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Torequl Islam M, Shimul Bhuia M, Paulo Martins de Lima J, Paulo Araujo Maia F, Beatriz Herminia Ducati A, Douglas Melo Coutinho H. Phytanic acid, an inconclusive phytol metabolite: A review. Curr Res Toxicol 2023; 5:100120. [PMID: 37744206 PMCID: PMC10515296 DOI: 10.1016/j.crtox.2023.100120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 07/28/2023] [Accepted: 08/30/2023] [Indexed: 09/26/2023] Open
Abstract
Phytanic acid (PA: 3,7,11,15-tetramethylhexadecanoic acid) is an important biometabolite of the chlorophyll-derived diterpenoid phytol. Its biological sources (occurrence) and ADME (absorption, distribution, metabolism, and elimination) profile are well-discussed in the literature. Cumulative literature suggests that PA has beneficial as well as harmful biological roles in humans and other animals. This study aimed to sketch a brief summary of PA's beneficial and harmful pharmacological effects in test systems on the basis of existing literature reports. Literature findings propose that PA has anti-inflammatory and immunomodulatory, antidiabetic, anti-obesity, anticancer, and oocyte maturation effects. Although a high plasma PA-level mediated SLS remains controversial, it is evident to link it with Refsum's disease and other peroxisomal enzyme deficiency diseases in humans, including RCDP and LD; ZHDA and Alzheimer's disease; progressive ataxia and dysarthria; and an increased risk of some lymphomas such as LBL, FL, and NHL. PA exerts toxic effects on different kinds of cells, including neuronal, cardiac, and renal cells, through diverse pathways such as oxidative stress, mitochondrial disturbance, apoptosis, disruption of Na+/K+-ATPase activity, Ca2+ homeostasis, alteration of AChE and MAO activities, etc. PA is considered a cardiac biomarker in humans. In conclusion, PA may be one of the most important biometabolites in humans.
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Affiliation(s)
- Muhammad Torequl Islam
- Department of Pharmacy, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalganj 8100, Bangladesh
| | - Md. Shimul Bhuia
- Department of Pharmacy, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalganj 8100, Bangladesh
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Phytol and its metabolites phytanic and pristanic acids for risk of cancer: current evidence and future directions. Eur J Cancer Prev 2019; 29:191-200. [PMID: 31436750 PMCID: PMC7012361 DOI: 10.1097/cej.0000000000000534] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This review summarizes the current evidence on the potential role of phytol, a microbial metabolite of chlorophyl A, and its metabolites, phytanic and pristanic acids, in carcinogenesis. Primary food sources in Western diets are the nut skin for phytol and lipids in dairy, beef and fish for its metabolites. Phytol and its metabolites gained interest as dietary compounds for cancer prevention because, as natural ligands of peroxisome proliferator-activated receptor-α and -γ and retinoid X receptor, phytol and its metabolites have provided some evidence in cell culture studies and limited evidence in animal models of anti-carcinogenic, anti-inflammatory and anti-metabolic-syndrome properties at physiological concentrations. However, there may be a narrow range of efficacy, because phytol and its metabolites at supra-physiological concentrations can cause in vitro cytotoxicity in non-cancer cells and can cause morbidity and mortality in animal models. In human studies, evidence for a role of phytol and its metabolites in cancer prevention is currently limited and inconclusive. In short, phytol and its metabolites are potential dietary compounds for cancer prevention, assuming the challenges in preventing cytotoxicity in non-cancer cells and animal models and understanding phytol metabolism can be mitigated.
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Dubot P, Astudillo L, Touati G, Baruteau J, Broué P, Roche S, Sabourdy F, Levade T. Pregnancy outcome in Refsum disease: Affected fetuses and children born to an affected mother. JIMD Rep 2019; 46:11-15. [PMID: 31240149 PMCID: PMC6498833 DOI: 10.1002/jmd2.12020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 11/06/2022] Open
Abstract
We describe the case of a young woman, from a consanguineous family, affected by adult Refsum disease (ARD, OMIM#266500). ARD is a rare peroxisomal autosomal recessive disease due to deficient alpha-oxidation of phytanic acid (PA), a branched-chain fatty acid. The accumulation of PA in organs is thought to be responsible for disease symptoms. The patient presented only bilateral shortening of metatarsals and has been treated with a low-PA diet. She is homoallelic for the c.135-2A > G mutation of PHYH, and she married her first cousin carrying the same mutation. She was pregnant seven times and had two homozygous girls. Due to a potential exacerbation of the disease during the third trimester of pregnancy, her weight and plasma PA levels were monitored. No specific events were noticed for the mother during the pregnancies and postpartum periods. This case also raised the question of potential exposure to PA (and its subsequent toxicity) of a homozygous fetus in a homozygous mother. Despite modestly elevated plasma concentrations of PA at birth (<30 μmol/L), the two affected girls did not present any specific sign of ARD and have so far developed normally. As only a few determinations of plasma PA levels in the mother could be performed during pregnancies, showing mild elevations (<350 μmol/L), it remains difficult to conclude as to a possible transplacental crossing of PA.
