The cys-loop ligand-gated ion channel gene superfamilies of the cockroaches Blattella germanica and Periplaneta americana

Background. Cockroaches are serious urban pests that can transfer disease-causing microorganisms as well as trigger allergic reactions and asthma. They are commonly managed by pesticides that act on cys-loop ligand-gated ion channels (cysLGIC). To provide further information that will enhance our understanding of how insecticides act on their molecular targets in cockroaches, we used genome and reverse transcriptase PCR data to characterise the cysLGIC gene superfamilies from Blattella germanica and Periplaneta americana. Results. The B. germanica and P. americana cysLGIC superfamilies consist of 30 and 32 subunit-encoding genes, respectively, which are the largest insect cysLGIC superfamilies characterized to date. As with other insects, the cockroaches possess ion channels predicted to be gated by acetylcholine, gamma-aminobutyric acid, glutamate and histamine, as well as orthologues of the Drosophila pH-sensitive chloride channel (pHCl), CG8916 and CG12344. The large cysLGIC superfamilies of cockroaches are a result of an expanded number of divergent nicotinic acetylcholine receptor subunits, with B. germanica and P. americana respectively possessing eight and ten subunit genes. Diversity of the cockroach cysLGICs is also broadened by alternative splicing and RNA A-to-I editing. Unusually, both cockroach species possess a second glutamate-gated chloride channel as well as another CG8916 subunit. Conclusion. These findings on B. germanica and P. americana enhance our understanding of the evolution of the insect cysLGIC superfamily and provide a useful basis for the study of their function, the detection and management of insecticide resistance, and for the development of improved pesticides with greater specificity towards these major pests

Induction of Heme Oxygenase-1, Biliverdin Reductase and H-Ferritin in Lung Macrophage in Smokers with Primary Spontaneous Pneumothorax: Role of HIF-1α

Few data concern the pathophysiology of primary spontaneous pneumothorax (PSP), which is associated with alveolar hypoxia/reoxygenation. This study tested the hypothesis that PSP is associated with oxidative stress in lung macrophages. We analysed expression of the oxidative stress marker 4-HNE; the antioxidant and anti-inflammatory proteins heme oxygenase-1 (HO-1), biliverdin reductase (BVR) and heavy chain of ferritin (H-ferritin); and the transcription factors controlling their expression Nrf2 and HIF-1alpha, in lung samples from smoker and nonsmoker patients with PSP (PSP-S and PSP-NS), cigarette smoke being a risk factor of recurrence of the disease.mRNA was assessed by RT-PCR and proteins by western blot, immunohistochemistry and confocal laser analysis. 4-HNE, HO-1, BVR and H-ferritin were increased in macrophages from PSP-S as compared to PSP-NS and controls (C). HO-1 increase was associated with increased expression of HIF-1alpha mRNA and protein in alveolar macrophages in PSP-S patients, whereas Nrf2 was not modified. To understand the regulation of HO-1, BVR and H-ferritin, THP-1 macrophages were exposed to conditions mimicking conditions in C, PSP-S and PSP-NS patients: cigarette smoke condensate (CS) or air exposure followed or not by hypoxia/reoxygenation. Silencing RNA experiments confirmed that HIF-1alpha nuclear translocation was responsible for HO-1, BVR and H-ferritin induction mediated by CS and hypoxia/reoxygenation.PSP in smokers is associated with lung macrophage oxidative stress. The response to this condition involves HIF-1alpha-mediated induction of HO-1, BVR and H-ferritin

Regulation of heme oxygenase-1 in macrophages in smoking related pulmonary disease

