Lung Inflammatory Markers Research Articles

Uncovering the neuroenteric–pulmonary axis: Vagal nerve stimulation prevents acute lung injury following hemorrhagic shock

AimsTrauma/hemorrhagic shock (T/HS) induced gut injury is known to initiate a systemic inflammatory response which can lead to secondary lung injury. We have shown that vagal nerve stimulation (VNS) protects intestinal epithelial integrity after a severe burn insult. We hypothesize that VNS will protect the lung from injury following T/HS by preventing intestinal barrier failure. Main methodsMale Balb/c mice were subjected to a T/HS model with and without cervical VNS. Intestinal injury was evaluated by measuring changes in gut barrier function and tight junction protein localization. Lung injury was evaluated using histology and markers of lung inflammation. Using NF-kB-luciferase (NF-kB-luc) transgenic mice, NF-kb–DNA binding was measured by photon emission analysis at 4 after injury. Key findingsT/HS is associated gut injury characterized by histologic injury, increased epithelial permeability, and altered localization of gut tight junction proteins. Cervical VNS prevented the T/HS-induced changes in gut barrier integrity. Gut injury after T/HS was associated with acute lung injury at 24h characterized by histologic injury, increased number of MPO positive stained cells and MPO enzymatic activity, and increased ICAM-1 expression in lung endothelium. VNS decreased T/HS-induced lung injury with a marked decrease in lung inflammation compared to T/HS alone. Lungs harvested from NF-kB-luc mice at 4h post VNS+T/HS demonstrated decreased DNA binding of NF-kB compared to T/HS alone as measured by changes in bioluminescence. SignificanceVNS is effective in protecting against acute lung injury caused by hemorrhagic shock through its ability to prevent gut barrier dysfunction.

Airborne Particulate Matter and Acute Lung Inflammation

In their article, Strak et al. (2012) connected real-world exposure to markers of acute lung function and inflammation. However, some points in the paper require further explanation. Strak et al. used fractional exhaled nitric oxide (FENO) as a marker of lung inflammation. Exhaled NO is produced throughout the respiratory tract and shows significant variability in source strength across the respiratory tract (Barnes et al. 2010; Kharitonov and Barnes 2001). Factors such as particle size, hygroscopicity, composition, and concentration; lung function parameters; and environmental temperature and humidity (Varghese and Gangamma 2006, 2009), which vary across experimental locations and between participants, modify particle deposition sites in the lung. These changes in the deposition site may influence the amount of NO exhaled. In their paper, Strak et al. (2012) did not discuss how these parameters influenced their conclusions. Thus, how the linear regression model they used accounts for these influences needs to be explained. Inflammation in the lung resulting from air pollution exposure involves various cell types, such as epithelial cells in upper airways and macrophages and recruited neutrophils in the lower respiratory tract. A significant source of exhaled NO is epithelial cells in the upper airways, which are associated with eosinophilic inflammation (Barnes et al. 2010; Kharitonov and Barnes 2001). Many components of particulate matter (PM), such as endotoxin or bacteria, induce neutrophil inflammation in the lung, but the effects of these components may not be reflected in the concentration of exhaled NO. Thus, FENO measurements as a marker of inflammation could easily be misinterpreted by attributing a particular part of the total inflammatory response within the lung to air pollution. Strak et al. (2012) did not discuss such possibilities. In their article, Strak et al. (2012) did not provide sufficient details about the NIOX MINO monitor (Aerocrine 2010) they used to measure exhaled NO concentration. I assume that NO measurement involves flow measurement and diffusion of NO to a sensor. Temperature and humidity of exhaled air or body temperature of the subjects likely interfere with these operations. Strak et al. did not describe any of these parameters or how they may interfere with NO measurement. Moreover, the absolute values of FENO observed during the experiments are not readily available. However, in the “Discussion,” Strak et al. indicated that the observed variations between FENO measurements that are associated with particle number concentration (PNC) were most likely within the range of 5–15%. The technical specification of the instrument used for NO measurement has precision values of 5 ppb or 10% for concentrations > 30 ppb (Aerocrine 2010). Strak et al. used the difference between two sets of readings (preexposure and postexposure) as the input data for regression calculations. Thus, measurement error associated with the calculations could be much higher than that for a single set of measurements. Therefore, many of the observed differences in NO values were likely to fall within the error range of the instrument. Strak et al. should have discussed the propagation of error in the measurements or provided sufficient experimental data on the precision of the measurements. They should also have explained how the regression analysis is not biased by such instrument errors. Strak et al. (2012) reported measurement of PNC with a condensation particle counter (CPC model 3007; TSI 2007), but their Table S2 did not report the accuracy or limit of detection of this instrument. CPC measurement depends on parameters such as ion concentration and particle composition, but because the measurements in the paper were from different environments, it is likely that these parameters varied significantly across the sites. Moreover, the CPC has a low sampling flow rate, and it is not clear whether this sampling rate is suitable for ambient measurement (aspiration efficiency in case of fluctuations in ambient wind velocity). Overall, the article is an excellent attempt by Strak et al. (2012) to use noninvasive methods to understand the acute response of the respiratory system in response to air pollution exposure. However, a careful explanation of theory behind the experiments, experimental design, and limitations of measurement methods (if any) should have been discussed in the article.

