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Boyer MS, Widmer D, Cohidon C, Desvergne B, Cornuz J, Guessous I, Cerqui D. Representations of personalised medicine in family medicine: a qualitative analysis. BMC Prim Care 2022; 23:37. [PMID: 35232380 PMCID: PMC8889694 DOI: 10.1186/s12875-022-01650-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Accepted: 02/18/2022] [Indexed: 11/24/2022]
Abstract
Background The promise of personalised medicine (PM) to transform healthcare has sparked great enthusiasm in the last years. Yet, its lack of consensus around the nature and scope of the concept has ended in terminological confusion amongst the users in primary care. We aimed to investigate the perceptions of doctors and their patients in response to this evolving concept. This present article focuses on the general understanding of personalised medicine, underlining the confusion over the concept. Methods Semi-structured comprehensive interviews were conducted with 10 general practitioners (GPs) and 10 of their patients. The purposive sampling took into account the doctor’s age, sex, and place of practice (rural/urban); each doctor recruited one patient of the same age and sex. Each interview began with the same open-ended question about the participant’s knowledge of the topic, after which a working definition was provided to continue the discussion. Using the grounded theory method, the analysis consisted of open coding, axial coding and selective coding. Results From our present analysis focusing on the general understanding of PM, three main themes representing the concept emerged. The first two representations being “centred on the person as a whole” and “focused on alternative and complementary methods”, in which the therapeutic relationship was stated as key. The third theme “medicine open to innovation” involved the few participants who had a good understanding of the concept and could associate personalised medicine with genomics. For those who value therapeutic relationship, the risks of accepting innovation could result in “fast-food” medicine and interpersonal barriers. Discussion PM is predominantly unfamiliar in family medicine. It is misinterpreted as a holistic or integrative type of medicine. This semantic confusion probably lies in the choice of the label “personalised” or from the lack of a uniform definition for the term.
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Cohidon C, Desvergne B, Widmer D, Cerqui D, Guessous I, Cornuz J. [Personalized medicine and chronic disease prevention: Needs, attitudes and expectations regarding in general practice]. Rev Med Suisse 2021; 17:1939-1942. [PMID: 34755944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The ambition of personalized medicine now also concerns the prevention of chronic diseases, based on genetic risk profiles. The objective of this project was to describe the perception and attitudes of patients and general practitioners (GP) on this issue, in order to consider the consequences on the health system. The study included two axes, patients (questionnaire survey) and GPs (consensus study using the Delphi method), preceded by a qualitative exploratory phase. The study showed that genetic screening for disease risk factors was not a priority, either for patients or for GPs. On the other hand, the role of the GP in the use of these tests will probably be predominant. This implies the need for training and availability of up-to-date information.
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Affiliation(s)
- Christine Cohidon
- Département de médecine de famille, Centre universitaire de médecine générale et santé publique Unisanté, Université de Lausanne, 1015 Lausanne
| | - Béatrice Desvergne
- Centre intégratif de génomique (CIG), Université de Lausanne, 1015 Lausanne
| | - Daniel Widmer
- Département de médecine de famille, Centre universitaire de médecine générale et santé publique Unisanté, Université de Lausanne, 1015 Lausanne
- Place de la gare 9a-11, 1003 Lausanne
| | - Daniela Cerqui
- Institut des sciences sociales, Faculté des sciences politiques et sociales, Université de Lausanne, 1015 Lausanne
| | - Idris Guessous
- Service de médecine de premier recours, HUG, 1211 Genève 14
| | - Jacques Cornuz
- Centre universitaire de médecine générale et santé publique Unisanté, Université de Lausanne, 1015 Lausanne
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Schiffrin M, Winkler C, Quignodon L, Naldi A, Trötzmüller M, Köfeler H, Henry H, Parini P, Desvergne B, Gilardi F. Sex Dimorphism of Nonalcoholic Fatty Liver Disease (NAFLD) in Pparg-Null Mice. Int J Mol Sci 2021; 22:9969. [PMID: 34576136 PMCID: PMC8467431 DOI: 10.3390/ijms22189969] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 09/09/2021] [Accepted: 09/11/2021] [Indexed: 12/12/2022] Open
Abstract
Men with nonalcoholic fatty liver disease (NAFLD) are more exposed to nonalcoholic steatohepatitis (NASH) and liver fibrosis than women. However, the underlying molecular mechanisms of NALFD sex dimorphism are unclear. We combined gene expression, histological and lipidomic analyses to systematically compare male and female liver steatosis. We characterized hepatosteatosis in three independent mouse models of NAFLD, ob/ob and lipodystrophic fat-specific (PpargFΔ/Δ) and whole-body PPARγ-null (PpargΔ/Δ) mice. We identified a clear sex dimorphism occurring only in PpargΔ/Δ mice, with females showing macro- and microvesicular hepatosteatosis throughout their entire life, while males had fewer lipid droplets starting from 20 weeks. This sex dimorphism in hepatosteatosis was lost in gonadectomized PpargΔ/Δ mice. Lipidomics revealed hepatic accumulation of short and highly saturated TGs in females, while TGs were enriched in long and unsaturated hydrocarbon chains in males. Strikingly, sex-biased genes were particularly perturbed in both sexes, affecting lipid metabolism, drug metabolism, inflammatory and cellular stress response pathways. Most importantly, we found that the expression of key sex-biased genes was severely affected in all the NAFLD models we tested. Thus, hepatosteatosis strongly affects hepatic sex-biased gene expression. With NAFLD increasing in prevalence, this emphasizes the urgent need to specifically address the consequences of this deregulation in humans.
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Affiliation(s)
- Mariano Schiffrin
- Center of Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, CH-1015 Lausanne, Switzerland; (M.S.); (C.W.); (L.Q.); (A.N.); (B.D.)
| | - Carine Winkler
- Center of Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, CH-1015 Lausanne, Switzerland; (M.S.); (C.W.); (L.Q.); (A.N.); (B.D.)
| | - Laure Quignodon
- Center of Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, CH-1015 Lausanne, Switzerland; (M.S.); (C.W.); (L.Q.); (A.N.); (B.D.)
| | - Aurélien Naldi
- Center of Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, CH-1015 Lausanne, Switzerland; (M.S.); (C.W.); (L.Q.); (A.N.); (B.D.)
| | - Martin Trötzmüller
- Core Facility Mass Spectrometry, Medical University of Graz, 8036 Graz, Austria; (M.T.); (H.K.)
| | - Harald Köfeler
- Core Facility Mass Spectrometry, Medical University of Graz, 8036 Graz, Austria; (M.T.); (H.K.)
| | - Hugues Henry
- Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne Faculty of Biology and Medicine, CH-1011 Lausanne, Switzerland;
| | - Paolo Parini
- CardioMetabolic Unit, Department of Medicine and Department of Laboratory Medicine, Karolinska Insititutet and Theme Inflammation and Ageing Karolinska University Hospital Huddinge, 14186 Stockholm, Sweden;
| | - Béatrice Desvergne
- Center of Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, CH-1015 Lausanne, Switzerland; (M.S.); (C.W.); (L.Q.); (A.N.); (B.D.)
| | - Federica Gilardi
- Center of Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, CH-1015 Lausanne, Switzerland; (M.S.); (C.W.); (L.Q.); (A.N.); (B.D.)
- Faculty Unit of Toxicology, University Center of Legal Medicine, Faculty of Biology and Medicine, Lausanne University Hospital, CH-1000 Lausanne, Switzerland
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Cardinaux R, Cohidon C, Guessous I, Chenal R, Widmer D, Cerqui D, Cornuz J, Desvergne B. Médecine personnalisée et prévention des maladies chroniques : l’attitude des médecins généralistes. Sante Publique 2021; Vol. 33:121-126. [PMID: 34372631 DOI: 10.3917/spub.211.0121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVES In a context of future generalization of access to genetic risk profiles, general practitioners (GP) will have a major role to play. The objective of this study was to understand their attitude towards this approach and the potential consequences on their practice. METHODS In 2018, the University Center of General Medicine and Public Health of Lausanne, the Department of Primary Care Medicine of the University Hospitals of Geneva, and the Institute of Social Sciences of the University of Lausanne set up a study with patients and general practitioners concerning the access to genetic risk profiles. The GPs attitude, the subject of this study, was explored using the two-round Delphi consensus method. 120 interns and senior clinicians responded to 24 statements. RESULTS A consensus was reached for 80% of the statements. The GP’s significant role in terms of access to genetic profiles became evident, even if their position seems conditioned by their position as front-line health workers, and doubts remain as to the impact of this process in guiding their practice. The need for training was widely emphasized as well as the possibility multidisciplinary support and management. There was also a consensus for the need of a legislative framework for these practices. CONCLUSION This study has underlined the importance of anticipating the needs in developing an advanced and evolving training and information program for GPs in the domain of genomic medicine in light of the prevention activities that could result.
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Cohidon C, Cardinaux R, Cornuz J, Chenal R, Desvergne B, Guessous I, Cerqui D, Widmer D. May direct-to-consumer genetic testing have an impact on general practitioners' daily practice? a cross-sectional study of patients' intentions towards this approach. BMC Fam Pract 2021; 22:79. [PMID: 33902442 PMCID: PMC8077756 DOI: 10.1186/s12875-021-01428-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Accepted: 04/02/2021] [Indexed: 11/23/2022]
Abstract
BACKGROUND Direct-to-consumer genetic testing (DTCGT) offers individuals access to information on their probable risks of suffering from a wide range of chronic diseases. General practitioners (GPs) will probably play a major role in supporting its use, but patients' perception of DTCGT remain unclear. This study aimed to describe those attitudes and expectations and how they might affect GPs' daily practices. METHODS In 2018-2019, a study related to the use of DTCGT for preventive care in general medicine was conducted among patients in Switzerland's French-speaking areas. Data were collected in the waiting room using a self-administrated questionnaire about patients' interest in DTCGT and what their attitudes might be if testing revealed an elevated risk of diabetes, colorectal cancer, or Alzheimer's disease. RESULTS About 40% of the 929 participating (participation rate about 80%) patients had heard about DTCGT and, once the test had been explained, 43% reported that they would be interested in being tested. If that testing suggested an elevated risk of disease, the majority of patients reported that they would change their lifestyle (65%-81%, depending on the disease), request more examinations (63%-77%), and expect changes in their GP's follow-up (48%-59%). Personal characteristics such as sex, age, urbanity, marital status, and perceived health were factors predictive of patients' attitudes. CONCLUSION Findings indicated that the generalization of DTCGT might affect GPs' daily practices in terms of workload and knowledge about this approach. However, this result must be qualified by the fact that it is based on hypothetical situations.
