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La pollution de l’air ‒ ou pollution atmospherique ‒ est une modification de la composition de l’air par des polluants nuisibles a la sante et a l’environnement ; elle constitue la plus grande cause environnementale de maladies et de deces prematures dans le monde actuel. Negligee initialement car consideree comme un effet adverse de la pollution atmospherique, la relation entre la pollution et la survenue et/ou la severite d’infections respiratoires est devenue ces dernieres annees une preoccupation croissante en sante publique. En ce qui concerne les infections virales, qui constituent une majorite des infections respiratoires, differentes etudes montrent que leur incidence et/ou leur severite peuvent etre correlees aux concentrations des polluants atmospheriques, tels que le dioxyde d’azote (NO2), l’ozone (O3) et les particules. Les mecanismes sous-jacents ne sont pas completement elucides a l’heure actuelle, ils font probablement intervenir une facilitation de la transmission des virus et/ou une susceptibilite accrue aux effets des virus. Bien que d’autres etudes soient necessaires pour mieux comprendre ces phenomenes, les donnees disponibles doivent inciter la prise de mesures pour diminuer la concentration des polluants dans l’air afin de contrer la surmortalite liee a la pollution, y compris les infections virales.

International audience; Obstructive sleep apnea is a common chronic disorder that leads to chronic intermittent hypoxia described as an important factor contributing to the pathogenesis of OSA-related comorbidities. Besides, recent data suggest that intermittent hypoxia can induce adaptative cardiovascular pathways inducing a relative resistance to ischemic insults. Adaptative pathways induced by hypoxia could implicate autophagic processes and Beclin-1, one of the first mammalian autophagy effectors. Thus, activation of autophagy could protect against cardiovascular events in patients with OSA and could be considered as biomarker of a better prognosis.

La pollution atmospherique constitue un risque environnemental majeur pour la sante. Une exposition a des niveaux eleves de pollution atmospherique entraine des effets respiratoires, mais aussi au niveau cardiovasculaire ou du systeme nerveux, notamment. Un important constat est que ces effets dependent non seulement de la qualite de l’air, mais aussi des sujets concernes et de leur vulnerabilite individuelle (enfants, personnes âgees, patients avec pathologies prealables...). Du point de vue de la sante, les constituants de la pollution atmospherique le plus souvent associes a des effets deleteres sont les polluants gazeux (ozone, dioxyde de soufre, oxydes d’azote...) et les particules. Cependant, l’une des principales difficultes tient a l’extreme complexite du melange atmospherique, le developpement de dispositifs experimentaux innovants est donc necessaire pour mieux apprehender ces effets. Les efforts doivent etre poursuivis pour proteger les populations des effets deleteres de la pollution de l’air sur leur sante.

Introduction: Alveolar type 2 cells (AT2) play a key role in alveolar regeneration after alveolar damage. Mechanisms involved in this process are not well known. Aims and Objectives: Targeting p16INK4a, a cell cycle inhibitor, in AT2 could be a way to promote alveolar regeneration. Methods: In vitro alveolar organoids were obtained by co-culturing EpCAM+ cells (sorted with magnetic beads from lungs of p16INK4a-/- or wild type (WT) mice) with WT lung primary fibroblasts. Colony forming units (CFU), organoid size, organoid types (alveolar, bronchoalveolar by pro-SpC and ACT staining) were quantified at D14 and D21. Organoids from emphysematous mice (elastase model) were compared to organoids from PBS-injected mice as a control with the same genetic background (p16INK4a-/- or WT). In vivo, morphological analysis (mean linear intercept) and AT2 number were quantified in elastase or PBS injected mice at D21 and D90 to assess alveolar destruction and regeneration according to WT or p16INK4a-/- genotype. Results: Organoids made with p16INK4a-/- EpCAM+ cells were as numerous but had an increased size compared to those made from WT EpCAM+ cells at D14 and D21. CFU and organoid size from emphysematous mice were significantly decreased compared to control mice. Number and size of organoids made with p16INK4a-/- EpCAM+cells from emphysematous mice were higher than organoids made with WT EpCAM + cells from emphysematous mice. In vivo, p16INK4a deletion was associated with an increase of AT2 at D21 without a protective effect on alveolar architecture. At D90, p16INK4a-/- mice had less emphysema than WT mice. Conclusions: p16INK4a deletion increases endogenous alveolar regeneration by AT2 cells. Mechanisms involved remain to be determined.

Gold (Au) can be deposited as nanoparticles (NPs) smaller than 10 nm in diameter on a variety of metal oxide (MOx) NPs. Au/MOx NPs have high catalytic performance and selective oxidation capacity which could have implications in terms of biological activity, and more specifically in modulation of the inflammatory reaction. Therefore, the aim of this study was to examine the effect of Au/TiO2, Au/ZrO2 and Au/Ce/O2 on viability, phagocytic capacity and inflammatory profile (TNF-α and IL-1β secretion) of murine macrophages. The most important result of this study is an anti-inflammatory effect of Au/MOx NPs depending on the MOx nature with particle internalization and no alteration of cell viability and phagocytosis. The effect was dependent on the MOx NPs chemical nature (Au/TiO2> Au/ZrO2> Au/CeO2 if we consider the number of cytokines whose concentration was reduced by the NPs), and on the inflammatory mediator considered. The effect of Au/TiO2 NPs was not related to Au NPs size (at least in the case of Au/TiO2 NPs in the range of 3-8 nm). To the best of our knowledge, this is the first demonstration of an anti-inflammatory effect of Au/MOx NPs.

BackgroundCerium (Ce) is a rare earth element, rapidly oxidizing to form CeO2, and currently used in numerous commercial applications, especially as nanoparticles (NP). The potential health effects of Ce remain uncertain, but literature indicates the development of rare earth pneumoconiosis accompanied with granuloma formation, interstitial fibrosis and inflammation. The exact underlying mechanisms are yet not completely understood, and we propose that autophagy could be an interesting target to study, particularly in macrophages. Therefore, the objective of our study was to investigate the role of macrophagic autophagy after pulmonary exposure to CeO2 NP in mice. Mice lacking the early autophagy gene Atg5 in their myeloid lineage and their wildtype counterparts were exposed to CeO2 NP by single oropharyngeal administration and sacrificed up to one month after. At that time, lung remodeling was thoroughly characterized (inflammatory cells infiltration, expression of fibrotic markers such as αSMA, TGFβ1, total and type I and III collagen deposition), as well as macrophage infiltration (quantification and M1/M2 phenotype). Results: Such pulmonary exposure to CeO2 NP induces a progressive and dose-dependent lung fibrosis in the bronchiolar and alveolar walls, together with the activation of autophagy. Blockade of macrophagic autophagy protects from alveolar but not bronchiolar fibrosis, via the modulation of macrophage polarization towards M2 phenotype. Conclusion: In conclusion, our findings bring novel insight on the role of macrophagic autophagy in lung fibrogenesis, and add to the current awareness of pulmonary macrophages as potential new therapeutic targets for future anti-fibrotic therapies.