Reduction of influenza virus-induced lung inflammation and mortality in animals treated with a phosophodisestrase-4 inhibitor and a selective serotonin reuptake inhibitor

Inflammatory responses contribute to the morbidity and mortality of severe influenza. Current antiviral therapy offers limited success in treating severe influenza infection with both H1N1 and H5N1 viruses. We evaluated the effect of a neuraminidase inhibitor in combination with immunomodulatory drugs in vitro and in a mouse model of influenza A H1N1 infection by determining survival rate, lung inflammation markers and histopathology. Sertraline and rolipram significantly improved survival in mice infected with a lethal dose of influenza A H1N1 virus. Prophylactic treatment resulted in survival rates of 40% (rolipram), 30% (oseltamivir), 0% (sertraline), 100% (rolipram/oseltamivir) and 70% (sertraline/oseltamivir). Treatment in a therapeutic setting (24 h post-infection) resulted in 80% (rolipram/oseltamivir) and 40% (sertraline/oseltamivir) survival. Sertraline and rolipram had no effect on virus replication in vitro and in vivo, but significantly reduced lung inflammation. A significant reduction in cellular infiltration (10-fold) along with inflammatory cytokines monocyte chemotactic protein-1 (10-fold), interleukin-6 (5-fold) and regulated on activation normal T cell expressed and secreted (5-fold) was observed in the animals treated with the combination compared to oseltamivir alone. Lung histopathology of mice treated with combinations revealed significantly reduced consolidation, infiltration and alveolitis compared to oseltamivir alone. Rolipram and sertraline reduced H1N1 virus-induced lung inflammation and mortality. These data support further development of immunomodulatory agents for severe influenza.

The Nitrated Fatty Acid 10-Nitro-oleate Diminishes Severity of LPS-Induced Acute Lung Injury in Mice

Acute lung injury (ALI) is an inflammatory condition culminating in respiratory failure. There is currently no effective pharmacological treatment. Nitrated fatty acids (NFAs) have been shown to exert anti-inflammatory effects. We therefore hypothesized that delivery of NFAs directly to the site of inflammation would reduce the severity of ALI. Pulmonary delivery of 10-nitro-oleate following endotoxin-induced ALI in mice reduced markers of lung inflammation and injury, including capillary leakage, lung edema, infiltration of neutrophils into the lung, and oxidant stress, as well as plasma levels of proinflammatory cytokines. Nitro-oleate delivery likewise downregulated expression of proinflammatory genes by alveolar macrophages, key cells in regulation of lung inflammation. These effects may be accounted for by the observed increases in the activity of PPAR-γ and the PPAR-γ-induced antioxidant transcription factor Nrf2, together with the decreased activity of NF-κB. Our results demonstrate that pulmonary delivery of NFAs reduces severity of acute lung injury and suggest potential utility of these molecules in other inflammatory lung diseases.

