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Latorre-Leal M, Rodriguez-Rodriguez P, Franchini L, Nikolidakis O, Daniilidou M, Delac L, Varshney MK, Arroyo-García LE, Eroli F, Winblad B, Blennow K, Zetterberg H, Kivipelto M, Pacciarini M, Wang Y, Griffiths WJ, Björkhem I, Matton A, Nalvarte I, Merino-Serrais P, Cedazo-Minguez A, Maioli S. CYP46A1-mediated cholesterol turnover induces sex-specific changes in cognition and counteracts memory loss in ovariectomized mice. SCIENCE ADVANCES 2024; 10:eadj1354. [PMID: 38266095 PMCID: PMC10807813 DOI: 10.1126/sciadv.adj1354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 12/22/2023] [Indexed: 01/26/2024]
Abstract
The brain-specific enzyme CYP46A1 controls cholesterol turnover by converting cholesterol into 24S-hydroxycholesterol (24OH). Dysregulation of brain cholesterol turnover and reduced CYP46A1 levels are observed in Alzheimer's disease (AD). In this study, we report that CYP46A1 overexpression in aged female mice leads to enhanced estrogen signaling in the hippocampus and improved cognitive functions. In contrast, age-matched CYP46A1 overexpressing males show anxiety-like behavior, worsened memory, and elevated levels of 5α-dihydrotestosterone in the hippocampus. We report that, in neurons, 24OH contributes to these divergent effects by activating sex hormone signaling, including estrogen receptors. CYP46A1 overexpression in female mice protects from memory impairments induced by ovariectomy while having no effects in gonadectomized males. Last, we measured cerebrospinal fluid levels of 24OH in a clinical cohort of patients with AD and found that 24OH negatively correlates with neurodegeneration markers only in women. We suggest that CYP46A1 activation is a valuable pharmacological target for enhancing estrogen signaling in women at risk of developing neurodegenerative diseases.
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Affiliation(s)
- María Latorre-Leal
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Patricia Rodriguez-Rodriguez
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Luca Franchini
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Orestis Nikolidakis
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Makrina Daniilidou
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
- Department of Neurobiology Care Sciences and Society, Division of Clinical Geriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Ljerka Delac
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Mukesh K. Varshney
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Luis E. Arroyo-García
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Francesca Eroli
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Bengt Winblad
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Kaj Blennow
- Institute of Neuroscience and Physiology, University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Institut du Cerveau et de la Moelle épinière (ICM), Pitié-Salpêtrière Hospital, Sorbonne Université, Paris, France
- University of Science and Technology of China, Hefei, Anhui, P.R. China
| | - Henrik Zetterberg
- Institute of Neuroscience and Physiology, University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Miia Kivipelto
- Department of Neurobiology Care Sciences and Society, Division of Clinical Geriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
- Theme Aging, Karolinska University Hospital, Stockholm, Sweden
| | | | - Yuqin Wang
- Swansea University Medical School, SA2 8PP Swansea, UK
| | | | - Ingemar Björkhem
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Anna Matton
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
- Department of Neurobiology Care Sciences and Society, Division of Clinical Geriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Ivan Nalvarte
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Paula Merino-Serrais
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
- Departamento de Neurobiología Funcional y de Sistemas, Instituto Cajal, CSIC, Madrid, Spain
- Laboratorio Cajal de Circuitos Corticales, Centro de Tecnología Biomédica, UPM, Madrid, Spain
| | - Angel Cedazo-Minguez
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Silvia Maioli
- Department of Neurobiology Care Sciences and Society, Division of Neurogeriatrics, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
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2
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Dhar I, Lysne V, Ulvik A, Svingen GFT, Pedersen ER, Bjørnestad EØ, Olsen T, Borsholm R, Laupsa-Borge J, Ueland PM, Tell GS, Berge RK, Mellgren G, Bønaa KH, Nygård OK. Plasma methylmalonic acid predicts risk of acute myocardial infarction and mortality in patients with coronary heart disease: A prospective 2-cohort study. J Intern Med 2023; 293:508-519. [PMID: 36682040 DOI: 10.1111/joim.13610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
BACKGROUND Elevated plasma methylmalonic acid (MMA) is reported in patients with established coronary heart disease (CHD) and is considered a marker of vitamin B12 deficiency. Moreover, MMA-dependent reactions have been linked to alterations in mitochondrial energy metabolism and oxidative stress, key features in the pathophysiology of cardiovascular diseases (CVDs). OBJECTIVES We examined whether plasma MMA prospectively predicted the long-term risk of acute myocardial infarction (AMI) and mortality. METHODS AND RESULTS Using Cox modeling, we estimated hazard ratios (HRs) for endpoints according to per 1-SD increment of log-transformed plasma MMA in two independent populations: the Western Norway Coronary Angiography Cohort (WECAC) (patients evaluated for CHD; n = 4137) and the Norwegian Vitamin Trial (NORVIT) (patients hospitalized with AMI; n = 3525). In WECAC and NORVIT, 12.8% and 18.0% experienced an AMI, whereas 21.8% and 19.9% died, of whom 45.5% and 60.3% from CVD-related causes during follow-up (range 3-11 years), respectively. In WECAC, age- and gender-adjusted HRs (95% confidence interval) were 1.18 (1.09-1.28), 1.25 (1.18-1.33), and 1.28 (1.17-1.40) for future AMI, total mortality, and CVD mortality, respectively. Corresponding risk estimates were 1.19 (1.10-1.28), 1.22 (1.14-1.31), and 1.30 (1.19-1.42) in NORVIT. These estimates were only slightly attenuated after multivariable adjustments. Across both cohorts, the MMA-risk association was stronger in older adults, women, and non-smokers. CONCLUSIONS Elevated MMA was associated with an increased risk of AMI and mortality in patients with suspected or verified CHD.
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Affiliation(s)
- Indu Dhar
- Centre for Nutrition, Department of Clinical Science, University of Bergen, Bergen, Norway.,Mohn Nutrition Research Laboratory, University of Bergen, Bergen, Norway
| | - Vegard Lysne
- Centre for Nutrition, Department of Clinical Science, University of Bergen, Bergen, Norway.,Mohn Nutrition Research Laboratory, University of Bergen, Bergen, Norway.,Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | | | - Gard F T Svingen
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Eva R Pedersen
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Espen Ø Bjørnestad
- Department of Cardiology, Stavanger University Hospital, Stavanger, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Thomas Olsen
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Robert Borsholm
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Johnny Laupsa-Borge
- Centre for Nutrition, Department of Clinical Science, University of Bergen, Bergen, Norway
| | | | - Grethe S Tell
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
| | - Rolf K Berge
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Gunnar Mellgren
- Mohn Nutrition Research Laboratory, University of Bergen, Bergen, Norway.,Hormone Laboratory, Department of Medical Biochemistry and Pharmacology, Haukeland University Hospital, Bergen, Norway
| | - Kaare H Bønaa
- Department of Circulation and medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.,Clinic for Heart Diseases, St. Olav's University Hospital, Trondheim, Norway
| | - Ottar K Nygård
- Centre for Nutrition, Department of Clinical Science, University of Bergen, Bergen, Norway.,Mohn Nutrition Research Laboratory, University of Bergen, Bergen, Norway.,Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
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3
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Bang YJ. Vitamin A: a key coordinator of host-microbe interactions in the intestine. BMB Rep 2023; 56:133-139. [PMID: 36751944 PMCID: PMC10068342 DOI: 10.5483/bmbrep.2023-0005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 01/25/2023] [Accepted: 02/06/2023] [Indexed: 09/29/2023] Open
Abstract
The human intestine is home to a dense community of microbiota that plays a key role in human health and disease. Nutrients are essential regulators of both host and microbial physiology and function as key coordinators of host-microbe interactions. Therefore, understanding the specific roles and underlying mechanisms of each nutrient in regulating the host-microbe interactions will be essential in developing new strategies for improving human health through microbiota and nutrient intervention. This review will give a basic overview of the role of vitamin A, an essential micronutrient, on human health, and highlight recent findings on the mechanisms by which it regulates the host-microbe interactions. [BMB Reports 2023; 56(3): 133-139].
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Affiliation(s)
- Ye-Ji Bang
- Department of Biomedical Science, College of Medicine, Seoul National University, Seoul 03080, Korea
- Department of Microbiology and Immunology, College of Medicine, Seoul National University, Seoul 03080, Korea
- Institute of Infectious Diseases, Seoul National University College of Medicine, Seoul 03080, Korea
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4
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Maioli S, Leander K, Nilsson P, Nalvarte I. Estrogen receptors and the aging brain. Essays Biochem 2021; 65:913-925. [PMID: 34623401 PMCID: PMC8628183 DOI: 10.1042/ebc20200162] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 09/09/2021] [Accepted: 09/10/2021] [Indexed: 12/14/2022]
Abstract
The female sex hormone estrogen has been ascribed potent neuroprotective properties. It signals by binding and activating estrogen receptors that, depending on receptor subtype and upstream or downstream effectors, can mediate gene transcription and rapid non-genomic actions. In this way, estrogen receptors in the brain participate in modulating neural differentiation, proliferation, neuroinflammation, cholesterol metabolism, synaptic plasticity, and behavior. Circulating sex hormones decrease in the course of aging, more rapidly at menopause in women, and slower in men. This review will discuss what this drop entails in terms of modulating neuroprotection and resilience in the aging brain downstream of spatiotemporal estrogen receptor alpha (ERα) and beta (ERβ) signaling, as well as in terms of the sex differences observed in Alzheimer's disease (AD) and Parkinson's disease (PD). In addition, controversies related to ER expression in the brain will be discussed. Understanding the spatiotemporal signaling of sex hormones in the brain can lead to more personalized prevention strategies or therapies combating neurodegenerative diseases.