SummaryUsing CESAM, an atmospheric simulation chamber (cesam.cnrs.fr), we have developed a totally innovative platform for exposing mice to realistic atmospheric conditions. Here we present the first toxicological analyses of the organs of these mice after 48 hours to several days of exposure, carried out as part of feasibility experiments aimed at testing this experimental concept. This platform has received funding from the European Union’s Horizon 2020 research and innovation programme through the EUROCHAMP-2020 Infrastructure Activity under grant agreement N° 730997, and is now supporting the new REMEDIA H-2020 project (call H2020 “Exposome”) IntroductionThe World Health Organization (WHO) estimated that there were 3.7 million premature deaths due to air pollution in 2014, and confirmed that air pollution is the greatest environmental risk to health (responsible for a loss of more than 3% of productivity).The studies conducted so far show that the effects of air pollution on health depend not only on the quality of the surrounding air, but also on the subjects exposed and their individual vulnerability (asthma, obesity, period of life, etc.). Despite the evidence on the adverse health effects of exposure to air micro-pollutants, there are still uncertainties about the nature of these effects, and progress need to be made on their quantification. This limitation of knowledge is mainly attributed to the complexity of the polluted atmospheres, and to the great difficulty to model the impact of realistic situations of exposure. MethodologyThe innovative approach we set up is to realistically simulate, at the laboratory, the atmospheric mixture in all its complexity, thus keeping the ability to control, reproduce and carefully characterize the experimental conditions. We used the CESAM chamber (4.2 m3 stainless steel atmospheric simulation, evacuable down to a few 10-7 atm, temperature controlled between +15°C and +60°C) in order to study the myriad of products arising from the atmospheric oxidation of primary organic compounds.The experimental protocol consists in the continuous injection of relevant mixtures of primary pollutants (mainly nitrogen oxides, organic compounds from a representative mix of anthropogenic emissions, sulphur dioxide, soot, inorganic salts and potentially mineral dust particles if needed - e.g. to simulate Beijing’s atmosphere) at low concentrations (ppb levels) in air in the CESAM simulation chamber operated as a slow flow reactor. The residence time of simulated air parcels in the experimental volume is fixed to 4 hours, in order to represent air masses of regional scale. During this time the synthetic mixture is exposed to an artificial solar irradiation, allowing secondary pollutants such as ozone, nitric acid, formaldehyde, peroxyacetyl nitrate as well as complex polyfunctional organics including SOA to be produced and to reach their chemical steady state. Mice are exposed to constant flows of such a mixture during time scales of week to address their effects on health. ConclusionsHere we present the first toxicological analyses related to organs/tissue of these mice after exposure of 48h to several day, carried out with a representative atmosphere of Beijing or a representative atmosphere of Paris. ReferencesColl P. et al., 2018, WIT Transactions on Ecology and the Environment, 230.

Introduction Les pneumocytes de type 2 (p2) jouent un role cle dans les processus de regeneration apres des dommages alveolaires. Les mecanismes sous-jacents sont peu connus. L’objectif de ce travail est d’examiner si l’inhibiteur du cycle cellulaire p16INK4a module des proprietes des p2 et augmentant leurs capacites a induire une regeneration alveolaire. Methodes Des organoides pulmonaires ont ete realises par la mise en co-culture de cellules EpCAM+ obtenues par tri cellulaire magnetique (CD31-, CD45-, CD16/32-, CD90-, CD271-, Ter119-, EpCAM+) a partir de poumon de souris p16INK4a-/− ou WT avec des fibroblastes primaires pulmonaires WT. Une analyse de la taille et du nombre de colonies d’organoides formees (colony forming unit : CFU) et du type d’organoides (alveolaires ou bronchiques avec les marquages proSpC et acetylated tubulin-ACT) a ete realisee a 14 et 21 jours de culture. Dans un deuxieme temps, ces organoides ont ete obtenus a partir de poumon de souris emphysemateuses (J21 apres instillation d’elastase 2UI) compare a des souris controles (serum physiologique), p16INK4a-/− ou WT. Des analyses morphometriques (mean linear intercept) et le nombre de p2 ont ete realises 21 et 90 jours apres elastase. Resultats Les organoides formes de cellule EpCAM- p16INK4a-/− avaient une taille plus importante que ceux forme a partir d’EpCAM-WT a J14 (p = 0,046) et J21 (p = 0,0001). La majorite des organoides etaient alveolaires. La taille des organoides issus de souris emphysemateuses etait plus basse par rapport aux controles (p = 0,019), avec une tendance a la diminution du nombre de CFU. Les organoides issus de souris emphysemateuses p16INK4a-/− etaient de taille plus importante et plus nombreux que ceux issus de souris emphysemateuses WT. In vivo, la deletion de p16 etait associee 21 jours apres instillation d’elastase a un nombre plus important de p2 dans le poumon sans impact sur l’emphyseme. 90 jours apres elastase, les souris p16INK4a-/− avaient moins d’emphyseme (mean linear intercept) que les souris WT. Conclusions Inhiber p16INK4a augmente les capacites de regeneration endogene alveolaire des p2. Les mecanismes impliques restent a determiner.

Background: Fetal determinants of airway function, such as in utero exposure to maternal cigarette smoke (CS), may create a predisposition to adult airflow obstruction and chronic obstructive pulmonary disease (COPD) in adulthood. It has been suggested that active smoking in adolescence and preexisting airflow obstruction have synergistic deleterious effects. Objective: We used a mouse model to investigate whether there is a synergistic effect of exposure to CS in utero and during adolescence on lung function. Methods: Female C57Bl/6J mice were exposed to CS or to filtered room air during pregnancy. Exposure to CS began 2 weeks before mating and continued until delivery. After birth, the pups were not exposed to CS until day 21 (D21). Between D21 and D49, corresponding to “adolescence,” litters were randomized for an additional 4 weeks of exposure to CS. Lung morphometry, lung mechanics, and the expression of genes involved in senescence were evaluated in different subsets of mice on D21 and D49. Results: In utero exposure to CS induced significant lung function impairment by D21. CS exposure between D21 and D49 induced significant functional impairment only in mice exposed to CS prenatally. On D49, no difference was observed between subgroups in terms of lung p53, p16, p21, and Bax mRNA levels. Conclusions: Our findings suggest that prenatal and adolescent CS exposure have a synergistic effect on lung function in mice. The combined effect did not appear to be a consequence of early pulmonary senescence. Citation: Drummond D, Baravalle-Einaudi M, Lezmi G, Vibhushan S, Franco-Montoya ML, Hadchouel A, Boczkowski J, Delacourt C. 2017. Combined effects of in utero and adolescent tobacco smoke exposure on lung function in C57Bl/6J mice. Environ Health Perspect 125:392–399; http://dx.doi.org/10.1289/EHP54

Chronic exposure to environmental pollutants is often associated with systemic inflammation. As such, cigarette smoking contributes to inflammation and lung diseases by inducing senescence of pulmonary cells such as pneumocytes, fibroblasts, and endothelial cells. Yet, how smoking worsens evolution of chronic inflammatory disorders associated with Th17 lymphocytes, such as rheumatoid arthritis, psoriasis, Crohn’s disease, and multiple sclerosis, is largely unknown. Results from human studies show an increase in inflammatory CD4+ Th17 lymphocytes at blood- and pulmonary level in smokers. The aim of the study was to evaluate the sensitivity of CD4+ Th17 lymphocytes to cigarette smoke-induced senescence. Mucosa-homing CCR6+ Th17- were compared to CCR6neg -and regulatory T peripheral lymphocytes after exposure to cigarette smoke extract (CSE). Senescence sensitivity of CSE-exposed cells was assessed by determination of various senescence biomarkers (β-galactosidase activity, p16Ink4a- and p21 expression) and cytokines production. CCR6+ Th17 cells showed a higher sensitivity to CSE-induced senescence compared to controls, which is associated to oxidative stress and higher VEGFα secretion. Pharmacological targeting of ROS- and ERK1/2 signalling pathways prevented CSE-induced senescence of CCR6+Th17 lymphocytes as well as VEGFα secretion. Altogether, these results identify mechanisms by which pro-oxidant environmental pollutants contribute to pro-angiogenic and pathogenic CCR6+Th17 cells, therefore potential targets for therapeutic purposes.

