Search

Whether the systemic manifestations observed in Chronic Obstructive Pulmonary Disease (COPD) are ascribable to lung dysfunction or direct effects of smoking is in debate. Structural Equations Modeling (SEM), a causal-oriented statistical approach, could help unraveling the pathways involved, by enabling estimation of direct and indirect associations between variables. The objectives of the study was to investigate the relative impact of smoking and COPD on systemic manifestations, inflammation and telomere length. In 292 individuals (103 women; 97 smokers with COPD, 96 smokers without COPD, 99 non-smokers), we used SEM to explore the pathways between smoking (pack-years), lung disease (FEV1, KCO), and the following parameters: arterial stiffness (aortic pulse wave velocity, PWV), bone mineral density (BMD), appendicular skeletal muscle mass (ASMM), grip strength, insulin resistance (HOMA-IR), creatinine clearance (eGFR), blood leukocyte telomere length and inflammatory markers (Luminex assay). All models were adjusted on age and gender. Latent variables were created for systemic inflammation (inflammatory markers) and musculoskeletal parameters (ASMM, grip strength, BMD). SEM showed that most effects of smoking were indirectly mediated by lung dysfunction: e.g. via FEV1 on musculoskeletal factor, eGFR, HOMA-IR, PWV, telomere length, CRP, white blood cells count (WBC) and inflammation factor, and via KCO on musculoskeletal factor, eGFR and PWV. Direct effects of smoking were limited to CRP and WBC. Models had excellent fit. In conclusion, SEM highlighted the major role of COPD in the occurrence of systemic manifestations while smoking effects were mostly mediated by lung function.

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.

Chronic obstructive pulmonary disease, a disease of increasing incidence, is related mainly to smoking. Although symptoms only appear at adulthood, the disease can develop from early life events. For example, bronchopulmonary dysplasia, which occurs in preterm infants, is characterized by airspace enlargement and could lead to late lung consequences. Once the lesions are established, no curative treatment is available. Stimulating lung regeneration from endogenous stem cells is therefore an exciting research domain, particularly through the activation of the mesenchymal contingent located in the lung stem cell niche., La bronchopneumopathie chronique obstructive, affection d’incidence croissante, est liée principalement au tabagisme. Bien que les symptômes n’apparaissent qu’à l’âge adulte, la maladie peut se développer à partir d’événements précoces de la vie. La dysplasie bronchopulmonaire, par exemple, survenant chez le nouveau-né prématuré, est caractérisée par un élargissement des espaces aériens et peut avoir des conséquences pulmonaires tardives. Une fois les lésions établies, aucun traitement curatif n’est disponible. Stimuler la régénération pulmonaire à partir de cellules souches endogènes est donc une perspective de recherche séduisante, notamment par le biais de l’activation du contingent mésenchymateux présent dans la niche des cellules souches pulmonaires.

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.

Obese patients could be more susceptible to mechanical ventilation (MV)-induced lung injury than non-obese patients due to weight-dependent changes in lung properties. The aim of this study was therefore to evaluate the pulmonary effects of 2 hours low VT MV in a diet-induced obese mice model, with VT calculated on either the actual body weight (VTaw) or the ideal body weight (VTiw) . First, we hypothesized that a MV with VTaw would be associated with altered lung mechanics and an increased lung inflammation. Second, we hypothesised that a MV with a VTiw would preserve lung mechanics and limit lung inflammation. We analyzed lung mechanics and inflammation using bronchoalveolar lavage (BAL) cell counts, flow cytometry tissue analysis and histology. Lung mechanics and inflammation were comparable in control and obese mice receiving VTiw. By contrast, obese mice receiving VTaw had significantly more alterations in lung mechanics, BAL cellularity and lung influx of monocytes as compared to control mice. Their monocyte expression of Gr1 and CD62L was also increased. Alveolar neutrophil infiltration was significantly increased in all obese mice as compared to controls. In conclusion, our findings suggest that protective MV with a VTaw is deleterious, with a marked alteration in lung mechanics and associated lung inflammation as compared to lean mice. With VTiw, lung mechanics and inflammation were close to that of control mice, except for an increased alveolar infiltrate of polymorphonuclear neutrophils. This inflammation might be attenuated by a blunted recruitment of inflammatory cells associated with obesity.

BackgroundAn excessive pulmonary inflammatory response could explain the poor prognosis of chronic obstructive pulmonary disease (COPD) patients submitted to invasive mechanical ventilation. The aim of this study was to evaluate the response to normal tidal volume (Vt) mechanical ventilation in a murine model of pulmonary emphysema, which represents the alveolar component of COPD. In this model, two time points associated with different levels of lung inflammation but similar lung destruction, were analyzed.MethodsC57BL/6 mice received a tracheal instillation of 5 IU of porcine pancreatic elastase (Elastase mice) or the same volume of saline (Saline mice). Fourteen (D14) and 21 (D21) days after instillation, mice were anesthetized, intubated, and either mechanically ventilated (MV) with a normal Vt (8 mL/kg) or maintained on spontaneous ventilation (SV) during two hours. We analyzed respiratory mechanics, emphysema degree (mean chord length by lung histological analysis), and lung inflammation (bronchoalveolar lavage (BAL) cellularity, proportion and activation of total lung inflammatory cells by flow cytometry).ResultsAs compared with Saline mice, Elastase mice showed a similarly increased mean chord length and pulmonary compliance at D14 and D21, while BAL cellularity was comparable between groups. Lung mechanics was similarly altered during mechanical ventilation in Elastase and Saline mice. Activated alveolar macrophages CD11bmid were present in lung parenchyma in both Elastase SV mice and Elastase MV mice at D14 but were absent at D21 and in Saline mice, indicating an inflammatory state with elastase at D14 only. At D14, Elastase MV mice showed a significant increase in percentage of neutrophils concomitant with a decrease in percentage of alveolar macrophages in total lung, as compared with Elastase SV mice. Furthermore, alveolar macrophages of Elastase MV mice at D14 overexpressed Gr1, and monocytes showed a trend to overexpression of CD62L, compared with Elastase SV mice.ConclusionsIn an elastase-induced model of pulmonary emphysema, normal Vt mechanical ventilation produced an increase in the proportion of pulmonary neutrophils, and an activation of alveolar macrophages and pulmonary monocytes. This response was observed only when the emphysema model showed an underlying inflammation (D14), reflected by the presence of activated alveolar macrophages CD11bmid.