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Affiliation(s)
- Silvia Maioli
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Karin Leander
- Institute of Environmental Medicine, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Per Nilsson
- Division of Neurogeriatrics, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Karolinska Institutet, 171 77 Stockholm, Sweden
| | - Ivan Nalvarte
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 57 Huddinge, Sweden
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5
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D'Espessailles A, Campos V, Juretić N, Tapia GS, Pettinelli P. Hepatic retinaldehyde dehydrogenases are modulated by tocopherol supplementation in mice with hepatic steatosis. Nutrition 2021; 94:111539. [PMID: 34974285 DOI: 10.1016/j.nut.2021.111539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 09/19/2021] [Accepted: 11/05/2021] [Indexed: 10/19/2022]
Abstract
OBJECTIVES An altered retinol metabolism might play a role in the development of nonalcoholic fatty liver disease (NAFLD). Tocopherols (TF) modulate metabolic pathways and have been proposed as a complementary treatment of obesity-induced metabolic alterations. Moreover, there is evidence suggesting that TF may modulate retinol metabolism. The aim of this study was to evaluate whether the dietary supplementation of α- and γ-TF modulates the expression of hepatic retinaldehyde dehydrogenases, RALDH1, RALDH2, and RALDH3 (involved in retinol metabolism) and, lipogenic factors sterol regulatory element binding protein-1c (SREBP-1c) and cluster differentiation 36 (CD36) in an animal model of diet-induced NAFLD. METHODS Male C57BL/6J mice were divided into four groups: a control diet (CD) group (10% fat, 20% protein, 70% carbohydrates); a CD + TF group (α-tocopherol: 0.7 mg·kg·d-1, γ-tocopherol: 3.5 mg·kg·d-1); a high-fat diet (HFD) group (60% fat, 20% protein, 20% carbohydrates); and a HFD + TF group (0.01 mL·g body weight·d-1), for 12 wk. General parameters (body-adipose tissue weight, glucose-triacylglyceride serum levels), liver steatosis (histology, liver triacylglycerides content), and hepatic RALDH1, RALDH2, RALDH3, SREBP-1c and CD36 (qPCR, quantitative polymerase chain reaction; IHQ, immunohistochemistry) were measured. RESULTS TF supplementation in HFD-fed mice decreased the presence of lipid vesicles (90%) and total lipid content (75%) and downregulated the expression of RALDH1, RALDH3, SREBP-1c, and CD36. CONCLUSIONS The present study demonstrated that α- and γ-TF (1:5 ratio) might play a role in modulating retinol metabolism in the prevention of NAFLD induced by a HFD.
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Affiliation(s)
| | - Valeria Campos
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Nevenka Juretić
- Cellular and Molecular Biology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Gladys S Tapia
- Molecular and Clinical Pharmacology Program, Institute of Biomedical Sciences, University of Chile, Santiago, Chile
| | - Paulina Pettinelli
- Department of Health Sciences, Nutrition and Dietetics Career, Faculty of Medicine, Pontificia Universidad Católica de Chile, Santiago, Chile.
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6
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Toledo EM, Yang S, Gyllborg D, van Wijk KE, Sinha I, Varas-Godoy M, Grigsby CL, Lönnerberg P, Islam S, Steffensen KR, Linnarsson S, Arenas E. Srebf1 Controls Midbrain Dopaminergic Neurogenesis. Cell Rep 2021; 31:107601. [PMID: 32375051 DOI: 10.1016/j.celrep.2020.107601] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 02/17/2020] [Accepted: 04/10/2020] [Indexed: 12/20/2022] Open
Abstract
Liver X receptors (LXRs) and their ligands are potent regulators of midbrain dopaminergic (mDA) neurogenesis and differentiation. However, the molecular mechanisms by which LXRs control these functions remain to be elucidated. Here, we perform a combined transcriptome and chromatin immunoprecipitation sequencing (ChIP-seq) analysis of midbrain cells after LXR activation, followed by bioinformatic analysis to elucidate the transcriptional networks controlling mDA neurogenesis. Our results identify the basic helix-loop-helix transcription factor sterol regulatory element binding protein 1 (SREBP1) as part of a cluster of proneural transcription factors in radial glia and as a regulator of transcription factors controlling mDA neurogenesis, such as Foxa2. Moreover, loss- and gain-of-function experiments in vitro and in vivo demonstrate that Srebf1 is both required and sufficient for mDA neurogenesis. Our data, thus, identify Srebf1 as a central player in mDA neurogenesis.
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Affiliation(s)
- Enrique M Toledo
- Laboratory for Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden
| | - Shanzheng Yang
- Laboratory for Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden
| | - Daniel Gyllborg
- Laboratory for Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden
| | - Kim E van Wijk
- Laboratory for Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden
| | - Indranil Sinha
- Department of Biosciences and Nutrition, Karolinska Institutet, Huddinge, Sweden
| | - Manuel Varas-Godoy
- Laboratory for Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden
| | - Christopher L Grigsby
- Laboratory for Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden; Division of Biomaterials, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden
| | - Peter Lönnerberg
- Laboratory for Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden
| | - Saiful Islam
- Laboratory for Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden
| | - Knut R Steffensen
- Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Sten Linnarsson
- Laboratory for Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden
| | - Ernest Arenas
- Laboratory for Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Biomedicum, Solnavägen 9, 17177 Stockholm, Sweden.
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7
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Dhar I, Siddique S, R Pedersen E, F T Svingen G, Lysne V, Olsen T, Nilsen DW, Nordrehaug JE, Midttun Ø, M Ueland P, S Tell G, K Nygård O. Lipid parameters and vitamin A modify cardiovascular risk prediction by plasma neopterin. Heart 2020; 106:1073-1079. [PMID: 32398245 DOI: 10.1136/heartjnl-2019-316165] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES Oxidised cholesterol metabolites are linked to increased production of the active vitamin A (Vit-A) form and monocyte/macrophage activation, which may be reflected by neopterin, a marker of both interferon-γ-mediated immune activation and coronary artery disease risk. We examined the influence of serum lipid parameters and Vit-A on the risk association between neopterin and incident acute myocardial infarction (AMI). METHODS We included 4130 patients with suspected stable angina pectoris (SAP), of whom 80% received lipid-lowering treatment with statins. Risk associations between plasma neopterin and AMI are given as HRs per SD increase in log-transformed neopterin. RESULTS During a median follow-up of 7.5 years, 530 (12.8%) patients experienced an AMI. In age-adjusted and sex-adjusted analysis, plasma neopterin was positively associated with incident AMI (HR (95% CI) per SD: 1.26 (1.17 to 1.35)). However, the estimates were most pronounced in patients with serum low-density lipoprotein cholesterol (LDL-C) or apolipoprotein (apo) B100 below-median (HR (95% CI) per SD: 1.35 (1.24 to 1.48) and 1.42 (1.27 to 1.58), respectively; both pinteraction ≤0.03). We also observed a particularly strong risk association in those with above-median Vit-A (HR (95% CI) per SD: 1.32 (1.21 to 1.44); pinteraction=0.03). The estimates were slightly modified after multivariable adjustment. CONCLUSIONS In patients with suspected SAP, the majority of whom receiving statin therapy, high plasma neopterin was associated with increased risk of AMI particularly among those with low LDL-C and apoB100 or high Vit-A levels. The particularly strong relationship of plasma neopterin with residual cardiovascular risk in patients with low lipid levels should be further investigated.
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Affiliation(s)
- Indu Dhar
- Centre for Nutrition, Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Sumia Siddique
- Faculty of Medicine, University of Bergen, Bergen, Norway
| | - Eva R Pedersen
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Gard F T Svingen
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Vegard Lysne
- Centre for Nutrition, Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Thomas Olsen
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Dennis W Nilsen
- Department of Cardiology, Stavanger University Hospital, Stavanger, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Jan Erik Nordrehaug
- Department of Cardiology, Stavanger University Hospital, Stavanger, Norway.,Department of Clinical Science, University of Bergen, Bergen, Norway
| | | | | | - Grethe S Tell
- Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.,Division of Mental and Physical Health, Norwegian Institute of Public Health, Bergen, Norway
| | - Ottar K Nygård
- Centre for Nutrition, Department of Clinical Science, University of Bergen, Bergen, Norway.,Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
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8
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Maguire M, Larsen MC, Vezina CM, Quadro L, Kim YK, Tanumihardjo SA, Jefcoate CR. Cyp1b1 directs Srebp-mediated cholesterol and retinoid synthesis in perinatal liver; Association with retinoic acid activity during fetal development. PLoS One 2020; 15:e0228436. [PMID: 32027669 PMCID: PMC7004353 DOI: 10.1371/journal.pone.0228436] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 01/16/2020] [Indexed: 12/13/2022] Open
Abstract
Background Cytochrome P450 1b1 (Cyp1b1) deletion and dietary retinol deficiency during pregnancy (GVAD) affect perinatal liver functions regulated by Srebp. Cyp1b1 is not expressed in perinatal liver but appears in the E9.5 embryo, close to sites of retinoic acid (RA) signaling. Hypothesis Parallel effects of Cyp1b1 and retinol on postnatal Srebp derive from effects in the developing liver or systemic signaling. Approach Cluster postnatal increases in hepatic genes in relation to effects of GVAD or Cyp1b1 deletion. Sort expression changes in relation to genes regulated by Srebp1 and Srebp2.Test these treatments on embryos at E9.5, examining changes at the site of liver initiation. Use in situ hybridization to resolve effects on mRNA distributions of Aldh1a2 and Cyp26a1 (RA homeostasis); Hoxb1 and Pax6 (RA targets). Assess mice lacking Lrat and Rbp4 (DKO mice) that severely limits retinol supply to embryos. Results At birth, GVAD and Cyp1b1 deletion stimulate gene markers of hepatic stellate cell (HSC) activation but also suppress Hamp. These treatments then selectively prevent the postnatal onset of genes that synthesize cholesterol (Hmgcr, Sqle) and fatty acids (Fasn, Scd1), but also direct cholesterol transport (Ldlr, Pcsk9, Stard4) and retinoid synthesis (Aldh1a1, Rdh11). Extensive support by Cyp1b1 is implicated, but with distinct GVAD interventions for Srebp1 and Srebp2. At E9.5, Cyp1b1 is expressed in the septum transversum mesenchyme (STM) with β-carotene oxygenase (Bco1) that generates retinaldehyde. STM provides progenitors for the HSC and supports liver expansion. GVAD and Cyp1b1-/- do not affect RA-dependent Hoxb1 and Pax6. In DKO embryos, RA-dependent Cyp26a1 is lost but Hoxb1 is sustained with Cyp1b1 at multiple sites. Conclusion Cyp1b1-/- suppresses genes supported by Srebp. GVAD effects distinguish Srebp1 and Srebp2 mediation. Srebp regulation overlaps appreciably in cholesterol and retinoid homeostasis. Bco1/Cyp1b1 partnership in the STM may contribute to this later liver regulation.
