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Sales PF, do Nascimento AL, Pinheiro FC, Alberto AKM, Teixeira dos Santos AVTDL, Carvalho HDO, de Souza GC, Carvalho JCT. Effect of the Association of Fixed Oils from Abelmoschus esculentus (L.) Moench, Euterpe oleracea Martius, Bixa orellana Linné and Chronic SM ® on Atherogenic Dyslipidemia in Wistar Rats. Molecules 2023; 28:6689. [PMID: 37764465 PMCID: PMC10534590 DOI: 10.3390/molecules28186689] [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: 07/19/2023] [Revised: 08/25/2023] [Accepted: 08/31/2023] [Indexed: 09/29/2023] Open
Abstract
Dyslipidemia presents high levels of serum cholesterol and is characterized as a risk factor for cardiovascular diseases, especially for the development of atherosclerosis. E. oleracea oil (OFEO), A. esculentus oil (OFAE), B. orellana oil (OFBO), and Chronic SM® granules (CHR) are rich in bioactive compounds with the potential to treat changes in lipid metabolism. This study investigated the effects of treatments with oils from A. esculentus, E. oleracea, B. orellana, and Chronic SM® on Cocos nucifera L. saturated-fat-induced dyslipidemia. The chromatographic profile showed the majority presence of unsaturated fatty acids in the tested oils. The quantification of tocotrienols and geranylgeraniol in OFBO and CHR was obtained. Treatments with OFEO, OFAE, OFBO, and CHR were able to significantly reduce glycemia, as well as hypertriglyceridemia, total cholesterol, and LDL-cholesterol, besides increasing HDL-cholesterol. The treatments inhibited the formation of atheromatous plaques in the vascular endothelium of the treated rats. The obtained results suggest that the OFEO, OFAE, OFBO, and CHR exhibit antidyslipidemic effects and antiatherogenic activity.
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Affiliation(s)
- Priscila Faimann Sales
- Laboratory of Drugs Research, Biology and Healthy Sciences Department, Pharmacy Faculty, Federal University of Amapá, Rod. JK, Km 02, Amapá, Macapá 68902-280, Brazil; (P.F.S.); (A.L.d.N.); (F.C.P.); (A.K.M.A.); (A.V.T.d.L.T.d.S.); (H.d.O.C.); (G.C.d.S.)
| | - Aline Lopes do Nascimento
- Laboratory of Drugs Research, Biology and Healthy Sciences Department, Pharmacy Faculty, Federal University of Amapá, Rod. JK, Km 02, Amapá, Macapá 68902-280, Brazil; (P.F.S.); (A.L.d.N.); (F.C.P.); (A.K.M.A.); (A.V.T.d.L.T.d.S.); (H.d.O.C.); (G.C.d.S.)
| | - Fernanda Cavalcante Pinheiro
- Laboratory of Drugs Research, Biology and Healthy Sciences Department, Pharmacy Faculty, Federal University of Amapá, Rod. JK, Km 02, Amapá, Macapá 68902-280, Brazil; (P.F.S.); (A.L.d.N.); (F.C.P.); (A.K.M.A.); (A.V.T.d.L.T.d.S.); (H.d.O.C.); (G.C.d.S.)
| | - Andressa Ketelem Meireles Alberto
- Laboratory of Drugs Research, Biology and Healthy Sciences Department, Pharmacy Faculty, Federal University of Amapá, Rod. JK, Km 02, Amapá, Macapá 68902-280, Brazil; (P.F.S.); (A.L.d.N.); (F.C.P.); (A.K.M.A.); (A.V.T.d.L.T.d.S.); (H.d.O.C.); (G.C.d.S.)
| | - Abrahão Victor Tavares de Lima Teixeira dos Santos
- Laboratory of Drugs Research, Biology and Healthy Sciences Department, Pharmacy Faculty, Federal University of Amapá, Rod. JK, Km 02, Amapá, Macapá 68902-280, Brazil; (P.F.S.); (A.L.d.N.); (F.C.P.); (A.K.M.A.); (A.V.T.d.L.T.d.S.); (H.d.O.C.); (G.C.d.S.)
| | - Helison de Oliveira Carvalho
- Laboratory of Drugs Research, Biology and Healthy Sciences Department, Pharmacy Faculty, Federal University of Amapá, Rod. JK, Km 02, Amapá, Macapá 68902-280, Brazil; (P.F.S.); (A.L.d.N.); (F.C.P.); (A.K.M.A.); (A.V.T.d.L.T.d.S.); (H.d.O.C.); (G.C.d.S.)
| | - Gisele Custódio de Souza
- Laboratory of Drugs Research, Biology and Healthy Sciences Department, Pharmacy Faculty, Federal University of Amapá, Rod. JK, Km 02, Amapá, Macapá 68902-280, Brazil; (P.F.S.); (A.L.d.N.); (F.C.P.); (A.K.M.A.); (A.V.T.d.L.T.d.S.); (H.d.O.C.); (G.C.d.S.)
| | - José Carlos Tavares Carvalho
- Laboratory of Drugs Research, Biology and Healthy Sciences Department, Pharmacy Faculty, Federal University of Amapá, Rod. JK, Km 02, Amapá, Macapá 68902-280, Brazil; (P.F.S.); (A.L.d.N.); (F.C.P.); (A.K.M.A.); (A.V.T.d.L.T.d.S.); (H.d.O.C.); (G.C.d.S.)
- University Hospital of Federal University of Amapá, Rodovia Josmar Chaves Pinto, Macapá 68903-419, Brazil
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2
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Bae JH, Jo A, Cho SC, Lee YI, Kam TI, You CL, Jeong HJ, Kim H, Jeong MH, Jeong Y, Ha YW, Kim YS, Kim J, Woo SH, Kim MS, Shin ES, Song SO, Kang H, Khang R, Park S, Park J, Dawson VL, Dawson TM, Park SC, Shin JH, Kang JS. Farnesol prevents aging-related muscle weakness in mice through enhanced farnesylation of Parkin-interacting substrate. Sci Transl Med 2023; 15:eabh3489. [PMID: 37647389 DOI: 10.1126/scitranslmed.abh3489] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 08/11/2023] [Indexed: 09/01/2023]
Abstract
Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α) is a master regulator of mitochondrial biogenesis. Reduced PGC-1α abundance is linked to skeletal muscle weakness in aging or pathological conditions, such as neurodegenerative diseases and diabetes; thus, elevating PGC-1α abundance might be a promising strategy to treat muscle aging. Here, we performed high-throughput screening and identified a natural compound, farnesol, as a potent inducer of PGC-1α. Farnesol administration enhanced oxidative muscle capacity and muscle strength, leading to metabolic rejuvenation in aged mice. Moreover, farnesol treatment accelerated the recovery of muscle injury associated with enhanced muscle stem cell function. The protein expression of Parkin-interacting substrate (PARIS/Zfp746), a transcriptional repressor of PGC-1α, was elevated in aged muscles, likely contributing to PGC-1α reduction. The beneficial effect of farnesol on aged muscle was mediated through enhanced PARIS farnesylation, thereby relieving PARIS-mediated PGC-1α suppression. Furthermore, short-term exercise increased PARIS farnesylation in the muscles of young and aged mice, whereas long-term exercise decreased PARIS expression in the muscles of aged mice, leading to the elevation of PGC-1α. Collectively, the current study demonstrated that the PARIS-PGC-1α pathway is linked to muscle aging and that farnesol treatment can restore muscle functionality in aged mice through increased farnesylation of PARIS.
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Affiliation(s)
- Ju-Hyeon Bae
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
| | - Areum Jo
- Department of Pharmacology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
| | - Sung Chun Cho
- Well Aging Research Center, Division of Biotechnology, DGIST, Daegu 42988, South Korea
| | - Yun-Il Lee
- Well Aging Research Center, Division of Biotechnology, DGIST, Daegu 42988, South Korea
- Department of Interdisciplinary Studies, DGIST, Daegu 42988, South Korea
| | - Tae-In Kam
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Chang-Lim You
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
| | - Hyeon-Ju Jeong
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
| | - Hyebeen Kim
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
| | - Myong-Ho Jeong
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
| | - Yideul Jeong
- Research Institute of Aging-related Diseases, AniMusCure Inc., Suwon 440-746, South Korea
| | - Young Wan Ha
- Well Aging Research Center, Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., Suwon, Gyeonggi-do 446-712, South Korea
| | - Yu Seon Kim
- Well Aging Research Center, Division of Biotechnology, DGIST, Daegu 42988, South Korea
| | - Jiwoon Kim
- Well Aging Research Center, Division of Biotechnology, DGIST, Daegu 42988, South Korea
- Department of New Biology, DGIST, Daegu 42988, South Korea
| | - Seung-Hwa Woo
- Well Aging Research Center, Division of Biotechnology, DGIST, Daegu 42988, South Korea
- Department of New Biology, DGIST, Daegu 42988, South Korea
| | - Minseok S Kim
- Department of New Biology, DGIST, Daegu 42988, South Korea
| | - Eui Seok Shin
- Well Aging Research Center, Samsung Advanced Institute of Technology, Samsung Electronics Co. Ltd., Suwon, Gyeonggi-do 446-712, South Korea
| | | | - Hojin Kang
- Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Department of Pharmacology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
| | - Rin Khang
- Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Department of Pharmacology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
| | - Soojeong Park
- Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Department of Pharmacology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
| | - Joobae Park
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
| | - Valina L Dawson
- Neuroregeneration and Stem Cell Programs, Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, LA 70130-2685, USA
- Diana Helis Henry Medical Research Foundation, New Orleans, LA 70130-2685, USA
| | - Ted M Dawson
- Department of Interdisciplinary Studies, DGIST, Daegu 42988, South Korea
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
- Adrienne Helis Malvin Medical Research Foundation, New Orleans, LA 70130-2685, USA
- Diana Helis Henry Medical Research Foundation, New Orleans, LA 70130-2685, USA
| | - Sang Chul Park
- Well Aging Research Center, Division of Biotechnology, DGIST, Daegu 42988, South Korea
- Future Life & Society Research Center, Chonnam National University, Gwangju 61469, South Korea
| | - Joo-Ho Shin
- Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Department of Pharmacology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Samsung Biomedical Research Institute, Samsung Medical Center, Seoul 06351, South Korea
| | - Jong-Sun Kang
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Single Cell Network Research Center, Sungkyunkwan University School of Medicine, Suwon 440-746, South Korea
- Research Institute of Aging-related Diseases, AniMusCure Inc., Suwon 440-746, South Korea
- Samsung Biomedical Research Institute, Samsung Medical Center, Seoul 06351, South Korea
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3
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Azzam HN, El-Derany MO, Wahdan SA, Faheim RM, Helal GK, El-Demerdash E. Metabolic/hypoxial axis predicts tamoxifen resistance in breast cancer. Sci Rep 2022; 12:16118. [PMID: 36167713 PMCID: PMC9515205 DOI: 10.1038/s41598-022-19977-w] [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: 05/14/2022] [Accepted: 09/07/2022] [Indexed: 11/25/2022] Open
Abstract
We sought in our cross-sectional study to investigate the role of metabolic/hypoxial axis in the development of tamoxifen (TMX) resistance in BC patients. Quantification of plasma LncRNA Taurine upregulated-1 (TUG-1), miRNA 186-5p (miR-186), serum Sirtuin-3 (SIRT3), Peroxisome Proliferator Activator Receptor alpha (PPAR-1 α) and Hypoxia Inducible Factor-1 (HIF-1α) was done in a cohort of patients divided into TMX-sensitive and TMX-resistant candidates. Multiple logistic regression and Receiver Operating Characteristic curve were developed for significant predictors. Plasma TUG-1 and miR-186 were significantly elevated in TMX resistant patients. Serum proteins SIRT3, PPAR-1 α and HIF-1α were deficient in TMX resistant patients compared to TMX sensitive patients, respectively. miR-186 was associated with respiratory symptoms, while, HIF-1α was associated with metastases in TMX resistant patients. Strong correlations were found between all parameters. A predictive model was constructed with TUG-1 and HIF-1α to estimate TMX resistance in BC patients with 88.3% sensitivity and 91.6% specificity. Hypoxia and metabolic dysregulations play important role in the development of TMX resistance in BC patients. Correlation between hypoxia, carcinogenesis and patient’s mortality have led to more aggressive phenotypes, increased risk of metastasis and resistance to TMX.
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Affiliation(s)
- Hany N Azzam
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Heliopolis University, Cairo, Egypt
| | - Marwa O El-Derany
- Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Sara A Wahdan
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Reham M Faheim
- Department of Clinical Oncology and Nuclear Medicine, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Gouda K Helal
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Heliopolis University, Cairo, Egypt
| | - Ebtehal El-Demerdash
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt.