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.

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.

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.

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.

Due to several commercial applications of manufactured nanoparticles (NPs), such as silver (Ag NPs), titanium dioxide (TiO2 NPs) and cerium dioxide (CeO2 NPs), knowledge of the toxicity of those NPs is of great importance. Many studies have linked exposure to fine and ultrafine particles (from air pollution) to an increase of morbidity or mortality due to various respiratory or cardiovascular diseases. Several works have focused on the effects of pulmonary exposure to manufactured NPs. It has been shown that exposure to NPs may lead to an inflammatory response, pulmonary fibrosis and emphysema. However, less is known on the effect of exposure to NPs on the offspring. It has been reported that exposure during pregnancy to TiO2 NPs and SiO2 NPs is associated with fetal hypertrophy, neurotoxicity, and exposure to carbon black NPs induced renal disease in the offspring. NPs may interfere with normal fetal lung development. In addition, a recent study reported that pulmonary exposure of newborn mice to TiO2 NPs was associated with pulmonary inflammation and impaired lung development. Therefore, the aim of this study is to assess the impact of exposure by the respiratory route to various NP during pregnancy on lung development of the offspring in a mouse model, and to determine the key parameters involved in lung alterations. For this study, we used three metal NPs: TiO2, Ag, and CeO2 with the same size and shape, to assess the impact of NPs physico-chemical properties in the potential effects on lung development. C57Bl6/J pregnant mice were exposed weekly to 100 μg NPs by nonsurgical intratracheal instillation. Analysis (biological, histological and functional) of the lungs of the offspring were made at different time of lung development: one day before delivery (18GD for gestational day), 14 days after birth (pulmonary alveolization) and 21 days after birth (lung maturity). Preliminary results show that the exposure to TiO2 NPs during pregnancy did not affect the number of fetuses per litter, or the weight of uterus and placenta. However, the weight of fetuses whose mothers were exposed to TiO2 NPs is significantly decreased. A decrease of VEGF-A gene expression, involved in lung development, was also observed at 18GD. These preliminary results suggest that exposure to TiO2 NPs during pregnancy could affect the development of the offspring. For the remainder of this work, pregnant mice will be exposed to other NPs (Ag and CeO2) in order to see if this effect depends on the type of NP. Moreover additional analyzes will be performed to confirm whether lung alterations are observed at later times after birth, and to understand the key parameters and mechanism associated with these changes.

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.

Nitric oxide (NO) has been implicated in the development of heart failure, although the source, significance, and functional role of the different NO synthase (NOS) isoforms in this pathology are controversial. The presence of a neuronal-type NOS isoform (NOS1) in the cardiac sarcoplasmic reticulum has been recently discovered, leading to the hypothesis that NOS1-derived NO may notably alter myocardial inotropy. However, the regulation and role(s) of NOS1 in cardiac diseases remain to be determined. Using an experimental model of myocardial infarction (MI) in senescent rats, we demonstrated a significant increase in cardiac NOS1 expression and activity in MI, coupled with the translocation of this enzyme to the sarcolemma through interactions with caveolin-3. The enhanced NOS1 activity counteracts the decrease in cardiac NOS3 expression and activity observed in heart failure. We demonstrated an increased interaction between NOS1 and its regulatory protein HSP90 in post-MI hearts, a potential mechanism for the higher NOS1 activity in this setting. Finally, preferential in vivo inhibition of NOS1 activity enhanced basal post-MI left ventricular dysfunction in senescent rats. These results provide the first evidence that increased NOS1-derived NO production may play a significant role in the autocrine regulation of myocardial contractility after MI in aging rats.

Rationale Chronic obstructive pulmonary disease (COPD) is often associated with age-related systemic abnormalities that adversely affect the prognosis. Whether these manifestations are linked to the lung alterations or are independent complications of smoking remains unclear. Objectives To look for aging-related systemic manifestations and telomere shortening in COPD patients and smokers with minor lung destruction responsible for a decline in the diffusing capacity for carbon monoxide (DLCO) corrected for alveolar volume (KCO). Methods Cross-sectional study in 301 individuals (100 with COPD, 100 smokers without COPD, and 101 nonsmokers without COPD). Measurements and Main Results Compared to control smokers, patients with COPD had higher aortic pulse-wave velocity (PWV), lower bone mineral density (BMD) and appendicular skeletal muscle mass index (ASMMI), and shorter telomere length (TL). Insulin resistance (HOMA-IR) and glomerular filtration rate (GFR) were similar between control smokers and COPD patients. Smokers did not differ from nonsmokers for any of these parameters. However, smokers with normal spirometry but low KCO had lower ASMMI values compared to those with normal KCO. Moreover, female smokers with low KCO, had lower BMD and shorter TL compared to those with normal KCO. Conclusions Aging-related abnormalities in patients with COPD are also found in smokers with minor lung dysfunction manifesting as a KCO decrease. Decreased KCO might be useful, particularly among women, for identifying smokers at high risk for aging-related systemic manifestations and telomere shortening.