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Affiliation(s)
- Meghan Maguire
- Endocrinology and Reproductive Physiology Program, University of Wisconsin-Madison, Madison, WI
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
| | | | - Chad M. Vezina
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI
| | - Loredana Quadro
- Department of Food Science and Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey
| | - Youn-Kyung Kim
- Department of Food Science and Rutgers Center for Lipid Research, Rutgers University, New Brunswick, New Jersey
| | | | - Colin R. Jefcoate
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
- * E-mail:
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9
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Verma P, Kureel AK, Saini S, Prakash S, Kumari S, Kottarath SK, Srivastava SK, Bhat M, Dinda AK, Thakur CP, Sharma S, Rai AK. Leishmania donovani reduces the levels of retinoic acid-synthesizing enzymes in infected macrophages and favoring its own survival. Parasitol Res 2018; 118:63-71. [PMID: 30338372 DOI: 10.1007/s00436-018-6115-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 10/07/2018] [Indexed: 11/29/2022]
Abstract
People suffering from malnutrition become susceptible to the infection like Leishmania sp., as it results in a compromised immune response. Retinoic acid (RA), an important constituent of nutrition, shows an immune-modulatory activity. However, its role in the containment of infection is not yet ascertained, particularly in case of visceral leishmaniasis (VL). VL patients (n = 10) and healthy endemic controls (n = 9) were recruited to measure the serum levels of RA. An in vitro model of Leishmania infection using the murine mφ cell line J774.1 was used to investigate the RA-synthesizing enzymes (RALDH-1 and RALDH-2). Parasite loads among infected mφ were measured by quantitative expression of kDNA in the presence of an inhibitor of the RALDH-2 enzyme. We found a significant decrease in the serum levels of RA in VL cases. Importantly, we observed decreased levels of RALDH-1 and RALDH-2 among L. donovani-infected mφ along with simultaneous decrease as well as increase in the Th-1 and Th-2-associated factors, respectively. Furthermore, the pretreatment of mφ with an RALDH-2 inhibitor improved parasite in vitro infection. Our findings show impaired RA pathway among infected mφ and indicate that an intact RA pathway is critical for anti-Leishmania immune response. Graphical abstract ᅟ.
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Affiliation(s)
- Pankaj Verma
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, 211004, India
| | - Amit Kumar Kureel
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, 211004, India
| | - Sheetal Saini
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, 211004, India
| | - Satya Prakash
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, 211004, India
| | - Smita Kumari
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, 211004, India
| | - Sarath Kumar Kottarath
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | | | - Madhusudan Bhat
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | - Amit Kumar Dinda
- Department of Pathology, All India Institute of Medical Sciences, New Delhi, 110029, India
| | | | - Shivesh Sharma
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, 211004, India
| | - Ambak Kumar Rai
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad, 211004, India.
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10
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Olsen T, Vinknes KJ, Svingen GFT, Pedersen ER, Dhar I, Tell GS, Blomhoff R, Ueland PM, Midttun Ø, Refsum H, Nygård OK. The risk association of plasma total homocysteine with acute myocardial infarction is modified by serum vitamin A. Eur J Prev Cardiol 2018; 25:1612-1620. [DOI: 10.1177/2047487318788587] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Background Plasma total homocysteine (tHcy) has been implicated in the development of cardiovascular disease, but the mechanisms remain unclear. Vitamin A (Vit-A) is involved in homocysteine metabolism and we therefore explored the potential interaction between plasma tHcy and serum Vit-A in relation to incident acute myocardial infarction. Methods Cox proportional hazards models were used to assess the prospective relationships between tHcy and acute myocardial infarction in 2205 patients from Western Norway undergoing elective coronary angiography for suspected stable angina pectoris. Results are reported as hazard ratio per standard deviation increase in log-transformed tHcy. An interaction term for tHcy × Vit-A was added to multivariate models including age, sex, smoking, apolipoprotein B fasting, statin and aspirin prescription and estimated glomerular filtration rate. Results Geometric mean (geometric standard deviation) age of the participants (64.3% men) was 62.3 (1.24) years. Plasma tHcy was higher among participants in the upper versus lower Vit-A tertile. During 7 (2.4) years of follow-up, 15.1% suffered an AMI. A significant association of plasma tHcy with AMI in the total study population was observed. When we stratified the population according to Vit-A tertiles, plasma tHcy was associated with acute myocardial infarction only in the upper Vit-A tertile (hazard ratio per SD: 1.25, 95% confidence interval: 1.04–1.53, pinteraction = 0.03). Conclusions The risk relationship between plasma tHcy and acute myocardial infarction was modified by serum concentrations of Vit-A in patients with suspected stable angina pectoris. This finding may clarify the relationship between tHcy and cardiovascular disease.
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Affiliation(s)
- Thomas Olsen
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Norway
| | - Kathrine J Vinknes
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Norway
| | - Gard FT Svingen
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
| | - Eva R Pedersen
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
- KG Jebsen Centre for Diabetes Research, University of Bergen, Norway
| | - Indu Dhar
- Department of Clinical Science, Faculty of Medicine, University of Bergen, Norway
| | - Grethe S Tell
- Department of Global Public Health and Primary Care, University of Bergen, Norway
- Division of Mental and Physical Health, Norwegian Institute of Public Health, Bergen, Norway
| | - Rune Blomhoff
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Norway
- Department of Clinical Service, Division of Cancer Medicine, Oslo University Hospital, Norway
| | - Per M Ueland
- Laboratory of Clinical Biochemistry, Haukeland University Hospital, Bergen, Norway
- Bevital AS, Bergen, Norway
| | | | - Helga Refsum
- Department of Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Norway
| | - Ottar K Nygård
- Department of Heart Disease, Haukeland University Hospital, Bergen, Norway
- KG Jebsen Centre for Diabetes Research, University of Bergen, Norway
- Department of Clinical Science, Faculty of Medicine, University of Bergen, Norway
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11
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Landrier JF, Kasiri E, Karkeni E, Mihály J, Béke G, Weiss K, Lucas R, Aydemir G, Salles J, Walrand S, de Lera AR, Rühl R. Reduced adiponectin expression after high-fat diet is associated with selective up-regulation of ALDH1A1 and further retinoic acid receptor signaling in adipose tissue. FASEB J 2016; 31:203-211. [PMID: 27729412 PMCID: PMC5161515 DOI: 10.1096/fj.201600263rr] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 09/22/2016] [Indexed: 12/22/2022]
Abstract
Adiponectin is an adipocyte-derived adipokine with potent antidiabetic, anti-inflammatory, and antiatherogenic activity. Long-term, high-fat diet results in gain of body weight, adiposity, further inflammatory-based cardiovascular diseases, and reduced adiponectin secretion. Vitamin A derivatives/retinoids are involved in several of these processes, which mainly take place in white adipose tissue (WAT). In this study, we examined adiponectin expression as a function of dietary high-fat and high–vitamin A conditions in mice. A decrease of adiponectin expression in addition to an up-regulation of aldehyde dehydrogenase A1 (ALDH1A1), retinoid signaling, and retinoic acid response element signaling was selectively observed in WAT of mice fed a normal–vitamin A, high-fat diet. Reduced adiponectin expression in WAT was also observed in mice fed a high–vitamin A diet. Adipocyte cell culture revealed that endogenous and synthetic retinoic acid receptor (RAR)α- and RARγ-selective agonists, as well as a synthetic retinoid X receptor agonist, efficiently reduced adiponectin expression, whereas ALDH1A1 expression only increased with RAR agonists. We conclude that reduced adiponectin expression under high-fat dietary conditions is dependent on 1) increased ALDH1A1 expression in adipocytes, which does not increase all-trans-retinoic acid levels; 2) further RAR ligand–induced, WAT-selective, increased retinoic acid response element–mediated signaling; and 3) RAR ligand–dependent reduction of adiponectin expression.—Landrier, J.-F., Kasiri, E., Karkeni, E., Mihály, J., Béke, G., Weiss, K., Lucas, R., Aydemir, G., Salles, J., Walrand, S., de Lera, A. R., Rühl, R. Reduced adiponectin expression after high-fat diet is associated with selective up-regulation of ALDH1A1 and further retinoic acid receptor signaling in adipose tissue.
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Affiliation(s)
- Jean-Francois Landrier
- Institut National de la Recherche Agronomique, Unités Mixtes de Recherche 1260, Marseille, France.,INSERM, Unités Mixtes de Recherche 1062, Nutrition, Obésité et Risque Thrombotique, Marseille, France.,Aix-Marseille Université, Faculté de Médecine, Marseille, France
| | - Elnaz Kasiri
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary.,MTA-DE Public Health Research Group, Hungarian Academy of Sciences, Faculty of Public Health, University of Debrecen, Debrecen, Hungary
| | - Esma Karkeni
- Institut National de la Recherche Agronomique, Unités Mixtes de Recherche 1260, Marseille, France.,INSERM, Unités Mixtes de Recherche 1062, Nutrition, Obésité et Risque Thrombotique, Marseille, France.,Aix-Marseille Université, Faculté de Médecine, Marseille, France
| | - Johanna Mihály
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Gabriella Béke
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Kathrin Weiss
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Renata Lucas
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Gamze Aydemir
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary
| | - Jérome Salles
- Unités Mixtes de Recherche, Institut National de la Recherche Agronomique (INRA) 1019 Unité de Nutrition Humaine, Centre de Recherches INRA de Clermont-Ferrand/Theix, Saint-Genès-Champanelle, France
| | - Stéphane Walrand
- Unités Mixtes de Recherche, Institut National de la Recherche Agronomique (INRA) 1019 Unité de Nutrition Humaine, Centre de Recherches INRA de Clermont-Ferrand/Theix, Saint-Genès-Champanelle, France
| | - Angel R de Lera
- Departamento de Química Orgánica, Universidade de Vigo, Facultad de Química, Centro de Investigaciones Biomédicas and Instituto de Investigación Biomédica de Vigo, Vigo, Spain; and
| | - Ralph Rühl
- Department of Biochemistry and Molecular Biology, University of Debrecen, Debrecen, Hungary; .,MTA-DE Public Health Research Group, Hungarian Academy of Sciences, Faculty of Public Health, University of Debrecen, Debrecen, Hungary.,Paprika Bioanalytics BT, Debrecen, Hungary
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12
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Madreiter-Sokolowski CT, Klec C, Parichatikanond W, Stryeck S, Gottschalk B, Pulido S, Rost R, Eroglu E, Hofmann NA, Bondarenko AI, Madl T, Waldeck-Weiermair M, Malli R, Graier WF. PRMT1-mediated methylation of MICU1 determines the UCP2/3 dependency of mitochondrial Ca(2+) uptake in immortalized cells. Nat Commun 2016; 7:12897. [PMID: 27642082 PMCID: PMC5031806 DOI: 10.1038/ncomms12897] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 08/12/2016] [Indexed: 12/18/2022] Open
Abstract
Recent studies revealed that mitochondrial Ca2+ channels, which control energy flow, cell signalling and death, are macromolecular complexes that basically consist of the pore-forming mitochondrial Ca2+ uniporter (MCU) protein, the essential MCU regulator (EMRE), and the mitochondrial Ca2+ uptake 1 (MICU1). MICU1 is a regulatory subunit that shields mitochondria from Ca2+ overload. Before the identification of these core elements, the novel uncoupling proteins 2 and 3 (UCP2/3) have been shown to be fundamental for mitochondrial Ca2+ uptake. Here we clarify the molecular mechanism that determines the UCP2/3 dependency of mitochondrial Ca2+ uptake. Our data demonstrate that mitochondrial Ca2+ uptake is controlled by protein arginine methyl transferase 1 (PRMT1) that asymmetrically methylates MICU1, resulting in decreased Ca2+ sensitivity. UCP2/3 normalize Ca2+ sensitivity of methylated MICU1 and, thus, re-establish mitochondrial Ca2+ uptake activity. These data provide novel insights in the complex regulation of the mitochondrial Ca2+ uniporter by PRMT1 and UCP2/3. MICU1 is a regulatory subunit of mitochondrial Ca2+ channels that shields mitochondria from Ca2+ overload. Here the authors show that MICU1 methylation by PRMT1 reduces Ca2+ sensitivity, which is normalized by UCP2/3, re-establishing mitochondrial Ca2+ uptake activity.