Dose-Related Effects of Hyperoxia on the Lung Inflammatory Response in Septic Rats

We evaluated the effects of hyperoxia on pulmonary inflammatory changes in sepsis induced by cecal ligation and puncture (CLP) in rats. Seven groups were studied: sham-operated rats breathing air for 20 or 48 h; CLP breathing air for 20 or 48 h; and CLP + 100% oxygen for 20 h, or 70% oxygen for 48 h, or 100% oxygen intermittently (6 h/d) for 48 h. Video microscopy was used to monitor lung macromolecular leak, microvascular flow velocity, and shear rates, and lung morphometry was used for leukocyte infiltration and solid tissue area. Cell counts, tumor necrosis factor α, and nitrites were determined in peripheral blood and lung lavage fluid. Expression of adhesion molecules in blood leukocytes was evaluated by flow cytometry. Cecal ligation and puncture induced inflammation manifested in leukopenia, left shift, thrombocytopenia, increased expression of L selectin and CD11, increased serum and lavage fluid tumor necrosis factor α and leukocytes, and increased lung tissue area, macromolecular leak, and sequestration of leukocytes. Inhalation of 100% oxygen for 20 h increased nitrites (P < 0.01) and decreased leukocyte count in lavage fluid (P < 0.05) and attenuated lung macromolecular leak and changes in solid tissue area (P < 0.01). Inhalation of 70% oxygen (48 h) attenuated expression of adhesion molecules (P < 0.001) but failed to attenuate markers of lung inflammation. In contrast, intermittent 100% oxygen exerted favorable effects on markers of inflammation, attenuated leukocyte expression of L selectin and CD11 (P < 0.01), decreased pulmonary sequestration of leukocytes (P < 0.001), and ameliorated changes in macromolecular leak (P < 0.01) and lung solid tissue area (P < 0.05). Our data support the beneficial effects of safe subtoxic regimens of normobaric hyperoxia on the systemic and pulmonary inflammatory response following CLP.

HIV antiretroviral therapy reduces circulating surfactant protein-D levels

Untreated HIV infection is associated with abnormal lung inflammation, even when CD4+ counts are relatively well preserved. Compared to patients without HIV infection, patients with HIV infection demonstrate increases in CD8+ T cells in bronchoalveolar lavage (BAL) fluid1 that normalize within 6 months of antiretroviral therapy (ART) initiation2. BAL allows direct sampling of lung inflammatory cells, but requires an invasive procedure and specialized personnel to perform. Therefore, we investigated the effects of ART on a non-invasive blood marker of lung inflammation, surfactant protein D (SP-D). Study participants were required to have HIV infection and not have taken ART for at least 3 months prior to enrollment. Exclusion criteria included age 65 years, pregnancy, concurrent self-limited bacterial infection, and active illicit drug or alcohol use. The protocol was registered at ClinicalTrials.gov (NCT 00783614) and approved by the local ethics committee. Plasma was collected at baseline, then again at month 3 and month 5 following ART initiation. Plasma SP-D levels were determined using a commercially available sandwich ELISA assay (BioVendor, Candler, NC). Paired differences in SP-D were compared from baseline to month 3 and baseline to month 5. Statistical analyses were performed using STATA 9 (College Station, TX) Stored specimens from 15 patients were available: 12 and 13 had plasma specimens at month 3 and 5, respectively, to characterize changes from baseline. Mean age was 37 years, 80% were male, and 33% were Caucasian. Baseline median CD4+ cell count was 320 cells/mm3, increased to 412 cells/mm3 at month 3 (p=0.01 vs. baseline) and was 466 cells/mm3 at month 5 (p=0.007 vs. baseline). Median baseline viral load was 17,970 copies/mL and was fully suppressed at <75 copies/mL among all participants at month 3 and at month 5 visits (both p<0.001 vs. baseline). Eleven participants started a protease inhibitor and 4 participants started a non-nucleoside reverse transcriptase inhibitor; all participants started nucleoside reverse transcriptase inhibitors. No patients had known lung disease. Median baseline SP-D was 64.1 ng/mL (interquartile range 49.2 – 73.6 ng/mL). Smoking is known to increase blood SP-D levels3, and our sample of smokers (n=9, 60%) had a higher baseline median SP-D level compared to non-smokers that was not statistically significant (64.3 ng/mL vs. 53.2 ng/mL, respectively, p=0.19). At month 3, there was a non-significant reduction in median SP-D level to 51.6 ng/mL (p=0.10) and at month 5, the reduction became significant to a median SP-D level of 47.3 ng/mL (p=0.01) (Figure). A random effects regression model test for trend showed a slope of −2.7 ng/mL change in SP-D per month (p=0.009). Figure Boxplots of paired plasma surfactant protein D (SP-D) comparisons from baseline to 3 months after ART initiation (n=12), and baseline to 5 months after ART initiation (n=13). p-values derived using Wilcoxon signed rank testing. Random effects regression ... We have demonstrated for the first time that ART initiation and suppression of HIV replication appears to be associated with a reduction in blood SP-D levels. Studies in non-HIV populations have suggested a relationship between SP-D blood levels and mortality in pulmonary fibrosis4, lung function in cystic fibrosis5, and respiratory health status in chronic obstructive pulmonary disease6. Thus, while our study was a small pilot study, we believe our study provides rationale for expanding research into pulmonary outcomes among patients with HIV infection. The ongoing Strategic Timing of AntiRetrovital Therapy (START) trial will evaluate early (CD4+ cell counts >500 cells/mm3) vs. deferred ART initiation in randomized fashion. Lung function, respiratory health status, and respiratory medication use will be ascertained in a subset of 1000 participants (ClinicalTrials.gov NCT00867048). Such studies are required to better understand HIV-specific consequences for pulmonary disease, and whether treatment with ART will improve pulmonary outcomes.