Objective: To study the expression (mRNA and protein) and activity of the constitutive isoforms of nitric oxide synthase (NOS1 and NOS3) in a skeletal muscle of septic patients. Design: Prospective study. Setting: An adult trauma/surgical intensive care unit in an urban teaching hospital. Patients: Sixteen septic patients and 21 controls. Interventions: None. Measurements and Main Results: Samples of the rectus abdominis muscle were obtained during surgical procedure. NOS mRNA, protein, and activity were detected by reverse-transcriptase polymerase chain reaction, Western blot, and the conversion of [ 3H ]L-arginine to [ 3H ]L-citrulline, respectively. The main results of this study are as follows: a) Levels of NOS1 mRNA and protein were significantly higher than those of NOS3 in the rectus abdominis muscle of control patients; b) NOS1 expression was down-regulated in septic patients, whereas NOS3 was up-regulated; c) these modulations were associated with a reduction in constitutive NOS activity; and d) modifications of NOS1 and NOS3 protein expression were correlated significantly with the severity of sepsis, assessed by the Simplified Acute Physiology Score II. Conclusions: Sepsis induces reciprocal expressional modifications of NOS1 and NOS3 in human skeletal muscle, which decreases muscular constitutive NOS activity. These modifications may have implications for muscle impairment in septic patients.

Skeletal muscle failure is a frequent manifestation of sepsis that affects prognosis and rehabilitation by impairing respiration and ambulation. Animal studies have shown that the inducible NO synthase (NOS2) is expressed in skeletal muscles during sepsis, likely affecting muscular function, by promoting the formation of the strong oxidant peroxynitrite. In contrast, whether human skeletal muscle expresses a functional NOS2 in similar conditions is unknown. We studied NOS2 expression (mRNA and protein) and activity and its role in contractile function in samples from rectus abdominis muscle obtained during surgical procedure in 16 septic patients and in 21 controls. Peroxynitrite formation was detected by immunohistochemical detection of nitrotyrosine residues. The main results of this study are as follows: (1) A significant increase in NOS2 mRNA, protein, and activity was found in muscles from septic patients, the expression of NOS2 protein positively correlating with sepsis severity. (2) Contractile force was significantly lower in septic than in control muscles. This phenomenon was not reverted by muscle incubation ex vivo with the NOS inhibitor L-NMMA, indicating that NO was not involved in force reduction at the time of biopsy. (3) NOS2 expression in skeletal myocytes was strongly co-localized with nitrotyrosine, revealing muscular peroxynitrite generation during the septic process, before the muscle was biopsied. Exposure of control muscles to an amount of peroxynitrite similar to that generated in septic muscles during the septic process resulted in a nonreversible reduction in force generation. These results suggest that NOS2 could be involved in the decreased muscular force of septic patients via the local generation of peroxynitrite.

1 We investigated by intravital microscopy in rats, the in vivo direct effects of theophylline on the diameters of second and third order diaphragm arterioles. 2 Theophylline (1–100 μm) dilated second and third order diaphragm arterioles significantly, and with an amplitude which was not statistically different from the one obtained with adenosine (1–100 μm). Enprofylline (1–100 μm), a theophylline analogue with poor adenosine-receptor antagonism but with similar or higher phosphodiesterases inhibition properties than theophylline, also dilated diaphragm arterioles, causing however, a significantly smaller dilatation than theophylline. 3 Neither the A1 adenosine receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine (CPX, 50 nm), nor the A2 adenosine receptor antagonist 3,7-dimethyl-1-proparglyxanthine (DMPX, 10 μm) reduced significantly theophylline-induced arteriolar dilatation. 4 Theophylline (100 nm) abolished adenosine-induced arteriolar dilatation. 5 The dilatation induced by theophylline was unchanged by the nitric oxide (NO) synthase inhibitor Nω-nitro-l-arginine (NNA, 300 μm). 6 Theophylline-induced arteriolar dilatation was abolished by the prostaglandin synthesis inhibitors mefenamic acid or indomethacin (20 μm). 7 These findings show that theophylline induced a significant dilatation of diaphragm arterioles via the release of prostaglandins. British Journal of Pharmacology (1998) 124, 1355–1362; doi:10.1038/sj.bjp.0701962

To evaluate the effect of systemic hypoxia on leukocyte-endothelium interactions in peripheral tissues, we studied by intravital microscopy leukocyte rolling velocity and adherence in venules of rat cremaster muscle. We examined the possible roles of changes in blood oxygenation, peripheral tissue oxygenation, changes in local shear rate, and the involvement of integrins. Six groups of rats submitted to either control normoxic conditions, or systemic hypoxia (PO2 = 51 mm Hg) associated with either low O2 tension of Krebs superfusing the muscle, high O2 tension of the Krebs superfusing the muscle, anti-lymphocyte function-associated antigen (LFA)-1beta antibody, pentoxifylline, or normoxic conditions associated with partial occlusion of the artery perfusing the muscle. We found that: (1) systemic moderate hypoxia resulting from purely respiratory disturbance even in the absence of local stop-flow phenomenon or circulatory shock can induce an increase in leukocyte adhesion and a decrease in leukocyte rolling velocity in the microcirculation of peripheral tissues; (2) to be present, this increase in leukocyte adhesion does not require tissue hypoxia of the peripheral tissue but the effect of systemic hypoxia on rolling velocity is prevented by tissue oxygenation; (3) this increase in leukocyte adhesion is mediated by CD11/CD18 integrins but is not due to changes in local shear rate.