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Affiliation(s)
- Corina T Madreiter-Sokolowski
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Christiane Klec
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Warisara Parichatikanond
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Sarah Stryeck
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Benjamin Gottschalk
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Sergio Pulido
- Institute of Chemistry, University of Graz, Graz 8010, Austria
| | - Rene Rost
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Emrah Eroglu
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Nicole A Hofmann
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Alexander I Bondarenko
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Tobias Madl
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria.,Center for Integrated Protein Science, Department Chemistry, Technical University Munich, Garching 85748, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg 85764, Germany
| | - Markus Waldeck-Weiermair
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Roland Malli
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
| | - Wolfgang F Graier
- Center for Molecular Medicine, Institute of Molecular Biology and Biochemistry, Medical University of Graz, Harrachgasse 21/III, Graz 8010, Austria
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13
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Shiri-Shahsavar MR, Mirshafiee A, Parastouei K, Ebrahimi-Kalan A, Yekaninejad S, Soleymani F, Chahardoli R, Mazaheri Nezhad Fard R, Saboor-Yaraghi AA. A Novel Combination of Docosahexaenoic Acid, All-Trans Retinoic Acid, and 1, 25-Dihydroxyvitamin D3 Reduces T-Bet Gene Expression, Serum Interferon Gamma, and Clinical Scores but Promotes PPARγ Gene Expression in Experimental Autoimmune Encephalomyelitis. J Mol Neurosci 2016; 60:498-508. [DOI: 10.1007/s12031-016-0834-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 08/30/2016] [Indexed: 12/19/2022]
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14
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Stoney PN, Helfer G, Rodrigues D, Morgan PJ, McCaffery P. Thyroid hormone activation of retinoic acid synthesis in hypothalamic tanycytes. Glia 2015; 64:425-39. [PMID: 26527258 PMCID: PMC4949630 DOI: 10.1002/glia.22938] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 10/08/2015] [Accepted: 10/12/2015] [Indexed: 11/11/2022]
Abstract
Thyroid hormone (TH) is essential for adult brain function and its actions include several key roles in the hypothalamus. Although TH controls gene expression via specific TH receptors of the nuclear receptor class, surprisingly few genes have been demonstrated to be directly regulated by TH in the hypothalamus, or the adult brain as a whole. This study explored the rapid induction by TH of retinaldehyde dehydrogenase 1 (Raldh1), encoding a retinoic acid (RA)-synthesizing enzyme, as a gene specifically expressed in hypothalamic tanycytes, cells that mediate a number of actions of TH in the hypothalamus. The resulting increase in RA may then regulate gene expression via the RA receptors, also of the nuclear receptor class. In vivo exposure of the rat to TH led to a significant and rapid increase in hypothalamic Raldh1 within 4 hours. That this may lead to an in vivo increase in RA is suggested by the later induction by TH of the RA-responsive gene Cyp26b1. To explore the actions of RA in the hypothalamus as a potential mediator of TH control of gene regulation, an ex vivo hypothalamic rat slice culture method was developed in which the Raldh1-expressing tanycytes were maintained. These slice cultures confirmed that TH did not act on genes regulating energy balance but could induce Raldh1. RA has the potential to upregulate expression of genes involved in growth and appetite, Ghrh and Agrp. This regulation is acutely sensitive to epigenetic changes, as has been shown for TH action in vivo. These results indicate that sequential triggering of two nuclear receptor signalling systems has the capability to mediate some of the functions of TH in the hypothalamus.
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Affiliation(s)
- Patrick N Stoney
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, AB25 2ZD, United Kingdom
| | - Gisela Helfer
- Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen, Scotland, AB21 9SB, United Kingdom
| | - Diana Rodrigues
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, AB25 2ZD, United Kingdom
| | - Peter J Morgan
- Rowett Institute of Nutrition and Health, University of Aberdeen, Bucksburn, Aberdeen, Scotland, AB21 9SB, United Kingdom
| | - Peter McCaffery
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, Scotland, AB25 2ZD, United Kingdom
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15
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Glucocorticoids enhance prolonged clearance of apoptotic cells by upregulating liver X receptor, peroxisome proliferator-activated receptor-δ and UCP2. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:573-82. [PMID: 25523142 DOI: 10.1016/j.bbamcr.2014.12.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/05/2014] [Accepted: 12/10/2014] [Indexed: 01/02/2023]
Abstract
Efficient phagocytic clearance of apoptotic cells (efferocytosis) is essential to prevent the development of chronic inflammation and autoimmunity. Glucocorticoids are widely used in the therapy of chronic inflammatory diseases, and increasing evidence suggests that they act partly via enhancing efferocytosis by macrophages. Glucocorticoids were previously shown to promote both protein S- and MFG-E8-dependent efferocytosis. Since previous studies in our laboratory have demonstrated that glucocorticoids induce the expression of retinaldehyde dehydrogenases in macrophages, in the present experiments the possible involvement of retinoids in the glucocorticoid-induced efferocytosis was studied in mouse bone marrow derived macrophages. Here we show that glucocorticoids promote not only short-term, but also long-term clearance of apoptotic cells. Glucocorticoids seem to directly induce the expression of the phagocytosis-related genes MERTK, C1q, UCP2, and the transcription factor C/EBPβ. C/EBPβ contributes to the further induction of the phagocytosis-related genes, and is required for the induction of lipid sensing receptors LXRs, PPARδ, RARα, RXRα and RALDH1, the latter one in an LXR- and RARα-dependent manner. Glucocorticoid-induced enhancement in long-term efferocytosis was dependent on the induction of lipid sensing receptors known to be triggered by the lipid content of the engulfed cells to enhance phagocytic capacity. Retinoids did not affect the glucocorticoid-induced short term phagocytosis of apoptotic cells, but were required for the glucocorticoid-induced enhancement of efferocytosis during prolonged clearance of apoptotic cells by promoting efficient LXR and PPARδ upregulation. Our data indicate that retinoids could be considered as potential promoters of the efficacy of glucocorticoid treatment in inflammatory diseases.
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16
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Ito K, Zolfaghari R, Hao L, Ross AC. Inflammation rapidly modulates the expression of ALDH1A1 (RALDH1) and vimentin in the liver and hepatic macrophages of rats in vivo. Nutr Metab (Lond) 2014; 11:54. [PMID: 25926859 PMCID: PMC4414379 DOI: 10.1186/1743-7075-11-54] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 11/16/2014] [Indexed: 12/21/2022] Open
Abstract
Background Members of the ALDH1 protein family, known as retinal dehydrogenases (RALDH), produce retinoic acid (RA), a metabolite of vitamin A, and may also oxidize other lipid aldehydes. Of three related ALDH1 genes, ALDH1A1 is most highly expressed in liver. ALDH1A1 is also rapidly gaining importance as a stem cell marker. We hypothesized that ALDH1A1 may have a broad cellular distribution in the liver, and that its expression may be regulated by RA and perturbed by inflammation. Methods Studies were conducted in vitamin A-deficient and –adequate rats that were further treated with all-trans-RA or lipopolysaccharide (LPS) to induce a state of moderate inflammation. RALDH1A1 expression was determined by quantitative PCR and RALDH1, as well as marker gene expression, was determined by immunocytochemical methods. Results Inflammation reduced ALDH1A1 mRNA in whole liver regardless of the level of vitamin A in the diet (P < 0.05), while treatment with RA reduced ALDH1A1 expression only in chow-fed rats. ALDH1A1 protein exhibited diffuse staining in hepatocytes, with greater intensity in the periportal region including surrounding bile ducts. Six h after administration of LPS, portal region macrophages were more numerous and some of these cells contained ALDH1A1. Vimentin, which was used as a marker for stellate cells and fibroblasts, was increased by LPS, P = 0.011 vs. without LPS, in both ED1 (CD68)-positive macrophages and fibroblastic stellate-like cells in the parenchyma as well as portal regions. Alpha-smooth muscle actin staining was intense around blood vessels, but did not change after LPS or RA, nor overlap with staining for vimentin. Conclusions Acute inflammation rapidly downregulates ALDH1A1 expression in whole liver while increasing its expression in periportal macrophages. Changes in ALDH1A1 expression appear to be part of the early acute-phase inflammatory response, which has been shown to alter the expression of other retinoid homeostatic genes. In addition, the rapid strong response of vimentin expression after treatment with LPS suggests that increased vimentin may be a useful marker of early hepatic inflammation.
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Affiliation(s)
- Kyoko Ito
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA 16802 USA
| | - Reza Zolfaghari
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA 16802 USA
| | - Lei Hao
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA 16802 USA ; Graduate Program in Nutrition, The Pennsylvania State University, University Park, PA 16802 USA
| | - A Catharine Ross
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA 16802 USA ; Center for Immunology and Infectious Disease, Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA 16802 USA ; Huck Institutes for Life Sciences and Department of Nutritional Sciences, Pennsylvania State University, 110 Chandlee Laboratory, University Park, PA 16803 USA
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17
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DiSilvestro D, Petrosino J, Aldoori A, Melgar-Bermudez E, Wells A, Ziouzenkova O. Enzymatic intracrine regulation of white adipose tissue. Horm Mol Biol Clin Investig 2014; 19:39-55. [PMID: 25390015 DOI: 10.1515/hmbci-2014-0019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Accepted: 05/28/2014] [Indexed: 11/15/2022]
Abstract
Abdominal fat formation has become a permanent risk factor for metabolic syndrome and various cancers in one-third of the world's population of obese and even lean patients. Formation of abdominal fat involves additional mechanisms beyond an imbalance in energy intake and expenditure, which explains systemic obesity. In this review, we briefly summarized autonomous regulatory circuits that locally produce hormones from inactive precursors or nutrients for intra-/auto-/paracrine signaling in white adipose depots. Enzymatic pathways activating steroid and thyroid hormones in adipose depots were compared with enzymatic production of retinoic acid from vitamin A. We discussed the role of intracrine circuits in fat-depot functions and strategies to reduce abdominal adiposity through thermogenic adipocytes with interrupted generation of retinoic acid.