Introduction: Lung regeneration is essential for damage recovering after lung injury at different age of life. Whether lipofibroblasts (LIF) are able to enhance endogenous alveolar regeneration once alveoli are damaged remains to be determined. Aim: To determine in a mouse model of bronchopulmonary dysplasia if a lipid switch of fibroblasts to LIF induce a curative lung regeneration. Methods: Wt C57BL/6J mice were exposed to hyperoxia (85% O2) or room air from days 3 to 14 of post-natal life. Rosiglitazone (RGZ), a PPARγ agonist which activates fibroblasts differentiation into LIF, was administered intraperitoneally at a dose of 5µg/g of mice daily, 5 days a week, starting after hyperoxia exposure, until adulthood (D60). Tissues were immunostained with anti-ADRP and anti-proSpC antibodies for LIF and AT2 detection respectively. Number of alveoli were estimated by the mean linear intercept and secondary septation by septal crest number (Weigert). Results: Compared to mice exposed to room air, mice exposed to hyperoxia presented a significant decreased number of LIF in lung associated with an arrested alveolar development revealed by a reduced number of alveoli and a concomitant disruption of secondary septation. Compared to hyperoxic, non-treated mice, RGZ administration increased the number of LIF and AT2 cells in the lung, associated with an increase in the number of alveoli and septal crests at adulthood. Conclusion: Switching fibroblasts towards LIF through PPARγ agonist administration induces lung regeneration after hypoalveolization due to post-natal hyperoxia. Administration of PPARγ agonists can be a new pharmacologic strategy to promote lung recovery after injury.

Baarsma et al. report increased expression and posttranslational modification of the noncanonical ligand WNT-5A in COPD. Fibroblast-derived WNT-5A inhibits canonical WNT–β-catenin–driven alveolar epithelial cell–mediated wound healing and transdifferentiation, and thus contributes to impaired lung regeneration and COPD pathogenesis., Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide. One main pathological feature of COPD is the loss of functional alveolar tissue without adequate repair (emphysema), yet the underlying mechanisms are poorly defined. Reduced WNT–β-catenin signaling is linked to impaired lung repair in COPD; however, the factors responsible for attenuating this pathway remain to be elucidated. Here, we identify a canonical to noncanonical WNT signaling shift contributing to COPD pathogenesis. We demonstrate enhanced expression of noncanonical WNT-5A in two experimental models of COPD and increased posttranslationally modified WNT-5A in human COPD tissue specimens. WNT-5A was increased in primary lung fibroblasts from COPD patients and induced by COPD-related stimuli, such as TGF-β, cigarette smoke (CS), and cellular senescence. Functionally, mature WNT-5A attenuated canonical WNT-driven alveolar epithelial cell wound healing and transdifferentiation in vitro. Lung-specific WNT-5A overexpression exacerbated airspace enlargement in elastase-induced emphysema in vivo. Accordingly, inhibition of WNT-5A in vivo attenuated lung tissue destruction, improved lung function, and restored expression of β-catenin–driven target genes and alveolar epithelial cell markers in the elastase, as well as in CS-induced models of COPD. We thus identify a novel essential mechanism involved in impaired mesenchymal–epithelial cross talk in COPD pathogenesis, which is amenable to therapy.

The transcription factor p53 is overexpressed in the lung of patients with emphysema, but it remains unclear if it has a deleterious or protective effect in disease progression. We investigated the role of p53 in the elastase-induced emphysema model and the molecular underlining mechanisms. Wild-type (WT) and p53(-/-) mice were instilled with pancreatic porcine elastase. We quantified emphysema (morphometric analysis), chemokine (C-C motif) ligand 2 (CCL2), and TNF-α in bronchoalveolar lavage (BAL) (ELISA), oxidative stress markers [heme oxygenase 1 (HO1), NAD(P)H dehydrogenase quinone 1 (NQO1), and quantitative RT-PCR], matrix metalloproteinase 12 (MMP12) expression, and macrophage apoptosis (cleaved caspase-3, immunofluorescence). p53 gene expression was up-regulated in the lung of elastase-instilled mice. p53 deletion aggravated elastase-induced emphysema severity, pulmonary inflammation (macrophage and neutrophil numbers and CCL2 and TNF-α levels in BAL), and lung oxidative stress. These findings, except for the increase in CCL2, were reproduced in WT mice transplanted with p53(-/-) bone marrow cells. The increased number of macrophages in p53(-/-) mice was not a consequence of reduced apoptosis or an excess of chemotaxis toward CCL2. Macrophage expression of MMP12 was higher in p53(-/-) mice compared with WT mice after elastase instillation. These findings provide evidence that p53(-/-) mice and WT mice grafted with p53(-/-) bone marrow cells are more prone to developing elastase-induced emphysema, supporting a protective role of p53, and more precisely p53 expressed in macrophages, against emphysema development. The pivotal role played by macrophages in this phenomenon may involve the MMP12-TNF-α pathway.

Introduction: Pulmonary emphysema is an aging-related disease. However, the mechanisms underlying this phenomenon still remain poorly unknown. P16Ink4 is a key factor implicated in aging-related diseases. Whether p16 is involved in elastase-induced emphysema in mice remains to be determined. Aim: To determine if p16 deletion protects against elastase-induced emphysema in mice. Methods: Wild-type (WT) and p16-/- mice were instilled with pancreatic porcine elastase and sacrificed three weeks or three months later to address the degree of emphysema (morphometric analysis), alveolar septal thickness, collagen deposition (sirius red) and myofibroblasts content (α smooth muscle actin immunostaining). Results: Three weeks after instillation, elastase induced airspace enlargement in the same way in WT and p16-/- mice. However, three months later, elastase-instilled WT mice showed airspace enlargement and, without modification of collagen deposition while elastase-instilled p16-/- mice have reduced airspace enlargement, and increased septal thickness with enhanced collagen deposition, and more myofibroblasts. Conclusions: p16-/- mice are not immediately but later protected against elastase-induced emphysema, and develop a concomitant alveolar fibrosis suggesting a process of repair partially defective.

Introduction: Air pollution (AP) represents the largest environmental risk for health. Such considerations however rely on the static quantification of only a few individual components of AP, without considering their interactions, chemical reactivity and synergistic toxicity. We therefore developed an innovative approach to analyze the health effects of “real life” model atmospheres at the preclinical level. Here, we report the first results of the feasibility study. Methods: A realistic atmosphere, representative of a 2017 pollution event in Paris, was generated (CESAM atmospheric simulation chamber - cesam.cnrs.fr). The chamber was connected to stalling cabinets where mice were exposed during 6 or 48 hours. Lungs, spleen, adipose tissue, heart, mesenteric ganglions were then harvested to address the expression of detoxification and antioxidant genes, as well as total cell count (TCC) and inflammatory cytokines expression in BAL fluid Results: The atmosphere contained 57.3 µg/m3 particulate matter, 114±11 ppb NO2 and 242±101 ppb O3. No mortality and no weight loss was observed. Increased expression of Ahr, Cyp1a1, Hmox1 and NQO1 was detected in the lungs, and increased TCC and KC concentrations in the BAL. Interestingly, we found extra pulmonary modifications; increased expression of Ahr, Cyp1a1, Hmox1 and NQO1 in the spleen, Hmox1, Cyp1a1 and Cyp1b1 in ganglions, and Hmox1 in the adipose tissue and heart. Limited modifications were detected after 6h. Conclusion: These preliminary results demonstrate the feasibility of our innovative experimental approach, which represents a versatile tool to get a better understanding of AP impacts on health.

