and streptozotocin (STZ) induced T2DM mice were analysed by gut microbiome and metabolomics methods in this study.Results: The results demonstrated that glucose and lipid metabolism parameters, oxidative stress biomarkers and inflammation cytokines were down-regulated in the CCS and CE groups. A comparative analysis of the fecal samples from mice in the model and experimental groups showed that experimental groups resulted in a higher abundance of Firmicutes/Bacteroidetes.Conclusion: This study provides evidence that C. militaris can be used as a food supplement to relieve T2DM, which provides a promising prospect for new functional food in it.
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Affiliation(s)
- Xinyuan Liu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, SD, China
| | - Mengqian Dun
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, SD, China
| | - Tongtong Jian
- Shandong University of Traditional Chinese Medicine, Jinan, SD, China
| | - Yuqing Sun
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, SD, China
| | - Mingyu Wang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, SD, China
- *Correspondence: Jianya Ling, ; Guoying Zhang, ; Mingyu Wang,
| | - Guoying Zhang
- Shandong University of Traditional Chinese Medicine, Jinan, SD, China
- *Correspondence: Jianya Ling, ; Guoying Zhang, ; Mingyu Wang,
| | - Jianya Ling
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, SD, China
- *Correspondence: Jianya Ling, ; Guoying Zhang, ; Mingyu Wang,
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6
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Peroxisome Proliferator-Activated Receptor-Targeted Therapies: Challenges upon Infectious Diseases. Cells 2023; 12:cells12040650. [PMID: 36831317 PMCID: PMC9954612 DOI: 10.3390/cells12040650] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/13/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) α, β, and γ are nuclear receptors that orchestrate the transcriptional regulation of genes involved in a variety of biological responses, such as energy metabolism and homeostasis, regulation of inflammation, cellular development, and differentiation. The many roles played by the PPAR signaling pathways indicate that PPARs may be useful targets for various human diseases, including metabolic and inflammatory conditions and tumors. Accumulating evidence suggests that each PPAR plays prominent but different roles in viral, bacterial, and parasitic infectious disease development. In this review, we discuss recent PPAR research works that are focused on how PPARs control various infections and immune responses. In addition, we describe the current and potential therapeutic uses of PPAR agonists/antagonists in the context of infectious diseases. A more comprehensive understanding of the roles played by PPARs in terms of host-pathogen interactions will yield potential adjunctive personalized therapies employing PPAR-modulating agents.
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7
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Karmakar E, Das N, Mukherjee B, Das P, Mukhopadhyay S, Roy SS. Lipid-induced alteration in retinoic acid signaling leads to mitochondrial dysfunction in HepG2 and Huh7 cells. Biochem Cell Biol 2023. [PMID: 36787544 DOI: 10.1139/bcb-2022-0266] [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: 02/16/2023] Open
Abstract
A surfeit of mitochondrial reactive oxygen species (ROS) and inflammation serve as obligatory mediators of lipid-associated hepatocellular maladies. While retinoid homeostasis is essential in restoring systemic energy balance, its role in hepatic mitochondrial function remains elusive. The role of lecithin-retinol acyltransferase (LRAT) in maintenance of retinoid homeostasis is appreciated earlier; however, its role in modulating retinoic acid (RA) bioavailability upon lipid-imposition is unexplored. We identified LRAT overexpression in high-fat diet (HFD)-fed rats and palmitate-treated hepatoma cells. Elevation in LRAT expression depletes RA production and deregulates RA signaling. This altered RA metabolism enhances fat accumulation, accompanied by inflammation that leads to impaired mitochondrial function through enhanced ROS generation. Hence, LRAT inhibition could be a novel approach preventing lipid-induced mitochondrial dysfunction in hepatoma cells.
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Affiliation(s)
- Eshani Karmakar
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata, 700032, India
| | - Nabanita Das
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata, 700032, India.,Department of Pharmacology and Toxicology, National Institute of Pharmaceutical Education and Research, Raebareli, Bijnor-sisendi Road, Lucknow, Uttar Pradesh, 226002, India
| | - Bidisha Mukherjee
- Department of Endocrinology and Metabolism, Institute of Post Graduate Medical Education and Research, 244, A.J.C. Bose Road, Kolkata, 700020, India
| | - Prosenjit Das
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata, 700032, India
| | - Satinath Mukhopadhyay
- Department of Endocrinology and Metabolism, Institute of Post Graduate Medical Education and Research, 244, A.J.C. Bose Road, Kolkata, 700020, India
| | - Sib Sankar Roy
- Cell Biology and Physiology Division, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Kolkata, 700032, India.,Academy of Scientific & Innovative Research (AcSIR), India
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8
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Kim J, Ko H, Hur JS, An S, Lee JW, Deyrup ST, Noh M, Shim SH. Discovery of Pan-peroxisome Proliferator-Activated Receptor Modulators from an Endolichenic Fungus, Daldinia childiae. JOURNAL OF NATURAL PRODUCTS 2022; 85:2804-2816. [PMID: 36475432 DOI: 10.1021/acs.jnatprod.2c00791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Adiponectin-synthesis-promoting compounds possess therapeutic potential to treat diverse metabolic diseases, including obesity and diabetes. Phenotypic screening to find adiponectin-synthesis-promoting compounds was performed using the adipogenesis model of human bone marrow mesenchymal stem cells. The extract of the endolichenic fungus Daldinia childiae 047215 significantly promoted adiponectin production. Bioactivity-guided isolation led to 13 active polyketides (1-13), which include naphthol monomers, dimers, and trimers. To the best of our knowledge, trimers of naphthol (1-4) have not been previously isolated as either natural or synthetic products. The novel naphthol trimer 3,1',3',3″-ternaphthalene-5,5',5″-trimethoxy-4,4',4″-triol (2) and a dimer, nodulisporin A (12), exhibited concentration-dependent adiponectin-synthesis-promoting activity (EC50 30.8 and 15.2 μM, respectively). Compounds 2 and 12 bound to all three peroxisome proliferator-activated receptor (PPAR) subtypes, PPARα, PPARγ, and PPARδ. In addition, compound 2 transactivated retinoid X receptor α, whereas 12 did not. Naphthol oligomers 2 and 12 represent novel pan-PPAR modulators and are potential pharmacophores for designing new therapeutic agents against hypoadiponectinemia-associated metabolic diseases.
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Affiliation(s)
- Jaekyeong Kim
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyejin Ko
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Jae-Seoun Hur
- Korean Lichen Research Institute, Sunchon National University, Suncheon 57922, Republic of Korea
| | - Seungchan An
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Jin Woo Lee
- College of Pharmacy, Duksung Women's University, Seoul 01369, Republic of Korea
| | - Stephen T Deyrup
- Department of Chemistry and Biochemistry, Siena College, Londonville, New York 12211, United States
| | - Minsoo Noh
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Sang Hee Shim
- Natural Products Research Institute, College of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
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9
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Petunina NA, Goncharova EV, Kuzina IA, Nedosugova LV, Martirosyan NS, Теlnova MЕ. The role of pioglitazone in the fight against insulin resistance, atherosclerosis, cardiovascular disease, and non-alcoholic fatty liver disease. DIABETES MELLITUS 2022. [DOI: 10.14341/dm12859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Modern strategies for the treatment of type 2 diabetes mellitus involve the use of pathogenetically based approaches aimed at achieving optimal glycemic control and its long-term retention. Timely and rational use of 9 classes of hypoglycemic drugs, including as part of combination therapy, makes it possible to achieve significant success in diabetes therapy. One of the fundamental principles in the treatment of type 2 diabetes mellitus is the effect on insulin resistance. For this purpose, two groups of drugs are used: biguanides and thiazolidinediones (glitazones). The action of glitazones is directly related to an increase in the sensitivity of insulin-dependent tissues to insulin and a pronounced decrease in hyperinsulinemia in patients with type 2 diabetes. Of particular interest are the pathways of insulin signal transduction, the mechanisms of insulin resistance, and the possibilities of pathogenetic therapy with thiazolidinediones. Pioglitazone is currently the only available member of the thiazolidinedione class in the world, allowing to expand the management of diabetes mellitus by reducing insulin resistance in muscle and adipose tissue and glucose production by the liver. Its use can have a number of pleiotropic effects, including on cardiovascular diseases and non-alcoholic fatty liver disease, which expands the priorities for choosing hypoglycemic therapy in patients with type 2 diabetes at various stages of therapy.
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Affiliation(s)
- N. A. Petunina
- I.M. Sechenov First Moscow State Medical University (Sechenov University)
| | - E. V. Goncharova
- I.M. Sechenov First Moscow State Medical University (Sechenov University)
| | - I. A. Kuzina
- I.M. Sechenov First Moscow State Medical University (Sechenov University)
| | - L. V. Nedosugova
- I.M. Sechenov First Moscow State Medical University (Sechenov University)
| | - N. S. Martirosyan
- I.M. Sechenov First Moscow State Medical University (Sechenov University)
| | - M. Е. Теlnova
- I.M. Sechenov First Moscow State Medical University (Sechenov University)
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10
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The Potential Role of PPARs in the Fetal Origins of Adult Disease. Cells 2022; 11:cells11213474. [PMID: 36359869 PMCID: PMC9653757 DOI: 10.3390/cells11213474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Revised: 10/19/2022] [Accepted: 10/27/2022] [Indexed: 11/06/2022] Open
Abstract
The fetal origins of adult disease (FOAD) hypothesis holds that events during early development have a profound impact on one’s risk for the development of future adult disease. Studies from humans and animals have demonstrated that many diseases can begin in childhood and are caused by a variety of early life traumas, including maternal malnutrition, maternal disease conditions, lifestyle changes, exposure to toxins/chemicals, improper medication during pregnancy, and so on. Recently, the roles of Peroxisome proliferator-activated receptors (PPARs) in FOAD have been increasingly appreciated due to their wide variety of biological actions. PPARs are members of the nuclear hormone receptor subfamily, consisting of three distinct subtypes: PPARα, β/δ, and γ, highly expressed in the reproductive tissues. By controlling the maturation of the oocyte, ovulation, implantation of the embryo, development of the placenta, and male fertility, the PPARs play a crucial role in the transition from embryo to fetus in developing mammals. Exposure to adverse events in early life exerts a profound influence on the methylation pattern of PPARs in offspring organs, which can affect development and health throughout the life course, and even across generations. In this review, we summarize the latest research on PPARs in the area of FOAD, highlight the important role of PPARs in FOAD, and provide a potential strategy for early prevention of FOAD.
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11
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The Role of Transcription Factor PPAR-γ in the Pathogenesis of Psoriasis, Skin Cells, and Immune Cells. Int J Mol Sci 2022; 23:ijms23179708. [PMID: 36077103 PMCID: PMC9456565 DOI: 10.3390/ijms23179708] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 11/22/2022] Open
Abstract
The peroxisome proliferator-activated receptor PPAR-γ is one of three PPAR nuclear receptors that act as ligand-activated transcription factors. In immune cells, the skin, and other organs, PPAR-γ regulates lipid, glucose, and amino acid metabolism. The receptor translates nutritional, pharmacological, and metabolic stimuli into the changes in gene expression. The activation of PPAR-γ promotes cell differentiation, reduces the proliferation rate, and modulates the immune response. In the skin, PPARs also contribute to the functioning of the skin barrier. Since we know that the route from identification to the registration of drugs is long and expensive, PPAR-γ agonists already approved for other diseases may also represent a high interest for psoriasis. In this review, we discuss the role of PPAR-γ in the activation, differentiation, and proliferation of skin and immune cells affected by psoriasis and in contributing to the pathogenesis of the disease. We also evaluate whether the agonists of PPAR-γ may become one of the therapeutic options to suppress the inflammatory response in lesional psoriatic skin and decrease the influence of comorbidities associated with psoriasis.