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18
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Sarang Z, Joós G, Garabuczi É, Rühl R, Gregory CD, Szondy Z. Macrophages engulfing apoptotic cells produce nonclassical retinoids to enhance their phagocytic capacity. THE JOURNAL OF IMMUNOLOGY 2014; 192:5730-8. [PMID: 24850721 DOI: 10.4049/jimmunol.1400284] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Previous work in our laboratory has shown that transglutaminase 2 (TG2) acting as a coreceptor for integrin β3 is required for proper phagocytosis of apoptotic cells. In the absence of TG2, systemic lupus erythematosus-like autoimmunity develops in mice, similarly to other mice characterized by a deficiency in the clearance of apoptotic cells. In this study, we demonstrate that increasing TG2 expression alone in wild-type macrophages is not sufficient to enhance engulfment. However, during engulfment, the lipid content of the apoptotic cells triggers the lipid-sensing receptor liver X receptor (LXR), which in response upregulates the expression of the phagocytic receptor Mer tyrosine kinase and the phagocytosis-related ABCA1, and that of retinaldehyde dehydrogenases leading to the synthesis of a nonclassical retinoid. Based on our retinoid analysis, this compound might be a dihydro-retinoic acid derivative. The novel retinoid then contributes to the upregulation of further phagocytic receptors including TG2 by ligating retinoic acid receptors. Inhibition of retinoid synthesis prevents the enhanced phagocytic uptake induced by LXR ligation. Our data indicate that stimulation of LXR enhances the engulfment of apoptotic cells via regulating directly and indirectly the expression of a range of phagocytosis-related molecules, and its signaling pathway involves the synthesis of a nonclassical retinoid. We propose that retinoids could be used for enhancing the phagocytic capacity of macrophages in diseases such as systemic lupus erythematosus, where impaired phagocytosis of apoptotic cells plays a role in the pathogenesis of the disease.
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Affiliation(s)
- Zsolt Sarang
- Dental Biochemistry Section, Research Center of Molecular Medicine, University of Debrecen, Debrecen H-4012, Hungary
| | - Gergely Joós
- Dental Biochemistry Section, Research Center of Molecular Medicine, University of Debrecen, Debrecen H-4012, Hungary
| | - Éva Garabuczi
- Dental Biochemistry Section, Research Center of Molecular Medicine, University of Debrecen, Debrecen H-4012, Hungary
| | - Ralph Rühl
- Department of Biochemistry and Molecular Biology, Research Center of Molecular Medicine, University of Debrecen, Debrecen, H-4012 Hungary; and
| | - Christopher D Gregory
- Medical Research Council, Centre for Inflammation Research, Queen's Medical Research Institute, University of Edinburgh, Edinburgh EH16 4TJ, United Kingdom
| | - Zsuzsa Szondy
- Dental Biochemistry Section, Research Center of Molecular Medicine, University of Debrecen, Debrecen H-4012, Hungary;
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Ohoka Y, Yokota-Nakatsuma A, Maeda N, Takeuchi H, Iwata M. Retinoic acid and GM-CSF coordinately induce retinal dehydrogenase 2 (RALDH2) expression through cooperation between the RAR/RXR complex and Sp1 in dendritic cells. PLoS One 2014; 9:e96512. [PMID: 24788806 PMCID: PMC4008585 DOI: 10.1371/journal.pone.0096512] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Accepted: 04/07/2014] [Indexed: 11/27/2022] Open
Abstract
Retinoic acid (RA)-producing dendritic cells (DCs) play critical roles in gut immunity. Retinal dehydrogenase 2 (RALDH2) encoded by Aldh1a2 is a key enzyme for generating RA in DCs. Granulocyte–macrophage colony-stimulating factor (GM-CSF) potently induces RALDH2 expression in DCs in an RA-dependent manner, and RA alone weakly induces the expression. However, how GM-CSF and RA induce RALDH2 expression remains unclear. Here, we show that GM-CSF-induced activation of the transcription factor Sp1 and RA-dependent signaling via the RA receptor (RAR)/retinoid X receptor (RXR) complex contribute to Aldh1a2 expression. The RAR antagonist LE540 and the Sp1 inhibitor mithramycin A inhibited GM-CSF-induced Aldh1a2 expression in fms-related tyrosine kinase 3 ligand-generated bone marrow-derived DCs (BM-DCs). ERK and p38 MAPK inhibitors suppressed GM-CSF-induced nuclear translocation of Sp1 and Aldh1a2 expression. Sp1 and the RARα/RXRα complex bound to GC-rich Sp1-binding sites and an RA response element (RARE) half-site, respectively, near the TATA box in the mouse Aldh1a2 promoter. The DNA sequences around these sites were highly conserved among different species. In the presence of RA, ectopic expression of RARα/RXRα and Sp1 synergistically enhanced Aldh1a2 promoter-reporter activity. GM-CSF did not significantly induce Aldh1a2 expression in plasmacytoid DCs, peritoneal macrophages, or T cells, and the Aldh1a2 promoter in these cells was mostly unmethylated. These results suggest that GM-CSF/RA-induced RALDH2 expression in DCs requires cooperative binding of Sp1 and the RAR/RXR complex to the Aldh1a2 promoter, and can be regulated by a DNA methylation-independent mechanism.
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Affiliation(s)
- Yoshiharu Ohoka
- Laboratory of Immunology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki-shi, Kagawa, Japan
- Japan Science and Technology Agency, CREST, Chiyoda-ku, Tokyo, Japan
- * E-mail: (YO); (MI)
| | - Aya Yokota-Nakatsuma
- Laboratory of Immunology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki-shi, Kagawa, Japan
- Japan Science and Technology Agency, CREST, Chiyoda-ku, Tokyo, Japan
| | - Naoko Maeda
- Laboratory of Immunology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki-shi, Kagawa, Japan
- Japan Science and Technology Agency, CREST, Chiyoda-ku, Tokyo, Japan
| | - Hajime Takeuchi
- Laboratory of Immunology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki-shi, Kagawa, Japan
- Japan Science and Technology Agency, CREST, Chiyoda-ku, Tokyo, Japan
| | - Makoto Iwata
- Laboratory of Immunology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki-shi, Kagawa, Japan
- Japan Science and Technology Agency, CREST, Chiyoda-ku, Tokyo, Japan
- * E-mail: (YO); (MI)
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Aldehyde dehydrogenase 1A1: friend or foe to female metabolism? Nutrients 2014; 6:950-73. [PMID: 24594504 PMCID: PMC3967171 DOI: 10.3390/nu6030950] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Revised: 02/08/2014] [Accepted: 02/18/2014] [Indexed: 02/08/2023] Open
Abstract
In this review, we summarize recent advances in understanding vitamin A-dependent regulation of sex-specific differences in metabolic diseases, inflammation, and certain cancers. We focus on the characterization of the aldehyde dehydrogenase-1 family of enzymes (ALDH1A1, ALDH1A2, ALDH1A3) that catalyze conversion of retinaldehyde to retinoic acid. Additionally, we propose a “horizontal transfer of signaling” from estrogen to retinoids through the action of ALDH1A1. Although estrogen does not directly influence expression of Aldh1a1, it has the ability to suppress Aldh1a2 and Aldh1a3, thereby establishing a female-specific mechanism for retinoic acid generation in target tissues. ALDH1A1 regulates adipogenesis, abdominal fat formation, glucose tolerance, and suppression of thermogenesis in adipocytes; in B cells, ALDH1A1 plays a protective role by inducing oncogene suppressors Rara and Pparg. Considering the conflicting responses of Aldh1a1 in a multitude of physiological processes, only tissue-specific regulation of Aldh1a1 can result in therapeutic effects. We have shown through successful implantation of tissue-specific Aldh1a1−/− preadipocytes that thermogenesis can be induced in wild-type adipose tissues to resolve diet-induced visceral obesity in females. We will briefly discuss the emerging role of ALDH1A1 in multiple myeloma, the regulation of reproduction, and immune responses, and conclude by discussing the role of ALDH1A1 in future therapeutic applications.
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Simandi Z, Cuaranta-Monroy I, Nagy L. Nuclear receptors as regulators of stem cell and cancer stem cell metabolism. Semin Cell Dev Biol 2013; 24:716-23. [DOI: 10.1016/j.semcdb.2013.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Chen G. Roles of Vitamin A Metabolism in the Development of Hepatic Insulin Resistance. ISRN HEPATOLOGY 2013; 2013:534972. [PMID: 27335827 PMCID: PMC4890907 DOI: 10.1155/2013/534972] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Accepted: 08/18/2013] [Indexed: 02/07/2023]
Abstract
The increase in the number of people with obesity- and noninsulin-dependent diabetes mellitus has become a major public health concern. Insulin resistance is a common feature closely associated with human obesity and diabetes. Insulin regulates metabolism, at least in part, via the control of the expression of the hepatic genes involved in glucose and fatty acid metabolism. Insulin resistance is always associated with profound changes of the expression of hepatic genes for glucose and lipid metabolism. As an essential micronutrient, vitamin A (VA) is needed in a variety of physiological functions. The active metablite of VA, retinoic acid (RA), regulates the expression of genes through the activation of transcription factors bound to the RA-responsive elements in the promoters of RA-targeted genes. Recently, retinoids have been proposed to play roles in glucose and lipid metabolism and energy homeostasis. This paper summarizes the recent progresses in our understanding of VA metabolism in the liver and of the potential transcription factors mediating RA responses. These transcription factors are the retinoic acid receptor, the retinoid X receptor, the hepatocyte nuclear factor 4α, the chicken ovalbumin upstream promoter-transcription factor II, and the peroxisome proliferator-activated receptor β/δ. This paper also summarizes the effects of VA status and RA treatments on the glucose and lipid metabolism in vivo and the effects of retinoid treatments on the expression of insulin-regulated genes involved in the glucose and fatty acid metabolism in the primary hepatocytes. I discuss the roles of RA production in the development of insulin resistance in hepatocytes and proposes a mechanism by which RA production may contribute to hepatic insulin resistance. Given the large amount of information and progresses regarding the physiological functions of VA, this paper mainly focuses on the findings in the liver and hepatocytes and only mentions the relative findings in other tissues and cells.