We hypothesized that O2 tension influences the redox state and the immunomodulatory responses of inflammatory cells to dimethyl fumarate (DMF), an activator of the nuclear factor Nrf2 that controls antioxidant genes expression. This concept was investigated in macrophages permanently cultured at either physiological (5% O2) or atmospheric (20% O2) oxygen levels and then treated with DMF or challenged with lipopolysaccharide (LPS) to induce inflammation. RAW 264.7 macrophages cultured at 20% O2 exhibited a pro-oxidant phenotype, reflected by a lower content of reduced glutathione, higher oxidized glutathione and increased production of reactive oxygen species when compared to macrophages continuously grown at 5% O2. At 20% O2, DMF induced a stronger antioxidant response compared to 5% O2 as evidenced by a higher expression of heme oxygenase-1, NAD(P)H:quinone oxydoreductase-1 and superoxide dismutase-2. After challenge of macrophages with LPS, several pro-inflammatory (iNOS, TNF-α, MMP-2, MMP-9), anti-inflammatory (arginase-1, IL-10) and pro-angiogenic (VEGF-A) mediators were evaluated in the presence or absence of DMF. All markers, with few interesting exceptions, were significantly reduced at 5% O2. This study brings new insights on the effects of O2 in the cellular adaptation to oxidative and inflammatory stimuli and highlights the importance of characterizing the effects of chemicals and drugs at physiologically relevant O2 tension. Our results demonstrate that the common practice of culturing cells at atmospheric O2 drives the endogenous cellular environment towards an oxidative stress phenotype, affecting inflammation and the expression of antioxidant pathways by exogenous modulators. J. Cell. Physiol. 230: 1128–1138, 2015. © 2014 Wiley Periodicals, Inc., A Wiley Company

Chronic obstructive pulmonary disease (COPD) is a highly prevalent and devastating condition for which no curative treatment is available. Exaggerated lung-cell senescence may contribute substantially to the pathogenesis of COPD. Here, we explored the potential role for the mTOR signaling pathway in cell senescence and lung alterations in COPD, using lung specimens and derived cultured cells from patients with COPD and from age- and sex-matched control smokers. Cell senescence in COPD was linked to mTOR activation, and mTOR inhibition by low-dose rapamycin prevented cell senescence and inhibited the pro-inflammatory senescence-associated secretory phenotype. To assess whether mTOR activation was causal in lung pathology, we generated mice with constitutive or conditional deletion of the tuberous sclerosis complex heterodimer TSC1 (a negative regulator of mTOR complex 1), in smooth muscle cells (SMCs), endothelial cells (ECs), or alveolar epithelial cells (AECs). In this model, mTOR activation was sufficient to induce early-onset replicative cell senescence in cultured pulmonary artery SMCs from mice with TSC1 deletion. Mice with conditional TSC1 deletion in ECs or AECs developed lung emphysema, pulmonary hypertension, and inflammation in the absence of any other stimuli and concomitantly with the accumulation of senescent lung cells. Rapamycin prevented all these effects. These results support causal links between mTOR activation, cell senescence, and lung alterations in COPD, thereby identifying the mTOR pathway as a new therapeutic target for COPD. Keywords: mTOR, senescence, COPD

Introduction: Bronchopulmonary dysplasia (BPD), characterized by airspace enlargement, develops in premature infants. BPD leads to persistent lung consequences in adulthood, being considered as an early determinant of adult lung diseases. P16Ink4 is a key factor implicated in aging-related lung diseases and its levels are increased in cord blood cells of preterm infants. Whether p16 is involved in BPD and its persistent consequences at the adult age remains to be determined. Aims: To determine in a mouse model of BPD: 1) if p16 deletion protects against lung alterations in new born and adult mice, and 2) if these effects are mediated by cellular senescence. Methods: Mouse pups were exposed to hyperoxia (85% O2) or room air from day 3 to 14 of life. Morphometry (mean linear intercept), elastin content (Weigert), collagen deposition (sirius red), cell senescence (βgalactosidase activity and p21) and cell proliferation (Ki67) were evaluated. Results: At day 14, hyperoxia induced airspace enlargement and cellular senescence, without modification of collagen deposition, nor cell proliferation. Hyperoxic p16-/- mice were not protected against alveolar disruption, but presented an increased alveolar wall thickness and cell proliferation. At day 60, hyperoxic mice showed persistence of airspace enlargement and senescence, without modification of collagen deposition, nor cellular proliferation. Hyperoxic p16-/- mice have reduced airspace enlargement, but increased collagen deposition, without modulation of senescence markers. Conclusions: P16 did not modulated hyperoxia-induced alveolar disruption at young age but could play a crucial role in BPD consequences in adults. This effect may be independent of cellular senescence.

Introduction La bronchopneumopathie chronique obstructive represente la 4e cause de mortalite dans le monde et ne dispose a ce jour d’aucun traitement curatif. L’emphyseme, qui en est une des composantes, resulte de la destruction progressive des septums inter-alveolaires, conduisant a une insuffisance respiratoire. Parmi les marqueurs de senescence, des etudes montrent une surexpression du suppresseur de tumeurs p16 Ink4a dans les poumons de patients ayant un emphyseme compare aux fumeurs ou non-fumeurs sains. D’autres etudes ont montre l’influence de p16 Ink4a sur l’adipogenese. L’objectif est de determiner si la deletion de p16 Ink4a previent le developpement d’un emphyseme pulmonaire induit par une instillation d’elastase a un temps precoce ou tardif ainsi que les mecanismes impliques, en particulier l’induction de la lipogenese et l’activation des lipofibroblastes. Methodes Des souris adultes p16 Ink4a ko et sauvages (WT) ont recu une instillation intratracheale de 2UI d’elastase porcine pancreatique. Les souris ont ete sacrifiees 21 jours ou 90 jours apres l’instillation pour quantification morphometrique de l’emphyseme, evaluation de la septation secondaire et analyse de l’expression des genes de l’adipogenese et des marqueurs de pneumocytes. Evaluation dans un second temps des remaniements de la matrice extracellulaire. Resultats A 21 jours, la deletion de p16 Ink4a n’influence pas le degre d’emphyseme mais entraine une proliferation des pneumocytes de types 2, atteste par qPCR ou immunohistochimie ainsi qu’une activation de la lipogenese par rapport aux souris WT. A 90 jours, les souris p16 Ink4a presentaient un emphyseme significativement moins severe, des marqueurs de proliferation de pneumocytes 2 mais pas d’activation de l’adipogenese. A ce temps tardif, apparaissaient chez les souris p16 Ink4a des remaniements fibrotiques. Conclusion La deletion de p16 Ink4a ne protege pas de l’emphyseme induit par l’elastase dans un premier temps mais est associee a une amelioration des lesions a un temps tardif. Cet effet sous-tend un processus de regeneration alveolaire avec un remaniement secondaire la matrice extracellulaire.

The biological mechanisms of aging, and more specifically cellular senescence, are increasingly a subject of research. Cellular senescence may be a common determinant of many age-related diseases, including some chronic lung diseases such as chronic obstructive pulmonary disease (COPD) or idiopathic pulmonary fibrosis. Many arguments suggest that these diseases are associated with premature senescence of lung cells, which may be involved in the pathophysiology of respiratory alterations. Furthermore, these diseases are associated with systemic manifestations, such as bone loss, muscle wasting and atherosclerosis, which impact on symptoms and prognosis. Whether these alterations are related to a common pathogenic mechanism or develop independently in patients with COPD remains an open question. In this review, we will focus on cellular senescence and COPD. Two concepts will be discussed: (1) the role of cell senescence in the pathophysiology of lung destruction, vascular remodeling and inflammation in COPD, (2) the possible link between the pulmonary and systemic manifestations of COPD which could reflect a general process of accelerated aging.