L’intoxication tabagique, source d’oxydants, est un facteur de risque important de développement de l’emphysème pulmonaire et du pneumothorax spontané primitif. Les macrophages alvéolaires contribuent pour une large part à l’inflammation pulmonaire au cours de ces pathologies en produisant des métalloprotéases et des espèces réactives de l’oxygène à l’origine du déséquilibre des balances protéase/anti-protéase et oxydant/antioxydant. L'hème oxygénase-1 (HO-1), exprimée principalement par les macrophages, est une enzyme clé des défenses anti-oxydantes pulmonaires. Nous avons initialement étudié l’expression et la localisation cellulaire de l’HO-1 et de ses régulateurs potentiels (Nrf2, Keap1, Bach1 et HIF-1a) dans les macrophages alvéolaires au cours de l’emphysème pulmonaire post-tabagique et du pneumothorax spontané primitif. Les voies de régulation de l’expression de ces protéines ont été analysées in vitro sur des macrophages dérivés de la lignée THP-1 exposés ou non au condensat de fumée de cigarette et à l’hypoxieréoxygénation visant à mimer une partie des effets de l’atélectasie-réexpansion observée lors de la prise en charge thérapeutique des pneumothorax récidivants. Les travaux présentés dans cette thèse nous ont permis de mettre en évidence une altération de l’expression de la voie Nrf2/Keap1-Bach1 associée à une diminution de l’expression des enzymes anti-oxydantes, dont l’HO-1, dans les macrophages alvéolaires au cours de l’emphysème pulmonaire sévère post-tabagique, malgré un stress oxydant important. In vitro, ces altérations pourraient être liées à une activation spécifique des MAPKinases ERK1/2 et JNK par le condensat de fumée de cigarette. Nous avons également montré que la stimulation du système de l’HO-1 était probablement orchestrée par la voie du facteur HIF-1a, et non par celle de Nrf2, dans les macrophages alvéolaires au cours du pneumothorax spontané primitif récidivant du sujet fumeur. Ces résultats pourraient contribuer à une meilleure connaissance de la physiopathologie de l’emphysème pulmonaire et permettre d’envisager de nouvelles approches thérapeutiques basées sur la préservation et/ou la restauration de l’équilibre Nrf2/Keap1-Bach1. Nos travaux suggèrent également que la physiopathologie du pneumothorax spontané primitif est différente chez les patients fumeurs et non fumeurs. Le pneumothorax du sujet fumeur est associé à un stress oxydant pulmonaire et à une induction de l’HO-1 probablement orchestrée par HIF-1a. Ces résultats, confirmés in vitro, mettent en évidence une interaction potentielle entre le stress oxydant et l’hypoxie-réoxygénationChronic cigarette smoking, a source of oxidants, is an important risk factor for lung emphysema and primary spontaneous pneumothorax development. Alveolar macrophages are mainly involved in lung inflammation observed in these pathologies through the production of metalloproteases and reactive oxygen species resulting to protease/anti-protease and oxidant/anti-oxidant imbalances. Heme oxygenase-1 (HO-1), mainly expressed in macrophages, is a key enzyme in pulmonary anti-oxidant defences. Therefore, the first aim of our studies was to investigate the expression and cellular localisation of HO-1 and its potential regulators (Nrf2, Keap1, Bach1 and HIF-1a) in alveolar macrophages from smoking related lung emphysema and primary spontaneous pneumothorax. Regulation pathways involved in expression of these proteins were assessed in vitro in macrophage cell line THP-1 exposed or not to cigarette smoke condensate and with or without hypoxia-reoxygenation mimicking parts of events induced by atelectasia-reexpansion during recurrent pneumothorax constitution and treatment. In these studies, we showed an altered expression of Nrf2/Keap1- Bach1 pathway associated with a reduced expression of anti-oxidants enzymes, like HO-1, in alveolar macrophages from smoking related lung emphysema patients, despite an important oxidative stress. These alterations might be related to cigarette smoke condensate activated ERK1/2 and JNK MAPKinases as observed in THP-1 cells. Furthermore, we showed that HO- 1 system induction was mediated by HIF-1a instead of Nrf2 pathway in alveolar macrophages from smoking related recurrent primary spontaneous pneumothorax. These findings may contribute to a better knowledge of the pathophysiology of lung emphysema and could provide new therapeutic approaches based on preservation and/or restoration of Nrf2/Keap1-Bach1 equilibrium. Our results also suggest that the pathophysiology of primary spontaneous pneumothorax could be different in smokers and non smokers. Spontaneous pneumothorax in smokers is associated with lung oxidative stress and the orchestrated induction of HO-1 probably via HIF-1a. These results provide a new link between oxidative stress and hypoxia/reoxygenatio

Régulation de l'hème oxygénase-1 dans les macrophages au cours des pathologies pulmonaires liées à l'exposition de la fumée de cigarette

