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1. Differential Effects of Homologous Transcriptional Regulators NicR2A, NicR2B1, and NicR2B2 and Endogenous Ectopic Strong Promoters on Nicotine Metabolism in Pseudomonas sp. Strain JY-Q.

Author

Huang C, Shan L, Chen Z, He Z, Li J, Yang Y, Shu M, Pan F, Jiao Y, Zhang F, Linhardt RJ, and Zhong W

Subjects
Promoter Regions, Genetic, Pseudomonas genetics, Transcription, Genetic, Bacterial Proteins genetics, Nicotine metabolism, Pseudomonas metabolism, Transcription Factors genetics
Abstract

Nicotine is a toxic environmental pollutant that widely exists in tobacco wastes. As a natural nicotine-degrading strain, Pseudomonas sp. strain JY-Q still has difficulties degrading high concentrations of nicotine. In this study, we investigated the effect of two homologous transcriptional regulators and endogenous ectopic strong promoters on the efficiency of nicotine degradation. Comparative genomics analysis showed that two homologous transcriptional regulators, namely, NicR2A and NicR2Bs (NicR2B1 plus NicR2B2), can repress nicotine degradation gene expression. When both nicR2A and nicR2Bs were deleted, the resulting mutant JY-Q Δ nicR2A Δ nicR2B1 Δ nicR2B2 (QΔABs) exhibits a 17% higher nicotine degradation efficiency than wild-type JY-Q. Transcriptome sequencing (RNA-seq) analysis showed that the transcription levels (fragments per kilobase per million [FPKM] value) of six genes were higher than those of the other genes in JY-Q. Based on the genetic organization of these genes, three putative promoters, P RS28250 , P RS09985 , and P RS24685 , were identified. Their promoter activities were evaluated by comparing their expression levels using reverse transcriptase quantitative PCR (RT-qPCR). We found that the transcription levels of RS28250 , RS09985 , and RS24685 were respectively 16.8, 2.6, and 1.6 times higher than that of hspB2 , encoding 6-hydroxy-3-succinylpyridine hydroxylase, which is involved in nicotine degradation. Thus, two strong endogenous promoters, namely, P RS28250 and P RS09985 , were selected to replace the original promoters of nic2 gene clusters. The effect of the endogenous ectopic promoter was also related to the position of target gene clusters. When the promoter P RS28250 replaced the promoter of hspB2 , the resultant mutant QΔABs-Δ P hspB2 :: P RS28250 exhibited nicotine-degrading efficiency 69% higher than that of JY-Q. This research suggests a feasible strategy to enhance strains' capacity for nicotine degradation by removal of repressing regulatory proteins and replacing the target promoter with strong endogenous ectopic promoters. IMPORTANCE This study evaluated the differential effects of homologous NicR2A and NicR2Bs and endogenous ectopic strong promoters on nicotine metabolism in Pseudomonas sp. strain JY-Q. Based on our differential analysis, a feasible strategy is presented to modify wild-type (WT) strain JY-Q by removing repressing regulatory proteins NicR2A and NicR2Bs and replacing the target promoter with strong endogenous ectopic promoters. The resulting mutants exhibited high tolerance and degradation of nicotine. These findings should be beneficial for improving the pollutant-degrading capacity of natural strains through genomic modification., (Copyright © 2021 American Society for Microbiology.)

Published
2021
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3. Climbing Brain Levels of Organisation from Genes to Consciousness

Author

Jean-Pierre Changeux, CNRS UMR3571, Centre National de la Recherche Scientifique (CNRS), Institut Pasteur [Paris], Collège de France (CdF (institution)), This paper received funding from the European Union's Horizon 2020 research and innovation programmeunder grant agreement No 720270 (HBP SGA1) and SCR 130008 0, 1UE 64102 (HBP ramp up), European Project: 720270,H2020 Pilier Excellent Science,H2020-Adhoc-2014-20,HBP SGA1(2016), and Institut Pasteur [Paris] (IP)