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12
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Kim SW, Alci K, Van Gaever F, Driege Y, Bicalho K, Goeminne G, Libert C, Goossens A, Beyaert R, Staal J. Engineering a highly sensitive biosensor for abscisic acid in mammalian cells. FEBS Lett 2022; 596:2576-2590. [PMID: 35727199 DOI: 10.1002/1873-3468.14431] [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: 01/03/2022] [Revised: 05/21/2022] [Accepted: 05/24/2022] [Indexed: 11/10/2022]
Abstract
Abscisic acid (ABA) is a signaling molecule conserved in plants, bacteria, fungi and animals. Recently, ABA has gained attention for its pharmacological activities and its potential as a biomarker for the severity of chronic obstructive pulmonary disease (COPD) and glioma. This prompts the development of a reliable, sensitive, rapid, and cost-effective method to quantify ABA levels in mammalian cells and tissues. The previously described ABA biosensor system based on the ABA-dependent interaction between the plant ABA receptor PYL1 and co-receptor ABI1 is not sensitive enough for the low ABA levels seen in mammals. Therefore, we optimized this system by replacing PYL1 with other high-affinity plant PYL proteins. The optimized biosensor system engineered with the PYL8 receptor enabled the quantification of ABA at low concentrations in HEK293T cells.
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Affiliation(s)
- Seo Woo Kim
- Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Center for Plant Systems Biology, VIB, Ghent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
| | - Kübra Alci
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,BCCM/GeneCorner, Ghent University, Ghent, Belgium
| | - Femke Van Gaever
- Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Yasmine Driege
- Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | | | | | - Claude Libert
- Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Alain Goossens
- Center for Plant Systems Biology, VIB, Ghent, Belgium.,Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
| | - Rudi Beyaert
- Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Jens Staal
- Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium.,Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
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13
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Wang F, Guo L, Wu Z, Zhang T, Dong D, Wu B. The Clock gene regulates kainic acid-induced seizures through inhibiting ferroptosis in mice. J Pharm Pharmacol 2022; 74:1640-1650. [PMID: 35704277 DOI: 10.1093/jpp/rgac042] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 05/20/2022] [Indexed: 12/28/2022]
Abstract
OBJECTIVES Temporal lobe epilepsy (TLE) is a common and intractable form of epilepsy. There is a strong need to better understand molecular events underlying TLE and to find novel therapeutic agents. Here we aimed to investigate the role of Clock and ferroptosis in regulating TLE. METHODS TLE model was established by treating mice with kainic acid (KA). Regulatory effects of the Clock gene on KA-induced seizures and ferroptosis were evaluated using Clock knockout (Clock-/-) mice. mRNA and protein levels were determined by quantitative real-time PCR and western blotting, respectively. Ferroptosis was assessed by measuring the levels of iron, GSH and ROS. Transcriptional regulation was studied using a combination of luciferase reporter, mobility shift and chromatin immunoprecipitation (ChIP) assays. KEY FINDINGS We found that Clock ablation exacerbated KA-induced seizures in mice, accompanied by enhanced ferroptosis in the hippocampus. Clock ablation reduced the hippocampal expression of GPX4 and PPAR-γ, two ferroptosis-inhibitory factors, in mice and in N2a cells. Moreover, Clock regulates diurnal expression of GPX4 and PPAR-γ in mouse hippocampus and rhythmicity in KA-induced seizures. Consistent with this finding, Clock overexpression up-regulated GPX4 and PPAR-γ and protected against ferroptosis in N2a cells. In addition, luciferase reporter, mobility shift and ChIP assays showed that CLOCK trans-activated Gpx4 and Ppar-γ through direct binding to the E-box elements in the gene promoters. CONCLUSION CLOCK protects against KA-induced seizures through increased expression of GPX4 and PPAR-γ and inhibition of ferroptosis.
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Affiliation(s)
- Fei Wang
- College of Pharmacy, Jinan University, Guangzhou, China.,Institute of Molecular Rhythm and Metabolism, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Lianxia Guo
- College of Pharmacy, Jinan University, Guangzhou, China.,Institute of Molecular Rhythm and Metabolism, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhengping Wu
- School of Medicine, Yichun University, Yichun, China
| | - Tianpeng Zhang
- Institute of Molecular Rhythm and Metabolism, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Dong Dong
- School of Medicine, Jinan University, Guangzhou, China
| | - Baojian Wu
- Institute of Molecular Rhythm and Metabolism, Guangzhou University of Chinese Medicine, Guangzhou, China
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Gupta V, Hammond CL, Roztocil E, Gonzalez MO, Feldon SE, Woeller CF. Thinking inside the box: Current insights into targeting orbital tissue remodeling and inflammation in thyroid eye disease. Surv Ophthalmol 2022; 67:858-874. [PMID: 34487739 PMCID: PMC8891393 DOI: 10.1016/j.survophthal.2021.08.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 08/24/2021] [Accepted: 08/30/2021] [Indexed: 12/21/2022]
Abstract
Thyroid eye disease (TED) is an autoimmune disorder that manifests in the orbit. In TED, the connective tissue behind the eye becomes inflamed and remodels with increased fat accumulation and/or increased muscle and scar tissue. As orbital tissue expands, patients develop edema, exophthalmos, diplopia, and optic neuropathy. In severe cases vision loss may occur secondary to corneal scarring from exposure or optic nerve compression. Currently there is no cure for TED, and treatments are limited. A major breakthrough in TED therapy occurred with the FDA approval of teprotumumab, a monoclonal insulin-like growth factor 1 receptor (IGF1R) blocking antibody. Yet, teprotumumab therapy has limitations, including cost, infusion method of drug delivery, variable response, and relapse. We describe approaches to target orbital fibroblasts and the complex pathophysiology that underlies tissue remodeling and inflammation driving TED. Further advances in the elucidation of the mechanisms of TED may lead to prophylaxis based upon early biomarkers as well as lead to more convenient, less expensive therapies.
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Affiliation(s)
- Vardaan Gupta
- Flaum Eye Institute, University of Rochester, 210 Crittenden Boulevard, Rochester, New York 14642, USA
| | - Christine L Hammond
- Flaum Eye Institute, University of Rochester, 210 Crittenden Boulevard, Rochester, New York 14642, USA
| | - Elisa Roztocil
- Flaum Eye Institute, University of Rochester, 210 Crittenden Boulevard, Rochester, New York 14642, USA
| | - Mithra O Gonzalez
- Flaum Eye Institute, University of Rochester, 210 Crittenden Boulevard, Rochester, New York 14642, USA
| | - Steven E Feldon
- Flaum Eye Institute, University of Rochester, 210 Crittenden Boulevard, Rochester, New York 14642, USA
| | - Collynn F Woeller
- Flaum Eye Institute, University of Rochester, 210 Crittenden Boulevard, Rochester, New York 14642, USA.
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15
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Wang B, Chen D, Jiang R, Ntim M, Lu J, Xia M, Yang X, Wang Y, Kundu S, Guan R, Li S. TIP60 buffers acute stress response and depressive behaviour by controlling PPARγ-mediated transcription. Brain Behav Immun 2022; 101:410-422. [PMID: 35114329 DOI: 10.1016/j.bbi.2022.01.022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/29/2021] [Accepted: 01/25/2022] [Indexed: 12/23/2022] Open
Abstract
Tat-interacting protein 60 (TIP60) as nuclear receptors (NRs) coregulator, acts as a tumor suppressor and also has promising therapeutic potential to target Alzheimer's disease. Stress has been implicated in many psychiatric disorders, and these disorders are characterized by impairments in cognitive function. Until now, there are no experimental data available on the regulatory effect of TIP60 in acute stress and depression. There is also no definitive explanation on which specific modulation of target gene expression is achieved by TIP60. Here, we identify TIP60 as a novel positive regulator in response to acute restraint stress (ARS) and a potentially effective target of antidepressants. Firstly, we discovered increased hippocampal TIP60 expressions in the ARS model. Furthermore, using the TIP60 inhibitor, MG149, we proved that TIP60 function correlates with behavioral and synaptic activation in the two-hour ARS. Secondly, the lentivirus vector (LV)-TIP60overexpression (OE) was injected into the hippocampus prior to the chronic restraint stress (CRS) experiments and it was found that over-expressed TIP60 compensates for TIP60 decrease and improves depression index in CRS. Thirdly, through the intervention of TIP60 expression in vitro, we established the genetic regulation of TIP60 on synaptic proteins, confirmed the TIP60 function as a specific coactivator for PPARγ and found that the PPARγ-mediated TIP60 function modulates transcriptional activation of synaptic proteins. Finally, the LV-TIP60OE and PPARγ antagonist, GW9662, were both administered in the CRS model and the data indicated that blocking PPARγ significantly weakened the protective effect of TIP60 against the CRS-induced depression. Conclusively, these findings together support TIP60 as a novel positive factor in response to acute stress and interacts with PPARγ to modulate the pathological mechanism of CRS-induced depression.
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Affiliation(s)
- Bin Wang
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, Liaoning, China
| | - Defang Chen
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, Liaoning, China
| | - Rong Jiang
- Department of Physiology, Binzhou Medical University, Yantai Campus, 346 Guanhai Road, Laishan District, Yantai, Shandong, China
| | - Michael Ntim
- Department of Physiology, School of Medicine and Dentistry, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Jincheng Lu
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, Liaoning, China
| | - Min Xia
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, Liaoning, China
| | - XueWei Yang
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, Liaoning, China
| | - Ying Wang
- Department of Cardiology, Institute of Heart and Vessel Diseases of Dalian Medical University, the Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Supratik Kundu
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, Liaoning, China
| | - Rongxiao Guan
- Department of Cardiology, Institute of Heart and Vessel Diseases of Dalian Medical University, the Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Shao Li
- Department of Physiology, College of Basic Medical Sciences, Liaoning Provincial Key Laboratory of Cerebral Diseases, National-Local Joint Engineering Research Center for Drug-Research and Development (R&D) of Neurodegenerative Diseases, Dalian Medical University, Dalian, Liaoning, China.