1. We investigated, by intravital microscopy in rats, the role of the subtypes of adenosine receptors A1 (A1/AR) and A2 (A2AR) in mediating adenosine-induced vasodilatation of second and third order arterioles of the diaphragm. 2. Adenosine, and the A1AR selective agonists R(-)-N6-(2-phenylisopropyl)-adenosine (R-PIA) and N6-cyclo-pentyl-adenosine (CPA) induced a similar concentration-dependent dilatation of diaphragmatic arterioles. The non selective A2AR subtype agonist N6-[2-(3,5-dimethoxyphenyl)-2-(2-methylphenyl) ethyl]adenosine (DPMA) also dilated diaphragmatic arterioles but induced a significantly smaller dilatation than adenosine. By contrast the selective A(2a)AR subtype agonist 2-[p-(2-carboxyethyl)phenyl amino]-5'-N-ethyl carboxamido adenosine (CGS 21680) did not modify diaphragmatic arteriolar diameter. 3. The non selective adenosine receptor antagonist 1,3-dipropyl-8-p-sulphophenylxanthine (SPX, 100 microM) and the selective A1AR antagonist 8-cyclopentyl-1,3-dipropylxanthine (CPX, 50 nM) significantly attenuated adenosine-induced dilatation of diaphragmatic arterioles. By contrast, adenosine significantly dilated diaphragmatic arterioles in the presence of A2AR antagonist 3,7-dimethyl-1-propargylxanthine (DMPX, 10 microM). 4. The dilatation induced by adenosine was unchanged by the mast cell stabilizing agent sodium cromoglycate (cromolyn, 10 microM). 5. The nitric oxide (NO) synthase inhibitor N omega-nitro-L-arginine (L-NOARG, 300 microM) attenuated the dilatation induced by adenosine, and by the A1AR and A2AR agonists. 6. The ATP-dependent K+ channel blocker glibenclamide (3 microM) significantly attenuated diaphragmatic arteriolar dilatation induced by adenosine and by the A1AR agonists R-PIA and CPA. By contrast, glibenclamide did not significantly modify arteriolar dilatation induced by the A2AR agonist DPMA. 7. These findings suggest that adenosine-induced dilatation of diaphragmatic arterioles in the rat is predominantly mediated by the A1AR, via the release of NO and activation of the ATP-dependent K+ channels.

Objective— Carbon monoxide–releasing molecules (CORMs) represent a pharmacological alternative to CO gas inhalation. Here, we questioned whether CORM-3, a well-characterized water-soluble CORM, could prevent and reverse pulmonary hypertension (PH) in chronically hypoxic mice and in smooth muscle promoter 22 serotonin transporter mice overexpressing the serotonin transporter in smooth muscle cells (SMCs). Approach and Results— Treatment with CORM-3 (50 mg/kg per day once daily) for 3 weeks prevented PH, right ventricular hypertrophy, and distal pulmonary artery muscularization in mice exposed to chronic hypoxia and partially reversed PH in smooth muscle promoter 22 serotonin transporter mice by reducing Ki67 dividing pulmonary artery SMCs (PA-SMCs). In these models, CORM-3 markedly increased lung p21 mRNA and protein levels and p21-stained PA-SMCs. These effects contrasted with the transient pulmonary vasodilatation and rise in lung cGMP levels induced by a single injection of CORM-3 in mice exposed to acute hypoxia. Studies in cultured rat PA-SMCs revealed that the inhibitory effects of CORM-3 on cell growth were independent of cGMP formation but associated with increased p21 mRNA and protein levels. Protection against PH by CORM-3 required increased lung expression of p21, as indicated by the inability of CORM-3 to prevent chronic hypoxia-induced PH in p21-deficient mice and to alter the growth of PA-SMCs derived from p21-deficient mice. CORM-3–induced p21 overexpression was linked to p53 activation as assessed by the inability of CORM-3 to prevent PH and induce p21 expression in p53-deficient mice and in PA-SMCs derived from p53-deficient mice. Conclusions— CORM-3 inhibits pulmonary vascular remodeling via p21, which may represent a useful approach for treating PH.

The mucociliary system, consisting of mucus-secreting goblet cells and ciliated cells, generates a constant overturning layer of protective mucus that lines the airway epithelium. Mucus hypersecretion and the pathophysiological changes associated are hallmarks of many pulmonary diseases including asthma, chronic obstructive pulmonary disease, and cystic fibrosis. Excessive mucus production leads to airway obstruction and, because there is currently no effective treatment, contributes to morbidity and mortality of many patients. Goblet cell differentiation and mucus production are subject to extensive control. An emerging concept is that not all goblet cells are phenotypically identical suggesting that specific molecular pathways orchestrate mucin overproduction. This paper attempts to describe the cellular and molecular mechanisms governing the differentiation of goblet cells in pulmonary diseases, a prerequisite for the development of new therapeutic agents.

We investigated the effects of nitric oxide (NO) synthesis inhibition on mortality rate and TNF alpha serum levels in rats inoculated with E. Coli endotoxin (30 mg/kg i.v.) Pre-treatment of endotoxemic rats with NG-monomethyl-L-arginine (L-NMMA), an inhibitor of NO synthesis by both the constitutive and the inducible isoforms of the NO synthase, did not change the mortality rate but significantly reduced TNF alpha serum levels. By contrast, administration of aminoguanidine, a more specific inhibitor of the inducible NO synthase, did not modify serum TNF alpha. These results suggest that, in E. Coli endotoxemic rats, NO synthetized by the constitutive isoform of the NO synthase positively modulates TNF alpha synthesis.