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Affiliation(s)
- Patricia Dubot
- Laboratoire de Biochimie MétaboliqueCentre de Référence en Maladies Héréditaires du Métabolisme, Institut Fédératif de Biologie, CHU de ToulouseToulouseFrance
- INSERM UMR1037CRCT (Cancer Research Center of Toulouse)ToulouseFrance
| | - Léonardo Astudillo
- INSERM UMR1037CRCT (Cancer Research Center of Toulouse)ToulouseFrance
- Service de Médecine InterneCentre de Référence en Maladies Héréditaires du Métabolisme, CHU de ToulouseToulouseFrance
| | - Guy Touati
- Département d'Hépato‐gastroentérologie pédiatrique, Centre de Référence en Maladies Héréditaires du MétabolismeHôpital des Enfants, CHU de ToulouseToulouseFrance
| | - Julien Baruteau
- Département d'Hépato‐gastroentérologie pédiatrique, Centre de Référence en Maladies Héréditaires du MétabolismeHôpital des Enfants, CHU de ToulouseToulouseFrance
| | - Pierre Broué
- Département d'Hépato‐gastroentérologie pédiatrique, Centre de Référence en Maladies Héréditaires du MétabolismeHôpital des Enfants, CHU de ToulouseToulouseFrance
| | - Sandrine Roche
- Département d'Hépato‐gastroentérologie pédiatrique, Centre de Référence en Maladies Héréditaires du MétabolismeHôpital des Enfants, CHU de ToulouseToulouseFrance
| | - Frédérique Sabourdy
- Laboratoire de Biochimie MétaboliqueCentre de Référence en Maladies Héréditaires du Métabolisme, Institut Fédératif de Biologie, CHU de ToulouseToulouseFrance
- INSERM UMR1037CRCT (Cancer Research Center of Toulouse)ToulouseFrance
| | - Thierry Levade
- Laboratoire de Biochimie MétaboliqueCentre de Référence en Maladies Héréditaires du Métabolisme, Institut Fédératif de Biologie, CHU de ToulouseToulouseFrance
- INSERM UMR1037CRCT (Cancer Research Center of Toulouse)ToulouseFrance
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Phytol in a pharma-medico-stance. Chem Biol Interact 2015; 240:60-73. [DOI: 10.1016/j.cbi.2015.07.010] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 07/01/2015] [Accepted: 07/24/2015] [Indexed: 01/02/2023]
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Warkus ELL, Yuen AAYQ, Lau CGY, Marikawa Y. Use ofIn VitroMorphogenesis of Mouse Embryoid Bodies to Assess Developmental Toxicity of Therapeutic Drugs Contraindicated in Pregnancy. Toxicol Sci 2015; 149:15-30. [DOI: 10.1093/toxsci/kfv209] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Elmazar MM, El-Abhar HS, Schaalan MF, Farag NA. Phytol/Phytanic acid and insulin resistance: potential role of phytanic acid proven by docking simulation and modulation of biochemical alterations. PLoS One 2013; 8:e45638. [PMID: 23300941 PMCID: PMC3534692 DOI: 10.1371/journal.pone.0045638] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Accepted: 08/22/2012] [Indexed: 11/20/2022] Open
Abstract
Since activation of PPARγ is the main target for the antidiabetic effect of TZDs, especially when it heterodimerizes with RXR, we aimed to test the potential antidiabetic effect of phytol (250 mg/kg), the natural precursor of phytanic acid, a RXR ligand and/or pioglitazone (5 mg/kg) to diabetic insulin-resistant rats. Regarding the molecular docking simulation on PPARγ, phytanic acid, rather than phytol, showed a binding mode that mimics the crystal orientation of rosiglitazone and pioglitazone, forming H bonds with the same amino acids (S289, H 323, H 449 and Y 473), and the least energy level, which emphasizes their importance for PPARγ molecular recognition, activation, hence antidiabetic activity. In addition, docking on the RXRα/PPARγ heterodimer, revealed that phytanic acid has higher binding affinity and lesser energy score on RXRα, compared to the original ligand, retinoic acid. Phytanic acid binds by 3H bonds and shares retinoic acid in arginine (R 316). These results were further supported biochemically, where oral phytol and/or pioglitazone (5 mg/kg) improved significantly glucose homeostasis, lipid panel, raised serum adiponectin level and lowered TNF-α, reaching in most cases the effect of the 10 mg/kg pioglitazone. The study concluded that the insulin sensitizing/anti-diabetic effect of phytol is mediated by partly from activation of nuclear receptors and heterodimerization of RXR with PPARγ by phytanic acid.