Increased concentrations of breath haloamines are not detectable in airways inflammation using SIFT-MS

The haloamines, including the chloramines (H2NCl, HNCl2) and bromamine (H2NBr), are diffusible gases that are likely to be produced during inflammation and so may be present as markers of lung inflammation on breath. Although haloamines are quite reactive, it is possible to measure these compounds in humid samples using SIFT-MS. Until recently the quantification of haloamines in breath suffered from interference from other common breath compounds. This was overcome by heating the flow tube which removed major water cluster product ions. Despite the improvements to the method, previous attempts to measure the haloamines in breath samples from normal volunteers had found no evidence to support their presence. Since it is proposed that the haloamines may be present in higher concentrations during airways inflammation we have attempted to detect the compounds in the exhaled breath of patients with airways inflammatory conditions. On-line and off-line breath samples were analyzed; however, there was no discernable change to any of product ions when compared to ambient air or normal subjects. This suggests that despite sensitivity in the mid part per trillion range haloamines are not significantly raised in airways inflammation.

Comparative pulmonary toxicity assessment of pristine and functionalized multi-walled carbon nanotubes intratracheally instilled in rats: morphohistochemical evaluations.

Increasing interest in safety evaluation of carbon nanotubes (CNTs) has risen in relation to their wide applications, together with the evidence of their cytotoxic effects. It has been shown that chemical functionalization extends the applications of CNTs, conferring them new functions that cannot otherwise be acquired by pristine CNTs, but also impacts on biological response to CNTs, modifying their toxicological profile. We assessed the onset of pulmonary toxic effects caused by pristine MW-CNTs and functionalized MW-NH₂ or MW-COOH, 16 days after intratracheal instillation (1 mg/kg b.w.); major endpoints tested included (i) histopathology of lung (Haematoxylin/Eosin Staining), (ii) apoptotic/proliferating features examined by TUNEL and PCNA immunostaining, and (iii) presence/distribution of (1) Transforming Growth Factor-beta1 (TGFß1), (2) Interleukin-6 (IL-6) and (3) Collagen (Type I) investigated by immunochemical methods, as markers of lung toxicity, inflammation, and fibrosis, respectively. Lung histopathology from exposed animals showed dark, particulate-laden macrophages, reflecting carbon nanomaterial engulfing, both at alveolar and bronchiolar levels, after treatment with all the tested CNTs. Alteration of lung architecture was also observed in several areas showing collapsed thick-walled alveoli and the presence of micro-haemorrhagic foci. TUNEL and PCNA, indicative of apoptosis and cell proliferation respectively, showed a significant increase of immunopositive cells at bronchiolar, alveolar and macrophagic levels, as expression of an improved cellular turnover. Increased immunoreactivity for pulmonary TGFß1 and IL-6 was observed in treated rats, particularly in bronchiolar areas, collapsed alveoli and at stromal level, while evident changes for collagen were not detected. Taken together these findings demonstrated the general pulmonary toxicity coupled with inflammatory response after in vivo exposure to CNTs, without overt signs of fibrosis and granuloma formation, irrespectively of nanotube functionalization.