Subjects
0301 basic medicine, Consciousness, Cognitive Neuroscience, media_common.quotation_subject, Brain, Gene Expression Regulation, Developmental, [SDV.NEU.SC]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC]/Cognitive Sciences, Experimental and Cognitive Psychology, 03 medical and health sciences, 030104 developmental biology, 0302 clinical medicine, Neuropsychology and Physiological Psychology, Climbing, Gene Regulatory Networks, Psychology, Neuroscience, Gene, 030217 neurology & neurosurgery, Transcription Factors, media_common, Epigenesis
Abstract

International audience; Given the tremendous complexity of brain organisation, here I propose a strategy that dynamically links stages of brain organisation from genes to consciousness, at four privileged structural levels: genes; transcription factors (TFs)-gene networks; synaptic epigenesis; and long-range connectivity. These structures are viewed as nested and reciprocally inter-regulated, with a hierarchical organisation that proceeds on different timescales during the course of evolution and development. Interlevel bridging mechanisms include intrinsic variation-selection mechanisms, which offer a community of bottom-up and top-down models linking genes to consciousness in a stepwise manner.

Published
2017

4. RNA sequencing revealed novel actors of the acquisition of drug resistance in Candida albicans

Author

Jean-Yves Coppée, Gaëlle Lelandais, Odile Sismeiro, Sophie Lemoine, Frédéric Devaux, Stéphane Le Crom, Rajendra Prasad, Maria Bernard, Sanjiveeni Dhamgaye, Membrane Biology Laboratory, Jawaharlal Nehru University (JNU), Institut de biologie de l'ENS Paris (UMR 8197/1024) (IBENS), Département de Biologie - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Dynamique des Structures et Interactions des Macromolécules Biologiques - Pôle de La Réunion (DSIMB Réunion), Biologie Intégrée du Globule Rouge (BIGR (UMR_S_1134 / U1134)), Institut National de la Transfusion Sanguine [Paris] (INTS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université des Antilles (UA)-Institut National de la Transfusion Sanguine [Paris] (INTS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université des Antilles (UA), Transcriptome et Epigénome (PF2), Institut Pasteur [Paris], Génomique des Microorganismes (LGM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), The work presented in this paper has been supported in part by grants to R.P. from Indo-French Center for the Promotion of Advanced Scientific Research (IFC-3403-2/2006) and DST INT/SWISS/P-31/2009., Institut de biologie de l'ENS Paris (IBENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Institut Pasteur [Paris] (IP), BMC, Ed., Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Département de Biologie - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM), and Institut National de la Transfusion Sanguine [Paris] (INTS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Université des Antilles (UA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut National de la Transfusion Sanguine [Paris] (INTS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Université des Antilles (UA)-Institut National de la Santé et de la Recherche Médicale (INSERM)

Subjects
Candida albicans, beta-Glucans, lcsh:QH426-470, lcsh:Biotechnology, Repressor, RNA-Seq, Drug resistance, Multidrug resistance, Fungal Proteins, 03 medical and health sciences, Drug Resistance, Fungal, lcsh:TP248.13-248.65, [SDV.BBM.GTP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], Transcriptional regulation, Genetics, CZF1, Gene, 030304 developmental biology, 0303 health sciences, biology, 030306 microbiology, Sequence Analysis, RNA, Gene Expression Profiling, biology.organism_classification, Yeast, 3. Good health, Multiple drug resistance, Gene expression profiling, lcsh:Genetics, [SDV.BBM.GTP] Life Sciences [q-bio]/Biochemistry, Molecular Biology/Genomics [q-bio.GN], RNA-seq, Biotechnology, Transcription Factors, Research Article
Abstract