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Affiliation(s)
- Guoxun Chen
- Department of Nutrition, University of Tennessee at Knoxville, Knoxville, TN 37996, USA
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Kedishvili NY. Enzymology of retinoic acid biosynthesis and degradation. J Lipid Res 2013; 54:1744-60. [PMID: 23630397 PMCID: PMC3679379 DOI: 10.1194/jlr.r037028] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Revised: 04/17/2013] [Indexed: 12/18/2022] Open
Abstract
All-trans-retinoic acid is a biologically active derivative of vitamin A that regulates numerous physiological processes. The concentration of retinoic acid in the cells is tightly regulated, but the exact mechanisms responsible for this regulation are not completely understood, largely because the enzymes involved in the biosynthesis of retinoic acid have not been fully defined. Recent studies using in vitro and in vivo models suggest that several members of the short-chain dehydrogenase/reductase superfamily of proteins are essential for retinoic acid biosynthesis and the maintenance of retinoic acid homeostasis. However, the exact roles of some of these recently identified enzymes are yet to be characterized. The properties of the known contributors to retinoid metabolism have now been better defined and allow for more detailed understanding of their interactions with retinoid-binding proteins and other retinoid enzymes. At the same time, further studies are needed to clarify the interactions between the cytoplasmic and membrane-bound proteins involved in the processing of hydrophobic retinoid metabolites. This review summarizes current knowledge about the roles of various biosynthetic and catabolic enzymes in the regulation of retinoic acid homeostasis and outlines the remaining questions in the field.
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Affiliation(s)
- Natalia Y Kedishvili
- Department of Biochemistry and Molecular Genetics, Schools of Medicine and Dentistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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Li Y, Zhang Y, Li R, Chen W, Howell M, Zhang R, Chen G. The hepatic Raldh1 expression is elevated in Zucker fatty rats and its over-expression introduced the retinal-induced Srebp-1c expression in INS-1 cells. PLoS One 2012; 7:e45210. [PMID: 23028851 PMCID: PMC3441598 DOI: 10.1371/journal.pone.0045210] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Accepted: 08/14/2012] [Indexed: 02/07/2023] Open
Abstract
The roles of vitamin A (VA) in the development of metabolic diseases remain unanswered. We have reported that retinoids synergized with insulin to induce the expression of sterol-regulatory element-binding protein 1c gene (Srebp-1c) expression in primary rat hepatocytes. Additionally, the hepatic Srebp-1c expression is elevated in Zucker fatty (ZF) rats, and reduced in those fed a VA deficient diet. VA is metabolized to retinoic acid (RA) for regulating gene expression. We hypothesized that the expression of RA production enzymes contributes to the regulation of the hepatic Srebp-1c expression. Therefore, we analyzed their expression levels in Zucker lean (ZL) and ZF rats. The mRNA levels of retinaldehyde dehydrogenase family 1 gene (Raldh1) were found to be higher in the isolated and cultured primary hepatocytes from ZF rats than that from ZL rats. The RALDH1 protein level was elevated in the liver of ZF rats. Retinol and retinal dose- and time-dependently induced the expression of RA responsive Cyp26a1 gene in hepatocytes and hepatoma cells. INS-1 cells were identified as an ideal tool to study the effects of RA production on the regulation of gene expression because only RA, but not retinal, induced Srebp-1c mRNA expression in them. Recombinant adenovirus containing rat Raldh1 cDNA was made and used to infect INS-1 cells. The over-expression of RALDH1 introduced the retinal-mediated induction of Srebp-1c expression in INS-1 cells. We conclude that the expression levels of the enzymes for RA production may contribute to the regulation of RA responsive genes, and determine the responses of the cells to retinoid treatments. The elevated hepatic expression of Raldh1 in ZF rats may cause the excessive RA production from retinol, and in turn, result in higher Srebp-1c expression. This excessive RA production may be one of the factors contributing to the elevated lipogenesis in the liver of ZF rats.
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Affiliation(s)
- Yang Li
- Department of Nutrition, the University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Yan Zhang
- Department of Nutrition, the University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Rui Li
- Department of Nutrition, the University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Wei Chen
- Department of Nutrition, the University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Meredith Howell
- Department of Nutrition, the University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Rui Zhang
- Department of Nutrition, the University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
| | - Guoxun Chen
- Department of Nutrition, the University of Tennessee at Knoxville, Knoxville, Tennessee, United States of America
- * E-mail:
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Cassani B, Villablanca EJ, De Calisto J, Wang S, Mora JR. Vitamin A and immune regulation: role of retinoic acid in gut-associated dendritic cell education, immune protection and tolerance. Mol Aspects Med 2011; 33:63-76. [PMID: 22120429 DOI: 10.1016/j.mam.2011.11.001] [Citation(s) in RCA: 138] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 11/01/2011] [Accepted: 11/10/2011] [Indexed: 01/27/2023]
Abstract
The vitamin A (VA) metabolite all-trans retinoic acid (RA) plays a key role in mucosal immune responses. RA is produced by gut-associated dendritic cells (DC) and is required for generating gut-tropic lymphocytes and IgA-antibody-secreting cells (IgA-ASC). Moreover, RA modulates Foxp3(+) regulatory T cell (T(REG)) and Th17 effector T cell differentiation. Thus, although RA could be used as an effective "mucosal adjuvant" in vaccines, it also appears to be required for establishing intestinal immune tolerance. Here we discuss the roles proposed for RA in shaping intestinal immune responses and tolerance at the gut mucosal interface. We also focus on recent data exploring the mechanisms by which gut-associated DC acquire RA-producing capacity.
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Affiliation(s)
- Barbara Cassani
- Gastrointestinal Unit, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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26
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Sarıkaya E, Bozdağ S, Deveer R, Oğuz SS, Dilmen U, Mollamahmutoglu L. Possible association of medications during pregnancy with low estriol level of the triple antenatal screening test. J Matern Fetal Neonatal Med 2011; 25:930-3. [PMID: 22007901 DOI: 10.3109/14767058.2011.600368] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Our purpose was to reach the reasons of isolated low levels of maternal serum unconjugated estriol (uE3) levels (≤ 0.3 multiples of the median (MoM)) in the triple-marker screen with special emphasis on maternal diseases and medications used for them. METHODS Single center retrospective cross-sectional analysis. Of 13,367 non-smoking women with identified singleton pregnancies screened for triple test, during 3-year period (2007-2009), a group of women with isolated low serum uE3 levels (≤ 0.3 MoM) (n = 14) were selected as the study group. RESULTS Of these 14 women, no one gave birth with ichthyosis. Five patients had, isolated very low uE3 levels (<0.01 MoM). Of these women, one had umbilical cord knot, one was on corticosteroid and three were on propylthiouracil treatment. So, there was history of maternal drug intake in 28.5% of cases with isolated low uE3 (≤ 0.3 MoM). This rate increases to 80% in cases with very low uE3 levels (<0.01 MoM). CONCLUSIONS Maternal diseases and medications used during pregnancy can affect fetus and antenatal screening test results. This is important during counseling of patients and to perform the appropriate antenatal and postnatal evaluation of the mother and fetus with multidisciplinary approach.
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Affiliation(s)
- Esma Sarıkaya
- Department of Obstetrics and Gynecology, Zekai Tahir Burak Women's Health Research and Education Hospital, Ankara, Turkey.
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Keber R, Motaln H, Wagner KD, Debeljak N, Rassoulzadegan M, Ačimovič J, Rozman D, Horvat S. Mouse knockout of the cholesterogenic cytochrome P450 lanosterol 14alpha-demethylase (Cyp51) resembles Antley-Bixler syndrome. J Biol Chem 2011; 286:29086-29097. [PMID: 21705796 DOI: 10.1074/jbc.m111.253245] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Antley-Bixler syndrome (ABS) represents a group of heterogeneous disorders characterized by skeletal, cardiac, and urogenital abnormalities that have frequently been associated with mutations in fibroblast growth factor receptor 2 or cytochrome P450 reductase genes. In some ABS patients, reduced activity of the cholesterogenic cytochrome P450 CYP51A1, an ortholog of the mouse CYP51, and accumulation of lanosterol and 24,25-dihydrolanosterol has been reported, but the role of CYP51A1 in the ABS etiology has remained obscure. To test whether Cyp51 could be involved in generating an ABS-like phenotype, a mouse knock-out model was developed that exhibited several prenatal ABS-like features leading to lethality at embryonic day 15. Cyp51(-/-) mice had no functional Cyp51 mRNA and no immunodetectable CYP51 protein. The two CYP51 enzyme substrates (lanosterol and 24,25-dihydrolanosterol) were markedly accumulated. Cholesterol precursors downstream of the CYP51 enzymatic step were not detected, indicating that the targeting in this study blocked de novo cholesterol synthesis. This was reflected in the up-regulation of 10 cholesterol synthesis genes, with the exception of 7-dehydrocholesterol reductase. Lethality was ascribed to heart failure due to hypoplasia, ventricle septum, and epicardial and vasculogenesis defects, suggesting that Cyp51 deficiency was involved in heart development and coronary vessel formation. As the most likely downstream molecular mechanisms, alterations were identified in the sonic hedgehog and retinoic acid signaling pathways. Cyp51 knock-out mice provide evidence that Cyp51 is essential for embryogenesis and present a potential animal model for studying ABS syndrome in humans.
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Affiliation(s)
- Rok Keber
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Helena Motaln
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, 1000 Ljubljana, Slovenia
| | - Kay D Wagner
- INSERM U907, Parc Valrose, Nice, France; Université de Nice, Sophia-Antipolis, Parc Valrose, Nice, France
| | - Nataša Debeljak
- Institute of Biochemistry, Centre for Functional Genomics and Bio-Chips, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Minoo Rassoulzadegan
- Université de Nice, Sophia-Antipolis, Parc Valrose, Nice, France; Centre de Biochimie, INSERM U636, Parc Valrose, Nice, France
| | - Jure Ačimovič
- Institute of Biochemistry, Centre for Functional Genomics and Bio-Chips, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Damjana Rozman
- Institute of Biochemistry, Centre for Functional Genomics and Bio-Chips, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Simon Horvat
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia; National Institute of Chemistry, 1000 Ljubljana, Slovenia and.