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4
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Castro-Gil MP, Torres-Mena JE, Salgado RM, Muñoz-Montero SA, Martínez-Garcés JM, López-Torres CD, Mendoza-Vargas A, Gabiño-López NB, Villa-Treviño S, Del Pozo-Yauner L, Arellanes-Robledo J, Krötzsch E, Pérez-Carreón JI. The transcriptome of early GGT/KRT19-positive hepatocellular carcinoma reveals a downregulated gene expression profile associated with fatty acid metabolism. Genomics 2021; 114:72-83. [PMID: 34861383 DOI: 10.1016/j.ygeno.2021.11.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/05/2021] [Accepted: 11/26/2021] [Indexed: 01/14/2023]
Abstract
Hepatocellular carcinoma expressing hepatobiliary progenitor markers, is considered of poor prognosis. By using a hepatocarcinogenesis model, laser capture microdissection, and RNA-Sequencing analysis, we identified an expression profile in GGT/KRT19-positive experimental tumors; 438 differentially expressed genes were found in early and late nodules along with increased collagen deposition. Dysregulated genes were involved in Fatty Acid Metabolism, RXR function, and Hepatic Stellate Cells Activation. Downregulation of Slc27a5, Acsl1, and Cyp2e1, demonstrated that Retinoid X Receptor α (RXRα) function is compromised in GGT/KRT19-positive nodules. Since RXRα controls NRF2 pathway activation, we determined the expression of NRF2 targeted genes; Akr1b8, Akr7a3, Gstp1, Abcc3, Ptgr1, and Txnrd1 were upregulated, indicating NRF2 pathway activation. A comparative analysis in human HCC showed that SLC27A5, ACSL1, CYP2E1, and RXRα gene expression is mutually exclusive with KRT19 gene expression. Our results indicate that the downregulation of Slc27a5, Acsl1, Rxrα, and Cyp2e1 genes is an early event within GGT/KRT19-positive HCC.
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Affiliation(s)
| | | | - Rosa M Salgado
- Laboratory of Connective Tissue, Centro Nacional de Investigación y Atención de Quemados, Instituto Nacional de Rehabilitación "Luis Guillermo Ibarra Ibarra", CDMX, Mexico
| | - Said A Muñoz-Montero
- Department of Computational Genomics, National Institute of Genomic Medicine, CDMX, Mexico
| | | | | | | | | | - Saúl Villa-Treviño
- Department of Cell Biology, Center for Research and Advanced Studies of the National Polytechnic Institute, CDMX, Mexico
| | - Luis Del Pozo-Yauner
- Department of Pathology, College of Medicine, University of South Alabama, Mobile, AL, USA
| | - Jaime Arellanes-Robledo
- Laboratory of Liver Diseases, National Institute of Genomic Medicine, CDMX, Mexico; Directorate of Cátedras, National Council of Science and Technology, CDMX, Mexico
| | - Edgar Krötzsch
- Laboratory of Connective Tissue, Centro Nacional de Investigación y Atención de Quemados, Instituto Nacional de Rehabilitación "Luis Guillermo Ibarra Ibarra", CDMX, Mexico
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5
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Kochansky CJ, Lyman MJ, Fauty SE, Vlasakova K, D'mello AP. Administration of Fenofibrate Markedly Elevates Fabp3 in Rat Liver and Plasma and Confounds Its Use as a Preclinical Biomarker of Cardiac and Muscle Toxicity. Lipids 2018; 53:947-960. [PMID: 30592062 DOI: 10.1002/lipd.12110] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 10/25/2018] [Accepted: 11/07/2018] [Indexed: 02/05/2023]
Abstract
Proteins involved in lipid homeostasis are often regulated through the nuclear peroxisome proliferator-activated receptors (PPAR). PPARα is the target for the fibrate-class of drugs. Fenofibrate has been approved for its lipid-lowering effects in patients with hypercholesterolemia and hypertriglyceridemia. We were interested in understanding the expression of the energy transporters in energy-utilizing tissues like liver, heart, muscle, and adipose tissues in rat with the hypothesis that the change in transporter expression would align with the known lipid-lowering effects of PPARα agonists like fenofibrate. We found that several fatty-acid transporter proteins had significantly altered levels following 8 days of fenofibrate dosing. The mRNA levels of the highly abundant Fatp2 and Fatp5 in rat liver increased approximately twofold and decreased fourfold, respectively. Several fatty-acid-binding proteins and acyl-CoA-binding proteins had a significant increase in mRNA abundance but not the major liver fatty-acid-binding protein, Fabp1. Of particular interest was the increased liver expression of Fabp3 also known as heart-fatty acid binding protein (H-FABP or FABP3). FABP3 has been proposed as a circulating clinical biomarker for cardiomyopathy and muscle toxicity, as well as a preclinical marker for PPARα-induced muscle toxicity. Here, we show that fenofibrate induces liver mRNA levels of Fabp3 ~5000-fold resulting in an approximately 50-fold increase in FABP3 protein levels in the whole liver. This increased liver expression complicates the interpretation and potential use of FABP3 as a specific biomarker for PPARα-induced muscle toxicities.
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Affiliation(s)
- Christopher J Kochansky
- Pharmacokinetics, Pharmacodynamics and Drug Metabolism, Merck & Co., Inc., 770 Sumneytown Pike, WP75A-203A, West Point, PA, 19486, USA.,Department of Pharmaceutical Sciences, University of the Sciences in Philadelphia, 600 South 43rd Street, Philadelphia, PA, 19104-4495, USA
| | - Michael J Lyman
- Pharmacokinetics, Pharmacodynamics and Drug Metabolism, Merck & Co., Inc., 770 Sumneytown Pike, WP75A-203A, West Point, PA, 19486, USA
| | - Scott E Fauty
- Safety Assessment, Merck & Co., Inc., 770 Sumneytown Pike, WP81-217, West Point, PA, 19486, USA
| | - Katerina Vlasakova
- Safety Assessment, Merck & Co., Inc., 770 Sumneytown Pike, WP81-217, West Point, PA, 19486, USA
| | - Anil P D'mello
- Department of Pharmaceutical Sciences, University of the Sciences in Philadelphia, 600 South 43rd Street, Philadelphia, PA, 19104-4495, USA
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6
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Haynes HR, Scott HL, Killick-Cole CL, Shaw G, Brend T, Hares KM, Redondo J, Kemp KC, Ballesteros LS, Herman A, Cordero-Llana O, Singleton WG, Mills F, Batstone T, Bulstrode H, Kauppinen RA, Wurdak H, Uney JB, Short SC, Wilkins A, Kurian KM. shRNA-mediated PPARα knockdown in human glioma stem cells reduces in vitro proliferation and inhibits orthotopic xenograft tumour growth. J Pathol 2018; 247:422-434. [PMID: 30565681 PMCID: PMC6462812 DOI: 10.1002/path.5201] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 10/18/2018] [Accepted: 11/13/2018] [Indexed: 12/12/2022]
Abstract
The overall survival for patients with primary glioblastoma is very poor. Glioblastoma contains a subpopulation of glioma stem cells (GSC) that are responsible for tumour initiation, treatment resistance and recurrence. PPARα is a transcription factor involved in the control of lipid, carbohydrate and amino acid metabolism. We have recently shown that PPARα gene and protein expression is increased in glioblastoma and has independent clinical prognostic significance in multivariate analyses. In this work, we report that PPARα is overexpressed in GSC compared to foetal neural stem cells. To investigate the role of PPARα in GSC, we knocked down its expression using lentiviral transduction with short hairpin RNA (shRNA). Transduced GSC were tagged with luciferase and stereotactically xenografted into the striatum of NOD-SCID mice. Bioluminescent and magnetic resonance imaging showed that knockdown (KD) of PPARα reduced the tumourigenicity of GSC in vivo. PPARα-expressing control GSC xenografts formed invasive histological phenocopies of human glioblastoma, whereas PPARα KD GSC xenografts failed to establish viable intracranial tumours. PPARα KD GSC showed significantly reduced proliferative capacity and clonogenic potential in vitro with an increase in cellular senescence. In addition, PPARα KD resulted in significant downregulation of the stem cell factors c-Myc, nestin and SOX2. This was accompanied by downregulation of the PPARα-target genes and key regulators of fatty acid oxygenation ACOX1 and CPT1A, with no compensatory increase in glycolytic flux. These data establish the aberrant overexpression of PPARα in GSC and demonstrate that this expression functions as an important regulator of tumourigenesis, linking self-renewal and the malignant phenotype in this aggressive cancer stem cell subpopulation. We conclude that targeting GSC PPARα expression may be a therapeutically beneficial strategy with translational potential as an adjuvant treatment. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Harry R Haynes
- Brain Tumour Research Group, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.,Department of Cellular Pathology, North Bristol NHS Trust, Bristol, UK
| | - Helen L Scott
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Clare L Killick-Cole
- Functional Neurosurgery Research Group, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Gary Shaw
- Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, UK
| | - Tim Brend
- Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, UK
| | - Kelly M Hares
- Multiple Sclerosis and Stem Cell Group, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Juliana Redondo
- Multiple Sclerosis and Stem Cell Group, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Kevin C Kemp
- Multiple Sclerosis and Stem Cell Group, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Lorena S Ballesteros
- Flow Cytometry Facility, School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Andrew Herman
- Flow Cytometry Facility, School of Cellular and Molecular Medicine, University of Bristol, Bristol, UK
| | - Oscar Cordero-Llana
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - William G Singleton
- Functional Neurosurgery Research Group, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.,Department of Neurosurgery, North Bristol NHS Trust, Bristol, UK
| | - Francesca Mills
- Department of Clinical Biochemistry, North Bristol NHS Trust, Bristol, UK
| | - Tom Batstone
- Bioinformatics Facility, School of Biological Sciences, University of Bristol, Bristol, UK
| | - Harry Bulstrode
- Department of Clinical Neuroscience and Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Risto A Kauppinen
- Clinical Research and Imaging Centre, University of Bristol, Bristol, UK
| | - Heiko Wurdak
- Stem Cells and Brain Tumour Group, Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, UK
| | - James B Uney
- Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Susan C Short
- Leeds Institute of Cancer and Pathology, University of Leeds, Leeds, UK
| | - Alastair Wilkins
- Multiple Sclerosis and Stem Cell Group, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Kathreena M Kurian
- Brain Tumour Research Group, Translational Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
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7
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Gellrich L, Merk D. Therapeutic Potential of Peroxisome Proliferator-Activated Receptor Modulation in Non-Alcoholic Fatty Liver Disease and Non-Alcoholic Steatohepatitis. NUCLEAR RECEPTOR RESEARCH 2017. [DOI: 10.11131/2017/101310] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
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8
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Yasutake Y, Mizokami A, Kawakubo-Yasukochi T, Chishaki S, Takahashi I, Takeuchi H, Hirata M. Long-term oral administration of osteocalcin induces insulin resistance in male mice fed a high-fat, high-sucrose diet. Am J Physiol Endocrinol Metab 2016; 310:E662-E675. [PMID: 26884384 DOI: 10.1152/ajpendo.00334.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 02/05/2016] [Indexed: 01/13/2023]
Abstract
Uncarboxylated osteocalcin (GluOC), a bone-derived hormone, regulates energy metabolism by stimulating insulin secretion, pancreatic β-cell proliferation, and adiponectin expression in adipocytes. Previously, we showed that long-term intermittent or daily oral administration of GluOC reduced the fasting blood glucose level, improved glucose tolerance, and increased the fasting serum insulin concentration as well as pancreatic β-cell area in female mice fed a normal or high-fat, high-sucrose diet. We have now performed similar experiments with male mice and found that such GluOC administration induced glucose intolerance, insulin resistance, and adipocyte hypertrophy in those fed a high-fat, high-sucrose diet. In addition, GluOC increased the circulating concentration of testosterone and reduced that of adiponectin in such mice. These phenotypes were not observed in male mice fed a high-fat, high-sucrose diet after orchidectomy, but they were apparent in orchidectomized male mice or intact female mice that were fed such a diet and subjected to continuous testosterone supplementation. Our results thus reveal a sex difference in the effects of GluOC on glucose homeostasis. Given that oral administration of GluOC has been considered a potentially safe and convenient option for the treatment or prevention of metabolic disorders, this sex difference will need to be taken into account in further investigations.