Effects of physical exercise on lung injury and oxidant stress in children with asthma

Background The aim of this study was to investigate the influence of exercise training on oxidative stress and markers of lung inflammation in children with asthma. Methods Thirty children aged 8-13 years diagnosed with asthma were enrolled in the study as well as 13 healthy children. One group received only pharmacological treatment and the other group was also enrolled in an exercise programme. Venous blood and 24-hour urine samples were obtained from the children enrolled in the study at the beginning and end of the study. Leukotriene E4 and creatinine levels were measured in the urine and matrix metallopeptidase (MMP-9), endothelin-1(ET-1), malnodialdehyde (MDA), IgE and specific IgE levels were measured in blood samples. Results Leukotriene E4, MDA and MMP9 levels decreased significantly with treatment in both groups (p<0.001). However, ET-1 levels decreased significant only in the exercise group (26.5 ± 3.6 vs 21.3 ± 2.4pg/ml respectively, p=0.001). Moreover, ET-1 levels were found to be significantly lower in the exercise group compared to the only pharmacotherapy group (24.2 ± 3.1 vs 21.3 ± 2.4pg/ml, p=0.007). Conclusions Positive influences of exercise training in children with asthma may be mediated by decrease in ET-1 levels.

Respiratory Health Effects of Commuters

S-30A1-2 Background/Aims: People spend a significant amount of time in traffic, during which they are exposed to high levels of air pollution. Very few studies measured acute health effects after real life exposure in traffic. The large TRAVEL study assessed exposure and related acute health effects of people commuting by bicycle, car, and bus. Methods: Exposure to and inhalation of ultrafine particles, particulate matter (PM10), PM2.5, and soot were measured during 2-hour commutes in Arnhem, a medium-sized city in the Netherlands. Commuting took place from 8 till 10 am. Before, immediately after, and 6 hours after exposure, we measured lung function, airway resistance, and nitric oxide in exhaled air as a marker of lung inflammation. Results: During the 47 measurement days, we collected 352 pre- and post-health measurements of 34 healthy, nonsmoking, adult volunteers. Exposures differed by mode of transport, route, and fuel type. Using mixed model analysis, we found negative associations between ultrafines and FEV1, and positive associations between ultrafines and airway resistance, and exhaled NO. Ambient NO2, but not ambient ozone, was significantly associated with increased exhaled NO levels. Conclusion: Two hour in-traffic exposures to particle number counts were associated with decrease in FEV1, increase in airway resistance, and increase in exhaled NO, a marker of airway inflammation. Effects of exposure in traffic to PM2.5, PM10, and soot were not consistently associated with respiratory health outcomes.

Markers of lung function and inflammation in West Indian diabetics

Markers of lung function and inflammation in West Indian diabetics

Quantifying proximal and distal sources of NO in asthma using a multicompartment model