Background Titanium dioxide (TiO2) and carbon black (CB) nanoparticles (NPs) have biological effects that could aggravate pulmonary emphysema. The aim of this study was to evaluate whether pulmonary administration of TiO2 or CB NPs in rats could induce and/or aggravate elastase-induced emphysema, and to investigate the underlying molecular mechanisms. Methods On day 1, Sprague-Dawley rats were intratracheally instilled with 25 U kg−1 pancreatic porcine elastase or saline. On day 7, they received an intratracheal instillation of TiO2 or CB (at 100 and 500 μg) dispersed in bovine serum albumin or bovine serum albumin alone. Animals were sacrificed at days 8 or 21, and bronchoalveolar lavage (BAL) cellularity, histological analysis of inflammation and emphysema, and lung mRNA expression of heme oxygenase-1 (HO-1), interleukin-1β (IL-1β), macrophage inflammatory protein-2, monocyte chemotactic protein-1, and matrix metalloprotease (MMP)-1, and -12 were measured. In addition, pulmonary MMP-12 expression was also analyzed at the protein level by immunohistochemistry. Results TiO2 NPs per se did not modify the parameters investigated, but CB NPs increased perivascular/peribronchial infiltration, and macrophage MMP-12 expression, without inducing emphysema. Elastase administration increased BAL cellularity, histological inflammation, HO-1, IL-1β and macrophage MMP-12 expression and induced emphysema. Exposure to TiO2 NPs did not modify pulmonary responses to elastase, but exposure to CB NPs aggravated elastase-induced histological inflammation without aggravating emphysema. Conclusions TiO2 and CB NPs did not aggravate elastase-induced emphysema. However, CB NPs induced histological inflammation and MMP-12 mRNA and protein expression in macrophages.

Particulate pollution is suspected to contribute to obstructive lung diseases characterized by chronic inflammation, mucus hypersecretion and bronchial remodeling. Our aim was to study the effect of real-world particulate matter (PM) on the expression of a mucin, MUC5AC, focusing on the role of the epidermal growth factor receptor (EGFR) pathway. MUC5AC induction was studied in vivo in mice trachea and in vitro in human bronchial epithelial cells (HBEC) exposed to urban fine PM. Fine PM were able to induce MUC5AC mRNA in mice trachea after 48 h of exposure (50 μg PM/mouse), and MUC5AC mRNA and protein in HBEC after 24 h of exposure (from 5 μg PM/cm(2)). It was associated with the increased expression of amphiregulin (AREG), an EGFR ligand. Experiments with conditioned media (media from PM-treated cells) demonstrated the involvement of AREG on MUC5AC induction as MUC5AC induction by media from PM-treated cells was prevented in the presence of either EGFR- or AREG-neutralizing antibodies. The effect of an inhibitor of a metalloprotease involved in the AREG shedding confirmed the autocrine loop made by AREG leading to MUC5AC induction by fine PM. We also demonstrated that IL-8 pro-inflammatory cytokine induction was dependent on the same autocrine mechanisms. We demonstrate for the first time that MUC5AC expression and production is increased by short-term exposure to fine PM through an autocrine effect of AREG. Our study provides mechanistic explanations to the exacerbation of obstructive lung diseases induced by particulate pollution characterized by mucus hypersecretion and chronic inflammation.

International audience; Chronic obstructive pulmonary disease (COPD) is a major risk factor for cardiovascular disease. Polycythemia, a common complication of hypoxic COPD, may affect systemic vascular function by altering blood viscosity, vessel wall shear stress (WSS), and endothelium-derived nitric oxide (NO) release. Here, we evaluated the effects of hypoxia-related polycythemia on systemic endothelial function in patients with COPD. We investigated blood viscosity, WSS, and endothelial function in 15 polycythemic and 13 normocythemic patients with COPD of equal severity, by recording brachial artery diameter variations in response to hyperemia and by using venous occlusion plethysmography (VOP) to measure forearm blood flow (FBF) responses to a brachial artery infusion of acetylcholine (ACh), bradykinin (BK), sodium nitroprusside (SNP), substance P (SP), isoptin, and N-monomethyl-l-arginine (l-NMMA). At baseline, polycythemic patients had higher blood viscosity and larger brachial artery diameter than normocythemic patients but similar calculated WSS. Flow-mediated brachial artery vasodilation was increased in the polycythemic patients, in proportion to the hemoglobin levels. ACh-induced vasodilation was markedly impaired in the polycythemic patients and negatively correlated with hemoglobin levels. FBF responses to endothelium- (BK, SP) and non-endothelium-dependent (SNP, isoptin) vasodilators were not significantly different between the two groups. l-NMMA infusion induced a similar vasoconstrictor response in both groups, in accordance with their similar baseline WSS. In conclusion, systemic arteries in polycythemic patients adjust appropriately to chronic or acute WSS elevations by appropriate basal and stimulated NO release. Overall, our results suggest that moderate polycythemia has no adverse effect on vascular function in COPD.

Ultrashort echo time (550 μs) MR imaging was implemented to track the emphysema development in mice lung challenged with elastase. Two parameters, namely, signal intensity and T, were used to monitor the disease evolution. Nine mice were imaged before and at 24 h as well as at 3 and 8 weeks after elastase instillation. Five mice instilled with saline served as controls. At week 8, the mean normalized signal intensity ± SD was 0.89 ± 0.20 for healthy controls and 0.64 ± 0.10 for animals with emphysema. Similarly, a reduced value of T (1.27 ± 0.35 ms vs 0.96 ± 0.18 ms) was found in the emphysema group. The mean signal intensity drop and the reduction of T were prominent at 3 weeks following elastase instillation and stabilized between 3 and 8 weeks. The results indicated an excellent agreement between MR findings and histological morphometry (signal intensity, r = −0.78, P = 0.004; T, r = −0.78, P = 0.001). This result shows that proton MRI allows structural changes at alveolar level to be monitored longitudinally. This technique, applied routinely in preclinical trials will represent a valuable tool for assessment of drug therapy efficacy. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.