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Napoli JL. Physiological insights into all-trans-retinoic acid biosynthesis. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1821:152-67. [PMID: 21621639 DOI: 10.1016/j.bbalip.2011.05.004] [Citation(s) in RCA: 246] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Revised: 05/05/2011] [Accepted: 05/12/2011] [Indexed: 01/25/2023]
Abstract
All-trans-retinoic acid (atRA) provides essential support to diverse biological systems and physiological processes. Epithelial differentiation and its relationship to cancer, and embryogenesis have typified intense areas of interest into atRA function. Recently, however, interest in atRA action in the nervous system, the immune system, energy balance and obesity has increased considerably, especially concerning postnatal function. atRA action depends on atRA biosynthesis: defects in retinoid-dependent processes increasingly relate to defects in atRA biogenesis. Considerable evidence indicates that physiological atRA biosynthesis occurs via a regulated process, consisting of a complex interaction of retinoid binding-proteins and retinoid recognizing enzymes. An accrual of biochemical, physiological and genetic data have identified specific functional outcomes for the retinol dehydrogenases, RDH1, RDH10, and DHRS9, as physiological catalysts of the first step in atRA biosynthesis, and for the retinal dehydrogenases RALDH1, RALDH2, and RALDH3, as catalysts of the second and irreversible step. Each of these enzymes associates with explicit biological processes mediated by atRA. Redundancy occurs, but seems limited. Cumulative data support a model of interactions among these enzymes with retinoid binding-proteins, with feedback regulation and/or control by atRA via modulating gene expression of multiple participants. The ratio apo-CRBP1/holo-CRBP1 participates by influencing retinol flux into and out of storage as retinyl esters, thereby modulating substrate to support atRA biosynthesis. atRA biosynthesis requires the presence of both an RDH and an RALDH: conversely, absence of one isozyme of either step does not indicate lack of atRA biosynthesis at the site. This article is part of a Special Issue entitled: Retinoid and Lipid Metabolism.
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Reichert B, Yasmeen R, Jeyakumar SM, Yang F, Thomou T, Alder H, Duester G, Maiseyeu A, Mihai G, Harrison EH, Rajagopalan S, Kirkland JL, Ziouzenkova O. Concerted action of aldehyde dehydrogenases influences depot-specific fat formation. Mol Endocrinol 2011; 25:799-809. [PMID: 21436255 DOI: 10.1210/me.2010-0465] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Vitamin A metabolite retinoic acid (RA) regulates life-sustaining differentiation processes and metabolic homeostasis. The aldehyde dehydrogenase-1 (Aldh1) family of enzymes (Aldh1a1, a2, and a3) catalyzes RA production from retinaldehyde and thereby controls concentrations of this transcriptionally active metabolite. The hierarchy of Aldh1 functions in adipose tissue has not been elucidated. We hypothesized that Aldh1 enzymes produce endogenous RA and regulate adipogenesis and fat formation in a fat depot-specific manner. We demonstrate that adipogenesis in vitro is accompanied by RA production generated primarily by Aldh1a1. In Aldh1a1-deficient adipocytes, adipogenesis is impaired compared with wild-type adipocytes due to markedly reduced expression of PPARγ regulated through zinc-finger protein 423 (ZFP423)-dependent mechanisms. These effects were recovered to some extent either by RA stimulation or overexpression of any of the Aldh1 enzymes in Aldh1a1(-/-) cells arguing that Aldh1a1 plays a dominant role in autocrine RA production. In vivo studies in C57/BL6 and Aldh1a1(-/-) mice on a regular diet revealed that multiple Aldh1 enzymes regulate differences in the formation of sc and visceral fat. In Aldh1a1(-/-) mice, visceral fat essentially lacked all Aldh1 expression. This loss of RA-producing enzymes was accompanied by 70% decreased expression of ZFP423, PPARγ, and Fabp4 in visceral fat of Aldh1a1(-/-) vs. wild-type mice and by the predominant loss of visceral fat. Subcutaneous fat of Aldh1a1(-/-) mice expressed Aldh1a3 for RA production that was sufficient to maintain expression of ZFP423 and PPARγ and sc fat mass. Our data suggest a paradigm for regulation of fat depots through the concerted action of Aldh1 enzymes that establish RA-dependent tandem regulation of transcription factors ZFP423 and PPARγ in a depot-specific manner.
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Affiliation(s)
- Barbara Reichert
- Department of Human Nutrition, Ohio State University, Columbus, Ohio, 43210, USA
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Iwata M, Yokota A. Retinoic acid production by intestinal dendritic cells. VITAMINS AND HORMONES 2011; 86:127-52. [PMID: 21419270 DOI: 10.1016/b978-0-12-386960-9.00006-x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Subpopulations of dendritic cells (DCs) in the small intestine and its related lymphoid organs can produce retinoic acid (RA) from vitamin A (retinol). Through the RA production, these DCs play a pivotal role in imprinting lymphocytes with gut-homing specificity, and contribute to the development of immune tolerance by enhancing the differentiation of Foxp3(+) regulatory T cells and inhibiting that of inflammatory Th17 cells. The RA-producing capacity in these DCs mostly depends on the expression of retinal dehydrogenase 2 (RALDH2, ALDH1A2). It is likely that the RALDH2 expression is induced in DCs by the microenvironmental factors in the small intestine and its related lymphoid organs. The major factor responsible for the RALDH2 expression appears to be GM-CSF. RA itself is essential for the GM-CSF-induced RALDH2 expression. IL-4 and IL-13 also enhance RALDH2 expression, but are dispensable. Toll-like receptor-mediated signals can also enhance the GM-CSF-induced RALDH2 expression in immature DCs.
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Affiliation(s)
- Makoto Iwata
- Faculty of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, Sanuki-shi, Kagawa, Japan
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Rébé C, Raveneau M, Chevriaux A, Lakomy D, Sberna AL, Costa A, Bessède G, Athias A, Steinmetz E, Lobaccaro JMA, Alves G, Menicacci A, Vachenc S, Solary E, Gambert P, Masson D. Induction of transglutaminase 2 by a liver X receptor/retinoic acid receptor alpha pathway increases the clearance of apoptotic cells by human macrophages. Circ Res 2009; 105:393-401. [PMID: 19628791 DOI: 10.1161/circresaha.109.201855] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
RATIONALE Liver X receptors (LXRs) are oxysterol-activated nuclear receptors that are involved in the control of cholesterol homeostasis and inflammatory response. Human monocytes and macrophages express high levels of these receptors and are appropriate cells to study the response to LXR agonists. OBJECTIVE The purpose of this study was to identify new LXR targets in human primary monocytes and macrophages and the consequences of their activation. METHODS AND RESULTS We show that LXR agonists significantly increase the mRNA and protein levels of the retinoic acid receptor (RAR)alpha in primary monocytes and macrophages. LXR agonists promote RARalpha gene transcription through binding to a specific LXR response element on RARalpha gene promoter. Preincubation of monocytes or macrophages with LXR agonists before RARalpha agonist treatment enhances synergistically the expression of several RARalpha target genes. One of these genes encodes transglutaminase (TGM)2, a key factor required for macrophage phagocytosis. Accordingly, the combination of LXR and RARalpha agonists at concentrations found in human atherosclerotic plaques markedly enhances the capabilities of macrophages to engulf apoptotic cells in a TGM2-dependent manner. CONCLUSIONS These results indicate an important role for LXRs in the control of phagocytosis through an RARalpha-TGM2-dependent mechanism. A combination of LXR/RARalpha agonists that may operate in atherosclerosis could also constitute a promising strategy to improve the clearance of apoptotic cells by macrophages in other pathological situations.
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Affiliation(s)
- Cédric Rébé
- Institut Fédératif de Recherche Santé-STIC, Faculté de Médecine, Université de Bourgogne, Dijon, France.
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Cholesterol metabolism: the main pathway acting downstream of cytochrome P450 oxidoreductase in skeletal development of the limb. Mol Cell Biol 2009; 29:2716-29. [PMID: 19273610 DOI: 10.1128/mcb.01638-08] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Cytochrome P450 oxidoreductase (POR) is the obligate electron donor for all microsomal cytochrome P450 enzymes, which catalyze the metabolism of a wide spectrum of xenobiotic and endobiotic compounds. Point mutations in POR have been found recently in patients with Antley-Bixler-like syndrome, which includes limb skeletal defects. In order to study P450 function during limb and skeletal development, we deleted POR specifically in mouse limb bud mesenchyme. Forelimbs and hind limbs in conditional knockout (CKO) mice were short with thin skeletal elements and fused joints. POR deletion occurred earlier in forelimbs than in hind limbs, leading additionally to soft tissue syndactyly and loss of wrist elements and phalanges due to changes in growth, cell death, and skeletal segmentation. Transcriptional analysis of E12.5 mouse forelimb buds demonstrated the expression of P450s involved in retinoic acid, cholesterol, and arachidonic acid metabolism. Biochemical analysis of CKO limbs confirmed retinoic acid excess. In CKO limbs, expression of genes throughout the whole cholesterol biosynthetic pathway was upregulated, and cholesterol deficiency can explain most aspects of the phenotype. Thus, cellular POR-dependent cholesterol synthesis is essential during limb and skeletal development. Modulation of P450 activity could contribute to susceptibility of the embryo and developing organs to teratogenesis.
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Yokota A, Takeuchi H, Maeda N, Ohoka Y, Kato C, Song SY, Iwata M. GM-CSF and IL-4 synergistically trigger dendritic cells to acquire retinoic acid-producing capacity. Int Immunol 2009; 21:361-77. [PMID: 19190084 PMCID: PMC2660862 DOI: 10.1093/intimm/dxp003] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Retinoic acid (RA) produced by intestinal dendritic cells (DCs) imprints gut-homing specificity on lymphocytes and enhances Foxp3+ regulatory T-cell differentiation. The expression of aldehyde dehydrogenase (ALDH) 1A in these DCs is essential for the RA production. However, it remains unclear how the steady-state ALDH1A expression is induced under specific pathogen-free (SPF) conditions. Here, we found that bone marrow-derived dendritic cells (BM-DCs) generated with granulocyte-macrophage colony-stimulating factor (GM-CSF) expressed Aldh1a2, an isoform of Aldh1a, but that fms-related tyrosine kinase 3 ligand-generated BM-DCs did not. DCs from mesenteric lymph nodes (MLN) and Peyer's patches (PP) of normal SPF mice expressed ALDH1A2, but not the other known RA-producing enzymes. Employing a flow cytometric method, we detected ALDH activities in 10–30% of PP-DCs and MLN-DCs. They were CD11chighCD4−/lowCD8αintermediateCD11b−/low F4/80low/intermediateCD45RBlowCD86highMHC class IIhighB220−CD103+. Equivalent levels of aldehyde dehydrogenase activity (ALDHact) and ALDH1A2 expression were induced synergistically by GM-CSF and IL-4 in splenic DCs in vitro. In BM-DCs, however, additional signals via Toll-like receptors or RA receptors were required for inducing the equivalent levels. The generated ALDH1A2+ DCs triggered T cells to express gut-homing receptors or Foxp3. GM-CSF receptor-deficient or vitamin A-deficient mice exhibited marked reductions in the ALDHact in intestinal DCs and the T cell number in the intestinal lamina propria, whereas IL-4 receptor-mediated signals were dispensable. GM-CSF+CD11c−F4/80+ cells existed constitutively in the intestinal tissues. The results suggest that GM-CSF and RA itself are pivotal among multiple microenvironment factors that enable intestinal DCs to produce RA.