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Affiliation(s)
| | - Hanan S. El-Abhar
- Department of Pharmacology & Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Mona F. Schaalan
- Department of Biochemistry, Faculty of Pharmacy, Misr International University (MIU), Cairo, Egypt
| | - Nahla A. Farag
- Department of Pharmaceutical Medicinal Chemistry, Faculty of Pharmacy, Misr International University (MIU), Cairo, Egypt
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Ma C, Shaw GM, Scheuerle AE, Canfield MA, Carmichael SL. Association of microtia with maternal nutrition. ACTA ACUST UNITED AC 2012; 94:1026-32. [DOI: 10.1002/bdra.23053] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 06/01/2012] [Accepted: 06/06/2012] [Indexed: 11/09/2022]
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Zheng B, Han M, Shu YN, Li YJ, Miao SB, Zhang XH, Shi HJ, Zhang T, Wen JK. HDAC2 phosphorylation-dependent Klf5 deacetylation and RARα acetylation induced by RAR agonist switch the transcription regulatory programs of p21 in VSMCs. Cell Res 2011; 21:1487-508. [PMID: 21383775 PMCID: PMC3193446 DOI: 10.1038/cr.2011.34] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Revised: 12/19/2010] [Accepted: 01/10/2011] [Indexed: 02/03/2023] Open
Abstract
Abnormal proliferation of vascular smooth muscle cells (VSMCs) occurs in hypertension, atherosclerosis and restenosis after angioplasty, leading to pathophysiological vascular remodeling. As an important growth arrest gene, p21 plays critical roles in vascular remodeling. Regulation of p21 expression by retinoic acid receptor (RAR) and its ligand has important implications for control of pathological vascular remodeling. Nevertheless, the mechanism of RAR-mediated p21 expression in VSMCs remains poorly understood. Here, we show that, under basal conditions, RARα forms a complex with histone deacetylase 2 (HDAC2) and Krüppel-like factor 5 (Klf5) at the p21 promoter to inhibit its expression. Upon RARα agonist stimulation, HDAC2 is phosphorylated by CK2α. Phosphorylation of HDAC2, on the one hand, promotes its dissociation from RARα, thus allowing the liganded-RARα to interact with co-activators; on the other hand, it increases its interaction with Klf5, thus leading to deacetylation of Klf5. Deacetylation of Klf5 facilitates its dissociation from the p21 promoter, relieving its repressive effect on the p21 promoter. Interference with HDAC2 phosphorylation by either CK2α knockdown or the use of phosphorylation-deficient mutant of HDAC2 prevents the dissociation of Klf5 from the p21 promoter and impairs RAR agonist-induced p21 activation. Our results reveal a novel mechanism involving a phosphorylation-deacetylation cascade that functions to remove the basal repression complex from the p21 promoter upon RAR agonist treatment, allowing for optimum agonist-induced p21 expression.