Nitric oxide (NO) in combination with superoxide produces peroxynitrites and induces protein nitration, which participates in a number of chronic degenerative diseases. NO is produced at high levels in the human emphysematous lung, but its role in this disease is unknown. The aim of this study was to determine whether the NO synthases contribute to the development of elastase-induced emphysema in mice. nNOS, iNOS, and eNOS were quantified and immunolocalized in the lung after a tracheal instillation of elastase in mice. To determine whether eNOS or iNOS had a role in the development of emphysema, mice bearing a germline deletion of the eNOS and iNOS genes and mice treated with a pharmacological iNOS inhibitor were exposed to elastase. Protein nitration was determined by immunofluorescence, protein oxidation was determined by ELISA. Inflammation and MMP activity were quantified by cell counts, RT-PCR and zymography in bronchoalveolar lavage fluid. Cell proliferation was determined by Ki67 immunostaining. Emphysema was quantified morphometrically. iNOS and eNOS were diffusely upregulated in the lung of elastase-treated mice and a 12-fold increase in the number of 3-nitrotyrosine-expressing cells was observed. Over 80% of these cells were alveolar type 2 cells. In elastase-instilled mice, iNOS inactivation reduced protein nitration and increased protein oxidation but had no effect on inflammation, MMP activity, cell proliferation or the subsequent development of emphysema. eNOS inactivation had no effect. In conclusion, in the elastase-injured lung, iNOS mediates protein nitration in alveolar type 2 cells and alleviates oxidative injury. Neither eNOS nor iNOS are required for the development of elastase-induced emphysema.

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.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.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.NOX4 is critical for modulation of the pulmonary myofibroblast phenotype in IPF, probably by modulating the response to TGFbeta1 and PDGF.

We evaluated the effects of sublethal Escherichia coli endotoxemia with or without concomitant administration of N-acetylcysteine, an antioxidant agent, on diaphragmatic strength, endurance, and malondialdehyde (MDA) content in rats. One hundred ninety rats were inoculated subcutaneously on 2 successive days with 0.6 and 1.2 mg/100 g body weight of E. coli lipopolysaccharide respectively (E animals, n = 100) or saline (C group, n = 90). E and C animals were divided into two groups based on administration of endotoxin or saline alone (E group, n = 55; C group, n = 47, respectively) or endotoxin or saline plus N-acetylcysteine (1 g/kg body weight/day intraperitoneally) (E-NAC group, n = 45; C-NAC group, n = 43, respectively). Diaphragmatic strength was assessed in vivo 48 h after the first endotoxin or saline administration by measuring the transdiaphragmatic pressure (Pdl) generated during electrical stimulation of the phrenic nerves at 0.5, 10, 20, 30, 50, and 100 Hz. Endurance index was calculated as the percent ratio of Pdl generated after 30 s of phrenic stimulation at 10 Hz divided by the initial force. Diaphragmatic MDA (fluorometric technique) was measured 0, 6, 18, 30, 42, and 48 h after the first dose of endotoxin or saline. Pdl for 50 and 100 Hz was significantly reduced in Group E as compared with group C. This phenomenon was associated with a reduced endurance performance as assessed by a lower diaphragmatic endurance index in E as compared with C animals (90.9 +/- 4.2 versus 114.3 +/- 4.1 respectively; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

International audience; Bronchopulmonary dysplasia of the premature neonate and emphysema of the adult lung are common diseases that are characterized by increased airspace size and respiratory insufficiency and that presently lack efficient treatment. Although the former leads to impaired alveolar development and the latter to alveolar destruction, they have striking similarities in their pathophysiology, including the precipitating effect of oxidative stress, sustained inflammation, enhanced apoptosis, protease-antiprotease imbalance, elastic fiber deterioration and altered microvascularization. This review aims to comparatively analyze their molecular mechanisms to try identify common therapeutic targets. The recent discovery that alveolar developmental and maintenance programs share the same signal molecules and pathways, together with considerable increase in their understanding, have facilitated the development of common innovative strategies that have started to be tested in experimental models and pilot clinical studies.

International audience; BACKGROUND: All-trans retinoic acid (ATRA) stimulates elastin synthesis by lung fibroblasts and induces alveolar regeneration in animal models of pulmonary emphysema. However, ATRA treatment has had disappointing results in human emphysema. It was hypothesised that a defect in the ATRA signalling pathway contributes to the defect of alveolar repair in the human emphysematous lung. METHODS: Fibroblasts were cultured from the lung of 10 control subjects and eight patients with emphysema. Elastin and retinoic acid receptor (RAR)-beta mRNAs were measured in those cells in the presence of incremental concentrations of ATRA. RARs, retinoic X receptors (RXRs) and cellular retinoic acid binding protein (CRABP) 1 and 2 mRNAs were measured as well as CRABP2 protein content. The effect of CRABP2 silencing on elastin and RAR-beta expression in response to ATRA was measured in MRC5 lung fibroblasts. RESULTS: ATRA at 10(-9) M and 10(-8) M increased median elastin mRNA expression by 182% and 126% in control but not in emphysema fibroblasts. RAR-beta mRNA expression was induced by ATRA in control as well as emphysema fibroblasts. RARs, RXRs and CRABP1 mRNAs were similarly expressed in control and emphysema fibroblasts while CRABP2 mRNA and protein were lower in emphysema fibroblasts. CRABP2 silencing abrogated the induction of elastin but not RAR-beta expression by ATRA in MRC5 fibroblasts. CONCLUSION: Pulmonary emphysema fibroblasts fail to express elastin under ATRA stimulation. CRABP2, which is necessary for elastin induction by ATRA in MRC-5 cells, is expressed at low levels in emphysema fibroblasts. This alteration in the retinoic acid signalling pathway in lung fibroblasts may contribute to the defect of alveolar repair in human pulmonary emphysema. These results are the first demonstration of the involvement of CRABP2 in elastin expression.