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Affiliation(s)
- Christine Cohidon
- Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland.
| | - Regula Cardinaux
- Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland
| | - Jacques Cornuz
- Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland
| | - Robin Chenal
- Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland
| | - Béatrice Desvergne
- Centre for Integrative Genomics (CIG), University of Lausanne, Lausanne, Switzerland
| | - Idris Guessous
- Division and Department of Primary Care Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - Daniela Cerqui
- Institute of Social Sciences, Faculty of Social and Political Sciences, University of Lausanne, Lausanne, Switzerland
| | - Daniel Widmer
- Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland
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Madel MB, Fu H, Pierroz DD, Schiffrin M, Winkler C, Wilson A, Pochon C, Toffoli B, Taïeb M, Jouzeau JY, Gilardi F, Ferrari S, Bonnet N, Blin-Wakkach C, Desvergne B, Moulin D. Lack of Adiponectin Drives Hyperosteoclastogenesis in Lipoatrophic Mice. Front Cell Dev Biol 2021; 9:627153. [PMID: 33869176 PMCID: PMC8047205 DOI: 10.3389/fcell.2021.627153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 02/22/2021] [Indexed: 11/13/2022] Open
Abstract
Long bones from mammals host blood cell formation and contain multiple cell types, including adipocytes. Physiological functions of bone marrow adipocytes are poorly documented. Herein, we used adipocyte-deficient PPARγ-whole body null mice to investigate the consequence of total adipocyte deficiency on bone homeostasis in mice. We first highlighted the dual bone phenotype of PPARγ null mice: one the one hand, the increased bone formation and subsequent trabecularization extending in the long bone diaphysis, due to the well-known impact of PPARγ deficiency on osteoblasts formation and activity; on the other hand, an increased osteoclastogenesis in the cortical bone. We then further explored the cause of this unexpected increased osteoclastogenesis using two independent models of lipoatrophy, which recapitulated this phenotype. This demonstrates that hyperosteoclastogenesis is not intrinsically linked to PPARγ deficiency, but is a consequence of the total lipodystrophy. We further showed that adiponectin, a cytokine produced by adipocytes and mesenchymal stromal cells is a potent inhibitor of osteoclastogenesis in vitro and in vivo. Moreover, pharmacological activation of adiponectin receptors by the synthetic agonist AdipoRon inhibited mature osteoclast activity both in mouse and human cells by blocking podosome formation through AMPK activation. Finally, we demonstrated that AdipoRon treatment blocks bone erosion in vivo in a murine model of inflammatory bone loss, providing potential new approaches to treat osteoporosis.
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Affiliation(s)
- Maria-Bernadette Madel
- Université Côte d'Azur, CNRS, UMR 7370, Laboratoire de PhysioMédecine Moléculaire, Nice, France
| | - He Fu
- Center for Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, Lausanne, Switzerland
| | | | - Mariano Schiffrin
- Center for Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, Lausanne, Switzerland
| | - Carine Winkler
- Center for Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, Lausanne, Switzerland
| | - Anne Wilson
- Department of Oncology, University of Lausanne, Epalinges, Switzerland
| | | | - Barbara Toffoli
- Center for Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, Lausanne, Switzerland
| | - Mahdia Taïeb
- Université Côte d'Azur, CNRS, UMR 7370, Laboratoire de PhysioMédecine Moléculaire, Nice, France
| | | | - Federica Gilardi
- Center for Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, Lausanne, Switzerland
| | - Serge Ferrari
- Division of Bone Diseases, Department of Internal Medicine Specialties, Geneva University Hospital, Faculty of Medicine, Geneva, Switzerland
| | | | - Claudine Blin-Wakkach
- Université Côte d'Azur, CNRS, UMR 7370, Laboratoire de PhysioMédecine Moléculaire, Nice, France
| | - Béatrice Desvergne
- Center for Integrative Genomics, Genopode, Lausanne Faculty of Biology and Medicine, Lausanne, Switzerland
| | - David Moulin
- Université de Lorraine, CNRS, IMoPA, Nancy, France
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Caputo T, Tran VDT, Bararpour N, Winkler C, Aguileta G, Trang KB, Giordano Attianese GMP, Wilson A, Thomas A, Pagni M, Guex N, Desvergne B, Gilardi F. Anti-adipogenic signals at the onset of obesity-related inflammation in white adipose tissue. Cell Mol Life Sci 2020; 78:227-247. [PMID: 32157317 PMCID: PMC7867564 DOI: 10.1007/s00018-020-03485-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 02/07/2020] [Accepted: 02/17/2020] [Indexed: 12/17/2022]
Abstract
Chronic inflammation that affects primarily metabolic organs, such as white adipose tissue (WAT), is considered as a major cause of human obesity-associated co-morbidities. However, the molecular mechanisms initiating this inflammation in WAT are poorly understood. By combining transcriptomics, ChIP-seq and modeling approaches, we studied the global early and late responses to a high-fat diet (HFD) in visceral (vWAT) and subcutaneous (scWAT) AT, the first being more prone to obesity-induced inflammation. HFD rapidly triggers proliferation of adipocyte precursors within vWAT. However, concomitant antiadipogenic signals limit vWAT hyperplastic expansion by interfering with the differentiation of proliferating adipocyte precursors. Conversely, in scWAT, residing beige adipocytes lose their oxidizing properties and allow storage of excessive fatty acids. This phase is followed by tissue hyperplastic growth and increased angiogenic signals, which further enable scWAT expansion without generating inflammation. Our data indicate that scWAT and vWAT differential ability to modulate adipocyte number and differentiation in response to obesogenic stimuli has a crucial impact on the different susceptibility to obesity-related inflammation of these adipose tissue depots.
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Affiliation(s)
- Tiziana Caputo
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Van Du T Tran
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Nasim Bararpour
- Unit of Forensic Toxicology and Chemistry, CURML, Lausanne University Hospital, Geneva University Hospitals, Lausanne, Switzerland.,Faculty Unit of Toxicology, Faculty of Biology and Medicine, CURML, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Carine Winkler
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Gabriela Aguileta
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Khanh Bao Trang
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | | | - Anne Wilson
- Department of Oncology, University of Lausanne, Epalinges, Switzerland
| | - Aurelien Thomas
- Unit of Forensic Toxicology and Chemistry, CURML, Lausanne University Hospital, Geneva University Hospitals, Lausanne, Switzerland.,Faculty Unit of Toxicology, Faculty of Biology and Medicine, CURML, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Marco Pagni
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Nicolas Guex
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland.,Bioinformatics Competence Center, University of Lausanne, Lausanne, Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland.
| | - Federica Gilardi
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland. .,Unit of Forensic Toxicology and Chemistry, CURML, Lausanne University Hospital, Geneva University Hospitals, Lausanne, Switzerland. .,Faculty Unit of Toxicology, Faculty of Biology and Medicine, CURML, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland.
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Gilardi F, Winkler C, Quignodon L, Diserens JG, Toffoli B, Schiffrin M, Sardella C, Preitner F, Desvergne B. Systemic PPARγ deletion in mice provokes lipoatrophy, organomegaly, severe type 2 diabetes and metabolic inflexibility. Metabolism 2019; 95:8-20. [PMID: 30878493 DOI: 10.1016/j.metabol.2019.03.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 02/27/2019] [Accepted: 03/12/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND The peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-dependent transcription factor involved in many aspects of metabolism, immune response and development. Numerous studies relying on tissue-specific invalidation of the Pparg gene have shown distinct facets of its activity, whereas the effects of its systemic inactivation remain unexplored due to embryonic lethality. By maintaining PPARγ expression in the placenta, we recently generated a mouse model carrying Pparg full body deletion (PpargΔ/Δ), which in contrast to a previously published model is totally deprived of any form of adipose tissue. Herein, we propose an in-depth study of the metabolic alterations observed in this new model. METHODS Young adult mice, both males and females analyzed separately, were first phenotyped for their gross anatomical alterations. Systemic metabolic parameters were analyzed in the blood, in static and in dynamic conditions. A full exploration of energy metabolism was performed in calorimetric cages as well as in metabolic cages. Our study was completed by expression analyses of a set of specific genes. MAIN FINDINGS PpargΔ/Δ mice show a striking complete absence of any form of adipose tissue, which triggers a complex metabolic phenotype including increased lean mass with organomegaly, hypermetabolism, urinary energy loss, hyperphagia, and increased amino acid metabolism. PpargΔ/Δ mice develop severe type 2 diabetes, characterized by hyperglycemia, hyperinsulinemia, polyuria and polydispsia. They show a remarkable metabolic inflexibility, as indicated by the inability to shift substrate oxidation between glucose and lipids, in both ad libitum fed state and fed/fasted/refed transitions. Moreover, upon fasting PpargΔ/Δ mice enter a severe hypometabolic state. CONCLUSIONS Our data comprehensively describe the impact of lipoatrophy on metabolic homeostasis. As such, the presented data on PpargΔ/Δ mice gives new clues on what and how to explore severe lipodystrophy and its subsequent metabolic complications in human.
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Affiliation(s)
- Federica Gilardi
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland.
| | - Carine Winkler
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Laure Quignodon
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Jean-Gael Diserens
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Barbara Toffoli
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Mariano Schiffrin
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Chiara Sardella
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Frédéric Preitner
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland.
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Toffoli B, Bernardi S, Winkler C, Carrascosa C, Gilardi F, Desvergne B. Renal mineralocorticoid receptor expression is reduced in lipoatrophy. FEBS Open Bio 2019; 9:328-334. [PMID: 30761257 PMCID: PMC6356154 DOI: 10.1002/2211-5463.12579] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 11/29/2018] [Accepted: 12/12/2018] [Indexed: 11/29/2022] Open
Abstract
Obesity is a condition characterized by adipose tissue hypertrophy; it is estimated that the obesity epidemic accounted for 4 million deaths in 2015 and that 70% of these were due to cardiovascular disease (CVD). One of the mechanisms linking obesity to CVD is the ability of adipose tissue to secrete circulating factors. We hypothesized that adipose tissue and its secretory products may influence mineralocorticoid receptor (MR) expression. Here, we showed that expression of MR and its downstream targets (Cnksr3, Scnn1b, and Sgk1) were significantly reduced in the kidneys of peroxisome proliferator‐activated receptor‐γ null (PpargΔ/Δ) and A‐ZIP/F‐1 (AZIPtg/+) lipoatrophic mice with respect to their controls. Intriguingly, MR expression was also found to be significantly reduced in the kidneys of genetically obese ob/ob mice. Our data suggest that adipose tissue contributes to the regulation of MR expression. Given that leptin deficiency seems to be the major feature shared by PpargΔ/Δ, AZIPtg/+, and ob/ob mice, we speculate that adipose tissue modulates MR expression through the leptin system.
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Affiliation(s)
- Barbara Toffoli
- Center for Integrative Genomics Faculty of Biology and Medicine University of Lausanne Switzerland
| | | | - Carine Winkler
- Center for Integrative Genomics Faculty of Biology and Medicine University of Lausanne Switzerland
| | - Coralie Carrascosa
- Center for Integrative Genomics Faculty of Biology and Medicine University of Lausanne Switzerland
| | - Federica Gilardi
- Center for Integrative Genomics Faculty of Biology and Medicine University of Lausanne Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics Faculty of Biology and Medicine University of Lausanne Switzerland
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10
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Wilson A, Fu H, Schiffrin M, Winkler C, Koufany M, Jouzeau JY, Bonnet N, Gilardi F, Renevey F, Luther SA, Moulin D, Desvergne B. Lack of Adipocytes Alters Hematopoiesis in Lipodystrophic Mice. Front Immunol 2018; 9:2573. [PMID: 30483254 PMCID: PMC6244608 DOI: 10.3389/fimmu.2018.02573] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 10/18/2018] [Indexed: 12/14/2022] Open
Abstract
Adult hematopoiesis takes place in the perivascular zone of the bone cavity, where endothelial cells, mesenchymal stromal/stem cells and their derivatives such as osteoblasts are key components of bone marrow (BM) niches. Defining the contribution of BM adipocytes to the hematopoietic stem cell niche remains controversial. While an excess of medullar adiposity is generally considered deleterious for hematopoiesis, an active role for adipocytes in shaping the niche has also been proposed. We thus investigated the consequences of total adipocyte deletion, including in the BM niche, on adult hematopoiesis using mice carrying a constitutive deletion of the gene coding for the nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ). We show that Pparg Δ/Δ lipodystrophic mice exhibit severe extramedullary hematopoiesis (EMH), which we found to be non-cell autonomous, as it is reproduced when wild-type donor BM cells are transferred into Pparg Δ/Δ recipients. This phenotype is not due to a specific alteration linked to Pparg deletion, such as chronic inflammation, since it is also found in AZIPtg/+ mice, another lipodystrophic mouse model with normal PPARγ expression, that display only very moderate levels of inflammation. In both models, the lack of adipocytes alters subpopulations of both myeloid and lymphoid cells. The CXCL12/CXCR4 axis in the BM is also dysregulated in an adipocyte deprived environment supporting the hypothesis that adipocytes are required for normal hematopoietic stem cell mobilization or retention. Altogether, these data suggest an important role for adipocytes, and possibly for the molecular interactions they provide within the BM, in maintaining the appropriate microenvironment for hematopoietic homeostasis.