Background Drug susceptible clinical isolates of Candida albicans frequently become highly tolerant to drugs during chemotherapy, with dreadful consequences to patient health. We used RNA sequencing (RNA-seq) to analyze the transcriptomes of a CDR (Candida Drug Resistance) strain and its isogenic drug sensitive counterpart. Results RNA-seq unveiled differential expression of 228 genes including a) genes previously identified as involved in CDR, b) genes not previously associated to the CDR phenotype, and c) novel transcripts whose function as a gene is uncharacterized. In particular, we show for the first time that CDR acquisition is correlated with an overexpression of the transcription factor encoding gene CZF1. CZF1 null mutants were susceptible to many drugs, independently of known multidrug resistance mechanisms. We show that CZF1 acts as a repressor of β-glucan synthesis, thus negatively regulating cell wall integrity. Finally, our RNA-seq data allowed us to identify a new transcribed region, upstream of the TAC1 gene, which encodes the major CDR transcriptional regulator. Conclusion Our results open new perspectives of the role of Czf1 and of our understanding of the transcriptional and post-transcriptional mechanisms that lead to the acquisition of drug resistance in C. albicans, with potential for future improvements of therapeutic strategies.

Published
2012

5. p53 regulates epithelial–mesenchymal transition through microRNAs targeting ZEB1 and ZEB2

Author

Young-Jun Jeon, Flavia Pichiorri, Angelo Veronese, Pascal Pineau, Anne Dejean, Tae Jin Lee, Hansjuerg Alder, Agnès Marchio, Stefano Volinia, Taewan Kim, Jeff Palatini, Chang Gong Liu, Sung Suk Suh, Carlo M. Croce, Comprehensive Cancer Center [Colombus], Ohio State University [Columbus] (OSU), Molecular, Cellular, and Developmental Biology Program [Columbus] (MCDB), Organisation Nucléaire et Oncogenèse, Institut Pasteur [Paris] (IP)-Institut National de la Santé et de la Recherche Médicale (INSERM), This work was funded by National Cancer Institute grant RC2 CA148302., We thank Dr. B. Vogelstein for p53+/+ and p53−/− RKO cells, Dr. Gustavo Leone for p53+/+ and p53−/− MEFs, Dr. Gregory J. Goodall for pCIneo-hRL-ZEB1/2 constructs, and Dr. Anders H. Lund for pcDNA3-Zeb2-HA constructs. We also thank Dr. Kay Huebner (The Ohio State University), Dr. Thomas D. Schmittgen (The Ohio State University), and Susan Lutz for careful editing of this paper, and Sharon Palko and Dorothee Wernicke-Jameson for the administrative support., Pineau, Pascal, and Institut Pasteur [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM)

Subjects
Male, MESH: Zinc Finger E-box-Binding Homeobox 1, genetics/metabolism, biosynthesis/genetics, Metastasis, genetics/metabolism/pathology, 0302 clinical medicine, MESH: Liver Neoplasms, Immunology and Allergy, genetics, RNA, Neoplasm, Neoplasm Metastasis, MESH: Carcinoma, Hepatocellular, MESH: Tumor Suppressor Protein p53, 0303 health sciences, digestive, oral, and skin physiology, Liver Neoplasms, Hep G2 Cells, MESH: Gene Expression Regulation, Neoplastic, MESH: Transcription Factors, Gene Expression Regulation, Neoplastic, MESH: Repressor Proteins, 030220 oncology & carcinogenesis, embryonic structures, Female, Transcriptional Activation, Carcinoma, Hepatocellular, Epithelial-Mesenchymal Transition, Immunology, Repressor, MESH: Hep G2 Cells, [SDV.CAN]Life Sciences [q-bio]/Cancer, Biology, 03 medical and health sciences, MESH: Gene Expression Profiling, [SDV.CAN] Life Sciences [q-bio]/Cancer, microRNA, MESH: Homeodomain Proteins, medicine, [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, Humans, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Epithelial–mesenchymal transition, Transcription factor, Zinc Finger E-box Binding Homeobox 2, 030304 developmental biology, MESH: Zinc Finger E-box Binding Homeobox 2, Homeodomain Proteins, Neoplastic, MESH: Humans, Gene Expression Profiling, Carcinoma, Brief Definitive Report, Zinc Finger E-box-Binding Homeobox 1, Hepatocellular, Cell Biology, HCCS, medicine.disease, MESH: RNA, Neoplasm, MESH: Neoplasm Metastasis, MESH: Male, Repressor Proteins, Gene expression profiling, MicroRNAs, MESH: Epithelial-Mesenchymal Transition, Gene Expression Regulation, Tumor progression, Cancer research, RNA, Neoplasm, MESH: Transcriptional Activation, genetics/metabolism/pathology, Epithelial-Mesenchymal Transition, Female, Gene Expression Profiling, Gene Expression Regulation, Neoplastic, Hep G2 Cells, Homeodomain Proteins, biosynthesis/genetics, Humans, Liver Neoplasms, genetics/metabolism/pathology, Male, MicroRNAs, genetics/metabolism, Neoplasm Metastasis, RNA, genetics/metabolism, Repressor Proteins, biosynthesis/genetics, Transcription Factors, biosynthesis/genetics, Transcriptional Activation, genetics, Tumor Suppressor Protein p53, Tumor Suppressor Protein p53, MESH: Female, MESH: MicroRNAs, 030215 immunology, Transcription Factors
Abstract