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16
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Hayashi Y, Nakase H. The Molecular Mechanisms of Intestinal Inflammation and Fibrosis in Crohn’s Disease. Front Physiol 2022; 13:845078. [PMID: 35222098 PMCID: PMC8874128 DOI: 10.3389/fphys.2022.845078] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 01/26/2022] [Indexed: 12/20/2022] Open
Abstract
Crohn’s disease (CD) is an inflammatory bowel disease (IBD) with repeated remissions and relapses. As the disease progresses, fibrosis and narrowing of the intestine occur, leading to severe complications such as intestinal obstruction. Endoscopic balloon dilatation, surgical stricture plasty, and bowel resection have been performed to treat intestinal stenosis. The clinical issue is that some patients with CD have a recurrence of intestinal stenosis even after the medical treatments. On the other hand, there exist no established medical therapies to prevent stenosis. With the progressive intestinal inflammation, cytokines and growth factors, including transforming growth factor (TGF-β), stimulate intestinal myofibroblasts, contributing to fibrosis of the intestine, smooth muscle hypertrophy, and mesenteric fat hypertrophy. Therefore, chronically sustained inflammation has long been considered a cause of intestinal fibrosis and stenosis. Still, even after the advent of biologics and tighter control of inflammation, intestinal fibrosis’s surgical rate has not necessarily decreased. It is essential to elucidate the mechanisms involved in intestinal fibrosis in CD from a molecular biological level to overcome clinical issues. Recently, much attention has been paid to several key molecules of intestinal fibrosis: peroxisome proliferator-activating receptor gamma (PPARγ), toll-like receptor 4 (TLR4), adherent-invasive Escherichia coli (AIEC), Th17 immune response, and plasminogen activator inhibitor 1 (PAI-1). As a major problem in the treatment of CD, the pathophysiology of patients with CD is not the same and varies depending on each patient. It is necessary to integrate these key molecules for a better understanding of the mechanism of intestinal inflammation and fibrosis.
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17
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Potential Therapeutic Effects of PPAR Ligands in Glioblastoma. Cells 2022; 11:cells11040621. [PMID: 35203272 PMCID: PMC8869892 DOI: 10.3390/cells11040621] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/03/2022] [Accepted: 02/08/2022] [Indexed: 02/04/2023] Open
Abstract
Glioblastoma (GB), also known as grade IV astrocytoma, represents the most aggressive form of brain tumor, characterized by extraordinary heterogeneity and high invasiveness and mortality. Thus, a great deal of interest is currently being directed to investigate a new therapeutic strategy and in recent years, the research has focused its attention on the evaluation of the anticancer effects of some drugs already in use for other diseases. This is the case of peroxisome proliferator-activated receptors (PPARs) ligands, which over the years have been revealed to possess anticancer properties. PPARs belong to the nuclear receptor superfamily and are divided into three main subtypes: PPAR-α, PPAR-β/δ, and PPAR-γ. These receptors, once activated by specific natural or synthetic ligands, translocate to the nucleus and dimerize with the retinoid X receptors (RXR), starting the signal transduction of numerous genes involved in many physiological processes. PPARs receptors are activated by specific ligands and participate principally in the preservation of homeostasis and in lipid and glucose metabolism. In fact, synthetic PPAR-α agonists, such as fibrates, are drugs currently in use for the clinical treatment of hypertriglyceridemia, while PPAR-γ agonists, including thiazolidinediones (TZDs), are known as insulin-sensitizing drugs. In this review, we will analyze the role of PPARs receptors in the progression of tumorigenesis and the action of PPARs agonists in promoting, or not, the induction of cell death in GB cells, highlighting the conflicting opinions present in the literature.
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18
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Frias-Soler RC, Kelsey NA, Villarín Pildaín L, Wink M, Bairlein F. Transcriptome signature changes in the liver of a migratory passerine. Genomics 2022; 114:110283. [PMID: 35143886 DOI: 10.1016/j.ygeno.2022.110283] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 12/13/2021] [Accepted: 01/31/2022] [Indexed: 12/01/2022]
Abstract
The liver plays a principal role in avian migration. Here, we characterised the liver transcriptome of a long-distance migrant, the Northern Wheatear (Oenanthe oenanthe), sampled at different migratory stages, looking for molecular processes linked with adaptations to migration. The analysis of the differentially expressed genes suggested changes in the periods of the circadian rhythm, variation in the proportion of cells in G1/S cell-cycle stages and the putative polyploidization of this cell population. This may explain the dramatic increment in the liver's metabolic capacities towards migration. Additionally, genes involved in anti-oxidative stress, detoxification and innate immune responses, lipid metabolism, inflammation and angiogenesis were regulated. Lipophagy and lipid catabolism were active at all migratory stages and increased towards the fattening and fat periods, explaining the relevance of lipolysis in controlling steatosis and maintaining liver health. Our study clears the way for future functional studies regarding long-distance avian migration.
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Affiliation(s)
- Roberto Carlos Frias-Soler
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany; Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany.
| | - Natalie A Kelsey
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany.
| | - Lilian Villarín Pildaín
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany
| | - Michael Wink
- Institute of Pharmacy and Molecular Biotechnology, Heidelberg University, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany.
| | - Franz Bairlein
- Institute of Avian Research, An der Vogelwarte 21, 26386 Wilhelmshaven, Germany; Max Planck Institute of Animal Behavior, Am Obstberg 1, 78315 Radolfzell, Germany.
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19
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Peroxisome Proliferator-Activated Receptor Gamma Pro12Ala/C161T Genotypes and Risky Haplotype Altering Risk of Breast Cancer: A Turkish Case-Control Study. Biochem Genet 2021; 59:1413-1426. [PMID: 33893920 DOI: 10.1007/s10528-021-10068-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 04/06/2021] [Indexed: 01/26/2023]
Abstract
Breast cancer (BC) has a high incidence rate among women worldwide, and the mechanisms and etiology of this disease are not yet fully understood. The peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear hormone receptor that plays important roles in energy metabolism and cellular differentiation, is also suggested to be effective in cancer development. However, the results of studies investigating the cancer association with PPARgamma are inconsistent, creating a need for further investigation of the effects of this transcription factor on BC risk. We have examined the Pro12Ala-(rs1801282) and C161T-(rs3856806) polymorphisms of the PPARgamma gene in Turkish patients with BC in this case-control study. A total of 95 women diagnosed with BC as cases and 119 controls were genotyped for PPARgamma polymorphisms by polymerase chain reaction and restriction fragment length polymorphism techniques. The ProPro genotype and T161 allele were associated with an increased risk of BC comparing with the Ala12 allele and CC161 genotype, respectively (p < 0.001). The multivariate regression analysis confirmed that the ProPro genotype (p < 0.011), T161 allele (p < 0.001), smoking (p = 0.019), and advanced age (> 60 years) (p = 0.007) are risk factors for breast cancer. We also found that the PPARgamma Pro12Ala and C161T polymorphisms were in linkage disequilibrium (D':0.511, r2:0.099). It was determined that carrying ProPro-T161 risky PPARgamma haplotype was associated with a higher risk of BC compared to protective Ala12-CC161 haplotype (p < 0.01, OR:7.797, 95% CI:3.521-17.263). We concluded that PPARgamma Pro12Ala and C161T polymorphisms are associated with increased BC risk, and ProPro-T161 risky haplotype, which is in linkage disequilibrium, increases this effect.
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20
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Wu J, Nagy LE, Liangpunsakul S, Wang L. Non-coding RNA crosstalk with nuclear receptors in liver disease. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166083. [PMID: 33497819 DOI: 10.1016/j.bbadis.2021.166083] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 12/28/2020] [Accepted: 01/16/2021] [Indexed: 02/06/2023]
Abstract
The dysregulation of nuclear receptors (NRs) underlies the pathogenesis of a variety of liver disorders. Non-coding RNAs (ncRNAs) are defined as RNA molecules transcribed from DNA but not translated into proteins. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) are two types of ncRNAs that have been extensively studied for regulating gene expression during diverse cellular processes. NRs as therapeutic targets in liver disease have been exemplified by the successful application of their pharmacological ligands in clinics. MiRNA-based reagents or drugs are emerging as flagship products in clinical trials. Advancing our understanding of the crosstalk between NRs and ncRNAs is critical to the development of diagnostic and therapeutic strategies. This review summarizes recent findings on the reciprocal regulation between NRs and ncRNAs (mainly on miRNAs and lncRNAs) and their implication in liver pathophysiology, which might be informative to the translational medicine of targeting NRs and ncRNAs in liver disease.
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Affiliation(s)
- Jianguo Wu
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America; Department of Molecular Medicine, Case Western Reserve University, Cleveland, OH, United States of America.
| | - Laura E Nagy
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America; Department of Gastroenterology and Hepatology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States of America; Department of Molecular Medicine, Case Western Reserve University, Cleveland, OH, United States of America
| | - Suthat Liangpunsakul
- Division of Gastroenterology and Hepatology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States of America; Roudebush Veterans Administration Medical Center, Indianapolis, IN, United States of America; Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN, United States of America
| | - Li Wang
- Department of Internal Medicine, Section of Digestive Diseases, Yale University, New Haven, CT, United States of America
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21
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Fadel L, Rehó B, Volkó J, Bojcsuk D, Kolostyák Z, Nagy G, Müller G, Simandi Z, Hegedüs É, Szabó G, Tóth K, Nagy L, Vámosi G. Agonist binding directs dynamic competition among nuclear receptors for heterodimerization with retinoid X receptor. J Biol Chem 2020; 295:10045-10061. [PMID: 32513869 DOI: 10.1074/jbc.ra119.011614] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 06/05/2020] [Indexed: 12/16/2022] Open
Abstract
Retinoid X receptor (RXR) plays a pivotal role as a transcriptional regulator and serves as an obligatory heterodimerization partner for at least 20 other nuclear receptors (NRs). Given a potentially limiting/sequestered pool of RXR and simultaneous expression of several RXR partners, we hypothesized that NRs compete for binding to RXR and that this competition is directed by specific agonist treatment. Here, we tested this hypothesis on three NRs: peroxisome proliferator-activated receptor gamma (PPARγ), vitamin D receptor (VDR), and retinoic acid receptor alpha (RARα). The evaluation of competition relied on a nuclear translocation assay applied in a three-color imaging model system by detecting changes in heterodimerization between RXRα and one of its partners (NR1) in the presence of another competing partner (NR2). Our results indicated dynamic competition between the NRs governed by two mechanisms. First, in the absence of agonist treatment, there is a hierarchy of affinities between RXRα and its partners in the following order: RARα > PPARγ > VDR. Second, upon agonist treatment, RXRα favors the liganded partner. We conclude that recruiting RXRα by the liganded NR not only facilitates a stimulus-specific cellular response but also might impede other NR pathways involving RXRα.