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Affiliation(s)
- Yu Yasutake
- Laboratory of Molecular and Cellular Biochemistry
- Division of Orthodontics, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Akiko Mizokami
- Laboratory of Molecular and Cellular Biochemistry
- OBT Research Center, and
| | - Tomoyo Kawakubo-Yasukochi
- Department of Immunological and Molecular Pharmacology, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan; and
| | | | - Ichiro Takahashi
- Division of Orthodontics, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Hiroshi Takeuchi
- Division of Applied Pharmacology, Kyushu Dental University, Kitakyushu, Japan
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9
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Medium-chain dicarboxylic acylcarnitines as markers of n-3 PUFA-induced peroxisomal oxidation of fatty acids. Mol Nutr Food Res 2015; 59:1573-83. [DOI: 10.1002/mnfr.201400743] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 03/29/2015] [Accepted: 03/30/2015] [Indexed: 02/02/2023]
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10
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Guo X, Liang XF, Fang L, Yuan X, Zhou Y, He S, Shen D. Effects of lipid-lowering pharmaceutical clofibrate on lipid and lipoprotein metabolism of grass carp (Ctenopharyngodon idellal Val.) fed with the high non-protein energy diets. FISH PHYSIOLOGY AND BIOCHEMISTRY 2015; 41:331-343. [PMID: 25213789 DOI: 10.1007/s10695-014-9986-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Accepted: 09/07/2014] [Indexed: 06/03/2023]
Abstract
This study investigated the effects of clofibrate treatment on blood lipids, hepatic enzyme activities and relative expression of genes involved in lipid metabolism of grass carp fed with high non-protein energy diets. For that purpose, five diets were formulated: a commercial-like diet (Control), a high-carbohydrate diet (HC), a high-fat diet (HF) and two diets identical to the HC and HF diets, but supplemented with 1.25 g kg(-1) clofibrate (HC + Clo and HF + Clo diets). Grass carp fed the HC and HF diet exhibited increases in blood lipids and body fat compared with the control group after 4 weeks. In the clofibrate treatment groups, there was a marked decrease in triacylglycerol and cholesterol concentrations of plasma, and total lipids of the whole body, mesentery adipose tissue and liver tissue. Fish treated with clofibrate exhibited increased hepatic acyl-CoA oxidase activity, but did not show any changes in carnitine palmitoyltransferase (CPT) I activity compared with HC and HF diets without clofibrate. Clofibrate treatment had no effect on peroxisome proliferator-activated receptor alpha and CPT I mRNA expression. However, there was an increase in lipoprotein lipase expression in the clofibrate-treated groups. In addition, the relative mRNA expression levels of hepatic de novo lipogenic enzymes (fatty acid synthetase and acetyl coenzyme-A carboxylase) were significantly higher in the fish fed the HC diet than those of other groups, and clofibrate inhibited this increase. These results suggest that clofibrate has the hypolipidaemic effects and affects lipid metabolism in grass carp.
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Affiliation(s)
- Xiaoze Guo
- College of Fisheries, Key Lab of Freshwater Animal Breeding, Ministry of Agriculture, Huazhong Agricultural University, Hubei Collaborative Innovation Center for Freshwater Aquaculture, No.1, Shizishan Street, Hongshan District, Wuhan, 430070, Hubei, China,
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11
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Deficiency of the transcriptional repressor B cell lymphoma 6 (Bcl6) is accompanied by dysregulated lipid metabolism. PLoS One 2014; 9:e97090. [PMID: 24892698 PMCID: PMC4043531 DOI: 10.1371/journal.pone.0097090] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 04/15/2014] [Indexed: 12/28/2022] Open
Abstract
The transcriptional repressor B-cell Lymphoma 6 (Bcl6) was recently identified in a profile of genes regulated in adipocytes, suggesting a relationship between Bcl6 and metabolic regulation. As a representative target gene repressed by Bcl6, Suppressor of Cytokine Signaling (Socs) 2 expression was elevated in Bcl6 deficient (KO) mice, including metabolic tissues liver, adipose tissue and muscle, as well as in spleen and thymus. Bcl6 occupied the Socs2 promoter in wild-type, but not Bcl6 KO mice, suggesting direct regulation of Socs2 by Bcl6 in vivo. Mice deficient in Bcl6 were found to exhibit multiple features of dysregulated lipid metabolism. Adipose tissue mass was dramatically reduced or absent in Bcl6 KO mice. Further, hepatic and serum triglycerides were low. Bcl6 deficiency was accompanied by decreased hepatic expression of Stearoyl-CoA desaturase 1 (Scd1) and Fatty acid synthase (Fasn) genes which encode lipogenic enzymes. Expression of the gene for the transcription factor Carbohydrate-Responsive Element Binding Protein (Chrebp), which regulates expression of lipogenic genes, was also reduced in liver of Bcl6 KO mice. Bcl6 deficiency disrupted fasting-induced increases in hepatic triglyceride deposition, but not decreases in lipogenic gene expression. Taken together, these findings suggest that in addition to its well-recognized roles in immune regulation, Bcl6 plays a role in regulatory events of lipid metabolism, and that in the absence of Bcl6, lipid metabolism in liver and adipose tissue is dysregulated.
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12
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Grabacka M, Pierzchalska M, Reiss K. Peroxisome proliferator activated receptor α ligands as anticancer drugs targeting mitochondrial metabolism. Curr Pharm Biotechnol 2013; 14:342-56. [PMID: 21133850 DOI: 10.2174/1389201011314030009] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 07/15/2010] [Accepted: 09/17/2010] [Indexed: 12/15/2022]
Abstract
Tumor cells show metabolic features distinctive from normal tissues, with characteristically enhanced aerobic glycolysis, glutaminolysis and lipid synthesis. Peroxisome proliferator activated receptor α (PPAR α) is activated by nutrients (fatty acids and their derivatives) and influences these metabolic pathways acting antagonistically to oncogenic Akt and c-Myc. Therefore PPAR α can be regarded as a candidate target molecule in supplementary anticancer pharmacotherapy as well as dietary therapeutic approach. This idea is based on hitting the cancer cell metabolic weak points through PPAR α mediated stimulation of mitochondrial fatty acid oxidation and ketogenesis with simultaneous reduction of glucose and glutamine consumption. PPAR α activity is induced by fasting and its molecular consequences overlap with the effects of calorie restriction and ketogenic diet (CRKD). CRKD induces increase of NAD+/NADH ratio and drop in ATP/AMP ratio. The first one is the main stimulus for enhanced protein deacetylase SIRT1 activity; the second one activates AMP-dependent protein kinase (AMPK). Both SIRT1 and AMPK exert their major metabolic activities such as fatty acid oxidation and block of glycolysis and protein, nucleotide and fatty acid synthesis through the effector protein peroxisome proliferator activated receptor gamma 1 α coactivator (PGC-1α). PGC-1α cooperates with PPAR α and their activities might contribute to potential anticancer effects of CRKD, which were reported for various brain tumors. Therefore, PPAR α activation can engage molecular interplay among SIRT1, AMPK, and PGC-1α that provides a new, low toxicity dietary approach supplementing traditional anticancer regimen.
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Affiliation(s)
- Maja Grabacka
- Department of Food Biotechnology, Faculty of Food Technology, University of Agriculture, Krakow 30- 149, ul. Balicka 122, Poland.
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13
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Seok H, Cha BS. Refocusing Peroxisome Proliferator Activated Receptor-α: A New Insight for Therapeutic Roles in Diabetes. Diabetes Metab J 2013; 37:326-32. [PMID: 24199160 PMCID: PMC3816132 DOI: 10.4093/dmj.2013.37.5.326] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Although glucose-lowering treatment shows some risk lowering effects in cardiovascular diseases, risks of macrovascular and microvascular complications have still remained, and development of new therapeutic strategies is needed. Recent data have shown that peroxisome proliferator activated receptor-α (PPAR-α) plays a pivotal role in the regulation of lipid homeostasis, fatty acid oxidation, cellular differentiation, and immune response such as inflammation or vascularization related to diabetic complication. This review will re-examine the metabolic role of PPAR-α, summarize data from clinical studies on the effect of PPAR-α agonist in diabetes, and will discuss the possible therapeutic role of PPAR-α activation.
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Affiliation(s)
- Hannah Seok
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
| | - Bong Soo Cha
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea
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Chai JT, Choudhury RP. Cardiometabolic interventions - focus on transcriptional regulators. THE EUROPEAN JOURNAL OF CARDIOVASCULAR MEDICINE 2013; 2:212-218. [PMID: 24040490 PMCID: PMC3769682 DOI: 10.5083/ejcm.20424884.102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cardiovascular disease (CVD) remains the largest healthcare burden in the Western world; and the increasing prevalence of type II diabetes mellitus, at least partially driven by a trend in lifestyle changes associated with global economic development, is likely to fuel this CVD burden worldwide. Over the past two decades, there has been an increased awareness of the convergence of risk factors contributing to both cardiovascular disease and diabetes leading to the concept of the metabolic syndrome, and the realisation of the opportunity to intervene at this intersection to simultaneously target CVD and metabolic dysfunction. This brings together the fields of cardiovascular medicine, diabetology, and increasingly clinical immunology for a unified and concerted effort to reduce risk for both conditions simultaneously. The discovery of the targeted pathways of drugs already in clinical use such as fibrates and thiazolidinediones (TZD) has led to accelerated basic and clinical research into selective and dual PPAR-α and PPAR-γ agonists, which can theoretically target glucose, lipid and lipoprotein metabolism, as well as potentially exerting inhibitoryeffects in vascular inflammation, all of which might be predicted to reduce atherosclerosis. In this article, we will discuss the basic science as well as recent clinical development in the pursuit of optimal cardiometabolic intervention along with insight into strategies for future drug development.
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Affiliation(s)
- Joshua T Chai
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine University of Oxford, United Kingdom
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15
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Akbar H, Schmitt E, Ballou MA, Corrêa MN, Depeters EJ, Loor JJ. Dietary Lipid During Late-Pregnancy and Early-Lactation to Manipulate Metabolic and Inflammatory Gene Network Expression in Dairy Cattle Liver with a Focus on PPARs. GENE REGULATION AND SYSTEMS BIOLOGY 2013; 7:103-23. [PMID: 23825924 PMCID: PMC3699062 DOI: 10.4137/grsb.s12005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Polyunsaturated (PUFA) long-chain fatty acids (LCFAs) are more potent in eliciting molecular and tissue functional changes in monogastrics than saturated LCFA. From −21 through 10 days relative to parturition dairy cows were fed no supplemental LCFA (control), saturated LCFA (SFAT; mainly 16:0 and 18:0), or fish oil (FISH; high-PUFA). Twenty-seven genes were measured via quantitative RT-PCR in liver tissue on day −14 and day 10. Expression of nuclear receptor co-activators (CARM1, MED1), LCFA metabolism (ACSL1, SCD, ACOX1), and inflammation (IL6, TBK1, IKBKE) genes was lower with SFAT than control on day −14. Expression of SCD, however, was markedly lower with FISH than control or SFAT on both −14 and 10 days. FISH led to further decreases in expression on day 10 of LCFA metabolism (CD36, PLIN2, ACSL1, ACOX1), intracellular energy (UCP2, STK11, PRKAA1), de novo cholesterol synthesis (SREBF2), inflammation (IL6, TBK1, IKBKE), and nuclear receptor signaling genes (PPARD, MED1, NRIP1). No change in expression was observed for PPARA and RXRA. The increase of DGAT2, PLIN2, ACSL1, and ACOX1 on day 10 versus −14 in cows fed SFAT suggested upregulation of both beta-oxidation and lipid droplet (LD) formation. However, liver triacylglycerol concentration was similar among treatments. The hepatokine FGF21 and the gluconeogenic genes PC and PCK1 increased markedly on day 10 versus −14 only in controls. At the levels supplemented, the change in the profile of metabolic genes after parturition in cows fed saturated fat suggested a greater capacity for uptake of fatty acids and intracellular handling without excessive storage of LD.