Nitric oxide (NO) is detectable in exhaled breath and is thought to be a marker of lung inflammation. The multicompartment model of NO exchange in the lungs, which was previously introduced by our laboratory, considers parallel and serial heterogeneity in the proximal and distal regions and can simulate dynamic features of the NO exhalation profile, such as a sloping phase III region. Here, we present a detailed sensitivity analysis of the multicompartment model and then apply the model to a population of children with mild asthma. Latin hypercube sampling demonstrated that ventilation and structural parameters were not significant relative to NO production terms in determining the NO profile, thus reducing the number of free parameters from nine to five. Analysis of exhaled NO profiles at three flows (50, 100, and 200 ml/s) from 20 children (age 7-17 yr) with mild asthma representing a wide range of exhaled NO (4.9 ppb < fractional exhaled NO at 50 ml/s < 120 ppb) demonstrated that 90% of the children had a negative phase III slope. The multicompartment model could simulate the negative phase III slope by increasing the large airway NO flux and/or distal airway/alveolar concentration in the well-ventilated regions. In all subjects, the multicompartment model analysis improved the least-squares fit to the data relative to a single-path two-compartment model. We conclude that features of the NO exhalation profile that are commonly observed in mild asthma are more accurately simulated with the multicompartment model than with the two-compartment model. The negative phase III slope may be due to increased NO production in well-ventilated regions of the lungs.

Early Assessment of Pulmonary Inflammation by 19 F MRI In Vivo

Emulsified perfluorocarbons (PFCs) are preferentially phagocytized by monocytes/macrophages and are readily detected by (19)F MRI. This study tests the hypothesis that (19)F MRI can be used to quantitate pulmonary inflammation by tracking of infiltrating PFC-loaded monocytes. Pneumonia was induced in mice by intratracheal instillation of lipopolysaccharides (LPS) followed by intravenous injection of PFCs. Whereas regular (1)H MRI provided no evidence of lung injury 24 hours after LPS, the concurrent (19)F images clearly show PFC accumulation in both pulmonary lobes. Imaging at 48 hours after LPS revealed signals in (1)H images at the same location as the 24-hour (19)F signals. Thus, progressive pneumonia was first predicted by (19)F MRI early after PFC administration. Without LPS, at no time were (19)F signals observed within the lung. Histology and fluorescence-activated cell sorting (FACS) combined with (19)F MRI confirmed the presence of infiltrating PFC-loaded monocytes/macrophages after LPS challenge. Additional experiments with graded doses of LPS demonstrated that (19)F signal intensity strongly correlated with both LPS dose and pathological markers of lung inflammation. In separate studies, dexamethasone and CGS21680 (adenosine 2A receptor agonist) were used to demonstrate the ability of (19)F MRI to monitor anti-inflammatory therapies. PFCs serve as a contrast agent for the prognostic and quantitative assessment of pulmonary inflammation by in vivo (19)F MRI, which is characterized by a high degree of specificity due to the lack of any (19)F background. Because PFCs are biochemically inert, this approach may also be suitable for human applications.

Granzyme A- and B-Cluster Deficiency Delays Acute Lung Injury in Pneumovirus-Infected Mice

Lower respiratory tract infection by the human pneumovirus respiratory syncytial virus is a frequent cause of acute lung injury in children. Severe pneumovirus disease in humans is associated with activation of the granzyme pathway by effector lymphocytes, which may promote pathology by exaggerating proapoptotic caspase activity and proinflammatory activity. The main goal of this study was to determine whether granzymes contribute to the development of acute lung injury in pneumovirus-infected mice. Granzyme-expressing mice and granzyme A- and B-cluster single- and double-knockout mice were inoculated with the rodent pneumovirus pneumonia virus of mice strain J3666, and were studied for markers of lung inflammation and injury. Expression of granzyme A and B is detected in effector lymphocytes in mouse lungs in response to pneumovirus infection. Mice deficient for granzyme A and the granzyme B cluster have unchanged virus titers in the lungs but show a significantly delayed clinical response to fatal pneumovirus infection, a feature that is associated with delayed neutrophil recruitment, diminished activation of caspase-3, and reduced lung permeability. We conclude that granzyme A- and B-cluster deficiency delays the acute progression of pneumovirus disease by reducing alveolar injury.