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Affiliation(s)
- Lina Fadel
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Bálint Rehó
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Julianna Volkó
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Dóra Bojcsuk
- Department of Biochemistry and Molecular Biology, Doctoral School of Molecular Cell and Immune Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Zsuzsanna Kolostyák
- Department of Biochemistry and Molecular Biology, Doctoral School of Molecular Cell and Immune Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gergely Nagy
- Department of Biochemistry and Molecular Biology, Doctoral School of Molecular Cell and Immune Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gabriele Müller
- Biophysics of Macromolecules, German Cancer Research Center, Heidelberg, Germany
| | - Zoltan Simandi
- Department of Biochemistry and Molecular Biology, Doctoral School of Molecular Cell and Immune Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Éva Hegedüs
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gábor Szabó
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Katalin Tóth
- Biophysics of Macromolecules, German Cancer Research Center, Heidelberg, Germany
| | - Laszlo Nagy
- Department of Biochemistry and Molecular Biology, Doctoral School of Molecular Cell and Immune Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary .,Johns Hopkins University School of Medicine, Department of Medicine and Biological Chemistry, Institute for Fundamental Biomedical Research, Johns Hopkins All Children's Hospital, Saint Petersburg, Florida, USA
| | - György Vámosi
- Department of Biophysics and Cell Biology, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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Yao PL, Peavey J, Malek G. Leveraging Nuclear Receptors as Targets for Pathological Ocular Vascular Diseases. Int J Mol Sci 2020; 21:ijms21082889. [PMID: 32326149 PMCID: PMC7215709 DOI: 10.3390/ijms21082889] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 04/18/2020] [Accepted: 04/19/2020] [Indexed: 02/07/2023] Open
Abstract
Vasculogenesis and angiogenesis are physiological mechanisms occurring throughout the body. Any disruption to the precise balance of blood vessel growth necessary to support healthy tissue, and the inhibition of abnormal vessel sprouting has the potential to negatively impact stages of development and/or healing. Therefore, the identification of key regulators of these vascular processes is critical to identifying therapeutic means by which to target vascular-associated compromises and complications. Nuclear receptors are a family of transcription factors that have been shown to be involved in modulating different aspects of vascular biology in many tissues systems. Most recently, the role of nuclear receptors in ocular biology and vasculopathies has garnered interest. Herein, we review studies that have used in vitro assays and in vivo models to investigate nuclear receptor-driven pathways in two ocular vascular diseases associated with blindness, wet or exudative age-related macular degeneration, and proliferative diabetic retinopathy. The potential therapeutic targeting of nuclear receptors for ocular diseases is also discussed.
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Affiliation(s)
- Pei-Li Yao
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC 27503, USA; (P.-L.Y.); (J.P.)
| | - Jeremy Peavey
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC 27503, USA; (P.-L.Y.); (J.P.)
| | - Goldis Malek
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC 27503, USA; (P.-L.Y.); (J.P.)
- Department of Pathology, Duke University School of Medicine, Durham, NC 27503, USA
- Correspondence: ; Tel.: +919-684-0820
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23
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Jang HS, Noh MR, Jung EM, Kim WY, Southekal S, Guda C, Foster KW, Oupicky D, Ferrer FA, Padanilam BJ. Proximal tubule cyclophilin D regulates fatty acid oxidation in cisplatin-induced acute kidney injury. Kidney Int 2020; 97:327-339. [PMID: 31733829 PMCID: PMC6983334 DOI: 10.1016/j.kint.2019.08.019] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 07/25/2019] [Accepted: 08/02/2019] [Indexed: 12/12/2022]
Abstract
Regardless of the etiology, acute kidney injury involves aspects of mitochondrial dysfunction and ATP depletion. Fatty acid oxidation is the preferred energy source of the kidney and is inhibited during acute kidney injury. A pivotal role for the mitochondrial matrix protein, cyclophilin D in regulating overall cell metabolism is being unraveled. We hypothesize that mitochondrial interaction of proximal tubule cyclophilin D and the transcription factor PPARα modulate fatty acid beta-oxidation in cisplatin-induced acute kidney injury. Cisplatin injury resulted in histological and functional damage in the kidney with downregulation of fatty acid oxidation genes and increase of intrarenal lipid accumulation. However, proximal tubule-specific deletion of cyclophilin D protected the kidneys from the aforementioned effects. Mitochondrial translocation of PPARα, its binding to cyclophilin D, and sequestration led to inhibition of its nuclear translocation and transcription of PPARα-regulated fatty acid oxidation genes during cisplatin-induced acute kidney injury. Genetic or pharmacological inhibition of cyclophilin D preserved nuclear expression and transcriptional activity of PPARα and prevented the impairment of fatty acid oxidation and intracellular lipid accumulation. Docking analysis identified potential binding sites between PPARα and cyclophilin D. Thus, our results indicate that proximal tubule cyclophilin D elicits impaired mitochondrial fatty acid oxidation via mitochondrial interaction between cyclophilin D and PPARα. Hence, targeting their interaction may be a potential therapeutic strategy to prevent energy depletion, lipotoxicity and cell death in cisplatin-induced acute kidney injury.
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Affiliation(s)
- Hee-Seong Jang
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska, USA.
| | - Mi Ra Noh
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Eui-Man Jung
- Laboratory of Veterinary Biochemistry and Molecular Biology, College of Veterinary Medicine, Chungbuk National University, Cheongju, Chungbuk, Republic of Korea
| | - Woo-Yang Kim
- Department of Biological Sciences, Kent State University, Kent, Ohio, USA
| | - Siddesh Southekal
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Chittibabu Guda
- Department of Genetics, Cell Biology, and Anatomy, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Kirk W Foster
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - David Oupicky
- Center for Drug Delivery and Nanomedicine, Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Fernando A Ferrer
- Department of Surgery, Children's Hospital and Medical Center, Omaha, Nebraska, USA; Department of Pediatrics, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Babu J Padanilam
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska, USA; Department of Internal Medicine, Section of Nephrology, University of Nebraska Medical Center, Omaha, Nebraska, USA.
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Childebayeva A, Harman T, Weinstein J, Goodrich JM, Dolinoy DC, Day TA, Bigham AW, Brutsaert TD. DNA Methylation Changes Are Associated With an Incremental Ascent to High Altitude. Front Genet 2019; 10:1062. [PMID: 31737045 PMCID: PMC6828981 DOI: 10.3389/fgene.2019.01062] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 10/03/2019] [Indexed: 12/15/2022] Open
Abstract
Genetic and nongenetic factors are involved in the individual ability to physiologically acclimatize to high-altitude hypoxia through processes that include increased heart rate and ventilation. High-altitude acclimatization is thought to have a genetic component, yet it is unclear if other factors, such as epigenetic gene regulation, are involved in acclimatization to high-altitude hypoxia in nonacclimatized individuals. We collected saliva samples from a group of healthy adults of European ancestry (n = 21) in Kathmandu (1,400 m; baseline) and three altitudes during a trek to the Everest Base Camp: Namche (3,440 m; day 3), Pheriche (4,240 m; day 7), and Gorak Shep (5,160 m; day 10). We used quantitative bisulfite pyrosequencing to determine changes in DNA methylation, a well-studied epigenetic marker, in LINE-1, EPAS1, EPO, PPARa, and RXRa. We found significantly lower DNA methylation between baseline (1,400 m) and high altitudes in LINE-1, EPO (at 4,240 m only), and RXRa. We found increased methylation in EPAS1 (at 4,240 m only) and PPARa. We also found positive associations between EPO methylation and systolic blood pressure and RXRa methylation and hemoglobin. Our results show that incremental exposure to hypoxia can affect the epigenome. Changes to the epigenome, in turn, could underlie the process of altitude acclimatization.
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Affiliation(s)
- Ainash Childebayeva
- Department of Anthropology, University of Michigan, Ann Arbor, MI, United States.,Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, United States.,Department of Archaeogenetics, Max Planck Institute for the Science of Human History, Jena, Germany
| | - Taylor Harman
- Department of Exercise Science, Syracuse University, Syracuse, NY, United States
| | - Julien Weinstein
- Department of Anthropology, University of Michigan, Ann Arbor, MI, United States
| | - Jaclyn M Goodrich
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, United States
| | - Dana C Dolinoy
- Department of Environmental Health Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, United States.,Department of Nutritional Sciences, School of Public Health, University of Michigan, Ann Arbor, MI, United States
| | - Trevor A Day
- Department of Biology, Faculty of Science and Technology, Mount Royal University, Calgary, AB, Canada
| | - Abigail W Bigham
- Department of Anthropology, University of Michigan, Ann Arbor, MI, United States.,Department of Anthropology, University of California, Los Angeles, CA, United States
| | - Tom D Brutsaert
- Department of Exercise Science, Syracuse University, Syracuse, NY, United States
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25
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Cheng HS, Tan WR, Low ZS, Marvalim C, Lee JYH, Tan NS. Exploration and Development of PPAR Modulators in Health and Disease: An Update of Clinical Evidence. Int J Mol Sci 2019; 20:E5055. [PMID: 31614690 PMCID: PMC6834327 DOI: 10.3390/ijms20205055] [Citation(s) in RCA: 130] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/10/2019] [Accepted: 10/10/2019] [Indexed: 12/20/2022] Open
Abstract
Peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that govern the expression of genes responsible for energy metabolism, cellular development, and differentiation. Their crucial biological roles dictate the significance of PPAR-targeting synthetic ligands in medical research and drug discovery. Clinical implications of PPAR agonists span across a wide range of health conditions, including metabolic diseases, chronic inflammatory diseases, infections, autoimmune diseases, neurological and psychiatric disorders, and malignancies. In this review we aim to consolidate existing clinical evidence of PPAR modulators, highlighting their clinical prospects and challenges. Findings from clinical trials revealed that different agonists of the same PPAR subtype could present different safety profiles and clinical outcomes in a disease-dependent manner. Pemafibrate, due to its high selectivity, is likely to replace other PPARα agonists for dyslipidemia and cardiovascular diseases. PPARγ agonist pioglitazone showed tremendous promises in many non-metabolic disorders like chronic kidney disease, depression, inflammation, and autoimmune diseases. The clinical niche of PPARβ/δ agonists is less well-explored. Interestingly, dual- or pan-PPAR agonists, namely chiglitazar, saroglitazar, elafibranor, and lanifibranor, are gaining momentum with their optimistic outcomes in many diseases including type 2 diabetes, dyslipidemia, non-alcoholic fatty liver disease, and primary biliary cholangitis. Notably, the preclinical and clinical development for PPAR antagonists remains unacceptably deficient. We anticipate the future design of better PPAR modulators with minimal off-target effects, high selectivity, superior bioavailability, and pharmacokinetics. This will open new possibilities for PPAR ligands in medicine.
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Affiliation(s)
- Hong Sheng Cheng
- School of Biological Sciences, Nanyang Technological University Singapore, 60 Nanyang Drive, Singapore 637551, Singapore.
| | - Wei Ren Tan
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 11 Mandalay Road, Singapore 308232, Singapore.
| | - Zun Siong Low
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 11 Mandalay Road, Singapore 308232, Singapore.
| | - Charlie Marvalim
- School of Biological Sciences, Nanyang Technological University Singapore, 60 Nanyang Drive, Singapore 637551, Singapore.
| | - Justin Yin Hao Lee
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 11 Mandalay Road, Singapore 308232, Singapore.
| | - Nguan Soon Tan
- School of Biological Sciences, Nanyang Technological University Singapore, 60 Nanyang Drive, Singapore 637551, Singapore.
- Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, 11 Mandalay Road, Singapore 308232, Singapore.