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Affiliation(s)
- Aya Yokota
- Laboratory of Biodefense Research, Faculty of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, Sanuki-shi, Kagawa, Japan
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Meng ZX, Nie J, Ling JJ, Sun JX, Zhu YX, Gao L, Lv JH, Zhu DY, Sun YJ, Han X. Activation of liver X receptors inhibits pancreatic islet beta cell proliferation through cell cycle arrest. Diabetologia 2009; 52:125-35. [PMID: 18949453 DOI: 10.1007/s00125-008-1174-x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Accepted: 09/09/2008] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS Liver X receptors (LXRs) are important transcriptional regulators of lipid homeostasis and proliferation in several cell types. However, the roles of LXRs in pancreatic beta cells have not been fully established. The aim of this study was to investigate the effects of LXRs on pancreatic beta cell proliferation. METHODS Gene expression was analysed using real-time RT-PCR. Transient transfection and reporter gene assays were used to determine the transcriptional activity of LXRs in pancreatic beta cells. Cell viability and proliferation were analysed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), DNA fluorometric, BrdU labelling and [(3)H]thymidine incorporation assays. Cell cycle distribution was investigated by flow cytometry analysis. Adenovirus-based RNA interference was used to knockdown LXRalpha, LXRbeta and p27 in MIN6 cells and mouse islets. RESULTS We found that both Lxralpha (also known as Nr1h3) and Lxrbeta (also known as Nr1h2) were expressed and transactivated the LXR response element in HIT-T15 and MIN6 cells. Activation of LXRs dose-dependently inhibited pancreatic beta cell viability and proliferation. This was accompanied by beta cell cycle arrest at the G1 phase. Furthermore, LXR activation increased levels of the p27 protein by inhibiting its degradation. Knockdown of p27 reversed these effects of LXR activation on growth inhibition and cell cycle arrest. CONCLUSIONS/INTERPRETATION Our observations indicate that LXR activation inhibits pancreatic beta cell proliferation through cell cycle arrest. A well-known regulator of pancreatic beta cell cycle progression, p27, is upregulated and mediates the effects of LXRs on growth inhibition in beta cells. These observations suggest the involvement of aberrant activation of LXR in beta cell mass inadequacy, which is an important step in the development of type 2 diabetes.
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Affiliation(s)
- Z X Meng
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Clinical Diabetes Centre of Jiangsu Province, Nanjing Medical University, Nanjing, People's Republic of China
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Aoto J, Nam CI, Poon MM, Ting P, Chen L. Synaptic signaling by all-trans retinoic acid in homeostatic synaptic plasticity. Neuron 2008; 60:308-20. [PMID: 18957222 DOI: 10.1016/j.neuron.2008.08.012] [Citation(s) in RCA: 289] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Revised: 06/16/2008] [Accepted: 08/15/2008] [Indexed: 11/30/2022]
Abstract
Normal brain function requires that the overall synaptic activity in neural circuits be kept constant. Long-term alterations of neural activity lead to homeostatic regulation of synaptic strength by a process known as synaptic scaling. The molecular mechanisms underlying synaptic scaling are largely unknown. Here, we report that all-trans retinoic acid (RA), a well-known developmental morphogen, unexpectedly mediates synaptic scaling in response to activity blockade. We show that activity blockade increases RA synthesis in neurons and that acute RA treatment enhances synaptic transmission. The RA-induced increase in synaptic strength is occluded by activity blockade-induced synaptic scaling. Suppression of RA synthesis prevents synaptic scaling. This form of RA signaling operates via a translation-dependent but transcription-independent mechanism, causes an upregulation of postsynaptic glutamate receptor levels, and requires RARalpha receptors. Together, our data suggest that RA functions in homeostatic plasticity as a signaling molecule that increases synaptic strength by a protein synthesis-dependent mechanism.
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Affiliation(s)
- Jason Aoto
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, CA 94720-3200, USA
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Iwata M. Retinoic acid production by intestinal dendritic cells and its role in T-cell trafficking. Semin Immunol 2008; 21:8-13. [PMID: 18849172 DOI: 10.1016/j.smim.2008.09.002] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2008] [Revised: 08/29/2008] [Accepted: 09/01/2008] [Indexed: 12/13/2022]
Abstract
Vitamin A deficiency causes a marked reduction in the number of T and B cells in the small intestinal tissues. The vitamin A metabolite retinoic acid imprints lymphocytes with gut-homing specificity upon antigenic stimulation. In the small intestinal lamina propria, Peyer's patches, and mesenteric lymph nodes, there are dendritic cells capable of producing retinoic acid. Their capacity depends on the expression of retinal dehydrogenases (RALDH). RALDH2, encoded by Aldh1a2, is a major isoform of RALDH in the intestinal dendritic cells under specific pathogen-free conditions, and can be induced by multiple factors constitutively present or induced in the small intestinal microenvironment.
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Affiliation(s)
- Makoto Iwata
- Laboratory of Biodefense Research, Faculty of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Sanuki-shi, Kagawa 769-2193, Japan.
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Meissburger B, Wolfrum C. The role of retinoids and their receptors in metabolic disorders. EUR J LIPID SCI TECH 2008. [DOI: 10.1002/ejlt.200700291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Hoover LL, Burton EG, Brooks BA, Kubalak SW. The expanding role for retinoid signaling in heart development. ScientificWorldJournal 2008; 8:194-211. [PMID: 18661045 PMCID: PMC2559957 DOI: 10.1100/tsw.2008.39] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The importance of retinoid signaling during cardiac development has long been appreciated, but recently has become a rapidly expanding field of research. Experiments performed over 50 years ago showed that too much or too little maternal intake of vitamin A proved detrimental for embryos, resulting in a cadre of predictable cardiac developmental defects. Germline and conditional knockout mice have revealed which molecular players in the vitamin A signaling cascade are potentially responsible for regulating specific developmental events, and many of these molecules have been temporally and spatially characterized. It is evident that intact and controlled retinoid signaling is necessary for each stage of cardiac development to proceed normally, including cardiac lineage determination, heart tube formation, looping, epicardium formation, ventricular maturation, chamber and outflow tract septation, and coronary arteriogenesis. This review summarizes many of the significant milestones in this field and particular attention is given to recently uncovered cross-talk between retinoid signaling and other developmentally significant pathways. It is our hope that this review of the role of retinoid signaling during formation, remodeling, and maturation of the developing heart will serve as a tool for future discoveries.
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Affiliation(s)
- Loretta L Hoover
- Department of Cell Biology and Anatomy, Cardiovascular Developmental Biology Center, Medical University of South Carolina, Charleston, SC, USA.
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Tsai NP, Bi J, Wei LN. The adaptor Grb7 links netrin-1 signaling to regulation of mRNA translation. EMBO J 2007; 26:1522-31. [PMID: 17318180 PMCID: PMC1829368 DOI: 10.1038/sj.emboj.7601598] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2006] [Accepted: 01/08/2007] [Indexed: 01/04/2023] Open
Abstract
We previously reported a novel biological activity of Netrin-1 in translational stimulation of kappa opioid receptor (KOR). We now identify Grb7 as a new RNA-binding protein that serves as the molecular adaptor for transmitting Netrin-1 signals, through focal adhesion kinase (FAK), to the translation machinery. Grb7 binds specifically to the first stem loop of kor mRNA 5'-UTR through a new RNA-binding domain located in its amino terminus. Upon binding to its capped, target mRNA, Grb7 blocks the recruitment of eIF4E, rendering mRNA untranslatable. The RNA-binding and translation-repressive activity is reduced by FAK-mediated hyperphosphorylation on two tyrosine residues of its carboxyl terminus. This study reports an adaptor protein Grb7 that transmits the stimulating signals of Netrin-1 to the translational machinery to rapidly regulate mRNA translation.
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Affiliation(s)
- Nien-Pei Tsai
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Jing Bi
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Li-Na Wei
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, USA
- Department of Pharmacology, University of Minnesota Medical School, 6-120 Jackson Hall, 321 Church St SE, Minneapolis, MN 55455, USA. Tel.: +1 612 6259402; Fax: +1 612 6258408, E-mail:
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Huq MDM, Tsai NP, Khan SA, Wei LN. Lysine trimethylation of retinoic acid receptor-alpha: a novel means to regulate receptor function. Mol Cell Proteomics 2007; 6:677-88. [PMID: 17205979 DOI: 10.1074/mcp.m600223-mcp200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Retinoic acid receptors (RARs) belong to the nuclear receptor superfamily. The mechanism of ligand-dependent activation of RARs is well known. The effect of protein phosphorylation on the activity of RARs has also been demonstrated. However, it is unclear whether other types of modifications exist and if so whether they can affect the activity of RARs. In a mass spectrometric analysis of mouse RARalpha expressed in insect cells, we identified a trimethylation site on Lys(347) in the ligand binding domain. The modification site was verified in mammalian cells, and site-directed mutagenesis studies revealed the functionality of Lys(347) methylation in vivo. Constitutive negative mutants, mimicking hypomethylated RARalpha, were prepared by replacing methylated Lys(347) with either alanine or glutamine. A constitutive positive mutant partially mimicking the hypermethylated RARalpha was generated by replacing the methylated lysine residue with phenylalanine, a bulky hydrophobic amino acid, to introduce a site-specific hydrophobicity similar to that contributed by lysine methylation. Studies of these mutants revealed that trimethylation of Lys(347) of RARalpha facilitated its interactions with cofactors p300/CREB-binding protein-associated factor and receptor-interacting protein 140 as well as its heterodimeric partner retinoid X receptor, suggesting that site-specific hydrophobicity at Lys(347) enhanced molecular interaction of RARalpha with its modulators. This study uncovers the first example of lysine trimethylation on a mammalian non-histone protein that has an important biological consequence. Our finding also provides the evidence for lysine methylation for the family of nuclear receptors for the first time.
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Affiliation(s)
- M D Mostaqul Huq
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA
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