International audience; Exposure to titanium dioxide (TiO2) nanoparticles (NPs) is associated with lung remodeling, but the underlying mechanisms are unknown. Matrix metalloprotease (MMP)-1 is an important actor in matrix homeostasis and could therefore participate in TiO2 NP effects. Our aim was to evaluate the effects of TiO2 NPs on MMP-1 expression and activity in lung pulmonary fibroblasts and to understand the underlying mechanisms and assess the importance of the physicochemical characteristics of the particles in these effects. Human pulmonary fibroblasts (MRC-5 cell line and primary cells) were exposed to 10 or 100 μg/cm(2) TiO2 (two anatases, two anatase/rutile mix, one rutile NP, and one micrometric) and carbon black (CB) NPs for 6 to 48 hours. We examined cell viability, MMP-1 expression and activity, and the implication of oxidative stress, transforming growth factor (TGF)-β, extracellular MMP inducer, and IL-1β in MMP-1 expression. All TiO2 NPs induced MMP-1 (mRNA and protein expression), repression of procollagen-1, and α-actin expression, but only the two anatase/rutile mix induced MMP-1 activity. Micrometric TiO2 had smaller effects than TiO2 NPs, and CB NPs did not induce MMP-1. MMP-1 induction by TiO2 NPs was not related to TGF-β, oxidative stress, or EMPRIN expression but was related to IL-1β expression, which partly drives MMP-1 induction by two TiO2 NPs (one anatase/rutile mix and the rutile one). Taken together, our results show that TiO2 NPs are potent inducers and regulators of MMP-1 expression and activity, partly via an IL-1β-dependent mechanism. This may explain TiO2 lung remodeling effects.

International audience; Rationale: Sleep disorders may lead to stress-induced premature aging and telomere shortening.Objectives: To determine whether obstructive sleep apnea syndrome causing intermittent hypoxemic episodes was associated with telomere shortening independently from the comorbidities associated with this syndrome.Methods: We conducted a cross-sectional study in 161prospectivelly enrolled, untreated, middle-aged men free of known comorbidities related or unrelated to sleep apnea. Each participant underwent full standard overnight polysomnography. Patients with apnea sleep syndrome were naive to treatment.Measurements and main results: In univariate analysis, we found that telomere shortening was associated with older age, apnea-hypopnea index, oxygen desaturation index, waist circumference, and fat mass. After adjustment for age, only apnea-hypopnea index and oxygen desaturation index were significantly related to telomere shortening. The mean telomere length ratio was 0.70 ± 0.37 in the participants without sleep apnea, compared with 0.61 ± 0.22 and 0.53 ± 0.16 in those with mild to moderate and severe sleep apnea, respectively (P = 0.01). In multivariate analysis, we found that oxygen desaturation index was the only factor independently associated with telomere length. Arterial stiffness assessed by carotid-femoral pulse wave velocity correlated negatively with telomere length.Conclusions: Intermittent hypoxemia due to obstructive sleep apnea syndrome is a major contributor to telomere shortening in middle-aged men. Oxidative stress may explain this finding.

Several convergent destructive mechanisms such as oxidative stress, alveolar cell apoptosis, extracellular matrix proteolysis and chronic inflammation contribute to chronic obstructive pulmonary disease (COPD) development. Evidence suggests that oxidative stress contributes to the pathophysiology of COPD, particularly during exacerbations. Nuclear factor erythroid-2-related factor 2 (NRF2), a transcription factor expressed predominantly in epithelium and alveolar macrophages, has an essential protective role in the lungs through the activation of antioxidant response element-regulated antioxidant and cytoprotective genes. Animal models and human studies have identified NRF2 and several NRF2 target genes as a protective system against inflammation and oxidative stress from cigarette smoke, a major causative factor in COPD development. Hence, NRF2 targeting might provide clinical benefit by reducing both oxidative stress and inflammation in COPD.

Introduction La dysplasie bronchopulmonaire (DBP), caracterisee par un arret de l’alveolisation, se developpe chez les prematures et entraine des consequences pulmonaires durables. Le facteur de transcription p16Ink4 est implique dans le cycle cellulaire et son expression est augmentee dans les cellules progenitrices leucocytaires du sang de cordon des nouveau-nes prematures. Objectifs Determiner dans un modele murin de BPD, si la deletion de p16 favorise la regeneration pulmonaire chez les souris nouveau-nees, et protege contre les consequences pulmonaires a l’âge adulte. Methodes Des souris sauvages et p16−/− ont ete exposees a l’hyperoxie (85 % FiO2) ou a l’air ambiant du jour (j) 3 a 14. Les mesures suivantes ont ete realisees a j14, 16 et 60 et 120 : morphometrie, elastine (Weigert), collagene (rouge sirius), identification des lipofibroblastes (IHC : ADRP, lipidtox), etudes transcriptomique et lipidomique, voies du metabolisme lipidique LXR (par q PCR : SREBP, SCAP, ADRP). Puis des souris sauvages ont ete traitees quotidiennement a partir de j14 apres l’hyperoxie, par un activateur de la voie LXR, T0901317, ou la rosiglitazone activateur de PPARg. Resultats A j14, l’hyperoxie a provoque un arret de l’alveolisation et une augmentation des marqueurs de senescence et d’inflammation (avec polarisation des macrophages en M1). Les souris hyperoxiques p16−/− ne sont pas protegees contre cette hypoalveolarisation mais presentent moins d’inflammation (avec switch des macrophages de M1 a M2) par rapport aux souris sauvages. A l’âge adulte, la deletion de p16 permet une restauration de l’architecture pulmonaire, associee a une augmentation du nombre de lipofibroblastes (ADRP, lipidtox en IHC) et du metabolisme lipidique (expressions augmentees de SREBP, ADRP en qPCR, contenu augmente en lipides neutres). De la meme maniere, l’administration la rosiglitazone, et T0901317, a permis d’ameliorer significativement l’architecture pulmonaire. Conclusion La deletion de p16 limite les sequelles parenchymateuses de la DBP a l’âge adulte, via l’induction des lipofibroblastes, secondaire a l’activation de la voie LXR favorisant ainsi les processus de regeneration pulmonaire. L’activation de la voie LXR induit les memes benefices et pourrait ouvrir des perspectives therapeutiques dans la prise en charge de la DBP.

Les nanotechnologies produisent des matériaux à l’échelle du nanomètre appelés nanomatériaux. Les nanomatériaux ont des propriétés spécifiques, très intéressantes d’un point de vue industriel, ce qui explique leur production et leur utilisation croissantes dans des produits de consommation courante, et en particulier dans des produits d’hygiène personnelle. Cependant, des inquiétudes s’expriment concernant leur potentielle toxicité pour la santé humaine. Dans cet article, nous proposons une synthèse des connaissances actuelles concernant les effets des nanomatériaux sur la santé. Devant le champ quasi-vierge de ces connaissances, il apparaît urgent, d’une part, de développer les recherches en toxicologie sur ces nouveaux matériaux et, d’autre part, de disposer d’informations de la part des producteurs de nanomatériaux pour pouvoir mesurer les niveaux d’exposition des personnes qui les manipulent. Ceci est un préalable à la mise en place de mesures de précaution sanitaire appropriées, si cela s’avère nécessaire.

Here, we review several articles of original research published in 2008 that concerned the toxicity of metal and carbon-based nanoparticles. Articles were selected from the MEDLINE PubMed database, all published or pre-published during 2008 and relating to nanomaterials, -particles or -structures and toxicity or health. From the 746 articles, we concentrated on research into carbonaceous (carbon nanotubes [CNTs] and fullerenes) and metallic materials (pure metal, oxides), because these nanomaterials are produced and used worldwide and are the most relevant for public health. Unfortunately, due to the large variability in materials used and methods used conflicting data are generated hampering the risk assessment.