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MESH Headings
- Acetylation
- Animals
- Casein Kinase II/genetics
- Casein Kinase II/metabolism
- Cell Line
- Cyclin-Dependent Kinase Inhibitor p21/genetics
- Cyclin-Dependent Kinase Inhibitor p21/metabolism
- Gene Expression Regulation/physiology
- Histone Deacetylase 2/genetics
- Histone Deacetylase 2/metabolism
- Kruppel-Like Transcription Factors/genetics
- Kruppel-Like Transcription Factors/metabolism
- Male
- Multiprotein Complexes/genetics
- Multiprotein Complexes/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Mutation
- Myocytes, Smooth Muscle/cytology
- Myocytes, Smooth Muscle/metabolism
- Phosphorylation/physiology
- Promoter Regions, Genetic/physiology
- Rats
- Rats, Sprague-Dawley
- Receptors, Retinoic Acid/agonists
- Receptors, Retinoic Acid/genetics
- Receptors, Retinoic Acid/metabolism
- Repressor Proteins/genetics
- Repressor Proteins/metabolism
- Retinoic Acid Receptor alpha
- Transcription, Genetic/physiology
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Affiliation(s)
- Bin Zheng
- Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China
| | - Mei Han
- Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China
| | - Ya-nan Shu
- Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China
| | - Ying-jie Li
- Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China
| | - Sui-bing Miao
- Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China
| | - Xin-hua Zhang
- Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China
| | - Hui-jing Shi
- Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China
| | - Tian Zhang
- Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China
| | - Jin-kun Wen
- Department of Biochemistry and Molecular Biology, Key Laboratory of Neural and Vascular Biology, Ministry of Education, Hebei Medical University, No. 361, Zhongshan East Road, Shijiazhuang 050017, China
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Vieux-Rochas M, Coen L, Sato T, Kurihara Y, Gitton Y, Barbieri O, Blay KL, Merlo G, Ekker M, Kurihara H, Janvier P, Levi G. Molecular dynamics of retinoic acid-induced craniofacial malformations: implications for the origin of gnathostome jaws. PLoS One 2007; 2:e510. [PMID: 17551590 PMCID: PMC1876820 DOI: 10.1371/journal.pone.0000510] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Accepted: 05/15/2007] [Indexed: 02/02/2023] Open
Abstract
Background Intake of retinoic acid (RA) or of its precursor, vitamin A, during early pregnancy is associated with increased incidence of craniofacial lesions. The origin of these teratogenic effects remains enigmatic as in cranial neural crest cells (CNCCs), which largely contribute to craniofacial structures, the RA-transduction pathway is not active. Recent results suggest that RA could act on the endoderm of the first pharyngeal arch (1stPA), through a RARß-dependent mechanism. Methodology/Principal Findings Here we show that RA provokes dramatically different craniofacial malformations when administered at slightly different developmental times within a narrow temporal interval corresponding to the colonization of the 1st PA by CNCCs. We provide evidence showing that RA acts on the signalling epithelium of the 1st PA, gradually reducing the expression of endothelin-1 and Fgf8. These two molecular signals are instrumental in activating Dlx genes in incoming CNCCs, thereby triggering the morphogenetic programs, which specify different jaw elements. Conclusions/Significance The anatomical series induced by RA-treatments at different developmental times parallels, at least in some instances, the supposed origin of modern jaws (e.g., the fate of the incus). Our results might provide a conceptual framework for the rise of jaw morphotypes characteristic of gnathostomes.
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Affiliation(s)
- Maxence Vieux-Rochas
- Evolution des Régulations Endocriniennes, CNRS, UMR5166, Muséum National d'Histoire Naturelle, Paris, France
| | - Laurent Coen
- Evolution des Régulations Endocriniennes, CNRS, UMR5166, Muséum National d'Histoire Naturelle, Paris, France
| | - Takahiro Sato
- Department of Physiological Chemistry and Metabolism, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Yukiko Kurihara
- Department of Physiological Chemistry and Metabolism, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Yorick Gitton
- Evolution des Régulations Endocriniennes, CNRS, UMR5166, Muséum National d'Histoire Naturelle, Paris, France
| | - Ottavia Barbieri
- Transgenic Unit, Department of Oncology, Biology and Genetic University of Genova, Genova, Italy
| | - Karine Le Blay
- Evolution des Régulations Endocriniennes, CNRS, UMR5166, Muséum National d'Histoire Naturelle, Paris, France
| | | | - Marc Ekker
- Centre for Advanced Research in Environmental Genomics, Department of Biology, University of Ottawa, Ottawa, Canada
| | - Hiroki Kurihara
- Department of Physiological Chemistry and Metabolism, Graduate School of Medicine, University of Tokyo, Tokyo, Japan
| | - Philippe Janvier
- CNRS, UMR 5143, Département Histoire de la Terre, Muséum National d'Histoire Naturelle, Paris, France
- Palaeontology Department, The Natural History Museum, London, United Kingdom
| | - Giovanni Levi
- Evolution des Régulations Endocriniennes, CNRS, UMR5166, Muséum National d'Histoire Naturelle, Paris, France
- * To whom correspondence should be addressed. E-mail:
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Scarth JP. Modulation of the growth hormone-insulin-like growth factor (GH-IGF) axis by pharmaceutical, nutraceutical and environmental xenobiotics: an emerging role for xenobiotic-metabolizing enzymes and the transcription factors regulating their expression. A review. Xenobiotica 2006; 36:119-218. [PMID: 16702112 DOI: 10.1080/00498250600621627] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The growth hormone-insulin-like growth factor (GH-IGF) axis has gained considerable focus over recent years. One cause of this increased interest is due to a correlation of age-related decline in plasma GH/IGF levels with age-related degenerative processes, and it has led to the prescribing of GH replacement therapy by some practitioners. On the other hand, however, research has also focused on the pro-carcinogenic effects of high GH-IGF levels, providing strong impetus for finding regimes that reduce its activity. Whereas the effects of GH/IGF activity on the action of xenobiotic-metabolizing enzyme systems is reasonably well appreciated, the effects of xenobiotic exposure on the GH-IGF axis has not received substantial review. Relevant xenobiotics are derived from pharmaceutical, nutraceutical and environmental exposure, and many of the mechanisms involved are highly complex in nature, not easily predictable from existing in vitro tests and do not always predict well from in vivo animal models. After a review of the human and animal in vivo and in vitro literature, a framework for considering the different levels of direct and indirect modulation by xenobiotics is developed herein, and areas that still require further investigation are highlighted, i.e. the actions of common endocrine disruptors such as pesticides and phytoestrogens, as well as the role of xenobiotic-metabolizing enzymes and the transcription factors regulating their expression. It is anticipated that a fuller appreciation of the existing human paradigms for GH-IGF axis modulation gained through this review may help explain some of the variation in levels of plasma IGF-1 and its binding proteins in the population, aid in the prescription of particular dietary regimens to certain individuals such as those with particular medical conditions, guide the direction of long-term drug/nutraceutical safety trials, and stimulate ideas for future research. It also serves to warn athletes that using compounds touted as performance enhancing because they promote short-term GH release could in fact be detrimental to performance in the long-run.