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Affiliation(s)
- Haji Akbar
- Mammalian NutriPhysioGenomics Department of Animal Sciences and Division of Nutritional Sciences, University of Illinois, Urbana, Illinois, USA
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16
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Fiamoncini J, Turner N, Hirabara SM, Salgado TML, Marçal AC, Leslie S, da Silva SMA, Deschamps FC, Luz J, Cooney GJ, Curi R. Enhanced peroxisomal β-oxidation is associated with prevention of obesity and glucose intolerance by fish oil-enriched diets. Obesity (Silver Spring) 2013; 21:1200-7. [PMID: 23666909 DOI: 10.1002/oby.20132] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Accepted: 10/07/2012] [Indexed: 11/11/2022]
Abstract
OBJECTIVE The effects of different amounts of omega 3-polyunsaturated fatty acids in diets with normal or high content of fat on lipid and carbohydrate metabolism were investigated. DESIGN AND METHODS Mice were fed for 8 weeks on diets enriched with fish oil or lard at 10% or 60% of energy. Energy balance and energy expenditure were analyzed. Fatty acid (FA) oxidative capacity of the liver and the activity of enzymes involved in this pathway were assessed. RESULTS Fish oil-fed mice had lower body weight and adiposity compared with lard-fed animals, despite having lower rates of oxygen consumption. Mice fed diets containing fish oil also displayed lower glycemia, reduced fat content in the liver, and improved glucose tolerance compared with lard-fed animals. The fish oil-containing diets increased markers of hepatic peroxisomal content and increased the generation of metabolites derived from FA β-oxidation in liver homogenates. In contrast, no changes were observed in the content of mitochondrial electron transport chain proteins or carnitine palmitoyl transferase-1 in the liver, indicating little direct effect of fish oil on mitochondrial metabolism. CONCLUSION Collectively, our findings suggest that the energy inefficient oxidation of FAs in peroxisomes may be an important mechanism underlying the protection against obesity and glucose intolerance of fish oil administration.
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Affiliation(s)
- J Fiamoncini
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
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Benjamin S, Flotho S, Börchers T, Spener F. Conjugated linoleic acid isomers and their precursor fatty acids regulate peroxisome proliferator-activated receptor subtypes and major peroxisome proliferator responsive element-bearing target genes in HepG2 cell model. J Zhejiang Univ Sci B 2013; 14:115-23. [PMID: 23365010 PMCID: PMC3566404 DOI: 10.1631/jzus.b1200175] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2012] [Accepted: 09/04/2012] [Indexed: 02/03/2023]
Abstract
The purpose of this study was to examine the induction profiles (as judged by quantitative reverse transcription polymerase chain reaction (qRT-PCR)) of peroxisome proliferator-activated receptor (PPAR) α, β, γ subtypes and major PPAR-target genes bearing a functional peroxisome proliferator responsive element (PPRE) in HepG2 cell model upon feeding with cis-9,trans-11-octadecadienoic acid (9-CLA) or trans-10,cis-12-octadecadienoic acid (10-CLA) or their precursor fatty acids (FAs). HepG2 cells were treated with 100 μmol/L 9-CLA or 10-CLA or their precursor FAs, viz., oleic, linoleic, and trans-11-vaccenic acids against bezafibrate control to evaluate the induction/expression profiles of PPAR α, β, γ subtypes and major PPAR-target genes bearing a functional PPRE, i.e., fatty acid transporter (FAT), glucose transporter-2 (GLUT-2), liver-type FA binding protein (L-FABP), acyl CoA oxidase-1 (ACOX-1), and peroxisomal bifunctional enzyme (PBE) with reference to β-actin as house keeping gene. Of the three housekeeping genes (glyceraldehyde 3-phosphate dehydrogenase (GAPDH), β-actin, and ubiquitin), β-actin was found to be stable. Dimethyl sulfoxide (DMSO), the common solubilizer of agonists, showed a significantly higher induction of genes analyzed. qRT-PCR profiles of CLAs and their precursor FAs clearly showed upregulation of FAT, GLUT-2, and L-FABP (~0.5-2.0-fold). Compared to 10-CLA, 9-CLA decreased the induction of the FA metabolizing gene ACOX-1 less than did PBE, while 10-CLA decreased the induction of PBE less than did ACOX-1. Both CLAs and precursor FAs upregulated PPRE-bearing genes, but with comparatively less or marginal activation of PPAR subtypes. This indicates that the binding of CLAs and their precursor FAs to PPAR subtypes results in PPAR activation, thereby induction of the target transporter genes coupled with downstream lipid metabolising genes such as ACOX-1 and PBE. To sum up, the expression profiles of these candidate genes showed that CLAs and their precursor FAs are involved in lipid signalling by modulating the PPAR α, β, or γ subtype for the indirect activation of the PPAR-target genes, which may in turn be responsible for the supposed health effects of CLA, and that care should be taken while calculating the actual fold induction values of candidate genes with reference to housekeeping gene and DMSO as they may impart false positive results.
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Affiliation(s)
- Sailas Benjamin
- Department of Biochemistry, University of Münster, 48149 Münster, Germany.
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18
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Tan F, Jin Y, Liu W, Quan X, Chen J, Liang Z. Global liver proteome analysis using iTRAQ labeling quantitative proteomic technology to reveal biomarkers in mice exposed to perfluorooctane sulfonate (PFOS). ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:12170-12177. [PMID: 23046066 DOI: 10.1021/es3027715] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Proteomic analysis allows detection of changes of proteins expression in organisms exposed to environmental pollutants, leading to the discovery of biomarkers of exposure and understanding of the action mechanism of toxicity. In the present study, we applied iTRAQ labeling quantitative proteomic technology for global characterization of the liver proteome in mice exposed to perfluorooctane sulfonate (PFOS). This successfully identified and quantified 1038 unique proteins. Seventy-one proteins showed a significant expression change in the treated groups (1.0, 2.5, 5.0 mg/kg of body weight) compared with the control group, and 16 proteins displayed strong dose-dependent changes. Gene ontology analysis showed that these differential proteins were significantly enriched and mainly involved in lipid metabolism, transport, biosynthetic processes, and response to stimulus. We detected significantly increased expression levels of enzymes regulating peroxisomal β-oxidation-including long-chain acyl-CoA synthetase, acyl-CoA oxidase 1, bifunctional enzyme, and 3-ketoacyl-CoA thiolase A. PFOS also significantly induced cytochrome P450s and glutathione S-transferases that are responsible for the metabolism of xenobiotic compounds. The expressions of several proteins with important biological functions-such as cysteine sulfinic acid decarboxylase, aldehyde dehydrogenase, and apolipoprotein A-I, also correlated with PFOS exposure. Together, the present results provide insight into the molecular mechanism and biomarkers for PFOS-induced effects.
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Affiliation(s)
- Feng Tan
- Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China.
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Friedland SN, Leong A, Filion KB, Genest J, Lega IC, Mottillo S, Poirier P, Reoch J, Eisenberg MJ. The cardiovascular effects of peroxisome proliferator-activated receptor agonists. Am J Med 2012; 125:126-33. [PMID: 22269613 DOI: 10.1016/j.amjmed.2011.08.025] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 08/20/2011] [Accepted: 08/22/2011] [Indexed: 12/30/2022]
Abstract
Although peroxisome proliferator-activated receptor agonists are prescribed to improve cardiovascular risk factors, their cardiovascular safety is controversial. We therefore reviewed the literature to identify landmark randomized controlled trials evaluating the effect of peroxisome proliferator-activated receptor gamma agonists (pioglitazone and rosiglitazone), alpha agonists (fenofibrate and gemfibrozil), and pan agonists (bezafibrate, muraglitazar, ragaglitazar, tesaglitazar, and aleglitazar) on cardiovascular outcomes. Pioglitazone may modestly reduce cardiovascular events but also may increase the risk of bladder cancer. Rosiglitazone increases the risk of myocardial infarction and has been withdrawn in European and restricted in the United States. Fibrates improve cardiovascular outcomes only in select subgroups: fenofibrate in diabetic patients with metabolic syndrome, gemfibrozil in patients with dyslipidemia, and bezafibrate in patients with diabetes or metabolic syndrome. The cardiovascular safety of the new pan agonist aleglitazar, currently in phase II trials, remains to be determined. The heterogenous effects of peroxisome proliferator-activated receptor agonists to date highlight the importance of postmarketing surveillance. The critical question of why peroxisome proliferator-activated receptor agonists seem to improve cardiovascular risk factors without significantly improving cardiovascular outcomes requires further investigation.
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Affiliation(s)
- Sayuri N Friedland
- Division of Cardiology, Jewish General Hospital/McGill University, Montreal, Quebec, Canada
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20
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Song M, Salam N, Roufogalis BD, Huang T. Lycium barbarum (Goji Berry) extracts and its taurine component inhibit PPAR-γ-dependent gene transcription in human retinal pigment epithelial cells: Possible implications for diabetic retinopathy treatment. Biochem Pharmacol 2011; 82:1209-18. [DOI: 10.1016/j.bcp.2011.07.089] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Revised: 07/18/2011] [Accepted: 07/20/2011] [Indexed: 01/12/2023]
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Xia W, Wan YJ, Wang X, Li YY, Yang WJ, Wang CX, Xu SQ. Sensitive bioassay for detection of PPARα potentially hazardous ligands with gold nanoparticle probe. JOURNAL OF HAZARDOUS MATERIALS 2011; 192:1148-1154. [PMID: 21726938 DOI: 10.1016/j.jhazmat.2011.06.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2010] [Revised: 06/04/2011] [Accepted: 06/09/2011] [Indexed: 05/31/2023]
Abstract
There are so many kinds of peroxisome proliferator-activated receptor α (PPARα) ligands with hazardous effect for human health in the environment, such as certain herbicides, plasticizers and drugs. Among these agonists, perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), and mono-(2-ethylhexyl) phthalate (MEHP) are mostly investigated due to their persistence and accumulation in environment and their potential toxicity via PPARα. This investigation aims at developing a bioassay method to detect PPARα ligands based on the ligand-receptor interaction on microplate. PPARα, which formed heterodimers with retinoid X receptor-α (RXRα), were activated by PPARα ligands to form ligands-PPARα-RXRα complexes. Then the complexes were transferred into a microplate and captured via monoclonal anti-PPARα antibody. The PPARα responsive elements (PPRE) modified-gold nanoparticle probes were captured by the ligand-PPARα-RXRα complexes immobilized on the microplate, and then could be quantified through measuring the optical density after silver enhancement. The results showed that PFOS was quantified with a linear range from 100 pM to 1 μM and the detection limit was 10 pM. In addition to PFOS, PFOA and MEHP were also quantified within a proper range through the proposed bioassay. This bioassay was compared with that of liquid chromatography tandem-mass spectrometry (LC-MS) for water spiked samples with a significant correlation (r = 0.9893). This study provides a high-throughput detection method for PPARα ligands in microplate with high sensitivity and wide linear range. It may serve as an assistant of LC-MS for prescreening of PPARα ligands like PFOS.
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Affiliation(s)
- Wei Xia
- Minister of Education Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, Hubei Province 430030, PR China
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Stable reporter cell lines for peroxisome proliferator-activated receptor γ (PPARγ)-mediated modulation of gene expression. Anal Biochem 2011; 414:77-83. [PMID: 21354099 DOI: 10.1016/j.ab.2011.02.032] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Accepted: 02/18/2011] [Indexed: 12/12/2022]
Abstract
Activation of peroxisome proliferator-activated receptor γ (PPARγ) by ligands is associated with beneficial health effects, including anti-inflammatory and insulin-sensitizing effects. The aim of the current study was to develop luciferase reporter gene assays to enable fast and low-cost measurement of PPARγ agonist and antagonist activity. Two reporter gene assays, PPARγ1 CALUX and PPARγ2 CALUX, were developed by stable transfection of U2OS cells with an expression vector for PPARγ1 or PPARγ2 and a pGL3-3xPPRE-tata-luc or pGL4-3xPPRE-tata-luc reporter construct, respectively. PPARγ1 CALUX and PPARγ2 CALUX cells showed similar concentration-dependent luciferase induction upon exposure to the PPARγ agonists rosiglitazone, troglitazone, pioglitazone, ciglitazone, netoglitazone, and 15-deoxy-Δ(12,14)-prostaglandin J(2). The potency to induce luciferase decreased in the following order: rosiglitazone>troglitazone=pioglitazone>netoglitazone>ciglitazone. A concentration-dependent decrease in the response to 50nM rosiglitazone was observed on the addition of PPARγ antagonist GW9662 or T0070907 in both PPARγ1 CALUX and PPARγ2 CALUX cells. The PPARα agonists WY14643 and fenofibrate failed to induce luciferase activity, confirming the specificity of these cell lines for PPARγ agonists. In conclusion, PPARγ1 CALUX and PPARγ2 CALUX cells provide a reliable and useful tool to screen (bio)chemicals for PPARγ agonist or antagonist activity.