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Affiliation(s)
- Anne Wilson
- Department of Oncology, University of Lausanne, Epalinges, Switzerland
| | - He Fu
- Faculty of Biology and Medicine, Center for Integrative Genomics, Genopode, University of Lausanne, Lausanne, Switzerland
| | - Mariano Schiffrin
- Faculty of Biology and Medicine, Center for Integrative Genomics, Genopode, University of Lausanne, Lausanne, Switzerland
| | - Carine Winkler
- Faculty of Biology and Medicine, Center for Integrative Genomics, Genopode, University of Lausanne, Lausanne, Switzerland
| | - Meriem Koufany
- IMoPA, UMR7365 CNRS-Université de Lorraine, Vandœuvre-lès-Nancy, France
| | - Jean-Yves Jouzeau
- IMoPA, UMR7365 CNRS-Université de Lorraine, Vandœuvre-lès-Nancy, France
| | - Nicolas Bonnet
- Division of Bone Diseases, Department of Internal Medicine Specialties, Faculty of Medicine, Geneva University Hospital, Geneva, Switzerland
| | - Federica Gilardi
- Faculty of Biology and Medicine, Center for Integrative Genomics, Genopode, University of Lausanne, Lausanne, Switzerland
| | - François Renevey
- Department of Biochemistry, Center for Immunity and Infection, University of Lausanne, Epalinges, Switzerland
| | - Sanjiv A Luther
- Department of Biochemistry, Center for Immunity and Infection, University of Lausanne, Epalinges, Switzerland
| | - David Moulin
- IMoPA, UMR7365 CNRS-Université de Lorraine, Vandœuvre-lès-Nancy, France.,CHRU de Nancy, Contrat d'interface, Vandœuvre-lès-Nancy, France
| | - Béatrice Desvergne
- Faculty of Biology and Medicine, Center for Integrative Genomics, Genopode, University of Lausanne, Lausanne, Switzerland
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11
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Toffoli B, Zennaro C, Winkler C, Giordano Attianese GMP, Bernardi S, Carraro M, Gilardi F, Desvergne B. Hemicentin 1 influences podocyte dynamic changes in glomerular diseases. Am J Physiol Renal Physiol 2018; 314:F1154-F1165. [DOI: 10.1152/ajprenal.00198.2017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/10/2022] Open
Abstract
Different complex mechanisms control the morphology of podocyte foot processes and their interactions with the underlying basement membrane. Injuries to this system often cause glomerular dysfunction and albuminuria. The present study aimed at identifying early markers of glomerular damage in diabetic nephropathy. For this purpose, we performed a microarray analysis on kidneys of 3-wk-old peroxisome proliferator-activated receptor-γ (PPARγ)-null and AZIP/F1 mice, which are two models of diabetic nephropathy due to lipodystrophy. This was followed by functional annotation of the enriched clusters of genes. One of the significant changes in the early stages of glomerular damage was the increase of hemicentin 1 (HMCN1). Its expression and distribution were then studied by real-time PCR and immunofluorescence in various models of glomerular damage and on podocyte cell cultures. HMCN1 progressively increased in the glomeruli of diabetic mice, according to disease severity, as well as in puromycin aminonucleoside (PA)-treated rats. Studies on murine and human podocytes showed an increased HMCN1 deposition upon different pathological stimuli, such as hyperglycemia, transforming growth factor-β (TGF-β), and PA. In vitro silencing studies showed that HMCN1 mediated the rearrangements of podocyte cytoskeleton induced by TGF-β. Finally, we demonstrated an increased expression of HMCN1 in the kidneys of patients with proteinuric nephropathies. In summary, our studies identified HMCN1 as a new molecule involved in the dynamic changes of podocyte foot processes. Its increased expression associated with podocyte dysfunction points to HMCN1 as a possible marker for the early glomerular damage occurring in different proteinuric nephropathies.
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Affiliation(s)
- Barbara Toffoli
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Cristina Zennaro
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Carine Winkler
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | | | - Stella Bernardi
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Michele Carraro
- Department of Medical, Surgical and Health Sciences, University of Trieste, Trieste, Italy
| | - Federica Gilardi
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
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12
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Sardella C, Winkler C, Quignodon L, Hardman JA, Toffoli B, Giordano Attianese GMP, Hundt JE, Michalik L, Vinson CR, Paus R, Desvergne B, Gilardi F. Delayed Hair Follicle Morphogenesis and Hair Follicle Dystrophy in a Lipoatrophy Mouse Model of Pparg Total Deletion. J Invest Dermatol 2017; 138:500-510. [PMID: 28964716 DOI: 10.1016/j.jid.2017.09.024] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 09/08/2017] [Accepted: 09/08/2017] [Indexed: 01/06/2023]
Abstract
PPARγ regulates multiple aspects of skin physiology, including sebocyte differentiation, keratinocyte proliferation, epithelial stem cell survival, adipocyte biology, and inflammatory skin responses. However, the effects of its global deletion, namely of nonredundant key functions of PPARγ signaling in mammalian skin, are yet unknown because of embryonic lethality. Here, we describe the skin and hair phenotype of a whole-body PPARγ-null mouse (PpargΔ/Δ), obtained by preserving PPARγ expression in the placenta. PpargΔ/Δ mice exhibited total lipoatrophy and complete absence of sebaceous glands. Right after birth, hair follicle (HF) morphogenesis was transiently delayed, along with reduced expression of HF differentiation markers and of transcriptional regulators necessary for HF development. Later, adult PpargΔ/Δ mice developed scarring alopecia and severe perifollicular inflammation. Skin analyses in other models of lipodystrophy, AZIPtg/+ and Adipoq-Cretg/+Ppargfl/fl mice, coupled with skin graft experiments, showed that the early defects observed in hair morphogenesis were caused by the absence of adipose tissue. In contrast, the late alteration of HF cycle and appearance of inflammation were observed only in PpargΔ/Δ mice and likely were due to the lack sebaceous glands. Our findings underscore the increasing appreciation for the importance of adipose tissue-mediated signals in HF development and function.
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Affiliation(s)
- Chiara Sardella
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Carine Winkler
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Laure Quignodon
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Jonathan A Hardman
- Centre for Dermatology Research, School of Biological Sciences, University of Manchester, Manchester, UK
| | - Barbara Toffoli
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | | | - Jennifer E Hundt
- Department of Dermatology, University of Lübeck, Lübeck, Germany
| | - Liliane Michalik
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Charles R Vinson
- Center for Cancer Research, National Cancer Institute, Laboratory of Metabolism, Bethesda, Maryland, USA
| | - Ralf Paus
- Centre for Dermatology Research, School of Biological Sciences, University of Manchester, Manchester, UK
| | - Béatrice Desvergne
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Federica Gilardi
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland.
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13
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Caputo T, Gilardi F, Desvergne B. From chronic overnutrition to metaflammation and insulin resistance: adipose tissue and liver contributions. FEBS Lett 2017; 591:3061-3088. [DOI: 10.1002/1873-3468.12742] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 06/28/2017] [Accepted: 07/02/2017] [Indexed: 12/16/2022]
Affiliation(s)
- Tiziana Caputo
- Center for Integrative Genomics; Lausanne Faculty of Biology and Medicine; University of Lausanne; Switzerland
| | - Federica Gilardi
- Center for Integrative Genomics; Lausanne Faculty of Biology and Medicine; University of Lausanne; Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics; Lausanne Faculty of Biology and Medicine; University of Lausanne; Switzerland
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14
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Ferrari A, Longo R, Fiorino E, Silva R, Mitro N, Cermenati G, Gilardi F, Desvergne B, Andolfo A, Magagnotti C, Caruso D, Fabiani ED, Hiebert SW, Crestani M. HDAC3 is a molecular brake of the metabolic switch supporting white adipose tissue browning. Nat Commun 2017; 8:93. [PMID: 28733645 PMCID: PMC5522415 DOI: 10.1038/s41467-017-00182-7] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 04/26/2017] [Indexed: 12/25/2022] Open
Abstract
White adipose tissue (WAT) can undergo a phenotypic switch, known as browning, in response to environmental stimuli such as cold. Post-translational modifications of histones have been shown to regulate cellular energy metabolism, but their role in white adipose tissue physiology remains incompletely understood. Here we show that histone deacetylase 3 (HDAC3) regulates WAT metabolism and function. Selective ablation of Hdac3 in fat switches the metabolic signature of WAT by activating a futile cycle of de novo fatty acid synthesis and β-oxidation that potentiates WAT oxidative capacity and ultimately supports browning. Specific ablation of Hdac3 in adipose tissue increases acetylation of enhancers in Pparg and Ucp1 genes, and of putative regulatory regions of the Ppara gene. Our results unveil HDAC3 as a regulator of WAT physiology, which acts as a molecular brake that inhibits fatty acid metabolism and WAT browning.Histone deacetylases, such as HDAC3, have been shown to alter cellular metabolism in various tissues. Here the authors show that HDAC3 regulates WAT metabolism by activating a futile cycle of fatty acid synthesis and oxidation, which supports WAT browning.
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Affiliation(s)
- Alessandra Ferrari
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, 20133, Italy
- Department of Pathology and Laboratory Medicine, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Raffaella Longo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, 20133, Italy
| | - Erika Fiorino
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, 20133, Italy
| | - Rui Silva
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, 20133, Italy
| | - Nico Mitro
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, 20133, Italy
| | - Gaia Cermenati
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, 20133, Italy
| | - Federica Gilardi
- Centre Intégratif de Génomique, Université de Lausanne, Lausanne, 1015, Switzerland
| | - Béatrice Desvergne
- Centre Intégratif de Génomique, Université de Lausanne, Lausanne, 1015, Switzerland
| | - Annapaola Andolfo
- ProMiFa, Protein Microsequencing Facility, San Raffaele Scientific Institute, Milano, 20132, Italy
| | - Cinzia Magagnotti
- ProMiFa, Protein Microsequencing Facility, San Raffaele Scientific Institute, Milano, 20132, Italy
| | - Donatella Caruso
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, 20133, Italy
| | - Emma De Fabiani
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, 20133, Italy
| | - Scott W Hiebert
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN, 37232, USA
| | - Maurizio Crestani
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milano, 20133, Italy.