Tobacco may be involved in the decreased macrophage heme oxygenase-1 (HO-1) expression described in smoking-induced severe emphysema, via the nuclear factor erythroid 2-related factor 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1)–BTB and CNC homology 1, basic leucine zipper transcription factor 1 (Bach1) pathway. We assessed in vitro effects of cigarette smoke condensate (CS) in the human monocyte/macrophage cell line (THP-1). CS exposure led to increased HO-1 and nuclear Nrf2 expression (6h) followed by decreased HO-1 expression concomitantly with nuclear Nrf2/Bach1 ratio decrease (72h). CS-induced mitogen-activated protein kinase (MAPK) phosphorylation. Extracellular-signal-regulated kinase1/2 (ERK1/2) and c-Jun NH2-terminal kinase (JNK) inhibition completely abrogated CS effects on HO-1 expression and nuclear Nrf2/Bach1 translocation. These results suggest that ERK1/2 and JNK are involved in CS-induced biphasic HO-1 expression by a specific regulation of Nrf2/Keap1–Bach1.

Les nanotechnologies sont definies comme l’ensemble des techniques visant a concevoir, caracteriser et produire des materiaux a l’echelle du nanometre dans au moins une de leurs dimensions. Ces nanomateriaux sont eux-memes constitues de nano-objets (nanoparticules, nanotubes…). Leur dimension nanometrique leur confere, du fait des lois de la physique quantique, de nouvelles proprietes physicochimiques et des comportements inedits. Les applications des nanotechnologies sont multiples (cosmetologie, industrie, medecine…). La production et l’utilisation des nanomateriaux connaissent une croissance importante. Cependant, des inquietudes sont emises sur les effets potentiels des nanoparticules sur la sante, a court et a long terme. Ces questions sont motivees par la connaissance des effets toxiques sur la sante des particules micrometriques de la pollution atmospherique et par la crainte de voir ces effets s’amplifier du fait de la nanodimension de ces materiaux. Dans cet article, est proposee une synthese globale mais non exhaustive des connaissances actuelles concernant la penetration, la deposition, la translocation et l’elimination dans l’appareil respiratoire, ainsi que les effets respiratoires des nanoparticules metalliques (plus particulierement du dioxyde de titane) et des nanotubes de carbone. L’ensemble des etudes experimentales in vivo et in vitro actuellement disponibles met en evidence l’existence d’effets biologiques des nanoparticules sur l’appareil respiratoire avec, notamment, la generation de stress oxydant, un effet pro-inflammatoire, un effet prothrombotique, la possibilite de survenue de fibrose et d’emphyseme pulmonaire ou de dommages a l’ADN. Une meilleure connaissance des effets biologiques potentiels des nanoparticules est requise, afin de mettre en place des mesures de prevention appropriees en milieu de travail et/ou en population generale, si cela s’averait necessaire.

Telomere length is considered a marker for biological aging. Chronic obstructive pulmonary disease (COPD) may be associated with premature aging.To test the hypothesis that patients with COPD experience accelerated telomere shortening and that inflammation is linked to this process.We measured telomere length, using a quantitative polymerase chain reaction-based method, and plasma levels of various cytokines in 136 patients with COPD, 113 age- and sex-matched smokers, and 42 nonsmokers with normal lung function.Median (range) telomere length ratio was significantly lower in patients with COPD (0.57 [0.23-1.18]) than in control smokers (0.79 [0.34-1.58]) or nonsmokers (0.85 [0.38-1.55]) (P0.001). The difference remained highly significant when using logistic regression analysis adjusted for age, sex, and tobacco exposure. Both females and males with COPD had shorter telomere length than same-sex control subjects. Telomere length was related to age in patients and control subjects but was shorter in patients than in control subjects in all age groups. No relationship was found between telomere length and tobacco exposure in patients or control subjects, with no difference between control smokers and nonsmokers. In patients with COPD, telomere length was related to PaO2 (P0.001) and PaCO2 (P0.001) but not to lung function parameters or the BODE Index. Patients with COPD also had elevated plasma levels of various cytokines, interleukin-6 correlating negatively with telomere length (P0.001).Given that in vivo telomere length reflects cellular turnover and exposure to oxidative and inflammatory damage, our data support accelerated aging in COPD.

The search for new molecules to fight Pseudomonas aeruginosa is of paramount importance. Carbon monoxide (CO) is known to act as an effective inhibitor of the respiratory chain in P. aeruginosa, but the practical use of this gas as an antibacterial molecule is hampered by its toxicity and difficulty to manipulate. Here, we show that a water-soluble CO releaser (CORM-3) possesses bactericidal properties against laboratory and antibiotic-resistant P. aeruginosa. CORM-3 reduced the bacterial count by 4 logs 180 min after in vitro treatment. CORM-3-treated bacteria had a lower O(2) consumption than vehicle-treated bacteria, and the decrease in O(2) consumption temporally preceded the bactericidal action of CORM-3. These results support the hypothesis that the antimicrobial effect of CORM-3 is mediated by an interaction of CO liberated by the carrier with the bacterial respiratory chain. The antibacterial effect occurred at concentrations of CORM-3 that are 50-fold lower than toxic concentrations for eukaryotic cells. CORM-3 treatment compared to vehicle treatment decreased bacterial counts in the spleen and increased survival in immunocompetent and immunosuppressed mice following P. aeruginosa bacteremia. Our results suggest that CORMs could form the basis for developing a new therapeutic strategy against P. aeruginosa-induced infection.

Introduction Le deficit en alpha-1 antitrypsine est associe a un risque accru d’emphyseme pulmonaire. L’objectif de cette etude est de decrire les caracteristiques des patients emphysemateux deficitaires. Methodes Etude de cohorte prospective multicentrique. Criteres d’inclusion : patients adultes, presentant un emphyseme identifie au scanner, deficitaires en alpha-1 antitrypsine et suivis en France. Les caracteristiques cliniques, fonctionnelles, la qualite de vie et les modalites therapeutiques sont recueillies tous les 6 mois pendant 5 ans. Resultats Deux cent un patients ont ete recenses par 56 centres entre 2005 et 2008. Les caracteristiques a l’inclusion des 110 premiers patients ont ete analysees. L’âge moyen etait de 50 ans (DS : 11,8), 62,7 % etaient des hommes, 90 % etaient fumeurs. Caracteristiques fonctionnelles (% theo.) : VEMS : 42,8 (19,6), CPT : 128,3 (21,7), CRF : 167,0 (46,0), test de marche de 6 minutes (metres) : 413 (130). 51 (46,4 %) patients recevaient un traitement substitutif ; le mode d’administration etait hebdomadaire (37,5 %), bimensuel (35,4 %) ou mensuel (25,5 %). Le seul facteur associe a la probabilite d’etre traite etait le centre de suivi du patient. Conclusion Cette etude revele les grandes disparites de presentation clinique et de prise en charge des patients emphysemateux deficitaires en alpha-1 antitrypsine et souligne la necessite d’une homogeneisation des pratiques.

Background: Oxidative stress, resulting from the increased oxidative burden and decreased level of antioxidant proteins, plays a role in the pathophysiology of smoking-related pulmonary emphysema. Expression of several antioxidant proteins, such as heme oxygenase-1 (HO-1), glutathione peroxidase 2 (GPX2) and NAD(P)H:quinone oxidoreductase 1 (NQO1), results from an equilibrium created by positive or negative regulation by the transcription factors Nrf2, Keap1 and Bach1, respectively. However, whether the expression of these transcription factors is altered in emphysema and could account for decreased expression of antioxidant proteins is not known. A study was undertaken to investigate the expression and subcellular localisation of Nrf2, Keap1 and Bach1 as potential regulators of HO-1, GPX2 and NQO1 in alveolar macrophages, a key cell in oxidative stress, in lung surgical specimens from non-smokers without emphysema and smokers with and without emphysema. Methods and results: Western blot, immunohistochemical and laser scanning confocal analysis revealed that the Nrf2 protein level decreased significantly in whole lung tissue and alveolar macrophages (cytosol and nucleus) in patients with emphysema compared with those without emphysema. Conversely, Bach1 and Keap1 levels were increased in patients with emphysema. These modifications were associated with a parallel decrease in the expression of HO-1, GPX2 and NQO1 at the cellular level, which was inversely correlated with airway obstruction and distension indexes, and increased macrophage expression of the lipid peroxidation product 4-hydroxy-2-nonenal. Silencing RNA experiments in vitro in THP-1 cells were performed to confirm the cause-effect relation between the loss of Nrf2 and the decrease in HO-1, NQO1 and GPX2 expression. Nrf2/Keap1-Bach1 equilibrium was altered in alveolar macrophages in pulmonary emphysema, which points to a decreased stress response phenotype. Conclusions: This finding opens a new view of the pathophysiology of emphysema and could provide the basis for new therapeutic approaches based on preservation and/or restoration of such equilibrium.