By transactivating expression of miRNAs that repress expression of the ZEB1 and ZEB2 transcription factors, p53 inhibits the epithelial–mesenchymal transition., p53 suppresses tumor progression and metastasis. Epithelial–mesenchymal transition (EMT) is a key process in tumor progression and metastasis. The transcription factors ZEB1 and ZEB2 promote EMT. Here, we show that p53 suppresses EMT by repressing expression of ZEB1 and ZEB2. By profiling 92 primary hepatocellular carcinomas (HCCs) and 9 HCC cell lines, we found that p53 up-regulates microRNAs (miRNAs), including miR-200 and miR-192 family members. The miR-200 family members transactivated by p53 then repress ZEB1/2 expression. p53-regulated miR-192 family members also repress ZEB2 expression. Inhibition or overexpression of the miRNAs affects p53-regulated EMT by altering ZEB1 and ZEB2 expression. Our findings indicate that p53 can regulate EMT, and that p53-regulated miRNAs are critical mediators of p53-regulated EMT.

Published
2011

6. PGC-1β: A Regulator of Mitochondrial Function with Subtle Roles in Energy Metabolism

Author

Adrienn Kis, Mark Campbell, Mohammad Bohlooly-Y, Keira Curtis, Barbara Cannon, Matej Orešič, E. Dale Abel, Vlad G. Zaha, Gema Medina-Gomez, Sheldon E. Litwin, Mercedes Jimenez-Linan, Antonio Vidal-Puig, Sihem Boudina, Kimberly T Fountain, Leonard H Storlien, Miguel López, Margaret Blount, Ping Hu, Helena M. Feldmann, Christopher J. Lelliott, Mikael Bjursell, Natasa Petrovic, Dongfang Zhang, Nadeene Parker, Maria Strömstedt, Aline Meirhaeghe, Michael Snaith, Autard, Delphine, Department of Clinical Biochemistry, University of Cambridge [UK] (CAM), AstraZeneca, The Wenner-Gren Institute, Stockholm University, Division of Cardiology, University of Utah, Division of Endocrinology, Metabolism, and Diabetes, Epidémiologie des maladies chroniques : impact des interactions gène environnement sur la santé des populations, Institut Pasteur de Lille, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille, Droit et Santé, Technical Research Centre of Finland, VTT Technical Research Centre of Finland (VTT), The work presented in this paper was supported by grants from the British Heart Foundation, Wellcome Trust Integrative Physiology, and Diabetes Wellness Research Foundation (to AVP lab), and NIH grants RO1HL73167 and UO1HL70525 from the National Institutes of Health and the Ben and Iris Margolis Foundation (to EDA - Established Investigator of the American Heart Association). Support was from the European Union (DLARFID), the Swedish Research Council, and the Swedish Cancer Society (to BC lab).