5129 Surfactant protein D as a serological marker of lung inflammation in breast cancer patients under radiation treatment

5129 Surfactant protein D as a serological marker of lung inflammation in breast cancer patients under radiation treatment

A multi-target antisense approach against PDE4 and PDE7 reduces smoke-induced lung inflammation in mice

BackgroundRecent development in the field of COPD has focused on strategies aimed at reducing the underlying inflammation through selective inhibition of the phosphodiesterase type IV (PDE4) isoform. Although the anti-inflammatory and bronchodilator activity of selective PDE4 inhibitors has been well documented, their low therapeutic ratio and dose-dependent systemic side effects have limited their clinical utility. This study examined the effect of 2'-deoxy-2'-Fluoro-β-D-Arabinonucleic Acid (FANA)-containing antisense oligonucleotides (AON) targeting the mRNA for the PDE4B/4D and 7A subtypes on lung inflammatory markers, both in vitro and in vivo.MethodsNormal human bronchial epithelial (NHBE) cells were transfected with FANA AON against PDE4B/4D and 7A alone or in combination. mRNA levels for target PDE subtypes, as well as secretion of pro-inflammatory chemokines were then measured following cell stimulation. Mice were treated with combined PDE4B/4D and 7A AON via endo-tracheal delivery, or with roflumilast via oral delivery, and exposed to cigarette smoke for one week. Target mRNA inhibition, as well as influx of inflammatory cells and mediators were measured in lung lavages. A two-week smoke exposure protocol was also used to test the longer term potency of PDE4B/4D and 7A AONs.ResultsIn NHBE cells, PDE4B/4D and 7A AONs dose-dependently and specifically inhibited expression of their respective target mRNA. When used in combination, PDE4B/4D and 7A AONs significantly abrogated the cytokine-induced secretion of IL-8 and MCP-1 to near baseline levels. In mice treated with combined PDE4B/4D and 7A AONs and exposed to cigarette smoke, significant protection against the smoke-induced recruitment of neutrophils and production of KC and pro-MMP-9 was obtained, which was correlated with inhibition of target mRNA in cells from lung lavages. In this model, PDE AONs exerted more potent and broader anti-inflammatory effects against smoke-induced lung inflammation than roflumilast. Moreover, the protective effect of PDE4B/4D and 7A AON was maintained when a once-weekly treatment schedule was used.ConclusionThese results indicate that inhaled AON against PDE4B/4D and 7A have unique effects on biomarkers that are believed to be important in the pathophysiology of COPD, which supports further development as a potential therapy in this disease.

CD27 Expression on CD4+ T Cells Differentiates Effector from Regulatory T Cell Subsets in the Lung

Beryllium exposure in the workplace can result in chronic beryllium disease, a granulomatous lung disorder characterized by CD4(+) T cell alveolitis and progressive lung fibrosis. A large number of the CD4(+) T cells recruited to the lung in chronic beryllium disease recognize beryllium in an Ag-specific manner and express Th1-type cytokines following T cell activation. Beryllium-responsive CD4(+) T cells in the bronchoalveolar lavage (BAL) express an effector memory T cell phenotype and recognize beryllium in a CD28-independent manner. In this study, we show that the majority of beryllium-responsive CD4(+) T cells in BAL have lost CD27 expression, whereas a subset of beryllium-responsive cells in blood retains expression of this costimulatory molecule. In addition, loss of CD27 on BAL CD4(+) T cells inversely correlates with markers of lung inflammation. A small population of BAL CD4(+) T cells retains CD27 expression, and these CD4(+)CD27(+) T cells contain the FoxP3-expressing, naturally occurring regulatory T (T(reg)) cell subset. Coexpression of CD27 and CD25 identifies the majority of FoxP3-expressing T(reg) cells in blood and BAL, and these cells express potent suppressor function. Taken together, these findings suggest that CD27 is differentially expressed between effector T cells from the inflamed lung and can be used in conjunction with CD25 to isolate T(reg) cells and assess their functional capacity in an ongoing adaptive immune response in a target organ.