L intoxication tabagique, source d oxydants, est un facteur de risque important de développement de l emphysème pulmonaire et du pneumothorax spontané primitif. Les macrophages alvéolaires contribuent pour une large part à l inflammation pulmonaire au cours de ces pathologies en produisant des métalloprotéases et des espèces réactives de l oxygène à l origine du déséquilibre des balances protéase/anti-protéase et oxydant/antioxydant. L'hème oxygénase-1 (HO-1), exprimée principalement par les macrophages, est une enzyme clé des défenses anti-oxydantes pulmonaires. Nous avons initialement étudié l expression et la localisation cellulaire de l HO-1 et de ses régulateurs potentiels (Nrf2, Keap1, Bach1 et HIF-1a) dans les macrophages alvéolaires au cours de l emphysème pulmonaire post-tabagique et du pneumothorax spontané primitif. Les voies de régulation de l expression de ces protéines ont été analysées in vitro sur des macrophages dérivés de la lignée THP-1 exposés ou non au condensat de fumée de cigarette et à l hypoxieréoxygénation visant à mimer une partie des effets de l atélectasie-réexpansion observée lors de la prise en charge thérapeutique des pneumothorax récidivants. Les travaux présentés dans cette thèse nous ont permis de mettre en évidence une altération de l expression de la voie Nrf2/Keap1-Bach1 associée à une diminution de l expression des enzymes anti-oxydantes, dont l HO-1, dans les macrophages alvéolaires au cours de l emphysème pulmonaire sévère post-tabagique, malgré un stress oxydant important. In vitro, ces altérations pourraient être liées à une activation spécifique des MAPKinases ERK1/2 et JNK par le condensat de fumée de cigarette. Nous avons également montré que la stimulation du système de l HO-1 était probablement orchestrée par la voie du facteur HIF-1a, et non par celle de Nrf2, dans les macrophages alvéolaires au cours du pneumothorax spontané primitif récidivant du sujet fumeur. Ces résultats pourraient contribuer à une meilleure connaissance de la physiopathologie de l emphysème pulmonaire et permettre d envisager de nouvelles approches thérapeutiques basées sur la préservation et/ou la restauration de l équilibre Nrf2/Keap1-Bach1. Nos travaux suggèrent également que la physiopathologie du pneumothorax spontané primitif est différente chez les patients fumeurs et non fumeurs. Le pneumothorax du sujet fumeur est associé à un stress oxydant pulmonaire et à une induction de l HO-1 probablement orchestrée par HIF-1a. Ces résultats, confirmés in vitro, mettent en évidence une interaction potentielle entre le stress oxydant et l hypoxie-réoxygénationChronic cigarette smoking, a source of oxidants, is an important risk factor for lung emphysema and primary spontaneous pneumothorax development. Alveolar macrophages are mainly involved in lung inflammation observed in these pathologies through the production of metalloproteases and reactive oxygen species resulting to protease/anti-protease and oxidant/anti-oxidant imbalances. Heme oxygenase-1 (HO-1), mainly expressed in macrophages, is a key enzyme in pulmonary anti-oxidant defences. Therefore, the first aim of our studies was to investigate the expression and cellular localisation of HO-1 and its potential regulators (Nrf2, Keap1, Bach1 and HIF-1a) in alveolar macrophages from smoking related lung emphysema and primary spontaneous pneumothorax. Regulation pathways involved in expression of these proteins were assessed in vitro in macrophage cell line THP-1 exposed or not to cigarette smoke condensate and with or without hypoxia-reoxygenation mimicking parts of events induced by atelectasia-reexpansion during recurrent pneumothorax constitution and treatment. In these studies, we showed an altered expression of Nrf2/Keap1- Bach1 pathway associated with a reduced expression of anti-oxidants enzymes, like HO-1, in alveolar macrophages from smoking related lung emphysema patients, despite an important oxidative stress. These alterations might be related to cigarette smoke condensate activated ERK1/2 and JNK MAPKinases as observed in THP-1 cells. Furthermore, we showed that HO- 1 system induction was mediated by HIF-1a instead of Nrf2 pathway in alveolar macrophages from smoking related recurrent primary spontaneous pneumothorax. These findings may contribute to a better knowledge of the pathophysiology of lung emphysema and could provide new therapeutic approaches based on preservation and/or restoration of Nrf2/Keap1-Bach1 equilibrium. Our results also suggest that the pathophysiology of primary spontaneous pneumothorax could be different in smokers and non smokers. Spontaneous pneumothorax in smokers is associated with lung oxidative stress and the orchestrated induction of HO-1 probably via HIF-1a. These results provide a new link between oxidative stress and hypoxia/reoxygenationPARIS-EST-Université (770839901) / SudocSudocFranceF