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15
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Toffoli B, Gilardi F, Winkler C, Soderberg M, Kowalczuk L, Arsenijevic Y, Bamberg K, Bonny O, Desvergne B. Nephropathy in Pparg-null mice highlights PPARγ systemic activities in metabolism and in the immune system. PLoS One 2017; 12:e0171474. [PMID: 28182703 PMCID: PMC5300244 DOI: 10.1371/journal.pone.0171474] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 01/20/2017] [Indexed: 01/10/2023] Open
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) is a ligand-dependent transcription factor involved in many aspects of metabolism, immune response, and development. Total-body deletion of the two Pparg alleles provoked generalized lipoatrophy along with severe type 2 diabetes. Herein, we explore the appearance and development of structural and functional alterations of the kidney, comparing Pparg null-mice to their littermate controls (carrying Pparg floxed alleles). We show that renal hypertrophy and functional alterations with increased glucosuria and albuminuria are already present in 3 weeks-old Pparg null-mice. Renal insufficiency with decreased creatinine clearance progress at 7 weeks of age, with the advance of the type 2 diabetes. At 52 weeks of age, these alterations are accompanied by signs of fibrosis and mesangial expansion. More intriguingly, aged Pparg null-mice concomitantly present an anti-phospholipid syndrome (APS), characterized by the late appearance of microthrombi and a mesangioproliferative pattern of glomerular injury, associated with significant plasmatic levels of anti-β2- glycoprotein1 antibodies and renal deposition of IgG, IgM, and C3. Thus, in line with the role of PPARγ in metabolic homeostasis, Pparg null-mice first represent a potent model for studying the initiation and the development of diabetic nephropathy. Second, and in relation with the important PPARγ activity in inflammation and in immune system, these mice also highlight a new role for PPARγ signaling in the promotion of APS, a syndrome whose pathogenesis is poorly known and whose current treatment is limited to prevention of thrombosis events.
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Affiliation(s)
- Barbara Toffoli
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Federica Gilardi
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Carine Winkler
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | | | - Laura Kowalczuk
- Unit of Gene Therapy & Stem Cell Biology, University of Lausanne, Department of Ophthalmology, Fondation Asile des Aveugles, Jules-Gonin Eye Hospital, Lausanne, Switzerland
| | - Yvan Arsenijevic
- Unit of Gene Therapy & Stem Cell Biology, University of Lausanne, Department of Ophthalmology, Fondation Asile des Aveugles, Jules-Gonin Eye Hospital, Lausanne, Switzerland
| | | | - Olivier Bonny
- Service of Nephrology, Lausanne University Hospital and Department of Pharmacology and Toxicology, University of Lausanne, Lausanne, Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
- * E-mail:
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16
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Giordano Attianese GMP, Desvergne B. Integrative and systemic approaches for evaluating PPARβ/δ (PPARD) function. Nucl Recept Signal 2015; 13:e001. [PMID: 25945080 PMCID: PMC4419664 DOI: 10.1621/nrs.13001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 03/09/2015] [Indexed: 12/13/2022]
Abstract
The peroxisome proliferator-activated receptors (PPARs) are a group of nuclear receptors that function as transcription factors regulating the expression of genes involved in cellular differentiation, development, metabolism and also tumorigenesis. Three PPAR isotypes (α, β/δ and γ) have been identified, among which PPARβ/δ is the most difficult to functionally examine due to its tissue-specific diversity in cell fate determination, energy metabolism and housekeeping activities. PPARβ/δ acts both in a ligand-dependent and -independent manner. The specific type of regulation, activation or repression, is determined by many factors, among which the type of ligand, the presence/absence of PPARβ/δ-interacting corepressor or coactivator complexes and PPARβ/δ protein post-translational modifications play major roles. Recently, new global approaches to the study of nuclear receptors have made it possible to evaluate their molecular activity in a more systemic fashion, rather than deeply digging into a single pathway/function. This systemic approach is ideally suited for studying PPARβ/δ, due to its ubiquitous expression in various organs and its overlapping and tissue-specific transcriptomic signatures. The aim of the present review is to present in detail the diversity of PPARβ/δ function, focusing on the different information gained at the systemic level, and describing the global and unbiased approaches that combine a systems view with molecular understanding.
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17
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Koufany M, Gilardi F, Schiffrin M, Winkler C, Bianchi A, Jouzeau JY, Desvergne B, Moulin D. OP0174 Ppar Gamma Deficient Mice Develop Spontaneous Polyarthritis. Ann Rheum Dis 2014. [DOI: 10.1136/annrheumdis-2014-eular.3291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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18
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Abstract
Retinoid X Receptors (RXR) were initially identified as nuclear receptors binding with stereo-selectivity the vitamin A derivative 9-cis retinoic acid, although the relevance of this molecule as endogenous activator of RXRs is still elusive. Importantly, within the nuclear receptor superfamily, RXRs occupy a peculiar place, as they are obligatory partners for a number of other nuclear receptors, thus integrating the corresponding signaling pathways. In this chapter, we describe the structural features allowing RXR to form homo- and heterodimers, and the functional consequences of this unique ability. Furthermore, we discuss the importance of studying RXR activity at a genome-wide level in order to comprehensively address the biological implications of their action that is fundamental to understand to what extent RXRs could be exploited as new therapeutic targets.
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Affiliation(s)
- Federica Gilardi
- Center for Integrative Genomics, University of Lausanne, Genopode Building, 1015, Lausanne, Switzerland,
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19
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Berger H, Végran F, Chikh M, Gilardi F, Ladoire S, Bugaut H, Mignot G, Chalmin F, Bruchard M, Derangère V, Chevriaux A, Rébé C, Ryffel B, Pot C, Hichami A, Desvergne B, Ghiringhelli F, Apetoh L. SOCS3 transactivation by PPARγ prevents IL-17-driven cancer growth. Cancer Res 2013; 73:3578-90. [PMID: 23619236 DOI: 10.1158/0008-5472.can-12-4018] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Activation of the transcription factor PPARγ by the n-3 fatty acid docosahexaenoic acid (DHA) is implicated in controlling proinflammatory cytokine secretion, but the intracellular signaling pathways engaged by PPARγ are incompletely characterized. Here, we identify the adapter-encoding gene SOCS3 as a critical transcriptional target of PPARγ. SOCS3 promoter binding and gene transactivation by PPARγ was associated with a repression in differentiation of proinflammatory T-helper (TH)17 cells. Accordingly, TH17 cells induced in vitro displayed increased SOCS3 expression and diminished capacity to produce interleukin (IL)-17 following activation of PPARγ by DHA. Furthermore, naïve CD4 T cells derived from mice fed a DHA-enriched diet displayed less capability to differentiate into TH17 cells. In two different mouse models of cancer, DHA prevented tumor outgrowth and angiogenesis in an IL-17-dependent manner. Altogether, our results uncover a novel molecular pathway by which PPARγ-induced SOCS3 expression prevents IL-17-mediated cancer growth.
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Affiliation(s)
- Hélène Berger
- Institut National de la Santé et de la Recherche Medicale (INSERM), U866, France
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20
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Le Martelot G, Canella D, Symul L, Migliavacca E, Gilardi F, Liechti R, Martin O, Harshman K, Delorenzi M, Desvergne B, Herr W, Deplancke B, Schibler U, Rougemont J, Guex N, Hernandez N, Naef F. Genome-wide RNA polymerase II profiles and RNA accumulation reveal kinetics of transcription and associated epigenetic changes during diurnal cycles. PLoS Biol 2012; 10:e1001442. [PMID: 23209382 PMCID: PMC3507959 DOI: 10.1371/journal.pbio.1001442] [Citation(s) in RCA: 155] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 10/25/2012] [Indexed: 01/01/2023] Open
Abstract
Genome-wide rhythms in RNA polymerase II loading and dynamic chromatin remodeling underlie periodic gene expression during diurnal cycles in the mouse liver. Interactions of cell-autonomous circadian oscillators with diurnal cycles govern the temporal compartmentalization of cell physiology in mammals. To understand the transcriptional and epigenetic basis of diurnal rhythms in mouse liver genome-wide, we generated temporal DNA occupancy profiles by RNA polymerase II (Pol II) as well as profiles of the histone modifications H3K4me3 and H3K36me3. We used these data to quantify the relationships of phases and amplitudes between different marks. We found that rhythmic Pol II recruitment at promoters rather than rhythmic transition from paused to productive elongation underlies diurnal gene transcription, a conclusion further supported by modeling. Moreover, Pol II occupancy preceded mRNA accumulation by 3 hours, consistent with mRNA half-lives. Both methylation marks showed that the epigenetic landscape is highly dynamic and globally remodeled during the 24-hour cycle. While promoters of transcribed genes had tri-methylated H3K4 even at their trough activity times, tri-methylation levels reached their peak, on average, 1 hour after Pol II. Meanwhile, rhythms in tri-methylation of H3K36 lagged transcription by 3 hours. Finally, modeling profiles of Pol II occupancy and mRNA accumulation identified three classes of genes: one showing rhythmicity both in transcriptional and mRNA accumulation, a second class with rhythmic transcription but flat mRNA levels, and a third with constant transcription but rhythmic mRNAs. The latter class emphasizes widespread temporally gated posttranscriptional regulation in the mouse liver. In mammalian organs such as the liver, many metabolic and physiological processes occur preferentially at specific times during the 24-hour daily cycle. The timing of these rhythmic functions depends on a complex interplay between the endogenous circadian clock and environmental timing cues relayed through the master circadian clock in the suprachiasmatic nucleus, or via feeding rhythms. These rhythms can be implemented on several regulatory levels, and here we aimed at a better understanding of the transcriptional and epigenetic changes that regulate diurnal rhythms. We performed genome-wide analysis of the locations of RNA polymerase II (Pol II) and the epigenetic histone modifications H3K4me3 and H3K36me3 at specific times of day, relating these data to mRNA expression levels. Our analyses show that Pol II transcriptional rhythms are biphasic in mouse liver, having predominant peak activities in the morning and evening. Moreover, dynamic changes in histone marks lag transcription rhythms genome-wide, indicating that the epigenetic landscape can be remodeled during the 24-hour cycle. Finally, a quantitative analysis of temporal Pol II and mRNA accumulation profiles indicates that posttranscriptional regulation significantly contributes to the amplitude and phase of mRNA accumulation profiles. While many studies have analyzed how transcription and chromatin states are modified during irreversible cell differentiation processes, our work highlights how these states can evolve reversibly in a system exhibiting periodicity in time.
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Affiliation(s)
| | - Donatella Canella
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Laura Symul
- The Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Eugenia Migliavacca
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Federica Gilardi
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Robin Liechti
- Vital IT, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Olivier Martin
- Vital IT, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Keith Harshman
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Mauro Delorenzi
- Département de Formation et de Recherche, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Winship Herr
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Bart Deplancke
- The Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Ueli Schibler
- Department of Molecular Biology, University of Geneva, Geneva, Switzerland
| | - Jacques Rougemont
- Bioinformatics and Biostatistics Core Facility, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Nicolas Guex
- Vital IT, Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Nouria Hernandez
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
- * E-mail: (NH); (FN)
| | - Felix Naef
- The Institute of Bioengineering, School of Life Sciences, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- * E-mail: (NH); (FN)
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Nadra K, Médard JJ, Quignodon L, Verheijen MHG, Desvergne B, Chrast R. Epineurial adipocytes are dispensable for Schwann cell myelination. J Neurochem 2012; 123:662-7. [PMID: 22849425 DOI: 10.1111/j.1471-4159.2012.07896.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Revised: 07/11/2012] [Accepted: 07/12/2012] [Indexed: 12/18/2022]
Abstract
Previous clinical observations and data from mouse models with defects in lipid metabolism suggested that epineurial adipocytes may play a role in peripheral nervous system myelination. We have used adipocyte-specific Lpin1 knockout mice to characterize the consequences of the presence of impaired epineurial adipocytes on the myelinating peripheral nerve. Our data revealed that the capacity of Schwann cells to establish myelin, and the functional properties of peripheral nerves, were not affected by compromised epineurial adipocytes in adipocyte-specific Lpin1 knockout mice. To evaluate the possibility that Lpin1-negative adipocytes are still able to support endoneurial Schwann cells, we also characterized sciatic nerves from mice carrying epiblast-specific deletion of peroxisome proliferator-activated receptor gamma, which develop general lipoatrophy. Interestingly, even the complete loss of adipocytes in the epineurium of peroxisome proliferator-activated receptor gamma knockout mice did not lead to detectable defects in Schwann cell myelination. However, probably as a consequence of their hyperglycemia, these mice have reduced nerve conduction velocity, thus mimicking the phenotype observed under diabetic condition. Together, our data indicate that while adipocytes, as regulators of lipid and glucose homeostasis, play a role in nerve function, their presence in epineurium is not essential for establishment or maintenance of proper myelin.