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Peroxisome proliferator-activated receptor gamma (PPARγ), a key regulatory gene of lipid metabolism in chicken. WORLD POULTRY SCI J 2019. [DOI: 10.1017/s0043933916000684] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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de Almeida NR, Conda-Sheridan M. A review of the molecular design and biological activities of RXR agonists. Med Res Rev 2019; 39:1372-1397. [PMID: 30941786 DOI: 10.1002/med.21578] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 03/09/2019] [Accepted: 03/16/2019] [Indexed: 12/13/2022]
Abstract
An attractive approach to combat disease is to target theregulation of cell function. At the heart of this task are nuclear receptors (NRs); which control functions such as gene transcription. Arguably, the key player in this regulatory machinery is the retinoid X receptor (RXR). This NR associates with a third of the NRs found in humans. Scientists have hypothesized that controlling the activity of RXR is an attractive approach to control cellular functions that modulate diseases such as cancer, diabetes, Alzheimer's disease and Parkinson's disease. In this review, we will describe the key features of the RXR, present a historic perspective of the first RXR agonists, and discuss various templates that have been reported to activate RXR with a focus on their molecular structure, biological activity, and limitations. Finally, we will present an outlook of the field and future directions and considerations to synthesize or modulate RXR agonists to make these compounds a clinical reality.
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Affiliation(s)
| | - Martin Conda-Sheridan
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska
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Castellano-Castillo D, Moreno-Indias I, Sanchez-Alcoholado L, Ramos-Molina B, Alcaide-Torres J, Morcillo S, Ocaña-Wilhelmi L, Tinahones F, Queipo-Ortuño MI, Cardona F. Altered Adipose Tissue DNA Methylation Status in Metabolic Syndrome: Relationships Between Global DNA Methylation and Specific Methylation at Adipogenic, Lipid Metabolism and Inflammatory Candidate Genes and Metabolic Variables. J Clin Med 2019; 8:jcm8010087. [PMID: 30642114 PMCID: PMC6352101 DOI: 10.3390/jcm8010087] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/09/2019] [Accepted: 01/10/2019] [Indexed: 02/07/2023] Open
Abstract
Metabolic syndrome (MetS) has been postulated to increase the risk for type 2 diabetes, cardiovascular disease and cancer. Adipose tissue (AT) plays an important role in metabolic homeostasis, and AT dysfunction has an active role in metabolic diseases. MetS is closely related to lifestyle and environmental factors. Epigenetics has emerged as an interesting landscape to evaluate the possible interconnection between AT and metabolic disease, since it can be modulated by environmental factors and metabolic status. The aim of this study was to determine whether MetS has an impact on the global DNA methylation pattern and the DNA methylation of several genes related to adipogenesis (PPARG, PPARA), lipid metabolism (RXRA, SREBF2, SREBF1, SCD, LPL, LXRb), and inflammation (LRP1 C3, LEP and TNF) in visceral adipose tissue. LPL and TNF DNA methylation values were significantly different in the control-case comparisons, with higher and lower methylation respectively in the MetS group. Negative correlations were found between global DNA methylation (measured by LINE-1 methylation levels) and the metabolic deterioration and glucose levels. There were associations among variables of MetS, BMI, and HOMA-IR with DNA methylation at several CpG positions for the studied genes. In particular, there was a strong positive association between serum triglyceride levels (TG) with PPARA and LPL methylation levels. TNF methylation was negatively associated with the metabolic worsening and could be an important factor in preventing MetS occurrence according to logistic regression analysis. Therefore, global DNA methylation and methylation at specific genes related to adipogenesis, lipid metabolism and inflammation are related to the etiology of MetS and might explain in part some of the features associated to metabolic disorders.
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Affiliation(s)
- Daniel Castellano-Castillo
- Unidad de Gestión Clínica de Endocrinología y Nutrición del Hospital Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29010 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición, CIBERobn, 28029 Madrid, Spain.
| | - Isabel Moreno-Indias
- Unidad de Gestión Clínica de Endocrinología y Nutrición del Hospital Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29010 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición, CIBERobn, 28029 Madrid, Spain.
| | - Lidia Sanchez-Alcoholado
- Unidad de Gestión Clínica de Endocrinología y Nutrición del Hospital Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29010 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición, CIBERobn, 28029 Madrid, Spain.
| | - Bruno Ramos-Molina
- Unidad de Gestión Clínica de Endocrinología y Nutrición del Hospital Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29010 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición, CIBERobn, 28029 Madrid, Spain.
| | - Juan Alcaide-Torres
- Unidad de Gestión Clínica de Endocrinología y Nutrición del Hospital Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29010 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición, CIBERobn, 28029 Madrid, Spain.
| | - Sonsoles Morcillo
- Unidad de Gestión Clínica de Endocrinología y Nutrición del Hospital Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29010 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición, CIBERobn, 28029 Madrid, Spain.
| | - Luis Ocaña-Wilhelmi
- Unidad de Cirugía Metabólica, Hospital Clínico Virgen de la Victoria, 29010 Málaga, Spain.
| | - Francisco Tinahones
- Unidad de Gestión Clínica de Endocrinología y Nutrición del Hospital Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29010 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición, CIBERobn, 28029 Madrid, Spain.
| | - María Isabel Queipo-Ortuño
- Unidad de Gestión Clínica de Endocrinología y Nutrición del Hospital Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29010 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición, CIBERobn, 28029 Madrid, Spain.
- Unidad de Gestión Clínica de Oncología Médica del Hospital Virgen de la Victoria, 29010 Málaga, Spain.
| | - Fernando Cardona
- Unidad de Gestión Clínica de Endocrinología y Nutrición del Hospital Virgen de la Victoria, Instituto de Investigación Biomédica de Málaga (IBIMA), Universidad de Málaga, 29010 Málaga, Spain.
- Centro de Investigación Biomédica en Red de Fisiopatología de la Obesidad y la Nutrición, CIBERobn, 28029 Madrid, Spain.
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Liland NS, Pittman K, Whatmore P, Torstensen BE, Sissener NH. Fucosterol Causes Small Changes in Lipid Storage and Brassicasterol Affects some Markers of Lipid Metabolism in Atlantic Salmon Hepatocytes. Lipids 2018; 53:737-747. [DOI: 10.1002/lipd.12083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 08/01/2018] [Accepted: 08/03/2018] [Indexed: 12/28/2022]
Affiliation(s)
- Nina S. Liland
- Research group Requirement and Welfare, Institute of Marine Research, Nordnes gaten 50; 5005 Bergen Norway
| | - Karin Pittman
- Department of Biology; University of Bergen, Thormøhlensgate 53B; 5020 Bergen Norway
| | - Paul Whatmore
- Research group Requirement and Welfare, Institute of Marine Research, Nordnes gaten 50; 5005 Bergen Norway
| | - Bente E. Torstensen
- Research group Requirement and Welfare, Institute of Marine Research, Nordnes gaten 50; 5005 Bergen Norway
| | - Nini H. Sissener
- Research group Requirement and Welfare, Institute of Marine Research, Nordnes gaten 50; 5005 Bergen Norway
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30
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Girish B, Swetha CH, Srilatha M, Hemalatha M, Sreenivasula Reddy P. Evidence for retinoic acid involvement in the regulation of vitellogenesis in the fresh water edible crab, Oziotelphusa senex senex. Comp Biochem Physiol A Mol Integr Physiol 2018; 222:1-6. [DOI: 10.1016/j.cbpa.2018.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 04/06/2018] [Accepted: 04/10/2018] [Indexed: 10/17/2022]
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Dziedzic B, Bewicz-Binkowska D, Zgorzynska E, Stulczewski D, Wieteska L, Kaza B, Walczewska A. DHA upregulates FADS2 expression in primary cortical astrocytes exposed to vitamin A. Physiol Res 2018; 67:663-668. [PMID: 29750879 DOI: 10.33549/physiolres.933708] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The fads2 gene encoding delta6-desaturase, the rate-limiting enzyme of the LCPUFA biosynthesis is expressed in astrocytes. Dietary fatty acids, which cross the blood-brain barrier, may regulate the transcription of lipogenic enzymes through activation of transcription factors such as peroxisome proliferator-activated receptors (PPARs). The PPARs form the transcription complex with retinoid X receptors (RXRs) that are activated by 9-cis retinoic acid, a metabolite of vitamin A (VA). The study examines whether challenge of astrocytes with VA, prior 24-h treatment with palmitic acid (PA), alpha-linolenic acid (ALA) or docosahexaenoic acid (DHA) has the effect on the FADS2 expression. RT-qPCR showed that in astrocytes not challenged with VA, PA increased fads2 gene expression and DHA decreased it. However, in VA-primed astrocytes, PA doubled the FADS2 mRNA levels, while DHA increased fads2 gene expression, oppositely to non-primed cells. Furthermore, similar changes were seen in VA-primed astrocytes with regard to delta6-desaturase protein levels following PA and DHA treatment. ALA did not have any effect on the FADS2 mRNA and protein levels in either VA-primed or non-primed astrocytes. These findings indicate that in the presence of vitamin A, DHA upregulates fads2 gene expression in astrocytes.
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Affiliation(s)
- B Dziedzic
- Department of Cell-to-Cell Communication, Medical University of Lodz, Lodz, Poland.
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32
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Dose-dependent effects of peroxisome proliferator-activated receptors β/δ agonist on systemic inflammation after haemorrhagic shock. Cytokine 2017; 103:127-132. [PMID: 28969938 DOI: 10.1016/j.cyto.2017.09.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 08/27/2017] [Accepted: 09/20/2017] [Indexed: 11/20/2022]
Abstract
INTRODUCTION PPARβ/δ agonists are known to modulate the systemic inflammatory response after sepsis. In this study, inflammation modulation effects of PPARβ/δ are investigated using the selective PPARβ/δ agonist (GW0742) in a model of haemorrhagic shock (HS)-induced sterile systemic inflammation. METHODS Blood pressure-controlled (35±5mmHg) HS was performed in C57/BL6 mice for 90min. Low-dose GW0742 (0.03mg/kg/BW) and high-dose GW0742 (0.3mg/kg/BW) were then administered at the beginning of resuscitation. Mice were sacrificed 6h after induction of HS. Plasma levels of IL-6, IL-1β, IL-10, TNFα, KC, MCP-1, and GM-CSF were determined by ELISA. Myeloperoxidase (MPO) activity in pulmonary and liver tissues was analysed with standardised MPO kits. RESULTS In mice treated with high-dose GW0742, plasma levels of IL-6, IL-1β, and MCP-1 were significantly increased compared to the control group mice. When compared to mice treated with low-dose GW0742 plasma levels of IL-6, IL-1β, GM-CSF, KC, and MCP-1 were significantly elevated in high-dose-treated mice. Low-dose GW0742 treatment was associated with a non-significant downtrend of inflammatory factors in mice with HS. No significant changes of MPO activity in lung and liver were observed between the control group and the GW0742 treatment groups. CONCLUSION This study identified dose-dependent effects of GW0742 on systemic inflammation after HS. While high-dose GW0742 substantially enhanced the systemic inflammatory response, low-dose GW0742 led to a downtrend of pro-inflammation cytokine expression. The exact mechanisms are yet unknown and need to be assessed in further studies.