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Differential regulation of human apolipoprotein AI and high-density lipoprotein by fenofibrate in hapoAI and hapoAI-CIII-AIV transgenic mice. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1811:76-83. [PMID: 21081177 DOI: 10.1016/j.bbalip.2010.11.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 11/05/2010] [Accepted: 11/09/2010] [Indexed: 01/11/2023]
Abstract
Fenofibrate, a PPAR-α agonist, lowers triglycerides (TG) and raises high-density lipoproteins (HDL-C) in humans. While fenofibrate is very effective in lowering TG, it does not raise HDL-C in humans to the same extent as seen in human apoAI transgenic (hAI-Tg) mice. We studied the mechanism of this discordance using the following compounds as tools: cholic acid that down-regulates human apoAI, and fenofibrate, that elevates hapoAI and HDL-C in hAI-Tg mice. We hypothesized that additional sequences, including apoCIII and AIV genes on chromosome 11, not present in the hapoAI transgene may be responsible for the dampened effect of fibrates on HDL-C seen in humans. For this, hAI-Tg mice with 11kb DNA segment and hapoAI-CIII-AIV-Tg mice with 33kb DNA segment harboring apoCIII and AIV genes were employed. These mice were treated with fenofibrate and cholic acid. Fenofibrate increased apoAI and HDL-C levels, and HDL size in the apoAI-Tg mice via up-regulation of the hapoAI mRNA and increased activity and mRNA of PLTP, respectively. Consistent with earlier findings, cholic acid showed similar effects of lowering HDL-C, and elevating LDL-C in hAI-Tg mice as well as in the hAI-CIII-AIV-Tg mice. Fenofibrate decreased TG and increased HDL size in hAI-CIII-AIV-Tg mice as well, but surprisingly, did not elevate serum levels of hapoAI or hepatic AI mRNA, suggesting that additional sequences not present in the hapoAI transgene (11kb) may be partly responsible for the dampened effect on HDL-C seen in hAI-CIII-AIV-Tg mice. Since hAI-CIII-AIV-Tg mouse mimics fenofibrate effects seen in humans, this transgenic mouse could serve as a better predictive model for screening HDL-C raising compounds.
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Gene Expression Changes Induced by PPAR Gamma Agonists in Animal and Human Liver. PPAR Res 2010; 2010:325183. [PMID: 20981297 PMCID: PMC2963138 DOI: 10.1155/2010/325183] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2010] [Accepted: 07/15/2010] [Indexed: 01/15/2023] Open
Abstract
Thiazolidinediones are a class of Peroxisome Proliferator Activated Receptor γ (PPARγ) agonists that reduce insulin resistance in type 2 diabetic patients. Although no detectable hepatic toxicity has been evidenced in animal studies during preclinical trials, these molecules have nevertheless induced hepatic adverse effects in some treated patients. The mechanism(s) of hepatotoxicity remains equivocal. Several studies have been conducted using PCR analysis and microarray technology to identify possible target genes and here we review the data obtained from various in vivo and in vitro experimental models. Although PPARγ is expressed at a much lower level in liver than in adipose tissue, PPARγ agonists exert various PPARγ-dependent effects in liver in addition to PPARγ-independent effects. Differences in effects are dependent on the choice of agonist and experimental conditions in rodent animal studies and in rodent and human liver cell cultures. These effects are much more pronounced in obese and diabetic liver. Moreover, our own recent studies have shown major interindividual variability in the response of primary human hepatocyte populations to troglitazone treatment, supporting the occurrence of hepatotoxicity in only some individuals.
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Bu SY, Mashek DG. Hepatic long-chain acyl-CoA synthetase 5 mediates fatty acid channeling between anabolic and catabolic pathways. J Lipid Res 2010; 51:3270-80. [PMID: 20798351 DOI: 10.1194/jlr.m009407] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Long-chain acyl-CoA synthetases (ACSLs) and fatty acid transport proteins (FATPs) activate fatty acids (FAs) to acyl-CoAs prior to their downstream metabolism. Of numerous ACSL and FATP isoforms, ACSL5 is expressed predominantly in tissues with high rates of triacylglycerol (TAG) synthesis, suggesting it may have an anabolic role in lipid metabolism. To characterize the role of ACSL5 in hepatic energy metabolism, we used small interference RNA (siRNA) to knock down ACSL5 in rat primary hepatocytes. Compared with cells transfected with control siRNA, suppression of ACSL5 expression significantly decreased FA-induced lipid droplet formation. These findings were further extended with metabolic labeling studies showing that ACSL5 knockdown resulted in decreased [1-(14)C]oleic acid or acetic acid incorporation into intracellular TAG, phospholipids, and cholesterol esters without altering FA uptake or lipogenic gene expression. ACSL5 knockdown also decreased hepatic TAG secretion proportionate to the observed decrease in neutral lipid synthesis. ACSL5 knockdown did not alter lipid turnover or mediate the effects of insulin on lipid metabolism. Hepatocytes treated with ACSL5 siRNA had increased rates of FA oxidation without changing PPAR-α activity and target gene expression. These results suggest that ACSL5 activates and channels FAs toward anabolic pathways and, therefore, is an important branch point in hepatic FA metabolism.
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Affiliation(s)
- So Young Bu
- Department of Food Science and Nutrition, University of Minnesota, St Paul, MN, USA
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Djaouti L, Jourdan T, Demizieux L, Chevrot M, Gresti J, Vergès B, Degrace P. Different effects of pioglitazone and rosiglitazone on lipid metabolism in mouse cultured liver explants. Diabetes Metab Res Rev 2010; 26:297-305. [PMID: 20503262 DOI: 10.1002/dmrr.1081] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Pioglitazone (PIO) and rosiglitazone (ROSI) are widely used as oral antidiabetic agents for treatment of type 2 diabetes. Although these medications exert similar effects on blood glucose, recent clinical studies indicated that PIO has a more pronounced beneficial effect on lipid parameters than ROSI. In order to get further insight into the lipid effects of both drugs, we tested whether PIO, compared to ROSI, could exert direct effects on lipid liver metabolism in relation with plasma lipids. METHODS We performed in vitro studies using mice liver slices incubated 21 h either with ROSI (1 micromol/L) or PIO (7.5 micromol/L). RESULTS We showed that both glitazones slightly reduced HMG-CoA reductase mRNA levels at the same degree but only PIO reduced intracellular cholesterol content, suggesting an alteration of cholesterol uptake rather than an inhibition of cholesterol biosynthesis. This concept was supported by the reduction of scavenger receptor class B type I expression, hepatic lipase activity and high-density lipoprotein cholesterol uptake in PIO-treated liver explants. Conversely, hepatic lipase mRNA levels were increased 3.5-fold. ROSI, but not PIO, induced acetyl-CoA carboxylase and fatty acid synthase gene expression and increased apoB secretion suggesting a stimulation of lipogenesis. Concurrently, peroxisome proliferator-activated receptor-gamma mRNA levels were induced by ROSI and not significantly changed by PIO. Besides, PIO appeared to be a more potent activator of AMP-Activated Protein Kinase than ROSI. CONCLUSIONS PIO and ROSI exert specific direct effects on liver and extrapolating these data to humans could explain the significant improvements in plasma lipids observed in diabetic patients treated with PIO.
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Affiliation(s)
- Louiza Djaouti
- UMR 866 INSERM-UB, Team Physiopathology of dyslipidemias, Faculty of Sciences Gabriel, University of Burgundy, Dijon 21000, France
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Li LO, Ellis JM, Paich HA, Wang S, Gong N, Altshuller G, Thresher RJ, Koves TR, Watkins SM, Muoio DM, Cline GW, Shulman GI, Coleman RA. Liver-specific loss of long chain acyl-CoA synthetase-1 decreases triacylglycerol synthesis and beta-oxidation and alters phospholipid fatty acid composition. J Biol Chem 2009; 284:27816-27826. [PMID: 19648649 DOI: 10.1074/jbc.m109.022467] [Citation(s) in RCA: 168] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In mammals, a family of five acyl-CoA synthetases (ACSLs), each the product of a separate gene, activates long chain fatty acids to form acyl-CoAs. Because the ACSL isoforms have overlapping preferences for fatty acid chain length and saturation and are expressed in many of the same tissues, the individual function of each isoform has remained uncertain. Thus, we constructed a mouse model with a liver-specific knock-out of ACSL1, a major ACSL isoform in liver. Eliminating ACSL1 in liver resulted in a 50% decrease in total hepatic ACSL activity and a 25-35% decrease in long chain acyl-CoA content. Although the content of triacylglycerol was unchanged in Acsl1(L)(-/-) liver after mice were fed either low or high fat diets, in isolated primary hepatocytes the absence of ACSL1 diminished the incorporation of [(14)C]oleate into triacylglycerol. Further, small but consistent increases were observed in the percentage of 16:0 in phosphatidylcholine and phosphatidylethanolamine and of 18:1 in phosphatidylethanolamine and lysophosphatidylcholine, whereas concomitant decreases were seen in 18:0 in phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, and lysophosphatidylcholine. In addition, decreases in long chain acylcarnitine content and diminished production of acid-soluble metabolites from [(14)C]oleate suggested that hepatic ACSL1 is important for mitochondrial beta-oxidation of long chain fatty acids. Because the Acsl1(L)(-/-) mice were not protected from developing either high fat diet-induced hepatic steatosis or insulin resistance, our study suggests that lowering the content of hepatic acyl-CoA without a concomitant decrease in triacylglycerol and other lipid intermediates is insufficient to protect against hepatic insulin resistance.
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Affiliation(s)
- Lei O Li
- Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Jessica M Ellis
- Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Heather A Paich
- Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Shuli Wang
- Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Nan Gong
- Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina 27599
| | - George Altshuller
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Randy J Thresher
- Department of Genetics, University of North Carolina, Chapel Hill, North Carolina 27599
| | - Timothy R Koves
- Department of Medicine, Duke University, Durham, North Carolina 27710
| | | | - Deborah M Muoio
- Department of Medicine, Duke University, Durham, North Carolina 27710
| | - Gary W Cline
- Department of Internal Medicine and Cellular and Molecular Physiology, Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06510
| | - Gerald I Shulman
- Department of Internal Medicine and Cellular and Molecular Physiology, Howard Hughes Medical Institute, Yale University, New Haven, Connecticut 06510
| | - Rosalind A Coleman
- Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina 27599.
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Cignarella A. Animal and cellular models for hypolipidemic drugs. Expert Opin Drug Discov 2009; 4:61-9. [PMID: 23480337 DOI: 10.1517/17460440802624987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND The development of effective and safe lipid-lowering agents should set out from and rely on robust preclinical investigation. OBJECTIVE To accomplish this aim, the selection of proper cellular and animal models is crucial. RESULTS Because lipid-lowering agents are ultimately supposed to reduce the atherosclerotic burden in the arterial wall, they need to tackle directly or indirectly the multifactorial nature of atherosclerotic disease. Hence, these drugs may essentially prevent triglyceride-rich lipoprotein assembly or enhance low-density lipoprotein (LDL) clearance through the LDL or related receptors in the liver. Established animal models such as the apolipoprotein E- and the LDL-receptor knockout mice are widely used to test drug actions on these pathways. A different approach is testing the ability of candidate drugs to increase plasma high-density lipoprotein (HDL) levels. More recently, the focus has shifted to drugs enhancing HDL function rather than just plasma HDL levels. This in turn requires in vitro and particularly in vivo models of reverse cholesterol transport, which have become available by now. CONCLUSION A positive outcome of preclinical studies is necessary but not sufficient for an investigational new drug to be eventually approved for clinical use.
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Affiliation(s)
- Andrea Cignarella
- University of Padova, Department of Pharmacology and Anaesthesiology, Largo Meneghetti 2, 35131 Padova, Italy +39 049 8275091 ; +39 049 8275093 ;
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Ringseis R, Luci S, Spielmann J, Kluge H, Fischer M, Geissler S, Wen G, Hirche F, Eder K. Clofibrate treatment up-regulates novel organic cation transporter (OCTN)-2 in tissues of pigs as a model of non-proliferating species. Eur J Pharmacol 2008; 583:11-7. [DOI: 10.1016/j.ejphar.2008.01.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2007] [Revised: 12/17/2007] [Accepted: 01/14/2008] [Indexed: 01/09/2023]
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Heinäniemi M, Uski JO, Degenhardt T, Carlberg C. Meta-analysis of primary target genes of peroxisome proliferator-activated receptors. Genome Biol 2008; 8:R147. [PMID: 17650321 PMCID: PMC2323243 DOI: 10.1186/gb-2007-8-7-r147] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2007] [Revised: 07/02/2007] [Accepted: 07/25/2007] [Indexed: 12/20/2022] Open
Abstract
A combined experimental and in silico approach identifies Peroxisome Proliferator Activated Receptor (PPAR) binding sites and six novel target genes in the human genome. Background Peroxisome proliferator-activated receptors (PPARs) are known for their critical role in the development of diseases, such as obesity, cardiovascular disease, type 2 diabetes and cancer. Here, an in silico screening method is presented, which incorporates experiment- and informatics-derived evidence, such as DNA-binding data of PPAR subtypes to a panel of PPAR response elements (PPREs), PPRE location relative to the transcription start site (TSS) and PPRE conservation across multiple species, for more reliable prediction of PPREs. Results In vitro binding and in vivo functionality evidence agrees with in silico predictions, validating the approach. The experimental analysis of 30 putative PPREs in eight validated PPAR target genes indicates that each gene contains at least one functional, strong PPRE that occurs without positional bias relative to the TSS. An extended analysis of the cross-species conservation of PPREs reveals limited conservation of PPRE patterns, although PPAR target genes typically contain strong or multiple medium strength PPREs. Human chromosome 19 was screened using this method, with validation of six novel PPAR target genes. Conclusion An in silico screening approach is presented, which allows increased sensitivity of PPAR binding site and target gene detection.