The use and commercial potential of engineered nanomaterials is increasing, but questions of occupational and public health safety remain. Here, we review research published in 2007 concerning toxicology of nanomaterials. Articles were selected from the Medline Pubmed database, published or pre-published during 2007, using keywords (nanomaterials or nanoparticles or nanostructures) and (toxicity or health). From the 238 articles, we chose to concentrate mainly on research into carbonaceous (carbon nanotubes [CNTs] and fullerenes) and metallic materials (pure metal, oxides), because of their relevance. The induction of oxidative stress was repeatedly reported, and new information on the movement of nanomaterials through membranes was publicized. Concerning CNTs, information was revealed on DNA damage in vitro and pulmonary and systemic in vivo effects. Several of the reports failed to follow recent expert recommendations concerning good practice for nanotoxicologic research, complicating the integration of...

The toxic effect of high concentrations of CO gas in living organisms is coherently typified at biochemical levels by the high affinity of CO for hemoglobin and cytochromes, heme-dependent proteins that are indispensable for oxygen transport and mitochondrial respiration. However, the basal production of CO during heme degradation and the ability of heme oxygenase-1 (HO-1) to increase CO availability pose the question of how this gaseous molecule interacts with metal centers within the intracellular milieu to serve as one of the most unconventional signaling mediators. Emerging evidence indicates that the diverse and multifaceted beneficial effects exerted by "low concentrations" of CO cannot be explained solely by the activation of classic prototypic targets (i.e., guanylate cyclase/potassium channels) but entails the dynamic and concerted activation/inhibition of a group of CO-responsive proteins. As the complexity of the temporal and spatial action of CO is progressively being appreciated, this review aims to (a) highlight the current knowledge on certain metal-containing proteins that interact directly with CO; (b) analyze the latest notions on their functional role in response to CO; and finally (c) propose a rational view on the mode these CO targets may interrelate with and be regulated by the HO/CO pathway.

Oxidative stress is thought to play a major role in the pathogenesis of chronic obstructive pulmonary disease, characterized by impaired lung function. A large number (> or =33) of GT repeats (L-allele) in the gene of the powerful antioxidant enzyme heme oxygenase-1 has been associated with susceptibility to accelerated lung function decline. In contrast, beta-carotene may help to protect against accelerated decline. To determine whether high serum levels of beta-carotene might counterbalance the greater susceptibility of L-allele carriers, the authors analyzed the annual decline in forced expiratory volume in 1 second (FEV1) in a general population sample of 523 French subjects (20-44 years, 50% men) examined in 1992 and 2000 as part of the European Community Respiratory Health Survey. Analysis of covariance, adjusted for sex as well as baseline age, body mass index, smoking, and FEV1, showed that, among subjects with low beta-carotene levels, L-allele carriers experienced a steeper mean FEV1 decline than did noncarriers (mean = -58.8, 95% confidence interval: -73.2, -44.5 vs. mean = -34.7, 95% confidence interval: -38.9, -29.8 ml/year) (p = 0.009), whereas among subjects with high beta-carotene levels, the FEV1 decline was not different in L-allele carriers and noncarriers (two-sided p = 0.9). The results suggest that high levels of beta-carotene might counterbalance the effects on FEV1 decline of a genetically determined deficiency in antioxidant response.

Carbon nanotubes (CNTs) are cylinders of one or several coaxial graphite layer(s) (single-walled [SW]CNTs or multiwalled [MW]CNTs, respectively) with a catalytic material (iron, nickel or cobalt) often present inside and/or at their extremity, as well as variable amounts of inert synthesis support, depending on the synthesis method [1]. Their diameter is in the order of nanometers (depending on the number of walls) and they can reach several micrometers in length. Owing to their unique electrical properties, unusual strength and particular effectiveness in heat conduction [2], CNTs are particularly promising nanomaterials for industrial use (see [101] for inventory) and, therefore, one can easily imagine that their production will continue to increase in the future. However, the same novel properties that make CNTs interesting raise concerns about their potential adverse effects on biological systems, which could lead to health issues, particularly when thinking of their potential use in the medical field.

Chronic exposure to particulate air pollution is associated with lung function impairment. To determine the molecular mechanism(s) of this phenomenon, we investigated, in an alveolar human epithelial cell line (A549), whether diesel exhaust particles (DEPs), a main component of particulate air pollution, modulates the expression and activity of the matrix metalloprotease (MMP)-1, a collagenase involved in alveolar wall degradation. Interaction of DEPs with cigarette smoke, which also produces structural and functional lung alterations, was also investigated. A noncytotoxic concentration of DEPs induced an increase in MMP-1 mRNA and protein expression and activity in A549 cells without modifying the expression of the MMP inhibitors TIMP-1 and -2. This effect was not potentiated when cells were coexposed to noncytotoxic concentrations of cigarette smoke condensate. DEP-induced MMP-1 was associated with increased ERK 1/2 phosphorylation and upregulation of expression and activity of the NADPH oxidase analog NOX4. Cell transfection with a NOX4 small interfering RNA prevented these phenomena, showing the critical role of a NOX4 ERK 1/2 pathway in DEP-induced MMP-1 expression and activity. Similar results to those observed in A549 cells were obtained in another human lung epithelial cell line, NCI-H292. Furthermore, experiments in mice intratracheally instilled with DEPs confirmed the in vitro findings, showing the induction of NOX4 and MMP-1 protein expression in alveolar epithelial cells. We conclude that alveolar alterations secondary to MMP-1 induction could explain lung function impairment associated with exposure to particulate pollution.

Objective To determine the consequences of pharmacologic up-regulation of heme oxygenase 1 (HO-1), and inhibition of HO-1 by injection of an anti–HO-1 small interfering RNA (siRNA), in vivo in the acute phase of a mouse model of nonautoimmune arthritis. Methods In the K/BxN mouse serum transfer model, which mimics human inflammatory arthritis without lymphocyte influence, HO-1 was up-regulated by intraperitoneal injection of cobalt protoporphyrin IX (CoPP), a potent pharmacologic inducer, and was inhibited using a specific siRNA. The clinical progress of arthritis was monitored by measurement of paw thickness. Interleukin-1β (IL-1β), IL-6, tumor necrosis factor α (TNFα), serum antioxidant, and nitric oxide (NO) levels, prostaglandin E2 (PGE2) production, and matrix metalloproteinase 9 (MMP-9) activity were measured in serum. At the end of the experiments, joints were examined for immunohistopathologic changes. Results Intraperitoneal injection of CoPP alleviated disease symptoms, such as joint swelling, cartilage degradation, and proliferation of inflammatory tissue in joints, in the acute phase of inflammatory arthritis. The CoPP-induced expression of HO-1 in the joints and liver was associated with marked decreases in IL-1β, IL-6, and TNFα levels, PGE2 secretion, and MMP-9 activity in serum, and with a marked increase in systemic antioxidant activity. In contrast, NO production in serum and inducible NO synthase expression in chondrocytes were not affected by HO-1 induction. Specific inhibition of HO-1 by in vivo delivery of anti–HO-1 siRNA repressed the protective effects. Conclusion Our data provide the first evidence that pharmacologically induced up-regulation of HO-1 triggers a robust protective antiinflammatory response in a model of nonautoimmune arthritis in mice. This suggests that exogenously induced HO-1 may have potential as therapy in the acute phase of inflammatory arthritis in humans.