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Gong X, Marisiddaiah R, Rubin LP. Inhibition of pulmonary β-carotene 15, 15'-oxygenase expression by glucocorticoid involves PPARα. PLoS One 2017; 12:e0181466. [PMID: 28732066 PMCID: PMC5521778 DOI: 10.1371/journal.pone.0181466] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 06/30/2017] [Indexed: 01/19/2023] Open
Abstract
β-carotene 15,15'-oxygenase (BCO1) catalyzes the first step in the conversion of dietary provitamin A carotenoids to vitamin A. This enzyme is expressed in a variety of developing and adult tissues, suggesting that its activity may regulate local retinoid synthesis. Vitamin A and related compounds (retinoids) are critical regulators of lung epithelial development, integrity, and injury repair. A balance between the actions of retinoids and glucocorticoids (GCs) promotes normal lung development and, in particular, alveolarization. Alterations in this balance, including vitamin A deficiency and GC excess, contribute to the development of chronic lung disorders. Consequently, we investigated if GCs counteract retinoid effects in alveolar epithelial cells by mechanisms involving BCO1-dependent local vitamin A metabolism. We demonstrate that BCO1 is expressed in human fetal lung tissue and human alveolar epithelial-like A549 cells. Our results indicate A549 cells metabolize β-carotene to retinal and retinoic acid (RA). GCs exposure using dexamethasone (DEX) decreases BCO1 mRNA and protein levels in A549 cells and reduces BCO1 promoter activity via inhibiting peroxisome proliferator-activated receptor γ (PPARγ) DNA binding. DEX also induces expression of PPARα, which in turn most likely causes a decrease in PPARγ/RXRα heterodimer binding to the bco1 gene promoter and consequent inhibition of bco1 gene expression. PPARα knockdown with siRNA abolishes DEX-induced suppression of BCO1 expression, confirming the requirement for PPARα in this DEX-mediated BCO1 mechanism. Taken together, these findings provide the first evidence that GCs regulate vitamin A (retinoid) signaling via inhibition of bco1 gene expression in a PPARα-dependent manner. These results explicate novel aspects of local GC:retinoid interactions that may contribute to alveolar tissue remodeling in chronic lung diseases that affect children and, possibly, adults.
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Affiliation(s)
- Xiaoming Gong
- Department of Pediatrics, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
- * E-mail: (XG); (LPR)
| | - Raju Marisiddaiah
- All Children’s Research Institute, St. Petersburg, Florida, United States of America
| | - Lewis P. Rubin
- Department of Pediatrics, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
- Department of Biomedical Sciences, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, Texas, United States of America
- * E-mail: (XG); (LPR)
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Bakiri L, Hamacher R, Graña O, Guío-Carrión A, Campos-Olivas R, Martinez L, Dienes HP, Thomsen MK, Hasenfuss SC, Wagner EF. Liver carcinogenesis by FOS-dependent inflammation and cholesterol dysregulation. J Exp Med 2017; 214:1387-1409. [PMID: 28356389 PMCID: PMC5413325 DOI: 10.1084/jem.20160935] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 12/12/2016] [Accepted: 02/07/2017] [Indexed: 12/14/2022] Open
Abstract
Hepatocellular cancers arise in a background of liver damage and inflammation. Bakiri et al. describe the function of the transcription factor c-Fos/AP-1 using mouse models and human data. c-Fos affects cholesterol and bile acid metabolism and induces DNA damage and inflammation, thus promoting liver cancer. Human hepatocellular carcinomas (HCCs), which arise on a background of chronic liver damage and inflammation, express c-Fos, a component of the AP-1 transcription factor. Using mouse models, we show that hepatocyte-specific deletion of c-Fos protects against diethylnitrosamine (DEN)-induced HCCs, whereas liver-specific c-Fos expression leads to reversible premalignant hepatocyte transformation and enhanced DEN-carcinogenesis. c-Fos–expressing livers display necrotic foci, immune cell infiltration, and altered hepatocyte morphology. Furthermore, increased proliferation, dedifferentiation, activation of the DNA damage response, and gene signatures of aggressive HCCs are observed. Mechanistically, c-Fos decreases expression and activity of the nuclear receptor LXRα, leading to increased hepatic cholesterol and accumulation of toxic oxysterols and bile acids. The phenotypic consequences of c-Fos expression are partially ameliorated by the anti-inflammatory drug sulindac and largely prevented by statin treatment. An inverse correlation between c-FOS and the LXRα pathway was also observed in human HCC cell lines and datasets. These findings provide a novel link between chronic inflammation and metabolic pathways important in liver cancer.
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Affiliation(s)
- Latifa Bakiri
- Genes, Development and Disease Group, Cancer Cell Biology Programme, Spanish National Cancer Research Centre (CNIO), E-28029 Madrid, Spain
| | - Rainer Hamacher
- Genes, Development and Disease Group, Cancer Cell Biology Programme, Spanish National Cancer Research Centre (CNIO), E-28029 Madrid, Spain
| | - Osvaldo Graña
- Bioinformatics Unit, Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), E-28029 Madrid, Spain
| | - Ana Guío-Carrión
- Genes, Development and Disease Group, Cancer Cell Biology Programme, Spanish National Cancer Research Centre (CNIO), E-28029 Madrid, Spain
| | - Ramón Campos-Olivas
- Spectroscopy and Nuclear Magnetic Resonance Spectroscopy Unit, Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), E-28029 Madrid, Spain
| | - Lola Martinez
- Flow Cytometry Core Unit, Biotechnology Programme, Spanish National Cancer Research Centre (CNIO), E-28029 Madrid, Spain
| | - Hans P Dienes
- Institute of Pathology, Medical University of Vienna, 1090 Vienna, Austria
| | - Martin K Thomsen
- Department of Clinical Biomedicine, Aarhus University, DK-8000 Aarhus, Denmark
| | - Sebastian C Hasenfuss
- Genes, Development and Disease Group, Cancer Cell Biology Programme, Spanish National Cancer Research Centre (CNIO), E-28029 Madrid, Spain
| | - Erwin F Wagner
- Genes, Development and Disease Group, Cancer Cell Biology Programme, Spanish National Cancer Research Centre (CNIO), E-28029 Madrid, Spain
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Certo M, Endo Y, Ohta K, Sakurada S, Bagetta G, Amantea D. Activation of RXR/PPARγ underlies neuroprotection by bexarotene in ischemic stroke. Pharmacol Res 2015; 102:298-307. [PMID: 26546745 DOI: 10.1016/j.phrs.2015.10.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 09/14/2015] [Accepted: 10/12/2015] [Indexed: 10/22/2022]
Abstract
The identification of novel drug targets for the treatment of ischemic stroke is currently an urgent challenge. Recent experimental findings have highlighted the neuroprotective potential of immunomodulatory strategies, based on polarization of myeloid cells toward non-inflammatory, beneficial phenotypes. Given the role of retinoid X receptors (RXR) in myeloid cells differentiation and polarization, here we have explored the neuroprotective potential of the RXR agonist bexarotene in mice subjected to focal cerebral ischemia. Acute administration of bexarotene significantly reduced blood brain barrier leakage, brain infarct damage and neurological deficit produced by transient middle cerebral artery occlusion in mice, without affecting cerebral blood flow. The rexinoid exerted neuroprotection with a wide time-window, being effective when administered up to 4.5h after the insult. The amelioration of histological outcome, as well as the ability of bexarotene to revert middle cerebral artery occlusion (MCAo)-induced spleen atrophy, was antagonised by BR1211, a pan-RXR antagonist, or by the selective peroxisome proliferator-activated receptor (PPAR)γ antagonist bisphenol A diglycidyl ether (BADGE), highlighting the involvement of the RXR/PPARγ heterodimer in the beneficial effects exerted by the drug. Immunofluorescence analysis revealed that bexarotene elevates Ym1-immunopositive N2 neutrophils both in the ipsilateral hemisphere and in the spleen of mice subjected to transient middle cerebral artery occlusion, pointing to a major role for peripheral neutrophil polarization in neuroprotection. Thus, our findings suggest that the RXR agonist bexarotene exerts peripheral immunomodulatory effects under ischemic conditions to be effectively repurposed for the acute therapy of ischemic stroke.
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Affiliation(s)
- Michelangelo Certo
- Section of Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, CS, Italy
| | - Yasuyuki Endo
- Faculty of Pharmaceutical Sciences, Tohoku Pharmaceutical University, Sendai, Japan
| | - Kiminori Ohta
- Faculty of Pharmaceutical Sciences, Tohoku Pharmaceutical University, Sendai, Japan
| | - Shinobu Sakurada
- Faculty of Pharmaceutical Sciences, Tohoku Pharmaceutical University, Sendai, Japan
| | - Giacinto Bagetta
- Section of Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, CS, Italy
| | - Diana Amantea
- Section of Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, CS, Italy.
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Yao PL, Chen LP, Dobrzański TP, Phillips DA, Zhu B, Kang BH, Gonzalez FJ, Peters JM. Inhibition of testicular embryonal carcinoma cell tumorigenicity by peroxisome proliferator-activated receptor-β/δ- and retinoic acid receptor-dependent mechanisms. Oncotarget 2015; 6:36319-37. [PMID: 26431381 PMCID: PMC4742180 DOI: 10.18632/oncotarget.5415] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 09/15/2015] [Indexed: 01/10/2023] Open
Abstract
Peroxisome proliferator-activated receptor-β/δ (PPARβ/δ) has important physiological functions in control of cell growth, lipid and glucose homeostasis, differentiation and inflammation. To investigate the role of PPARβ/δ in cancer, stable human testicular embryonal carcinoma cell lines were developed that constitutively express PPARβ/δ. Expression of PPARβ/δ caused enhanced activation of the receptor, and this significantly decreased proliferation, migration, invasion, anchorage-independent growth, and also reduced tumor mass and volume of ectopic xenografts derived from NT2/D1 cells compared to controls. The changes observed in xenografts were associated with decreased PPARβ/δ-dependent expression of proliferating cell nuclear antigen and octamer-binding transcription factor-3/4, suggesting suppressed tumor proliferation and induction of differentiation. Inhibition of migration and invasion was mediated by PPARβ/δ competing with formation of the retinoic acid receptor (RAR)/retinoid X receptor (RXR) complex, resulting in attenuation of RARα-dependent matrix metalloproteinase-2 expression and activity. These results demonstrate that PPARβ/δ mediates attenuation of human testicular embryonal carcinoma cell progression through a novel RAR-dependent mechanism and suggest that activation of PPARβ/δ inhibits RAR/RXR dimerization and represents a new therapeutic strategy.