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Affiliation(s)
- Merja Heinäniemi
- Department of Biochemistry, University of Kuopio, FIN-70211 Kuopio, Finland
- Life Sciences Research Unit, University of Luxembourg, L-1511 Luxembourg
| | - J Oskari Uski
- Department of Biochemistry, University of Kuopio, FIN-70211 Kuopio, Finland
| | - Tatjana Degenhardt
- Department of Biochemistry, University of Kuopio, FIN-70211 Kuopio, Finland
| | - Carsten Carlberg
- Department of Biochemistry, University of Kuopio, FIN-70211 Kuopio, Finland
- Life Sciences Research Unit, University of Luxembourg, L-1511 Luxembourg
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Bajwa PJ, Alioua A, Lee JW, Straus DS, Toro L, Lytle C. Fenofibrate inhibits intestinal Cl- secretion by blocking basolateral KCNQ1 K+ channels. Am J Physiol Gastrointest Liver Physiol 2007; 293:G1288-99. [PMID: 17916649 DOI: 10.1152/ajpgi.00234.2007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Fibrates are peroxisome proliferator-activated receptor-alpha (PPARalpha) ligands in widespread clinical use to lower plasma triglyceride levels. We investigated the effect of fenofibrate and clofibrate on ion transport in mouse intestine and in human T84 colonic adenocarcinoma cells through the use of short-circuit current (I(sc)) and ion flux analysis. In mice, oral administration of fenofibrate produced a persistent inhibition of cAMP-stimulated electrogenic Cl(-) secretion by isolated jejunum and colon without affecting electroneutral fluxes of (22)Na(+) or (86)Rb(+) (K(+)) across unstimulated colonic mucosa. When applied acutely to isolated mouse intestinal mucosa, 100 microM fenofibrate inhibited cAMP-stimulated I(sc) within 5 min. In T84 cells, fenofibrate rapidly inhibited approximately 80% the Cl(-) secretory responses to forskolin (cAMP) and to heat stable enterotoxin STa (cGMP) without affecting the response to carbachol (Ca(2+)). Both fenofibrate and clofibrate inhibited cAMP-stimulated I(sc) with an IC(50) approximately 1 muM, whereas other PPARalpha activators (gemfibrozil and Wy-14,643) were without effect. Membrane permeabilization experiments on T84 cells indicated that fenofibrate inhibits basolateral cAMP-stimulated K(+) channels (putatively KCNQ1/KCNE3) without affecting Ca(2+)-stimulated K(+) channel activity, whereas clofibrate inhibits both K(+) pathways. Fenofibrate had no effect on apical cAMP-stimulated Cl(-) channel activity. Patch-clamp analysis of HEK-293T cells confirmed that 100 microM fenofibrate rapidly inhibits K(+) currents associated with ectopic expression of human KCNQ1 with or without the KCNE3 beta-subunit. We conclude that fenofibrate inhibits intestinal cAMP-stimulated Cl(-) secretion through a nongenomic mechanism that involves a selective inhibition of basolateral KCNQ1/KCNE3 channel complexes. Our findings raise the prospect of fenofibrate as a safe and effective antidiarrheal agent.
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Affiliation(s)
- Poonam J Bajwa
- Division of Biomedical Sciences, University of California, Riverside, CA 92521-0121, USA
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Degenhardt T, Saramäki A, Malinen M, Rieck M, Väisänen S, Huotari A, Herzig KH, Müller R, Carlberg C. Three members of the human pyruvate dehydrogenase kinase gene family are direct targets of the peroxisome proliferator-activated receptor beta/delta. J Mol Biol 2007; 372:341-55. [PMID: 17669420 DOI: 10.1016/j.jmb.2007.06.091] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Revised: 06/28/2007] [Accepted: 06/29/2007] [Indexed: 12/26/2022]
Abstract
The nuclear receptors peroxisome proliferator-activated receptors (PPARs) are known for their critical role in the metabolic syndrome. Here, we show that they are direct regulators of the family of pyruvate dehydrogenase kinase (PDK) genes, whose products act as metabolic homeostats in sensing hunger and satiety levels in key metabolic tissues by modulating the activity of the pyruvate dehydrogenase complex. Mis-regulation of this tightly controlled network may lead to hyperglycemia. In human embryonal kidney cells we found the mRNA expression of PDK2, PDK3 and PDK4 to be under direct primary control of PPAR ligands, and in normal mouse kidney tissue Pdk2 and Pdk4 are PPAR targets. Both, treatment of HEK cells with PPARbeta/delta-specific siRNA and the genetic disruption of the Pparbeta/delta gene in mouse fibroblasts resulted in reduced expression of Pdk genes and abolition of induction by PPARbeta/delta ligands. These findings suggest that PPARbeta/delta is a key regulator of PDK genes, in particular the PDK4/Pdk4 gene. In silico analysis of the human PDK genes revealed two candidate PPAR response elements in the PDK2 gene, five in the PDK3 gene and two in the PDK4 gene, but none in the PDK1 gene. For seven of these sites we could demonstrate both PPARbeta/delta ligand responsiveness in context of their chromatin region and simultaneous association of PPARbeta/delta with its functional partner proteins, such as retinoidXreceptor, co-activator and mediator proteins and phosphorylated RNA polymerase II. In conclusion, PDK2, PDK3 and PDK4 are primary PPARbeta/delta target genes in humans underlining the importance of the receptor in the control of metabolism.
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Affiliation(s)
- Tatjana Degenhardt
- Department of Biochemistry, University of Kuopio, FIN-70211, Kuopio, Finland
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Luci S, Giemsa B, Kluge H, Eder K. Clofibrate causes an upregulation of PPAR-α target genes but does not alter expression of SREBP target genes in liver and adipose tissue of pigs. Am J Physiol Regul Integr Comp Physiol 2007; 293:R70-7. [PMID: 17363680 DOI: 10.1152/ajpregu.00603.2006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study investigated the effect of clofibrate treatment on expression of target genes of peroxisome proliferator-activated receptor (PPAR)-α and various genes of the lipid metabolism in liver and adipose tissue of pigs. An experiment with 18 pigs was performed in which pigs were fed either a control diet or the same diet supplemented with 5 g clofibrate/kg for 28 days. Pigs treated with clofibrate had heavier livers, moderately increased mRNA concentrations of various PPAR-α target genes in liver and adipose tissue, a higher concentration of 3-hydroxybutyrate, and markedly lower concentrations of triglycerides and cholesterol in plasma and lipoproteins than control pigs ( P < 0.05). mRNA concentrations of sterol regulatory element-binding proteins (SREBP)-1 and -2, insulin-induced genes ( Insig) -1 and Insig-2, and the SREBP target genes acetyl-CoA carboxylase, 3-methyl-3-hydroxyglutaryl-CoA reductase, and low-density lipoprotein receptor in liver and adipose tissue and mRNA concentrations of apolipoproteins A-I, A-II, and C-III in the liver were not different between both groups of pigs. In conclusion, this study shows that clofibrate treatment activates PPAR-α in liver and adipose tissue and has a strong hypotriglyceridemic and hypocholesterolemic effect in pigs. The finding that mRNA concentrations of some proteins responsible for the hypolipidemic action of fibrates in humans were not altered suggests that there were certain differences in the mode of action compared with humans. It is also shown that PPAR-α activation by clofibrate does not affect hepatic expression of SREBP target genes involved in synthesis of triglycerides and cholesterol homeostasis in liver and adipose tissue of pigs.
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Affiliation(s)
- Sebastian Luci
- Institut für Agrar- und Ernährungswissenschaften, Martin-Luther-Universität Halle-Wittenberg, Emil-Abderhalden-Strasse 26, D-06108 Halle/Saale, Germany
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Abstract
Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors involved in the transcriptional regulation of key metabolic pathways such as lipid metabolism, adipogenesis, and insulin sensitivity. More recent work implicates all 3 PPAR isotypes (alpha, gamma, and delta, also known as beta or beta/delta) in inflammatory and atherosclerotic pathways. Because these nuclear receptors are activated by extracellular signals and control multiple gene targets, PPARs can be seen as nodes that control multiple inputs and outputs involved in energy balance, providing insight into how metabolism and the vasculature may be integrated. The ongoing clinical use of fibrates, which activate PPARalpha, and thiazolidinediones, which activate PPARgamma, establishes these receptors as viable drug targets, whereas considerable in vitro animal model and human surrogate marker studies suggest that PPAR activation may limit inflammation and atherosclerosis. Together, these various observations have stimulated intense interest in PPARs as therapeutic targets and led to large-scale cardiovascular end-point trials with PPAR agonists. The first of these studies has generated mixed results that require careful review, especially in anticipation of additional clinical trial data and ongoing attempts to develop novel PPAR modulators. Such analysis of the existing PPAR data, the appropriate use of currently approved PPAR agonists, and continued progress in PPAR therapeutics will be predicated on a better understanding of PPAR biology.
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Affiliation(s)
- Jonathan D Brown
- Cardiovascular Division, Brigham and Women's Hospital, Boston, Mass, USA
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Ringseis R, Muschick A, Eder K. Dietary oxidized fat prevents ethanol-induced triacylglycerol accumulation and increases expression of PPARalpha target genes in rat liver. J Nutr 2007; 137:77-83. [PMID: 17182804 DOI: 10.1093/jn/137.1.77] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Alcoholic fatty liver results from an impaired fatty acid catabolism due to blockade of PPARalpha and increased lipogenesis due to activation of sterol regulatory element-binding protein (SREBP)-1c. Because both oxidized fats (OF) and conjugated linoleic acids (CLA) have been demonstrated in rats to activate hepatic PPARalpha, we tested the hypothesis that these fats are able to prevent ethanol-induced triacylglycerol accumulation in the liver by upregulation of PPARalpha-responsive genes. Forty-eight male rats were assigned to 6 groups and fed isocaloric liquid diets containing either sunflower oil (SFO) as a control fat, OF prepared by heating of SFO, or CLA, in the presence and absence of ethanol, for 4 wk. Administration of ethanol lowered mRNA concentrations of PPARalpha and the PPARalpha-responsive genes medium chain acyl-CoA dehydrogenase, long chain acyl-CoA dehydrogenase, acyl-CoA oxidase, carnitine palmitoyl-CoA transferase I, and cytochrome P450 4A1 and increased triacylglycerol concentrations in the liver (P < 0.05). OF increased hepatic mRNA concentrations of PPARalpha-responsive genes and lowered hepatic triacylglycerol concentrations compared with SFO (P < 0.05) whereas CLA did not. Rats fed OF with ethanol had similar mRNA concentrations of PPARalpha-responsive genes and similar triacylglycerol concentrations in the liver as rats fed SFO or CLA without ethanol. In contrast, hepatic mRNA concentrations of SREBP-1c and fatty acid synthase were not altered by OF or CLA compared with SFO. This study shows that OF prevents an alcohol-induced triacylglycerol accumulation in rats possibly by upregulation of hepatic PPARalpha-responsive genes involved in oxidation of fatty acids, whereas CLA does not exert such an effect.