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Affiliation(s)
- Karim Nadra
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland
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Michalik L, Desvergne B, Wahli W. Les bases moléculaires de l'obésité : vers de nouvelles cibles thérapeutiques ? Med Sci (Paris) 2012. [DOI: 10.4267/10608/1521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Brunner JM, Plattet P, Doucey MA, Rosso L, Curie T, Montagner A, Wittek R, Vandelvelde M, Zurbriggen A, Hirling H, Desvergne B. Morbillivirus glycoprotein expression induces ER stress, alters Ca2+ homeostasis and results in the release of vasostatin. PLoS One 2012; 7:e32803. [PMID: 22403712 PMCID: PMC3293893 DOI: 10.1371/journal.pone.0032803] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 02/04/2012] [Indexed: 11/26/2022] Open
Abstract
Although the pathology of Morbillivirus in the central nervous system (CNS) is well described, the molecular basis of neurodegenerative events still remains poorly understood. As a model to explore Morbillivirus-mediated CNS dysfunctions, we used canine distemper virus (CDV) that we inoculated into two different cell systems: a monkey cell line (Vero) and rat primary hippocampal neurons. Importantly, the recombinant CDV used in these studies not only efficiently infects both cell types but recapitulates the uncommon, non-cytolytic cell-to-cell spread mediated by virulent CDVs in brain of dogs. Here, we demonstrated that both CDV surface glycoproteins (F and H) markedly accumulated in the endoplasmic reticulum (ER). This accumulation triggered an ER stress, characterized by increased expression of the ER resident chaperon calnexin and the proapoptotic transcription factor CHOP/GADD 153. The expression of calreticulin (CRT), another ER resident chaperon critically involved in the response to misfolded proteins and in Ca(2+) homeostasis, was also upregulated. Transient expression of recombinant CDV F and H surface glycoproteins in Vero cells and primary hippocampal neurons further confirmed a correlation between their accumulation in the ER, CRT upregulation, ER stress and disruption of ER Ca(2+) homeostasis. Furthermore, CDV infection induced CRT fragmentation with re-localisation of a CRT amino-terminal fragment, also known as vasostatin, on the surface of infected and neighbouring non-infected cells. Altogether, these results suggest that ER stress, CRT fragmentation and re-localization on the cell surface may contribute to cytotoxic effects and ensuing cell dysfunctions triggered by Morbillivirus, a mechanism that might potentially be relevant for other neurotropic viruses.
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Affiliation(s)
- Jean-Marc Brunner
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
- Institut de Biotechnologie, University of Lausanne, Lausanne, Switzerland
| | - Philippe Plattet
- Department of Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Marie-Agnès Doucey
- Division of Experimental Oncology, Multidisciplinary Oncology Center, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Lausanne, Switzerland
| | - Lia Rosso
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Thomas Curie
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Alexandra Montagner
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
| | - Riccardo Wittek
- Institut de Biotechnologie, University of Lausanne, Lausanne, Switzerland
| | - Marc Vandelvelde
- Department of Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Andreas Zurbriggen
- Department of Clinical Research and Veterinary Public Health, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Harald Hirling
- Brain Mind Institute, Faculté des Sciences de la Vie, Ecole Polytechnique Fédérale de Lausanne EPFL, Lausanne, Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics, University of Lausanne, Lausanne, Switzerland
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Lescoat G, Jouanolle H, Desvergne B, Pasdeloup N, Kneip B, Deugnier Y, Guillouzo A, Brissot P. Effects of iron overload on transferrin secretion by cultured fetal rat hepatocytes. Biol Cell 2012. [DOI: 10.1111/j.1768-322x.1989.tb00793.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
Synthetic chemicals currently used in a variety of industrial and agricultural applications are leading to widespread contamination of the environment. Even though the intended uses of pesticides, plasticizers, antimicrobials, and flame retardants are beneficial, effects on human health are a global concern. These so-called endocrine-disrupting chemicals (EDCs) can disrupt hormonal balance and result in developmental and reproductive abnormalities. New in vitro, in vivo, and epidemiological studies link human EDC exposure with obesity, metabolic syndrome, and type 2 diabetes. Here we review the main chemical compounds that may contribute to metabolic disruption. We then present their demonstrated or suggested mechanisms of action with respect to nuclear receptor signaling. Finally, we discuss the difficulties of fairly assessing the risks linked to EDC exposure, including developmental exposure, problems of high- and low-dose exposure, and the complexity of current chemical environments.
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Affiliation(s)
- Cristina Casals-Casas
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Switzerland
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Abstract
Synthetic chemicals currently used in a variety of industrial and agricultural applications are leading to widespread contamination of the environment. Even though the intended uses of pesticides, plasticizers, antimicrobials, and flame retardants are beneficial, effects on human health are a global concern. These so-called endocrine-disrupting chemicals (EDCs) can disrupt hormonal balance and result in developmental and reproductive abnormalities. New in vitro, in vivo, and epidemiological studies link human EDC exposure with obesity, metabolic syndrome, and type 2 diabetes. Here we review the main chemical compounds that may contribute to metabolic disruption. We then present their demonstrated or suggested mechanisms of action with respect to nuclear receptor signaling. Finally, we discuss the difficulties of fairly assessing the risks linked to EDC exposure, including developmental exposure, problems of high- and low-dose exposure, and the complexity of current chemical environments.
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Affiliation(s)
- Cristina Casals-Casas
- Center for Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, Switzerland
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Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) is a nuclear receptor involved in diverse biological processes including adipocyte differentiation, glucose homeostasis, and inflammatory responses. Analyses of PPARγ knockout animals have been so far preempted by the early embryonic death of PPARγ-/- embryos as a consequence of the severe alteration of their placental vasculature. Using Sox2Cre/PPARγL2/L2 mice, we obtained fully viable PPARγ-null mice through specific and total epiblastic gene deletion, thereby demonstrating that the placental defect is the unique cause of PPARγ-/- embryonic lethality. The vasculature defects observed in PPARγ-/- placentas at embryonic d 9.5 correlated with an unsettled balance of pro- and antiangiogenic factors as demonstrated by increased levels of proliferin (Prl2c2, PLF) and decreased levels of proliferin-related protein (Prl7d1, PRP), respectively. To analyze the role of PPARγ in the later stage of placental development, when its expression peaks, we treated pregnant wild-type mice with the PPARγ agonist rosiglitazone. This treatment resulted in a disorganization of the placental layers and an altered placental microvasculature, accompanied by the decreased expression of proangiogenic genes such as Prl2c2, vascular endothelial growth factor, and Pecam1. Together our data demonstrate that PPARγ plays a pivotal role in controlling placental vascular proliferation and contributes to its termination in late pregnancy.
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Affiliation(s)
- Karim Nadra
- Center for Integrative Genomics, Department of Medical Genetics and Electron Microscopy Platform, University of Lausanne, CH-1015 Lausanne, Switzerland
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Kapoor A, Shintani Y, Collino M, Osuchowski MF, Busch D, Patel NSA, Sepodes B, Castiglia S, Fantozzi R, Bishop-Bailey D, Mota-Filipe H, Yaqoob MM, Suzuki K, Bahrami S, Desvergne B, Mitchell JA, Thiemermann C. Protective role of peroxisome proliferator-activated receptor-β/δ in septic shock. Am J Respir Crit Care Med 2010; 182:1506-15. [PMID: 20693380 DOI: 10.1164/rccm.201002-0240oc] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Peroxisome proliferator-activated receptor (PPAR)-β/δ is a transcription factor that belongs to the PPAR nuclear hormone receptor family, but the role of PPAR-β/δ in sepsis is unknown. OBJECTIVES We investigated the role of PPAR-β/δ in murine models of LPS-induced organ injury and dysfunction and cecal ligation and puncture (CLP)-induced polymicrobial sepsis. METHODS Wild-type (WT) and PPAR-β/δ knockout (KO) mice and C57BL/6 mice were subjected to LPS for 16 hours. C57BL/6 mice received the PPAR-β/δ agonist GW0742 (0.03 mg/kg intravenously, 1 h after LPS) or GW0742 plus the PPAR-β/δ antagonist GSK0660 (0.1 mg/kg intravenously, 30 min before LPS). CD-1 mice subjected to CLP received GW0742 or GW0742 plus GSK0660. MEASUREMENTS AND MAIN RESULTS In PPAR-β/δ KO mice, endotoxemia exacerbated organ injury and dysfunction (cardiac, renal, and hepatic) and inflammation (lung) compared with WT mice. In C57BL/6 mice subjected to endotoxemia, GW0742 significantly (1) attenuated organ (cardiac and renal) dysfunction and inflammation (lung); (2) increased the phosphorylation of Akt and glycogen synthase kinase (GSK)-3β; (3) attenuated the increase in extracellular signal-regulated kinase (ERK)1/2 and signal transducer and activator of transcription (STAT)-3 phosphorylation; and (4) attenuated the activation of nuclear factor (NF)-κB and the expression of inducible nitric oxide synthase (iNOS). In CD-1 mice subjected to CLP, GW0742 improved 10-day survival. All the observed beneficial effects of GW0742 were attenuated by the PPAR-β/δ antagonist GSK0660. CONCLUSIONS PPAR-β/δ protects against multiple organ injury and dysfunction, and inflammation caused by endotoxic shock and improves survival in polymicrobial sepsis by a mechanism that may involve activation of Akt and inhibition of GSK-3β and NF-κB.
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Affiliation(s)
- Amar Kapoor
- Centre for Translational Medicine and Therapeutics, William Harvey Research Institute, London, United Kingdom
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Harrington LS, Moreno L, Reed A, Wort SJ, Desvergne B, Garland C, Zhao L, Mitchell JA. The PPARbeta/delta agonist GW0742 relaxes pulmonary vessels and limits right heart hypertrophy in rats with hypoxia-induced pulmonary hypertension. PLoS One 2010; 5:e9526. [PMID: 20209098 PMCID: PMC2831997 DOI: 10.1371/journal.pone.0009526] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Accepted: 12/28/2009] [Indexed: 01/29/2023] Open
Abstract
Background Pulmonary vascular diseases are increasingly recognised as important clinical conditions. Pulmonary hypertension associated with a range of aetiologies is difficult to treat and associated with progressive morbidity and mortality. Current therapies for pulmonary hypertension include phosphodiesterase type 5 inhibitors, endothelin receptor antagonists, or prostacyclin mimetics. However, none of these provide a cure and the clinical benefits of these drugs individually decline over time. There is, therefore, an urgent need to identify new treatment strategies for pulmonary hypertension. Methodology/Principal Findings Here we show that the PPARβ/δ agonist GW0742 induces vasorelaxation in systemic and pulmonary vessels. Using tissue from genetically modified mice, we show that the dilator effects of GW0742 are independent of the target receptor PPARβ/δ or cell surface prostacyclin (IP) receptors. In aortic tissue, vascular relaxant effects of GW0742 were not associated with increases in cGMP, cAMP or hyperpolarisation, but were attributed to inhibition of RhoA activity. In a rat model of hypoxia-induced pulmonary hypertension, daily oral dosing of animals with GW0742 (30 mg/kg) for 3 weeks significantly reduced the associated right heart hypertrophy and right ventricular systolic pressure. GW0742 had no effect on vascular remodelling induced by hypoxia in this model. Conclusions/Significance These observations are the first to show a therapeutic benefit of ‘PPARβ/δ’ agonists in experimental pulmonary arterial hypertension and provide pre-clinical evidence to favour clinical trials in man.