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Affiliation(s)
- Pei-Li Yao
- Department of Veterinary and Biomedical Sciences, The Center of Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Li Ping Chen
- Department of Veterinary and Biomedical Sciences, The Center of Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Tomasz P. Dobrzański
- Department of Veterinary and Biomedical Sciences, The Center of Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Dylan A. Phillips
- Department of Veterinary and Biomedical Sciences, The Center of Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Bokai Zhu
- Department of Veterinary and Biomedical Sciences, The Center of Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Boo-Hyon Kang
- Chemon Nonclinical Research Institute, Nampyeong-ro, Yangji-myeon, Cheoin-gu, Yongin-si, Gyeonggi-do, Korea
| | - Frank J. Gonzalez
- Laboratory of Metabolism, National Cancer Institute, Bethesda, Maryland, USA
| | - Jeffrey M. Peters
- Department of Veterinary and Biomedical Sciences, The Center of Molecular Toxicology and Carcinogenesis, The Pennsylvania State University, University Park, Pennsylvania, USA
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Wu Y, Wu Q, Beland FA, Ge P, Manjanatha MG, Fang JL. Differential effects of triclosan on the activation of mouse and human peroxisome proliferator-activated receptor alpha. Toxicol Lett 2014; 231:17-28. [PMID: 25193434 DOI: 10.1016/j.toxlet.2014.09.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Revised: 08/25/2014] [Accepted: 09/01/2014] [Indexed: 12/23/2022]
Abstract
Triclosan is an anti-bacterial agent used in many personal care products, household items, medical devices, and clinical settings. Liver tumors occur in mice exposed to triclosan, a response attributed to peroxisome proliferator-activated receptor alpha (PPARα) activation; however, the effects of triclosan on mouse and human PPARα have not been fully evaluated. We compared the effects of triclosan on mouse and human PPARα using PPARα reporter assays and on downstream events of PPARα activation using mouse hepatoma Hepa1c1c7 cells and human hepatoma HepG2 cells. PPARα transcriptional activity was increased by triclosan in a mouse PPARα reporter assay and decreased in a human PPARα reporter assay. Concentrations of triclosan inhibiting 50% cell growth were similar in both human and mouse hepatoma cells. Western blotting analysis showed that triclosan increased acyl-coenzyme A oxidase (ACOX1), a PPARα target, in Hepa1c1c7 cells but decreased the level in HepG2 cells. Treatment of Hepa1c1c7 cells with triclosan enhanced DNA synthesis and suppressed transforming growth factor beta-mediated apoptosis. This did not occur in HepG2 cells. These data demonstrate that triclosan had similar cytotoxicity in Hepa1c1c7 and HepG2 cells, but differential effects on the activation of PPARα, the expression of ACOX1, and downstream events including DNA synthesis and apoptosis.
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Affiliation(s)
- Yuanfeng Wu
- Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, HFT-110, Jefferson, AR 72079, USA
| | - Qiangen Wu
- Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, HFT-110, Jefferson, AR 72079, USA
| | - Frederick A Beland
- Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, HFT-110, Jefferson, AR 72079, USA
| | - Peter Ge
- Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, HFT-110, Jefferson, AR 72079, USA
| | - Mugimane G Manjanatha
- Division of Genetic and Molecular Toxicology, National Center for Toxicological Research, Food and Drug Administration, Jefferson, AR 72079, USA
| | - Jia-Long Fang
- Division of Biochemical Toxicology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, HFT-110, Jefferson, AR 72079, USA.
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Yamamoto A, Kakuta H, Sugimoto Y. Involvement of glucocorticoid receptor activation on anti-inflammatory effect induced by peroxisome proliferator-activated receptor γ agonist in mice. Int Immunopharmacol 2014; 22:204-8. [PMID: 24975659 DOI: 10.1016/j.intimp.2014.06.028] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 06/04/2014] [Accepted: 06/13/2014] [Indexed: 02/03/2023]
Abstract
Glucocorticoids are effective anti-inflammatory agents widely used for the treatment of acute and chronic inflammatory diseases. Recent in vitro studies have proposed that glucocorticoid receptor (GR) activation is involved in peroxisome proliferator-activated receptor γ (PPARγ) agonist-induced effects. In this study, to examine the involvement of the GR in PPARγ agonist- and retinoid X receptor (RXR) agonist-mediated anti-inflammatory effects in vivo, we tested the anti-inflammatory effects of dexamethasone (a GR agonist) with pioglitazone (a PPARγ agonist) or 6-[N-ethyl-N-(3-isopropoxy-4-isopropylphenyl)-amino] nicotinic acid (NEt-3IP; an RXR agonist) by using an experimental model of carrageenan-induced inflammation. We also evaluated the effects of a GR antagonist on PPARγ agonist- or RXR agonist-induced anti-inflammatory effects. Results showed that the GR antagonist RU486 reduced the anti-inflammatory effects of GR or PPARγ agonists but not those of the RXR agonist. In addition, combinations of GR and PPARγ agonists or GR and RXR agonists had no effect on carrageenan-induced paw edema. Moreover, the PPARγ antagonist GW9662 and RXR antagonist 6-[N-4-(trifluoromethyl)-benzenesulfonyl-N-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-2-naphthyl)-amino] nicotinic acid (NS-4TF) had no effect on the anti-inflammatory effect of the GR agonist dexamethasone. Therefore, it is suggested that GR activation in vivo does not play a direct role in PPARγ/RXR heterodimer signaling. In contrast, pioglitazone showed a partial anti-inflammatory effect via GR activation. These data provide evidence for the pro-inflammatory activity of pioglitazone.
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Affiliation(s)
- Atsuki Yamamoto
- Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka 1-1-1, Kita-ku, Okayama 700-8530, Japan
| | - Hiroki Kakuta
- Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka 1-1-1, Kita-ku, Okayama 700-8530, Japan
| | - Yukio Sugimoto
- Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Tsushima-naka 1-1-1, Kita-ku, Okayama 700-8530, Japan.
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Kozakov D, Li K, Hall DR, Beglov D, Zheng J, Vakili P, Schueler-Furman O, Paschalidis IC, Clore GM, Vajda S. Encounter complexes and dimensionality reduction in protein-protein association. eLife 2014; 3:e01370. [PMID: 24714491 PMCID: PMC3978769 DOI: 10.7554/elife.01370] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
An outstanding challenge has been to understand the mechanism whereby proteins associate. We report here the results of exhaustively sampling the conformational space in protein–protein association using a physics-based energy function. The agreement between experimental intermolecular paramagnetic relaxation enhancement (PRE) data and the PRE profiles calculated from the docked structures shows that the method captures both specific and non-specific encounter complexes. To explore the energy landscape in the vicinity of the native structure, the nonlinear manifold describing the relative orientation of two solid bodies is projected onto a Euclidean space in which the shape of low energy regions is studied by principal component analysis. Results show that the energy surface is canyon-like, with a smooth funnel within a two dimensional subspace capturing over 75% of the total motion. Thus, proteins tend to associate along preferred pathways, similar to sliding of a protein along DNA in the process of protein-DNA recognition. DOI:http://dx.doi.org/10.7554/eLife.01370.001 Proteins rarely act alone. Instead, they tend to bind to other proteins to form structures known as complexes. When two proteins come together to form a complex, they twist and turn through a series of intermediate states before they form the actual complex. These intermediate states are difficult to study because they don’t last for very long, which means that our knowledge of how complexes are formed remains incomplete. One promising approach for studying the formation of complexes is called paramagnetic relaxation enhancement. In this technique certain areas in one of the proteins are labelled with magnetic particles, which produce signals when the two proteins are close to each other. Repeating the measurement several times with the magnetic particles in different positions provides information about the overall structure of the complex. Computational modelling can then be used to work out the fine details of the structure, including the shapes of the intermediate structures made by the proteins as they interact. A computer method called docking can be used to predict the most favourable positions that the proteins can take, relative to one another, in a complex. This involves calculating the energy contained in the system, with the correct structure having the lowest energy. Docking methods also predict protein models with slightly higher energies, but with structures that are radically different. Modellers usually ignore these structures, but comparing the docking results to paramagnetic relaxation enhancement data, Kozakov et al. found that these structures actually represent the intermediate states. Analysing the structure of the intermediate states revealed that the movement of the two proteins relative to one another is severely restricted as they form the final complex. Kozakov et al. found that proteins associate along preferred pathways, similar to the way a protein slides along DNA in the process of protein-DNA recognition. Knowing that the movement of the proteins is restricted in this way will enable researchers to improve the efficiency of docking calculations. DOI:http://dx.doi.org/10.7554/eLife.01370.002
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Affiliation(s)
- Dima Kozakov
- Department of Biomedical Engineering, Boston University, Boston, United States
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Abstract
Retinoid X Receptors (RXR) were initially identified as nuclear receptors binding with stereo-selectivity the vitamin A derivative 9-cis retinoic acid, although the relevance of this molecule as endogenous activator of RXRs is still elusive. Importantly, within the nuclear receptor superfamily, RXRs occupy a peculiar place, as they are obligatory partners for a number of other nuclear receptors, thus integrating the corresponding signaling pathways. In this chapter, we describe the structural features allowing RXR to form homo- and heterodimers, and the functional consequences of this unique ability. Furthermore, we discuss the importance of studying RXR activity at a genome-wide level in order to comprehensively address the biological implications of their action that is fundamental to understand to what extent RXRs could be exploited as new therapeutic targets.
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Affiliation(s)
- Federica Gilardi
- Center for Integrative Genomics, University of Lausanne, Genopode Building, 1015, Lausanne, Switzerland,
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41
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Corzo C, Griffin PR. Targeting the Peroxisome Proliferator-Activated Receptor-γ to Counter the Inflammatory Milieu in Obesity. Diabetes Metab J 2013; 37:395-403. [PMID: 24404510 PMCID: PMC3881323 DOI: 10.4093/dmj.2013.37.6.395] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Adipose tissue, which was once viewed as a simple organ for storage of triglycerides, is now considered an important endocrine organ. Abnormal adipose tissue mass is associated with defects in endocrine and metabolic functions which are the underlying causes of the metabolic syndrome. Many adipokines, hormones secreted by adipose tissue, regulate cells from the immune system. Interestingly, most of these adipokines are proinflammatory mediators, which increase dramatically in the obese state and are believed to be involved in the pathogenesis of insulin resistance. Drugs that target peroxisome proliferator-activated receptor-γ have been shown to possess anti-inflammatory effects in animal models of diabetes. These findings, and the link between inflammation and the metabolic syndrome, will be reviewed here.
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Affiliation(s)
- Cesar Corzo
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL, USA
| | - Patrick R. Griffin
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL, USA
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Konstandi M, Shah YM, Matsubara T, Gonzalez FJ. Role of PPARα and HNF4α in stress-mediated alterations in lipid homeostasis. PLoS One 2013; 8:e70675. [PMID: 23967086 PMCID: PMC3743822 DOI: 10.1371/journal.pone.0070675] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 06/20/2013] [Indexed: 12/13/2022] Open
Abstract
Stress is a risk factor for several cardiovascular pathologies. PPARα holds a fundamental role in control of lipid homeostasis by directly regulating genes involved in fatty acid transport and oxidation. Importantly, PPARα agonists are effective in raising HDL-cholesterol and lowering triglycerides, properties that reduce the risk for cardiovascular diseases. This study investigated the role of stress and adrenergic receptor (AR)-related pathways in PPARα and HNF4α regulation and signaling in mice following repeated restraint stress or treatment with AR-antagonists administered prior to stress to block AR-linked pathways. Repeated restraint stress up-regulated Pparα and its target genes in the liver, including Acox, Acot1, Acot4, Cyp4a10, Cyp4a14 and Lipin2, an effect that was highly correlated with Hnf4α. In vitro studies using primary hepatocyte cultures treated with epinephrine or AR-agonists confirmed that hepatic AR/cAMP/PKA/CREB- and JNK-linked pathways are involved in PPARα and HNF4α regulation. Notably, restraint stress, independent of PPARα, suppressed plasma triglyceride levels. This stress-induced effect could be attributed in part to hormone sensitive lipase activation in the white adipose tissue, which was not prevented by the increased levels of perilipin. Overall, this study identifies a mechanistic basis for the modification of lipid homeostasis following stress and potentially indicates novel roles for PPARα and HNF4α in stress-induced lipid metabolism.
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Affiliation(s)
- Maria Konstandi
- Laboratory of Metabolism, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America.