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Affiliation(s)
- Robert Ringseis
- Institut für Ernährungswissenschaften, Martin-Luther-Universität Halle-Wittenberg, D-06108 Halle (Saale), Germany
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Degenhardt T, Matilainen M, Herzig KH, Dunlop TW, Carlberg C. The Insulin-like Growth Factor-binding Protein 1 Gene Is a Primary Target of Peroxisome Proliferator-activated Receptors. J Biol Chem 2006; 281:39607-19. [PMID: 17062566 DOI: 10.1074/jbc.m605623200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Insulin-like growth factor-binding protein 1 (IGFBP-1) is a biomarker for metabolic and hyperproliferative diseases. At the same time, the nuclear receptors peroxisome proliferator-activated receptors (PPARs) are known for their critical role in the development of both the metabolic syndrome and various cancers. Here we demonstrate, in human hepatocellular carcinoma cells and in normal mouse liver, that IGFBP-1 mRNA expression is under the primary control of PPAR ligands. We applied an improved in silico screening approach for PPAR response elements (PPREs) and identified five candidate PPREs located within 10 kb of the transcription start site (TSS) of the IGFBP-1 gene. Chromatin immunoprecipitation assays showed that, in living cells, the genomic region containing the most proximal PPRE, at position -1200 (relative to the TSS), preferentially associates with multiple PPAR subtypes and various other components of the transcriptional apparatus, which include their heterodimerizing partner, retinoid X receptor, as well as phosphorylated RNA polymerase II, co-repressor, co-activator, and mediator proteins. Moreover, further chromatin immunoprecipitation assays demonstrated that the TSS regions of the IGFBP-1 gene and those of the related IGFBP-2, -5, and -6, but not of IGFBP-3 and -4 genes, bind PPARs as well. We also show that these additional PPAR binding genes contain a number of candidate PPREs and that their mRNA levels respond quickly to the presence of PPAR ligands, indicating that they are also primary PPAR target genes.
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Affiliation(s)
- Tatjana Degenhardt
- Department of Biochemistry and A.I. Virtanen Institute, University of Kuopio, FIN-70211 Kuopio, Finland
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Frigerio F, Chaffard G, Berwaer M, Maechler P. The antiepileptic drug topiramate preserves metabolism-secretion coupling in insulin secreting cells chronically exposed to the fatty acid oleate. Biochem Pharmacol 2006; 72:965-73. [PMID: 16934763 DOI: 10.1016/j.bcp.2006.07.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Revised: 07/10/2006] [Accepted: 07/17/2006] [Indexed: 11/16/2022]
Abstract
Topiramate (Topamax), primarily prescribed against epilepsy, was reported to reduce body weight and to ameliorate glycemic control in obese patients with diabetes. In rodent models of obesity and diabetes, topiramate treatment counteracts hyperglycemia and increases insulin levels upon glucose tolerance test. These observations suggest that topiramate might exert direct action on insulin secreting cells, in particular regarding obesity associated beta-cell dysfunction. In this study, INS-1E beta-cells were exposed for 3 days to the fatty acid oleate (0.4mM) and concomitantly treated with therapeutic concentrations of topiramate before measurements of insulin secretion and metabolic parameters. In healthy cells, topiramate had no acute or chronic effects on insulin release. Exposure of INS-1E cells to oleate for 3 days increased insulin release at basal 2.5mM glucose and blunted the response to stimulatory glucose concentration (15mM). Such lipotoxic effects were associated with impaired mitochondrial function, as evidenced by partial loss of resting mitochondrial membrane potential and reduced hyperpolarization in response to glucose. Oil-red-O staining and triglyceride measurements revealed lipid accumulation in oleate treated cells. Topiramate treatment counteracted oleate-induced lipid load and partially protected against mitochondrial membrane dysfunction. In particular, topiramate restored glucose stimulated insulin secretion, essentially by maintaining low insulin release at basal glucose. Topiramate increased expression of the nutrient sensor PPARalpha and of the mitochondrial fatty acid carrier CPT-1, correlating with enhancement of beta-oxidation rate. The data demonstrate that a drug originally used as mood stabilizer exerts a direct action on beta-cells, protecting against lipid-induced dysfunction.
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Affiliation(s)
- Francesca Frigerio
- Department of Cell Physiology and Metabolism, University Medical Centre, 1 rue Michel-Servet, CH-1211 Geneva 4, Switzerland
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Luci S, Kluge H, Hirche F, Eder K. Clofibrate Increases Hepatic Triiodothyronine (T3)- and Thyroxine (T4)-Glucuronosyltransferase Activities and Lowers Plasma T3and T4Concentrations in Pigs. Drug Metab Dispos 2006; 34:1887-92. [PMID: 16896063 DOI: 10.1124/dmd.106.011379] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In rats, clofibrate acts as a microsomal enzyme inducer and disrupts the metabolism of thyroid hormones by increasing hepatic glucuronidation of thyroxine. Whether similar effects occur in the pig has not yet been investigated. This study was performed to investigate the effect of clofibrate treatment on metabolism of thyroid hormones in pigs. To this end, an experiment with 18 pigs, which were assigned to two groups, was performed. One group received a control diet, and the other group was fed the same diet supplemented with 5 g of clofibrate/kg for 28 days. Pigs treated with clofibrate had higher hepatic activities of T(3)- and T(4)-UDP glucuronosyltransferases (UGT) and lower concentrations of total and free T(4) and total T(3) in plasma than control pigs (P < 0.05). Weights and histology of the thyroid gland (epithelial height, follicle lumen diameter) did not differ between the two groups, but pigs treated with clofibrate had higher mRNA concentrations of various genes in the thyroid responsive to thyroid-stimulating hormone (TSH) such as TSH receptor, sodium iodine symporter, thyroid peroxidase, and cathepsin B than control pigs (P < 0.05). Pigs treated with clofibrate also had lower hepatic mRNA concentrations of proteins involved in plasma thyroid hormone transport [thyroxine-binding globulin (P < 0.10), transthyretin (P < 0.05), and albumin (P < 0.05)] and thyroid hormone receptor alpha(1) (P < 0.05) than control pigs. In conclusion, this study shows that clofibrate treatment induces a strong activation of T(3)- and T(4)-UGT in pigs, leading to increased glucuronidation and markedly reduced plasma concentrations of these hormones, accompanied by a moderate stimulation of thyroid function.
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Affiliation(s)
- Sebastian Luci
- Institut für Ernährungswissenschaften, Martin-Luther-Universität Halle-Wittenberg, Emil-Abderhalden-Str 26, Halle/S, Germany
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39
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Tavera-Mendoza LE, Mader S, White JH. Genome-wide approaches for identification of nuclear receptor target genes. NUCLEAR RECEPTOR SIGNALING 2006; 4:e018. [PMID: 16862224 PMCID: PMC1513072 DOI: 10.1621/nrs.04018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2005] [Accepted: 04/06/2006] [Indexed: 11/20/2022]
Abstract
Large-scale genomics analyses have grown by leaps and bounds with the rapid advances in high throughput DNA sequencing and synthesis techniques. Nuclear receptor signaling is ideally suited to genomics studies because receptors function as ligand-regulated gene switches. This review will survey the strengths and limitations of three major classes of high throughput techniques widely used in the nuclear receptor field to characterize ligand-dependent gene regulation: expression profiling studies (microarrays, SAGE and related techniques), chromatin immunoprecipitation followed by microarray (ChIP-on-chip), and genome-wide in silico hormone response element screens. We will discuss each technique, and how each has contributed to our understanding of nuclear receptor signaling.
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Huang THW, Li Y, Razmovski-Naumovski V, Tran VH, Li GQ, Duke CC, Roufogalis BD. Gypenoside XLIX isolated from Gynostemma pentaphyllum inhibits nuclear factor-kappaB activation via a PPAR-alpha-dependent pathway. J Biomed Sci 2006; 13:535-48. [PMID: 16525884 DOI: 10.1007/s11373-006-9076-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2005] [Accepted: 01/26/2006] [Indexed: 01/10/2023] Open
Abstract
Nuclear factor (NF)-kappaB is important in the generation of inflammation. Besides regulating lipid metabolism, peroxisome proliferator-activated receptor (PPAR)-alpha activators also reduce NF-kappaB activation to terminate activation of inflammatory pathways. Gynostemma pentaphyllum (GP) has been used to treat various inflammatory diseases and hyperlipidemia. Here, we demonstrate that GP extract and one of its main components, Gypenoside XLIX (Gyp-XLIX) inhibited LPS-induced NF-kappaB activation in murine macrophages. Furthermore, Gyp-XLIX restored the LPS- and TNF-alpha-induced decrease in cytosolic I-kappaBalpha protein expression and inhibited the translocation of NF-kappaB(p65) to the nucleus in THP-1 monocyte and HUVEC cells. The inhibition of LPS- and TNF-alpha-induced NF-kappaB luciferase activity in macrophages was abolished by MK-886, a selective PPAR-alpha antagonist. GP extract and Gyp-XLIX (EC(50): 10.1 microM) enhanced PPAR-alpha luciferase activity in HEK293 cells transfected with the tK-PPREx3-Luc reporter plasmid and expression vectors for PPAR-alpha. Additionally, Gyp-XLIX specifically enhanced PPAR-alpha mRNA and protein expression in THP-1-derived macrophage cells. The selectivity of Gyp-XLIX for PPAR-alpha was demonstrated by the activation of only PPAR-alpha in HEK293 cells transfected with expression vectors for PPAR-alpha, PPAR-beta/delta or PPAR-gamma1 plasmids and in THP-1-derived macrophage naturally expressing all three PPAR isoforms. The present study demonstrates that Gyp-XLIX, a naturally occurring gynosaponin, inhibits NF-kappaB activation via a PPAR-alpha-dependent pathway.
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Affiliation(s)
- Tom Hsun-Wei Huang
- Pharmaceutical Chemistry Discipline and Herbal Medicines Research and Education Centre, Faculty of Pharmacy, University of Sydney, A15 S322, Sydney, NSW 2006, Australia
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Srivastava RAK, Jahagirdar R, Azhar S, Sharma S, Bisgaier CL. Peroxisome proliferator-activated receptor-alpha selective ligand reduces adiposity, improves insulin sensitivity and inhibits atherosclerosis in LDL receptor-deficient mice. Mol Cell Biochem 2006; 285:35-50. [PMID: 16477380 DOI: 10.1007/s11010-005-9053-y] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2005] [Accepted: 10/14/2005] [Indexed: 01/18/2023]
Abstract
Fenofibrate, a selective (1)PPAR-alpha activator, is prescribed to treat human dyslipidemia. The aim of this study was to delineate the mechanism of fenofibrate-mediated reductions in adiposity, improvements in insulin sensitivity, and lowering of triglycerides (TG) and free fatty acids (FFA) and to investigate if these favorable changes are related to the inhibition of lipid deposition in the aorta. To test this hypothesis we used male LDLr deficient mice that exhibit the clinical features of metabolic syndrome X when fed a high fat high cholesterol (HF) diet. LDLr deficient mice fed HF diet and simultaneously treated with fenofibrate (100 mg/kg body weight) prevented development of obesity, lowered serum triglycerides and cholesterol, improved insulin sensitivity, and prevented accumulation of lipids in the aorta. Lowering of circulating lipids occurred via down-regulation of lipogenic genes, including fatty acid synthase, acetyl CoA carboxylase and diacyl glycerol acyl transferase-2, concomitant with decreased liver TG and cholesterol, and TG output rate. Fenofibrate also suppressed liver apoCIII mRNA levels and markedly increased lipoprotein lipase mRNA levels, known to enhance serum TG catabolism. In addition, fenofibrate profoundly reduced epididymal fat and mesenteric fat mass to the levels seen in lean mice. The reductions in body weight were associated with elevation of hepatic uncoupling protein 2 (UCP2) mRNA, a concomitant increase in the ketone body formation, and improved insulin sensitivity associated with tumor necrosis factor-alpha reductions and phosphoenol pyruvate carboxykinase down-regulation. These results demonstrate that fenofibrate improves lipid abnormalities partly via inhibition of TG production and partly via clearance of TG-rich apoB particles by elevating LPL and reduced apoCIII. The prevention of obesity development occurred via energy expenditure. Fenofibrate-mediated hypolipidemic effects together with improved insulin sensitivity and loss of adiposity led to the reductions in the aortic lipid deposition by inhibiting early stages of atherosclerosis possibly via vascular cell adhesion molecule-1 (VCAM-1) modulation. These results suggest that potent PPAR-alpha activators may be useful in the treatment of syndrome X.
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Denning GM, Stoll LL. Peroxisome proliferator-activated receptors: potential therapeutic targets in lung disease? Pediatr Pulmonol 2006; 41:23-34. [PMID: 16267824 DOI: 10.1002/ppul.20338] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The peroxisome proliferator-activated receptors (PPARs) are a family of nuclear hormone receptors that play central roles in lipid and glucose homeostasis, cellular differentiation, and the immune/inflammatory response. Growing evidence indicates that changes in expression and activation of PPARs likely modulate conditions as diverse as diabetes, atherosclerosis, cancer, asthma, Parkinson's disease, and Alzheimer's disease. Activation of these receptors by natural or pharmacologic ligands leads to both gene-dependent and gene-independent effects that alter the expression of a wide array of proteins. In the lung, PPARs are expressed by alveolar macrophages, as well as by epithelial, endothelial, and smooth muscle cells. Studies both in vitro and in vivo suggest that PPAR ligands may have anti-inflammatory effects in asthma, pulmonary sarcoidosis, and pulmonary alveolar proteinosis, as well as antiproliferative and antiangiogenic effects in epithelial lung cancers. Further studies to understand the contribution of these receptors to health and disease will be important for determining whether they represent a promising target for therapeutic intervention.