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Affiliation(s)
- J P Scarth
- The Horseracing Forensic Laboratories (HFL), Fordham, UK.
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Mark M, Ghyselinck NB, Chambon P. Function of retinoid nuclear receptors: lessons from genetic and pharmacological dissections of the retinoic acid signaling pathway during mouse embryogenesis. Annu Rev Pharmacol Toxicol 2006; 46:451-80. [PMID: 16402912 DOI: 10.1146/annurev.pharmtox.46.120604.141156] [Citation(s) in RCA: 470] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Retinoic acid (RA) is involved in vertebrate morphogenesis, growth, cellular differentiation, and tissue homeostasis. The use of in vitro systems initially led to the identification of nuclear receptor RXR/RAR heterodimers as possible transducers of the RA signal. To unveil the physiological functions of RARs and RXRs, genetic and pharmacological studies have been performed in the mouse. Together, their results demonstrate that (a) RXR/RAR heterodimers in which RXR is either transcriptionally active or silent are involved in the transduction of the RA signal during prenatal development, (b) specific RXRalpha/RAR heterodimers are required at many distinct stages during early embryogenesis and organogenesis, (c) the physiological role of RA and its receptors cannot be extrapolated from teratogenesis studies using retinoids in excess. Additional cell type-restricted and temporally controlled somatic mutagenesis is required to determine the functions of RARs and RXRs during postnatal life.
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Affiliation(s)
- Manuel Mark
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Institut Clinique de la Souris, Centre National de la Recherche Scientifique/INSERM, Université Louis Pasteur de Strasbourg, Collège de France, 67404 Illkirch Cedex, CU de Strasbourg, France
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Yu Z, Han J, Lin J, Xiao Y, Zhang X, Li Y. Apoptosis Induced by atRA in MEPM Cells Is Mediated through Activation of Caspase and RAR. Toxicol Sci 2005; 89:504-9. [PMID: 16291826 DOI: 10.1093/toxsci/kfj046] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
We have previously demonstrated that all-trans retinoic (atRA) induced growth inhibition and apoptosis in mouse embryonic palate mesenchymal cells (MEPM). In the present study, we investigated the molecular mechanisms of atRA-induced apoptosis and its putative action pathway. atRA-induced apoptosis is associated with activation of the initiator caspase-9 and the effector caspase-3, but not of the effector caspase-8. A broad caspase inhibitor (z-VAD-fmk), caspase-9 inhibitor z-LEHD-fmk and caspase-3 inhibitor (z-DEVD-fmk) blocked atRA-induced DNA fragmentation and sub-G1 fraction, but not caspase-8 inhibitor z-IETD-fmk. We further showed that atRA dose-dependently promoted mRNA expression of retinoic acid receptor beta (RAR-beta) and gamma. A weaker increase in RAR-alpha mRNA was seen only at the highest concentration of atRA (5 muM). The pan RAR antagonist, BMS493, completely abrogated atRA-induced DNA fragmentation, Sub-G1 fraction, and caspase-3 activation. Taken together, these findings show that caspase-mediated induction of apoptosis by atRA is an RAR-dependent signaling pathway.
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Affiliation(s)
- Zengli Yu
- School of Stomatology, Peking University Health Science Center, Beijing, China
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