Subjects
Male, MESH: Cold Temperature, Adipose tissue, White adipose tissue, Mitochondrion, MESH: Mice, Knockout, Mitochondria, Heart, chemistry.chemical_compound, Mice, Norepinephrine, 0302 clinical medicine, Adipose Tissue, Brown, Heart Rate, Brown adipose tissue, Body Fat Distribution, Diabetes/Endocrinology/Metabolism, MESH: Thermogenesis, MESH: Animals, Biology (General), MESH: Heart Rate, Mice, Knockout, Mammals, 0303 health sciences, MESH: Muscle, Skeletal, General Neuroscience, MESH: Energy Metabolism, Heart, Thermogenesis, Mus (Mouse), Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha, MESH: Gene Expression Regulation, Mitochondria, Cold Temperature, medicine.anatomical_structure, Liver, MESH: Adipose Tissue, White, Synopsis, Female, MESH: Mitochondria, Heart, General Agricultural and Biological Sciences, Metabolic Networks and Pathways, Research Article, MESH: Electron Transport Chain Complex Proteins, medicine.medical_specialty, QH301-705.5, MESH: Mitochondria, MESH: Trans-Activators, Adipose Tissue, White, Biology, MESH: Diet, Atherogenic, MESH: Adipose Tissue, Brown, General Biochemistry, Genetics and Molecular Biology, 03 medical and health sciences, Adrenergic Agents, Internal medicine, MESH: Norepinephrine, medicine, [SDV.BBM] Life Sciences [q-bio]/Biochemistry, Molecular Biology, Animals, MESH: Body Fat Distribution, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Muscle, Skeletal, MESH: Mice, 030304 developmental biology, Soleus muscle, General Immunology and Microbiology, Triglyceride, Body Weight, medicine.disease, MESH: Adrenergic Agents, MESH: Male, MESH: Body Weight, MESH: Heart, Endocrinology, chemistry, Electron Transport Chain Complex Proteins, Gene Expression Regulation, MESH: Metabolic Networks and Pathways, Trans-Activators, Diet, Atherogenic, Steatosis, Energy Metabolism, MESH: Female, 030217 neurology & neurosurgery, Transcription Factors, MESH: Liver
Abstract

The transcriptional coactivator peroxisome proliferator-activated receptor-gamma coactivator-1β (PGC-1β) has been implicated in important metabolic processes. A mouse lacking PGC-1β (PGC1βKO) was generated and phenotyped using physiological, molecular, and bioinformatic approaches. PGC1βKO mice are generally viable and metabolically healthy. Using systems biology, we identified a general defect in the expression of genes involved in mitochondrial function and, specifically, the electron transport chain. This defect correlated with reduced mitochondrial volume fraction in soleus muscle and heart, but not brown adipose tissue (BAT). Under ambient temperature conditions, PGC-1β ablation was partially compensated by up-regulation of PGC-1α in BAT and white adipose tissue (WAT) that lead to increased thermogenesis, reduced body weight, and reduced fat mass. Despite their decreased fat mass, PGC1βKO mice had hypertrophic adipocytes in WAT. The thermogenic role of PGC-1β was identified in thermoneutral and cold-adapted conditions by inadequate responses to norepinephrine injection. Furthermore, PGC1βKO hearts showed a blunted chronotropic response to dobutamine stimulation, and isolated soleus muscle fibres from PGC1βKO mice have impaired mitochondrial function. Lack of PGC-1β also impaired hepatic lipid metabolism in response to acute high fat dietary loads, resulting in hepatic steatosis and reduced lipoprotein-associated triglyceride and cholesterol content. Altogether, our data suggest that PGC-1β plays a general role in controlling basal mitochondrial function and also participates in tissue-specific adaptive responses during metabolic stress., The authors conduct an in-depth analysis of a PGC-1β knockout mouse; these animals posses specific defects in basal mitochondrial function and adaptation to metabolic stress.