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Affiliation(s)
| | - Laura Moreno
- Cardiothoracic Pharmacology, NHLI, Imperial College London, United Kingdom
| | - Anna Reed
- Cardiothoracic Pharmacology, NHLI, Imperial College London, United Kingdom
| | - Stephen J. Wort
- Critical Care Medicine, NHLI, Royal Brompton Hospital, London, United Kingdom
| | - Béatrice Desvergne
- Center for Integrative Genomics, University of Lausanne, Genopode, Lausanne, Switzerland
| | | | - Lan Zhao
- Experimental Medicine and Toxicology, Hammersmith Hospital, Imperial College London, London, United Kingdom
| | - Jane A. Mitchell
- Cardiothoracic Pharmacology, NHLI, Imperial College London, United Kingdom
- * E-mail:
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Feige JN, Gerber A, Casals-Casas C, Yang Q, Winkler C, Bedu E, Bueno M, Gelman L, Auwerx J, Gonzalez FJ, Desvergne B. The pollutant diethylhexyl phthalate regulates hepatic energy metabolism via species-specific PPARalpha-dependent mechanisms. Environ Health Perspect 2010; 118:234-41. [PMID: 20123618 PMCID: PMC2831923 DOI: 10.1289/ehp.0901217] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2009] [Accepted: 10/08/2009] [Indexed: 05/21/2023]
Abstract
BACKGROUND The modulation of energetic homeostasis by pollutants has recently emerged as a potential contributor to the onset of metabolic disorders. Diethylhexyl phthalate (DEHP) is a widely used industrial plasticizer to which humans are widely exposed. Phthalates can activate the three peroxisome proliferator-activated receptor (PPAR) isotypes on cellular models and induce peroxisome proliferation in rodents. OBJECTIVES In this study, we aimed to evaluate the systemic and metabolic consequences of DEHP exposure that have remained so far unexplored and to characterize the underlying molecular mechanisms of action. METHODS As a proof of concept and mechanism, genetically engineered mouse models of PPARs were exposed to high doses of DEHP, followed by metabolic and molecular analyses. RESULTS DEHP-treated mice were protected from diet-induced obesity via PPARalpha-dependent activation of hepatic fatty acid catabolism, whereas the activity of neither PPARbeta nor PPARgamma was affected. However, the lean phenotype observed in response to DEHP in wild-type mice was surprisingly abolished in PPARalpha-humanized mice. These species differences are associated with a different pattern of coregulator recruitment. CONCLUSION These results demonstrate that DEHP exerts species-specific metabolic actions that rely to a large extent on PPARalpha signaling and highlight the metabolic importance of the species-specific activation of PPARalpha by xenobiotic compounds.
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Affiliation(s)
- Jérôme N. Feige
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Alan Gerber
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Cristina Casals-Casas
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Qian Yang
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
| | - Carine Winkler
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Elodie Bedu
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Manuel Bueno
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Laurent Gelman
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
| | - Johan Auwerx
- Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Frank J. Gonzalez
- Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland, USA
| | - Béatrice Desvergne
- Center for Integrative Genomics, National Research Center “Frontiers in Genetics,” University of Lausanne, Lausanne, Switzerland
- Address correspondence to B. Desvergne, Center for Integrative Genomics, Le Génopode, Université de Lausanne, CH-1015 Lausanne, Switzerland. Telephone: 41-0-21-692-41-40. Fax: 41-0-21-692-41-15. E-mail:
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Ali FY, Hall MG, Desvergne B, Warner TD, Mitchell JA. PPARbeta/delta agonists modulate platelet function via a mechanism involving PPAR receptors and specific association/repression of PKCalpha--brief report. Arterioscler Thromb Vasc Biol 2009; 29:1871-3. [PMID: 19696401 DOI: 10.1161/atvbaha.109.193367] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Peroxisome proliferator-activated receptor beta/delta (PPARbeta/delta) is a nuclear receptor found in platelets. PPARbeta/delta agonists acutely inhibit platelet function within a few minutes of addition. As platelets are anucleated, the effects of PPARbeta/delta agonists on platelets must be nongenomic. Currently, the particular role of PPARbeta/delta receptors and their intracellular signaling pathways in platelets are not known. METHODS AND RESULTS We have used mice lacking PPARbeta/delta (PPARbeta/delta(-/-)) to show the effects of the PPARbeta/delta agonist GW501516 on platelet adhesion and cAMP levels are mediated specifically by PPARbeta/delta, however GW501516 had no PPARbeta/delta-specific effect on platelet aggregation. Studies in human platelets showed that PKCalpha, which can mediate platelet activation, was bound and repressed by PPARbeta/delta after platelets were treated with GW501516. CONCLUSIONS These data provide evidence of a novel mechanism by which PPAR receptors influence platelet activity and thereby thrombotic risk.
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Affiliation(s)
- Ferhana Y Ali
- Cardiothoracic Pharmacology, National Heart and Lung Institute, Imperial College London, London, UK
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Abstract
The endocrine disruption hypothesis asserts that exposure to small amounts of some chemicals in the environment may interfere with the endocrine system and lead to harmful effects in wildlife and humans. Many of these chemicals may interact with members of the nuclear receptor superfamily. Peroxisome proliferator-activated receptors (PPARs) are such candidate members, which interact with many different endogenous and exogenous lipophilic compounds. More particularly, the roles of PPARs in lipid and carbohydrate metabolism raise the question of their activation by a sub-class of pollutants, tentatively named "metabolic disrupters". Phthalates are abundant environmental micro-pollutants in Europe and North America and may belong to this class. Mono-ethyl-hexyl-phthalate (MEHP), a metabolite of the widespread plasticizer di-ethyl-hexyl-phthalate (DEHP), has been found in exposed organisms and interacts with all three PPARs. A thorough analysis of its interactions with PPARgamma identified MEHP as a selective PPARgamma modulator, and thus a possible contributor to the obesity epidemic.
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Abstract
Macrophages, which belong to the immune system, are increasingly being recognized for their contribution to metabolic regulation. In two studies by Kang et al. (2008) and Odegaard et al. (2008) in this issue of Cell Metabolism, we learn that alternative activation (M2a) of resident macrophages in liver and adipose tissue depends highly on PPARdelta/beta activity, leading to improved fatty acid metabolism and insulin sensitivity.
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Affiliation(s)
- Béatrice Desvergne
- Center of Integrative Genomics, Faculty of Biology and Medicine, University of Lausanne, CH-1015 Lausanne, Switzerland.
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Rotman N, Haftek-Terreau Z, Lücke S, Feige J, Gelman L, Desvergne B, Wahli W. PPAR Disruption: Cellular Mechanisms and Physiological Consequences. Chimia (Aarau) 2008. [DOI: 10.2533/chimia.2008.340] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Wang H, Xie H, Sun X, Tranguch S, Zhang H, Jia X, Wang D, Das SK, Desvergne B, Wahli W, DuBois RN, Dey SK. Stage-specific integration of maternal and embryonic peroxisome proliferator-activated receptor delta signaling is critical to pregnancy success. J Biol Chem 2007; 282:37770-82. [PMID: 17965409 DOI: 10.1074/jbc.m706577200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Successful pregnancy depends on well coordinated developmental events involving both maternal and embryonic components. Although a host of signaling pathways participate in implantation, decidualization, and placentation, whether there is a common molecular link that coordinates these processes remains unknown. By exploiting genetic, molecular, pharmacological, and physiological approaches, we show here that the nuclear transcription factor peroxisome proliferator-activated receptor (PPAR) delta plays a central role at various stages of pregnancy, whereas maternal PPARdelta is critical to implantation and decidualization, and embryonic PPARdelta is vital for placentation. Using trophoblast stem cells, we further elucidate that a reciprocal relationship between PPARdelta-AKT and leukemia inhibitory factor-STAT3 signaling pathways serves as a cell lineage sensor to direct trophoblast cell fates during placentation. This novel finding of stage-specific integration of maternal and embryonic PPARdelta signaling provides evidence that PPARdelta is a molecular link that coordinates implantation, decidualization, and placentation crucial to pregnancy success. This study is clinically relevant because deferral of on time implantation leads to spontaneous pregnancy loss, and defective trophoblast invasion is one cause of preeclampsia in humans.
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Affiliation(s)
- Haibin Wang
- Department of Pediatrics, Division of Reproductive and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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Mandard S, Stienstra R, Escher P, Tan NS, Kim I, Gonzalez FJ, Wahli W, Desvergne B, Müller M, Kersten S. Glycogen synthase 2 is a novel target gene of peroxisome proliferator-activated receptors. Cell Mol Life Sci 2007; 64:1145-57. [PMID: 17437057 PMCID: PMC2771145 DOI: 10.1007/s00018-007-7006-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Glycogen synthase 2 (Gys-2) is the ratelimiting enzyme in the storage of glycogen in liver and adipose tissue, yet little is known about regulation of Gys-2 transcription. The peroxisome proliferator-activated receptors (PPARs) are transcription factors involved in the regulation of lipid and glucose metabolism and might be hypothesized to govern glycogen synthesis as well. Here, we show that Gys-2 is a direct target gene of PPARalpha, PPARbeta/delta and PPARgamma. Expression of Gys-2 is significantly reduced in adipose tissue of PPARalpha-/-, PPARbeta/delta-/- and PPARgamma+/- mice. Furthermore, synthetic PPARbeta/delta, and gamma agonists markedly up-regulate Gys-2 mRNA and protein expression in mouse 3T3-L1 adipocytes. In liver, PPARalpha deletion leads to decreased glycogen levels in the refed state, which is paralleled by decreased expression of Gys-2 in fasted and refed state. Two putative PPAR response elements (PPREs) were identified in the mouse Gys-2 gene: one in the upstream promoter (DR-1prom) and one in intron 1 (DR-1int). It is shown that DR-1int is the response element for PPARs, while DR-1prom is the response element for Hepatic Nuclear Factor 4 alpha (HNF4alpha). In adipose tissue, which does not express HNF4alpha, DR-1prom is occupied by PPARbeta/delta and PPARgamma, yet binding does not translate into transcriptional activation of Gys-2. Overall, we conclude that mouse Gys-2 is a novel PPAR target gene and that transactivation by PPARs and HNF4alpha is mediated by two distinct response elements.