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Affiliation(s)
- Gerene M Denning
- Department of Emergency Medicine, Roy J. and Lucille Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
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Montanaro MA, Bernasconi AM, González MS, Rimoldi OJ, Brenner RR. Effects of fenofibrate and insulin on the biosynthesis of unsaturated fatty acids in streptozotocin diabetic rats. Prostaglandins Leukot Essent Fatty Acids 2005; 73:369-78. [PMID: 16099631 DOI: 10.1016/j.plefa.2005.06.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2005] [Accepted: 06/18/2005] [Indexed: 10/25/2022]
Abstract
Both insulin and PPAR-alpha up-modulate hepatic Delta9, Delta6 and Delta5 desaturating enzymes involved in the biosynthesis of mono- and polyunsaturated fatty acids. Currently, we have examined for 9 days the independent and simultaneous effects of daily glargine insulin and fenofibrate administration on the insulinemia, glycemia, hepatic acyl-CoA oxidase activity and mRNAs and enzymatic activities of stearoyl-CoA desaturase-1 (SCD-1) and Delta5 desaturase in streptozotocin diabetic rats. Glargine insulin depressed the hyperglycemia of diabetic rats at 4h, but not after 24h of injection. Fenofibrate increased the radioimmunoreactive insulinemia in non-diabetic rats without changing the glycemia. Insulin increased the mRNAs and activities of SCD-1 and Delta5 desaturase depressed in diabetic rats. Fenofibrate increased acyl-CoA oxidase activity, and the mRNAs and activities of both desaturating enzymes in non-diabetic, diabetic and insulin-treated diabetic rats, but was less effective in the mRNAs modification of diabetic animals. Therefore, insulin, and fenofibrate through PPAR-alpha activation, enhance liver mRNAs and activities of SCD-1 and Delta5 desaturases independently and synergistically through different mechanisms. Insulin and fenofibrate independently increased the 18:1/18:0 ratio in liver lipids, increasing the fluidity of the membranes. The 20:4/18:2 ratio was maintained. Fenofibrate increased palmitic acid, but decreased stearic acid percentage in liver lipids.
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Affiliation(s)
- Mauro A Montanaro
- Facultad de Ciencias Médicas,Instituto de Investigaciones Bioquímicas de La Plata (INIBIOLP), CONICET-UNLP, calles 60 y 120, Argentina
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Huang THW, Peng G, Kota BP, Li GQ, Yamahara J, Roufogalis BD, Li Y. Pomegranate flower improves cardiac lipid metabolism in a diabetic rat model: role of lowering circulating lipids. Br J Pharmacol 2005; 145:767-74. [PMID: 15880139 PMCID: PMC1576197 DOI: 10.1038/sj.bjp.0706245] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Excess triglyceride (TG) accumulation and increased fatty acid (FA) oxidation in the diabetic heart contribute to cardiac dysfunction. Punica granatum flower (PGF) is a traditional antidiabetic medicine. Here, we investigated the effects and mechanisms of action of PGF extract on abnormal cardiac lipid metabolism both in vivo and in vitro. Long-term oral administration of PGF extract (500 mg kg(-1)) reduced cardiac TG content, accompanied by a decrease in plasma levels of TG and total cholesterol in Zucker diabetic fatty (ZDF) rats, indicating improvement by PGF extract of abnormal cardiac TG accumulation and hyperlipidemia in this diabetic model. Treatment of ZDF rats with PGF extract lowered plasma FA levels. Furthermore, the treatment suppressed cardiac overexpression of mRNAs encoding for FA transport protein, peroxisome proliferator-activated receptor (PPAR)-alpha, carnitine palmitoyltransferase-1, acyl-CoA oxidase and 5'-AMP-activated protein kinase alpha2, and restored downregulated cardiac acetyl-CoA carboxylase mRNA expression in ZDF rats, whereas it showed little effect in Zucker lean rats. The results suggest that PGF extract inhibits increased cardiac FA uptake and oxidation in the diabetic condition. PGF extract and its component oleanolic acid enhanced PPAR-alpha luciferase reporter gene activity in human embryonic kidney 293 cells, and this effect was completely suppressed by a selective PPAR-alpha antagonist MK-886, consistent with the presence of PPAR-alpha activator activity in the extract and this component. Our findings suggest that PGF extract improves abnormal cardiac lipid metabolism in ZDF rats by activating PPAR-alpha and thereby lowering circulating lipid and inhibiting its cardiac uptake.
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Affiliation(s)
- Tom Hsun-Wei Huang
- Herbal Medicines Research and Education Centre, Faculty of Pharmacy, The University of Sydney, NSW, 2006, Australia
| | - Gang Peng
- Herbal Medicines Research and Education Centre, Faculty of Pharmacy, The University of Sydney, NSW, 2006, Australia
| | - Bhavani Prasad Kota
- Herbal Medicines Research and Education Centre, Faculty of Pharmacy, The University of Sydney, NSW, 2006, Australia
| | - George Qian Li
- Herbal Medicines Research and Education Centre, Faculty of Pharmacy, The University of Sydney, NSW, 2006, Australia
| | | | - Basil D Roufogalis
- Herbal Medicines Research and Education Centre, Faculty of Pharmacy, The University of Sydney, NSW, 2006, Australia
| | - Yuhao Li
- Herbal Medicines Research and Education Centre, Faculty of Pharmacy, The University of Sydney, NSW, 2006, Australia
- Author for correspondence:
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Cariello NF, Romach EH, Colton HM, Ni H, Yoon L, Falls JG, Casey W, Creech D, Anderson SP, Benavides GR, Hoivik DJ, Brown R, Miller RT. Gene expression profiling of the PPAR-alpha agonist ciprofibrate in the cynomolgus monkey liver. Toxicol Sci 2005; 88:250-64. [PMID: 16081524 DOI: 10.1093/toxsci/kfi273] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Fibrates, such as ciprofibrate, fenofibrate, and clofibrate, are peroxisome proliferator-activated receptor-alpha (PPARalpha) agonists that have been in clinical use for many decades for treatment of dyslipidemia. When mice and rats are given PPARalpha agonists, these drugs cause hepatic peroxisome proliferation, hypertrophy, hyperplasia, and eventually hepatocarcinogenesis. Importantly, primates are relatively refractory to these effects; however, the mechanisms for the species differences are not clearly understood. Cynomolgus monkeys were exposed to ciprofibrate at various dose levels for either 4 or 15 days, and the liver transcriptional profiles were examined using Affymetrix human GeneChips. Strong upregulation of many genes relating to fatty acid metabolism and mitochondrial oxidative phosphorylation was observed; this reflects the known pharmacology and activity of the fibrates. In addition, (1) many genes related to ribosome and proteasome biosynthesis were upregulated, (2) a large number of genes downregulated were in the complement and coagulation cascades, (3) a number of key regulatory genes, including members of the JUN, MYC, and NFkappaB families were downregulated, which appears to be in contrast to the rodent, where JUN and MYC are reported to upregulated after PPARalpha agonist treatment, (4) no transcriptional signal for DNA damage or oxidative stress was observed, and (5) transcriptional signals consistent with an anti-proliferative and a pro-apoptotic effect were seen. We also compared the primate data to literature reports of hepatic transcriptional profiling in PPARalpha-treated rodents, which showed that the magnitude of induction in beta-oxidation pathways was substantially greater in the rodent than the primate.
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Affiliation(s)
- Neal F Cariello
- GlaxoSmithKline Inc., Safety Assessment, Research Triangle Park, North Carolina 27709, USA.
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Molnár F, Matilainen M, Carlberg C. Structural Determinants of the Agonist-independent Association of Human Peroxisome Proliferator-activated Receptors with Coactivators. J Biol Chem 2005; 280:26543-56. [PMID: 15888456 DOI: 10.1074/jbc.m502463200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Lipid homeostasis is controlled by various nuclear receptors (NRs), including the peroxisome proliferator-activated receptors (PPARalpha, delta, and gamma), which sense lipid levels and regulate their metabolism. Here we demonstrate that human PPARs have a high basal activity and show ligand-independent coactivator (CoA) association comparable with the NR constitutive androstane receptor. Using PPARgamma as an example, we found that four different amino acid groups contribute to the ligand-independent stabilization of helix 12 of the PPAR ligand-binding domain. These are: (i) Lys329 and Glu499, mediating a charge clamp-type stabilization of helix 12 via a CoA bridge; (ii) Glu352, Arg425, and Tyr505, directly stabilizing the helix via salt bridges and hydrogen bonds; (iii) Lys347 and Asp503, interacting with each other as well as contacting the CoA; and (iv) His351, Tyr(355), His477, and Tyr501, forming a hydrogen bond network. These amino acids are highly conserved within the PPAR subfamily, suggesting that the same mechanism may apply for all three PPARs. Phylogenetic trees of helix 12 amino acid and nucleotide sequences of all crystallized NRs and all human NRs, respectively, indicated a close relationship of PPARs with constitutive androstane receptor and other constitutive active members of the NR superfamily. Taking together, the ligand-independent tight control of the position of the PPAR helix 12 provides an effective alternative for establishing an interaction with CoA proteins. This leads to high basal activity of PPARs and provides an additional view on PPAR signaling.
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Affiliation(s)
- Ferdinand Molnár
- Department of Biochemistry, University of Kuopio, Kuopio FIN-70211, Finland
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47
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Kitajka K, Sinclair AJ, Weisinger RS, Weisinger HS, Mathai M, Jayasooriya AP, Halver JE, Puskás LG. Effects of dietary omega-3 polyunsaturated fatty acids on brain gene expression. Proc Natl Acad Sci U S A 2004; 101:10931-6. [PMID: 15263092 PMCID: PMC503722 DOI: 10.1073/pnas.0402342101] [Citation(s) in RCA: 227] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Polyunsaturated fatty acids (PUFA) are essential structural components of the central nervous system. Their role in controlling learning and memory has been well documented. A nutrigenomic approach with high-density microarrays was used to reveal brain gene-expression changes in response to different PUFA-enriched diets in rats. In aged rats fed throughout life with PUFA-enriched diets, genes with altered expressions included transthyretin, alpha-synuclein, and calmodulins, which play important roles in synaptic plasticity and learning. The effect of perinatal omega-3 PUFA supply on gene expression later in life also was studied. Several genes showed similar changes in expression in rats fed omega-3-deficient diets in the perinatal period, regardless of whether they or their mothers were fed omega-3 PUFA-sufficient diets after giving birth. In this experiment, among the down-regulated genes were a kainate glutamate receptor and a DEAD-box polypeptide. Among the up-regulated genes were a chemokine-like factor, a tumor necrosis factor receptor, and cytochrome c. The possible involvement of the genes with altered expression attributable to different diets in different brain regions in young and aged rats and the possible mode of regulatory action of PUFA also are discussed. We conclude that PUFA-enriched diets lead to significant changes in expression of several genes in the central nervous tissue, and these effects appear to be mainly independent of their effects on membrane composition. The direct effects of PUFA on transcriptional modulators, the downstream developmentally and tissue-specifically activated elements might be one of the clues to understanding the beneficial effects of the omega-3 PUFA on the nervous system.
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Affiliation(s)
- Klára Kitajka
- Laboratory of Functional Genomics, Biological Research Center, Hungarian Academy of Sciences, H-6701, Szeged, Hungary
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48
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Daniel H, tom Dieck H. Nutrient-gene interactions: a single nutrient and hundreds of target genes. Biol Chem 2004; 385:571-83. [PMID: 15318805 DOI: 10.1515/bc.2004.071] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
AbstractBased on the effects of a selective experimental zinc deficiency in a rodent model we explore the use of transcriptome profiling for assessing nutrient-gene interactions in the liver at the molecular and cellular levels. Zinc deficiency caused pleiotropic alterations in mRNA/protein levels of hundreds of genes. In the context of observed metabolic alterations in hepatic metabolism, possible mechanisms are discussed for how a low zinc status may be sensed and transmitted into changes in various metabolic pathways. However, it also becomes obvious that analysis of such complex nutrient-gene interactions beyond the descriptional level is a real challenge for systems biology.
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Affiliation(s)
- Hannelore Daniel
- Molecular Nutrition Unit, Technical University of Munich, Life and Food Science Center, Hochfeldweg 2, D-85350 Freising-Weihenstephan, Germany.
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