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43
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Worsham MJ, Chen KM, Ghanem T, Stephen JK, Divine G. Epigenetic modulation of signal transduction pathways in HPV-associated HNSCC. Otolaryngol Head Neck Surg 2013; 149:409-16. [PMID: 23736812 DOI: 10.1177/0194599813490895] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Human papilloma virus (HPV) positive and HPV negative head and neck squamous cell cancer (HNSCC) are biologically distinct with a prognostic advantage for HPV positive patients compared to HPV negative cases. DNA promoter methylation is central to human diseases such as cancer, including HNSCC, with reported genome-wide hypomethylaton and promoter hypermethylation in HPV positive HNSCC tumors. The goal of this study was to identify differentially methylated genes in HPV positive versus HPV negative primary HNSCC genomes with clues to signaling networks. STUDY DESIGN Laboratory-based study. SETTING Primary care academic health care system. SUBJECTS AND METHODS DNA from 4 HPV positive and 4 HPV negative freshly frozen primary HNSCC were subject to comprehensive genome-wide methylation profiling. Differentially methylated gene lists were examined using the Signal Transduction Pathways (canonical) filter in the Genomatix Pathway System (GePS). RESULTS Twofold methylation differences were observed between HPV positive and HPV negative cases for 1168 genes. Pathway analysis applied to investigate the biological role of the 1168 differentially methylated genes revealed 8 signal transduction pathways forming a network of 66 genes, of which 62% are hypermethylated. CONCLUSION Our study reveals a predominant hypermethylation profile for genes in signal transduction pathways of HPV positive HNSCC tumor genomes. Because signaling events in the cell play a critical role in the execution of key biological functions, insights into how complex cellular signaling cascades and networks may be programmed in HNSCC are likely to be critical in the development of new biological agents designed to hit multiple targets.
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Affiliation(s)
- Maria J Worsham
- Department of Otolaryngology/Head and Neck Research, Henry Ford Hospital, Detroit, Michigan 48202, USA.
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Quantitative real-time PCR as a sensitive protein–protein interaction quantification method and a partial solution for non-accessible autoactivator and false-negative molecule analysis in the yeast two-hybrid system. Methods 2012; 58:376-84. [DOI: 10.1016/j.ymeth.2012.09.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2011] [Revised: 09/03/2012] [Accepted: 09/06/2012] [Indexed: 12/15/2022] Open
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Umemoto T, Fujiki Y. Ligand-dependent nucleo-cytoplasmic shuttling of peroxisome proliferator-activated receptors, PPARα and PPARγ. Genes Cells 2012; 17:576-96. [PMID: 22646292 DOI: 10.1111/j.1365-2443.2012.01607.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 03/26/2012] [Indexed: 11/28/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) play important roles in diverse biological processes including metabolisms of sugars and lipids and differentiation of cells such as adipocytes. PPARs are transcription factors belonging to the ligand-dependent hormone receptor group. To function as transcription factors, PPARs translocate into nucleus where they associate with transcription apparatus. However, mechanisms underlying nuclear transport of PPARs remain enigmatic. We show here that PPARα and PPARγ dynamically shuttle between nucleus and cytoplasm, although they constitutively and predominantly appear in nucleus. With a series of truncation mutants, we identify that PPAR nuclear transport is mediated by at least two nuclear localization signals (NLSs) in DNA-binding domain (DBD)-hinge and activation function 1 (AF1) regions and their respective receptors including importinα/β, importin 7, and an unidentified receptor. PPARs also harbor two nuclear export signals in DBD and ligand-binding domain regions that are recognized by distinct export receptors, calreticulin and CRM1. Moreover, we show that nuclear-cytoplasmic shuttling of PPARs is regulated by respective PPAR ligands and Ca2+ concentration. Taken together, we suggest that the multiple pathways for the nuclear-cytoplasmic transport of PPARs regulate the biological functions of PPARs in response to external signals.
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Affiliation(s)
- Tomoe Umemoto
- Department of Biology, Faculty of Sciences, Kyushu University Graduate School, 6-10-1 Hakozaki, Higashi-ku, Fukuoka, 812-8581, Japan
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Gurevich I, Zhang C, Encarnacao PC, Struzynski CP, Livings SE, Aneskievich BJ. PPARγ and NF-κB regulate the gene promoter activity of their shared repressor, TNIP1. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1819:1-15. [PMID: 22001530 PMCID: PMC3249470 DOI: 10.1016/j.bbagrm.2011.09.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Revised: 09/27/2011] [Accepted: 09/30/2011] [Indexed: 11/27/2022]
Abstract
Human TNFAIP3 interacting protein 1 (TNIP1) has diverse functions including support of HIV replication through its interaction with viral Nef and matrix proteins, reduction of TNFα-induced signaling through its interaction with NF-κB pathway proteins, and corepression of agonist-bound retinoic acid receptors and peroxisome proliferator-activated receptors (PPAR). The wide tissue distribution of TNIP1 provides the opportunity to influence numerous cellular responses in these roles and defining control of TNIP1 expression would be central to improved understanding of its impact on cell function. We cloned 6kb of the human TNIP1 promoter and performed predictive and functional analyses to identify regulatory elements. The promoter region proximal to the transcription start site is GC-rich without a recognizable TATA box. In contrast to this proximal ~500bp region, 6kb of the promoter increased reporter construct constitutive activity over five-fold. Throughout the 6kb length, in silico analysis identified several potential binding sites for both constitutive and inducible transcription factors; among the latter were candidate NF-κB binding sequences and peroxisome proliferator response elements (PPREs). We tested NF-κB and PPAR regulation of the endogenous TNIP1 gene and cloned promoter by expression studies, electrophoretic mobility shift assays, and chromatin immunoprecipitations. We validated NF-κB sites in the TNIP1 promoter proximal and distal regions as well as one PPRE in the distal region. The ultimate control of the TNIP1 promoter is likely to be a combination of constitutive transcription factors and those subject to activation such as NF-κB and PPAR.
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Affiliation(s)
- Igor Gurevich
- Graduate Program in Pharmacology & Toxicology, University of Connecticut, Storrs, CT 06269-3092; USA
| | - Carmen Zhang
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269-3092; USA
| | - Priscilla C. Encarnacao
- Graduate Program in Pharmacology & Toxicology, University of Connecticut, Storrs, CT 06269-3092; USA
| | - Charles P. Struzynski
- Doctor of Pharmacy Program, School of Pharmacy, University of Connecticut, Storrs, CT 06269-3092; USA
| | - Sarah E. Livings
- Doctor of Pharmacy Program, School of Pharmacy, University of Connecticut, Storrs, CT 06269-3092; USA
| | - Brian J. Aneskievich
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269-3092; USA
- Center for Regenerative Biology, University of Connecticut, Storrs, CT 06269-3092; USA
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Involvement of the Retinoid X Receptor Ligand in the Anti-Inflammatory Effect Induced by Peroxisome Proliferator-Activated Receptor γ Agonist In Vivo. PPAR Res 2011; 2011:840194. [PMID: 22190910 PMCID: PMC3236425 DOI: 10.1155/2011/840194] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2011] [Accepted: 09/13/2011] [Indexed: 12/18/2022] Open
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) forms a heterodimeric DNA-binding complex with retinoid X receptors (RXRs). It has been reported that the effect of the PPAR agonist is reduced in hepatocyte RXR-deficient mice. Therefore, it is suggested that the endogenous RXR ligand is involved in the PPARγ agonist-induced anti-inflammatory effect. However, the participation of the RXR ligand in the PPARγ-induced anti-inflammatory effect is unknown. Here, we investigated the influence of RXR antagonist on the anti-inflammatory effect of PPARγ agonist pioglitazone in carrageenan test. In addition, we also examined the influence of PPAR antagonist on the anti-inflammatory effect induced by RXR agonist NEt-3IP. The RXR antagonist suppressed the antiedema effect of PPARγ agonist. In addition, the anti-inflammatory effect of RXR agonist was suppressed by PPARγ antagonist. PPARγ agonist-induced anti-inflammatory effects were reversed by the RXR antagonist. Thus, we showed that the endogenous RXR ligand might contribute to the PPARγ agonist-induced anti-inflammatory effect.
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48
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Ulke-Lemée A, Turner SR, Mughal SH, Borman MA, Winkfein RJ, MacDonald JA. Mapping and functional characterization of the murine smoothelin-like 1 promoter. BMC Mol Biol 2011; 12:10. [PMID: 21352594 PMCID: PMC3050715 DOI: 10.1186/1471-2199-12-10] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2010] [Accepted: 02/27/2011] [Indexed: 11/23/2022] Open
Abstract
Background Smoothelin-like 1 (SMTNL1, also known as CHASM) plays a role in promoting relaxation as well as adaptive responses to exercise, pregnancy and sexual development in smooth and skeletal muscle. Investigations of Smtnl1 transcriptional regulation are still lacking. Thus, in this study, we identify and characterize key regulatory elements of the mouse Smtnl1 gene. Results We mapped the key regulatory elements of the Smtnl1 promoter region: the transcriptional start site (TSS) lays -44 bp from the translational start codon and a TATA-box motif at -75 bp was conserved amongst all mammalian Smtnl1 promoters investigated. The Smtnl1 proximal promoter enhances expression up to 8-fold in smooth muscle cells and a second activating region lays 500 bp further upstream. Two repressing motifs were present (-118 to -218 bp and -1637 to -1869 bp). The proximal promoter is highly conserved in mammals and contains a mirror repeat sequence. In silico analysis suggests many transcription factors (notably MyoD) could potentially bind within the Smtnl1 proximal promoter sequence. Conclusion Smtnl1 transcript was identified in all smooth muscle tissues examined to date, albeit at much lower levels than found in skeletal muscle. It is unlikely that multiple SMTNL1 isoforms exist since a single Smtnl1 transcription start site was identified in both skeletal and intestinal smooth muscle. Promoter studies suggest restrictive control of Smtnl1 expression in non-muscle cells.
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Affiliation(s)
- Annegret Ulke-Lemée
- Smooth Muscle Research Group, Department of Biochemistry & Molecular Biology, University of Calgary, Alberta, Canada
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49
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Iwamoto F, Umemoto T, Motojima K, Fujiki Y. Nuclear transport of peroxisome-proliferator activated receptor α. J Biochem 2010; 149:311-9. [PMID: 21138946 DOI: 10.1093/jb/mvq144] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Peroxisome-proliferator activated receptor α (PPARα) is a ligand-activated transcription factor, playing a key role in several essential pathways including lipid metabolism. Although nuclear localization of PPARα is essential for its transactivation activity, mechanisms underlying intracellular traffics of PPARα remain undefined. We here identify and characterize a nuclear localization signal (NLS) residing in the junction between DNA-binding domain and hinge regions of PPARα. The NLS consists of two basic-amino acid clusters locating in the sequence encompassing amino acid residues at 144-187. We evidently show by mutational analysis that the basic residues in this NLS are essential for the nuclear import. Moreover, the PPARα NLS binds well-known nuclear transporters, importin α and importin β, in a manner independent of DNA-binding activity.
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Affiliation(s)
- Fumiko Iwamoto
- Department of Biology, Faculty of Sciences, Kyushu University Graduate School, Fukuoka, Japan
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