We investigated the role of heme oxygenase-1 (HO-1), a powerful anti-inflammatory and anti-oxidant enzyme, in modulating cigarette smoke (CS)-induced mucus secretion. In both rats and mice, 5-day CS exposure increased HO-1 expression and activity, mucus secretion, MUCIN 5AC (MUC5AC) gene and protein expression, and local inflammation, along with up-regulation of dual oxidase 1 gene expression and both the activity and phosphorylation of the epidermal growth factor receptor, which is involved in MUC5AC induction. Pharmacological induction of HO-1 prevented these actions and inhibition of HO-1 expression by a specific siRNA potentiated them. In French participants to the European Community Respiratory Health Survey II (n = 210, 30 to 53 years of age, 50% males) exposed to CS, a significant increase in the percentage of participants with chronic sputum was observed in those harboring at least one allele with a long (GT)(n) in the HO-1 promoter gene (33 repeats), which is associated with a low level of HO-1 protein expression, compared with those with a short number of (GT)n repeats (21.7% versus 8.6%, P = 0.047). No such results were observed in those who had never smoked (n = 297). We conclude that HO-1 has a significant protective effect against airway mucus hypersecretion in animals and humans exposed to CS.

International audience; Several studies performed by intratracheal instillation showed that carbon nanotubes (CNT) induced pulmonary fibrosis, granulomas or inflammation. But, recently, two inhalation Studies did not observed Such pathological phenomena and suggest that granulomas Could be due to the instillation of unbreathable agglomerates. In a previous study, we have described a simple method (using albumin as dispersing agent) which produced Solutions containing more than 80% of agglomerate ol'breathable size. We report here results from intratracheal instillation of rats by 0, 1, 10 or 100 mu g of MWCNT dispersed with albumin. After 1, 7, 30, 90, and 180 days, inflammation, apoptosis, fibrosis, respiratory parameters and granuloma formation were assessed. Results obtained by plethysmography, soluble collagen quantification, qRT-PCR and luminex measurement of cytokines expression and histopathological observation showed only evidence of apoptosis of alveolar macrophages.These result underline the importance of controlling MWCNT agglomerate size when exposing animals, through appropriate dispersion methods

Background Constituted only by carbon atoms, CNT are hydrophobic and hardly detectable in biological tissues. These properties make biokinetics and toxicology studies more complex. Methods We propose here a method to investigate the biopersistence of CNT in organism, based on detection of nickel, a metal present in the MWCNT we investigated. Results and conclusion Our results in rats that received MWCNT by intratracheal instillation, reveal that MWCNT can be eliminated and do not significantly cross the pulmonary barrier but are still present in lungs 6 months after a unique instillation. MWCNT structure was also showed to be chemically modified and cleaved in the lung. These results provide the first data of CNT biopersistence and clearance at 6 months after respiratory administration.

We evaluated the effects of a sublethal Escherichia coli endotoxemia with and without concomitant administration of indomethacin on diaphragmatic strength in an in vivo rat model. Ninety-six rats were inoculated subcutaneously on two successive days with 0.3 and 0.6 mg/100 g body weight of E. coli lipopolysaccharide, respectively (E animals, n = 64), or saline (C group, n = 32). E animals were divided into two groups based on subcutaneous administration of endotoxin alone (E group, n = 32) or endotoxin plus indomethacin (2.5 mg/kg body weight/day) (EI group, n = 32). Diaphragmatic strength was evaluated in 14 animals from each group 2 days after the first endotoxin or saline administration. Diaphragmatic strength was assessed by measuring the transdiaphragmatic pressure (Pdi) during electrical stimulation of the phrenic nerves at different frequencies (0.5, 10, 20, 30, 50, and 100 Hz). Lung histologic examination and measurements of lung weights were performed 1 and 2 days after the first endotoxin or saline administration in nine animals of each group each day. A slight increase in the number of neutrophils without alveolar septal thickening and alveolar edema was observed in the lungs of endotoxin-inoculated animals. No differences in the lung weight to body weight ratio nor in the dry to wet weight ratio of the lungs were noted between C, E, and EI groups. Diaphragmatic weight was not different in the three groups, whereas the weights of the extensor digitorum longus, tibialis anterior, and soleus muscles were significantly reduced in E compared with C and EI animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary emphysema is characterized by persistent inflammation and progressive alveolar destruction. The keratinocyte growth factor (KGF) favorably influences alveolar maintenance and repair and possesses anti-inflammatory properties. We aimed to determine whether exogenous KGF prevented or corrected elastase-induced pulmonary emphysema in vivo. Treatment with 5 mg·kg−1·day−1 KGF before elastase instillation prevented pulmonary emphysema. This effect was associated with 1) a sharp reduction in bronchoalveolar lavage fluid total protein and inflammatory cell recruitment, 2) a reduction in the pulmonary expression of the chemokines CCL2 (or monocyte chemoattractant protein-1) and CXCL2 (or macrophage inflammatory protein-2α) and of the adhesion molecules ICAM-1 and VCAM-1, 3) a reduction in matrix metalloproteinase (MMP)-2 and MMP-9 activity at day 3, and 4) a major reduction in DNA damage detected by terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) in alveolar cells at day 7. Treatment with KGF after elastase instillation had no effect on elastase-induced emphysema despite the conserved expression of the KGF receptor in the lungs of elastase-instilled animals as determined by immunohistochemistry. In vitro, KGF abolished the elastase-induced increase in CCL2, CXCL2, and ICAM-1 mRNA in the MLE-12 murine alveolar epithelial cell line. We conclude that KGF pretreatment protected against elastase-induced pulmonary inflammation, activation of MMPs, alveolar cell DNA damage, and subsequent emphysema in mice.