Functional and molecular characterisation of An. gambiae muscarinic receptors

International audienc

Functional and molecular characterization of Anopheles gambiae muscarinic receptors

International audienc

Exposure to sublethal doses of insecticides can induce insecticide sensitivity changes linked to molecular and cellular modifications

International audienc

La voie Nrf2 en pathologie respiratoire

Les voies respiratoires sont la première cible des oxydants inhalés (polluants atmosphériques) ou générés localement par les cellules médiatrices de la réponse inflammatoires. Pour faire face à ces agressions, le poumon possède des défenses antioxydantes. Le facteur de transcription nuclear factor erythroid-2-related factor 2 (Nrf2) contrôle l’expression des gènes antioxydants et cytoprotecteurs via la séquence régulatrice appelée élément de réponse antioxydant (ARE). Le stress oxydant et la voie de signalisation Nrf2/Keap1-Bach1 ont un rôle essentiel dans la physiopathologie de nombreuses pathologies respiratoires aiguës et chroniques. La voie Nrf2 participe à la protection pulmonaire au cours de la bronchopneumopathie chronique obstructive, l’emphysème, l’asthme, la fibrose et les agressions pulmonaires aiguës. Nous présentons dans cette revue les données récentes concernant les mécanismes de la protection pulmonaire induite par Nrf2 et l’intérêt potentiel d’une thérapeutique ciblant ce facteur

Relative mRNA quantity of SWS1 and LWS opsin genes for newt larvae raised in UV+ and UV- lighting conditions

Opsin, SWS1 or LWS opsin genes. Rear, UV+ and UV- lighting conditions during development. Ind, individual identity. RNA, relative mRNA quantity

NOX4/NADPH oxidase expression is increased in pulmonary fibroblasts from patients with idiopathic pulmonary fibrosis and mediates TGFbeta1-induced fibroblast differentiation into myofibroblasts.: NOX4/NADPH oxidase in idiopathic pulmonary fibrosis

International audienceBACKGROUND: Persistence of myofibroblasts is believed to contribute to the development of fibrosis in idiopathic pulmonary fibrosis (IPF). Transforming growth factor beta1 (TGFbeta1) irreversibly converts fibroblasts into pathological myofibroblasts, which express smooth muscle alpha-actin (alpha-SMA) and produce extracellular matrix proteins, such as procollagen I (alpha1). Reactive oxygen species produced by NADPH oxidases (NOXs) have been shown to regulate cell differentiation. It was hypothesised that NOX could be expressed in parenchymal pulmonary fibroblasts and could mediate TGFbeta1-stimulated conversion of fibroblasts into myofibroblasts. METHODS: Fibroblasts were cultured from the lung of nine controls and eight patients with IPF. NOX4, alpha-SMA and procollagen I (alpha1) mRNA and protein expression, reactive oxygen species production and Smad2/3 phosphorylation were quantified, in the absence and in the presence of incubation with TGFbeta1. Migration of platelet-derived growth factor (PDGF)-induced fibroblasts was also assessed. RESULTS: It was found that (1) NOX4 mRNA and protein expression was upregulated in pulmonary fibroblasts from patients with IPF and correlated with mRNA expression of alpha-SMA and procollagen I (alpha1) mRNA; (2) TGFbeta1 upregulated NOX4, alpha-SMA and procollagen I (alpha1) expression in control and IPF fibroblasts; (3) the change in alpha-SMA and procollagen I (alpha1) expression in response to TGFbeta1 was inhibited by antioxidants and by a NOX4 small interfering RNA (siRNA); (4) NOX4 modulated alpha-SMA and procollagen I (alpha1) expression by controlling activation of Smad2/3; and (5) NOX4 modulated PDGF-induced fibroblast migration. CONCLUSION: NOX4 is critical for modulation of the pulmonary myofibroblast phenotype in IPF, probably by modulating the response to TGFbeta1 and PDGF