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Affiliation(s)
- S. Mandard
- Nutrition, Metabolism and Genomics group and Nutrigenomics Consortium, Division of Human Nutrition, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands
- INSERM UMR 866 (Lipides, Nutrition et Cancer, équipe Biochimie Métabolique et Nutritionnelle), Faculté des Sciences Gabriel, Université de Bourgogne, 6 Bd Gabriel, 21000 Dijon, France
| | - R. Stienstra
- Nutrition, Metabolism and Genomics group and Nutrigenomics Consortium, Division of Human Nutrition, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands
| | - P. Escher
- Institute of Physiology, Pharmazentrum, University of Basel, Basel, Switzerland
| | - N. S. Tan
- Center for Integrative Genomics, Université de Lausanne, Lausanne, Switzerland
| | - I. Kim
- Laboratory of Metabolism, Division of Basic Sciences, National Cancer Institute, Bethesda, MD 20892 USA
| | - F. J. Gonzalez
- Laboratory of Metabolism, Division of Basic Sciences, National Cancer Institute, Bethesda, MD 20892 USA
| | - W. Wahli
- Center for Integrative Genomics, Université de Lausanne, Lausanne, Switzerland
| | - B. Desvergne
- Center for Integrative Genomics, Université de Lausanne, Lausanne, Switzerland
| | - M. Müller
- Nutrition, Metabolism and Genomics group and Nutrigenomics Consortium, Division of Human Nutrition, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands
| | - S. Kersten
- Nutrition, Metabolism and Genomics group and Nutrigenomics Consortium, Division of Human Nutrition, Wageningen University, PO Box 8129, 6700 EV Wageningen, The Netherlands
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Anghel SI, Bedu E, Vivier CD, Descombes P, Desvergne B, Wahli W. Adipose tissue integrity as a prerequisite for systemic energy balance: a critical role for peroxisome proliferator-activated receptor gamma. J Biol Chem 2007; 282:29946-57. [PMID: 17699161 DOI: 10.1074/jbc.m702490200] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Peroxisome proliferator-activated receptor gamma (PPARgamma) is an essential regulator of adipocyte differentiation, maintenance, and survival. Deregulations of its functions are associated with metabolic diseases. We show here that deletion of one PPARgamma allele not only affected lipid storage but, more surprisingly, also the expression of genes involved in glucose uptake and utilization, the pentose phosphate pathway, fatty acid synthesis, lipolysis, and glycerol export as well as in IR/IGF-1 signaling. These deregulations led to reduced circulating adiponectin levels and an energy crisis in the WAT, reflected in a decrease to nearly half of its intracellular ATP content. In addition, there was a decrease in the metabolic rate and physical activity of the PPARgamma(+/-) mice, which was abolished by thiazolidinedione treatment, thereby linking regulation of the metabolic rate and physical activity to PPARgamma. It is likely that the PPARgamma(+/-) phenotype was due to the observed WAT dysfunction, since the gene expression profiles associated with metabolic pathways were not affected either in the liver or the skeletal muscle. These findings highlight novel roles of PPARgamma in the adipose tissue and underscore the multifaceted action of this receptor in the functional fine tuning of a tissue that is crucial for maintaining the organism in good health.
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Affiliation(s)
- Silvia I Anghel
- Center for Integrative Genomics, National Research Center Frontiers in Genetics, University of Lausanne, Génopode Bldg., CH-1015 Lausanne, Switzerland
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Gelman L, Feige JN, Desvergne B. Molecular basis of selective PPARγ modulation for the treatment of Type 2 diabetes. Biochim Biophys Acta Mol Cell Biol Lipids 2007; 1771:1094-107. [PMID: 17459763 DOI: 10.1016/j.bbalip.2007.03.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2007] [Revised: 03/02/2007] [Accepted: 03/06/2007] [Indexed: 11/25/2022]
Abstract
Peroxisome proliferator-activated receptors (PPARs) (alpha, beta/delta and gamma) are lipid sensors capable of adapting gene expression to integrate various lipid signals. As such, PPARs are also very important pharmaceutical targets, and specific synthetic ligands exist for the different isotypes and are either currently used or hold promises in the treatment of major metabolic disorders. In particular, compounds of the class of the thiazolinediones (TZDs) are PPARgamma agonists and potent insulin-sensitizers. The specific but still broad expression patterns of PPARgamma, as well as its implication in numerous pathways, constitutes also a disadvantage regarding drug administration, since this potentially increases the chance to generate side-effects through the activation of the receptor in tissues or cells not affected by the disease. Actually, numerous side effects associated with the administration of TZDs have been reported. Today, a new generation of PPARgamma modulators is being actively developed to activate the receptor more specifically, in a cell and time-dependent manner, in order to induce a specific subset of target genes only and modulate a restricted number of metabolic pathways. We will discuss here why and how the development of such selective PPARgamma modulators is possible, and summarize the results obtained with the published molecules.
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Affiliation(s)
- Laurent Gelman
- Friedrich Miescher Institut, WRO 1066.0.52, Maulbeerstrasse 66, 4058 Basel, Switzerland.
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40
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Bedu E, Desplanches D, Pequignot J, Bordier B, Desvergne B. Double gene deletion reveals the lack of cooperation between PPARα and PPARβ in skeletal muscle. Biochem Biophys Res Commun 2007; 357:877-81. [PMID: 17466944 DOI: 10.1016/j.bbrc.2007.04.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2007] [Accepted: 04/02/2007] [Indexed: 11/19/2022]
Abstract
The peroxisome proliferator-activated receptors (PPARs) are involved in the regulation of most of the pathways linked to lipid metabolism. PPARalpha and PPARbeta isotypes are known to regulate muscle fatty acid oxidation and a reciprocal compensation of their function has been proposed. Herein, we investigated muscle contractile and metabolic phenotypes in PPARalpha-/-, PPARbeta-/-, and double PPARalpha-/- beta-/- mice. Heart and soleus muscle analyses show that the deletion of PPARalpha induces a decrease of the HAD activity (beta-oxidation) while soleus contractile phenotype remains unchanged. A PPARbeta deletion alone has no effect. However, these mild phenotypes are not due to a reciprocal compensation of PPARbeta and PPARalpha functions since double gene deletion PPARalpha-PPARbeta mostly reproduces the null PPARalpha-mediated reduced beta-oxidation, in addition to a shift from fast to slow fibers. In conclusion, PPARbeta is not required for maintaining skeletal muscle metabolic activity and does not compensate the lack of PPARalpha in PPARalpha null mice.
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Affiliation(s)
- E Bedu
- Center of Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland
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41
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42
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Berry A, Balard P, Coste A, Olagnier D, Lagane C, Authier H, Benoit-Vical F, Lepert JC, Séguéla JP, Magnaval JF, Chambon P, Metzger D, Desvergne B, Wahli W, Auwerx J, Pipy B. IL-13 induces expression of CD36 in human monocytes through PPARγ activation. Eur J Immunol 2007; 37:1642-52. [PMID: 17458857 DOI: 10.1002/eji.200636625] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The class B scavenger receptor CD36 is a component of the pattern recognition receptors on monocytes that recognizes a variety of molecules. CD36 expression in monocytes depends on exposure to soluble mediators. We demonstrate here that CD36 expression is induced in human monocytes following exposure to IL-13, a Th2 cytokine, via the peroxisome proliferator-activated receptor (PPAR)gamma pathway. Induction of CD36 protein was paralleled by an increase in CD36 mRNA. The PPARgamma pathway was demonstrated using transfection of a PPARgamma expression plasmid into the murine macrophage cell line RAW264.7, expressing very low levels of PPARgamma, and in peritoneal macrophages from PPARgamma-conditional null mice. We also show that CD36 induction by IL-13 via PPARgamma is dependent on phospholipase A2 activation and that IL-13 induces the production of endogenous 15-deoxy-Delta12,14-prostaglandin J2, an endogenous PPARgamma ligand, and its nuclear localization in human monocytes. Finally, we demonstrate that CD36 and PPARgamma are involved in IL-13-mediated phagocytosis of Plasmodium falciparum-parasitized erythrocytes. These results reveal a novel role for PPARgamma in the alternative activation of monocytes by IL-13, suggesting that endogenous PPARgamma ligands, produced by phospholipase A2 activation, could contribute to the biochemical and cellular functions of CD36.
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Affiliation(s)
- Antoine Berry
- Macrophages, Mediateurs de l'Inflammation et Interactions Cellulaires, Université Paul Sabatier Toulouse III, INSERM IFR 31, Toulouse, France.
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43
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Pialat JB, Cho TH, Beuf O, Joye E, Moucharrafie S, Moucharaffie S, Langlois JB, Nemoz C, Janier M, Berthezene Y, Nighoghossian N, Desvergne B, Wiart M. MRI monitoring of focal cerebral ischemia in peroxisome proliferator-activated receptor (PPAR)-deficient mice. NMR Biomed 2007; 20:335-42. [PMID: 17451173 DOI: 10.1002/nbm.1157] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Peroxisome proliferator-activated receptors (PPARs) are a potential target for neuroprotection in focal ischemic stroke. These nuclear receptors have major effects in lipid metabolism, but they are also involved in inflammatory processes. Three PPAR isotypes have been identified: alpha, beta (or delta) and gamma. The development of PPAR transgenic mice offers a promising tool for prospective therapeutic studies. This study used MRI to assess the role of PPARalpha and PPARbeta in the development of stroke. Permanent middle cerebral artery occlusion induced focal ischemia in wild-type, PPARalpha-null mice and PPARbeta-null mice. T(2)-weighted MRI was performed with a 7 T MRI scan on day 0, 1, 3, 7 and 14 to monitor lesion growth in the various genotypes. General Linear Model statistical analysis found a significant difference in lesion volume between wild-type and PPAR-null mice for both alpha and beta isotypes. These data validate high-resolution MRI for monitoring cerebral ischemic lesions, and confirm the neuroprotective role of PPARalpha and PPARbeta in the brain.
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Affiliation(s)
- Jean-Baptiste Pialat
- Université Lyon 1, Laboratoire CREATIS, INSA de Lyon, CNRS UMR 5515, INSERM U630, Villeurbanne, France
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44
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Feige JN, Gelman L, Rossi D, Zoete V, Métivier R, Tudor C, Anghel SI, Grosdidier A, Lathion C, Engelborghs Y, Michielin O, Wahli W, Desvergne B. The endocrine disruptor monoethyl-hexyl-phthalate is a selective peroxisome proliferator-activated receptor gamma modulator that promotes adipogenesis. J Biol Chem 2007; 282:19152-66. [PMID: 17468099 DOI: 10.1074/jbc.m702724200] [Citation(s) in RCA: 255] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The ability of pollutants to affect human health is a major concern, justified by the wide demonstration that reproductive functions are altered by endocrine disrupting chemicals. The definition of endocrine disruption is today extended to broader endocrine regulations, and includes activation of metabolic sensors, such as the peroxisome proliferator-activated receptors (PPARs). Toxicology approaches have demonstrated that phthalate plasticizers can directly influence PPAR activity. What is now missing is a detailed molecular understanding of the fundamental basis of endocrine disrupting chemical interference with PPAR signaling. We thus performed structural and functional analyses that demonstrate how monoethyl-hexyl-phthalate (MEHP) directly activates PPARgamma and promotes adipogenesis, albeit to a lower extent than the full agonist rosiglitazone. Importantly, we demonstrate that MEHP induces a selective activation of different PPARgamma target genes. Chromatin immunoprecipitation and fluorescence microscopy in living cells reveal that this selective activity correlates with the recruitment of a specific subset of PPARgamma coregulators that includes Med1 and PGC-1alpha, but not p300 and SRC-1. These results highlight some key mechanisms in metabolic disruption but are also instrumental in the context of selective PPAR modulation, a promising field for new therapeutic development based on PPAR modulation.