Nanotechnologies, defined as techniques aimed to conceive, characterize and produce material at the nanometer scale, represent a fully expanding domain, and one can predict without risk that production and utilization of nanomaterials will increase exponentially in the coming years. Applications of nanotechnologies are numerous, in constant development, and their potential use in the medical field as diagnosis and therapeutics tools is very attractive. The size particularity of these nanomaterials gives them novel properties, allowing them to adopt new comportments because of the laws of quantum physics that exist at this scale. However, worries are expressed regarding the exact properties that make these nanomaterials attractive, and questions are raised regarding their potential toxicity, their long-term secondary effects or their biodegradability, particularly when thinking of their use in the (nano)medical field. These questions are justified by the knowledge of the toxic effects of atmospheric pollution micrometric particles on health, and the fear to get an amplification of these effects because of the size of the materials blamed. In this paper, we first expose the sensed medical applications of nanomaterials, and the physicochemical and molecular determinants potentially responsible for nanomaterials biological effects. Finally, we present a synthesis of the actual knowledge regarding toxicological effects of nanomaterials. It is clear that, in regard to the almost empty field of what is known on the subject, there's an urge to better understand biological effects of nanomaterials, which will allow their safe use, in particular in the nanomedicine field.

RESUME Les oxydants pourraient etre impliques dans la Physiopathologie de la BPCO (Broncho-Pneumopathie Chronique Obstructive), definie par une diminution des debits aeriens progressive et incompletement reversible. L’HO-1 (heme oxygenase-1 ) est un antioxydant puissant. Il a ete montre qu’un polymorphisme microsatellite du promoteur du gene de l’HO-1 (repetition de paires de bases (GT)) etait capable de moduler la transcription du gene en reponse au stress oxydant. Un promoteur long serait associe a une expression de la proteine HO-1 moindre. Nous avons emis l’hypothese que ce polymorphisme pourrait etre associe au declin de la fonction pulmonaire chez des sujets exposes a une agression oxydante importante comme les fumeurs. Pour tester cette hypothese, nous avons genotype 749 sujets (âges de 20 a 44 ans, 50 % d’hommes et 40 % de non-fumeurs) examines en 1992 et en 2000 dans le cadre du recueil des donnees francaises de l’etude ECRHS. Nous avons compare les porteurs d’allele long (L) ((GT)n ≥ 33 repetitions sur un ou deux allele (s)) aux autres. En longitudinal, nous avons observe que le declin de la fonction pulmonaire etait accelere chez les porteurs de l’allele L par rapport aux autres. En outre, il y avait une interaction entre l’allele L et le tabagisme : le declin de la fonction pulmonaire etait accelere dans le groupe des gros fumeurs porteurs de l’allele L par rapport aux gros fumeurs non-porteurs de l’allele L et aux porteurs de l’allele L non-gros fumeurs. Nos resultats suggerent donc qu’un promoteur long du gene de l’HO-1 serait associe, chez les gros fumeurs, au developpement d’un trouble ventilatoire obstructif.

In the United States sepsis annually affects 700,000 people and accounts for about 210,000 deaths. Respiratory failure has long been known to be a frequent occurrence of this pathological condition and to represent a major contributor to the high associated mortality [1]. This contribution discusses of the effects of sepsis and septic shock on respiratory muscle function and focuses on some of the possible mechanisms involved in the genesis of these effects.

Heme oxygenase (HO), the heme-degrading enzyme, has shown anti-inflammatory effects in several models of pulmonary diseases. HO is induced in airways during asthma; however, its functional role is unclear. Therefore, we evaluated the role of HO on airway inflammation [evaluated by bronchoalveolar lavage (BAL) cellularity and BAL levels of eotaxin, PGE2, and proteins], mucus secretion (evaluated by analysis of MUC5AC gene expression and periodic acid-Schiff staining), oxidative stress (evaluated by quantification of 4-hydroxynonenal adducts and carbonylated protein levels in lung homogenates), and airway responsiveness to histamine in ovalbumin (OVA)-sensitized and multiple aerosol OVA or saline-challenged guinea pigs (6 challenges, once daily, OVA group and control group, respectively). Airway inflammation, mucus secretion, oxidative stress, and responsiveness were significantly increased in the OVA group compared with the control group. HO upregulation by repeated administrations of hemin (50 mg/kg ip) significantly decreased airway responsiveness in control animals and airway inflammation, mucus secretion, oxidative stress, and responsiveness in OVA animals. These effects were reversed by the concomitant administration of the HO inhibitor tin protoporphyrin-IX (50 μmol/kg ip). Repeated administrations of tin protoporphyrin-IX alone significantly increased airway responsiveness in control animals but did not modify airway inflammation, mucus secretion, oxidative stress, and responsiveness in OVA animals. These results suggest that upregulation of the HO pathway has a significant protective effect against airway inflammation, mucus hypersecretion, oxidative stress, and hyperresponsiveness in a model of allergic asthma in guinea pigs.

Contexte La biometrologie des particules minerales non fibreuses (PMNF) est un ensemble de techniques permettant d’evaluer le niveau de retention en PMNF dans differents milieux biologiques. Ces analyses aident a l’identification d’expositions professionnelles ou environnementales a rapprocher de diverses maladies, notamment respiratoires. Leur interpretation necessite de connaitre le profil de retention pulmonaire dans des series de patients indemnes d’exposition significative (temoins). Objectif L’objectif de cette etude est d’evaluer l’evolution du niveau de retention pulmonaire en PMNF et de valider l’hypothese d’une augmentation sur une periode de 20 ans, du niveau de retention en particules de titane dans 2 series de patients non exposes professionnellement a ces PMNF. Patients et methodes Deux series de patients atteints de cancer broncho-pulmonaire ont ete recrutees a partir de services de pneumologie : serie 1 (entre 1994 et 1999, n = 33, âge moyen : 58,7 ans, tous fumeurs) et serie 2 (entre 2009 et 2014, n = 36, âge moyen : 63,2 ans, 31 fumeurs). L’analyse detaillee de l’interrogatoire professionnel par des experts en pathologie professionnelle ne retrouvait pas d’exposition a des PMNF. Les echantillons de parenchyme pulmonaire preleves lors de l’intervention d’exerese pulmonaire ont ete analyses en microscopie electronique a transmission couplee a un dispositif d’analyse chimique elementaire, afin d’identifier et de quantifier les PMNF mesurant au moins 0,1 μm. Resultats Il a ete observe une augmentation de la retention pulmonaire pour la totalite des PMNF entre les series 1 et 2. L’element le plus notable etait l’augmentation du niveau de retention en particules de titane (mediane : 5 × 107 et 8,8 × 107 p/g, pour les series 1 et 2, respectivement ; p = 0,005). Au sein de la serie 2, il n’y avait pas d’influence du sexe, de l’âge, du tabagisme ou du mode de recueil des echantillons (paraffine/formaldehyde) sur le resultat de la mesure de concentration des particules de titane. Discussion-Conclusion Ces resultats, obtenus sur des series importantes comparativement aux donnees de la litterature, confirment l’hypothese d’une augmentation du niveau de retention pulmonaire en particules de titane entre 1994–1999 et 2009–2014 chez des personnes sans exposition professionnelle specifique identifiee a des PMNF. Il apparait important de documenter les sources d’expositions potentielles responsables de cette augmentation. La prise en compte du resultat de populations « temoins » est essentielle a l’interpretation des resultats biometrologiques chez les patients atteints d’une pathologie respiratoire pour laquelle le role d’une exposition professionnelle a des particules minerales est suspecte.