Inducible heme oxygenase (HO-1) acts against oxidants that are thought to play a major role in the pathogenesis of chronic obstructive pulmonary disease (COPD), characterised by impaired lung function. A (GT)(n) repeat polymorphism in the HO-1 gene promoter can modulate the gene transcription in response to oxidative stress. We hypothesised that this polymorphism could be associated with the level of lung function and decline in subjects exposed to oxidative aggression (smokers). We genotyped 749 French subjects (20-44 years, 50% men, 40% never smokers) examined in both 1992 and 2000 as part of the ECRHS. Lung function was assessed by forced expiratory volume in 1 second (FEV1) and FEV1/forced ventilatory capacity (FVC) ratio. We compared long (L) allele carriers ((GT)(n) > or =33 repeats for one or two alleles) to non-carriers. Cross sectionally, in 2000, L allele carriers showed lower FEV1/FVC than non-carriers. During the 8 year period, the mean annual FEV1 and FEV1/FVC declines were -30.9 (31.1) ml/year and -1.8 (6.1) U/year, respectively. FEV1/FVC decline was steeper in L allele carriers than in non-carriers (-2.6 (5.5) v -1.5 (6.4), p = 0.07). There was a strong interaction between the L allele and smoking. In 2000, the L allele was associated with lower FEV(1) and FEV(1)/FVC in heavy smokers (> or =20 cigarettes/day) only (p for interaction = 0.07 and 0.002 respectively). Baseline heavy smokers carrying the L allele showed the steepest FEV1 decline (-62.0 (29.5 ml/year) and the steepest FEV1/FVC decline (-8.8 (5.4 U/year) (p for interaction = 0.009 and 0.0006). These results suggest that a long (L) HO-1 gene promoter in heavy smokers is associated with susceptibility to develop airway obstruction.

Background and Purpose— It is not well established what are the features, if any, that distinguish symptomatic from asymptomatic carotid atherosclerotic plaques. Inducible heme oxygenase-1 (HO-1) is a component of cellular defense mechanisms against oxidative stress. We aimed to assess the presence of Helicobacter pylori (H pylori ) and the expression of HO-1 in carotid atherosclerotic plaques of patients with and without prior neurologic symptoms attributable to the operated artery. Methods— We examined 25 symptomatic and 23 asymptomatic carotid atherosclerotic plaques removed during endarterectomy and 7 normal carotid arteries obtained at autopsy. We investigated the presence of H pylori DNA in the vessel wall and performed immunohistochemical detection of HO-1. Results— H pylori DNA was present in 28 plaques and HO-1 was expressed in 30 plaques. HO-1 was found in 27 H pylori- positive specimens but in only 3 H pylori- negative specimens ( P H pylori and HO-1. Although 82% of asymptomatic specimens were positive for H pylori and 87% for HO-1, only 36% of symptomatic specimens were positive for both H pylori and HO-1 ( P Conclusions— This study suggests a strong association between H pylori infection and expression of HO-1 in carotid atherosclerotic plaques. There was a substantial prevalence of these features in specimens obtained from asymptomatic subjects.

International audience; OBJECTIVE: Caveolins, the structural proteins of caveolae, modulate numerous signaling pathways including Nitric Oxide (NO) production. Among the caveolin family, caveolin-1 and -3 are mainly expressed in endothelial and muscle cells, respectively. In this study, we investigate whether (i) changes in caveolin abundance and/or distribution occur during cardiac aging and failure in rat, and (ii) the process could influence NO synthase (NOS) activity. METHODS: Using immunohistolabelling and Western blot approaches, expression and distribution of caveolins were analysed in adult (Ad), senescent (S-Sh) and myocardial infarction-induced failing (S-MI) hearts. NOS3/caveolin-1 interactions were evaluated by immunoprecipitation assays. RESULTS: At the microscope level, caveolin-1 distribution in the endothelial cells was unchanged between the groups. Conversely the typical distribution of caveolin-3 in myocyte sarcolemma was dramatically altered in S-MI rats, resulting in a heterogeneous pattern throughout the septum. Total abundance of caveolin-1 and -3 remained stable whatever the group. In the fractions free of caveolae (Triton X-100 soluble), the levels of caveolin-1 alpha and -3 increased with aging (+20%, and +104%, P

Sepsis is a common cause of morbidity and mortality, particularly in elderly, immunocompromised, and critically ill patients. Indeed, severe sepsis is at present the most common cause of death in intensive care unit in the United States (Bone et al., 1992).Respiratory failure is a major clinical manifestation of sepsis, greatly contributing to the mortality of this pathologic condition (Montgomery et al., 1985). In this context, respiratory failure has been traditionally related to the development of adult respiratory distress syndrome (Montgomery et al., 1985). However, different experimental studies demonstrated that an impaired contractile function of respiratory muscles, including the diaphragm, is another important mechanism of respiratory failure during sepsis (Boczkowski et al., 1990 and Boczkowski et al. 1996; El Dwairi et al., 1998; Shindoh et al., 1992; Hussain et al., 1985; Van Surell et al., 1992). Diaphragmatic dysfunction during sepsis appears to be mediated mainly by oxidative stress (Shindoh et al., 1992; Supinski et al., 1996; Van Surell et al., 1992). In fact, we and others have recently shown an increased production of oxidants, such as superoxide anion and peroxynitrite, in the diaphragm of endotoxemic rats (El Dwairi et al, 1998; Boczkowski et al., 1999). The expression of the inducible isoform of nitric oxide (NO) synthase (NOS2) is partly responsible for this effect (Boczkowski et al., 1999).