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Affiliation(s)
- Jérôme N Feige
- Center for Integrative Genomics, University of Lausanne, Genopode, 1015 Lausanne, Switzerland
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45
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Indra AK, Castaneda E, Antal MC, Jiang M, Messaddeq N, Meng X, Loehr CV, Gariglio P, Kato S, Wahli W, Desvergne B, Metzger D, Chambon P. Malignant transformation of DMBA/TPA-induced papillomas and nevi in the skin of mice selectively lacking retinoid-X-receptor alpha in epidermal keratinocytes. J Invest Dermatol 2007; 127:1250-60. [PMID: 17301838 DOI: 10.1038/sj.jid.5700672] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Retinoid-X-receptor alpha (RXRalpha), a member of the nuclear receptor (NR) superfamily, is a ligand-dependent transcriptional regulatory factor. It plays a crucial role in NR signalling through heterodimerization with some 15 NRs. We investigated the role of RXRalpha and its partners on mouse skin tumor formation and malignant progression upon topical DMBA/TPA treatment. In mutants selectively ablated for RXRalpha in keratinocytes, epidermal tumors increased in size and number, and frequently progressed to carcinomas. As keratinocyte-selective peroxisome proliferator-activated receptor gamma (PPARgamma) ablation had similar effects, RXRalpha/PPARgamma heterodimers most probably mediate epidermal tumor suppression. Keratinocyte-selective RXRalpha-null and vitamin-D-receptor null mice also exhibited more numerous dermal melanocytic growths (nevi) than control mice, but only nevi from RXRalpha mutant mice progressed to invasive human-melanoma-like tumors. Distinct RXRalpha-mediated molecular events appear therefore to be involved, in keratinocytes, in cell-autonomous suppression of epidermal tumorigenesis and malignant progression, and in non-cell-autonomous suppression of nevi formation and progression. Our study emphasizes the crucial role of keratinocytes in chemically induced epidermal and melanocytic tumorigenesis, and raises the possibility that they could play a similar role in UV-induced tumorigenesis, notably in nevi formation and progression to melanoma.
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Affiliation(s)
- Arup Kumar Indra
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (CNRS UMR7104; INSERM U596; ULP, Collège de France), Illkirch, Strasbourg, France.
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46
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Tudor C, Feige JN, Pingali H, Lohray VB, Wahli W, Desvergne B, Engelborghs Y, Gelman L. Association with Coregulators Is the Major Determinant Governing Peroxisome Proliferator-activated Receptor Mobility in Living Cells. J Biol Chem 2007; 282:4417-4426. [PMID: 17164241 DOI: 10.1074/jbc.m608172200] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The nucleus is an extremely dynamic compartment, and protein mobility represents a key factor in transcriptional regulation. We showed in a previous study that the diffusion of peroxisome proliferator-activated receptors (PPARs), a family of nuclear receptors regulating major cellular and metabolic functions, is modulated by ligand binding. In this study, we combine fluorescence correlation spectroscopy, dual color fluorescence cross-correlation microscopy, and fluorescence resonance energy transfer to dissect the molecular mechanisms controlling PPAR mobility and transcriptional activity in living cells. First, we bring new evidence that in vivo a high percentage of PPARs and retinoid X receptors is associated even in the absence of ligand. Second, we demonstrate that coregulator recruitment (and not DNA binding) plays a crucial role in receptor mobility, suggesting that transcriptional complexes are formed prior to promoter binding. In addition, association with coactivators in the absence of a ligand in living cells, both through the N-terminal AB domain and the AF-2 function of the ligand binding domain, provides a molecular basis to explain PPAR constitutive activity.
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Affiliation(s)
- Cicerone Tudor
- Laboratory of Biomolecular Dynamics, Katholieke Universiteit, Leuven B-3001, Belgium
| | - Jérôme N Feige
- Center for Integrative Genomics, National Research Center "Frontiers in Genetics," University of Lausanne, Lausanne CH-1015, Switzerland, and
| | | | | | - Walter Wahli
- Center for Integrative Genomics, National Research Center "Frontiers in Genetics," University of Lausanne, Lausanne CH-1015, Switzerland, and
| | - Béatrice Desvergne
- Center for Integrative Genomics, National Research Center "Frontiers in Genetics," University of Lausanne, Lausanne CH-1015, Switzerland, and
| | - Yves Engelborghs
- Laboratory of Biomolecular Dynamics, Katholieke Universiteit, Leuven B-3001, Belgium.
| | - Laurent Gelman
- Center for Integrative Genomics, National Research Center "Frontiers in Genetics," University of Lausanne, Lausanne CH-1015, Switzerland, and.
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Abstract
The peroxisome proliferator-activated receptor (PPAR) family comprises three distinct isotypes: PPARalpha, PPARbeta/delta and PPARgamma. PPARs are nuclear hormone receptors that mediate the effects of fatty acids and their derivatives at the transcriptional level. Until recently, the characterisation of the important role of PPARalpha in fatty acid oxidation and of PPARgamma in lipid storage contrasted with the sparse information concerning PPARbeta/delta. However, evidence is now emerging for a role of PPARbeta/delta in tissue repair and energy homeostasis. Experiments with tissue-specific overexpression of PPARbeta/delta or treatment of mice with selective PPARbeta/delta agonists demonstrated that activation of PPARbeta/delta in vivo increases lipid catabolism in skeletal muscle, heart and adipose tissue and improves the serum lipid profile and insulin sensitivity in several animal models. PPARbeta/delta activation also prevents the development of obesity and improves cholesterol homeostasis in obesity-prone mouse models. These new insights into PPARbeta/delta functions suggest that targeting PPARbeta/delta may be helpful for treating disorders associated with the metabolic syndrome. Although these perspectives are promising, several independent and contradictory reports raise concerns about the safety of PPARbeta/delta ligands with respect to tumourigenic activity in the gut. Thus, it appears that further exploration of PPARbeta/delta functions is necessary to better define its potential as a therapeutic target.
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Affiliation(s)
- Elodie Bedu
- Center for Integrative Genomics, University of Lausanne, CH-1015 Lausanne, Switzerland
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48
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Michalik L, Zoete V, Krey G, Grosdidier A, Gelman L, Chodanowski P, Feige JN, Desvergne B, Wahli W, Michielin O. Combined simulation and mutagenesis analyses reveal the involvement of key residues for peroxisome proliferator-activated receptor alpha helix 12 dynamic behavior. J Biol Chem 2007; 282:9666-9677. [PMID: 17200111 DOI: 10.1074/jbc.m610523200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The dynamic properties of helix 12 in the ligand binding domain of nuclear receptors are a major determinant of AF-2 domain activity. We investigated the molecular and structural basis of helix 12 mobility, as well as the involvement of individual residues with regard to peroxisome proliferator-activated receptor alpha (PPARalpha) constitutive and ligand-dependent transcriptional activity. Functional assays of the activity of PPARalpha helix 12 mutants were combined with free energy molecular dynamics simulations. The agreement between the results from these approaches allows us to make robust claims concerning the mechanisms that govern helix 12 functions. Our data support a model in which PPARalpha helix 12 transiently adopts a relatively stable active conformation even in the absence of a ligand. This conformation provides the interface for the recruitment of a coactivator and results in constitutive activity. The receptor agonists stabilize this conformation and increase PPARalpha transcription activation potential. Finally, we disclose important functions of residues in PPARalpha AF-2, which determine the positioning of helix 12 in the active conformation in the absence of a ligand. Substitution of these residues suppresses PPARalpha constitutive activity, without changing PPARalpha ligand-dependent activation potential.
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Affiliation(s)
- Liliane Michalik
- Center for Integrative Genomics and National Research Center "Frontiers in Genetics," University of Lausanne, Le Génopode, CH-1015 Lausanne, Switzerland
| | - Vincent Zoete
- Swiss Institute for Bioinformatics, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Grigorios Krey
- National Agricultural Research Foundation, Fisheries Research Institute, Nea Peramos, GR-64007 Kavala, Greece
| | - Aurélien Grosdidier
- Swiss Institute for Bioinformatics, University of Lausanne, CH-1015 Lausanne, Switzerland; Ludwig Institute for Cancer Research and National Research Center "Molecular Oncology," CH-1066 Epalinges, Switzerland
| | - Laurent Gelman
- Center for Integrative Genomics and National Research Center "Frontiers in Genetics," University of Lausanne, Le Génopode, CH-1015 Lausanne, Switzerland
| | - Pierre Chodanowski
- Swiss Institute for Bioinformatics, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Jérôme N Feige
- Center for Integrative Genomics and National Research Center "Frontiers in Genetics," University of Lausanne, Le Génopode, CH-1015 Lausanne, Switzerland
| | - Béatrice Desvergne
- Center for Integrative Genomics and National Research Center "Frontiers in Genetics," University of Lausanne, Le Génopode, CH-1015 Lausanne, Switzerland
| | - Walter Wahli
- Center for Integrative Genomics and National Research Center "Frontiers in Genetics," University of Lausanne, Le Génopode, CH-1015 Lausanne, Switzerland.
| | - Olivier Michielin
- Swiss Institute for Bioinformatics, University of Lausanne, CH-1015 Lausanne, Switzerland; Ludwig Institute for Cancer Research and National Research Center "Molecular Oncology," CH-1066 Epalinges, Switzerland; Multidisciplinary Oncology Center (CePO), Lausanne University Hospital, CH-1011 Lausanne, Switzerland.
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Abstract
Vitamin A signaling occurs through nuclear receptors recognizing diverse forms of retinoic acid (RA). The retinoic acid receptors (RARs) bind all-trans RA and its 9-cis isomer (9-cis RA). They convey most of the activity of RA, particularly during embryogenesis. The second subset of receptors, the rexinoid receptors (RXRs), binds 9-cis RA only. However, RXRs are obligatory DNA-binding partners for a number of nuclear receptors, broadening the spectrum of their biological activity to the corresponding nuclear receptor-signaling pathways. The present chapter more particularly focuses on RXR-containing transcriptional complexes for which RXR is not only a structural component necessary for DNA binding but also acts as a ligand-activated partner. After positioning RXR among the nuclear receptor superfamily in the first part, we will give an overview of three major signaling pathways involved in metabolism, which are sensitive to RXR activation: LXR:RXR, FXR:RXR, and PPAR:RXR. The third and last part is focused on RXR signaling and its potential role in metabolic regulation. Indeed, while the nature of the endogenous ligand for RXR is still in question, as we will discuss herein, a better understanding of RXR activities is necessary to envisage the potential therapeutic applications of synthetic RXR ligands.
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Affiliation(s)
- Béatrice Desvergne
- Center for Integrative Genomics, Building Génopode, University of Lausanne, CH-1015 Lausanne, Switzerland
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50
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Schuler M, Ali F, Chambon C, Duteil D, Bornert JM, Tardivel A, Desvergne B, Wahli W, Chambon P, Metzger D. PGC1alpha expression is controlled in skeletal muscles by PPARbeta, whose ablation results in fiber-type switching, obesity, and type 2 diabetes. Cell Metab 2006; 4:407-14. [PMID: 17084713 DOI: 10.1016/j.cmet.2006.10.003] [Citation(s) in RCA: 276] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2006] [Revised: 08/20/2006] [Accepted: 10/03/2006] [Indexed: 01/06/2023]
Abstract
Mice in which peroxisome proliferator-activated receptor beta (PPARbeta) is selectively ablated in skeletal muscle myocytes were generated to elucidate the role played by PPARbeta signaling in these myocytes. These somatic mutant mice exhibited a muscle fiber-type switching toward lower oxidative capacity that preceded the development of obesity and diabetes, thus demonstrating that PPARbeta is instrumental in myocytes to the maintenance of oxidative fibers and that fiber-type switching is likely to be the cause and not the consequence of these metabolic disorders. We also show that PPARbeta stimulates in myocytes the expression of PGC1alpha, a coactivator of various transcription factors, known to play an important role in slow muscle fiber formation. Moreover, as the PGC1alpha promoter contains a PPAR response element, the effect of PPARbeta on the formation and/or maintenance of slow muscle fibers can be ascribed, at least in part, to a stimulation of PGC1alpha expression at the transcriptional level.
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Affiliation(s)
- Michael Schuler
- IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Department of Physiological Genetics, Illkirch, F-67400 France
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