Effect of heterogeneous ventilation and nitric oxide production on exhaled nitric oxide profiles

Elevated exhaled nitric oxide (NO) in the breath of asthmatic subjects is thought to be a noninvasive marker of lung inflammation. Asthma is also characterized by heterogeneous bronchoconstriction and inflammation, which impact the spatial distribution of ventilation in the lungs. Since exhaled NO arises from both airway and alveolar regions, and its level in exhaled breath depends strongly on flow, spatial heterogeneity in flow patterns and NO production may significantly affect the exhaled NO signal. To investigate the effect of these factors on exhaled NO profiles, we developed a multicompartment mathematical model of NO exchange using a trumpet-shaped central airway segment that bifurcates into two similarly shaped peripheral airway segments, each of which empties into an alveolar compartment. Heterogeneity in flow alone has only a minimal impact on the exhaled NO profile. In contrast, placing 70% of the total airway NO production in the central compartment or the distal poorly ventilated compartment can significantly increase (35%) or decrease (-10%) the plateau concentration, respectively. Reduced ventilation of the peripheral and acinar regions of the lungs with concomitant elevated NO production delays the rise of NO during exhalation, resulting in a positive phase III slope and reduced plateau concentration (-11%). These features compare favorably with experimentally observed profiles in exercise-induced asthma and cannot be simulated with single-path models. We conclude that variability in ventilation and NO production in asthmatic subjects impacts the shape of the exhaled NO profile and thus impacts the physiological interpretation.

Source Apportionment of Particulate Matter in the U.S. and Associations with Lung Inflammatory Markers

Size-fractionated particulate matter (PM) samples were collected from six U.S. cities and chemically analyzed as part of the Multiple Air Pollutant Study. Particles were administered to cultured lung cells and the production of three different proinflammatory markers was measured to explore the association between the health effect markers and PM. Ultrafine, fine, and coarse PM samples were collected between December 2003 and May 2004 over a 4-wk period in each city. Filters were pooled for each city and the PM samples were extracted then analyzed for trace metals, ions, and elemental carbon. Particle extracts were applied to cultured human primary airway epithelial cells, and the secreted levels of interleukin-8 (IL-8), heme oxygenase-1, and cyclooxygenase-2 were measured 1 and 24 h following exposure. Fine PM sources were quantified by the chemical mass balance (CMB) model. The relationship between toxicological measures, PM sources, and individual species were evaluated using linear regression. Ultrafine and fine PM mass were associated with increases in IL-8 (r2 = .80 for ultrafine and r2 = .52 for fine). Sources of fine PM and their relative contributions varied across the sampling sites and a strong linear association was observed between IL-8 and secondary sulfate from coal combustion (r2 = .79). Ultrafine vanadium, lead, copper, and sulfate were also associated with increases in IL-8. Increases in inflammatory markers were not observed for coarse PM mass and source markers. These findings suggest that certain PM size fractions and sources are associated with markers of lung injury or inflammation.

Gas exchange and lung inflammation using nasal intermittent positive-pressure ventilation versus synchronized intermittent mandatory ventilation in piglets with saline lavage-induced lung injury: An observational study*

Physiologic and pathologic comparison of two modes of assisted ventilation, nasal intermittent positive-pressure ventilation (NIPPV) and synchronized intermittent mandatory ventilation (SIMV), in spontaneously breathing term newborn piglets with saline lavage-induced lung injury. After inducing acute lung injury via repetitive saline lavage, piglets were randomized to NIPPV (n = 12) or SIMV (n = 11) and treated for 6 hrs. Clinical laboratory. Spontaneously breathing term newborn piglets. Invasive (SIMV) or noninvasive (NIPPV) assisted ventilation for 6 hrs. Physiologic parameters and arterial blood gases were continuously monitored. At the conclusion of the study, lung tissue was obtained to analyze for evidence of inflammation, including myeloperoxidase, interleukin-8, and hydrogen peroxide levels, as well as for evidence of pathologic injury. Piglets treated with NIPPV demonstrated higher arterial blood gas pH (p < .001), lower PaCO2 (p < .05), and a lower set respiratory rate (p < .0001) as compared with the SIMV-treated piglets. The piglets in the SIMV group had higher PaO2/PaO2 ratio than those in the NIPPV group (p = .001). There was significantly more interstitial inflammation (p = .04) in the SIMV-treated piglets compared with the NIPPV-treated piglets. Total respiratory rate, heart rate, blood pressure, oxygen saturation, and biochemical markers of lung inflammation were not different between the groups. In surfactant-deficient term newborn piglets, NIPPV offers an effective and noninvasive ventilatory strategy with the potential for less pathologic lung inflammation.