Published
2006

7. Peroxisome proliferator-activated receptor-α activation as a mechanism of preventive neuroprotection induced by chronic fenofibrate treatment

Author

Olivier Pétrault, Bernard Dupuis, Isabelle Six, Régis Bordet, Patrick Gelé, Christophe Furman, Bart Staels, Dominique Deplanque, Roméo Cecchelli, Patrick Duriez, Muriel Bouly, Didier Leys, Jean-Charles Fruchart, Stéphane Nion, Université Lille 2 - Faculté de Médecine, Centre Hospitalier Régional Universitaire [Lille] (CHRU Lille), Récepteurs nucléaires, lipoprotéines et athérosclérose, Institut Pasteur de Lille, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lille, Droit et Santé, Réseau International des Instituts Pasteur (RIIP), Université d'Artois (UA), Laboratoire de Physiopathologie de la Barrière Hémato-Encéphalique (LBHE), P.G. was supported by a grant from 'Conseil Régional Nord Pas de Calais et Centre Hospitalier Régional et Universitaire de Lille. ' This work was supported by grants from ' Génopole Lille Nord-Pas de Calais '(#01360124) and Institut National de la Santé et de la Recherche Médicale (CReS4CR02F)., and We thank Alexandra Tavernier-Sommerville for her assistance with the English version of this paper.

Subjects
Middle Cerebral Artery, Mouse, Nitric Oxide Synthase Type II, Receptors, Cytoplasmic and Nuclear, Peroxisome proliferator-activated receptor, medicine.disease_cause, Rats, Inbred WKY, Mice, 0302 clinical medicine, Fenofibrate, Mice, Knockout, chemistry.chemical_classification, 0303 health sciences, biology, General Neuroscience, Infarction, Middle Cerebral Artery, Cerebral Infarction, Intercellular Adhesion Molecule-1, Neuroprotection, Vasodilation, Nitric oxide synthase, Stroke, Neuroprotective Agents, Cerebrovascular Circulation, Middle cerebral artery, medicine.symptom, medicine.drug, PPAR-α, medicine.medical_specialty, Adhesion proteins, Nitric Oxide Synthase Type III, Development/Plasticity/Repair, Ischemia, Vascular Cell Adhesion Molecule-1, Mice, Transgenic, Inflammation, Time, 03 medical and health sciences, Apolipoproteins E, medicine.artery, Internal medicine, medicine, Animals, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, 030304 developmental biology, business.industry, Prevention, medicine.disease, Rats, Mice, Inbred C57BL, Disease Models, Animal, Endocrinology, chemistry, Oxidative stress, biology.protein, Nitric Oxide Synthase, business, 030217 neurology & neurosurgery, Transcription Factors
Abstract

International audience; The treatment of ischemic strokes is limited to the prevention of cerebrovascular risk factors and to the modulation of the coagulation cascade during the acute phase. Anew therapeutic strategy could be to preventively protect the brain against noxious biological reactions induced by cerebral ischemia such as oxidative stress and inflammation to minimize their neurological consequences. Here, we show that a peroxisome proliferator-activated receptor (PPAR-α) activator, fenofibrate, protects against cerebral injury by anti-oxidant and antiinflammatory mechanisms. A 14 d preventive treatment with fenofibrate reduces susceptibility to stroke in apolipoprotein E-deficient mice as well as decreases cerebral infarct volume in C57BL/6 wild-type mice. The neuroprotective effect of fenofibrate is completely absent in PPAR-α-deficient mice, suggesting that PPAR-α activation is involved as a mechanism of the protection against cerebral injury. Furthermore, this neuroprotective effect appears independently of any improvement in plasma lipids or glycemia and is associated with (1) an improvement in middle cerebral artery sensitivity to endothelium-dependent relaxation unrelated to an increase in nitric oxide synthase (NOS) type III expression, (2) a decrease in cerebral oxidative stress depending on the increase in numerous antioxidant enzyme activities, and (3) the prevention of ischemia-induced expression of vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 in cerebral vessels without any change in NOS II expression. These data demonstrate that PPAR-α could be a new pharmacological target to preventively reduce the deleterious neurological consequences of stroke in mice and suggest that PPAR-α activators could preventively decrease the severity of stroke in humans.

Published
2003